Enhancement of cotton hydrophobicity through modified styrene admicellar polymerization

A novel modified admicellar polymerization (ADPM) technique has been proposed for achieving hydrophobicity oncotton fabrics by synthesizing an ultrathin layer of polystyrene on them. The effect of ethanol and methanol on styreneADPM has been investigated and polymerization time is halved by using methanol at a concentration as low as 0.3 M.Evaluation of the hydrophobic effect is performed through drop tests, contact angle measurements and durability tests.Contact angle of water is as high as ~ 130° and water droplets are repelled for more than 30 min. ADPM delivershydrophobicity which is comparable with commercially available water repellents based on stearic acid melamine resins.Characterization through SEM confirms the formation of ultrathin layers of polystyrene on cotton. Thus, the findingssuccessfully exhibit a modified ADPM process as a potential water repellent finish affording conservation of time andchemicals

An experimental study on micro-structural and geotechnical characteristics of expansive clay mixed with EPS granules

© 2020 Pavement structures constructed on the expansive soil subgrade experience a higher upward pressure compared to any other subgrade material. The upward pressure is caused due to high swelling and shrinkage characteristics of expansive clay soil. The present study has investigated and identified the mechanisms by which a remolded expansive soil can be modified to reduce the upward pressure and swelling (heave). To achieve this, a lightweight, environmentally friendly, and high pressure resistive expanded polystyrene (EPS) granules have been used with expansive soil s from three different locations of Madhya Pradesh state, India. The study has been performed to understand the swelling and strength characteristics of soil with and without the use of EPS (density = 21.6 kg/m3) as per ASTM specifications. The chemical and microstructural components of the expansive soil were investigated using autotuned total reflectance Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). Several laboratory experiments, including optimum moisture content, maximum dry unit weight, grain-size distribution, liquid limit, plastic limit, shrinkage limit, free swell index, unconfined compressive strength, and pressure swelling tests were carried out on the statically compacted expansive clay soil specimen with and without EPS (0.25%, 0.50%, 1.00%). The maximum addition of EPS was considered as 1% as the very high expansion was observed, and beyond this, further addition of EPS was not feasible. The results show that the swelling pressure, expansion percentage, and time rate of swell decrease, whereas the unconfined compressive strength (UCS) increases with the addition of EPS. The inclusion of EPS in expansive clay soil exponentially reduced the heave and the upward pressure, whereas the maximum UCS was observed at 0.5%

Nonlinear electromagnetic wave equations for superdense magnetized plasmas

By using the quantum hydrodynamic and Maxwell equations, we derive the generalized nonlinear electron magnetohydrodynamic, the generalized nonlinear Hall-MHD (HMHD), and the generalized nonlinear dust HMHD equations in a self-gravitating dense magnetoplasma. Our nonlinear equations include the self-gravitating, the electromagnetic, the quantum statistical electron pressure, as well as the quantum electron tunneling and electron spin forces. They are useful for investigating a number of wave phenomena including linear and nonlinear electromagnetic waves, as well as three-dimensional electromagnetic wave turbulence spectra and structures arising from mode coupling processes at nanoscales in dense quantum magnetoplasmas

Chemolithotrophic and chemoheterotrophic microorganisms in sedimented and rock-hosted hydrothermal systems

Deep-sea hydrothermal vent systems are highly productive ecosystems, where reduced energy sources fuel complex communities of microorganisms, invertebrates and vertebrates. Since decades the oxidation of methane, hydrogen and inorganic sulfur compounds has been extensively studied. However, the role of inorganic nitrogen and of organic compounds as energy source has been investigated only scarcely in hydrothermal fluids, in particular at the sea floor, where hydrothermal fluids exit subsurface. The aim of my thesis was to shed light on these under-investigated topics. In my first project I studied nitrification and the involved microbes that are associated with large, nitrate-respiring and sulfur-oxidizing bacteria (SOB) of the genus Beggiatoa. These SOB formed mats and covered sulfide- and ammonia-rich hydrothermal sediments in the Guaymas Basin. In these mats, nitrification rates were measured using 15N-labeled ammonium. With up to 605 Mikromol N l-1 mat d-1 the nitrification rates were the highest measured for a deep-sea ecosystem. Diversity and quantitative PCR of the ammonia monooxygenase subunit A gene (amoA) indicated association of ammonia-oxidizing archaea (AOA) and bacteria (AOB) with Beggiatoa mats. In line with this, single cells of AOB and potentially ammonia-oxidizing thaumarchaotes were attached to narrow Beggiatoa-like filaments. Nitrite oxidizing bacteria were also found. Nitrifying bacteria associated with Beggiatoa mats that respire nitrate to ammonium (DNRA) could display a syntrophic consortium that internally cycle nitrogen and thereby reduce loss of bioavailable nitrogen. However, it is not clear whether large SOB in general respire nitrate also to dinitrogen. Therefore, I analyzed the genetic potential of the large SOB Candidatus Thiomargarita nelsonii , a close relative of Beggiatoa. The comparison to four other Beggiatoaceae identified genes for both denitrification and DNRA in Ca. T. nelsonii and three other Beggiatoaceae. This indicates that both pathways are widely distributed among large SOB and questions the hypothesis of internal N-cycling in mats of large SOB. In my third project I investigated the microbial consumption of organic compounds that are produced in hydrothermal systems. In particular I studied acetate-assimilating heterotrophic communities in the diffuse fluids (temperature range of 4-72 degree Celsius) of two rock-hosted hydrothermal systems. 16S rRNA gene-based diversity analysis and fluorescence in situ hybridization (FISH) showed that either Gammaproteobacteria or Epsilonproteobacteria rapidly grew during short-term (8-12 h) incubations with 13C-acetate. Single cells of both groups incorporated 13C-acetate as shown by nanoSIMS. Marinobacter spp. and a novel group among the Nautiliales could be heterotrophs in these systems. These are potential r-strategists that quickly respond to the fluctuating availabilities of energy sources in hydrothermal fluids

Reconstruction Methods for Providing Privacy in Data Mining

Data mining is the process of finding correlations or patterns among the dozens of fields in large database. A fruitful direction for data mining research will be the development of techniques that incorporate privacy concerns. Since primary task in our paper is that accurate data which we retrieve should be somewhat changed while providing to users. For this reason, recently much research effort has been devoted for addressing the problem of providing security in data mining. We consider the concrete case of building a decision tree classifier from data in which the values of individual records have been reconstructed. The resulting data records look very different from the original records and the distribution of data values is also very different from the original distribution. By using these reconstructed distribution we are able to build classifiers whose accuracy is comparable to the accuracy of classifiers built with the original data

Development of sunlight-driven eutectic phase change material nanocomposite for applications in solar water heating

Organic phase change materials (PCMs) have been utilized as latent heat energy storage medium for effective thermal management. In this work, a PCM nanocomposite, consisting of a mixture of two organic PCMs (referred to as eutectic gel PCM) and minimal amount (0.5 wt%) of nanographite (NG) as a supporting material, was prepared. Differential scanning calorimeter was used to determine the melting temperature and latent heat of pristine PCM, paraffin (61.5 °C and 161.5 J/g), eutectic gel PCM (54 °C and 158 J/g) and eutectic gel PCM nanocomposite (53.5 °C and 155 J/g). The prepared PCM nanocomposites exhibited enhanced thermal conductivity and ultrafast thermal charging characteristics. The nanocomposites were employed for two different applications: (i) providing hot water using an indigenously fabricated solar water heating (SWH) system and (ii) solar rechargeable glove that can be rapidly warmed and used. Experimental results on SWH system show that the use of PCM nanocomposites helps to increase the charging rate of PCM while reducing the discharging rate of heat by PCM to water, thus enhancing the maximum utilization of solar energy and hence improving the efficiency of the SWH system. The experimental results on solar rechargeable glove revealed that the glove has the ability to retain the temperature up to 3 hours

Impact of terminal heat stress on pollen viability and yield attributes of rice (Oryza sativa L.)

Global warming is rising as a serious concern affecting agricultural production worldwide. Rice is a staple food crop and the threshold temperature for its pollination is 35 °C. A rise in temperature above this value can cause pollen sterility and may severely affect fertilization. Therefore, a study emphasizing the rise in temperature with respect to pollen viability was conducted with eleven rice genotypes during kharif seasons of 2010 and 2011 in indigenous field conditions. Increasing mean temperature by 12 °C at full flowering was found to severely affect the spikelet attributes of the crop. All genotypes showed spikelet sterility above 90% during both seasons. The study indicated that increased temperature may limit rice yield by affecting spikelet fertility and grain filling. The net reduction in grain yield was 30.4% and 27.6% in 2010 and 2011, respectively. A clear reduction in pollen size under high temperature was shown by scanning electron microscopy