First-principles search of hot superconductivity in La-X-H ternary hydrides

Motivated by the recent claim of hot superconductivity with critical temperatures up to 550 K in La + x hydrides, we investigate the high-pressure phase diagram of compounds that may have formed in the experiment, using first-principles calculations for evolutionary crystal structure prediction and superconductivity. Starting from the hypothesis that the observed Tc may be realized by successive heating upon a pre-formed LaH10 phase, we examine plausible ternaries of lanthanum, hydrogen and other elements present in the diamond anvil cell: boron, nitrogen, carbon, platinum, gallium, gold. We find that only boron and, to a lesser extent, gallium form metastable superhydride-like structures that can host high-Tc superconductivity, but the predicted Tc’s are incompatible with the experimental reports. Our results indicate that, while the claims of hot superconductivity should be reconsidered, it is very likely that unknown H-rich ternary or multinary phases containing lanthanum, hydrogen, and possibly boron or gallium may have formed under the reported experimental conditions, and that these may exhibit superconducting properties comparable, or even superior, to those of currently known hydrides.

Energy Production and vapor condensating in Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"

This paper aims to present the outline of two additional process for "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[1]. For more detail information refer to the article "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[1], the preprint "Detail Design - Linear Fresnel concentrator Steam Generator"[2] , the preprint Steam Flow formulation of the Linear Fresnel concentrator Steam Generator[3] and the preprint ‘Solar Heat Transfer formulation for the Steam generation from seawater based on Linear Fresnel Concentrator’[4].The first process is the condensation process which reuse an existing process. We recommend to use the HeatSink technology combined to cooling plate. For more information about this condensation process we can refer to this article ‘Improvement of condensation step of water vapor in solar desalination of seawater and the development of three-ply membrane system’[5]. The second process, which the innovation aspect for this paper, is to generate hydro-electrical energy from the condensate water in the first process.

Solar Heat Transfer formulation for the Steam generation from seawater based on Linear Fresnel Concentrator

The purpose of this paper is to formulate the heat transfer needed to generate continuously the steam from the “Linear Fresnel concentrator Steam Generator” according to its dimensions. For more detail information refer to the article "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[1], the preprint "Detail Design - Linear Fresnel concentrator Steam Generator"[2] and the preprint Steam Flow formulation of the Linear Fresnel concentrator Steam Generator[3]. The heat transfer flow assessment depending of many dimensions is the key point out put of this paper. At the glance, these dimensions are the geometry of the Linear Fresnel Concentrator, the tilt to the sun's rays, the length , the radius of the tangled cylinders, the thickness of the annulus spaces and the cavity between the composed device absorber and mirror. The device absorber is composed of the tangled cylinders and the steam collector. Note that the known LFR applications for both industrial and power sectors requires medium temperatures ranging from 100°C to 250°C. The flat plate solar collectors are suitable for low temperature applications maximum up to 80°C and parabolic concentrators are suitable for high temperatures applications above 300°C. Hence, the present work will focus on LFR with parabolic concentrator because sea water desalination requires reaching the boiling point under pressure near atmospheric pressure which is 100 °C. Furthermore, the diameter of absorber device for parabolic concentrator may vary from 5 in to 10 in which is much greater than tubes dimensions for trapezoidal cavity. Then, this dimension fact allows efficient flow water circulation and meaningful steam flow generation.[1] touzani, s. (2019, March 28). Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator. https://doi.org/10.31219/osf.io/dvr9y[2] touzani, s. (2020, September 12). Detail Design - Linear Fresnel concentrator Steam Generator. https://doi.org/10.31219/osf.io/wuq92[3] touzani, s. (2020, September 21). Steam Flow formulation of the Linear Fresnel concentrator Steam Generator. https://doi.org/10.31219/osf.io/ske5c

Steam Flow formulation of the Linear Fresnel concentrator Steam Generator

The purpose of this paper is to formulate the steam flow that will be generated by the “Linear Fresnel concentrator Steam Generator” according to its dimensions. For mor detail information refer to the article "Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator"[https://doi.org/10.31219/osf.io/dvr9y] and the preprint "Detail Design - Linear Fresnel concentrator Steam Generator"[https://doi.org/10.31219/osf.io/wuq92] . The steam Flow is the key point out put of this paper. It will allow to figure out the impact of the sea water desalination engine, its cost and its benefits.

Chemical composition, fatty acids and oil stability of Chrozophora brochiana (Vis.) Schweinf. seed germination

The chemical composition of seeds of Chrozophora brochiana (Vis.) Schweinf. as well as stability of the oil extracted from the seeds affected by germination have been investigated. C. brochiana seed was found to be a rich source of oil (42.9%) and protein (18.2%). Seed germination increased the moisture, protein, fiber and ash contents and decreased the fat and carbohydrate contents. The fatty acid composition was also influenced by germination where linoleic and oleic acids increased and stearic acid decreased. The concentrations of Na, K, Cu and Ca were higher in germinated seeds. FTIR spectroscopy was utilized to screen changes in the germinated and ungerminated seeds during the successive heating at 70°C for 72 hrs. It was found that the oil extracted from germinated seeds was oxidized faster than ungerminated seeds when subjected to successive heating.

Desalination of seawater by successive heating of thin layers of water using solar radiations from a Fresnel concentrator

The seawater desalination technique presented in this article is based on a new technique for the production of water vapor which has the advantage of using solar energy with maximum evaporation efficiency. This innovation is limited to the production of steam and can be combined with a known technique of condensation of the steam in order to complete the desalination cycle of seawater. This technique is based on the simple principle that the heat transferred from the hot source to the cold source is maximum if the difference between their respective temperatures is kept at its maximum. Thus, by carrying out successive operations of heating thin layers of water, the technique makes it possible to maximize the efficiency of the evaporation by bringing the temperature of the fluid to its initial value at each iteration, thus enabling, according to the Newton's law, to favor the transfer of heat to water.Then, in this paper, we present the theoretical demonstration of the soundness of this technique by using the analogy with electricity using the equivalent resistance for circuits in parallel. Next, an application of the technique which is the subject of a patent of invention is presented in the detal. It is a desalination engine for seawater using solar radiation from a Fresnel concentrator. The presented invention makes it possible to produce steam continuously by heating thin layers of sea water by the Fresnel concentrator. The development prospects of the invention are also presented using the techniques of Nanotechnology.

Study on Al-Si Alloys Properties Enhancement

The paper presents a study about aluminum alloy, allied with Si, Cu, Mn, Mg. The Al-Si-Cu-Mg alloys for foundry are used for parts strongly required and which work at high temperatures, due to their good wear resistance. The industrial Al-Cu alloys contain 12 % cooper, are hipo-eutectic and may be for foundry or deformable. By alloying with magnesium, the Al-Cu alloys become with remarkable properties of resistance and plastic deformation processing. The improvement of mechanical characteristics for Al-Si alloys is realized with metals which forms the intermediate phases with silicon or aluminum, with variable solubility in solid state and which permits the structural hardening by heat treatments (quenching and ageing). From the analysis of dilatogramms, grouped for each sample, with the specific initial length, subjected to successive heating, from ambiance temperature up to 500°C, it is found that, with the appearance of ageing phenomena, on the samples aren’t significant modifications for elongation (few microns), only different may be the form of elongation-temperature curve. This analysis permits the determination of experimental data, regarding the behavior of Al-Si alloy subjected to heat treatments and repeated warming. Therefore, the Al-Si-Cu-Mg alloys, for foundry, are used for manufacture the parts strong required and which work at high temperatures, like pistons for engines with internal burn, parts for machines and reinforcements construction, due to their high usage resistance.

Synthesis of Ceramics in Different Colors from Industrial Waste

The synthesis of arsenic-free ceramics from industrial waste is studied. Samples of waste containing siliceous material passed the exploitation leap-guard layer shift reactor whose main oxide is -Al2O3and, with the addition of natural raw materials and pure oxide, arsenic-free ceramics were synthesized with thermal and electrical properties related to the main phase of spinel group minerals; solid solutions were also formed in the process of synthesis. Insulating properties were established by successive heating and cooling of the specimen for six cycles. Electrical insulating properties were established by the method of resistance to arcing. The relative density was determined by hydrostatic method and diffusion lines of molecules at the main phase were characterized by X-ray diffraction analysis. The experimental procedures followed in this study allowed mixing on a molecular level due to the small dimensions of the crystallite which in turn explains the relatively high density.

Pertumbuhan Material Interlayer di Mineral Lempung Smekit di Tanah Leptic Hapludert yang Berkembang di atas Ca-Bentonit di Nanggulan Kulon Progo

The objective of this study was to understand the mineralogical characteristics of the bentonite and its upper developed soil, at Nanggulan Kulonprogo. Separation and collection of clay fraction were done by fractionation on suspension at pH 10 after organic matter was oxidized using H2O2. Characteristics of clay mineral was analyzed using X-ray diffraction on parallel oriented samples after Mg saturation, glycerol solvation, or K saturation, and its following successive heating at 100°C, 300°C and 550°C. Cation exchange capacity (CEC) and the exchangeable bases were analyzed using saturation of NH4OAc 1N pH 7. Results showed that clay materials of both samples were Ca-bentonite. Comparing with clay from soil, bentonite had peak intensity of the semctite minerals and low value of CEC and exchangeable Ca. Potassium saturation caused incompletely shrinkage of the studied smectite minerals, and it was reflected by a broader peaks at 13,11 Å. The presence of these broader peaks was interpreted as a growth of interlayer materials that it may alter to smectite-chlorite intergrade minerals.