Functional Materials

Vanadium dioxide shows a passive and reversible change from a monoclinic insulator phase to a metallic tetragonal rutile structure when the sample temperature is close to and over 68°C. As a kind of functional material, VO2 thin films deposited on fused quartz substrates were successfully prepared by the pulsed laser deposition (PLD) technique. With laser illumination at 400nm on the

The application of cross-linking resin is an effective method for improving and controlling dimensional stability, such as the shrinkage of viscose single jersey knits. However, such treatment often leads to a significant deterioration in the bursting strength of treated fabrics. In this regard, resin treatment using a softening agent can be an additional potential solution for retaining the bursting strength of treated fabrics. Resin treatment is one kind of chemical finishing process that inhibits cellulosic textile fibre swelling during wetting, provides fibre resistance to deformation and prevents shrinkage. The key objective of this study was to model the effect of resin-finishing process variables for predicting the shrinkage control and bursting strength of viscose single jersey knitted fabrics. The MATLAB (Version 8.2.0.701) fuzzy expert system was used to model the optimum resin and softener concentrations, as well as the best curing time for the prediction of maximum shrinkage control with a minimum loss in fabric bursting strength. The optimal process variables were found to be a resin concentration of 75 g/l, a softener concentration of 45 g/l and a curing time of 225 seconds. The fuzzy expert model developed in this study was validated using experimental data. It was found that the model has the ability and accuracy to predict fabric shrinkage and bursting strength effectively in the non-linear field.

In the area of water purification, nanotechnology offers the possibility of an efficient removal of pollutants and germs. Today nanoparticles, nanomembrane and nanopowder used for detection and removal of chemical and biological substances include metals (e.g. Cadmium, copper, lead, mercury, nickel, zinc), nutrients (e.g. Phosphate, ammonia, nitrate and nitrite), cyanide, organics, algae (e.g. cyanobacterial toxins) viruses, bacteria, parasites and antibiotics.

SUMMARY: Anodization is an electrochemical conversion process to form an oxide film on certain metals to increase the thickness of the natural oxide layer on metal surface parts. Most of the anodizing works are done by AC power supply at high voltages and current densities. We studied here the anodizing of zinc using DC power supply at low voltages and current densities. In this study, the work was conducted with galvanized steel (GS) sheet using three different baths containing varying concentrations of NaOH, Na 2 B 2 O 7 .10H 2 O, Na 2 Si 2 O 3 .9H 2 O, NaNO 2 and NiSO 4. Galvanized steel was anodized by applying 25 and 30 DC volts from each bath and 0.2, 0.25 and 0.3 A/cm 2 current densities on each applied voltage. Galvanized steel could not be anodized from the bath containing NaOH, Na 2 Si 2 O 3 .9H 2 O and NaNO 2 under the applied working conditions. However a uniform, adherent and bright anodized surface could be obtained from the borate solutions. The anodized samples thus obtained were characterized by corrosion test using immersion in a 5% NaCl solution, chemical composition analysis using Energy Dispersive X-ray (EDX), morphology study using Scanning Electron Microscopy (SEM), and microhardness measurement using Shimadzu microhardness tester. The corrosion resistance of the anodized zinc coatings was found much higher (about 6-15 times) than the galvanized steel without anodizing. The anodized coatings were composed mainly of Zn, O and Si. Microhardness of anodized zinc coatings increased with increasing applied current density. The application of low voltages eliminates the economic and risk objections of high voltage, high current zinc anodization.

Facile commercial production of versatile polyfunctional compounds from biomass constitutes a great challenge for establishing a sustainable chemical industry. One such example is the production of furfural and hydroxymethyl furfural via dehydration of pentoses and hexoses. Identified as primary building blocks in polymer industry, their massive production is highly desired, yet suffers from several problems, such as feedstock availability, low

There is a growing demand for flexible and soft electronic devices. In particular, stretchable, skin-mountable, and wearable strain sensors are needed for several potential applications including personalized health-monitoring, human motion detection, human-machine interfaces, soft robotics, and so forth. This Feature Article presents recent advancements in the development of flexible and stretchable strain sensors. The article shows that highly stretchable strain sensors are successfully being developed by new mechanisms such as disconnection between overlapped nanomaterials, crack propagation in thin films, and tunneling effect, different from traditional strain sensing mechanisms. Strain sensing performances of recently reported strain sensors are comprehensively studied and discussed, showing that appropriate choice of composite structures as well as suitable interaction between functional nanomaterials and polymers are essential for the high performance strain sensing. Next, simulation results of piezoresistivity of stretchable strain sensors by computational models are reported. Finally, potential applications of flexible strain sensors are described. This survey reveals that flexible, skin-mountable, and wearable strain sensors have potential in diverse applications while several grand challenges have to be still overcome.

Recent advances in the design and implementation of wearable resistive, capacitive, and optical strain sensors are summarized herein. Wearable and stretchable strain sensors have received extensive research interest due to their applications in personalized healthcare, human motion detection, human–machine interfaces, soft robotics, and beyond. The disconnection of overlapped nanomaterials, reversible opening/closing of microcracks in sensing films, and alteration of the tunneling resistance have been successfully adopted to develop high‐performance resistive‐type sensors. On the other hand, the sensing behavior of capacitive‐type and optical strain sensors is largely governed by their geometrical changes under stretching/releasing cycles. The sensor design parameters, including stretchability, sensitivity, linearity, hysteresis, and dynamic durability, are comprehensively discussed. Finally, the promising applications of wearable strain sensors are highlighted in detail. Although considerable progress has been made so far, wearable strain sensors are still in their prototype stage, and several challenges in the manufacturing of integrated and multifunctional strain sensors should be yet tackled.

In this study, boron doped and undoped poly(vinyl) alcohol/zirconium-barium acetate (PVA/Zr-Ba) nanofibers were prepared using an electrospinning technique then calcinated at three different temperatures; 250 oC, 500 oC, 800 oC for 2 h. The
originality of this study is the addition of boron to metal acetates. The fibers were characterized by FT-IR, DSC, XRD and SEM. The addition of boron did not only increase the thermal stability of the fibers, but also increased their diameters, which gave stronger fibers. The FT-IR spectra of the fibers were in good accordance with literature data. The DSC results indicate that the glass transition (Tg) and melting temperatures (Tm) showed a change with the addition of boron. Also, boron doped fibers were observed to degrade at higher temperatures. XRD analyses showed that after further heat treatment at 800 oC, zirconia exists in two phases of tetragonal and monoclinic modifications. The systematic evolution of morphological features in the spun and the processed fibers were studied by scanning electron microscopy. The SEM appearance of the fibers showed
that the addition of boron resulted in the formation of cross linked bright surfaced fibers.

Rationale In a previous study in healthy volunteers, the anti-Parkinsonian drug pramipexole caused sedation and pupil dilatation, consistent with the stimulation of inhibitory D2/D3 autoreceptors on the ventral tegmental area dopaminergic neurones. The sedation may be related to the removal of the dopaminergic excitation of the locus coeruleus (via the meso-coerulear pathway), whereas the pupil dilatation may be due to the removal of the dopaminergic excitation of the Edinger–Westphal nucleus (via a putative meso-pupillomotor pathway). Objectives We investigated the hypothesis that amisulpride, a D2/D3 receptor antagonist, would have effects opposite to those of pramipexole on alertness, pupillary and endocrine functions. Materials and methods Pramipexole (0.5 mg), amisulpride (50 mg), and their combination were administered to 16 healthy males in a balanced, cross-over, double-blind design. Tests included measures of alertness (Pupillographic Sleepiness Test, critical flicker fusion frequency, visual analogue scales), pupillary functions (resting pupil diameter, light and darkness reflex responses), non-pupillary autonomic functions (heart rate, blood pressure, salivation, core temperature), and endocrine functions [blood concentrations of prolactin, growth hormone (GH) and thyroid stimulating hormone (TSH)]. Data were analysed by ANOVA. Results Pramipexole reduced alertness and pupillary light reflex response amplitude, tended to reduce core temperature, reduced prolactin levels and increased GH levels. Amisulpride reduced pupil diameter, increased the amplitude of the light reflex response and prolactin and TSH levels. Conclusions The opposite effects of pramipexole and amisulpride on alertness, pupillary function and pituitary hormone levels are consistent with their interactions with inhibitory D2/D3 receptors on VTA neurones and in the tuberoinfundibular system.

Wearable transdermal delivery systems have recently received tremendous attention due to their noninvasive, convenient, and prolonged administration of pharmacological agents. Here, the material prospects, fabrication processes, and drug-release mechanisms of these types of therapeutic delivery systems are critically reviewed. The latest progress in the development of multifunctional wearable devices capable of closed-loop sensation and drug delivery is also discussed. This survey reveals that wearable transdermal delivery has already made an impact in diverse healthcare applications, while several grand challenges remain.

The differences between amorphous and glassy state are discussed and the methods of their preparation reviewed. The role of crystallization during fast cooling is analyzed and nucleation-growth process is shown in two attitude models, which characterization are depicted on DTA curves. Specificity of non- and nano-crystalline metallic glasses is revealed.