Risk assessment of short-chain chlorinated paraffins in Japan based on the first market basket study and species sensitivity distributions

The chemical risks of short-chain chlorinated paraffins (SCCPs) to human health and ecological species in Japan were assessed in this study. SCCPs are used as extreme pressure additives in metal-working fluids and flame retardant agents in plastic materials. The first market basket study with a high resolution gas chromatography and mass spectrometry with electron capture negative ionization is reported. Total daily food intakes for Japanese residents of different ages were estimated using Latin Hypercube simulations, and the highest 95th percentile intake is 6.8 x 10(2) ng/kg/day for a 1-year-old child. Based on the reported no-observed-adverse-effect-level (NOAEL) and the estimated exposure mainly from food, it was concluded thatSCCPs are not posing risks to humans in Japan. Ecological risks to aquatic and sediment organisms were estimated using species sensitivity distributions. The 95th percentiles of the distributions obtained by fitting several environmental SCCP concentration data of river water and sediment were 41.8 ng/L and 558 ng/g wet weight as the possible highest concentrations, respectively. No-observed-effect-concentrations (NOEC) were determined by calculating the fifth percentiles of a species sensitivity distribution, which were 2.2 microg/L for aquatic organisms and 1.7 to 13.5 mg/ kg wet weight for sediment organisms. While it is likely that there is no imminent environmental chemical risk for aquatic organisms at a regional level in Japan, this study concluded that a more detailed risk assessment is necessary for sediment organisms.     

Observation and analysis of self-organized surface grain structures in silica films under nonepitaxial growth mode

Silica films under present reactive electron beam deposition conditions have depicted a novel self-organized surface grain structures when probed through atomic force microscopy, 2D fast Fourier transform and glancing incidence X-ray diffraction techniques. The formation of such ordered surface grain structures is observed to be strongly correlated to the nucleation and growth process of the silica films. However, the nature of the substrate (amorphous or crystalline) and multilayer geometries have influenced the shapes, sizes and abundances in the grain structures and the ordering. The strain mediation of such ordered structures when buried under polycrystalline layers like Gd₂O₃ have shown to influence both the grain size as well as roughness. A variety of grain structure evolutions and morphological changes in silica layers were noticed in different multilayer geometries. It is, hence, inferred that by appropriately using combinations of these materials, it is possible to have a control over the multilayer morphology and grain structures, which is a very relevant factor in developing precision ultraviolet laser coatings.     

Characterization of poly(vinylidene fluoride-trifluoroethylene) 50/50 copolymer films as a gate dielectric

Thin films of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) 50/50 copolymer were prepared by spin coating on p-Si substrate. Thermal behavior of the film was observed by measuring the film thickness with ellipsometry as a function of the temperature and abrupt volume expansion was observed at 130–150 °C. Capacitance-voltage (C-V) and current-voltage (I-V) behavior of the aluminum/P(VDF-TrFE)/p-Si MIS (metal-insulator-semiconductor) structures were studied and dielectric constant of the P(VDF-TrFE) film was measured to be about 15.3 at optimum condition. No hysteresis was observed in the C-V curve for films as deposited and annealed (70–200 °C). Films annealed at temperatures higher than the volume expansion temperature showed substantial surface roughness due to the crystallization. Flat band voltage (V_FB) of the MIS structure with as deposited films was about −0.3 V and increased up to −2.0 V with annealing. This suggested that positive charges were generated in the film. Electronic properties of the annealed P(VDF-TrFE) film at above melting temperature were degraded substantially with larger shift in flat band voltage, low dielectric constant and low breakdown voltage. Organic thin film transistor with pentacene active layer and P(VDF-TrFE) as a gate dielectric layer showed a mobility of 0.31 cm²/V·s and threshold voltage of −0.45 V.     

Effect of Low Feed Rate FSP on Microstructure and Mechanical Properties of Extruded Cast 2285 Aluminum Alloy

Friction stir processing （FSP）, a variation of FSW （friction stir welding） is an emerging surface engineering technology that can locally eliminate casting defects and refine microstructures, thereby improving the mechanical properties of material. FSP can also produce fine grained microstructures through the thickness to impart superplasticity. The technology involves plunging a rapidly rotating, non consumable tool, comprising a profiled pin and larger diameter shoulder, into the surface and then traversing the tool across the surface. The pin and the shoulder friction heat the surface which alters the grain structure in the processed area thereby improving the mechanical properties. This paper presents the effects of FSP on microstructure and mechanical properties of extruded cast 2285 aluminum alloy at three different feed rates viz. 10, 12 and 15 mm/min. With the increase in the feed speed the material was observed to have increased impact strength. FSP also increased the tensile and yield strengths with increases in hardness and ductility values also. The observation has been listed in detail and pictorially represented.     

PEDOT-Au nanocomposite films for electrochemical sensing of dopamine and uric acid

In this work, conducting polymer impregnated gold nanoparticles are synthesized through a sequence of chemical and electrochemical routes. The nanocomposite film is characterized using UV-vis, FTIR spectroscopy, and SEM techniques to study the formation of oxidized PEDOT and Au0. The advantages of these films are demonstrated for sensing biologically important compounds such as dopamine and uric acid in presence of excess ascorbic acid, one of the major interferants in the detection of DA and UA (mimicking the physiological conditions), with superior selectivity and sensitivity when compared to the polymer film alone. Simultaneous determination is realized at 115 mV and 246 mV for DA and UA, respectively. The PEDOT matrix is recognized to be responsible for the peak separation (selectivity) while also favouring catalytic oxidation of the above compounds and the nanometer-sized gold particles allow nanomolar sensing of DA and UA (sensitivity). Thus, it is possible to detect nanomolar levels of DA and UA in presence of excess of AA. The combined effect of Au nanoparticles and the PEDOT matrix is rationalized that the Aunano surrounded by a "hydrophobic sheath (PEDOT)" tending to reside within these hydrophobic regions of PEDOT, thus favouring the selectivity and sensitivity of the DA/UA detection. This new generation of nanocomposites is expected to enhance the value of electroanalytical techniques, as it is possible to tune their properties suiting the analytical needs.     

Effect of Plasma Treatment on Air and Water-Vapor Permeability of Bamboo Knitted Fabric

In this paper, the effects of oxygen and atmospheric plasma on air and water-vapor permeability properties of single jersey bamboo fabric have been investigated. The changes in these properties are believed to be related closely to the inter-fiber and inter-yarn friction force induced by the plasma treatments. The outcomes showed that the water-vapor permeability increased, although the air permeability decreased along with the plasma treatments. The SEM images clearly showed that the plasma modified the fiber surface outwardly. The results showed that the atmospheric plasma has an etching effect and increases the functionality of a bamboo surface, which is evident from SEM and FTIR–ATR analysis. These results reveal that atmospheric pressure plasma treatment is an effective method to improve the performance of bamboo fabric. Statistical analysis also indicates that the results are significant for air permeability and water-vapor permeability of the plasma-treated bamboo fabric.     

In vitro antitumor assessments of peptide nanocomplexes on Dalton's lymphoma ascites tumor model

This research work reports the in vitro antitumor personality of few novel peptide nanocomplexes synthesized via a phase-assisted, modified Brust–Schiffrin methodology. Here, a series of metallo(copper, cobalt, nickel and zinc) nanocomplexes engineered with a pre-prepared peptide [N,N′-(1,2-ethylene)-bis-hippuricamide] have been synthesized for damaging the Dalton's lymphoma ascites tumor model. All the peptide nanocomplexes are spectrally, thermally and morphologically examined. The peptide bound zinc and cobalt nanocomplexes deliver excellent antitumor behavior against both the animal and human cancer cell lines, which has been pre-documented by their efficient DNA damaging skills under physiological conditions. Additionally, all the nanocomplexes are evaluated for the inhibition of microbial augmentation against few fungal and bacterial strains. The above results demonstrate that, a consecutive development of these kinds of peptide nanocomplexes may exemplify their uniqueness in biomedical applications as useful molecular-level devices.     

Performance investigation of heat pipe using aqueous solution of n-Pentanol with different inclinations

The orientation of the heat pipe plays the significant role in its performance. In specific orientations, the performance of the heat pipe is directly related to the wick structure. In conventional heat pipe, the working fluid is used a negative surface-tension gradient with temperature. It is an unfavorable one and it decreases the heat transport between the evaporator section and the condenser section. An Aqueous solution of n-Pentanol having a positive surface tension gradient with temperature is suggested as a working medium for heat pipe to improve the performance of capillary limit and operating stability. The objective of this paper is to perform a comparative study of heat pipe performance using the aqueous solution of n-Pentanol with water at various inclinations. The results are presented to demonstrate the merits and suitability of the aqueous solution of n-Pentanol as a working fluid for heat pipe.     

Shape engineering vs organic modification of inorganic nanoparticles as a tool for enhancing cellular internalization

ABSTRACT: In nanomedicine, physicochemical properties of the nanocarrier affect the nanoparticle's pharmacokinetics and biodistribution, which are also decisive for the passive targeting and nonspecific cellular uptake of nanoparticles. Size and surface charge are, consequently, two main determining factors in nanomedicine applications. Another important parameter which has received much less attention is the morphology (shape) of the nanocarrier. In order to investigate the morphology effect on the extent of cellular internalization, two similarly sized but differently shaped, rod-like and spherical, mesoporous silica nanoparticles were synthesized, characterized and functionalized to yield different surface charges. The uptake in two different cancer cell lines was investigated as a function of particle shape, coating (organic modification), surface charge and dose. According to the presented results, particle morphology is a decisive property regardless of both the different surface charges and doses tested, whereby rod-like particles internalized more efficiently in both cell lines. At lower doses, whereby the shape-induced advantage is less dominant, however, charge-induced effects can be used to fine-tune the cellular uptake as a prospectively "secondary" uptake regulator for tight dose-control in nanoparticle-based drug formulations.     

Developing Temperature–Time and Pressure–Time Diagrams for Diffusion Bonding AZ31B Magnesium and AA6061 Aluminium Alloys

Diffusion bonding is a suitable process for joining dissimilar materials without much difficulty. In this investigation, an attempt was made to develop temperature–time and pressure–time diagrams for effective diffusion bonding of AZ31B magnesium and AA6061 aluminium alloys. The bonding quality of the joints was checked by microstructure analysis, lap shear tensile testing and ram tensile testing. Based on the results, temperature–time and pressure–time diagrams were constructed and these diagrams will act as reference maps for selecting appropriate process parameters to get quality bonds.