2,430 research outputs found

    Evaluating Potable Water Production of a Single Slope Solar Still for Waste Water under Jordan Climate Conditions

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    The scarcity of potable water constitutes a major problem in underdeveloped and also some developing countries. Economical and applicable water desalination solar still coupled with a solar collector was designed and investigated experimentally. Solar still can be considered an appropriate solution for solving the water scarcity in remote and semi-arid areas. The aim of this work is to determine the performance and productivity of a single slope solar still system using different operational parameters such as ambient temperature and solar intensity. The experimental results showed that water production is significantly affected by the solar radiation intensity during the day and the instantaneous productivity of distilled water increases gradually during the experiment. The water production reaches its maximum value of 0.13 L/m² at 13:00 pm were the solar radiation is higher. Keywords: Feed water, Instantaneous productivity, solar still, solar radiation intensity, Potable water

    A Flood Risk Management Program of Wadi Baysh Dam on the Downstream Area: An Integration of Hydrologic and Hydraulic Models, Jizan Region, KSA

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    For public safety, especially for people who dwell in the valley that is located downstream of a dam site, as well as the protection of economic and environmental resources, risk management programs are urgently required all over the world. Despite the high safety standards of dams because of improved engineering and excellent construction in recent times, a zero-risk guarantee is not possible, and accidents can happen, triggered by natural hazards, human actions, or just because the dam is aging. In addition to that is the impact of potential climate change, which may not have been taken into account in the original design. A flood risk management program, which is essential for protecting downstream dam areas, is required. Part of this program is to prepare an inundation map to simulate the impact of dam failure on the downstream areas. The Baysh dam has crucial importance both to protect the downstream areas against flooding, to provide drinking water to cities in the surrounding areas, and to use the excess water for irrigation of the agricultural areas located downstream of the dam. Recently, the Kingdom of Saudi Arabia (KSA) was affected by extraordinary rainstorm events causing many problems in many different areas. One of these events happened along the basin of the Baysh dam, which raised the alarm to the decision makers and to the public to take suitable action before dam failure occurs. The current study deals with a flood risk analysis of Wadi Baysh using an integration of hydrologic and hydraulic models. A detailed field investigation of the dam site and the downstream areas down to the Red Sea coast has been undertaken. Three scenarios were applied to check the dam and the reservoir functionality; the first scenario at 100-and 200-year return period rainfall events, the second scenario according to the Probable Maximum Precipitation (PMP), and the third scenario if the dam fails. Our findings indicated that the Baysh dam and reservoir at 100-and 200-year rainfall events are adequate, however, at the PMP the water will spill out from the spillway at ~8900 m3/s causing flooding to the downstream areas; thus, a well-designed channel along the downstream wadi portion up to the Red Sea coast is required. However, at dam failure, the inundation model indicated that a vast area of the section downstream of the dam will be utterly devastated, causing a significant loss of lives and destruction of urban areas and agricultural lands. Eventually, an effective warning system and flood hazard management system are imperative

    Design and implementation of an intelligent monitoring system for household added salt consumption in China based on a real-world study: a randomized controlled trial.

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    A high intake of salt is a major risk factor for cardiovascular diseases. Despite decades of effort to reduce salt consumption, the salt intake in China is still considerably above the recommended level. Thus, this study aims to design and implement an intelligent household added salt monitoring system (SALTCHECKER) to monitor and control added salt consumption in Chinese households. A randomized controlled trial will be conducted among households to test the effect of a SALTCHECKER in Chongqing, China. The test modalities are the SALTCHECKER (with a smart salt checker and a salt-limiting WeChat mini programme) compared to a salt checker (with only a weighing function). The effectiveness of the system will be investigated by assessing the daily added salt intake of each household member and the salt consumption-related knowledge, attitude and practice (KAP) of the household's main cook. Assessments will be performed at baseline and at 3 and 6 months. This study will be the first to explore the effect of the household added salt monitoring system on the reduction in salt intake in households. If the intelligent monitoring system is found to be effective in limiting household added salt consumption, it could provide scientific evidence on reducing salt consumption and preventing salt-related chronic diseases. Chinese clinical trial registry (Primary registry in the World Health Organization registry network): ChiCTR1800018586. Date of registration: September 25, 2018

    Maturing pattern for body weight, body length and height at withers of Jamnapari and Boer goats

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    The objective of this study was to examine the growth pattern of three size measurements, namely body weight, body length, and height at withers of Jamnapari and Boer goats reared under common semi-intensive environment in Johor, Malaysia. Cross-sectional data of the above measurements of 234 Jamnapari and 312 Boer female goats (age ranged from 6 to 54 months) were used to fit Gompertz and von Bertalanffy growth curve models for the estimation of mature size, constant of integration, and maturing rate for the three size measurements. Jamnapari and Boer female goats were found to be significantly different (p<0.05) in term of their mature weight (52.19 and 58.23 kg, respectively, for the Gompertz model and 53.89 and 59.31 kg, respectively, for the von Bertalanffy model). The estimates of height at maturity were significantly larger (p<0.05) for the Jamnapari than Boer females. Although the maturing rate for body weight of the Jamnapari and Boer goats was not different, but their rates of maturing for body length and height at withers were found to be significantly different (p<0.05). The correlation coefficients between the mature size and rate of maturing for their body weight, body length, and height at withers were negative, implying that goats of larger size measurements tended to have a slower growth rate in relation to their mature size

    Factorial design in optimizing parameters for thermoresponsive ionic liquids as draw solution

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    This study aims to optimize the operating conditions of the forward osmosis (FO) process by introducing thermo-responsive ionic liquids (TRILs) namely 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) as a draw solution for seawater desalination applications. The influence of the operation parameters, such as the feed and draw flowrate (60–300 ml/min), draw solution concentration (0.6–3.0 M), temperature (25–50 °C), and type of flow with feed concentration using artificial seawater (0.6 M NaCl). The interaction between parameters has been specified using fractional factorial design (FrFD). The draw solution concentration and the interactions between draw and feed flowrate were the most significant factors in achieving high water flux 5.1 LMH. Besides that, the draw flowrate and the interaction of both draw and feed flowrate give high significance toward adverse effects (such as concentration polarization), which is good to obtain low reverse salt at 1.3 gMH. Use the desirability function (DF) to obtain the highest water flux of 5.04 LMH and the lowest reverse salt flux of 1.71 gMH, with a desirability of 0.95. The optimal condition for FO performance is 300 ml/min feed and draw flowrate with 3.0 M draw solution at 25 °C and co-current flow

    Numerical investigation of soot mass concentration in compression ignition diesel engine

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    Soot particles, carbon monoxide, oxides of nitrogen, oxides of sulphur, and hydrocarbon are the emissions produced from diesel engine combustion. Those emissions species are undesirable since they give detrimental impacts to the atmosphere and human well-being. Several numerical investigations conducted by various researchers provide different soot mass concentration values. As an alternative, this study was carried out to investigate the soot mass level produced by a single cylinder diesel engine, using a commercial multidimensional computational fluid dynamic software. The result obtained from simulation effort was then validated by experimental testing during the same engine condition (engine speed of 1600 rpm at 40% load). Soot mass predicted by simulation gives a value of 3.43 × 10-8 kg at end of simulation, while measured soot mass via experimental testing gives a value of 1.52 × 10-8 kg. Both results differ by 56% thus indicating that the simple soot model applied was not sufficient to represent the actual soot mass emitted through exhaust manifold. This leads to the conclusion that more detailed soot model is needed to make the simulation results more meaningful and comparable to the experimental testing
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