A tantalum electrolytic capacitor  is an electrolytic capacitor, a passive component of electronic circuits. It consists of a pellet of porous tantalum metal as an anode, covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode. Because of its very thin and relatively high permittivity dielectric layer, the tantalum capacitor distinguishes itself from other conventional and electrolytic capacitors in having high capacitance per volume (high volumetric efficiency) and lower weight.

Tantalum is a conflict mineral. Tantalum electrolytic capacitors are considerably more expensive than comparable aluminum electrolytic capacitors.

Tantalum capacitors are inherently polarized components. Reverse voltage can destroy the capacitor. Non-polar or bipolar tantalum capacitors are made by effectively connecting two polarized capacitors in series, with the anodes oriented in opposite directions.

Basic information

Basic principle

Electrolytic capacitors use a chemical feature of some special metals, historically called valve metals, which can form an insulating oxide layer. Applying a positive voltage to the tantalum anode material in an electrolytic bath forms an oxide barrier layer with a thickness proportional to the applied voltage. This oxide layer serves as the dielectric in an electrolytic capacitor. The properties of this oxide layer compared with niobium oxide layer are given in the following table:

After forming a dielectric oxide on the rough anode structures, a cathode is needed. An electrolyte acts as the cathode of electrolytic capacitors. There are many different electrolytes in use. Generally, the electrolytes will be distinguished into two species, non-solid and solid electrolytes. Non-solid electrolytes are a liquid medium whose conductivity is ionic.
The oxide layer may be destroyed if the polarity of the applied voltage is reversed.

Every electrolytic capacitor in principle forms a plate capacitor whose capacitance is greater the larger the electrode area, A, and the permittivity, ε, are and the thinner the thickness, d, of the dielectric is.

The dielectric thickness of electrolytic capacitors is very thin, in the range of nanometers per volt. Despite this, the dielectric strengths of these oxide layers are quite high. Thus, tantalum capacitors can achieve a high volumetric capacitance compared to other capacitor types.

All etched or sintered anodes have a much larger total surface area compared to a smooth surface of the same overall dimensions. This surface area increase boosts the capacitance value by a factor of up to 200 (depending on the rated voltage) for solid tantalum electrolytic capacitors.

The volume of an electrolytic capacitor is defined by the product of capacitance and voltage, the so-called CV-volume. However, in comparing the permittivities of different oxide materials, it is seen that tantalum pentoxide has an approximately 3 times higher permittivity than aluminum oxide. Tantalum electrolytic capacitors of a given CV value can therefore be smaller than aluminum electrolytic capacitors.

Basic construction of solid tantalum electrolytic capacitors

A typical tantalum capacitor is a chip capacitor and consists of tantalum powder pressed and sintered into a pellet as the anode of the capacitor, with the oxide layer of tantalum pentoxide as a dielectric, and a solid manganese dioxide electrolyte as the cathode.

Materials, production and styles

Anode

Tantalum capacitors are manufactured from a powder of relatively pure elemental tantalum metal. A common figure of merit for comparing volumetric efficiency of powders is expressed in capacitance (C, usually in μF) times volts (V) per gram (g). Since the mid-1980s, manufactured tantalum powders have exhibited around a ten-fold improvement in CV/g values (from approximately 20k to 200k). The typical particle size is between 2 and 10 μm. Figure 1 shows powders of successively finer grain, resulting in greater surface area per unit volume. Note the very great difference in particle size between the powders.

The powder is compressed around a tantalum wire (known as the riser wire) to form a "pellet". The riser wire ultimately becomes the anode connection to the capacitor. This pellet/wire combination is subsequently vacuum sintered at high temperature (typically 1200 to 1800 °C) which produces a mechanically strong pellet and drives off many impurities within the powder. During sintering, the powder takes on a sponge-like structure, with all the particles interconnected into a monolithic spatial lattice. This structure is of predictable mechanical strength and density, but is also highly porous, producing a large internal surface area (see Figure 2).

Larger surface areas produce higher capacitance; thus high CV/g powders, which have lower average particle sizes, are used for low voltage, high capacitance parts. By choosing the correct powder type and sintering temperature, a specific capacitance or voltage rating can be achieved. For example, a 220 μF 6 V capacitor will have a surface area close to 346 cm2, or 80% of the size of a sheet of paper (US Letter, 8.5×11 inch paper has area ~413 cm2), although the total volume of the pellet is only about 0.0016 cm3.

Dielectric

The dielectric is then formed over all the tantalum particle surfaces by the electrochemical process of anodization. To achieve this, the "pellet" is submerged into a very weak solution of acid and DC voltage is applied. The total dielectric thickness is determined by the final voltage applied during the forming process. Initially the power supply is kept in a constant current mode until the correct voltage (i.e. dielectric thickness) has been reached; it then holds this voltage and the current decays to close to zero to provide a uniform thickness throughout the device and production lot.
The chemical equations describing the dielectric formation process at the anode are as follows:
2 Ta → 2 Ta5+ + 10 e−
2 Ta5+ + 10 OH− → Ta2O5 + 5 H2O

The oxide forms on the surface of the tantalum, but it also grows into the material. For each unit thickness of oxide growth, one third grows out and two thirds grows in. Due to the limits of oxide growth, there is a limit on the maximum voltage rating of tantalum oxide for each of the presently available tantalum powders (see Figure 3).

The dielectric layer thickness generated by the forming voltage is directly proportional to the voltage proof of electrolytic capacitors. Electrolytic capacitors are manufactured with a safety margin in oxide layer thickness, which is the ratio between voltage used for electrolytical creation of dielectric and rated voltage of the capacitor, to ensure reliable functionality.

The safety margin for solid tantalum capacitors with manganese dioxide electrolyte is typically between 2 and 4. That means that for a 25 V tantalum capacitor with a safety margin of 4 the dielectric voltage proof can withstand 100 V to provide a more robust dielectric. This very high safety factor is substantiated by the failure mechanism of solid tantalum capacitors, "field crystallization".

For tantalum capacitors with solid polymer electrolyte the safety margin is much lower, typically around 2.

Cathode

The next stage for solid tantalum capacitors is the application of the cathode plate (wet tantalum capacitors use a liquid electrolyte as a cathode in conjunction with their casing). This is achieved by pyrolysis of manganese nitrate into manganese dioxide. The "pellet" is dipped into an aqueous solution of nitrate and then baked in an oven at approximately 250 °C to produce the dioxide coat. The chemical equation is:

Mn(NO3)2 → MnO2 + 2 NO2

This process is repeated several times through varying specific gravities of nitrate solution, to build up a thick coat over all internal and external surfaces of the "pellet", as shown in Figure 4.

In traditional construction, the "pellet" is successively dipped into graphite and then silver to provide a good connection from the manganese dioxide cathode plate to the external cathode termination(see Figure 5).

Production flow
The picture below shows the production flow of tantalum electrolytic chip capacitors with sintered anode and solid manganese dioxide electrolyte.

Styles of tantalum capacitors

Tantalum electrolytic capacitors are made in three different styles:
 Tantalum chip capacitors:  SMD style for surface mounting, 80% of all tantalum capacitors are SMDs
 Tantalum "pearls", resin-dipped, single-ended style for PCB mounting
 Axial-leaded tantalum capacitors, with solid and non-solid electrolyte, mostly used for military, medical and space applications.

Chip capacitors (case size)
More than 90% of all tantalum electrolytic capacitors are manufactured in SMD style as tantalum chip capacitors. It has contact surfaces on the end faces of the case and is manufactured in different sizes, typically following the EIA-535-BAAC standard. The different sizes can also be identified by case code letters. For some case sizes (A to E), which have been manufactured for many decades, the dimensions and case coding over all manufactures are still largely the same. However, new developments in tantalum electrolytic capacitors such as the multi-anode technique to reduce the ESR or the "face down" technique to reduce the inductance have led to a much wider range of chip sizes and their case codes. These departures from EIA standards mean devices from different manufacturers are no longer always uniform.

An overview of the dimensions of conventional tantalum rectangular chip capacitors and their coding is shown in the following table:

 Note: EIA 3528 metric is also known as EIA 1411 imperial (inches).

Wet tantalum capacitors

The main feature of modern non-solid (wet) tantalum electrolytic capacitors is their energy density compared with that of solid tantalum and wet aluminum electrolytic capacitors within the same temperature range. Due to their self-healing properties (the non-solid electrolyte can deliver oxygen to form new oxide layer in weak areas of the dielectric), the dielectric thickness can be formed with much lower safety margins and consequently with much thinner dielectric than for solid types, resulting in a higher CV value per volume unit. Additionally, wet tantalum capacitors are able to operate at voltages in excess of 100 V up to 630 V, have a relatively low ESR, and have the lowest leakage current of all electrolytic capacitors.

The original wet tantalum capacitors developed in the 1930s were axial capacitors, having a wound cell consisting of a tantalum anode and foil cathode separated by a paper stripe soaked with an electrolyte, mounted in a silver case and non-hermetic elastomer sealed. Because of the inertness and stability of the tantalum dielectric oxide layer against strong acids, the wet tantalum capacitors could use sulfuric acid as an electrolyte, thus providing them with a relatively low ESR.

Because in the past, silver casings had problems with silver migration and whiskers which led to increasing leakage currents and short circuits, new styles of wet tantalum capacitors use a sintered tantalum pellet cell and a gelled sulfuric acid electrolyte mounted in a pure tantalum case.

Due to their relatively high price, wet tantalum electrolytic capacitors have few consumer applications. They are used in ruggedized industrial applications, such as in probes for oil exploration. Types with military approvals can provide the extended capacitance and voltage ratings, along with the high quality levels required for avionics, military, and space applications.

History

The group of "valve metals" capable of forming an insulating oxide film was discovered in 1875. In 1896 Karol Pollak patented a capacitor using aluminum electrodes and a liquid electrolyte. Aluminum electrolytic capacitors were commercially manufactured in the 1930s.

The first tantalum electrolytic capacitors with wound tantalum foils and non-solid electrolyte were developed in 1930 by Tansitor Electronic Inc. (US), and were used for military purposes.

Solid electrolyte tantalum capacitors were invented by Bell Laboratories in the early 1950s as a miniaturized and more reliable low-voltage support capacitor to complement their newly invented transistor. The solution R. L. Taylor and H. E. Haring from the Bell Labs found for the new miniaturized capacitor found in early 1950 was based on experience with ceramics. They ground metallic tantalum to a powder, pressed this powder into a cylindrical form and then sintered the powder particles at high temperature between  under vacuum conditions,  into a pellet ("slug").

These first sintered tantalum capacitors used a liquid electrolyte. In 1952 Bell Labs researchers discovered the use manganese dioxide as a solid electrolyte for a sintered tantalum capacitor.

Although the fundamental inventions came from the Bell Labs, the innovations for manufacturing commercially viable tantalum electrolytic capacitors were done by the researchers of the Sprague Electric Company. Preston Robinson, Sprague's Director of Research, is considered to be the actual inventor of tantalum capacitors in 1954. His invention was supported by R. J. Millard, who introduced the "reform" step in 1955, a significant improvement in which the dielectric of the capacitor was repaired after each dip-and-convert cycle of MnO2 deposition. This dramatically reduced the leakage current of the finished capacitors.

This first solid electrolyte manganese dioxide had 10 times better conductivity than all other types of non-solid electrolyte capacitors. In the style of tantalum pearls, they soon found wide use in radio and new television devices.

In 1971, Intel launched its first microcomputer (the MCS 4) and 1972 Hewlett Packard launched one of the first pocket calculators (the HP 35). The requirements for capacitors increased, especially the demand for lower losses. The equivalent series resistance (ESR) for bypass and decoupling capacitors of standard electrolytic capacitors needed to be decreased.

Although solid tantalum capacitors offered lower ESR and leakage current values than the aluminum electrolytics, in 1980 a price shock for tantalum in the industry dramatically reduced the usability of tantalum capacitors, especially in consumer entertainment electronics.
 In search of cheaper alternatives, the industry switched back to using aluminum electrolytic capacitors.

The development of conducting polymers by Alan J. Heeger, Alan MacDiarmid and Hideki Shirakawa in 1975 was a break-through in point of lower ESR. The conductivities of conductive polymers such as polypyrrole (PPy) or PEDOT are better by a factor of 1000 than that of manganese dioxide, and are close to the conductivity of metals.
In 1993 NEC introduced their SMD polymer tantalum electrolytic capacitors, called "NeoCap". In 1997 Sanyo followed with their "POSCAP" polymer tantalum chips.

A new conductive polymer for tantalum polymer capacitors was presented by Kemet at the "1999 Carts" conference. This capacitor used the newly developed organic conductive polymer PEDT Poly(3,4-ethylenedioxythiophene), also known as PEDOT (trade name Baytron).

This development to low ESR capacitors with high CV-volumes in chip style for the rapid growing SMD technology in the 1990s increased the demand on tantalum chips dramatically. However, another price explosion for tantalum in 2000/2001 forced the development of niobium electrolytic capacitors with manganese dioxide electrolyte, which have been available since 2002. The materials and processes used to produce niobium-dielectric capacitors are essentially the same as for existing tantalum-dielectric capacitors. The characteristics of niobium electrolytic capacitors and tantalum electrolytic capacitors are roughly comparable.

Electrical characteristics

Series-equivalent circuit

Tantalum electrolytic capacitors as discrete components are not ideal capacitors, as they have losses and parasitic inductive parts. All properties can be defined and specified by a series equivalent circuit composed of an idealized capacitance and additional electrical components which model all losses and inductive parameters of a capacitor. In this series-equivalent circuit the electrical characteristics are defined by:
 C, the capacitance of the capacitor
 Rleak, the resistance representing the leakage current of the capacitor
 RESR, the equivalent series resistance which summarizes all ohmic losses of the capacitor, usually abbreviated as "ESR"
 LESL, the equivalent series inductance which is the effective self-inductance of the capacitor, usually abbreviated as "ESL".

Using a series equivalent circuit rather than a parallel equivalent circuit is specified by IEC/EN 60384-1.

Capacitance standard values and tolerances

The electrical characteristics of tantalum electrolytic capacitors depend on the structure of the anode and the electrolyte used. This influences the capacitance value of tantalum capacitors, which depend on operating frequency and temperature. The basic unit of electrolytic capacitors capacitance is microfarad (μF).

The capacitance value specified in the data sheets of the manufacturers is called rated capacitance CR or nominal capacitance CN and is the value for which the capacitor has been designed. Standardized measuring condition for electrolytic capacitors is an AC measuring method with a frequency of 100 to 120 Hz. Electrolytic capacitors differ from other capacitor types, whose capacitances are typically measured at 1 kHz or higher. For tantalum capacitors a DC bias voltage of 1.1 to 1.5 V for types with a rated voltage of ≤2.5 V or 2.1 to 2.5 V for types with a rated voltage of >2.5 V may be applied during the measurement to avoid reverse voltage.

The percentage of allowed deviation of the measured capacitance from the rated value is called capacitance tolerance. Electrolytic capacitors are available in different tolerance series classifications, whose values are specified in the E series specified in IEC 60063. For abbreviated marking in tight spaces, a letter code for each tolerance is specified in IEC 60062.
 rated capacitance, E3 series, tolerance ±20%, letter code "M"
 rated capacitance, E6 series, tolerance ±20%, letter code "M"
 rated capacitance, E12 series, tolerance ±10%, letter code "K"

The required capacitance tolerance is determined by the particular application. Electrolytic capacitors, which are often used for filtering and bypassing capacitors don't have the need for narrow tolerances because they are mostly not used for accurate frequency applications like oscillators.

Rated and category voltage

Referring to IEC/EN 60384-1 standard the allowed operating voltage for tantalum capacitors is called "rated voltage UR " or "nominal voltage UN". The rated voltage UR is the maximum DC voltage or peak pulse voltage that may be applied continuously at any temperature within the rated temperature range TR (IEC/EN 60384-1).

The voltage rating of electrolytic capacitors decreases with increasing temperature. For some applications it is important to use a higher temperature range. Lowering the voltage applied at a higher temperature maintains safety margins. For some capacitor types therefore the IEC standard specify a "temperature derated voltage" for a higher temperature, the "category voltage UC". The category voltage is the maximum DC voltage or peak pulse voltage that may be applied continuously to a capacitor at any temperature within the category temperature range TC. The relation between both voltages and temperatures is given in the picture right.

Lower voltage applied may have positive influences for tantalum electrolytic capacitors. Lowering the voltage applied increases the reliability and reduces the expected failure rate.

Applying a higher voltage than specified may destroy tantalum electrolytic capacitors.

Surge voltage

The surge voltage indicates the maximum peak voltage value that may be applied to electrolytic capacitors during their application for a limited number of cycles. The surge voltage is standardized in IEC/EN 60384-1. For tantalum electrolytic capacitors the surge voltage shall be 1.3 times of the rated voltage, rounded off to the nearest volt.
The surge voltage applied to tantalum capacitors may influence the capacitors failure rate.

Transient voltage

Transient voltage or a current spike applied to tantalum electrolytic capacitors with solid manganese dioxide electrolyte can cause some tantalum capacitors to fail and may directly lead to a short.

Reverse voltage

Tantalum electrolytic are polarized and generally require anode electrode voltage to be positive relative to the cathode voltage.

With a reverse voltage applied, a reverse leakage current flows in very small areas of microcracks or other defects across the dielectric layer to the anode of the electrolytic capacitor. Although the current may only be a few microamps, it represents a very high localized current density which can cause a tiny hot-spot. This can cause some conversion of amorphous tantalum pentoxide to the more conductive crystalline form. When a high current is available, this effect can avalanche and the capacitor may become a total short.

Nevertheless, tantalum electrolytic capacitors can withstand for short instants a reverse voltage for a limited number of cycles. The most common guidelines for tantalum reverse voltage are:
 10% of rated voltage to a maximum of 1 V at 25 °C,
 3% of rated voltage to a maximum of 0.5 V at 85 °C,
 1% of rated voltage to a maximum of 0.1 V at 125 °C.

These guidelines apply for short excursion and should never be used to determine the maximum reverse voltage under which a capacitor can be used permanently.

Impedance

Tantalum electrolytic capacitors, as well as other conventional capacitors, have two electrical functions. For timers or similar applications, capacitors are seen as a storage component to store electrical energy. But for smoothing, bypassing, or decoupling applications like in power supplies, the capacitors work additionally as AC resistors to filter undesired AC components from voltage rails. For this (biased) AC function the frequency dependent AC resistance (impedance "Z") is as important as the capacitance value.

The impedance is the complex ratio of the voltage to the current with both magnitude and phase at a particular frequency in an AC circuit. In this sense impedance is a measure of the ability of the capacitor to attenuate alternating currents and can be used like Ohms law

The impedance is a frequency dependent AC resistance and possesses both magnitude and phase at a particular frequency. In data sheets of electrolytic capacitors, only the impedance magnitude |Z| is specified, and simply written as "Z". Regarding to the IEC/EN 60384-1 standard, the impedance values of tantalum electrolytic capacitors are measured and specified at 10 kHz or 100 kHz depending on the capacitance and voltage of the capacitor.

Besides measuring, the impedance can also be calculated using the idealized components out of a capacitor's series-equivalent circuit, including an ideal capacitor C, a resistor ESR, and an inductance ESL. In this case the impedance at the angular frequency ω therefore is given by the geometric (complex) addition of ESR, by a capacitive reactance XC

and by an inductive reactance XL (Inductance)

.

Then Z is given by

 .

In the special case of resonance, in which the both reactive resistances XC and XL have the same value (XC=XL), then the impedance will only be determined by ESR. With frequencies above the resonance the impedance increases again due to the ESL of the capacitor. At this point, the capacitor begins to behave primarily as an inductance.

ESR and dissipation factor tan δ

The equivalent series resistance (ESR) summarizes all resistive losses of the capacitor. These are the terminal resistances, the contact resistance of the electrode contact, the line resistance of the electrodes, the electrolyte resistance, and the dielectric losses in the dielectric oxide layer.

ESR influences the remaining superimposed AC ripple behind smoothing and may influence the circuit functionality. Related to the capacitor ESR is accountable for internal heat generation if a #ripple current flows over the capacitor. This internal heat may influence the reliability of tantalum electrolytic capacitors.

Generally, the ESR decreases with increasing frequency and temperature.

Discussions of electrolytic capacitors historically sometimes refer to the dissipation factor, tan δ, in the relevant data sheets instead of ESR. The dissipation factor is determined by the tangent of the phase angle between the subtraction of capacitive reactance XC from inductive reactance XL, and the ESR. If the capacitor's inductance ESL is small, the dissipation factor can be approximated as:

The dissipation factor tan δ is used for capacitors with very low losses in frequency determining circuits or resonant circuits where the reciprocal value of the dissipation factor is called the quality factor (Q) which represents a resonator's bandwidth.

Ripple current

A "ripple current" is the RMS value of a superimposed AC current of any frequency upon a DC current. It arises mainly in power supplies (including switched-mode power supplies) after rectifying an AC voltage and flows as charge and discharge current through the decoupling or smoothing capacitor.

Ripple currents generate heat inside the capacitor body. This dissipation power loss PL is caused by ESR and is the squared value of the effective (RMS) ripple current IR.

This internal generated heat, in addition to the ambient temperature and possibly other external heat sources, leads to a capacitor body temperature having a temperature difference of Δ T against the ambient. This heat has to be distributed as thermal losses Pth over the capacitors surface A and the thermal resistance β to the ambient.

The internal generated heat has to be distributed to the ambient by thermal radiation, convection, and thermal conduction. The temperature of the capacitor, which is established on the balance between heat produced and distributed, should not exceed the capacitors maximum specified temperature.

The ripple current is specified as an effective (RMS) value at 100 or 120 Hz or at 10 kHz at upper category temperature. Non-sinusoidal ripple currents have to be analyzed and separated into their component sinusoidal frequencies by means of Fourier analysis and the equivalent ripple current calculated as the square root of the sum of the squares of the individual currents.

In solid tantalum electrolytic capacitors the heat generated by the ripple current influences the reliability of the capacitors. Exceeding the limit tends to result in catastrophic failures with shorts and burning components.

Current surge, peak or pulse current

Solid tantalum electrolytic capacitors can be damaged by surge, peak or pulse currents. Tantalum capacitors, which are exposed to surge, peak or pulse currents should be used with a voltage derating up to 70% in highly inductive circuits. If possible, the voltage profile should be a ramp turn-on, as this reduces the peak current seen by the capacitor.

Leakage current

The DC leakage current is a special characteristic for electrolytic capacitors other conventional capacitors don't have. This current is represented by the resistor Rleak in parallel with the capacitor in the series-equivalent circuit of electrolytic capacitors. The main causes of leakage current for solid tantalum capacitors are electrical breakdown of the dielectric, conductive paths due to impurities or due to poor anodization, bypassing of dielectric due to excess manganese dioxide, due to moisture paths or due to cathode conductors (carbon, silver). This leakage current in solid electrolyte capacitors cannot be reduced by "healing" in the sense of generating new oxide because under normal conditions solid electrolytes are unable to deliver oxygen for forming processes. This statement should not be confused with the self-healing process during field crystallization, as described in Reliability (failure rate).

The specification of the leakage current in datasheets often will be given by multiplication of the rated capacitance value CR  with the value of the rated voltage UR together with an addendum figure, measured after a measuring time of 2 or 5 minutes, for example:

The value of the leakage current depends on the voltage applied, on temperature of the capacitor, on measuring time, and on influence of moisture caused by case sealing conditions. They normally have a very low leakage current, most much lower than the specified worst-case.

Dielectric absorption (soakage)

Dielectric absorption occurs when a capacitor that has remained charged for a long time retains some charge when briefly discharged. Although an ideal capacitor would reach zero volts after discharge, real capacitors develop a small voltage from time-delayed dipole discharging, a phenomenon that is also called dielectric relaxation, "soakage" or "battery action".

Dielectric absorption can cause a problem in circuits where very small currents are used, such as long-time-constant integrators or sample-and-hold circuits. However, in most applications where tantalum electrolytic capacitors are supporting power supply lines, dielectric absorption is not a problem.

Reliability and life time

Reliability (failure rate)

The reliability of a component is a property that indicates how well a component performs its function in a time interval. It is subject to a stochastic process and can be described qualitatively and quantitatively; it is not directly measurable. The reliability of electrolytic capacitors are empirically determined by identifying the failure rate in production-accompanying endurance tests,  see Reliability engineering#Reliability testing.

The reliability normally is shown in a bathtub curve and is divided into three areas: Early failures or infant mortality failures, constant random failures and wear out failures. Failure types included in the total failure rate are short circuit, open circuit, and degradation failures (exceeding electrical parameters).

The reliability prediction is generally expressed in a failure rate λ, abbreviation FIT (failures in time). This is the number of failures that can be expected in one billion (109) component-hours of operation (e.g. 1000 components for 1 million hours, or 1  million components for 1000 hours which is 1 ppm/1000 hours) at fixed working conditions during the period of constant random failures. These failure rate model implicitly assume the idea of "random failure". Individual components fail at random times but at a predictable rate. The standard operation conditions for the failure rate FIT are 40 °C and 0.5 UR.

The reciprocal value of FIT is mean time between failures (MTBF).

For tantalum capacitors, often the failure rate is specified at 85 °C and rated voltage UR as reference conditions and expressed as per cent failed components per thousand hours (n %/1000 h). That is "n" number of failed components per 105 hours or in FIT the ten-thousand-fold value per 109 hours.

For conditions other than the standard operation conditions 40 °C and 0.5 UR, for other temperature and voltage applied, for current load, capacitance value, circuit resistance, mechanical influences and humidity, the FIT figure can recalculated with acceleration factors standardized for industrial or military contexts. For example, higher temperature and applied voltage cause the failure rate to increase.

The most often cited source for recalculation the failure rate is the MIL-HDBK-217F, the "bible" of failure rate calculations for electronic components.  SQC Online, the online statistical calculators for acceptance sampling and quality control gives an online tool for short examination to calculate given failure rate values to application conditions.

Some manufacturers of tantalum capacitors may have their own FIT calculation tables.

Tantalum capacitors are reliable components. Continuous improvement in tantalum powder and capacitor technologies have resulted in a significant reduction in the amount of impurities present, which formerly have caused most of the field crystallization failures. Commercially available tantalum capacitors now have reached as standard products the high MIL standard "C" level which is 0.01%/1000h at 85 °C and UR or 1 failure per 107 hours at 85 °C and UR. Recalculated in FIT with the acceleration factors coming from MIL HDKB 217F at 40 °C and 0.5 UR is this failure rate for a 100 μF/25 V tantalum chip capacitor used with a series resistance of 0.1 Ω  the failure rate is 0.02 FIT.

Life time
The life time, service life, load life or useful life of tantalum electrolytic capacitors depends entirely on the electrolyte used:
 Those using liquid electrolytes do not have a life time specification. (When hermetically sealed)
 Those using manganese dioxide electrolytes do not have a life time specification.
 Those using polymer electrolytes do have a life time specification.

The polymer electrolyte have a small deterioration of conductivity by a thermal degradation mechanism of the conductive polymer. The electrical conductivity decreased, as a function of time, in agreement with a granular metal type structure, in which aging is due to the shrinking of the conductive polymer grains. The life time of polymer electrolytic capacitors is specified in similar terms to the non-solid electrolytic caps, but its life time calculation follows other rules which lead to much longer operational life times.

Failure modes and self-healing mechanism
Tantalum capacitors show different electrical long-term behaviors depending on the electrolyte used. Application rules for types with an inherent failure mode are specified to ensure high reliability and long life.

Tantalum capacitors are reliable on the same very high level as other electronic components with very low failure rates. However, they have a single unique failure mode called "field crystallization". Field crystallization is the major reason for degradation and catastrophic failures of solid tantalum capacitors. More than 90% of the today's rare failures in tantalum solid-state electrolytic capacitors are caused by shorts or increased leakage current due to this failure mode.

The extremely thin oxide film of a tantalum electrolytic capacitor, the dielectric layer, must be formed in an amorphous structure. Changing the amorphous structure into a crystallized structure is reported to increase the conductivity by 1000 times, combined with an enlargement of the oxide volume. The field crystallization followed by a dielectric breakdown is characterized by a sudden rise in leakage current within a few milliseconds, from nanoamp magnitude to amp magnitude in low-impedance circuits. Increasing current flow can accelerate in an "avalanche effect" and rapidly spread through the metal/oxide. This can result in various degrees of destruction from rather small, burned areas on the oxide to zigzag burned streaks covering large areas of the pellet or complete oxidation of the metal. If the current source is unlimited a field crystallization may cause a capacitor short circuit.  In this circumstance, the failure can be catastrophic if there is nothing to limit the available current, as the series resistance of the capacitor can become very low.

Impurities, tiny mechanical damages, or imperfections in the dielectric can affect the structure, changing it from amorphous to crystalline structure and thus lowering the dielectric strength. The purity of the tantalum powder is one of the most important parameters for defining its risk of crystallization. Since the mid-1980s, manufactured tantalum powders have exhibited an increase in purity.

Surge currents after soldering-induced stresses may start crystallization, leading to insulation breakdown. The only way to avoid catastrophic failures is to limit the current which can flow from the source in order to reduce the breakdown to a limited area. Current flowing through the crystallized area causes heating in the manganese dioxide cathode near the fault. At increased temperatures a chemical reaction then reduces the surrounding conductive manganese dioxide to the insulating manganese(III) oxide (Mn2O3) and insulates the crystallized oxide in the tantalum oxide layer, stopping local current flow.

Failure avoidance

Solid tantalum capacitors with crystallization are most likely to fail at power-on. It is believed that the voltage across the dielectric layer is the trigger mechanism for the breakdown and that the switch-on current pushes the collapse to a catastrophic failure. To prevent such sudden failures, manufacturers recommend:
 50% application voltage derating against rated voltage
 using a series resistance of 3 Ω/V or
 using of circuits with slow power-up modes (soft-start circuits).

Additional information

Capacitor symbols

Electrolytic capacitor symbols

Parallel connection
Small or low voltage electrolytic capacitors may be safely connected in parallel. Large sizes capacitors, especially large sizes and high voltage types should be individually protected against sudden discharge of the whole bank due to a failed capacitor.

Series connection
Some applications like AC/AC converters with DC-link for frequency controls in three-phase grids need higher voltages than aluminum electrolytic capacitors usually offer. For such applications electrolytic capacitors can be connected in series for increased voltage withstanding capability. During charging, the voltage across each of the capacitors connected in series is proportional to the inverse of the individual capacitor's leakage current. Since every capacitor differs a little bit in individual leakage current the capacitors with a higher leakage current will get less voltage. The voltage balance over the series connected capacitors is not symmetrically. Passive or active voltage balance has to be provided in order to stabilize the voltage over each individual capacitor.

Polarity marking

All tantalum capacitors are polarized components, with distinctly marked positive or negative terminals. When subjected to reversed polarity (even briefly), the capacitor depolarizes and the dielectric oxide layer breaks down, which can cause it to fail even when later operated with correct polarity. If the failure is a short circuit (the most common occurrence), and current is not limited to a safe value, catastrophic thermal runaway may occur. This failure can even result in the capacitor forcefully ejecting its burning core.

Tantalum electrolytic capacitors with solid electrolyte are marked at their positive terminal with a bar or a "+". Tantalum electrolytic capacitors with non-solid electrolyte (axial leaded style) are marked on the negative terminal with a bar or a "-" (minus). The polarity better can be identified on the shaped side of the case, which has the positive terminal. The different marking styles can cause dangerous confusion.

A particular cause of confusion is that on surface mount tantalum capacitors the positive terminal is marked with a bar. Whereas on aluminium surface mount capacitors it is the negative terminal that is so marked.

For Tantalum capacitors from the early 1970s the polarity is indicated by a dot. Positive lead is the lead on the right when the side with the dot is facing you. The positive lead may also be very slightly longer. Furthermore the polarity is marked on PCBs by different shaped soldering spots if there are no "+" or "-" signs printed on the PCB.  For example a square shaped soldering spot is used for positiv polarity (needs to be verified on particular case measuring connection against ground, negative or positive voltage pins)

Imprinted markings

Tantalum capacitors, like most other electronic components and if enough space is available, have imprinted markings to indicate manufacturer, type, electrical and thermal characteristics, and date of manufacture. But most tantalum capacitors are chip types so the reduced space limits the imprinted signs to capacitance, tolerance, voltage and polarity.

Smaller capacitors use a shorthand notation. The most commonly used format is: XYZ J/K/M "V", where XYZ represents the capacitance (calculated as XY × 10Z pF), the letters K or M indicate the tolerance (±10% and ±20% respectively) and "V" represents the working voltage.

Examples:
 105K 330V implies a capacitance of 10 × 105 pF = 1 μF (K = ±10%) with a working voltage of 330 V.
 476M 100V implies a capacitance of 47 × 106 pF = 47 μF (M = ±20%) with a working voltage of 100 V.

Capacitance, tolerance and date of manufacture can be indicated with a short code specified in IEC/EN 60062. Examples of short-marking of the rated capacitance (microfarads): μ47 = 0,47 μF, 4μ7 = 4.7 μF, 47μ = 47 μF

The date of manufacture is often printed in accordance with international standards.
 Version 1: coding with year/week numeral code, "1208" is "2012, week number 8".
 Version 2: coding with year code/month code. The year codes are: "R" = 2003, "S"= 2004, "T" = 2005, "U" = 2006, "V" = 2007, "W" = 2008, "X" = 2009, "A" = 2010, "B" = 2011, "C" = 2012, "D" = 2013, "E" = 2014 etc. Month codes are: "1" to "9" = Jan. to Sept., "O" = October, "N" = November, "D" = December. "X5" is then "2009, May"

For very small capacitors no marking is possible, only the component's packaging or the assembly manufacturer's records of the components used can be used to identify a component fully.

Standardization
Standard definitions of characteristics and test methods for electrical and electronic components and related technologies are published by the International Electrotechnical Commission (IEC), a non-profit, non-governmental international standards organization, which defer to the standards of other industry organizations for particular application characteristics, e.g. the EIA size standards, IPC solderability standards, etc. The quality and reliability standards and methods of the US MIL-STD specifications are used for components requiring a higher reliability or a less benign operating environment are required.

The definition of the characteristics and the procedure of the test methods for capacitors for use in electronic equipment are set out in the Generic specification:
 IEC/EN 60384-1: Fixed capacitors for use in electronic equipment

The tests and requirements to be met by aluminum and tantalum electrolytic capacitors for use in electronic equipment for approval as standardized types are set out in the following sectional specifications:
 IEC/EN 60384-3—Surface mount fixed tantalum electrolytic capacitors with manganese dioxide solid electrolyte
 IEC/EN 60384-15—fixed tantalum capacitors with non-solid and solid electrolyte
 IEC/EN 60384-24—Surface mount fixed tantalum electrolytic capacitors with conductive polymer solid electrolyte

Tantalum ore
Tantalum capacitors are the main use of the element tantalum. Tantalum ore is one of the conflict minerals. Some non-governmental organizations are working together to raise awareness of the relationship between consumer electronic devices and conflict minerals.

Market
The market of tantalum electrolytic capacitors in 2008 was approximately US$2.2 billion, which was roughly 12% of the total capacitor market.

Uses
The low leakage and high capacity of tantalum capacitors favor their use in sample and hold circuits to achieve long hold duration, and some long duration timing circuits where precise timing is not critical. They are also often used for power supply rail decoupling in parallel with film or ceramic capacitors which provide low ESR and low reactance at high frequency. Tantalum capacitors can replace aluminum electrolytic capacitors in situations where the external environment or dense component packing results in a sustained hot internal environment and where high reliability is important. Equipment such as medical electronics and space equipment that require high quality and reliability makes use of tantalum capacitors.

An especially common application for low-voltage tantalum capacitors is power supply filtering on computer motherboards and in peripherals, due to their small size and long-term reliability.

See also

 Aluminum electrolytic capacitor
 Coltan mining and ethics
 Electrolytic capacitor
 List of capacitor manufacturers
 Niobium capacitor
 Polymer capacitor
 Solid aluminum capacitor (SAL)
 Surface-mount technology
 Types of capacitor

References

External links

Capacitors


Archibald Clavering Gunter (25 October 1847 – 24 February 1907) was a British-American writer primarily known today for authoring the novel that the film A Florida Enchantment was based upon, and for his hand in popularizing "Casey at the Bat". He clipped the original publication of the poem from the San Francisco Examiner and passed it on to DeWolf Hopper, whose performances brought it fame.

Born in Liverpool, Gunter's family emigrated to the United States when he was six and settled in San Francisco. In 1879 he moved to New York.
Gunter was a playwright and prolific self-published novelist, novels that were translated into other languages and adapted several times into films. His Home Publishing Company also published Gunter's Magazine (1905–1907), featuring short fiction or serialized novels by himself and others. He also published others' novels, including ones by Richard Henry Savage and Gilbert Parker.

Selected works
1872 – Found the True Vein, a play dealing with life in a mining camp
1880 – Two Nights in Rome, a play
1881 – Fresh, the American, a comedy about a Yankee who rescues an Egyptian harem girl
1886 – Prince Karl, written as serious drama, actor Richard Mansfield recast it as a farce
1887 – Mr. Barnes of New York, a book about an adventurer, allegedly sold three million copies, though certainly was quite popular even if sales claims were inflated.  Adapted to film in 1914 and again in 1922.
1888 – Mr. Potter of Texas
1889 – That Frenchman
1890 – Miss Nobody of Nowhere
1890 – Small Boys in Big Boots
1892 – My Official Wife, play adaptation of novel by Richard Henry Savage
1892 – Miss Dividends
1893 – Baron Montez of Panama and Paris
1893 – A Florida Enchantment
1894 – A Princess in Paris
1894 – The Kings Stockbrother
1895 – The First of the English
1897 – Susan Turnbull; or, The Power of Woman, a novel set at Dr. Andrew Turnbull's New Smyrna settlement

References

Burt, Daniel S. (2009) The chronology of American literature: America's literary achievements from the colonial era to modern times, pp. 244, 260, 269, 271. Houghton Mifflin Harcourt.

Sources
Author and Bookinfo.com

External links

1847 births
1907 deaths
19th-century American novelists
American male novelists
American male dramatists and playwrights
19th-century American dramatists and playwrights
19th-century American male writers
19th-century British novelists
19th-century British dramatists and playwrights
19th-century British male writers
British male novelists
British male dramatists and playwrights
Writers from Liverpool


Guilty Pleasure  is the second studio album by American recording artist Ashley Tisdale. It was released on June 11, 2009, by Warner Bros. Records. The lead single from the album, "It's Alright, It's OK", was officially released in Canada on April 13, 2009. The album debuted at number 12 on the Billboard 200, selling 25,000 copies in its first week. The second single from Guilty Pleasure, "Crank It Up"  was released on October 9, 2009, in Europe. The album ranked #7 on Billboard's reader poll for album of the decade and best album of 2009.

Background and release
In April 2008, she said that she has recorded a few songs for the album and she would fully focus on the album after filming High School Musical 3. Tisdale has noted that the songs in the album have a message and a story that anyone can relate to, and hoped to reveal her "edgier" side with more mature songs. She also said the album was titled Guilty Pleasure because of her guilty pleasures. Tisdale was involved in every aspect of the album's production. Tisdale's music inspirations for the album include Katy Perry and Pat Benatar. The song "Switch" is also featured in the motion picture Aliens in the Attic, which Tisdale starred in.

Warner Bros. said the first component of the label's album roll out was revealing Tisdale's new look with a relaunch of her web site in March and the cover of Cosmopolitans April issue. "We wanted to create a conversation and then follow quickly with the music," he said. The album was to be released on June 16, 2009 in North America, but it was pushed back to July 28, 2009, although it was released a month before, on June 12, 2009 in several countries such as Germany, Italy and Spain. The album's release date in the US and Canada was preceded by an exclusive "Countdown to Guilty Pleasure" on iTunes for the U.S. and Canada, on which "Overrated", "What If" and "Acting Out" had promotional releases in each week. The first two songs debuted on the Billboard Bubbling Under Hot 100 Singles chart due to digital downloads at number three and number one, respectively.

Composition

The first single, "It's Alright, It's OK", Tisdale said, "is a strong, empowering song that kind of helps you move on" and continued to say: I have definitely  on and with someone you really like, if they are cheating on you, you don't want to believe it. But, unfortunately, you either stay in the relationship and keep getting hurt because it keeps happening or you get up and you move on. You don't look back. Tisdale said the song "Hot Mess" is "about hanging out with a motorcycle bad boy that makes life more interesting" and the song "How Do You Love Someone", written by Porcelain Black, is "about a girl who deals with the split of her parents". Tisdale said the song could also be about "when you have been cheated on or you're in a relationship". Black was initially reluctant to let Tisdale record the song, but eventually green-lit the track; however, she also recorded her own version, produced by RedOne. Tisdale co-wrote several songs on the album such as "What If", which was co-written with Kara DioGuardi. Tisdale described "What If" as the most personal song on the album, and said the song "is about when you’re in a relationship and you say 'If I really needed you, would you actually be there?’" "Time's Up" it was first recorded by American pop singer Katy Perry, for her second album One of the Boys (2008), though it was never included for the album and was passed on to Tisdale.

Reception

Critical response

Following its release, Guilty Pleasure generated mixed reviews from critics and has a 48 out of 100 on Metacritic, based on six critical reviews. The most positive of reviews came from Allmusic's Stephen Erlewine, who gave the album three and a half stars out of five, stating that when Tisdale "sticks to the surface, she makes sure that Guilty Pleasure lives up to its title". The ballads however, were not as well received, stating Tisdale "isn't convincing when she tries to deal in either pain or carnality".
Billboard gave the album a mixed review with four and a half stars out of ten, stating Tisdale "can deliver the radio-ready goods" but criticized the album as a whole and that it "doesn't give the singer room to comfortably let loose". Digital Spy's Nick Levine praised Guilty Pleasure for Tisdale's new sound, comparing her to the likes of Kelly Clarkson and Ashlee Simpson. Levine praised tracks such as "It's Alright, It's OK", "Erase and Rewind" and "Hot Mess", however was not impressed with "Crank It Up", stating it "shamelessly rips off Britney's robopop sound, right down to the Spears-aping vocals"; he went on to give the album three out of five stars. The most negative of reviews came from Margaret Wappler of the Los Angeles Times who only gave the album one and a half out of four stars. Wappler said the album has "few glimmers of hope" and went on to criticize the producers as "not seem[ing] to have gifted Tisdale with their best work". The album was also ranked #7 on Billboard.com's Reader Poll for album of the decade and best album of 2009.

Chart performance
The album debuted on several European charts, the first appearances of the album were in the last week of June 2009, on Austrian Albums Chart and German Albums Chart, peaking at number seven and nine respectively, in the same week the album debuted at number 51 on Irish Albums Chart and rose to number 30 in the following week while in Spain, the album debuted at number 21 and rose to number nine in the second week. In the first week on August 2009, the album debuted at number 12 on the Billboard 200 selling 25,000 copies in its first week. The album dropped out of the Billboard 200 after eight weeks on the chart. The album had sold 245,000 copies in the United States as of December 9, 2010.

Promotion

Tisdale embarked on a press European promo tour in March 2009, where she visited the United Kingdom, France, Germany, and Italy. Tisdale started a promo radio tour in May 2009 for United States. On April 14, 2009, she was presenting the lead single of the album on On Air with Ryan Seacrest, one month later she performed for first time a few songs from the album at the 2009 KISS Concert on May 17, 2009. The music video of "It's Alright, It's OK" was shown in 6,600 movie theatres in the United States. In early June 2009, she started her second promotional tour for Europe, visiting Germany, Italy and Spain, here performed on several television shows, such as German Wetten, dass..? and Comet Awards, Spanish Fama and Operación Triunfo, and Italian TRL. Her first performance in the American television was on June 16, 2009, performing the first single and "Masquerade" on Good Morning America, later Tisdale and her band promoted the album on several American television shows including Today Show and America's Got Talent. Tisdale along with her band performed several free concerts across the United States, including the opening for the first Microsoft Store on Scottsdale, Arizona, on October 22, 2009. Later in the month she performed "It's Alright, It's OK" at the MTV Latin Video Music Awards held in Mexico. She also performed songs from Guilty Pleasure and recorded live performances for AOL Sessions and Walmart Soundcheck, the last being released as a digital Extended Play on August 4, 2009.

Singles
"It's Alright, It's OK" was released as the album's lead single on April 13, 2009 in Canada, and in the United States on the next day, in both radio airplay and digital download formats. The single debuted at #99 on the Billboard Hot 100 in the same week, making it Tisdale's lowest-charting official single on the chart. The song's highest peak position was #5 on the Austrian Singles Chart.

"Crank It Up" was released on October 9, 2009, as the album's second and final international single. The music video premiered on October 5, 2009, via VIVA and was featured on MySpace on October 6, 2009.

Track listingNotes'
 signifies a vocal producer
 signifies a remixer

Charts

Release history

References

2009 albums
Albums produced by Billy Steinberg
Albums produced by Dreamlab
Albums produced by Emanuel Kiriakou
Albums produced by the Matrix (production team)
Albums produced by Toby Gad
Albums produced by Twin
Ashley Tisdale albums
Warner Records albums
Albums produced by Oak Felder


José Santiago Vidaurri Valdez (July 24, 1809 – July 8, 1867) was a controversial and powerful governor of the northern Mexican states of Nuevo León and Coahuila between 1855 and 1864. He was an advocate of federalism.

In 1855, he supported the liberal Revolution of Ayutla, which overthrew the dictatorship of Antonio López de Santa Anna, the military strongman who dominated Mexican politics in the 1830s until his overthrow in 1855. Vidaurri stood by the liberal president Benito Juárez during the subsequent War of the Reform, a bloody civil war following Mexican conservatives' repudiation of the liberal government and the Constitution of 1857. During the war, Vidaurri commanded the liberal armies of the north. During the American Civil War (1861–65), Southern slave states had seceded from the United States and formed the Confederate States of America. Vidaurri sought advantageous trade relationships with the CSA, which bordered northern Mexico. Confederate forces had early successes in 1861–62 against the northern Union troops, so that it was entirely possible that its existence as a sovereign nation would continue.  It was a pragmatic move for Vidaurri and northern Mexico to establish such a connection.  Although Mexican conservatives had been defeated militarily in the Reform War, they still sought a way to power so that when Juárez cancelled payment on foreign bonds in 1861 there was an opening for Mexican monarchists. A coalition of European powers sought intervention for debt collection, with France using the opportunity for regime change in Mexico, with the support of Mexican conservatives.   The French invaded, displacing Juárez from the capital Mexico City. Although Mexican conservatives had invited Hapsburg Archduke Maximilian to be emperor of Mexico, put into power by the French, Maximilian was in fact a political liberal. Vidaurri broke with Juárez, who never went into foreign exile, but whose government did not effectively control territory.  Vidaurri was one of several moderate liberals who joined the cabinet of Emperor Maximilian of Mexico in the Second Mexican Empire and served in early 1867 as the emperor's final First Minister. When the Empire fell in 1867, Vidaurri was captured and summarily executed by the restored Republican government. His place in Mexican history remains clouded by his collaboration with the Empire, but in Nuevo León he remains an important historical figure.

Early life
Vidaurri was born in Villa Punta de Lampazos, New Kingdom of León on July 24, 1809, the oldest of the four sons of Pedro José Vidaurri de la Cruz and María Teodora Valdez Solís. A rumor circulated that "he was the son of an unknown Indian brave, raised to adulthood by roaming bands of indios bárbaros, but his baptismal record shows that he was born in Lampazos in 1809.

Political career

Vidaurri is best known as the strongman of northeast Mexico during the 1850s and 1860s who defended that territory against outside intervention. The first notice of him appears when he cut off a soldier's hand in 1832, with unknown adverse consequences to him, but he went on to become a clerk for the police of Nuevo León and then, in 1837, an assistant to the governor of the state, Joaquín García, and then Manuel María de Llano. Vidaurri then became his secretary and was chosen by General Arista to spy on the Texan Santa Fe Expedition, sponsored by Texas President Mirabeau B. Lamar.  The purpose was to divert the Santa Fe Trail into Texas and establish control over New Mexico. In the 1840s and early 1850s, Vidaurri worked with Mexican conservatives, but broke with them and joined the liberal revolt against Antonio López de Santa Anna. Santa Anna attempted to strengthen central government rule over Mexican states, which had held considerable autonomy. Vidaurri promulgated a plan called "Restaurador de la Libertad" (restorer of liberty), captured the main city of Nuevo León, Monterrery, in May 1855, and became both military commander in the state.

In the southern state of Guerrero, strongman Juan Álvarez organized resistance to Santa Anna and a political plan to oust him. The Plan of Ayutla resulted in uprisings in southern Mexico and were then joined by many in northern Mexico. The revolution of Ayutla then gained the necessary speed it needed when it was joined by Santos Degollado and Manuel Doblado. Vidaurri supported the Revolution of Ayutla and had already seized the opportunity to create his own area of political control in northern Mexico. The northern supporters of the Revolution of Ayutla were important to its success; without such support it might well have been a southern regional rebellion penned in and suffering a war of attrition. In this period Vidaurri's reputation as a liberal was solidified. "Vidaurri had become one of the champions of Mexican liberalism during the first years of his cacicazgo [political area of control] over the northeast, especially its most radical faction, the puros.

Historian Brian Hamnett argues that, following Mexican independence, the support for federalism for which many Liberals advocated was a kind of institutionalized centrifugalism. Santa Anna's attempts to centralize power met resistance from areas that had exercised a level of autonomy, such as Guerrero under Álvarez and northeast Mexico under Vidaurri.  Vidaurri had overthrown the governor of Nuevo León and annexed Coahuila, eliminating any opposition. The forced merger of Coahuila and Nuevo León in April 1856 was opposed by President Ignacio Comonfort, with Vidaurri appealing to the federal congress for support. The central government was too weak to counter his defiance, and it acquiesced to the situation out of necessity. With the ratification of the liberal Constitution of 1857, which had federalist principles of a weak central state and strong states' rights, Vidaurri, as leader of Coahuila-Nuevo León, was de facto head of a sovereign nation. He had an army, collected customs revenues, and was free of central government interference. He was powerful and potentially dangerous, given the size and location of the territory he controlled in northern Mexico. In Nuevo León-Coahuila, he had dealings with one of the elite families of the region, the Sánchez Navarros, the largest landowners in Mexico.  At various points, Vidaurri attempted to force the family to sell him an hacienda, shook them down for a 10,000 pesos "contribution" to shore up the Vidaurri administration when it was short of funds, and sacked a family mansion in Saltillo.

War of the Reform
During the War of the Reform (1858–1860), Vidaurri supported the Mexican Republic headed by Benito Juárez, but, during the French intervention in Mexico, he supported the French. Vidaurri raised an army in his merged states of Coahuila and Nuevo León. In September 1858, Vidaurri's forces were defeated by conservative general Miguel Miramón. One way Liberals sought to finance the civil war against the Conservatives was the sale or confiscation of property held by the Catholic Church. Vidaurri did not wait for formal sanctioning of this policy, but implemented it in his territory, as did Jesús González Ortega. A major source of revenue for Vidaurri were those that were collected by the customs houses along the U.S.–Mexico border, which he kept rather than turning them over to the federal Liberals. For that, Benito Juárez denounced him, and some of Vidaurri's allies deserted him to follow Juárez. Evaristo Madero, grandfather of Francisco I. Madero, who challenged Porfirio Díaz for the presidency in 1910, was a successful businessman in Northeast Mexico, and was for a time an ally of Vidaurri; The elder Madero broke with Vidaurri and supported Juárez. Later the Madero family married into the Milmo Vidaurri Family.

Second Mexican Empire
With the secession of Southern states from the United States and the formation of the Confederate States of America, Vidaurri established relationships with the nascent Confederate government. Vidaurri met with Confederate agent Juan A. Quintero in June 1861. Vidaurri believed that relations with the Confederacy could prove profitable for his territory and insure border peace, and he made his overture to Confederate President Jefferson Davis.

During the Second French Intervention in Mexico and the establishment of the Second Mexican Empire, Vidaurri broke with Juárez, as early as March 1864, over the administration and finances of his state, and even held a referendum on joining the Empire. Republican troops drove him into Texas, but troops loyal to Vidaurri remained active in the region. As Republican forces in the north were diverted by Imperial advances. Vidaurrist troops captured Monterrey on 15 August 1864, with President Juárez barely escaping, and pursued as far as Parras in a bullet-riddled carriage. The triumphant Vidaurri then headed towards the capital where he was made a councilor of Emperor Maximilian. By the end of the year, the imperialists controlled Nuevo León and the greater part of Coahuila to the banks of the Rio Grande, the border with the Confederate States of America.

Death
The Empire collapsed in 1867 and Emperor Maximilian was captured by Republican forces. Vidaurri was arrested by a squadron "and executed without a trial as a traitor to the Mexican nation."

Legacy
Although Vidaurri is often written out of the historiography of Mexico or disparaged for his support of the Second Mexican Empire, he remains an important historical figure in his home state of Nuevo León. A 2007 attempt to erect a statue of Vidaurri in Lampazos, where he was born, was embroiled in controversy.

On April 23, 1857, his daughter, Prudenciana Vidaurri, married prominent Irish businessman Patrick Milmo O'Dowd, of Irish descent, who profited from the cotton trade with the Confederate States of America. The family continued to play an important role in late nineteenth-century Monterrey. The union produced a son, Patricio Milmo Vidaurri, who would marry Patricia Hickman Morales. Patricio and Patricia become the parents of Laura Milmo Hickman, wife of Emilio Azcarraga Vidaurreta, pioneer of Mexican television and one of the founders of Televisa. Emilio and Laura were the parents of Mexican entrepreneur Emilio Azcarraga Milmo, father in turn of the current board president of Grupo Televisa, Emilio Azcarraga Jean.

Further reading

Broussard, Ray F. "Vidaurri, Juárez, and Comonfort's Return from Exile." Hispanic American Historical Review, vol. 49, No. 2 (May 1969), pp. 268–280.
Cavazos Garza, Israel,ed. Epistolario Zaragoza-Vidaurri, 1855–1859. Mexico City: Primer Congreso Nacional de Historia para el Estudio de la Guerra de Intervención, 1962.
Hamnett, Brian. Juárez. New York: Longman 1994.
Mahoney, Harry T. and Marjorie Locke Mahoney. Mexico and the Confederacy, 1860–67. San Francisco: Austin & Winfield 1998.
Martínez Sánchez, Lucas. Coahuila durante la Intervención Francesa, 1860–1867. Saltillo, Coahuila: Consejo Editorial del Estado 2008.
Mora-Torres, Juan. The Making of the Mexican Border: The State, Capitalism, and Society in Nuevo León, 1848–1910. Austin: University of Texas Press 2001.
Moseley, Edward H. "The Public Career of Santiago Vidaurri, 1855-1858". PhD dissertation, University of Alabama 1963.
Moseley, Edward H. "Santiago Vidaurri: héroe de la reforma", Humánitas (1970)
Moseley, Edward H. "Santiago Vidaurri, Champion of States' Rights: 1855-1857" West Georgia College Studies in the Social Sciences, VI, (June 1967), 69-80
Owsley, Frank Lawrence, King Cotton Diplomacy: Foreign Relations of the Confederate States of America. 2nd. edition, rev. Chicago: University of Chicago Press 1959.
Roel, Santiago, ed. Correspondencia particular de Santiago Vidaurri, gobernador de Nuevo León. Monterrey 1946.
Tyler, R. Curtis.  Santiago Vidaurri and the Southern Confederacy. The Americas Vol. 26, No. 1, (July 1969), pp. 66–76.
Wahlstrom, Todd W. The Southern Exodus to Mexico: Migration Across the Borderlands after the American Civil War. Lincoln: University of Nebraska Press 2015.

References

External links
Handbook of Texas Online, Edward H. Moseley, "Vidaurri, Santiago," accessed March 14, 2017, http://www.tshaonline.org/handbook/online/articles/fvi24.
Video on the career of Vidaurri https://www.youtube.com/watch?v=DDjgJZdf1GI

Bibliography
 LosVidaurri.com (Vidaurri Family portal)
 Guillermo Prieto – Lecciones de historia Patria

Santiago
Governors of Nuevo León
People from Lampazos, Nuevo León
Mexican Secretaries of Finance
Mexican monarchists
Governors of Coahuila
Second French intervention in Mexico
Liberalism in Mexico
Mexican generals
1809 births
1867 deaths

19th-century Mexican politicians
Politicians from Nuevo León


The chairman of the Estates of Suriname () was the presiding officer of the Estates of Suriname.

List of chairmen
The following is a complete list of office-holders from 1935 to 1975:

Political parties

See also
 List of chairmen of the National Assembly of Suriname
 List of colonial governors of Suriname

References

Suriname
Lists of political office-holders in Suriname


Night of the Demons is an American comedy-horror franchise consisting of four films. The original film, Night of the Demons, was released in 1988. Written and produced by Joe Augustyn, and directed by Kevin S. Tenney, the sequels have had various writers and directors attached to them, with the character of Angela Franklin remaining the only constant in all of the films in the franchise. Tenney, who directed the first sequel, also wrote the third film in the franchise and co-produced the remake.

Films

Original series

Night of the Demons (1988)
The first film in the series, Night of the Demons was released in 1988. The film was written and produced by Joe Augustyn and directed by Kevin S. Tenney. The film follows several teenagers as they attend a party thrown by school outcast Angela (played by Amelia Kinkade) and her best friend (scream queen Linnea Quigley) at an abandoned funeral home.

The film was picked up for theatrical release by Paragon Arts International. Rather than a nationwide release, it was released regionally, debuting in Detroit, Michigan, on September 9, 1988.

Night of the Demons 2 (1994)
Night of the Demons 2 was released in 1994, with the story picking up six years after the end of the previous film. The story follows the character of Angela's younger sister Melissa as she and several of her fellow students visit Hull House on Halloween. Unlike its predecessor, which took place entirely inside of the funeral parlor, the sequel has demonic activity occurring outside of the limits of the property on the school's campus.

The film was given a limited theatrical release in California by Republic Pictures from May 17, 1994.

Night of the Demons 3 (1997)
Night of the Demons 3 (also known as Demon House) is a 1997 sequel to the previous two films. Written by Kevin S. Tenney, the plot features several teens that find themselves on the run after a misunderstanding leading to a shoot out with police. They try to hide out at Hull House.

The film was given a limited theatrical release in California by Republic Pictures from October 7, 1997.

Remake series

Night of the Demons (2009)
Night of the Demons is a 2009 remake that was loosely based on the original 1988 film. The film takes place in a seemingly haunted mansion in New Orleans, with the plot following several adults rather than teenagers. It was directed by Adam Gierasch and produced by Kevin S. Tenney.

The film originally premiered at the London FrightFest in August 2009. Although it was originally scheduled to arrive in theaters, it was instead released straight-to-DVD/Blu-ray on October 19, 2010.

Night of the Demons: After-Party (TBA)
In June 2013, Kevin S. Tenney intended to create a sequel to the 2009 Night of the Demons film, subtitled "After-Party" and directed by Anthony Hickox. A Kickstarter campaign was launched with a goal of $250,000 but was unsuccessful, with the project remaining in development hell since 2013.

The projected plot for After-Party was to center on the character of Diana, one of Angela's former friends and associates, who would hold a party in the same mansion and become possessed by the now-demonic Angela.

Cast and characters
 A dark gray cell indicates that the character was not in the film or that the character's presence in the film has yet to be announced.
 An  indicates an appearance through archival footage or stills.
 A  indicates a cameo role.
 An  indicates a role shared with another actor.
 A  indicates an uncredited role.
 A  indicates a voice-only role.

Box office

References

External links

Night of the Demons
Films set in California
Comedy film series
Horror film series
Film series introduced in 1988


Adelaide has two city ring routes, that loop around the Adelaide city centre and North Adelaide, known as the Inner and Outer Ring Routes.

Inner ring route
The Inner Ring Route is a collection of major roads signposted as state route R1 (was A21 before 2017). Listed clockwise from Main North Road, the inner route consists of:
 Robe Terrace
 Park Road /Mann Road
 Hackney Road
 Dequetteville Terrace
 Britannia Roundabout
 Fullarton Road
 Greenhill Road
 Richmond Road
 South Road
 James Congdon Drive
 Port Road
 Park Terrace
 Fitzroy Terrace

The Inner Ring Route is adjacent to the outer edge of the Adelaide Park Lands except on the western side between Anzac Highway and Port Road where railway lines occupy the space along the parklands, and the road ring route is further out. The earlier A21 route using West Terrace passed inside the ring of parklands instead.

History
Prior to the renumbering as route R1 in 2017, the western side of the previous route A21 was different from the current route. It followed moore of Port Road southeast, West Terrace and Goodwood Road. Route R1 uses James Congdon Drive, a short section of South Road and Richmond Road instead.

The Park Terrace section had a level crossing of the Outer Harbor railway line until 2017. The crossing was replaced by a bridge when the railway was lowered as part of a project to separate the Torrens Junction so that suburban trains to Outer Harbor did not conflict with interstate trains on the standard gauge line.

The Park Terrace bridge over the Gawler railway line and interstate freight line was constructed in 1990. When it was built, it replaced an awkward 30-degree level crossing.  In 2017, it was named after the engineer who supervised its construction, David Fitzsimons.

Route description

Outer ring route
The Outer Ring Route is not signposted. It also consists of major roads surrounding the city. They are:
 Grand Junction Road
 Hampstead Road/Portrush Road
 Cross Road
 South Road

See also

References

Roads in Adelaide
Ring roads in Australia


Sir John Grey Egerton, 8th Baronet (11 July 1766 – 24 May 1825) was a politician from the Egerton family in Cheshire, England. He was Member of Parliament (MP) for Chester from 1807 to 1818.

Born John Egerton, the son of Philip Egerton of Oulton by his cousin, Mary, sister and sole heiress of Sir John Haskin Eyles Styles, 4th Bt. He was educated at King's School, Chester and Tarvin School. He served as High Sheriff of Cheshire for 1793–94.

In 1814, he succeeded to the Egerton baronetcy on the death of Thomas Egerton, Viscount Grey de Wilton and Earl of Wilton, a distant relative, and took the surname Grey Egerton. His family seat was Oulton Park. He became a successful racehorse owner, and served as Grand Master of the Cheshire Freemasons.

On 9 April 1795 he married Maria, daughter of and sole heir of Thomas Scott Jackson, a Director of Bank of England.

He died childless in London, aged 58, a few days after a carriage accident on 19 May 1825 at Epsom Races. His funeral at Little Budworth on 8 June 1825 was attended by 10,000–12,000 people, with 17 of the 19 Cheshire Freemason Lodges being present.

He was succeeded by his brother, Philip. His wife, Maria, died, and then was buried on 23 August 1830.

References

Bibliography
 Burke's Peerage, 106h ed., (1999)
 Burke's Peerage, 107th ed., (2003)
 Cokayne and Gibbs, The Complete Peerage, XV vols, (1910-1998)

External links

1766 births
1825 deaths
Members of the Parliament of the United Kingdom for English constituencies
UK MPs 1807–1812
UK MPs 1812–1818
Baronets in the Baronetage of England


Polygamy in Eswatini is legal but rare due to high bride prices. Eswatini has a dual legal system of common law, based on Roman-Dutch law, and traditional unwritten Swazi law. Polygamous marriages are mostly performed under traditional law but also sometimes under civil marriage.

References

Polygamy in Africa
Eswatini
Society of Eswatini
Women's rights in Eswatini


John I of Münsterberg (ca. 1380 – 27 August 1428) was a Duke of Münsterberg (Ziębice) from 1410 until his death; until 1420 with his brother as co-ruler.

He was the second son of Duke Bolko III of Münsterberg by his wife Euphemia, daughter of Duke Bolesław of Bytom.

Life
The death of his older brother Nicholas (on 9 November 1405) made him his father's heir. Bolko III died in 1410 and was succeeded by John.  Like his father, he didn't need a regent, since he was an adult at the time. John nominally co-ruled with his younger brother Henry II, but he retained all the government in his hands. Henry II died childless in 1420 and since then John ruled over Münsterberg alone. Like his father and grandfather, he remained a faithful vassal of the House of Luxembourg.

During the first years of his rule the Polish–Lithuanian–Teutonic War took place. He participated there at the side of the Teutonic Order; however, his interference in the war was limited, especially after the Battle of Tuchola (4 November 1410), where he escaped from the battlefield with other noble and Teutonic knights.

On 6 January 1420 John was present in the Reichstag of Breslau (Wrocław), where he spent a major disincentive to the Polish sentence in the process against the Teutonic Order.

The previous politics of his predecessors was negligible, so when John assumed the government over his Duchy, he only had the town of Münsterberg. For this reasons, he married around 19 March 1408 with Elizabeth (d. 22 February/27 December 1424), widow of the powerful Polish magnate Spytek II of Melsztyn and daughter of Emeric I Lackfi, General Starost of Ruthenia, Ban of Dalmatia (Transylvanian Voivodship) and of Hungary. Thanks to this union, John obtain a huge dowry and the needed financial autonomy. The case was more strange by the fact that Elisabeth's first husband was one of the most closest advisers of King Władysław II Jogaila of Poland, the long-time enemy of John's sovereign, the Sigismund of Luxembourg, King of Hungary and Germany. Moreover, despite the hostile politics of King Sigismund, Elizabeth successfully continued with her many Polish contacts, even after her remarriage with the Duke of Münsterberg. The union proved to be childless, so John was the last male representative of Münsterberg branch of the Piast dynasty.

By 1428 Silesia was in the middle of the Hussite Wars. Initially, seeing no chances of victory, Duke Louis II of Brieg entered into an arrangement with John, under which he was compelled to not interfere with the movements of enemy troops. However, for unknown reasons, John broke the ceasefire, and with this he began his participation in the war.

John died on 27 August 1428 in the battle of Altwilmsdorf (Stary Wielisław), in the Valley of Glatz (Kłodzko), fighting against the Hussite leader Jan Kralovca. The cause of the disaster was a thoughtless attack of the Hussite troops, or earthwork built wagons from the battle. It's unknown where John was buried. On the alleged place of the Duke's death was built a Chapel during 1904–1905 designed by Ludwig Schneider.

After his death, and according to the treaty of 1343, the Duchy of Münsterberg was annexed by the Kingdom of Bohemia.

References

 Genealogical database by Herbert Stoyan
 Genealogy of the Dukes of Ziębice

1380s births
1428 deaths
Dukes of Münsterberg
Piast dynasty


The East Villager was a newspaper published monthly in New York City by Everything for Everybody, a group founded by Jack Scully.

Targeting the neighborhood for which it was named, East Village, Manhattan, the paper's masthead stated that it had been published monthly since June 1966 and said of itself, "No One Slighted, Nothing Overlooked."  Notable editors included Heidi Boghosian, presently executive director of the National Lawyers Guild, and Steven Vincent, an author and journalist who was abducted and murdered while working freelance in Iraq in 2005.

From 1974 to 1977 the newspaper had been called "Everything for Everybody" which was edited by Alec Clayton and published out of the organization's West Village branch at 406 West 13th Street. Clayton is now a novelist and freelance writer in Olympia, Washington.

Controversy
The paper was criticized by some and supported by others as it took a somewhat more conservative turn under editor Steven Vincent, who was said to oppose the neighborhood squatters who had moved into vacant buildings and the "Tent City" of homeless people in Tompkins Square Park.  Vincent was also a key organizer of the successful effort to elect Antonio Pagan, one of New York City's first openly gay councilpersons and a conservative Democrat who would later support Mayor Rudy Giuliani.

References

East Village, Manhattan
Newspapers published in New York City
Newspapers established in 1966
1966 establishments in New York City


This list includes properties and districts listed on the National Register of Historic Places in Buncombe County, North Carolina. Click the "Map of all coordinates" link to the right to view an online map of all properties and districts with latitude and longitude coordinates in the table below.

Current listings

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See also

National Register of Historic Places listings in North Carolina
List of National Historic Landmarks in North Carolina

References

Buncombe County


Richard Harrison Bachman (born July 25, 1987) is an American former professional ice hockey goaltender who is currently the goaltending coach for the Iowa Wild of the American Hockey League (AHL). He played two seasons of college ice hockey at Colorado College before enjoying a career in the National Hockey League with the Dallas Stars, Edmonton Oilers and the Vancouver Canucks. Bachman was born in Salt Lake City, Utah, but grew up in Highlands Ranch, Colorado.

Playing career

Early career
As a youth, Bachman played in the 2001 Quebec International Pee-Wee Hockey Tournament with the Colorado Junior Avalanche minor ice hockey team from Littleton, Colorado.

During his time at Cushing Academy, Bachman compiled a GAA of 1.28 with 3 shutouts in 28 games He also split this time independently with the Boston Jr. Bruins. While at the Cedar Rapids RoughRiders of the United States Hockey League after a trade from the Chicago Steel, Bachman compiled a .913 save percentage in 26 regular-season starts. Bachman was chosen in the fourth round, 120th overall in the 2006 NHL Entry Draft by the Dallas Stars.

Colorado College
During his freshman year, Bachman became the second player in WCHA history to be named Player and Rookie of the Year in the same season.

As a sophomore in the 2008–09 season, Bachman posted a .914 save percentage with a 2.63 GAA.

Dallas Stars

On March 27, 2009, Bachman signed a three-year entry-level contract with the Dallas Stars, ending his college career. After spending his first professional season with American Hockey League affiliate the Texas Stars, Bachman was called up to Dallas in the following 2010–11 season on December 8, 2011. Bachman was called to back up Andrew Raycroft after the Stars' primary goalie, Kari Lehtonen, was placed on the Injury Reserve. He then made his debut with the Stars that day. With the Stars, Bachman started a trend for his goalie masks to
have a theme of The Shining, acknowledging that "Richard Bachman" was also a pen name for Shining author Stephen King.

After he was initially reassigned to the Texas Stars to begin the 2011–12 season, Bachman was recalled a month into the season and replaced Andrew Raycroft as the primary backup to Kari Lehtonen. On December 13, 2011, Bachman earned his first NHL shutout, blanking the New York Rangers 1–0.

Edmonton Oilers
On July 6, 2013, Bachman signed a one-year deal with the Edmonton Oilers after becoming a free agent. Bachman competed with Jason LaBarbera for the backup goaltender position behind Devan Dubnyk. On October 27, Bachman had his first start with the Edmonton Oilers, making 47 saves but losing in a shootout to the Los Angeles Kings. In the 2013-14 NHL season Bachman suffered a hamstring injury and was eventually sent down to Oklahoma City, where he would play for the remainder of the season.

Vancouver Canucks
On July 1, 2015, Bachman signed as a free agent to a two-year contract with the Vancouver Canucks. Relegated to third goalie, Bachman only played one game for the Canucks and spent most of the season in the AHL, playing for the Utica Comets; the following season was spent entirely with the Comets.

On July 13, 2016, Bachman signed a contract extension to stay with Vancouver through 2018. On June 20, 2018, Bachman signed a two-year, two-way contract to remain with the Canucks organization through 2020.

While playing with Utica, Bachman suffered an Achilles injury which prematurely ended his 2018–19 AHL season on December 21, 2018.

In the following 2019–20 season, Bachman through injury found himself as the Comet's third choice upon recovery. Limited to just 3 games, while in the final season of his contract, Bachman sought and was loaned by the Canucks to Swedish club, IK Oskarshamn of the Swedish Hockey League, for the remainder of the season on February 12, 2020. He made just 3 appearances in Sweden, going winless, before the season was cancelled due to the COVID-19 pandemic.

Coaching career
On October 2, 2020, Bachman announced his retirement from professional hockey after 11 seasons and became the goaltending coach for the Iowa Wild in the AHL.

Career statistics

Regular season and playoffs

International

Awards and honors

References

External links

1987 births
Living people
American men's ice hockey goaltenders
Cedar Rapids RoughRiders players
Chicago Steel players
Colorado College Tigers men's ice hockey players
Dallas Stars draft picks
Dallas Stars players
Edmonton Oilers players
Ice hockey players from Colorado
Sportspeople from Salt Lake City
Idaho Steelheads (ECHL) players
IK Oskarshamn players
Oklahoma City Barons players
People from Highlands Ranch, Colorado
Sportspeople from Douglas County, Colorado
Texas Stars players
Utica Comets players
Vancouver Canucks players
AHCA Division I men's ice hockey All-Americans


Kevin Mathews (born 15 February 1961) is a Singaporean singer-songwriter and film music composer.

Watchmen
Mathews formed The Watchmen in 1989 with his Anglo Chinese School classmates Tony and James Makarome. Originally a five-man band called The Hornets, The Watchmen put out three independent releases in the early 1990s, Who Watches the Watchmen, Industry & Commerce and the acclaimed This Savage Garden. This garnered the trio an invitation from BigO magazine to contribute to their New School Rock III CD in 1993. The Watchmen contributed two songs, "Please Believe Me" and "Orchard Road", which went on to become a radio favourite. New School Rock III was nominated by 987FM for the Best Local Album of 1993.

In May 1993, The Watchmen contributed the song "The High Cost Of Living" to BigO'''s Death Valley 92328 CD. This protest song gained attention for its local content and topical issues, which led music critic Chris Ho to describe Mathews as "the first protest singer to be recognized as such in Singaporean pop this decade."

Odyssey Music, a local distributor, decided to sign The Watchmen to a two-year contract, and in August 1993, The Watchmen released their debut album Democracy. A track from the album, "My One and Only", became a radio hit, garnering pole position on the Radio Heart Top Ten and the number three spot on the 987FM Perfect Ten. Democracy sold more than 1,000 copies, and BigO readers voted for it as the Best Local Album of 1993.

To cash in on the public's apparent infatuation with Mathews' balladeering, Odyssey Music persuaded Mathews to rush-release an EP of songs about love – called Love – in time for Valentine's Day. A track from the EP, "I Love Singapore", was later included on the Mee Pok Man movie soundtrack, with Mathews going under the nom de plume of "The Crowd".

In April 1994, Mathews' Watchmen bandmates Tony and James Makarome wrote an open letter to the press accusing him of failing to acknowledge their contributions. In particular, they were especially disappointed with his public remark that he had "got rid" of his bandmates, saying he had "accidentally dropped them into the Indian Ocean". Mathews denied this and the band broke up soon after, with Mathews announcing that he was going solo.

Popland
In 1998, Mathews formed Popland, a musical duo between him and British-born bass player, Tim Nolan. The duo's first CD, Pop was released in 1997 under the name "The Crowd", which they later changed to avoid confusion with a US band of the same name. They followed this with 1998's Groovy, featuring Singaporean musician Ray Aziz on drums. Aziz also played drums on their 2002 release Action, released on Zip Records.

Popland was featured by Singapore's national newspaper, The Straits Times, played on several Singapore TV shows and various radio stations. Their music was used in the Warner Bros. hit TV show High School Reunion. The duo split in 2006 when Mathews decided to pursue a solo career.

Solo career
In 2006, Mathews embarked on a solo career. In November 2008, he released the EP watchmen@midnight and his debut solo full-length album Emo FASCISM on 1 August 2013. In 2014, Mathews released the #alpacablues EP.

Mathews has been a live performer for more than thirty years and has performed at Central Park NYC (for Singapore Day 2007), the Esplanade, *SCAPE, Home Club, Blu-Jaz Cafe, Library @ Esplanade, Library @ Orchard, Timbre @ The Substation, Timbre @ The Arts House, TAB, the Prince of Wales Backpackers' Pub and other venues.

Other areas of interest
In addition, Mathews is an accomplished film score writer, and has composed music for acclaimed Singapore director Eric Khoo's feature films and has also contributed music to other Singaporean films like Stories About Love, One Leg Kicking, Invisible Children, Lucky 7, Anita's Complaint and The Carrot Cake Conversations as well as TV series such as Drive and Seventh Month''.

Mathews is also a prominent contributor to the Singapore music scene. He is currently a mentor under the National Arts Council's Noise Music Mentorship Programme, a mentor for the Esplanade Youth Budding Writers Programme and a judge for the 2009 and 2010 editions of the Baybeats Festival, one of the biggest indie rock festivals in the region. In addition, he manages Singapore bands like Cheating Sons and TypeWriter and operates KAMCO Music, an artist management company.

Mathews is also the owner of Power of Pop, a pop culture blog which has been commenting on music, film, comics and books for more than a decade.

He is also a tutor of business law at Ngee Ann Polytechnic. Also tutor Company Law in Temasek Polytechnic.

References

Living people
Singaporean people of European descent
20th-century Singaporean male singers
1961 births
Singaporean film score composers
Male film score composers
21st-century Singaporean male singers


The Char Dham (), also rendered the Chatur Dhama () is a set of four pilgrimage sites in India. It is believed that visiting these sites helps achieve moksha (salvation). The four Dhams are Badrinath, Dwarka, Jagannath and Rameswaram. It is believed that every Hindu should visit the Char Dhams during one's lifetime. The Char Dham as defined by Adi Shankara (686–717 CE) consists of four Hindu pilgrimage sites.
These main 'dhamas' are the shrines of Vishnu and Rameshwaram is a shrine of Shiva.
All the 'dhamas' are related to four epochs,(1) Dham of Satyuga- Badrinath, Uttarakhand (2) Dham of Tretayuga -Rameswaram, Tamil Nadu (3) Dham of Dwaparayuga - Dvaraka, Gujarat (4) Dham of Kaliyuga - Jagannatha Puri, Odisha.

Description

According to Hindu belief, Badrinath became prominent when Nara-Narayana, an avatar of Vishnu, did Tapasya there. At that time that place was filled with berry trees. In the Sanskrit language, berries are called "badari", so the place was named Badarika-Vana, that is, the forest of berries. The particular spot where the Nara-Narayana did Tapasya, a large berry tree formed covering him to save him from the rain and the sun. Local people believe that Lakshmi became the berry tree to save Narayana. Post-Tapasya, Narayana said, people will always take Her Name before His Name, hence Hindus always refer "Lakshmi-Narayana". It was therefore called Badri-Nath, that is, the Lord of Berry forest. This all happened in the Satya Yuga. So Badrinath came to be known as the first Dhama. The temple is located on the banks of the Alaknanda River in the Chamoli district of Uttrakhand.

The second place, Rameswaram, got its importance in the Treta Yuga when Rama built a Shiva-Lingam here and worshipped it to get the blessings of Shiva. The name Rameswaram means "God of Rama". It is also believed that Rama's footprints are imprinted there.

The third, Dwaraka, got its importance in the Dvapara Yuga when Krishna made Dwaraka his residence instead of Mathura, his birthplace.

At the fourth, Puri, Vishnu is worshipped as Jagannatha, his avatara for the current epoch i.e Kali Yuga.

The four Shankaracharya Peetha (Seats) at the Char Dham school of Hinduism, created at least four Hindu monastic institutions. He organised the Hindu practitioners under four  (Sanskrit: ) (institutions/monasteries), with the headquarters at Dvārakā in the West, Jagannatha Puri in the East, Sringeri Sharada Peetham in the South and Badarikashrama in the North.

The table below gives an overview of the four Amnaya Mathas founded by Adi Shankara, and their details.

The four associated places of the Char Dham
Hari (Vishnu) and Hara (Shiva) are called eternal friends in the Puranas. It is said wherever Vishnu resides; Shiva resides nearby. The Char Dham follows this rule. So Kedarnath is considered as the pair of Badrinath, Rama Setu is regarded as the pair of Rameswaram, Somnath is considered as the pair of Dwaraka, and Lingaraja is regarded as the pair of Jagannatha Puri. However, according to some traditions, the Char Dham are Badrinath, Ranganatha-Swami, Dwaraka, and Jagannatha-Puri, all of which are Vaishnava sites, and their associated places are Kedarnath, Rameswaram, Somnath and Lingaraja Temple, Bhubaneswar (or maybe Gupteshwar) respectively.

The Char Dham Highway project (Kedarnath, Bhadrinath, Gangotri, Yamunotri) is functional, and many service providers offer a Char Dham Yatra by helicopter to ease pilgrims.

Puri

Puri, located in the east, is located in the state of Odisha, India. Puri is one of the oldest cities in the eastern part of the country. It is situated on the Bay of Bengal coast. The main deity is Krishna, revered as Jagannatha. It is the only shrine in India where goddess Subhadra, sister of Krishna, is worshipped along with her brothers, Jagannatha and Balabhadra. The main temple here is about 1000 years old and constructed by Raja Choda Ganga Deva and Raja Tritiya Ananga Bhima Deva. Puri is the site of the Govardhana Matha, one of the four cardinal institutions or Mathas converted by Adi Shankara. Pandit Nilakantha Das suggested that Jagannath was a deity of Jain origin because of the appending of Nath to many Jain tirthankaras.  Jagannath meant the 'World personified' in the Jain context and was derived from Jinanath. Evidence of the Jain terminology such as of Kaivalya, which means moksha or salvation, is found in the Jagannath tradition. Similarly, the twenty two steps leading to the temple, called the Baisi Pahacha, have been proposed as symbolic reverence for the first 22 of the 24 Tirthankaras of Jainism.

According to Annirudh Das, the original Jagannath deity was influenced by Jainism and is none other than the Jina of Kalinga taken to Magadha by Mahapadma Nanda. The theory of Jain origins is supported by the Jain Hathigumpha inscription. It mentions the worship of a relic memorial in Khandagiri-Udayagiri, on the Kumara hill. This location is stated to be the same as the Jagannath temple site. However, states Starza, a Jain text mentions Jains restored the Jagannath shrine, but the authenticity and date of this text are unclear. This is the plume for Oriya people to celebrate a special day in this Dham which is known as Ratha Yatra ("Chariot Festival").

Rameswaram

Rameswaram is located in the state of Tamil Nadu, in the southern part of the Indian peninsula. According to legends, this is the place where Rama, along with his brother Lakshmana and devotee Hanuman, built a bridge (Rama Setu) to reach Lanka to rescue his wife Sita, who had been abducted earlier by Ravana, the ruler of Lanka. The Ramanathaswamy Temple, dedicated to Shiva, occupies a significant area of Rameswaram. The temple is believed to have been consecrated by Rama. Rameswaram is important for the Hindus as a pilgrimage to Benaras is incomplete without a pilgrimage to Rameswaram. The presiding deity here is in the form of a Linga with the name Sri Ramanatha Swamy; it also is one of the twelve Jyotirlingas.

Dwarka

Dwarka is located in the state of Gujarat, on the western coast of India. The city derives its name from the word "dvara" meaning door or gate in the Sanskrit language. It is located confluence where the Gomti River merges into the Arabian Sea. However, this river Gomti is not the same Gomti River, which is a tributary of Ganga River. The city lies in the westernmost part of India. The legendary city of Dvārakā was the dwelling place of Krishna. It is generally believed that due to damage and destruction by the sea, Dvārakā had submerged six times, and modern-day Dwarka is the 7th such city to be built in the area.

Badrinath

Badrinath is located in the state of Uttarakhand. It is in the Garhwal hills, on the Alaknanda River banks. The town lies between the Nar and Narayana mountain ranges and in the shadow of Nilkantha peak (6,560 m).
There are other interesting sightseeing spots like Mana, Vyas Gufa, Maatamoorti, Charanpaduka, Bhimkund, and the Mukh of the Saraswati River, within 3  km of Badrinathjee. Joshimath is situated on the slopes above the confluence of the Alaknanda and Dhauliganga rivers. Of the four Maths established by Adi Shankaracharya, Joshimath is the winter seat of Chardham.

While the three other Dhams remain open throughout the year, Badrinath Dham only stays open for pilgrims' darshan from April to October each year.

Chota Char Dham
Another circuit of four ancient pilgrimage sites in the Indian state of Uttarakhand viz. Yamunotri, Gangotri, Kedarnath, and Badrinath is referred to as Chota Char Dham to differentiate it from this bigger circuit of Char Dham sites. The Chota Char Dham shrines are closed in winter due to snowfall and reopen for pilgrims with the advent of summer.

See also
 Chota Char Dham
 Sapta Puri
 Jyotirlinga
 Famous Hindu yatras
 Hindu pilgrimage sites in India
 List of Hindu festivals
 Padayatra
 Ratha Yatra
 Tirtha
 Tirtha and Kshetra
 Chari Kshetra

References

External links

Hindu pilgrimage sites in India
Char Dham temples
Hindu holy cities