Zinc oxide-decorated multiwalled carbon nanotubes: a selective electrochemical sensor for the detection of Pb(II) ion in aqueous media

Journal of Materials Science: Materials in Electronics - Multiwalled carbon nanotubes, due to high conductivity, stability, and large specific surface area, have a potential ability to promote...     

Brain attack: the multifaceted potential for action

BACKGROUND: Stroke is the number 3 killer in Singapore and a common contributor to morbidity statistics. This study was done to look at the profile of patients with acute stroke presenting to the Emergency Department, Singapore General Hospital, from 1 October to 31 November 1996. The data will help plan and guide future early interventional trials as well as look into possible areas of improvement in the multidisciplinary approach to stroke. METHOD: This is a retrospective study and patients records were traced using ICD-9 codes. A total of 309 patients were identified for the period of review; of this, the records of 240 patients were obtained (77.7%). RESULTS: The results revealed that local stroke patients are young (two-thirds are < 70 years) and live in high-rise accommodation (84.2%) with their families. The predominant risk factor was hypertension (80%) and weakness was the most common presentation (25%). Stroke patients are presenting at a later stage (only 16.7% presented within 6 hours of onset) and the average length of hospital stay was between 10 and 12 days. CONCLUSION: This study identified the multiple measures at various stages of the stroke chain, required to build up a concerted effort against Brain Attack.     

DanNet: the challenge of compiling a wordnet for Danish by reusing a monolingual dictionary

This paper is a contribution to the discussion on compiling computational lexical resources from conventional dictionaries. It describes the theoretical as well as practical problems that are encountered when reusing a conventional dictionary for compiling a lexical-semantic resource in terms of a wordnet. More specifically, it describes the methodological issues of compiling a wordnet for Danish, DanNet, from a monolingual basis, and not—as is often seen—by applying the translational expansion method with Princeton WordNet as the English source. Thus, we apply as our basis a large, corpus-based printed dictionary of modern Danish. Using this approach, we discuss the issues of readjusting inconsistent and/or underspecified hyponymy hierarchies taken from the conventional dictionary, sense distinctions as opposed to the synonym sets of wordnets, generating semantic wordnet relations on the basis of sense definitions, and finally, supplementing missing or implicit information.     

Fungal xylanases‐mediated synthesis of silver nanoparticles for catalytic and biomedical applications

Green synthesis of nanoparticles has fuelled the use of biomaterials to synthesise a variety of metallic nanoparticles. The current study investigates the use of xylanases of Aspergillus niger L3 (NEA) and Trichoderma longibrachiatum L2 (TEA) to synthesise silver nanoparticles (AgNPs). Characterisation of AgNPs was carried out using UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy, while their effectiveness as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were determined. The colloidal AgNPs was brownish with surface plasmon resonance at 402.5 and 410 nm for NEA‐AgNPs and TEA‐AgNPs, respectively; while FTIR indicated that protein molecules were responsible for the capping and stabilisation of the nanoparticles. The spherical nanoparticles had size of 15.21–77.49 nm. The nanoparticles significantly inhibited the growth of tested bacteria (63.20–88.10%) and fungi (82.20–86.10%), and also scavenged DPPH (37.48–79.42%) and hydrogen peroxide (20.50–96.50%). In addition, the AgNPs degraded malachite green (78.97%) and methylene blue (25.30%). Furthermore, the AgNPs displayed excellent anticoagulant and thrombolytic activities using human blood. This study has demonstrated the potential of xylanases to synthesise AgNPs which is to the best of our knowledge the first record of such. The present study underscores the relevance of xylanases in nanobiotechnology.Inspec keywords: visible spectra, catalysis, ultraviolet spectra, silver, microorganisms, antibacterial activity, transmission electron microscopy, surface plasmon resonance, nanoparticles, nanofabrication, colloids, blood, Fourier transform infrared spectra, particle sizeOther keywords: Ag, fungal xylanases‐mediated synthesis, silver nanoparticles, catalytic applications, biomedical applications, green synthesis, metallic nanoparticles, Trichoderma longibrachiatum L2, transmission electron microscopy, antimicrobial agents, antioxidant agents, catalytic agents, thrombolytic agents, surface plasmon resonance, spherical nanoparticles, FTIR spectra, anticoagulant agents, colloidal nanoparticles, biomaterials, Aspergillus niger L3, UV‐vis spectroscopy, Fourier transform infrared spectroscopy, protein molecules, DPPH, hydrogen peroxide, malachite green, methylene blue, human blood, nanobiotechnology     

Inhibitive Behaviour of Zinc Gluconate on Aluminium Alloy in 3.5 % Nacl Solution

The present work investigates corrosion behaviour of aluminium alloy in 3.5 % sodium chloride medium at 28 °C in the absence and presence of 0.5, 1.0, 1.5 and 2.0 % g/v concentrations of zinc gluconate using gravimetric and electrochemical techniques. The aluminium alloy was cut to corrosion coupons, and immersed into 3.5 % sodium chloride solution containing different inhibitor concentrations (0.5, 1.0, 1.5 and 2.0 % g/v) within a period of twenty-eight days. The surface morphology of the metal was examined by high resolution scanning electron microscopy equipped with energy dispersive spectroscopy (HR-SEM/EDS). From the results, it was found that the adsorption of zinc gluconate reduced aluminium alloy corrosion in the sodium chloride medium. Experimental results also showed that inhibition efficiency increased with an increase in zinc gluconate concentration. Furthermore, potentiodynamic polarization results revealed decrease in corrosion rates (CR), corrosion current densities (Icorr), and increasing corrosion resistance (Rp) in the presence of zinc gluconate in 3.5 % NaCl solution. Tafel polarization analyses indicated that zinc gluconate is a mixed type inhibitor. The adsorption of zinc gluconate on the aluminium alloy surface followed Langmuir adsorption isotherm.     

全钢载重子午线轮胎垫胶4条挤出工艺问题原因分析及解决措施

分析全钢载重子午线轮胎垫胶由2条挤出变为4条挤出产生的工艺问题,并提出相应的解决措施。通过采取改造口型板、预口型及调整胶料配方适当减小垫胶粘性等措施,解决了挤出垫胶破边、宽度不一致和粘连等问题,大幅提高了垫胶半成品的尺寸合格率和生产效率,降低了轮胎生产成本和水电消耗。     

Fabrication and optimization of polypyrrole/cerium oxide/glassy carbon sensing platform for the electrochemical detection of flupirtine

Journal of Applied Electrochemistry - In spite of single nanomaterials, nanocomposites have come to be the superior modifying materials for electrochemical sensing.&nbsp;Herein, the highly...     

The influence of electrolyte reduction potential on weld corrosion

Electrochemical potentiodynamic sweeps and galvanic studies are performed to determine conditions that will initiate localized corrosion in welded areas. The reduction potential and pH in the electrolyte seemed to be essential with respect to where corrosion attacks occur in a welded area of carbon steel. The interpretation of the polarization diagrams for the different parts of the weld showed that they actually had different anodic Tafel slopes and this interpretation could be used to make predictions concerning preferential corrosion behavior. A variance of brine composition causes a change of attacked areas in a weld.     

Effect of cassava varieties on the sorption isotherm of tapioca grits

Cassava (Manihot esculenta Cranzt) deteriorates rapidly. Hence it is processed into various products within 2 to 3 days after harvesting. For this work, tapioca was produced from three different varieties of cassava. They are Odongbo, Okoiyawo and TMS30572. The sorption isotherm for the tapioca grits from three different varieties of cassava at temperatures 25, 32 and 45 °C were determined experimentally and modelled using five different models. Using analysis of variance at 0.01 level, it was shown that the experimental sorption isotherms of the tapioca from the various cassava varieties are not significantly different from each other. However, the Guggenheim (1966) , Anderson (1946) & de Boer (1953) (GAB) model gave the best fit for sorption isotherm of tapioca from either the Odongbo or Okoiyawo varieties, while the exponential model was the best for that from TMS30572 variety.