Green synthesis has recently attracted extensive attention from scientists all over the world for the production of metal nanoparticles. Selenium nanoparticles (Se NPs) have been demonstrated as a suitable supplement nutrient for the replacement of selenium ions in terms of safety and efficiency. This work presented a friendly and facile approach to synthesize the Se NPs using polyphenols content in the Cleistocalyx operculatus (CO) leaves extract. The synthesizing conditions were optimized to obtain the Se NPs with uniform distribution and shape. The prepared Se NPs were well-characterized using scanning electron microscopy, X-ray diffraction, energy diffractive spectroscopy, and Fourier-transform infrared spectroscopy. The resultant Se NPs were in spherical shape with the particle size in a range from 50–200 nm. The antimicrobial properties of Se NPs were investigated against Echerichia coli and Staphylococcus aureus, which showed reasonable activity. The acute oral toxicity of Se NPs in mice was also studied. The result indicated that Se NPs exhibited lower toxicity than that of SeO₂ with the lethal concentration (50% death of mice) of 7.75 mg kg⁻¹_.

Graphite is a versatile material used in various fields, particularly in the power source manufacturing industry. Nowadays, graphite holds a unique position in materials for anode electrodes in lithium-ion batteries. With a carbon content of over 99% being a requirement for graphite to serve as an electrode material, the graphite refinement process plays a pivotal role in the research and development of anode materials for lithium-ion batteries. This study used three different processes to purify spherical graphite through wet chemical methods. The spherical graphite after the purification processes was analysed for carbon content by using energy-dispersive X-ray (EDX) spectroscopy and was evaluated for structural and morphological characteristics through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses. The analyses results indicate that the three-step process via H₂SO₄–NaOH–HCl cleaning can elevate the carbon content from 90% to above 99.9% while still maintaining the graphite structure and spherical morphology, thus enhancing the surface area of the material for anode application. Furthermore, the spherical graphite was studied for electrochemical properties when used as an anode for Li-ion batteries using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements. The results demonstrated that the purification process significantly improves the material’s capacity with a specific capacity of 350 mAh/g compared to the 280 mAh/g capacity of the anode made of spherical graphite without purification.

Selenium element is considered as one of the most important micronutrients for many biological systems. It has been well demonstrated that Se nanoparticles (Se NPs) express greater bioavailability, biocompatability, and less toxicity than that of Se in ion form. In this work, the Se NPs were facilely fabricated by a one-step plasma process in the ethanol–water solution mixture. The as-prepared Se NPs were well characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis spectroscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDX). The prepared Se NPs were a light red color with a spherical shape and particle size in the range of 100–200 nm. The average diameter of the Se NPs calculated from the ImageJ software and TEM image was approximately 154 nm. The EDX results showed that the Se NPs prepared by the plasma process in the solution were highly pure and stable. The acute oral toxicity of the obtained Se NPs toward mice was also studied, which revealed that the Se NPs were safe for the human body. The mechanism for the formation of Se NPs from the Se ions under the solution plasma condition was also studied and discussed.

Pin nhiệt là pin dự trữ dùng một lần, sử dụng chất điện ly là các muối vô cơ nóng chảy ở trong dải nhiệt độ 400 ÷ 550 oC. Cùng với sự phát triển của khoa học công nghệ, pin nhiệt không ngừng được nghiên cứu nhằm nâng cao tính năng kỹ thuật, như giảm thời gian hoạt hóa, giảm khối lượng, tăng dung lượng, mật độ năng lượng, thời gian làm việc, thời gian bảo quản, chịu được điều kiện làm việc khắc nghiệt. Trong bài báo này, chúng tôi trình bày các kết quả nghiên cứu phân tích thành phần hóa học của pin nhiệt hệ Li-Si/FeS2 và khả năng làm việc của pin nhiệt và các hợp phần pin đơn. Kết quả phân tích cho thấy pin nhiệt hệ Li-Si/FeS2 sử dụng công nghệ ép viên, với vật liệu cực dương là FeS2, vật liệu cực âm là hợp kim Li-Si, chất điện ly hệ LiCl:KCl và hỏa thuật hệ Fe:KClO4; điện áp pin đơn khoảng 1,8 V và pin nhiệt khoảng 22 V ở dòng xả 1,5 A.

This study reports on the fabrication and performance evaluation of camouflage coatings based on Cr2O3 nanoparticles and polyurethane resin. Cr2O3 nanoparticles were synthesized via a combustion method using Cr(NO3)3·9H2O as the precursor and glycine as a fuel at a glycine/NO3 ratio of 9:1. The obtained Cr2O3 nanoparticles, with sizes ranging from 40 to 60 nm, were uniformly dispersed within the polyurethane (PU) matrix coated onto the polyester fabric surface. Thermal imaging analysis using a FLIR BHM-Series Bi-Ocular Thermal Imaging Camera confirmed that the coatings provided enhanced and prolonged camouflage effectiveness.