Surface Penetration Research Articles

ASSESSMENT OF POTASSIUM SILICATE BASED SURFACE PENETRATION MATERIALS WITH LOW VISCOSITY IN THE REPAIR OF CONCRETE STRUCTURES

In recent years, surface penetration has attracted attention as a repair method for concretes structures. Silicate based penetration materials have been used in this method. In this study, visual appearance, water permeability, water absorption, water-vapor permeability, neutralization (carbonation) and chloride ion penetration testing of a silicate based surface penetration material are performed. The protection and waterproofing effects of a silicate based surface penetration material are evaluated based on the results. The silicate based surface penetration material penetrates deeply into the concrete surface, shows self-repair functionality, is effective to the neutralization (the carbonation) of the concrete and improves the performance of waterproofing. The penetration depth of the silicate based surface penetration materials plays an important role in the surface penetration method. Therefore, permeability testing of a mortar specimen, penetration depth testing of the mortar specimens with various silicate based surface penetration materials, viscosity testing of the materials and modelling of the one dimensional penetration into the mortar specimens are performed. The results of viscosity testing and coefficient of permeability suggest that these silicate based surface penetration materials will perform well surface penetration materials.

Microhardness and Penetration of Artificial White Spot Lesions Treated with Resin or Colloidal Silica Infiltration.

Infiltration of early enamel lesions by materials having remineralizing capacity seems to improve aesthetics and arrests caries progression. To evaluate and compare the surface microhardness and penetration depth of a low viscosity resin and colloidal silica nanoparticle infiltrates into artificially created white spot lesions. Forty extracted human central incisors were embedded in acrylic resin blocks exposing the labial surfaces of the crowns. The specimens were immersed in demineralizing solution for 96 hours to create white spot lesions on labial surfaces. The samples were then divided into two groups (n=20 each), where in Group 1-resin infiltration (ICON DMG, Hamburg, Germany) and Group 2-colloidal silica infiltration (Arrow Fine chemicals, Rajkot, Gujarat, India) was done. Samples were subjected to vicker's microhardness testing at baseline, after demineralization and after treatment with resin or colloidal silica infiltrates. Then, the crowns were sectioned longitudinally and penetration depth of the infiltrants was measured using confocal laser scanning microscope and compared the readings to lesion depth. All the collected data was subjected to statistical analysis using t-test. Resin infiltration group showed significantly greater increase in microhardness compared to colloidal silica infiltration (p=0.001). The percentage of penetration of the resin group was 67.14% and that of colloidal silica group was 54.53% indicating significant difference between the two. Resin infiltrates performed better in regaining the baseline microhardness and penetrating deep into the porous white spot lesions, when compared to colloidal silica infiltrates.

Stabilisation of periarticular fractures and osteotomies with a notched head locking T-plate.

To report the clinical outcomes and complications of small animals that had articular or periarticular fractures or osteotomies stabilised with a notched head locking T-plate. Medical records were searched retrospectively to identify animals that had a notched head locking T-plate used to stabilise a small articular or periarticular bone fragment. Nine dogs and two cats had an articular or periarticular bone fragment stabilised with a 2.0- or 2.4-mm notched head locking T-plate (12 procedures). The median body weight was 4.7 kg. The plate was modified by removing holes in 10/12 procedures and a combination of locking and non-locking screws were used in 7/12 procedures. All fractures or osteotomies progressed to clinical union. There were two intraoperative complications (intra-articular screw placement and overlong screw) and two postoperative complications (skin necrosis and stress protection) This study reports the successful use of a 2.0- or 2.4-mm notched head locking T-plate for articular or periarticular fractures or osteotomies in a variety of small-breed dogs and cats. Care must be taken to prevent inadvertent penetration of the articular surface, particularly in regions such as the proximal tibia. The ability to modify the plate dimensions intraoperatively proved beneficial in most cases.

Parameters and structure of lunar regolith in Chang'E-3 landing area from lunar penetrating radar (LPR) data

Chang'E-3 (CE-3) landed in the northwest Mare Imbrium, a region that has not been explored before. Yutu rover that released by CE-3 lander carried the first lunar surface penetrating radar (LPR) for exploring lunar regolith thickness and subsurface shallow geological structures. In this paper, based on the LPR data and the Panoramic Camera (PC) data, we first calculate the lunar surface regolith parameters in CE-3 landing area including its permittivity, density, conductivity and FeO+TiO2 content. LPR data provides a higher spatial resolution and more accuracy for the lunar regolith parameters comparing to other remote sensing techniques, such as orbit radar sounder and microwave sensing or earth-based powerful radar. We also derived the regolith thickness and its weathered rate with much better accuracy in the landing area. The results indicate that the regolith growth rate is much faster than previous estimation, the regolith parameters are not uniform even in such a small study area and the thickness and growth rate of lunar regolith here are different from other areas in Mare Imbrium. We infer that the main reason should be geological deformation that caused by multiple impacts of meteorites in different sizes.

Influence of spatially variable ground heat flux on closed-loop geothermal systems: Line source model with nonhomogeneous Cauchy-type top boundary conditions

Borehole heat exchangers (BHEs) utilize the shallow ground to extract geothermal energy. Mostly they are installed in urbanized areas, where the thermal regime is strongly influenced by pavements, buildings and other urban infrastructures. In order to account for the spatial and temporal variability in the above-ground urban temperatures, a new semi-analytical model with a Cauchy-type top boundary is introduced. With this model, it is possible to estimate the transient three-dimensional temperature field in the near-surface ground influenced by the interaction of BHEs, horizontal groundwater flow, land use type and associated surface air temperature (SAT). It is verified with a numerical model and sensitivity analyses are conducted to examine the relevance of the prevailing thermal regime. By adopting a dimensionless formulation, it is shown that the decoupling between temperature fields at the ground surface restraints heat fluxes and penetration depth of thermal signals above ground. A systematic comparison with traditional Dirichlet-type boundary conditions shows that a fixed temperature formulation generally overestimates the thermal effect of land surface signals on thermal plumes of BHEs. This is also addressed by investigating the ground energy balance during operation of the geothermal system.

Spin-orbit torque induced reversible coercivity change in Co/Pd multilayer thin films

Abstract In this work, we report reversible reduction in coercivity of Co/Pd multilayer thin films under high-density direct current biasing. We carried out in-situ focused magneto optic Kerr effect based hysteresis measurement while the specimen was under DC bias. The experiments show a reversible reduction in coercivity during the application of direct current. We propose this reduction occurs due to the field like spin-orbit torque generated by spin Hall effect. These results are further supported by the anomalous Hall effect measurement, which do not show any change in coercivity. The magneto-optic Kerr measurement probes the surface (penetration depth) whereas anomalous Hall effect is a bulk transport behavior. These complimentary measurements prove that the origin of spin-orbit torques in ferromagnetic metal/ heavy metal multilayer thin films is spin-Hall effect.

Diffusion of tebuconazole into softwood under ambient conditions and its distribution in freshly treated and aged wood

Due to the nonhomogeneous nature of wood, diffusion of preservatives is a complex, multifactorial process. A proper understanding of this process is essential for the development of enhanced wood treatment protocols ensuring long-term stability of wood products. In order to assess the effectiveness of commercially used wood preservative treatments, the penetration of a representative radiolabeled fungicide in softwood was measured and then modeled using a double-logarithmic model. The longitudinal and surface penetration of 14C-labeled tebuconazole (TAZ) dissolved in a naphtha-based solvent was investigated at ambient pressure and temperature. Solvent and TAZ time dependent diffusion coefficients were estimated employing both experimental and computational methods using solvent mass uptake data spanning 6months and complete TAZ immersion data spanning 3min. Results obtained by these two methods were matching for short treatment times suggesting that the bulk of the TAZ traveled together with the solvent. No TAZ redistribution was observed in treated wood samples upon laboratory aging for 6months other than subsurface evaporative losses.

Excitation of Bloch-like surface waves in quasi-crystals and aperiodic dielectric multilayers.

The existence of Bloch surface waves in periodic dielectric multilayer structures with a surface defect is well known. Not yet recognized is that quasi-crystals and aperiodic dielectric multilayers can also support Bloch-like surface waves. In this work, we numerically show the excitation of Bloch-like surface waves in Fibonacci quasi-crystals and Thue-Morse aperiodic dielectric multilayers using the prism coupling method. We report improved surface electric field intensity and penetration depth of Bloch-like surface waves in the air side in such structures compared to their periodic counterparts.

Reactivity with water vapor and hydrogen storage capacity of Be2Ti compound

Beryllium intermetallic compounds show a variety of excellent properties such as neutron multiplication, refractory function, hydrogen storage, and superconductivity. Be12M compounds (M = Ti, V, and Zr) have been investigated as neutron multipliers for fusion reactors, while Be17M2 compounds have been explored as refractory materials. Furthermore, Be2Ms are known to have Laves phases, which are characterized by an A2B type compound having high H2 gas storage potential. Because of its low density, the hydrogen properties of Be2Ms have attracted great interest from viewpoints of reactivity with H2O, trap site of hydrogen, and amount of H2 gas in this compound. However, few studies have dealt with Be2M, and its database remains unsatisfactory.Preliminary synthesis of a beryllium intermetallic compound (=Be2Ti) as a hydrogen storage material was conducted to clarify its reactivity with water vapor at high temperatures and high hydrogen storage capacity. X-ray diffraction profiles and electron-probe microanalysis results confirmed that the preliminary synthesis of single-phase Be2Ti by homogenization treatment and plasma sintering was successful. The hydrogen generation rate of Be2Ti by reaction with 1% H2O increased as the test temperature increased. High temperature exposure to H2O led to the formation of TiO2 on the surface. Furthermore, the hydrogen gas storage concentration of Be2Ti, evaluated using the pressure–concentration–temperature curve, was 0.56 wt.% (=0.125 H/M) at 298 K, which is relatively low considering that H2 pressure was increased up to 13 MPa. Based on additional pressure–composition–temperature measurements, it does not appear to have particle size dependence with regard to hydrogen capacity.A simulation based on first-principles calculation indicated the presence of two hydrogen trap sites, tetrahedral and center of triangle with solution energies of −0.52 and −0.05 eV, respectively, implying that the maximum trap site of hydrogen with 5.4 wt.%. This dissimilarity might be attributed to the fact that the Be2Ti sample contained a large fraction of surface oxide layer, which disturbed the surface penetration of hydrogen.

Inhibition of auxin transport and auxin signaling and treatment with far red light induces root coiling in the phospholipase-A mutant ppla-I-1. Significance for surface penetration?

When grown on a non-penetretable at a surface angle of 45°, Arabidopsis roots form wave-like structures and, in wild type rarely, but in certain mutants the tip root even may form circles. These circles are called coils. The formation of coils depends on the complex interaction of circumnutation, gravitropism and negative thigmotropism where – at least – gravitropism is intimately linked to auxin transport and signaling. The knockout mutant of patatin-related phospholipase-AI-1 (pplaI-1) is an auxin-signaling mutant which forms moderately increased numbers of coils on tilted agar plates. We tested the effects of the auxin efflux transport inhibitor NPA (1-naphthylphtalamic acid) and of the influx transport inhibitor 1-NOA (1-naphthoxyacetic acid) which both further increased root coil formation. The pPLAI-1 inhibitors HELSS (haloenol lactone suicide substrate=E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one) and ETYA (eicosatetraynoic acid) which are auxin signaling inhibitors also increased coil formation. In addition, far red light treatment increased coil formation. The results point out that a disturbance of auxin transport and signaling is one potential cause for root coils. As we show that the mutant pplaI-1 penetrates horizontal agar plates better than wild type plants root movements may help penetrating the soil.

Proton and hydrogen transport through two-dimensional monolayers

Diffusion of protons and hydrogen atoms in representative two-dimensional materials is investigated. Specifically, density functional calculations were performed on graphene, hexagonal boron nitride (h-BN), phosphorene, silicene, and molybdenum disulfide (MoS2) monolayers to study the surface interaction and penetration barriers for protons and hydrogen atoms employing finite cluster models. The calculated barrier heights correlate approximately with the size of the opening formed by the three-fold open sites in the monolayers considered. They range from 1.56 eV (proton) and 4.61 eV (H) for graphene to 0.12 eV (proton) and 0.20 eV (H) for silicene. The results indicate that only graphene and h-BN monolayers have the potential for membranes with high selective permeability. The MoS2 monolayer behaves differently: protons and H atoms become trapped between the outer S layers in the Mo plane in a well with a depth of 1.56 eV (proton) and 1.5 eV (H atom), possibly explaining why no proton transport was detected, suggesting MoS2 as a hydrogen storage material instead. For graphene and h-BN, off-center proton penetration reduces the barrier to 1.38 eV for graphene and 0.11 eV for h-BN. Furthermore, Pt acting as a substrate was found to have a negligible effect on the barrier height. In defective graphene, the smallest barrier for proton diffusion (1.05 eV) is found for an oxygen-terminated defect. Therefore, it seems more likely that thermal protons can penetrate a monolayer of h-BN but not graphene and defects are necessary to facilitate the proton transport in graphene.

Beryllium-7 and lead-210 chronometry of modern soil processes: The Linked Radionuclide aCcumulation model, LRC

Soil systems are known to be repositories for atmospheric carbon and metal contaminants, but the complex processes that regulate the introduction, migration and fate of atmospheric elements in soils are poorly understood. This gap in knowledge is attributable, in part, to the lack of an established chronometer that is required for quantifying rates of relevant processes. Here we develop and test a framework for adapting atmospheric lead-210 chronometry (210Pb; half-life 22years) to soil systems. We propose a new empirical model, the Linked Radionuclide aCcumulation model (LRC, aka “lark”), that incorporates measurements of beryllium-7 (7Be; half-life 54days) to account for 210Pb penetration of the soil surface during initial deposition, a process which is endemic to soils but omitted from conventional 210Pb models (e.g., the Constant Rate of Supply, CRS model) and their application to sedimentary systems. We validate the LRC model using the 1963–1964 peak in bomb-fallout americium-241 (241Am; half-life of 432years) as an independent, corroborating time marker. In three different soils we locate a sharp 241Am weapons horizon at disparate depths ranging from 2.5 to 6cm, but with concordant ages averaging 1967±4 via the LRC model. Similarly, at one site contaminated with mercury (HgT) we find that the LRC model is consistent with the recorded history of Hg emission. The close agreement of Pb, Am and Hg behavior demonstrated here suggests that organo-metallic colloid formation and migration incorporates many trace metals in universal soil processes and that these processes may be described quantitatively using atmospheric 210Pb chronometry. The 210Pb models evaluated here show that migration rates of soil colloids on the order of 1mmyr−1 are typical, but also that these rates vary systematically with depth and are attributable to horizon-specific processes of leaf-litter decay, eluviation and illuviation. We thus interpret 210Pb models to quantify (i) exposure of the soil system to atmospheric aerosol deposition in the context of (ii) organic carbon assimilation, colloid production, and advection through the soil profile. The behavior of some other elements, such as Cs, diverges from the conservative colloid behavior exemplified by Pb and Am, and in these cases the value of empirical 210Pb chronometry models like LRC and CRS is as a comparator rather than as an absolute chronometer. We conclude that 210Pb chronometry is valuable for tracing colloidally-mediated transport of Pb and similarly-refractory metals, as well as the mobile pool of carbon in soils.

Redefining the induction of periodontal tissue regeneration in primates by the osteogenic proteins of the transforming growth factor‐β supergene family

The molecular bases of periodontal tissue induction and regeneration are the osteogenic proteins of the transforming growth factor-β (TGF-β) supergene family. These morphogens act as soluble mediators for the induction of tissues morphogenesis sculpting the multicellular mineralized structures of the periodontal tissues with functionally oriented ligament fibers into newly formed cementum. Human TGF-β3 (hTGF-β3 ) in growth factor-reduced Matrigel® matrix induces cementogenesis when implanted in class II mandibular furcation defects surgically prepared in the non-human primate Chacma baboon, Papio ursinus. The newly formed periodontal ligament space is characterized by running fibers tightly attached to the cementoid surface penetrating as mineralized constructs within the newly formed cementum assembling and initiating within the mineralized dentine. Angiogenesis heralds the newly formed periodontal ligament space, and newly sprouting capillaries are lined by cellular elements with condensed chromatin interpreted as angioblasts responsible for the rapid and sustained induction of angiogenesis. The inductive activity of hTGF-β3 in Matrigel® matrix is enhanced by the addition of autogenous morcellated fragments of the rectus abdominis muscle potentially providing myoblastic, pericytic/perivascular stem cells for continuous tissue induction and morphogenesis. The striated rectus abdominis muscle is endowed with stem cell niches in para/perivascular location, which can be dominant, thus imposing stem cell features or stemness to the surrounding cells. This capacity to impose stemness is morphologically shown by greater alveolar bone induction and cementogenesis when hTGF-β3 in Matrigel® matrix is combined with morcellated fragments of autogenous rectus abdominis muscle. The induction of periodontal tissue morphogenesis develops as a mosaic structure in which the osteogenic proteins of the TGF-β supergene family singly, synergistically and synchronously initiate and maintain tissue induction and morphogenesis. In primates, the presence of several homologous yet molecularly different isoforms with osteogenic activity highlights the biological significance of this apparent redundancy and indicates multiple interactions during embryonic development and bone regeneration in postnatal life. Molecular redundancy with associated different biological functionalities in primate tissues may simply represent the fine-tuning of speciation-related molecular evolution in anthropoid apes at the early Pliocene boundary, which resulted in finer tuning of the bone induction cascade.

Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files.

AimTo evaluate the incidence of apical crack initiation during canal preparation with stainless steel K-files and hand protaper files (in vitro study).Materials and methodsSixty extracted mandibular premo-lar teeth are randomly selected and embedded in an acrylic tube filled with autopolymerizing resin. A baseline image of the apical surface of each specimen was recorded under a digital microscope (80×). The cervical and middle thirds of all samples were flared with #2 and #1 Gates-Glidden (GG) drills, and a second image was recorded. The teeth were randomly divided into four groups of 15 teeth each according to the file type (hand K-file and hand-protaper) and working length (WL) (instrumented at WL and 1 mm less than WL). Final image after dye penetration and photomicrograph of the apical root surface were digitally recorded.ResultsMaximum numbers of cracks were observed with hand protaper files compared with hand K-file at the WL and 1 mm short of WL. Chi-square testing revealed a highly significant effect of WL on crack formation at WL and 1 mm short of WL (p = 0.000).ConclusionMinimum numbers of cracks at WL and 1 mm short of WL were observed with hand K-file and maximum with hand protaper files.How to cite this articleSoni D, Raisingani D, Mathur R, Madan N, Visnoi S. Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files. Int J Clin Pediatr Dent 2016;9(4):303-307.

On the influence of surface tension during the impact of particles on a liquid-gaseous interface

A numerical study of the water entry of non-rotating and rotating rigid spheres under varying impact angles and Weber numbers is presented. The numerical algorithm uses a finite-volume discretization and the interface between the liquid and the gaseous phase is described by means of a volume-of-fluid method. An appropriate mesh translation allows the boundary condition at the surface of the moving and rotating particle to be accounted for. The simulation results are validated with experiments and found to be in very good agreement both qualitatively (evolution of cavity shape) and quantitatively (motion of particle with respect to time). An investigation of the influence of particle rotation on its water entry behavior is carried out as well as an analysis of the effect of wettability upon cavity formation. Notably, wettability of the sphere plays a role during the penetration of a free liquid surface, even at higher Weber numbers. During impact of small particles at low Weber numbers, the influence of capillary forces rises and the force emerging at the three phase contact line becomes predominant. This force is taken into account and its influence on the impact behavior is presented. It is shown that the interface penetration behavior, either water entry or escaping from water, mostly depends on the Weber number, the solid to liquid density ratio, and the particle’s wettability, while the impact angle has nearly no influence.

表面応力計測における圧子押込み法とX線回折法の差異について

In this study, the effect of machined surface layer on stress measurement by means of instrumented indentation technique and X-ray diffraction method was comparatively investigated through the use of three weld specimens of low-carbon austenitic stainless steel with different machined surface layers; as-cutout, mechanically-polished and electrolytically-polished specimens. Tensile and compressive stresses exist respectively in the machined surface layer of as-cutout and mechanically-polished specimens. Meanwhile, no stress and no machined surface layer exist in electrolytically-polished specimen. Tungsten Inert Gas (TIG) bead-on-plate welding was performed under the same welding heat input condition to introduce the residual stress into these three specimens. Against these three specimens, firstly the X-ray diffraction method was applied, then the instrumented indentation technique was applied and finally the stress relief technique was applied to measure the distributions of residual stress after welding. Based on a comparison between these stress measurement results, the instrumented indentation technique was in good agreement with the stress relief technique rather than the X-ray diffraction method, even though both machined surface layer and penetration of indenter had almost the same depths. That is why it can be considered that the instrumented indentation technique measures the residual stress in deeper areas of material surface than penetration depth of indenter. A distinction between the instrumented indentation technique and X-ray diffraction method in surface stress measurement was thus clarified from a viewpoint of measurement depth.

Phase equilibria of Ce–Mg–Ni ternary system at 673 K and hydrogen storage properties of selected alloy

The isothermal section of Ce–Mg–Ni ternary system at 673 K was constructed through thermodynamic calculation coupled with experimental verification. Under guidance of the phase diagram in Mg-rich corner, Ce2.92Mg91.84Ni5.24 was designed to investigate its hydrogen storage properties. Moreover, the mechanism of α-to-β (α: diluted phase and β: hydride) phase transformation in the Ce2.92Mg91.84Ni5.24–H2 system was elucidated by in situ synchrotron powder X-ray diffraction (SR-PXRD). The alloy showed a good activated ability and displayed two plateaus in the pressure–composition–temperature curves. The kinetic mechanisms of hydriding and dehydriding reactions were analyzed by Chou model. The rate-controlling steps were the diffusion for the initial stage in hydriding reaction and the surface penetration for dehydriding reaction. SR-PXRD patterns indicated that the activated Ce2.92Mg91.84Ni5.24 gradually transformed into CeH2.51, (Mg) (with solid solution of H atoms) and Mg2NiH0.3, finally transformed into CeH2.51, MgH2 and Mg2NiH4 during the first hydriding process.

A miniature microbial fuel cell with conducting nanofibers-based 3D porous biofilm

Miniature microbial fuel cell (MFC) technology has received growing interest due to its potential applications in high-throughput screening of bacteria and mutants to elucidate mechanisms of electricity generation. This paper reports a novel miniature MFC with an improved output power density and short startup time, utilizing electrospun conducting poly(3,4-ethylenedioxythiophene) (PEDOT) nanofibers as a 3D porous anode within a 12 μl anolyte chamber. This device results in 423 μW cm−3 power density based on the volume of the anolyte chamber, using Shewanella oneidensis MR-1 as a model biocatalyst without any optimization of bacterial culture. The device also excels in a startup time of only 1hr. The high conductivity of the electrospun nanofibers makes them suitable for efficient electron transfer. The mean pore size of the conducting nanofibers is several micrometers, which is favorable for bacterial penetration and colonization of surfaces of the nanofibers. We demonstrate that S. oneidensis can fully colonize the interior region of this nanofibers-based porous anode. This work represents a new attempt to explore the use of electrospun PEDOT nanofibers as a 3D anode material for MFCs. The presented miniature MFC potentially will provide a high-sensitivity, high-throughput tool to screen suitable bacterial species and mutant strains for use in large-size MFCs.

Phase Equilibria, Crystal Structure and Hydriding/Dehydriding Mechanism of Nd4Mg80Ni8 Compound.

In order to find out the optimal composition of novel Nd-Mg-Ni alloys for hydrogen storage, the isothermal section of Nd-Mg-Ni system at 400 °C is established by examining the equilibrated alloys. A new ternary compound Nd4Mg80Ni8 is discovered in the Mg-rich corner. It has the crystal structure of space group I41/amd with lattice parameters of a = b = 11.2743(1) Å and c = 15.9170(2) Å, characterized by the synchrotron powder X-ray diffraction (SR-PXRD). High-resolution transmission electron microscopy (HR-TEM) is used to investigate the microstructure of Nd4Mg80Ni8 and its hydrogen-induced microstructure evolution. The hydrogenation leads to Nd4Mg80Ni8 decomposing into NdH2.61-MgH2-Mg2NiH0.3 nanocomposites, where the high density phase boundaries provide a great deal of hydrogen atoms diffusion channels and nucleation sites of hydrides, which greatly enhances the hydriding/dehydriding (H/D) properties. The Nd4Mg80Ni8 exhibits a good cycle ability. The kinetic mechanisms of H/D reactions are studied by Real Physical Picture (RPP) model. The rate controlling steps are diffusion for hydriding reaction in the temperature range of 100 ~ 350 °C and surface penetration for dehydriding reaction at 291 ~ 347 °C. In-situ SR-PXRD results reveal the phase transformations of Mg to MgH2 and Mg2Ni to Mg2NiH4 as functions of hydrogen pressure and hydriding time.

Residents' journal review

Residents' journal review