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251.
Productivity monitoring, which involves frequent monitoring and analysis of on-going construction activities, helps in assessing a project's performance and in enabling identification of opportunities for improvement. It often involves finding answers for dynamic user queries that require data to be fused from different combinations of heterogeneous data sources having different levels of detail, representations and reference systems. Digital elements of these sources are expanding exponentially, and yet fusing and processing them manually remains a challenging problem. In this paper, the authors present a formal approach for capturing dynamic user queries and identifying applicable sets of data sources from a given set of available data sources to answer such queries. This approach is an important step to enable automated and efficient multi-source data fusion. 相似文献
252.
In this study, α‐amylase was immobilized on glutaraldehyde activated silanized calcium carbonate nanoparticles by a using covalent binding method. The surface modified nano calcium carbonate (CaCO3) were characterized using FTIR and SEM. Immobilization yield was found as 199.43 mg/g of calcium carbonate nanoparticles. The maximum activity was observed at pH 6.5. The immobilized enzyme had a higher activity at elevated temperature (50–90°C) than the free one. Reuse studies demonstrated that the immobilized enzyme could reuse 25 times while retaining 18.2% of its activity. Free enzyme lost its activity completely within 15 days. Vmax values for the free and immobilized enzymes were calculated as 10 and 0.35 mg/mL/min, respectively. 相似文献
253.
It has been well documented that excess concentrations of boron (B) causes toxic effects on many of the environmental systems. Although Chlorella sp. has been studied to remove pollutants from water, its capacity to remove B has not been investigated yet. Boron removal levels of newly isolated Chlorella sp. were investigated in BG 11 media with stimulators as triacontanol (TRIA) and/or sodium bicarbonate (NaHCO3) and without them, to test if they could increase the removal efficiency by increasing biomass. The assays were performed to determine the effect of different medial compositions, B concentrations, pH and biomass concentrations onto removal efficiency. Boron removal was investigated at 5-10 mg/L range at pH 8 in different medial compositions and maximum removal yield was found as 32.95% at 5.45 mg/L B in media with TRIA and NaHCO3. The effect of different pH values on the maximum removal yield was investigated at pH 5-9, and the optimum pH was found again 8. The interactive effect of biomass concentration and B removal yield was also investigated at 0.386-1.061 g wet weight/L biomass. The highest removal yield was found as 38.03% at the highest biomass range. This study highlights the importance of using new isolate Chlorella sp. as a new biomaterial for B removal process of waters containing B. 相似文献
254.
Sara Wadia-Fascetti & Burcu Gunes 《Computer-Aided Civil and Infrastructure Engineering》2000,15(2):134-146
It is well accepted that the ground motion at a site depends on the rupture mechanism, source-to-site distance, local geologic conditions, and energy released by the earthquake. However, design spectra represent expected responses that do not explicitly include the influence of the uncertainties associated with these fundamental features. The objective of this article is to present a viable methodology that can be used to develop a response spectra using fuzzy logic and statistical analysis and to demonstrate how fuzzy-statistical response spectra can be used to evaluate potential structural response.
Site-specific response spectra from the Northridge earthquake are used to develop response spectra models that quantify uncertainties inherent to the ground motion. The uncertainty in these computational models is quantified using fuzzy-set logic, statistics, and random vibrations. The local geologic conditions are characterized as rock or alluvium, and fuzzy sets are used to represent near, intermediate, and far epicentral distances. Proposed ground-motion models are used to define uncertain input motion for use in dynamic analyses of an example building. The resulting structural responses are compared with those obtained from time-dependent accelerations. Comparisons are made with the current design codes, and suggested implementation strategies for the proposed models are discussed. 相似文献
Site-specific response spectra from the Northridge earthquake are used to develop response spectra models that quantify uncertainties inherent to the ground motion. The uncertainty in these computational models is quantified using fuzzy-set logic, statistics, and random vibrations. The local geologic conditions are characterized as rock or alluvium, and fuzzy sets are used to represent near, intermediate, and far epicentral distances. Proposed ground-motion models are used to define uncertain input motion for use in dynamic analyses of an example building. The resulting structural responses are compared with those obtained from time-dependent accelerations. Comparisons are made with the current design codes, and suggested implementation strategies for the proposed models are discussed. 相似文献
255.
Elif Erdinç Burcu Selen Caglayan A. Erhan Aksoylu 《International Journal of Hydrogen Energy》2017,42(32):20568-20578
Methane oxidative steam reforming (OSR) performance of two bimetallic Pt-Ni/δ-Al2O3 catalysts, having Pt:Ni loadings, 0.2:10 and 0.3:10, were tested first. In the tests, residence time (W/F), carbon-to-oxygen (C/O2) feed ratio, and temperature were used as the experimental parameters. Increase in temperature resulted in direct and indirect - through enhanced TOX yielding higher energy - increase in SR rate. As Pt:Ni metal loading ratio did not lead to significant changes in activity, the preliminary kinetic tests to determine merely kinetically controlled region were conducted over 0.2Pt-10Ni catalyst. Considering the outcomes of the preliminary tests, the kinetic experiments were performed for practical reaction conditions extending up to 20% methane conversion with feed ratio intervals of 4.0 < C/O2 < 7.34 and 2.03 < S/C < 3.08 at two different residence time (W/F) values to obtain a power-law type rate equation. Reaction orders were estimated as 0.81, 1.60 and 0.44 for methane, oxygen and steam, respectively, by using multivariable non-linear optimization function of MATLAB?. The apparent activation energy of methane OSR was calculated as 24.61 kJ mol?1 and pre-exponential factor as 0.110 μmol mgcat?1 s?1 kPa?2.85 for the 375–450 °C temperature interval. The same analysis performed for a narrower temperature range, 375–425 °C, gave k0 and EA values as 0.251 μmol mgcat?1 s?1 kPa?2.85 and 29.17 kJ mol?1, respectively, confirming the high sensitivity of OSR pathway to temperature. 相似文献
256.