Nucleation and Growth of Anatase Crystallites on Cotton Fabrics at Low Temperatures

Anatase nanocrystalline titania coatings were produced on cotton fabrics from alkoxide solutions using a low-temperature sol–gel process under ambient pressure. Titania coatings of the anatase form were obtained via a classical hydrolysis and condensation reaction of titanium isopropoxide that was followed by a boiling water treatment for 180 min. Spectroscopic and microscopic characterizations of the titania thin films showed that the anatase form is predominant throughout the film after the boiling water treatment and that the size of the grains is about 20 nm. The titania coating on fabrics is a promising process for use as an antibacterial photocatalyst in the textile industry.     

A modified model predictions and experimental results of weld-line strength in injection molded PS/PMMA blends

In this paper, the model based on melt diffusion and Flory-Huggins free energy theory for predicting the weld-line strength of injection molded amorphous polymers and polymer blends parts were modified by considering the diffusion thickness in the interface as a function of contact time. The modified model for weld-line strength prediction of homopolymers and polymer blends were, respectively, used to evaluate the weld-line strength of Polystyrene (PS) and Poly(methylmethacrylate) (PMMA), and that of PS/PMMA blends. The model predictions show that the theoretic predictions as a function of temperature and contact time for PS, PMMA and PS/PMMA (80/20, 70/30) are in good agreements with corresponding experimental results. However, the model predictions for PS/PMMA (20/80, 30/70) blends are much higher than experimental results. The morphology in weld-line regions for PS/PMMA (20/80, 30/70) shows lack of dispersed PS phase. Near the weld-line regions, dispersed PS phase is highly oriented along the weld-line. In theoretic prediction for polymer blends, three kinds of diffusion: Polymer A-Polymer A and Polymer B-Polymer B self-diffusions and Polymer A-Polymer B mutual diffusion were considered. This is why model predictions for PS/PMMA (20/80, 30/70) blends are higher than experimental results.     

Superhydrophobic Silica Nanocomposite Coating by a Low-Temperature Process

We successfully prepared transparent and durable superhydrophobic silica-coating films on cotton substrates at low temperatures. The coatings were produced via cohydrolysis and polycondensation of a hexadecyltrimethoxysilane (HDTMS), tetraethoxyorthosilcate (TEOS), and 3-glycidyloxypropyltrimethoxysilane (GPTMS) mixture. The hydrophobic properties of the nanocomposite coatings were determined using contact-angle and water-gain measurements. The water contact angle for the coated substrates was 141°, whereas, before coating, the contact angle was 0° because of the superhydrophilic nature of cotton. The nanocomposite coating has new applications in daily used materials, especially those with low heat resistance, such as textiles and plastics, and as an environmentally friendly water-repellent substitute for fluorine compounds.     

Extraction of Vanadium(V) from Mixed Chloride/Thiocyanate Solutions with Two Commercial Solvating Extractants

Studies on the extraction and separation of vanadium(V) from mixed hydrochloric acid/ammonium thiocyanate solution with CYANEX 921 and CYANEX 925 in kerosene were carried out. The effects of various factors affecting the extraction process as well as temperature were investigated. Addition of thiocyanate to the chloride solution was found to enhance markedly the extraction of vanadium. HCl solution efficiently stripped V(V). The number of stages required for extraction and stripping of vanadium ions was determined from the McCabe–Thiele diagram. Based on the obtained results, the separation of V(V) from spent catalyst leach indicates the efficiency of the proposed process.     

Hydrodynamic study of the granular flow in the solar dryer

There are a great many drying processes and types of equipment, such as dryers with immersed channels; the main advantage of this type of dryer, and the reason why it is chosen by manufacturers, is the homogeneous distribution of the drying air, made possible by dihedrons. In our work, we have investigated a flow model with a random double dispersion and have finally shown that the dispersion coefficients are not constant but vary depending on the position of the granular material in the column of dihedrons.     

Effects of electromagnetic near-field stress on SiGe HBT’s reliability

In this paper, a reliability damage mechanism was presented in SiGe Heterojunction Bipolar Transistor (HBT). This new stress methodology differs from conventional SiGe, HBT device reliability associated with other stresses, since it was obtained by applying electromagnetic near-field aggression. The near-field set-up is used to disturb with electromagnetic field the Device Under test (DUT) on a localized area. Degradations in the base current and the current gain are identified. They are induced by a large base current leakage due to hot carrier which introduces generation/recombination trap centers at the silicon–oxide interface of the emitter–base spacer. By using the S-parameters measurements, we find that both forward transmission scattering parameter (S₂₁) and the input scattering parameter (S₁₁) are affected by this stress. In addition the power characteristics of DUT are also affected by stress. A Direct Power Injection (DPI) method is used to understand the near-field stress behaviour.     

Dialysis Disequilibrium Syndrome Revisited

An aggressive dialysis in a grossly azotemic patient, especially one with severe metabolic acidosis, can lead to dialysis disequilibrium syndrome (DDS). Mild forms present as nausea, vomiting, restlessness, and headache. Severe manifestations include seizures, obtundation, coma, and even death. This clinical picture is caused by cerebral edema induced by one or more of the following mechanisms:

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STEM nanoanalysis of Au/Pt/Ti-Si3N4 interfacial defects and reactions during local stress of SiGe HBTs

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The dynamics of local quantum uncertainty and trace distance discord for two-qubit <Emphasis Type="Italic">X</Emphasis> states under decoherence: a comparative study

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