Chalcogenide based all-solid-state thin electroplated ion-selective membrane for Hg(II) flow-injection determinations

The response to Hg(II) of a thin all-solid-state Te-doped silver chalcogenide membrane, described by the general formula Ag₂ + δSe_{1 − x}Te_x, which has been electrochemically prepared following a previously proposed approach, has been investigated. The kinetics of formation of the membrane's secondary dynamic response to Hg(II) has been successfully combined with the precise timing and transient signal, typical for flow-injection (FI) measurements, in developing a sensitive and reliable mercury FI detector. Under optimized stream conditions it exhibits a linear Nernstian response, with a double slope of the calibration graph of 59 mV dec⁻¹, over the mercury(II) concentration range 10⁻⁶ − 10⁻³ M, the typical sample throughput amounting to about 70 samples per hour. The observed chemical amplification of the signal is due to the specificity of the processes dominating the initial step in formation of the steady-state signal of the membrane to mercury. The analytical performance of the Hg(II) FI detector, as regards sensitivity, reproducibility, selectivity and long-term stability has been thoroughly investigated. The exact procedure for membrane electrodeposition is given and the potential of the proposed approach as a cost-effective way for preparing chalcogenides of unique structure and properties has been outlined in the above context.     

ICP-OES determination of metals present in textile materials

The aim of this work was to quantify the content of elements present in textile materials since it is known that textiles containing metals may represent a health hazard to consumers. Determination of metal content can be also useful to the textile industry since some metals present in textiles may contribute to problems during textile production. Extraction of metals from different textile materials was performed in an artificial acidic sweat solution according to the Öko Tex standard for materials coming into direct contact with the skin. After extraction from textile products made of cotton, flax, wool, silk, viscose, and polyester materials, all elements were determined by means of inductively coupled plasma-optical emission spectrometry (ICP-OES). Results in the sweat extracts (minimum-maximum in μg/mL) were: Al 0.11-1.58, Cd 0.02-0.05, Cr 0.01-0.32, Cu 0.05-1.95, Mn 0.01-2.17, and Ni 0.05-0.10. Concentrations of other elements were bellow detection limits. The total amount of metals present was determined after microwave assisted acidic digestion of textile materials with 7 M nitric acid. According to the results, the majority of the detected elements were below the concentration limits given by the Öko Tex, and for this reason the textile materials investigated do not represent a health hazard to consumers.     

Characterization of ligno-cellulosic seed fibre from Wrightia Tinctoria plant for textile applications—an exploratory investigation

A hitherto uninvestigated ligno-cellulosic seed fibre from the plant Wrightia Tinctoria has been chosen for the current study to unravel its physical properties, and potentialities in textile applications. Both raw and partially delignified fibres were tested for their morphological and structural features by X-ray diffraction, optical microscope and FT-IR spectra, thermal properties by thermogravimetry and differential scanning calorimetry and fibre fineness properties. The non-spinnable brittle virgin fibre becomes spinnable after partial delignification due to the decreased fibre rigidity imparted by lignin. Knitted fabrics were made successfully with (20%) and without cotton blending.     

Pultruded Kenaf Fibre Reinforced Composites: Effect of Different Kenaf Fibre Yarn Tex

Manufacturing high performance composites from natural fibres is one of an ambitious goal currently being pursued by researchers across the globe. The ecological benefits of this material among many others are environmentally friendly and do not cause health problems. In terms of sustainability, the natural fibre is an appropriate alternative candidate to replace the synthetic and other types of reinforcement since it is a renewable resource. In order for natural fibre reinforced composite to become competitive, it has to accommodate the processing avenues of which has long being associated with its synthetic counterpart. Among those proven technology in manufacturing advanced engineering component is pultrusion. In this paper, an attempt has been made to produce pultrudedkenaf fibre reinforced unsaturated polyester composites via pultrusion. The properties of the pultrudedkenaf fibre reinforced composites with different kenaf yarn sizes are reported and compared. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties.     

苎麻纤维细度测试与分析的灰色模型

基于灰色系统理论的灰色建模应用于试验数据的相关分析 ,比基于数理统计的回归分析在实际应用中由于所需样本容量较小而具有明显的优点 ,特别对贫信息系统适用 .从而可避免在回归分析中因样本容量太小而致使回归方程的误差不可预测的弊端 .鉴于上述原理 ,本文采用灰色系统理论建立了苎麻纤维Tex数 Y与投影宽度 X之间的灰色 GM( 1 ,2 )模型 ,并进行了误差分析 .利用此模型探索了通过测定苎麻纤维投影宽度来计算其 Tex数的方法 .为生产工艺控制、产品质量检验和监督提供了一种简便而科学的办法 .