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Topic Review
Carbon Anode
Carbon anode refers to a broad family of essentially pure carbon, whose members can be tailored to vary widely in their strength, density, conductivity, pore structure, and crystalline development. These attributes contribute to their widespread applicability. Specific characteristics are imparted to the finished product by controlling the selection of precursor materials (including cokes, polymers and fibers) and the method of processing. In general, carbon anode electrodes are characterized by low cost production, high surface area, a wide working potential window in many media, high electrocatalytic activities for different redox-active chemical and biochemical systems, and chemical inertness.Moreover, their surface chemistry enables the functionalization of these carbon platforms via strong covalent or noncovalent methods with surface modifiers, which improves their electrochemical performance. Recent achievements of carbon anode materials and their structural design for better performances of aluminium production, lithium-ion secondary batteries, lithium cobalt oxide batteries, nano-tube production, substitution of amorphous electrode materials, photoanodes production, solar cells, fuel cells, supercapacitors, sensors and pumps, neurochemical monitors, etc., are finding enormous applications in industrial, commercial and social sectors. 
  • 5.3K
  • 31 Aug 2021
Topic Review
Meaning and Determination of Electrode Surface Area
The interfacial contact area between an electronically conducting and an ionically conducting phase is the area where an electrode meets an electrolyte or an electrolyte solution. This area may differ significantly from the geometric, microscopic, real, or true surface area of the electronically conducting solid (the electrode) determined with a variety of experimental methods. This contact area may also differ from the electrochemically active surface area. These different surface or interface areas are relevant in electrochemical energy conversion and storage. They are not necessarily identical; there are even no simple relationships between them. This entry provides an overview of the various terms, briefly describes experimental methods for their determination and puts the data in perspective with respect to electrochemical energy conversion and storage.
  • 5.2K
  • 24 Feb 2023
Topic Review
Armenia
Armenia, officially the Republic of Armenia, is a landlocked country in the Armenian Highlands of Eastern Europe. Due to its location in the South Caucasus, Armenia is sometimes described as transcontinental, spanning both Eastern Europe and Western Asia. It is bordered by Turkey to the west, Georgia to the north, the Lachin corridor (under a Russian peacekeeping force) and Azerbaijan to the east, and Iran and the Azerbaijani exclave of Nakhchivan to the south. Yerevan is the capital and largest city. Armenia is a unitary, multi-party, democratic nation-state with an ancient cultural heritage. The first Armenian state of Urartu was established in 860 BC, and by the 6th century BC it was replaced by the Satrapy of Armenia. The Kingdom of Armenia reached its height under Tigranes the Great in the 1st century BC and in the year 301 became the first state in the world to adopt Christianity as its official religion, The ancient Armenian kingdom was split between the Byzantine and Sasanian Empires around the early 5th century. Under the Bagratuni dynasty, the Bagratid Kingdom of Armenia was restored in the 9th century. Declining due to the wars against the Byzantines, the kingdom fell in 1045 and Armenia was soon after invaded by the Seljuk Turks. An Armenian principality and later a kingdom Cilician Armenia was located on the coast of the Mediterranean Sea between the 11th and 14th centuries. Between the 16th and 19th centuries, the traditional Armenian homeland composed of Eastern Armenia and Western Armenia came under the rule of the Ottoman and Persian empires, repeatedly ruled by either of the two over the centuries. By the 19th century, Eastern Armenia had been conquered by the Russian Empire, while most of the western parts of the traditional Armenian homeland remained under Ottoman rule. During World War I, 1.5 million Armenians living in their ancestral lands in the Ottoman Empire were systematically exterminated in the Armenian genocide. In 1918, following the Russian Revolution, all non-Russian countries declared their independence after the Russian Empire ceased to exist, leading to the establishment of the First Republic of Armenia. By 1920, the state was incorporated into the Transcaucasian Socialist Federative Soviet Republic, and in 1922 became a founding member of the Soviet Union. In 1936, the Transcaucasian state was dissolved, transforming its constituent states, including the Armenian Soviet Socialist Republic, into full Union republics. The modern Republic of Armenia became independent in 1991 during the dissolution of the Soviet Union. Armenia is a developing country and ranks 81st on the Human Development Index (2018). Its economy is primarily based on industrial output and mineral extraction. While Armenia is geographically located in the South Caucasus, it is generally considered geopolitically European. Since Armenia aligns itself in many respects geopolitically with Europe, the country is a member of numerous European organizations including the Council of Europe, the Eastern Partnership, Eurocontrol, the Assembly of European Regions, and the European Bank for Reconstruction and Development. Armenia is also a member of certain regional groups throughout Eurasia, including the Asian Development Bank, the Collective Security Treaty Organization, the Eurasian Union, and the Eurasian Development Bank. Armenia supports the de facto independent Artsakh, which was proclaimed in 1991. Armenia also recognises the Armenian Apostolic Church, the world's oldest national church, as the country's primary religious establishment. The unique Armenian alphabet was created by Mesrop Mashtots in 405 AD.
  • 5.2K
  • 10 May 2023
Topic Review
Mopar Automatic Transmission Fluid
Mopar branded automatic transmission fluids (ATF) have been available for use in Chrysler fully automatic transmissions since 1953. Other Mopar branded fluids for their Fluid Drive semi-automatic transmissions were available as early as 1938. Chrysler used General Motors (GM) automatic transmission fluid specifications from 1952 through 1966 and marketed them under the Mopar brand name. In 1966, Chrysler began releasing their own automatic transmission fluid specifications. Chrysler licenses their ATF specifications to companies which manufacture the fluid and sell it under their own brand names. Not all Chrysler fluids are licensed for reselling under another brand name. All licensed Chrysler fluids must have a license number on the container. If no license number is found, the fluid may not be Chrysler approved and the fluid cannot be guaranteed to meet Chrysler specifications. Chrysler, like many automobile manufacturers, uses transmissions sourced from other suppliers or transmission manufacturers around the world; these transmissions are not manufactured by Chrysler. Many of these automatic transmissions use unique fluids that might not be shown on this page.
  • 5.2K
  • 07 Nov 2022
Topic Review
Prajñā (Hinduism)
Pragña or Pragya (Sanskrit: प्रज्ञ) as प्रज्ञा, प्राज्ञ and प्राज्ञा is used to refer to the highest and purest form of wisdom, intelligence and understanding. Pragya is the state of wisdom which is higher than the knowledge obtained by reasoning and inference.
  • 5.2K
  • 25 Oct 2022
Topic Review
Design of Block Shear Failure
The block shear failure was reported firstly in 1978 for joints with not optimal geometry from an internal forces point of view. The test results proved the potential failure mode of tearing out in the web of the beam. Several studies concerning block shear failure were published in the last twenty years predicting the block shear capacity as a combination of fracture on the tension and shear plane. Block shear rupture is the potential failure mode for gusset plates, fin plates, coped beams, single/double angles and tee connections, where significant tension/shear forces are present. 
  • 5.2K
  • 21 Jul 2021
Topic Review
Derringer
A derringer is a small handgun that is neither a revolver nor a semi/fully automatic pistol. It is not to be confused with mini-revolvers or pocket pistols, although some later derringers were manufactured with the pepperbox configuration. The modern derringer is often multi-barreled, and is generally the smallest usable handgun of any given caliber and barrel length due to the lack of a moving action, which takes up more space behind the barrel. It is frequently used by women because it is easily concealable in a purse or a stocking. The original Philadelphia Deringer was a muzzleloading caplock single-shot pistol introduced in 1825 by Henry Deringer. In total, approximately 15,000 Deringer pistols were manufactured. All were single barrel pistols with back-action percussion locks, typically .41 caliber with rifled bores, and walnut stocks. Barrel length varied from 1.5 to 6 in (38 to 152 mm), and the hardware was commonly a copper-nickel alloy known as "German silver". The term "derringer" (/ˈdɛrɪndʒər/) became a genericized misspelling during the reporting of the Lincoln assassination, which was committed with a concealed Philadelphia Deringer. Many copies of the original Philadelphia Deringer pistol were made by other gunmakers worldwide, and the name remained often misspelled; this misspelling soon became an alternative generic term for any pocket pistol, along with the generic phrase "palm pistol'", which Deringer's competitors invented and used in their advertising. With the advent of metallic cartridges, pistols produced in the modern form are still commonly called "derringers".
  • 5.2K
  • 01 Nov 2022
Topic Review
Can CFD Analysis Help PEM Fuel Cell Design and Operation?
Polymer electrolyte membrane (PEM) fuel cell system is an advanced power system for the future that is sustainable, clean and environmental friendly. PEM fuel cells are growing in importance as sources of sustainable energy and will doubtless form part of the changing program of energy resources in the future. PEM fuel cells are still undergoing intense development, and the combination of new and optimized materials, improved product development, novel architectures, more efficient transport processes, and design optimization and integration are expected to lead to major gains in performance, efficiency, reliability, manufacturability and cost-effectiveness. The difficult experimental environment of PEM fuel cell systems has stimulated efforts to develop models that could simulate and predict multi-dimensional coupled transport of reactants, heat and charged species using computational fluid dynamic (CFD) technology. The strength of the CFD numerical approach is in providing detailed insight into the various transport mechanisms and their interaction, and in the possibility of performing parameters sensitivity analyses. The results of CFD analyses are relevant in: conceptual studies of new designs, detailed product development, troubleshooting, and redesign. CFD analysis complements testing and experimentation, by reduces the total effort required in the experiment design and data acquisition. Relevant case studies and recent progress in CFD techniques used in PEM fuel cell development have been presented and analyzed. The CFD models are shown to be able to provide a computer-aided tool for design and optimize future PEM fuel cell with much higher power density, long cell life, and lower cost.
  • 5.2K
  • 26 Apr 2020
Topic Review
Allelopathy
Allelopathy is an ecological phenomenon in which organisms interfere with each other. As a management strategy in agricultural systems, allelopathy can be mainly used to control weeds, resist pests, and disease and improve the interaction of soil nutrition and microorganisms. Volatile organic compounds (VOCs) are allelochemicals volatilized from plants and have been widely demonstrated to have different ecological functions.
  • 5.2K
  • 09 Sep 2021
Topic Review
Conservation-Restoration of Cultural Heritage
The conservation-restoration of cultural heritage focuses on protection and care of tangible cultural heritage, including artworks, architecture, archaeology, and museum collections. Conservation activities include preventive conservation, examination, documentation, research, treatment, and education. This field is closely allied with conservation science, curators and registrars.
  • 5.2K
  • 30 Nov 2022
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