All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be availa...All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be available in the market as early as in 2018, but mostly in 2020’s. When FAAVs will be available to and become affordable by the average consumers, the implications to the society would be far reaching. The purpose of the paper is to examine the prospect of the popularity of FAAVs and their socio-economic implications to the future society of the World. The paper examines potential impacts on selected sectors of the society including changes in demand for automobiles, its impact on the use of oil, on the environment, and on urban land uses, to list a few.展开更多
Fault management study in smart grid systems (SGSs) is important to ensure the stability of the system. Also, it is important to know the major types of power failures for the effective operation of the SGS. This pape...Fault management study in smart grid systems (SGSs) is important to ensure the stability of the system. Also, it is important to know the major types of power failures for the effective operation of the SGS. This paper reviews diverse types of faults that might appear in the SGS and gives a survey about the impact of renewable energy resources (RERs) on the behavior of the system. Moreover, this paper offers different fault detection and localization techniques that can be used for SGSs. Furthermore, a potential fault management case study is proposed in this paper. The SGS model in this paper is investigated using both of the Matlab/Simulink and the Real Time Digital Simulation (RTDS) to compute the fault management study. Simulation results show the fast response to a power failure in the system which improves the stability of the SGS.展开更多
An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve misc...An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.展开更多
Floods are the most devastating hazards that have significant adverse impacts on people and their livelihoods. Their impacts can be reduced by investing on: 1) improving the forecasting skills of extreme and heavy rai...Floods are the most devastating hazards that have significant adverse impacts on people and their livelihoods. Their impacts can be reduced by investing on: 1) improving the forecasting skills of extreme and heavy rainfall events, 2) development of Impacts Based Flood Early Warning System (IBFEWS) and 3) effective communication of impacts from anticipated extreme or heavy rainfall event. The development of IBFEWS however, requires a complete understanding of factors that relates to the formation of extreme or heavy rainfall events and their associated socio-economic impacts. This information is crucial in the development of Impacts Based Flood Forecasting Models (IBFFMs). In this study, we assess the socio-economic impacts of the December 2011 flood event in Dar es Salaam as the preliminary stage in the development of IBFFMs for the City of Dar es Salaam. Data from household survey collected using systematic random sampling techniques and structured questionnaires are used. The survey was conducted to acquire respondent’s views on the causes of floods impacts, adaptive capacity to extreme or heavy rainfall events and adaptation options to minimize flood impact. It is found that the main causes of floods were river overflow due to heavy rainfall and blocked drainage system. Poor infrastructure such as drainage and sewage systems, and ocean surge were identified to be the causes of observed impacts of the December 2011 flood event in Dar es Salaam. Death cases analysis showed that 43 people were reported dead. The flood event damaged properties worth of 7.5 million Tanzania shillings. Furthermore, the Tanzania Government spent a total amount of 1.83 billion Tanzanian shillings to rescue and relocate vulnerable communities that lived-in low-lying areas of Jagwani to high ground areas of Mabwepande in Kinondoni district.展开更多
The stationary response of viscoelastic dynamical system with the right unilateral nonzero offset barrier impacts subjected to stochastic excitations is investigated.First,the viscoelastic force is approximately treat...The stationary response of viscoelastic dynamical system with the right unilateral nonzero offset barrier impacts subjected to stochastic excitations is investigated.First,the viscoelastic force is approximately treated as equivalent terms associated with effects.Then,the free vibro-impact(VI)system is absorbed to describe the periodic motion without impacts and quasi-periodic motion with impacts based upon the level of system energy.The stochastic averaging of energy envelope(SAEE)is adopted to seek the stationary probability density functions(PDFs).The detailed theoretical results for Van der Pol viscoelastic VI system with the right unilateral nonzero offset barrier are solved to demonstrate the important effects of the viscoelastic damping and nonzero rigid barrier impacts condition.Monte Carlo(MC)simulation is also performed to verify the reliability of the suggested approach.The stochastic P-bifurcation caused by certain system parameters is further explored.The variation of elastic modulus from negative to zero and then to positive witnesses the evolution process of stochastic P-bifurcation.From the vicinity of the common value to a wider range,the relaxation time induces the stochastic P-bifurcation in the two interval schemes.展开更多
Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highli...Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highlights sex-specific differences in caffeine metabolism,which may influence its role in cardiovascular health.This perspective examines the interaction between caffeine,hormonal changes,metabolic processes,and lifestyle factors,focusing on older women compared to men.Understanding these differences is essential for tailoring dietary and clinical recommendations to mitigate cardiovascular risks and promote healthy aging.展开更多
The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(...The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(N)use efficiency and reduce environmental impacts is still unclear.Here,we examined the data from 502 valid questionnaires collected from WFFPs in the major grain-producing area,the Huang-Huai-Hai Region(HHHR)in China,with 429 samples for wheat,328 for maize,and 122 for rice.We identified gaps in N use efficiency(NUE)and N losses from the production of the three crops between the sampled WFFPs and counties based on the statistical data.The results showed that compared to the county-level(wheat,39.1%;maize,33.8%;rice,35.1%),the NUEs for wheat(55.2%),maize(52.1%),and rice(50.2%)in the WFFPs were significantly improved(P<0.05).In addition,the intensities of ammonia(NH3)volatilization(9.9-12.2 kg N ha–1),N leaching(6.5-16.9 kg N ha–1),and nitrous oxide(N2O)emissions(1.2-1.6 kg N ha–1)from crop production in the sampled WFFPs were significantly lower than the county averages(P<0.05).Simulations showed that if the N rates are reduced by 10.0,15.0,and 20.0%for the counties,the NUEs of wheat,maize,and rice in the HHHR will increase by 2.9-6.3,2.4-5.2,and 2.6-5.7%,respectively.If the N rate is reduced to the WFFP level in each county,the NUEs of the three crops will increase by 12.9-19.5%,and the N leaching,NH3,and N2O emissions will be reduced by 48.9-56.2,37.4-42.9,and 46.0-66.5%,respectively.Our findings highlight that efficient N management practices in sustainable intensive farmland have considerable potential for reducing environmental impacts.展开更多
The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lan...The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lands “the well-known Toshka Project”. The hydrogeological conditions of the area are subjected to detailed investigation based upon the construction of the water table maps, hydrologeologic cross-sections, pumping tests, aquifer geometry, and recharge-discharge relationship. The study revealed that the Quaternary and the Nubia sediments are the main water bearing layers in the area. The Quaternary aquifer is of limited potential and made of mixed sand with clay deposit ranges in thickness between 5 to 10 m. The Nubia aquifer is the oldest sedimentary formation and the main groundwater resources in the area. It is represented by multilayered of sand and silt exists generally under artesian conditions. It is composed of three water bearing horizons partially separated by two confining horizons and extends in thickness ranges between 70 and 230 meters. The thickness increases away from the high dam lake. The analysis of pumping tests of the aquifer indicated that its potentiality is increasing north of the High Dam Lake (HDL) whereas it decreases in the other direction. This is due to high hydraulic conductivity and aquifer thickness in the area northeast of Khor Toshka and at west of Garf Hussein. The hydraulic conductivity of the aquifer ranges between 12.73 and 0.9 m/day. The review of the changes in groundwater levels in the area showed that there is a drop in ranges between 1 and 14 meters in the last few years indicating that the extraction from the groundwater is much more higher that the replacement rate. Also, the analysis of the fluctuation of water levels of the HDL and the groundwater level indicated that the influence of water on groundwater level in the area is observed only at a distance less than 10 km from the lake shore line. Seepage from the HDL is estimated as 238.13 × 106 m3/year. The geo-environmental impacts of the development on the surface water and groundwater in the area are evaluated.展开更多
During times of war, it is rare to find a government willing and able to require the military to fund and support environmental impact studies. In the 1960s, many United States scientists expressed concerns about the ...During times of war, it is rare to find a government willing and able to require the military to fund and support environmental impact studies. In the 1960s, many United States scientists expressed concerns about the use of herbicides during the Vietnam War. This protest was led by Dr. Arthur Galston and eventually included scientists with the National Academy of Science. By 1970, the Department of Defense (DoD) was ordered to permit the scientists to visit South Vietnam during the war to document these impacts. In all 1500 scientist days were spent in South Vietnam. In addition, the US government and military funded research studies on the impact of herbicides on animals. The goal of military use of herbicides, as chemical weapons, was to defoliate jungle forests and destroy food crops as a strategy to win battles and the war. The primary objective of this research study is to describe how it is possible for a country to fund and carry out scientific studies during the conduct of a war rather than decades later. The environmental impact study findings often lack boots on the ground validation and can be inaccurate or misleading in some situations. The United States (US) and other countries, including Russia and Ukraine, need to learn the historical lessons from the US use of herbicides, containing dioxin TCDD and/or arsenic (As), as chemical weapons during the Vietnam War.展开更多
The aim of this work is to investigate the soil water budget across China by means of hydrological modeling under current and future climate conditions and to evaluate the sensitivity to soil parameters. For this purp...The aim of this work is to investigate the soil water budget across China by means of hydrological modeling under current and future climate conditions and to evaluate the sensitivity to soil parameters. For this purpose, observed precipitation and temperature data(1981-2010) and climate simulations(2021-2050, 2071-2100) at high resolution(about 14 km) on a large part of China are used as weather forcing. The simulated weather forcing has been bias corrected by means of the distribution derived quantile mapping method to eliminate the effects of systematic biases in current climate modeling on water cycle components. As hydrological models, two 1D models are tested: TERRA-ML and HELP. Concerning soil properties, two datasets, provided respectively by Food and Agriculture Organization and U.S. Department of Agriculture, are separately tested. The combination of two hydrological models, two soil parameter datasets and three weather forcing inputs(observations, raw and bias corrected climate simulations) results in ?ve different simulation chains.The study highlights how the choice of some approaches or soil parameterizations can affect the results both in absolute and in relative terms and how these differences could be highly related to weather forcing in inputs or investigated soil. The analyses point out a decrease in average water content in the shallower part of the soil with different extents according to climate zone, concentration scenario and soil/cover features.Moreover, the projected increase in temperature and then in evapotranspirative demand do not ever result in higher actual evapotranspiration values, due to the concurrent variations in precipitation patterns.展开更多
One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely...One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely open to the Atlantic Ocean,is thus confronted with hydrodynamic agents and a possible sea level rise,whose impacts will result in an immersion of the low topography areas。展开更多
The environmental impacts are commonly quantified in the EIA studies by rating, ranking and scaling. The National EIA Guidelines, 1993, Nepal provides a guideline to score the impacts in terms of magnitude, extent, an...The environmental impacts are commonly quantified in the EIA studies by rating, ranking and scaling. The National EIA Guidelines, 1993, Nepal provides a guideline to score the impacts in terms of magnitude, extent, and duration. This step is commonly known as impact prediction in the EIA process. The predicted scores are multiplied by the weightage value of the resource;likely to be affected. The application of the weightage transforms the predicted values of the impacts into their “significance”—a concept used in the environmental decision making. In other words the significance value entails assignment of relative judgment values to the impacts. The impacts, thus, can ranked based on their significance. The impact ranking is more useful in evaluating the socio-economic impacts. Unlike air, water and noise quality, which can be assessed against established standards;the socio-economic impacts do not have standard scale and are difficult to rank. Importance weighting of socio-economic impacts are commonly determined by the consensus obtained from the interaction with the local people, agencies, NGOs and experts. The impact ranking in the EIA process is unavoidable, firstly to prioritize the urgent environmental issues and design mitigation measures accordingly and also provide coherent linkages among the issues, and plan monitoring and auditing linkage with the proposed mitigation measures. Furthermore, it also provide strong basis of decision making, and thus facilitate the decision makers. The process of impact prediction, determination of significance and ranking were applied in the EIA of Indrwati-3 Hydroelectric Project, which is one of the successful cases of EIA in Nepal. The authors believe that the impacts predicted and quantified through this method are being focussed to more on the local concerns, since it seeks an active involvement of the local people who are likely to be affected.展开更多
Droughts have serious and widespread impacts on crop production with substantial economic losses. The frequency and severity of drought events may increase in the future due to climate change. We have developed three ...Droughts have serious and widespread impacts on crop production with substantial economic losses. The frequency and severity of drought events may increase in the future due to climate change. We have developed three meteorological drought scenarios for Austria in the period 2008-2040. The scenarios are defined based on a dry day index which is combined with bootstrapping from an observed daily weather dataset of the period 1975-2007. The severity of long-term drought scenarios is characterized by lower annual and seasonal precipitation amounts as well as more significant temperature increases compared to the observations. The long-term impacts of the drought scenarios on Austrian crop production have been analyzed with the biophysical process model EPIC (Environmental Policy Integrated Climate). Our simulation outputs show that—for areas with historical mean annual precipitation sums below 850 mm— already slight increases in dryness result in significantly lower crop yields i.e. depending on the drought severity, between 0.6% and 0.9% decreases in mean annual dry matter crop yields per 1.0% decrease in mean annual precipitation sums. The EPIC results of more severe droughts show that spring and summer precipitation may become a limiting factor in crop production even in regions with historical abundant precipitation.展开更多
Multiple studies have identified links between climate and West Nile virus disease since the virus arrived in North America. Here we sought to extend these results by developing a Health Impact Function (HIF) to gener...Multiple studies have identified links between climate and West Nile virus disease since the virus arrived in North America. Here we sought to extend these results by developing a Health Impact Function (HIF) to generate county-level estimates of the expected annual number of West Nile neuroinvasive disease (WNND) cases based on the county’s historical WNND incidence, annual average temperature, and population size. To better understand the potential impact of projected temperature change on WNND risk, we used the HIF to project the change in expected annual number of WNND cases attributable to changing temperatures by 2050 and by 2090 using data from five global climate models under two representative concentration pathways (RCP4.5 and RCP8.5). To estimate the costs of anticipated changes, as well as to enable comparisons with other public health impacts, projected WNND cases were allocated to nonfatal and fatal outcomes, then monetized using a cost-of-illness estimate and the U.S. Environmental Protection Agency’s value of a statistical life, respectively. We found that projected future temperature and population changes could increase the expected annual number of WNND cases to ≈2000 - 2200 cases by 2050 and to ≈2700 - 4300 cases by 2090, from a baseline of 970 cases. Holding population constant at future levels while varying temperature from a 1995 baseline, we estimated projected temperature change alone is responsible for ≈590 and ≈960 incremental WNND cases in 2050 and 2090 (respectively) under the RCP4.5 scenario, and ≈820 and ≈2500 cases in 2050 and 2090 (respectively) for the RCP8.5 scenario, with substantial regional variation. The monetized impact of these temperature-attributable incremental cases is estimated at $0.5 billion in 2050 and $1.0 billion in 2090 under the RCP4.5 scenario, and $0.7 billion in 2050 and $2.6 billion in 2090 under the RCP8.5 scenario (undiscounted 2015 U.S. dollars).展开更多
The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current interest.This article proposes a new method for identifying nodes of impact and influe...The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current interest.This article proposes a new method for identifying nodes of impact and influential nodes,which will provide a guaranteed positive system response over the growth model.The task is posed as an optimization problem to maximize the ratio of the norms of the accumulated increments of the growth vector and the exogenous impact vector.The algorithm is reduced to solving a quadratic programming problem with nonlinear restrictions.The selection of the most effective vertices is based on the cumulative gains of the component projections onto the solution vector.Numerical examples arc provided to illustrate the effectiveness of the proposed method.展开更多
This study evaluated the impacts of future climate change on the hydrological response of the Richmond River Catchment in New South Wales(NSW), Australia, using the conceptual rainfall-runoff modeling approach(the Hyd...This study evaluated the impacts of future climate change on the hydrological response of the Richmond River Catchment in New South Wales(NSW), Australia, using the conceptual rainfall-runoff modeling approach(the Hydrologiska Byrans Vattenbalansavdelning(HBV)model). Daily observations of rainfall, temperature, and streamflow and long-term monthly mean potential evapotranspiration from the meteorological and hydrological stations within the catchment for the period of 1972 e2014 were used to run, calibrate, and validate the HBV model prior to the streamflow prediction. Future climate signals of rainfall and temperature were extracted from a multi-model ensemble of seven global climate models(GCMs) of the Coupled Model Intercomparison Project Phase 3(CMIP3) with three regional climate scenarios, A2, A1 B,and B1. The calibrated HBV model was then forced with the ensemble mean of the downscaled daily rainfall and temperature to simulate daily future runoff at the catchment outlet for the early part(2016 e2043), middle part(2044 e2071), and late part(2072 e2099) of the 21 st century.All scenarios during the future periods present decreasing tendencies in the annual mean streamflow ranging between 1% and 24.3% as compared with the observed period. For the maximum and minimum flows, all scenarios during the early, middle, and late parts of the century revealed significant declining tendencies in the annual mean maximum and minimum streamflows, ranging between 30% and 44.4% relative to the observed period. These findings can assist the water managers and the community of the Richmond River Catchment in managing the usage of future water resources in a more sustainable way.展开更多
The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biolog...The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel-Atlantic coasts are discussed.展开更多
Rock structures are often subjected to dynamic loads,such as blasts,impacts and earthquakes,and their loading rates differ largely.To investigate the effect of loading rates on the dynamic behavior of crack propagatio...Rock structures are often subjected to dynamic loads,such as blasts,impacts and earthquakes,and their loading rates differ largely.To investigate the effect of loading rates on the dynamic behavior of crack propagation,impact tests were conducted on large single-cleavage semicircle compression(LSCSC)specimens using a drop weight impact test system.Five types of rock materials were selected to prepare the LSCSC specimens,and crack propagation gauges were mounted along the crack propagation paths to measure crack initiation time and propagation speeds.Finite element models were established by using ABAQUS code,and the dynamic stress intensity factors(SIFs)were calculated.The curves of dynamic SIFs versus time were obtained,and the initiation toughness was determined by using these curves and the initiation time measured in the impact tests.The results show that loading rate has a significant effect on crack propagation behavior,and both the crack propagation speed and initiation toughness increase with the loading rate,whereas the delayed fracture time decreases with the increase in loading rate.展开更多
The paper has focused on the challenges/impacts of tannery effluent and evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water. The paper was done entirely on secon...The paper has focused on the challenges/impacts of tannery effluent and evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water. The paper was done entirely on secondary data by consulting literature sources including scientific journals, chapters of books, conference report papers and websites. The results of this review paper indicated that chromium is highly toxic and carcinogenic to human beings, animals, plants and the general environment (soil and water sediment). It is found out that chrome is the primary threat when ever tanning industry comes in to practice. Though many treatment options were evaluated to prevent its consequence on the environment, neither of them could achieve to treat or recover chrome 100%. Treatment options are either;inef-ficient, complicated, energy demanding, costly or applicable to a certain parts of the world due to technology or skilled man power demand. Therefore, to tackle this serious challenge stringent environmental regulation with law enforce-ment has to be exercised to use better treatment system which is widely applicable. Polluters must also know the envi-ronmental cost of their industry and treated according to polluter pay or precautionary principles. Moreover, the gen-eral public has to be aware of it and all concerned organizations and governments has to work hand in hand to reach zero discharge level or at least to attain the EPA chrome discharge展开更多
文摘All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be available in the market as early as in 2018, but mostly in 2020’s. When FAAVs will be available to and become affordable by the average consumers, the implications to the society would be far reaching. The purpose of the paper is to examine the prospect of the popularity of FAAVs and their socio-economic implications to the future society of the World. The paper examines potential impacts on selected sectors of the society including changes in demand for automobiles, its impact on the use of oil, on the environment, and on urban land uses, to list a few.
文摘Fault management study in smart grid systems (SGSs) is important to ensure the stability of the system. Also, it is important to know the major types of power failures for the effective operation of the SGS. This paper reviews diverse types of faults that might appear in the SGS and gives a survey about the impact of renewable energy resources (RERs) on the behavior of the system. Moreover, this paper offers different fault detection and localization techniques that can be used for SGSs. Furthermore, a potential fault management case study is proposed in this paper. The SGS model in this paper is investigated using both of the Matlab/Simulink and the Real Time Digital Simulation (RTDS) to compute the fault management study. Simulation results show the fast response to a power failure in the system which improves the stability of the SGS.
文摘An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.
文摘Floods are the most devastating hazards that have significant adverse impacts on people and their livelihoods. Their impacts can be reduced by investing on: 1) improving the forecasting skills of extreme and heavy rainfall events, 2) development of Impacts Based Flood Early Warning System (IBFEWS) and 3) effective communication of impacts from anticipated extreme or heavy rainfall event. The development of IBFEWS however, requires a complete understanding of factors that relates to the formation of extreme or heavy rainfall events and their associated socio-economic impacts. This information is crucial in the development of Impacts Based Flood Forecasting Models (IBFFMs). In this study, we assess the socio-economic impacts of the December 2011 flood event in Dar es Salaam as the preliminary stage in the development of IBFFMs for the City of Dar es Salaam. Data from household survey collected using systematic random sampling techniques and structured questionnaires are used. The survey was conducted to acquire respondent’s views on the causes of floods impacts, adaptive capacity to extreme or heavy rainfall events and adaptation options to minimize flood impact. It is found that the main causes of floods were river overflow due to heavy rainfall and blocked drainage system. Poor infrastructure such as drainage and sewage systems, and ocean surge were identified to be the causes of observed impacts of the December 2011 flood event in Dar es Salaam. Death cases analysis showed that 43 people were reported dead. The flood event damaged properties worth of 7.5 million Tanzania shillings. Furthermore, the Tanzania Government spent a total amount of 1.83 billion Tanzanian shillings to rescue and relocate vulnerable communities that lived-in low-lying areas of Jagwani to high ground areas of Mabwepande in Kinondoni district.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11872305 and 11872307)the Excellent Doctorate Cultivating Foundation of Northwestern Polytechnical University,China
文摘The stationary response of viscoelastic dynamical system with the right unilateral nonzero offset barrier impacts subjected to stochastic excitations is investigated.First,the viscoelastic force is approximately treated as equivalent terms associated with effects.Then,the free vibro-impact(VI)system is absorbed to describe the periodic motion without impacts and quasi-periodic motion with impacts based upon the level of system energy.The stochastic averaging of energy envelope(SAEE)is adopted to seek the stationary probability density functions(PDFs).The detailed theoretical results for Van der Pol viscoelastic VI system with the right unilateral nonzero offset barrier are solved to demonstrate the important effects of the viscoelastic damping and nonzero rigid barrier impacts condition.Monte Carlo(MC)simulation is also performed to verify the reliability of the suggested approach.The stochastic P-bifurcation caused by certain system parameters is further explored.The variation of elastic modulus from negative to zero and then to positive witnesses the evolution process of stochastic P-bifurcation.From the vicinity of the common value to a wider range,the relaxation time induces the stochastic P-bifurcation in the two interval schemes.
文摘Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highlights sex-specific differences in caffeine metabolism,which may influence its role in cardiovascular health.This perspective examines the interaction between caffeine,hormonal changes,metabolic processes,and lifestyle factors,focusing on older women compared to men.Understanding these differences is essential for tailoring dietary and clinical recommendations to mitigate cardiovascular risks and promote healthy aging.
基金supported by the National Key Research and Development Program of China(2022YFB3903505)the National Natural Science Foundation of China(72221002)。
文摘The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(N)use efficiency and reduce environmental impacts is still unclear.Here,we examined the data from 502 valid questionnaires collected from WFFPs in the major grain-producing area,the Huang-Huai-Hai Region(HHHR)in China,with 429 samples for wheat,328 for maize,and 122 for rice.We identified gaps in N use efficiency(NUE)and N losses from the production of the three crops between the sampled WFFPs and counties based on the statistical data.The results showed that compared to the county-level(wheat,39.1%;maize,33.8%;rice,35.1%),the NUEs for wheat(55.2%),maize(52.1%),and rice(50.2%)in the WFFPs were significantly improved(P<0.05).In addition,the intensities of ammonia(NH3)volatilization(9.9-12.2 kg N ha–1),N leaching(6.5-16.9 kg N ha–1),and nitrous oxide(N2O)emissions(1.2-1.6 kg N ha–1)from crop production in the sampled WFFPs were significantly lower than the county averages(P<0.05).Simulations showed that if the N rates are reduced by 10.0,15.0,and 20.0%for the counties,the NUEs of wheat,maize,and rice in the HHHR will increase by 2.9-6.3,2.4-5.2,and 2.6-5.7%,respectively.If the N rate is reduced to the WFFP level in each county,the NUEs of the three crops will increase by 12.9-19.5%,and the N leaching,NH3,and N2O emissions will be reduced by 48.9-56.2,37.4-42.9,and 46.0-66.5%,respectively.Our findings highlight that efficient N management practices in sustainable intensive farmland have considerable potential for reducing environmental impacts.
文摘The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lands “the well-known Toshka Project”. The hydrogeological conditions of the area are subjected to detailed investigation based upon the construction of the water table maps, hydrologeologic cross-sections, pumping tests, aquifer geometry, and recharge-discharge relationship. The study revealed that the Quaternary and the Nubia sediments are the main water bearing layers in the area. The Quaternary aquifer is of limited potential and made of mixed sand with clay deposit ranges in thickness between 5 to 10 m. The Nubia aquifer is the oldest sedimentary formation and the main groundwater resources in the area. It is represented by multilayered of sand and silt exists generally under artesian conditions. It is composed of three water bearing horizons partially separated by two confining horizons and extends in thickness ranges between 70 and 230 meters. The thickness increases away from the high dam lake. The analysis of pumping tests of the aquifer indicated that its potentiality is increasing north of the High Dam Lake (HDL) whereas it decreases in the other direction. This is due to high hydraulic conductivity and aquifer thickness in the area northeast of Khor Toshka and at west of Garf Hussein. The hydraulic conductivity of the aquifer ranges between 12.73 and 0.9 m/day. The review of the changes in groundwater levels in the area showed that there is a drop in ranges between 1 and 14 meters in the last few years indicating that the extraction from the groundwater is much more higher that the replacement rate. Also, the analysis of the fluctuation of water levels of the HDL and the groundwater level indicated that the influence of water on groundwater level in the area is observed only at a distance less than 10 km from the lake shore line. Seepage from the HDL is estimated as 238.13 × 106 m3/year. The geo-environmental impacts of the development on the surface water and groundwater in the area are evaluated.
文摘During times of war, it is rare to find a government willing and able to require the military to fund and support environmental impact studies. In the 1960s, many United States scientists expressed concerns about the use of herbicides during the Vietnam War. This protest was led by Dr. Arthur Galston and eventually included scientists with the National Academy of Science. By 1970, the Department of Defense (DoD) was ordered to permit the scientists to visit South Vietnam during the war to document these impacts. In all 1500 scientist days were spent in South Vietnam. In addition, the US government and military funded research studies on the impact of herbicides on animals. The goal of military use of herbicides, as chemical weapons, was to defoliate jungle forests and destroy food crops as a strategy to win battles and the war. The primary objective of this research study is to describe how it is possible for a country to fund and carry out scientific studies during the conduct of a war rather than decades later. The environmental impact study findings often lack boots on the ground validation and can be inaccurate or misleading in some situations. The United States (US) and other countries, including Russia and Ukraine, need to learn the historical lessons from the US use of herbicides, containing dioxin TCDD and/or arsenic (As), as chemical weapons during the Vietnam War.
基金the framework of the GEMINA project,Work Package 7.1.6,“B action”(Italye-China cooperation on climate changes),funded by the Italian Ministry of Education,University,and Research and the Italian Ministry of the Environment,Land,and Sea
文摘The aim of this work is to investigate the soil water budget across China by means of hydrological modeling under current and future climate conditions and to evaluate the sensitivity to soil parameters. For this purpose, observed precipitation and temperature data(1981-2010) and climate simulations(2021-2050, 2071-2100) at high resolution(about 14 km) on a large part of China are used as weather forcing. The simulated weather forcing has been bias corrected by means of the distribution derived quantile mapping method to eliminate the effects of systematic biases in current climate modeling on water cycle components. As hydrological models, two 1D models are tested: TERRA-ML and HELP. Concerning soil properties, two datasets, provided respectively by Food and Agriculture Organization and U.S. Department of Agriculture, are separately tested. The combination of two hydrological models, two soil parameter datasets and three weather forcing inputs(observations, raw and bias corrected climate simulations) results in ?ve different simulation chains.The study highlights how the choice of some approaches or soil parameterizations can affect the results both in absolute and in relative terms and how these differences could be highly related to weather forcing in inputs or investigated soil. The analyses point out a decrease in average water content in the shallower part of the soil with different extents according to climate zone, concentration scenario and soil/cover features.Moreover, the projected increase in temperature and then in evapotranspirative demand do not ever result in higher actual evapotranspiration values, due to the concurrent variations in precipitation patterns.
文摘One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely open to the Atlantic Ocean,is thus confronted with hydrodynamic agents and a possible sea level rise,whose impacts will result in an immersion of the low topography areas。
文摘The environmental impacts are commonly quantified in the EIA studies by rating, ranking and scaling. The National EIA Guidelines, 1993, Nepal provides a guideline to score the impacts in terms of magnitude, extent, and duration. This step is commonly known as impact prediction in the EIA process. The predicted scores are multiplied by the weightage value of the resource;likely to be affected. The application of the weightage transforms the predicted values of the impacts into their “significance”—a concept used in the environmental decision making. In other words the significance value entails assignment of relative judgment values to the impacts. The impacts, thus, can ranked based on their significance. The impact ranking is more useful in evaluating the socio-economic impacts. Unlike air, water and noise quality, which can be assessed against established standards;the socio-economic impacts do not have standard scale and are difficult to rank. Importance weighting of socio-economic impacts are commonly determined by the consensus obtained from the interaction with the local people, agencies, NGOs and experts. The impact ranking in the EIA process is unavoidable, firstly to prioritize the urgent environmental issues and design mitigation measures accordingly and also provide coherent linkages among the issues, and plan monitoring and auditing linkage with the proposed mitigation measures. Furthermore, it also provide strong basis of decision making, and thus facilitate the decision makers. The process of impact prediction, determination of significance and ranking were applied in the EIA of Indrwati-3 Hydroelectric Project, which is one of the successful cases of EIA in Nepal. The authors believe that the impacts predicted and quantified through this method are being focussed to more on the local concerns, since it seeks an active involvement of the local people who are likely to be affected.
文摘Droughts have serious and widespread impacts on crop production with substantial economic losses. The frequency and severity of drought events may increase in the future due to climate change. We have developed three meteorological drought scenarios for Austria in the period 2008-2040. The scenarios are defined based on a dry day index which is combined with bootstrapping from an observed daily weather dataset of the period 1975-2007. The severity of long-term drought scenarios is characterized by lower annual and seasonal precipitation amounts as well as more significant temperature increases compared to the observations. The long-term impacts of the drought scenarios on Austrian crop production have been analyzed with the biophysical process model EPIC (Environmental Policy Integrated Climate). Our simulation outputs show that—for areas with historical mean annual precipitation sums below 850 mm— already slight increases in dryness result in significantly lower crop yields i.e. depending on the drought severity, between 0.6% and 0.9% decreases in mean annual dry matter crop yields per 1.0% decrease in mean annual precipitation sums. The EPIC results of more severe droughts show that spring and summer precipitation may become a limiting factor in crop production even in regions with historical abundant precipitation.
文摘Multiple studies have identified links between climate and West Nile virus disease since the virus arrived in North America. Here we sought to extend these results by developing a Health Impact Function (HIF) to generate county-level estimates of the expected annual number of West Nile neuroinvasive disease (WNND) cases based on the county’s historical WNND incidence, annual average temperature, and population size. To better understand the potential impact of projected temperature change on WNND risk, we used the HIF to project the change in expected annual number of WNND cases attributable to changing temperatures by 2050 and by 2090 using data from five global climate models under two representative concentration pathways (RCP4.5 and RCP8.5). To estimate the costs of anticipated changes, as well as to enable comparisons with other public health impacts, projected WNND cases were allocated to nonfatal and fatal outcomes, then monetized using a cost-of-illness estimate and the U.S. Environmental Protection Agency’s value of a statistical life, respectively. We found that projected future temperature and population changes could increase the expected annual number of WNND cases to ≈2000 - 2200 cases by 2050 and to ≈2700 - 4300 cases by 2090, from a baseline of 970 cases. Holding population constant at future levels while varying temperature from a 1995 baseline, we estimated projected temperature change alone is responsible for ≈590 and ≈960 incremental WNND cases in 2050 and 2090 (respectively) under the RCP4.5 scenario, and ≈820 and ≈2500 cases in 2050 and 2090 (respectively) for the RCP8.5 scenario, with substantial regional variation. The monetized impact of these temperature-attributable incremental cases is estimated at $0.5 billion in 2050 and $1.0 billion in 2090 under the RCP4.5 scenario, and $0.7 billion in 2050 and $2.6 billion in 2090 under the RCP8.5 scenario (undiscounted 2015 U.S. dollars).
基金supported by the Russian Foundation for Basic Research (No. 17-01-00076)
文摘The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current interest.This article proposes a new method for identifying nodes of impact and influential nodes,which will provide a guaranteed positive system response over the growth model.The task is posed as an optimization problem to maximize the ratio of the norms of the accumulated increments of the growth vector and the exogenous impact vector.The algorithm is reduced to solving a quadratic programming problem with nonlinear restrictions.The selection of the most effective vertices is based on the cumulative gains of the component projections onto the solution vector.Numerical examples arc provided to illustrate the effectiveness of the proposed method.
文摘This study evaluated the impacts of future climate change on the hydrological response of the Richmond River Catchment in New South Wales(NSW), Australia, using the conceptual rainfall-runoff modeling approach(the Hydrologiska Byrans Vattenbalansavdelning(HBV)model). Daily observations of rainfall, temperature, and streamflow and long-term monthly mean potential evapotranspiration from the meteorological and hydrological stations within the catchment for the period of 1972 e2014 were used to run, calibrate, and validate the HBV model prior to the streamflow prediction. Future climate signals of rainfall and temperature were extracted from a multi-model ensemble of seven global climate models(GCMs) of the Coupled Model Intercomparison Project Phase 3(CMIP3) with three regional climate scenarios, A2, A1 B,and B1. The calibrated HBV model was then forced with the ensemble mean of the downscaled daily rainfall and temperature to simulate daily future runoff at the catchment outlet for the early part(2016 e2043), middle part(2044 e2071), and late part(2072 e2099) of the 21 st century.All scenarios during the future periods present decreasing tendencies in the annual mean streamflow ranging between 1% and 24.3% as compared with the observed period. For the maximum and minimum flows, all scenarios during the early, middle, and late parts of the century revealed significant declining tendencies in the annual mean maximum and minimum streamflows, ranging between 30% and 44.4% relative to the observed period. These findings can assist the water managers and the community of the Richmond River Catchment in managing the usage of future water resources in a more sustainable way.
文摘The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel-Atlantic coasts are discussed.
基金the National Natural Science Foundation of China(1167219411702181)+1 种基金by Sichuan Administration of Work Safety(aj20170515161307)the project of Science and Technology of Sichuan province(2018JZ0036).
文摘Rock structures are often subjected to dynamic loads,such as blasts,impacts and earthquakes,and their loading rates differ largely.To investigate the effect of loading rates on the dynamic behavior of crack propagation,impact tests were conducted on large single-cleavage semicircle compression(LSCSC)specimens using a drop weight impact test system.Five types of rock materials were selected to prepare the LSCSC specimens,and crack propagation gauges were mounted along the crack propagation paths to measure crack initiation time and propagation speeds.Finite element models were established by using ABAQUS code,and the dynamic stress intensity factors(SIFs)were calculated.The curves of dynamic SIFs versus time were obtained,and the initiation toughness was determined by using these curves and the initiation time measured in the impact tests.The results show that loading rate has a significant effect on crack propagation behavior,and both the crack propagation speed and initiation toughness increase with the loading rate,whereas the delayed fracture time decreases with the increase in loading rate.
文摘The paper has focused on the challenges/impacts of tannery effluent and evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water. The paper was done entirely on secondary data by consulting literature sources including scientific journals, chapters of books, conference report papers and websites. The results of this review paper indicated that chromium is highly toxic and carcinogenic to human beings, animals, plants and the general environment (soil and water sediment). It is found out that chrome is the primary threat when ever tanning industry comes in to practice. Though many treatment options were evaluated to prevent its consequence on the environment, neither of them could achieve to treat or recover chrome 100%. Treatment options are either;inef-ficient, complicated, energy demanding, costly or applicable to a certain parts of the world due to technology or skilled man power demand. Therefore, to tackle this serious challenge stringent environmental regulation with law enforce-ment has to be exercised to use better treatment system which is widely applicable. Polluters must also know the envi-ronmental cost of their industry and treated according to polluter pay or precautionary principles. Moreover, the gen-eral public has to be aware of it and all concerned organizations and governments has to work hand in hand to reach zero discharge level or at least to attain the EPA chrome discharge
