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1.
Smart and sustainable campuses demand three components. First, there is the need to have a Strategic Master Plan (SMP) for all infrastructures that include energy, transportation, water, waste and telecommunications along with the traditional dimensions of research, curricula, outreach and assessments. Secondarily, there is the array of issues pertaining to the sitting of buildings and overall facility master planning which must be addressed from the perspective of “green” energy, efficient orientation and be designed for multiple-use by the academic and local community.Thirdly, the development of sustainable buildings in one area that is compact and walkable campuses thus enable a range of transportation choices leads to reduced energy consumption. Historically, college campuses were often like towns and villages in that they are self-sustaining for family, business and recreational activities. Any sustainable smart campus is a vibrant, “experiential” applied educational model that should catalyze creative learning. More significantly, today, campuses and communities must be secure in terms of not only their own energy use and needs, but also for the resource demands of their power. Otherwise, the community(s) will never be secure economically or politically.Recognizing global warming and climate change, in the spring of 2001, the Board of Trustee (BOT) for the Los Angeles Community College District (LACCD) took the critical initial policy steps to turn these sustainable developments into goals. For example, the LACCD decided to have new “green” buildings to replace or renovate existing ones. The building program led to sustainable communities that included recycling, product reuse from waste as well as smart growth in terms of reduced energy use, efficiency and the use of telecommunication and wireless systems. The paper focuses primarily on the energy programs for the LACCD campuses.The paper considers the overall energy situation in California and the Southern California region, primarily Los Angeles. Then the paper looks at the state and regional energy contexts which lay the ground work and rationale why LACCD and other communities must act on their own to counteract climate change and global warming. Finally, the paper discusses how a community becomes sustainable, and hence “energy independent”. By doing so, any community can generate its own energy through the production or acquisition of its energy from renewable sources such as solar, wind or biomass among other local resources. Even more significant consequences come in terms of carbon control, lower impact on the environment and reduced global warming.  相似文献   

2.
Lars Hkanson 《Water research》1984,18(9):1107-1118
The aim of this paper has been to introduce a conceptual model concerning the causal relationships determining the “road between dose and response” of toxic substances in aquatic environments. The paper is focused on metals and utilizes mercury as a type element. The approach puts special emphasis on the environmental factors regulating the potential effects of contaminants and stresses the importance of sedimentology in ecotoxicology. The approach discusses concepts like ecological effect, dose and sensitivity. A potential ecological risk index to be used in practical environmental control programs must also be based upon tested and comparatively inexpensive standard methods. Such an index should account for “biological contact area”, “biological contact time” and “additive effects”. A fundamental concept in this approach is the residual term, which describes the fact that it is impossible in ecological contexts to reach a complete understanding.  相似文献   

3.
The purpose of this article is to discuss alternative sources for the Brazilian Electric System to sustain a growth rate of 4% in its economy. From this perspective, issues like the country dependence on hydraulic energy, the potential of inserting other forms of “renewable sources” and the required modulation with thermal use, preferably internal resources, are addressed.  相似文献   

4.
The change from a global economy dependent upon fossil fuels to renewable fuels for the hydrogen economy is occurring now. Not in 50–60 years, but the hydrogen economy exists today. This is a “paradigm shift” of such significance and so dramatic as to underlie the making of the Third Industrial Revolution. And more importantly, the Third Industrial Revolution includes three “pillars”: distributed as on-site renewable energy generation, “green” hydrogen and advanced storage devices. Each of these pillars is not an adjustment or economic cycle or business bubble. Indeed, the hydrogen economy is global with the European Union and the nation-state of California taking the lead toward sustainable energy infrastructures.This paper addresses that paradigm shift, but also the immediate economic and business development for any region or nation-state. More significantly, when the production of hydrogen is derived from renewable energy resources, not only are there societal benefits (no pollution and atmospheric impact), but also sustainable economic development and job growth. Some of the immediate evidence can be seen in California where “civic markets” are indeed working, but also with the combination of infrastructures into hybrid systems. Herein the combination of hydrogen for stationary power with transportation fuel needs is expediting the paradigm change into sustainable economic feasibility today, not in 50 years or the next century.  相似文献   

5.
A method of selective dissolution was used for analysis of particulate forms of radium and barium in a system consisting of uranium mine waste waters purified by coprecipitation with barium sulphate and of adjacent river waters. Four particulate forms of both the elements were distinguished: “loosely bound”, “acid soluble”, Ba(Ra)SO4 and “in crystalline detritus”. It was found that the distribution of radium and barium between dissolved and particulate forms in waste waters depended on the time interval elapsing between the sampling and membrane filtration of the waters. No such dependence occurred in river water. The main particulate form of radium and barium in the system was Ba(Ra)SO4. River water upstream of the mine water discharge contained radium mainly in “acid soluble” form or “in crystalline detritus” and barium as BaSO4 or “crystalline detritus”. In unpurified mine effluents, a large part of radium and barium was present as “crystalline detritus”. Abundance of the “loosely bound” form was very low in all the samples analyzed. The bond of radium in bottom sediments was approximately the same as that in the solids suspended in waste waters. Suitability and accuracy of the selective dissolution method for analysis of surface and waste waters has been demonstrated by the analysis of the results and by radiotracer experiments.  相似文献   

6.
An improved version of rotatory-flow apparatus is described, allowing tests of fitness with fish of different size at constant temperature. Cod (Gadus morrhua, L.) was used as experimental animal, and its treatment and behaviour during different phases of the test are described in some detail. Each test results in determination of the “critical rev min−1” at which the fish is just brought to rotate with the water. The mean of a series of 10 critical rev min−1 with the same fish, multiplied by the interior circumference of the rotational tube used, gives the “critical peripheral velocity” of the specimen. Critical peripheral velocities of a sample of fish, plotted against the standard length of the fish, arrange themselves along a straight line which intersects the vertical axis near the origin. Divided by the corresponding standard lengths the critical peripheral velocities give “reaction quotients”, the mean of which describe the reaction of the whole sample of fish.Optimal experimental conditions have been found by investigating the effects of systematic variation in streaming velocity, relationship between rotational tube diameter and fin-breadth, temperature, and effects of repetition of test-series on successive days etc. on the results of testing.  相似文献   

7.
Agroforestry networks can be a means to achieve landscape amelioration. Some authorities of the Lagoon of Venice drainage basin (Italy) are planning, amongst other actions to control pollution in the Lagoon, to reintroduce agroforestry by means of a GIS-supported design procedure. The goals of this paper were to assess (i) the contingent valuation (CV) (willingness to pay and willingness to accept) of agroforestry networks and its relationship with socioeconomic and agroforestry role variables, (ii) the coherence between agro-economic policies and farmers expectations, (iii) the relationship between the value of agroforestry as a “shared good” and water quality (non-point source pollution). Respondents associate a positive value/preference to the agroforestry network implementation, although this value is strongly affected firstly by their identity with the landscape and secondly by their income. The motivations of farmers’ evaluation are precise and the agroforestry network is considered not only as an “ethical object” but also as a concrete element of their own cultural and economic world. In this case the contingent value (in particular, in terms of acceptance) increases with the farmer’s economic capacity, and the farmer’s valuation is not linked only to the “good” but also to the “service” offered for implementing it. The expectations of farmers regarding an agroforestry plantation were lower than European Union incentives at the time of survey, and a lack of results in this field is probably linked to poor information and to bureaucratic difficulties. Even if there is general knowledge on water quality, there is little awareness on the non-point source pollution control effect of agroforestry buffer plantations, either in the common people or in those who are environmentally trained (e.g. planning university students). In every case the agroforestry “shared good” evaluation is high enough to permit efficient and supported intervention policies. These results confirm that landscape choices strongly involve issues of identity, perceived rights and evaluation capacity that cannot be simply resolved in terms of preference cost benefit analyses, but a clever use of the CV allows an identification of these same limitations and a partial estimation of them.  相似文献   

8.
This paper reports the investigation results of capital budgeting evaluation practices of Hong Kong building contractors. The survey aims to identify the popularity of various techniques for capital budgeting evaluation and to measure the changes of the practices longitudinally by comparing the results of the current study (2004) with those of the similar surveys conducted in 1994 and 1999. The current survey results revealed that the “formal financial evaluation” was the most popular technique for capital budget evaluation. The “payback period” was the mostly used investment appraisal technique. For risk appraisal techniques, “shortening payback period” occupied the first position. The “planning programming” remained as the most popular management science technique. Moreover, a comparison of the practices of large contracting firms was carried out to view the changes over the last 10 years. The results showed that the practice of capital budget evaluation was emphasized. The popularity of employing investment appraisal and risk analysis techniques was dropping. In addition, the capital budgeting evaluation techniques examined were fitted into a discriminant function analysis (DFA), which allowed contracting firms to be classified in accordance with their predominant characteristics in the practices. The classification result was 89.1% of all cases were correctly classified.  相似文献   

9.
Hongtao Wang  James G.A. Croll   《Thin》2008,46(7-9):1011
In the context of aerospace and marine applications there are considerable incentives for designers to adopt thin shells, whose performances are enhanced by appropriately chosen rib stiffeners or using high-performance composite materials. Imperfection-sensitive buckling in these circumstances is controlled by extremely high numbers of independent material and geometric parameters. As a basis for design, traditional reliance upon scatter of test results is suggested to be untenable and the increasing tendency to replace this approach by use of nonlinear finite elements is argued to bring with it all sorts of other quite considerable practical problems.This paper describes how the long established and very simple “reduced stiffness method” (RSM) is able to provide an alternative design strategy. It shows how a very straightforward extension of classical critical load analysis allows the definition of lower bounds to the potential imperfection sensitivity in each mode and consequently the delineation of the mode and load likely to provide the controlling influence on design. Reliability of its predictions is briefly demonstrated through comparisons with extensive test programmes and confirmation through carefully controlled nonlinear numerical studies. Use of the RSM is shown to offer scope for identifying material and geometric parameters that result in improved and even “optimum” buckling loads. Case studies from past and a current programme of research looking at the buckling of composite shells are used to illustrate this design potential.  相似文献   

10.
A survey of the “chlorination practice” of swimming-pool waters is presented taking the case of covered pools in Bremen. Chlorination of water may result in specific health hazards by various halogenated chemicals. Trihalomethanes (THMs), among others, are determined in water and air samples. We succeeded in identifying one organic “precursor” of the synthesis of THMs in swimming pools. An estimate of the average and maximum burden of the user/swimmer is given. Short and long range alternative measures are proposed to diminish the health hazards. We conclude from this work that the application of chlorine for disinfection should be minimized.  相似文献   

11.
The stability of two systems of bell-shaped caverns excavated some 1000 years ago at Bet Guvrin National Park is investigated. The caverns were excavated in a weak, anisotropic, and moderately discontinuous chalk. The cavern stability is considered based on two separate and independent methods: a continuum model framework—FLAC, used for stress analysis, and a discontinuous approach—block theory, used for critical key block analysis.The numerical stress analysis reveals that in the case of very large span openings, tensile fracture of intact rock may be responsible for instabilities, which may lead to global failure. Evidence of tensile rupture at margins of failed caverns is abundant at the Park.The discontinuous block theory analysis reveals that the moderate joint set spacing at Bet Guvrin, up to 45% of the roof area may be comprised of removable blocks. The removable keyblocks in the roof remain in place due to arching stresses, which develop through the roof material. The chalk at the roof can sustain the maximum loads in existing caverns, as predicted by the numerical stress analysis. However, local failures due to exceedingly high compressive stresses at the abutments or by tensile fracture at the roof, may lead to relaxation of arching stresses followed by keyblock displacement. Such a “mixed failure mode” process could eventually lead, over time, to global collapse. Indications that “mixed failure mode” processes are presently active in the studied caverns are substantiated by in-situ measurement of keyblock displacements.It is suggested that in weak and discontinuous rock environments where “mixed failure mode” processes may be active, long term stability evaluation should be based on both continuous and discontinuous stability analyses.  相似文献   

12.
Due to the new threats and challenges faced by the construction industry today, construction companies must seek new solutions in order to remain ahead of the competition. Knowledge has been identified to be a significant organisational resource, which if used effectively can provide competitive advantage. A lot of emphasis is being put on how to identify, capture and share knowledge in today's organisations. It has been argued over the years that due to the fragmented nature of the construction industry and ad-hoc nature of the construction projects, capture and reuse of valuable knowledge gathered during a construction project pose a challenge. As a result critical mistakes are repeated on projects and construction professionals have to keep “reinventing the wheel”. Given the nature of construction projects, collaborative knowledge management seems to be the most appropriate solution to capture project based knowledge. Information and communication technologies offer a number of solutions to implement collaborative knowledge management solutions. This paper discusses a range of these solutions and presents a case study where a collaborative knowledge management solution is implemented across a multi functional construction company.The work presented in the case study was carried out while the first author was employed by the case study organisation. A social web application was implemented to solve a particular knowledge sharing problem within the organisation's concrete pumping business. The new solution provided an effective and simple way to create knowledge by taking employees' ideas through an iterative cycle of discussion.  相似文献   

13.
Jan Blaha 《Water research》1976,10(9):821-828
An essentially new method of chemical analysis was developed and named “the non-experimental chemical analysis”. The subject of the method is the qualitative and quantitative analysis of chemical properties of the system of complex forming reagents and central atoms. The method is based on the application of the general system equation. An application of the general system equation for the toxic system “cyanide-heavy metals” in water solutions is advanced.  相似文献   

14.
Soil Stabilization with Cement Grouts   总被引:1,自引:0,他引:1  
“New” advertizable injection methods of enhancing the bearing capacity of soils by the “ geomass” and “geocomposite” methods with use of high-pressure injection of cement and cement-sand grouts, as well as stabilization of sandy soils with “microdur” cement are analyzed. Significant drawbacks of the “geomass-geocomposite” methods, which do not permit prediction and operational monitoring of results of changes in the physico-mechanical properties of the soils in a mass, are noted.__________Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 24–28, March–April, 2005.  相似文献   

15.
Energy hierarchy and urban landscape system   总被引:2,自引:0,他引:2  
The study of ecosystems suggests principles by which the flow of energy generates hierarchies in all systems. From viewpoint of ecological energetics, urban system lies on the highest level of ecosystem hierarchy. The main objective of this paper is to study the effect of energy flows on the hierarchies and spatial organization of urban zonation. This research uses Taipei metropolitan region as the area for the case study. “Emergy” is used as the principal conceptual tool for energy analysis; “transformity” is used to measure the hierarchies of land uses and urban landscape systems. Based on the calculation of the spatial distribution of energy flows, using GIS, the empower density and transformity increase from rural to urban center. In order to delineate zones of different energetics, the 1178 administrative districts of the Taipei metropolitan region are used as units for multivariate classification, in which 19 variables of energy flows are condensed into four factors. The factor scores of each districts are then used as input for cluster analysis and discriminate analysis. As a result, different energy structures, and subsequently, different types and amount of energy flows tend to associate with different intensities of urbanization. The Taipei metropolitan region is classified into six energetic zones: mixed-use urban core; high density urban residential district; service and manufacturing urban district; agricultural district, newly developed suburban district; and natural area. The calculation of transformity and emergy indices further establish the hierarchical order of these zones. The distribution of the six energetic zones, reveals the spatial energetic hierarchies of Taipei metropolitan region. The implication of energetic characteristics to planning practice is also discussed to conclude this research.  相似文献   

16.
In France, the creation of a “Ministère de l'Environnement et du Cadre de Vie” and “Agences Financieres de Bassin” has made it possible to obtain information on the water quality of rivers and on the measures necessary to improve water quality. Particularly in the Adour-Garonne Basin, much information is now available. The methodology needed to draw conclusions concerning the quality of the rivers and to show the effectiveness of control measures has been developed.This method has been tested in two catchments (Fig. 1): L'Adour (15,000 km2) and La Dordogne (24,000 km2). The steps that were necessary before this method could be used were: critical assessment of the available data; identification and measurements of pollution sources. This called for the collection of information, annual statistics for each sampling station and information concerning the value and importance of measured parameters.Detailed information is available from 1971 and 1976 and this is shown by maps and graphical representations of the variations in the value of different parameters (Fig. 2).Statistical analysis has also been carried out on the information available for the period 1971–1976.Two methods were used: analysis of the principal components, the method most used being shown by Figs 3 and 4 and the “STATIS” method developed recently which treats the whole data “At 3 indices” (Fig. 5).Research has been carried out on the causal relations between the water quality and the sources of pollution.A simple graphical method is proposed to explain the effect of a strongly preponderant pollutant source. It allows easy visualisation of the change in the relationship between two series of variables (Fig. 8).In general cases of several sources of pollution a simplified method using BOD exclusively has been developed. It consists in comparing the values measured in the river and the estimates obtained from inflows of various sources and those from upstream basins (Fig. 9).The application of this method has made it possible to distinguish local or general tendencies in reference to the intervention realised by the “Agence Financiere de Bassin”.Attention has been given to the variations obtained between laboratories and research information and the necessity to extend application of the statistical method to parameters other than BOD5.Comparable action is being taken for the whole basin of the Rhone (French). The information obtained for “L'Adour and La Dordogne” has led to a study not only of the concentration of pollutants but two types of flow, with flow measurements and concentration being taken into account in order to eliminate hydraulic effects.  相似文献   

17.
The benefits of street vegetation, in particular the importance of trees, for urban dwellers have been given wide attention. There is, however, a lack of research on flowers as an element of street vegetation. This paper explores preferences for various street-planting models, particularly those with different compositions of flowers, with or without trees. Eighty-one residents of Sapporo evaluated 59 photomontage simulations and answered a questionnaire concerning their attitudes to street flowers. Results revealed trees to be the factor with the greatest influence on preference. Among possible elements for the space beneath trees from a choice including soil, grass, hedge and flowers, flowers were the most favoured. In particular, low and ordered compositions of brightly coloured flowers were the most preferred. Tall flowers were not found to be either attractive or appropriate for streetscapes in this case study. A factor analysis of the variables related to attitudes towards street flowers revealed the following five factors: “psychological benefits and aesthetic value”, “natural–environmental”, “practical concerns”, “effort to maintain” and “non-aesthetic”. The highest rated items were all related to the aesthetic and psychological benefits of street flowers. Flowers were the most preferred element beneath street trees and were seen as not only contributing to the aesthetic quality of a street but as also having a positive influence on psychological well-being.  相似文献   

18.
After centuries of cultural and economic conquest of the Americas by European and Euro-American conquistadors, contemporary rhetoric in ex-colonial powers heralds the decline of material and ideological imperialism. Instead, it is purported that today's world is peopled by a great brotherhood, with the more affluent striving to relieve their less fortunate, underdeveloped kith. This conviction is inherent in organizations which dispense money, information, training, and other resources in the name of community development and endangered species and environmental conservation. What is rarely perceived – and practically never said – is that these “benevolent” foreign aid activities typically result in the concentration of resources and power in the hands of a few, the building of empires, and the compounding of already difficult situations, counter-productive to stated objectives. The Yucatán Peninsula is a classic case of persistent imperialism: the geographic name is a corruption of the Mayan “matan cub a than” (“I do not understand you”), while contemporary development and conservation programs habitually exhibit cultural ignorance and dominance. This paper explores a diverse literature on non-governmental organizations, reflects on likely consequences of cultural dominance, and implores professional anthropologists to be adventurous in propagating anthropological knowledge relevant to environmental protection.  相似文献   

19.
Projects are carried out by temporary organizations. These organizations can function independently or in cooperation with stationary organizations. To enable efficient project and program management, these differences in organization structure have to be considered. This paper therefore contrasts organizations formed to carry out activities at project sites based on forms of employment, work processes and resource networks used. Findings indicate that temporary organizations that are dominated by stationary “parent” organizations often rely on its abilities to secure access to crucial resources and to identify suitable work processes. “Pure” or virtually “pure” temporary organizations instead rely on their employees’ skills and contacts to develop suitable routines and gain access to resources.  相似文献   

20.
Search-based importance sampling   总被引:1,自引:0,他引:1  
Importance sampling as a special technique in Monte Carlo probability integration has been shown to be a highly efficient and rather unrestricted method. Non-Gaussian and dependent random variables and nonlinear limit functions can be treated relatively easily and with reasonable rates of convergence. A major draw-back, however, is the need to identify so-called “interesting” or “important” regions for integration. Reference to first-order second-moment (FOSM) methods may help, as well as numerical maximization routines applied. Each involves certain difficulties. An alternative procedure, based on directing and correcting the importance sampling function as sampling is carried out, is presented herein. In particular it is possible to have a multi-modal sampling function.  相似文献   

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