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Topic Review
Photovoltaic Cell Generations
Solar energy is one of the most demanding renewable sources of electricity. Electricity production using photovoltaic technology not only helps meet the growing demand for energy, but also contributes to mitigating global climate change by reducing dependence on fossil fuels. The level of competitiveness of innovative next-generation solar cells is increasing due to the efforts of researchers and scientists related to the development of new materials, particularly nanomaterials and nanotechnology.
  • 14.7K
  • 25 Aug 2022
Topic Review
Thermoelectric Generators: Progress and Applications
A thermoelectric effect is a physical phenomenon consisting of the direct conversion of heat into electrical energy (Seebeck effect) or inversely from electrical current into heat (Peltier effect) without moving mechanical parts. In this review, state-of-the-art thermoelectric generators, applications and recent progress are reported.
  • 14.6K
  • 27 Aug 2020
Topic Review
Hydrogen Storage and Transportation
In the current hydrocarbon economy, transportation is fueled primarily by petroleum. Burning of hydrocarbon fuels emits carbon dioxide and other pollutants. The supply of economically usable hydrocarbon resources in the world is limited, and the demand of hydrocarbon fuels is increasing, particularly in China, India and other countries. Proponents of a world-scale hydrogen economy argue that hydrogen can be environmentally cleaner source of energy to end-users, particularly in transportation applications, without release of pollutants (such as particulate matter) or carbon dioxide at the point of end use. A recent analysis asserted that “most of the hydrogen supply chain pathways would release significantly less carbon dioxide into the atmosphere than would gasoline used in hybrid electric vehicles” and that significant reductions in carbon dioxide emissions would be possible if carbon capture or carbon sequestration methods were utilized at the site od energy or hydrogen production. Hydrogen storage can be distributed continuously in pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system also pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels. Furthermore, hydrogen is regenerative and environment friendly. But two difficulties with hydrogen are that hydrogen is just an energy carrier and has a low critical temperature of 35 K, i.e., hydrogen is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific surface area (at T< 100K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent and ionic compounds (at ambient pressure), oxidation of reactive metals e.g., Li, Na, Mg, Al, Zn with water. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can be thermally reduced to the metals in a solar furnace. In conclusion, routes for the transmission and storage of hydrogen for chemical processes, and hydrogen-based energy systems are increasing their establishment. Here, these routes are described, considering their attractions and difficulties.
  • 14.4K
  • 18 Jun 2021
Topic Review
BMW 5 Series (E39)
The BMW E39 is the fourth generation of BMW 5 Series, which was sold from 1995 to 2004. It was launched in the sedan body style, with the wagon/estate body style (marketed as "Touring") introduced in 1996. The E39 was replaced by the E60 5 Series in 2003, however E39 Touring models remained in production until May 2004. The proportion of chassis components using aluminium significantly increased for the E39, and it was the first 5 Series to use aluminium for all major components in the front suspension or any in the rear. It was also the first 5 Series where a four-cylinder diesel engine was available. Rack and pinion steering was used for the first time in a 5 Series (with the exception of the E34 525iX), being fitted to the four-cylinder and six-cylinder models. Unlike its E34 predecessor and E60 successor, the E39 was not available with all-wheel drive. The high performance M5 sedan was introduced in 1998, powered by the 4.9-litre S62 V8 engine. It was the first M5 model to be powered by a V8 engine.
  • 13.6K
  • 05 Dec 2022
Topic Review
CCR Model (DEA)
The first Data Envelopment Analysis (DEA) model developed by Charnes, Cooper and Rhodes (1978) under the assumption of a Constant Returns to Scale production technology, i.e.,  when an increase in the production resources results in a proportional increase in the output.
  • 13.5K
  • 30 May 2021
Topic Review
Yield
In chemistry, yield, also referred to as reaction yield, is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. Yield is one of the primary factors that scientists must consider in organic and inorganic chemical synthesis processes. In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms used to describe ratios of how much of a reactant was consumed (conversion), how much desired product was formed (yield) in relation to the undesired product (selectivity), represented as X, Y, and S.
  • 12.3K
  • 18 Oct 2022
Topic Review
Energy Management Strategy
A Comprehensive Review on Classification, Energy Management Strategy, and Control Algorithm for Hybrid Electric Vehicles
  • 12.3K
  • 22 Oct 2020
Topic Review
In-Vehicle Networks
Modern vehicles are no longer simply mechanical devices. Connectivity between the vehicular network and the outside world has widened the security holes that hackers can use to exploit a vehicular network. Controller Area Network (CAN), FlexRay, and automotive Ethernet are popular protocols for in-vehicle networks (IVNs) and will stay in the industry for many more years. However, these protocols were not designed with security in mind. They have several vulnerabilities, such as lack of message authentication, lack of message encryption, and an ID-based arbitration mechanism for contention resolution. Adversaries can use these vulnerabilities to launch sophisticated attacks that may lead to loss of life and damage to property. Thus, the security of the vehicles should be handled carefully. In this paper, we investigate the security vulnerabilities with in-vehicle network protocols such as CAN, automotive Ethernet, and FlexRay. A comprehensive survey on security attacks launched against in-vehicle networks is presented along with countermeasures adopted by various researchers. Various algorithms have been proposed in the past for intrusion detection in IVNs. However, those approaches have several limitations that need special attention from the research community. Blockchain is a good approach to solving the existing security issues in IVNs, and we suggest a way to improve IVN security based on a hybrid blockchain.
  • 12.1K
  • 15 Apr 2021
Topic Review
Process of Converting Ammonia to Hydrogen
Hydrogen technology for transition to a hydrogen-based economy requires supplying clean and renewable energy and capture of CO2 from current fossil hydrogen production. Ammonia is the most popular substance as a green hydrogen carrier because it does not carry carbon, and the total hydrogen content of ammonia is higher than other fuels and is thus suitable to convert to hydrogen. Ammonia cracking is a process of producing hydrogen from ammonia decomposition over a catalyst at high temperatures and is preferentially performed at normal pressures. 
  • 11.8K
  • 12 Dec 2022
Topic Review
Mercedes-Benz CLS-Class (W219)
The C219 Mercedes-Benz CLS-Class is the first generation of the CLS-Class range of four-door coupe features a fastback body style by Mercedes-Benz, and was produced between 2004 and 2010. The CLS-Class has only four seats and is marketed by Mercedes as a four-door coupé. For this reason, in Germany and in whole Europe the model code name is C219 while in US the CLS is more commonly named as W219 model. It was the first model globally to introduce this four-door coupe style and VW followed with the Volkswagen CC model in 2008. The car is less practical than the W211 E-Class that it is based on, with less legroom, headroom, and boot space. The CLS-Class is priced above the E-Class, but below the S-Class in the Mercedes model range. It was replaced by the Mercedes-Benz CLS-Class (W218) in 2011.
  • 11.6K
  • 04 Nov 2022
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