406 research outputs found

    Thermodynamic function of valineacid in n-n dimethyl formamide mixtures from conductance measurement

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    Some physical properties enthalpy (?H), entropy (?s), free energy (?G),capacities(?cp?) and Pka values) for valine in dimethyl foramideover the temperature range 293.15-318.15K, were determined by direct conductance measurements. The acid dissociation at six temperature was examined at solvent composition x2) involving 0.141 of dimethyl foramide . As results, calculated values have been used to determine the dissociation constant and the associated thermodynamic function for the valine in the solvent mixture over temperatures in the range 293.15-318.15 k. The Pka1, and Pka2 were increased with increasing temperature

    Turmeric dyeing and chitosan/titanium dioxide nanoparticle colloid finishing of cotton fabric

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    The possibility of combining the finishing and natural dyeing of cotton fabric has been studied using a single-stage, paddry-cure technique, by treating it with chitosan/titanium dioxide nanoparticle colloids and turmeric dye. Differentparameters have been studied to optimise the process, such as the chitosan/TiO2 nanoparticle colloid concentration, citricacid crosslinker concentration, sodium pyrophosphate catalyst concentration, dye concentration, pH, curing time, andtemperature. To investigate the effects of combined treatment on the dyeing and functional properties of the treated cottonfabric, its ultraviolet protection factor, antibacterial activity, self-cleaning properties, rigidity, colour strength (K/S), fastnessbehaviour, nitrogen content, and wettability are determined. In addition, the cotton fabric surface is characterised usingscanning electron microscopy. The samples treated with chitosan/TiO2 in the presence of citric acid exhibit excellentprotection against ultraviolet radiation as well as antibacterial activity. The optimum conditions are 0.75% TiO2 (w/v), 10% dye (w/v), 2.5% chitosan (w/v), 30 g/L citric acid, 4 g/L sodium pyrophosphate, 70°C drying temp. and 5 min drying time,180°C curing temp. and 2 min curing time. The results also indicate the efficiency of the treatment in improving the selfcleaningproperties of the fabric. A significant improvement in the colour fastness is observed for the treated fabrics

    An advection-diffusion model to explain thermal surface anomalies off Cape Trafalgar

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    The authors describe an almost permanent thermal anomaly, with low surface-temperature values, off Cape Trafalgar. The existence of strong tidal currents in the alongshore direction, and the local offshore orientation of isobaths at this point, support the hypothesis of vertical forcing by interaction between the barotropic tide and topography. This is simplified for modelisation as the pass of a tidal current over a ridge, which is considered uniform in the crossshore direction. A bidimensional model in finite differences is developed to reproduce the main features observed experimentally. The combined effects of advection (both vertical and horizontal) and diffusion appear to be very important. The model is sensitive to the assumed values of thermal diffusion coefficients and their depth dependence, as well as to heat flux through the sea surface. To have realistic values for these parameters, a unidimensional diffusion model aimed at reproducing the mixed layer and thermocline observed in this area during summer has been developed. Heat flux and diffusion coefficients are adjustment parameters of the model, and, once determined, they are introduced in the 2-D advection-diffusion model. Results from simulation seem to be in good agreement with CTD observations, confirming our initial hypothesis.Se describe una anomalía térmica caracterizada por bajas temperaturas superficiales frente al cabo de Trafalgar. Debido a que la orientación de las isóbatas en esta área es casi perpendicular a la costa y a que existen fuertes corrientes de marea a lo largo de ella, se desarrolla la hipótesis de que la interacción entre las corrientes de marea y la topografía son los mecanismos responsables de esta anomalía. Para revisar esta hipótesis se desarrolla en el presente trabajo un modelo de advección-difusión que estudia el efecto del paso de una corriente de marea sobre un obstáculo. El modelo es sensible a ciertos parámetros, como los coeficientes de difusión térmica y el flujo de calor en la superficie del mar. Por ello desarrollamos un modelo monodimensional que reproduce la formación de la capa de mezcla y la termoclina estacional usando estos parámetros como parámetros de ajuste. Una vez encontrados los valores adecuados, son introducidos en el modelo de advección-difusión. Los resultados obtenidos parecen estar de acuerdo con los datos experimentales.Instituto Español de Oceanografí

    Advances in crowd analysis for urban applications through urban event detection

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    The recent expansion of pervasive computing technology has contributed with novel means to pursue human activities in urban space. The urban dynamics unveiled by these means generate an enormous amount of data. These data are mainly endowed by portable and radio-frequency devices, transportation systems, video surveillance, satellites, unmanned aerial vehicles, and social networking services. This has opened a new avenue of opportunities, to understand and predict urban dynamics in detail, and plan various real-time services and applications in response to that. Over the last decade, certain aspects of the crowd, e.g., mobility, sentimental, size estimation and behavioral, have been analyzed in detail and the outcomes have been reported. This paper mainly conducted an extensive survey on various data sources used for different urban applications, the state-of-the-art on urban data generation techniques and associated processing methods in order to demonstrate their merits and capabilities. Then, available open-access crowd data sets for urban event detection are provided along with relevant application programming interfaces. In addition, an outlook on a support system for urban application is provided which fuses data from all the available pervasive technology sources and finally, some open challenges and promising research directions are outlined

    2-(1H-1,3-Benzodiazol-2-ylsulfan­yl)-1-(4-chloro­phen­yl)ethanone

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    The mol­ecule in the structure of the title compound, C15H11ClN2OS, displays two planar residues [r.m.s. deviation = 0.014 Å for the benzimidazole residue, and the ketone group is co-planar with the benzene ring to which it is attached forming a O—C—C—C torsion angle of −173.18 (14) °] linked at the S atom. The overall shape is based on a twisted V, the dihedral angle formed between the two planes being 82.4 (2) °. The amine-H atom is bifurcated, forming N—H⋯O and N—H⋯S hydrogen bonds leading to dimeric aggregates. These are linked into a supra­molecular chain along the c axis via C—H⋯π hydrogen bonds. Chains form layers in the ab plane being connected along the c axis via weak π–π inter­actions [3.9578 (8) Å] formed between centrosymmetrically related chloro-substituted benzene rings

    Poly(ionic liquid) nanovesicles via polymerization induced self-assembly and their stabilization of Cu nanoparticles for tailored CO2 electroreduction

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    Herein, we report a straightforward, scalable synthetic route towards poly(ionic liquid) (PIL) homopolymer nanovesicles (NVs) with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm via one-step free radical polymerization induced self-assembly. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multilamellar packing of PIL chains occurred in all samples. The transformation mechanism of NVs’ internal morphology is studied in detail by coarse-grained simulations, revealing a correlation between the PIL chain length and the shell thickness of NVs. To explore their potential applications, PIL NVs with varied shell thickness are in situ functionalized with ultra-small (1 ∼ 3 nm in size) copper nanoparticles (CuNPs) and employed as electrocatalysts for CO2 electroreduction. The composite electrocatalysts exhibit a 2.5-fold enhancement in selectivity towards C1 products (e.g., CH4), compared to the pristine CuNPs. This enhancement is attributed to the strong electronic interactions between the CuNPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as new electrocatalyst supports in CO2 conversion to C1 products

    Clinical characteristics of women diagnosed with carcinoma who tested positive for cervical and anal high-risk human papillomavirus DNA and E6 RNA

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    High-risk human papillomavirus (hrHPV) is an essential cause of cervical carcinoma and is also strongly related to anal cancer development. The hrHPV E6 oncoprotein plays a major role in carcinogenesis. We aimed to evaluate the frequency of hrHPV DNA and E6 oncoprotein in the anuses of women with cervical carcinoma. We analyzed 117 women with cervical cancer and 103 controls for hrHPV and the E6 oncogene. Positive test results for a cervical carcinoma included 66.7 % with hrHPV-16 and 7.7 % with hrHPV-18. One case tested positive for both HPV variants (0.9 %). The samples from the anal canal were positive for HPV-16 in 59.8 % of the cases. Simultaneous presence of HPV in the cervix and anal canal was found in 53.8 % of the cases. Regarding expression of E6 RNA, positivity for HPV-16 in the anal canal was found in 21.2 % of the cases, positivity for HPV-16 in the cervix was found in 75.0 %, and positivity for HPV-18 in the cervix was found in 1.9 %. E6 expression in both the cervix and anal canal was found in 19.2 % of the cases. In the controls, 1 % tested positive for HPV-16 and 0 % for HPV-18. Anal samples from the controls showed a hrHPV frequency of 4.9 % (only HPV16). The presence of hrHPV in the anal canal of women with cervical cancer was detected at a high frequency. We also detected E6 RNA expression in the anal canal of women with cervical cancer, suggesting that these women are at risk for anal hrHPV infection.We acknowledge the Research Support Fund of the State of São Paulo (FAPESP), process number 2010/16795–4), for the financial support grants. FAPESP had no other type of influence on this manuscript beyond the financial suppor

    Impact of family structure and sociodemographic characteristics on parents headed families in Ramadi City, Iraq

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    Background: Several factors in the family profile contribute significantly to determining the effective policy when heading the family. This study aims to evaluate the sociodemographic and economic burdens on parents-headed families in Ramadi City, west of Iraq. Methods: A prospective cross-sectional household-based survey was conducted from 1st to 28th February 2019 among Iraqi people residents in Ramadi city, Anbar province. A multistage sampling technique was recruited to identify the eligible sample. A semi-structured questionnaire was used to interview (face-to-face) the respondents. Data from 267 households have undergone univariate and bivariate analyses. Multiple logistic regression, odds ratio (OR), and confidence intervals (CIs) were estimated to explore the predicting variables. The statistically significant is considered at less than 0.05. Results: The mean age of respondents was 43.88 (± 12.1) years (range: 25 to 69 years). Out of the total surveyed people, 52.8% were young (less than 44 years), male-headed families (59.6%), low educated level (65.5%), unemployed (52.4%), married (67.4%) and headed big families of seven members and above (43.1%). History of chronic diseases and smoking habits was positive among 46.4% and 45.7% of respondents, respectively. Findings of the binary logistic regressions showed that history of smoking (OR = 7.201, 95% CI: 3.254 to15.936), families of 7 members and above (OR = 6.239, 95% CI: 2.938 to 13.250), unhappy (OR = 5.237, 95% CI: 2.140 to 12.818), aged 44 years and above (OR = 3.518, 95% CI: 1.581 to 7.829), being single (unmarried, divorced, widow) (OR = 2.697, 95% CI: 1.230 to 5.914), and had a monthly income of less than USD400 (OR = 2.333, 95% CI: 1.112 to 4.859) are significantly associated with female-headed family. Conclusion: Priority must be given to some elements such as genetic, physical differences, biopsychosocial factors, and the economic situation when discussing parents' behavior in heading the family

    The Role of Structural Flexibility in Plasmon Driven Coupling Reactions Kinetic Limitations in the Dimerization of Nitro Benzenes

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    Abstract The plasmon-driven dimerization of 4-nitrothiophenol (4NTP) to 4-4′-dimercaptoazobenzene (DMAB) is a testbed for understanding bimolecular photoreactions enhanced by nanoscale metals, in particular, regarding the relevance of electron transfer and heat transfer from the metal to the molecule. By adding a methylene group between the thiol bond and the nitrophenyl, structural flexibility is added to the reactant molecule. Time-resolved surface-enhanced Raman-spectroscopy proves that this (4-nitrobenzyl)mercaptan (4NBM) molecule has a larger dimerization rate and dimerization yield than 4NTP and higher selectivity toward dimerization. X-ray photoelectron spectroscopy and density functional theory calculations show that the electron transfer prefers activation of 4NTP over 4NBM. It is concluded that the rate limiting step of this plasmonic reaction is the dimerization step, which is dramatically enhanced by the additional flexibility of the reactant. This study may serve as an example for using nanoscale metals to simultaneously provide charge carriers for bond activation and localized heat for driving bimolecular reaction steps. The molecular structure of reactants can be tuned to control the reaction kinetics

    Poly(ionic liquid) nanovesicles via polymerization induced self-assembly and their stabilization of Cu nanoparticles for tailored CO2 electroreduction

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    Herein, we report a straightforward, scalable synthetic route towards poly(ionic liquid) (PIL) homopolymer nanovesicles (NVs) with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm via one-step free radical polymerization induced self-assembly. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multilamellar packing of PIL chains occurred in all samples. The transformation mechanism of NVs’ internal morphology is studied in detail by coarse-grained simulations, revealing a correlation between the PIL chain length and the shell thickness of NVs. To explore their potential applications, PIL NVs with varied shell thickness are in situ functionalized with ultra-small (1 ∼ 3 nm in size) copper nanoparticles (CuNPs) and employed as electrocatalysts for CO2 electroreduction. The composite electrocatalysts exhibit a 2.5-fold enhancement in selectivity towards C1 products (e.g., CH4), compared to the pristine CuNPs. This enhancement is attributed to the strong electronic interactions between the CuNPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as new electrocatalyst supports in CO2 conversion to C1 products
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