Liquid membranes for gas/vapor separations

A review on developments of liquid membranes (LMs) in the field of gas and vapor separation of the last 16 years is presented. Liquid membrane configurations employing supports, i.e. immobilized, supported and contained liquid membranes are focussed and detailed information on the respective materials, i.e. supports (supplier, type, thickness, pore width, porosity, tortuosity), liquids and carriers, are presented together with their specific separation tasks. Performance of different LMs in terms of permeability and selectivity as well as stability (duration of testing, applied differential pressures) are compared and discussed. Finally, different preparation methods of LMs are illustrated.     

Formation of Si structure in glass with a femtosecond laser

Mixing metallic Al into the starting material for silicate glass is proposed as a means of forming Si structures in glass. We confirmed that Si nanocrystals are space-selectively deposited in silicate glass via a thermite reaction triggered by femtosecond laser pulses. Small Si particles were transformed into larger, but still micrometer sized, Si particles by laser irradiation. These structures grew to micro-size particles due to the thermite reaction promoted by heat treatment. We discuss what effect the irradiation of the focused laser pulse had on the Si deposition process in the laser-irradiated region. Localized high temperatures and pressures and generation of shock waves appear to be very important in forming Si-rich structures that contribute to the growth of Si particles. The diffusion of calcium ions by the generation of shock waves and the presence of Al-rich structures is important for forming Si-rich structures such as Si clusters, which is achieved by continuously breaking Si–O bonds using localized high temperatures.     

Antiglioma pseurotin A from marine Bacillus sp. FS8D regulating tumour metabolic enzymes

Pseurotin A was isolated from a culture of marine Bacillus sp. FS8D and showed to be active against the proliferation of four different glioma cells with IC₅₀ values of 0.51–29.3 μM. It has been found that pseurotin A downregulated the expression of tumour glycolytic enzymes pyruvate kinase M2 (PKM2) and lactate dehydrogenase 5 (LDH5) and upregulated the expression of pyruvate dehydrogenase beta (PDHB), adenosine triphosphate synthase beta (ATPB) and cytochrome C (Cyto-C), the important regulators for tricarboxylic acid cycle and oxidative phosphorylation. The data suggested that targeting multiple metabolic enzymes might be one of the antiglioma mechanisms of pseurotin A.     

An Electric Fish-Based Arithmetic Optimization Algorithm for Feature Selection

With the widespread use of intelligent information systems, a massive amount of data with lots of irrelevant, noisy, and redundant features are collected; moreover, many features should be handled. Therefore, introducing an efficient feature selection (FS) approach becomes a challenging aim. In the recent decade, various artificial methods and swarm models inspired by biological and social systems have been proposed to solve different problems, including FS. Thus, in this paper, an innovative approach is proposed based on a hybrid integration between two intelligent algorithms, Electric fish optimization (EFO) and the arithmetic optimization algorithm (AOA), to boost the exploration stage of EFO to process the high dimensional FS problems with a remarkable convergence speed. The proposed EFOAOA is examined with eighteen datasets for different real-life applications. The EFOAOA results are compared with a set of recent state-of-the-art optimizers using a set of statistical metrics and the Friedman test. The comparisons show the positive impact of integrating the AOA operator in the EFO, as the proposed EFOAOA can identify the most important features with high accuracy and efficiency. Compared to the other FS methods whereas, it got the lowest features number and the highest accuracy in 50% and 67% of the datasets, respectively.     

The influences of cations on the properties of Y-Mg-Si-Al-O-N glasses

Two series (A and B series) of oxynitride glasses were prepared by melting batches at 1580 °C for 3 h under local CO reducing atmosphere in a Si-Mo-heated resistance furnace. Nominal compositions of A and B series glasses in equivalent percent (eq.%) are (28−x)Y:xMg:48Si:24Al:83O:17N and (28−x)Y:xMg:56Si:16Al:83O:17N (x = 0, 7, 14, 21), respectively. The influences of Mg/Y and Al/Si ratios on the properties such as glass transition temperature (T_g), crystallization temperature (T_C), knoop hardness (H), three-point bending strength (σ) and chemical durability in 20%HF were investigated. At the same time, the relationship between these properties and the structures of the glasses were discussed. At constant ratio Si-Al-O-N, T_g decreases nonlinearly but glass leaching ratio increases linearly with increasing Mg/Y ratio. However, H and σ increase first and then decrease as the Mg/Y ratio increases. When the Y/Mg/O/N ratio is constant, T_g decreases slightly but H and σ increase slightly as the Al/Si ratio increases.     

铁磁-超导隧道结中粗糙界面散射对直流Josephson电流的影响

通过求解Bogoliubov—de Gennes(BdG)方程得到铁磁超导共存态(FS)的自洽方程，在考虑结界面的粗糙情形下，由推广的Furusaki—Tsukada(FT)的电流公式计算了铁磁超导态／绝缘层／s波超导体(FS／I／S)结的直流Josephson电流，讨论了FS/I／S结的直流Josephson临界电流随磁交换能、温度的变化情况．研究表明：铁磁超导态中磁交换能和结界面的粗糙势垒散射均对FS／I／S结的直流Josephson电流有抑制作用．     

用FS多体势模型模拟金属铜的冷却过程

采用常温、常压分子动力学模拟方法模拟了在周期性边界条件下由500个原子构成的液态Cu模型系统的凝固过程,考察了不同降温速率下液态Cu的凝固行为.模拟结果很好地重现了实验值.模拟中原子间作用势采用FS势,结构分析采用双体分布函数、对分析技术、内能、均方位移等方法,得到了原子体系微观结构组态变化的重要信息,并利用能量分析的方法对体系微观结构的变化进行了说明.     

The role of the acquisition methods in the analysis of the non-steroidal anti-inflammatory drugs in Danube River by gas chromatography - mass spectrometry

In this paper authors describe a GC-MS acquisition study, relating to the most common, non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, naproxen, ketoprofen and diclofenac. As novelties to the field, for the trimethylsilyl (TMS) oxime ester derivatives of NSAIDs, at first, a tandem mass spectrometric (MS/MS) acquisition method has been developed, and, also for the first time, the three acquisition techniques, the full scan (FS), the selective ion monitoring (SIM) and the currently optimized MS/MS ones, have been compared: all three in parallel, under strictly the same derivatization/instrumental conditions, both from model solutions and from the Danube River samples. Critical evaluation of the three acquisition protocols was collated on their analytical performances and validated with the same characteristics like the six point calibration curve, the relative standard deviation percentages (RSD%) of parallel tests, the limit of quantitation (LOQ) and the instrumental limit of quantitation (ILQ) values. Data of six point calibration (r² ≥ 0.997) and RSD% (average: 5.8 RSD%) values proved to be independent on the acquisition methods, while, LOQ and ILQ values furnished considerable differences. Decreasing LOQ data, (expressed in ng/L concentrations) were obtained in the FS, SIM, MS/MS line for ibuprofen (1.0, 0.43, 0.41), naproxen (1.1, 1.0, 0.42), ketoprofen (2.6, 1.0, 0.49) and diclofenac (1.4, 0.41, 0.21), respectively. The same trend was determined in terms of the ILQ values. The practical utility of the optimized MS/MS technique was confirmed by the quantitation of the NSAID contents of the Danube River samples, determined by all three acquisition techniques. Results obtained confirmed the primary importance of the MS/MS acquisition method, even in comparison to the SIM one: avoiding the extreme overestimation of the ibuprofen (≈100%) and ketoprofen (≈400%) concentrations in the Danube River samples.     

Evaluation and Application of the Internal Standard Technique for the Direct Determination of Copper in Fruit Juices Employing Fast Sequential Flame Atomic Absorption Spectrometry

Abstract

The present paper describes the evaluation and application of internal standard for the determination of copper in fruit juices, employing Fast Sequential Flame Atomic Absorption Spectrometry (FS FAAS). The internal standards tested were indium, cobalt, and nickel using correlation graphs. However, indium was used, considering the composition of the samples. After this step, copper was determined in fruit juices using indium as internal standard. This method allows the determination of copper with a limit of quantification of 0.011 mg L^?1. The fruit juice samples selected for analysis were of grape, orange, pineapple, peach, cashew, and strawberry. The contents of copper in these samples varied from 0.02 to 0.42 mg L^?1. The analytical results were compared with the results obtained by analysis of these samples after complete mineralization using acid digestion and determination employing FS FAAS. The statistical comparison by a t-test (95% confidence level) showed no significant difference between the results. The relative standard deviations (RSD) with and without the use of the internal standard for a copper solution containing 0.4 mg L^?1 were of 0.62 and 1.94%, respectively. The use of indium as internal standard provided more accurate analytical results, as well as better analytical performance for the determination of copper in juice samples.