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161.
This study presents results from shake table experiments of a wood‐frame building conducted at the University of California, Berkeley. A 13.5‐ft × 19.5‐ft two‐story wood‐frame building representing San Francisco 1940s design of a residential building with a garage space on the first story (house‐over‐garage) was tested. The test building was subjected to scaled ground motion based on Los Gatos record from Loma Prieta 1989 earthquake. The strong motion time history was scaled to match design spectra of a site in Richmond district of San Francisco. The test results demonstrated the seismic vulnerability of the test building due to soft story mechanism and significant twisting when shaken in two horizontal directions. In addition to conventional instrumentation for measuring acceleration and position of selected points of the test building, high‐definition laser scanning technology was employed to assess global and local anomalies of the building after the shake table tests. The analysis conducted in this study showed very good correlation between conventional data recorded from position transducers and the laser scans. These laser scans expanded limits of conventional data at discrete points and allowed analyzing the whole building after shaking. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
162.
MD Nurul Islam Siddique Zaied Bin Khalid M. Zamri Bin Ibrahim Muhammad Syarifuddin Yahya 《洁净——土壤、空气、水》2023,51(2):2200031
A comparative study of methane recovery by co-digesting kitchen waste and saline sewage sludge is performed to evaluate its feasibility for waste minimization. The experiment is performed at 37 °C having a mixing speed of 100 rpm and pH of 6.49–7.5 in anaerobic mixed batch reactors. The higher salinity level of the saline sewage sludge reduces the degradation rate of kitchen waste causing an enhancement in soluble chemical oxygen demand by 133% compared with 280% when co-digesting with the non-saline sample. The inhibitory behavior is in line with the low volatile solid elimination efficiency of 31% of saline against 55% of non-saline sludge. The Gompertz modeling, based on the outcomes, fits the cumulative methane generation trends quite well, with a strong correlation coefficient (>0.994). Besides, use of the non-saline sludge results in three times more methane production than the saline sample digestion. Sludge recovery is 0.07 m3 sludge m−3 wastewater, and water recovery is 0.84 m3 m−3 wastewater. The liquid produced from the fermentation of the slurry can be used for irrigation as well as fertilization. Kitchen waste co-digestion with both sludge samples has been proven to be a practical method for exploiting the extra digestion capacity of wastewater treatment plants currently in operation, but it is more practical for non-saline sludge. 相似文献
163.
对虾冷藏过程中肌肉蛋白特性的变化比较 总被引:1,自引:0,他引:1
从生物化学、物理学两方面,比较养殖对虾和海捕对虾在冷冻贮藏过程中肌动球蛋白的特性变化,探讨不同贮藏温度和时间对蛋白特性的影响,及特性指标之间的相关性。冷藏后AM溶解度下降,ATPase活性下降,总SH和未遮盖SH数均减少,疏水性增大,而ATP感度呈下降趋势。所有指标变化表明随着冻藏时间的延长,蛋白质变性加剧,变性程度为-10℃>-18℃>-30℃。各项指标均显示养殖对虾蛋白质的耐冻性比海捕对虾弱。 相似文献
164.
Sobia Ashraf Farhat Abbas Muhammad Ibrahim Umer Rashid Shoaib Khalid Hammad Raza Ahmad Khalid Rehman Hakeem Tahir Majeed 《地理学报(英文版)》2015,(2):225-235
Groundwater is the most appropriate and widely used source of drinking water,which is increasingly threatened by pollution from industrial and agricultural activities.To check the severity of the problem,156 groundwater samples were collected from various depths(60-110 ft) of 52 different localities in Faisalabad city,the third largest metropolis in Pakistan,and analyzed for the metals(Zn,Cu,Cd,Ni,Pb,Mn and Fe) concentration in 2009.Quantification was done by using Flame Atomic Absorption Spectrophotometer technique and the results were compared with WHO standards for drinking water quality.Results showed that the levels of Cu,Mn and Fe were below the WHO standards while the concentrations of Zn,Cd,Ni and Pb were above the recommended levels of safe drinking water.Correlation analysis among the occurrence of these heavy metals revealed a highly significant and positive correlation of Mn with Zn and Fe.A significant and positive correlation of Cd was also found with Cu and groundwater depth showing that there is strong association between Cu-Cd pair and that the Cd concentration varies with depth of groundwater in the study area.Regional patterns of heavy metals occurrence were mapped using Geographical Information System(GIS) for the identification and demarcation of risk areas.The concentration maps may be used by policymakers of the city to mitigate groundwater pollution. 相似文献
165.
Seismic evaluation of the shear behavior in reinforced concrete bridge columns including effect of vertical accelerations
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The effect of vertical excitation on shear capacity of reinforced concrete columns is important. Field evidences, analytical studies and static or hybrid simulations suggested that excessive tension or tensile strain of the column may lead to shear strength degradation, and therefore vertical excitation can be one of the causes of shear failure. This paper describes an experimental study consisting of shaking table tests on reduced‐scale bridge columns. Results of the tests indicate that tension in the columns has the potential to degrade the shear capacity, which is mainly due to the degradation of the concrete contribution to this capacity. The presented computational results and code evaluations also support this shear strength degradation. The presented dynamic tests contribute to better understanding of the effect of vertical excitation on the shear failure, which is one of the most critical brittle failure mechanisms. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
166.
167.
Response evaluation of interconnected electrical substation equipment using real‐time hybrid simulation on multiple shaking tables
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In an attempt to quantify the conductor cable effect on substation electrical equipment, real‐time hybrid simulation (RTHS) is conducted on interconnected equipment using two shaking tables. For this purpose, the existing RTHS system with advanced control capabilities at the Pacific Earthquake Engineering Research Center structural laboratory is enhanced to accommodate the simultaneous use of two shaking tables. An experimental parametric study is conducted to investigate the conductor cable effect using this system with a two‐table RTHS setup. Post insulators of disconnect switches, important components of substations that are usually tested with conventional methods for evaluating their seismic performance, are utilized as experimental substructures for realistic representation of the electrical equipment. Various global and local response parameters, including accelerations, forces, displacements, and strains, are considered to evaluate the effect of the tested conductor cable configuration for a wide range of support structure configurations, which are modeled in the computer as analytical substructures. The experimental parametric study results indicate that the conductor cable has a significant effect on the response of the interconnected equipment over the whole range of investigated support structures and needs to be explicitly considered for seismic testing of electrical equipment. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
168.
Natural Resources Research - This paper emphasizes the use of the particle swarm optimization to infer second moving average residual magnetic anomalies. This approach was used to remove the impact... 相似文献
169.
This paper presents a new approach to constrain paleoburial and subsequent uplift by folding in fold-thrust belts, combining differential stress estimates from mechanically-induced calcite twins with the assumption that stress in the upper crust is in frictional equilibrium. Calcite twin data were collected from pre-folding veins in late Cretaceous limestones from the Ionian zone in Albania in order to (1) determine Paleogene-Neogene stresses associated with the development of the major vein sets in the frontal anticlines of the Outer Albanides and (2) estimate paleoburial of the Cretaceous reservoir rocks during pre-folding flexural subsidence of the foreland. The first vein set (set I) trends N140 (± 20) and the second set (set II) is oriented N060 (± 20). Calcite twinning analysis from set I veins reveals a pre-folding N030° extension likely related to foreland flexure; a later pre-folding, NE-directed compression (LPS) is identified either from one or from both vein sets in the samples from the Saranda anticline; this NE compression is instead recorded by twinning in set II veins from the Kremenara anticline during late stage fold tightening. This NE compression well agrees with independent microtectonic data, regional transport direction and contemporary stress. The differential stress values related to this NE compression are combined with the hypothesis of crustal frictional stress equilibrium to derive first-order estimates of paleoburial of the Cretaceous limestones just before they were uplifted by folding. The ~ 4 km paleoburial of these limestones estimated in the Saranda anticline is consistent with independent paleoburial estimates from stratigraphy, maturity rank of organic matter, paleotemperature/paleogeothermal gradients from fluid inclusions and predictions of kinematic modelling of the Albanian foreland. Our results therefore place reliable constraints on the amount and rate of vertical uplift of these Cretaceous limestones and yield a promising methodology for better constraining paleoburial and therefore erosion and uplift in fold-thrust belts. 相似文献
170.
Khalid Omar Murtaza 《国际地球制图》2017,32(2):188-205
Using Landsat data at decadal interval (1980–2013), the glacier fluctuations (glacier area, equilibrium line altitude and specific mass balance) of nine benchmark glaciers in Kashmir Himalaya were estimated. The observed changes were related to topographic and climatic variables in order to understand their influence. From the data analysis, it was observed that the glaciers have shrunk by 17%, ELA has shifted upwards (80–300 m) and SMB shows variation in glacier mass loss from ?0.77 to ?0.16 m.w.e. Annual air temperature showed a significant increasing trend, and a slight but insignificant decrease in precipitation was observed during the period. It is evident that in the same climatic regime, varying topography plays a key role in determining the glacier changes. It is believed that the observed changes in the glacier geometry and dynamics, if continued, shall have adverse effect on the streamflows, water supplies and other dependent sectors in the region. 相似文献