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With the development of nuclear energy, microreactors have received increasing interest among researchers in recent years. In this paper, a megawatt heat pipe reactor with metal hydride moderators and burnable poisons is proposed. The hydrogen stability of the reactor under accident conditions, including reactivity insertion accidents, loss of power conversion unit heat sink accidents, and heat pipe failure accidents are analyzed. In this work, Gd2O3 is introduced as a burnable poison in the form of mixing with the UO2 fuel. According to the results of the burnable poison design, the 0.1% mass fraction of Gd[sub 2]O[sub 3] is selected as the burnable poison loaded in the core. Safety analysis indicates that the introduction of burnable poisons can be beneficial during the positive reactivity insertion accident as it can reduce the excessive reactivity at BOL, thus reducing power peak and preventing hydrogen dissociation in ZrH1.4 rods. However, during the loss of PCU heat sink accident, ZrH1.4 rods will dissociate regardless of the presence of burnable poisons, whereas YH1.7 rods show better hydrogen stability. Moreover, in the event of the heat pipe failure accident, ZrH1.4 rods aremore susceptible to dissociation than YH1.7 rods. As a result, the YH1.7+BP core is a better choice compared with other designs proposed in this paper as it provides a relatively high temperature margin. [ABSTRACT FROM AUTHOR]

The microstructure of three rolling surfaces of TC4 sheet is different, and their resistance ability to hydrogen damage lacks systematic research. Thus, the hydrogen damage behavior of TC4 rolling sheet was investigated in this paper. The hydrogen diffusion law along different rolling directions and the precipitation of hydrides on different rolling surfaces were compared. It is found that the shape and distribution of α and β phases are changed under the action of extrusion force during the rolling process, and they are arranged in striped shape on the R-N surface along the R direction, and the diffusion of hydrogen along the R direction is faster due to the existence of continuous β phases as hydrogen diffusion channels, resulting in the more serious hydrogen damage. Besides the hydrides mainly deposited at the α and β phase boundaries, the hydrides precipitated in the interior of α phases on the R-N surface are more than that on the R-T surface due to the different distribution state of β phases. [ABSTRACT FROM AUTHOR]

Fuel Cells (FCs) constitute an enabling technology for the integration of renewable energies and for the deployment of the next generation of power grids, the so-called Smart Grids/Microgrids. These devices perform the process of converting hydrogen into electricity without emitting pollutant emissions. Characteristic curves, mainly polarization curves, are a paramount resource to study the performance of FCs and to determine accurate models that fit their behavior. This paper presents the characterization of a commercial Polymer Electrolyte Membrane (PEM) FC consisting of 24 cells in series with a nominal output of 500 W, used to supply electricity in a Smart Microgrid involving renewable energies and hydrogen. The process evolution takes place under different laboratory conditions, so voltage, current, and hydrogen flow are measured and plotted to build the polarization curves. The equipment and components involved in the operation of the FC are described, as well as their technical features. Namely, a metal-hydride bottle is used to store the hydrogen that feeds the FC, an electronic programmable load establishes different charge conditions, and a precision multimeter collects the measurements provided by a set of sensors physically coupled to the FC. The characterization conducted in this research is envisioned to be used to build a digital twin of the FC. The developed experimentation and achieved results are described. The obtained results show a proper match between the experimental data and the curves reported in the literature and in the FC datasheet. [ABSTRACT FROM AUTHOR]

11713542 4 Pasquini L. The effect of nanostructure on the hydrogen sorption properties of magnesium-based metallic compounds: A review. To date, the majority of energy supply is still generated by non-renewable sources, which places a dramatic burden on our environment. A recent review paper by Ahmad et al. targets Mg(BH SB 4 sb ) SB 2 sb , which is the best candidate of the borohydride family owing to its very high gravimetric H storage capacity (14.9 wt.%) [[8]]. [Extracted from the article]

In this paper, based on the study of hydrogen accumulation in the electrodes of nickel–cadmium batteries, a high-capacity hydrogen storage system (HSS) is proposed. It has been experimentally proven that hydrogen accumulates in the electrodes of nickel–cadmium batteries in large quantities over the course of their operation. It has been shown that hydrogen accumulates in metal–ceramic matrices of sintered oxide–nickel electrodes in the form of metal hydrides. The gravimetric capacity of the nickel matrix is 20.3 wt% and the volumetric capacity is 406 kg m−3. The obtained gravimetric capacities for metal–ceramic matrices exceed almost four times the criteria for onboard hydrogen storage systems established by the US Department of Energy (DOE), as well as previously obtained results for any reversible hydrogen accumulation materials. In addition, in our previous papers, it was proved that if we use thermal runaway for the desorption of hydrogen from metal hydrides then the kinetic and thermodynamic criteria established by the US DOE may be significantly exceeded. Thus, within the framework of the proposed HSS, using the electrochemical method of hydrogen accumulation and the thermal runaway process, one can not only achieve all of the criteria established by the US DOE for HSS but also significantly exceed them. [ABSTRACT FROM AUTHOR]

Nowadays, due to the increasing use of electric vehicles, manufacturers are making more and more innovations in the batteries used in electromobility, in order to make these vehicles more efficient and provide them with greater autonomy. This has led to the need to evaluate and compare the efficiency of different batteries used in electric vehicles to determine which one is the best to be implemented. This paper characterises, models and compares three batteries used in electromobility: lithium-ion, lead-acid, and nickel metal hydride, and determines which of these three is the most efficient based on their state of charge. The main drawback to determine the state of charge is that there are a great variety of methods and models used for this purpose; in this article, the Thévenin model and the Coulomb Count method are used to determine the state of charge of the battery. When obtaining the electrical parameters, the simulation of the same is carried out, which indicates that the most efficient battery is the Lithium-ion battery presenting the best performance of state of charge, reaching 99.05% in the charging scenario, while, in the discharge scenario, it reaches a minimum value of 40.68%; in contrast, the least efficient battery is the lead acid battery, presenting in the charging scenario a maximum value of 98.42%, and in the discharge scenario a minimum value of 10.35%, presenting a deep discharge. This indicates that the lithium-ion battery is the most efficient in both the charge and discharge scenarios, and is the best option for use in electric vehicles. In this paper, it was decided to use the Coulomb ampere counting method together with the Thévenin equivalent circuit model because it was determined that the combination of these two methods to estimate the SOC can be applied to any battery, not only applicable to electric vehicle batteries, but to battery banks, BESS systems, or any system or equipment that has batteries for its operation, while the models based on Kalman, or models based on fuzzy mathematics and neural networks, as they are often used and are applicable only to a specific battery system. [ABSTRACT FROM AUTHOR]

This paper is a synthesis of the methods used for hydrogen production and the storage of hydrogen in the form of metal hydrides and different methods of hydrogen storage in various materials are presented. It also presents the Romanian vision in relation to the existing and future projects that include the production of hydrogen and its use in energy. [ABSTRACT FROM AUTHOR]

Superconductivity in metals and alloys, i.e., conventional superconductivity, has seen many new developments in recent years, leading to a renewed interest in the principles of superconductivity and the search for new materials. The most striking discoveries include the near-room-temperature superconductivity in metal hydrides (LaH 10 ) under pressure, the extreme stability of superconductivity in NbTi up to 261 GPa pressure, the discovery of high-entropy alloy (HEA) superconductor materials, and the machine learning prediction of new superconducting materials. Other interesting research concerns the properties of 2D superconductors, topological superconductors, e.g., in hybrid systems, and the use of nanotechnology to create nanowires and nanostructures with new properties. Furthermore, and most importantly, the drive from new accelerator and fusion reactors for stronger superconducting magnets has lead to improved cable materials, showing the highest critical current densities ever. Thus, this Special Issue aims to bring together a collection of papers reflecting the present activity in this field. [ABSTRACT FROM AUTHOR]

The efficient operation of a metal hydride reactor depends on the hydrogen sorption and desorption reaction rate. In this regard, special attention is paid to heat management solutions when designing metal hydride hydrogen storage systems. One of the effective solutions for improving the heat and mass transfer effect in metal hydride beds is the use of heat exchangers. The design of modern cylindrical-shaped reactors makes it possible to optimize the number of heat exchange elements, design of fins and cooling tubes, filter arrangement and geometrical distribution of metal hydride bed elements. Thus, the development of a metal hydride reactor design with optimal weight and size characteristics, taking into account the efficiency of heat transfer and metal hydride bed design, is the relevant task. This paper discusses the influence of different configurations of heat exchangers and metal hydride bed for modern solid-state hydrogen storage systems. The main advantages and disadvantages of various configurations are considered in terms of heat transfer as well as weight and size characteristics. A comparative analysis of the heat exchangers, fins and other solutions efficiency has been performed, which makes it possible to summarize and facilitate the choice of the reactor configuration in the future. [ABSTRACT FROM AUTHOR]

In this paper, we studied the effect of the Cr/Mn ratio on the microstructure, crystal structure and hydrogen absorption properties of the quaternary alloys of compositions Ti30V60Mn(10−x)Crx (x = 0, 3.3, 6.6 and 10) + 4 wt.% Zr. The addition of Hf instead of Zr was also investigated. We found that all alloys are single-phase BCC (Body Centred Cubic) but with regions of high concentration of Zr (or Hf). The first hydrogenation at room temperature under 2 MPa of hydrogen happens quickly without any incubation time. The Ti30V60Mn3.3Cr6.6 + 4 wt.% Zr alloy showed the fastest kinetics and highest hydrogen absorption (3.8 wt.%). For this composition, replacing Zr with Hf made the first hydrogenation slower and reduced the capacity to 3.4 wt.%. No activation was observed for the same alloy without additives. As the alloy without additives did not absorb hydrogen at all, it means that the presence of these high concentrations of Zr (or Hf) is essential for quick first hydrogenation. [ABSTRACT FROM AUTHOR]

Metal alloys and intermetallic compounds offer an attractive method for safely storing hydrogen (H2). The metal alloys absorb H2 into their structure, often swelling and fracturing as a result of phase transformation during hydride formation/decomposition cycles. The absorption of H2 is an exothermic process, requiring the effective and efficient removal of heat. This can be challenging as heat transfer to/from powdered beds is notoriously difficult, and often limited by poor thermal conductivity. Hence, the observed reaction kinetics for absorption and desorption of H2 is dominated by heat flow. The most common method for improving the thermal conductivity of the alloy powders is to prepare them into composite structures with other high thermal conductivity materials, such as carbons and expanded natural graphite. Such composite structures, some also combined with polymers/resins, can also mitigate safety issues related to swelling and improve cyclic durability. This paper reviews the methods that have been used to prepare such composite structures and evaluates the observed impact on thermal conductivity. [ABSTRACT FROM AUTHOR]

This paper presents results on the kinetics of the synthesis of the Cr2Ta intermetallic compound via calcium hydride reduction and the influence of various technological parameters on this process. We have observed anomalous Cr2Ta formation kinetics, in particular, an explosive increase in the amount of this phase as a certain synthesis temperature is reached. The apparent activation energy for the calcium hydride synthesis of the Cr2Ta intermetallic compound has been determined to be ~291 kJ/mol, approaching the activation energy for heterodiffusion in various Laves phases (Cr2Ti, Cr2Nb, Co2Nb, and Fe2Ti). The results obtained in this study are used to gain insight into the mechanism of the calcium hydride synthesis of Cr2Ta. Calcium hydride reduction has been shown to be potentially attractive for the preparation of refractory intermetallics. Further work in this direction will make it possible to obtain high-quality powder and compact articles from it. [ABSTRACT FROM AUTHOR]

Despite the apparent simplicity of palladium hydride systems, interactions between hydrogen and palladium are multifaceted. Electrochemical hydrogen stripping allows measuring the stoichiometric coefficient of hydrogen atoms inside PdHx structures, whose properties greatly depend on x. In this paper, the insertion of H into Pd nanoparticles has been studied in a three‐electrode setup (RDE) and a proton pump cell. An original way of modelling the hydrogen desorption curve is proposed, helping in the separation of hydrogen absorption from other contributions. The loading voltage exhibits the highest impact on the H absorption into Pd, reaching Habs/Pd up to 0.47±0.02 in the RDE setup, at −0.2 VRHE. Conversely, the loading duration presents only little influence in the very first seconds. Finally, maximal Habs/Pd ratios are measured around 30–40 °C, likely due to an optimal balance between the H adsorption rate, and the H diffusion rate into Pd. [ABSTRACT FROM AUTHOR]

The recycling of REEs from the end of life (EoL) products, such as nickel metal hydride batteries (NiMH), offers great opportunities for their supply in Europe. In the presented paper, the application of 'green' extractants such as citric (CA), metatartaric (TA), and ethylenediaminedisuccinic acid (EDDS) (also with H2O2 addition) for the recovery of REEs was studied. The studies were conducted considering the effects of the phase contact time, the initial concentration of CA, TA, and EDDS, as well as H2O2, pH, and temperature. It was found that the addition of TA to the CA solution meant that higher rates of metal ion binding and, thus, leaching was observed. The optimal conditions were obtained in the system: CA-TA and H2O2 for the concentration 0.6M-0.3 M-2%. [ABSTRACT FROM AUTHOR]

There have been several reviews and numerous papers on hydrogen-embrittlement phenomena and mechanisms in the past few years, but long-standing controversies regarding mechanisms of embrittlement (when hydride phases are not involved) are no closer to being resolved despite all the recent research. These controversies have arisen partly because there have been significant misunderstandings of some of the proposed mechanisms, and some misinterpretation of experimental observations. There has also been a lack of consideration of all the evidence, with some researchers ignoring observations that do not fit their favoured hypothesis. Some recent reviews and papers illustrating the above points are discussed in the present paper, although a comprehensive coverage is not attempted. It is concluded that the adsorption-induced dislocation-emission/void-coalescence mechanism predominates for cleavage-like and intergranular fracture modes that exhibit microscale or nanoscale dimples. Hydrogen-enhanced decohesion, hydrogen-enhanced localised plasticity, and vacancy-based mechanisms may play secondary roles for such fracture modes and could be more important in other cases. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study of shock compression of titanium hydride (TiH2) and the deuterides of zirconium (ZrD2), tantalum (TaD0.8), and titanium (TiD2, TiD1.6, and TiD1.1) in the pressure range 30–220 GPa. The synthesis of titanium and zirconium deuterides from titanium and zirconium powders and tantalum deuterides from tantalum rods is described. Experiments to determine the Hugoniots of deuterides and hydrides were performed using the well-known reflection method. Shock-wave generators with explosive charges of different power were used for compression of samples. A description of the obtained experimental data using simple equations of state is proposed. [ABSTRACT FROM AUTHOR]

Apart from being emission-free, electric vehicles enjoy benefits such as low maintenance and operating costs, noise-free, easy to drive, and the convenience of charging at home. All these benefits are directly dependent on the performance of the battery used in the vehicle. In this paper, one-dimensional modeling of Li-ion and NiMH batteries was developed, and their performances were studied. The performance characteristics of the batteries, such as the charging and discharging characteristics, the constituent losses of over-potential voltage, and the electrolyte concentration profile at various stages of charge and discharge cycles, were also studied. It is found that the electrolyte concentration profiles of Li-ion batteries show a drooping behavior at the start of the discharge cycle and a rising behavior at the end of discharge because of the concentration polarization due to the low diffusion coefficient. The electrolyte concentration profiles of NiMH batteries show rising behavior throughout the discharge cycle without any deviations. The reason behind this even behavior throughout the discharge cycle is attributed to the reduced concentration polarization due to electrolyte transport limitations. It is found that the losses associated with the NiMH battery are larger and almost constant throughout the battery's operation. Whereas for the Li-ion batteries, the losses are less variable. The electrolyte concentration directly affects the overpotential losses incurred during the charging and discharging phases. [ABSTRACT FROM AUTHOR]

Applied to a hydrogen absorption-desorption cycle, the hydrogen storage bed will experience higher exchange temperatures and variety of mechanical load. Due to the complex structure of the double-layered annulus metal hydride bed and the importance of thermal stress on the failure of a metal hydride bed, the numerical modeling of its hot spot stress was carefully carried out. Moreover, in this paper, an analysis method considering the limit failure mode condition is proposed to deal with the stress analysis in the process of hydrogen absorption and desorption. According to the proposed analysis method, the maximum stress of thermal-structural coupling in the process of hydrogen absorption occurs at about 1/3 along the diameter direction and at the geometric mutation of the connection between the cooling pipe and the main body of the hydrogen storage bed in the process of hydrogen desorption. Apart from that, the hydrogen storage bed is also subjected to thermal-mechanical fatigue by the iterative process of absorption and desorption, and its operating temperature range is in the thermal creep temperature region. Based on the distribution of the stress and temperature, evaluation hot sites were selected and the ASME-NB and ASME-NH codes were used to evaluate fatigue and fatigue creep, respectively. The evaluation showed that the fatigue damage generated during its service life is small, while the creep damage is relatively large and the total damage generated during the service life of the hydrogen storage bed is within the safe range. Aiming at the structure and complex process of a double-layer hydrogen storage bed, creep and fatigue evaluation methods are proposed, various failure modes of hydrogen storage bed are highlighted, and the relationship between process parameters and life is established. [ABSTRACT FROM AUTHOR]

In this paper, it is experimentally proven that the generalized Peukert equation C(i,T) = Cm(T)/(1 + (i/i0(T))n(T)) is applicable to nickel–metal hydride batteries at any discharge currents, while the classical Peukert equation can be used only in a limited range of the discharge currents (approximately from 0.3 Cn to 3 Cn). In addition, the classical Peikert equation does not take into account the influence of the temperature of a battery on its released capacity. It is also proven that for the nickel–metal hydride batteries, the generalized Peukert equation heavily depends on battery temperature (via the parameters Cm(T), i0(T) and n(T)). The temperature dependencies of the parameters of the generalized Peukert equation and their physical meaning are also established. The obtained generalized Peukert equation, which considers the batteries' temperature, can be used at any discharge current and temperature of the batteries. [ABSTRACT FROM AUTHOR]

The Meissner effect, magnetic field expulsion, is a hallmark of superconductivity. Associated with it, superconductors exclude applied magnetic fields. Recently, Minkov et al. [Nat. Commun. 13, 3194 (2022)] presented experimental results reportedly showing "definitive evidence of the Meissner effect" in sulfur hydride and lanthanum hydride under high pressure, and Eremets et al. [J. Supercond. Nov. Magn. 35, 965 (2022)] argued that "the arguments against superconductivity (in hydrides) can be either refuted or explained." Instead, we show here that the evidence presented in those papers does not support the case for superconductivity in these materials. Together with experimental evidence discussed in earlier papers, we argue that this strongly suggests that hydrides under pressure are not high-temperature superconductors. [ABSTRACT FROM AUTHOR]

In this paper, detailed comparisons of the driving force in thermodynamics and intrinsic force in the kinetics of 1,2-dihydropyridine and 1,4-dihydropyridine isomers of PNAH, HEH, and PYH in hydride transfer reactions are made. For 1,2-PNAH and 1,4-PNAH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 60.50 and 61.90 kcal/mol, 27.92 and 26.34 kcal/mol, and 44.21 and 44.12 kcal/mol, respectively. For 1,2-HEH and 1,4-HEH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 63.40 and 65.00 kcal/mol, 31.68 and 34.96 kcal/mol, and 47.54 and 49.98 kcal/mol, respectively. For 1,2-PYH and 1,4-PYH, the order of thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 69.90 and 72.60 kcal/mol, 33.06 and 25.74 kcal/mol, and 51.48 and 49.17 kcal/mol, respectively. It is not difficult to find that thermodynamically favorable structures are not necessarily kinetically favorable. In addition, according to the analysis of thermo-kinetic parameters, 1,4-PNAH, 1,2-HEH, and 1,4-PYH have a strong hydride-donating ability in actual chemical reactions. [ABSTRACT FROM AUTHOR]

Aluminum hydride (AlH3), as a potential new metal fuel, has attracted extensive attention in the field of hydrogen storage materials, propellants and energetic materials due to its excellent properties. In this paper, a new organic liquid phase reduction method was used to prepare AlH3, and the microstructure and composition of the prepared samples were characterized by SEM–EDS, XRD, FT-IR, XPS, etc. The main crystal phase of the prepared AlH3 was α-AlH3, with high quality and no other impurities. The thermal decomposition behavior and non-isothermal reaction kinetics of AlH3 were investigated by TG-DSC. The results show that there are three exothermic stages in the heating process of AlH3: dehydrogenation of AlH3, first oxidation of Al, and second oxidation of Al. The activation energy of the dehydrogenation of AlH3 is 77.8675 kJ/mol (Kissinger method) and 81.4862 kJ/mol (Ozawa method), respectively. The morphology evolution of AlH3 particles during the heating process (300–3000 K) was simulated using a reaction kinetics method based on the ReaxFF force field. The response behavior of AlH3 in the instantaneous high-temperature detonation environment was investigated using the high-energy laser-induced shock wave technique. Under the impact of a high-energy laser (1006 mJ), the AlH3 sample undergoes an ultra-fast reaction and generates a large amount of plasma. The expansion of the plasma pushes the surrounding air to form a supersonic shock wave and propagates forward. The shock wave propagation velocity of AlH3 is 690.99 m/s in the range of 2.1–12.35 μs, and the higher the laser energy, the faster the shock wave propagation velocity. This study provides the basis for the application of AlH3. [ABSTRACT FROM AUTHOR]

In a fuel cell electric vehicle (FCEV) powered by a metal hydride tank, the performance of the tank is an indicator of the overall health status, which is used to predict its behaviour and make appropriate energy management decisions. The aim of this paper is to investigate how to evaluate the effects of charge/discharge cycles on the performance of a commercial automotive metal hydride hydrogen storage system applied to a real FCEV. For this purpose, a mathematical model is proposed based on uncertain physical parameters that are identified using the stochastic particle swarm optimisation (PSO) algorithm combined with experimental measurements. The variation of these parameters allows an assessment of the degradation level of the tank's performance on both the quantitative and qualitative aspects. Simulated results derived from the proposed model and experimental measurements were in good agreement, with a maximum relative error of less than 2 % . The validated model was used to establish the correlations between the observed degradations in a hydride tank recovered from a real FCEV. The results obtained show that it is possible to predict tank degradations by developing laws of variation of these parameters as a function of the real conditions of the use of the FCEV (number of charging/discharging cycles, pressures, mass flow rates, temperatures). [ABSTRACT FROM AUTHOR]

Humanity is confronted with one of the most significant challenges in its history. The excessive use of fossil fuel energy sources is causing extreme climate change, which threatens our way of life and poses huge social and technological problems. It is imperative to look for alternate energy sources that can replace environmentally destructive fossil fuels. In this scenario, hydrogen is seen as a potential energy vector capable of enabling the better and synergic exploitation of renewable energy sources. A brief review of the use of hydrogen as a tool for decarbonizing our society is given in this work. Special emphasis is placed on the possibility of storing hydrogen in solid-state form (in hydride species), on the potential fields of application of solid-state hydrogen storage, and on the technological challenges solid-state hydrogen storage faces. A potential approach to reduce the carbon footprint of hydrogen storage materials is presented in the concluding section of this paper. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication of Ge1−ySny layers with 2%–13% Sn, utilizing a unique method that combines high-order Ge4H10 and Ge5H12 hydrides and gas source molecular epitaxy techniques. The latter operate at very low working pressures of 10−6–10−7 Torr leading to molecular flow regime conditions, promoting layer-by-layer epitaxy of crystalline materials at ultralow-temperatures (250–160 °C) that cannot be achieved by conventional thermal CVD. In both cases, a "direct injection" approach is employed, using the pure vapor of Ge4H10 and Ge5H12 as the source of the Ge flux, which is then reacted on the substrate surface with SnD4 in the absence of gaseous carriers. Ge4H10 reactions were conducted at 215–190 °C, producing 6%–12% Sn samples. These were grown on both conductive, resistive, single-side, and double-side polished Si(100) with n-type Ge1−xSix buffer layers (x = 2%–3%) to explore conditions and substrate formats that facilitate back-side illumination, enabling transparency and enhanced responsivity at 1550 nm in prototype p-i-n devices. Exploratory reactions of Ge5H12 with SnD4 produced Ge1−ySny with 2%–13% Sn at 250–160 °C for the first time. All samples were characterized by XRD, RBS, IR-ellipsometry, AFM, and TEM to investigate the structure, composition, strain state, and morphology. The samples grow partially relaxed (T > 180 °C) and their compressive strains gradually diminish in situ with increasing film thickness (up to 700 nm) without epitaxial breakdown and Sn segregation. Residual strains are further reduced by RTA processing. The experiments described here demonstrate the practicality of our chemistry-based method as an alternative to thermal CVD for the fabrication of high crystal quality samples on larger area wafers for potential applications in IR devices. [ABSTRACT FROM AUTHOR]

A solid-state storage system is the most practical option for hydrogen because it is more convenient and safer. Metal hydrides, especially MgH 2 , are the most promising materials that offer high gravimetric capacity and good reversibility. However, the practical application of MgH 2 is restricted by slow sorption kinetics and high stability of thermodynamic properties. Hydrogen storage performance of MgH 2 was enhanced by introducing the Mg – Na – Al system that destabilises MgH 2 with NaAlH 4. The Mg – Na – Al system has superior performance compared to that of unary MgH 2 and NaAlH 4. To boost the performance of the Mg – Na – Al system, the ball milling method and the addition of a catalyst were introduced. The Mg – Na – Al system resulted in a low onset decomposition temperature, superior cyclability and enhanced kinetics performances. The Al 12 Mg 17 and NaMgH 3 that formed in situ during the dehydrogenation process modify the reaction pathway of the Mg – Na – Al system and alter the thermodynamic properties. In this paper, the overview of the recent progress in hydrogen storage of the Mg – Na – Al system is detailed. The remaining challenges and future development of Mg – Na – Al system are also discussed. This paper is the first review report on hydrogen storage properties of the Mg – Na – Al system. [ABSTRACT FROM AUTHOR]

The fate of the hydrogen atoms at C-3 and C-4 of uridine diphospho-D-glucuronic acid (UDPGlcUA) in the course of its conversion to uridine diphospho-apiose (UDP-api) was investigated. The specifically labeled UDP-GlcUA substrates were prepared enzymatically from D-[3-³H]glucose and D-[4-³H]glucose by the combined action of hexokinase, phosphoglucomutase, UDPGpyrophosphorylase, and UDPG dehydrogenase. UDP-[U-14C, 3-³H]GlcUA, UDP-[U14C, 4-³H]GlcUA, and UDP-[U14C, 3,4-³H2]GlcUA were separately converted to UDP-Api by an enzyme preparation from Lemna minor. In order to obtain an apiose (3-C-hydroxymethyl-D-erythrofuranose) derivative which was reasonably stable and which could be produced without passing through the aldehydo form, the apiosyl radical of UDP-Api was enzymatically transferred to 7-glucosylapigenin by an enzyme preparation from parsley. The product of this reaction, apiin (7-O-[β-D-apiofuranosyl-(1→2)-β-D-glucosyl-5,7,4'-trihydroxyflavone), was subjected to mild periodate oxidation to convert the branch hydroxymethyl group of the apiosyl residue to formaldehyde. Approximately 14-16% of each of the substrates was converted to UDP-Api. The transfer of the apiosyl moiety to 7-glucosylapigenin was essentially quantitative in all cases. The isolated apiin was shown to have retained 53.5% of the tritium from the substrate labeled at C-3, 99% from the substrate labeled at C-4, and 73% from the substrate labeled at C-3,4. All of the tritium and one-fifth of the 14C of apiin produced from the variously labeled substrate was accounted for in the formaldehyde-dimedone derivative. These results establish the occurrence of a hydride shift from C-4 of UDP-GlcUA to C-3' of apiose in the biosynthesis of UDP-Api from UDPGlcUA. [ABSTRACT FROM AUTHOR]

Nowadays, batteries used in many areas such as RES have an important place in energy storage. Because of the unstable and intermittent structure of RES, battery energy storage technology is becoming important. There are many different types of batteries in the market, such as lead-acid, nickel-metal hydride, and lithium- ion. It is very important that these batteries are well recognized and controlled accordingly to extend their cycle life. In this study, necessary parameter values were obtained by conducting lead acid, nickel-metal hydride and lithium-ion charge-discharge experiments by using climatic chamber in the laboratory environment. A single model was created using curve fitting for three different battery types. In addition the electrical model of the batteries, the temperature model was also combined to conduct state analyzes at different operating temperatures of the batteries and a mathematical model was derived. The obtained mathematical model MATLAB/M-File program was used to compare with the experimental results. In this paper, electrical and thermal mathematical equations for different types of batteries are compared with experimental and model results and the accuracy ratios are given. [ABSTRACT FROM AUTHOR]

The history and state of knowledge of techniques available to analysts before the development of modern spectrometric techniques are surveyed in this paper. A variety of evaluative methods developed in the 19th century, with relatively minor improvements, remain in the repertoire of analysts even though they are at best semi-quantitative. Interferences with the vapour-generation reaction were identified early, as were the advantages and drawbacks of electrochemical vapour generation. This review attempts to present the earliest descriptions of vapour generation of elements and of the devices that have been used for their determination; phase-separation devices, in particular, are described. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSN) are low-resource devices that run on small batteries. The availability of battery energy, device drive cycles, and environmental conditions all have an impact on node lifetime. The state of charge (SoC) is an important factor in determining the amount of energy available in the batteries. Accurate SoC estimation is critical for device lifetime prediction and safe device operation. We present a novel approach for adaptive SoC estimation based on Gaussian Process Regression in this paper (GPR). The training data was obtained in a climate-controlled laboratory setting by using IEEE 802.15.4-based drive loads at various temperatures for three different batteries such as Lithium-Ion, Nickel-metal hydride, and Lithium-Polymer. To estimate the SoC, battery parameters such as voltage, capacity, and temperature were directly mapped to the corresponding models. For each battery parameter, the GPR model with hyper tuned Radial Bias Filter (RBF) was trained at temperatures ranging from 5 °C to 45 °C. For model accuracy, the proposed scheme was compared to polynomial regression and support vector machines (SVM). In this regard, the proposed model provided Mean Absolute Error (MAE) values of 2.53 percent, 2.54 percent, and 2 percent, respectively, and Root Mean Square Error (RMSE) values of 0.295, 0.292, and 0.35 for Nickel-metal hydride, Lithium-Polymer, and Lithium-Ion batteries at 25 °C. Our proposed lightweight GPR scheme is, to the best of our knowledge, the only active implementation on embedded platforms for SoC estimation of WSN. Finally, the model was rigorously tested on ARM Cortex M4-based microcontrollers to report real-time online SoC estimation on WSN nodes. [ABSTRACT FROM AUTHOR]

Catalytic CO 2 hydrogenation is considered one of the most efficient strategies for CO 2 reduction, provided that we have efficient and selective catalysts. This paper explores a mass-spectrometric approach to rapidly compare the reactivities of 21 metal complexes (iron, cobalt, and nickel complexes with three bidentate N,N′- ligands and four bidentate P,P′- ligands) by energy-resolved MS/MS experiments. The experiments show relative hydricities of these complexes, singling out iron complexes with N,N′- ligands and cobalt complexes with P,P′- ligands as particularly reactive for hydride-donor reactions. Comparing these results with relative affinities of metal hydrides for CO 2 led to the conclusion that iron hydrides should be particularly suited for CO 2 hydrogenation reactions. The results, however, cannot account for the effects of the polar reaction environment in the condensed phase. [Display omitted] • The properties of metal hydrides of the iron triad were studied by mass spectrometry. • Supported by N,N′-bidentate ligands, iron hydrides have the smallest hydricities. • Supported by P,P′-bidentate ligands, cobalt hydrides have the smallest hydricities. • Qualitatively, iron hydrides should react fastest in CO 2 hydrogenation reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of aluminum doping on the solid helium properties of scandium hydride was evaluated. • The doping of Al in ScH 2 has a repulsive effect on the neighboring tetrahedral interstitial He atom. • Provides a theoretical basis for the solidification of helium in materials. Helium (He) in rare-earth metal hydrogen storage materials tends to aggregate and produce bubbles and release them, which has an impact on the lifetime of the materials. Therefore, it is crucial to study the aggregation behavior of He to improve the lifetime of the materials. In this paper, two forms of interstitial doping and substitution doping are selected by density-functional theory (DFT) calculations, and the effects of Al doping in ScH 2 on the geometries, formation energies, and binding energies of He atoms, as well as the migration behaviors of the doped Al atoms on the migration of the He atoms are investigated in detail. Finally, it is demonstrated that Al doping in ScH 2 makes it difficult for He atoms to exist near and stabilize the vacancies close to Al atoms, which is likely to inhibit the formation of clusters of He, and provides a strong basis for the realization of the improvement of helium-solidifying properties of ScH 2 materials. [ABSTRACT FROM AUTHOR]

Using metal hydride for hydrogen storage in stationary applications and for transportation is a promising technology due to its advantages of large hydrogen storage capacity, low pressure and low energy consumption. Combining the metal hydride reactor with PCM is expected to recover the heat generated during the hydrogen absorption and use it for hydrogen desorption, thus improving the energy efficiency of the system. This paper proposes a metal hydride reactor integrated with honeycomb fins and PCM to enhance heat transfer. Based on simulations, the results show that the achieved hydrogen storage capacity is 1.326 wt%, the gravimetric and volumetric storage densities are 0.411% and 14.76 kg of H 2 per m3, respectively, and the mean saturated rates are 1.222 × 10−3 g s−1 and 0.773 × 10−3 g s−1 for absorption and desorption processes. Compared with the reactor without fins, the mass and volume of the reactor using honeycomb fins are increased, resulting in a decrease in gravimetric and volumetric storage density, but a increase in reaction rate during hydrogen absorption and desorption processes. Based on this structure, we also propose a honeycomb fin reactor filled with sandwich PCM to further accelerate the heat transfer in the reaction process. Compare to the reactor with PCM only filled on the periphery of the honeycomb fins, the hydrogen absorption and desorption times are shortened by about 86.4% and 81.1%, respectively. In addition, different reactor structures are compared using multiple KPIs to provide relevant suggestions for the reactor optimization. The obtained research results can provide a reference for effective thermal management methods in MH storage systems. • A metal hydride reactor integrated with honeycomb fins and PCM was proposed. • The comparison of reactor without fins and the effects of fin size were studied. • The placement of PCM and MH was optimized. • Multiple KPIs were used to evaluate the hydrogen absorption and desorption processes. • The optimized reactor performed better than other forms of reactors. [ABSTRACT FROM AUTHOR]

Metal hydrides are crucial intermediates in numerous catalytic reactions. Intensive efforts have been dedicated to constructing molecular metal hydrides, where toxic precursors and delicate mediators are usually involved. Herein, we demonstrate a facile pressure-induced methodology to generate a cost-effective heterogeneous electrocatalytic metal hydride surface for sustainable hydrogen transfer. Taking carbon dioxide (CO2) electroreduction as a model system and zinc (Zn), a well-known carbon monoxide (CO)-selective catalyst, as a model catalyst, we showcase a homogeneous-type hydrogen atom transfer process induced by heterogeneous hydride surfaces, enabling direct hydrogenation pathways traditionally considered "prohibited". Specifically, the maximal Faradaic efficiency for formate is enhanced by ~fivefold to 83% under ambient conditions. Experimental and theoretical analyses reveal that unlike the distal hydrogenation route for CO2 to CO over pristine Zn, the Zn hydride surface enables direct hydrogenation at the carbon site of CO2 to form formate. This work provides a promising material platform for sustainable synthesis. The authors demonstrate a facile pressure-induced methodology to generate a cost-effective heterogeneous electrocatalytic metal hydride surface for sustainable hydrogen transfer. [ABSTRACT FROM AUTHOR]

The preparation method of transmission electron microscopy (TEM) samples for pure zirconium was successfully executed using a focused ion beam (FIB) system. These samples unveiled artifact hydrides induced during the FIB sample preparation process, which resulted from stress damage, ion implantation, and ion irradiation. An innovative solution was proposed to effectively reduce the effect of artifact hydrides for FIB-prepared samples of hydrogen-sensitive materials, such as zirconium alloys. This development lays the groundwork for further research on the micro/nanostructures of zirconium alloys after ion irradiation, thereby facilitating the study of corrosion mechanisms and the prediction of service life for nuclear fuel cladding materials. Furthermore, the solution proposed in this study is also applicable to TEM sample preparation using FIB for other hydrogen-sensitive materials such as titanium, magnesium, and palladium. [ABSTRACT FROM AUTHOR]

This document discusses the importance of renewable and sustainable energy sources in light of the negative impact of fossil fuels on climate change. It focuses on the development of advanced catalytic materials for fuel cells, batteries, electrolysers, and solar cells. The research explores various types of fuel cells and investigates the mechanisms and kinetics of energy conversion reactions. Specific contributions include the oxidation of borohydride and the oxygen evolution reaction. The document also explores the use of PET bottle waste and perovskite-structured catalysts for energy conversion. The goal is to develop cost-effective and efficient catalysts for renewable energy generation and storage. The article discusses several studies on the development of catalytic materials for energy conversion reactions. These studies highlight the importance of diverse catalysts in renewable energy applications. [Extracted from the article]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

There are many papers concerning H in Pd alloys but their corresponding para-equilibrium phase diagrams have not been given. Para-equilibrium is the most common condition under which data are obtained for Pd alloy-H systems and refers to the condition where the mobile interstitial species (H) reaches equlibrium within an immobile metal alloy framework. Based on these para-equilibrium phase diagrams, an explanation will be offered for the experimental observation that the terminal hydrogen solubilities are always greater in fcc, substitutional Pd alloys than in Pd itself where this term refers to the limiting solubility of H in the dilute phase before the hydride phase forms. [ABSTRACT FROM AUTHOR]

Batteries have been extensively used in many applications; however, very little is explored regarding the possible environmental impacts for their whole life cycle, even though a lot of studies have been carried out for augmenting performance in many ways. This research paper addresses the environmental effects of two different types of batteries, lithium-ion (LiIo) and nickel-metal hydride (NiMH) batteries, in terms of their chemical constituents. Life cycle impact analysis has been carried out by the CML, ReCiPe, EcoPoints 97, IPCC, and CED methods. The impacts are considered in categories such as global warming, eutrophication, freshwater aquatic ecotoxicity, human toxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity. The results reveal that there is a significant environmental impact caused by nickel-metal hydride batteries in comparison with lithium-ion batteries. The reason behind these impacts is the relatively large amount of toxic chemical elements which are present as constituents of NiMH batteries. It can be anticipated that a better environmental performance can be achieved through optimization, especially by cautiously picking the constituents, taking into account the toxicity aspects, and by minimizing the impacts related to these chemicals. [ABSTRACT FROM AUTHOR]