Early warning system for rainfall- and snowmelt-induced slope failure in seasonally cold regions

In 2005, the Japanese government launched a new nationwide early warning system for predicting debris flow and slope failure disasters based on rainfall intensity and the Soil Water Index (SWI). However, the Japanese government has not set early warning criteria in many mountain areas. In addition, the existing early warning criteria in some areas are much higher than realistic ones, and snowmelt water is not considered in the calculation of the SWI. These two factors have been the cause of many slope failures in seasonally cold regions, induced by rainfall and/or snowmelt, which were not predicted. Therefore, this study attempts to propose a new determination method for setting early warning criteria for rainfall- and/or snowmelt-induced slope failures in seasonally cold regions. For this purpose, the study firstly proposes a combination model for estimating snow density that incorporates the hourly snowmelt water into the Japanese early warning system more accurately by using meteorological monitoring data and modeled snow density. Next, based on case studies and parametric analyses for slope stability assessment, new early warning criteria are proposed for predicting three different patterns of slope failures under two typical types of precipitation (rainfall and snowmelt) conditions. Finally, a new determination method for setting early warning criteria in seasonally cold regions is proposed by referring to the existing early warning criteria near the target area, in accordance with the precipitation types and the local ground conditions of the slopes. Since the existing early warning criteria near the target area already take the effects of the variations in local geology and geography into account, the new determination method for early warning criteria can be applied to arbitrary areas in seasonally cold regions, without directly considering the local soil properties, in the actual design and maintenance works.     

Sulfonated polyether sulfone‐poly(vinylidene fluoride) blend membrane for DMFC applications

Direct methanol fuel cell (DMFC) proton exchange membranes were prepared by blending poly (vinylidene fluoride) (PVDF) with sulfonated poly(ether sulfone) (SPES). Using a diffusion cell and gas chromatographic technique, the effects of PVDF content on methanol permeability in the blended membranes were investigated. The thermal resistance and proton conductivity of the membranes were also determined by using a thermal gravimetric analysis (TGA) and an impedance analysis technique respectively. The presence of sulfonic acid groups in SPES was confirmed by Fourier transform infrared (FTIR). It was found that the methanol permeability in the blended membranes decreased with PVDF content at the expense of proton conductivity. Blended membranes show methanol permeability values much lower than that of Nafion 115, whereas the proton conductivities of the membranes are comparable with that of Nafion. The thermal stability of these blended membranes is above 250°C, which is sufficiently high for use in DMFC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Photocatalytic degradation of phenol in a rotating annular reactor

Batch photocatalytic degradation studies of phenol were conducted in an annular slurry reactor, to evaluate its performance under different operating and design conditions. The reactor had two concentric cylinders with the inner one rotating at specified revolutions per minute. The reactor also had provisions for aerating the slurry present in the annular gap. The inner cylinder housed the UV-lamps. The effects of catalyst loading (0–8 g/L), inner cylinder rotation speed (0–50 rpm), annular gap-width (7.5, 17.5 and 32.5 mm), initial pollutant concentration (10–50 mg/L) and mode of illumination (continuous or periodic) were studied. Light intensity received by the slurry was measured using Actinometry. Depending on the catalyst loading, annular gap-width and number of illuminated lamps the intensity values ranged from 0.58×10^?4 to 6.4×10^?4 Einsteins/L min. Under well mixed conditions, the reactor performance was found to increase with increase in catalyst loading. At low/medium annular gap width configurations, agitation induced by continuous aeration was found to provide sufficient mixing even when the inner cylinder was stationary. Rotation of the inner cylinder was required only in the high gap width configuration at high catalyst loadings. Scale-up of the reactor was investigated by increasing the gap-width of the annulus and hence increasing the quantity of feed processed. Controlled periodic illumination created by Taylor vortices did not show any improved performance over the regular continuous illumination. Modeling of reaction kinetics was investigated with different approaches and their efficacy in fitting the concentration–time trends of both the primary pollutant and the intermediates are discussed.     

Relative element levels in the paired samples of scalp hair and fingernails of patients from New Delhi

Specific elements are bioconcentrated in human hair and nails, which have unique advantages of application in population monitoring studies thereby, recognized as biological tools for disease diagnosis and prevention. However, investigations are meager for relative element profile in hair and nails of same subjects. In this study, hair and nails were analyzed to find effects of age, sex, smoking habit, diet, urban and rural exposure gradients, occupation, and health on element levels. Scalp hair and fingernails were sampled along with a questionnaire from urban and rural subjects of New Delhi; patients of hypertension, coronary heart disease, and diabetes were identified clinically. Cadmium, chromium, copper, nickel, lead and zinc concentrations were determined by AAS in both the samples; CRM (human hair powder) analysis showed acceptable precision and accuracy in element measurement. In comparison to controls, Cr-H and Zn-H levels were lower respectively in female hypertensive and total hypertensive subjects, whereas, Zn-N and Cu-N were lower respectively in total CHD and diabetic subjects, and hypertensive and CHD urban subjects. Cd concentrations were higher in both the samples of tobacco smoking rural subjects than that of non-smokers. Farmers had lower Pb-H than rural businessmen did. Cr, Cu, Ni, and Zn concentrations were different due to rural and urban gradient but not to the influence of age, sex, and diet. Pb value was alone correlated between the paired samples. Thus, higher Cd levels in the smokers and lower Cr, Cu and Zn levels in the patients were observed.     

Total sugar content in sorghum stalks and grains of selected cultivars from the world germplasm collection

Seventy sorghum cultivars from the world germplasm collection maintained at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) were screened for total sugar content of the stalks. The total sugar content in stalks harvested after physiological maturity ranged from 17.8 to 40.3% on dry weight basis. The total sugar content in grains of 15 selected cultivars ranged from 1.02 to 2.23%. Nine cultivars having more than 34% total sugar content in stalks showed consistency for sugar content when grown for two seasons. Juiciness of stalks from five cultivars as estimated by the quantity of juice extracted varied from 266 to 464 ml per kilogram of fresh stalks. The total sugar content in the juice of five cultivars varied from 7.0 to 15.9%.     

Phthalocyanine- and Calixarene-Templating Effect on the Catalytic Performance of Solid Supported Vanadates

Abstract  

Catalytic performance of solid supported monovanadate catalysts toward oxidation of propane is significantly affected by the templating effect of: (1) pretreatment of the solid support with calixarene derivatives before deposition of ammonium vanadate, (2) direct deposition of vanadyl phthalocyanine as the vanadate precursor. This effect is believed to be linked to the accessibility of the active sites, and was studied in comparison with a reference mesoporous support.     

Applications of wittig reactions in dibenzo 18‐crown‐6‐ether substituted phenylenevinylene oligomer—synthesis,photo luminescent,and dielectric properties

Novel phenylenevinylene oligomer substituted dibenzo 18‐crown‐6 ether ring (DB‐OPV) was synthesized using dibenzo 18‐crown‐6 with terephthaldicarboxaldehyde via Wittig reaction. Formation of the oligomer was confirmed by spectral (FT‐IR, ¹H and¹³C‐NMR), gel‐permeation chromatography and elemental analysis. The morphology of the oligomer film of one‐dimensional and three‐dimensional architectures was observed using atomic force microscopy. The oligomer showed excellent photoluminescence with bluish green emission maxima at shorter wavelengths of 505 nm. Stability of the oligomer was analyzed using UV spectroscopy with varying time and temperature. The dielectric properties such as dielectric constant and loss factor for the oligomer have also been studied with respect to change of frequency (50 Hz–5 MHz) and temperature (30–60°C). The value of dielectric constant decreased with increasing frequency, which indicates that the major contribution to the polarization comes from orientation polarization. The value of dielectric constant increased with increasing temperature which is due to greater freedom of movement of the dipole molecular chains within the oligomer at high temperature © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of nitrate ions on the corrosion of stellite in permanganate media

The dissolution behaviour of stellite #3 in two oxidizing agents of equivalent acidity namely, permanganic acid (HMnO₄) and a mixture of nitric acid and potassium permanganate (NP) was evaluated. The presence of nitrate in the permanganate formulation was found to reduce its efficiency for oxidizing stellite. Electrochemical polarization and impedance studies were carried out at 90 °C in NP and HMnO₄. The redox potential of both the oxidizing agents favoured transpassive dissolution of chromium from the alloy. In NP, only the chromium depleted inter-phase boundary was attacked while most of the chromium rich carbide phases were intact. In contrast, in HMnO₄, uniform corrosion of the surface was observed. The impedance response was found to change with duration of exposure. The nitrate ions in permanganate were found to promote the repassivation of the surface. HMnO₄ was found to be a better formulation for dissolving cobalt from the alloy as compared to NP.