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241.
242.
Marija Drev Urša Opara Krašovec Mateja Hočevar Marko Berginc Marjeta Kržmanc Maček Marko Topič 《Journal of Sol-Gel Science and Technology》2011,59(2):245-251
The influence that the degree of polyesterification has on a titanium sol (Ti-sol) prepared via the Pechini method that acts
as a matrix in TiO2 pastes used for dye sensitized solar cells is reported. The different content of the polyester in the Ti-sol was realized
by varying the heating time of the Ti-sol. Titanium dioxide pastes were prepared by introducing a commercial TiO2 nanopowder into the Ti-sols. The TiO2 layers were tested as photoanodes in dye-sensitized solar cells (DSSCs). The most appropriate degree of polyesterification
was achieved by heating the Ti-sol for 0.5 and 1 h, while longer heating deteriorates the TiO2 layer morphology. The highest efficiency of the DSSCs based on an ionic liquid electrolyte was 6.3% measured under standard
test conditions (100 mW/cm2, AM 1.5, 25 °C). 相似文献
243.
Muhammad Rafique Abdul Jabbar Abdul Razzaq Khan Saeed Ur Rahman Muhammad Basharat Azhar Mehmood Matiullah 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):2049-2056
In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (232Th, 226Ra and 40K) and anthropogenic (137Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides 226Ra, 232Th and 40K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg?1 respectively. Whilst, in rock samples 226Ra, 232Th and 40K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg?1, respectively. The 137Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg?1, respectively. The average radium equivalent activity (R aeq) was found as 143.16 and 142.93 Bq kg?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg?1 as given in OECD report (1979). The values of external (H ex) and internal hazard index (H in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world. 相似文献
244.
Kezheng Chen Weili Luo Zia Ur Rahman Yu Guo A. Schulte 《Journal of Dispersion Science and Technology》2013,34(3):471-476
Biocompatible magneto‐vesicles (MVs) with multiple magnetic nanoparticles encapsulated inside were synthesized by the hydration‐sonication method in the presence of magnetic fluid with a mixture of two types of phospholipid molecules. The dimension and the size distribution of these MVs are in the same order as the vesicles synthesized in the similar method, indicating that the encapsulation does not change vesicles' properties dramatically. Releasing fluorophore molecules—carboxylfluorescein (CF) from MVs demonstrates that MVs with DOPE/DDAB layers can be a new type of magnetic carrier for biomedical applications. 相似文献
245.
Ixone Esnal Dr. Ismael Valois‐Escamilla César F. A. Gómez‐Durán Arlette Urías‐Benavides María L. Betancourt‐Mendiola Prof. Iñigo López‐Arbeloa Dr. Jorge Bañuelos Prof. Inmaculada García‐Moreno Prof. Angel Costela Prof. Eduardo Peña‐Cabrera 《Chemphyschem》2013,14(18):4134-4142
A series of meso‐substituted boron‐bipyrromethene (BODIPY) dyes are synthesized and their laser and photophysical properties systematically studied. Laser emission covering a wide visible spectral region (from blue to orange) is obtained by just changing the electron donor character of the heteroatom at position 8. The additional presence of methyl groups at positions 3 and 5 results in dyes with a photostability similar to that of the unsubstituted dye but with much improved efficiency. Correlation of the lasing properties of the different dyes to their photophysical properties provides inklings to define synthetic strategies of new BODIPY dyes with enhanced efficiency and modulated wavelength emission over the visible spectral region. 相似文献
246.
Static and adaptive feedback control for synchronization of different chaotic oscillators with mutually Lipschitz nonlinearities
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Muhammad Riaz Muhammad Rehan Keum-Shik Hong Muhammad Ashraf Haroon Ur Rasheed 《中国物理 B》2014,(11):227-235
This paper addresses the control law design for synchronization of two different chaotic oscillators with mutually Lipschitz nonlinearities. For analysis of the properties of two different nonlinearities, an advanced mutually Lipschitz condition is proposed. This mutually Lipschitz condition is more general than the traditional Lipschitz condition. Unlike the latter, it can be used for the design of a feedback controller for synchronization of chaotic oscillators of different dynamics. It is shown that any two different Lipschitz nonlinearities always satisfy the mutually Lipschitz condition. Applying the mutually Lipschitz condition, a quadratic Lyapunov function and uniformly ultimately bounded stability, easily designable and implementable robust control strategies utilizing algebraic Riccati equation and linear matrix inequalities, are derived for synchronization of two distinct chaotic oscillators. Furthermore, a novel adaptive control scheme for mutually Lipschitz chaotic systems is established by addressing the issue of adaptive cancellation of unknown mismatch between the dynamics of different chaotic systems. The proposed control technique is numerically tested for synchronization of two different chaotic Chua's circuits and for obtaining identical behavior between the modified Chua's circuit and the R6ssler system. 相似文献
247.
Tabassum Nasir Matiullah Muhammad Rafique Saeed Ur Rahman Muhammad Khalil Naveed Anwar 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1209-1215
In order to carry out indoor radon measurement in new and old buildings of the Dera Ismail Khan city, CR-39 based radon detectors were installed in bed rooms and sitting rooms/TV lounges in 25 (each) old and new houses and were exposed to indoor radon for 90 days. After processing, mean weighted average indoor radon concentrations in old and new houses were found to be 275 ± 33 and 86 ± 18 Bq m?3 whereas mean annual effective doses expected to be received by the occupants were 6.86 ± 0.79 and 2.1 ± 0.43 mSv year?1, respectively. From the measured weighted average indoor radon concentration, excess relative risk factor was calculated using the risk model of BEIR VI for the age group of 35 and 55 years. Average excess lung cancer risk was found to be 1.63 ± 0.19 and 1.35 ± 0.16 and 0.5 ± 0.10 and 0.4 ± 0.08 for old and new houses, respectively. 相似文献
248.
For air-cleaning, TiO2 photocatalysis represents one of the very efficient advanced oxidation processes (AOPs) that can decompose chemically and microbiologically stable volatile organic compounds (VOCs). However, the photocatalytic activity of nanocrystalline TiO2 powders can be significantly suppressed due to TiO2’s poor adsorption characteristics for organic compounds and its relatively low surface area. The present study sought to solve this problem by immobilising nanocrystalline TiO2 in the porous silicate substrate. Two titania sources were used in an aqueous solution form: a suspension from a TiO2 producer in Slovenia, Cinkarna Celje (CC-40) and a TiO2 sol, prepared by a low-temperature synthesis developed at the University of Nova Gorica (TiO2-UNG). Two different types of mesoporous silica were used: SBA-15 with an ordered hexagonal pore arrangement and KIL-2 with disordered inter-particle mesoporosity. The structural characteristics, adsorption properties and photocatalytic activity of catalysts deposited on aluminium plates as thin films were investigated. CC-40 exhibited higher adsorption and photocatalytic activity than TiO2-UNG due to the greater quantity of Ti-OH groups on its surface. The addition of mesoporous silica led to higher adsorption and catalytic activity for both TiO2 sources. SBA-15 was more efficient than KIL-2. 相似文献
249.
Unusual Structural Features in the Lysozyme Derivative of the Tetrakis(acetato)chloridodiruthenium(II,III) Complex
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Prof. Luigi Messori Tiziano Marzo Rute Nazaré Fernandes Sanches Hanif‐Ur‐Rehman Prof. Denise de Oliveira Silva Dr. Antonello Merlino 《Angewandte Chemie (International ed. in English)》2014,53(24):6172-6175
The reaction between the paddle‐wheel tetrakis(acetato)chloridodiruthenium(II,III) complex, [Ru2(μ‐O2CCH3)4Cl] and hen egg‐white lysozyme (HEWL) was investigated through ESI‐MS and UV/Vis spectroscopy and the formation of a stable metal–protein adduct was unambiguously demonstrated. Remarkably, the diruthenium core is conserved in the adduct while two of the four acetate ligands are released. The crystal structure of this diruthenium–protein derivative was subsequently solved through X‐ray diffraction analysis to 2.1 Å resolution. The structural data are in agreement with the solution results. It was found that HEWL binds two diruthenium moieties, at Asp101 and Asp119, respectively, with the concomitant release of two acetate ligands from each diruthenium center. 相似文献
250.
A. Afaq Azmat Iqbal Amin Ur Rahman Naveed Khan Fazal-e- Aleem M. Mushraf Ansari 《Brazilian Journal of Physics》2016,46(5):489-495
Photodetachment of negative ions near surfaces is of great interest in view of its fundamental significance and technological applications. We reinvestigate the dynamics of photoelectrons in H? photodetachment near a partially reflecting spherical surface by the semiclassical closed-orbit theory. Reflection parameter R and curvature K is used to observe inelastic and spherical effects of the surface, respectively. The classical action is evaluated from the photodetached electron trajectories incident normally at the surface, arising simultaneously from the source and its image. The derived analytical formula of photodetachment cross section correctly recovers the results of reflective spherical surface published recently based on theoretical imaging method. 相似文献