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The very high theoretical capacity of the silicon (4200mAh/g more than 10 times larger than graphite), environmental-friendly, abundant and low-cost, makes it a potential candidate to replace graphite in high energy density Li-ion batteries. As a drawback, silicon suffers from huge volume changes (300%) on alloying and dealloying with Li, leading a structural deformation that induces disruption. The use of nanostructured silicon materials has been shown to be an effective way to avoid this mechanical degradation of the active material. In this paper the synthesis of silicon nanowires, grown on a highly porous 3D-like carbon paper substrate by CVD using Cu as the catalyst, is presented. The use of carbon paper allows to achieve remarkable loadings of active material (2-5 mg/cm²) and, consequently, high capacity densities. The silicon electrode was investigated both morphologically and electrochemically. To improve the electrochemical performance various strategies have been carried out. It was observed that a very slow first cycle (C/40), which helps the formation of a stable solid electrolyte interphase on the silicon surface, improves the performance of the cells; nevertheless, their cycle life has been found not fully satisfactory. Morphological analysis of the Si-NWs electrodes before and after cycling showed the presence of a dense silicon layer below the nanowires which could reduce the electrical contact between the active material and the substrate. [ABSTRACT FROM AUTHOR]

Due to high densities of energy, power, and remarkable operational efficiency of Li-on battery when in contrast to Lead-acid batteries and nickel-cadmium batteries are examples of other types of batteries. Vehicles, electronics, aircraft, and other industries are all interested in lithium-ion batteries right now. However, some critical variables, such as performance degradation under extreme driving circumstances due to temperature difference in the lithium-ion cell, limit its usefulness. As a result, it's important to decide the optimal course of action based on the consequences of heat generation on various lithium-ion cell components. This paper looked at how heat is generated and how it affects each component of a li-ion battery. An analysis of different heat-controlling systems employing various design structures in numerous techniques of cooling such as liquid convection, phase transition material, air Convection and a combination of these techniques are used. Finally, utilizing a variety of design frameworks, a summary is created [ABSTRACT FROM AUTHOR]

To reach the increasing demand of miniature electronic products and variousness of electronic products, wearable and flexible portable products are being used. Flexible electronics is helping in creating a era of fundamentally diverse devices that opens up a completely new range of potential. Traditionally, all the electronics are being designed around the battery that takes up a large space and contributes to half of the weight of the device. Now the problem is quiet solved as researchers found a better solution of energy storage in small space that is flexible, light weight and very thin. The devices of new generation are self-preserving, self-sensing and self repairing. However, due to insufficiency of flexible materials having both properties i.e. flexible and electrical, it is very complicated chore to fabricate flexible batteries. A brief discussion on carbon based materials has done in this paper. Electrodes based on graphene are also in use for flexible batteries as it come up with magnificent power density and energy density in storage system. A brief discussion on flexible electrolytes has also been discussed in the paper. This review summarizes the recent configuration of flexible batteries and advancement in its structure. Some specific applications are discussed as key component in real life. [ABSTRACT FROM AUTHOR]

In present, EVs manufacturing with the use of Li-ion batteries, provides longer driving range and higher energy concentration because of high energy. As we all know, the performance of electric cars is mostly determined by energy storage components. For electric and high-voltage cars, batteries are the most efficient and conventional energy storage components. In current or upcoming EVs the unique energy storage element is only ultra capacitor, the UC incarcerate and deliver quick rupture of energy because UC has high power density. As a consequence, a battery-UC combination has established a hybrid energy storage system (HESS) for high-efficiency electric automobiles. The Battery-UC HESS system combines the battery's high energy density with Cu's high energy density. With use of this harmonizing feature of battery-UC, HESS achieved the high power abilities and great energy storage at the same time with small size and light weight as compared to high power battery-only ESS equivalent. Because of previous research and investigations, the papers evaluates and talk about the benefits of hybridization of Battery-UC HESS, control strategies for an energy management needed to optimize or divide the power demand between the battery and UC. The paper concentrated on the investigation of energy supervision of rule based algorithm for control of energy, control algorithm on optimization based and other control mechanism. [ABSTRACT FROM AUTHOR]

This paper emphasizes on the characterization techniques for high energy and high-power cell dedicated to electric vehicles (EV's), as across the past few years the number of EV's has rapidly increased. Projections are such that, more than 250 million EV's will be used for transportation by next few years. The main requirement of energy storage is provided by the Li-ion cells/batteries. Lithium-ion cells are now being widely adapted owing to its properties such as specific power and energy density. In this paper, in order to achieve high performance of battery cells and to carry out the ageing study, we have designed and implemented a test bench to characterize energy and power optimized cells. [ABSTRACT FROM AUTHOR]

As the world is moving towards technological advancement and industrial revolution, the need for eco-friendly and portable energy sources for various applications is and will going to increase. We are surrounded by so many gadgets to run our daily life smoothly. Li-ion battery stood out as the most reliable and suitable device for storing energy so far which have applications from small scale to bigger applications like electric vehicles. Highest theoretical capacity of 3860 mAhg−1 for Li metal anodes, lightweight, high energy density and many other parameters makes it attractive choice for the applications whereas it shows the lowest electrochemical potential of −3.04V versus standard hydrogen electrode (SHE). Researchers are trying the alternate materials for cathode and anode where different structural cathode materials are being tested and various anode chemistries have been tried. Silicon anode has the potential to replace the regular graphite anode-material as it has 10 times the specific capacity as compare to graphite. This paper reviews the anode materials which are currently under research to enhance the characteristics of Li-ion battery in comparison with the currently commercialized graphite anode (372 mAhg−1) that how structural and morphological modification can change the properties like cycle life, shelf life, specific capacity, charge rate and stability of the materials. [ABSTRACT FROM AUTHOR]

This paper highlights the significance of battery and super-capacitor devices that are favored as storage technologies because of their high power density, energy densities, charging and discharging capabilities, longevity and ability to function across a broad range of temperatures. A comparison is made between a battery energy storage system (BESS) and a hybrid energy storage system (HESS), which integrates both batteries and super capacitors. The HESS stands out by effectively recycling surplus energy. The study proposes a hybrid energy storage system that can be employed in conjunction with renewable energy sources like solar and wind. Such a system is particularly suitable for remote or backup systems lacking access to a power grid. By incorporating super capacitors in parallel with the battery and a periodic load, the aim is to achieve the highest level of efficiency. Additionally, the research includes a MATLAB/Simulink model illustrating the configuration of a hybrid energy storage system comprising batteries and super capacitors. [ABSTRACT FROM AUTHOR]

The miniaturization of small-size power supply systems with high energy density is becoming essential nowadays. The demand for compact, lightweight power has motivated researchers to actively develop the small reacting system. However, reducing size in the combustion system has encountered some technical challenges. This study has also been motivated by the speedy development of mesoscale electrical and mechanical systems. This paper presents biogas' numerical flame characteristics (60% CH4 − 40% CO2) in an asymmetric mesoscale vortex combustor. The results indicate that the lean equivalence ratio limit was Ø 0.51 for all Re, the stable range is large at low Re (0.51< Ø <1.86 at Re 2500), decreasing with increasing Re until (0.51< Ø <0.56) at Re 7840. A strong vortex forms a stable zone for the flame and demonstrates the high stability of biogas flame for the mesoscale combustor. Flame stability in mesoscale vortex combustion has been due to two important effects; the strong tangential vortex controls the flame field and vortex influence. The rich equivalence ratio at Ø 1.86 was recorded as the highest peak temperature at 1870 K. It produced the highest value for CO and NOx gases emissions, at 5.65 e−04 ppm and 10.06 ppm, respectively. Meanwhile, the lean equivalence ratio, Ø 0.56, recorded the lowest peak temperature at 1533 K but interestingly managed to produce the lowest CO and NOx gas emissions value, at 1.43 e-07 ppm 1.2132 ppm, respectively. Thus, it concluded that the higher ratio of air in the fuel, the lower the temperature and emissions. [ABSTRACT FROM AUTHOR]

Torrefaction is a thermochemical process in an inert or limited oxygen environment where biomass is slowly heated to a specified temperature range. The art of torrefaction has caught the attention of power industries to produce biochar and coal substitute from biomass. In recent years, there has been an increasing interest in torrefaction technology. The main difference between technologies is the reactor design and the heating mode. These parameters influence the product quality of torrefied biomass. Microwave torrefaction is one of the available technologies that recently received considerable attention due to some advantages. Along with this growth, there is increasing concern over comparing microwave torrefaction with conventional ones. So far, there has been little discussion about the technical comparison of reactor design of microwave torrefaction itself. This paper will review the research conducted on the microwave design of biomass torrefaction. The use of microwave as an apparatus for torrefaction process reported is mainly dominated by domestic microwave oven followed by the single-mode microwave oven, non-modified microwave oven and only a few studies of large-scale microwave reactor. Each type of microwave reactor design determines mass yield, energy density, and energy yield as quality parameters of torrefied biomass. The findings should contribute to the field of a microwave as an apparatus for torrefaction technology. [ABSTRACT FROM AUTHOR]

Batteries plays a key role in eco-friendly environment that are being widely used in various applications. The high specific energy and energy density makes Lithium-ion Batteries (LIB) to have an important role in the energy storage sector, relative to other rechargeable batteries. The final mission for the LIB is to provide smoother performance at higher temperatures which is related to the Battery Thermal Management. Thermal management of batteries, especially cooling of electric vehicles, is of great significance to guarantee the performance of battery at various working conditions of electric vehicle. There are different methods of cooling but, liquid cooling is best of all cooling possibilities. Since the heat transfer rate is more in liquids, which is a powerful way to keep the temperature range of battery. This paper aims at the cooling of lithium-ion battery by liquid cooing which is cooled by using ethylene glycol. [ABSTRACT FROM AUTHOR]

Additive technology (AM) using selective laser melting (SLM) is widely used to produce parts with complex shapes made of metal alloys, composites and ceramics. One of the main problems of SLM is ensuring dimensional accuracy. The paper presents the study of the influence of selected parameters of the SLM process, such as laser power, scanning speed, distance between tracks, powder layer thickness and volumetric energy density on the dimensional accuracy of the product. The mathematical model was obtained based on a dimensional analysis describing the dependence of the SLM process parameters on the dimensional deviations of the product. Computer simulation of the SLM process was carried out using COMSOL Multiphysics® software. Theoretical results were verified experimentally on Cr-Co alloys. [ABSTRACT FROM AUTHOR]

EDM is a process of machining conductive materials by precision controlled in electrical discharge through a small clearance gap. Through EDM process, the electrical discharge energy will be converted into thermal energy which in turn causes the erosion of the workpiece. The discharge current determines the energy density used in erosion of the workpiece. During the discharges, the current pulse in used should be of a square pulse wave. In practical, EDM circuits tends to have parasitic components which causes the non-square waveform characteristics to the current pulses. In this paper, the simulation of a parasitic components is conducted capable to change the signal waveform and affecting the square pulse wave on the Material Removal Rate (MRR) characteristics. It is discovered that the parasitic component causes the discharge current to have transient current as well as in decreasing the MRR value. [ABSTRACT FROM AUTHOR]

Background/Objectives: Graphene is a revolutionary discovery. It is credited as the lightest and strongest material available in the world. Its high-power density and energy density it is being considered a potential candidates as electrodes in supercapacitors, which in themselves are new to the market. The main objective of this paper is to highlight the usage and benefits of graphene in supercapacitors. Methods/Statistical analysis: Super-capacitors are barely a new technology. Due to its unique property of handling high power and high rate of charging or discharging, it is seeming as a solution for many problems. It is observed that using graphene in supercapacitors makes it more efficient and reliable. Therefore, here an attempt is made to review the effects and advantages of graphene-based supercapacitors. Findings: The graphene-based supercapacitors are highly efficient and able to handle more power and energy density as compared with the conventional ones. The numerous beneficial properties of graphene such as high conductivity, lightweight, high-power density, high energy density, high surface area, etc. make it the most suitable candidate for the electrode used for supercapacitors and have opened the gates for more graphene and other carbon nanostructure-based supercapacitors. Improvements/Applications: Supercapacitors prove themselves as an important element in the field of the flexible electronics industry. It is observed that the usage of graphene-based electrodes improves the performance of super-capacitors. Therefore, applications which involve flexible and stretchable consumer electronics graphene-based supercapacitors are highly desirable. [ABSTRACT FROM AUTHOR]

Water use as a heat storage material in solar water heaters (SWH) has disadvantages, including its low energy density, which requires a large volume of thermal energy storage. Phase-change material (PCM) is a latent type of heat storage material that has the advantage of being a high energy density. Therefore, PCM is quite interesting to be applied to SWH systems. In the operation of SWH, it is necessary to know the characteristics of hot water usage. This paper aimed to determine the characteristics of a continuous and gradual discharging method on SWH that applies PCM. This study used a thermosyphon type of SWH. The tank was placed horizontally on the top side of the collector with a volume of 60 liters. Twenty-four cylindrical capsules containing paraffin wax were inserted into the tank. Thermocouples were installed on the waterside and the PCM side. Continuous and gradual methods were carried out in the discharging experiment. Experiments using a continuous discharging method given information that water temperature decrease continuously in the tank. Experiments with a gradual discharging method showed PCM's contribution, which can transfer thermal energy to the water. The gradual discharging method explained that the SWH system produced hot water that can be used for bathing as many as five people every day with water temperatures of 45 °C at an average solar radiation intensity of 514.89 W/m2. The use of PCM makes a positive contribution to the thermal energy storage in the tank. [ABSTRACT FROM AUTHOR]

In this paper, we have studied electrochemical performance of rod shaped ZnO nanostructure (NS) for supercapacitor application. We have performed the electrochemical performance by using cyclic voltammetry (CV) and chrono charge-discharge galvanostatic with three electrode systems. Herein we have synthesized the ZnO NS by using leaf extract of Tabernaemontana divericata as capping/stabilizing agent at 40°C. The morphology of synthesized ZnO NS has been determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) and powder x-ray diffraction (PXRD) have been used for elemental composition. The band gap has been calculated 3.01eV with talc plot by using data of UV-Visible spectrum. The specific capacitance of the drop casted ZnO supercapacitor on glassy carbon electrode (GCE) has been investigated by using CV curves at the voltage scan rates 20 mV/s, 40 mV/s, 60 mV/s, 80 mV/s and 100 mV/s. The obtained values of specific capacitance are 535.7142 F g−1, 401.7857 F g−1, 304.7619 F g-1, 229.9107 F g-1 and 189.2857 F g-1 respectively. The values of energy density and power density have also been calculated. The obtained values at the abovementioned scan rates are 36.4583Wh/kg and 65.6249W/kg, 27.3438 Wh/kg and 49.218820 W/kg, 20.7407 Wh/kg 37.3332 W/kg, 15.6470, Wh/kg and 28.1646 W/kg, 12.8819 Wh/kg and 23.1874 W/kg respectively. [ABSTRACT FROM AUTHOR]

Thermal applications are drawing increasing attention in the solar energy research field, due to their high performance in energy storage density and energy conversion efficiency. Thermal energy storage (TES) is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used at a later time for heating and cooling applications and power generation. This paper presents a review on TES systemsand different technologies of TES that are commercially available or under investigation. Sensible heat storage technologies, including water tank and packed-bed storage methods, are discussed in detail. Latent-heat storage systems associated with phase-change materials, thermo-chemical storage as well as cool thermal energy storage are also discussed. [ABSTRACT FROM AUTHOR]

The main aim of the paper is to present the results of experimental investigations on the deformation process of cellular structures with gradient topologies under quasi-static loading conditions. The specimens used in the tests were designed with the use of a hexagon shape of a unit cell with a graded size preserving the equivalent global size and wall thickness dimensions. The manufacturing process of structure samples was realized by two different 3D printing methods: FFF (Fused Filament Fabrication) and SLA (Selective Laser Sintering). Additionally, two types of materials differing with mechanical properties were used to determine the mechanism of structure damage during the deformation process. As a result of the conducted investigations, it was possible to define a relationship between a structure topology and relative density versus energy absorption capacity. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (Li-ion) are the first option in applications that demand energy storage devices due to their high capacity, high depth of discharging, high energy density, long life cycle, no effect memory, and low self-discharge capability. Li-ion of necessity must be controlled in anticipation of an operation to be in a safe situation and get the best performance, so it must be utilized battery management system (BMS). BMS functionality monitors, control, and protects the battery pack from over-discharge, active balancing cells, and over-temperature. This paper utilized BMS to compare several charge methods to validate an efficient approach for maintaining battery performance. Proposed state I multi-stage current (MSC) based on Fuzzy Logic Controller (FLC) depending on the state of charge (SoC) as input for specifying the charging current as FLC output. State II, based on FLC, considers the temperature as a factor with SoC in specifying charging current. The state II charge method prefers because the rising temperature during the charging process reduces other charge methods, preserving the battery performance and life cycle. [ABSTRACT FROM AUTHOR]

This is the second in a series of papers aimed at exploring the fundamental limitations to chemical energy storage. In the previous work, we summarized the lessons learned in various high energy density materials (HEDM) programs, the different degrees of freedom in which to store energy in materials, and the fundamental limitations and orders of magnitude of the energies involved. That discussion focused almost exclusively on the topic of molar energy density (J/mol) from the perspective of the energy of oxidation of the elements and Fritz Zwicky's "free atom limit." In this study, we extend the analysis by considering a different, though equally important, aspect of the energy density calculation: the volumetric density of the energetic material. Specifically, we examine how the distances between individual atoms (i.e. intra- and inter-molecular bond lengths) are coupled to (in fact, approximately inversely proportional to) the energy stored in the bonds of the molecule. This relationship further limits the chemical energy that theoretically can be stored in a material below that predicted by the "free atom limit." This talk will give specific examples of the trends with different bonding motifs and the implications to the fundamental limitations of chemical energy storage. [ABSTRACT FROM AUTHOR]

The performance of the propellant depends on its energy density, which is equal to the density of the propellant multiplied by the energy of the propellant. The actual density of composite propellant can be determined by the Archimedes Principle. And the present theoretical density of composite propellant is calculated by the assumption their component is the same phase and the mixing is homogeneous. But, the apparent density (actual density divided by theoretical density) still more significant low than 100%, which means the actual density more significant difference from the theoretical density. This paper proposed the sphere packing density theory was added to improve the calculation theoretical density of composite propellant. This method produced the result of apparent density a better value close to 100%. The improvement of the theoretical calculation method for composite propellant density can be used as a reference in making a composite propellant formulation design, checking the homogeneity of the composition mixture, and improving the propellant process method. [ABSTRACT FROM AUTHOR]

The paper describes investigation of the possibility of generation of relatively high current (up to 25 A) largeradius electron beam with pulse duration of 4.2 ms by plasma-cathode source based on an arc discharge in the forevacuum pressure range. We research arc discharge features, electron emission from the discharge plasma, the threshold parameters (maximal working gas pressure and maximal emission current) of plasma-cathode source and propagation of electron beam with millisecond pulse duration in the fore-vacuum pressure range 3-28 Pa. It is shown, that for the arc with 4.2 ms pulse duration operating in the fore-vacuum plasma source a decrease of the arc current leads to an increase of discharge voltage, and the arc threshold (minimal) current is about 6-7 A. The sort of working gas and its pressure influence on the electron emission and the threshold parameters of plasma-cathode electron source. We obtained the electron beam generated in the pressure range 3-28 Pa with a pulse duration of 4.2 ms and an emission current of up to 25 A. The features of propagation of a millisecond electron beam are studied. Cross-sectional energy density distribution of electron beam for different distances and emission currents are presented. The obtained beam parameters provide to use 4.2 ms electron beam for the surface treatment of various materials by few (1-10) beam pulses. [ABSTRACT FROM AUTHOR]

In this paper, Se60Te40-xSnx chalcogenide glasses with different concentrations of Tin (x=0, 5, 10, 15 and 20) were prepared) by melting point method. The electrical properties, i.e. electrical conductivity as a function of temperature, were studied. The activation energy was calculated and was found that at the extended state it changes from 0.223 to 0.281, local state, the activation energy changes from 0.159 to 0.306 and at the Fermi level; it is found that it changes from 0.151 to 0.231. As for the width of energy tails, they are decreasing, and this indicates that the randomness of the compound is decreased, meaning that it has become more crystalline. The Energy density of state the extended, localized, at Fermi energy and the effect of adding Sn on it also was calculated. The increase in Tin (Sn) concentration led to a change in the density of extended, localized, and at Fermi level. it was found that the extended levels changed from 1.650x1024 to 6.226x1025, localize state, they change from 2.881x1020 to 2.113x1024, as for Fermi level, the density of states changed from 5.033x1021 to 1.942x1023 when the Tin concentration increased from 0 to 20. [ABSTRACT FROM AUTHOR]

In this paper, the Se60Te40-xsbx compound was prepared with different concentrations of antimony (Sb) (where x = 0, 5, 10, 15, 20) by melting point method. The electrical measurements of semiconductors were studied by analyzing the results of electrical conductivity as a function of temperature. The Moot-Davis model has been adopted as the emblem of three mechanisms that can control the conduction of electrons through amorphous semiconductors. The densities of energy states extended, localized and at Fermi level were calculated for different samples of antimony. It was Found that the extended states changed from 1.650 × 1024 to 2.159 × 1027, while local states, it changed from 2.881 × 1020 to 5.259 × 1023, as for the Fermi level, the density of states changed from 5.033 × 1021 to 1.571 × 1021 when the antimony concentration increased from 0 to 20 respectively. The activation energy was also calculated and found that in the extended state it changes from 0.223 to 0.557, and for the local case, the activation energy changes from 0.159 to 0.515 and at the Fermi level it changes from 0.151 to 0.332 when the antimony concentration is increased from zero to 20. As for the width of the energy tails, it was found that they are in a decreasing state, and this indicates that the randomness of the compound is decreasing, that is, it has become more crystalline. [ABSTRACT FROM AUTHOR]

In this paper, the Se60Te40-xsbx compound was prepared with different concentrations of antimony (Sb) (where x = 0, 5, 10, 15, 20) by melting point method. The electrical measurements of semiconductors were studied by analyzing the results of electrical conductivity as a function of temperature. The Moot-Davis model has been adopted as the emblem of three mechanisms that can control the conduction of electrons through amorphous semiconductors. The densities of energy states extended, localized and at Fermi level were calculated for different samples of antimony. It was Found that the extended states changed from 1.650 × 1024 to 2.159 × 1027, while local states, it changed from 2.881 × 1020 to 5.259 × 1023, as for the Fermi level, the density of states changed from 5.033 × 1021 to 1.571 × 1021 when the antimony concentration increased from 0 to 20 respectively. The activation energy was also calculated and found that in the extended state it changes from 0.223 to 0.557, and for the local case, the activation energy changes from 0.159 to 0.515 and at the Fermi level it changes from 0.151 to 0.332 when the antimony concentration is increased from zero to 20. As for the width of the energy tails, it was found that they are in a decreasing state, and this indicates that the randomness of the compound is decreasing, that is, it has become more crystalline. [ABSTRACT FROM AUTHOR]

Recently, there has been a rise in renewable energy cause an increased demand for energy storage (ESS) devices, the most important of type which are batteries. Work has begun on studies to develop batteries in terms of performance, reduce cost and minimize time charging. Lithium batteries surpassed other than battery type through high energy density, low self-discharge, but to gain maximum performance and safety of the battery, and there must be a control unit named Battery Management System (BMS). BMS plants monitor and control the battery pack. In this paper, BMS was proposed in MATLAB/Simulink 2020a version to protect and managed the batteries from overcharging, discharging, overheating, and exercised cell passive balancing in addition to alluding to a charging method which depending on the State of Charge (SoC) and Temperature to specify the charging current, the proposed method based fuzzy logic controller (FLC). The results show that protection features were the best performance and the proposed charging method that maintains of the battery because the temperature increase during the charging process impacts the performance and life cycle. [ABSTRACT FROM AUTHOR]

The aim of this work is a two-way converter integrated into a micro wind power system (WECS). There are two responsibilities for the converter establish the optimum wind turbine through regulation of the load of the electric generator and charging a super capacitor high energy density that's also component of a hybrid storage unit which is also included batteries that can be recharged.The fundamental objective of a wind turbine (WECS) would be to get the greatest available electricity at every instant from the wind turbine.The paper explains a continuous and discontinuous state-of-the-art analysis of the converter unique to this application. The maximum power point (MPP) based control technique is used for the bidirectional converter (BDC) for achieving highest power from the wind system and maintain the load demand. The diode bridge rectifier is used for the purpose of rectification. The super capacitor (SC) is used as energy storage element in this system and SC is charged through the BDC which is powered by the wind turbine. The proposed system is verified and validated using the MATLAB/Simulink environment. [ABSTRACT FROM AUTHOR]

In this paper we have successfully synthesized ZnMn2O4 via hydrothermal method. The electrochemical performance is studied by cyclic voltammetry (C-V) and Impedance analyzer from cyclic voltammetry technique the parameters such as specific capacitance, charge-discharge, power density and energy density is calculated. Impedance is analyzed by impedance analyzer. ZnMn2O4 synthesized via hydrothermal method have great stability and uniformity, better specific capacitance and enhanced electrochemical performance. [ABSTRACT FROM AUTHOR]

Powering of remotely placed sensors or health monitoring devices for bridges, large buildings or aircrafts, are more difficult. Here comes the need of an energy harvesting system that can scavenge energy from the vibrations produced by the wind or vibrations from the surroundings. Piezoelectric Energy Harvesting System (PEHS) is found suitable for these applications, since it is capable of converting the mechanical vibrations or pressure variations into electrical output. Piezoelectric materials are preferred due to the attractive features like high energy density, compactness and light weight. They are most suitable for powering Structural Health Monitoring (SHM) sensors of aircraft structures, bridges, buildings etc. For optimizing the PEHS, understanding and characterization of the sources of vibration/ stress and the displacement are helpful. Introduction of interdigitated electrodes in the PEHS ensure the uni form electric field along the piezoelectric fiber material and hence, enhance the actuation. This is really good news for the electronic designers that, the energy harvested from the Interdigitated PEHS can be used for providing power to many remote applications like structural health monitoring, wireless sensors and other such requirements. [ABSTRACT FROM AUTHOR]

In this paper, we analyze superfluid, insulator and various magnetic phases of ultracold spin-1 bosonic atoms in two-dimensional optical superlattices. Our studies have been performed using Cluster Mean Field Theory. Calculations have been carried out for a wide range of densities and the energy shifts due to the superlattice potential. We find superlattice potential do not change the symmetry of the polar superfluid phases. Superlattice potentials induce Mott insulator phases with half-integer densities. The phase diagram is obtained using superfluid density, nematic order and singlet density. Second order Rényi entanglement entropy is also calculated in different phases. The results show that Rényi entanglement entropy is large in the nematic Mott insulator phase. [ABSTRACT FROM AUTHOR]

Maximizing the performance of hydroelectric power plant by utilizing the incoming flow of hydropower channel through conversion of the hydrokinetic turbine is the main topic of this paper. In this case, the design of the diameter and velocity of the rotor is very basic and depends on the depth and speed of the canal flow. This research will take place on canals at PT Vale Indonesia Tbk through theoretical potential approach, primary and secondary data collection and CFD simulation. To assess the potential of these hydrokinetic resources, research is needed to analyze channel characteristic, and to determine energy density and annual energy yield. Determination of potential location energy density requires information on the nature of temporal and spatial flows (annual flow fluctuations) of the channel along with changes in depth, curves, and cross sections. To obtain detailed information on the hydrokinetic energy generation plan on the Larona hydropower discharge channel so that the potential assessment (resource assessment) becomes important for further study. [ABSTRACT FROM AUTHOR]

Starting in January 2017, AMADEUS (www.amadeus-project.eu) is the first project funded by the European Commission to research on a new generation of materials and solid state devices for ultra-high temperature energy storage and conversion. By exploring storage temperatures well beyond 1000 ºC the project aims at breaking the mark of ~ 600ºC rarely exceeded by current state of the art thermal energy storage (TES) systems. AMADEUS Project, through a collaborative research between seven European partners, aims to develop a novel concept of latent heat thermal energy storage (LHTES) systems with unprecedented high energy density. One of the main objectives of the project is to create new PCMs (phase change materials) with latent heat in the range of 1000-2000 kWh/m3, an order of magnitude greater than that of typical salt-based PCMs used in concentrated solar power (CSP), along with developing advanced thermal insulation, PCM casing designs, and novel solid-state heat to power conversion technologies able to operate at temperatures in the range of 1000-2000 ºC. In particular, the project will investigate Silicon-Boron alloys as PCMs and hybrid thermionic-photovoltaic (TIPV) devices for heat-to-power conversion. This paper describes the project R&D activities and the main results that have been attained during the first 6 months of work. This includes the first wettability and solubility analysis of liquid Si-B alloys, the numerical simulation of silicon phase-change and heat loss analysis through thermal insulation cover, as well as the first steps for the realization of the two main AMADEUS proof-ofconcept experiments: the TIPV converter, and the full LHTES device. [ABSTRACT FROM AUTHOR]

Modern solid-propellant rocket motors are characterized by high operating pressure and energy in the gas cavity of combustion chamber. High energy density causes a lot of emergency situations (self-explosions) which are connected with unknown reasons and unknown physical phenomena (as a rule, when developing new motors). In this matter science has not kept pace with development of technology. Physics and mechanics of these phenomena are not clear. This means that developers can always meet again to this phenomenon. The combination of the described facts causes the urgency of this work. In these paper the mathematical model of hydro-elastic waves in a combustion chamber of the SRM is presented. Using this model the strongly nonlinear hydroelastic waves are described. The possibility of formation of strong discontinuities of these waves with the help of methods of the theory of weak discontinuities for nonlinear hyperbolic systems is proved. It is clear that the formation of strong discontinuities is very bad for the SRM. This is because a strong discontinuities can tear solid propellant at the walls of the SRM. It usually leads to self-detonation of propellant. [ABSTRACT FROM AUTHOR]

Latent heat storage (LHS) has been widely used for energy storage. Compare to sensible heat storage, LHS has several benefits because of its high energy density, small unit sized and operating at low temperature. This paper is aimed to investigate the melting characteristic of phase change material (PCM) implemented in concentric double pipe heat exchanger. The investigation is carried out by both simulation as well as validation. The simulation is conducted using ANSYS FLUENT with double pipe shape of heat storage. The geometrical shape of the storage is double pipe heat exchanger, the PCM is stored in the inner tube meanwhile hot water is circulated in the outer tube. The dimension of the inner tube are 5 cm of diameter and 50 cm length. The diameter of outer tube is 10 cm and 60 cm length. The hot liquid is circulated from the inlet port and withdrawing from the outer port. The inlet and outlet ports are located away at the distance of 5 cm from the edge of the outer tube. The inlet and outlet ports are constructed at the bottom and upper part of the outer tube. The simulation is carried out at temperature 60oC of the hot liquid and flow rate at 4 liters per minute. The validation is also conducted at the same configuration with that on the simulation. The tweaked parameters are number of mesh and mushy-zone value. Results revealed that validation is numerically accepted at deviation less than 5% for melting time deviation. The validation is obtained at number of mesh is 144,000 and mushy-zone value is 1.4x107. On the evaluation of temperature distribution similarity, all of coefficient correlation are obtained greater than 0.8 between simulation and experiment. Being a valid simulation model, it is enabled to be enhanced for predicting melting of phase change materials on the heat energy storage system. [ABSTRACT FROM AUTHOR]

The paper discusses the multiparametric description of the stress fields in the vicinity of two collinear cracks of different lengths in an infinite isotropic elastic medium subjected to mixed (Mode I and Mode II) mode loading. The multiparameter asymptotic expansions of the stress filed containing higher-order terms are obtained. The amplitude coefficients of the multiparameter series expansion are found in the closed form. Having obtained the coefficients of the Williams series expansion, one can keep any preassigned number of terms in the asymptotic series. The asymptotic analysis of the number of terms in the Williams asymptotic series which is necessary to be kept in the asymptotic series at different distances from the crack tip is given. It is demonstrated that the longer the distance from the crack tip, the more terms in the Williams asymptotic expansion need to be kept. The crack propagation direction angle is evaluated. The crack propagation direction angle for different values of the mixity parameter is found with the use of 1) the maximum tangential stress criterion and 2) the minimum elastic strain energy density criterion. It is shown that the higher-order terms of the Williams series expansion affect the crack propagation direction angle. [ABSTRACT FROM AUTHOR]

The paper reports on a study of commercially pure VT1-0 titanium irradiated with a submillisecond intense low-energy pulsed electron beam: electron energy 16 keV, pulse repetition frequency 0.3 Hz, pulse duration 150 μs, energy density 25 J/cm², and number of pulses N = 3. The composition of VT1-0 titanium (up to mass %): 0.18Fe, 0.07C, 0.04N, 0.1Si, 0.12O, 0.004H; other impurities 0.3 and the rest being Ti. The study shows that the irradiated material assumes a multilayer gradient structure. The irradiated material represents a polycrystalline aggregate, and its grain substructure depends on the depth from the irradiated surface. Its surface layer 10.4 μm thick reveals a lamellar structure. In its subsurface layer 7.7 μm thick, a subgrain structure with submillimeter crystallite sizes is formed. The heat affected layer assumes a lamellar structure at a depth of 18.1 μm and a grain-subgrain structure at a depth of 50 μm. At a depth of ≥180 μm, the material has a polycrystalline structure based on α-Ti. [ABSTRACT FROM AUTHOR]

The paper contains two-dimensional model of laser beam melting of powders from binary alloy. The model takes into consideration the melting of alloy in some temperature interval between solidus and liquidus temperatures. The external source corresponds to laser beam with energy density distributed by Gauss law. The source moves along the treated surface according to given trajectory. The model allows investigating the temperature distribution and thickness of powder layer depending on technological parameters. [ABSTRACT FROM AUTHOR]

In this paper, a detailed thermodynamic model for a heat exchanger (HX) working with a dense particle suspension (DPS) as heat transfer fluid (HTF) in the solar loop and water-steam as working fluid is presented. HX modelling is based on fluidized bed (FB) technology and its design has been conceived to couple solar plant using DPS as HTF and storage media with Rankine cycle for power generation. Using DPS as heat transfer fluid allows extending operating temperature range what will help to reduce thermal energy storage costs favoring higher energy densities but will also allow running power cycle at higher temperature what will increase its efficiency. Besides HX modelling description, this model will be used to reproduce solar plant performance under steady state and transient conditions. [ABSTRACT FROM AUTHOR]

The dense plasma focus is blessed not only with copious multi-radiations ranging from electron and ion beams, x-rays both soft and hard, fusion neutrons D-D and D-T but also with the property of enhanced compression from radiative collapse leading to HED (high energy density) states. The Lee code has been used in extensive systematic numerical experiments tied to reality through fitting with measured current waveforms and verified through comparison of measured and computed yields and measurements of multi-radiation. The studies have led to establishment of scaling laws with respect to storage energy, discharge current and pinch currents for fusion neutrons, characteristic soft x-rays, all-line radiation and ion beams. These are summarized here together with a first-time presentation of a scaling law of radiatively enhanced compression as a function of atomic number of operational gas. This paper emphasizes that such a broad range of scaling laws signals the coming of age of the DPF and presents a reference platform for planning the many potential applications such as in advanced SXR lithography, materials synthesizing and testing, medical isotopes, imaging and energy and high energy density (HED). [ABSTRACT FROM AUTHOR]

High Order Mode (HOM) power is produced by high current linear accelerators. In this paper, we report a new method to estimate the HOM power generation and energy spread from multiple bunch patterns in the time domain on multiple HOMs. These methods can be used to evaluate the HOM power and energy spread induced by the HOM field, and to optimize the design of SRF cavities to minimize the HOM power and the energy spread induced by the HOMs. [ABSTRACT FROM AUTHOR]

The aims of this paper are to investigate the characteristic of the wind speed and wind energy potential in the northern coastal region of Semarang, Central Java, Indonesia. The wind data was gained from Meteorological Station of Semarang, with ten-min average time series wind data for one year period, at the height of 10 m. Weibull distribution has been used to determine the wind power density and wind energy density of the site. It was shown that the value of the two parameters, shape parameter k, and scale parameter c, were 3.37 and 5.61 m/s, respectively. The annual mean wind speed and wind speed carrying the maximum energy were 5.32 m/s and 6.45 m/s, respectively. Further, the annual energy density at the site was found at a value of 103.87 W/m², and based on Pacific North-west Laboratory (PNL) wind power classification, at the height of 10 m, the value of annual energy density is classified into class 2. The commercial wind turbine is chosen to simulate the wind energy potential of the site. The POLARIS P25-100 is most suitable to the site. It has the capacity factor 29.79% and can produce energy 261 MWh/year. [ABSTRACT FROM AUTHOR]

In this paper for the first time, a comparison was made of the electrochemical activity of graphene oxides synthesized by modified Hummer's, Brodie and electrochemical methods in aprotic media. Electrodes based on these GOs exhibit electrochemical activity in an aprotic solvent of propylene carbonate with 0.1 M (C4H9)4NClO4 electrolytes in the potential range from -3 to 1 V rel. Ag+/Ag in 0.01M AgNO3 0.1M (C4H9)4NClO4 in acetonitrile. These redox processes are irreversible. Despite the fact that the types of oxygen groups in GO synthesized by different methods are the same, the ratio of these groups is different. The specific capacity of electrodes based on GO during redox processes in aprotic media correlates with the C:O ratio determined from elemental analysis. The use of new active electrode materials based on graphene in electrochemical processes will allow the creation of electrochemical energy storage devices with a higher energy density and capacity. [ABSTRACT FROM AUTHOR]

Solid-state batteries are regarded as reliable battery systems that overcome some issues in current lithium-ion batteries originated from the organic-solvent electrolytes; however, their power densities have not been high enough to practical use. Intensive studies aiming at the improvement of the rate capability have provided solid electrolytes with high ionic conductivities, in which lithium-ion transport properties are comparable or superior to those in the liquid electrolytes. However, there are further resistances still remaining at interfaces, which are rate-determining; high-power solid-state batteries will not be realized without reducing the interfacial resistances. This paper reviews such highly-resistive interfaces in some solid-state systems and some attempts made to reduce the interfacial resistances. [ABSTRACT FROM AUTHOR]

We report the experimental results for new type electrochemical capacitor using iodine redox reaction in single-walled carbon nanotubes (SWCNTs). It was found that the energy density of the present redox capacitor using SWCNTs is almost three times larger than that of the normal electric double layer capacitor. [ABSTRACT FROM AUTHOR]

The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a multiterawatt pulsed power driver, which can deliver a ~10 MA, 70 ns rise-time (10%-90%) current to a short circuit load and has important applications in Z-pinch driven inertial confinement fusion and high energy density physics. In this paper, primary results of tungsten wire-array Z-pinch experiments on PTS are presented. The load geometries investigated include 15-mm-tall cylindrical single and nested arrays with diameter ranging from 14.4-26.4 mm, and consisting of 132~276 tungsten wires with 5~10 m in diameter. Multiple diagnostics were fielded to determine the characteristics of x-ray radiations and to obtain self-emitting images of imploding plasmas. X-ray power up to 80 TW with ~3 ns FWMH is achieved by using nested wire arrays. The total x-ray energy exceeds 500 kJ and the peak radiation temperature is about 150 eV. Typical velocity of imploding plasmas goes around 3~5x107 cm/s and the radial convergence ratio is between 10 and 20. [ABSTRACT FROM AUTHOR]

In a hydrocode simulation the knowledge of pressure as a function of density and energy is needed to solve the hydrodynamic equations. This is obtained from the equation of state (EoS) of a material. For routine use the EoS should be accurate, time efficient, and robust. It is thus advantageous for complex models to tabulate the EoS beforehand, and during the hydrocode simulation to interpolate (or extrapolate) using this grid. A common EoS table format is the SESAME format developed at LANL. However, when this format was developed EoS models that accurately capture the discontinuous changes seen with phase transitions were not commonplace. This talk describes additions to the SESAME format that provide a route for tabulating a multiphase EoS. The final product is found to give an accurate and robust response as well as having an acceptable time penalty. [ABSTRACT FROM AUTHOR]

The law states that energy and time want to be or remain in equilibrium. At the time of the big bang, this time was constricted so much, and singularity was present. The whole universe came and expanded from that singularity, the energy was produced and cosmic inflation of the time limit of 10−36 s happened. However, why did this happen? Why did energy at that time expanded and evolved into the universe as we know it to be present? Also, why the only universe as we know it as it is and not something else, why did the energy did not evolve into something else? These are some questions which we will explain and answer using the law of energy time equilibrium. We have discussed the properties of time correlation with energy for several systems that are simple enough to illustrate the extraction of energy through fluctuation and distortion of equilibrium. We develop a succinct theory of extraction of electrical energy from a classical system subjected to cyclic change between electric and magnetic energy via virtue of fluctuation of energy-time-equilibrium. We show the range inside of which energy-time-equilibrium is established, outside of which it gets distort or disturbed. To sustain the system and extracting the electrical energy, we introduce an engineering machine named Eklavya, which periodically comes out and goes inside of the energy density (with respect of time) sphere of range of equilibrium. In this paper we will not give detailed information about Eklavya. [ABSTRACT FROM AUTHOR]

Using ab initio approach interrelations between the grain boundary energy, the atomic packing density in the interface plane and the magnetic states of atoms was studied for <110> and <001> symmetrical tilt grain boundaries in α- Fe. In the latter case three variants of Σ5(210) GB was studied. It is shown that a decrease of the grain boundary energy is correlated with an increase of the packing density and a decrease of deviation of the magnetic moment of Fe atoms from bulk value. Additionally, the peculiarities of the interatomic interaction near GB plane are discussed. [ABSTRACT FROM AUTHOR]

Many electrochemical energy storage technologies utilize anodes that are specific to the chemistry of the device. Anodes must be designed for devices including primary and secondary batteries, fuel cells and capacitors. These applications include a diverse range of operational conditions, including aqueous, solid or organic media. This paper will provide a brief overview of anode technologies for medium (e.g. electric and hybrid electric vehicles) and large (e.g. integration of renewable energy generation to electrical networks) battery applications. Established and developing storage technologies will be discussed to provide an insight into how anodes (materials, manufacturing processes and modes of operation) differ between specific applications and devices. Lead-acid batteries are used as a case study to provide a practical example and guide discussion onto the question of future challenges and opportunities. [ABSTRACT FROM AUTHOR]

Recently we have reported on the existence of finite energy SU(2) Yang-Mills-Higgs particle of one-half topological charge. In this paper, we show that this one-half monopole can co-exist with a 't Hooft-Polyakov monopole. The magnetic charge of the one-half monopole is -½ while the magnetic charge of the 't Hooft-Polyakov monopole is positive unity. However the net magnetic charge of the configuration is zero due to the presence of a semi-infinite Dirac string along the positive z-axis that carries the magnetic monopole charge of another -½. The solution possesses gauge potentials that are singular along the z-axis, elsewhere they are regular. This monopole configuration possesses finite total energy and magnetic dipole moment. The total energy is found to increase with the strength of the Higgs field self-coupling constant λ. However the dipole separation and the magnetic dipole moment decrease with λ. This solution is non-BPS even in the BPS limit when the Higgs self-coupling constant vanishes. [ABSTRACT FROM AUTHOR]

Pulse tube coolers operating at higher frequency lead to a high energy density and result in a more compact system. This paper describes the performance of a 300 Hz pulse tube cooler driven by a linear compressor. Such high frequency operation leads to decreased thermal penetration, which requires a smaller hydraulic diameter and smaller wire diameter in the regenerator. In our previous experiments, the stainless steel mesh with a mesh number of 635 was used as the regenerator material, and a no-load temperature of 63 K was obtained. Both the numerical and experimental results indicate this material causes a large loss in the regenerator. A stainless steel fiber regenerator is introduced and studied in this article. Because this fiber has a wide range of wire diameter and porosity, such material might be more suitable for higher frequency pulse tube coolers. With the fiber as the regenerator material and after a series of optimizations, a noload temperature of 45 K is acquired in the experiment. Influences of various parameters such as frequency and inertance tube length have been investigated experimentally. [ABSTRACT FROM AUTHOR]