1,283 research outputs found
Evaluating the costs of desalination and water transport
Many regions of the world are facing formidable freshwater scarcity. Although there is substantial scope for economizing on the consumption of water without affecting its service level, the main response to water scarcity has been to increase the supply. To a large extent, this is done by transporting water from places where it is abundant to places where it is scarce. At a smaller scale, and without a lot of public and political attention, people have started to tap into the sheer limitless resource of desalinated water. This study looks at the development of desalination and its costs over time. The unit costs of desalinated water for five main processes are evaluated, followed by regressions to analyze the main influencing factors to the costs. The unit costs for all processes have fallen considerably over the years. This study suggests that a cost of 1 /m3 for brackish water would be feasible today. The costs will continue to decline in the future as technology progresses. In addition, a literature review on the costs of water transport is conducted in order to estimate the total cost of desalination and the transport of desalinated water to selected water stress cities. Transport costs range from a few cents per cubic meter to over a dollar. A 100 m vertical lift is about as costly as a 100 km horizontal transport (0.05-0.06$/m3). Transport makes desalinated water prohibitively expensive in highlands and continental interiors, but not elsewhere.water cost, desalination, water transport, MSF, RO, water shortage
Valuing the health impacts from particulate air pollution in Tianjin
Although China has made dramatic economic progress in recent years, air pollution continues to be the most visible environmental problem and imposes significant health and economic costs on society. Using data on pollutant concentration and population for 2003, this paper estimates the economic costs of health related effects due to particulate air pollution in urban areas of Tianjin, China. Exposure-response functions are used to quantify the impact on human health. Value of a statistical life and benefit transfer are used to obtain the unit value of some health effects. Our results show significant health costs associated with air pollution in Tianjin. The total economic cost is estimated to be US$1.1 billion, about 3.7% of Tianjinâs GDP in 2003. The findings underscore the importance of urban air pollution control. Finally, the policy implications for alternative energy options and climate policies are given.particulate air pollution, PM10, economic valuation, Tianjin
Water Use in Chinaâs Domestic, Industrial and Agricultural Sectors: An Empirical Analysis
Demand management plays an increasingly important role in dealing with water scarcity in China. It is important to understand the level and pattern of water use in various sectors across the regions for any measures being put into effect. The aim of this study is to enhance the understanding of the factors that influence water demand by examining closely the water use in domestic, industrial and agricultural sectors. Using province level panel data from 1997 to 2003, the examination shows that the regional disparity in the level and pattern of water uses is considerable. The estimation of water demand shows that both economic and climatic variables have significant effects on water demand. The results suggest an income elasticity of 0.42 for the domestic sector, an output elasticity of -0.32 for industrial water use (per unit of output), and an output elasticity of â0.24 for irrigated agriculture (per land area).water use, regional variation, elasticity, demand management
A Global Database of Domestic and International Tourist Numbers at National and Subnational Level
We present a new, global data base on tourist destinations. The data base differs from other data bases in that it includes both domestic and international tourists; and it contains data, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet.Tourism, Data
A GLOBAL DATABASE OF DOMESTIC AND INTERNATIONAL TOURIST NUMBERS AT NATIONAL AND SUBNATIONAL LEVEL
We present a new, global data base on tourist destinations. The data base differs from other data bases in that it includes both domestic and international tourists; and it contains data, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet.tourism, data
Parity Nonconservation in Neutron Resonances in 133Cs
Spatial parity nonconservation (PNC) has been studied in the compound-nuclear states of 134Cs by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick 133Cs target were performed by the time-of-flight method at the Manuel Lujan Neutron Scattering Center with a longitudinally polarized neutron beam in the energy range from 5 to 400 eV. A total of 28 new p-wave resonances were found, their neutron widths determined, and the PNC longitudinal asymmetries of the resonance cross sections measured. The value obtained for the root-mean-square PNC element M=(0.06-0.02+0.25) meV in 133Cs is the smallest among all targets studied. This value corresponds to a weak spreading width Îw=(0.006-0.003+0.154)Ă10-7 eV
Thermal properties of coal during low temperature oxidation using a grey correlation method
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The low temperature oxidation of coal is a contradictory and unified dynamic process of coexisting mass and heat transfer. The thermophysical properties are crucial during coal spontaneous combustion. In the current paper, the variations of moisture, ash, volatiles, fixed carbon and thermophysical properties (thermal diffusivity, specific heat and thermal conductivity) of three coal samples from 30 °C to 300 °C were studied, and their grey correlation was analyzed. The results indicated that with the increase of temperature, the free moisture of Coals A and B decreased first but then increased, while the free moisture of Coal C kept decreasing without a later increase. The variation of surface moisture was consistent with that of free moisture. The trend of volatiles and fixed carbon was completely the opposite, showing a significant negative correlation. Ash was less affected by temperature. Along with the rise of temperature, the thermal diffusivity of three coal samples decreased first but later increased, and the specific heat was always in a state of increasing. The change in thermal conductivity was mainly affected by specific heat. By calculating the gray correlation degree, the major factors affecting the thermophysical properties were obtained
Generalized Parton Distributions at x->1
Generalized parton distributions at large are studied in perturbative QCD
approach. As and at finite , there is no dependence for the
GPDs which means that the active quark is at the center of the transverse
space. We also obtain the power behavior: for pion; and
for nucleon, where
represents the additional dependence on .Comment: 7 pages, 2 figure
Quark initiated coherent diffractive production of muon pair and W boson at hadron colliders
The large transverse momentum muon pair and W boson productions in the quark
initiated coherent diffractive processes at hadron colliders are discussed
under the framework of the two-gluon exchange parametrization of the Pomeron
model. In this approach, the production cross sections are related to the
small-x off-diagonal gluon distribution and the large-x quark distribution in
the proton (antiproton). By approximating the off-diagonal gluon distribution
by the usual gluon distribution function, we estimate the production rates of
these processes at the Fermilab Tevatron.Comment: 11pages, 6 PS figures, to appear in PR
Calculus of Tangent Sets and Derivatives of Set Valued Maps under Metric Subregularity Conditions
In this paper we intend to give some calculus rules for tangent sets in the
sense of Bouligand and Ursescu, as well as for corresponding derivatives of
set-valued maps. Both first and second order objects are envisaged and the
assumptions we impose in order to get the calculus are in terms of metric
subregularity of the assembly of the initial data. This approach is different
from those used in alternative recent papers in literature and allows us to
avoid compactness conditions. A special attention is paid for the case of
perturbation set-valued maps which appear naturally in optimization problems.Comment: 17 page
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