Low Melting Temperature Research Articles

Removing Ti5Si3 phase in Ti alloy via desilication of upgraded titania slag using low-temperature alkali leaching

Silicon in two types of upgraded titania slag (UGS) containing different components was removed using a low-temperature alkali solution and melt leaching. The effects of temperature, time, and NaOH solution concentration on desilication rate were investigated. Desilication in melt can lead to the loss of titanium in upgraded titania slag. After agitating at a speed of 600 r/min and 80 °C for 300 min, the silicon content in domestic slag decreased from 0.96 wt.% to 0.29 wt.%, and the leaching rate was 69.8% after leaching in 4 mol/L sodium hydroxide solution. Under the same conditions, the silicon content in imported slag decreased from 1.11 wt.% to 0.12 wt.%, and the desilication rate was up to 89.2%. The alloy powders obtained from the reduction of upgraded titania slag with magnesium were sintered to produce titanium alloy, and the alloy was characterized. It was determined that the Ti5Si3 phase in the titanium alloy product was successfully eliminated. In addition, the two UGS materials and the chemical principle of desiliconization were analyzed using a thermodynamic software.

Development and characterization of a quaternary nitrate based molten salt heat transfer fluid for concentrated solar power plant

Over the past few years, there has been growing interest in using inorganic quaternary nitrate-based molten salt mixtures as a highly effective heat transfer fluid (HTF) for concentrated power plants, primarily because they can achieve low melting temperatures. However, the high viscosity of these salt mixtures is still a significant challenge that hinders their widespread adoption. The high viscosity leads to high pumping power requirements, which increases operational costs, and reduces the efficiency of the Rankine cycle. To address this challenge, this study developed and characterized a novel quaternary molten salt, focusing on the effect of LiNO3 additions on the salt's viscosity, thermal conductivity, melting point temperature, heat capacity, and thermal stability. The quaternary mixture comprised KNO3, LiNO3, Ca(NO3)2, and NaNO2, with varying percentages of each salt. The study utilized various standard techniques to examine the characteristics of the developed mixture. Results showed that increasing LiNO3 content led to a decrease in melting temperature, higher heat capacity, improved thermal stability, conductivity, and reduced viscosity at solidification temperature. The lowest endothermic peak for the new mixture emerged at 73.5 °C, which is significantly lower than that of commercial Hitec and Hitec XL, indicating better potential for use as a heat transfer fluid for concentrated solar thermal power plant applications. Furthermore, the thermal stability results showed high stability up to 590 °C for all the samples examined. Overall, the new quaternary molten salt shows promise as a potential replacement for current organic synthetic oil, offering a more efficient solution.

Synthesis and characterization of novel (S)-5′-C-aminopropyl-2′-fluorouridine modified oligonucleotides as therapeutic siRNAs

The lack of stability of natural nucleosides limits their application in small interfering RNA (siRNA)-mediated RNA interference (RNAi). Various chemical modifications have been reported to improve their pharmacokinetic behavior; however, the development of potential candidates is still underway. In this study, we designed and synthesized (S)-5′-C-aminopropyl-2′-fluorouridine (5′-AP-2′-FU) and evaluated the properties of siRNAs containing this analog. A comparative thermodynamic study revealed the enhanced thermal stability of double-stranded RNAs (dsRNAs) containing 5′-AP-2′-FU in a position-specific manner, whereas (S)-5′-C-aminopropyl-2′-O-methyluridine (5′-AP-2′-MoU)-modified dsRNAs exhibited lower melting temperatures. This improved thermal stability of RNA duplexes is attributed to favorable entropy loss, which induces the duplex into an N-type (C3′-endo) conformation and enhances duplex binding in this case. The 5′-AP-2′-FU analog was also suitable for incorporation into the passenger strand to induce gene-silencing activity. Gene knockdown efficacy was comparable to that of unmodified siRNAs, and the best response was observed by introducing 5′-AP-2′-FU near the 3′-terminal end of the passenger strand. In addition, the single-stranded RNAs (ssRNAs) modified with 5′-AP-2′-FU showed strong resistance against decomposition by nucleases when treated with buffer containing bovine serum, which was similar to 5′-AP-2′-MoU.

Effective Removal of Methyl Orange Dyes Using an Adsorbent Prepared from Porous Starch Aerogel and Organoclay

Intending to provide efficient and compact wastewater remediation, the present work is exploiting and introducing a novel composite prepared from porous starch aerogel (PSA) and organically modified Ca-montmorillonite (OMMT) for the removal of dyes from aqueous samples. First, potato starch components were used as a hydrolysis precursor to obtain PSA. The organoclay samples were prepared by co-intercalation of octadecylamine (ODA) into Ca-MMT using a low-temperature melting procedure. Composites with different starch-to-organoclay ratios of 10:1, 1:1, and 1:10 were then prepared by a blending process in distilled water and used for methyl orange (MO) uptake. The removal of methyl orange dyes increased with the amount of organoclay in the PSA matrix. Characterization revealed that organoclay synergy improved the PSA surface chemistry, while an important improvement in textural properties and thermal stability was also observed. The composite’s efficiency was demonstrated by high removal capabilities towards MO in most experimental runs, with a maximum adsorption capacity beyond 344.7 mg/g. The fitting result showed that MO adsorption follows a monolayer adsorption model, and chemisorption was the rate-controlling step. Nonetheless, this study proved the great potential of PSA/OMMT in dyeing wastewater treatment. Furthermore, starch modification is proven as an effective approach to enhancing the performance of starch-derived adsorbents.

Geochemistry of Trace Elements in Minerals of Porphyritic and Nonporphyritic Chondrules from Equilibrated Ordinary Chondrites

The paper presents the results of SIMS and EPMA studies of silicate minerals and bulk compositions (SEM-EDS) of porphyritic and nonporphyritic chondrules from equilibrated ordinary chondrites. The trace-element distribution in olivine, low-Ca pyroxene, and mesostasis of porphyritic and nonporphyritic chondrules in the equilibrated ordinary chondrites reflects heterogeneous conditions of chondrule-forming processes in the protoplanetary disk and provides insight in their evolution. The porphyritic chondrules are composed of olivine with the low content of Y and Yb relative to nonporphyritic chondrules. The enrichment of low-Ca pyroxene from porphyritic chondrules in trace elements correlates with the amount of pyroxene in the chondrule. Olivine composition in granular chondrules is close to that of porphyritic chondrules, but low-Ca pyroxene is distinguished by the high content of Y, Ti, Sr, Ba, V, and REE compared to all other chondrules. Barred chondrules are characterized by olivine enriched in trace elements (Zr, Y, Ti, Ba, Cr, and HREE) and low-Ca pyroxene highly depleted in trace elements (Zr, Y, Nb). The pyroxene of radial chondrules is enriched in Nb, Sr, and Ba. Trace elements in olivine and low-Ca pyroxene indicate the formation of the porphyritic and granular chondrules in a stable region of the protoplanetary disk, which is responsible for low-temperature heating and slow cooling of a chondrule. Trace element enrichment of olivine from the barred chondrules testifies strong heating of a precursor material and rapid cooling of the chondrule melt. Mineral composition of radial chondrules demonstrate rapid cooling of a low-temperature melt depleted in Mg and trace elements. High melt temperatures of barred chondrules and rapid cooling of nonporphyritic chondrules indicate their formation in an unstable region of the protoplanetary disk. Trace elements in silicate minerals of porphyritic and nonporphyritic chondrules reflect their formation as a result of melting of precursor minerals.

Mechanical Properties of the (81Sn–xCu–(19-x) In) % Alloys with x=1, 2, 3, 4, and 5

Research on Material Science has a long tradition, and lead has been used widely in many applications. Because of their low melting temperatures, low cost, and good wettability, tin -lead alloys have been preferred as solder alloys in industrial production, particularly in the electronics sector. However, due to the negative effects of lead on the environment and human health, studies on lead-free solder alloys have been increasing, and the subject is still important today. Furthermore, environmental protection agencies (RoHS and WEEE) have prohibited the use of lead-containing solder alloys in the manufacture of electronic and microelectronic products. In this work, the effect of adding Cu to alloys in five compositions of (81Sn-xCu-(19-x)In) % with x=1, 2, 3, 4, and 5 on the mechanical properties has been studied. The five samples were prepared from high purity (99%) elements (Sn –Cu –In ) using the melting technique. The creep of the ternary alloys was examined at different temperatures (25, 50, and 80 ) under three different loads (2.5, 6.3, and 11.4 MPa). It was found that the creep rate of the ternary alloys was increasing with the increases in Cu –content in all samples at different temperatures and loads. The mean values of the stress exponent were found to be in the range of (0.1-2.5) as well as the activation energies vaied in the range of (0.48-5.33) eV for all alloys under different loads (2.5, 6.3, and 11.4 MPa).

Novel soda lignin/PLA/EPO biocomposite: A promising and sustainable material for 3D printing filament

Polylactic acid (PLA) has been extensively used in 3D printing due to its low melting temperature and minimal warping. This study investigated the reinforcement of PLA filament with soda lignin from oil palm empty fruit bunches (OPEFB) in the presence of epoxidised palm oil (EPO) as 3D printable filament. The alkaline extraction method was carried out used sodium hydroxide (NaOH), followed by precipitation with mineral acids utilising one-factor-at-a-time (OFAT). The highest extraction yield was 30 % using 1 M NaOH and 20 % phosphoric acid. Fourier transforms infra-red (FTIR) confirmed the removal of lignin in the absence of 1740 cm⁻1 and 1513 cm⁻1 peaks. Scanning electron microscopy images revealed rough surface and less voids observed at the cross-section of filament. The addition of 1 phr lignin and 5 phr EPO (PLAE1) showed improvement in thermal and mechanical properties, with higher Tₒ around 5 °C and 10 % crystallinity. Brittleness is reduced by 5 % for PLAE1 compared to unfilled PLA due to increase of elongation at break. Rheology analysis revealed that PLA/lignin filament appeared to be more viscous, shown by lower complex viscosity of roughly 100 Pa compared to 800 Pa for PLA at 1 rad/s. PLAE1 exhibiting decreased in brittleness by 4 %, and high impact strength of 37 %. Dynamic mechanical analysis revealed that PLAE1 had lower rigidity than unfilled PLA with lower damping factor and storage modulus of 1.67 and 1.54 GPa. The findings revealed that the PLAE1 biocomposite has potential as alternative filament for sustainable 3D printing.

Green Strategy for Improving the Formation of Reconstituted Wood-Based Composites

In this study, a novel strategy inspired by the low melting temperature of a deep eutectic system (DES) was proposed to improve the efficient formation of reconstituted wood-based composites prepared via hot pressing. Hydrogen bond acceptors were used to prepare DES with lignin and hemicelluloses in a wood matrix in situ to achieve this goal. The feasibility and performance mechanism of this method were investigated in depth. Results show that the glass-transition point, Tg, of the amorphous components could reduce by more than 30 °C after the formation of DES. The dimensional stability and mechanical performances of the reconstituted wood-based composites were synchronously improved. The uniform bonding structure formed due to the efficient distribution of amorphous components (lignin and hemicelluloses) between the bonded interface driven by low-temperature melting of DES was an important reason for this phenomenon. In addition, the re-condensation of the degradation products of the amorphous components in wood also contributed to this. The consumption of a synthetic adhesive for wood interface bonding will be reduced in this situation. This work created a revolutionary approach for the preparation of green wood-based composites.

Influence of Triple Sintering Additives (BaO-CuO-B2O3) on the Sintering Behavior and Conductivity of the Proton-Conducting BaZr0.1Ce0.7Y0.2O3−δ Electrolyte Sintered at 1150 °C

The effects of multiple sintering additives BaO-CuO-B2O3 on the sintering behavior, microstructure, and electrochemical performance of BaZr0.1Ce0.7Y0.2O3−δ (BZCY) as an electrolyte were investigated for intermediate temperature solid oxide fuel cell application. BZCY was prepared by adding 0, 1, 2, and 3 mol % sintering additives through the freeze-drying method. Microstructure analysis and shrinkage measurement reveal that BZCY with 3 mol % sintering additive effectively reduces the sintering temperature to 1150 °C. BZCY pellets with 3 mol % sintering additives sintered at 1150 °C for 8 h increased the linear shrinkage from 2.6 to 17.0%. Thermochemical analysis reveals that the low melting temperature eutectic phase formation resulted in liquid-phase sintering, which supports the rearrangement and densification of BZCY particles. BZCY with 3 mol % sintering additives presented a proton conductivity of 0.016 S cm–1 and good durability at 600 °C with a low activation energy of 0.44 eV and low grain boundary resistance.

Nickel complexes bearing substituted 2-(naphthylen-1-yl)iminopyridines as catalysts for the formation of highly branched unsaturated PE waxes

A set of six 2-iminopyridine-nickel(II) complexes, [2-{C(Me)=NAr}C5H4N]NiCl2 (Ar = 1-C10H7Ni1, 2-Me-1-C10H6Ni2, 2-(CHMePh)-1-C10H6Ni3, 4-(NNC6H5)-1-C10H6Ni4, 4-(NNC6H4-4-Me)-1-C10H6Ni5, 4-(NNC6H4-4-F)-1-C10H6Ni6), all N-functionalized with naphthalen-1-yl or its substituted alkyl or aryldiazenyl derivatives, have been readily synthesized from their corresponding free N,N-ligand, L1 – L6. On crystallization of Ni3, the chloride-bridged trimetallic species, [(L3)3Ni3Cl6(OH2)], was identified as an aqua adduct by single crystal X-ray diffraction. When activated with either MAO or MMAO, high catalytic activity for ethylene polymerization was achieved using Ni1–Ni6 (up to 10.1 × 106 g (PE) mol−1 h−1 for Ni3/MAO), affording low molecular weight polyethylene (Mw range: 0.81–3.50 kg mol−1) with low melting temperature and narrow dispersity. 13C NMR spectroscopic analyses of these polyethylenic waxes revealed the formation of branched macromolecules with branching densities up to 69 per 1000 carbons. Further analysis revealed these polymers to contain predominantly methyl branches (%Me range: 7.8–9.0), with lower levels of longer chain branching and some branch-on branch structure (%sec-Bu range: 0.07–0.12%). Moreover, their 1H and 13C NMR spectra showed various levels of unsaturated functionality in the form of terminal and internal olefins.

Effect of nonwoven interlayer melting temperature and matrix toughness on mode I and mode II fracture toughness of carbon fiber/benzoxazine composites

Two toughening approaches were investigated in this study to improve the interlaminar fracture toughness (ILFTs) of carbon fiber/benzoxazine composites. A matrix modification as well as an incorporation of thermoplastic polyamide (PA) veils were utilized to investigate the change in the ILFT properties. Two PA veils with different melting temperatures were analyzed and the ILFT properties of the resultant laminates were determined by the Mode-I and Mode-II critical strain energy release rates (GIC and GIIC). The incorporation of both veils was found to increase both GIC and GIIC performances. The veil with a lower melting temperature than the curing temperature of the resin resisted a Mode-I crack propagation better than the veil with a high-melting temperature. A significant increase in the GIC measurements could therefore be achieved with the use of the toughened matrix system. In the Mode-II ILFT testing, the high-melting temperature veil outperformed the low-melting temperature veil in resisting both crack initiation and propagation. No significant toughening improvement was observed with the use of a toughened matrix system in the Mode-II experiment. A combination between matrix toughening and interleaving with the high-melting temperature veil led to an enhancement in Mode-II properties. The fracture surfaces of the tested specimens were then examined for a determination of toughening effects of the interleaved veils on the composites.

Melting of Fe-bearing and Fe-free carbonated pelites under fluid-saturated conditions at 6 GPa

Abstract Although the induced melting of pelitic sediments, i.e. the devolatilization of hydrous and carbonate minerals, has been widely studied at fluid-undersaturated conditions, the flush dissolution of carbonated pelite has not been fully understood yet. In addition, the role of iron in the melting of carbonated pelite has not received much attention. To address these issues, we conducted two sets of experiments for carbonated pelite with an iron-bearing (LH-gloss) and an iron-free (LHIF-gloss) starting bulk composition at 5.5-6 GPa, 800-1600°C at fluid-saturated conditions. The phase assemblages for both experiments at 800°C are composed of garnet + clinopyroxene + coesite + kyanite + phengite + aragonite + magnesite ± lawsonite ± rutile. Higher jadeite component and lower diopside-hedenbergite solid solution (Di-Hdss) in omphacitic clinopyroxene are observed in the LH-gloss experiment; also, garnet remains stable to higher temperatures (800-1400°C) in the LH-gloss than in the LHIF-gloss (900-1200°C). Carbonate- and phengite-out temperature boundaries are overlapping in the respective system, with the temperature boundary in the LH-gloss (800-900°C) slightly lower than that in the LHIF-gloss experiment (900-1000°C). The different stability fields of volatile-bearing minerals can be ascribed not only to variable bulk XH2O [H2O/(H2O + CO2)], which in turn, depends on bulk H2O, CO2 and K2O contents, but also to bulk FeO*(Total Fe as FeO) content. Both the characteristic “fish egg” texture and the strong increase of the amount of dissolved solids in the liquid phase over a narrow temperature interval at 6 GPa testify the possible existence of supercritical fluid. The marked solvent power of supercritical fluid can explain the earlier disappearance of experimental products including phengite, aragonite and magnesite. For the produced liquid phase (supercritical fluid or melt), the K2O/Na2O weight ratio decreases, whereas that of the SiO2/CaO increases with increasing temperature, placing potassium-rich carbonatitic supercritical fluids in the low-temperature and sodium-rich (carbonated) silicate melts in the high-temperature sections of both systems. The produced ultrapotassic (supercritical) liquid, when liberated from the subducting slab, may evolve into a melt parental to carbonatites and possibly result in the formation of diamonds. While those (carbonated) silicate melts, especially for the more oxidized and buoyant ones produced by the melting of ferrous iron-depleted carbonated pelite, are expected to intensely interact with the peridotite during the upward migration, which could lead to the formation of the metasomatic garnet pyroxenite.

Kinetic characterization of phosphorus removal from the surface of metallurgical grade (MG) silicon droplets during electromagnetic levitation

In this study, the kinetic mechanism of phosphorus atoms removal under partial pressure condition was analyzed by developing a full-domain control model of phosphorus migration behavior in the liquid phase, at the liquid-gas interface, and in the gas phase. Simultaneously, the dephosphorization experiments of metallurgical grade silicon by electromagnetic levitation in different melting time and temperature were investigated to verify the model results. The results show that the limiting step for phosphorus atoms removal at lower melting temperatures (<1800 K) is the evaporation of phosphorus from the surface under finite vacuum conditions. When the system temperature increases (>1900 K), the limiting step becomes to phosphorus atoms diffusion within the boundary layer of liquid phase. In the melting temperature range 1823–2123 K, the total mass transfer coefficient predicted by EML refining model for P removal from Si melt has the following relationship with temperature: lnk(P)=−8.49−12609/T.

Modulating Liquid-Liquid Transitions and Glass Formation in Zeolitic Imidazolate Frameworks by Decoration with Electron-Withdrawing Cyano Groups.

The liquid phase of metal-organic frameworks (MOFs) is key for the preparation of melt-quenched bulk glasses as well as the shaping of these materials for various applications; however, only very few MOFs can be melted and transformed into stable glasses. Here, the solvothermal and mechanochemical preparation of a new series of functionalized derivatives of ZIF-4 (Zn(im)2, where im- = imidazolate and ZIF = zeolitic imidazolate framework) containing the cyano-functionalized imidazolate linkers CNim- (4-cynanoimidazolate) and dCNim- (4,5-dicyanoimidazolate) is reported. The strongly electron-withdrawing nature of the CN groups facilitates low-temperature melting of the materials (below 310 °C for some derivatives) and the formation of microporous ZIF glasses with remarkably low glass-transition temperatures (down to only about 250 °C) and strong resistance against recrystallization. Besides conventional ZIF-4, the CN-functionalized ZIFs are so far the only MOFs to show an exothermic framework collapse to a low-density liquid phase and a subsequent transition to a high-density liquid phase. By systematic adjustment of the fraction of cyano-functionalized linkers in the ZIFs, we derive fundamental insights into the thermodynamics of the unique polyamorphic nature of these glass formers as well as further design rules for the porosity of the ZIF glasses and the viscosity of their corresponding liquids. The results provide new insights into the unusual phenomenon of liquid-liquid transitions as well as a guide for the chemical diversification of meltable MOFs, likely with implications beyond the archetypal ZIF glass formers.

NbThermo: a new thermostability database for nanobodies.

We present NbThermo-a first-in-class database that collects melting temperatures (Tm), amino acid sequences and several other categories of useful data for hundreds of nanobodies (Nbs), compiled from an extensive literature search. This so-far unique database currently contains up-to-date, manually curated data for 564 Nbs. It represents a contribution to efforts aimed at developing new algorithms for reliable Tm prediction to assist Nb engineering for a wide range of applications of these unique biomolecules. Nbs from the two most common source organisms-llama and camel-show similar distributions of melting temperatures. A first exploratory research that takes advantage of this large data collection evidences that understanding the structural bases of Nb thermostability is a complex task, since there are no apparent differences in sequence patterns between the frameworks of Nbs with lower and higher melting temperatures, indicating that the highly variable loops play a relevant role in defining Nb thermostability. Database URL https://valdes-tresanco-ms.github.io/NbThermo.

Low-Cost, High-Sensitivity Paper-Based Bacteria Impedance Sensor Based on Vertical Flow Assay

This study proposes a low-cost, portable paper-fluidic vertical flow assay bacterium counter with high accuracy. We designed sensors with low fabrication costs based on e-beam evaporation and three-dimensional printing based on the impedance measurement principle. Interdigitated (IDT) electrodes were coated on the filter membrane by e-beam evaporation with a shadow mask. We could print wafer-scale frames with low melting temperature three-dimensional-printing materials for confining liquid bacterial samples within the IDT sensing region. This novel fabrication technique significantly reduced the chip’s cost to less than 1% of that of silicon-based chips. Two equivalent circuit models were proposed for different concentration ranges to analyze the principle of paper-based impedance bacterial sensors. We proposed an improved model based on the Randles model for low concentrations by considering the leaky double-layer capacitor effect and spherical diffusion from the nano-structural electrodes of the gold-coated filter membrane. The phenomenon in which charge transfer resistance, Rct, declines at high concentration ranges was found and explained by the pearl chain effect. The pearl effect could cause a false-negative at high concentrations. We modeled the pearl chain effect as an R and C, connected parallel to the low-concentration model. When users properly applied both models for analyses, this sensor could quantitatively measure cell concentrations from 400 to 400 M per milliliter with superior linearity.

Organic Cation Design of Manganese Halide Hybrids Glass toward Low‐Temperature Integrated Efficient, Scaling, and Reproducible X‐Ray Detector

AbstractZero‐dimensional (0D) structure‐based manganese metal halides (MHs) are believed to be the most promising candidates for the next‐generation X‐ray scintillators due to their intense radioluminescence and environmental friendliness. However, low‐temperature (&lt;180 °C), large‐area integration with more efficient X‐ray detection remains a tremendous challenge. Herein, from the perspective of cation (ionic liquids) structure design, the basic physical parameters of 0D MHs are regulated. And the calculations and experimental results demonstrate larger‐size cations that induce lower melting temperatures, larger exciton‐binding energies, larger ion migration energy, and tunable hardness, which are most desirable for MHscintillators. As a result, the champion materialHTP2MnBr4is achieved as glassy transparency wafer by low‐temperature (165 °C) melt‐quenching. Its application to X‐ray imaging features high spatial resolution (17.28 lp mm−1), scalability (&gt;30 × 30 cm2), and integration with strong coupling force. Furthermore, HTP2MnBr4 glass with reproducible properties demonstrates a high light yield (38 000 photon MeV−1), excellent irradiation stability, and low detection limit (0.13 µGy s−1). The authors believe this work will provide guidance for MHscintillators to further commercial applications.

Evaluation and analysis of the improvement in charging time for the high-power fast charging module using phase change material

The advancement of charging time for the fast charging piles facilitates the full adoption of EVs. The benefits of adding the suitable phase change material (PCM) to the thermal control system of the high-power fast charging power module are demonstrated in this experimental study. The effects of different PCM's melting temperature, thermal conductivity, and filling thickness on the improvement of charging time are explored, and the PCM melting rate is visualized to reveal the mechanism of PCM in improving the charging time. The results show that the extension in charging time of 2370 s is found for the charging power module coupled with PCM at the heat generating power of 15 W, and it is extended by 54% and 39% at heat generating power of 25 W and 35 W, respectively. The benefit of applying the PCM in the improvement of charging time for the charging power module is lessened with increasing the air velocity. The optimal PCM melting temperature is 47.5 °C, and it achieves the maximum charging time of 1540 s. The maximum available charging time is 1620 s at the filling PCM thickness of 5.5 mm. Also, the charging time is extended by 510 s when the thermal conductivity of PCM increases from 0.2 W/(m K) to 5 W/(m K). Increasing the heat generating power or decreasing the air velocity will shorten the completed melting time of the used PCM, and the initial melting time is also ahead. A faster PCM melting rate is observed at the lower PCM melting temperature and filling thickness, and this shortens the PCM latent heat role in the thermal control for the charging power module.

Modeling of the Phase Assemblage of the LiF–Li2CrO4–LiRbCrO4–LiKCrO4 Stable Tetrahedron of the Li+, K+, Rb+||F–, Quaternary Reciprocal System

Here, phase equilibria in a quaternary reciprocal system comprised of fluorides and chromates of lithium, potassium, and rubidium was studied. The phase assemblage of the system was partitioned to stable simplices. The Li–Li2CrO4–LiRbCrO4–LiKCrO4 stable tetrahedron was selected as the subject matter of this study due to its undoubted scientific importance. The analysis of the boundary elements predicted, and the DTA experimental study of phase equilibria in the system proved, that monovariant phase equilibrium L ⇄ LiF + α-Li2CrO4 + (LiKxRb1 – xCrO4)ss is realized in the system, described by line Е 397–Е 400; the characteristics of the minimum point of this monovariant equilibrium (Min◻ 367) were elucidated. The mass balance of the phase reaction for this point is presented. A 3D model of the phase assemblage of the system was designed based on experimental data. The system preserves the continuity of (LiKxRb1 – xCrO4)ss solid solutions. The mixture whose composition corresponds to point Min◻ 367 has a relatively low melting temperature and can serve as a material for new fusible electrolytes in chemical current sources; it can also be of interest as an electrolytic bath for recovery of metals from melts.

PCL and DMSO2 Composites for Bio-Scaffold Materials.

Polycaprolactone (PCL) has been one of the most popular biomaterials in tissue engineering due to its relatively low melting temperature, excellent thermal stability, and cost-effectiveness. However, its low cell attraction, low elastic modulus, and long-term degradation time have limited its application in a wide range of scaffold studies. Dimethyl sulfone (DMSO2) is a stable and non-hazardous organosulfur compound with low viscosity and high surface tension. PCL and DMSO2 composites may overcome the limitations of PCL as a biomaterial and tailor the properties of biocomposites. In this study, PCL and DMSO2 composites were investigated as a new bio-scaffold material to increase hydrophilicity and mechanical properties and tailor degradation properties in vitro. PCL and DMSO2 were physically mixed with 10, 20, and 30 wt% of DMSO2 to evaluate thermal, hydrophilicity, mechanical, and degradation properties of the composites. The water contact angle of the composites for hydrophilicity decreased by 15.5% compared to pure PCL. The experimental results showed that the mechanical and degradation properties of PCL and DMSO2 were better than those of pure PCL, and the properties can be tuned by regulating DMSO2 concentration in the PCL matrix. The elastic modulus of the composite with 30 wt% of DMSO2 showed 532 MPa, and its degradation time was 18 times faster than that of PCL.