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91.
D. Mohan V. N. Singh S. N. Kaul Y. C. Sharma 《The International journal of environmental studies》2013,70(1):115-124
Feasibility of a waste material, flyash, as a material for purification of wastewater containing Lissamine Red has been studied. Effects of time and concentration, temperature and pH on the removal of the dye have been studied. Lower concentrations favour the uptake of dye from water and the maximum removal was observed at a dye concentration of 20 mgL m 1 , 30°C, pH of 7 and adsorbent particle size of 53 µm. Dynamics of the uptake was studied using Lagergren's equation. The mass transfer coefficient was found to be 0.05 cmmin m 1 at a concentration of 20 mgL m 1 , 30°C and 53 µm particle size. 相似文献
92.
Fire and cork can be considered both the most serious problem and the most valuable resource of Portuguese forests. The existence of important areas of burned cork oak stands resulting from severe fire seasons in recent years is an environmental problem which deserves special attention. This paper makes a multidisciplinary survey of the problem of burned cork oak stands focusing on: the dimensions of the problem in Portugal, the remarkable resistance of cork oak to fire, the post‐fire management of cork oak stands, and the economic and ecological effects of fire in cork oak stands. Particular emphasis is given to knowledge gaps in this context. 相似文献
93.
In this paper, we study the energy decay characteristics of the nozzle at supersonic velocity. We have taken three types of configuration: circular, square and elliptical. The results are compared to the circular exit design. The experimental data are compared in relation to the pressure ratio. The throat area assumed to be constant. The supersonic potential core length of the different orientations is calculated. From the results, we have found that the exit geometry plays an important role in mixing promotion. The core length of a non-circular jet is less intense than a circular jet. The core length of the nozzle is the same in both under and overexpanded case. In addition to that, there is no sign of axis switching due to weak shock. The results are obtained in two different categories, total pressure data and numerical simulation. An empirical relation is used to investigate the core length experimentally. 相似文献
94.
A linear programming model has been developed for optimal cash flow management addressing specific cash flow issues related to the construction industry. These include typical financial transactions, possible delays on payments, use of available credit lines, effect of changing interest rates, and budget constraints that often occur in the construction industry. A small size project from the Brazilian construction industry is provided as a case study, aiming at evaluating the potential benefits from using the model. Different changes to the basic structure of the model allow and establish the consistency of the results. Alternative formulations are suggested to deal with uncertainties, longer planning horizons, and multiple subcontractors and suppliers. In addition to the tangible financial earnings derived from the optimization process, the simple structure of the model, as a network flow and corresponding equations, provides much visual insight concerning the relationships between the external inputs and the variables of the problem. Optimal results have yet to be achieved in a real life situation, but a better view of whole cash flow management is provided when using the model. 相似文献
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97.
Roger L. Creighton J. Douglas Carroll Jr. Graham S. Finney 《Journal of the American Planning Association. American Planning Association》2013,79(2):96-103
In city planning, data-processing machines permit the rapid handling and summarization of data in housing, renewal, land use, transportation, and basic urban research. Electronic computers. specifically, are exciting because they offer a means of solving complex city planning problems, especially in forecasting land use and travel demand. For most planning operations punched card data processing is superior to other processes. The functions of these machines are described herein and three examples of data processing are elaborated on. In future years, planning techniques may have to be altered considerably to take advantage of the potentials of data processing. 相似文献
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99.
Globalization today encompasses multinational dialogues on the appropriate role for planning in mediating relationships between individual and community, state and citizen, government and market, and people and property. Yet confusion persists as speakers from one country attempt to convey concepts different from what listeners from another country hear. This paper provides a cross-national contemplation on the sources of that confusion, comparing the USA to Western Continental Europe, primarily Germany. Americans and Europeans engage fundamentally different worldviews in promoting progress while reconciling harms, stemming from different philosophical traditions that can be broadly characterized as a Millian versus a Hegelian liberalism, respectively. 相似文献
100.
This study highlights the effect of membrane action in improving load carrying capacity of Profiled Steel Sheeting Dry Board (PSSDB) floor system. PSSDB system is a lightweight composite structural system composed of profiled steel sheeting and dry board, attached together by self-drilling and self-tapping screws. Many literatures have reported that restricting conventional slabs, such as reinforced concrete slab, at the supports against translation and/or rotation while it is subjected to vertical loading develops the compressive membrane action in the slab. The development of this phenomenon is considered in the PSSDB system with concrete infill for continuous and practical spans, with and without topping concrete. Previous authors’ experimentally verified non-linear finite element model for the PSSDB floor without topping was extended to parametrically predict the effect of different boundary conditions on the performance of the system for practical applications. It was revealed that preventing the in-plane movement of the slab ends improves the flexural rigidities of the slab up to more than three times when considering central deflection of serviceability limit state. This was observed when the deflection limit load of the fixed both end supports model was compared to the pin-roller support model. Moreover, the topping concrete enhances the applicability of the system in longer span and the developed compressive membrane action dramatically boosts the load carrying capacity of the slab with restricted translation and/or rotation of the slab ends. 相似文献