Structural, electronic, and optical properties of ZnOl_xSex alloys using first-principles calculations

The structural, electronic, and optical properties of binary ZnO, ZnSe compounds, and their ternary ZnOl_xSex alloys are computed using the accurate full potential linearized augmented plane wave plus local orbital （FP-LAPW ＋ lo） method in the rocksalt （B 1） and zincblende （B3） crystallographic phases. The electronic band structures, fundamental energy band gaps, and densities of states for ZnO1_xSex are evaluated in the range 0 〈 x 〈 1 using Wu-Cohen （WC） generalized gradient approximation （GGA） for the exchange-correlation potential. Our calculated results of lattice parameters and bulk modulus reveal a nonlinear variation for pseudo-binary and their ternary alloys in both phases and show a considerable deviation from Vegard＇s law. It is observed that the predicted lattice parameter and bulk modulus are in good agreement with the available experimental and theoretical data. We establish that the composition dependence of band gap is semi-metallic in B1 phase, while a direct band gap is observed in B3 phase. The calculated density of states is described by taking into account the contribution of Zn 3d, O 2p, and Se 4s, and the optical properties are studied in terms of dielectric functions, refractive index, reflectivity, and energy loss function for the B3 phase and are compared with the available experimental data.     

Mechanical behavior of Cu-Zr bulk metallic glasses （BMGs）： A molecular dynamics approach

In the present work, three-dimensional molecular dynamics simulation is carried out to elucidate the nanoindentation behaviors of CuZr Bulk metallic glasses (BMGs). The substrate indenter system is modeled using hybrid interatomic potentials including both many-body Finnis Sinclair (FS) and two-body Morse potentials. A spherical rigid indenter (diameter = 60(1 = 10-10 m)) is employed to simulate the indentation process. Three samples of BMGs including Cu25Zr75 , Cu50Zr50 , and Cu75Zr25 are designed and the metallic glasses are formed by rapid cooling from the melt state at about 2000 K. The radial distribution functions are analyzed to reveal the dynamical evolution of the structure of the atoms with different compositions and different cooling rates. The mechanical behavior can be well understood in terms of load-depth curves and Hardness-depth curves during the nanoindentation process. Our results indicate a positive linear relationship between the hardness and the Cu concentration of the BMG sample. To reveal the importance of cooling rate provided during the processing of BMGs, we investigate the indentation behaviors of Cu50Zr50 at three different quenching rates. Nanoindentation results and radial distribution function (RDF) curves at room temperature indicate that a sample can be made harder and more stable by slowing down the quenching rate.     

Elemental Analysis of Cement by Calibration-Free Laser Induced Breakdown Spectroscopy (CF-LIBS) and Comparison with Laser Ablation – Time-of-Flight – Mass Spectrometry (LA-TOF-MS), Energy Dispersive X-Ray Spectrometry (EDX), X-Ray Fluorescence Spectroscopy (XRF), and Proton Induced X-Ray Emission Spectrometry (PIXE)

The purpose of the present study is to determine the elemental composition of Pakistani cement brands using calibration-free laser induced breakdown spectroscopy (CF-LIBS) and to compare the obtained results with the other analytical techniques such as, laser ablation – time-of-flight – mass spectrometry (LA-TOF-MS), energy dispersive X-ray spectrometry (EDX), X-ray fluorescence spectroscopy (XRF) and proton induced X-ray emission spectrometry (PIXE). Compositional results reveal that all the cement brands are mainly composed of calcium, silicon, iron, aluminum, magnesium, potassium, sodium, titanium, lithium and strontium with varying concentrations. The compositions obtained by LIBS and LA-TOF-MS are in good agreement with results obtained by the other standard techniques and demonstrate the potential use of LIBS for the online monitoring of industrial cement production.     

Enrichment of HDL proteome and phospholipidome from human serum via IMAC/MOAC affinity

High-density lipoproteins (HDLs) have anti-inflammatory and antioxidant properties and are potentially cardio-protective. Defective HDL function is caused by alterations in both the proteome and lipidome of HDL particles. As potential biomarkers, the development of analytical methods is necessary for the enrichment of HDLs. Therefore, a method for selective enrichment of HDLs using immobilized metal ion affinity chromatography (IMAC) and metal oxide affinity chromatography (MOAC) is presented. SPE-based isolation of HDLs from whole serum is adopted as an alternative to traditional ultracentrifugation methods followed by SDS–PAGE. The enrichment mechanism relies on isoelectric points of lipoproteins and metal oxide. Negatively charged lipoprotein particles interact with positively charged metal oxides and IMAC affinity, which acts as a cation. Identified proteins from HDL through MALDI–MS analysis are apo AI, AII, AIV, CI, CIII, E, J, M, H, serum amyloid A and other nonapoproteins that are part of HDL particles and perform cellular functions. This serum-based proteomics approach gives insight into the functional role of HDL. HDL-associated phospholipids have also been analyzed by LDI–MS. Results suggest that the adopted analytical strategy is a feasible idea to extract lipoproteins from serum. A comparative study of healthy and diseased samples using this approach will provide valuable information in future.     

Comparative study of the alignment method on experimental and simulated chromatographic data

One of the major problems in the signal comparison of chromatographic data is the variability of response caused by instrumental drifts and others instabilities. Measures of quality control and evaluation of conformity are inherently sensitive to shift. It is essential to be able to compare test samples to reference samples in an evolutionary analytical environment by offsetting the inevitable drift. Therefore, prior to any multivariate analysis, the alignment of analytical signals is a compulsory preprocessing step. During recent years, many researchers have taken a greater interest in the study of the alignment. The present paper is an updated review on the alignment algorithms, methods, and improvements used in chromatography. The study is dedicated to one‐dimensional signals. Several of the exposed methods have common theoretical bases and can differ through their optimization methods. The main issue for the operator is to choose the appropriate method according to the type of signals to be processed.     

A microwave-assisted and heteropolyacids-catalysed cyclocondensation reaction for the synthesis of 4(3H)-quinazolinones

We have investigated a microwave-assisted synthesis of 4(3H)-quinazolinones by condensation of anthranilic acid, orthoesters (or formic acid) and substituted anilines,using Keggin-type heteropolyacids (H(3)PW(12)O(40).13H(2)O, H(4)SiW(12)O(40).13H(2)O,H(4)SiMo(12)O(40).13H(2)O or H(3)PMo(12)O(40).13H(2)O) as catalysts. We found that the the use of H(3)PW(12)O(40).13H(2)O acid coupled to microwave irradiation allows a solvent-free, rapid (approximately 13min) and high-yielding reaction.     

Synthesis of ciprofloxacin-based compounds: A review

Ciprofloxacin is a broad-spectrum antibiotic that plays an important role in inhibiting the growth of both Gram-positive and Gram-negative bacteria. Medicinal chemists are extensively involved in the synthesis of novel ciprofloxacin derivatives, in search of new ciprofloxacin-based drugs with enhanced activity. This review article summarizes the major synthetic approaches involved in the synthesis of ciprofloxacin-based molecules.     

A local boundary condition coupled to a finite element method to compute guided modes of optical fibres under the weak guidance assumptions

An efficient method coupling a local boundary condition to a finite element technique is proposed to compute guided modes of optical fibres under the weak guidance assumptions. This method is designed to provide accurate solutions for optical fibres with no restriction on their shape as well as on their refractive index profile. Several numerical experiments are performed to demonstrate this point. Copyright © 2000 John Wiley & Sons, Ltd.     

Belief and Possibility Belief Interval-Valued N-Soft Set and Their Applications in Multi-Attribute Decision-Making Problems

In this research article, we motivate and introduce the concept of possibility belief interval-valued N-soft sets. It has a great significance for enhancing the performance of decision-making procedures in many theories of uncertainty. The N-soft set theory is arising as an effective mathematical tool for dealing with precision and uncertainties more than the soft set theory. In this regard, we extend the concept of belief interval-valued soft set to possibility belief interval-valued N-soft set (by accumulating possibility and belief interval with N-soft set), and we also explain its practical calculations. To this objective, we defined related theoretical notions, for example, belief interval-valued N-soft set, possibility belief interval-valued N-soft set, their algebraic operations, and examined some of their fundamental properties. Furthermore, we developed two algorithms by using max-AND and min-OR operations of possibility belief interval-valued N-soft set for decision-making problems and also justify its applicability with numerical examples.     

Small amplitude variable charge dust Bernstein-Greene-Kruskal double layers

A first theoretical attempt is made to investigate small amplitude, variable charge dust Bernstein-Greene-Kruskal (BGK) double layers (DLs). The nature of the dust BGK-DLs (compressive or rarefactive), their strength and thickness depend sensitively on the net negative charge residing on the grain surface, the dust grain dynamics and, more interestingly, on the ion-to-electron temperatures ratio.