Grain Boundary Wetting by a Second Solid Phase in the High Entropy Alloys: A Review

In this review, the phenomenon of grain boundary (GB) wetting by the second solid phase is analyzed for the high entropy alloys (HEAs). Similar to the GB wetting by the liquid phase, the GB wetting by the second solid phase can be incomplete (partial) or complete. In the former case, the second solid phase forms in the GB of a matrix, the chain of (usually lenticular) precipitates with a certain non-zero contact angle. In the latter case, it forms in the GB continuous layers between matrix grains which completely separate the matrix crystallites. The GB wetting by the second solid phase can be observed in HEAs produced by all solidification-based technologies. The particle chains or continuous layers of a second solid phase form in GBs also without the mediation of a liquid phase, for example by solid-phase sintering or coatings deposition. To describe the GB wetting by the second solid phase, the new GB tie-lines should be considered in the two- or multiphase areas in the multicomponent phase diagrams for HEAs. The GB wetting by the second solid phase can be used to improve the properties of HEAs by applying the so-called grain boundary engineering methods.

Thermal analysis of Indonesian copper sulphide

The development of extracting hydrometallurgical process for copper sulphide mineral becomes one of the promising fields, not only for the copper production but also for the production of metal by-products. The advantage of the thermal analysis is to get the phase form of the minerals on a certain temperature. With this result, the chosen metal can be selectively extracted. The goal of this study is to understand the thermal reaction of the copper sulphide as the basic data to develop a process flowsheet of extracting copper and other important metals from the copper concentrates by using an alternative new hydrometallurgy process to increase the value of the minerals. The thermal behaviour was investigated by simultaneous thermal analysis consisting of differential scanning calorimetry (DSC) in combination with thermo gravimetry (TG) and fourier transform infrared (FTIR) spectroscopy. Samples were pre-treated by roasting at the several temperature transitions and subsequently characterized by XRD and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS).

Novel Orange Color Pigments Based on La3LiMnO7

La3LiMn1−xTixO7 (0 ≤ x ≤ 0.05) samples were synthesized by a solid-state reaction method, and a single-phase form was observed for the samples in the range of x ≤ 0.03. Crystal structure, optical properties, and color of the La3LiMn1−xTixO7 (0 ≤ x ≤ 0.03) samples were characterized. Strong optical absorption was observed at a wavelength between 400 and 550 nm, and a shoulder absorption peak also appeared around 690 nm in all samples; orange colors were also exhibited. Among the samples synthesized, the most brilliant orange color was obtained at La3LiMn0.97Ti0.03O7. The redness (a*) and yellowness (b*) values of this pigment were higher than those of the commercially available orange pigments. Therefore, the orange color of this pigment is brighter than those of the commercial products. Since the La3LiMn0.97Ti0.03O pigment is composed of non-toxic elements, it could be a new environmentally friendly inorganic orange pigment.

A Correction Method for Wet Gas Flow Metering Using a Standard Orifice and Slotted Orifices

Flow measurements that utilize differential pressure meters are commonly applied in industry. In such conditions, gas flow is often accompanied by liquid condensation. For this reason, errors occur in the metering process that can be attributed to the fluctuations in continuous phase parameters in the flow. Furthermore, the occurrence of a dispersed phase results in flow disturbance and dynamic pressure pulsations. For the above reasons, new methods and tools are sought with the purpose of performing measurements of gas-liquid flows providing measurement results that can be considered as fairly accurate in the cases when flow involves a liquid phase form. The paper reports the results of a study involving measurement of wet gas flow using differential pressure flowmeters. The experiments were conducted for three constant mass air flow rates equal to 0.06, 0.078 and 0.086 kg/s. After stabilization of the air flow rates, water was fed into the pipe with flow rates in the range from 0.01 to 0.16 kg/s. The research involved a standard orifice and three types of slotted orifices with various slot arrangements and geometries. The analysis focused on the effect of orifice geometry on the flow metering results. On the basis of the results, it was found that the slotted orifice generates smaller differential pressure values compared to the standard orifice. The water mass fraction in the gas leads to overestimated results of measurements across the flowmeter. Regardless of the type of the orifice, is necessary to undertake a correction of the results. The paper proposes a method of gas mass flow correction. The results were compared with the common over-reading correction models available in the literature.

INFLUENCE OF PRECURSES AND SOWING DATE ON OVER-WINTERING AND WINTER WHEAT PRODUCTIVITY UNDER CHANGING REGIONAL CONDITIONS

The research was carried out in order to determine the optimal time for sowing winter wheat according to various predecessors in the changing climate of Volga forest-steppe. The work was carried out in 2013–2019 in Ulyanovsk region on heavy loamy leached chernozem using conventional techniques. The experimental scheme provided for the study of two predecessors (peas and pure fallow) of winter soft wheat of Marafon variety, sown at 6 sowing dates with an interval of 10 days (from August 20 to October 10). The seeding rate for pure fallow is 5.0 million viable seeds per hectare, for peas - 5.5 million viable seeds per hectare. Average annual air temperature for 1961–2018 increased by 1.8°С. Its most significant increase was noted in the last twenty-five year period of time in the winter months. The increase in the frequency of extremely warm winters and temperature variability in the winter period significantly changed the conditions for overwintering winter crops. The danger of the development of wintering weeds, damping diseases, and soaking of winter crops has increased, and the conditions for overwintering pests have improved. It is possible to mitigate the danger of the natural and climatic vulnerability of crops during the wintering period by observing the optimal sowing dates, which should be postponed to a later period (7 ... 12 days), compared with the previously recommended ones. The optimal sowing period for winter wheat in Ulyanovsk region is from August 30 to September 10. Earlier crops are more intensively affected by diseases (powdery mildew and brown rust), and later crops, which have left in the winter in the germination phase, form a low density, form a small ear and provide low productivity or completely die

Surface Tension/Contact Angle Characters of Aprotic Binary Borneol-Dimethyl Sulphoxide Mixture

Borneol and dimethyl sulphoxide (DMSO) have been used as the skin penetration enhancers. Different concentrated borneol solutions in aprotic DMSO were prepared as the binary mixtures and determined their surface tension and contact angle behaviors using goniometer. Low borneol concentration minimized the surface tension and there was nearly stable contact angle for 30-70% borneol solutions. The trend contact angle value was decreased on glass slide, acrylic and LDPE whereas increasing on agarose gel and porcine tissues including buccal mucosa, gum and tongue with borneol concentration dependence. However, the borneol-DMSO binary mixture exhibited high wettability owing to its contact angle on glass surface was less than 90°. The solvent exchange between DMSO of borneol solutions and aqueous phase form agarose gel and porcine tissues including tongue, gum and buccal mucosa initiated the phase transformation from solution into matrix-like and promoted the higher contact angle with borneol concentration dependence. The understanding of surface tension and contact angle behaviors of aprotic borneol-DMSO binary mixture is useful for developing them into in situ forming gel for drug delivery such as in the oral cavity.

Crystal forms and phase transformation of 1,5-pentanediamine-terephthalate: a bio-based nylon 5T monomer

Nylon 5T is one of the bio-based nylons, its raw material 1,5-pentanediamine is derived from biomass resources and produced by biological methods. 1,5-pentanediamine-terephthalate (PDA-TPA) is the monomeric salt for nylon 5T polymerization, and its own product quality has a significant impact on the performance of nylon 5T. PDA-TPA was prepared by anti-solvent crystallization in this study. It exists in two solid forms, a monohydrate [form (I)] and an anhydrous phase [form (II)]. The transition temperature of the two phases was around 65°C in the given ethanol–water binary (7:1) mixture. The characterization of monohydrate and anhydrate phases regarding structures and stabilities was carefully carried out using powder X-ray diffraction, single crystal X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, hot-stage microscopy and Fourier transform infrared spectroscopy. The relationship between the molecular interactions of monohydrate and anhydrate phases under different packing architectures and their thermal behaviours was analysed and established. In addition, the relationships between the structures and thermal behaviours for the two solid forms were analysed and established. In addition, the effect of solvent on phase conversion, the relationships between the temperature and water activity, as well as the relative stability of monohydrate and anhydrate phases under different thermodynamic conditions, were investigated by solid–solid transformation and solvent-mediated transformation experiments. It was obvious that the transition temperature of monohydrate and anhydrate phases of PDA-TPA was significantly influenced by water activity, and the larger the value of water activity is, the higher is the transition temperature. These studies give insight into the transformation of nylon 5T monomer salt and contribute to the control of target crystal preparation.

Morphological and Structural Analysis of Nd1(Fe)0.2Ba1.8Cu3O7-δ Oxide Material

Nd1(Fe)0.2Ba1.8Cu3O7-δ oxide material have been successfully synthesized by solid-state reaction with modified heat treatment process to improve the heat time efficiency, calcination at 950°C for six hours, sintering at 975°C fo six hours, and annealing at 450°C for six hours, respectively. The X-ray diffraction pattern shows that a single-phase form of Nd1(Fe)0.2Ba1.8Cu3O7-δ is an orthorhombic (Pmmm) structure. The Rietveld refinement analysis found, the lattice parameter are a = 3.8758Å, b = 3.9101Å, and c = 11.7190Å with χ2 = 1.394%. The SEM-EDAX image shows that the samples are form clusters with size estimates of 10 - 40μm, and the elemental composition of the oxide materials is Ba rich.

Visualizing Interactions Between Liquid Propane and Heavy Oil

In this study, we use a custom-designed visual cell to investigate nonequilibrium interactions between liquid propane (C3(l)) and a heavy oil sample (7.2 deg API) at varying experimental conditions. We inject C3(l) into the visual cell containing the heavy oil sample (pressure-buildup process) and allow the injected C3(l) to interact with the oil sample (soaking process). We measure visual-cell pressure and visualize the C3/heavy oil interactions during the pressure-buildup and soaking processes. Nonequilibrium interactions occurring at the interfaces of C3(l)/heavy oil and C3(l)/C3(g) are recorded with respect to time. The results show that the complete mixing of heavy oil with C3(l) occurs in two stages. First, upward extracting flows of oil components from bulk heavy oil phase toward C3(l) phase form a distinguished layer (L1) during the soaking process. The extracted oil components become denser over time and move downward (draining flows) toward the C3(l)/heavy oil interface due to gravity. The gradual color change of L1 from colorless (color of pure C3(l)) to black suggests the mixing of oil components with C3(l). After L1 appears to be uniform, a second layer (L2) is formed above L1 in the bulk C3(l) phase. Extracting and draining flows become active once again, leading to the mixing of oil components from L1 into L2. At final conditions, heavy oil and C3(l) appear to be mixed and form a single uniform phase.

Macropinocytosis drives T cell growth by sustaining the activation of mTORC1

Macropinocytosis is an evolutionarily-conserved, large-scale, fluid-phase form of endocytosis that has been ascribed different functions including antigen presentation in macrophages and dendritic cells, regulation of receptor density in neurons, and regulation of tumor growth under nutrient-limiting conditions. However, whether macropinocytosis regulates the expansion of non-transformed mammalian cells is unknown. Here we show that primary mouse and human T cells engage in macropinocytosis that increases in magnitude upon T cell activation to support T cell growth even under amino acid (AA) replete conditions. Mechanistically, macropinocytosis in T cells provides access of extracellular AA to an endolysosomal compartment to sustain activation of the mechanistic target of rapamycin complex 1 (mTORC1) that promotes T cell growth. Our results thus implicate a function of macropinocytosis in mammalian cell growth beyond Ras-transformed tumor cells via sustained mTORC1 activation.