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101.
《分离科学与技术》2012,47(15):2528-2535
ABSTRACTThe Ni(II) ion flotation kinetics with sodium dodecylsulfate as collector was studied with the aim of developing new models to predict the flotation rate constant (k) of Ni(II) ions and water removal during the process of Ni(II) ion flotation. In this regard, the most influential parameters on Ni(II) ion flotation efficiency including the ratio of collector concentration on the Ni(II) ion concentration, impeller speed, activity coefficient, and pH were used to develop predictive models. The results show that the proposed gene expression programming models can be used to predict the flotation rate constant of Ni(II) ions and water removal. 相似文献
102.
A simple, fast, and effective analytical technique known as in situ solvent formation microextraction was used to preconcentrate/separate trace amounts of Cu(II) ions in water samples prior to determination by flame atomic absorption spectroscopy. In the present method, 6,6′-(1Z,1′Z)(butane-1,4-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis-3-bromophenol (Schiff base ligand) as the complexing agent and 1-methyl-3-pentylimidazolium bromide (ionic liquid) as an extracting agent were successfully synthesized and characterized by FTIR, C-NMR, and H-NMR spectroscopies. The effects of several analytical parameters on the method were studied and optimized, and the merits of the method, such as LDR (0.2–1000 µg L?1), LOD (0.12 µg L?1), RSD (4.1%), and preconcentration factor (70) were evaluated. 相似文献
103.
Loadbearing capacity of infill masonry walls considering the deformation‐based membrane effect
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《Mauerwerk》2018,22(3):151-161
According to currently valid codes, it is not possible to determine the loadbearing capacity of unreinforced infill walls considering the deformation‐based membrane effect by incorporating the exact support conditions. One reason for this is the lack of a validated calculation procedure, which in addition to the equilibrium conditions also realistically represents the compatibility conditions of these systems. In the present paper, therefore, a new non‐linear analytical calculation procedure is presented. The main focus of the analysis of walls subject to area loading is the incorporation of the support conditions and thus the consideration of the deformation‐based membrane compressive force. Through generalised formulation and a standardised notation of the determination equations, different material behaviours and various support conditions can be taken into account with few parameters. On the action side, both lighter loading like wind loads and heavier loading like explosion loads can be considered. Through the implementation of the partial factor concept, it is possible to comply with the requirements of European codes and thus ensure the applicability of the analysis model. 相似文献
104.
由于地质情况和施工原因造成的预应力管桩基础出现的Ⅲ类、Ⅳ类桩的实际情况,综合考虑了多方面的因素后采用了注浆技术对Ⅲ类、Ⅳ类桩进行了处理使其桩身完整性达到Ⅰ类、Ⅱ类桩的要求。结合工程实例,就该注浆技术方案的设计及其注浆施工工艺,并对注浆效果进行的检测及评价。对类似工程的Ⅲ类、Ⅳ类桩处理进行了简要的阐述,起一定的借鉴作用。 相似文献
105.
Priyanka Devi Pantula Srinivas Soumitri Miriyala 《Materials and Manufacturing Processes》2017,32(10):1162-1171
KERNEL – A novel parameter-free surrogate building algorithm using Adaptive Neuro Fuzzy Inference System (ANFIS) is presented to provide an intelligent and robust technology to optimally estimate the configuration of ANFIS along with Sobol-based fast sample size determination (SSD) methodology. The proposed algorithm is capable of fine-tuning the existing knowledge base about the physics of the process in terms of human experience. It also enables knowledge discovery through a multi-objective optimization problem (MOOP) solved by non-dominated sorting genetic algorithm, NSGA-II, thus presenting machine-invented physics of the process. Experimentally validated polymerization reaction network model is considered and ANFIS surrogates are built using KERNEL. Surrogate-based optimization was found to be nine times faster than conventional optimization using the time expensive model, thus enabling its online implementation. Comparison of ANFIS with Kriging is also included. 相似文献
106.
Structural parts used in boilers, turbines, ships, and many household purposes are manufactured through sheet metal forming processes. During manufacturing, the micro structure of the material is deformed and micro cracks along with anisotropic properties get induced. Present research deals with a thin sheet metal plate containing a central crack subjected to mixed mode (I+II) loading. With special reference to Lankford's coefficient and degree of anisotropy, the effect of anisotropic triaxiality on crack initiation angle has been investigated. The result reveals the combinations of Lankford's coefficient and degree of anisotropy for which crack initiation angle do not change. 相似文献
107.
108.
Federica Goffi 《Architectural Design》2016,86(1):24-33
Differentiating between the static impulse to preserve and the more open-ended and imaginative process of conservation, Federica Goffi presents a building as ‘a fabric that, even when complete, is unfinished and open to change’. Associate Professor and Associate Director of Graduate Programs at the Azrieli School of Architecture and Urbanism at Carleton University in Ottawa, Goffi has written widely on the topic of time, particularly taking St Peter's in the Vatican by way of example. 相似文献
109.
Y. C. Sharma G. Prasad D. I. Rupainwar 《The International journal of environmental studies》2013,70(4):315-320
The adsorption of Cd(II) onto wollastonite has been reported. Adsorption increased from 55.7 to 93.6% by decreasing the concentration of Cd(II) from 2.0 x 10‐4M to 0.5 x 10‐4M. The rearranged Lagergren equation has been used for dynamic modelling of the process. However, the value of rate constant at 30°C was found to be 3.17 x 10‐2min‐1. Equilibrium modelling was carried out using the Freundlich isotherm equation and constants have been calculated. Thermodynamic studies were carried out and values of standard free energy (?G°), enthalpy (?H°) and entropy (AS°) were calculated at various temperatures. Low temperatures favour the uptake of Cd(II) in the process. 相似文献
110.
Edward T. Urbansky Michael R. Schock 《The International journal of environmental studies》2013,70(5):597-637
Recent reports have attempted to show that fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of hexafluoro‐silicate hydrolysis is of paramount importance in ensuring that total water quality is maintained. The possible impacts of such complexes as PbII—F—SiF5 or PbFx (2‐x) are discussed as are the contributions of fluoridation byproducts to total acid content. We calculate the fractional distribution of aqueous species based on known chemical equilibria and show the species concentrations for several different model tap waters. We discuss and quantitatively show the effects of other complexing anions, such as carbonate or hydroxide. Overall, we conclude that no credible evidence exists to show that water fluoridation has any quantitatable effects on the solubility, bioavailability, bio‐accumulation, or reactivity of lead(0) or lead(II) compounds. The governing factors are the concentrations of a number of other species, such as (bi)carbonate, hydroxide, or chloride, whose effects far exceed those of fluoride or fluorosilicates under drinking water conditions. Lastly, we consider some previous epidemiological studies of lead(II) exposure and how recent papers fare methodologically. 相似文献