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We modified a passive capillary sampler (PCS) to collect snowmelt water for isotopic analysis. Past applications of PCSs have been to sample soil water, but the novel aspect of this study was the placement of the PCSs at the ground-snowpack interface to collect snowmelt. We deployed arrays of PCSs at 11 sites in ten partner countries on five continents representing a range of climate and snow cover worldwide. The PCS reliably collected snowmelt at all sites and caused negligible evaporative fractionation effects in the samples. PCS is low-cost, easy to install, and collects a representative integrated snowmelt sample throughout the melt season or at the melt event scale. Unlike snow cores, the PCS collects the water that would actually infiltrate the soil; thus, its isotopic composition is appropriate to use for tracing snowmelt water through the hydrologic cycle. The purpose of this Briefing is to show the potential advantages of PCSs and recommend guidelines for constructing and installing them based on our preliminary results from two snowmelt seasons.

The present study deals with the electrochemical investigation of seven different phenols through cyclic voltammetry (CV). Phenols can be partly eliminated from aqueous solutions by electrochemically initiated polymerization. Thus, the basic CV behavior was studied under the optimized conditions such as; pH of the medium, concentration of the analyte, the supporting electrolyte, potential window, and scan rate. The CV curves of all of the phenols showed that the electropolymerization phenomenon on the electrode surface causes surface fouling for further electrooxidation of these compounds. The influence of substituents in the ring was especially noted in terms of their tendency to foul the electrode surface. The formation of new intermediates during the electrooxidation was observed whose nature was found to be highly dependent on the type and position of the substituent. As far as the influence of pH is concerned, phenols in basic medium were electrooxidized earlier but with low current. Difference in CV response because of the substituent attached under varied pH was also noted. From the diffusion coefficient (D) and heterogeneous rate constant (k sh ) mixed nature of electron transfer process was proposed.

We report here first measurements of the odd-parity 6p 3/2 ns J = 1, 2 and 6p 3/2 nd J = 0, 1, 2, 3 autoionizing Rydberg levels of lead using a three-step laser excitation scheme in conjunction with an atomic beam apparatus. Four initial levels 6p 3/2 7p 1/2,3/2 J = 1, 2 were chosen for the excitation of the final levels. The assignments have been made using the j 1 K-coupling scheme for the observed levels. The Rydberg series 6pnd 3/2[1/2] 0,1 (13 n 38), 3/2[3/2] 2 (16 n 73), 3/2[5/2] 2,3 (13 n 37) and 3/2[7/2] 3 (16 n 39) as well as 6p 3/2 ns3/2[3/2] 1,2 (14 n 40) are reported. All the observed series exhibit constant quantum defects with respect to the ionization potential value 73 900.65 ± 0.05 cm −1 . The full widths at half the maximum of the observed levels are also reported.

Electronic speckle photography (ESP) for in-plane displacement (IPD) and deformation measurements is well known with its more modern form, digital image correlation (DIC). Two speckle images of an optically rough surface before and after deformation, called reference and test images, are recorded and processed for IPD or deformation measurement of the test image with respect to the reference image. The reliability of ESP in measurements depends strongly on the postprocessing of the two images by DIC, which we have referred to as conventional DIC. In this paper, we are proposing a small but useful modification in the existing DIC methods by introducing some additional steps, which drastically improves the results obtained with the existing techniques. The modification to the conventional DIC method has been referred to as modified DIC. Computer-simulated and experimental results have been presented to validate the superiority of modified DIC over conventional DIC methods.

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in the isotopic composition of leaf and stem water from an arid region of Southeast Asia. Hydrol. Sci. J. 55(5), 844-848.Abstract Stable isotopes are powerful research tools in environmental sciences and their use in ecosystem research is increasing. Stable isotope measurements allow the study of evapotranspiration fluxes, soil evaporation and leaf transpiration phenomena. Soil water and leaf water are the sources of the evapotranspiration that transfers large quantities of water from land to the atmosphere; as a result the isotopic composition of water left in the leaves is modified towards enrichment. Evaporation also changes the isotopic composition of water bodies creating a natural isotopic signal. The isotopic identity of soil water affects the oxygen isotopic signature of leaf and stem water. In this paper we present the isotopic data of bulk leaf water, showing the enrichment in isotopic value of oxygen due to evapotranspiration from leaves in conjunction with the isotopic signal of rainwater and other environmental factors such as humidity and temperature. Results suggest that the variation in the values of d 18 O of Eucalyptus citriodora, Dalbergia sissoo, Melia azedarach and Pinus roxburghii is due to the seasonal changes in the d 18 O of the source water for plants, i. e. rain. It is further observed that leaf water d 18 O values are depleted during the months of July, August and September. This occurs due to the following reasons: (a) the sampling areas receive about 50% of the average annual rain during these months, and (b) rainfalls during these months are isotopically depleted compared with winter rains.