VOLUME 37, NO3, JUNE-2015

Quinacridone-Based Small Acceptor Molecule for Obtaining High Open Circuit Voltage in Solution Processed Organic Solar Cells

Dioctylquinacridone di(cyanoimine) CN-DOQA was synthesized according to previously reported method. CN-DOQA having suitable HOMO_LUMO energy levels due to _CN groups as electron withdrawing groups was used in organic solar cells as an acceptor in a blend with poly (3-hexyl thiophene) (P3HT) as donor. The photovoltaic devices have shown reasonable high open circuit voltage (Voc) although solar cells have not been fully optimized. Photovoltaic study was supported by thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC) of CN-DOQA and morphological study of the blend films by atomic force microscopy (AFM).read more

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Iqbal Javed, Iqbal Saleem, Yue Wang and Muhammad Nadeem Akhtar

Development of Simple and Precise Method of Arginine Determination in Rumen Fluid by Spectrophotometer

The objective of current study was to build up a convenient, economic and accurate procedure to determine arginine (ARG) concentration in rumen fluid. Rumen fluid was collected from 3 rumen fistulated Chinese Holstein dairy cows and added with or without (control) 1mmol/l unprotected ARG and blank (with only medium) in to syringe system in triplicate as a replicate. All syringes were incubated in water bath at 39 °C for 0, 2, 4, 6, 12 and 24 h and were terminated to measure the ARG concentration. Sakaguchi reaction method was used to analyze the ARG concentration in rumen fluid by determining the rumen degradation rate of protected and unprotected ARG. Temperature, time and absorbance were optimized in the procedure based on Sakaguchi reaction. Color consistency remained 4-6 min. The optimum temperature (0-5) °C was observed for maximum optical density 0.663 at wave length 500 nm. Minimum ARG that could be determined in rumen fluid by spectrophotometer was 4-5 µg/ml. No significance (P>0.05) difference were observed between two results derived from spectrophotometer and amino acid analyzer methods. In conclusion, the spectrophotometer method of ARG determination in rumen fluid based on Sakaguchi reaction is easy, accurate, and economical and could be useful in learning ARG metabolism in the rumen.read more

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Bahram Chacher, Jian-Xin Liu, Hong-Yun Liu and Illahi Bakhsh Marghazani

The Effect of Temperature, pH and SO2 on Ethanol Concentration and Sugar Consumption Rate (SCR) in Apple Wine Process

The goal of this study was to examine the effects of operating parameters on ethanol concentration (ethanol) in apple wine production process. Examined parameters were temperature (T), pH and sulphurdioxide concentration (SO2). Experiments were planned and executed according to a full two-level factorial experimental design method. The studied levels were 18°C and 25°C for temperature, 3 and 4 for pH and 50 and 150 ppm for SO2. Ethanol concentration of apple wine for each set of experiments was determined by GC/MS. Experimental data were analyzed by using both graphical and quantitative Exploratory Data Analysis (EDA) Techniques. The main effect of each factor on sugar consumption rate (SCR) was also examined. The results show that the effect of examined operating parameters on ethanol was negative. High temperature level caused faster fermentation rate than the one caused by low temperature. Low level of pH and high level of SO2 inhibited the activities of both harmful microorganisms and wine yeast.read more

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M. Deniz Bozoglu, Suna Ertunc, Bulent Akay, Nihal Bursali, Nilufer Vural, Hale Hapoglu and Yavuz Demirci

Diffusion Coefficient of Iodide ions in Aqueous Medium and in Vacuum: An Appraisal

Diffusion Coefficient of iodide ion was determined through cyclic voltammetric technique and compared with the values in literature. The contribution of (a) the fractal surface of the electrode, and (b) possible involvement of subsequent chemical reaction (EC) to the peak current affecting the diffusion coefficient were analyzed. It was concluded that the diffusion coefficient obtained via peak current of the cyclic voltammogram corrected for sweep dependence could be relied upon. The diffusion coefficient, D, of ion in aqueous media is deduced to be 1.95 (+0.05) ×10-5 cm2s-1. Fractal analysis showed there is very negligible effect of fractal surface of the electrode. Diffusion coefficient of iodide ion in vacuum was calculated from equation , where h is Planck’s constant and mI-, is the mass of iodide ion. D of in vacuum came out to be much smaller, 2.5 ×10-6 cm2s-1, as compared to the one in aqueous solution. This D may be considered as the lower limit of the diffusion coefficient of a species, here.read more

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Mahboob Mohammad, Muhammad Tariq, Muhammad Samiuddin Qadri, Muhammad Latif, Iftikhar Ahmed Tahiri and Lubna Naz

Catalytic Production of Hydroxymethylfurfural from Fructose Using Brönsted-Lewis Acidic Ionic Liquid

The dehydration of fructose to 5-hydroxymethylfurfural (HMF) was investigated in the presence of the Brönsted-Lewis acidic ionic liquids (ILs). It was found that IL (3-sulfonic acid)-propyl-triethylammonium chlorochrominate [HO3S-(CH2)3-NEt3]Cl-CrCl2 (molar fraction of CrCl2 x = 0.55) had a good catalytic performance with 93.4% yield of HMF. IL acid site played a more significant role than its Brönsted counterpart in the reaction, and a synergetic effect of Brönsted and Lewis acid sites enhanced IL catalytic performance. The reusability of IL was good which could be reused up to 5 times without apparent decrease in the yield of HMF.read more

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Shi-Wei Liu, Shan-Shan Kong, Lu Li, Shi-Tao Yu, Fu-Sheng Liu and Cong-Xia Xie

Study on the Interaction of Zinc Ion Binding with Human Serum Albumin using Isothermal Titration Calorimetry

The interaction between zinc ion and human serum albumin (HSA) was investigated by nano-Watt- scale isothermal titration calorimetry (ITC). From the analysis of the ITC data, the binding characteristics and thermodynamic properties of the system were obtained and the binding mechanism was discussed. It was found that the experimental data fit well with the Langmuir’s binding theory and the system behaved as a system with two classes of binding sites (high-affinity and low-affinity binding site). The binding number of high-affinity binding site (N1) is 1.40 and the binding constant (K1) is 2.72×105 L/mol. For the low-affinity binding site, the binding number (N2) is 1.55 and the binding constant (K2) is 3.78×103 L/mol. Moreover, it was indicated by the thermodynamic analysis that the binding processes of both types of binding sites were exothermic and spontaneous. The high-affinity binding was an enthalpy-entropy synergically driven process and the electrostatic interaction was the main force, while the low-affinity binding was an enthalpy-driven process and this process was mainly driven by the van der Waals forces.read more

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Ming Guo, Huidong Li, Yan Zhang, Shuang Shao, Min Guo and Xiaomeng Wang

Use of Surrogated Snow Surface Sampler to Determine Dry Deposition of PAHs

Polycyclic aromatic hydrocarbons (PAHs) have recently begun to attract attentions due to their cancerogenic and mutagenic effects on genes and human health. Some of related studies in literature focused on atmospheric concentrations while others investigated atmospheric dry and wet deposition fluxes. In literature, dry deposition studies used the results of coated and uncoated surrogated surfaces and reported an appropriate extraction and analysis steps. In such dry deposition studies, losses (infiltration, etc.) of snow samples are a fact and therefore, findings and results should contain uncertainties. In this study, a surrogated snow surface sampler was used to determine dry deposition of PAHs in the city centre of Erzurum. Snow samples were collected in 8 distinct locations in Erzurum city centre taken on trays and on surface without using trays. Analysis results of the snow samples taken on surface as well as on trays were compared. The proportion of total filtrate PAH compounds from surface versus from tray were found to be 53%, whereas this proportion was 68% for solid phase samples. Though the infiltration or loss varied depending on different samples, average loss was 2 times more for liquid phase whereas it was 2.4 times more for solid phase samplings.read more

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Cihan Paloluoğlu and Hanefi Bayraktar

Nanofabrication of Block Copolymers of PDMS/Polyamide having Trichlorogermyl Pendant Using LbL Technique

Block copolymers [AB]x type of aminopropyl-terminated poly(dimethylsiloxane) (NH2-PDMS) and polyamides trichlorogermyl pendant group were prepared by a solution phase one pot polycondensation method. The prepared block copolymers were assembled with polyethylene-alt-(maleic) anhydride (PEMA) as multilayered thin film assembly through covalently linked Layer by Layer (LbL) technique using dipping method. The prepared thin films had thickness in the range of 15 to 20 nm as measured on an ellipsometer. In the systems where quartz was used as substrate, film growth after each deposition was monitored through UV-Vis spectrophotometer, which substantiated the multilayer film build-up. Atomic Force Microscopic (AFM) images showed homogeneous and robust film, which were strong enough to endure the force of 400 nN. As the block copolymers are thermally stable and have the capacity to absorb water, so their prepared robust ultra-thin films can show potential of thermally resistant nano thin films, protective hydrophilic coatings in addition to separation membranes.read more

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Rohama Gill, Sadia Batool, Shahid Saeed Qureshi and Raziya Khalid

Antioxidant Potential of Cyclopeptide Alkaloids Isolated from Zizyphus oxyphylla

The present study reports on the antioxidant potential of five cyclopeptide alkaloids isolated from Zizyphus oxyphylla including Oxyphylline-D 1, Nummularin-C 2, Nummularin-R 3, Oxyphylline-B 4, Oxyphylline C 5 using DPPH free radical assay, nitric oxide radical assay and reducing power assay. The isolated alkaloids demonstrated marked antioxidant potential in a concentration dependent manner. Among the tested molecules, the compounds, 2 was most potent with IC50 values of 27.23, 32.03 and 22.45 µg/ml in DPPH free radical assay, nitric oxide radical assay and reducing power assay respectively.read more

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Waqar Ahmad Kaleem, Naveed Muhammad, Haroon Khan, Abdur Rauf, Muhammad Zia-ul-Haq, Mughal Qayum, Amir Zada Khan, Muhammad Nisar and Obaidullah

Synthesis of Benzophenone Hydrazone Analogs and th

Benzophenone hydrazone analogs 1-25 were synthesized and evaluated for antioxidant (DPPH radical scavenging), and urease inhibitory activities. Out of twenty-five analogs, compounds 8, 23, and 1 showed potent free radical scavenging activities with IC50 values 19.45 ± 1.25, 21.72 ± 1.49, and 26.0 ± 0.52 μM, respectively, while compound 8 (IC50 = 36.36 ± 0.94 µM), and 15 (IC50 = 55.5 ± 0.69 µM), showed good to moderate urease inhibitory potential.read more

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Khalid Mohammed Khan, Fazal Rahim, Ajmal Khan, Sajjad Ali, Muhammad Taha, Syed Muhammad Saad, Momin Khan, Najeebullah, A. Shaikh, Shahnaz Perveen and Muhammad. Iqbal Choudhary