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 $/m3 for seawater desalination and 0.6$/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 Tianjin’s 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 China’s 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 –0.24 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

Flow interaction between a streamwise oscillating cylinder and a downstream stationary cylinder

In this paper, we present some experimental results about the physical effects of a cylinder’s streamwise oscillation motion on a downstream one in a tandem arrangement. The upstream cylinder undergoes a controlled simple harmonic oscillation at amplitudes A/d = 0.2–0.8, where d is the cylinder diameter, and the frequency ratio of fe/fsfe/fs = 0–3.0, where fefe is the cylinder oscillation frequency and fsfs is the natural frequency of vortex shedding from a single stationary cylinder. Under these conditions, the vortex shedding is locked to the controlled oscillation motion. Flow visualisation using the planar laser-induced fluorescence and qualitative measurements using hot-wire anemometry reveal three distinct flow regimes behind the downstream cylinder. For fe/fs>(fe/fs)cfe/fs>(fe/fs)c , where (fe/fs)c(fe/fs)c is a critical frequency ratio which depends on A/d and Reynolds number Re, a so-called SA-mode occurs. The upstream oscillating cylinder generates binary vortices symmetrically arranged about the centreline, each containing a pair of counter-rotating vortices, and the downstream cylinder sheds vortices alternately at 0.5fe0.5fe . For 0.7–1.

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

Iron ochre: a pre-catalyst for the cracking of methane

Background: Iron ochres are gelatinous sludges which can cause problems in terms of water management. In this manuscript, the application of iron ochre obtained from a river has been applied to catalytically crack methane – another potential waste product - into two useful products, hydrogen and a magnetic carbon containing composite.<p></p> Results: The powder XRD pattern of the iron ochre was found to be consistent with the expected 2-line ferrihydrite and EDX analysis showed Fe to be a major component although some Si was present. The sample was observed to contain a fraction with a tubular morphology consistent with the presence of extra-cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transform into an active catalyst for hydrogen production yielding a magnetic carbon containing composite material comprising filamentous carbon and encapsulating graphite.<p></p> Conclusion: The application of two waste products – iron ochre and methane – to generate two useful products – hydrogen and a magnetic carbon containing composite- has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra-cellular biogenic iron oxide which may be of interest in terms of other applications.<p></p&gt

Proton strangeness form factors in (4,1) clustering configurations

We reexamine a recent result within a nonrelativistic constituent quark model (NRCQM) which maintains that the uuds\bar s component in the proton has its uuds subsystem in P state, with its \bar s in S state (configuration I). When the result are corrected, contrary to the previous result, we find that all the empirical signs of the form factors data can be described by the lowest-lying uuds\bar s configuration with \bar s in P state that has its uuds subsystem in $S$ state (configuration II). Further, it is also found that the removal of the center-of-mass (CM) motion of the clusters will enhance the contributions of the transition current considerably. We also show that a reasonable description of the existing form factors data can be obtained with a very small probability P_{s\bar s}=0.025% for the uuds\bar s component. We further see that the agreement of our prediction with the data for G_A^s at low-q^2 region can be markedly improved by a small admixture of configuration I. It is also found that by not removing CM motion, P_{s\bar s} would be overestimated by about a factor of four in the case when transition dominates over direct currents. Then, we also study the consequence of a recent estimate reached from analyzing the existing data on quark distributions that P_{s\bar s} lies between 2.4-2.9% which would lead to a large size for the five-quark (5q) system, as well as a small bump in both G^s_E+\eta G^s_M and G^s_E in the region of q^2 =< 0.1 GeV^2.Comment: Prepared for The Fifth Asia-Pacific Conference on Few-Body Problems in Physics 2011 in Seoul, South Korea, 22-26 August 201

Studies on bonding properties between polypropylene waterproof plate and concrete segment in shield tunnels

This paper studies the threaded polypropylene bar as the connecting piece to line the polypropylene waterproof plate inside concrete segment. The polypropylene bars are welded to the polypropylene waterproof plate so that the polypropylene waterproof plate and the concrete segment can be cast together to achieve high-efficient waterproofing. The bonding properties between polypropylene bar and concrete have been tested. A pullout test including 16 pull-out specimens composed of concrete cube block and polypropylene bar was conducted under pull-out loading. The parameters included surface type and diameter of polypropylene bar and concrete strength grade. Test results show that the maximum bond strength between polypropylene bar with threads on the surface and concrete reaches 3.14MPa, which is 12.8 times stronger than polypropylene bar with smooth surface. The bond strength between polypropylene bars with a diameter of 30mm has doubled strength than polypropylene bars with a diameter of 25mm. The concrete strength has no significant effect on the bond strength. 3D model of pull-out specimens was established in simulation software ABAQUS. The bonding connection was performed by utilizing the non-linear spring elements. The results display that the stress distributed on concrete starts to radiate from the bonding interface to the surroundings in a dumbbell shape and gradually decreases. The stress distribution on polypropylene bar gradually decreases from the loaded end to the free end. The deviation between calculated value and test value within anchoring range 14%. The finite element model can closely reflect bond-slip characteristics between polypropylene bar and concrete.Papers presented at the 40th International Southern African Transport Conference on 04 -08 July 202

Avalanche Breakdown Timing Statistics for Silicon Single Photon Avalanche Diodes

CCBY Silicon-based Single Photon Avalanche Diodes (SPADs) are widely used as single photon detectors of visible and near infrared photons. There has however been a lack of models accurately interpreting the physics of impact ionization (the mechanism behind avalanche breakdown) for these devices. In this work, we present a statistical simulation model for silicon SPADs that is capable of predicting breakdown probability, mean time to breakdown and timing jitter. Our model inherently incorporates carriers & #x0027; dead space due to phonon scattering and allows for non-uniform electric fields. Model validation included avalanche gain, excess noise factor, breakdown voltage, breakdown probability, and timing statistics. Simulating an n on-p and a p-on-n SPAD design using our model, we found that the n-on-p design offers significantly improved mean time to breakdown and timing jitter characteristics. For a breakdown probability of 0.5, mean time to breakdown and timing jitter from the n-on-p design were 3 and 4 times smaller compared to those from the p on n design. The data reported in this paper is available from the ORDA digital repository (DOI: 10.15131/shef.data.4823248)