Melting Point Research Articles

Exploring synthesis techniques for an imidazole-based one-component epoxy latent curing agent: Chemical capping and mechano-chemical capsuling

The increasing demand for one-component epoxy is driven by its eco-friendliness, convenience, and cost-effectiveness, underscoring the importance of developing latent curing agents that trigger reactions under specific conditions. This study introduces an imidazole-based latent curing agent (ICM-SU) characterized by superior storage stability and low-temperature curing capabilities, achieved through dual protections of chemical capping and mechano-chemical capsuling. The process commences with the synthesis of isophorone diisocyanate capped 2-methylimidazole (ICM), wherein the reactivity of 2-methylimidazole (2MI) is controlled via the inductive effect of isophorone diisocyanate, achieved through chemical capping. Subsequently, ICM-SU is produced by uniformly coating it with silica nanoparticles and a urea shell through mechano-fusion system’s dry processing for mechano-chemical capsuling, effectively isolating it from contact with epoxy. The curing mechanism and chemical structure of ICM-SU are identified in four stages: de-capping, de-shelling, formation of epoxy-imidazole adducts, and chain growth. Notably, the melting point of the urea shell (122 °C) closely matches the curing onset temperature, suggesting that the exposure of epoxy to restored 2MI initiates the curing process. As a result, ICM-SU demonstrates significantly enhances storage stability at 20 °C for over 42 days, a stark improvement over 2MI, which solidifies within 8 h. Moreover, specimens cured with ICM-SU exhibits a 32 % increase in tensile strength and a 25 % improvement in Young’s modulus compared to those cured with 2MI, attributed to the reinforcing filler effect of silica nanoparticles.

Glass-ceramic binder of cordierite composition for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds

The mechanical properties of composite ceramic materials obtained based on oxygen-free silicon compounds are largely determined by the properties of the glass binder. This paper presents the results of studies aimed at determining the most fusible glass in the pseudo-binary system 2MgO2Al2O35SiO2–2MnO2Al2O35SiO2 with a high tendency to crystallize as a glass-ceramic binder for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds. The crystallization tendency of the experimental melts decreases with an increase in in the content of manganese cordierite, as confirmed by X-ray and infrared spectroscopic studies. Based on experimental studies, a melting diagram was constructed, which was used to determine the ratio between magnesium cordierite and manganese cordierite (50:50 wt.%), ensuring a minimum melt temperature of 12750C. The melting point of the glass of the specified composition is 14500C. The synthesized glass is characterized by a softening point of 8000C and crystallizes intensively at 10300C. The The thermal coefficient of linear expansion of the crystallized glass samples is 20.810–7 0C–1. X-ray diffraction and electron microscopic studies have shown that the developed glass is almost completely crystallized during heat treatment for 2 hours, forming a cordierite solid solution 2(Mg,Mn)O2Al2O35SiO2. The size of the cordierite phase crystals ranges from 0.5 to 3.0 m. Due to its fusibility and high crystallization tendency, the developed glass, can be proposed as a promising glass-ceramic binder for the production of high-strength ceramic materials (wear and impact resistant) based on SiC and Si3N4 with reduced sintering temperatures.

In situ iron coating of amorphous boron and characterization of its energy release behavior

Boron was widely employed as metal fuel in solid propellants for its higher gravimetric and volumetric combustion enthalpies. However, the low melting point and high boiling point of B2O3 on the surface of boron particles significantly hinder its ignition and combustion performance, seriously preventing the full realization of its thermodynamic potential. To address this issue, B@Fe composite fuels with different iron contents from 1.59 % to 7.09 % were prepared via liquid phase reduction in this paper and the quasi-static high temperature oxidation, ignition and combustion reaction characteristics and corresponding mechanism were studied, in order to provide effective modification techniques in supporting the large-scale engineering application of boron as metal fuel. The study results show that B@Fe can effectively reduce the ignition temperature and maximum heat flow temperature of amorphous boron, and increase the maximum mass gain rate. The ignition temperature and maximum heat flow temperature have an exponential function with the iron coating content. Iron coated amorphous boron can effectively shorten the laser ignition delay time by more than 50 %, and significantly change the flame structure, flame evolution process and combustion duration. Both amorphous boron and iron-coated amorphous boron flame showed a multi-layer structure, including the outer green flame, the middle yellow flame and the central incandescent flame. However, with the increase of the iron coating content, the flame height increased from 5.5 cm to 6.3 cm, the flame structure changed from mushroom type to triangle type, and the central incandescent flame area increased significantly. The equivalent combustion duration increased from 975 ms to 1997 ms, and the flame temperature increased from 1288 to 1505 °C. The emission spectra of BO2 and BO lines are captured during combustion. B@Fe with the increase of iron content, a large number of small diameter micropores appear in the condensed combustion products(CCPs) of composite fuels, and a grid-like structure was formed. With the increase of iron coating content, the boron content of condensed combustion products decreases, and the oxygen content increases. The main components of CCP include B, B2O3, B6O, FeB, Fe2B and Fe3B. Based on the ignition combustion experiment of B@Fe composite fuel, ignition combustion analysis model of B@Fe composite fuel was established.

Outer Helmholtz plane adsorption regulation to achieve low-concentration of pure propylene carbonate solvent electrolytes compatible with graphite anode

The low melting point and high polarity of propylene carbonate (PC) make it an ideal solvent for electrolytes of lithium-ion batteries (LIBs), but the incompatibility with graphite anode hinders the application. In the present study, a new method is developed to solve this problem from a new viewpoint. Introduction of saturated LiNO3 (0.14 mol L‒1) into pure PC electrolyte containing lithium salt with normal concentration (1.38 mol L‒1) leads to a perfect compatibility with graphite anode. Li/Graphite cell using this pure PC electrolyte shows a reversible capacity of 350.0 mAh g‒1 and a 200-cycle capacity retention of 96.3 %. Further mechanism study and theoretical computation indicate that the NO3‒ anions are adsorbed to outer Helmholtz plane of the electric double layer at the graphite anode interface. This changes the Li+ solvation structure in the electric double layer, facilitating the Li+ desolvation process hence resulting in high compatibility with the graphite anode. The most prominent advantage of the present strategy is that, because of the adsorption of NO3‒ anions to the outer Helmholtz plane, the compatibility with graphite anode could be improved by introduction of tiny amount of Li salt without large change of the bulk phase properties of the electrolyte. This work provides a new understanding of the compatibility from the viewpoint of outer Helmholtz plane, which might deliver new insights for the optimization of electrolytes for LIBs.

Improving strength and plasticity via pre-assembled dislocation networks in additively manufactured refractory high entropy alloy

Refractory high entropy alloys (RHEAs), as a novel class of multi-principal element alloys, have attracted significant attention owing to their excellent properties. However, their low plasticity limits their potential applications, while the high melting points of the alloying elements face challenges to additive manufacturing (AM). Herein, RHEA, with extensively distributed cellular structure within their grains, was successfully fabricated using AM. Furthermore, we proposed a simple strategy to form a complete dislocation network within the cellular structure region in advance through cyclic deformation processing in the elastic stage (microplastic deformation). Dislocation networks are entangled with other dislocations, creating numerous pinned points adjacent cell walls, which impede dislocation motion. As a result, the cyclic deformation processing of RHEA achieves a yield strength of 1136 MPa while maintaining 50% deformation strain without fracturing. The cyclic deformation processing method provides a route to strengthen additively manufactured alloys, offering a solution to overcome the trade-off between strength and plasticity.

Effect of Source-Sink Misalignment and Sink Cavity Aspect Ratio on the Thermal Performance of Gallium Heat Sinks

Herein, we numerically investigated methods to improve heat dissipation from the base of a phase-change material (PCM) heat sink exposed to high heat flux (15 W/cm2). The sink cavity exhibited a rectangular cross-section with two opposite vertical walls of high thermal conductivity. These walls serve as heat-dissipating fins. We used gallium, a metallic PCM with high thermal conductivity and a low melting point to improve heat dissipation by leveraging buoyancy-driven circulations within the molten gallium. We adopted a method to position the sink base on top of the heat source surface in such a way to augment temperature gradients within the liquid to induce imbalances in gallium density and consequent internal circulations. In this technique, one vertical wall is subjected to forced-convective heat exchange with the surroundings, while the other remains adiabatic. Subsequently, for the case which showed optimum performance, we relaxed the adiabatic thermal boundary condition applied at one of the vertical walls and replaced it with convective heat transfer condition, and assessed the sink performance based on that. Further, we analyzed the impact of various aspect ratios of the sink cavity on the induced internal circulations and base cooling. Sink cavities with aspect ratios of 1.33, 0.96, and 0.64 corresponding to sink heights of 20, 17, and 14 mm, respectively, were examined under a consistent heat flux applied across a 15-mm base length. We also investigated the precise positioning of the sink base relative to the heat source surface and explored its influence on temperature gradients and gallium density imbalances crucial for induced internal circulations. Results indicate that a sink cavity aspect ratio of 0.96 yields the optimal heat dissipation from the base. Further, aligning the left bottom edge of the sink base with the left edge of the heat source surface maximizes heat dissipation to the ambient surroundings, thereby prolonging latent-heat dumping into the sink before the gallium completely melts. Any misalignment between the sink base and the surface of the heat source may have a profound impact on the temporal evolution of induced internal circulations within the molten gallium, essentially affecting heat dissipation from the sink base.

High-entropy engineering improved the corrosion resistance of rare earth tantalates

High-entropy RETa3O9 ceramics have garnered significant interest in materials science due to their impressive high melting points and lower thermal conductivity. This study focuses on three types of these ceramics: (La0.2Ce0.2Nd0.2Sm0.2Dy0.2)Ta3O9, (La0.2Ce0.2Nd0.2Sm0.2Tm0.2)Ta3O9, and SmTa3O9.The results indicate that the coefficient of thermal expansion (TEC) for RETa3O9 ceramics remains in the range of approximately 5.94×10-6 K-1 to 6.05×10-6 K-1 when subjected to temperatures from room temperature up to 1400°C. This TEC is notably similar to that of silicon carbide ceramic matrix composites (SiC-CMC), which is essential for compatibility in applications where these materials are used together.Moreover, the study highlights an important finding: after 20 hours of exposure to a CMAS (calcium-magnesium-alumino-silicate) environment at 1300°C, the high-entropy tantalates exhibit significantly reduced susceptibility to corrosion compared to traditional single-component tantalate ceramics. While single-component materials, including SmTa3O9, showed greater degradation, the high-entropy RETa3O9 ceramics maintained their original morphology, free from porosity and cracking.This impressive resistance to CMAS corrosion indicates that the high-entropy design is beneficial in enhancing the durability of tantalates in extreme environments. Consequently, these findings suggest that high-entropy RETa3O9 ceramics hold promise for use as thermal/environmental barrier coating (T/EBC) materials in applications involving SiC-CMCs, potentially leading to improved performance and longevity in high-temperature applications.

Effects of La2Ce2O7 on the phase composition, microstructure, wetting behaviour and corrosion resistance of magnesia refractory

The addition of rare earth oxides has a significant impact on the improvement of thermal properties of refractory materials. Magnesia refractory with La2Ce2O7 was prepared by high-temperature solid-phase synthetic sintering at 1873 K for 5h using fused magnesia as raw materials, CeO2 and La2O3 as addition, respectively. The effect of La2Ce2O7 on the phase composition, microstructure, apparent porosity, bulk density, wetting behaviour and corrosion resistance with steel of fused magnesia were investigated. When the content of La2Ce2O7 was 20wt%, the results showed that as-prepared samples from fused magnesia with an apparent porosity of 17.63% and a bulk density of 3.11g·cm-3 were obtained by high temperature solid-phase sintering reaction at 1873 K for 5h, respectively. Due to the addition of La2Ce2O7, and raw materials in the impurity phase CaO and SiO2 for the reaction, the generation of a small amount of CaLa4(SiO4)3O and La8.89Si6O25.9 high melting point phase, plugging the air holes, thus improving the bulk density of the fused magnesia and reduce its apparent porosity. The ability of steel corrosion of as-prepared samples from fused magnesia doped with La2Ce2O7 have better resistance than conventional fused magnesia, which the thickness of the corrosion layer was reduced by 42.1% compared to as-prepared samples without La2Ce2O7.

Multicomponent crystals: Solubility enhancement of simvastatin using arginine and glycine coformers

Context: Simvastatin can be modified by the formation of multicomponent crystals to increase its solubility. Aims: To compare the solubility of multicomponent simvastatin crystals to pure simvastatin. Methods: The in silico study of simvastatin and the coformers arginine and glycine revealed non-covalent interactions, so multicomponent preparations of simvastatin crystals were prepared by solvent evaporation using a mole ratio of 1:1; 1:2 and 2:1. Results: Each simvastatin-arginine and simvastatin-glycine ratio increased the solubility, with the highest increase observed for the 1:2 ratio compared to pure simvastatin. Conclusions: Simvastatin-arginine multicomponent crystals (1:2) showed the best dissolution profile in phosphate buffer medium pH 7.0 with 67.69% dissolution, while simvastatin-glycine multicomponent crystals (1:2) exhibited the best dissolution profile in buffer media pH 1.2 with 16.19% dissolution. Characterization of the multicomponent crystals revealed a shift in the peaks, a decreased melting point, and enthalpy, indicating decreased % crystallinity and the formation of a new solid phase.

Retinol-Loaded Deep Eutectic Solvent emulsion: Improved Stability and Therapeutic Efficiency

Retinol is used to manage epidermal and keratin metabolism, promote collagen formation, erase wrinkles for firmer skin, and restore suppleness and smoothness. Retinol can be difficult to store and use owing to the potential for skin irritation, oxidation, and biological ineffectiveness. The linolenic acid and phosphatidylcholine deep eutectic solvent (DES) had a low melting point, high bioactivity, and integrated capsule technology for retinol encapsulation. Safety evaluation tests revealed that the formulated DES-retinol emulsion was less cytotoxic than free retinol, as well as less irritant toward chicken embryos, pig skin, and human patches. In a keratinocyte inflammatory factor inhibition assay, the DES-retinol emulsion reduced monocyte chemoattractant protein-1 expression, indicating the potential to reduce the inflammatory response of the skin to retinol-induced irritation. The DES-retinol emulsion exhibited pro-permeability, anti-wrinkle, firming, and antioxidant characteristics in cellular, skin, and clinical investigations. The DES-retinol emulsion promoted type I collagen production, suppressed matrix metalloproteinase-1 activity, and reduced the release of reactive oxygen species. Consequently, the quantity, size, and depth of wrinkles were substantially improved, along with an enhanced anti-aging effect, heightened skin hydration, increased collagen intensity and flexibility, and diminished retinol-induced irritation. In conclusion, the retinol-loaded linolenic acid and phosphatidylcholine DES emulsion exhibited improved stability, enhanced transdermal efficiency, and notable therapeutic effects.

L12 strengthening of WC-CoNiFe cemented carbides by spark plasma sintering

Binder phase has very significant effect on the growth of WC grains, grain morphology, the microstructure and properties of cemented carbide. In this paper, Co, Fe and Ni were used as binder phase, cemented carbides with different sintering temperatures were prepared by spark plasma sintering. The differences in the microstructure and properties of 10Co and 8Co-3NiFe were analyzed. The results showed that the 8Co-3NiFe cemented carbide generated the highly ordered FeNi3 phase with FCC of L12. The addition of Fe and Ni decreases the melting point of 8Co-3NiFe, makes the grain morphology of WC more rounded and more homogeneous distribution of the cemented carbide microstructure. The WC grain sizes of the 10Co and 8Co-3NiFe cemented carbides are very similar, but the 8Co-3NiFe cemented carbide shows a slight increase in grain size. Low-temperature densification of the 8Co-3NiFe cemented carbide can be achieved at sintering temperature of 1050°C. The fracture toughness of the 8Co-3NiFe cemented carbide improves by about 10% compared to the 10Co cemented carbide.

Alkylation of low eutectic energy-containing carrier molecules: Design and synthesis

A novel low eutectic energy-carrying carrier molecule has been developed that satisfies three criteria: intrinsic energy, effective lowering of the melting point of other carriers, and a wide range of thermal stability. In this study, two new compounds, APAD1 and APAD2, were synthesized by alkylation of molecular side groups and their structures were confirmed by FT-IR, NMR, and XRD. The melting points of APAD1 and APAD2 were 117 °C and 97 °C, respectively, and the decomposition temperatures were 266 °C and 242 °C, respectively, which were significantly lower compared to DATNEB. This method extends the synthesis of low eutectic carrier molecules for composite casting.

Ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chlorided: Synthesis and application for voltammetric determination of doxycycline in real samples

The study describes on the preparation of a new homobinuclear mixed ligand complex µ-ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chloridedihydrate (EP4Cu2CH2) from a previously reported complex chlorobis(1,10-phenanthroline)copper(II) chloridemonohydrate (CP2CuCH). The synthesis was checked by spectroscopy (UV–Vis, FT IR), CHN elemental analysis, Cu determination using ICP-OES, electrolytic conductivity, qualitative and quantitative chloride estimation, and melting point measurements. The new complex was applied for the modification of a glassy carbon electrode (poly(EP4Cu2CH2)/GCE) for determination of doxycycline (Doxy), (which belongs to a tetracycline antibiotic, mainly used for the treatment of a wide bacterial infections) by selective, accurate, and precise differential pulse voltammetric method. Electrode characterization revealed modification of the electrode surface by a conductive, and electroactive polymer film (poly(EP4Cu2CH2)/GCE) leading to improved effective electrode surface area. In contrast to the bare electrode, the appearance of two well-resolved irreversible oxidative peaks at much reduced potential with sevenfold current enhancement at poly(EP4Cu2CH2)/GCE showed the catalytic effect of the modifier towards Doxy. Differential pulse voltammetric current response of poly(EP4Cu2CH2)/GCE showed a linear dependence on the concentration of Doxy in the range 5 × 10−8 – 3.5 × 10−4 M with a detection limit of 3.5 × 10−9. The Doxy levels in four tablet brands were in the range 96.00–101.30 % of their labeled values. Spike recovery results in tablet, cow milk, and human urine samples were 98.90–100.73 %, 98.30–100.00 %, and 98.50–100.54 %, respectively. Based on the innovative mixed ligand poly(EP4Cu2CH2)/GCE, the interference recovery results about 4.79 % error, lesser LoD, and a broader concentrationrange than most previously published methods validated the present method’s potential applicability with excellent accuracy and sensitivity for Doxy determination in various real samples with complex matrix.

Hydrolysis of Poly(ester urethane): In-depth Mechanistic Pathway Determination through Thermal and Chemical Characterization

Many structure/property relationships of hydrolyzed poly(ester urethane) (PEU) – a thermoplastic polymer have been reported. Examples include changes in molecular weight vs. elongation at break and crosslink density vs. mechanical strength. However, the effect of molecular weight reduction on some physical, thermal, and chemical properties of hydrolyzed PEU have not been reported. Therefore, a large set of hydrolyzed PEU (Estane®5703) samples were obtained from two aging experiments: 1) accelerated aging conducted under various environments (air, nitrogen, moisture) and at 64°C and below for almost three years, and 2) natural aging conducted under ambient conditions for more than four decades. The hydrolyzed samples were characterized via multi-detection gel permeation chromatography (GPC), thermogravimetric analysis (TGA), modulated differential scanning colorimetry (mDSC), UV-vis spectroscopy, nuclear magnetic resonance (NMR), and Fourier-transform infrared (FTIR) spectroscopy techniques. Hydrolysis of ester linkages in the soft-segments decreases both the molecular weight of the polymer and the melting point of Estane from ∼55°C to 39°C. Aging above this melting temperature (Tm), increased mobility of polymer chains and water diffusivity alter the PEU degradation pathway from those expected at aging temperatures below Tm and have significant bearing on the critical molecular weight (MC) at which the physical, chemical, thermal, and mechanical properties of Estane change abruptly. While a MC value of 20 kDa is found for PEU hydrolysis at mild temperatures (e.g., below 39°C), the MC increases with increasing aging temperature. To complement the existing structure/property relationships reported in the literature, more correlations are obtained, which include the effect of Mw on polydispersity, intrinsic viscosity (Mark-Houwink equation), UV extinction coefficient, and dn/dc (GPC analysis) values. Furthermore, we seek to augment previously reported aging models for PEU by developing a practical model with which the extent of degradation and material performance can be predicted based on aging under different temperature ranges both above and below the melting point of the hard-segments.

Enhancing Solar Water Heater Performance Using Phase Change Materials and Modified Encapsulation Geometry

ABSTRACTSolar energy's abundant availability in India makes it a potential solution to meet increasing energy needs without harming environment. Solar water heating (SWH) systems are effective in converting solar radiation into heat for domestic and industrial applications. However, their inability to provide hot water during nighttime or off‐sunshine hours due to the intermittent nature of solar energy presents a challenge. Thermal energy storage, particularly using phase change materials (PCMs), has emerged as a solution. In this study, spherical ball‐type encapsulated PCM, specifically RT60, was incorporated into a solar water heater tank under variable atmospheric conditions. The PCM stores excess energy during daylight and releases it when the water temperature drops below the PCM's melting point. The results reveal a significant reduction in the temperature drop of water from 4.5°C to 1.4°C when utilizing PCM compared to conventional storage water tanks without PCM. Additionally, energy storage capacity is enhanced by 5.13% with PCM incorporation. Furthermore, modifying the encapsulation geometry to a rectangular shape enhances heat transfer and reduces temperature drop even further to 0.9°C, making it a promising approach to improving SWH system performance. This study highlights the possibility of enhancing encapsulation shape and applying PCM to enhance SWH system performance. The results highlight the possibility of increasing solar thermal systems' energy efficiency and usefulness, which will support sustainable energy sources.

The Effect of Process Parameters on the Pore Structure of Lotus-Type Porous Copper Fabricated via Continuous Casting

The pores in lotus-type porous copper are formed due to the difference in hydrogen solubility between the liquid and solid phases of copper. In a pressurized hydrogen atmosphere, hydrogen gas is released at the gas release and crystallization temperature, which is the melting point of copper. This study systematically analyzes the effects of process parameters, including hydrogen ratio, total pressure, and continuous casting speed, on the pore structure of lotus-type porous copper, with the aim of identifying the most critical process parameters for controlling pore diameter and density. Within the hydrogen ratio up to 50%, it was observed that as the hydrogen ratio increases, the pores tend to increase in porosity, and the pore diameter increases. As the hydrogen ratio increased from 25% to 50%, the pore diameter increased from 300 μm to 400 μm, while the pore density decreased from 3.3 N·mm−2 to 2.8 N·mm−2. As the total pressure increased, the pore diameter tended to decrease, and the pore density increased. Specifically, when the total pressure increased from 0.2 MPa to 0.4 MPa, the pore diameter decreased from 1100 μm to 400 μm, while the pore density increased significantly from 0.5 N·mm−2 to 2.8 N·mm−2. In addition, as the continuous casting speed increased, 30 to 90 mm·min−1, the pore diameter decreased from 850 μm to 400 μm, and the pore density increased from 0.7 N·mm−2 to 2.8. N·mm−2. Specifically, the increase in total pressure led to a decrease in Gibbs free energy and a reduction in the critical pore nucleation radius, which promoted pore formation and resulted in the creation of more, smaller pores. These results suggest that total pressure is the primary factor influencing both pore diameter and density in lotus-type porous copper.

Effect of Sintering Conditions on the Microstructure of an FeCrMnNiCo High-Entropy Alloy

We investigated the microstructure of an FeCrMnNiCo alloy fabricated by spark plasma sintering under different sintering temperatures (1000–1100°C) and times (1–600 s). All sintered alloys consisted of a single face-centered cubic phase. As the sintering time or temperature increased, the grains of the sintered alloys became partially coarse. The formation of Cr7C3 carbide occurred on the surface of the sintered alloys due to carbon diffusion from the graphite crucible. The depth of the layer containing Cr7C3 carbides increased to ~110 μm under severe sintering conditions (1100°C, 60 s). A molten zone was observed on the surface of the alloys sintered at higher temperatures (>1060°C) due to severe carbon diffusion that reduced the melting point of the alloy. The porosity of the sintered alloys decreased with increasing time at 1000°C, but increased at higher temperatures above 1060°C due to melting-induced porosity formation.

Electro-optical and thermal characterization of copper tartrate crystals grown in silica gel

Copper Tartrate crystals were grown by Gel Growth technique by single diffusion. Silica gel of Optimum specific gravity was set with tartaric acid at optimum pH and aging period. Band gap of copper tartrate crystal is determined using UV-Visible spectroscopy to be 5.24 eV. In PL spectra broad peak is observed at nearly 367.44186 nm in the range 287 nm to 458 nm along with the sharp, intense transmission maxima peak at wavelength nearly 505.03876 nm which is characteristic of a material composition and electronic band structure. This shows the transparency in UV-visible region and material is a filter in this range .TGA analysis concluded that Copper tartrate has one half water molecule as crystalline water and is stable up to 85.02 0 C.DSC analysis assigns the temperature value 314.5 0C as melting point and apparent enthalpy of fusion determined is 10.18 mW.

Synthesis and characterization of new organometallic lanthanides metal complexes for photodynamic therapy

New Schiff base ligand: 4-methoxy salicaldhyde-2-2-phenyl-hydrazono acetaldehíyde prepared by facile method. The molecular structures characterized by elemental analysis and proton magnetic resonance spectra (1H-NMR spectra). This spectra at the chemical shifts (3.5–10.39 ppm) confirmed the types and the numbers of protons. The sharp melting point at the range 110–112 °C confirmed purity. New optically active metal (samarium, terbium and gadolinium) complexes of the Schiff base synthesized in a one pot reaction. Vibrational IR spectra confirmed functional groups. Scanning electron microscopy micrographs confirmed that the modified microstructure of the metal complexes differed in morphology than the ligand. Powder X-ray diffraction patterns confirmed good crystalline structure. The optically activity of the solid metal complexes confirmed from electronic absorption spectra. The UV absorbance band at the wavelength range 280–390 nm and the intense phosphorescence bands up to 830 nm enabled application in photo dynamic therapy for apoptosis cancer cells by conversion triplet oxygen in the tissues into reactive singlet oxygen. Low charge transfer energy: 2.59–2.61 eV, high molar extinction coefficients (ε) at the order of magnitude \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:{10}^{6}$$\\end{document} M− 1 cm− 1 and the intense phosphorescence bands reflected good photodynamic activity. The metal complexes are thermally stable.

The effect of CD4 injection on WD molecule sputtering at the divertor target in EAST

Tungsten (W) is one of the preferred plasma-facing materials for future fusion reactors because of the advantages of high melting point, low physical sputtering rate and low fuel retention. The lifetime and service performance of W materials are limited by erosion processes. In recent years, tungsten deuteride molecular (WD) sputtering has been discovered in tokamak. Studying WD sputtering helps to better understand the erosion of tungsten materials in tokamak. EAST adopts the method of injecting impurity gas in the divertor to alleviate the particle flux and heat flux bombarding the tungsten divertor, and CD4 is one of the impurities used. CD4 injection experiments on EAST show that after CD4 is injected from the upper outer (UO) divertor target, despite that the electron temperature (Te) around the strike point on the UO divertor target drops to about 8 eV, strong WD sputtering occurs in the far scrape-off layer (SOL) region. The divertor probe data shows that after CD4 injection, the particle flux from the upstream plasma onto the divertor split into two bands, creating a new particle flux strike point in the far SOL region. The energy of incident particles at the original strike point is significantly reduced, while the energy of incident particles at the far SOL region is enhanced. The edge electron density profile at mid-plane indicates that CD4 injection causes an increase of density in the SOL, which could improve the coupling of Lower-Hybrid Wave (LHW) with the edge plasma as evidenced by the decreasing reflected power of LHW. The increase in absorbed power of LHW could change the particle and energy transport in the edge plasma, thus plays an important role in the enhanced WD sputtering in the far SOL region after CD4 injection.