On the predictability of the water-table variation in a ditch-drainage system

The irrigation in regions of brackish groundwater in many parts of the world results in the rise of the water-table very close to the groundsurface. The salinity of the productive soils is therefore increased. A proper layout of the ditch-drainage system and the prediction of the spatio-temporal variation of the water table under such conditions are of crucial importance in order to control the undesirable growth of the water-table. In this paper, an approximate solution of the nonlinear Boussinesq equation has been derived to describe the water-table variations in a ditch-drainage system with a random initial condition and transient recharge. The applications of the solution is discussed with the help of a synthetic example.Notations a lower value of the random variable representing the initial water-table height at the groundwater divide - a+b upper value of the random variable representing the initial water-table height at the groundwater divide - h variable water-table height measured from the base of the aquifer - K hydraulic conductivity - L half width between ditches - m ₀ initial water-table height at the groundwater divide - N(t) rate of transient recharge at time t - N ₀ initial rate of transient recharge - P N ₀/K - S Specific yield - t time of observation - t ₀ logarithmic decrement of the recharge function - T Kt/SL - x distance measured from the ditch boundary - X x/L - Y h/L - Y mean of Y - Y Variance of Y     

Quantification of crustal geotherms along with their error bounds for seismically active regions of India: A Matlab toolbox

Determination of the thermo-mechanical structure of the crust for seismically active regions using available geophysical and geological data is of great importance. The most important feature of the intraplate earthquakes in the Indian region are that the seismicity occurs within the entire crust. In Latur region of India an earthquake occurred in the upper crust. In such situations, quantifying the uncertainties in seismogenic depths becomes very important. The stochastic heat conduction equation has been solved for different sets of boundary conditions, an exponentially decreasing radiogenic heat generation and randomness in thermal conductivity. Closed form analytical expressions for mean and variance in the temperature depth distribution have been used and an automatic formulation has been developed in Matlab for computing and plotting the thermal structure. The Matlab toolbox presented allows us to display the controlling thermal parameters on the screen directly, and plot the subsurface thermal structure along with its error bounds. The software can be used to quantify the thermal structure for any given region and is applied here to the Latur earthquake region of India.     

电力电子和未来的航海电气系统(上)

明天的航海电气系统将同今天的系统有极大的不同。电力电子给予船舶上包括推进、电力分配、备用电源、声纳和雷达等在内的各种系统的进展以重要的影响。刚刚出现的新材料、新器件和新的系统概念(诸如宽带半导体材料、碳化硅基的电力半导体器件、电力电子模组(PEBB),以及集成功率系统)正在使、并将持续地使未来的航海系统有别于今天的系统,如同内燃船舶有别于蒸汽船舶。但是,这些正在实现的技术和有关概念还未被大家所周知,而且还有难于理解的地方。本文就将介绍这些新概念和新技术,指出潜在的影响力,并揭示新的设计方法,以推动航海电气系统的发展。     

Thermo‐responsive polymers for drag reduction in turbulent Taylor–Couette flow

The addition of a small amount of high molecular weight polymer to a solvent can substantially decrease friction losses by approximately 80%. This phenomenon known as drag reduction (DR) is used extensively in oil recovery during hydraulic fracturing and in many other applications to reduce the pumping costs. However, because of long chain length, these polymers get adsorbed on the surface of reservoir, diminishing the effectiveness of fracking. In the current study, a thermo‐responsive polymer, i.e., poly(N‐isopropylacrylamide) (PNIPAM) is investigated as a drag reducing agent (DRA), which collapses reversibly above 33 °C known as lower critical solution temperature (LCST), thereby preventing it from getting adsorbed beyond this temperature. Free radical polymerization was used to synthesize the PNIPAM and a Taylor–Couette (TC) setup with a rotating inner cylinder was utilized for measuring the DR. The effect of concentration, Reynolds number (Re), and temperature on DR were studied and a maximum of 50% DR was observed at 400 PPM concentration. PNIPAM demonstrated significant decrease in DR beyond LCST, validating its thermo‐responsive nature that could be beneficial for DR in oil recovery or in providing a control modality to DR technologies.DR versus temperature for PNIPAM solution (500 PPM) at Re = 100,000 demonstrating responsive behavior with temperature © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44191.     

Dynamic Assessment of Functional Lipidomic Analysis in Human Urine

The development of enabling mass spectrometry platforms for the quantification of diverse lipid species in human urine is of paramount importance for understanding metabolic homeostasis in normal and pathophysiological conditions. Urine represents a non‐invasive biofluid that can capture distinct differences in an individual's physiological status. However, currently there is a lack of quantitative workflows to engage in high throughput lipidomic analysis. This study describes the development of a MS/MS^ALL shotgun lipidomic workflow and a micro liquid chromatography–high resolution tandem mass spectrometry (LC–MS/MS) workflow for urine structural and mediator lipid analysis, respectively. This workflow was deployed to understand biofluid sample handling and collection, extraction efficiency, and natural human variation over time. Utilization of 0.5 mL of urine for structural lipidomic analysis resulted in reproducible quantification of more than 600 lipid molecular species from over 20 lipid classes. Analysis of 1 mL of urine routinely quantified in excess of 55 mediator lipid metabolites comprised of octadecanoids, eicosanoids, and docosanoids generated by lipoxygenase, cyclooxygenase, and cytochrome P450 activities. In summary, the high‐throughput functional lipidomics workflow described in this study demonstrates an impressive robustness and reproducibility that can be utilized for population health and precision medicine applications.     

Transmission Disequilibrium Test (TDT) for a pair of linked marker loci

A general theory of the Transmission Disequilibrium Test for two linked flanking marker loci used in interval mapping of a disease gene with an arbitrary mode of inheritance based on the genotypic relative risk model is presented from first principles. The expectations of all the cells in a contingency table possible with four marker haplotypes (transmitted vs. not transmitted) are derived. Although algebraic details of the six possible linkage tests are given, only the test involving doubly heterozygous parents has been considered in detail. Based on a test of symmetry of a square contingency table, chi-square tests are proposed for the null hypothesis of no linkage between the markers and the disease gene. The power of the tests is discussed in terms of the corresponding non-centrality parameters for each of the four modes of inheritance viz. additive, recessive, dominant and multiplicative. Sample sizes required for 80% power at the significance level of 0.05 have also been computed in each case. The results have been presented both for the case when the pair of markers is at the disease susceptibility locus as well as for the case when it is not so. In addition to the marker gene frequencies, recombination probabilities, and various association parameters, etc., it is found that the results depend on a composite parameter involving the genotypic relative risk of the homozygous disease genotype and the disease gene frequency instead of its constituents individually. The power increases with the decrease in the recombination probability in general but their magnitudes differ across the modes of inheritance. Additive and multiplicative modes of inheritance, in general, are found to give almost similar sample sizes. The sample sizes are found to be higher when the marker haplotype is not at the disease susceptibility locus than when the markers are there, indicating loss of power of the tests in the former case. But these are lower than the sample sizes required in the single marker case, thereby showing the superiority of the strategy in adopting the two marker loci for the transmission disequilibrium test. The use of linkage information between the markers seems to improve matters when this strategy is adapted for disease gene identification. The computations for sample sizes required for 80% power at the significance level of 5×10⁻⁸ used in TDT for fine mapping and genome-wide association studies indicate that the sample sizes needed could be several times larger than those for the traditional significance level of 0.05.     

Synthesis,characterisation and use of 2-tetradecylcyclobutanone together with other cyclobutanones as markers for irradiated liquid whole egg

The synthesis and characterisation of 2-tetradecylcyclobutanone (TCB) is described. Both 2-dodecykyclobutanone and TCB were shown to be present in liquid whole egg irradiated at doses of 2.5 and 10.0 kGy. These compounds were absent from the unirradiated pasteurised samples. Using gas chromatography and infrared spectroscopy, there was also evidence for the presence in irradiated egg of 2-tetradeccnyl- and 2-tetradecadienylyclobutanone which are formed from oleic and linoleic acids, respectively. Authentic standards for these unsaturated cyclobutanones were not available commercially but the presence of 2-tetra-decenylcyclobutanone was substantiated by hydrogenating the egg extracts so converting this unsaturated cyclobutanone to TCB. Saturated and unsaturated cyclobutanones appear to be specific products of irradiation and are potential markers for detection of irradiated liquid egg and probably other fat-containing foods.     

Heterophyid eggs in human stool samples in Assam: first report for India

Two cases from a Muslim family in upper Assam were found to pass trematode eggs morphologically similar to the members of the family Heterophyidae Odhner, 1914. The eggs characteristically yellowish brown in colour, ovoid, have a thick shell and are operculate. They measured 31.5 +/- 2.0 um SD x 22.4 +/- 1.9 um SD with well developed miracidium. This is the first record of human heterophyid infection from India.