1,462 research outputs found
Bengali women's ideas about water quality
Respecting cultural beliefs and customary practices is part of the rights- and commons-based thinking about water. The focus is on place-based practices and beliefs. Incorporating indigenous beliefs into any new, participatory approach to water management, however, is quite challenging to the scientifically oriented development professional. This paper explains to the basics of cultural views of water among Bengali-speaking people of the southern, eastern, and western parts of the Bangladesh delta. Examples are drawn from the authors’ work on arsenic in drinking water and other WASH issues. Ideas such as hot/cold or pure/impure are perceived as “superstitions” by many scientists. If our thinking about water life is to change in the direction the commons-based approach suggests -- to incorporate indigenous views into place-based planning – the main obstacle will be with those who now have the upper hand, not those who are marginalized. Planning processes should be organized in ways that respect local views and take them into consideration when introducing new technologies
Self modulated dynamics of a relativistic charged particle beam in plasma wake field excitation
Self modulated dynamics of a relativistic charged particle beam is reviewed
within the context of the theory of plasma wake field excitation. The
self-consistent description of the beam dynamics is provided by coupling the
Vlasov equation with a Poisson-type equation relating the plasma wake potential
to the beam density. An analysis of the beam envelope self-modulation is then
carried out and the criteria for the occurrence of the instability are
discussed thereby.Comment: This is a 10 pages manuscript which contain 4 figures. This
manuscript is recently submitted in 'Nuclear Instruments and Methods in
Physics Research Section A' as a proceeding of the conference 'EAAC 2015
Sensor failure detection for jet engines
Revisions to the advanced sensor failure detection, isolation, and accommodation (DIA) algorithm, developed under the sensor failure detection system program were studied to eliminate the steady state errors due to estimation filter biases. Three algorithm revisions were formulated and one revision for detailed evaluation was chosen. The selected version modifies the DIA algorithm to feedback the actual sensor outputs to the integral portion of the control for the nofailure case. In case of a failure, the estimates of the failed sensor output is fed back to the integral portion. The estimator outputs are fed back to the linear regulator portion of the control all the time. The revised algorithm is evaluated and compared to the baseline algorithm developed previously
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Surface Water Hydrology of the Proposed Low-Level Radioactive Waste Isolation Site, Hudspeth County, Texas
This report describes the surface-water hydrology at the proposed low-level radioactive waste isolation site in Hudspeth County, Texas. The objective of these investigations was to evaluate the flooding potential at the site based on computer simulation of runoff from observed and hypothetical rain events. Analytic techniques and assumptions used in this study are based on recommendations of federal and state regulatory agencies regarding flood insurance and dam safety criteria. Published topographic maps, aerial photographs, and site surveys were used for delineating drainage basins and surface-water pathways on the study area. Surface-water runoff volumes were calculated for rain events monitored at the site during the study period. Hydrologic computer models were employed to determine correlation of rainfall to surface-water runoff. These computer models were calibrated using rainfall and stream-flow data measured at the site. Flood profiles were calculated for 100-yr and probable maximum rain events, which were estimated from historical data. The following conclusions regarding the flooding potential at the study area were drawn on the basis of these studies:
(1) Computer simulation indicates that floods resulting from hypothetical 100-yr and probable maximum precipitation events are contained within existing channels in the study area, leaving large interchannel areas unflooded. Some overland sheet flow is encountered over the flat area, but the velocities of flow are very small.
(2) Rainfall events recorded during the 1988-1989 period were short and localized. The response of runoff to rainfall is rapid and the duration of the peak water flow after rainfall is relatively short.
(3) Flow velocities range from 3 to 13 ft/sec (0.9 to 4 m/sec) in channels and are lower over flat areas. Maximum depth of flow due to a 100-yr flood in the better-defined channel on the central part of the study area is about 5 ft (1.5 m).Bureau of Economic Geolog
Comparing Food and Cash Transfers to the Ultra-Poor in Bangladesh
"Bangladesh has some social safety net programs that transfer food to the poor, some that transfer cash, and some that provide a combination of both. This study evaluates the relative impacts of food and cash transfers on food security and livelihood outcomes among the ultra poor in Bangladesh. The programs impacts are evaluated according to various measures, including how well transfers are delivered; which transfers beneficiaries prefer; how accurately the programs target the extremely poor; effects on food security, livelihoods, and women’s empowerment; and cost effectiveness. The report identifies what has and has not worked in food and cash transfers and recommends ways of improving these programs. This study will be valuable to policymakers and others concerned with poverty reduction in Bangladesh and elsewhere." from textCash transfers, cost effectiveness, food security, Poverty, Poverty reduction, safety net programs, women empowerment,
HYTESS: A hypothetical turbofan engine simplified simulation
A users manual for a hypothetical turbofan engine simplified simulation is presented. This digital simulation exists as FORTRAN source code. The program is self-contained and was developed to offer those interested in engine dynamics and controls research an efficient, realistic, and easily used engine simulation. The engine is modeled using a state space formulation. Matrix elements within the linear state space structure are nonlinear functions of various engine variables
Sensor failure detection system
Advanced concepts for detecting, isolating, and accommodating sensor failures were studied to determine their applicability to the gas turbine control problem. Five concepts were formulated based upon such techniques as Kalman filters and a screening process led to the selection of one advanced concept for further evaluation. The selected advanced concept uses a Kalman filter to generate residuals, a weighted sum square residuals technique to detect soft failures, likelihood ratio testing of a bank of Kalman filters for isolation, and reconfiguring of the normal mode Kalman filter by eliminating the failed input to accommodate the failure. The advanced concept was compared to a baseline parameter synthesis technique. The advanced concept was shown to be a viable concept for detecting, isolating, and accommodating sensor failures for the gas turbine applications
Amelioration of a saline sodic soil through cultivation of a salt-tolerant grass Leptochloa fusca
Reclamation of saline lands seems difficult for climatic and economic reasons, but cultivation of salt-tolerant plants is an approach to increasing productivity and improvement of salt-affected wastelands. A five-year field study was conducted to evaluate the effects of growing a salt-tolerant species Leptochloa fusca (L.) Kunth (kallar grass) on chemical properties of a saline sodic soil irrigated with poor quality groundwater. Soil salinity, sodicity and pH decreased exponentially by growing kallar grass as a result of leaching of salts from surface (0–20 cm) to lower depths (>100 cm). Concentrations of soluble cations (Na+, K+, Ca2+ and Mg2+) and anions (Cl−, SO42− and HCO3−) were reduced through to greater soil depths. A significant decline in soil pH was attributed to release of CO2 by grass roots and solublization of CaCO3. Both soil salinity and soil pH were significantly correlated with Na+, Ca2+, Mg2+, K+, Cl−, HCO3− and sodium adsorption ratio (SAR). Significant correlations were found between soluble cations (Na+, Ca2+ and K+), soluble anions (Cl−, SO42− and HCO3−) and the SAR. In contrast, there were negative correlations between soil organic matter content and all chemical properties. The ameliorative effects on the soil chemical environment were pronounced after three years of growing kallar grass. Cultivation of kallar grass enhanced leaching and interactions among soil chemical properties and thus restored soil fertility. The soil maintained the improved characteristics with further growth of the grass up to five years suggesting that growing salt-tolerant plants is a sustainable approach to biological amelioration of saline wastelands.J. Akhter, K. Mahmood, K.A. Malik, S. Ahmed and R. Murra
Geographical inequalities in health in a time of austerity: Baseline findings from the Stockton-on-Tees cohort study
Stockton-on-Tees has the highest geographical inequalities in health in England with the life expectancy at birth gap between the most and deprived neighbourhoods standing at over 17 years for men and 11 years for women. In this study, we provide the first detailed empirical examination of this geographical health divide by: estimating the gap in physical and general health (as measured by EQ. 5D, EQ. 5D-VAS and SF8PCS) between the most and least deprived areas; using a novel statistical technique to examining the causal role of compositional and contextual factors and their interaction; and doing so in a time of economic recession and austerity. Using a stratified random sampling technique, individual-level survey data was combined with secondary data sources and analysed using multi-level models with 95% confidence intervals obtained from nonparametric bootstrapping. The main findings indicate that there is a significant gap in health between the two areas, and that compositional level material factors, contextual factors and their interaction appear to be the major explanations of this gap. Contrary to the dominant policy discourse in this area, individual behavioural and psychosocial factors did not make a significant contribution towards explaining health inequalities in the study area. The findings are discussed in relation to geographical theories of health inequalities and the context of austerity
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