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131.
A. I. Gamal el Din I. A. Issa A. M. I. Osman F. Y. Kamal 《Astrophysics and Space Science》1992,190(1):89-117
Results about the standard photometric parameters of four galaxies are given. The equivalent and the integrated parameters defined according to de Vaucouleurs are listed. Effective values of the abovementioned ingredients, the reduced luminosity profiles and the dimensions defined by the quartiles are also given. 相似文献
132.
We expand the principal part of the planetary disturbing function, by Smart's method, using Taylor's theorem. In our expansion we neglect terms of degree higher than the fourth in the eccentricities and tangents of the inclinations.Now at the JPL Pasadena, California. 相似文献
133.
The coprecipitation method is widely used for the preconcentration of trace metal ions prior to their determination by flame atomic absorption spectrometry (FAAS). A simple and sensitive method based on coprecipitation of Fe(III) and Ni(II) ions with Cu(II)‐4‐(2‐pyridylazo)‐resorcinol was developed. The analytical parameters including pH, amount of copper (II), amount of reagent, sample volume, etc., were examined. It was found that the metal ions studied were quantitatively coprecipitated in the pH range of 5.0–6.5. The detection limits (DL) (n = 10, 3s/b) were found to be 0.68 µg L?1 for Fe(III) and 0.43 µg L?1 for Ni(II) and the relative standard deviations (RSD) were ≤4.0%. The proposed method was validated by the analysis of three certified reference materials (TMDA 54.4 fortified lake water, SRM 1568a rice flour, and GBW07605 tea) and recovery tests. The method was successfully applied to sea water, lake water, and various food samples. 相似文献
134.
N. Ayten Uyanık Osman Uyanık Filiz Gür İbrahim Aydın 《Environmental Earth Sciences》2013,68(2):499-506
Some of the rocks and soil-originated materials used in building construction are the serious natural radiation sources. Soil-originated bricks and roof-tiles and their raw material in the Salihli-Turgutlu area were tested in situ for natural radiation levels using a gamma-ray spectrometer. The concentrations of the radioelements 40K, 238U and 232Th and air-absorbed radiation rates were measured for soil, raw material heaps, brick and roof-tile stacks and waste brick heaps. The radium-equivalent activity Raeq of the raw material varied between 187.9 and 216.4 Bq kg?1. The external radiation hazard index Hex values ranged between 0.51 and 0.58. For building material and its products, recommended Raeq and Hex levels are 370 Bq kg-1 and 1.0, respectively. On the other hand, both Raeq and Hex values for waste brick heaps, containing broken brick pieces, coal pieces and ash, were higher than the recommended levels, i.e. Raeq values varied from 473.8 to 651.0 Bq kg-1 and Hex values were within the range 1.15–1.76. The annual dose rate and radium-equivalent activity values of the brick and roof-tiles were below the level of criteria. Annual dose rate ranged between 0.42 and 0.62 mSv y?1 and radium equivalent activity was in the range 172.9–245.2 Bq kg?1. The external and internal radiation hazard indices were all below the value of 1.0 for the Salihli-Turgutlu area bricks and roof-tiles. Results of this study were compared with results of previous studies. Natural radiation levels of construction raw material of study area are generally higher than of those of previous studies. 相似文献
135.
Fuzzy control of piezoelectric friction dampers for seismic protection of smart base isolated buildings 总被引:1,自引:0,他引:1
This study proposes two fuzzy logic controllers (FLCs) for operating control force of piezoelectric friction dampers used
for seismic protection of base-isolated buildings against various types of earthquake excitations. The first controller employs
a hierarchic control strategy in which a higher-level supervisory controller operates a single sub-level FLC by modifying
its input normalization factors in order to determine command voltage of the damper according to current level of ground motion.
The second controller is a self organizing FLC that employs genetic algorithms in order to build a knowledge base for the
fuzzy controller. Numerical simulations of a base-isolated building are conducted to evaluate the performance of the controllers.
For comparison purposes, an optimal controller is also developed and considered in the simulations together with maximum passive
operation of the friction damper. Results for several historical ground motions show that developed fuzzy logic controllers
can effectively reduce isolation system deformations without the loss of potential advantages of seismic base isolation. 相似文献
136.
This study aims to remove of Cu2+, Cd2+, and Pb2+ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion‐exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (qmax) were calculated as 0.478, 0.358, and 0.280 mmol g?1 for Cu2+, Cd2+, and Pb2+, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L?1 metal concentration was determined as 0.200, 0.167, and 0.155 mmol g?1 for Cu2+, Cd2+, and Pb2+ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g?1 for Cu2+, Cd2+, and Pb2+ ions, respectively, when initial metal concentration was 0.50 mmol L?1. In the multi‐metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu2+ > Cd2+ > Pb2+. In the presence of 100 mmol L?1 H+ ion, the order of ion‐exchange affinity with H+ was found as Cu2+ > Cd2+ > Pb2+. The adsorption kinetics were also found to be well described by the pseudo‐second‐order and intraparticle diffusion models. Two different rate constants were obtained as ki1 and ki2 and ki1 (first stage) was found to be higher than ki2 (second stage). 相似文献
137.
The effects of plant density of Melastoma malabathricum on the erosion rate of slope soil at different slope orientations 总被引:2,自引:0,他引:2
Malaysia’s cut slopes,especially for road lines accommodation,are prone to erosions and landslides.These problems mainly occur due to lack of vegetation cover and strong erosive forces.In addition,the topography factors have also become a major factor affecting soil degradation.Thus,this study is aimed at determining the effects of planting density of a selected species,namely Melastoma malabathricum;one,two,and three seedlings per box,on the erosion rate at selected slopes of different orientation(morning and evening sun) at the Guthrie Corridor Expressway,Selangor.In six months of observation,treatment with three seedlings/box on the morning sun slope showed a lower erosion rate by 69.2%than those with the same treatment on the evening sun slope.In addition,the treatment of the three seedlings recorded at month six(final observation) had the highest reduction of soil saturation level(STL),by 23.6%.Furthermore,the physiological values of the species studied,grown on the morning sun slope,were higher in terms of stomatal conductance and photosynthetic rate by 12.1%and 15.8%(three seedlings/box),respectively.The overall results showed that plant density was inversely related to the STL and erosion rate on the slope.In conclusion,a planting density of three seedlings/box and morning sun orientation gave positive effects on the plant’s physiological performance of the slope,reducing the STL,as well as alleviating the erosion rate of slope soils. 相似文献
138.
Mihriban Şahin Mehmet Emin Korkmaz Osman Agar Abdullah Dirican 《Environmental Earth Sciences》2017,76(3):121
A screening of natural radioactivity content has been carried out in thermal water samples collected from surrounding of Central Anatolia, Turkey. The concentration levels of gross alpha and beta of 19 different samples has been determined using the low background gas-flow proportional counter. The measured gross alpha and beta activities in waters range from 0.11 to 16 Bq/L and 0.10 to 16.9 Bq/L, respectively. The measured values of gross alpha and beta concentrations are compared to previous studies in the literature and recommend WHO guideline activity concentration. The data resulting from the measurement have been statistically analyzed. 相似文献
139.
Natural Hazards - The state of undivided Andhra Pradesh, India, spent around US$ 20 million per annum on drought relief programs during the period 1998–2008. However, till date, no long-term... 相似文献
140.
Osman M. Kamel 《Earth, Moon, and Planets》1989,45(2):127-137
We construct a U-N secular canonical planetary theory of the third order with respect to planetary masses. The Hori-Lie procedure is adopted to solve the problem. Expansions have been carried out by hand, neglecting powers higher than the second with respect to the eccentricity-inclination. We take into account the principal as well as the indirect part of the planetary disturbing function. The theory is expressed in terms of the Poincaré canonical variables, referring to the Jacobi-Radau set of origins. We assume that the 1:2 U-N critical terms and its multiples are the only periodic terms. 相似文献