Enzyme-Assisted Aqueous Extraction Of Cashew Nut (Anacardium occidentale L.) Oil

Enzyme-assisted aqueous extraction method was applied to extract oil from cashew nut (Anacardium occidentale L.). The commercial enzyme (Viscozyme cassava C) was tested for effectiveness in releasing oil during the aqueous extraction. The effect of several parameters such as material/water ratio, enzyme concentration and duration for enzyme incubation on the oil yield was investigated. The conditions for maximum oil release were found with the material/water ratio of 1:9, enzyme concentration of 1% (v/w E/S), and in 3 h of enzyme incubation at 50oC with constant shaking. The maximum oil yield obtained at those conditions (38.88 % raw material) was significantly (p <0.05) higher than that of the control (without enzyme) (35.92 %), and it represented 86.28 % recovery of the total oil in seed. No hexane and other organic solvents were needed for this process. The cashew nut oil by enzyme-assisted aqueous extraction was relatively stable. Both peroxide value and free fatty acid value were lower than those in the oil obtained by Soxhlet method. Total un-saturated fatty acid in the cashew nut oil was about 84.43 %, in which the most abundant was oleic acid (65.0 %), followed by linoleic acid (18.53%). Cashew nut oil is a good dietary source of un-saturated fatty acids

Testing the influence of factors on the timeliness of financial reporting – Empirical evidence of Vietnamese listed enterprises

Financial reporting of enterprises has important implications for information users. The timely provision of financial reporting by enterprises helps investors to make appropriate business decisions. The purpose of the paper is to test the influence of the factors on the timeliness of financial reporting of the Vietnamese listed enterprises. The timeliness of financial statements is determined by the total number of days of difference between the date of signing the audit report and the end of the financial year. The sample includes the top 100 best-listed enterprises of the Vietnamese stock market. The paper uses time series with panel data. The data are collected from annual and financial reports for the period from 2016 to 2020. The paper performs quantitative research to test the hypotheses. The results verify two factors, such as return on equity and audit type, have a negative effect on the timeliness of financial reporting. Audit type has the most influence on timeliness. Research also shows some listed enterprises have not yet complied with regulations on timely information disclosure. The paper proposes some appropriate policies for Vietnamese listed enterprises to ensure the timeliness of information

Influence Of Fabrication Condition on the Microstructural and Optical Properties of Lead-Free Ferroelectric Bi0.5_{0.5}Na0.5_{0.5}TiO3_{3} Materials

Lead-free ferroelectric materials have attracted considerable attention due to the increasing potential application in environmental benign materials. Among lead-free ferroelectric materials, the Bi0.5Na0.5TiO3 (BNT) materials were more studied because it exhibited the good ferroelectric and piezoelectric properties which could be promising candidate materials replacing Pb(Zr,Ti)O3. In this work, the lead-free ferroelectric BNT materials were synthesized by sol-gel method. The effects of fabrication process to microstructural and optical properties were studied which includes Na precursor concentration and calcining temperature. The result indicated that the Na precursor concentration were higher 40 mol.% and the calcining temperature

A THEORETICAL STUDY ON CHEMICAL BONDING AND INFRARED SPECTRA OF SinM (M = Sc, Y; n = 1-10) CLUSTERS

In this paper, we applied the B3P86 method and DGDZVP basis set to investigate electronic properties and infrared (IR) spectra for SinM (M = Sc, Y; n = 1-10) clusters. The NBO analyses show that electron transfers from the dopant atoms to silicon frame of the SinM clusters. It is remarkable that the Si-M bond is mainly formed by the overlaps of the 3s-AOs and 3p-AOs of Si atoms, and 3d-AOs and 4s-AOs of Sc (or 4d-AOs and AO-5s of Y). The chemical bonds in the SiM and Si2M clusters are dominated by the covalent character including sigma and pi bonds. In addition, the analysis of the IR spectra suggests that the vibrational modes of SinM clusters are delocalized over the whole cluster. Moreover, the high-frequency and strong-intensity modes usually involve the vibrations of the dopant atoms. The results of this work provide fundamental information for experimental studies on transition-metal doped silicon clusters

Effect of nanosilica/chitosan hybrid on leaf blast and blight diseases of rice in Vietnam

Nanosilica/chitosan (NSi/CTS) hybrid material was prepared using nanosilica (32.5 nm) from rice husk ash (RHA) and chitosan (CTS), and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The obtained NSi/CTS was used for protection of rice leaf from blast disease (Piriculariaoryzae) and blight disease (Xanthomonasoryzae). Results indicated that foliar spraying of NSi/CTS with 100 ppm NSiand150 ppm CTS were effective against blast and blight diseases on rice (Oryza spp.). The leaf blast disease index (DI) (1.49 %) and the blight DI (1.45 %) were significantly decreased compared with control of 8.08 % and 9.29 %, respectively at 14th day after the first treatment. Thus, NSi/CTS hybrid material is promising to use for controlling plant diseases, particularly for rice

QUÁ TRÌNH CHUYỂN PHA PHI CÂN BẰNG CỦA VẬT LIỆU HAI CHIỀU PENTA-GRAPHENE

Graphene has received enormous attention in the semiconductor industry during the last two decades. However, since graphene is a gapless semiconductor, it has critical challenges to be engineered into semiconductor devices. Recent reports have shown that penta-graphene stands out as a promising semiconductor candidate with an electronic bandgap between 2.2 and 4.3 eV; thus, it can surmount graphene’s obstacles. However, when being heated, penta-graphene can transform its configurations from pentagonal lattices to hexagonal graphene-like heterostructures, resulting in a significant electronic modification. In this paper, we investigate the effect of heating rates on the non-equilibrium phase transition of a two-dimensional penta-graphene by using molecular dynamic simulations. We have shown that, with a fast-heating process, penta-graphene naturally transforms to graphene without a clear phase separation point. Nevertheless, with a sufficiently slow heating protocol, this transition is a first-order phase transition from a pentagonal to a more stable hexagonal configuration. These results provide the possibility to implement penta-graphene in future optoelectronic devices.Graphene đã được chứng minh là vật liệu mang tính đột phá cho ngành vật liệu bán dẫn. Tuy nhiên, với độ rộng vùng cấm gần như bằng không, graphene có những hạn chế nhất định khi được ứng dụng để chế tạo linh kiện điện tử. Các nghiên cứu gần đây cho thấy penta-graphene với độ rộng vùng cấm 2,2–4,3 eV và độ bền cơ – nhiệt cao có thể dung hòa nhược điểm của graphene. Tuy nhiên, khi bị nung nóng, penta-graphene có thể chuyển từ cấu trúc vòng 5 điển hình sang cấu trúc vòng 6 của graphene, nhưng điều kiện cụ thể để quá trình chuyển pha này hình thành vẫn chưa được nghiên cứu chi tiết. Trong bài báo này, chúng tôi nghiên cứu sự ảnh hưởng của tốc độ nung đến tính chất nhiệt động phi cân bằng của penta-graphene bằng phương pháp mô phỏng động học phân tử. Ở tốc độ nung lớn, penta-graphene sẽ dần chuyển sang graphene mà không có điểm chuyển pha rõ nét. Tuy nhiên, nếu penta-graphene được nung rất chậm, quá trình chuyển pha từ penta-graphene sang graphene là quá trình chuyển pha loại I với sự gián đoạn của thông số nhiệt động tại điểm chuyển pha. Kết quả này sẽ góp phần bổ sung các thông số kỹ thuật quan trọng trong việc ứng dụng vật liệu penta-graphene để chế tạo các linh kiện quang – điện tử trong tương lai