Soft matter electrolytes based on polymethylmetacrylate dispersions in lithium bis(trifluoromethanesulfonyl)imide/1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquids

Ion transport in a polymer-ionic liquid (IL) soft matter composite electrolyte is discussed here in detail in the context of polymer-ionic liquid interaction and glass transition temperature The dispersion of polymethylmetacrylate (PMMA) in 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI) resulted in transparent composite electrolytes with a jelly-like consistency The composite ionic conductivity measured over the range -30 C to 60 C was always lower than that of the neat BMITFSI/BMIPF6 and LiTFSI-BMITFSI/LiTFSI-BMIPF6 electrolytes but still very high (>1 mS/cm at 25 degrees C up to 50 wt% PMMA) While addition of LiTFSI to IL does not influence the glass T-g and T-m melting temperature significantly dispersion of PMMA (especially at higher contents) resulted in increase in T-g and disappearance of T-m In general the profile of temperature-dependent ionic conductivity could be fitted to Vogel-Tamman-Fulcher (VTF) suggesting a solvent assisted ion transport However for higher PMMA concentration sharp demarcation of temperature regimes between thermally activated and solvent assisted ion transport were observed with the glass transition temperature acting as the reference point for transformation from one form of transport mechanism to the other Because of the beneficial physico-chemical properties and interesting ion transport mechanism we envisage the present soft matter electrolytes to be promising for application in electrochromic devices (C) 2010 Elsevier Ltd All rights reserved

Role of organic fluorine in crystal engineering

The design of compounds with novel and improved physico-chemical properties as advanced functional materials with a specific application spectrum requires the knowledge about possible supramolecular packing motifs and their experimental control in crystalline lattice. Besides the structure of the individual molecule, non-covalent interactions play a significant role in the determination of molecular conformation, along with the formation of three-dimensional supramolecular architecture in a crystal as a requirement for molecular recognition processes, and the related bioactivity. Involvement of functional groups will contribute to the formation of a predefined packing motif due to their well-defined interactions. The strength and directionality of these interactions create characteristic packing motifs, which can be used for the design of supramolecular arrangements by the development of appropriate strategies for the precise control of their topology. Most relevant of these non-covalent interactions are stacking interactions and hydrogen bonds, which have been subjects of extensive study in the last two decades. In recent literature, substantial efforts have been put in by various researchers towards the understanding of interactions involving organic fluorine and the role they play in generating different packing motifs which guides assembling of molecules in the crystal lattice.

Characterization and iodide adsorption behaviour of HDPY+ modified bentonite

Owing to its favourable physical, chemical and rheological properties, densely compacted bentonite or bentonite-sand mix is considered as a suitable buffer material in deep geological repositories to store high level nuclear waste. Iodine-129 is one of the significant nuclides in the high level waste owing to its long half life and poor sorption onto most geologic media. Bentonite by virtue of negatively charged surface has negligible affinity to retain iodide ions. As organo-bentonites are known to retain iodide ions, the present study characterizes hexadecylpyridinium chloride (HDPyCl.H2O) treated bentonite from Barmer India (referred as HDPy+B) for physico-chemical properties, engineering properties and the iodide adsorption behavior of the organo clay. Batch experiments revealed that HDPy+ ions are largely retained (94 % retention) via cation exchange; the ion-exchange process neutralizes the negative surface charge and bridges clay particles leading to reduction in Atterberg limits, clay content and sediment volume. The organo clay retains iodide by Coulombic attraction (at primary sites) and anion exchange (at secondary sites). The free-energy change (Delta G (o) = -25.5 kJ/mol) value indicated that iodide retention by organo clay is favored physical adsorption process. Iodide adsorption capacity of organo clay decreased significantly (85-100 %) on dilution with 50-80 % bentonite. On the other hand, dilution of bentonite with 50 % organo clay caused 58 % reduction in swell potential and 21 % reduction in swell pressure.

Review on atomization and sprays of biofuels for IC engine applications

Ever increasing energy requirements, environmental concerns and energy security needs are strongly influencing engine researchers to consider renewable biofuels as alternatives to fossil fuels. Spray process being important in IC engine combustion, existing literature on various biofuel sprays is reviewed and summarized. Both experimental and computational research findings are reviewed in a detailed manner for compression ignition (CI) engine sprays and briefly for spark ignition (SI) engine sprays. The physics of basic atomization process of sprays from various injectors is included to highlight the most recent research findings followed by discussion highlighting the effect of physico-chemical properties on spray atomization for both biofuels and fossil fuels. Biodiesel sprays are found to penetrate faster and haw narrow spray plume angle and larger droplet sizes compared to diesel. Results of analytical and computational models are shown to be useful in shedding light on the actual process of atomization. However, further studies on understanding primary atomization and the effect of fuel properties on primary atomization are required. As far as secondary atomization is concerned, changes in regimes are observed to occur at higher air-jet velocities for biodiesel compared to those of diesel. Evaporating sprays revealed that the liquid length is longer for biodiesel. Pure plant oil sprays with potential use in CI engines may require alternative injector technology due to slower breakup as compared to diesel. Application of ethanol to gasoline engines may be feasible without any modifications to port fuel injection (PFI) engines. More studies are required on the application of alternative fuels to high pressure sprays used in Gasoline Direct Injection (GDI) engines.

Modification of crosslinked chitosan membrane using NaY zeolite for pervaporation separation of water-isopropanol mixtures

The blocked diisocyanate crosslinked chitosan membrane was modified by incorporating different mass% of NaY zeolite. The physico-chemical properties of resulting composite membranes were studied using Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The mechanical properties of the membranes were studied using universal testing machine (UTM). After measuring the equilibrium swelling, membranes were subjected to pervaporation for separation of water-isopropanol mixtures. Both flux and selectivity were increased with increasing NaY zeolite content in the membranes. The membrane containing 40 mass% of NaY zeolite exhibited the highest separation selectivity of 11,241 with a flux of 11.37 x 10(-2) kg/m(2) h for 10 mass% of water in the feed. The total flux and flux of water are almost overlapping each other, suggesting that these membranes could be effectively used to break the azeotropic point of water-isopropanol mixture. From the temperature dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. All the composite membranes exhibited lower activation energy compared to crosslinked membrane, indicating that the permeants require less energy during the process because of molecular sieving action attributed to the presence of sodalite and super cages in the framework of Nay zeolite. The Henry's mode of sorption dominates the process, giving an endothermic contribution. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

CHEXVIS: a tool for molecular channel extraction and visualization

Background: Understanding channel structures that lead to active sites or traverse the molecule is important in the study of molecular functions such as ion, ligand, and small molecule transport. Efficient methods for extracting, storing, and analyzing protein channels are required to support such studies. Further, there is a need for an integrated framework that supports computation of the channels, interactive exploration of their structure, and detailed visual analysis of their properties. Results: We describe a method for molecular channel extraction based on the alpha complex representation. The method computes geometrically feasible channels, stores both the volume occupied by the channel and its centerline in a unified representation, and reports significant channels. The representation also supports efficient computation of channel profiles that help understand channel properties. We describe methods for effective visualization of the channels and their profiles. These methods and the visual analysis framework are implemented in a software tool, CHEXVIS. We apply the method on a number of known channel containing proteins to extract pore features. Results from these experiments on several proteins show that CHEXVIS performance is comparable to, and in some cases, better than existing channel extraction techniques. Using several case studies, we demonstrate how CHEXVIS can be used to study channels, extract their properties and gain insights into molecular function. Conclusion: CHEXVIS supports the visual exploration of multiple channels together with their geometric and physico-chemical properties thereby enabling the understanding of the basic biology of transport through protein channels. The CHEXVIS web-server is freely available at http://vgl.serc.iisc.ernet.in/chexvis/. The web-server is supported on all modern browsers with latest Java plug-in.

Ag-doped hydroxyapatite as efficient adsorbent for removal of Congo red dye from aqueous solution: Synthesis, kinetic and equilibrium adsorption isotherm analysis

In the present study a versatile and efficient adsorbent with high adsorption capacity for adsorption of Congo red dye in aqueous solution at ambient temperature without adjusting any pH is presented over the Ag modified calcium hydroxyapatite (CaHAp). CaHAp and Ag-doped CaHAp materials were synthesized using facile aqueous precipitation method. The physico-chemical properties of the materials were determined by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Transmission electron microscopy (TEM), UV-Visible spectroscopy, N-2 physisorption and acidity was determined by n-butylamine titration and pyridine adsorption methods. XRD analysis confirmed all adsorbents exhibit hexagonal CaHAp structure with P6(3)/m space group. TEM analysis confirms the rod like morphology of the adsorbents and the average length of the rods were in the range of 40-45 nm. Pyridine adsorption results indicate increase in number of Lewis acid sites with Ag doping in CaHAp. Adsorption capacity of CaHAp was found increased with Ag content in the adsorbents. Ag (10): CaHAp adsorbent showed superior adsorption performance among all the adsorbents for various concentrations of Congo red (CR) dye in aqueous solutions. The amount of CR dye adsorbed on Ag (10): CaHAp was found to be 49.89-267.81 mg g(-1) for 50-300 ppm in aqueous solution. A good correlation between adsorption capacity and acidity of the adsorbents was observed. The adsorption kinetic data of adsorbents fitted well with pseudo second-order kinetic model with correlation coefficients ranged from 0.998 to 0.999. The equilibrium adsorption data was found to best fit to the Langmuir adsorption isotherm model. (C) 2015 Elsevier Inc. All rights reserved.

Enzymatic degradation of polycaprolactone-gelatin blend

Blends of polycaprolactone (PCL), a synthetic polymer and gelatin, natural polymer offer a optimal combination of strength, water wettability and cytocompatibility for use as a resorbable biomaterial. The enzymatic degradation of PCL, gelatin and PCL-gelatin blended films was studied in the presence of lipase (Novozym 435, immobilized) and lysozyme. Novozym 435 degraded the PCL films whereas lysozyme degraded the gelatin. Though Novozym 435 and lysozyme individually could degrade PCL-gelatin blended films, the combination of these enzymes showed the highest degradation of these blended films. Moreover, the enzymatic degradation was much faster when fresh enzymes were added at regular intervals. The changes in physico-chemical properties of polymer films due to degradation were studied by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. These results have important implications for designing resorbable biomedical implants.

Enzymatic degradation of polycaprolactone-gelatin blend

Blends of polycaprolactone (PCL), a synthetic polymer and gelatin, natural polymer offer a optimal combination of strength, water wettability and cytocompatibility for use as a resorbable biomaterial. The enzymatic degradation of PCL, gelatin and PCL-gelatin blended films was studied in the presence of lipase (Novozym 435, immobilized) and lysozyme. Novozym 435 degraded the PCL films whereas lysozyme degraded the gelatin. Though Novozym 435 and lysozyme individually could degrade PCL-gelatin blended films, the combination of these enzymes showed the highest degradation of these blended films. Moreover, the enzymatic degradation was much faster when fresh enzymes were added at regular intervals. The changes in physico-chemical properties of polymer films due to degradation were studied by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. These results have important implications for designing resorbable biomedical implants.

Studies on the complex formation of iron with humic substances [Translation from: Vom Wasser 53, 243-247, 1979]

Most of the humic substances which occur in natural waters have an iron content of a few percent, indicated by the mg/1 content of organically-bonded carbon. This iron is apparently bound in a complex with the humic substances, for it quite plainly differs in its chemical and physico-chemical properties from what one would expect from the purely inorganic iron-water system. The deviations range from the solubility to the redox behaviour, and thus are frequently the basis of analytical and technical difficulties. The key to the solution of most of this problem lies in a better understanding of the aforementioned bonds between the iron and the humic substances. This paper studies the iron content of the humic substance concentration from a bog lake sample and the complexing of iron by humic substances from the surface of the bog lake.

Avaliação de correlações para propriedades físico-químicas de frações de petróleo

O petróleo é uma mistura complexa consistindo em um número muito grande de hidrocarbonetos. A descrição completa de todos os hidrocarbonetos existentes nessas misturas é inviável experimentalmente ou consome tempo excessivo em simulações computacionais. Por esta razão, uma abordagem molecular completa para cálculos de propriedades dessas misturas é substituído por uma abordagem pseudo-componente ou por correlações entre propriedades macroscópicas. Algumas dessas propriedades são utilizadas de acordo com a regulamentação de venda de combustíveis, e.g., para gasolina. Dependendo do esquema de refino e do óleo cru utilizado para produção desse combustível, uma larga variedade de valores é encontrada para as propriedades de correntes de processo que compõe o combustível final. A fim de planejar com precisão adequada a mistura dessas correntes, modelos devem estar disponíveis para o cálculo preciso das propriedades necessárias. Neste trabalho, oito séries de combustíveis brasileiros e duas séries de combustíveis estrangeiros foram analisadas: frações de gasolina, querosene, gasóleo e diesel. As propriedades analisadas para as frações são: número de octano, teor de aromáticos, teor de enxofre, índice de refração, densidade, ponto de fulgor, ponto de fluidez, ponto de congelamento, ponto de névoa, ponto de anilina, pressão de vapor Reid e número de cetano. Diversas correlações foram avaliadas e os melhores desempenhos foram destacados, permitindo uma estimação precisa das propriedades do combustível avaliado. Um processo de re-estimação de parâmetros foi aplicado e novos modelos foram ajustados em comparação com os dados experimentais. Esta estratégia permitiu uma estimativa mais exata das propriedades analisadas, sendo verificada por um aumento considerável no desempenho estatístico dos modelos. Além disso, foi apresentado o melhor modelo para cada propriedade e cada série

Pig dung as pond manure: effect on water quality, pond productivity and growth of carps in polyculture system

Pig dung was used as manure at 18 and 36 t/ha/year in carp polyculture (without supplementary feeding) for 270 days. It was observed that pig dung at both the levels did not degrade the physico-chemical properties (pH, dissolved oxygen and alkalinity) of water. The nutrient (phosphates and nitrates) level of water was higher in manured ponds than control ponds (no manuring, only supplementary feeding). Further, plankton levels (phyto- and zooplankton) were also significantly higher in manured ponds. The growth of Catla catla and Labeo rohita was significantly more in manured ponds than in control ponds. Growth of Cirrhinus cirrhosus and Cyprinus carpio was significantly more in ponds manured with pig dung at 18 t/ha/year than in control ponds and the growth of Ctenopharyngodon idellus was significantly more in control than in manured ponds.

Growth performance of Chlorella ellipsoidea as biomicrocapsule using supernatant of digested sugar mill waste effluent

Biomicrocapsules mean microscopic living organisms which carry important nutrients, very essential for the growth and development of aquatic organisms as well as other animals. Among these biomicrocapsules, Chlorella ellipsoidea, an important green microalga (Chlorophyceae) which contains 40-45% crude protein, 12-16% crude lipid, 14-15% minerals, colour pigments, vitamins and carotene. The microalga, C. ellipsoidea was cultured in four different dilutions of supernatant of digested sugar mill effluent (DSME) i.e. 25, 50, 75 and 100% DSME and Bold basal medium (BBM) as control in laboratory condition. Maximum cell growth and chlorophyll a content of C. ellipsoidea were obtained on l0th day of culture in supernatant of 50% diluted DSME followed by those of this biomicrocapsule grown in BBM, and 75, 25 and 100% DSME at stationary phase. Cell number had highly (p<0.01) direct correlation with chlorophyll a (r = 0.889) of C. ellipsoidea, and optical density (r = 0.926) of media. Chlorophyll a was also highly (p<0.01) and directly correlated with optical density (r= 0.877) of media. The specific growth rates (µ/day) of cell and chlorophyll a of C. ellipsoidea grown in supernatant of 50% DSME were significantly (p<0.01) varied from those of C. ellipsoidea cultured in BBM followed by other DSME. Total biomass of C. ellipsoidea cultured in supernatant of 50% DSME was found significantly (p<0.01) higher than that of this microalga cultured in BBM, and supernatant of 25, 75 and 100% DSME. Similar trend was also observed in the case of optical density. The physico-chemical properties of media were varied with the growth of cell of this microalga. It was recorded that cell number, chlorophyll a of biomicrocapsule, and optical density of media were highly (p<0.01) and directly correlated with pH, hardness and alkalinity, and inversely correlated with nitrate-N. Crude protein and crude lipid of C. ellipsoidea grown in supernatant of 50% DSME were significantly (p<0.01) higher than those of C. ellipsoidea cultured in other DSME and BBM. Due to best growth performance exhibited by this microalga grown in supernatant of 50% DSME, it may be used to grow in supernatant of 50% DSME to get more essential nutrients than that cultured in supernatant of other DSME media.

Fish muscle structural proteins

Based on the differences in their physico-chemical properties proteins are broadly categorised as sarcoplasmic or fibrillar. The properties are important in fish technology. The authors review some of these physico-chemical properties of the proteins which have distinguished themselves as 'structural' or 'textural' proteins. As denaturation in these proteins caused by a variety of factors manifests itself in terms in the quality attributes of the product, relevant mechanisms have been particularly highlighted.

Genetic diversity of Saccostrea cucullata population in the northern coast in Persian Gulf and Oman Sea

Genetic diversity of Saccostrea cucullata in the northern coast lines of the Persian Gulf and the Sea of Oman were determined using DNA extraction and RAPD - PCR. A total of 300 samples were collected from 6 station along the coastline. Two out of six primers showed positive results namely GCG - ATC - CCC - A (Primer 1) and GTC - CAC - ACG - C (Primer 5) which were in accordance with morphometric analysis. The number of bands in the two above - mentioned primers in Khor - Tang and Chabahar station (Province of Sistan and Balouchestan) was significantly different from the number of produced bands in Dayer and Bushehr station (Province of Bushehr) as well as Gheshm and Bandar - Lengeh station (Province of Hormozgan). The cluster analisys was used to confirm the above variations. The results showed that the oyster population can be divided into two separate clusters. The first cluster included Bushehr Dayer Gheshm and Bandar - Lengeh species. The second cluster included Khor - Tang and Chabahar species. The analysis also showed that the first cluster can be divided into two Sub — cluster. Bushehr and Dayer belong to one Sub - cluster whereas Gheshm and Bandar - Lengeh form the other Sub — cluster. The formation of different vluster can be related to Physico - Chemical properties of water and climatic variations in different habitats along the Persion Gulf and the Sea of Oman. Key words: Molecular genetics, Population, RAND, PCR' Saccostrea cucullata