Temperature dependence of the thermal conductivity of water: a molecular dynamics simulation study using the SPC/E model

In this study, molecular dynamics simulations of SPC/E (extended simple point charge) water model have been carried out in the canonical (NVT fixed) ensemble over the range of temperatures 300–550 K with Ewald summation. The evaluated thermal conductivity for SPC/E water overestimates the experimental data at 300–550 K. In accordance with experimental data, SPC/E predicts a maximum in the thermal conductivity at 400 K. The temperature dependence of thermal conductivity of SPC/E water was discussed.     

Simple computing of the viscosity of water–dioxane mixtures,according to a fluctuating SPC/E‐Ih interstitial model

In this contribution, we propose a new simple and fast computing approach to model liquid water and water‐1,4 dioxane mixture, which is intermediate between molecular dynamics calculation and lattice fluid H‐bonding theory in which water molecules are arranged according to a fluctuating hexagonal I_h network. It generalizes the interstitial mixture models of Samoilov and Pauling by increasing the number of spatial configurations into the space of phases due to the addition of rotations and vibrations of the molecules around their equilibrium positions. The potential energy landscape is determined by the generalization of the Madelung's approach to the molecular water network using simple point charge model (SPC/E partial charges). This approach allows useful predictions as the possibility of incorporation of a molecule of dioxane in the water I_h‐network or how some cooperative dynamic jumps (site ‐ hole) of water molecules, contribute to lower Eyring's activation energies and thus to facilitate the viscous flow. © 2017 Wiley Periodicals, Inc.     

Monitoring Parameter Change for Time Series Models of Counts Based on Minimum Density Power Divergence Estimator

In this study, we consider an online monitoring procedure to detect a parameter change for integer-valued generalized autoregressive heteroscedastic (INGARCH) models whose conditional density of present observations over past information follows one parameter exponential family distributions. For this purpose, we use the cumulative sum (CUSUM) of score functions deduced from the objective functions, constructed for the minimum power divergence estimator (MDPDE) that includes the maximum likelihood estimator (MLE), to diminish the influence of outliers. It is well-known that compared to the MLE, the MDPDE is robust against outliers with little loss of efficiency. This robustness property is properly inherited by the proposed monitoring procedure. A simulation study and real data analysis are conducted to affirm the validity of our method.     

Transport properties of bulk water at 243–550 K: a Comparative molecular dynamics simulation study using SPC/E,TIP4P,and TIP4P/2005 water models

ABSTRACT

Molecular dynamics simulations of various water models – SPC/E (extended simple point charge), TIP4P (transferable intermolecular potential 4 points), and TIP4P/2005 – have been carried out in the canonical (NVT fixed) ensemble over the range of temperatures 243–550?K with Ewald summation. The transport properties (self-diffusion coefficients D, viscosities η, and thermal conductivities λ) of SPC/E, TIP4P, and TIP4P/2005 water were evaluated at 243–550?K and compared with experimental data. The temperature dependence of transport properties of SPC/E, TIP4P and TIP4P/2005 water was discussed to determine how reliable the models are over this temperature range.     

A mononuclear copper(II) complex containing benzimidazole and pyridyl ligands: Synthesis,characterization, and antiproliferative activity against human cancer cells

Metal complexes are recently being hybridized with different moieties to discover new drugs due to their advantageous attributes. Among the metals, copper is a good one to synthesize a metal complex due to its being endogenous, redox and DNA cleavage potential, reported anti-cancer efficacies and selective permeability for cancer cells. In this study, first we synthesized a new copper (II) complex and determined its toxic doses on NIH/3T3 normal fibroblast cells, SPC212 mesothelioma and DU145 prostate cancer cells. Then, we ascertained anti-proliferative, apoptotic, morphological, oxidative and endoplasmic reticulum (ER) stress inducing effects of these newly synthesized compounds on DU145 prostate cancer cells. A novel Copper(II)/1-(4-(trifluoromethyl)benzyl)-1H-benzimidazole/2,2′-bipyridyl complex was synthesized and mainly characterized by single crystal X-ray diffraction analysis. Anti-proliferative effect of copper(II) complex was gauged by MTT. Oxidative and ER stress were evaluated by ELISA and Western blot. The morphological effect was examined by microscope analysis. Besides, immunocytochemistry of Bax, a pro-apoptotic protein and PCNA, a proliferation marker protein was performed. As a result, the inhibitory effect of newly synthesized substance was superior to the chemicals from which it was synthesized. Its IC₅₀s against DU145 were 37.0, 21.1 and 10.0 µM for 24, 48 and 72 h-treatments, respectively. Oxidative and ER stress increased after treatment. In microscopy, we observed apoptotic hallmarks like nuclear condensation, cellular shrinkage and membrane blebbings. In immunochemistry, increased Bax and decreased PCNA were apparent. Copper(II) complex with its relatively low IC₅₀ can also be tested on other cancer and normal cell lines.     

Quality control of wastewater treatment: A new approach

This paper presents a new approach to quality control of wastewater treatment. The first part formulates basic principles of statistical process control (SPC) and Taguchi Method. Then it is shown that the classical SPC technique used in industry, cannot be to applied to wastewater treatment plants without adaptation and that the Taguchi Method is inapplicable in this case. This is followed by an example from literature, which demonstrates the problems of applying the SPC method to wastewater treatment. The third part of the paper presents a case study where the performance of a greywater treatment plant is examined. The performance is analyzed by means of cross-correlation between input and output parameters. A new approach to SPC of wastewater treatment, either “Dynamic SPC” or “linear regression SPC”, is presented, and a permeability coefficient is developed (the ratio of the output and input energies). Both are proposed as monitoring tools for wastewater treatment systems.     

Synthesis of silica-pillared clay (SPC) with ordered mesoporous structure by one-step method without preswelling process

The simultaneous intercalation of surfactants and TEOS into clay interlayers and subsequent intragallery ammonia-catalyzed hydrolysis of TEOS resulted in mesoporous silica-pillared clay (SPC). These SPC materials exhibited refractions corresponding to a basal spacing of 3.7-4.3 nm, a uniform pore size of 2.5-3.16 nm and large surface areas of 567-576 m²/g. Our results indicate that surfactants play a decisive role in pore formation, because they act as micelle-like template during the hydrolysis of TOES. Moreover, the pore size of SPC derivatives is controllable by the molecular length of surfactant. All of the SPC materials reported here exhibit high catalytic activity and selectivity for coker gas oil (CGO) cracking reaction in comparison to parent MCM-41 and Al-MCM-41. The excellent acid catalytic activity, together with their sable, well-organized porous structure, opens up new opportunities for applications in catalysis.     

SPC cluster modeling of metal oxides: ways of determining the values of point charges in the embedded cluster model

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Synthesis of dendronized,chiral conjugated polymers with appendant Fréchet‐type dendrons

New chiral binaphthyl‐based polyarylenes [(S)‐ 3a and (S)‐ 3b ] with appendant Fréchet‐type poly(aryl ether) dendrons (first generation and second generation) were synthesized with Suzuki polycondensation from chiral (S)‐6,6′‐dibromo‐2,2′‐didendron‐substituted 1,1′‐binaphthyl derivatives and p‐phenylene diboronic acid. The polymers were studied with circular dichroism, fluorescence, and ultraviolet–visible spectra. Laser light scattering measurements of (S)‐ 3a and (S)‐ 3b showed that their weight‐average molecular weights were 2.39 × 10⁵ and 1.09 × 10⁴, respectively. The specific optical rotation [α]_D was ?59.6 for (S)‐ 3a and ?62.7 for (S)‐ 3b . These dendronized conjugated polymers exhibited good thermal stability. The glass‐transition temperatures and the initial decomposition temperatures were 187.5 and 265.3 °C for (S)‐ 3a and 173.8 and 308.9 °C for (S)‐ 3b , respectively. (S)‐ 3a and (S)‐ 3b had high fluorescence quantum efficiencies, 87 and 91%, respectively, in tetrahydrofuran. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1167–1172, 2002     

基于聚类的轮廓数据质量监控方法研究

轮廓线的变点识别是质量管理的研究热点之一,当前研究多以轮廓整体变化为识别对象,而对局部变化问题研究相对较少,且更少有在发现变异时间的同时能够寻找到变化区域在个体轮廓曲线上位置的系统方法。本文针对轮廓线局部变化识别问题,提出基于小波变换和聚类分析的方法。通过仿真性能评价,并与现有方法进行比较,结果显示本方法能够在更小的差异度检测出变化并准确定位变化区域。在文章的末尾,本文采用了一个实例对该方法的效果进行验证。