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161.
M. Y. A. Rahman A. A. Umar L. Roza M. M. Salleh 《Journal of Solid State Electrochemistry》2012,16(12):3947-3952
The morphology of photovoltaic material is able to influence of the performance of photoelectrochemical cell. Polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), and hexamethylenetetramine (HMT) surfactant were used to modify the morphology nanostructure of TiO2 films by a simple technique, namely, liquid phase deposition during their growth process. It was found that the untreated surfactant TiO2 film produces the morphology with the mixture nanosphere and nanoflower. The film treated with PVP, CTAB, and HMT produce the nanostructure shape of nanoflower, nanowire, and nanorod, respectively. These TiO2 samples were utilized as photovoltaic materials in a photoelectrochemical cell of ITO/TiO2/electrolyte/platinum. It was found that the photovoltaic parameters such as short-circuit current density (J sc), open-circuit voltage (V oc) and fill factor are influenced by the morphology in terms of shape and particle size of the TiO2 nanostructure. The cell utilizing the TiO2 nanowire treated with PVP possesses the highest J sc and V oc of 0.100 mAcm?2 and 0.44 V. The length of the TiO2 nanowire is 6?±?2 nm, while the cell with the untreated surfactant TiO2 sample demonstrates the lowest performance. It was also found that the J sc and V oc increase with the decrease in the length of the TiO2 nanostructures. The smallest length of TiO2 possesses the best interfacial contact at TiO2/electrolyte containing iodide/triiodide redox couple. Thus, the redox reaction is optimized at this interface. 相似文献
162.
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164.
Fumio Hosoi Yasushi Aoki Miyuki Hagiwara Hideki Omichi M. Mat. Salleh 《辐射效应与固体损伤》2013,168(1-4):351-354
Abstract Substituting metallic or rare-earth atoms or removing O in the superconductor YBa2Cu3O7 usually has a strong effect on the superconducting properties. We have made extensive XAFS studies on Co, Fe, Ni, Zn, Gd, and Pr substituted materials including some thin film samples. In nearly all cases, significant distortions are found. Although the lattice constant change is small (< 0.05 Å) the local distortions can be significant larger (~ 0.1 to 0.3 Å). The observed large local distortions of the lattice together with a change in the charge distribution at a site indicate that the interior of the unit cell is easily distorted. The correlation of a strong Tc suppression with large local distortions suggests that distortions of the nearby layers must play a significant role in models for superconductivity in high Tc materials. 相似文献
165.
166.
F. Matúš 《Acta Mathematica Hungarica》2018,154(2):511-524
Given finitely many events in a probability space, conditional independences among the indicators of events are considered simultaneously with the signs of covariances. Resulting discrete structures are studied restricting attention mostly to all couples and triples of events. Necessary and sufficient conditions for such structures to be represented by events are found. Consequences of the results for the patterns of conjunctive forks are discussed. 相似文献
167.
168.
Motivated by questions about square-free monomial ideals in polynomial rings, in 2010 Francisco et al. conjectured that for every positive integer k and every k-critical (i.e., critically k -chromatic) graph, there is a set of vertices whose replication produces a (k+1)-critical graph. (The replication of a set W of vertices of a graph is the operation that adds a copy of each vertex w in W, one at a time, and connects it to w and all its neighbours.) 相似文献
169.
Dariush Khezrimotlagh Shaharuddin Salleh Zahra Mohsenpour 《The Journal of the Operational Research Society》2014,65(5):694-707
This paper provides a new structure in data envelopment analysis (DEA) for assessing the performance of decision making units (DMUs). It proposes a technique to estimate the DEA efficient frontier based on the Arash Method in a way different from the statistical inferences. The technique allows decisions in the target regions instead of points to benchmark DMUs without requiring any more information in the case of interval/fuzzy DEA methods. It suggests three efficiency indexes, called the lowest, technical and highest efficiency scores, for each DMU where small errors occur in both input and output components of the Farrell frontier, even if the data are accurate. These efficiency indexes provide a sensitivity index for each DMU and arrange both inefficient and technically efficient DMUs together while simultaneously detecting and benchmarking outliers. Two numerical examples depicted the validity of the proposed method. 相似文献
170.
Ng Sook Han Mohd. Basyaruddin Abd. Rahman Raja Noor Zaliha Raja Abd. Rahman Abu Bakar Salleh Zahariah Ismail 《Journal of Dispersion Science and Technology》2013,34(10):1428-1433
Palm oil esters (POEs) are wax esters derived from palm oil and cis-9-octadecen-1-ol. The excellent wetting behaviour of the esters without the oily feel make them have great potentials in the manufacture of cosmeceutical and pharmaceutical products. However, little is known about their phase behaviors in ternary systems. The purpose of this investigation was to construct phase diagram of the POEs and mixed surfactants and to consequently select nanoemulsions composition for further studies. The preparation and characterization of oil-in-water nanoemulsions stabilized by hydrocolloid gums were then studied. Two types of nonionic surfactants were selected, namely Tween 80 (T80) and Span 80 (S80). Ternary phase diagram of POEs:Tocotrienol/T80:S80 (80:20)/water system was constructed at 25.0 ± 0.5°C. The emulsification properties of 2 hydrocolloids gum (xanthan gum, carbopol ultrez 20 copolymer) were investigated. Gum dispersions were prepared in water (0.8%) and emulsified with 30% oil using a Polytron homogenizer. The flow curve of the emulsions always exhibited shear thinning behavior and obeys the power law viscosity. The emulsions with carbopol ultrez 20 copolymer was the most stable emulsions which composed of very small oil droplets (50% < 142.43 nm) with a narrow size distribution. 相似文献