The paper aims to determine the irrigation water supply efficiency of different irrigation methods used in the challenging environment of Bal’ad district in Somalia. Data was collected from the literature, field visi...The paper aims to determine the irrigation water supply efficiency of different irrigation methods used in the challenging environment of Bal’ad district in Somalia. Data was collected from the literature, field visits using field records and scheduled interviews, GPS coordinates and from ancillary information, such as remote sensing images and existing national maps. A comparison was done by use of secondary sources, such as academic journals using information from authorities on irrigation and water loss. Sampling was done by use of Snow balling. The results highlighted response rate for farmers being 80% while that of NGO employees is 75.76%. According to the results, the main ways through which irrigation water is lost is through: evaporation;seepage through the canal bunds;overtopping the bunds;overflow losses and overwatering with the average field application efficiency of 25% and conveyance efficiency of 30%. These generated a scheme irrigation efficiency of 7.5% which is poor for surface irrigation prevalent in the study area. The loss of irrigation water was found to be reduced by the following: daily supervision;proper maintenance;water allocation to farmers;good management;lining of canals;management of irrigation methods;ongoing evaluation;good land preparation;and training farmers.展开更多
Geographical data are of great importance in meteorology and climate science. These data can create the areal distribution models analyzed by spatial interpolation methods. The values of the areas without measurement ...Geographical data are of great importance in meteorology and climate science. These data can create the areal distribution models analyzed by spatial interpolation methods. The values of the areas without measurement data are estimated with these distribution models. In this study, distribution of meteorological parameters such as precipitation, temperature and evaporation in Porsuk basin, which is determined as research area, was investigated by Inverse Distance Weighting (IDW) and Ordinary Kriging methods. Actual meteorological data analyzed of the basin do not show a normal distribution statistically. Therefore, the data were firstly subjected to normalization and then analyzed according to the IDW and Ordinary Kriging methods to create distribution maps of precipitation, temperature and evaporation data. Quadratic mean error values were compared to investigate the reliability of analyzes. In this study, the analysis results of precipitation, temperature and evaporation data have been calculated by two different methods. Ordinary Kriging method has been determined as the method making the most accurate estimation.展开更多
Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in t...Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in the United States. These plants range in size from a few hundred gallons per day (GPD) to over 1.445 billion gallons (MGD) per day. Wastewater treatment facilities are designed and constructed or upgraded to reduce the amount and diversity of pollutants. This article gives a review of the current industrial wastewater treatment technology in recent years, including treatment principles, advantages and disadvantages of each method, and the corresponding applications. Also, this article reviewed two common biological technologies Anaerobic Ammonium Oxidation (ANAMMOX) and Anaerobic Membrane Bioreactor (ANMBR) technology, by assessing their advantages, disadvantages, and costs, and provides resources for further technical research. This article can serve as a guide for anyone seeking information on innovative and emerging industry wastewater treatment technologies.展开更多
Solar water heaters which provide a cost-effective and environmental friendly approach to hot water generation are in widespread application. Evacuated tube solar water heaters perform better than flat plate solar wat...Solar water heaters which provide a cost-effective and environmental friendly approach to hot water generation are in widespread application. Evacuated tube solar water heaters perform better than flat plate solar water heaters as a result of their greater surface area exposed for sunlight absorption. Water-in-glass evacuated tube solar water heaters are widely used as compared to heat-pipe solar water heaters due to their short payback periods. In this study, the performance of water-in-glass evacuated tube solar water heater is investigated through experiments under the climatic conditions in Kenya. The results revealed a daily efficiency range of 0.58 - 0.65 and a daily final outlet temperature greater than 55<span style="white-space:normal;">°</span>C given an initial temperature of 25°C.展开更多
The production of hydrogen, vector of energy, by electrolysis way and by using photovoltaic solar energy can be optimized by suitable choice of electrolytes. Distilled water, usually used, due to membrane presence may...The production of hydrogen, vector of energy, by electrolysis way and by using photovoltaic solar energy can be optimized by suitable choice of electrolytes. Distilled water, usually used, due to membrane presence may be substituted by wastewaters, which enters more in their treatment. Waste water such as those of the Cleansing National Office, and also of the factories such as those referring with ammonia, the margines, and even urines that make it possible to produce much more hydrogen as distilled or salted water, more especially as they do not even require an additive or membranes: conventional electrolysers with two electrodes. This study seeks to optimize the choice among waste water and this, by electrolysis in laboratory or over the sun according to produced hydrogen flow criteria, electrolysis efficiency and electric power consumption. The additive used is NaCl. The most significant results are on the one hand the significant increase in the produced hydrogen flow by the addition of the additive;on the other hand the advantage of gas liquor and urine compared to the others tested electrolytes.展开更多
Climate change is a controversial topic of debate, especially in the US, where many do not believe in anthropogenic climate change. Because its consequences are predicted to be dire, such as a mass ocean extinction an...Climate change is a controversial topic of debate, especially in the US, where many do not believe in anthropogenic climate change. Because its consequences are predicted to be dire, such as a mass ocean extinction and frequent extreme weather events, it is important to learn what causes the warming in order to better combat it. In this study, the first challenge dwells on how to construct reliable statistical models based on massive climate data of 800,000 years and accurately capture the relationship between temperature and potential factors such as concentrations of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). We compared the performance several mainstream machine learning algorithms on our data, which includes linear regression, lasso, support vector regression and random forest, to build the state of the art model to verify the warming of the earth and identifying factors contributing the global warming. We found that random forest outperforms other algorithms to create accurate climate models which use features including concentrations of different greenhouse gases to precisely forecast global atmosphere. The other challenges in identifying factor importance can be met by the feature of ensemble tree-based random forest algorithm. It was found that CO2 is the largest contributor to temperature change, followed by CH4, then by N2O. They all had some sorts of impact, though, meaning their release into the atmosphere should all be controlled to help restrain temperature increase, and help prevent climate change’s potential ramifications.展开更多
In this study, 16 irrigation schemes (Baklan, Irgilli, Sutlac, Cal, Cürüksu, Nazilli, Saraykoy, Pamukkale, Sultanhisar, Akcay, Aydin, Topcam, Karpuzlu, Isikli, Gümüssu ve Soke) having 166,381 hecta...In this study, 16 irrigation schemes (Baklan, Irgilli, Sutlac, Cal, Cürüksu, Nazilli, Saraykoy, Pamukkale, Sultanhisar, Akcay, Aydin, Topcam, Karpuzlu, Isikli, Gümüssu ve Soke) having 166,381 hectares, built by State Hydraulic Works (DSI), and operated by participatory irrigation managements, and 14 hydroelectric power plants (HPP) operated and built on dams, canals and rivers by the public and private sectors are examined in the Büyük Menderes basin which is an important basin in terms of the agriculture, energy and ecology projects. Integrated basin management practices and the importance and role of irrigation and hydropower plant operation in integrated basin management, how it should be, optimal use of available water resources for irrigation and hydroelectric power plant operation, irrigation relationship with canal hydropower plants, operated under integrated basin management of irrigation and hydropower plants, environment and the ecological effects have been studied, and integrated basin management with the existing basin management conditions in terms of hydropower plant and irrigation operation on the basis of data of 2015 have been compared, reached important conclusions, and made recommendations on the subject.展开更多
The interdependency among water, food, and energy (WEF) in the GCC countries is strongly and closely interlinked, and is intensifying as demand for resources increases with population growth and changing consumption p...The interdependency among water, food, and energy (WEF) in the GCC countries is strongly and closely interlinked, and is intensifying as demand for resources increases with population growth and changing consumption patterns, and are expected to be further compounded by the impacts of climate change. Therefore, integrated management of the three sectors is crucial to reduce trade-offs and build synergies among them. This paper presents a comprehensive framework to assess the WEF nexus in Kuwait as a representative case for the GCC countries. The framework consists of three main steps: 1) evaluating the influence of socio-economic development and climate change on water, energy, and food resources;2) generating scenario-based projections;and 3) conducting an extensive quantitative nexus analysis. The WEF interlinkages in Kuwait are modelled quantitatively using the Q-Nexus model, and current critical interdependencies are evaluated. Then, various WEF-Nexus scenarios were conducted for the year 2035 to explore the effects of management interventions in one sector on the other two sectors. The main findings are that per capita municipal water consumption is a major influencer on the WEF-nexus due to the heavy reliance on thermal desalination in municipal water supply in Kuwait, which is attributed to its energy intensity, financial cost, GHGs emissions, and environmental impacts on the marine and air environments. To reduce WEF trade-offs, mitigate risks, and build synergies among the three sectors, it is important to shift the current policy focus on supply-side management approach to the demand-side management and efficiency approaches.展开更多
In quest for quality and sustainable development, it is necessary to find alternative materials, methods of brick making and house design. Bricks made in open kilns using locally available materials usually do not mee...In quest for quality and sustainable development, it is necessary to find alternative materials, methods of brick making and house design. Bricks made in open kilns using locally available materials usually do not meet the requirements of the South African Bureau of Standards;hence it needs to add some ingredients such as fly ash to produce better quality bricks. This paper reports the effects of fly ash on properties of clay bricks that can improve the thermal performance of buildings. Bricks of different clay and fly ash mixing proportions were molded. A passive solar house was designed and constructed using fly ash bricks. Results indicate that thermal conductivity and water absorption decrease with increase in fly ash. Compressive strength was found to in-creases with increase in amount of fly ash. A mixing proportion of 50% of fly ash to 50% clay by volume produced a brick with the highest compressive strength, lowest thermal conductivity and minimum water absorption. The bricks were observed to have uniform size as they experience minimal burning shrinkage. These properties were found to have a significant impact on the thermal performance of the house. The mean indoor temperature swing was found to be 11°C.展开更多
Insects such as Acheta domesticus account for over half of marsh fish and migratory bird diet. Therefore, insects are very important to marsh and island ecosy stems and are susceptible to oil contamination, but little...Insects such as Acheta domesticus account for over half of marsh fish and migratory bird diet. Therefore, insects are very important to marsh and island ecosy stems and are susceptible to oil contamination, but little research has been done to study the effects of oil spills on cricket populations. The purpose of this experiment was to determine the effects of an oil spill event on Acheta domesticus mortality and hatch rate to establish environmental sustainability. The treatment groups included 0% oil contamination, 5% oil contamination and 10% oil contamination. The scientist counted the number of deaths in two-week, four-week, and six-week-old crickets after oil contamination. In addition, the scientist counted the number of hatchlings among treated cricket eggs. Error bar lines in the results section supported the scientist’s hypothesis that the crickets would be affected by oil contamination. In fact, over 90% of the 10% oil treatment group died and over 80% of the 5% oil treatment group died after five days of oil contamination in the six-week-old experiment. The scientist used a Gas Chromatography Mass Spectrometer to determine if benzene, toluene, ethylbenzene, or xylene (total) were present in the sediment samples. BTEX exposure is suspected to possibly cause insect mortality. These volatile organic compounds were present in the samples and were found in higher quantities in samples with higher concentrations of oil. The highest quantity of volatile organic compounds present was xylene. After studying the population dynamics of the tested Acheta domesticus, the scientist found that the two-week and four-week-old crickets’ survivability could fit a linear model while the six-week-old crickets fit an exponential model. The scientist used these models to observe how long it took each treatment group to approach zero, and the oiled groups grew closer to a population of zero significantly faster. For example, it took about twenty-seven days for the 10% treatment group’s population to approach zero whereas the control, 0% treatment group, took about seven days in the two-week-old cricket experiment. Overall, the six-week-old crickets had the highest mortality, and the cricket egg experiment resulted in extremely low hatch rate. Specifically, the highest number of crickets that hatched in an oiled replication either 5% or 10% oil was eight out of the five thousand eggs laid. Since the adult crickets are the most physically able to reproduce and the cricket eggs had low hatch rates, the cricket population would significantly decrease after an oil spill with 5% or more soil contamination. However, if the plant matter that crickets consume is still present in their environment, they may be able to recover.展开更多
To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of...To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of various meteorological parameters namely the monthly averaged value of maximum temperature, minimum temperature, humidity and sunshine hours were used in this study. Assessment of the solar resources for the solar based renewable energy technologies of Bangladesh may be based upon this kind of measured data analyzed study. This study tried to estimate the monthly averaged solar radiation by presenting data in table and graph and finally analyze through equations and descriptions. Correlation between the measurements of monthly averaged solar radiation and the meteorological parameters was given for the selected 10 stations in Bangladesh. In conclusion, we tried to make a comparison among solar radiation on horizontal surface, fixed 20.83<sup> ° </sup> (degree) optimal tilt angle and variable optimal tilt surface at Dhaka station.展开更多
Photovoltaic cells are generally manufactured under standard test conditions. <span style="font-family:Verdana;">The operating conditions, very often induce performance losses different from </span&...Photovoltaic cells are generally manufactured under standard test conditions. <span style="font-family:Verdana;">The operating conditions, very often induce performance losses different from </span><span style="font-family:Verdana;">those initially given by the manufacturer. This article presents an experimental acquisition and analysis system that integrates the synthetic efficiency ra</span><span style="font-family:Verdana;">tio (SER) as a hybrid analysis tool to evaluate the performance of a monocrystalline</span> <span style="font-family:Verdana;">photovoltaic solar panel, in this case the LW-MS90 panel in the city of Douala. The meteorological data obtained experimentally was used to evaluate these performances according to the manufacturer</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">s model in MATLAB/Simulink</span><span style="font-family:;" "=""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">By comparison with the experimental performances, the results quantify through</span><span style="font-family:Verdana;"> a certain number of indices, a minimal power drop according to the acquired irradiance estimated at 3.45%. The interest of this approach is to contribute to the prediction of the operating performance of PV panels in the installation phase in non-standard areas.</span></span>展开更多
Passive sampling for the monitoring of organic pollutants (PAHs, PCBs, PBDEs) in ambient air has received increased attention in the last two decades. However, the accuracy of the concentration of organics obtained wi...Passive sampling for the monitoring of organic pollutants (PAHs, PCBs, PBDEs) in ambient air has received increased attention in the last two decades. However, the accuracy of the concentration of organics obtained with passive samplers under varying environmental conditions is a subject of controversy. In this study, effect of ambient temperature on passive samplers was evaluated by using three different sampler configurations. Additionally, passive samplers with polyurethane disks (PUF) were applied throughout the Island for the determination of the airborne concentration of polycyclic aromatic hydrocarbons (PAHs). The passive samplers were deployed in seven municipalities for three-month periods in two different sampling campaigns, representing hurricane and non-hurricane seasons. Here we present preliminary results obtained from those sampling campaigns. The total concentrations of 15 PAHs varied from 3.1 to 19.6 and from 5.5 to 38.5 ng/m3 for hurricane and non-hurricane seasons, respectively. Hurricane and non-hurricane season concentrations of PAH were significantly different for the samples taken in the northern municipalities of the Island. However, there was no significant difference in PAH concentrations between the hurricane and non-hurricane seasons for the southern sites. Increased rainfall and high-relative humidity during the hurricane season had an influence on the concentrations of PAHs derived by the passive PUF sampler.展开更多
The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, lo...The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.展开更多
Simulation of runoff in ungauged catchments has always been a challenging issue, receiving significant attention more importantly in practical applications. This study aims at calibration of an Artificial Neural Netwo...Simulation of runoff in ungauged catchments has always been a challenging issue, receiving significant attention more importantly in practical applications. This study aims at calibration of an Artificial Neural Network (ANN) model which is capable to apply in an ungauged basin. The methodology is applied to two sub-catchments located in the Northern East of Iran. To examine the effect of physical characteristics of the catchment on the capability of the model generalization, it is attempted to synthesize effective parameters using empirical methods of runoff estimation. Firstly, the model was designed for a pilot sub-catchment and the statistical comparison between simulated runoff, and target depicted the capability of ANN to accurately estimate runoff over a catchment. Then, the calibrated model was generalized to another sub-catchment assumed as an ungauged basin while there are runoff data to compare the result. The result showed that the designed model is relatively capable to estimate monthly runoff for a homogenous ungauged catchment. The method presented in this study in addition to adding effective spatial parameters in simulation runoff and calibration of model by using empirical methods and the integration of any useful accessible data, examines the adaptability of model to an ungauged catchment.展开更多
In ground water quality studies multivariate statistical techniques like Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), Factor Analysis (FA) and Multivariate Analysis of Variance (MANOVA) wer...In ground water quality studies multivariate statistical techniques like Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), Factor Analysis (FA) and Multivariate Analysis of Variance (MANOVA) were employed to evaluate the principal factors and mechanisms governing the spatial variations and to assess source apportionment at Lawspet area in Puducherry, India. PCA/FA has made the first known factor which showed the anthropogenic impact on ground water quality and this dominant factor explained 82.79% of the total variance. The other four factors identified geogenic and hardness components. The distribution of first factor scores portray high loading for EC, TDS, Na+ and Cl−(anthropogenic) in south east and south west parts of the study area, whereas other factor scores depict high loading for HCO3−, Mg2+, Ca2+ and TH (hardness and geogenic) in the north west and south west parts of the study area. K+ and SO42−(geogenic) are dominant in south eastern direction. Further MANOVA showed that there are significant differences between ground water quality parameters. The spatial distribution maps of water quality parameters have rendered a powerful and practical visual tool for defining, interpreting, and distinguishing the anthropogenic, hardness and geogenic factors in the study area. Further the study indicated that multivariate statistical methods have successfully assessed the ground water qualitatively and spatially with a more effective step towards ground water quality management.展开更多
This paper presents the fundamentals of direct inverse modeling using CFD simulations to detect air pollution sources in urban areas. Generally, there are four techniques used for detecting pollution sources: the anal...This paper presents the fundamentals of direct inverse modeling using CFD simulations to detect air pollution sources in urban areas. Generally, there are four techniques used for detecting pollution sources: the analytical technique, the optimization technique, the probabilistic technique, and the direct technique. The study discusses the potentialities and limits of each technique, where the direct inverse technique is focused. Two examples of applying the direct inverse technique in detecting pollution source are introduced. The difficulties of applying the direct inverse technique are investigated. The study reveals that the direct technique is a promising tool for detecting air pollution source in urban environments. However, more efforts are still needed to overcome the difficulties explained in the study.展开更多
In this paper, we are interested by the dissolution of NAPL (Non-Aqueous Phase Liquid) contaminants in heterogeneous soils or aquifers. The volume averaging technique is applied to 2D systems with Darcy-scale heteroge...In this paper, we are interested by the dissolution of NAPL (Non-Aqueous Phase Liquid) contaminants in heterogeneous soils or aquifers. The volume averaging technique is applied to 2D systems with Darcy-scale heterogeneities. A large-scale model is derived from a Darcy-scale dissolution model in the case of small and large Damkholer numbers, i.e., for smooth or sharp dissolution fronts. The resulting models in both cases have the mathematical structure of a non-equilibrium dissolution model. It is shown how to calculate the resulting mass exchange and relative permeability terms from the Darcy-scale heterogeneities and other fluid properties. One of the important finding is that the obtained values have a very different behavior compared to the Darcy-scale usual correlations. The large scale correlations are also very different between the two limit cases. The resulting large-scale models are compared favorably to Darcy-scale direct simulations.展开更多
This study evaluates the feasibility of groundwater banking in the Central Basin. The Central Basin is located in Sacramento County in northern California, USA. The study basin is bounded by three rivers (the Sacramen...This study evaluates the feasibility of groundwater banking in the Central Basin. The Central Basin is located in Sacramento County in northern California, USA. The study basin is bounded by three rivers (the Sacramento, the American, the Consumes and Mokelumne rivers), and by the Sierra-Nevada mountain range. This study focuses on the potential for groundwater recharge in the Central Basin for three water years (critical, wet, above normal). For that purpose, a 3-D Groundwater Modeling System (GMS) with MODFLOW was created. Three recharge wells were added to the calibrated groundwater model to recharge the water table with 10,000 Acre-Feet (AF) of water to the Central Basin. The banking of 10,000 AF during the critical and wet years was effective in raising the water table elevation in the cone of depression area without causing any negative impact elsewhere in the basin. According to the findings of the Central Basin model, banking up to 10,000 AF of groundwater during any year type is feasible. More than 10,000 AF of groundwater banking might cause more negative impacts than positive benefits.展开更多
The purpose of this paper is to investigate the spatial interpolation of rainfall variability with deterministic and geostatic inspections in the Prefecture of Kilkis (Greece). The precipitation data where recorded fr...The purpose of this paper is to investigate the spatial interpolation of rainfall variability with deterministic and geostatic inspections in the Prefecture of Kilkis (Greece). The precipitation data where recorded from 12 meteorological stations in the Prefecture of Kilkis for 36 hydrological years (1973-2008). The cumulative monthly values of rainfall were studied on an annual and seasonal basis as well as during the arid-dry season. In the deterministic tests, the I.D.W. and R.B.F. checks were inspected, while in the geostatic tests, Ordinary Kriging and Universal Kriging respectively. The selection of the optimum method was made based on the least Root Mean Square Error (R.M.S.E.), as well as on the Mean Error (M.E.), as assessed by the cross validation analysis. The geostatical Kriging also considered the impact of isotropy and anisotropy across all time periods of data collection. Moreover, for Universal Kriging, the study explored spherical, exponential and Gaussian models in various combinations. Geostatistical techniques consistently demonstrated greater reliability than deterministic techniques across all time periods of data collection. Specifically, during the annual period, anisotropy was the prevailing characteristic in geostatistical techniques. Moreover, the results for the irrigation and seasonal periods were generally comparable, with few exceptions where isotropic methods yielded lower (R.M.S.E.) in some seasonal observations.展开更多
文摘The paper aims to determine the irrigation water supply efficiency of different irrigation methods used in the challenging environment of Bal’ad district in Somalia. Data was collected from the literature, field visits using field records and scheduled interviews, GPS coordinates and from ancillary information, such as remote sensing images and existing national maps. A comparison was done by use of secondary sources, such as academic journals using information from authorities on irrigation and water loss. Sampling was done by use of Snow balling. The results highlighted response rate for farmers being 80% while that of NGO employees is 75.76%. According to the results, the main ways through which irrigation water is lost is through: evaporation;seepage through the canal bunds;overtopping the bunds;overflow losses and overwatering with the average field application efficiency of 25% and conveyance efficiency of 30%. These generated a scheme irrigation efficiency of 7.5% which is poor for surface irrigation prevalent in the study area. The loss of irrigation water was found to be reduced by the following: daily supervision;proper maintenance;water allocation to farmers;good management;lining of canals;management of irrigation methods;ongoing evaluation;good land preparation;and training farmers.
基金This study was supported by Anadolu University Scientific Research Projects Commission within the scope of project number 1506F500.
文摘Geographical data are of great importance in meteorology and climate science. These data can create the areal distribution models analyzed by spatial interpolation methods. The values of the areas without measurement data are estimated with these distribution models. In this study, distribution of meteorological parameters such as precipitation, temperature and evaporation in Porsuk basin, which is determined as research area, was investigated by Inverse Distance Weighting (IDW) and Ordinary Kriging methods. Actual meteorological data analyzed of the basin do not show a normal distribution statistically. Therefore, the data were firstly subjected to normalization and then analyzed according to the IDW and Ordinary Kriging methods to create distribution maps of precipitation, temperature and evaporation data. Quadratic mean error values were compared to investigate the reliability of analyzes. In this study, the analysis results of precipitation, temperature and evaporation data have been calculated by two different methods. Ordinary Kriging method has been determined as the method making the most accurate estimation.
文摘Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in the United States. These plants range in size from a few hundred gallons per day (GPD) to over 1.445 billion gallons (MGD) per day. Wastewater treatment facilities are designed and constructed or upgraded to reduce the amount and diversity of pollutants. This article gives a review of the current industrial wastewater treatment technology in recent years, including treatment principles, advantages and disadvantages of each method, and the corresponding applications. Also, this article reviewed two common biological technologies Anaerobic Ammonium Oxidation (ANAMMOX) and Anaerobic Membrane Bioreactor (ANMBR) technology, by assessing their advantages, disadvantages, and costs, and provides resources for further technical research. This article can serve as a guide for anyone seeking information on innovative and emerging industry wastewater treatment technologies.
文摘Solar water heaters which provide a cost-effective and environmental friendly approach to hot water generation are in widespread application. Evacuated tube solar water heaters perform better than flat plate solar water heaters as a result of their greater surface area exposed for sunlight absorption. Water-in-glass evacuated tube solar water heaters are widely used as compared to heat-pipe solar water heaters due to their short payback periods. In this study, the performance of water-in-glass evacuated tube solar water heater is investigated through experiments under the climatic conditions in Kenya. The results revealed a daily efficiency range of 0.58 - 0.65 and a daily final outlet temperature greater than 55<span style="white-space:normal;">°</span>C given an initial temperature of 25°C.
文摘The production of hydrogen, vector of energy, by electrolysis way and by using photovoltaic solar energy can be optimized by suitable choice of electrolytes. Distilled water, usually used, due to membrane presence may be substituted by wastewaters, which enters more in their treatment. Waste water such as those of the Cleansing National Office, and also of the factories such as those referring with ammonia, the margines, and even urines that make it possible to produce much more hydrogen as distilled or salted water, more especially as they do not even require an additive or membranes: conventional electrolysers with two electrodes. This study seeks to optimize the choice among waste water and this, by electrolysis in laboratory or over the sun according to produced hydrogen flow criteria, electrolysis efficiency and electric power consumption. The additive used is NaCl. The most significant results are on the one hand the significant increase in the produced hydrogen flow by the addition of the additive;on the other hand the advantage of gas liquor and urine compared to the others tested electrolytes.
文摘Climate change is a controversial topic of debate, especially in the US, where many do not believe in anthropogenic climate change. Because its consequences are predicted to be dire, such as a mass ocean extinction and frequent extreme weather events, it is important to learn what causes the warming in order to better combat it. In this study, the first challenge dwells on how to construct reliable statistical models based on massive climate data of 800,000 years and accurately capture the relationship between temperature and potential factors such as concentrations of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). We compared the performance several mainstream machine learning algorithms on our data, which includes linear regression, lasso, support vector regression and random forest, to build the state of the art model to verify the warming of the earth and identifying factors contributing the global warming. We found that random forest outperforms other algorithms to create accurate climate models which use features including concentrations of different greenhouse gases to precisely forecast global atmosphere. The other challenges in identifying factor importance can be met by the feature of ensemble tree-based random forest algorithm. It was found that CO2 is the largest contributor to temperature change, followed by CH4, then by N2O. They all had some sorts of impact, though, meaning their release into the atmosphere should all be controlled to help restrain temperature increase, and help prevent climate change’s potential ramifications.
文摘In this study, 16 irrigation schemes (Baklan, Irgilli, Sutlac, Cal, Cürüksu, Nazilli, Saraykoy, Pamukkale, Sultanhisar, Akcay, Aydin, Topcam, Karpuzlu, Isikli, Gümüssu ve Soke) having 166,381 hectares, built by State Hydraulic Works (DSI), and operated by participatory irrigation managements, and 14 hydroelectric power plants (HPP) operated and built on dams, canals and rivers by the public and private sectors are examined in the Büyük Menderes basin which is an important basin in terms of the agriculture, energy and ecology projects. Integrated basin management practices and the importance and role of irrigation and hydropower plant operation in integrated basin management, how it should be, optimal use of available water resources for irrigation and hydroelectric power plant operation, irrigation relationship with canal hydropower plants, operated under integrated basin management of irrigation and hydropower plants, environment and the ecological effects have been studied, and integrated basin management with the existing basin management conditions in terms of hydropower plant and irrigation operation on the basis of data of 2015 have been compared, reached important conclusions, and made recommendations on the subject.
文摘The interdependency among water, food, and energy (WEF) in the GCC countries is strongly and closely interlinked, and is intensifying as demand for resources increases with population growth and changing consumption patterns, and are expected to be further compounded by the impacts of climate change. Therefore, integrated management of the three sectors is crucial to reduce trade-offs and build synergies among them. This paper presents a comprehensive framework to assess the WEF nexus in Kuwait as a representative case for the GCC countries. The framework consists of three main steps: 1) evaluating the influence of socio-economic development and climate change on water, energy, and food resources;2) generating scenario-based projections;and 3) conducting an extensive quantitative nexus analysis. The WEF interlinkages in Kuwait are modelled quantitatively using the Q-Nexus model, and current critical interdependencies are evaluated. Then, various WEF-Nexus scenarios were conducted for the year 2035 to explore the effects of management interventions in one sector on the other two sectors. The main findings are that per capita municipal water consumption is a major influencer on the WEF-nexus due to the heavy reliance on thermal desalination in municipal water supply in Kuwait, which is attributed to its energy intensity, financial cost, GHGs emissions, and environmental impacts on the marine and air environments. To reduce WEF trade-offs, mitigate risks, and build synergies among the three sectors, it is important to shift the current policy focus on supply-side management approach to the demand-side management and efficiency approaches.
文摘In quest for quality and sustainable development, it is necessary to find alternative materials, methods of brick making and house design. Bricks made in open kilns using locally available materials usually do not meet the requirements of the South African Bureau of Standards;hence it needs to add some ingredients such as fly ash to produce better quality bricks. This paper reports the effects of fly ash on properties of clay bricks that can improve the thermal performance of buildings. Bricks of different clay and fly ash mixing proportions were molded. A passive solar house was designed and constructed using fly ash bricks. Results indicate that thermal conductivity and water absorption decrease with increase in fly ash. Compressive strength was found to in-creases with increase in amount of fly ash. A mixing proportion of 50% of fly ash to 50% clay by volume produced a brick with the highest compressive strength, lowest thermal conductivity and minimum water absorption. The bricks were observed to have uniform size as they experience minimal burning shrinkage. These properties were found to have a significant impact on the thermal performance of the house. The mean indoor temperature swing was found to be 11°C.
文摘Insects such as Acheta domesticus account for over half of marsh fish and migratory bird diet. Therefore, insects are very important to marsh and island ecosy stems and are susceptible to oil contamination, but little research has been done to study the effects of oil spills on cricket populations. The purpose of this experiment was to determine the effects of an oil spill event on Acheta domesticus mortality and hatch rate to establish environmental sustainability. The treatment groups included 0% oil contamination, 5% oil contamination and 10% oil contamination. The scientist counted the number of deaths in two-week, four-week, and six-week-old crickets after oil contamination. In addition, the scientist counted the number of hatchlings among treated cricket eggs. Error bar lines in the results section supported the scientist’s hypothesis that the crickets would be affected by oil contamination. In fact, over 90% of the 10% oil treatment group died and over 80% of the 5% oil treatment group died after five days of oil contamination in the six-week-old experiment. The scientist used a Gas Chromatography Mass Spectrometer to determine if benzene, toluene, ethylbenzene, or xylene (total) were present in the sediment samples. BTEX exposure is suspected to possibly cause insect mortality. These volatile organic compounds were present in the samples and were found in higher quantities in samples with higher concentrations of oil. The highest quantity of volatile organic compounds present was xylene. After studying the population dynamics of the tested Acheta domesticus, the scientist found that the two-week and four-week-old crickets’ survivability could fit a linear model while the six-week-old crickets fit an exponential model. The scientist used these models to observe how long it took each treatment group to approach zero, and the oiled groups grew closer to a population of zero significantly faster. For example, it took about twenty-seven days for the 10% treatment group’s population to approach zero whereas the control, 0% treatment group, took about seven days in the two-week-old cricket experiment. Overall, the six-week-old crickets had the highest mortality, and the cricket egg experiment resulted in extremely low hatch rate. Specifically, the highest number of crickets that hatched in an oiled replication either 5% or 10% oil was eight out of the five thousand eggs laid. Since the adult crickets are the most physically able to reproduce and the cricket eggs had low hatch rates, the cricket population would significantly decrease after an oil spill with 5% or more soil contamination. However, if the plant matter that crickets consume is still present in their environment, they may be able to recover.
文摘To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of various meteorological parameters namely the monthly averaged value of maximum temperature, minimum temperature, humidity and sunshine hours were used in this study. Assessment of the solar resources for the solar based renewable energy technologies of Bangladesh may be based upon this kind of measured data analyzed study. This study tried to estimate the monthly averaged solar radiation by presenting data in table and graph and finally analyze through equations and descriptions. Correlation between the measurements of monthly averaged solar radiation and the meteorological parameters was given for the selected 10 stations in Bangladesh. In conclusion, we tried to make a comparison among solar radiation on horizontal surface, fixed 20.83<sup> ° </sup> (degree) optimal tilt angle and variable optimal tilt surface at Dhaka station.
文摘Photovoltaic cells are generally manufactured under standard test conditions. <span style="font-family:Verdana;">The operating conditions, very often induce performance losses different from </span><span style="font-family:Verdana;">those initially given by the manufacturer. This article presents an experimental acquisition and analysis system that integrates the synthetic efficiency ra</span><span style="font-family:Verdana;">tio (SER) as a hybrid analysis tool to evaluate the performance of a monocrystalline</span> <span style="font-family:Verdana;">photovoltaic solar panel, in this case the LW-MS90 panel in the city of Douala. The meteorological data obtained experimentally was used to evaluate these performances according to the manufacturer</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">s model in MATLAB/Simulink</span><span style="font-family:;" "=""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">By comparison with the experimental performances, the results quantify through</span><span style="font-family:Verdana;"> a certain number of indices, a minimal power drop according to the acquired irradiance estimated at 3.45%. The interest of this approach is to contribute to the prediction of the operating performance of PV panels in the installation phase in non-standard areas.</span></span>
文摘Passive sampling for the monitoring of organic pollutants (PAHs, PCBs, PBDEs) in ambient air has received increased attention in the last two decades. However, the accuracy of the concentration of organics obtained with passive samplers under varying environmental conditions is a subject of controversy. In this study, effect of ambient temperature on passive samplers was evaluated by using three different sampler configurations. Additionally, passive samplers with polyurethane disks (PUF) were applied throughout the Island for the determination of the airborne concentration of polycyclic aromatic hydrocarbons (PAHs). The passive samplers were deployed in seven municipalities for three-month periods in two different sampling campaigns, representing hurricane and non-hurricane seasons. Here we present preliminary results obtained from those sampling campaigns. The total concentrations of 15 PAHs varied from 3.1 to 19.6 and from 5.5 to 38.5 ng/m3 for hurricane and non-hurricane seasons, respectively. Hurricane and non-hurricane season concentrations of PAH were significantly different for the samples taken in the northern municipalities of the Island. However, there was no significant difference in PAH concentrations between the hurricane and non-hurricane seasons for the southern sites. Increased rainfall and high-relative humidity during the hurricane season had an influence on the concentrations of PAHs derived by the passive PUF sampler.
文摘The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.
文摘Simulation of runoff in ungauged catchments has always been a challenging issue, receiving significant attention more importantly in practical applications. This study aims at calibration of an Artificial Neural Network (ANN) model which is capable to apply in an ungauged basin. The methodology is applied to two sub-catchments located in the Northern East of Iran. To examine the effect of physical characteristics of the catchment on the capability of the model generalization, it is attempted to synthesize effective parameters using empirical methods of runoff estimation. Firstly, the model was designed for a pilot sub-catchment and the statistical comparison between simulated runoff, and target depicted the capability of ANN to accurately estimate runoff over a catchment. Then, the calibrated model was generalized to another sub-catchment assumed as an ungauged basin while there are runoff data to compare the result. The result showed that the designed model is relatively capable to estimate monthly runoff for a homogenous ungauged catchment. The method presented in this study in addition to adding effective spatial parameters in simulation runoff and calibration of model by using empirical methods and the integration of any useful accessible data, examines the adaptability of model to an ungauged catchment.
文摘In ground water quality studies multivariate statistical techniques like Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), Factor Analysis (FA) and Multivariate Analysis of Variance (MANOVA) were employed to evaluate the principal factors and mechanisms governing the spatial variations and to assess source apportionment at Lawspet area in Puducherry, India. PCA/FA has made the first known factor which showed the anthropogenic impact on ground water quality and this dominant factor explained 82.79% of the total variance. The other four factors identified geogenic and hardness components. The distribution of first factor scores portray high loading for EC, TDS, Na+ and Cl−(anthropogenic) in south east and south west parts of the study area, whereas other factor scores depict high loading for HCO3−, Mg2+, Ca2+ and TH (hardness and geogenic) in the north west and south west parts of the study area. K+ and SO42−(geogenic) are dominant in south eastern direction. Further MANOVA showed that there are significant differences between ground water quality parameters. The spatial distribution maps of water quality parameters have rendered a powerful and practical visual tool for defining, interpreting, and distinguishing the anthropogenic, hardness and geogenic factors in the study area. Further the study indicated that multivariate statistical methods have successfully assessed the ground water qualitatively and spatially with a more effective step towards ground water quality management.
文摘This paper presents the fundamentals of direct inverse modeling using CFD simulations to detect air pollution sources in urban areas. Generally, there are four techniques used for detecting pollution sources: the analytical technique, the optimization technique, the probabilistic technique, and the direct technique. The study discusses the potentialities and limits of each technique, where the direct inverse technique is focused. Two examples of applying the direct inverse technique in detecting pollution source are introduced. The difficulties of applying the direct inverse technique are investigated. The study reveals that the direct technique is a promising tool for detecting air pollution source in urban environments. However, more efforts are still needed to overcome the difficulties explained in the study.
文摘In this paper, we are interested by the dissolution of NAPL (Non-Aqueous Phase Liquid) contaminants in heterogeneous soils or aquifers. The volume averaging technique is applied to 2D systems with Darcy-scale heterogeneities. A large-scale model is derived from a Darcy-scale dissolution model in the case of small and large Damkholer numbers, i.e., for smooth or sharp dissolution fronts. The resulting models in both cases have the mathematical structure of a non-equilibrium dissolution model. It is shown how to calculate the resulting mass exchange and relative permeability terms from the Darcy-scale heterogeneities and other fluid properties. One of the important finding is that the obtained values have a very different behavior compared to the Darcy-scale usual correlations. The large scale correlations are also very different between the two limit cases. The resulting large-scale models are compared favorably to Darcy-scale direct simulations.
文摘This study evaluates the feasibility of groundwater banking in the Central Basin. The Central Basin is located in Sacramento County in northern California, USA. The study basin is bounded by three rivers (the Sacramento, the American, the Consumes and Mokelumne rivers), and by the Sierra-Nevada mountain range. This study focuses on the potential for groundwater recharge in the Central Basin for three water years (critical, wet, above normal). For that purpose, a 3-D Groundwater Modeling System (GMS) with MODFLOW was created. Three recharge wells were added to the calibrated groundwater model to recharge the water table with 10,000 Acre-Feet (AF) of water to the Central Basin. The banking of 10,000 AF during the critical and wet years was effective in raising the water table elevation in the cone of depression area without causing any negative impact elsewhere in the basin. According to the findings of the Central Basin model, banking up to 10,000 AF of groundwater during any year type is feasible. More than 10,000 AF of groundwater banking might cause more negative impacts than positive benefits.
文摘The purpose of this paper is to investigate the spatial interpolation of rainfall variability with deterministic and geostatic inspections in the Prefecture of Kilkis (Greece). The precipitation data where recorded from 12 meteorological stations in the Prefecture of Kilkis for 36 hydrological years (1973-2008). The cumulative monthly values of rainfall were studied on an annual and seasonal basis as well as during the arid-dry season. In the deterministic tests, the I.D.W. and R.B.F. checks were inspected, while in the geostatic tests, Ordinary Kriging and Universal Kriging respectively. The selection of the optimum method was made based on the least Root Mean Square Error (R.M.S.E.), as well as on the Mean Error (M.E.), as assessed by the cross validation analysis. The geostatical Kriging also considered the impact of isotropy and anisotropy across all time periods of data collection. Moreover, for Universal Kriging, the study explored spherical, exponential and Gaussian models in various combinations. Geostatistical techniques consistently demonstrated greater reliability than deterministic techniques across all time periods of data collection. Specifically, during the annual period, anisotropy was the prevailing characteristic in geostatistical techniques. Moreover, the results for the irrigation and seasonal periods were generally comparable, with few exceptions where isotropic methods yielded lower (R.M.S.E.) in some seasonal observations.
