Ti/TiO<Subscript>2</Subscript> nanotube array electrode as a new sensor to photoelectrocatalytic determination of ethylene glycol

The photoelectrocatalytic oxidation behaviour of ethylene glycol (EG) was studied in the present work using the TiO₂-modified Ti foil (Ti/TiO₂) electrode. The Ti/TiO₂ nanotube array (Ti-NTA) electrode was prepared by anodizing of the Ti foil in the HF aqueous solution (0.2% v/v). The anodization was conducted in the constant 30 V for 2 h, and then the as-prepared Ti-NTA electrode was calcinated at 50 ^° C for 2 h. The surface morphology of Ti- NTA electrode was studied using scanning electron microscopy images. For EG determination, the photocurrent of EG (EG oxidation current in the UV irradiation) was assessed using the hydrodynamic photoamperometric method in the phosphate buffers. Ultimately, the optimum conditions of EG determination were studied in various pH values and applied bias potentials, and the pH = 3.0 and E= 1.0 V (vs. reference electrode) were determined as the optimum conditions. It was found that the photocurrent of EG was linearly dependent on the concentration of EG in the range of 3.0 × 10 ^?5 to 0.88 mol l ^?1 , and the detection limit of EG determination was found to be 7.2 × 10^?6 mol l^?1 (3 σ).     

减少离散大系统两级镇定控制的保守性

The aim of this paper is to propose a new algorithm for multilevel stabilization of large scale systems. In two-level stabilization method, a set of local stabilizers for the individual subsystems in a completely decentralized environment is designed. The solution of the control problem involves designing of a global controller on a higher hierarchical level that provides corrective signals to account for interconnections effect. The principle feature of this paper is to reduce conservativeness in global controller design. Here, the key point is to reduce the effect of interactions instead of neutralizing them. In fact, unlike prior methods, our idea does not ignore the possible beneficial aspects of the interactions and does not try to neutralize them.     

Corrosion protection of AM60B magnesium alloy by application of electroless nickel coating via a new chrome-free pretreatment

Cerium–vanadium (Ce–V) conversion coating was proposed as a new pretreatment for application of electroless Ni–P coating on AM60B magnesium alloy to replace the traditional chromium oxide pretreatment. Morphology and chemical composition of the conversion coating were investigated. The subsequent Ni–P coating deposited on the conversion coating was also characterized by morphology, chemical composition, microstructure, corrosion protection performance and micro-hardness. A uniform, compact and pore-free electroless coating with a moderate concentration of phosphorus (7.78 wt%) was obtained. The electroless coating showed a nobler open-circuit potential than that of the bare alloy during the first 13 h of immersion in 3.5 wt% NaCl solution. Also, the sample plated with the Ce–V conversion coating showed lower corrosion current density than the sample plated with traditional chromium oxide pretreatment. The micro-hardness of the bare alloy was significantly increased after electroless coating. The electroless coating is pore-free and there is suitable adhesion between the coating and alloy substrate.     

Preparation and characterization of silver nanoparticles in natural polymers using laser ablation

In this paper we have done a comparative study on efficiency of natural polymers for stabilizing silver nanoparticles (Ag-NPs) prepared by laser ablation technique. The selected polymers are starch (St), gelatin (Gt) and chitosan (Ct). The fabrication process was carried out through ablation of a pure Ag plate by nanosecond Q-switched Nd?CYg pulsed laser (?? = 532?nm, 360?mJ/pulse). The stability of the samples was studied by measuring UV-visible absorption spectra of the samples one month after preparation. The result showed that the formation efficiency of NPs in St were highest and also the prepared NPs in St solution were more stable than other polymers during one month storage.     

模糊环境下汽车故障模式风险水平综合评价方法

针对车辆故障模式风险评价,提出了一种新的模糊综合评价方法,即先利用基于维修数据的失效模式与效果分析(FMEA)筛选出关键故障模式进行进一步研究,再分别采用模糊层次分析法(AHP)与模糊扩展全乘比例多目标优化(MULTIMOORA)计算风险评价因素与故障模式的权重,通过计算车辆故障模式的最终权重得到故障模式进行风险排序.同时利用逻辑语言表征评审专家的评估信息并将其转化为三角模糊数,实现了客观维修数据与专家经验判断的有机结合.利用本文提出的新评价方法对现代一款轻型客车进行故障模式风险评估与排序,进行灵敏度分析验证此方法的有效性.     

ANTIBACTERIAL EFFECT, HISTOLOGICAL IMPACT AND OXIDATIVE STRESS STUDIES FROM LAURUS NOBILIS EXTRACT

Laurus nobilis is one of the most broadly used spices in Moroccan gastronomy. Its antimicrobial activity against both gram-positive and gram-negative bacterial species was demonstrated. Likewise, its toxicity was investigated on Swiss albinos' mice . Daily, mice were treated orally with 0.003 and 0.3 mg during 7 days. Plasmatic markers and enzymatic systems were assessed and histological alterations were evaluated. A significant increase in creatine phosphokinase level was observed. The microscopic evaluation showed that L. nobilis induces morphological perturbation in mice's liver. The results also showed an inhibitory effect of glyceraldehydes 3-phosphate dehydrogenase and an important increase in the level of thiobarbituric acid reactive substances and succinate dehydrogenase and no change in catalase activities. The results showed that L. nobilis induces toxicity at 0.3 mg/g mouse and affects energy metabolism and oxidative stress.

PRACTICAL APPLICATIONS

The aim of the present study is to determine the antimicrobial effect of Laurus nobilis on pathogens for potential application as herbal medicine in infusion or oral preparation. The effect of the spice extract was investigated on the metabolic markers, stress biomarkers and clinical parameters. This study was completed with histological coupes. To our knowledge, this is the first report to demonstrate the laurel effect on energy metabolism and oxidative stress.     

Fast generation of the gamma and digamma functions of complex argument

Using standard recurrence relations for the gamma and digamma functions, the real part is stepped up by integers until it is sufficiently large to permit the use of standard asymptotic expansions. It is shown that the technique is extremely simple and accurate and requires few milliseconds on a modern digital computer.