Controlled Growth of Indium Selenides by High-Pressure and High-Temperature Method

The controlled growth of indium selenides has attracted considerable research interests in condensed matter physics and materials science yet remains a challenge due to the complexity of the indium–selenium phase diagram. Here, we demonstrate the successful growth of indium selenides in a controllable manner using the high-pressure and high-temperature growth technique. The γ-InSe and α-In2Se3 crystals with completely different stoichiometries and stacking manner of atomic layers have been controlled grown by subtle tuning growth temperature, duration time, and growth pressure. The as-grown γ-InSe crystal features a semiconducting property with a prominent photoluminescence peak of ∼1.23 eV, while the α-In2Se3 crystal is ferroelectric. Our findings could lead to a surge of interest in the development of the controlled growth of high-quality van der Waal crystals using the high-pressure and high-temperature growth technique and will open perspectives for further investigation of fascinating properties and potential practical application of van der Waal crystals.

Synthesis and Characterization of New Boron Compounds Using Reaction of Diazonium Tetraphenylborate with Enaminoamides

A family of oxazaborines, diazaborinones, triazaborines, and triazaborinones was prepared by reaction of polarized ethylenes, such as β-enaminoamides, with 4-methylbenzenediazonium tetraphenylborates. The reaction conditions (stirring in CH2Cl2 at room temperature (Method A) or stirring with CH3COONa in CH2Cl2 at room temperature (Method B) or refluxing in the CH2Cl2/toluene mixture (Method C)) controlled the formation and relative content of these compounds in the reaction mixtures from one to three products. Substituted oxazaborines gradually rearranged into diazaborinones at 250 °C. The prepared compounds were characterized by 1H NMR, 13C NMR, IR, and UV–Vis spectroscopy, HRMS, or microanalysis. The structure of individual compounds was confirmed by 11B NMR, 15N NMR, 1D NOESY, and X-ray analysis. The mechanism of reaction of enaminoamides with 4-methylbenzenediazonium tetraphenylborate was proposed.

Optimal Selection of Empirical Reference Evapotranspiration Method in 36 Different Agricultural Zones of China

The Food and Agriculture Organization has proposed the current version of the Penman–Monteith method (FAO56-PM) as the standard for calculating reference evapotranspiration (ET0); however, high meteorological data requirements limit its application in many areas. There is thus an urgent need to identify the best alternative empirical method to accurately calculate ET0 in regions that lack sufficient meteorological data. In this study, three temperature-based methods and five radiation-based methods were evaluated using ET0 values generated using the FAO56-PM method in 36 agricultural zones in China based on meteorological data from 823 stations, measured between 2011 and 2020. The results showed that the optimal temperature-based method and radiation-based method differed for different agricultural zones, and no one temperature method or radiation method could be suitable for all agricultural zones. The eight empirical methods were regionally calibrated to improve the ET0 calculation accuracy in the different zones. The relationship between the optimal methods and climatic conditions showed that the most reliable empirical method could be selected according to the local annual mean temperature and aridity index. The results provide useful guidance for the selection of reliable empirical ET0 methods in agricultural zones outside China.

Influence of the Self-Heating Temperature on the Cyclic Durability of Composite Materials

Постановка задачи. Для определения выносливости полимерных композиционных материалов используют различные методы ускоренных испытаний. Одним из таких методов является температурный, который имеет свои ограничения применения. Это подразумевает необходимость установления возможности его применения для эпоксидных полимерных материалов. Результаты. Предложена формула для определения величины усталостной долговечности эпоксидного композиционного материала, опытным путем установлена достоверность величин, рассчитываемых по данной формуле. Доказано, что интенсивность роста температуры зависит от скорости загружения. Выводы. Достоверность расчетов по предложенной формуле для расчета показателей усталостной долговечности подтверждена сравнением результатов с опытными данными, значения достаточно близко коррелируют, что позволяет применять эту формулу при расчете выносливости для образцов из эпоксидного композита. Statement of the problem. Various methods of accelerated testing are used to determine the endurance of polymer composite materials. One of these methods is the temperature method which has its own limitations of application. Thus the possibility of its application for epoxy polymer materials should be established. Results. The article proposes a formula for identifying the value of the fatigue life of an epoxy composite material. The reliability of the values calculated using this formula is experimentally established. It is proved that the intensity of the temperature increase depends on the loading speed. Conclusions. The reliability of the calculations according to the proposed formula for calculating the fatigue life indicators is confirmed by comparing the results with experimental data, the values are quite closely correlated, which allows us to use this formula when calculating the endurance for samples made of epoxy composite.

Modified Low-Temperature Extraction Method for Isolation of Bletilla striata Polysaccharide as Antioxidant for the Prevention of Alzheimer’s Disease

Amyloid-β (Aβ) peptides play a key role in Alzheimer’s disease (AD), the most common type of dementia. In this study, a polysaccharide from Bletilla striata (BSP), with strong antioxidant and anti-inflammatory properties, was extracted using a low-temperature method and tested for its efficacy against AD, in vitro using N2a and BV-2 cells, and in vivo using an AD rat model. The characterization of the extracted BSP for its molecular structure and functional groups demonstrated the effectiveness of the modified method for retaining its bioactivity. In vitro, BSP reduced by 20% reactive oxygen species (ROS) levels in N2a cells (p = 0.0082) and the expression levels of inflammation-related genes by 3-fold TNF-α (p = 0.0048), 4-fold IL-6 (p = 0.0019), and 2.5-fold IL-10 (p = 0.0212) in BV-2 cells treated with Aβ fibrils. In vivo, BSP recovered learning memory, ameliorated morphological damage in the hippocampus and cortex, and reduced the expression of the β-secretase protein in AlCl3-induced AD rats. Collectively, these findings demonstrated the efficacy of BSP for preventing and alleviating the effects of AD.

Characterization of Nickel Oxide Nanoparticles Synthesized under Low Temperature

In this study, ultrafine nickel oxide nanoparticles (NiO NPs) were well synthesized using a simple wet chemical method under low temperature, 300 °C. An Ni(OH)2 precursor was well precipitated by dropping NH4OH into an Ni(Ac)2 solution. TG-DTA showed that the weight of the precipitate decreases until 300 °C; therefore, the precursor was heat-treated at 300 °C. X-ray diffraction (XRD) patterns indicated that hexagonal-structured NiO NPs with (200) preferred orientation was synthesized. In addition, BET specific surface area (SSA) and HRTEM analyses revealed that spherical NiO NPs were formed with SSA and particle size of 60.14 m2/g and ca. 5–15 nm by using the low temperature method. FT-IR spectra of the NiO NPs showed only a sharp vibrating absorption peak at around 550 cm−1 owing to the Ni-O bond. Additionally, in UV-vis absorption spectra, the wavelength for absorption edge and energy band gap of the ultrafine NiO NPs was 290 nm and 3.44 eV.

A review of technical solutions for RCCI engines

Nowadays, internal combustion engines are being developed in the directions that allow to maximize the efficiency of their work, in order to make the most economical use of fuels. The low-temperature method of burning fuels in HCCI engines - Homogenous Charge Compression Ignition - allows to improve the efficiency of the engine, thanks to the reduction of energy lost during cobustion process. For the further development of engines with this type of mixture auto-ignition, with increasing the range of fuels used for that king of engines, it is necessary to develop the RCCI engines. Reactivity-Controlled Compression Ignition - RCCI - is the way to control the air-fuel mixture auto-ignition by using the injection of second fuel injected into the combustion chamber before the combustion begins. The development of modern compression ignition engines is strongly dependent on engines with this type of ignition. Using two fuels with different physicochemical properties makes it possible to control the time of compression ignition and allows to use engine in full range of operation. RCCI is a special type of HCCI engine that allows to use many types of fuels with high combustion efficiency and low emission of harmful exhaust components. The paper analyzes the issues related to the adoption and development of engines with this method of ignition.

Relationship between Spinal Anesthesia and Hypothermia Incidence among Post Operative Patients in the Operating Recovery Room "JIH" Hospital Yogyakarta

Introduction: Complications of surgery may lead the patient to experience ill and even death. One of the complications in the patient after surgery with spinal anesthesia is the incidence of hypothermia. Hypothermia can occur as a result of a combination of anesthesia and surgery that causes disturbance in body temperature regulation that can make decreasing body temperature. Method: This research uses a descriptive correlational method with a retrospective approach, with total sampling technique amount of 106 respondents, using a checklist sheet research instrument.Data analysis techniques spearman rank. Results: The characteristics of surgery patients with spinal anesthesia in the operating room of Yogyakarta "JIH" Hospital were mostly female, 87.9%, most of whom were adults 74.1%, the highest frequency of surgery with spinal anesthesia duration >2 hours 55.7% and had an incidence of hypothermia 54.7%. Correlational statistical analysis obtained a Cramer's value of 0.371, a correlation coefficient value of 0.348 with a probability value (p-value) of 0.000. Conclusion: There is a relationship between spinal anesthesia and hypothermia incidence among postoperative patients in the operating recovery room "JIH" Hospital Yogyakarta. The direction of the correlation is positive and closeness is sufficient.