The carburizing process has been successfully carried out in multipurpose furnace employing the drip-feed atmosphere with the addition of rare earth (RE). The carbon transfer coefficients (BRE) and mean diffusion coef...The carburizing process has been successfully carried out in multipurpose furnace employing the drip-feed atmosphere with the addition of rare earth (RE). The carbon transfer coefficients (BRE) and mean diffusion coefficient (DRE) were calculated respectively based on the kinetics of the specimens weigh gain per unit area and the carburized layer growth. The results show that the BRE and DRE are all increased on basis of the incorporation of rare earth. In addition, the mathematical models of the carbon concentration profile under different carburizing conditions and the carbon diffusion coefficient DSRE (at x=0 for carburizing time t>0) have been deduced using the profile simulation method. Computer simulation results show that the simulated curves coincide quite well with the experimental data.展开更多
To achieve the goal of image content authentication and copyright protection simultaneously, this paper presents a novel image dual watermarking method based on chaotic map. Firstly, the host image was split into many...To achieve the goal of image content authentication and copyright protection simultaneously, this paper presents a novel image dual watermarking method based on chaotic map. Firstly, the host image was split into many nonoverlapping small blocks, and the block-wise discrete cosine transform (DCT) is computed. Secondly, the robust watermarks, shuffled by the chaotic sequences, are embedded in the DC coefficients of blocks to achieve the goal of copyright protection. The semi-fragile watermarks, generated by chaotic map, are embedded in the AC coefficients of blocks to obtain the aim of image authentication. Both of them can be extracted without the original image. Simulation results demonstrate the effectiveness of our algorithm in terms of robustness and fragility.展开更多
Leaves of multipurpose tree species (those providing more than one function or product of human use) can serve as sources of fer- tilizer for nutrient supply, especially nitrogen (N). In this study chopped leaves ...Leaves of multipurpose tree species (those providing more than one function or product of human use) can serve as sources of fer- tilizer for nutrient supply, especially nitrogen (N). In this study chopped leaves of tropical tree species (5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species) were in- corporated in soil to evaluate its effects on wheat biological productivity (including grain yield, GyIELD) under dryland conditions. High quality leaves of N-fixing tree species (e.g. Dalbergia sissoo, Cassia fistula and Prosopis cineraria) had lower carbon/nitrogen (C/N), lignin/nitrogen (L^o/N), polyphenol/nitrogen (PPt/N) and lignin+polyphenol /nitrogen (L~+PpL/N) ratios than low quality leaves of non-N-fixing species. Com- bination treatments had intermediate values of different parameters, Application of high quality leaves caused greater increases in wheat productivity and yield than other species.展开更多
Livestock is traditionally managed in mixed crop-livestock production systems in Sud-Kivu, D. R. Congo. Currently, livestock production is facing numerous constraints due to wars and insecurity in the country, with lo...Livestock is traditionally managed in mixed crop-livestock production systems in Sud-Kivu, D. R. Congo. Currently, livestock production is facing numerous constraints due to wars and insecurity in the country, with looting of animals, demographic pressure on natural resources, and lack of extension services. Multipurpose trees and shrubs with adequate forage quality could help overcome dry-season feed shortage. The objective of this research was to assess the agro-ecological adaptability of selected forage tree and shrub legumes combined with farmer participatory evaluation. The study was carried out at two distinct mid-altitude sites in Sud-Kivu. Trees and shrubs were planted randomly in eleven lines, with each species/accession consisting of nine plants split into three replications. Following a standardization cut after one year of growth, regular biomass harvests were performed every eight weeks during one year;Desmodium and Flemingia were cut at 0.5 m above soil surface, while Leucaena and Calliandra at 1 m. Before every harvest, plant height was measured and number of stems counted. Fresh leaf and stem biomass were weighted, sub samples dried and leaves analyzed for nutritive value. Results from agronomic evaluation show that Leucaena diversifolia ILRI 15551 and Leucaena leucocephala had the highest yield in the rainy season on fertile soil;during dry season, Leucaena diversifolia ILRI 15551 was superior. On poor soil, Flemingia macrophylla CIAT 17403 performed best in both seasons, however, its forage quality was relatively low. Forage tree and shrub legumes chosen by farmers were, in general, the same as those superior ones in agronomic evaluation.展开更多
Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Mult...Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Multipurpose Reservoir, Nepal. This study also focuses on interactions among various water quality parameters with planktons and how such interactions can affect the second major utility, the fish farming in the reservoir. The analyses of seasonal water samples collected from three different sampling locations in the reservoir showed that select water quality parameters varied significantly (P < 0.05) with sampling seasons (transparency: 30 - 250 cm, pH: 7 - 7.5, alkalinity: 30 - 120 mg/L, DO: 6 - 11.5 mg/L, CO2: 0.1 - 1.1 mg/L) and sampling locations (phosphate: 0.1 - 0.25 mg/L, nitrate 0.01 - 0.19 mg/L) in the reservoir. Three groups of zooplankton and four classes of phytoplankton, respectively with eleven and twelve genera, were identified and quantified in the reservoir. Among them, Cyclops, Asplanchana, and Keratella were most dominant zooplanktons while Synedra, Melosira and Peridinum were the most dominant phytoplankton in the reservoir water. The abundance of select zooplanktons (Cyclops, Keratella, Polyanthra), and phytoplankton (Navicula, Melosira, Amphora, Chroococcus, Staurastrum, Scendesmus) showed significant interaction between sampling sites and sampling seasons, while the other varied only with sampling seasons and/or sites. These results showed that seasonal water level fluctuations, along with the variation of water quality parameters, change the abundance and diversity of planktons’ in the reservoir. Such changes can negatively impact the fish in cage culture, affecting the livelihood of people extensively relying on these fish farming.展开更多
The Xiaolangdi multipurpose dam is located at the exit of the last gorge on the middle reaches of the Yellow River, 130 km downstream of Sanmenxia and 128 km upstreamfrom Huayuankou, Zhengzhou. It serves for flood con...The Xiaolangdi multipurpose dam is located at the exit of the last gorge on the middle reaches of the Yellow River, 130 km downstream of Sanmenxia and 128 km upstreamfrom Huayuankou, Zhengzhou. It serves for flood control, ice jam control, siltation control, irrigation, water supply and hydropower generation. The project consists of 10 intake towers, nine flood & sediment tunnels, six power tunnels, an underground powerhouse and a zoned earth and rockfill dam with a sloping展开更多
Although emission spectral tomography (EST) combines emission spectral measurement with optical computed tomography (OCT), it is difficult to gain transient emission data from a large number of views, therefore, h...Although emission spectral tomography (EST) combines emission spectral measurement with optical computed tomography (OCT), it is difficult to gain transient emission data from a large number of views, therefore, high precision OCT algorithms with few views ought to be studied for EST application. To improve the reconstruction precision in the case of few views, a new computed tomography reconstruction algorithm based on multipurpose optimal criterion and simulated annealing theory (multi-criterion simulated annealing reconstruction technique, MCSART) is proposed. This algorithm can suffice criterion of least squares, criterion of most uniformity, and criterion of most smoothness synchronously. We can get global optimal solution by MCSART algorithm with simulated annealing theory. The simulating experiment result shows that this algorithm is superior to the traditional algorithms under various noises.展开更多
To make speech watermarking achieve both copyright protection and integrity verification, a novel multipurpose speech watermarking algorithm based on the multistage vector quantization (MSVQ) of linear prediction co...To make speech watermarking achieve both copyright protection and integrity verification, a novel multipurpose speech watermarking algorithm based on the multistage vector quantization (MSVQ) of linear prediction coefficients (LPCs) is presented in this article. The property of natural speech that the vector quantization (VQ) indices of the LPCs amongst neighboring frames tend to be very similar is utilized to embed the robust watermark in the indices of the first-stage VQ(VQ1). Then, the semi-fragile watermark is embedded in the indices of the second-stage VQ(VQ2) with index constrained VQ encoding scheme. Both the robust watermark and the semi-fragile watermark can be extracted without host speech. Simulation results verify the effectiveness of the proposed algorithm in terms of robustness and semi-fragility.展开更多
The increasing demand of goods,the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their prod...The increasing demand of goods,the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units.Optimal scheduling of their processes can lead facilities towards this direction.Although a great number of mathematical models have been developed for such scheduling,they may still lead to large model sizes and computational time.In this work,we develop two novel mathematical models using the unit-specific eventbased modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points.The computational results demonstrate that both proposed mathematical models reduce the number of event points required.The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.展开更多
Background:The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases,including schistosomiasis.The current study was designed to investigat...Background:The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases,including schistosomiasis.The current study was designed to investigate the abundance and dynamics of schistosomiasis intermediate host snails and Schistosoma infections in humans during the construction and the first years of operation of a small multipurpose dam in Côte d’Ivoire.Methods:The study was carried out in Raffierkro and four neighbouring villages in central Côte d’Ivoire between 2007 and 2012.Snails were collected by two experienced investigators using scoops and forceps for 15 min at each site.Snails were identified at genera and,whenever possible,species level,and subjected to testing for cercarial shedding.Schoolchildren aged 6-15 years were examined once every year for Schistosoma haematobium and S.mansoni infection,using urine filtration and duplication Kato-Katz thick smears,respectively.Additionally,551 adults were examined for Schistosoma infection before(June 2007)and 359 individuals 2 years after dam construction(June 2009).Results:Overall,1700 snails belonging to nine different genera were collected from 19 sampling sites.Bulinus(potential intermediate host snails of S.haematobium)and Pila were the most common genera,whereas Biomphalaria(potential intermediate host snail of S.mansoni),Lymnaea,Physa and Melanoides were found in two villages.During the first-year sampling period,65 snails were collected,of which 13(20%)were schistosomiasis intermediate hosts.In subsequent years,out of 1635 snails collected,1079(66%)were identified as potential intermediate host for schistosomiasis,but none were shedding cercariae.The prevalence of S.mansoni among adults in the study area was low(0.4%in 2007 and 0.3%in 2009),whereas the prevalence of S.haematobium declined from 13.9%to 2.9%in this two-year period.Conclusions:The low prevalence of schistosomiasis in humans and the absence of infected intermediate host snails during the construction and early phase of operation of a small multipurpose dam suggest that there was no or only very little local transmission.However,the considerable increase in the number of intermediate host snails and their dispersion in irrigation canals call for rigorous surveillance,so that adequate public health measures can be taken in case of early signs of an outbreak.展开更多
There has been an immense endeavor to mitigate global warming in spite of which it has only been worse. This paper presents the design and imple- mentation of a low power and eco-friendly refrigeration system using th...There has been an immense endeavor to mitigate global warming in spite of which it has only been worse. This paper presents the design and imple- mentation of a low power and eco-friendly refrigeration system using the thermoelectric effect. The conventional refrigerators make use of complex mechanisms which involves synchronous operation of various units, namely the compressor, condensers, expansion valves, evaporator, refi'igerant and so on. But a thermoelectric refrigerator exploits the principle of the Peltier effect, thus avoiding the utilization of these complex components. This even helps curb the release of harmful chlorofluorocarbons (CFCs) into the atmosphere which contributes to the increase in global temperature. Moreover, the temperature can be controlled and set to required values with the help of a microcontroller. Hence, this can be used both for domestic and commercial purposes. The unit does not eject any harmful gases. Therefore, the heat expelled from the unit can be tapped for heating utilities, making the use of this device versatile in its application. Thus this proposal aims not only at reducing the air pollutants by not contributing to it but also at reducing the power consumption.展开更多
China’s first civilian mapping satellite will be launched next year China will launch its first highresolution,stereoscopic mapping satellite for civilian use,ZY-3,in 2011.According to the State Bureau of Surveying a...China’s first civilian mapping satellite will be launched next year China will launch its first highresolution,stereoscopic mapping satellite for civilian use,ZY-3,in 2011.According to the State Bureau of Surveying and Mapping(SBSM),the debugging and testing on the launch mechanism,launching site,ground receiving system and application system have already been completed.The satellite will be展开更多
From a world-wide plant introduction trial series utilising 25 central American species planted at over 100 sites in nearly 60 countries, eighteen species planted at 15 sites in the tropics were chosen for further stu...From a world-wide plant introduction trial series utilising 25 central American species planted at over 100 sites in nearly 60 countries, eighteen species planted at 15 sites in the tropics were chosen for further study of the factors determining site productivity and site by species interactions. The species were Acacia pennatula, Acacia farnesiana, Albizia guachapele, Ateleia herbert-smithii, Caesalpinia coriaria, Caesalpinia eriostachys, Caesalpinia velutina, Enterolobium cyclocarpum, Gliricidia sepi...展开更多
The current energy trend indicates a strong thrust toward transforming renewable energy as a major power source.To achieve this mission,battery energy storage systems(BESSs)are indispensable.Although BESSs are expensi...The current energy trend indicates a strong thrust toward transforming renewable energy as a major power source.To achieve this mission,battery energy storage systems(BESSs)are indispensable.Although BESSs are expensive,cost reduction can be achieved by using BESSs for multiple purposes,such as load leveling,business continuity planning,frequency control,capacity market,arbitrage,and emergency power.In this paper,various applications of BESSs are classified.The possibility of achieving conflict-free combination of different applications is demonstrated.The total required energy storage capacity in Japan is estimated to be 150–200 GWh by 2030.The present status of NaS batteries for multipurpose use and new trends in battery-based businesses are introduced.展开更多
This study presents a survey of wild plants commonly used by local inhabitants in the highlands of southwest Saudi Arabia. Based upon literature review, direct observation of local inhabitants, and questionnaire inter...This study presents a survey of wild plants commonly used by local inhabitants in the highlands of southwest Saudi Arabia. Based upon literature review, direct observation of local inhabitants, and questionnaire interviews, 36 plant species were assessed and given scores according to their use. The gaps between scientific and indigenous knowl- edge on the use of plants were estimated using a "compatibility ratio". The score values were estimated based on seven different use categories of ecosystem services, including food, forage, medicine, wood, beekeeping, research, and education. Additional structural categories include source of materials, shade, hedges, ornamental plantings, and soil stabilization. There are discrepancies between indigenous knowledge (IK) and scien- tific knowledge (SK) but in most cases, SK of the species supports the IK and plant users preference. The results also provide information that challenges assumptions about the consistency of IK with SK. Our study highlights the importance of understanding the cultural context and uses of wild plants. Biodiversity-based knowledge holds promise for contributing to sustainable use of wild plant resources and related traditions. The success of such endeavours depends on the compatibility and complementarity of indigenous and scientific knowledge.展开更多
The Francis turbine of Three Gorges hydropower station is one of the large turbines with great head variation in the world. The operational stability of the turbine has been the top subject for departments of design, ...The Francis turbine of Three Gorges hydropower station is one of the large turbines with great head variation in the world. The operational stability of the turbine has been the top subject for departments of design, research, manufacture and operation to be concerned about. During the course of preparing bid invitation documents and executing the contract for the Three Gorges left power plants turbogenerator units, the hydraulic stability of the turbine was regarded as the most important problem and specific stability indexes of the model turbine and the prototype turbine were respectively specified in the contract. In the model tests for turbine model acceptance, pressure fluctuation phenomena in the case of partial load were found to be different from the usual ones as people had known. Within the range of operating water head, there existed a peak value zone of pressure fluctuations with higher frequencies, and large amplitude pressure fluctuations simultaneously occurred in several localities from the spiral case entrance to the draft tube. On the basis of test results from the model, the influence of cavitation coefficient and aeration on pressure fluctuations is analyzed, and some measures to improve the hydraulic stability of turbines of Three Gorges hydropower station are expounded.展开更多
The general situation of the Three Gorges Projects reservoir inundation and its characteristics are presented. The investigation and verification of the Three Gorges Projects reservoir resettlement and its plannin...The general situation of the Three Gorges Projects reservoir inundation and its characteristics are presented. The investigation and verification of the Three Gorges Projects reservoir resettlement and its planning are summarized. Some key technical problems as environmental capacity of resettlement in the Three Gorges reservoir area, relations between compensation investment for resettlement and development investment, responsibility for the assigned resettlement investment and design under conditions of a limited investment, construction of mountain cities and towns and related geological disasters etc. are expounded. Facing new situations, several proposals are put forward to make the resettlement work well done, such as implementing resettlement project construction in accordance with the capital construction procedure strengthening regular management of the resettlement work, further perfecting the system of resettlement supervision, attaching great importance to the environmental protection in the reservoir area and to the planning work of resettling relocatees in other counties or provinces, speeding up the prevention and regulation, and the monitoring of landslides, etc.展开更多
The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedu...The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.展开更多
The effects of solid state fermentation on the mineral concentrations and in sacco degradation characteristics of dry matter in two multipurpose tree leaves was investigated. Biodegraded Enterolobium cyclocarpum (EC) ...The effects of solid state fermentation on the mineral concentrations and in sacco degradation characteristics of dry matter in two multipurpose tree leaves was investigated. Biodegraded Enterolobium cyclocarpum (EC) and Pterocarpus santalinoides (PS) leaves were previously inoculated with Aspergillus niger and incubated at 30°C for five incubation periods (0, 7, 14, 21 and 28 days). After each incubation period, samples were oven dried at 60°C, allowed to cool and ground for mineral analysis and in sacco dry matter degradability. Three fistulated West African Dwarf (WAD) rams (Ovis aries) were then used for the dry matter degradability. Five grams of each sample was emptied into nylon bag (Polymon, Switzeland) with pore size of 4 μ and effective size of 5 cm × 18 cm and incubated in the rumen of the fistulated animals for 6, 12, 24, 48, 72, and 96 h. The results showed that the mineral contents of biodegraded EC samples were affected by incubation period. Mean values of Ca, Cu, K, Na, and Zn were significantly increased (0.05), while mean values of Fe, Mg, and Mn were first reduced before significantly increasing (0.05). However, the composition of P showed significant reduction (0.05) up to day 28 where no change was observed. Mineral concentrations in biodegraded PS were also affected by incubation periods. Values of Ca, Fe, K, Mg, Mn, Na, and Zn were significantly increased (0.05). However values of Cu, and Fe only increased after day 14, while the value of P was reduced significantly over the different incubation periods. Potential degradability (PD) for biodegraded EC was highest at day 0 (50.79%) but not significantly different from potential degradability of longer incubation periods to day 28 (48.68%). PS had higher PD than EC. In spite of high PD values, PS comparatively degraded faster than EC. Effective degradability (ED) for EC was highest for day28 (36.71%) and not significantly different from days 21 (34.83%) and 7 (35.29%) but significantly different from days 0 (31.32%) and 14 (31.75%) respectively. However, the ED for PS was highest for day 0 (31.39) samples and significantly differed from other incubation periods, further increase in period only showed lower but similar ED values for days 7 (27.52%), 14 (26.76%), 21 (27.42%) and 28 (26.86%) respectively. In this study, the continued reduction in P concentrations in both biodegraded EC and PS suggest that Aspergillus niger has preferential demand for P and in sacco degradation showed increase in PD and ED values for fungal biodegraded EC and reduction in PS, suggesting improved quality of EC.展开更多
文摘The carburizing process has been successfully carried out in multipurpose furnace employing the drip-feed atmosphere with the addition of rare earth (RE). The carbon transfer coefficients (BRE) and mean diffusion coefficient (DRE) were calculated respectively based on the kinetics of the specimens weigh gain per unit area and the carburized layer growth. The results show that the BRE and DRE are all increased on basis of the incorporation of rare earth. In addition, the mathematical models of the carbon concentration profile under different carburizing conditions and the carbon diffusion coefficient DSRE (at x=0 for carburizing time t>0) have been deduced using the profile simulation method. Computer simulation results show that the simulated curves coincide quite well with the experimental data.
基金Supported by the National Natural Science Foun-dation of China (60573127)
文摘To achieve the goal of image content authentication and copyright protection simultaneously, this paper presents a novel image dual watermarking method based on chaotic map. Firstly, the host image was split into many nonoverlapping small blocks, and the block-wise discrete cosine transform (DCT) is computed. Secondly, the robust watermarks, shuffled by the chaotic sequences, are embedded in the DC coefficients of blocks to achieve the goal of copyright protection. The semi-fragile watermarks, generated by chaotic map, are embedded in the AC coefficients of blocks to obtain the aim of image authentication. Both of them can be extracted without the original image. Simulation results demonstrate the effectiveness of our algorithm in terms of robustness and fragility.
基金supported by Ministry of Environment and Forests,New Delhi,India
文摘Leaves of multipurpose tree species (those providing more than one function or product of human use) can serve as sources of fer- tilizer for nutrient supply, especially nitrogen (N). In this study chopped leaves of tropical tree species (5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species) were in- corporated in soil to evaluate its effects on wheat biological productivity (including grain yield, GyIELD) under dryland conditions. High quality leaves of N-fixing tree species (e.g. Dalbergia sissoo, Cassia fistula and Prosopis cineraria) had lower carbon/nitrogen (C/N), lignin/nitrogen (L^o/N), polyphenol/nitrogen (PPt/N) and lignin+polyphenol /nitrogen (L~+PpL/N) ratios than low quality leaves of non-N-fixing species. Com- bination treatments had intermediate values of different parameters, Application of high quality leaves caused greater increases in wheat productivity and yield than other species.
文摘Livestock is traditionally managed in mixed crop-livestock production systems in Sud-Kivu, D. R. Congo. Currently, livestock production is facing numerous constraints due to wars and insecurity in the country, with looting of animals, demographic pressure on natural resources, and lack of extension services. Multipurpose trees and shrubs with adequate forage quality could help overcome dry-season feed shortage. The objective of this research was to assess the agro-ecological adaptability of selected forage tree and shrub legumes combined with farmer participatory evaluation. The study was carried out at two distinct mid-altitude sites in Sud-Kivu. Trees and shrubs were planted randomly in eleven lines, with each species/accession consisting of nine plants split into three replications. Following a standardization cut after one year of growth, regular biomass harvests were performed every eight weeks during one year;Desmodium and Flemingia were cut at 0.5 m above soil surface, while Leucaena and Calliandra at 1 m. Before every harvest, plant height was measured and number of stems counted. Fresh leaf and stem biomass were weighted, sub samples dried and leaves analyzed for nutritive value. Results from agronomic evaluation show that Leucaena diversifolia ILRI 15551 and Leucaena leucocephala had the highest yield in the rainy season on fertile soil;during dry season, Leucaena diversifolia ILRI 15551 was superior. On poor soil, Flemingia macrophylla CIAT 17403 performed best in both seasons, however, its forage quality was relatively low. Forage tree and shrub legumes chosen by farmers were, in general, the same as those superior ones in agronomic evaluation.
文摘Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Multipurpose Reservoir, Nepal. This study also focuses on interactions among various water quality parameters with planktons and how such interactions can affect the second major utility, the fish farming in the reservoir. The analyses of seasonal water samples collected from three different sampling locations in the reservoir showed that select water quality parameters varied significantly (P < 0.05) with sampling seasons (transparency: 30 - 250 cm, pH: 7 - 7.5, alkalinity: 30 - 120 mg/L, DO: 6 - 11.5 mg/L, CO2: 0.1 - 1.1 mg/L) and sampling locations (phosphate: 0.1 - 0.25 mg/L, nitrate 0.01 - 0.19 mg/L) in the reservoir. Three groups of zooplankton and four classes of phytoplankton, respectively with eleven and twelve genera, were identified and quantified in the reservoir. Among them, Cyclops, Asplanchana, and Keratella were most dominant zooplanktons while Synedra, Melosira and Peridinum were the most dominant phytoplankton in the reservoir water. The abundance of select zooplanktons (Cyclops, Keratella, Polyanthra), and phytoplankton (Navicula, Melosira, Amphora, Chroococcus, Staurastrum, Scendesmus) showed significant interaction between sampling sites and sampling seasons, while the other varied only with sampling seasons and/or sites. These results showed that seasonal water level fluctuations, along with the variation of water quality parameters, change the abundance and diversity of planktons’ in the reservoir. Such changes can negatively impact the fish in cage culture, affecting the livelihood of people extensively relying on these fish farming.
文摘The Xiaolangdi multipurpose dam is located at the exit of the last gorge on the middle reaches of the Yellow River, 130 km downstream of Sanmenxia and 128 km upstreamfrom Huayuankou, Zhengzhou. It serves for flood control, ice jam control, siltation control, irrigation, water supply and hydropower generation. The project consists of 10 intake towers, nine flood & sediment tunnels, six power tunnels, an underground powerhouse and a zoned earth and rockfill dam with a sloping
基金This work was supported by the Chinese Natural Science Foundation of China(No.60577016)the Foundation(No. 0512034)of Jiangxi Natural Science+1 种基金the Science and Technology Program(No. 2006-164)of Jiangxi Provincial Department of Educationthe Program(No.2005-314)of Key Laboratory of Nondestructive Testing Technology,Ministry of Education.
文摘Although emission spectral tomography (EST) combines emission spectral measurement with optical computed tomography (OCT), it is difficult to gain transient emission data from a large number of views, therefore, high precision OCT algorithms with few views ought to be studied for EST application. To improve the reconstruction precision in the case of few views, a new computed tomography reconstruction algorithm based on multipurpose optimal criterion and simulated annealing theory (multi-criterion simulated annealing reconstruction technique, MCSART) is proposed. This algorithm can suffice criterion of least squares, criterion of most uniformity, and criterion of most smoothness synchronously. We can get global optimal solution by MCSART algorithm with simulated annealing theory. The simulating experiment result shows that this algorithm is superior to the traditional algorithms under various noises.
文摘To make speech watermarking achieve both copyright protection and integrity verification, a novel multipurpose speech watermarking algorithm based on the multistage vector quantization (MSVQ) of linear prediction coefficients (LPCs) is presented in this article. The property of natural speech that the vector quantization (VQ) indices of the LPCs amongst neighboring frames tend to be very similar is utilized to embed the robust watermark in the indices of the first-stage VQ(VQ1). Then, the semi-fragile watermark is embedded in the indices of the second-stage VQ(VQ2) with index constrained VQ encoding scheme. Both the robust watermark and the semi-fragile watermark can be extracted without host speech. Simulation results verify the effectiveness of the proposed algorithm in terms of robustness and semi-fragility.
基金Nikolaos Rakovitis would like to acknowledge financial support from the postgraduate award by The University of ManchesterLiping Zhang appreciates financial support from the National Natural Science Foundation of China(Grant No.51875420).
文摘The increasing demand of goods,the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units.Optimal scheduling of their processes can lead facilities towards this direction.Although a great number of mathematical models have been developed for such scheduling,they may still lead to large model sizes and computational time.In this work,we develop two novel mathematical models using the unit-specific eventbased modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points.The computational results demonstrate that both proposed mathematical models reduce the number of event points required.The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.
基金This study was financially supported by the Swiss-based non-governmental organization FAIRMED(Bern,Switzerland).
文摘Background:The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases,including schistosomiasis.The current study was designed to investigate the abundance and dynamics of schistosomiasis intermediate host snails and Schistosoma infections in humans during the construction and the first years of operation of a small multipurpose dam in Côte d’Ivoire.Methods:The study was carried out in Raffierkro and four neighbouring villages in central Côte d’Ivoire between 2007 and 2012.Snails were collected by two experienced investigators using scoops and forceps for 15 min at each site.Snails were identified at genera and,whenever possible,species level,and subjected to testing for cercarial shedding.Schoolchildren aged 6-15 years were examined once every year for Schistosoma haematobium and S.mansoni infection,using urine filtration and duplication Kato-Katz thick smears,respectively.Additionally,551 adults were examined for Schistosoma infection before(June 2007)and 359 individuals 2 years after dam construction(June 2009).Results:Overall,1700 snails belonging to nine different genera were collected from 19 sampling sites.Bulinus(potential intermediate host snails of S.haematobium)and Pila were the most common genera,whereas Biomphalaria(potential intermediate host snail of S.mansoni),Lymnaea,Physa and Melanoides were found in two villages.During the first-year sampling period,65 snails were collected,of which 13(20%)were schistosomiasis intermediate hosts.In subsequent years,out of 1635 snails collected,1079(66%)were identified as potential intermediate host for schistosomiasis,but none were shedding cercariae.The prevalence of S.mansoni among adults in the study area was low(0.4%in 2007 and 0.3%in 2009),whereas the prevalence of S.haematobium declined from 13.9%to 2.9%in this two-year period.Conclusions:The low prevalence of schistosomiasis in humans and the absence of infected intermediate host snails during the construction and early phase of operation of a small multipurpose dam suggest that there was no or only very little local transmission.However,the considerable increase in the number of intermediate host snails and their dispersion in irrigation canals call for rigorous surveillance,so that adequate public health measures can be taken in case of early signs of an outbreak.
文摘There has been an immense endeavor to mitigate global warming in spite of which it has only been worse. This paper presents the design and imple- mentation of a low power and eco-friendly refrigeration system using the thermoelectric effect. The conventional refrigerators make use of complex mechanisms which involves synchronous operation of various units, namely the compressor, condensers, expansion valves, evaporator, refi'igerant and so on. But a thermoelectric refrigerator exploits the principle of the Peltier effect, thus avoiding the utilization of these complex components. This even helps curb the release of harmful chlorofluorocarbons (CFCs) into the atmosphere which contributes to the increase in global temperature. Moreover, the temperature can be controlled and set to required values with the help of a microcontroller. Hence, this can be used both for domestic and commercial purposes. The unit does not eject any harmful gases. Therefore, the heat expelled from the unit can be tapped for heating utilities, making the use of this device versatile in its application. Thus this proposal aims not only at reducing the air pollutants by not contributing to it but also at reducing the power consumption.
文摘China’s first civilian mapping satellite will be launched next year China will launch its first highresolution,stereoscopic mapping satellite for civilian use,ZY-3,in 2011.According to the State Bureau of Surveying and Mapping(SBSM),the debugging and testing on the launch mechanism,launching site,ground receiving system and application system have already been completed.The satellite will be
文摘From a world-wide plant introduction trial series utilising 25 central American species planted at over 100 sites in nearly 60 countries, eighteen species planted at 15 sites in the tropics were chosen for further study of the factors determining site productivity and site by species interactions. The species were Acacia pennatula, Acacia farnesiana, Albizia guachapele, Ateleia herbert-smithii, Caesalpinia coriaria, Caesalpinia eriostachys, Caesalpinia velutina, Enterolobium cyclocarpum, Gliricidia sepi...
文摘The current energy trend indicates a strong thrust toward transforming renewable energy as a major power source.To achieve this mission,battery energy storage systems(BESSs)are indispensable.Although BESSs are expensive,cost reduction can be achieved by using BESSs for multiple purposes,such as load leveling,business continuity planning,frequency control,capacity market,arbitrage,and emergency power.In this paper,various applications of BESSs are classified.The possibility of achieving conflict-free combination of different applications is demonstrated.The total required energy storage capacity in Japan is estimated to be 150–200 GWh by 2030.The present status of NaS batteries for multipurpose use and new trends in battery-based businesses are introduced.
基金supported by project No.10-ENV1276-02 entitled"Conservation and valuation of plant diversity of potential economic value in mountain ecosystems,Saudi Arabia"funded by the National Plan for Science and Technology(NPST),Saudi Arabia
文摘This study presents a survey of wild plants commonly used by local inhabitants in the highlands of southwest Saudi Arabia. Based upon literature review, direct observation of local inhabitants, and questionnaire interviews, 36 plant species were assessed and given scores according to their use. The gaps between scientific and indigenous knowl- edge on the use of plants were estimated using a "compatibility ratio". The score values were estimated based on seven different use categories of ecosystem services, including food, forage, medicine, wood, beekeeping, research, and education. Additional structural categories include source of materials, shade, hedges, ornamental plantings, and soil stabilization. There are discrepancies between indigenous knowledge (IK) and scien- tific knowledge (SK) but in most cases, SK of the species supports the IK and plant users preference. The results also provide information that challenges assumptions about the consistency of IK with SK. Our study highlights the importance of understanding the cultural context and uses of wild plants. Biodiversity-based knowledge holds promise for contributing to sustainable use of wild plant resources and related traditions. The success of such endeavours depends on the compatibility and complementarity of indigenous and scientific knowledge.
文摘The Francis turbine of Three Gorges hydropower station is one of the large turbines with great head variation in the world. The operational stability of the turbine has been the top subject for departments of design, research, manufacture and operation to be concerned about. During the course of preparing bid invitation documents and executing the contract for the Three Gorges left power plants turbogenerator units, the hydraulic stability of the turbine was regarded as the most important problem and specific stability indexes of the model turbine and the prototype turbine were respectively specified in the contract. In the model tests for turbine model acceptance, pressure fluctuation phenomena in the case of partial load were found to be different from the usual ones as people had known. Within the range of operating water head, there existed a peak value zone of pressure fluctuations with higher frequencies, and large amplitude pressure fluctuations simultaneously occurred in several localities from the spiral case entrance to the draft tube. On the basis of test results from the model, the influence of cavitation coefficient and aeration on pressure fluctuations is analyzed, and some measures to improve the hydraulic stability of turbines of Three Gorges hydropower station are expounded.
文摘The general situation of the Three Gorges Projects reservoir inundation and its characteristics are presented. The investigation and verification of the Three Gorges Projects reservoir resettlement and its planning are summarized. Some key technical problems as environmental capacity of resettlement in the Three Gorges reservoir area, relations between compensation investment for resettlement and development investment, responsibility for the assigned resettlement investment and design under conditions of a limited investment, construction of mountain cities and towns and related geological disasters etc. are expounded. Facing new situations, several proposals are put forward to make the resettlement work well done, such as implementing resettlement project construction in accordance with the capital construction procedure strengthening regular management of the resettlement work, further perfecting the system of resettlement supervision, attaching great importance to the environmental protection in the reservoir area and to the planning work of resettling relocatees in other counties or provinces, speeding up the prevention and regulation, and the monitoring of landslides, etc.
文摘The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.
文摘The effects of solid state fermentation on the mineral concentrations and in sacco degradation characteristics of dry matter in two multipurpose tree leaves was investigated. Biodegraded Enterolobium cyclocarpum (EC) and Pterocarpus santalinoides (PS) leaves were previously inoculated with Aspergillus niger and incubated at 30°C for five incubation periods (0, 7, 14, 21 and 28 days). After each incubation period, samples were oven dried at 60°C, allowed to cool and ground for mineral analysis and in sacco dry matter degradability. Three fistulated West African Dwarf (WAD) rams (Ovis aries) were then used for the dry matter degradability. Five grams of each sample was emptied into nylon bag (Polymon, Switzeland) with pore size of 4 μ and effective size of 5 cm × 18 cm and incubated in the rumen of the fistulated animals for 6, 12, 24, 48, 72, and 96 h. The results showed that the mineral contents of biodegraded EC samples were affected by incubation period. Mean values of Ca, Cu, K, Na, and Zn were significantly increased (0.05), while mean values of Fe, Mg, and Mn were first reduced before significantly increasing (0.05). However, the composition of P showed significant reduction (0.05) up to day 28 where no change was observed. Mineral concentrations in biodegraded PS were also affected by incubation periods. Values of Ca, Fe, K, Mg, Mn, Na, and Zn were significantly increased (0.05). However values of Cu, and Fe only increased after day 14, while the value of P was reduced significantly over the different incubation periods. Potential degradability (PD) for biodegraded EC was highest at day 0 (50.79%) but not significantly different from potential degradability of longer incubation periods to day 28 (48.68%). PS had higher PD than EC. In spite of high PD values, PS comparatively degraded faster than EC. Effective degradability (ED) for EC was highest for day28 (36.71%) and not significantly different from days 21 (34.83%) and 7 (35.29%) but significantly different from days 0 (31.32%) and 14 (31.75%) respectively. However, the ED for PS was highest for day 0 (31.39) samples and significantly differed from other incubation periods, further increase in period only showed lower but similar ED values for days 7 (27.52%), 14 (26.76%), 21 (27.42%) and 28 (26.86%) respectively. In this study, the continued reduction in P concentrations in both biodegraded EC and PS suggest that Aspergillus niger has preferential demand for P and in sacco degradation showed increase in PD and ED values for fungal biodegraded EC and reduction in PS, suggesting improved quality of EC.