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241.
Utilization of wind energy in Bangladesh has been slow mainly due to lack of quality wind data. Recent measurements in some places have shown significant wind energy potentials in Bangladesh. In this paper, a wind map is presented which incorporates several microscale features, such as terrain roughness, elevation etc. with a mesoscale model. Several meso-maps were obtained from global databases and a suitable model was chosen and modified for a 30-m elevation. Ground data from various sources were collected and modified for height and land condition adjustments based on local knowledge and GIS information. It was found that, the generated wind map and the modified ground data resemble. Annual average wind speed at 30 m height along the coastal belt is above 5 m/s. Wind speed in northeastern parts is above 4.5 m/s while inland wind speed is around 3.5 m/s for most part of Bangladesh. Small-scale wind turbines could be installed and tested in locations such as St. Martins Island, Cox’s Bazar, Patenga, Bhola, Barguna, Dinajpur, Thakurgaon and Panchagar. 相似文献
242.
243.
Iqbal U Albaghdadi H Nieh MP Tuor UI Mester Z Stanimirovic D Katsaras J Abulrob A 《Nanotechnology》2011,22(19):195102
Molecular imaging enables the non-invasive investigation of cellular and molecular processes. Although there are challenges to overcome, the development of targeted contrast agents to increase the sensitivity of molecular imaging techniques is essential for their clinical translation. In this study, spontaneously forming, small unilamellar vesicles (sULVs) (30 nm diameter) were used as a platform to build a bimodal (i.e., optical and magnetic resonance imaging (MRI)) targeted contrast agent for the molecular imaging of brain tumors. sULVs were loaded with a gadolinium (Gd) chelated lipid (Gd-DPTA-BOA), functionalized with targeting antibodies (anti-EGFR monoclonal and anti-IGFBP7 single domain), and incorporated a near infrared dye (Cy5.5). The resultant sULVs were characterized in vitro using small angle neutron scattering (SANS), phantom MRI and dynamic light scattering (DLS). Antibody targeted and nontargeted Gd loaded sULVs labeled with Cy5.5 were assessed in vivo in a brain tumor model in mice using time domain optical imaging and MRI. The results demonstrated that a spontaneously forming, nanosized ULVs loaded with a high payload of Gd can selectively target and image, using MR and optical imaging, brain tumor vessels when functionalized with anti-IGFBP7 single domain antibodies. The unique features of these targeted sULVs make them promising molecular MRI contrast agents. 相似文献
244.
Asmiet?RamizyEmail author Z.?Hassan Khalid?Omar 《Journal of Materials Science: Materials in Electronics》2011,22(7):717-723
Electrochemical and laser-induced etching processes were simultaneously used to synthesize the nanowires structure of porous
silicon (PS). Surface morphology and structural properties of nanostructured silicon were characterized by using scanning
electron microscopy (SEM) and atomic forces microscopy (AFM) images. Nanowires with dimensions of few nanometers were formed
on the whole etched surface. The optical properties of silicon nanostructures were studied. Raman spectra were shifted and
broadened relatively to 519.9 cm−1 of PS prepared by electrochemical etching, and shifted to 517.2 cm−1 for laser-induced etching process and to 508.9 cm−1 for electrochemical and laser etching simultaneously. Blue shift luminescence was observed at 649.6 nm for PS produced by
electrochemical etching, and at 629.5 nm for laser-induced etching. PS produced a blue shift at 626.5 nm using both etching
procedures simultaneously. X-Ray diffraction (XRD) was used to investigate the crystallites size of the PS as well as to provide
an estimate of the degree of crystallinty of the etched sample. 相似文献
245.
M. Iqbal 《Solar Energy》1979,23(2):169-173
Empirical equations have been developed which correlate the monthly average daily horizontal diffuse and beam radiation with the fraction of maximum possible number of bright sunshine hours. These correlations are based on measured data from three widely spread Canadian stations.Depending upon whether or not the total horizontal radiation is known, the two correlations for the diffuse radiation are: .The correlation for beam radiation is: . 相似文献
246.
The effects of doping of MgAl2O4 by a binary mixture of Co and Zn ions on the absorbance, electrical resistivity, capacitance, thermal conductivity, heat capacity and thermal diffusivity are reported in this paper. The materials with the nominal composition Mg1−2x(Co,Zn)xAl2O4 (x = 0.0-0.5) are synthesized by solution combustion synthesis assisted by microwave irradiation. The substituted spinels are produced with a Scherrer crystallite size of 18-23 nm, as opposed to 45 nm for undoped samples, indicated by X-ray diffraction and confirmed by transmission electron microscopy. These materials also show better thermal stability in the temperature range of 298-1773 K. Three strong absorption bands at 536, 577 and 630 nm are observed for the doped samples which are attributed to the three spin allowed (4A2 (F) → 4T1 (P)) electronic transitions of Co2+ at tetrahedral lattice sites while pure magnesium aluminate remains transparent in the whole spectral range. The semiconducting behavior of the materials is evident from the temperature dependence of the electrical resistivity. Resistivity and activation energy are higher for the substituted samples. Fitting of the resistivity data is achieved according to the hopping polaron model of solids. Both dielectric constant and loss increase on account of doping. The dielectric data are explained on the basis of space charge polarization. The thermal conductivity and diffusivity are lowered and the heat capacity is increased in the doped materials. Wiedemann-Franz's law is used to compute the electronic and lattice contributions towards the total thermal conductivity. 相似文献
247.
Microwave dielectric ceramics in the Sr1−xCaxLa4Ti5O17 (0 ≤ x ≤ 1) composition series were prepared through a solid state mixed oxide route. All the compositions formed single phase ceramics within the detection limit of in-house X-ray diffraction when sintered in the temperature range 1450-1580 °C. Theoretical density and molar volume decreased due to the substitution of Ca2+ for Sr2+ which was associated with a decrease in the dielectric constant (?r) and temperature coefficient of resonant frequency (τf) but an increase in quality factor, Qfo. Optimum properties were achieved for Sr0.4Ca0.6La4Ti5O17 which exhibited, ?r ∼ 53.7, Qfo ∼ 11,532 GHz and τf ∼ −1.4 ppm/°C. 相似文献
248.
Djamel Mostefa Nicolas Moreau Khalid Choukri Gerasimos Potamianos Stephen M. Chu Ambrish Tyagi Josep R. Casas Jordi Turmo Luca Cristoforetti Francesco Tobia Aristodemos Pnevmatikakis Vassilis Mylonakis Fotios Talantzis Susanne Burger Rainer Stiefelhagen Keni Bernardin Cedrick Rochet 《Language Resources and Evaluation》2007,41(3-4):389-407
249.
A simple and efficient method of convexity-preserving interpolation for grid data is introduced. An earlier algorithm due to Roulier (1987), based on a shape-preserving curve interpolation scheme due to McAllister and Roulier (1981), is modified to use a simpler but equivalent curve interpolation scheme described in Iqbal (1992). Numerical examples are provided to test the performance of the method with the slopes that are further improved using iterative technique to produce more visually pleasing surfaces. 相似文献
250.
A case of a 53-year-old perimenopausal woman who presented with an 18-month history of irregular vaginal bleeding is reported. Vaginal ultrasonography revealed a 10 x 7 cm pelvic mass with an increased blood flow. Her serum CA125 was within the normal range. At laparotomy a normal spleen was found within the pelvic cavity. 相似文献