WorldWideScience

Sample records for rainwater harvesting system

  1. Rainwater Harvesting Systems

    OpenAIRE

    Ling, Erin; Benham, Brian Leslie, 1960-

    2014-01-01

    A properly designed, constructed, and maintained rainwater harvesting system can provide supplemental water in water-stressed areas and reduce downstream management and treatment. This publication reviews what rainwater harvesting is, why you would want to, and types of rainwater systems.

  2. Rooftop level rainwater harvesting system

    Science.gov (United States)

    Traboulsi, Hayssam; Traboulsi, Marwa

    2017-05-01

    Unfortunately, in Lebanon and other countries in the Middle East region, water becomes scarcer than ever before, and over the last decades the demand on domestic water has increased due to population and economic growth. Although rainwater harvesting is considered to be a safe and reliable alternative source for domestic water, the inconvenience or impracticalities related to the cost and space needed for the construction of ground or underground storage tanks makes this practice not widely common in rural areas and rarely implemented in urban cities. This paper introduces a new technique to rainwater harvesting which can be easily used in both rural and urban areas: it collects and stores rainwater directly in tanks already installed on building roofs and not necessarily in special ground or underground ones. If widely adopted in Lebanon, this technique could help in: (1) collecting around 23 MCM (70 % of the current deficit in the domestic water supply) of rainwater and thus increasing the available water per m2 of building by 0.4 m3 per year, (2) saving around 7 % of the amount of electric energy usually needed to pump water from an aquifer well and ground or underground tank, and (3) considerably reducing the rate of surface runoff of rainwater at the coastal zones where rainwater is not captured at all and goes directly to the sea.

  3. Risk Analysis Approach to Rainwater Harvesting Systems

    Directory of Open Access Journals (Sweden)

    Nadia Ursino

    2016-08-01

    Full Text Available Urban rainwater reuse preserves water resources and promotes sustainable development in rapidly growing urban areas. The efficiency of a large number of urban water reuse systems, operating under different climate and demand conditions, is evaluated here on the base of a new risk analysis approach. Results obtained by probability analysis (PA indicate that maximum efficiency in low demanding scenarios is above 0.5 and a threshold, distinguishing low from high demanding scenarios, indicates that in low demanding scenarios no significant improvement in performance may be attained by increasing the storage capacity of rainwater harvesting tanks. Threshold behaviour is displayed when tank storage capacity is designed to match both the average collected volume and the average reuse volume. The low demand limit cannot be achieved under climate and operating conditions characterized by a disproportion between harvesting and demand volume.

  4. Rainwater harvesting systems for low demanding applications.

    Science.gov (United States)

    Sanches Fernandes, Luís F; Terêncio, Daniela P S; Pacheco, Fernando A L

    2015-10-01

    A rainwater harvesting system (RHS) was designed for a waste treatment facility located near the town of Mirandela (northern Portugal), to be used in the washing of vehicles and other equipment, the cleaning of outside concrete or asphalt floors, and the watering of green areas. Water tank volumes representing 100% efficiency (Vr) were calculated by the Ripple method with different results depending on two consumption scenarios adopted for irrigation. The RHS design was based on a precipitation record spanning a rather long period (3 decades). The calculated storage capacities fulfilled the water demand even when prolonged droughts occurred during that timeframe. However, because the drought events have been rather scarce the Vr values were considered oversized and replaced by optimal volumes. Notwithstanding the new volumes were solely half of the original Vr values, the projected RHS efficiency remained very high (around 90%) while the probability of system failure (efficiencyrainwater harvesting, where water availability (Vw) largely exceeds water demand (Cw), that is to say where demand fractions (Cw/Vw) are very low. Based on the results of a literature review covering an ample geographic distribution and describing a very large number of demand fraction scenarios, a Cw/Vw=0.8 was defined as the threshold to generally distinguish the low from the high demanding RHS applications.

  5. Elemental composition at different points of the rainwater harvesting system.

    Science.gov (United States)

    Morrow, A C; Dunstan, R H; Coombes, P J

    2010-09-15

    Entry of contaminants, such as metals and non-metals, into rainwater harvesting systems can occur directly from rainfall with contributions from collection surfaces, accumulated debris and leachate from storage systems, pipes and taps. Ten rainwater harvesting systems on the east coast of Australia were selected for sampling of roof runoff, storage systems and tap outlets to investigate the variations in rainwater composition as it moved throughout the system, and to identify potential points of contribution to elemental loads. A total of 26 elements were screened at each site. Iron was the only element which was present in significantly higher concentrations in roof runoff samples compared with tank tap samples (Prainwater. Increased loads of copper were observed in hot tap samples supplied by the rainwater harvesting system via copper piping and a storage hot water system (Pcollected from a polyvinyl chloride pipe sampling point that does not supply household uses, compared with corresponding roof runoff samples (Pcollected rainwater between different study sites and between different sampling points. Atmospheric deposition was not a major contributor to the rainwater contaminant load at the sites tested. Piping materials, however, were shown to contribute significantly to the total elemental load at some locations.

  6. Land suitability for establishing rainwater harvesting systems for fighting wildfires

    Science.gov (United States)

    José María León Villalobos; Manuel Anaya Garduño; Enrique Ojeda Trejo; Dante Arturo Rodríguez Trejo; José Luis Oropeza Mota; Jorge Luis García Rodríguez

    2013-01-01

    Rainwater harvesting systems (RHSs) can be used to improve the efficiency of helicopter firefighting operations. To this end, RHSs need to be strategically located in areas with high wildfire occurrence to maximize their usefulness. In this study, spatial analysis was carried out to determine suitable sites for establishing RHSs intended for air attack operations in...

  7. Feasibility study of rainwater harvesting system in Sylhet City.

    Science.gov (United States)

    Alam, R; Munna, G; Chowdhury, M A I; Sarkar, M S K A; Ahmed, M; Rahman, M T; Jesmin, F; Toimoor, M A

    2012-01-01

    In rural areas in Bangladesh, groundwater is the principal source of water supply. This underground water is available in considerable amount in shallow aquifers. It is free from pathogenic microorganisms and hence water-borne diseases. In plain lands, other than hilly areas, water supply to 97% rural population comes from tube-wells, which is regarded to be a phenomenal achievement in preserving public health. Besides, a dependable water supply system all throughout the country is offset by two factors: (a) high salinity in surface plus groundwater in coastal areas; (b) want of suitable groundwater aquifers in hilly areas and the high cost of setting up tube-wells due to deep underground water table and stony layers. However, presence of arsenic in underground water now poses a serious threat to the success once made in water supply by setting up of manually operated tube-wells in the village areas-the achievement is now on the brink of total collapse. In about 61 districts out of 64, presence of arsenic exceeds a quantity of 0.05 mg/1, a permissible limit as per Bangladeshi water quality standard. Harvesting rainwater can be a pragmatic solution to this problem, which is common in many places in Sylhet especially in the hilly areas on the north eastern part of the city. This can be an alternative source of drinking water because of availability of rainwater from March to October. Heavy rain occurs from end of May till mid September, which is commonly known as the rainy season. This paper focuses on the possibility of harvesting rainwater in rural communities and thickly populated urban areas of Sylhet. It also demonstrates the scopes of harvesting rainwater using simple and low-cost technology. With setting up of a carefully planned rainwater storage tank, a family can have all of its drinking water from rain. Planned use of rainwater through rainwater harvesting in the roof catchments may fulfill the entire annual domestic water demand of a family in the rural

  8. Effects of rainwater harvesting on centralized urban water supply systems

    DEFF Research Database (Denmark)

    Grandet, C.; Binning, Philip John; Mikkelsen, Peter Steen

    2010-01-01

    The potential effect of widespread rainwater harvesting practices on mains water demand and quality management are investigated for three different types of urban areas characterized by different roof area to water demand ratios. Two rainfall patterns are considered with similar average annual de...... if they enable the deferment of requirements for new mains water infrastructure.......The potential effect of widespread rainwater harvesting practices on mains water demand and quality management are investigated for three different types of urban areas characterized by different roof area to water demand ratios. Two rainfall patterns are considered with similar average annual...... depths but very different temporal distributions. Supply reliability and the extent of reliance on the public distribution system are identified as suitable performance indicators for mains water infrastructure. A uniform temporal distribution of rainfall in an oceanic climate like that of Dinard...

  9. Rainwater harvesting in the United States: a survey of common system practices

    Science.gov (United States)

    Rainwater harvesting (RWH) systems in the United States vary in terms of design and operation. To better understand common practices in the RWH community and motivation for collecting harvested rainwater, an electronic survey was used to poll members of the American Rainwater Cat...

  10. Urban rainwater harvesting systems: Research, implementation and future perspectives.

    Science.gov (United States)

    Campisano, Alberto; Butler, David; Ward, Sarah; Burns, Matthew J; Friedler, Eran; DeBusk, Kathy; Fisher-Jeffes, Lloyd N; Ghisi, Enedir; Rahman, Ataur; Furumai, Hiroaki; Han, Mooyoung

    2017-03-02

    While the practice of rainwater harvesting (RWH) can be traced back millennia, the degree of its modern implementation varies greatly across the world, often with systems that do not maximize potential benefits. With a global focus, the pertinent practical, theoretical and social aspects of RWH are reviewed in order to ascertain the state of the art. Avenues for future research are also identified. A major finding is that the degree of RWH systems implementation and the technology selection are strongly influenced by economic constraints and local regulations. Moreover, despite design protocols having been set up in many countries, recommendations are still often organized only with the objective of conserving water without considering other potential benefits associated with the multiple-purpose nature of RWH. It is suggested that future work on RWH addresses three priority challenges. Firstly, more empirical data on system operation is needed to allow improved modelling by taking into account multiple objectives of RWH systems. Secondly, maintenance aspects and how they may impact the quality of collected rainwater should be explored in the future as a way to increase confidence on rainwater use. Finally, research should be devoted to the understanding of how institutional and socio-political support can be best targeted to improve system efficacy and community acceptance.

  11. Monsoon harvests: the living legacies of rainwater harvesting systems in South India.

    Science.gov (United States)

    Van Meter, Kimberly J; Basu, Nandita B; Tate, Eric; Wyckoff, Joseph

    2014-04-15

    Rainwater harvesting, a "soft path" approach toward water management, is increasingly recognized as a key strategy toward ensuring food security and alleviating problems of water scarcity. Interestingly this "modern" approach has been in use for millennia in numerous older civilizations. This article uses India as a case study to explore the social, economic, and environmental dimensions of agricultural rainwater harvesting ponds, and evaluates the viability of these centuries-old systems under current climate and population pressures. A holistic watershed-scale approach that accounts for trade-offs in water availability and socioeconomic wellbeing is recommended for assessing the sustainability of these systems.

  12. Modelling of a roof runoff harvesting system: The use of rainwater for toilet flushing

    OpenAIRE

    Vialle, Claire; Sablayrolles, Caroline; Lovera, Maurin; Huau, Marie-Christine; Montréjaud-Vignoles, Mireille

    2011-01-01

    The water balance of a four-people family rainwater harvesting system was calculated in a case study. The experimental water saving efficiency (WSE) was calculated as 87 %. A simple computer model was implemented to simulate the behaviour of the rainwater harvesting system. In general, the rainwater collector volumes predicted by the daily model had shown a good correlation with the experimental values. The difference between the experimental and the predicted values for the stored volume can...

  13. Performance of a large building rainwater harvesting system.

    Science.gov (United States)

    Ward, S; Memon, F A; Butler, D

    2012-10-15

    Rainwater harvesting is increasingly becoming an integral part of the sustainable water management toolkit. Despite a plethora of studies modelling the feasibility of the utilisation of rainwater harvesting (RWH) systems in particular contexts, there remains a significant gap in knowledge in relation to detailed empirical assessments of performance. Domestic systems have been investigated to a limited degree in the literature, including in the UK, but there are few recent longitudinal studies of larger non-domestic systems. Additionally, there are few studies comparing estimated and actual performance. This paper presents the results of a longitudinal empirical performance assessment of a non-domestic RWH system located in an office building in the UK. Furthermore, it compares actual performance with the estimated performance based on two methods recommended by the British Standards Institute - the Intermediate (simple calculations) and Detailed (simulation-based) Approaches. Results highlight that the average measured water saving efficiency (amount of mains water saved) of the office-based RWH system was 87% across an 8-month period, due to the system being over-sized for the actual occupancy level. Consequently, a similar level of performance could have been achieved using a smaller-sized tank. Estimated cost savings resulted in capital payback periods of 11 and 6 years for the actual over-sized tank and the smaller optimised tank, respectively. However, more detailed cost data on maintenance and operation is required to perform whole life cost analyses. These findings indicate that office-scale RWH systems potentially offer significant water and cost savings. They also emphasise the importance of monitoring data and that a transition to the use of Detailed Approaches (particularly in the UK) is required to (a) minimise over-sizing of storage tanks and (b) build confidence in RWH system performance.

  14. Sustainability of rainwater harvesting system in terms of water quality.

    Science.gov (United States)

    Rahman, Sadia; Khan, M T R; Akib, Shatirah; Din, Nazli Bin Che; Biswas, S K; Shirazi, S M

    2014-01-01

    Water is considered an everlasting free source that can be acquired naturally. Demand for processed supply water is growing higher due to an increasing population. Sustainable use of water could maintain a balance between its demand and supply. Rainwater harvesting (RWH) is the most traditional and sustainable method, which could be easily used for potable and nonpotable purposes both in residential and commercial buildings. This could reduce the pressure on processed supply water which enhances the green living. This paper ensures the sustainability of this system through assessing several water-quality parameters of collected rainwater with respect to allowable limits. A number of parameters were included in the analysis: pH, fecal coliform, total coliform, total dissolved solids, turbidity, NH3-N, lead, BOD5, and so forth. The study reveals that the overall quality of water is quite satisfactory as per Bangladesh standards. RWH system offers sufficient amount of water and energy savings through lower consumption. Moreover, considering the cost for installation and maintenance expenses, the system is effective and economical.

  15. Sustainability of Rainwater Harvesting System in terms of Water Quality

    Directory of Open Access Journals (Sweden)

    Sadia Rahman

    2014-01-01

    Full Text Available Water is considered an everlasting free source that can be acquired naturally. Demand for processed supply water is growing higher due to an increasing population. Sustainable use of water could maintain a balance between its demand and supply. Rainwater harvesting (RWH is the most traditional and sustainable method, which could be easily used for potable and nonpotable purposes both in residential and commercial buildings. This could reduce the pressure on processed supply water which enhances the green living. This paper ensures the sustainability of this system through assessing several water-quality parameters of collected rainwater with respect to allowable limits. A number of parameters were included in the analysis: pH, fecal coliform, total coliform, total dissolved solids, turbidity, NH3–N, lead, BOD5, and so forth. The study reveals that the overall quality of water is quite satisfactory as per Bangladesh standards. RWH system offers sufficient amount of water and energy savings through lower consumption. Moreover, considering the cost for installation and maintenance expenses, the system is effective and economical.

  16. Sustainability of Rainwater Harvesting Systems in Multistorey Residential Buildings

    Directory of Open Access Journals (Sweden)

    A. Rahman

    2010-01-01

    Full Text Available Problem statement: The urban water supply systems in Australian large cities, which generally depend on large surface water reservoirs, are highly stressed due to rapid urban growth and severe drought conditions during the current decade. To ensure the long term sustainability of urban water supply, various alternative water sources including rainwater tanks, grey water, wastewater and desalination plants are being examined in Australia. In the previous research, it has been shown that rainwater tank of appropriate size, installed in detached small dwellings, can meet a significant proportion of household water demand, but there has been limited study on water savings and financial viability of Rain Water Harvesting System (RWHS for multistorey residential buildings. This study examines the sustainability of RWHS in multistorey residential buildings in Sydney under different scenarios such as varying roof area, number of floors in the building, water price and interest rate to identify favorable condition where RWHS proves to be sustainable. Approach: A hypothetical multistorey building was considered and various scenarios in relation to site area and floor arrangement were established. A water balance model was developed to calculate water savings for various scenarios. Finally, life cycle costing was undertaken to identify most sustainable RWHS scenario for the hypothetical multistorey building. Results: It was found that a higher roof area is more favorable in terms of water savings and financial benefits. Capital and maintenance costs account for the majority of the expenditure of a RWHS. Plumbing cost forms the largest single component of the capital cost. It is shown that lower interest and increased water price regimes enhance the financial viability of RWHS. Conclusion: It was found that it is possible to achieve “pay back” for a RWHS under some favorable scenarios and conditions thus making the RWHS for multistorey buildings in Sydney

  17. Water and Energy Conservation of Rainwater Harvesting System in the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhi-yun; LI Xiao-yan; MA Yu-jun

    2013-01-01

    Water is the source of all the creatures on the earth and energy is the main factor driving the world. With the increasing population and global change, water and energy conservation have become worldwide focal issues, particularly in the water-stressed and energy-limited regions. Rainwater harvesting, based on the collection and storage of rainfall runoff, has been widely used for domestic use and agricultural production in arid and semiarid regions. It has advantages of simple operation, high adaption, low cost and less energy consumption. This study reviewed rainwater harvesting systems adopted in the Loess Plateau of China and analyzed water use efficiency (WUE) for various rainwater harvesting techniques. Supplemental irrigation using harvested rainwater could increase crop yield by more than 30%, and WUE ranged from 0.7 to 5.7 kg m-3 for spring wheat, corn and flax, and 30-40 kg m-3 for vegetables. Moreover, energy consumption for rainwater harvesting based on single family was compared with traditional water supply in the city of the Loess Plateau using the life cycle assessment (LCA) method. Results showed that energy consumption yielded per unit harvested rainwater was 25.96 MJ m-3 yr-1 which was much less than 62.25 MJ m-3 yr-1 for main water supply in Baoji City, Shanxi Province, meaning that rainwater harvesting saved energy by 139.8%as compared to the main water supply system. This study highlights the importance and potential of rainwater harvesting for water and energy conservation in the near future.

  18. Rainwater harvesting and management in rainfed agricultural systems in sub-Saharan Africa - A review

    Science.gov (United States)

    Biazin, Birhanu; Sterk, Geert; Temesgen, Melesse; Abdulkedir, Abdu; Stroosnijder, Leo

    Agricultural water scarcity in the predominantly rainfed agricultural system of sub-Saharan Africa (SSA) is more related to the variability of rainfall and excessive non-productive losses, than the total annual precipitation in the growing season. Less than 15% of the terrestrial precipitation takes the form of productive ‘green’ transpiration. Hence, rainwater harvesting and management (RWHM) technologies hold a significant potential for improving rainwater-use efficiency and sustaining rainfed agriculture in the region. This paper outlines the various RWHM techniques being practiced in SSA, and reviews recent research results on the performance of selected practices. So far, micro-catchment and in situ rainwater harvesting techniques are more common than rainwater irrigation techniques from macro-catchment systems. Depending on rainfall patterns and local soil characteristics, appropriate application of in situ and micro-catchment techniques could improve the soil water content of the rooting zone by up to 30%. Up to sixfold crop yields have been obtained through combinations of rainwater harvesting and fertiliser use, as compared to traditional practices. Supplemental irrigation of rainfed agriculture through rainwater harvesting not only reduces the risk of total crop failure due to dry spells, but also substantially improves water and crop productivity. Depending on the type of crop and the seasonal rainfall pattern, the application of RWHM techniques makes net profits more possible, compared to the meagre profit or net loss of existing systems. Implementation of rainwater harvesting may allow cereal-based smallholder farmers to shift to diversified crops, hence improving household food security, dietary status, and economic return. The much needed green revolution and adaptations to climate change in SSA should blend rainwater harvesting ideals with agronomic principles. More efforts are needed to improve the indigenous practices, and to disseminate best

  19. Exploring methods to minimize the risk of mosquitoes in rainwater harvesting systems

    Science.gov (United States)

    Moglia, Magnus; Gan, Kein; Delbridge, Nathan

    2016-12-01

    Rainwater harvesting in residential homes is emerging as an important complement to centralized water supplies in urban centres around the world. Domestic rainwater harvesting systems provide a variety of benefits for water management and contribute to sustainable and integrated urban water management. There are however risks associated with rainwater harvesting that requires appropriate mitigation. One such risk is that systems can become breeding grounds for mosquitoes. This can constitute a significant health risk through the spread of mosquito-borne diseases (i.e. arbovirus and malaria). This paper explores the extent to which mosquitoes breed in rainwater harvesting systems as well as the effectiveness of different risk mitigation actions. Data were sourced from a large-scale domestic rainwater tank inspection survey undertaken in Melbourne and were analysed using simple Bayesian Network models. The observed rate of mosquito breeding was too high and was identified as a serious concern for health officials and water managers. The most common access routes into the tank system were found to be through the tank inlet or overflow. By exploring different system set-ups it was found that in order to mitigate the risk of mosquito breeding in tanks, all potential access routes must be adequately sealed. The complete eradication of mosquitos in rainwater tanks, however, may need further investigation, as 4% of systems with adequate protection at the inlet and overflow were still found to have mosquitoes in them.

  20. Review and quantitative assessment of ex situ household rainwater harvesting systems in Ethiopia

    NARCIS (Netherlands)

    Moges, G.; Hengsdijk, H.; Jansen, H.C.

    2011-01-01

    Ex situ household rainwater harvesting (RWH) systems have been introduced at a large scale in Ethiopia to increase the water availability for smallholders through supplementary irrigation. The first objective of this paper is to review the performance of these systems in Ethiopia based on various as

  1. Rainwater harvesting in schools in Taiwan: system characteristics and water quality.

    Science.gov (United States)

    Sung, M; Kan, C C; Wan, M W; Yang, C R; Wang, J C; Yu, K C; Lee, S Z

    2010-01-01

    In order to understand the current status of rainwater harvesting (RWH) practices in Taiwan's schools, a study was carried out to examine the RWH system performance, water usage, and water quality in these sites. A total of 29 schools in various regions were selected for this investigation, including 7 in the northern, 7 in the central, 8 in the southern, and 7 in the eastern regions of Taiwan. Water quality indicators tested were: pH, temperature, conductivity, oxidation-reduction potential, suspended solid, total organic carbon, fecal coliform, and total coliform. From this study, it was found that RWH systems in these sites generally had two different designs: one that collected rainwater only, and one that collected both rainwater and grey water. From statistical analysis, it was found that water quality indicators such as suspended solids, total organic carbon, and fecal coliform were significantly affected by the water source and site location. Fecal coliforms in most of the sites we studied were high and not qualified for toilet flushing. The average water retention time of 2.4 months was long and considered to be the main reason to cause high fecal coliform counts. Finally, the benefit analysis was conducted to evaluate economic feasibility of rainwater harvesting for these schools. It turned out that 20% of them were able to gain economic benefits from using rainwater.

  2. Designing domestic rainwater harvesting systems under different climatic regimes in Italy.

    Science.gov (United States)

    Campisano, A; Gnecco, I; Modica, C; Palla, A

    2013-01-01

    Nowadays domestic rainwater harvesting practices are recognized as effective tools to improve the sustainability of drainage systems within the urban environment, by contributing to limiting the demand for potable water and, at the same time, by mitigating the generation of storm water runoff at the source. The final objective of this paper is to define regression curves to size domestic rainwater harvesting (DRWH) systems in the main Italian climatic regions. For this purpose, the Köppen-Geiger climatic classification is used and, furthermore, suitable precipitation sites are selected for each climatic region. A behavioural model is implemented to assess inflow, outflow and change in storage volume of a rainwater harvesting system according to daily mass balance simulations based on historical rainfall observations. The performance of the DRWH system under various climate and operational conditions is examined as a function of two non-dimensional parameters, namely the demand fraction (d) and the modified storage fraction (sm). This last parameter allowed the evaluation of the effects of the rainfall intra-annual variability on the system performance.

  3. Investigation of pump and pump switch failures in rainwater harvesting systems

    Science.gov (United States)

    Moglia, Magnus; Gan, Kein; Delbridge, Nathan; Sharma, Ashok K.; Tjandraatmadja, Grace

    2016-07-01

    Rainwater harvesting is an important technology in cities that can contribute to a number of functions, such as sustainable water management in the face of demand growth and drought as well as the detention of rainwater to increase flood protection and reduce damage to waterways. The objective of this article is to investigate the integrity of residential rainwater harvesting systems, drawing on the results of the field inspection of 417 rainwater systems across Melbourne that was combined with a survey of householders' situation, maintenance behaviour and attitudes. Specifically, the study moves beyond the assumption that rainwater systems are always operational and functional and draws on the collected data to explore the various reasons and rates of failure associated with pumps and pump switches, leaving for later further exploration of the failure in other components such as the collection area, gutters, tank, and overflows. To the best of the authors' knowledge, there is no data like this in academic literature or in the water sector. Straightforward Bayesian Network models were constructed in order to analyse the factors contributing to various types of failures, including system age, type of use, the reason for installation, installer, and maintenance behaviour. Results show that a number of issues commonly exist, such as failure of pumps (5% of systems), automatic pump switches that mediate between the tank and reticulated water (9% of systems), and systems with inadequate setups (i.e. no pump) limiting their use. In conclusion, there appears to be a lack of enforcement or quality controls in both installation practices by sometimes unskilled contractors and lack of ongoing maintenance checks. Mechanisms for quality control and asset management are required, but difficult to promote or enforce. Further work is needed into how privately owned assets that have public benefits could be better managed.

  4. Rainwater harvesting potential for farming system development in a hilly watershed of Bangladesh

    Science.gov (United States)

    Tariqul Islam, Md.; Mohabbat Ullah, Md.; Mostofa Amin, M. G.; Hossain, Sahadat

    2017-09-01

    Water resources management is an important part in farming system development. Agriculture in Chittagong Hill Tracts of Bangladesh is predominantly rainfed with an average 2210 mm monsoonal rain, but rainfall during dry winter period (December-February) is inadequate for winter crop production. The natural soil water content (as low as 7 %) of hillslope and hilltop during the dry season is not suitable for shallow-rooted crop cultivation. A study was conducted to investigate the potential of monsoonal rainwater harvesting and its impact on local cropping system development. Irrigation facilities provided by the managed rainwater harvesting reservoir increased research site's cropping intensity from 155 to 300 %. Both gravity flow irrigation of valley land and low lift pumping to hillslope and hilltop from rainwater harvesting reservoir were much more economical compared to forced mode pumping of groundwater because of the installation and annual operating cost of groundwater pumping. To abstract 7548 m3 of water, equivalent to the storage capacity of the studied reservoirs, from aquifer required 2174 kWh energy. The improved water supply system enabled triple cropping system for valley land and permanent horticultural intervention at hilltop and hillslope. The perennial vegetation in hilltop and hillslope would also conserve soil moisture. Water productivity and benefit-cost ratio analysis show that vegetables and fruit production were more profitable than rice cultivation under irrigation with harvested rainwater. Moreover, the reservoir showed potentiality of integrated farming in such adverse area by facilitating fish production. The study provides water resource managers and government officials working with similar problems with valuable information for formulation of plan, policy, and strategy.

  5. Rainwater harvesting potential for farming system development in a hilly watershed of Bangladesh

    Science.gov (United States)

    Tariqul Islam, Md.; Mohabbat Ullah, Md.; Mostofa Amin, M. G.; Hossain, Sahadat

    2016-07-01

    Water resources management is an important part in farming system development. Agriculture in Chittagong Hill Tracts of Bangladesh is predominantly rainfed with an average 2210 mm monsoonal rain, but rainfall during dry winter period (December-February) is inadequate for winter crop production. The natural soil water content (as low as 7 %) of hillslope and hilltop during the dry season is not suitable for shallow-rooted crop cultivation. A study was conducted to investigate the potential of monsoonal rainwater harvesting and its impact on local cropping system development. Irrigation facilities provided by the managed rainwater harvesting reservoir increased research site's cropping intensity from 155 to 300 %. Both gravity flow irrigation of valley land and low lift pumping to hillslope and hilltop from rainwater harvesting reservoir were much more economical compared to forced mode pumping of groundwater because of the installation and annual operating cost of groundwater pumping. To abstract 7548 m3 of water, equivalent to the storage capacity of the studied reservoirs, from aquifer required 2174 kWh energy. The improved water supply system enabled triple cropping system for valley land and permanent horticultural intervention at hilltop and hillslope. The perennial vegetation in hilltop and hillslope would also conserve soil moisture. Water productivity and benefit-cost ratio analysis show that vegetables and fruit production were more profitable than rice cultivation under irrigation with harvested rainwater. Moreover, the reservoir showed potentiality of integrated farming in such adverse area by facilitating fish production. The study provides water resource managers and government officials working with similar problems with valuable information for formulation of plan, policy, and strategy.

  6. Monitoring on The Quality and Quantity of DIY Rainwater Harvesting System

    Science.gov (United States)

    Kasmin, H.; Bakar, N. H.; Zubir, M. M.

    2016-07-01

    Rainwater harvesting is an alternative sources of water supply and can be used for potable and non-potable uses. It could helps to store treated rainwater for more beneficial use and also for flood mitigation. Sustainable approach for flooding problem reduction in urban areas is by slowing down the rate of surface runoff flows at source by providing more storage area/tank. In order to understand the performance of a rainwater harvesting system (RWH), a preliminary monitoring on a ‘do it yourself’ (DIY) RWH model with additional first -flush strategy for water quality treatment was done. The main concept behind first flush diversion is to prevent initial polluted rainwater from entering the storage tank. Based on seven rainfall events observed in Parit Raja, both quality and quantity of the rainfalls were analysed. For rainwater quality, the samples from first flush diverter and storage tank were taken to understand their performance based on pH, dissolved oxygen (DO), turbidity, total dissolved solid (TDS), total suspended solid (TSS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) parameters. While for rainwater quantity, hydrograph analysis were done based on the performance of total rainfall and runoff, peak flow of rainfall and runoff; and delayed time parameters. Based on Interim National Water Quality Standard (INWQS) and National Drinking Water Quality Standard (NDWQS), first flush diverter apparently helps on water quality improvement in storage tanks when pH, DO, TDS, TSS and turbidity were classified as Class I (INWQS) and is allowable for drinking; but BOD and COD parameters were classified as Class III (INWQS). Hence, it has potential to be used as potable usage but will need extensive treatment to reduce its poor microbial quality. Based on the maximum observed rainfall event which had total volume of 3195.5 liter, had peakflow reduction from 0.00071 m3/s to 0.00034 m3/s and delayed runoff between 5 and 10 minutes after rainfall

  7. Establishment of sustainable water supply system in small islands through rainwater harvesting (RWH): case study of Guja-do.

    Science.gov (United States)

    Han, Mooyoung; Ki, Jaehong

    2010-01-01

    Many islands in Korea have problems related to water source security and supply. In particular, the water supply condition is worse in small islands which are remote from the mainland. A couple of alternatives are developed and suggested to supply water to islands including water hauling, groundwater extraction, and desalination. However, these alternatives require much energy, cost, and concern in installation and operation. Rainwater harvesting is a sustainable option that supplies water with low energy and cost. However, lack of practical or comprehensive studies on rainwater harvesting systems in these regions hinders the promotion of the system. Therefore, this research examines defects of current RWH systems on an existing island, Guja-do, and provides technical suggestions in quantitative and qualitative aspects. A simple system design modification and expansion of system capacity using empty space such as a wharf structure can satisfy both the qualitative and the quantitative water demand of the island. Since rainwater harvesting is estimated to be a feasible water supply option under the Korean climate, which is an unfavorable condition for rainwater harvesting, implies a high potential applicability of rainwater harvesting technology to other regions over the world suffering from water shortage.

  8. Efficiency of a closed-coupled solar pasteurization system in treating roof harvested rainwater.

    Science.gov (United States)

    Dobrowsky, P H; Carstens, M; De Villiers, J; Cloete, T E; Khan, W

    2015-12-01

    Many studies have concluded that roof harvested rainwater is susceptible to chemical and microbial contamination. The aim of the study was thus to conduct a preliminary investigation into the efficiency of a closed-coupled solar pasteurization system in reducing the microbiological load in harvested rainwater and to determine the change in chemical components after pasteurization. The temperature of the pasteurized tank water samples collected ranged from 55 to 57°C, 64 to 66°C, 72 to 74°C, 78 to 81°C and 90 to 91°C. Cations analyzed were within drinking water guidelines, with the exception of iron [195.59 μg/L (55°C)-170.1 μg/L (91°C)], aluminum [130.98 μg/L (78°C)], lead [12.81 μg/L (55°C)-13.2 μg/L (91°C)] and nickel [46.43 μg/L (55°C)-32.82 μg/L (78°C)], which were detected at levels above the respective guidelines in the pasteurized tank water samples. Indicator bacteria including, heterotrophic bacteria, Escherichia coli and total coliforms were reduced to below the detection limit at pasteurization temperatures of 72°C and above. However, with the use of molecular techniques Yersinia spp., Legionella spp. and Pseudomonas spp. were detected in tank water samples pasteurized at temperatures greater than 72°C. The viability of the bacteria detected in this study at the higher temperature ranges should thus be assessed before pasteurized harvested rainwater is used as a potable water source. In addition, it is recommended that the storage tank of the pasteurization system be constructed from an alternative material, other than stainless steel, in order for a closed-coupled pasteurization system to be implemented and produce large quantities of potable water from roof harvested rainwater.

  9. Construction and Evaluation of Rainwater Harvesting System for Domestic Use in a Remote and Rural Area of Khulna, Bangladesh

    OpenAIRE

    Biswas, Biplob Kumar; Mandal, Bablu Hira

    2014-01-01

    Scarcity of pure drinking water during the dry season (November–March) is a major problem in Bangladesh, which needs to be addressed. This crisis has been further aggravated due to surging populations. Rainwater can provide some of the cleanest naturally occurring water and can hold a great potential in dealing with the current challenge of acute arsenic poisoning as well as physical water scarcity in many parts of Bangladesh. In this connection, rainwater harvesting (RWH) system has been con...

  10. Dimensionless Analysis for Designing Domestic Rainwater Harvesting Systems at the Regional Level in Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Chao-Hsien Liaw

    2014-12-01

    Full Text Available A regional-level and dimensionless analysis for designing a domestic rainwater harvesting system (DRWHS was developed. To consider various combinations of water demand, storage capacity, effective roof area, and rainfall in DRWHS design, two dimensionless ratios were used, namely, demand fraction and storage fraction, along with a relationship between the two ratios. Firstly, Northern Taiwan was divided into four sub-regions through cluster analysis based on the average annual 10-day rainfall distribution at rainfall stations and administrative districts. Easy-to-use dimensionless curves between demand fraction and storage fraction were obtained for five rainwater supply reliabilities of the DRWHS for the four sub-regions. Based on the dimensionless curves, a nomogram was constructed for designing DRWHSs at a rainwater supply reliability of 95% in the sub-region I. Storage capacities determined from the dimensionless curves showed a close fit with those determined from simulated values, but were larger than the values estimated from the method presented in the Green Building Evaluation Manual in most situations. The methodology developed herein can be used effectively for the preliminary design of a DRWHS and for overcoming the difficulties faced in designing a DRWHS without rainfall data and with incomplete rainfall data.

  11. Effects of catchment, first-flush, storage conditions, and time on microbial quality in rainwater harvesting systems.

    Science.gov (United States)

    Amin, M T; Kim, Tschung-il; Amin, M N; Han, M Y

    2013-12-01

    Rainwater collected from a rooftop rainwater harvesting (RWH) system is typically not considered suitable for potable uses, primarily because of poor microbial quality. The quality of stored rainwater, however, can be improved through basic design and maintenance practices during the construction and operation of an RWH system. This paper presents the microbial analysis of rainwater in two RWH systems installed at the Seoul National University Campus in South Korea. Rainwater samples were collected at different locations within each system and analyzed for total and fecal coliforms, Escherichia coli, and heterotrophic plate count bacteria. Within their storage tanks, water quality improved horizontally from inlet to outlet points, and higher quality was observed at the supply point (located about 0.5 m from the base of the tank) than at the surface or bottom of the tank. First-flush rainwater was found to be highly contaminated but rainwater quality improved following about 1 mm of precipitation. The catchment surface also had a significant effect on the quality of rainwater; samples collected from a rooftop exhibited better microbial quality than from a terrace catchment. Better water quality in underground tanks (dark storage conditions) compared to open weirs/ filters (exposed to natural light) demonstrated the importance of storage conditions. Water quality also improved with longer storage, and a decrease of 70% to 90% in microbial concentrations was observed after about 1 week of storage time. The findings of this study demonstrate that the microbial quality of harvested rainwater can be improved significantly by the adoption of proper design and maintenance guidelines such as those discussed in this paper.

  12. Uncertainty analysis of daily potable water demand on the performance evaluation of rainwater harvesting systems in residential buildings.

    Science.gov (United States)

    Silva, Arthur Santos; Ghisi, Enedir

    2016-09-15

    The objective of this paper is to perform a sensitivity analysis of design variables and an uncertainty analysis of daily potable water demand to evaluate the performance of rainwater harvesting systems in residential buildings. Eight cities in Brazil with different rainfall patterns were analysed. A numeric experiment was performed by means of computer simulation of rainwater harvesting. A sensitivity analysis was performed using variance-based indices for identifying the most important design parameters for rainwater harvesting systems when assessing the potential for potable water savings and underground tank capacity sizing. The uncertainty analysis was performed for different scenarios of potable water demand with stochastic variations in a normal distribution with different coefficients of variation throughout the simulated period. The results have shown that different design variables, such as potable water demand, number of occupants, rainwater demand, and roof area are important for obtaining the ideal underground tank capacity and estimating the potential for potable water savings. The stochastic variations on the potable water demand caused amplitudes of up to 4.8% on the potential for potable water savings and 9.4% on the ideal underground tank capacity. Average amplitudes were quite low for all cities. However, some combinations of parameters resulted in large amplitude of uncertainty and difference from uniform distribution for tank capacities and potential for potable water savings. Stochastic potable water demand generated low uncertainties in the performance evaluation of rainwater harvesting systems; therefore, uniform distribution could be used in computer simulation.

  13. Design and operational parameters of a rooftop rainwater harvesting system: definition, sensitivity and verification.

    Science.gov (United States)

    Mun, J S; Han, M Y

    2012-01-01

    The appropriate design and evaluation of a rainwater harvesting (RWH) system is necessary to improve system performance and the stability of the water supply. The main design parameters (DPs) of an RWH system are rainfall, catchment area, collection efficiency, tank volume and water demand. Its operational parameters (OPs) include rainwater use efficiency (RUE), water saving efficiency (WSE) and cycle number (CN). The sensitivity analysis of a rooftop RWH system's DPs to its OPs reveals that the ratio of tank volume to catchment area (V/A) for an RWH system in Seoul, South Korea is recommended between 0.03 and 0.08 in terms of rate of change in RUE. The appropriate design value of V/A is varied with D/A. The extra tank volume up to V/A of 0.15∼0.2 is also available, if necessary to secure more water. Accordingly, we should figure out suitable value or range of DPs based on the sensitivity analysis to optimize design of an RWH system or improve operation efficiency. The operational data employed in this study, which was carried out to validate the design and evaluation method of an RWH system, were obtained from the system in use at a dormitory complex at Seoul National University (SNU) in Korea. The results of these operational data are in good agreement with those used in the initial simulation. The proposed method and the results of this research will be useful in evaluating and comparing the performance of RWH systems. It is found that RUE can be increased by expanding the variety of rainwater uses, particularly in the high rainfall season.

  14. Acceptability of the rainwater harvesting system to the slum dwellers of Dhaka City.

    Science.gov (United States)

    Islam, M M; Chou, F N-F; Kabir, M R

    2010-01-01

    Urban area like Dhaka City, in Bangladesh, has scarcity of safe drinking water which is one of the prominent basic needs for human kind. This study explored the acceptability of harvested rainwater in a densely populated city like Dhaka, using a simple and low cost technology. A total of 200 random people from four slums of water-scarce Dhaka City were surveyed to determine the dwellers' perception on rainwater and its acceptability as a source of drinking water. The questionnaire was aimed at finding the socio-economic condition and the information on family housing, sanitation, health, existing water supply condition, knowledge about rainwater, willingness to accept rainwater as a drinking source etc. A Yield before Spillage (YBS) model was developed to know the actual rainwater availability and storage conditions which were used to justify the effective tank size. Cost-benefit analysis and feasibility analysis were performed using the survey results and the research findings. The survey result and overall study found that the low cost rainwater harvesting technique was acceptable to the slum dwellers as only the potential alternative source of safe drinking water.

  15. The application of an analytical probabilistic model for estimating the rainfall-runoff reductions achieved using a rainwater harvesting system.

    Science.gov (United States)

    Kim, Hyoungjun; Han, Mooyoung; Lee, Ju Young

    2012-05-01

    Rainwater harvesting systems cannot only supplement on-site water needs, but also reduce water runoff and lessen downstream flooding. In this study, an existing analytic model for estimating the runoff in urban areas is modified to provide a more economical and effective model that can be used for describing rainwater harvesting. This model calculates the rainfall-runoff reduction by taking into account the catchment, storage tank, and infiltration facility of a water harvesting system; this calculation is based on the water balance equation, and the cumulative distribution, probability density, and average rainfall-runoff functions. This model was applied to a water harvesting system at the Seoul National University in order to verify its practicality. The derived model was useful for evaluating runoff reduction and for designing the storage tank capacity.

  16. Evaluation benefits of rainwater harvesting using infiltration pits in rainfed cropping systems: Preliminary results from Rushinga district, Zimbabwe

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.; Chimweta, M.; Nyagumbo, I.

    2012-01-01

    ABSTRACT Occurrence of dry spells during the rainfall season is the major cause of crop failure in semi-arid areas. Rainwater harvesting (RWH) is regarded as a viable option for mitigating these dry spells. However, benefits of most RWH systems have not been adequately quantified. The objective of t

  17. Evaluating rainwater harvesting systems in arid and semi-arid regions

    NARCIS (Netherlands)

    Ammar, Adham Ali

    2017-01-01

    Rainwater harvesting (RWH) is an ancient traditional technology practised in many parts of the world, especially in arid and semi-arid regions (ASARs). ASARs represent 40% of the earth’s land surface and are characterised by low average annual rainfall and uneven temporal and spatial distribut

  18. Harvested rainwater quality before and after treatment in six full-scale residential systems

    Science.gov (United States)

    Rainwater harvesting (RWH) is an alternative method of providing water for indoor domestic use, but the water quality after treatment and distribution at individual residences is not well documented. In this study, water quality parameters were measured at the cistern and indoor ...

  19. Evaluating rainwater harvesting systems in arid and semi-arid regions

    NARCIS (Netherlands)

    Ammar, Adham Ali

    2017-01-01

    Rainwater harvesting (RWH) is an ancient traditional technology practised in many parts of the world, especially in arid and semi-arid regions (ASARs). ASARs represent 40% of the earth’s land surface and are characterised by low average annual rainfall and uneven temporal and spatial

  20. A GIS-based decision support system for rainwater harvesting (RHADESS)

    Science.gov (United States)

    Mwenge Kahinda, J.; Taigbenu, A. E.; Sejamoholo, B. B. P.; Lillie, E. S. B.; Boroto, R. J.

    Rainwater harvesting (RWH) is an unconventional water source that is increasingly adopted in South Africa. Its implementation is promoted by non-governmental organisations and government programmes to alleviate temporal and spatial water scarcity for domestic, crop and livestock production and support the overall water resources management. Unreliable water supply is one of the elements central to the poverty level of rural population. As the potential of RWH to improve water access for drinking and other basic human needs is still untapped, the technique will spread further in the coming decades. Studies on the hydrological impacts of RWH are focused on plot scale and very little is known about its impacts at catchment scale. To integrate RWH into the development and management of water resources in South Africa, there is a need to develop tools and methodologies that not only assist planners with the identification of areas suitable but also quantify the associated hydrological impacts of its wide scale adoption. This paper presents the rainwater harvesting decision support system (RHADESS) that was built to assist decision makers and stakeholders by indicating the suitability of RWH in any selected part of South Africa and quantifying the potential impacts associated with its adoption at catchment scale. RHADESS is GIS-based and uses ArcView 3.3 as a platform to assess the RWH suitability of any given area of South Africa. Results are thereafter exported into an Excel spreadsheet that contains the hydrological impact, as runoff reduction, of different levels of adoption of RWH assessed by using the Pitman model. The decision support system guides the implementation of the following RWH categories: Infield RWH and ex-field RWH and domestic RWH. RHADESS was tested in two selected quaternary catchments C52A and V13D located in the Upper Orange water management area and the Thukela water management area, respectively.

  1. Contributions to the design of rainwater harvesting systems in buildings with green roofs in a Mediterranean climate.

    Science.gov (United States)

    Monteiro, Cristina M; Calheiros, Cristina S C; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M L

    2016-01-01

    Green roofs (GRs) are becoming a trend in urban areas, favouring thermal performance of buildings, promoting removal of atmospheric pollutants, and acting as possible water collection spots. Rainwater harvesting systems in buildings can also contribute to the management of stormwater runoff reducing flood peaks. These technologies should be enhanced in Mediterranean countries where water scarcity is increasing and the occurrence of extreme events is becoming very significant, as a result of climate change. An extensive pilot GR with three aromatic plant species, Satureja montana, Thymus caespititius and Thymus pseudolanuginosus, designed to study several parameters affecting rainwater runoff, has been in operation for 12 months. Physico-chemical analyses of roof water runoff (turbidity, pH, conductivity, NH4(+), NO3(-), PO4(3-), chemical oxygen demand) have shown that water was of sufficient quality for non-potable uses in buildings, such as toilet flushing. An innovative approach allowed for the development of an expression to predict a 'monthly runoff coefficient' of the GR system. This parameter is essential when planning and designing GRs combined with rainwater harvesting systems in a Mediterranean climate. This study is a contribution to improving the basis for the design of rainwater harvesting systems in buildings with extensive GRs under a Mediterranean climate.

  2. Rainwater harvesting state regulations and technical resources

    Energy Technology Data Exchange (ETDEWEB)

    Loper, Susan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-01

    Pacific Northwest National Laboratory (PNNL) conducted in-depth research of state-level rainwater harvesting regulations for the Federal Energy Management Program (FEMP) to help federal agencies strategically identify locations conducive to rainwater harvesting projects. Currently, rainwater harvesting is not regulated by the federal government but rather it is up to individual states to regulate the collection and use of rainwater. There is no centralized information on state-level regulations on rainwater harvesting maintained by a federal agency or outside organization. To fill this information gap, PNNL performed detailed internet searches for each state, which included state agencies, universities, Cooperative Extension Offices, city governments, and related organizations. The state-by-state information on rainwater harvesting regulations was compiled and assembled into an interactive map that is color coded by state regulations. The map provides a visual representation of the general types of rainwater harvesting policies across the country as well as general information on the state programs if applicable. The map allows the user to quickly discern where rainwater harvesting is supported and regulated by the state. This map will be available on the FEMP website by September 2015.

  3. Performance of rainwater harvesting system based on roof catchment area and storage tank capacity

    Directory of Open Access Journals (Sweden)

    Juliana Imroatul C.

    2017-01-01

    Full Text Available Increasing population growth has created problems in water resources. Natural water resources become progressively more expensive and difficult to develop. In addition, it is also becoming increasingly polluted and difficult to obtain. Many countries shown a resurgent interest in the use of rainwater harvesting (RWH technique to overcome these problems. There are several factors that will influence the RWH performance, such as the rainfall, catchment area, storage tank capacity, and water demand. The performance parameter determines by the volumetric reliability, time reliability, and yield. The RWH system used in this study is a simple RWH system that utilizes roof as a catchment area, pipes as a distribution system and tank as a storage. An analysis is carried out to investigate the effect of altering the large of the catchment area and storage tank capacity to the RWH system performance parameters. A suitable behavioral model based on the water balance method is implemented to evaluate the inflow, outflow, and the storage volume. Results demonstrate that with up to 15 years daily rainfall data in 15 cities in Indonesia, the most influential parameters on the performance of RWH system is the time reliability.

  4. A new model for simulating supplemental irrigation and the hydro-economic potential of a rainwater harvesting system in humid subtropical climates

    NARCIS (Netherlands)

    Pandey, P.K.; Van der Zaag, P.; Soupir, M.L.; Singh, V.P.

    2013-01-01

    Here we have developed a new model to simulate supplemental irrigation and the hydro-economic potential of a rainwater harvesting system in rainfed agricultural areas. Using the model, soil moisture in rainfed crop land, supplemental irrigation requirements, rainwater storage in an on-farm reservoir

  5. Construction and Evaluation of Rainwater Harvesting System for Domestic Use in a Remote and Rural Area of Khulna, Bangladesh.

    Science.gov (United States)

    Biswas, Biplob Kumar; Mandal, Bablu Hira

    2014-01-01

    Scarcity of pure drinking water during the dry season (November-March) is a major problem in Bangladesh, which needs to be addressed. This crisis has been further aggravated due to surging populations. Rainwater can provide some of the cleanest naturally occurring water and can hold a great potential in dealing with the current challenge of acute arsenic poisoning as well as physical water scarcity in many parts of Bangladesh. In this connection, rainwater harvesting (RWH) system has been constructed in a very remote and rural village in Khulna, Bangladesh, for a 4-membered household. It consists of a concrete catchment of 40 m(2) area, a supporting and collection system made of PVC pipes, and two locally available plastic storage tanks having capacity of 2000 L each. The study also investigates the quality aspects of the stored rainwater, which include measurement of pH, alkalinity, hardness, total dissolved solids (TDS), iron, chloride, nitrate, and turbidity, using standard methods. The results showed that not only the quality of harvested rainwater is good but also the amount of water is enough for a 4-membered household to meet its domestic use throughout the year.

  6. Seeking urbanization security and sustainability: Multi-objective optimization of rainwater harvesting systems in China

    Science.gov (United States)

    Li, Yi; Ye, Quanliang; Liu, An; Meng, Fangang; Zhang, Wenlong; Xiong, Wei; Wang, Peifang; Wang, Chao

    2017-07-01

    Urban rainwater management need to achieve an optimal compromise among water resource augmentation, water loggings alleviation, economic investment and pollutants reduction. Rainwater harvesting (RWH) systems, such as green rooftops, porous pavements, and green lands, have been successfully implemented as viable approaches to alleviate water-logging disasters and water scarcity problems caused by rapid urbanization. However, there is limited guidance to determine the construction areas of RWH systems, especially for stormwater runoff control due to increasing extreme precipitation. This study firstly developed a multi-objective model to optimize the construction areas of green rooftops, porous pavements and green lands, considering the trade-offs among 24 h-interval RWH volume, stormwater runoff volume control ratio (R), economic cost, and rainfall runoff pollutant reduction. Pareto fronts of RWH system areas for 31 provinces of China were obtained through nondominated sorting genetic algorithm. On the national level, the control strategies for the construction rate (the ratio between the area of single RWH system and the total areas of RWH systems) of green rooftops (ηGR), porous pavements (ηPP) and green lands (ηGL) were 12%, 26% and 62%, and the corresponding RWH volume and total suspended solids reduction was 14.84 billion m3 and 228.19 kilotons, respectively. Optimal ηGR , ηPP and ηGL in different regions varied from 1 to 33%, 6 to 54%, and 30 to 89%, respectively. Particularly, green lands were the most important RWH system in 25 provinces with ηGL more than 50%, ηGR mainly less than 15%, and ηPP mainly between 10 and 30%. Results also indicated whether considering the objective MaxR made a non-significant difference for RWH system areas whereas exerted a great influence on the result of stormwater runoff control. Maximum daily rainfall under control increased, exceeding 200% after the construction of the optimal RWH system compared with that before

  7. Rainwater harvesting: model-based design evaluation.

    Science.gov (United States)

    Ward, S; Memon, F A; Butler, D

    2010-01-01

    The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The designs of two different new-build rainwater harvesting systems, based on simple methods, are evaluated using three different design methods, including a continuous simulation modelling approach. The RWH systems are shown to fulfill 36% and 46% of WC demand. Financial analyses reveal that RWH systems within large commercial buildings maybe more financially viable than smaller domestic systems. It is identified that design methods based on simple approaches generate tank sizes substantially larger than the continuous simulation. Comparison of the actual tank sizes and those calculated using continuous simulation established that the tanks installed are oversized for their associated demand level and catchment size. Oversizing tanks can lead to excessive system capital costs, which currently hinders the uptake of systems. Furthermore, it is demonstrated that the catchment area size is often overlooked when designing UK-based RWH systems. With respect to these findings, a recommendation for a transition from the use of simple tools to continuous simulation models is made.

  8. Optimal Spatial Design of Capacity and Quantity of Rainwater Harvesting Systems for Urban Flood Mitigation

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-09-01

    Full Text Available This study adopts rainwater harvesting systems (RWHS into a stormwater runoff management model (SWMM for the spatial design of capacities and quantities of rain barrel for urban flood mitigation. A simulation-optimization model is proposed for effectively identifying the optimal design. First of all, we particularly classified the characteristic zonal subregions for spatial design by using fuzzy C-means clustering with the investigated data of urban roof, land use and drainage system. In the simulation method, a series of regular spatial arrangements specification are designed by using statistical quartiles analysis for rooftop area and rainfall frequency analysis; accordingly, the corresponding reduced flooding circumstances can be simulated by SWMM. Moreover, the most effective solution for the simulation method is identified from the calculated net benefit, which is equivalent to the subtraction of the facility cost from the decreased inundation loss. It serves as the initially identified solution for the optimization model. In the optimization method, backpropagation neural network (BPNN are first applied for developing a water level simulation model of urban drainage systems to substitute for SWMM to conform to newly considered interdisciplinary multi-objective optimization model, and a tabu search-based algorithm is used with the embedded BPNN-based SWMM to optimize the planning solution. The developed method is applied to the Zhong-He District, Taiwan. Results demonstrate that the application of tabu search and the BPNN-based simulation model into the optimization model can effectively, accurately and fast search optimal design considering economic net benefit. Furthermore, the optimized spatial rain barrel design could reduce 72% of inundation losses according to the simulated flood events.

  9. Harvested rainwater quality: the importance of appropriate design.

    Science.gov (United States)

    Ward, S; Memon, F A; Butler, D

    2010-01-01

    This paper summarises the physicochemical and microbiological quality of water from a rainwater harvesting (RWH) system in a UK-based office building. 7 microbiological and 34 physicochemical parameters were analysed during an 8 month period. Physicochemically, harvested rainwater quality posed little health risk; most parameters showed concentrations below widely used guideline levels for drinking water. However, RWH system components (e.g. fittings and down pipes) appear to be affected soft water corrosion, resulting in high concentrations of some metals (copper, zinc and aluminium). This suggests the material selection of such fittings should be considered keeping in view the hardness of rainwater of an area. Microbiologically, Cryptosporidium, Salmonella and Legionella were not present in the samples analysed. However, faecal coliform counts were high at the beginning of the study, but did decrease over time in weak correlation with increasing pH. Enterococcus faecalis displayed counts consistently above UK rainwater harvesting standards. Inappropriate roof and rainwater good design, as well as material selection appear to be responsible for the reduced microbial quality, as they promoted contributions from avian sources and inhibited cleaning activities. Building and RWH system designs require greater consideration of local factors, which are critical for optimising harvested rainwater quality, to prevent both the development of contaminated sediments and health impacts.

  10. Identification of Decisive Factors Determining the Continued Use of Rainwater Harvesting Systems for Agriculture Irrigation in Beijing

    Directory of Open Access Journals (Sweden)

    Xiao Liang

    2015-12-01

    Full Text Available The success or failure of operating a rainwater harvesting system (RWH depends on both technological and non-technological factors. The importance of non-technological factors in attaining sustainable RWH operation is rarely emphasized. This study aims to assess the contribution of non-technological factors through determining decisive factors involved in the use of RWHs for agriculture irrigation in Beijing. The RWHs for agriculture irrigation in Beijing are not operating as well as expected. If the decisive factors are identified to be non-technological, the significance of non-technological factors will be highlighted. Firstly, 10 impact factors comprising non-technological and technological factors are selected according to both a literature review and interviews with RWH managers. Following this, through an artificial data mining method, rough set analysis, the decisive factors are identified. Results show that two non-technological factors, “doubts about rainwater quality” and “the availability of groundwater” determine whether these systems will continue or cease RWH operation in Beijing. It is, thus, considered necessary to improve public confidence in and motivation on using rainwater for agriculture irrigation, as this is the main obstacle in the sustainable and successful operation of RWHs. Through a case study of RWHs in Beijing, the study verifies the importance of acknowledging non-technological factors to achieve sustainable water management and considers that such factors should receive more attention by decision makers and researchers.

  11. Roof-Top rainwater harvesting system for official / multistoried building with reference to malda district, WB

    Directory of Open Access Journals (Sweden)

    Dr. Suman

    2017-01-01

    Full Text Available Rain water harvesting is received increased attention world wide as an alternative source of water. Roof-top rain water harvesting system is looked upon as one of the most feasible and economical ways of water conservation. With increasing problem of water scarcity, planning and designing roof top rain water harvesting is gaining wider importance to meet ever-increasing water demand, encouraging use of water or more sustainable basis. The rain water harvesting is the simple collection or storing of water for the domestic or the agriculture purpose. The method of rain water harvesting has been into practice since ancient times. The method is simple and cost effective too. Malda district of West Bengal is badly affected by Arsenic contamination in ground water. The present study finds its usefulness in developing awareness towards judicious use of water among masses and efficient ways to harvest roof top rain water resources at institutional / multistoried buildings in Malda district.

  12. RELIABILITY ANALYSIS OF URBAN RAINWATER HARVESTING FOR THREE TEXAS CITIES

    Directory of Open Access Journals (Sweden)

    Dustin Lawrence

    2016-01-01

    Full Text Available The purpose of this study was to inform decision makers at state and local levels, as well as property owners about the amount of water that can be supplied by rainwater harvesting systems in Texas so that it may be included in any future planning. Reliability of a rainwater tank is important because people want to know that a source of water can be depended on. Performance analyses were conducted on rainwater harvesting tanks for three Texas cities under different rainfall conditions and multiple scenarios to demonstrate the importance of optimizing rainwater tank design. Reliability curves were produced and reflect the percentage of days in a year that water can be supplied by a tank. Operational thresholds were reached in all scenarios and mark the point at which reliability increases by only 2% or less with an increase in tank size. A payback period analysis was conducted on tank sizes to estimate the amount of time it would take to recoup the cost of installing a rainwater harvesting system.

  13. Reliability and Cost Analysis of a Rainwater Harvesting System in Peri-Urban Regions of Greater Sydney, Australia

    Directory of Open Access Journals (Sweden)

    Evan Hajani

    2014-04-01

    Full Text Available In large cities, rainwater tanks are used to save mains water, but in peri-urban and rural areas, rainwater tanks are used as a sole water supply for many households, as these regions often do not have any other means of water supply. This paper investigates the performance of a rainwater harvesting system (RWHS in peri-urban regions of Greater Sydney, Australia. Considering the daily rainfall data over the entire period of record at ten different locations, it has been found that a 5 kL tank can meet 96% to 99% of the demand for toilet and laundry use depending on the location in Greater Sydney regions. However, in the driest year, a 5 kL tank can meet 69% to 99% of toilet and laundry demand depending on the location. Based on the results of life cycle cost analysis, it has been found that a 5 kL tank has the highest benefit–cost ratio (ranging from 0.86 to 0.97 among the eight possible tank sizes examined in this study. Interestingly, for a 5 kL tank, with a combined use (i.e., toilet, laundry and irrigation, the current water price in Sydney needs to be increased by 3% to 16% to achieve a benefit–cost ratio exceeding one. A set of regression equations are developed which can be used to estimate reliability using the average annual rainfall data at any arbitrary location in the peri-urban regions of Greater Sydney. The method presented in this paper can also be applied to other Australian states and other countries to estimate water savings and reliability of a RWHS using daily rainfall data.

  14. Recharging of borewells and analysis of harvested rooftop rainwater in houses of Udaipur city.

    Science.gov (United States)

    Yadav, Sangeeta; Singhvi, Ritu; Sharma, B K

    2007-07-01

    Water is an inorganic component, which covers about 3/4th of the earth's surface, but only 3 percent of it is available to man for use. The remaining 97 percent of water found in oceans is full of soluble salts, being unfit for human use and consumption. Rainwater is free source of nearly pure water. The concept of rainwater harvesting lies in tapping the rainwater it falls. The present study was conducted in houses of Udaipur city. In order to find out the water management practices adopted by the families, a sample of 100 households was selected. Out of the total samples, 30 houses were selected purposively for commissioning the rainwater harvesting system and the rooftop rainwater harvesting potential was also calculated among these 30 households. Field experiment was conducted for quantitative analysis of harvested rooftop rainwater in houses which reveals that rooftop rainwater harvesting system is very effective measure in increasing the quantity of water in borewells as compared to those borewells without having the rainwater harvesting system attached to them. The availability of water per day was found to be higher i.e. 269 litres in those houses where the rainwater harvesting potential was also higher i.e. 98.32 m3, as the catchment area of these houses was found to be more (186 sq m.) as compared to other houses.

  15. Problems and countermeasures on the safety of rainwater harvesting for drinking in China

    Directory of Open Access Journals (Sweden)

    Liu Laisheng

    2016-01-01

    Full Text Available China is increasingly confronted with serious water shortages, so rainwater harvesting and utilization have gradually received attention with advantages such as accessibility, simple operation and low cost. The harvested rainwater can be used for drinking, irrigation, municipal greening, etc., and when applied for drinking, the demand for water quality is highest. Most existing researches have put their focus on improving the accumulation of rainwater, but there is a lack of in-depth studies on how to enhance the quality of rainwater. Based on the above considerations, this paper, by summing up the situation of rainwater harvesting and utilization in China, has systematically analyzed the system components of rainwater harvesting for drinking, i.e., the consisting units of rainwater harvesting, delivering, processing and accumulating. It also explains the sources of rainwater pollution and how to deal with it. Considering that the water harvesting system can make a contribution to the society and public welfare, this paper proposes a framework of participatory management for projects of rainwater harvesting for drinking.

  16. Rainwater Harvesting Potential for Domestic Water Supply in Edo State

    OpenAIRE

    S. I. Oni; Emmanuel Ege

    2008-01-01

    In the face of increasing scarcity of water resources, there is a need for communities to undertake audits of their current rainwater harvesting potential as a practical and promising alternative solution for water shortage. Despite the importance of rainwater harvest in socio-economic development of communities, very little information exists in the literature concerning it. This paper is an attempt to bridge this gap by examining the techniques and materials used for rainwater harvest with ...

  17. Rainwater harvesting in arid and semi-arid zones (repr. 1997)

    NARCIS (Netherlands)

    Boers, Th.M.

    1994-01-01

    In arid and semi-arid regions, the scarcity of water can be alleviated by rainwater harvesting, which is defined as a method of inducing, collecting, storing, and conserving local surface runoff for agriculture. Rainwater harvesting can be applied with different systems, and this dissertation deals

  18. Sensitivity of Pumping Energy on the Life Cycle Impacts of a Commercial Rainwater Harvesting System

    Science.gov (United States)

    assessed using a functional unit of 1 m3 of rainwater and municipal water delivery for flushing toilets and urinals in a four story-commercial building in DC. We collect primary data on CRWH including designs and amount of materials from the ARCSA partners and compile the life cy...

  19. A Movable Combined Water Treatment Facility for Rainwater Harvesting

    Science.gov (United States)

    Zhang, L.; Liao, L.

    2003-12-01

    Alarming water shortage and increased water scarcity world wide has led to increased interests in alternative water sources. Rainwater harvesting is one of them which is getting more and more attention. There is a huge potential for generalization and extension of rainwater harvesting system as an alternative water supply. This is especially important for arid and semi-arid regions where the water shortage blocks further social, economical development. Earlier laboratory experiments and field study showed that harvested rainwater requires treatments of different degrees in order to meet the WHO drinking water standards. The main focus of this study is to ascertain the quality of stored rainwater for drinking purposes with emphasis on water disinfection and pollutants removal. A movable, low-cost, fully functional small scale treatment facility is proposed and tested under simulated field condition. A number of actual and potential hazardous pollutants were identified in the collected water samples together with laboratory test. The corresponding water purification procedure and fresh-keeping methods are discussed. The final proposal of this movable facility needs to be further examined to achieve optimal combined treatment efficiency.

  20. Design, Development, and Performance Evaluation of Solar Heating System for Disinfection of Domestic Roof-Harvested Rainwater.

    Science.gov (United States)

    Akintola, O A; Sangodoyin, A Y

    2015-01-01

    A box-type solar heater was designed, constructed, and used to determine the effect of solar heating on quality of domestic roof-harvested rainwater (DRHRW). During testing, naturally contaminated DRHRW was harvested in Ibadan, Nigeria, and released into the system at 93.96 Lh(-1) (2.61 × 10(-5) m(3) s(-1)) in a continuous flow process. Water temperatures at inlet, within the heating chamber, and at outlet from the heating chamber and solar radiation were monitored at 10 min interval. Samples were collected at both inlet to and outlet from the heating chamber at 10 min interval for microbiological analysis. The highest plate stagnation temperature, under no-load condition, was 100°C. The solar water heater attained a maximum operational temperature of 75°C with 89.6 and 94.4% reduction in total viable count and total coliform count, respectively, while Escherichia coli and Staphylococcus aureus were completely eradicated at this temperature. The solar heater developed proved to be effective in enhancing potability of DRHRW in Ibadan, Nigeria. This may be an appropriate household water treatment technology for developing countries, hence, a way of resolving problem of low quality water for potable uses.

  1. Evaluation of dual-mode rainwater harvesting system to mitigate typhoon-induced water shortage in Taiwan.

    Science.gov (United States)

    Islam, M M; Chou, F N-F; Liaw, C-H

    2010-01-01

    The water shortage of today's world is one of the most challenging problems and the world is looking for the best solution to reduce it. Some human made causes and also natural causes are liable for the shortage of the existing water supply system. In Taiwan, especially during typhoon, the turbidity of raw water increases beyond the treatment level and the plant cannot supply required amount of water. To make the system effective, a couple of days are needed and the shortage occurs. The purpose of this study is to solve this emergency shortage problem. A dual-mode Rainwater Harvesting System (RWHS) was designed for this study as a supplement to the existing water supply system to support some selected non-potable components such as toilet and urinal flushing of an elementary school. An optimal design algorithm was developed using YAS (yield after spillage) and YBS (yield before spillage) release rules. The study result proved that an optimum volume of tank can solve the emergency water shortage properly. The system was found to be more reliable in Taipei area than that of Tainan area. The study also discovered that a government subsidy would be needed to promote the system in Taiwan.

  2. The Water-Wise Vegetable Garden: An Analysis of the Potential for Irrigation through Rainwater Harvesting in Sunny Northern California

    OpenAIRE

    Smith, Adrienne; Esterer-Vogel, Elisabeth

    2009-01-01

    In drought-prone northern California, homeowners can collect rainwater to irrigate their waterintensive summer vegetable gardens. Rainwater harvesting requires a three-part system: a method of collection (commonly the roof), a form of storage (cistern) and a method of distribution (a pump, filter and soaker hose are proposed here). To optimize and properly size a rainwater harvesting system, homeowners should consider both their rainwater supply and their garden’s water demand. Gardeners can ...

  3. The impact of domestic rainwater harvesting systems in storm water runoff mitigation at the urban block scale.

    Science.gov (United States)

    Palla, A; Gnecco, I; La Barbera, P

    2017-04-15

    In the framework of storm water management, Domestic Rainwater Harvesting (DRWH) systems are recently recognized as source control solutions according to LID principles. In order to assess the impact of these systems in storm water runoff control, a simple methodological approach is proposed. The hydrologic-hydraulic modelling is undertaken using EPA SWMM; the DRWH is implemented in the model by using a storage unit linked to the building water supply system and to the drainage network. The proposed methodology has been implemented for a residential urban block located in Genoa (Italy). Continuous simulations are performed by using the high-resolution rainfall data series for the ''do nothing'' and DRWH scenarios. The latter includes the installation of a DRWH system for each building of the urban block. Referring to the test site, the peak and volume reduction rate evaluated for the 2125 rainfall events are respectively equal to 33 and 26 percent, on average (with maximum values of 65 percent for peak and 51 percent for volume). In general, the adopted methodology indicates that the hydrologic performance of the storm water drainage network equipped with DRWH systems is noticeable even for the design storm event (T = 10 years) and the rainfall depth seems to affect the hydrologic performance at least when the total depth exceeds 20 mm.

  4. Impacts of domestic and and agricultural rainwater harvesting system on watershed hydrology: A case study of Albemarle-Pamlico Watershed basins (NC, VA, USA)

    Science.gov (United States)

    Rainwater harvesting (RWH) is increasingly relevant in the context of growing population and its demands on water quantity. Here, we present a method to better understand the hydrologic impacts of urban domestic and agricultural rainwater harvesting and apply the approach to thre...

  5. Regional scale analysis for the design of storage tanks for domestic rainwater harvesting systems.

    Science.gov (United States)

    Campisano, A; Modica, C

    2012-01-01

    A regional scale analysis for the design of storage tanks for domestic rain water harvesting systems is presented. The analysis is based on the daily water balance simulation of the storage tank by the yield-after-spillage algorithm as tank release rule. Water balances are applied to 17 rainfall gauging stations in Sicily (Italy). Compared with literature existing methods, a novel dimensionless parameter is proposed to better describe the intra-annual character of the rainfall patterns. As a result, easy-to-use regional regressive models to evaluate the water saving performance and the overflow discharges from the tank are provided along with a stepwise procedure for practical application. The regional models demonstrate good fits between model predictions and simulated values of both water savings and overflows from the tank.

  6. Multi-purpose rainwater harvesting for water resource recovery and the cooling effect.

    Science.gov (United States)

    An, Kyoung Jin; Lam, Yun Fat; Hao, Song; Morakinyo, Tobi Eniolu; Furumai, Hiroaki

    2015-12-01

    The potential use of rainwater harvesting in conjunction with miscellaneous water supplies and a rooftop garden with rainwater harvesting facility for temperature reduction have been evaluated in this study for Hong Kong. Various water applications such as toilet flushing and areal climate controls have been systematically considered depending on the availability of seawater toilet flushing using the Geographic Information System (GIS). For water supplies, the district Area Precipitation per Demand Ratio (APDR) has been calculated to quantify the rainwater utilization potential of each administrative district in Hong Kong. Districts with freshwater toilet flushing prove to have higher potential for rainwater harvest and utilization compared to the areas with seawater toilet flushing. Furthermore, the effectiveness of using rainwater harvesting for miscellaneous water supplies in Hong Kong and Tokyo has been analyzed and compared; this revives serious consideration of diurnal and seasonal patterns of rainfall in applying such technology. In terms of the cooling effect, the implementation of a rooftop rainwater harvesting garden has been evaluated using the ENVI-met model. Our results show that a temperature drop of 1.3 °C has been observed due to the rainwater layer in the rain garden. This study provides valuable insight into the applicability of the rainwater harvesting for sustainable water management practice in a highly urbanized city.

  7. A Combination of Rainwater Harvesting System and Landscape Design%雨水收集系统与景观设计相结合的研究

    Institute of Scientific and Technical Information of China (English)

    张鎏; 陈飞虎

    2012-01-01

    随着人口增长与经济发展,水资源短缺问题日益严重,雨水的利用价值受到越来越多的关注,尤其在城市,收集雨水对解决城市用水具有十分积极的意义;同时,由于城市空间拮据,把雨水收集系统与景观设计结合起来,合理利用空间美化环境值得探讨.本文综合现有资料,对雨水收集系统和景观设计的关系进行了初步探讨,挖掘出两者结合的可能性.%With the growth of the population and the development of economy, we are now entering an era of water shortage. People begin to recognize the value of harvested rainwater in solving the water problem, especially in cities. But the rainwater harvesting system is often considered as a separated part in the urban design, and only its functionality is addressed, which brings about the problem that it will take up the precious urban field. This paper proposes to combine the rainwater harvesting system with the landscape design, and discusses the relationship between the rainwater harvesting system and the landscape design, to find out a proper way of their combination in both functionality and aesthetic. It is hoped that this proposal may provide some food of thought in the future design.

  8. Operational data of the Star City rainwater harvesting system and its role as a climate change adaptation and a social influence.

    Science.gov (United States)

    Han, M Y; Mun, J S

    2011-01-01

    The Star City rainwater harvesting system (RWHS) was featured in the December, 2008, issue of Water 21. The article highlighted that the RWHS has a 3,000 m3 rainwater tank used in water saving, flood mitigation, and emergency response. Since then, many news media, public officials, and people from both South Korea and abroad have visited the RWHS. In this paper, two years of the system's operational data are presented and its role in short- and long-term climate change adaptation is investigated. The downstream sewer system has become safe for a 50-year rainfall without upgrading the existing sewer system, which was designed for a 10-year period. The 26,000 m3 of water saved has reduced the energy requirement of transferring water from a distant area. The success of the Star City RWHS has influenced 47 cities across South Korea, including Seoul, to enact regulations on rainwater management. It has shown that decentralized rainwater management can supplement the existing centralized system to ensure its safety.

  9. Rainwater harvesting at Koysinjaq (Koya), Kurdistan region, Iraq

    OpenAIRE

    Zakaria, Saleh; Al-Ansari, Nadhir; Mustafa, Yaseen; Knutsson, Sven; Ahmed, Payman; Ghafour, Bahra

    2013-01-01

    Macro Rainwater Harvesting (RWH) has been tested at Koysinjaq (Koya) District, Kurdistan region of Iraq, due to its limited source of water.The studied area consists of four basins with total area of 228.96 km2. The estimating volumes of harvested runoff for the four selected basins together for the study period (2002-2011) were calculated using the Watershed Modeling System (WMS) which is based on Soil Conservation Service Curve Number (SCS-CN) method.In this research, a comparison between m...

  10. Financial feasibility of end-user designed rainwater harvesting and greywater reuse systems for high water use households.

    Science.gov (United States)

    Oviedo-Ocaña, Edgar Ricardo; Dominguez, Isabel; Ward, Sarah; Rivera-Sanchez, Miryam Lizeth; Zaraza-Peña, Julian Mauricio

    2017-03-30

    Water availability pressures, competing end-uses and sewers at capacity are all drivers for change in urban water management. Rainwater harvesting (RWH) and greywater reuse (GWR) systems constitute alternatives to reduce drinking water usage and in the case of RWH, reduce roof runoff entering sewers. Despite the increasing popularity of installations in commercial buildings, RWH and GWR technologies at a household scale have proved less popular, across a range of global contexts. For systems designed from the top-down, this is often due to the lack of a favourable cost-benefit (where subsidies are unavailable), though few studies have focused on performing full capital and operational financial assessments, particularly in high water consumption households. Using a bottom-up design approach, based on a questionnaire survey with 35 households in a residential complex in Bucaramanga, Colombia, this article considers the initial financial feasibility of three RWH and GWR system configurations proposed for high water using households (equivalent to >203 L per capita per day). A full capital and operational financial assessment was performed at a more detailed level for the most viable design using historic rainfall data. For the selected configuration ('Alt 2'), the estimated potable water saving was 44% (equivalent to 131 m(3)/year) with a rate of return on investment of 6.5% and an estimated payback period of 23 years. As an initial end-user-driven design exercise, these results are promising and constitute a starting point for facilitating such approaches to urban water management at the household scale.

  11. Designing Rainwater Harvesting Systems Cost-Effectively in a Urban Water-Energy Saving Scheme by Using a GIS-Simulation Based Design System

    Directory of Open Access Journals (Sweden)

    Yie-Ru Chiu

    2015-11-01

    Full Text Available Current centralized urban water supply depends largely on energy consumption, creating critical water-energy challenge especially for many rapid growing Asian cities. In this context, harvesting rooftop rainwater for non-potable use has enormous potential to ease the worsening water-energy issue. For this, we propose a geographic information system (GIS-simulation-based design system (GSBDS to explore how rainwater harvesting systems (RWHSs can be systematically and cost-effectively designed as an innovative water-energy conservation scheme on a city scale. This GSBDS integrated a rainfall data base, water balance model, spatial technologies, energy-saving investigation, and economic feasibility analysis based on a case study of eight communities in the Taipei metropolitan area, Taiwan. Addressing both the temporal and spatial variations in rainfall, the GSBDS enhanced the broad application of RWHS evaluations. The results indicate that the scheme is feasible based on the optimal design when both water and energy-savings are evaluated. RWHSs were observed to be cost-effective and facilitated 21.6% domestic water-use savings, and 138.6 (kWh/year-family energy-savings. Furthermore, the cost of per unit-energy-saving is lower than that from solar PV systems in 85% of the RWHS settings. Hence, RWHSs not only enable water-savings, but are also an alternative renewable energy-saving approach that can address the water-energy dilemma caused by rapid urbanization.

  12. 墨西哥城区雨水收集系统的家庭模式%Household model of rainwater harvesting system in Mexican urban zones

    Institute of Scientific and Technical Information of China (English)

    José A.Gleason-Espíndola

    2014-01-01

    详细介绍了墨西哥哈利斯科州特拉凯帕凯市住宅开发区雨水收集系统的一种家庭模式。为了设计出一个可以为家庭提供最大水量的雨水收集系统,对雨水收集量进行了估算。基于估算出的雨水收集量,对家庭总需水量进行了计算,以便探讨雨水的可能用途。雨水收集系统的主要组成部分如下:集水区;落水管(屋顶排水管),第一冲洗水箱;水箱;渗井;泵站,过滤系统;紫外( UV )处理设备。雨水收集系统被设计成中央供水系统的一部分。介绍了雨水收集系统的设计和建设过程及其造价。通过该方式,可提供一个技术参考,从而帮助市民来设计和建设他们的雨水系统。该模式既可促进此系统在墨西哥的发展,也可为国际社会提供宝贵的经验。%This paper describes a household model of the rainwater harvesting system in residential development of Tlaquepaque Jalisco Mexico. Harvested rainwater is estimated for designing a rainwater catchment system which reflects the maximum water supply to a household.Based on the estimation of the harvested rainwater the total water demand is calculated in order to explore the possible uses of rainwater. Major components in the rainwater catchment system are as follows catchment area downspout roof drain pipe and first flush tank cistern infiltration well pumping station and filtering system and ultraviolet UV water treatment.The rainwater harvesting system is designed to operate as the part of the central water supply system.This paper exposes the process of design and construction and its cost.In this way it aims to establish a technical and conceptual reference which enables the citizens to design their rainwater systems and their construction. This model will produce an important experience that can help to improve the systems in a Mexican context.It can be also useful for the international community.

  13. Effects of rainwater harvesting and afforestation on soil properties ...

    African Journals Online (AJOL)

    user

    Effect of rainwater harvesting (RWH) structures like Contour trench (CT), ... conserving soil and water facilitating plant growth and helped restore the degraded hill. .... Soil pH, electrical conductivity (EC) soil organic ...... Field Crop Res.

  14. Rainwater harvesting and management in rainfed agricultural systems in Sub-Saharan Africa - A review

    NARCIS (Netherlands)

    Biazin, B.; Sterk, G.; Temesgen, M.; Abdulkedir, A.; Stroosnijder, L.

    2012-01-01

    Agricultural water scarcity in the predominantly rainfed agricultural system of sub-Saharan Africa (SSA) is more related to the variability of rainfall and excessive non-productive losses, than the total annual precipitation in the growing season. Less than 15% of the terrestrial precipitation takes

  15. Rainwater harvesting potentials for drought mitigation in Iran.

    Science.gov (United States)

    Tabatabaee, J; Han, M Y

    2010-01-01

    In order to evaluate the potential of rainwater harvesting (RWH) for mitigating water scarcity in a semi-arid zone of the country (Mashhad-Iran), three typical RWH systems were installed and monitored. The first system consists of 5,000 m² natural ground catchment which was leveled and covered with plastic sheets allowing for maximum possible runoff generation. Surface runoff was conducted into a 500 m³ ground reservoir via a series of draining ditches and an end collection channel. The water collected from a plastic covered catchment was used for irrigation of dryland wheat cultivation. According to the result of two years measurements, grain yield was almost doubled in irrigated plots when compared to conventional rainfed cultivation. In the second RWH system, runoff generated from about 2 ha asphaltic road and parking was diverted into a 1,200 m³ ground reservoir. The results of 2 years measurement for reservoir inflow and outflow indicated that runoff generated during rainy season was sufficient to produce necessary water for irrigating 900 planted fruit trees during successive dry seasons. The last experiment reported here is about a 40 m² roof area which was connected to a plastic tank for runoff measurement. The conclusion was that the proposed RWH system can produce enough water for building's toilets' flashes and other sanitary purposes so that the potable water could be saved considerably. In general, the results of three rainwater harvesting experiments showed the importance of using rainwater for compensating the effect of water shortages which is repeatedly occurring due to the effect of current climate change and ever increasing water utilization for drinking and food production.

  16. Monsoon Harvests: The Socio-Ecohydrology of Agricultural Rainwater Harvesting and Groundwater Depletion in India

    Science.gov (United States)

    Basu, N. B.; Hora, T.; Van Meter, K. J.

    2016-12-01

    Rainwater harvesting (RWH), the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional RWH systems have fallen into disrepair due to increasing dependence on groundwater. This dependence has contributed to an accelerated decline in groundwater resources, which has in turn led to increased efforts at the state and national levels to revive older RWH systems. Critical to the success of such efforts is an improved understanding of how these ancient systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Here, we use a combination of data analyses and modeling to quantify the coupled natural and human controls on the spatiotemporal trajectories of groundwater depletion and rainwater harvesting in monsoonal India.

  17. Solar Disinfection of Pseudomonas aeruginosa in Harvested Rainwater: A Step towards Potability of Rainwater

    Science.gov (United States)

    Amin, Muhammad T.; Nawaz, Mohsin; Amin, Muhammad N.; Han, Mooyoung

    2014-01-01

    Efficiency of solar based disinfection of Pseudomonas aeruginosa (P. aeruginosa) in rooftop harvested rainwater was evaluated aiming the potability of rainwater. The rainwater samples were exposed to direct sunlight for about 8–9 hours and the effects of water temperature (°C), sunlight irradiance (W/m2), different rear surfaces of polyethylene terephthalate bottles, variable microbial concentrations, pH and turbidity were observed on P. aeruginosa inactivation at different weathers. In simple solar disinfection (SODIS), the complete inactivation of P. aeruginosa was obtained only under sunny weather conditions (>50°C and >700 W/m2) with absorptive rear surface. Solar collector disinfection (SOCODIS) system, used to improve the efficiency of simple SODIS under mild and weak weather, completely inactivated the P. aeruginosa by enhancing the disinfection efficiency of about 20% only at mild weather. Both SODIS and SOCODIS systems, however, were found inefficient at weak weather. Different initial concentrations of P. aeruginosa and/or Escherichia coli had little effects on the disinfection efficiency except for the SODIS with highest initial concentrations. The inactivation of P. aeruginosa increased by about 10–15% by lowering the initial pH values from 10 to 3. A high initial turbidity, adjusted by adding kaolin, adversely affected the efficiency of both systems and a decrease, about 15–25%; in inactivation of P. aeruginosa was observed. The kinetics of this study was investigated by Geeraerd Model for highlighting the best disinfection system based on reaction rate constant. The unique detailed investigation of P. aeruginosa disinfection with sunlight based disinfection systems under different weather conditions and variable parameters will help researchers to understand and further improve the newly invented SOCODIS system. PMID:24595188

  18. Solar disinfection of Pseudomonas aeruginosa in harvested rainwater: a step towards potability of rainwater.

    Directory of Open Access Journals (Sweden)

    Muhammad T Amin

    Full Text Available Efficiency of solar based disinfection of Pseudomonas aeruginosa (P. aeruginosa in rooftop harvested rainwater was evaluated aiming the potability of rainwater. The rainwater samples were exposed to direct sunlight for about 8-9 hours and the effects of water temperature (°C, sunlight irradiance (W/m2, different rear surfaces of polyethylene terephthalate bottles, variable microbial concentrations, pH and turbidity were observed on P. aeruginosa inactivation at different weathers. In simple solar disinfection (SODIS, the complete inactivation of P. aeruginosa was obtained only under sunny weather conditions (>50°C and >700 W/m2 with absorptive rear surface. Solar collector disinfection (SOCODIS system, used to improve the efficiency of simple SODIS under mild and weak weather, completely inactivated the P. aeruginosa by enhancing the disinfection efficiency of about 20% only at mild weather. Both SODIS and SOCODIS systems, however, were found inefficient at weak weather. Different initial concentrations of P. aeruginosa and/or Escherichia coli had little effects on the disinfection efficiency except for the SODIS with highest initial concentrations. The inactivation of P. aeruginosa increased by about 10-15% by lowering the initial pH values from 10 to 3. A high initial turbidity, adjusted by adding kaolin, adversely affected the efficiency of both systems and a decrease, about 15-25%; in inactivation of P. aeruginosa was observed. The kinetics of this study was investigated by Geeraerd Model for highlighting the best disinfection system based on reaction rate constant. The unique detailed investigation of P. aeruginosa disinfection with sunlight based disinfection systems under different weather conditions and variable parameters will help researchers to understand and further improve the newly invented SOCODIS system.

  19. Solar disinfection of Pseudomonas aeruginosa in harvested rainwater: a step towards potability of rainwater.

    Science.gov (United States)

    Amin, Muhammad T; Nawaz, Mohsin; Amin, Muhammad N; Han, Mooyoung

    2014-01-01

    Efficiency of solar based disinfection of Pseudomonas aeruginosa (P. aeruginosa) in rooftop harvested rainwater was evaluated aiming the potability of rainwater. The rainwater samples were exposed to direct sunlight for about 8-9 hours and the effects of water temperature (°C), sunlight irradiance (W/m2), different rear surfaces of polyethylene terephthalate bottles, variable microbial concentrations, pH and turbidity were observed on P. aeruginosa inactivation at different weathers. In simple solar disinfection (SODIS), the complete inactivation of P. aeruginosa was obtained only under sunny weather conditions (>50°C and >700 W/m2) with absorptive rear surface. Solar collector disinfection (SOCODIS) system, used to improve the efficiency of simple SODIS under mild and weak weather, completely inactivated the P. aeruginosa by enhancing the disinfection efficiency of about 20% only at mild weather. Both SODIS and SOCODIS systems, however, were found inefficient at weak weather. Different initial concentrations of P. aeruginosa and/or Escherichia coli had little effects on the disinfection efficiency except for the SODIS with highest initial concentrations. The inactivation of P. aeruginosa increased by about 10-15% by lowering the initial pH values from 10 to 3. A high initial turbidity, adjusted by adding kaolin, adversely affected the efficiency of both systems and a decrease, about 15-25%; in inactivation of P. aeruginosa was observed. The kinetics of this study was investigated by Geeraerd Model for highlighting the best disinfection system based on reaction rate constant. The unique detailed investigation of P. aeruginosa disinfection with sunlight based disinfection systems under different weather conditions and variable parameters will help researchers to understand and further improve the newly invented SOCODIS system.

  20. Temporal variation of rainwater quality storaged for harvesting purpose

    OpenAIRE

    Rodrigo Braga Moruzzi; Marcela Ferreira Murakami

    2009-01-01

    The aim of this paper was to evaluate the interference, in terms of corrosion and microbiological indicators, of rainwater storage time for non-potable uses. For this, the Langelier index (IL), and heterotrophic bacteria were performed in an experimental system considering the rainwater collection after the roof. Samples were monitored for six months after dividing the studied rainwater in different aliquots considering the first flush and the chlorine dosage. Results pointed out values of IL

  1. Best Management Practice, Fact Sheet 6. Rainwater Harvesting

    OpenAIRE

    2013-01-01

    This publication explains what rainwater harvesting is, where and how it is used, their limitations, routine and nonroutine maintenance, expected costs, and a glossary of terms. This fact sheet is one of a 15-part series on urban stormwater management practices.

  2. 干旱半干旱地区集雨利用模式及可持续发展对策%Models of Rainwater Harvesting System and Sustainable Development Countermeasures in Arid and Semi-arid Areas

    Institute of Scientific and Technical Information of China (English)

    赵文举; 李宗礼; 范严伟; 孙伟

    2011-01-01

    With the global drought and water shortage becoming more prominent, use of rainwater has drawn a worldwide concern. Based on the research development in arid and semi-arid regions over the world in recent years, this paper firstly summarizes three models of rainwater harvesting system in these kinds of areas, namely the model of collecting rainwater from courtyard and road for drinking of people and livestock and water supply in farmland, the model of harvesting rainwater on slope for ecological forestry grassland and animal husbandry and the model of rainwater harvesting by watershed for all-around use. Then the paper analyzes the existing major problems of rainwater harvesting techniques in arid and semi-arid areas, such as the poor comprehensive technology in rainwater harvesting system, the shortage of advanced water-saving irrigation facilities, poor efficiency of rainwater utilization, faultiness of environmental impact assessment system, low quality of ecological effects, insufficiency in capital investment and slow development in promotion and application of advanced technology, etc. On this basis, the paper puts forward the sustainable development strategies about rainwater harvesting technology from the following aspects, the potential of regional rainwater resources collecting, the efficient use of technology integration system for rainwater, the good matching of advanced water harvesting and efficient irrigation technology, the construction of environmental effect evaluation system of rainwater harvesting system, the broad channels of capital investment and the establishment of benefit compensation mechanism.%随着全球性干旱加剧与水资源问题的日益突出,雨水利用已成为世界范围内关注的一个热点问题.依据近年来集雨利用的研究和实践,总结归纳了集雨利用的3种模式:分别是道路庭院集雨的人畜用水与农业补灌利用模式,坡地集雨生态林草—畜牧型模式,小流域集雨综合利

  3. Presence of microbial and chemical source tracking markers in roof-harvested rainwater and catchment systems for the detection of fecal contamination.

    Science.gov (United States)

    Waso, M; Ndlovu, T; Dobrowsky, P H; Khan, S; Khan, W

    2016-09-01

    Microbial source tracking (MST) and chemical source tracking (CST) markers were utilized to identify fecal contamination in harvested rainwater and gutter debris samples. Throughout the sampling period, Bacteroides HF183 was detected in 57.5 % of the tank water samples and 95 % of the gutter debris samples, while adenovirus was detected in 42.5 and 52.5 % of the tank water and gutter debris samples, respectively. Human adenovirus was then detected at levels ranging from below the detection limit to 316 and 1253 genome copies/μL in the tank water and debris samples, respectively. Results for the CST markers showed that salicylic acid (average 4.62 μg/L) was the most prevalent marker (100 %) in the gutter debris samples, caffeine (average 18.0 μg/L) was the most prevalent in the tank water samples (100 %) and acetaminophen was detected sporadically throughout the study period. Bacteroides HF183 and salicylic acid (95 %) and Bacteroides HF183 and caffeine (80 %) yielded high concurrence frequencies in the gutter debris samples. In addition, the highest concurrence frequency in the tank water samples was observed for Bacteroides HF183 and caffeine (60 %). The current study thus indicates that Bacteroides HF183, salicylic acid and caffeine may potentially be applied as source tracking markers in rainwater catchment systems in order to supplement fecal indicator analyses.

  4. Temporal variation of rainwater quality storaged for harvesting purpose

    Directory of Open Access Journals (Sweden)

    Rodrigo Braga Moruzzi

    2009-12-01

    Full Text Available The aim of this paper was to evaluate the interference, in terms of corrosion and microbiological indicators, of rainwater storage time for non-potable uses. For this, the Langelier index (IL, and heterotrophic bacteria were performed in an experimental system considering the rainwater collection after the roof. Samples were monitored for six months after dividing the studied rainwater in different aliquots considering the first flush and the chlorine dosage. Results pointed out values of IL<0 for all aliquots, indicating the corrosive tendency even after the roof wash. Further, the heterotrophic bacteria were resistant on time of storage, indicating that the chlorine dosage keeping is an important issue.

  5. Design and construction of an experimental pervious paved parking area to harvest reusable rainwater.

    Science.gov (United States)

    Gomez-Ullate, E; Novo, A V; Bayon, J R; Hernandez, Jorge R; Castro-Fresno, Daniel

    2011-01-01

    Pervious pavements are sustainable urban drainage systems already known as rainwater infiltration techniques which reduce runoff formation and diffuse pollution in cities. The present research is focused on the design and construction of an experimental parking area, composed of 45 pervious pavement parking bays. Every pervious pavement was experimentally designed to store rainwater and measure the levels of the stored water and its quality over time. Six different pervious surfaces are combined with four different geotextiles in order to test which materials respond better to the good quality of rainwater storage over time and under the specific weather conditions of the north of Spain. The aim of this research was to obtain a good performance of pervious pavements that offered simultaneously a positive urban service and helped to harvest rainwater with a good quality to be used for non potable demands.

  6. Roof-harvested rainwater for potable purposes: application of solar collector disinfection (SOCO-DIS).

    Science.gov (United States)

    Amin, M T; Han, M Y

    2009-12-01

    The efficiency of solar disinfection (SODIS), recommended by the World Health Organization, has been determined for rainwater disinfection, and potential benefits and limitations discussed. The limitations of SODIS have now been overcome by the use of solar collector disinfection (SOCO-DIS), for potential use of rainwater as a small-scale potable water supply, especially in developing countries. Rainwater samples collected from the underground storage tanks of a rooftop rainwater harvesting (RWH) system were exposed to different conditions of sunlight radiation in 2-L polyethylene terephthalate bottles in a solar collector with rectangular base and reflective open wings. Total and fecal coliforms were used, together with Escherichia coli and heterotrophic plate counts, as basic microbial and indicator organisms of water quality for disinfection efficiency evaluation. In the SOCO-DIS system, disinfection improved by 20-30% compared with the SODIS system, and rainwater was fully disinfected even under moderate weather conditions, due to the effects of concentrated sunlight radiation and the synergistic effects of thermal and optical inactivation. The SOCO-DIS system was optimized based on the collector configuration and the reflective base: an inclined position led to an increased disinfection efficiency of 10-15%. Microbial inactivation increased by 10-20% simply by reducing the initial pH value of the rainwater to 5. High turbidities also affected the SOCO-DIS system; the disinfection efficiency decreased by 10-15%, which indicated that rainwater needed to be filtered before treatment. The problem of microbial regrowth was significantly reduced in the SOCO-DIS system compared with the SODIS system because of residual sunlight effects. Only total coliform regrowth was detected at higher turbidities. The SOCO-DIS system was ineffective only under poor weather conditions, when longer exposure times or other practical means of reducing the pH were required for the

  7. Sizing a rainwater harvesting cistern by minimizing costs

    Science.gov (United States)

    Pelak, Norman; Porporato, Amilcare

    2016-10-01

    Rainwater harvesting (RWH) has the potential to reduce water-related costs by providing an alternate source of water, in addition to relieving pressure on public water sources and reducing stormwater runoff. Existing methods for determining the optimal size of the cistern component of a RWH system have various drawbacks, such as specificity to a particular region, dependence on numerical optimization, and/or failure to consider the costs of the system. In this paper a formulation is developed for the optimal cistern volume which incorporates the fixed and distributed costs of a RWH system while also taking into account the random nature of the depth and timing of rainfall, with a focus on RWH to supply domestic, nonpotable uses. With rainfall inputs modeled as a marked Poisson process, and by comparing the costs associated with building a cistern with the costs of externally supplied water, an expression for the optimal cistern volume is found which minimizes the water-related costs. The volume is a function of the roof area, water use rate, climate parameters, and costs of the cistern and of the external water source. This analytically tractable expression makes clear the dependence of the optimal volume on the input parameters. An analysis of the rainfall partitioning also characterizes the efficiency of a particular RWH system configuration and its potential for runoff reduction. The results are compared to the RWH system at the Duke Smart Home in Durham, NC, USA to show how the method could be used in practice.

  8. Financial and environmental modelling of water hardness--implications for utilising harvested rainwater in washing machines.

    Science.gov (United States)

    Morales-Pinzón, Tito; Lurueña, Rodrigo; Gabarrell, Xavier; Gasol, Carles M; Rieradevall, Joan

    2014-02-01

    A study was conducted to determine the financial and environmental effects of water quality on rainwater harvesting systems. The potential for replacing tap water used in washing machines with rainwater was studied, and then analysis presented in this paper is valid for applications that include washing machines where tap water hardness may be important. A wide range of weather conditions, such as rainfall (284-1,794 mm/year); water hardness (14-315 mg/L CaCO3); tap water prices (0.85-2.65 Euros/m(3)) in different Spanish urban areas (from individual buildings to whole neighbourhoods); and other scenarios (including materials and water storage capacity) were analysed. Rainfall was essential for rainwater harvesting, but the tap water prices and the water hardness were the main factors for consideration in the financial and the environmental analyses, respectively. The local tap water hardness and prices can cause greater financial and environmental impacts than the type of material used for the water storage tank or the volume of the tank. The use of rainwater as a substitute for hard water in washing machines favours financial analysis. Although tap water hardness significantly affects the financial analysis, the greatest effect was found in the environmental analysis. When hard tap water needed to be replaced, it was found that a water price of 1 Euro/m(3) could render the use of rainwater financially feasible when using large-scale rainwater harvesting systems. When the water hardness was greater than 300 mg/L CaCO3, a financial analysis revealed that an net present value greater than 270 Euros/dwelling could be obtained at the neighbourhood scale, and there could be a reduction in the Global Warming Potential (100 years) ranging between 35 and 101 kg CO2 eq./dwelling/year.

  9. Rainwater harvesting, quality assessment and utilization in Kefalonia Island, Greece.

    Science.gov (United States)

    Sazakli, E; Alexopoulos, A; Leotsinidis, M

    2007-05-01

    The quality of harvested rainwater which is used for domestic and drinking purposes in the northern area of Kefalonia Island in SW Greece and the factors affecting it were assessed through 3-year surveillance. In 12 seasonal samplings, 156 rainwater and 144 ground- or mixed water samples were collected from ferroconcrete storage tanks (300-1000 m3 capacity), which are adjacent to cement-paved catchment areas (600-3000 m2). Common anions and major cations as well as the metals Fe, Mn, Cd, Pb, Cu, Cr, Ni and Zn were tested. The presence of three major groups of organic compounds, polycyclic aromatic hydrocarbons (PAHs), organochloride pesticides (OCPs) and volatile organic compounds (VOCs), was screened by common analytical techniques. All of the rainwater samples were within the guidelines for chemical parameters established by the 98/93/EU directive. As far as microbiological quality is concerned, total coliforms, Escherichia coli and enterococci were detected in 80.3%, 40.9% and 28.8% of the rainwater samples, respectively, although they were found in low concentrations. Chemical and microbiological parameters showed seasonal fluctuations. Principal component analysis revealed that microbiological parameters were affected mainly by the cleanness level of catchment areas, while chemical parameters were influenced by the sea proximity and human activities. Disinfection should be applied into the tanker trucks which distribute the water to the consumers and not into the big storage tanks in order to avoid by-products formation. Due to the lack of fluoride in rainwater samples, the consumers must become aware of the fact that the supplementation of this element is needed.

  10. Rainwater harvesting: theorising and modelling issues that influence household adoption.

    Science.gov (United States)

    White, I

    2010-01-01

    Household adoption of rainwater harvesting (RH) systems recently boomed in Australian urban centres. As a sustainable supplement to the mains supply, water authorities regarded RH as a demand management device. Yet what actually motivated household RH adoption was not well understood. Burawoy's 'extended case method' was used to link grounded enquiry with 13 core theoretical concepts drawn from an original synthesis of ecological modernisation and diffusion of innovation theories. This framework means the household experience extends ideas drawn from existing theory to explore issues that influence the household RH adoption decision. The framework was interrogated with data drawn from a self-report survey of 560 homes. It accommodated 100% of the RH adoption issues identified by households. Further staged quantitative and qualitative analyses particularized these core concepts out to 36 discrete 'subfactors' which were used in discriminant function analyses. 17 subfactors contribute to a discriminant function grouping 89.2% of households to the correct 'adopter' or 'nonadopter' category (pRH adoption and can be applied to social marketing aimed at facilitating further penetration of household RH.

  11. Potential of Rainwater Harvesting and Greywater Reuse for Water Consumption Reduction and Wastewater Minimization

    Directory of Open Access Journals (Sweden)

    Miguel Ángel López Zavala

    2016-06-01

    Full Text Available Northeastern Mexico is a semiarid region with water scarcity and a strong pressure on water sources caused by the rapid increase of population and industrialization. In this region, rainwater harvesting alone is not enough to meet water supply demands due to the irregular distribution of rainfall in time and space. Thus, in this study the reliability of integrating rainwater harvesting with greywater reuse to reduce water consumption and minimize wastewater generation in the Tecnológico de Monterrey, Monterrey Campus, was assessed. Potable water consumption and greywater generation in main facilities of the campus were determined. Rainwater that can be potentially harvested in roofs and parking areas of the campus was estimated based on a statistical analysis of the rainfall. Based on these data, potential water savings and wastewater minimization were determined. Characterization of rainwater and greywater was carried out to determine the treatment necessities for each water source. Additionally, the capacity of water storage tanks was estimated. For the selected treatment systems, an economic assessment was conducted to determine the viability of the alternatives proposed. Results showed that water consumption can be reduced by 48% and wastewater generation can be minimized by 59%. Implementation of rainwater harvesting and greywater reuse systems in the Monterrey Campus will generate important economic benefits to the institution. Amortization of the investments will be achieved in only six years, where the net present value (NPV will be on the order of US $50,483.2, the internal rate of return (IRR of 4.6% and the benefits–investment ratio (B/I of 1.7. From the seventh year, the project will present an IRR greater than the minimum acceptable rate of return (MARR. In a decade, the IRR will be 14.4%, more than twice the MARR, the NPV of US $290,412.1 and the B/I of 3.1, denoting economic feasibility. Based on these results, it is clear that

  12. Distribution of indigenous bacterial pathogens and potential pathogens associated with roof-harvested rainwater.

    Science.gov (United States)

    Dobrowsky, P H; De Kwaadsteniet, M; Cloete, T E; Khan, W

    2014-04-01

    The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed that Pseudomonas (19% of samples) was the dominant genus isolated, followed by Aeromonas (16%), Klebsiella (11%), and Enterobacter (9%). PCR assays employing genus-specific primers also confirmed the presence of Aeromonas spp. (16%), Klebsiella spp. (47%), Legionella spp. (73%), Pseudomonas spp. (13%), Salmonella spp. (6%), Shigella spp. (27%), and Yersinia spp. (28%) in the harvested rainwater samples. In addition, on one sampling occasion, Giardia spp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source.

  13. A water harvesting model for optimizing rainwater harvesting in the wadi Oum Zessar watershed, Tunisia

    NARCIS (Netherlands)

    Adham, Ammar; Wesseling, Jan G.; Riksen, Michel; Ouessar, Mohamed; Ritsema, Coen J.

    2016-01-01

    Rainwater harvesting (RWH) techniques have been adapted in arid and semi-arid regions to minimise the risk from droughts. The demand for water has increased but water resources have become scarcer, so the assessment and modelling of surface water related to RWH in catchments has become a necessit

  14. Problems and countermeasures on the safety of rainwater harvesting for drinking in China

    OpenAIRE

    Liu Laisheng; Liu Linghua; Wu Leixiang; Wu Jiapeng; Huo Weijie

    2016-01-01

    China is increasingly confronted with serious water shortages, so rainwater harvesting and utilization have gradually received attention with advantages such as accessibility, simple operation and low cost. The harvested rainwater can be used for drinking, irrigation, municipal greening, etc., and when applied for drinking, the demand for water quality is highest. Most existing researches have put their focus on improving the accumulation of rainwater, but there is a lack of in-depth studies ...

  15. Rainwater harvesting in South Africa: Challenges and opportunities

    Science.gov (United States)

    Mwenge Kahinda, J.; Taigbenu, A. E.

    Water paucity remains a major threat to poverty, hunger alleviation as well as sustainable development. Innovative water technologies such as rainwater harvesting (RWH) have the potential to improve rural water supply and contribute to the provision of the first 6 kl of water consumed monthly. RWH can also be the solution to South Africa food security by increasing water productivity of dryland agriculture and enabling homestead gardening. Although used for decades in South Africa, rainwater harvesting (RWH) is still far from being utilised to its full potential as unresolved challenges prevent its wide scale adoption. The paper presents the challenges and opportunities to the upscaling of RWH in South Africa. Key challenges preventing the nationwide expansion of RWH are the current water related legislations, the lack of finances and the absence of a national umbrella body that coordinates. While opportunities lie in the worth of knowledge gathered by research projects, funded over the last two decades, on the biophysical and socio-economic impacts of RWH.

  16. Silver disinfection of Pseudomonas aeruginosa and E. coli in rooftop harvested rainwater for potable purposes.

    Science.gov (United States)

    Nawaz, M; Han, M Y; Kim, Tschung-il; Manzoor, U; Amin, M T

    2012-08-01

    Rainwater harvesting being an alternate source in water scarce areas is becoming a common practice. Catchment contact, however, deteriorates the quality of rainwater making it unfit for potable purposes. To improve the quality of harvested rainwater, silver was used as antimicrobial agent in this study. Rainwater samples were taken from underground storage tank of a rooftop rainwater harvesting system installed in one of the buildings at Seoul National University, Seoul, South Korea. The target microorganisms (MOs) were Pseudomonas aeruginosa and Escherichia coli which were measured by using plate count method and standard MPN method, respectively. The efficiency of silver disinfection was evaluated at concentrations, ranging from 0.01 to 0.1 mg/l; the safe limit approved by WHO. The experiments were performed for 168 h with different time intervals to evaluate the parameters including inactivation rate, residual effect of silver and re-growth in both MOs at lower (i.e. 0.01-0.04 mg/l) as well as the higher concentrations of silver (i.e. 0.08-0.1 mg/l). Results showed the re-growth in both MOs was only in the case of lower concentrations of silver. The possible reason of re-growth at these concentrations of silver may be the halting of bacterial cell replication process for some time without permanent damage. The kinetics of this study suggest that higher inactivation and long term residual effect towards both MOs can be achieved with the application of silver at 0.08 mg/l or higher under safe limit.

  17. The effect of roofing material on the quality of harvested rainwater.

    Science.gov (United States)

    Mendez, Carolina B; Klenzendorf, J Brandon; Afshar, Brigit R; Simmons, Mark T; Barrett, Michael E; Kinney, Kerry A; Kirisits, Mary Jo

    2011-02-01

    Due to decreases in the availability and quality of traditional water resources, harvested rainwater is increasingly used for potable and non-potable purposes. In this study, we examined the effect of conventional roofing materials (i.e., asphalt fiberglass shingle, Galvalume(®) metal, and concrete tile) and alternative roofing materials (i.e., cool and green) on the quality of harvested rainwater. Results from pilot-scale and full-scale roofs demonstrated that rainwater harvested from any of these roofing materials would require treatment if the consumer wanted to meet United States Environmental Protection Agency primary and secondary drinking water standards or non-potable water reuse guidelines; at a minimum, first-flush diversion, filtration, and disinfection are recommended. Metal roofs are commonly recommended for rainwater harvesting applications, and this study showed that rainwater harvested from metal roofs tends to have lower concentrations of fecal indicator bacteria as compared to other roofing materials. However, concrete tile and cool roofs produced harvested rainwater quality similar to that from the metal roofs, indicating that these roofing materials also are suitable for rainwater harvesting applications. Although the shingle and green roofs produced water quality comparable in many respects to that from the other roofing materials, their dissolved organic carbon concentrations were very high (approximately one order of magnitude higher than what is typical for a finished drinking water in the United States), which might lead to high concentrations of disinfection byproducts after chlorination. Furthermore the concentrations of some metals (e.g., arsenic) in rainwater harvested from the green roof suggest that the quality of commercial growing media should be carefully examined if the harvested rainwater is being considered for domestic use. Hence, roofing material is an important consideration when designing a rainwater catchment.

  18. Roof selection for rainwater harvesting: quantity and quality assessments in Spain.

    Science.gov (United States)

    Farreny, Ramon; Morales-Pinzón, Tito; Guisasola, Albert; Tayà, Carlota; Rieradevall, Joan; Gabarrell, Xavier

    2011-05-01

    Roofs are the first candidates for rainwater harvesting in urban areas. This research integrates quantitative and qualitative data of rooftop stormwater runoff in an urban Mediterranean-weather environment. The objective of this paper is to provide criteria for the roof selection in order to maximise the availability and quality of rainwater. Four roofs have been selected and monitored over a period of 2 years (2008-2010): three sloping roofs - clay tiles, metal sheet and polycarbonate plastic - and one flat gravel roof. The authors offer a model for the estimation of the runoff volume and the initial abstraction of each roof, and assess the physicochemical contamination of roof runoff. Great differences in the runoff coefficient (RC) are observed, depending mostly on the slope and the roughness of the roof. Thus, sloping smooth roofs (RC>0.90) may harvest up to about 50% more rainwater than flat rough roofs (RC=0.62). Physicochemical runoff quality appears to be generally better than the average quality found in the literature review (conductivity: 85.0 ± 10.0 μS/cm, total suspended solids: 5.98 ± 0.95 mg/L, total organic carbon: 11.6 ± 1.7 mg/L, pH: 7.59 ± 0.07 upH). However, statistically significant differences are found between sloping and flat rough roofs for some parameters (conductivity, total organic carbon, total carbonates system and ammonium), with the former presenting better quality in all parameters (except for ammonium). The results have an important significance for local governments and urban planners in the (re)design of buildings and cities from the perspective of sustainable rainwater management. The inclusion of criteria related to the roof's slope and roughness in city planning may be useful to promote rainwater as an alternative water supply while preventing flooding and water scarcity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Development and application of EEAST: a life cycle based model for use of harvested rainwater and composting toilets in buildings.

    Science.gov (United States)

    Devkota, J; Schlachter, H; Anand, C; Phillips, R; Apul, Defne

    2013-11-30

    Harvested rainwater systems and composting toilets are expected to be an important part of sustainable solutions in buildings. Yet, to this date, a model evaluating their economic and environmental impact has been missing. To address this need, a life cycle based model, EEAST was developed. EEAST was designed to compare the business as usual (BAU) case of using potable water for toilet flushing and irrigation to alternative scenarios of rainwater harvesting and composting toilet based technologies. In EEAST, building characteristics, occupancy, and precipitation are used to size the harvested rainwater and composting toilet systems. Then, life cycle costing and life cycle assessment methods are used to estimate cost, energy, and greenhouse gas (GHG) emission payback periods (PPs) for five alternative scenarios. The scenarios modeled include use of harvested rainwater for toilet flushing, for irrigation, or both; and use of composting toilets with or without harvested rainwater use for irrigation. A sample simulation using EEAST showed that for the office building modeled, the cost PPs were greater than energy PPs which in turn were greater than GHG emission PPs. This was primarily due to energy and emission intensive nature of the centralized water and wastewater infrastructure. The sample simulation also suggested that the composting toilets may have the best performance in all criteria. However, EEAST does not explicitly model solids management and as such may give composting toilets an unfair advantage compared to flush based toilets. EEAST results were found to be very sensitive to cost values used in the model. With the availability of EEAST, life cycle cost, energy, and GHG emissions can now be performed fairly easily by building designers and researchers. Future work is recommended to further improve EEAST and evaluate it for different types of buildings and climates so as to better understand when composting toilets and harvested rainwater systems

  20. The Prospects of Rainwater Harvesting in the Ho Chi Minh City

    Directory of Open Access Journals (Sweden)

    Chi Nguyen Thuy Lan

    2015-12-01

    Full Text Available Wisely using natural water resources to serve human needs plays a decisive role in ensuring water and food security. In the natural water cycle, rainwater is considered as a valuable renewable resource. Rainwater harvesting (RWH for daily life and production is a simple but effective and also environmentally sound measure. It is also a positive solution in a climate change adaptation strategy. However, this resource is being wasted in our country in general and in the HCM City in particular. This paper provides an overview of the status of rainwater use in the world; the general situation, the potential of rainwater collection and a number of issues related to the potential of rainwater harvesting in the city. Some solutions to enhance the use of rainwater and improve water supply for city residents are also suggested in this discussion.

  1. 屋面集雨新技术研究——雨落管分流集雨装置%A new technique of rainwater harvesting on roofs: diversion system for roof drainage pipe

    Institute of Scientific and Technical Information of China (English)

    郑学琴; 吴林键; 高梧; 朱笛; 魏文馨; 张文敬; 李怡

    2012-01-01

    This paper introduces a new approach of collecting rainwater on building roofs based on the diversion of rainwater in roof drainage pipes. A case study for a fiat - topped apartment building in Chongqing is presented, in which every room was equipped with the diversion system. The cost of the systems was about¥ 1.59 per square meter, and might be recovered in about 2.2 years. The rainwater harvesting system shows advantages because of its simple structure, environmental materials, low cost, and considerable economical benefits. The systems may provide a promising way of the roof rainwater utilization for green building tech- nology.%提出了一种屋面集雨新技术——雨落管分流集雨装置,以重庆地区某高校一栋平顶学生宿舍单元楼作为实例,当每个单间都安装该装置时,定量计算得其材料成本费用约1.59元/m^2,2.2年左右即可全部收回成本.该装置具有整体构造简单、材料使用环保、成本费用低廉、直接经济效益可观等优点,在雨水综合利用系统领域内拥有广阔的发展前景.

  2. Analytical Modelling of Rainwater Harvesting and Groundwater Resources in Auchi, Nigeria

    Directory of Open Access Journals (Sweden)

    Olotu Yahaya

    2014-07-01

    Full Text Available Shortage in supply of water for potable and non-potable applications and exponential world population increase is a strong constrain to Human Development Index and social-economic advancement in Nigeria. ClimGen (Version 4.1.05 was used to simulate and create large dataset of annual rainfall depth. Generated average annual rainfall from 1430 mm to 1600 mm was subjected to varying roof plan surfaces of 250 m2 ; 500 m2 ; 1000 m2 ; and 2000 m2 respectively. Simulation analysis showed that an average of 5,300m 3 of rainwater was harvestable and this value of water could only meet water demand of 170 people annually. The relationship of roof plan surface (RPS and collected rainwater is very strong with R 2= 0.84 and 0.95 respectively. Again, the volume of groundwater withdrawal increased from 12.4×10 4 m 3 to 32.7×10 4 m 3 , this could only meet an annual water demand for 10,480 people representing about 6.2% of the population in Auchi. This development reveals that water supply from the alternative sources could not meet up to 6.3% of total water demand in Auchi and increasing water availability and accessibility to about 65% (31.3×105m3 coverage requires integrated rainwater harvesting system and technically-based groundwater exploration mechanism.

  3. Simulation Analysis for Rainwater Harvesting and Groundwater Withdrawal in Auchi, Nigeria

    Directory of Open Access Journals (Sweden)

    Philipa O. Idogho

    2015-09-01

    Full Text Available Shortage in supply of water for potable and non-potable applications and exponential world population increase is a strong constrain to Human Development Index and social-economic advancement in Nigeria. ClimGen (Version 4.1.05 was used to simulate and create large dataset of annual rainfall depth. Generated average annual rainfall from 1430 mm to 1600 mm was subjected to varying roof plan surfaces of 250 m 2 ; 500 m 2 ; 1000 m 2 ; and 2000 m 2 respectively. Simulation analysis showed that an average of 5,300m 3 of rainwater was harvestable and this value of water could only meet water demand of 170 people annually. The relationship of roof plan surface (RPS and collected rainwater is very strong with R 2 = 0.84 and 0.95 respectively. Again, the volume of groundwater withdrawal increased from 12.4×10 4 m 3 to 32.7×10 4 m 3 , this could only meet an annual water demand for 10,480 people representing about 6.2% of the population in Auchi. This development reveals that water supply from the alternative sources could not meet up to 6.3% of total water demand in Auchi and increasing water availability and accessibility to about 65% (31.3×10 5m3 coverage requires integrated rainwater harvesting system and technically-based groundwater exploration mechanism.

  4. Enhanced drinking water supply through harvested rainwater treatment

    Science.gov (United States)

    Naddeo, Vincenzo; Scannapieco, Davide; Belgiorno, Vincenzo

    2013-08-01

    Decentralized drinking water systems represent an important element in the process of achieving the Millennium Development Goals, as centralized systems are often inefficient or nonexistent in developing countries. In those countries, most water quality related problems are due to hygiene factors and pathogens. A potential solution might include decentralized systems, which might rely on thermal and/or UV disinfection methods as well as physical and chemical treatments to provide drinking water from rainwater. For application in developing countries, decentralized systems major constraints include low cost, ease of use, environmental sustainability, reduced maintenance and independence from energy sources. This work focuses on an innovative decentralized system that can be used to collect and treat rainwater for potable use (drinking and cooking purposes) of a single household, or a small community. The experimented treatment system combines in one compact unit a Filtration process with an adsorption step on GAC and a UV disinfection phase in an innovative design (FAD - Filtration Adsorption Disinfection). All tests have been carried out using a full scale FAD treatment unit. The efficiency of FAD technology has been discussed in terms of pH, turbidity, COD, TOC, DOC, Escherichia coli and Total coliforms. FAD technology is attractive since it provides a total barrier for pathogens and organic contaminants, and reduces turbidity, thus increasing the overall quality of the water. The FAD unit costs are low, especially if compared to other water treatment technologies and could become a viable option for developing countries.

  5. Rainwater Harvesting in South India: Understanding Water Storage and Release Dynamics at Tank and Catchment Scales

    Science.gov (United States)

    Basu, N. B.; Van Meter, K. J.; Mclaughlin, D. L.; Steiff, M.

    2015-12-01

    Rainwater harvesting, the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional rainwater harvesting systems have fallen into disrepair due to increasing dependence on groundwater. With elevated declines in groundwater resources, there is increased effort at the state and national levels to revive older systems. Critical to the success of such efforts is an improved understanding of how these ancient water-provisioning systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Knowledge is especially lacking regarding the water-exchange dynamics of these rainwater harvesting "tanks" at tank and catchment scales, and how these exchanges regulate tank performance and catchment water balances. Here, we use fine-scale water level variations to quantify daily fluxes of groundwater, evapotranspiration, and sluice outflows in four tanks over the 2013 northeast monsoon season in a tank cascade that covers a catchment area of 28.2 km2. Our results indicate a distinct spatial pattern in groundwater-exchange dynamics, with the frequency and magnitude of groundwater inflow events (as opposed to outflow) increasing down the cascade of tanks. The presence of tanks in the landscape dramatically alters the catchment water balance, with catchment-scale runoff:rainfall ratios decreasing from 0.29 without tanks to 0.04 - 0.09 with tanks. Recharge:rainfall ratios increase in the presence of tanks, from ~0.17 in catchments without tanks to ~ 0.26 in catchments with tanks. Finally, our results demonstrate how more efficient management of sluice outflows can lead to the tanks meeting a higher fraction of crop water requirements.

  6. COST-EFFICIENCY OF RAINWATER COLLECTING SYSTEMS FOR INDIVIDUAL HOUSEHOLD

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    Sebastian Kujawiak

    2014-12-01

    Full Text Available The aim of this investigation was an assessment of the application effectiveness of three alternatives for rainwater harvesting systems for individual households, in central Great Poland climatic conditions. During the study the amount of storm water, which can be collected from the 3 different size roof areas (80, 135, 185 m2 was assessed, in relation to the needs of a four-person family, for the region of the Tarnowo Podgórne. The receivable amount of rainwater was analysed at a rate of 10, 25, 50% of total annual precipitation occurrence probability, including the lower values, appeared in the period of 1960-2008. For the financial efficiency evaluation of investment, an indicator of the average annual cost per unit (Ws and the net present value (NPV were used. The results show that for the Great Poland region with the average annual sum of precipitation of 550mm, only the roof surfaces of 185 m2 and bigger allow obtaining the profits from collected rainwater and reimbursement for building rainwater harvesting installations within 30 years of its operation.

  7. Monsoon Harvests: Assessing the Impact of Rainwater Harvesting Ponds on Subsistence-Level Agriculture in the Gundar Basin, Tamil Nadu, India

    Science.gov (United States)

    Steiff, M.; Van Meter, K. J.; Basu, N. B.

    2013-12-01

    Lack of consistent water availability for irrigated agriculture is recognized as one of the primary constraints to meeting the UN Millennium Development Goals to alleviate hunger, and in semi-arid landscapes such as those of southern India, which are characterized by high intra-annual variability in rainfall, provision of capabilities for seasonal storage is recognized to be one of the key strategies towards alleviating water scarcity problems and ensuring food security. Although the issue of increased storage can be addressed by centralized infrastructure projects such as large-scale irrigation systems and dams, an alternative is the "soft path" approach, in which existing large-scale projects are complemented by small-scale, decentralized solutions. Such a decentralized approach has been utilized in southern India for thousands of years in the form of village rainwater harvesting tanks or ponds, providing a local and inherently sustainable approach to providing sufficient water for rice cultivation. Over the last century, however, large-scale canal projects and groundwater pumping have replaced rainwater harvesting as the primary source of irrigation water. But with groundwater withdrawals now exceeding recharge in many areas and water tables continuing to drop, many NGOs and government agencies are advocating for a revival of the older rainwater harvesting systems. Questions remain, however, regarding the limits to which rainwater harvesting can provide a solution to decades of water overexploitation. In the present work, we have utilized secondary data sources to analyze the linkages between the tank irrigation systems and the village communities that depend on them within the Gundar Basin of southern Tamil Nadu. Combining socioeconomic data with information regarding climate, land use, groundwater depletion, and tank density, we have developed indicators of sustainability for these systems. Using these indicators, we have attempted to unravel the close

  8. Probabilistic assessment of the rainwater harvesting potential of schools in South Africa

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    J. G. Ndiritu

    2014-09-01

    Full Text Available In comparison to other sources of water supply, rainwater harvesting (RWH has the typical advantages of being cheaper and easier to operate and maintain. This study aimed at assessing the hydrologic rainwater harvesting potential of rural schools in South Africa by obtaining RWH storage capacity (level of supply reliability relationships of representative schools. Thirty-two schools located in three rural areas that have varied rainfall characteristics were selected for the analysis. For each school, a daily time-step behaviour analysis of the rainwater harvesting system with a specified storage was carried out for a period of 101 years (over which rainfall data was available and the number of days that the school’s daily water demand was met in each year obtained. Using the Weibull plotting position formula, the expected number of days that the demand can be met per year was then obtained for 85, 90 and 95 % reliability. For the two summer rainfall regions where a large proportion of rain falls during school holidays, the expected number of days of supply per year improved up to a storage capacity of 25 m3. For the winter rainfall region where the rainfall periods and school learning times have more co-incidence, a tank volume of 5 m3 obtained similar supply levels as larger capacities. At 90 % reliability, the supply levels for different schools in the summer rainfall area with a mean annual precipitation (MAP of 800–1000 mm/year ranged from 60 to 120 days per year, while the summer rainfall region with a lower MAP (500–600 mm gave supply levels ranging from 40 to 70 days per year. The winter rainfall area had a MAP of 500–600 mm and obtained supply levels ranging from 60 to 80 days at 90 % reliability.

  9. Rainwater Harvesting, its Prospects and Challenges in the Uplands of Talugtog, Nueva Ecija, Philippines

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    Samuel M. Contreras

    2013-12-01

    Full Text Available The prospects and challenges facing eight small water impounding projects (SWIPs in Talugtog, Nueva Ecija, an upland municipality located in Central Luzon, Philippines were evaluated using rapid appraisal and documentation of projects, interview of farmers and local officials, and a review of related studies undertaken on the same project sites. The challenges include the deterioration of structural facilities, inactive farmers associations, watershed degradation, and climate change. It also aims to evaluate improvement and innovation in the future implementation of SWIPs as rainwater harvesting facilities. The site was selected because it has the largest number of SWIPs established as one of the coping strategies during the 1997 1998 severe El Nino. Because of its location, it has no major irrigation systems and relies only on local rainwater storage facilities. The study involves 8 SWIPs established in two clusters (i. e., 5 and 3 SWIPs in a watershed as rainwater conservation and management facilities. Results indicated these clusters of SWIPs offer multiple benefits in terms of supplemental irrigation, inland fish production, and water for domestic purposes and livestock production. They also serve as strategic small-scale upland structures that enhance recharging of groundwater, prevent flooding, and provide value-adding activities such as recreation, soil and water conservation, and environmental benefits. Previous studies also identified their benefits at the farm and community levels as conserved rainwater through storage in SWIPs is translated into more economic uses. However, some SWIPs are confronted with various challenges; deterioration of structural facilities, inactive farmer associations, unabated watershed degradation, and threats of climate change. These are seriously affecting the overall performance of SWIPs. Immediate actions should include the strengthening of small water impounding system associations (SWISA, repair and

  10. Potential of rainwater harvesting in Nepal : a case study

    OpenAIRE

    Gautam, Ravi

    2016-01-01

    This paper gives an overview of RWHS in urban Kathmandu valley (27°32’13”- 27°49’10” N 85°11’31” & 85°31’38” E). The rainwater collection is during monsoon season (June-August) and some amount of water can be collected by rainwater in dry period to minimize the daily water demand among different households. The main study of research is to analyze and interpret the collected rainwater and household catchment area together to know the capacity of individual household of different land sizes. T...

  11. Effects of local and spatial conditions on the quality of harvested rainwater in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Wilbers, Gert-Jan; Sebesvari, Zita; Rechenburg, Andrea; Renaud, Fabrice G

    2013-11-01

    The objective of this study was to assess the quality of harvested rainwater in the Mekong Delta (MD), Vietnam for local (roof types, storage system and duration) and spatial (proximity of industry, main roads, coastline) conditions. 78 harvested rainwater samples were collected in the MD and analyzed for pH, turbidity, TDS, COD, nutrients (NH4, NO3, NO2, o-PO4), trace metals and coliforms. The results show that thatch roofs lead to an increase of pollutants like COD (max 23.2 mgl(-1)) and turbidity (max 10.1 mgl(-1)) whereas galvanized roofs lead to an increase of Zn (max 2.2 mgl(-1)). The other local and spatial parameters had no or only minor influence on the quality of household harvested rainwater. However, lead (Pb) (max. 16.9 μgl(-1)) and total coliforms (max. 102 500 CFU100 ml(-1)) were recorded at high concentrations, probably due to a variety of household-specific conditions such as rainwater storage, collection and handling practices.

  12. Comparative analysis of solar pasteurization versus solar disinfection for the treatment of harvested rainwater.

    Science.gov (United States)

    Strauss, André; Dobrowsky, Penelope Heather; Ndlovu, Thando; Reyneke, Brandon; Khan, Wesaal

    2016-12-09

    Numerous pathogens and opportunistic pathogens have been detected in harvested rainwater. Developing countries, in particular, require time- and cost-effective treatment strategies to improve the quality of this water source. The primary aim of the current study was thus to compare solar pasteurization (SOPAS; 70 to 79 °C; 80 to 89 °C; and ≥90 °C) to solar disinfection (SODIS; 6 and 8 hrs) for their efficiency in reducing the level of microbial contamination in harvested rainwater. The chemical quality (anions and cations) of the SOPAS and SODIS treated and untreated rainwater samples were also monitored. While the anion concentrations in all the samples were within drinking water guidelines, the concentrations of lead (Pb) and nickel (Ni) exceeded the guidelines in all the SOPAS samples. Additionally, the iron (Fe) concentrations in both the SODIS 6 and 8 hr samples were above the drinking water guidelines. A >99% reduction in Escherichia coli and heterotrophic bacteria counts was then obtained in the SOPAS and SODIS samples. Ethidium monoazide bromide quantitative polymerase chain reaction (EMA-qPCR) analysis revealed a 94.70% reduction in viable Legionella copy numbers in the SOPAS samples, while SODIS after 6 and 8 hrs yielded a 50.60% and 75.22% decrease, respectively. Similarly, a 99.61% reduction in viable Pseudomonas copy numbers was observed after SOPAS treatment, while SODIS after 6 and 8 hrs yielded a 47.27% and 58.31% decrease, respectively. While both the SOPAS and SODIS systems reduced the indicator counts to below the detection limit, EMA-qPCR analysis indicated that SOPAS treatment yielded a 2- and 3-log reduction in viable Legionella and Pseudomonas copy numbers, respectively. Additionally, SODIS after 8 hrs yielded a 2-log and 1-log reduction in Legionella and Pseudomonas copy numbers, respectively and could be considered as an alternative, cost-effective treatment method for harvested rainwater.

  13. Hydrological impact of rainwater harvesting in the Modder river basin of central South Africa

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    W. A. Welderufael

    2011-05-01

    Full Text Available Along the path of water flowing in a river basin are many water-related human interventions that modify the natural systems. Rainwater harvesting is one such intervention that involves harnessing of water in the upstream catchment. Increased water usage at upstream level is an issue of concern for downstream water availability to sustain ecosystem services. The upstream Modder River basin, located in a semi arid region in the central South Africa, is experiencing intermittent meteorological droughts causing water shortages for agriculture, livestock and domestic purpose. To address this problem a technique was developed for small scale farmers with the objective of harnessing rainwater for crop production. However, the hydrological impact of a wider adoption of this technique by farmers has not been well quantified. In this regard, the SWAT hydrological model was used to simulate the hydrological impact of such practices. The scenarios studied were: (1 Baseline scenario, based on the actual land use of 2000, which is dominated by pasture (combination of natural and some improved grass lands (PAST; (2 Partial conversion of Land use 2000 (PAST to conventional agriculture (Agri-CON; and (3 Partial conversion of Land use 2000 (PAST to in-field rainwater harvesting which was aimed at improving the precipitation use efficiency (Agri-IRWH.

    SWAT was calibrated using observed daily mean stream flow data of a sub-catchment (419 km2 in the study area. SWAT performed well in simulating the stream flow giving Nash and Sutcliffe (1970 efficiency index of 0.57 for the monthly stream flow calibration. The simulated water balance results showed that the highest peak mean monthly direct flow was obtained on Agri-CON land use (18 mm, followed by PAST (12 mm and Agri-IRWH land use (9 mm. These were 19 %, 13 % and 11 % of the mean annual rainfall, respectively. The Agri-IRWH scenario reduced direct flow by 38 % compared to Agri-CON. On the other

  14. Stochastic rainfall modeling in West Africa: Parsimonious approaches for domestic rainwater harvesting assessment

    Science.gov (United States)

    Cowden, Joshua R.; Watkins, David W., Jr.; Mihelcic, James R.

    2008-10-01

    SummarySeveral parsimonious stochastic rainfall models are developed and compared for application to domestic rainwater harvesting (DRWH) assessment in West Africa. Worldwide, improved water access rates are lowest for Sub-Saharan Africa, including the West African region, and these low rates have important implications on the health and economy of the region. Domestic rainwater harvesting (DRWH) is proposed as a potential mechanism for water supply enhancement, especially for the poor urban households in the region, which is essential for development planning and poverty alleviation initiatives. The stochastic rainfall models examined are Markov models and LARS-WG, selected due to availability and ease of use for water planners in the developing world. A first-order Markov occurrence model with a mixed exponential amount model is selected as the best option for unconditioned Markov models. However, there is no clear advantage in selecting Markov models over the LARS-WG model for DRWH in West Africa, with each model having distinct strengths and weaknesses. A multi-model approach is used in assessing DRWH in the region to illustrate the variability associated with the rainfall models. It is clear DRWH can be successfully used as a water enhancement mechanism in West Africa for certain times of the year. A 200 L drum storage capacity could potentially optimize these simple, small roof area systems for many locations in the region.

  15. Rainwater catchment system design using simulated future climate data

    Science.gov (United States)

    Wallace, Corey D.; Bailey, Ryan T.; Arabi, Mazdak

    2015-10-01

    Rainwater harvesting techniques are used worldwide to augment potable water supply, provide water for small-scale irrigation practices, increase rainwater-use efficiency for sustained crop growth in arid and semi-arid regions, decrease urban stormwater flow volumes, and in general to relieve dependency on urban water resources cycles. A number of methods have been established in recent years to estimate reliability of rainwater catchment systems (RWCS) and thereby properly size the components (roof catchment area, storage tank size) of the system for a given climatic region. These methods typically use historical or stochastically-generated rainfall patterns to quantify system performance and optimally size the system, with the latter accounting for possible rainfall scenarios based on statistical relationships of historical rainfall patterns. To design RWCS systems that can sustainably meet water demand under future climate conditions, this paper introduces a method that employs climatic data from general circulation models (GCMs) to develop a suite of catchment area vs. storage size design curves that capture uncertainty in future climate scenarios. Monthly rainfall data for the 2010-2050 time period is statistically downscaled to daily values using a Markov chain algorithm, with results used only from GCMs that yield rainfall patterns that are statistically consistent with historical rainfall patterns. The process is demonstrated through application to two climatic regions of the Federated States of Micronesia (FSM) in the western Pacific, wherein the majority of the population relies on rainwater harvesting for potable water supply. Through the use of design curves, communities can provide household RWCS that achieve a certain degree of storage reliability. The method described herein can be applied generally to any geographic region. It can be used to first, assess the future performance of existing household systems; and second, to design or modify systems

  16. Sustainable urban water supply in south India: Desalination, efficiency improvement, or rainwater harvesting?

    Science.gov (United States)

    Srinivasan, Veena; Gorelick, Steven M.; Goulder, Lawrence

    2010-10-01

    Indian megacities face severe water supply problems owing to factors ranging from growing population to high municipal pipe leakage rates; no Indian city provides 24/7 water supply. Current approaches to addressing the problem have been "utility centric," overlooking the significance of decentralized activities by consumers, groundwater extraction via private wells, and aquifer recharge by rainwater harvesting. We propose a framework that makes it possible to evaluate a wider range of centralized and decentralized policies than previously considered. The framework was used to simulate water supply and demand in a simulation model of Chennai, India. Three very different policies, supply augmentation, efficiency improvement, and rainwater harvesting, were evaluated using the model. The model results showed that none of the three policies perfectly satisfied our criteria of efficiency, reliability, equity, financial viability, and revenue generation. Instead, a combination of rainwater harvesting and efficiency improvement best meets these criteria.

  17. Economic Analysis and Feasibility of Rainwater Harvesting Systems in Urban and Peri-Urban Environments: A Review of the Global Situation with a Special Focus on Australia and Kenya

    Directory of Open Access Journals (Sweden)

    Caleb Christian Amos

    2016-04-01

    Full Text Available Rainwater harvesting (RWH plays an important role in increasing water security for individuals and governments. The demand for tools to enable technical and economic analysis of RWH systems has led to a substantial body of research in the recent past. This paper focuses on the economic aspects of domestic RWH in urban and peri-urban environments. In this regard, key issues are identified and discussed including quality and quantity of harvested water, the water demand profile, the scale of installation, interest rates, the period of analysis, real estate value, and the water-energy-food nexus. Kenya and Australia are used as reference points having different economies and opposing RWH policies. It has been found that the previous studies on financial aspects of RWH systems often had conflicting results. Most of the economic analyses have ignored the full benefits that a RWH system can offer. In view of the varying and conflicting results, there is a need to standardize the methods of economic analysis of RWH systems.

  18. Rainwater Harvesting for Military Installations -The Time is Now

    Science.gov (United States)

    2010-06-01

    Building US Army Corps of Engineers® Engineer Research and Development Center Rainwater Vault Sizing • Review occupancy - High use after morning PT...WATER NO TOME El AGUA .. US Army Corps of Engineers® Engineer Research and Development Center Mitchell Physics RWH 386,800 GPY AC 1,058,300 GPY

  19. Domestic rainwater harvesting to improve water supply in rural South Africa

    Science.gov (United States)

    Mwenge Kahinda, Jean-marc; Taigbenu, Akpofure E.; Boroto, Jean R.

    Halving the proportion of people without sustainable access to safe drinking water and basic sanitation, is one of the targets of the 7th Millennium Development Goals (MDGs). In South Africa, with its mix of developed and developing regions, 9.7 million (20%) of the people do not have access to adequate water supply and 16 million (33%) lack proper sanitation services. Domestic Rainwater Harvesting (DRWH), which provides water directly to households enables a number of small-scale productive activities, has the potential to supply water even in rural and peri-urban areas that conventional technologies cannot supply. As part of the effort to achieve the MDGs, the South African government has committed itself to provide financial assistance to poor households for the capital cost of rainwater storage tanks and related works in the rural areas. Despite this financial assistance, the legal status of DRWH remains unclear and DRWH is in fact illegal by strict application of the water legislations. Beyond the cost of installation, maintenance and proper use of the DRWH system to ensure its sustainability, there is risk of waterborne diseases. This paper explores challenges to sustainable implementation of DRWH and proposes some interventions which the South African government could implement to overcome them.

  20. Integrated control of landscape irrigation and rainwater harvesting for urban water management

    Science.gov (United States)

    Lee, J. H.; Dhakal, B.; Noh, S.; Seo, D. J.

    2016-12-01

    Demand for freshwater is increasing rapidly in large and fast-growing urban areas such as the Dallas-Fort Worth Metroplex (DFW). With almost complete reliance on surface water, water supply for DFW is limited by the available storage in the reservoir systems which is now subject to larger variability due to climate change. Landscape irrigation is estimated to account for nearly one-third of all residential water use in the US and as much as 60% in dry climate areas. In landscape irrigation, a large portion of freshwater is commonly lost by sub-optimal practices. If practiced over a large area, one may expect optimized smart irrigation to significantly reduce urban freshwater demand. For increasing on-site water supply, rainwater harvesting (RHW) is particularly attractive in that it conserves potable water while reducing stormwater runoff. Traditional static RWH methods, however, have limited success due to the inefficient water usage. If, on the other hand, lawn irrigation and rainwater harvesting can be optimized as an integrated operation and controlled adaptively to the feedback from the environmental sensors, weather conditions and forecast, one may expect the combined benefits for water conservation and stormwater management to be larger. In this work, we develop a prototype system for integrated control of lawn irrigation and RWH for water conservation and stormwater management, and assess and demonstrate the potential impact and value of the system. For in-situ evaluation, we deploy a wireless sensor network consisting of low-cost off-the-shelf sensors and open-sourced components, and collect observations of temperature, humidity, soil moisture, and solar radiation at the test site at the UTA community garden in Arlington, Texas. We assess the health of the lawn grass using normalized vegetation index (NDVI) from the time lapse images at the site. In this poster, we describe the approach and share the initial results.

  1. A methodology to assess and evaluate rainwater harvesting techniques in (semi-) arid regions

    NARCIS (Netherlands)

    Adham, Ammar; Riksen, Michel; Ouessar, Mohamed; Ritsema, Coen J.

    2016-01-01

    Arid and semi-arid regions around the world face water scarcity problems due to lack of precipitation and unpredictable rainfall patterns. For thousands of years, rainwater harvesting (RWH) techniques have been applied to cope with water scarcity. Researchers have used many different methodologie

  2. Demystifying 'Tradition': The Politics of Rainwater Harvesting in Rural Rajasthan, India

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    Saurabh Gupta

    2011-10-01

    Full Text Available The debate on traditional rainwater harvesting has largely cast the issue in terms of 'for-or-against'. Much intellectual energy has been spent on demonstrating whether traditional rainwater harvesting works or not. Yet, we know very little about how it works in specific localities. This paper seeks to address this analytical question. Taking the case of a Gandhian activist organisation, Tarun Bharat Sangh (TBS, which has received international recognition for promoting traditional rainwater harvesting by means of small earthen dams (locally known as johads in Rajasthani villages, this paper explains how a grassroots organisation, while advocating the cause of people’s control of their local natural resources, uses and manipulates the concept of 'traditional' for creating a niche for itself in the arena of soil and water conservation. The paper problematises 'traditional' rainwater harvesting and the various positive connotations associated with it in the narrative of the TBS, and highlights the lack of attention given to issues of equity in its interventions. It is suggested that deliberate efforts on the part of grassroots organisations are required to address the issues of equity if the goals of sustainable ecological practices are to be achieved in any meaningful sense.

  3. Identifying the major influences on the microbial composition of roof harvested rainwater and the implications for water quality.

    Science.gov (United States)

    Evans, C A; Coombes, P J; Dunstan, R H; Harrison, T

    2007-01-01

    Perceptions of the quality of roof harvested rainwater remain an impediment to widespread implementation of rainwater tanks on urban allotments. Previous literature reports on roof water quality have given little consideration to the relative significance of airborne environmental micro-organisms to roof catchment contamination and the issue of tank water quality. This paper outlines the findings of a recent study into the influence of weather on roof water contamination conducted at an urban housing development in Newcastle, on the east coast of Australia. Samples of direct roof run-off were collected during a number of separate rainfall events, and microbial counts were matched to climatic data corresponding to each of the monitored events. Roof run-off contamination was found to be under the strong influence of both wind speed and direction. The preliminary findings of an investigation currently under way into the microbial diversity of rainwater harvesting systems have also been presented. The results indicate that the composition of organisms present varied considerably from source to source and throughout the collection system. In all cases, evidence of faecal contamination was found to be negligible. The implications of these findings to the issues of tank water quality, health risk analysis and monitoring protocols have been discussed.

  4. Framework for Assessing the Rainwater Harvesting Potential of Residential Buildings at a National Level as an Alternative Water Resource for Domestic Water Supply in Taiwan

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    Chao-Hsien Liaw

    2014-10-01

    Full Text Available Domestic rainwater harvesting (DRWH is widely recognized as an alternative source of water in Taiwan because of water shortages. This suggests that rainwater potential should be maximized and quantified. In this article, we assess the potential of DRWH at a national level. To consider the climatic, building characteristic, economic, and ecological aspects of DRWH, we propose three categories: (1 theoretical; (2 available; and (3 environmental bearable rainwater potential. Four main steps were followed to develop the proposed framework: (1 Fifteen rainfall zones across Taiwan were generated through cluster analysis based on the average annual 10-day rainfall distributions of rainfall stations and administrative districts; (2 The roof area in each rainfall zone was estimated using a geographic information system (GIS and land use classification database; (3 The weighted percentage of rainwater use in each rainfall zone was determined by the optimal point on the storage capacity and rainwater supply reliability curve for an equivalent building from each building type; (4 The percentage of the total roof area used to harvest rainwater in each region depends on the downstream impact of the stream flow. The procedures developed in this study constitute an effective tool for preliminarily estimation of the national DRWH potential.

  5. Holistic impact assessment and cost savings of rainwater harvesting at the watershed scale

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    Santosh R. Ghimire

    2017-03-01

    Full Text Available We evaluated the impacts of domestic and agricultural rainwater harvesting (RWH systems in three watersheds within the Albemarle-Pamlico river basin (southeastern U.S. using life cycle assessment (LCA and life cycle cost assessment. Life cycle impact assessment (LCIA categories included energy demand, fossil fuel, metals, ozone depletion, global warming, acidification, smog, blue and green water use, ecotoxicity, eutrophication, and human health effects. Building upon previous LCAs of near-optimal domestic and agricultural RWH systems in the region, we scaled functional unit LCIA scores for adoption rates of 25%, 50%, 75%, and 100% and compared these to conventional municipal water and well water systems. In addition to investigating watershed-scale impacts of RWH adoption, which few studies have addressed, potential life cycle cost savings due to reduced cumulative energy demand were scaled in each watershed for a more comprehensive analysis. The importance of managing the holistic water balance, including blue water (surface/ground water, green water (rainwater use, and annual precipitation and their relationship to RWH are also addressed. RWH contributes to water resource sustainability by offsetting surface and ground water consumption and by reducing environmental and human health impacts compared to conventional sources. A watershed-wide RWH adoption rate of 25% has a number of ecological and human health benefits including blue water use reduction ranging from 2–39 Mm3, cumulative energy savings of 12–210 TJ, and reduced global warming potential of 600–10,100 Mg CO2 eq. Potential maximum lifetime energy cost savings were estimated at $5M and $24M corresponding to domestic RWH in Greens Mill and agricultural RWH in Back Creek watersheds.

  6. Rainwater Harvesting-based Safe Water Access in Diarrhea-endemic Coastal Communities of Bangladesh under Threats of Climate Change

    Science.gov (United States)

    Akanda, A. S.; Redwan, A. M.; Ali, M. A.; Alam, M.; Jutla, A.; Colwell, R. R.

    2014-12-01

    The highly populated coastal floodplains of the Bengal Delta have a long history of water-related natural calamities such as droughts, floods, and cyclones. Population centers along the floodplain corridors of the GBM (Ganges-Brahmaputra-Meghna) river system remain vulnerable to such natural hazards and waterborne epidemic outbreaks due to increasing intensity and changing frequency of extreme events over many areas in the delta region. Such changes in hydrologic extremes and resulting environmental conditions would likely lengthen the transmission seasons of prevalent waterborne diseases and alter their geographic range as well as seasonality. In addition, the combination of changing upstream precipitation and temperature, and coastal sea-level rise are exposing a vast area in Southwestern Bangladesh to increased diarrheal disease outbreaks due to higher salinity and water scarcity in the dry season as well as coastal flooding and water resources contamination in the wet season. It is thus essential to establish sustainable safe water access practices in these regions for the rural communities of low-income people. The impact of climate change in the recent past on the people of coastal rural areas of Bangladesh has been severe, and the water sector is one of its biggest victims. Previously, pond and groundwater sources were considered dependable, but salinity intrusion in both water resources have left the vulnerable people with only a few scarce ponds and forced them to depend more on rainwater than before. The poorest group is suffering the most for this crisis even though paying more of the percentage of their income especially in the dry season (December-March). As rainwater is their most preferred and dependable option during this part of the year, outbreaks of waterborne diseases can be minimized by installing rainwater harvesting systems with effective disinfection system at both household and community levels. In this study, we explore the technical

  7. Quality and seasonal variation of rainwater harvested from concrete, asphalt, ceramic tile and green roofs in Chongqing, China.

    Science.gov (United States)

    Zhang, Qianqian; Wang, Xiaoke; Hou, Peiqiang; Wan, Wuxing; Li, Ruida; Ren, Yufen; Ouyang, Zhiyun

    2014-01-01

    There is an urgent requirement to examine the quality of harvested rainwater for potable and non-potable purposes, based on the type of roofing material. In this study, we examined the effect on the quality of harvested rainwater of conventional roofing materials (concrete, asphalt and ceramic tile roofs) compared with alternative roofing materials (green roof). The results showed that the ceramic tile roof was the most suitable for rainwater-harvesting applications because of the lower concentrations of leachable pollutants. However, in this study, the green roof was not suitable for rainwater harvesting applications. In addition, seasonal trends in water quality parameters showed that pollutants in roof runoff in summer and autumn were lower than those in winter and spring. This study revealed that the quality of harvested rainwater was significantly affected by the roofing material; therefore, local government and urban planners should develop stricter testing programs and produce more weathering resistant roofing materials to allow the harvesting of rainwater for domestic and public uses.

  8. Design of a Rainwater Catchment System

    OpenAIRE

    Neil Cammardella

    2011-01-01

    Certain dimensions of a rainwater catchment and storage system were optimized using climatological and sociological data. Using only daily demand and average daily rain fall data, the following dimensions were optimized: 1) The horizontal roof area needed to collect the daily demand of water, 2) The tank size needed to store all the water collected during a heavy rain event, 3) When full, how long the tank will be able to provide water without rain, and 4) The diameter of the outlet flow orif...

  9. Probabilistic Impact Assessment of Domestic Rainwater Harvesting in Urban Slums: West Africa Case Study

    Science.gov (United States)

    Cowden, J. R.; Watkins, D. W.; Mihelcic, J. R.; Fry, L. M.

    2007-12-01

    Urban populations now exceed rural populations worldwide, creating unique challenges in providing basic services, especially in developing countries where informal or illegal settlements grow in peri-urban areas. West Africa is an acute example of the problems created by rapid urban growth, with high levels of urban poverty and low water and sanitation access rates. Although considerable effort has been made in providing improved water access and urban services to slum communities, research indicates that clean water access rates are not keeping up with urbanization rates in several areas of the world and that rapidly growing slum communities are beginning to overwhelm many prior water improvements projects. In the face of these challenges, domestic rainwater harvesting is proposed as a technologically appropriate and economically viable option for enhancing water supplies to urban slum households. However, assessing the reliability, potential health impacts, and overall cost-effectiveness of these systems on a regional level is difficult for several reasons. First, long daily rainfall records are not readily available in much of the developing world, including many regions of sub-Saharan Africa. Second, significant uncertainties exist in the relevant cost, water use, and health data. Third, to estimate the potential future impacts at the regional scale, various global change scenarios should be investigated. Finally, in addition to these technical challenges, there is also a need to develop relatively simple and transparent assessment methods for informing policy makers. A procedure is presented for assessment of domestic rainwater harvesting systems using a combination of scenario, sensitivity, and trade-off analyses. Using data from West Africa, simple stochastic weather models are developed to generate rainfall sequences for the region, which are then used to estimate the reliability of providing a range of per capita water supplies. Next, a procedure is

  10. EMA-qPCR to monitor the efficiency of a closed-coupled solar pasteurization system in reducing Legionella contamination of roof-harvested rainwater.

    Science.gov (United States)

    Reyneke, B; Dobrowsky, P H; Ndlovu, T; Khan, S; Khan, W

    2016-05-15

    Solar pasteurization is effective in reducing the level of indicator organisms in stored rainwater to within drinking water standards. However, Legionella spp. were detected at temperatures exceeding the recommended pasteurization temperatures using polymerase chain reaction assays. The aim of the current study was thus to apply EMA quantitative polymerase chain reaction (EMA-qPCR) to determine whether the Legionella spp. detected were intact cells and therefore possibly viable at pasteurization temperatures >70°C. The BacTiter-Glo™ Microbial Cell Viability Assay was also used to detect the presence of ATP in the tested samples, as ATP indicates the presence of metabolically active cells. Chemical analysis also indicated that all anions and cations were within the respective drinking water guidelines, with the exception of iron (mean: 186.76 μg/L) and aluminium (mean: 188.13 μg/L), which were detected in the pasteurized tank water samples at levels exceeding recommended guidelines. The BacTiter-Glo™ Microbial Cell Viability Assay indicated the presence of viable cells for all pasteurized temperatures tested, with the percentage of ATP (in the form of relative light units) decreasing with increasing temperature [70-79°C (96.7%); 80- 89°C (99.2%); 90-95°C (99.7%)]. EMA-qPCR then indicated that while solar pasteurization significantly reduced (p0.05) in the mean copy numbers was detected with an increase in the pasteurization temperature, with 6 × 10(3) genomic copies/mL DNA sample obtained at 95°C. As intact Legionella cells were detected in the pasteurized tank water samples, quantitative microbial risk assessment studies need to be conducted to determine the potential health risk associated with using the water for domestic purposes.

  11. A Methodology to Assess and Evaluate Rainwater Harvesting Techniques in (Semi- Arid Regions

    Directory of Open Access Journals (Sweden)

    Ammar Adham

    2016-05-01

    Full Text Available Arid and semi-arid regions around the world face water scarcity problems due to lack of precipitation and unpredictable rainfall patterns. For thousands of years, rainwater harvesting (RWH techniques have been applied to cope with water scarcity. Researchers have used many different methodologies for determining suitable sites and techniques for RWH. However, limited attention has been given to the evaluation of RWH structure performance. The aim of this research was to design a scientifically-based, generally applicable methodology to better evaluate the performance of existing RWH techniques in (semi- arid regions. The methodology integrates engineering, biophysical and socio-economic criteria using the Analytical Hierarchy Process (AHP supported by the Geographic Information System (GIS. Jessour/Tabias are the most traditional RWH techniques in the Oum Zessar watershed in south-eastern Tunisia, which were used to test this evaluation tool. Fifty-eight RWH locations (14 jessr and 44 tabia in three main sub-catchments of the watershed were assessed and evaluated. Based on the criteria selected, more than 95% of the assessed sites received low or moderate suitability scores, with only two sites receiving high suitability scores. This integrated methodology, which is highly flexible, saves time and costs, is easy to adapt to different regions and can support designers and decision makers aiming to improve the performance of existing and new RWH sites.

  12. Rainwater Harvesting and Social Networks: Visualising Interactions for Niche Governance, Resilience and Sustainability

    Directory of Open Access Journals (Sweden)

    Sarah Ward

    2016-11-01

    Full Text Available Visualising interactions across urban water systems to explore transition and change processes requires the development of methods and models at different scales. This paper contributes a model representing the network interactions of rainwater harvesting (RWH infrastructure innovators and other organisations in the UK RWH niche to identify how resilience and sustainability feature within niche governance in practice. The RWH network interaction model was constructed using a modified participatory social network analysis (SNA. The SNA was further analysed through the application of a two-part analytical framework based on niche management and the safe, resilient and sustainable (‘Safe and SuRe’ framework. Weak interactions between some RWH infrastructure innovators and other organisations highlighted reliance on a limited number of persuaders to influence the regime and landscape, which were underrepresented. Features from niche creation and management were exhibited by the RWH network interaction model, though some observed characteristics were not represented. Additional Safe and SuRe features were identified covering diverse innovation, responsivity, no protection, unconverged expectations, primary influencers, polycentric or adaptive governance and multiple learning-types. These features enable RWH infrastructure innovators and other organisations to reflect on improving resilience and sustainability, though further research in other sectors would be useful to verify and validate observation of the seven features.

  13. Potentials and limits of urban rainwater harvesting in the Middle East

    Directory of Open Access Journals (Sweden)

    J. Lange

    2011-11-01

    Full Text Available In the Middle East, water is scarce and population growth causes a rapid rise of urban centers. Since many towns of the Palestinian Authority (PA suffer from water shortage, the use of rainwater harvesting (RWH as an alternative to conventional water supply has gained increasing interest among water resources planners. This study quantifies actual volumes of urban RWH to be expected from highly variable Mediterranean rainfall. A one-parameter model uses measured potential evaporation and high resolution rainfall data as input to calculate RWH volumes from rooftops inside Ramallah, a traditional Arab town. While during average seasons a 87% runoff harvest (480 from 550 mm of rainfall can be expected, this value decreases to about 75% (190 from 250 mm of rainfall during drought seasons. A survey comprising more than 500 questionnaires suggests that approximately 40% of the houses are equipped with RWH systems from which one third are out of use. Although water quality is perceived to be favourable, only 3% of the active RWH systems are actually used for drinking and only 18% for domestic purposes. All active RWH systems investigated may harvest approximately 16 × 103 m3 of rooftop runoff during an average season and 6 × 103 m3 during droughts. When these numbers are extrapolated to all houses in Ramallah, theoretical maximum potentials increase to approximately 298 × 103 m3 during average seasons and 118 × 103 m3 during droughts. A part of this potential can easily be exhausted by rehabilitation of installed RWH systems. Also, the use of collected water for drinking should be advocated. This should go along with regular checks of water quality and regulations concerning adequate water storage and treatment/disinfection procedures where necessary. Regional estimates for the entire Lower Jordan River Basin yielded RWH potentials of 20 × 106 m

  14. Potentials and limits of urban rainwater harvesting in the Middle East

    Directory of Open Access Journals (Sweden)

    J. Lange

    2012-03-01

    Full Text Available In the Middle East, water is scarce and population growth causes a rapid rise of urban centers. Since many towns of the Palestinian Authority (PA suffer from water shortage, the use of rainwater harvesting (RWH as an alternative to conventional water supply has gained increasing interest among water resources planners. This study quantifies actual volumes of urban RWH to be expected from highly variable Mediterranean rainfall. A one-parameter model uses measured potential evaporation and high resolution rainfall data as input to calculate RWH volumes from rooftops inside Ramallah, a traditional Arab town. While during average seasons a 87% runoff harvest (480 from 550 mm of rainfall can be expected, this value decreases to about 75% (190 from 250 mm of rainfall during drought seasons. A survey comprising more than 500 questionnaires suggests that approximately 40% of the houses are equipped with RWH systems from which one third are out of use. Although water quality is perceived to be favourable, only 3% of the active RWH systems are actually used for drinking and only 18% for domestic purposes. All active RWH systems investigated may harvest approximately 16 × 103 m3 of rooftop runoff during an average season and 6 × 103 m3 during droughts. When these numbers are extrapolated to all houses in Ramallah, theoretical maximum potentials increase to approximately 298 × 103 m3 during average seasons and 118 × 103 m3 during droughts. A part of this potential can easily be exhausted by rehabilitation of installed RWH systems. The use of RWH for emergency water supply should be advocated, although care is needed because of hygienic risks. Regional estimates for the entire Lower Jordan River Basin yielded RWH potentials of 20 × 106 m3 during the average season 2002/2003 but only 3 × 106 m3 during the drought season

  15. Potentials and limits of urban rainwater harvesting in the Middle East

    Science.gov (United States)

    Lange, J.; Husary, S.; Gunkel, A.; Bastian, D.; Grodek, T.

    2012-04-01

    In the Middle East, water is scarce and population growth causes a rapid rise of urban centers. Since many towns of the Palestinian Authority (PA) suffer from water shortage, the use of rainwater harvesting (RWH) as an alternative to conventional water supply has gained increasing interest among water resources planners. This study quantifies actual volumes of urban RWH to be expected from highly variable Mediterranean rainfall. A one-parameter model uses measured potential evaporation and high resolution rainfall data as input to calculate RWH volumes from rooftops inside Ramallah, a traditional Arab town. While during average seasons a 87% runoff harvest can be expected, this value decreases to about 75% during drought seasons. A survey comprising more than 500 questionnaires suggests that approximately 40% of the houses are equipped with RWH systems from which one third are out of use. Although water quality is perceived to be favourable, only 3% of the active RWH systems are actually used for drinking and only 18% for domestic purposes. All active RWH systems investigated may harvest approximately 16 x 103 m3 of rooftop runoff during an average season and 6 x 103 m3 during a typical drought. When these numbers are extrapolated to all houses in Ramallah, theoretical maximum potentials increase to approximately 298 x 103 m3 during an average season and 118 x 103 m3 during a typical drought. A part of this potential can easily be exhausted by rehabilitation of installed RWH systems. Also, the use of collected water for drinking should be advocated. This should go along with regular checks of water quality and regulations concerning adequate water storage and treatment/disinfection procedures where necessary. Finally, we extrapolate our findings to the entire Lower Jordan River Basin. Our analysis suggests that urban RWH is a relatively small contribution to overcome water scarcity in the region and decreases significantly during droughts. Yet it is a sustainable

  16. Rainwater harvesting to alleviate water scarcity in dry conditions: A case study in Faria Catchment, Palestine

    Directory of Open Access Journals (Sweden)

    Sameer SHADEED

    2010-06-01

    Full Text Available In arid and semi-arid regions, the availability of adequate water of appropriate quality has become a limiting factor for development. This paper aims to evaluate the potential for rainwater harvesting in the arid to semi-arid Faria Catchment, in the West Bank, Palestine. Under current conditions, the supply-demand gap is increasing due to the increasing water demands of a growing population with hydrologically limited and uncertain supplies. By 2015, the gap is estimated to reach 4.5 × 106 m3. This study used the process-oriented and physically-based TRAIN-ZIN model to evaluate two different rainwater harvesting techniques during two rainfall events. The analysis shows that there is a theoretical potential for harvesting an additional 4 × 106 m3 of surface water over the entire catchment. Thus, it is essential to manage the potential available surface water supplies in the catchment to save water for dry periods when the supply-demand gap is comparatively high. Then a valuable contribution to bridging the supply-demand gap can be made.

  17. water quality determination of rainwater harvesting birkas in harshin ...

    African Journals Online (AJOL)

    Osondu

    2012-03-14

    Mar 14, 2012 ... drinking water and accompanying illnesses live in Asia and Africa among which majority of .... explained in Bartram and Balance (1996) was followed. The sample ... potential to cause central nervous system damage will be ...

  18. Effects of Climate Change on Urban Rainwater Harvesting in Colombo City, Sri Lanka

    Directory of Open Access Journals (Sweden)

    Kwong Fai A. Lo

    2015-03-01

    Full Text Available Cities are becoming increasingly vulnerable to water-related issues due to rapid urbanization, installation of complex infrastructure and changes in rainfall patterns. This study aims at assessing the impacts of climate change on rainwater harvesting systems (RWH in the tropical urban city, Colombo, Sri Lanka. The future climate change projections are downscaled from global circulation models to the urban catchment scale using the Long Ashton Research Station Weather Generator (LARS-WG, described in the Intergovernmental Panel on Climate Change (IPCC Fourth Assessment Report (AR4, coupled with Inter Comparison Project (CMIP3 model results. Historical rainfall data from 1981–2010 is used to simulate long-term future rainfall data from 2011–2099. The percentage change of the rainfall is calculated. The rainfall patterns are analyzed based on the daily, monthly, seasonal and annual time scales. Water requirements are calculated based on the selected scenario types. Rainfall and water demand data are incorporated into a water balance model. Climate change impacts for the selected RWH scenarios are calculated based on the water security analysis for each scenario. Analysis of the future rainfall data of Colombo reveals that several extreme weather events with very heavy rainfall may occur in the future. However, the frequency of these big events may not occur too often. Most of the selected global circulation models (GCMs in this study predict that there will be more rainfall towards the end of this century (2080-2099. Residential RWH systems will be more affected than non-residential systems. RWH systems in Colombo should include potential future climate changes in their future design and planning and be prepared for excess runoff and additional measures against potential overflow and urban floods.

  19. Public health implications of Acanthamoeba and multiple potential opportunistic pathogens in roof-harvested rainwater tanks.

    Science.gov (United States)

    Hamilton, K A; Ahmed, W; Palmer, A; Sidhu, J P S; Hodgers, L; Toze, S; Haas, C N

    2016-10-01

    A study of six potential opportunistic pathogens (Acanthamoeba spp., Legionella spp., Legionella longbeachae, Pseudomonas aeruginosa, Mycobacterium avium and Mycobacterium intracellulare) and an accidental human pathogen (Legionella pneumophila) in 134 roof-harvested rainwater (RHRW) tank samples was conducted using quantitative PCR (qPCR). All five opportunistic pathogens and accidental pathogen L. pneumophila were detected in rainwater tanks except Legionella longbeachae. Concentrations ranged up to 3.1×10(6) gene copies per L rainwater for Legionella spp., 9.6×10(5) gene copies per L for P. aeruginosa, 6.8×10(5) gene copies per L for M. intracellulare, 6.6×10(5) gene copies per L for Acanthamoeba spp., 1.1×10(5) gene copies per L for M. avium, and 9.8×10(3) gene copies per L for L. pneumophila. Among the organisms tested, Legionella spp. (99% tanks) were the most prevalent followed by M. intracellulare (78%). A survey of tank-owners provided data on rainwater end-uses. Fecal indicator bacteria (FIB) Escherichia coli and Enterococcus spp. were enumerated using culture-based methods, and assessed for correlations with opportunistic pathogens and L. pneumophila tested in this study. Opportunistic pathogens did not correlate well with FIB except E. coli vs. Legionella spp. (tau=0.151, P=0.009) and E. coli vs. M. intracellulare (tau=0.14, P=0.015). However, M. avium weakly correlated with both L. pneumophila (Kendall's tau=0.017, P=0.006) and M. intracellulare (tau=0.088, P=0.027), and Legionella spp. also weakly correlated with M. intracellulare (tau=0.128, P=0.028). The presence of these potential opportunistic pathogens in tank water may present health risks from both the potable and non-potable uses documented from the current survey data.

  20. Rainwater harvesting for small-scale irrigation of maize in the Central Rift Valley, Ethiopia

    Science.gov (United States)

    Keesstra, Saskia; Hartog, Maaike; Muluneh, Alemayehu; Stroosnijder, Leo

    2013-04-01

    In the Central Rift Valley of Ethiopia, small scale farmers mostly rely on rainfall for crop production. The erratic nature of rainfall causes frequent crop failures and makes the region structurally dependent on food aid. Rainwater Harvesting (RWH) is a technique to collect and store runoff that could provide water for livestock, domestic use or small scale irrigation. Usually, such irrigation is promoted for high value crops, but in the light of regional food security it may become interesting to invest in irrigation of maize. In this research, two cemented RWH cisterns were investigated to determine their economic and social potential for supplemental irrigation of maize using drip irrigation. For this, data from test fields with irrigated maize and monitoring of water levels of the cisterns were used, as well as a survey under 30 farmers living close to the experimental site. The results show that catchment size and management should be in balance with the designed RWH system, to prevent too little runoff or flooding. An analysis with Cropwat 8.0 was used to investigate the possibility of irrigating maize with the observed amounts of water in the RWH cisterns. This would suffice for 0.3-0.8 ha of maize. For a RWH cistern with a drip irrigation system to be economically viable, the production on this acreage should become 3-4 ton/ha; 2.5 times higher than the current yield. But the biggest challenge would be to change the perception of respondents, who don't find it logical to spend precious water on a common crop like maize. Therefore, if the Ethiopian government considers the irrigation of maize to be important for regional food security, it is recommended to either subsidize the construction of RWH cisterns or provide credit on favourable terms.

  1. Scenario analysis of rainwater harvesting and use on a large scale–assessment of runoff, storage and economic performance for the case study Amsterdam Airport Schiphol

    NARCIS (Netherlands)

    Kuller, Martijn; Dolman, N.J.; Vreeburg, J.H.G.; Spiller, Marc

    2017-01-01

    Research on rainwater harvesting mainly focuses on a building scale. Scant information is available about its performance on a large scale. This study aims to determine the potential for, and economic viability of meeting non-potable water demand by rainwater harvesting for a large scale case

  2. Scenario analysis of rainwater harvesting and use on a large scale–assessment of runoff, storage and economic performance for the case study Amsterdam Airport Schiphol

    NARCIS (Netherlands)

    Kuller, Martijn; Dolman, N.J.; Vreeburg, J.H.G.; Spiller, Marc

    2017-01-01

    Research on rainwater harvesting mainly focuses on a building scale. Scant information is available about its performance on a large scale. This study aims to determine the potential for, and economic viability of meeting non-potable water demand by rainwater harvesting for a large scale case (21

  3. Effects of rainwater harvesting on herbage diversity and productivity in degraded Aravalli hills in western India

    Institute of Scientific and Technical Information of China (English)

    G. Singh; G.R. Choadhary; B.Ram; N.K. Limba

    2011-01-01

    Over-exploitation and rural growth have severely damagednative vegetations of Aravalli hills in Rajasthan, India. This study wasconducted to evaluate the effects of different restoration practices (I.e.,rainwater harvesting (RWH) and planting of tree seedlings) on improve-ment in soil water and nutrients and growth and biomass of herbaceousvegetation. Contour trench (CT), Gradonie (G), Box trench (BT), V-ditch(VD) and a control were imposed on 75 plots (each of 700 m) in naturalslope gradient defined as 20% slopes in 2005.Each plot had three micro-sites of 1-m at up (USP), middle (MSP) andlower (LSP) part of the plot for observation in 2008. The existed gradient(due to soil texture and topographic features) of soil Ph, EC, SOC, NH-N, NO-N and PO-P in June 2005 between >20% to 20% slopes, comparedwith -P. Further, CT treatment was found to be the best treat-ment in minimizing biomass variance in different slopes. Conclusively,soil texture and topographic features controlled soil water and nutrientsavailability. Rainwater harvesting techniques increased soil water storageand nutrient retention and also enhanced vegetation status and biomassby minimizing the effects of hillslopes. Thus depending upon the siteconditions, suitable RWH technique could be adopted to increase herb-age biomass while rehabilitating the degraded hills.

  4. Modelling and optimizing rainwater harvesting in the wadi Oum Zessar watershed, Tunisia

    Science.gov (United States)

    Ali, Ammar; Wesseling, Jan G.; Riksen, Michel; Ouessar, Mohamed; Ritsema, Coen

    2016-04-01

    Rainfall in arid and semi-arid regions is generally insufficient to meet crop water requirements. Rainwater harvesting (RWH) techniques have been adapted in these regions to minimise the risk from droughts. The demand for water has increased but water resources have become scarcer, so the assessment and modelling of surface water related to RWH in catchments has become a necessity. An understanding of the hydrological processes at the sub-catchment level is generally lacking, and little attention has been given to the assessment of RWH after implementation. A simple water-balance model was developed, combined with field measurements to analyse the performance of various RWH designs and management scenarios. The model was applied to rainfall data for 1980-2004 in 25 sub-catchments of the watershed of Wadi Oum Zessar (southeastern Tunisia), and the terms of the water-balance equation were calculated for more than 300 individual rainfall events. The performance and analysis of RWH in three types of years (dry, normal, and wet) are presented and discussed. This study emphasises the advantages of simulating long-term water balances at the sub-catchment level for improving our understanding of hydrological processes in the RWH system and provides several solutions for optimising RWH performance in various scenarios. Changing the spillway heights together with the flow directions had a significant impact on the performance of RWH by increasing the efficiency of water availability for crop requirements in 92% of all sub-catchments in a wet year compared to 44% in base scenario (no change in spillway heights/flow direction).

  5. Utilization state and thought on rainwater harvesting in Kenya%肯尼亚雨水集流利用现状及思考

    Institute of Scientific and Technical Information of China (English)

    曹建生; 董文旭; 李晓欣; 陈素英; 胡春胜

    2016-01-01

    AbstractKenya is in East Africa and has a tropical monsoon climate. Prolonged droughts and unexpected shifts in normal weather patterns are the main hurdles preventing Kenya from realizing poverty eradication, food security, and environmental sustainability. Rainwater harvesting, as a highly efficient old economic technique of saving additional water, has a history spanning over thousands of years. Due to lack efficient medium for natural rainwater storage in Kenya, rainwater harvesting has become a critical mode of fighting off drought in the country. A systemic analysis of the state of rainwater harvesting was conducted along with the local climatic, hydrological and geographic conditions for realistically determining highly efficient storage and use of rainwater. In this study, based on virtual field trips and discussions with local farmers and researchers in educational institutions, the state of utilization of various rainwater harvesting systems in Kenya was evaluated. The study analyzed the differences in space and time in rainwater collection methods at courtyard, farmland and basin levels. The study also determined rainfall, infiltration, runoff and evaporation in relation to regional water cycle and water balance. The analysis showed that it was critical to increase the total volume of water resources by using various rainwater harvesting techniques, and to reduce invalid evaporation, especially unproductive water evaporation. The main way of increasing the volume of available water resources was by scientifically using natural and artificial water storage media. Even though rainwater harvesting systems that had relatively mature technologies were very common in daily domestic life, there was still big development space for improvement in less than 500 mm annual rainfall in agricultural production area. The prevailing problems faced in the region were how to improve the low efficiency of rainwater harvesting, and to reasonably store and efficiently use

  6. Improved framework model to allocate optimal rainwater harvesting sites in small watersheds for agro-forestry uses

    Science.gov (United States)

    Terêncio, D. P. S.; Sanches Fernandes, L. F.; Cortes, R. M. V.; Pacheco, F. A. L.

    2017-07-01

    This study introduces an improved rainwater harvesting (RWH) suitability model to help the implementation of agro-forestry projects (irrigation, wildfire combat) in catchments. The model combines a planning workflow to define suitability of catchments based on physical, socio-economic and ecologic variables, with an allocation workflow to constrain suitable RWH sites as function of project specific features (e.g., distance from rainfall collection to application area). The planning workflow comprises a Multi Criteria Analysis (MCA) implemented on a Geographic Information System (GIS), whereas the allocation workflow is based on a multiple-parameter ranking analysis. When compared to other similar models, improvement comes with the flexible weights of MCA and the entire allocation workflow. The method is tested in a contaminated watershed (the Ave River basin) located in Portugal. The pilot project encompasses the irrigation of a 400 ha crop land that consumes 2.69 Mm3 of water per year. The application of harvested water in the irrigation replaces the use of stream water with excessive anthropogenic nutrients that may raise nitrosamines in the food and accumulation in the food chain, with severe consequences to human health (cancer). The selected rainfall collection catchment is capable to harvest 12 Mm3·yr-1 (≈ 4.5 × the requirement) and is roughly 3 km far from the application area assuring crop irrigation by gravity flow with modest transport costs. The RWH system is an 8-meter high that can be built in earth with reduced costs.

  7. SOFT PATH WATER MANAGEMENT IN DRY AND ARID REGIONS OF THE ARABIAN PENINSULA BY RAINWATER HARVESTING

    Directory of Open Access Journals (Sweden)

    M. T. Amin

    2013-01-01

    Full Text Available Saudi Arabia has limited renewable water resources and the groundwater is the main source of water in Saudi Arabia which. With an arid climate, it receives about 50-100 mm/year of rainfall in Central, Eastern and Northern regions. There are few studies investigating the future regional climate change and some has predicted a decrease in precipitation but with extreme climate events such as flood and stormy rainfall events. Authors have evaluated the thirty-one years record of the rainfall in different parts of the Kingdom and found an increasing trend in annual maximum daily rainfalls at investigated locations signifying the more extreme rainfall evens and resulting floods of short-durations. A brief review of the Rainwater Harvesting and Management (RWHM practices in the Arab region and the current use of rainwater in Saudi Arabia is presented and keeping in mind the climate impacts on the water resources, authors have suggested rooftop RWHM as a soft-path water management strategy to avoid short-term flooding problems in urban areas. Cooperation between government and non-government sectors is also recommended for successful implementations of small-scale, decentralized and cost-effective practice of RWHM at individual/community levels.

  8. Feasibility of Rainwater Harvesting to fulfill potable water demand using quantitative water management in low-lying delta regions of Asia

    Science.gov (United States)

    Mahmood, A.; Hossain, F.

    2016-12-01

    Low-lying deltas of Asian region are usually densely populated and located in developing countries situated at the downstream end of major rivers. Extensive dam construction by the upstream countries has now caused water scarcity in large portions of low-lying deltas. Most inhabitants depend on shallow tube well for safe drinking water that tend to suffer from water quality issues (e.g. Arsenic contamination). In addition, people also get infected from water borne diseases like Cholera and Typhoid due to lack of safe drinking water. Developing a centralized piped network based water supply system is often not a feasible option in rural regions. Due to social acceptability, environment friendliness, lower capital and maintenance cost, rainwater harvesting can be the most sustainable option to supply safe drinking water in rural areas. In this study, first we estimate the monthly rainfall variability using long precipitation climatology from satellite precipitation data. The upper and lower bounds of monthly harvestable rainwater were estimated for each satellite precipitation grid. Taking this lower bound of monthly harvestable rainwater as input, we use quantitative water management concept to determine the percent of the time of the year potable water demand can be fulfilled. Analysis indicates that a 6 m³ reservoir tank can fulfill the potable water demand of a 6 person family throughout a year in almost all parts of this region.

  9. The socioecohydrology of rainwater harvesting in India: understanding water storage and release dynamics across spatial scales

    Science.gov (United States)

    Van Meter, Kimberly J.; Steiff, Michael; McLaughlin, Daniel L.; Basu, Nandita B.

    2016-07-01

    Rainwater harvesting (RWH), the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional RWH systems have fallen into disrepair due to increasing dependence on groundwater. This dependence has contributed to accelerated decline in groundwater resources, which has in turn led to increased efforts at the state and national levels to revive older RWH systems. Critical to the success of such efforts is an improved understanding of how these ancient systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Knowledge is especially lacking regarding the water-exchange dynamics of these RWH tanks at tank and catchment scales, and how these exchanges regulate tank performance and catchment water balances. Here, we use fine-scale, water-level variation to quantify daily fluxes of groundwater, evapotranspiration (ET), and sluice outflows in four tanks over the 2013 northeast monsoon season in a tank cascade that covers a catchment area of 28 km2. At the tank scale, our results indicate that groundwater recharge and irrigation outflows comprise the largest fractions of the tank water budget, with ET accounting for only 13-22 % of the outflows. At the scale of the cascade, we observe a distinct spatial pattern in groundwater-exchange dynamics, with the frequency and magnitude of groundwater inflows increasing down the cascade of tanks. The significant magnitude of return flows along the tank cascade leads to the most downgradient tank in the cascade having an outflow-to-capacity ratio greater than 2. At the catchment scale, the presence of tanks in the landscape dramatically alters the catchment water balance, with runoff decreasing by

  10. Micrometeorological measurements and vapour pressure deficit relations under in-field rainwater harvesting

    Science.gov (United States)

    Tesfuhuney, Weldemichael A.; Walker, Sue; Van Rensburg, Leon D.; Steyn, A. Stephan

    2016-08-01

    In a cropped field, microclimate and thermal stability conditions depend on the canopy structures and the prevailing weather. The main aim of the study therefore was to characterize the vertical profiles of weather variables within and above a maize (Zea mays L.) canopy and to describe the water vapour pressure deficit (VPD) under different atmospheric and soil surface conditions for both wide and narrow runoff strips with the in-field rainwater harvesting (IRWH) system. Micrometeorological measurements of wind, temperature and relative humidity were performed at eight levels, within canopy (1.8 and 2.1 m), and just above the canopy (2.4, 2.7, 3.0, and 3.3 m) up to reference levels (3.9 and 4.5 m) when the maize reached a maximum height of 2.2 m. Under incomplete canopy cover of the IRWH system, two important factors complicated evapotranspiration estimation, namely the local advection and high temperatures of the bare soil between adjacent plant rows. Diurnal variations of water vapour related to turbulence at each locality and its position in the thermal internal boundary layers. Generally, advection was more pronounced in wide runoff strips than narrow strips. On wide runoff strips the wind was more effective in replacing the air between the rows and maintained a higher driving force for evaporation. The maximum VPD over the narrow strips was observed at reference level during a dry day, at about 2.2 kPa in the afternoon, while wet day VPD reached a maximum of 1.8 kPa. The VPD of the wide runoff strips correlated negatively with wind speed, but showed a fairly positive correlation with some scattered values on wet days after rain. Therefore, profile characteristics within and above plant canopies played a key role in determining the VPD and consequently, could help to explain transpiration rates of crops. Hence, VPD relations enhanced the understanding of the heat energy exchange processes under the heterogeneous nature of maize canopy of the IRWH tillage system.

  11. A New Approach to Urban Rainwater Management

    Institute of Scientific and Technical Information of China (English)

    ZENG Bing; TAN Hai-qiao; WU Li-juan

    2007-01-01

    Based on an analysis of our research results and the main problems relating to urban rainwater treatment, we propose a new approach to urban rainwater management in China. The necessity and feasibility of such a new approach are discussed. From an ecological point of view all components of the global system, including residents living in cities,have the same right to enjoy rainwater. Therefore, urban rainwater should neither be simply drained as waste water, nor be completely harvested as a kind of resource. The objective of this new approach is to maintain the natural hydrological cycle in urban areas during urbanization. When necessary, it could also be used to regulate the amount of runoff,evaporation and infiltration in a city in order to rehabilitate the hydrological cycle given the local conditions. Three basic principles should be adopted in rainwater management, i.e., separation of rainfall from sewage, limited utilization and small and decentralized facilities. Four methods can be used for urban rainwater management: rainwater harvest,rainwater infiltration, rainwater storage and rainwater pipes. The natural hydrological cycle in urban areas could be rehabilitated through rainwater management, which is of great importance for sustainable development of our cities.

  12. Prevalence of virulence genes associated with pathogenic Escherichia coli strains isolated from domestically harvested rainwater during low- and high-rainfall periods.

    Science.gov (United States)

    Dobrowsky, P H; van Deventer, A; De Kwaadsteniet, M; Ndlovu, T; Khan, S; Cloete, T E; Khan, W

    2014-03-01

    The possible health risks associated with the consumption of harvested rainwater remains one of the major obstacles hampering its large-scale implementation in water limited countries such as South Africa. Rainwater tank samples collected on eight occasions during the low- and high-rainfall periods (March to August 2012) in Kleinmond, South Africa, were monitored for the presence of virulence genes associated with Escherichia coli. The identity of presumptive E. coli isolates in rainwater samples collected from 10 domestic rainwater harvesting (DRWH) tanks throughout the sampling period was confirmed through universal 16S rRNA PCR with subsequent sequencing and phylogenetic analysis. Species-specific primers were also used to routinely screen for the virulent genes, aggR, stx, eae, and ipaH found in enteroaggregative E. coli (EAEC), enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and enteroinvasive E. coli, respectively, in the rainwater samples. Of the 92 E. coli strains isolated from the rainwater using culture based techniques, 6% were presumptively positively identified as E. coli O157:H7 using 16S rRNA. Furthermore, virulent pathogenic E. coli genes were detected in 3% (EPEC and EHEC) and 16% (EAEC) of the 80 rainwater samples collected during the sampling period from the 10 DRWH tanks. This study thus contributes valuable information to the limited data available regarding the ongoing prevalence of virulent pathotypes of E. coli in harvested rainwater during a longitudinal study in a high-population-density, periurban setting.

  13. A Reliability Analysis of a Rainfall Harvesting System in Southern Italy

    OpenAIRE

    Lorena Liuzzo; Vincenza Notaro; Gabriele Freni

    2016-01-01

    Rainwater harvesting (RWH) may be an effective alternative water supply solution in regions affected by water scarcity. It has recently become a particularly important option in arid and semi-arid areas (like Mediterranean basins), mostly because of its many benefits and affordable costs. This study provides an analysis of the reliability of using a rainwater harvesting system to supply water for toilet flushing and garden irrigation purposes, with reference to a single-family home in a resid...

  14. [Water impounding characteristics of bamboo-shaped rainwater harvesting ditch in the hilly loess region].

    Science.gov (United States)

    Lin, Jun; Wang, You-Ke; Wei, Xin-Dong; Xiao, Sen; Zhang, Xue

    2013-12-01

    Bamboo-shaped rainwater harvesting ditch (BRHD) is a new water harvesting and application technology being promoted in the hilly loess region of North Shannxi Province. This paper measured the soil moisture condition and water storage capacity of BRHDs filled with straw, branch or gravel through field and simulated rainfall experiments to evaluate the water holding and absorption capacity of different BRHD fillers. From May to October, the water storage of BRHDs showed a decrease trend at first and then increased in field experiment. The water storage depths within 30-200 cm profile of branch ditch (BD), gravel ditch (GD) and straw ditch (SD) were 186.76, 177.23 and 169.26 mm in May, respectively, and increased by 14.24, 20.28 and 21.23 mm in October, respectively. In contrast, the water storage depth of the level bench was reduced by 6.52 mm in October from 185.76 mm in May. The soil water restoration depth was different between BRHDs with different fillers and the level bench within 30-200 cm profile in October. The SD and BD had the deepest restoration depth (140 cm), followed by GD (110 cm), and the level bench was the minimum (80 cm). Through rainfall simulation experiment, the amount of water intercepted by BRHD was in the order of SD (99.5 L) > GD (91 L) > BD (71.5 L). The water-holding rate of straw and branch showed logarithmic function with soaking time, while the water-absorption rate followed a power function. Moreover, there was a negative logarithm correlation between water-holding rate and water-absorption rate. Straw showed a better water holding and absorption capacity than branch. Gravel had a weak water holding and absorption capacity which was almost not changed during soaking, while it displayed a negative liner correlation between water holding rate and absorption rate. The three kinds of BRHDs could be applied in the hilly loess region, and that filled with straw would exhibit the best capacity of water interception and holding.

  15. Fuzzy Logic Modelling of the Effects of Pollution on Domestic Roof-Harvested Rainwater Quality in Residential and Industrial Environments.

    Science.gov (United States)

    Akintola, Olayiwola Akin; Sangodoyin, Abimbola Yisau; Agunbiade, Foluso Oyedotun

    2016-07-01

    This study presents the effects of environmental pollution on the quality of domestic roof-harvested rainwater (DRHRW) using fuzzy comprehensive assessment (FCA). Seven metals (Cu, Cd, Pb, Zn, Fe, Ca, and Mg) and six water-quality parameters (Acidity, PO4 (3-), SO4 (2-), NO3 (-) , Cl(-), and pH) were investigated in DRHRW sampled from 12 sampling points each from Ibadan (residential) and Lagos (industrial) environments, Nigeria. The results of these parameters were formulated into membership function fuzzy matrices based on four contamination classifications of high, marginal, low, and poor qualities using regulatory limits as criteria. The products membership function matrices and weight matrices generated indices that classified the degree of anthropogenic activity impact on the sites. Results of FCA classified the DRHRW from residential environment as between high and marginal quality, whereas DRHRW from industrial environment is classified between marginal and low quality. Lead and Cd were major contaminants of concern found in these harvested water.

  16. Advances and Perspectives of Urban Rainwater Harvesting and Using Technologies in China%城市雨水收集利用的技术进展及在我国的应用前景

    Institute of Scientific and Technical Information of China (English)

    杨硕; 代政; 刘春光

    2015-01-01

    With increasing water consumption demands,the harvesting and using of rainwater has become an important choice for the alleviation of urban water deficiency. In this paper,rainwater harvesting technologies and their applications both at home and abroad were reviewed,and major methods,applicable areas and approaches for urban rainwater harvest-ing and using were summed up. From the perspectives of system management,process and facilities and etc.,application prospects of these technologies were forecasted.%随着用水需求的不断增大,收集利用雨水已成为缓解城市用水紧张的一个重要选择。简单介绍了国内外雨水收集技术的开发和应用情况,归纳了城市雨水收集利用的主要方式、适用区域和使用途径,从系统管理、工艺设施等方面分析了存在的问题,并进行了应用前景的展望。

  17. TRANSFER RESERVOIR AS A RAINWATER DRAINAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Robert Malmur

    2016-06-01

    Full Text Available Intensive rainfalls and snow melting often cause floods in protected areas and overflow the existing sewage systems. Such cases are particularly burdensome for the inhabitants and cause considerable physical losses. One of the possible constructional solutions to ensure the effective outflow of stormwater are transfer reservoirs located between the draining system and a receiver set discussed in this paper. If gravity outflow of sewage is impossible, the initial part of sewage volume is accumulated in the transfer reservoir and then it is transferred into the water receiver set. However, gravity discharge of sewage to the water receiver set occurs through transfer chambers in the transfer reservoir.

  18. Rainwater harvesting for dryland agriculture in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.

    2012-01-01

    The Ethiopian drylands occupy about 65% of the total land mass (close to 700,000km2) of the country. The predominantly rainfed agriculture in these drylands is highly constrained due to erratic rainfall, long dry-spells and excessive loss of rainwater through non-productive pathways (surf

  19. Rainwater harvesting for dryland agriculture in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.

    2012-01-01

    The Ethiopian drylands occupy about 65% of the total land mass (close to 700,000km2) of the country. The predominantly rainfed agriculture in these drylands is highly constrained due to erratic rainfall, long dry-spells and excessive loss of rainwater through non-productive pathways

  20. Reducing occurrence of Giardia duodenalis in children living in semiarid regions: impact of a large scale rainwater harvesting initiative.

    Directory of Open Access Journals (Sweden)

    Jacqueline Evangelista Fonseca

    2014-06-01

    Full Text Available BACKGROUND: In Brazil, about two million people living in rural semiarid regions were benefited with the construction of rainwater cement cisterns, as an initiative from the program "One Million Cisterns" (P1MC. Nevertheless, few epidemiological studies have been conducted to assess health risks or protection effects associated with consumption of this water source. The aim of this study was to evaluate whether access to rainwater harvesting cisterns is associated with the decrease in the occurrence of Giardia duodenalis infections in children, compared to other children living in households supplied by other water sources. METHODOLOGY/PRINCIPAL FINDINGS: A quasi-experimental study with two concurrent cohorts was developed in two rural municipalities of the semiarid region of Brazil. A sample of 664 children, aged between 4 months and 5 years old, was followed up, of which 332 had access to rainwater cisterns (cistern group and 332 did not, having water supplied from alternative sources (comparison group. In a period of approximately one year (2010 intestinal parasites were investigated in feces three times. The prevalence of G. duodenalis in children from the cistern group ranged from 4.8 to 10.5%, while the prevalence in the comparison group ranged from 7.6 to 16.7%. Multivariate analysis (GEE showed a higher risk of G. duodenalis infection in children who did not have access to rainwater cisterns, when compared to children who did (OR 1.72; 95% CI 1.14-2.59. The other variables associated with G. duodenalis infection were: number of rooms per house (OR 0.89; 95% CI 0.80-0.99; family income (OR0.48; 95% CI 0.26-0.88; birth order (OR 1.72; 95% CI 1.17-2.51; preterm children (OR 1.70; 95% CI 1.19-2.43; and improper hand hygiene prior to food preparation (OR 4.78; 95% CI 1.95-11.76. CONCLUSIONS/SIGNIFICANCE: Ownership of a rainwater cistern is associated with a lower prevalence of G. duodenalis infection in children after adjustment for

  1. Roof-harvested rainwater for potable purposes: application of solar disinfection (SODIS) and limitations.

    Science.gov (United States)

    Amin, Muhammad Tahir; Han, Mooyoung

    2009-01-01

    Efficiency of solar disinfection (SODIS) was evaluated for the potability of rainwater in view of the increasing water and energy crises especially in developing countries. Rainwater samples were collected from an underground storage tank in 2 L polyethylene terephthalate (PET) bottles and SODIS efficiency was evaluated at different weather conditions. For optimizing SODIS, PET bottles with different backing surfaces to enhance the optical and thermal effects of SODIS were used and different physicochemical parameters were selected and evaluated along with microbial re-growth observations and calculating microbial decay constants. Total and fecal coliforms were used along with Escherichia Coli and Heterotrophic Plate Counts (HPC) as basic microbial and indicator organisms of water quality. For irradiance less than 600 W/m(2), reflective type PET bottles were best types while for radiations greater than 700 W/m(2), absorptive type PET bottles offered best solution due to the synergistic effects of both thermal and UV radiations. Microbial inactivation did not improve significantly by changing the initial pH and turbidity values but optimum SODIS efficiency is achieved for rainwater with acidic pH and low initial turbidity values by keeping air-spaced PET bottles in undisturbed conditions. Microbial re-growth occurred after one day only at higher turbidity values and with basic pH values. First-order reaction rate constant was in accordance with recent findings for TC but contradicted with previous researches for E. coli. No microbial parameter met drinking water guidelines even under strong experimental weather conditions rendering SODIS ineffective for complete disinfection and hence needed more exposure time or stronger sunlight radiations. With maximum possible storage of rainwater, however, and by using some means for accelerating SODIS process, rainwater can be disinfected and used for potable purposes.

  2. Assessing the potential of rainwater harvesting to sustain livelihoods in Sub-Saharan Africa under climate change

    Science.gov (United States)

    Lebel, S.; Forster, P.; Fleskens, L.; Irvine, B.

    2013-12-01

    Food security in Africa is extremely susceptible to erratic rainfall patterns, with 90% of agriculture done under rainfed conditions. While climate change could lead to an increased frequency of dry-spell events and shortened growing seasons, impact studies tend to overestimate their negative impacts on crop production by ignoring the potential of adaptation strategies to mitigate those impacts. Improved soil and water management strategies such as in situ rainwater harvesting (RWH) can effectively increase the resilience of cropping systems to those factors by storing additional water in the soil profile. Here we evaluate the extent to which RWH acts to increase the flexibility in planting and harvest dates, and help stabilize crop yields under various environmental and climatic conditions. Three field sites located within probable livelihood transition zones identified by Jones and Thornton (2009) were selected for further analysis in Burkina Faso, Ethiopia, and Zambia. With the use of the Soil and Water Assessment Tool (SWAT), a watershed-scale process-based biophysical model combined with a crop model component (EPIC), the reduction in the probability of failed seasons associated with the use of RWH for three crops (sorghum, millet, and maize), as well as changes in simulated yields under current climatic conditions and for the 2050s under RCP8.5 were quantified. The climate change impacts methodology suggested in SWAT, which uses monthly historical climate statistics in a weather generator combined with a simple change in monthly means from GCM projections, was replaced by bias corrected daily time series from GCMs. In fact, the SWAT methodology assumes that the variance in rainfall remains unchanged in the future, while models predict a significant change in the frequency and intensity of rainfall events which have non-negligible impacts on hydrological and biological processes. As GCMs tend to underestimate the intensity of rainfall events and overestimate

  3. Quality of Rainwater from Different Roof Material

    Directory of Open Access Journals (Sweden)

    Olaoye, R.A

    2012-08-01

    Full Text Available Roof material is an important consideration when designing a rainwater catchment system .This is because it affects the quality of the harvested rainwater which invariably affects the usage as potable or non potable.This study was carried out to determine the quality of rainwater from four different roofing materials (asbestos, aluminium, concrete and corrugated plastic within Ogbomosho North Local Government Area of Oyo State, Nigeria, between the months of July to October, 2011. The rainwater samples were taken to the laboratory and analyzed as recommended by Nigerian standard for Drinking Water Quality (NSDQW and World Health Organization (WHO.All the Physical and most of the chemical parameters analyzed conformed to the recommended standard value apart from chloride and total hardness value. Of interest is the rainwater sample from asbestos roofing sheet which had the highest mean value for pH (6.75, total hardness (84 – 86mg/l, aluminium concentration (3 – 9 mg/l, copper (0.03 – 0.04 mg/l, nitrate (31.9 – 39mg/l, and sulphate value between 11- 14mg/l, although, all these parameters fell within the standard values. However, Coliform as bacterial indicator was present in samples from asbestos, concrete and corrugated plastic roof, only the aluminium roof was free from pathogenic contamination. To ensure that the rainwater harvested satisfies health requirement for consumption as specified, all the harvested rainwater should be given some level of treatment in terms of pH, total hardness, chloride concentration and bacterial contamination. It was recommended that the rainwater from all the roofs in this case study area, be carefully examined. Consequently, if the harvested rainwater is being considered for domestic use, the gutters and the catchment areas should be regularly cleaned to remove animal droppings and leaves from over hanging trees as well as boiled to adequate temperature.

  4. Microbial quality and suitability of roof-harvested rainwater in rural villages for crop irrigation and domestic use.

    Science.gov (United States)

    Jongman, Mosimanegape; Korsten, Lise

    2016-12-01

    The study aimed at assessing the microbiological quality and suitability of roof-harvested rainwater (RHRW) for crop irrigation and domestic use. In total, 80 rainwater tanks (246 samples) across three rural villages (Ga-Molepane, Jericho and Luthngele) were visited. Culture-based techniques were used to isolate bacterial microbes and identities were confirmed using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF-MS). Uncultured fungal populations were also identified using pyrosequencing. Salmonella spp. (3%), Listeria monocytogenes (22%), total coliforms (57.7%), Escherichia coli (30.5%), Enterococcus spp. (48.8%), Pseudomonas spp. (21.5%) were detected in RHRW samples after rainfall. Fungal sequences belonging to species known to cause fever, coughing and shortness of breath in humans (Cryptococcus spp.) were identified. This study indicates that RHRW quality can be affected by external factors such as faecal material and debris on rooftops. The use of untreated RHRW could pose a potential health risk if used for irrigation of crops or domestic use, especially in the case of a relative high population of immunocompromised individuals. This study does not dispute the fact that RHRW is an alternative irrigation water source but it recommends treatment before use for domestic purposes or for watering crops.

  5. The socio-ecohydrology of rainwater harvesting in India: understanding water storage and release dynamics at tank and catchment scales

    Science.gov (United States)

    Van Meter, K. J.; Basu, N. B.; McLaughlin, D. L.; Steiff, M.

    2015-11-01

    Rainwater harvesting (RWH), the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional RWH systems have fallen into disrepair due to increasing dependence on groundwater. This dependence has contributed to an accelerated decline in groundwater resources, which has in turn led to increased efforts at the state and national levels to revive older RWH systems. Critical to the success of such efforts is an improved understanding of how these ancient systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Knowledge is especially lacking regarding the water-exchange dynamics of these RWH "tanks" at tank and catchment scales, and how these exchanges regulate tank performance and catchment water balances. Here, we use fine-scale water-level variation to quantify daily fluxes of groundwater, evapotranspiration (ET), and sluice outflows in four tanks over the 2013 northeast monsoon season in a tank cascade that covers a catchment area of 28 km2. At the tank scale, our results indicate that groundwater recharge and irrigation outflows comprise the largest fractions of the tank water budget, with ET accounting for only 13-22 % of the outflows. At the scale of the cascade, we observe a distinct spatial pattern in groundwater-exchange dynamics, with the frequency and magnitude of groundwater inflows increasing down the cascade of tanks. The significant magnitude of return flows along the tank cascade leads to the most downgradient tank in the cascade having an outflow-to capacity ratio greater than 2. The presence of tanks in the landscape dramatically alters the catchment water balance, with runoff decreasing by nearly 75 %, and

  6. The socio-ecohydrology of rainwater harvesting in India: understanding water storage and release dynamics at tank and catchment scales

    Directory of Open Access Journals (Sweden)

    K. J. Van Meter

    2015-11-01

    Full Text Available Rainwater harvesting (RWH, the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional RWH systems have fallen into disrepair due to increasing dependence on groundwater. This dependence has contributed to an accelerated decline in groundwater resources, which has in turn led to increased efforts at the state and national levels to revive older RWH systems. Critical to the success of such efforts is an improved understanding of how these ancient systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Knowledge is especially lacking regarding the water-exchange dynamics of these RWH "tanks" at tank and catchment scales, and how these exchanges regulate tank performance and catchment water balances. Here, we use fine-scale water-level variation to quantify daily fluxes of groundwater, evapotranspiration (ET, and sluice outflows in four tanks over the 2013 northeast monsoon season in a tank cascade that covers a catchment area of 28 km2. At the tank scale, our results indicate that groundwater recharge and irrigation outflows comprise the largest fractions of the tank water budget, with ET accounting for only 13–22 % of the outflows. At the scale of the cascade, we observe a distinct spatial pattern in groundwater-exchange dynamics, with the frequency and magnitude of groundwater inflows increasing down the cascade of tanks. The significant magnitude of return flows along the tank cascade leads to the most downgradient tank in the cascade having an outflow-to capacity ratio greater than 2. The presence of tanks in the landscape dramatically alters the catchment water balance, with runoff decreasing by

  7. How much drinking water can be saved by using rainwater harvesting on a large urban area? application to Paris agglomeration.

    Science.gov (United States)

    Belmeziti, Ali; Coutard, Olivier; de Gouvello, Bernard

    2014-01-01

    This paper is based on a prospective scenario of development of rainwater harvesting (RWH) on a given large urban area (such as metropolitan area or region). In such a perspective, a new method is proposed to quantify the related potential of potable water savings (PPWS) indicator on this type of area by adapting the reference model usually used on the building level. The method is based on four setting-up principles: gathering (definition of buildings-types and municipalities-types), progressing (use of an intermediate level), increasing (choice of an upper estimation) and prioritizing (ranking the stakes of RWH). Its application to the Paris agglomeration shows that is possible to save up to 11% of the total current potable water through the use of RWH. It also shows that the residential sector offers the most important part because it holds two-thirds of the agglomeration PPWS.

  8. Artificial biological soil crust property and potential for rainwater harvest%人工生物土壤结皮特性及其集雨潜力的研究

    Institute of Scientific and Technical Information of China (English)

    周贵连; 张万军

    2012-01-01

    It is important to collect limited rainwater for agricultural and domestic use in arid and semiarid areas. Rainwater harvesting systems used for collection, storage and purification of rainwater are critical for rainwater utilization. Materials used in building the surfaces of rainwater harvesting plots determine the efficiency of rainwater harvesting system as they affect the hydrological characteristics of the plot surfaces. This paper discussed the potential and feasibility of artificially cultivated biological soil crusts (BSCs) as surface materials of rainwater harvesting plots. It investigated the effects of artificial BSCs on soil physical properties and infiltration and also on the efficiency of rainwater harvest. The results showed that the surface soil (0~1 cm) with artificial BSCs contained more tiny particles and less coarse particles than natural soil. However, no significant difference was noted in bulk density of 0~5 cm soil between artificial BSCs and natural soil. Infiltration rate decreased under artificial BSCs. Initial and stable infiltration rates as well as stable infiltration water volume of BSCs decreased by 59.1%, 44.4% and 50.0%, respectively. The investigation based on rainwater harvesting plots established on 30° slope loamy soil mountain showed that BSCs rainwater runoff efficiency increased. The average runoff efficiency of BSCs rainwater harvesting plot was 60.86% during six runoff events in May to August 2005. BSCs rainwater harvesting plot increased runoff efficiency over that of natural soil by 23.0%. Benefit analysis showed that BSCs not only increased runoff efficiency, but also longer-lasting with significantly less runoff sediment. BSCs were therefore recommended as potential green materials for rainwater harvest.%为探讨在太行山半干旱区利用人工土壤生物结皮进行集雨的潜力和可行性,以自然生长的生物土壤结皮为种子,通过培育建立人工土壤生物结皮和生物结皮集雨,对人

  9. Effects of Ridge-Mulching with Plastic Sheets for Rainwater-Harvesting Cultivation on WUE and Yield of Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    WANG Cai-rong; TIAN Xiao-hong; LI Sheng-xiu

    2004-01-01

    A field experiment was conducted in a manural loesial soil in middle of Shaanxi Province of China, a sub-humid area prone to drought, to study the effects of rainwater-harvesting cultivation on water use efficiency (WUE) and yield of winter wheat. Ridge-furrow tillage was used, the ridge being mulched by plastic sheets for rainwater harvesting while seeding in the furrows. Results showed that from sowing to reviving stage of winter wheat, water stored in 0-100 cm layer was significantly decreased whereas that in 100-200 cm layer did not change. Compared to the non-mulching, plastic mulch retained 6.5 mm more water as an average of the two N rate treatments, having a certain effect on conservation of soil moisture. In contrast, at harvest, water was remarkably reduced in both the 0-100 cm and the 100-200 cm layers, and mulched plots consumed 34.8 mm more water as an average of the two treatments: low N rate (75 kg N ha-1) with low plant density (2 300 000 plants ha-1) and high N rate (225 kg N ha-1)with high plant density (2 800 000 plants ha-1), in 0-200 cm layer than those without mulching, the former being beneficial to plants in utilization of deep layer water. Mulching was significant in harvesting water and in increase of yield. Mulched with plastic sheets, biological and grain yields were 22.5 and 22.6% higher for the average of the high N rate than for the low N rate, and the high N rate with low plant density was 29.8 and 29.1% higher in both biological and grain yields than that of the low N rate with low plant density. With high N rate and high plant density, the mulched biological and grain yields were 39.5 and 28.9% higher than the corresponding treatments without mulching. Of the treatments, that with high N rate and low plant density was the highest in both biological and grain yields, and the water use efficiency reached 43.7 kgmm-1 ha-1 for biological yield and 22 kg mm-1 ha-1 for grain yield, being the highest WUE reported in the world up to now.

  10. Diarrhoea prevention in a high-risk rural Kenyan population through point-of-use chlorination, safe water storage, sanitation, and rainwater harvesting.

    Science.gov (United States)

    Garrett, V; Ogutu, P; Mabonga, P; Ombeki, S; Mwaki, A; Aluoch, G; Phelan, M; Quick, R E

    2008-11-01

    Lack of access to safe water and sanitation contributes to diarrhoea moribidity and mortality in developing countries. We evaluated the impact of household water treatment, latrines, shallow wells, and rainwater harvesting on diarrhoea incidence in rural Kenyan children. We compared diarrhoea rates in 960 children aged home visits over an 8-week period. On multivariate analysis, chlorinating stored water [relative risk (RR) 0.44, 95% confidence interval (CI) 0.28-0.69], latrine presence (RR 0.71, 95% CI 0.54-0.92), rainwater use (RR 0.70, 95% CI 0.52-0.95), and living in an intervention village (RR 0.31, 95% CI 0.23-0.41), were independently associated with lower diarrhoea risk. Diarrhoea risk was higher among shallow well users (RR 1.78, 95% CI 1.12-2.83). Chlorinating stored water, latrines, and rainwater use all decreased diarrhoea risk; combined interventions may have increased health impact.

  11. The analysis on the city rainwater harvesting tech of the energy conservation%基于城市雨水利用收集技术的节能减排浅析

    Institute of Scientific and Technical Information of China (English)

    曾杰波

    2011-01-01

    本文分析了泉州某商圈拟建雨水收集系统,明确了雨水收集系统技术应用的造价成本以及影响因素,以便读者可以根据实际条件和使用要求选择适宜的方法和配套技术指导类似节水系统工程的实践。%This article analysed the annual rainwater collection yield of business quarter in Quan Zhou,emphatically pointed out the cost and the factor of influence of the rainwater harvesting system which was used,aiming at enlightening people to choose the appropriate way and put forward the rational treatment,according to the reality conditions and the operating requirements.

  12. Assessing Land Suitability for Rainwater Harvesting Using Geospatial Techniques: A Case Study of Njoro Catchment, Kenya

    OpenAIRE

    Maina, C. W.; J. M. Raude

    2016-01-01

    Water demand increases as population increases leading to overexploitation of water resource. Consequently, there is need for improved water resources management complemented with rain water harvesting within the catchments. This study sought to assess land suitability for surface runoff harvesting using geospatial techniques. Land use/land cover maps of the area were derived from Landsat image. Land use and soils data were used in generating curve number map of the catchment. Lineaments grea...

  13. Reevaluation of health risk benchmark for sustainable water practice through risk analysis of rooftop-harvested rainwater.

    Science.gov (United States)

    Lim, Keah-Ying; Jiang, Sunny C

    2013-12-15

    Health risk concerns associated with household use of rooftop-harvested rainwater (HRW) constitute one of the main impediments to exploit the benefits of rainwater harvesting in the United States. However, the benchmark based on the U.S. EPA acceptable annual infection risk level of ≤1 case per 10,000 persons per year (≤10(-4) pppy) developed to aid drinking water regulations may be unnecessarily stringent for sustainable water practice. In this study, we challenge the current risk benchmark by quantifying the potential microbial risk associated with consumption of HRW-irrigated home produce and comparing it against the current risk benchmark. Microbial pathogen data for HRW and exposure rates reported in literature are applied to assess the potential microbial risk posed to household consumers of their homegrown produce. A Quantitative Microbial Risk Assessment (QMRA) model based on worst-case scenario (e.g. overhead irrigation, no pathogen inactivation) is applied to three crops that are most popular among home gardeners (lettuce, cucumbers, and tomatoes) and commonly consumed raw. The infection risks of household consumers attributed to consumption of these home produce vary with the type of produce. The lettuce presents the highest risk, which is followed by tomato and cucumber, respectively. Results show that the 95th percentile values of infection risk per intake event of home produce are one to three orders of magnitude (10(-7) to 10(-5)) lower than U.S. EPA risk benchmark (≤10(-4) pppy). However, annual infection risks under the same scenario (multiple intake events in a year) are very likely to exceed the risk benchmark by one order of magnitude in some cases. Estimated 95th percentile values of the annual risk are in the 10(-4) to 10(-3) pppy range, which are still lower than the 10(-3) to 10(-1) pppy risk range of reclaimed water irrigated produce estimated in comparable studies. We further discuss the desirability of HRW for irrigating home

  14. Assessing Land Suitability for Rainwater Harvesting Using Geospatial Techniques: A Case Study of Njoro Catchment, Kenya

    Directory of Open Access Journals (Sweden)

    C. W. Maina

    2016-01-01

    Full Text Available Water demand increases as population increases leading to overexploitation of water resource. Consequently, there is need for improved water resources management complemented with rain water harvesting within the catchments. This study sought to assess land suitability for surface runoff harvesting using geospatial techniques. Land use/land cover maps of the area were derived from Landsat image. Land use and soils data were used in generating curve number map of the catchment. Lineaments greatly affect the storage depending on whether runoff is for surface storage or ground water recharge purposes. As a result, ArcGIS was used in delineating the lineaments from Digital Elevation Model (DEM of the catchment. Further, using weighted overlay the catchment was grouped into categories of restricted, not suitable, moderately suitable, suitable, or highly suitable. The study found that forest, agriculture, and built-up areas occupied about 39.42%, 36.32%, and 1.35% of catchment area, respectively. A large part of catchment was found to have curve number range of 82–89. About 50% of the catchment was found to fall within suitable and highly suitable categories. This implied that a great potential exists for rain water harvesting within the catchment.

  15. Modeling of a lot scale rainwater tank system in XP-SWMM: a case study in Western Sydney, Australia.

    Science.gov (United States)

    van der Sterren, Marlène; Rahman, Ataur; Ryan, Garry

    2014-08-01

    Lot scale rainwater tank system modeling is often used in sustainable urban storm water management, particularly to estimate the reduction in the storm water run-off and pollutant wash-off at the lot scale. These rainwater tank models often cannot be adequately calibrated and validated due to limited availability of observed rainwater tank quantity and quality data. This paper presents calibration and validation of a lot scale rainwater tank system model using XP-SWMM utilizing data collected from two rainwater tank systems located in Western Sydney, Australia. The modeling considers run-off peak and volume in and out of the rainwater tank system and also a number of water quality parameters (Total Phosphorus (TP), Total Nitrogen (TN) and Total Solids (TS)). It has been found that XP-SWMM can be used successfully to develop a lot scale rainwater system model within an acceptable error margin. It has been shown that TP and TS can be predicted more accurately than TN using the developed model. In addition, it was found that a significant reduction in storm water run-off discharge can be achieved as a result of the rainwater tank up to about one year average recurrence interval rainfall event. The model parameter set assembled in this study can be used for developing lot scale rainwater tank system models at other locations in the Western Sydney region and in other parts of Australia with necessary adjustments for the local site characteristics.

  16. Rainwater harvesting possibility under climate change: A basin-scale case study over western province of Saudi Arabia

    Science.gov (United States)

    Almazroui, Mansour; Islam, M. Nazrul; Balkhair, Khaled S.; Şen, Zekâi; Masood, Amjad

    2017-06-01

    Groundwater reservoirs are important water resources all over the world. Especially, they are of utmost significance for arid and semi-arid regions, and therefore, a sustainable exploitation of these reservoirs needs to be ensured. The natural and most exclusive water supplier to groundwater reservoirs in Saudi Arabia is rainfall, which is characterized by sporadic and random temporal and spatial distributions, particularly under the impacts of climate change; giving rise to uncertainty in groundwater recharge quantification. Although in Saudi Arabia, intense and frequent rainfall events are rare, but they generate significant flash floods with huge amounts of surface water. Under such circumstances, any simple but effective water storage augmentation facility such as rainwater harvesting (RWH) structures gain vital importance for sustainability of water supply and survivals in arid and semi-arid regions. The objective of this study is to explore the possibility of RWH over a basin in the western province of Saudi Arabia called Wadi Al-Lith under climate change. Climatic data is obtained from the IPCC AR5 GCMs, which is further downscaled using a regional climate model RegCM4 for the Arabian Peninsula domain. The RegCM4 is driven to simulate climatic parameters including rainfall at 25 km grid resolution for the present climate (1971-2000), and future climate (2006-2099) with representative concentration pathways, RCP4.5 and RCP8.5. Results indicate that more durable and longer wet durations are expected with increasing surplus rainfall amounts in the far future because of climate change impacts. Consequently, future climate scenarios are expected to enhance floods and flash floods occurrences, which call for progressive measures to harness the RWH opportunity.

  17. Reducing occurrence of Giardia duodenalis in children living in semiarid regions: impact of a large scale rainwater harvesting initiative

    National Research Council Canada - National Science Library

    Fonseca, Jacqueline Evangelista; Carneiro, Mariângela; Pena, João Luiz; Colosimo, Enrico A; da Silva, Nívea Bispo; da Costa, André Gabriel F C; Moreira, Luciano E; Cairncross, Sandy; Heller, Léo

    2014-01-01

    In Brazil, about two million people living in rural semiarid regions were benefited with the construction of rainwater cement cisterns, as an initiative from the program "One Million Cisterns" (P1MC...

  18. A Reliability Analysis of a Rainfall Harvesting System in Southern Italy

    Directory of Open Access Journals (Sweden)

    Lorena Liuzzo

    2016-01-01

    Full Text Available Rainwater harvesting (RWH may be an effective alternative water supply solution in regions affected by water scarcity. It has recently become a particularly important option in arid and semi-arid areas (like Mediterranean basins, mostly because of its many benefits and affordable costs. This study provides an analysis of the reliability of using a rainwater harvesting system to supply water for toilet flushing and garden irrigation purposes, with reference to a single-family home in a residential area of Sicily (Southern Italy. A flushing water demand pattern was evaluated using water consumption data collected from a sample of residential customers during an extended measurement campaign. A daily water balance simulation of the rainwater storage tank was performed, and the yield-after-spillage algorithm was used to define the tank release rule. The model’s performance was evaluated using rainfall data from more than 100 different sites located throughout the Sicilian territory. This regional analysis provided annual reliability curves for the system as a function of mean annual precipitation, which have practical applications in this area of study. The uncertainty related to the regional model predictions was also assessed. A cost-benefit analysis highlighted that the implementation of a rainwater harvesting system in Sicily can provide environmental and economic advantages over traditional water supply methods. In particular, the regional analysis identified areas where the application of this system would be most effective.

  19. Water Vapor, Temperature and Wind Profiles within Maize Canopy under in-Field Rainwater Harvesting with Wide and Narrow Runoff Strips

    Directory of Open Access Journals (Sweden)

    Weldemichael A. Tesfuhuney

    2013-11-01

    Full Text Available Micrometeorological measurements were used to evaluate heat and water vapor to describe the transpiration (Ev and soil evaporation (Es processes for wide and narrow runoff strips under in-field rainwater harvesting (IRWH system. The resulting sigmoid-shaped water vapor (ea in wide and narrow runoff strips varied in lower and upper parts of the maize canopy. In wide runoff strips, lapse conditions of ea extended from lowest measurement level (LP to the upper middle section (MU and inversion was apparent at the top of the canopy. The virtual potential temperature (θv profile showed no difference in middle section, but the lower and upper portion (UP had lower  in narrow, compared to wide, strips, and LP-UP changes of 0.6 K and 1.2 K were observed, respectively. The Ev and Es within the canopy increased the ea concentration as determined by the wind order of magnitude. The ea concentration reached peak at about 1.6 kPa at a range of wind speed value of 1.4–1.8 m∙s−1 and 2.0–2.4 m∙s−1 for wide and narrow treatments, respectively. The sparse maize canopy of the wide strips could supply more drying power of the air in response to atmospheric evaporative demand compared to narrow strips. This is due to the variation in air flow in wide and narrow runoff strips that change gradients in ea for evapotranspiration processes.

  20. A Feasibility Study of Rainwater Harvesting and Utilization in Xifeng Area%西峰区雨水集蓄利用可行性研究

    Institute of Scientific and Technical Information of China (English)

    郭龙; 张新民; 刘久如

    2015-01-01

    雨水集蓄利用是缓解城市水资源压力的一条经济、快捷、有效的途径。通过对西峰区下垫面类型和降雨条件综合分析,在降水保证率为75%时,该区不透水集雨面可收集雨水量为2964.96万 m3,其中李岭村雨水可收集量为14.328万 m3,对李岭村雨水可收集量进行经济效益分析可知,每年大约可为该村用水费用节约25万元,并结合西峰区自身特点,提出雨水综合利用的基本途径和措施,这对解决西峰区资源性缺水问题、减少洪涝灾害、改善生态环境、实现节水型社会的建设和水资源的可持续利用具有一定的指导意义。%Rainwater harvesting and utilization is an economic,rapid and effective way of alleviating the pressure of water resources of city. By analyzing the type of underlying surface and rainfall conditions in Xingfeng district,the impervious surface area can collect rainwater 29,649,600 m3 ,and the village LI ling collect 143,280 m3 ,when the assurance rainfall rate is 75%. At the same time,by analysis of economic benefit on rainwater harvesting in LI ling,water charge can be saved 250, 000. Meanwhile,according to the real situation of Xifeng area ,it also proposes some measures about the comprehensive utili-zation of rainwater ,aiming to provide the reference for solving the problem of water shortage,reducing flood disaster,impro-ving the ecological environment of city,achieve the sustainable use of water-saving ,and building water-saving society.

  1. Establishment of the Database for Rainwater-harvesting Facility Program in Mountainous Areas%山区雨水集蓄设施规划数据库的创建

    Institute of Scientific and Technical Information of China (English)

    武秋俊; 王建军

    2011-01-01

    针对规划必须处理当地气象、地形等大量资料和参照许多相关的水利、建筑规范的实际,使用数据库技术,创建了以雨水集蓄工程相关规范以及国内外雨水集蓄利用技术的成功经验及研究成果为内容的标准库和以当地实际情况为特点的用户库相结合的山区雨水集蓄设施规划数据库.该数据库提高了规划效率,加强了规划的管理,实现了雨水集蓄设施规划的自动化、规范化、系统化.%According to the fact that the rainwater-harvesting program should take into account local meteorological and topographical data and related water conservancy and construction specifications, the paper constructs the standard base involving relevant rainwater-harvesting engineering specifications and the successful practices and research achievements of rainwater-harvesting technology both at home and abroad, as well as establishes the rainwater-harvesting database in the mountainous areas combining with local practical conditions. The database improved the program efficiency, enhance the program management, and realize the automatization, systematization and standardization of the rainwater-harvesting program.

  2. Characterization of rainfall in the central South African Highveld for application in water harvesting

    NARCIS (Netherlands)

    Zerizghy, M.G.; Rensburg, van L.D.; Stigter, C.J.

    2012-01-01

    In-field rainwater harvesting (IRWH), a runoff farming system, is a beneficial water management technique for crop production in arid and semi-arid areas. In-field rainwater harvesting is influenced by rainfall characteristics, and hence this study aimed to identify and characterize rainfall events,

  3. Rotational Electromagnetic Energy Harvesting System

    Science.gov (United States)

    Dinulovic, Dragan; Brooks, Michael; Haug, Martin; Petrovic, Tomislav

    This paper presents development of the rotational electromagnetic energy harvesting transducer. The transducer is driven mechanically by pushing a button; therefore, the mechanical energy will be converted into electrical energy. The energy harvesting (EH) transducer consists of multilayer planar coils embedded in a PCB, multipolar NdFeB hard magnets, and a mechanical system for movement conversion. The EH transducer generate an energy of about 4 mJ at a load of 10 Ω. The maximum open circuit output voltage is as high as 2 V and the maximum short circuit output current is 800 mA.

  4. A low pressure gravity-driven membrane filtration (GDM) system for rainwater recycling: Flux stabilization and removal performance.

    Science.gov (United States)

    Ding, An; Wang, Jinlong; Lin, Dachao; Tang, Xiaobin; Cheng, Xiaoxiang; Wang, Hui; Bai, Langming; Li, Guibai; Liang, Heng

    2017-04-01

    Rainwater is a nature resource, which can be widely used for non-potable and potable applications in water scared countries after appropriate treatment. Gravity-driven membrane filtration (GDM) process is a promising technology for decentralized rainwater treatment due to no backwashing, flushing and chemical cleaning. In this study, we established a single lab-scale GDM system for the stored rainwater (simulative cellar rainwater) treatment with two months operation, and a stored tap water was used as a compared system to evaluate the permeability and organics removal performance. Results showed that GDM exhibited a good performance for bacteria and turbidity removals, but the removal performance of DOC was undesirable due to the low rejection of low molecular-weight fulvic. Additionally, the permeate flux reached stable with the value of 6-6.5 L/m(2)h during 60 days operation in the rainwater system, however, the tap water system stabilized only at 4 L/m(2)h. Hydraulically reversible resistance accounted for large proportions (90%) of the total resistance, which indicated that the flux could be recovered by simple physical flushing. The bio-fouling layer adhered on the membrane surface was characterized at the end of the filtration experiment. Higher bio-activity with lower EPS (polysaccharides and proteins) contents of the fouling layer were found in the rainwater system compared with the control system, which was the main reason for the higher flux. These results show that rainwater can be treated in a single GDM process with low maintenance, which makes the process suitable for decentralized water supply.

  5. THE INFLUENCE THE EXTENSIVE GREEN ROOFS ON THE OUTFLOW RAINWATER TO THE SEWAGE SYSTEM

    OpenAIRE

    Maciej Mrowiec; Małgorzata Sobczyk

    2015-01-01

    In times of rapid urbanization and climate change has drawn more attention to stormwater runoff to sewer systems. The phenomenon of flooding in urban areas have become increasingly common as a result of heavy rains. Sewage systems in such a short time are not able to accept such a large amount of rainwater flowing on the site, which we experience the phenomenon of rainfall flowing down the street in excessive amounts. The problem of such phenomena can be solved by the development of green roo...

  6. Water self-sufficiency with separate treatment of household rainwater and greywater

    OpenAIRE

    Lloveras Macià, Joaquín; García Blanch, Elisa; García Gisbert, Anna; Planas Gisbert, María; Rodríguez Farre, Ariadna

    2014-01-01

    This paper is based on an academic work conducted by a group of students of the Engineering Project course within the Chemical Engineering Degree at the Engineering School of Barcelona. The objective of the exercise was to design a rainwater harvesting and greywater recycling system for a detached house and calculate the number of people that could be self-sufficient. Local rainfall, roof area for collecting rainwater and daily water consumption per inhabitant were considered. The...

  7. The implementation of biofiltration systems, rainwater tanks and urban irrigation in a single-layer urban canopy model

    Science.gov (United States)

    Demuzere, Matthias; Coutts, Andrew; Goehler, Maren; Broadbent, Ashley; Wouters, Hendrik; van Lipzig, Nicole; Gebert, Luke

    2015-04-01

    Urban vegetation is generally considered as a key tool to modify the urban energy balance through enhanced evapotranspiration (ET). Given that vegetation is most effective when it is healthy, stormwater harvesting and retention strategies (such as water sensitive urban design) could be used to support vegetation and promote ET. This study presents the implementation of a vegetated lined bio-filtration system (BFS) combined with a rainwater tank (RWT) and urban irrigation system in the single-layer urban canopy model Community Land Model-Urban. Runoff from roof and impervious road surface fractions is harvested and used to support an adequate soil moisture level for vegetation in the BFS. In a first stage, modelled soil moisture dynamics are evaluated and found reliable compared to observed soil moisture levels from biofiltration pits in Smith Street, Melbourne (Australia). Secondly, the impact of BFS, RWT and urban irrigation on ET is illustrated for a two-month period in 2012 using varying characteristics for all components. Results indicate that (i) a large amount of stormwater is potentially available for indoor and outdoor water demands, including irrigation of urban vegetation, (ii) ET from the BFS is an order of magnitude larger compared to the contributions from the impervious surfaces, even though the former only covers 10% of the surface fraction and (iii) attention should be paid to the cover fraction and soil texture of the BFS, size of the RWT and the surface fractions contributing to the collection of water in the RWT. Overall, this study reveals that this model development can effectuate future research with state-of-the-art urban climate models to further explore the benefits of vegetated biofiltration systems as a water sensitive urban design tool optimised with an urban irrigation system to maintain healthy vegetation.

  8. Amplicon-based taxonomic characterization of bacteria in urban and peri-urban roof-harvested rainwater stored in tanks.

    Science.gov (United States)

    Ahmed, W; Staley, C; Hamilton, K A; Beale, D J; Sadowsky, M J; Toze, S; Haas, C N

    2017-01-15

    Overall, 26% of Australian households use rainwater tanks as a source of potable and nonpotable water. Limited information is available on the total bacterial communities in tank water. Therefore, identification of dominant bacterial communities, diversity, and their distribution is important in understanding the microbial quality of tank water. In this study, the abundance and diversity of bacterial communities in 88 tank water samples collected from the urban areas of Brisbane (n=44) and the peri-urban center of Currumbin (n=44) in Southeast Queensland, Australia were determined using amplicon-based Illumina next-generation sequencing. In addition, the SourceTracker program was used to identify the sources of fecal contamination in tank water samples. Sequence reads were also analyzed to detect potential bacterial pathogenic genera in the tank water samples collected. Differences in sample coverage, alpha diversity, and richness did not differ significantly between the Brisbane and Currumbin tank water samples. Comamonadaceae and Planctomycetaceae were the most abundant families in all tank water samples. Curvibacter was the most abundant genus in all tank water samples. SourceTracker revealed that around 34% (Brisbane) and 43% (Currumbin) of tank water samples had a signature for bird fecal contamination. The potential opportunistic pathogenic genera including Burkholderia, Chromobacterium, Clostridium, Legionella, Mycobacterium, Nocardia, and Pseudomonas were most prevalent in tank water samples. Next-generation sequencing can be used as an initial screening tool to identify a wide array of potential pathogenic genera in tank water samples followed by quantifying specific pathogen(s) of interest using more sensitive molecular assays such as quantitative PCR (qPCR).

  9. Deep excavation, no problem. Rainwater collector systems for technical facilities; Tiefbau kein Problem. Regenwasser fuer die Haustechnik

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, K.W. [Fachvereinigung Betriebs- und Regenwassernutzung e.V. (fbr), Darmstadt (Germany)

    2006-03-15

    The days of do-it-yourself systems are over. Rainwater collector systems have developed from modular to compact system components, including concrete cisterns placed directly in the excavation pit of new buildings. In case of malfunctions, if any, producers offer a hotline for customer problems. (orig.)

  10. W ater harvesting experiences from the southern and eastern Africa rainwater network%非洲东部及南部雨水管网中的雨水回用实践

    Institute of Scientific and Technical Information of China (English)

    Maimbo M.Malesu; Jan de Leeuw; Alex Oduor

    2014-01-01

    This paper shares experiences of the southern and eastern Africa rainwater network on rainwater harvesting.It also shares the lessons drawn from policy research awareness creation and networking building of national networks and assessment of promising water harvesting techniques in the Sub-Saharan Africa.The concerted promotional effort of the southern and eastern Africa rainwater network has resulted in the general acceptance of rainwater harvesting as a viable option for boosting domestic water supply agricultural production and environmental sustainability.To date twelve nationally registered rainwater harvesting associations have been established which are providing leadership and capacity building in rainwater harvesting.Governments and donors are also aligning their policies towards providing increased financial institutional and technical support for upscaling rainwater-harvesting techniques. This paper concludes that diligent land and water management is necessary for yielding the highest benefits from rainwater.In addition to enabling policies and institutions there must be ample budgetary support to increase adoption of the technology.%介绍了非洲东部和南部雨水管网系统中雨水回用的实践与经验,并介绍了在Sub-Saharan Africa开展的雨水回用工程实践情况,包括国家政策的调研、回用理念的构建、雨水系统的建设和回用技术的评估。雨水回用技术在非洲东南部地区被大力推广,并被普遍接受,应用于生活用水及农业用水的补充以及环境可持续发展建设的各个方面。截止目前,已有12个国家级的雨水回用机构建成,他们为雨水回用系统的建设提供整体规划和技术指导。政府和投资商也逐渐转变态度,为推进雨水回用技术在经济、制度和技术上提供了优惠政策。合理的土地与水体管理是雨水资源利用最大化的关键。除了政策和制度的协调外,还需要充足的预算支

  11. Research on Building of Rainwater-harvesting Green Infrastructure Pattern of Qian’an based on the Instruction of Sponge City Construction%基于海绵城市建设指引的迁安市集雨型绿色基础设施体系构建策略初探

    Institute of Scientific and Technical Information of China (English)

    戈晓宇; 李雄

    2016-01-01

    城市绿色基础设施作为海绵城市建设的重要载体,能够发挥出强大的集雨型功能。以迁安市集雨型绿色基础设施构建为研究对象,以汇水区划分、空间布局策略、径流控制级别、径流控制功能作为主要研究内容,通过田野调查和教学研讨等研究方法,梳理了京津冀地区由城市绿地系统作为主要载体的集雨型绿地系统的构建方法,归纳了集雨型绿色基础设施体系对绿地系统集雨功能的补充作用;结合专家访谈和课堂授课反馈信息,总结出海绵城市建设中存在的误区与偏差。以此来探讨符合京津冀地区城市实际情况的集雨型绿色基础设施体系构建策略,为海绵城市建设和城市绿地建设提供借鉴。%Urban green infrastructure plays a powerful function in rainwater-harvesting as an signiifcant carrier of Sponge City construction. With ifeld investigation and teaching research, the paper provides a summary of constructing methods of rainwater-harvesting green space system based on the green system in Beijing, Tianjin and Hebei areas. Choosing Qian'an rainwater-harvesting green infrastructure system as the research object, we put emphasis on catchment division, spatial layout strategy, runoff control level and runoff control function. The paper sums up the errors and deviations in the Sponge City construction, combined with expert interviews and teaching feedback information. It proposes the construction strategy of rainwater-harvesting green infrastructure system which could conform to the actual situation in cities of Beijing, Tianjin and Hebei areas and provides reference for the construction of Sponge City and urban green space.

  12. Low cost inlet filters for rainwater tanks

    OpenAIRE

    Martinson, Brett; Thomas, T.

    2005-01-01

    Inlet filters are a common method for enhancing water quality in rainwater harvesting systems. They range from cheap cloth or gravel filters to complex and expensive multi-stage systems. Field experience has shown, however that filters often suffer from a lack of maintenance so self-cleaning is an advantage. Filters can clean themselves by dividing the water stream into two components; the first and largest is the clean water passed to the tank, the second much smaller component can be used t...

  13. 采用SCS-CN水文模型和GIS确定雨水集蓄工程的位置%Identification of potential rainwater harvesting sites using SCS-CN and GIS

    Institute of Scientific and Technical Information of China (English)

    王红雷; 王秀茹; 王希; 姜丽娟

    2012-01-01

    Water shortage in mountainous areas is a prevailing problem in Northern China. In this study, the upstream of Qinghe River, a semiarid mountainous area in western Beijing, was investigated and relevant solutions were put forward. The Remote Sensing (Erdas imagine 9.1) and Geographic Information Systems (ArcGIS 10) software were adopted to process data about TM images, soil texture map and Digital Elevation Model (DEM). Soil Conservation Service' curve number (SCS-CN) method was used to calculate runoff and establishe constraint site selection criteria based on rainwater harvesting technology and technical code. Afterwards, spatial query and proximity analysis on the spatial thematic data and runoff potential were carried out using the ArcGIS 10. The site selection of potential rainwater harvesting projects was completed on the basis of the above-mentioned methods. The results showed that: The sites suitable for the construction of water storage pond was as follows: the area of 4.24 km2, 46 reservoirs, 50 water retaining dams, 53 open wells, and courtyard rainfall collection area 4.95 km2. The results provide a reference for the rational utilization of rainwater resources and projects construction.%针对北京西部清水河上游山区生产生活用水日趋紧张的问题,该文应用遥感与地理信息系统软件处理TM影像、土壤和质地图及数字高程模型等基础数据,结合soil conservation service (SCS)曲线数法计算径流量,根据雨水集蓄工程技术规范构建了雨水集蓄工程位置选择约束集.在此基础上,运用地理信息系统软件对坡度、径流潜力及集水路径的空间及属性数据进行叠加和邻域分析,得到适宜的雨水集蓄工程位置.主要结果如下:适宜修建蓄水坑塘的面积4.24 km2、蓄水池位置46处、拦水坝位置50处、大口井位置53处、适宜庭院集雨区的面积4.95 km2.结果可为合理开发利用雨水资源及工程建设提供理论支撑和科学指导.

  14. Reducing Occurrence of Giardia duodenalis in Children Living in Semiarid Regions: Impact of a Large Scale Rainwater Harvesting Initiative: e2943

    National Research Council Canada - National Science Library

    Jacqueline Evangelista Fonseca; Mariângela Carneiro; João Luiz Pena; Enrico A Colosimo; Nívea Bispo da Silva; F C da Costa; Luciano E Moreira; Sandy Cairncross; Léo Heller

    2014-01-01

      Background In Brazil, about two million people living in rural semiarid regions were benefited with the construction of rainwater cement cisterns, as an initiative from the program "One Million Cisterns" (P1MC...

  15. CONCENTRATIONS OF INDICATOR ORGANISMS IN THE STORED RAINWATER IN THE MAKANA MUNICIPALITY, SOUTH AFRICA

    Directory of Open Access Journals (Sweden)

    ROMAN TANDLICH

    2012-03-01

    Full Text Available Concentrations of indicator organisms in the stored rainwater in the Makana Municipality, South Africa. The United Nations Millennium Development Goals’ target 7C seeks to halve the number of people without sustainable access to safe drinking water and basic sanitation by 2015. At present, supply of safe drinking water is still intermittent in some parts of South Africa due to infrastructural problems and droughts. Rainwater harvesting could be a solution to this problem. Microbial rainwater quality was evaluated in the Makana Municipality, South Africa. Enumerations were done using the membrane-filtration technique with m-FC and m-Endo agar and the indole test. One sample contained E. coli at 1 colony-forming unit/100 cm3, while the faecal coliform concentrations ranged from 0 to 98 colony-forming units/100 cm3 in all samples. The total coliform concentrations ranged from 0 to 200 colony-forming units/100 cm3. On-site treatment of rainwater was insufficient due to missing first-flush devices. Rainwater is suitable for subsurface irrigation of vegetable gardens. Strategies are required to involve the community in the design and building of new rainwater harvesting systems.

  16. Microelectronic circuit design for energy harvesting systems

    CERN Document Server

    Di Paolo Emilio, Maurizio

    2017-01-01

    This book describes the design of microelectronic circuits for energy harvesting, broadband energy conversion, new methods and technologies for energy conversion. The author also discusses the design of power management circuits and the implementation of voltage regulators. Coverage includes advanced methods in low and high power electronics, as well as principles of micro-scale design based on piezoelectric, electromagnetic and thermoelectric technologies with control and conditioning circuit design. Provides a single-source reference to energy harvesting and its applications; Serves as a practical guide to microelectronics design for energy harvesting, with application to mobile power supplies; Enables readers to develop energy harvesting systems for wearable/mobile electronics.

  17. Cesium and strontium loads into a combined sewer system from rainwater runoff.

    Science.gov (United States)

    Kamei-Ishikawa, Nao; Yoshida, Daiki; Ito, Ayumi; Umita, Teruyuki

    2016-12-01

    In this study, combined sewage samples were taken with time in several rain events and sanitary sewage samples were taken with time in dry weather to calculate Cs and Sr loads to sewers from rainwater runoff. Cs and Sr in rainwater were present as particulate forms at first flush and the particulate Cs and Sr were mainly bound with inorganic suspended solids such as clay minerals in combined sewage samples. In addition, multiple linear regression analysis showed Cs and Sr loads from rainwater runoff could be estimated by the total amount of rainfall and antecedent dry weather days. The variation of the Sr load from rainwater to sewers was more sensitive to total amount of rainfall and antecedent dry weather days than that of the Cs load.

  18. Rainwater harvesting in the challenge of droughts and climate change in semi-arid Brazil%巴西半干旱地区干旱和气候多变情况下的雨水收集

    Institute of Scientific and Technical Information of China (English)

    Johann Gnadlinger

    2014-01-01

    Some successful experiences of rainwater harvesting in Brazil’s semi-arid region are shown how rural communities are living during the severe drought from 2011 to 2013 using technologies of rainwater harvesting for the household in agriculture livestock raising and the environment.Starting from the positive experiences principles of living in the challenge of droughts and climate change are elaborated and summarized into different guidelines for sustainable livelihood and production access to water and sufficient land area rainwater harvesting to provide water security to households and communities preservation recovering and management of drought-resistant vegetation emphases on raising of small and medium sized livestock and water and forage storage appropriate crop selection and sustainable extraction processing and marketing of crop products capacity building of the people. These principles contribute to preparing a national policy on living in harmony with the semi-arid climate. Rainwater harvesting is an important part of a package of measures which enables a sustainable livelihood in such a difficult environment.%通过巴西半干旱地区的一些成功案例,介绍了当地农村社区在2011~2013年严重旱灾期间所采取的有效措施:对生活用水、农业用水和畜牧用水采取水资源管理技术;对土壤湿度和含水层采取诸如蓄水池、地下水坝等环境保护措施。根据这些经验,总结出旱灾和气候变化环境下的生活原则,并制定成可持续性生活生产的指导方针:获取足够的水资源和土地面积;利用雨水以保证家庭和社区的用水安全;种植、养护与管理抗旱植物;倡导对中小型家畜养殖的水和饲料储存;加强农作物品种甄选及其产品的可持续生产、加工和销售;重视居民的水资源保护思想和能力培养。这些原则为指导干旱气候条件下人与环境和谐相处提供了宝贵的经验。

  19. Complete Charging for Piezoelectric Energy Harvesting System

    Institute of Scientific and Technical Information of China (English)

    樊康旗; 徐春辉; 王卫东

    2014-01-01

    Under an in-phase assumption, the complete charging for an energy harvesting system is studied, which consists of a piezoelectric energy harvester (PEH), a bridge rectifier, a filter capacitor, a switch, a controller and a rechargeable battery. For the transient charging, the results indicate that the voltage across the filter capacitor increases as the charging proceeds, which is consistent with that reported in the literature. However, a new finding shows that the charging rate and energy harvesting efficiency decrease over time after their respective peak values are acquired. For the steady-state charging, the results reveal that the energy harvesting efficiency can be adjusted by altering the critical charging voltage that controls the transition of the system. The optimal energy harvesting efficiency is limited by the optimal efficiency of the transient charging. Finally, the relationship between the critical charging voltage and the equivalent resistance of the controller and rechargeable battery is established explicitly.

  20. Novel heating and cooling concept employing rainwater cisterns and thermo-active building systems for a residential building

    Energy Technology Data Exchange (ETDEWEB)

    Kalz, Doreen E.; Wienold, Jan; Fischer, Martin; Cali, Davide [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

    2010-02-15

    This paper introduces and evaluates a novel heating and cooling concept employing thermo-active building systems and environmental energy, harnessed from two 11-m{sup 3} rainwater cisterns for a 285-m{sup 2} residential building in passive house standard in Germany. The building strives for a significantly reduced primary energy use with carefully coordinated measures, such as high quality building envelope, by means of vacuum insulated panels, supply and exhaust air system with heat recovery, reduced solar heat gains (solar shading), and the integration of thermal solar collectors and photovoltaic in the plant system. On this premise, a comprehensive long-term monitoring in high time-resolution was carried out for the building for two years with an accompanying commissioning of the building performance. Measurements comprise the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink (rainwater cistern), thermal comfort, and local climatic site conditions. The analysis focuses on the performance and the efficiency of rainwater cisterns as natural heat source and sink as well as the heat pump system. The paper discusses the performance of thermo-active building systems, investigates the thermal comfort, determines the efficiency of the heating/cooling system, and evaluates the total end and primary energy use of the building. (author)

  1. Photodynamics of Light Harvesting Systems

    NARCIS (Netherlands)

    Ruijter, Ward Piet Frans de

    2005-01-01

    Light harvesting (LH) lies at the basis of photosynthesis, the process in which energy from the sun is stored by a photochemical reaction. The photophysics of light absorption and energy transfer is the key to a detailed understanding of the first steps in this process. This thesis describes the

  2. Photodynamics of Light Harvesting Systems

    NARCIS (Netherlands)

    Ruijter, Ward Piet Frans de

    2005-01-01

    Light harvesting (LH) lies at the basis of photosynthesis, the process in which energy from the sun is stored by a photochemical reaction. The photophysics of light absorption and energy transfer is the key to a detailed understanding of the first steps in this process. This thesis describes the inv

  3. 虹吸式雨水系统在苏州火车站的应用%On application of siphon rainwater system at Suzhou Railway Station

    Institute of Scientific and Technical Information of China (English)

    徐海英

    2012-01-01

    The paper introduces the application of the siphon rainwater system at Suzhou Railway Station, indicates the work principle of the siphon rainwater, the selection for the siphon roof drain, the installation of risers, and its fixing, and sums up the advantages of the siphon rainwater system, so as to enhance the application of the siphon rainwater system.%详细介绍了虹吸式雨水系统在苏州火车站的应用,从虹吸式雨水工作原理、虹吸式雨水斗的选型、立管的安装、立管的固定等方面进行了论述,总结了虹吸式雨水系统的优点,以期促进虹吸式雨水系统的推广应用。

  4. Hybrid piezoelectric energy harvesting transducer system

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

    2008-01-01

    A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

  5. Urban Rainwater Infrastructure System in Arid and Semi-arid Regions Based on Low Impact Development%基于LID的干旱半干旱区城市雨水设施体系模式

    Institute of Scientific and Technical Information of China (English)

    苗展堂; 王昭

    2013-01-01

    The traditional rainwater infrastructure planning ignored rainwater harvesting and reuse. The significance of restructuring urban rainwater facilities system based on low impact development was illustrated. The soil infiltration capacity as well as annual and daily rainfall was analyzed, and the areas of infiltration facilities in arid and semi-arid regions were accounted. A new infrastructure plan in which 1/10 of the residential area should be built into rainfall garden was put forward to achieve rainfall zero discharge.%在指出传统雨水基础设施规划建设具有忽略雨水资源化特点的基础上,阐明了基于LID理念重构城市雨水设施体系的意义.并通过对土壤渗透能力及年、日降雨量等条件进行分析的基础上,对干旱半干旱区城市入渗模式的渗透设施面积进行核算,提出了将小区的1/10面积建设为雨水花园从而实现雨水“零排放”的基础设施规划新思路.

  6. 谈旧城区雨水系统改造方法%On reconstruction methods for rainwater system in old urban areas

    Institute of Scientific and Technical Information of China (English)

    王崇昊

    2012-01-01

    针对旧城区排水系统存在许多弊端的现象,对其进行了分析研究,从雨水管网改造利用方面进行了论述,最终提出了几点雨水管网改造及雨水收集利用的方法,从而更加合理的利用雨水资源。%According to some disadvantages in the drainage system of old urban areas,the paper undertakes the analysis and research on the system,indicates the reconstruction of the rainwater pipe network,and points out some methods for the reconstruction of the rainwater pipe network and the rainwater collection,so as to have a more reasonable utilization of the rainwater resource.

  7. Rainfall-runoff Characteristics of Artificial Micro-catchments for Rainwater Harvesting%人工集水面降雨径流观测实验研究

    Institute of Scientific and Technical Information of China (English)

    李小雁; 龚家栋

    2001-01-01

    The results of the field experiments indicated that runoff fromearth catchments (undisturbed loess slope, clearing loess slope and compacted catchments) occurr ed as infiltration-excess process, and it was mainly depended upon rainfall i nt ensity. Annual runoff mainly produced from a few high-intensity rainfall event s and the annual runoff efficiency ranged from 7.4% to 35.5%, therefore, more wate r would be collected from earth catchments by the increase of natural catchment area. The rainfall amount and intensity had little effect on the water yield fro m asphalt felt, asphalt spraying and concrete treated catchments with a mean ann ual runoff efficiency of 50%~80% and a high cost. The trend of high efficient us e of harvested water for such catchments is to combine the water harvesting syste m with installation agriculture. The plastic catchment had low cost and higher a nnual runoff efficiency, but it could not resist radiation and lasted only 4~5 m onths. So temporarily moveable plastic film catchment can be recommended to use in rainy period in the field or yard for storing rainwater in the cistern for supplementary irrigation.%野外降雨径流观测实验研究表明:土质集水面(自然黄土坡面、清除杂草自然黄土坡面和夯实集水面)的降雨产流方式为超渗产流,受降雨强度的影响大,径流的产生主要是由几次高强度的暴雨引起。此类集水面的年平均集水效率在7.4%~35.5%之间,因此,增大集水区面积是保证土质集水面收集到更多雨水的基本途径。油毡、沥青和混凝土处理集水面的产流过程受降雨量和降雨强度的影响小,年平均集水效率在50%~80%之间,但投资成本较高,其雨水利用方向是和设施农业相结合,修建固定集水面,发展高投入高产出农业。塑料膜集水面一次性投入低且平均集水效率较高,但寿命较短,建议利用简单临时性的移动塑料集水面收集雨水以

  8. In situ rainwater harvesting using dead level contours in semi-arid southern Zimbabwe: Insights on the role of socio-economic factors on performance and effectiveness in Gwanda District

    Science.gov (United States)

    Munamati, Muchaneta; Nyagumbo, Isaiah

    Droughts and dry spells which have characterised the past decade in Zimbabwe have seen a marked increase in the promotion and use of in situ rainwater harvesting technologies (RWHTs) as a drought mitigating strategy. A number of these technologies have been tried in recent years which include dead level contours with infiltration pits and deepened contours. Although in situ RWHTs are known to increase food security in drought prone areas, the role of socio-economic factors on their performance in terms of crop yield and scaling out is still not well understood. This study sought to investigate the socio-economic factors which influence the effectiveness of dead level contours for in situ rainwater harvesting and consequently on crop yield. The study involved 14 key informants interviews and questionnaire administration to a total of 55 respondent farmers practising in situ rainwater harvesting with dead level contours. A statistical package (Statistical Package for Social Scientists, SPSS) was used to analyse relationships between performance of RWHTs and attributes such as labour, resources, gender, experience and education. The results show a strong correlation between performance and resource status ( p = 0.004). For example, within the wealthy category, 42.1% were successful, while 14.3% and 13.8% were average and poor performers respectively. Thus within the successful category, 42.1% were wealthy, while 42.1% and 15.8% were medium-rich and resource-constrained respectively. Performance rating was also significantly correlated ( p = 0.007) to gender of household head e.g., within the most successful group 94.7% were men compared to 5.3% women. There was also a significant correlation between resource status and gender ( p = 0.039) such that within the wealthy category, 69.2% of the respondents were men compared to 30.8% women. Labour was found to have no significance on performance ( p > 0.05) even though the majority of key informants (93%) alluded that the

  9. THE INFLUENCE THE EXTENSIVE GREEN ROOFS ON THE OUTFLOW RAINWATER TO THE SEWAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Maciej Mrowiec

    2015-10-01

    Full Text Available In times of rapid urbanization and climate change has drawn more attention to stormwater runoff to sewer systems. The phenomenon of flooding in urban areas have become increasingly common as a result of heavy rains. Sewage systems in such a short time are not able to accept such a large amount of rainwater flowing on the site, which we experience the phenomenon of rainfall flowing down the street in excessive amounts. The problem of such phenomena can be solved by the development of green roof technology. Even in its simplest form that extensive green roof is able to delay outflow, and store in its entirety falling falls on the area. Everything depends on the layers and the size of the roof. The research study presented at two mini green roof, an area of 1.44 m2. Both cases have different layers. One of them has a layer of non-woven filter layer, the substrate and vegetation. The second station is built of layers of drainage, filter layer, a layer of substrate and vegetation. For experimental purposes a rain shower were used for testing, which allows to calibrate the right amount of water at a specified time. In the research of precipitation 10, 15 and 20-minute tested. On the bench number 1 a reduction in the range of 48.9 to 97.5% was achieved. The second experiment stand showed a higher retention capacity ranged from 74.5 to 94.7%. We concluded that the use of extensive green roofs in cities can help reduce storm water runoff from impervious surfaces.

  10. Forest harvesting systems friendly to the environment

    Energy Technology Data Exchange (ETDEWEB)

    Waesterlund, I. [Swedish Univ. of Agricultural Sciences, Garpenberg (Sweden); Hassan, A.E. [North Carolina State Univ. Col. of Forest Resources, Raleigh, NC (United States)

    1995-09-01

    The trend in forestry practices today in Europe and U.S.A. in general and Scandinavian countries in particular, is towards adapting systems based on landscape planning. Thus common harvesting equipment available on the market will have to be replaced to meet these tough demands. Environmentalists recommend that wood fiber should be harvested either by selection cutting or commercial thinning thus leaving the site undisturbed with no sign of machine traffic. This mandate will preserve ground water quality and assist in soil conservation. However, to meet the pulp and paper as well as saw mill industries demand for wood from this method of cutting (selection or commercial thinning), requires a thorough examination of our harvesting systems and techniques. This paper will discuss present and future machines that are friendly to the environment. Hypothetical designs and improvements of existing machine systems will be addressed and recommendations will be made for future research activities. 75 refs, 8 figs, 1 tab

  11. Optimal level of groundwater charge to promote rainwater usage for irrigation in rural Beijing

    NARCIS (Netherlands)

    X. Liang (Xiao); M.P. van Dijk (Meine Pieter)

    2011-01-01

    textabstractAbstract: Since groundwater is diminishing rapidly in rural Beijing, rainwater harvesting for irrigation is being promoted. As the cost of pumping up groundwater is low, farmers have few incentives to use rainwater. To promote the consumption of rainwater, the Beijing Water Authority may

  12. Mitigation of Natural Hazards and Disasters. International Perspectives. Improving Access to Water Resources through Rainwater Harvesting as A Mitigation Measure. The Case of the Brazilian Semi-Arid Region

    Energy Technology Data Exchange (ETDEWEB)

    De Melo Branco, A.; Suassuna, J.; Adler Vainsencher, S. [Independent Consultant, Rua Cardeal Arcoverde, 100/701, Gracas, Recife, Pernambuco (Brazil)

    2005-07-15

    This paper focuses on the importance of rainwater harvesting to mitigate the scarcity of water in the semi-arid region of Brazil. It is a case study about the Million Cisterns Project, an initiative developed by NGOs with the support of Brazilian Federal Government Institutions and international funding organizations. The project is innovative in a series of ways when compared to mitigation measures previously implemented by the government. Instead of focussing on short-term, top-down, palliative measures based on the construction of dams and wells, it focuses on low cost, bottom-up, long-term measures and, most importantly, it involves an educational component. Thus, the provision of water is closely related to the empowerment of the most destitute population and this leads to the sustainability of the actions. The case study serves to illustrate the relevance of the partnership between grassroots organizations and governmental institutions in the context of mitigation.

  13. Energy harvesting devices, systems, and related methods

    Science.gov (United States)

    Kotter, Dale K.

    2016-10-18

    Energy harvesting devices include a substrate and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to collect energy in the visible and infrared light spectra and to reradiate energy having a wavelength in the range of about 0.8 .mu.m to about 0.9 .mu.m. The resonance elements are arranged in groups of two or more resonance elements. Systems for harvesting electromagnetic radiation include a substrate, a plurality of resonance elements including a conductive material carried by the substrate, and a photovoltaic material coupled to the substrate and to at least one resonance element. The resonance elements are arranged in groups, such as in a dipole, a tripole, or a bowtie configuration. Methods for forming an energy harvesting device include forming groups of two or more discrete resonance elements in a substrate and coupling a photovoltaic material to the groups of discrete resonance elements.

  14. 雨水收集反馈发电系统研究%Power Generation System Based on the Feedback of Rainwater Collection

    Institute of Scientific and Technical Information of China (English)

    刘志伟; 陶宇飞

    2015-01-01

    Nowadays ,rainwater collection technology is popular in the world ,but there's no combination of rainwater collection and power generation .The article designs an integrated power generation system in high architectures based on the rainwater collection and analyzes the benefits of economy and environment of this system .This innovative system is simple constructed ,environment -friendly and easy -promoted ,which has a vast potential for future .%设计了一套适用于高楼雨水收集发电的整体系统,并对该系统的经济及环境效益进行了分析。结果表明:该系统结构简单,节约资源,也易于推广,具有广阔的发展前景。

  15. COMMUNITY PARTICIPATION IN SURFACE WATER HARVESTING ...

    African Journals Online (AJOL)

    USER

    2014-11-25

    Nov 25, 2014 ... There is seasonal water scarcity in Marigat Division and the water demand has been ... with improved storage and rainwater harvesting methods. Such water can be ..... in the planning process and decision making and this ... The organizations support the community ... systems for domestic uses in urban.

  16. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  17. The design idea of urban road rainwater collection and utilization system%城市道路雨水收集利用系统设计思路

    Institute of Scientific and Technical Information of China (English)

    姚敏

    2016-01-01

    This paper briefly described the meaning of urban road rainwater collection and utilization,discussed the design idea of urban road rainwater collection system,and from falling green space,pits,ecological pond and other aspects,elaborated the urban road rainwater utilization construction scheme,based on effective use of natural resources,reduced the pressure of urban flood control.%简述了城市道路雨水收集利用的意义,探讨了城市道路雨水收集利用系统的设计思路,并从下沉式绿地、渗井、生态水塘等方面,阐述了城市道路雨水利用建设方案,在有效利用自然资源的基础上,减轻了城市防洪压力。

  18. Harvesting

    Science.gov (United States)

    Since the introduction of the first successful mechanical harvester, mechanized cotton harvest has continued to decrease the cost and man hours required to produce a bale of cotton. Cotton harvesting in the US is completely mechanized and is accomplished by two primary machines, the spindle picker a...

  19. Classified Ads Harvesting Agent and Notification System

    CERN Document Server

    Doomun, Razvi; Nadeem, Auleear; Aukin, Mozafar

    2010-01-01

    The shift from an information society to a knowledge society require rapid information harvesting, reliable search and instantaneous on demand delivery. Information extraction agents are used to explore and collect data available from Web, in order to effectively exploit such data for business purposes, such as automatic news filtering, advertisement or product searching and price comparing. In this paper, we develop a real-time automatic harvesting agent for adverts posted on Servihoo web portal and an SMS-based notification system. It uses the URL of the web portal and the object model, i.e., the fields of interests and a set of rules written using the HTML parsing functions to extract latest adverts information. The extraction engine executes the extraction rules and stores the information in a database to be processed for automatic notification. This intelligent system helps to tremendously save time. It also enables users or potential product buyers to react more quickly to changes and newly posted sales...

  20. Development and Analysis of SRIC Harvesting Systems

    Science.gov (United States)

    Bryce J. Stokes; Bruce R. Hartsough

    1993-01-01

    This paper reviews several machine combinations for harvesting short-rotation, intensive-culture (SRIC) plantations. Productivity and cost information for individual machines was obtained from published sources. Three felling and skidding systems were analyzed for two stands, a 7.6-cm (3-in) average d.b.h. sycamore and a 15.2-cm (6-in) average d.b.h. eucalyptus. The...

  1. 厂房内排雨水系统分析与设计%Analysis and Design of the Inner Rainwater System of Factory Buildings

    Institute of Scientific and Technical Information of China (English)

    田新莲; 崔云川

    2001-01-01

    The inner rainwater system of large factory buildings is analyzed and discussed in this paper.And the personal opinion is put forward.%对大型厂房内排雨水系统水流情况进行分析,对系统设计 进行了探讨,提出了个人的见解。

  2. 屋顶花园雨水利用系统设计与实践%Design and practice of rainwater utilization system for roof garden

    Institute of Scientific and Technical Information of China (English)

    曹传生; 刘慧民; 王南

    2013-01-01

      该文意在探讨利用屋面雨水对屋顶花园进行灌溉的可行性。以北大荒集团某酒店屋顶花园为例,从植物需水量、雨水可收集量、蓄水池容量及雨水收集系统等方面进行屋面雨水回收利用设计,利用彭曼-蒙特斯公式计算屋顶花园植物需水量,结果表明:5-10月屋顶花园植物需水总量为3521.78 m3,各月份间差异较大,10月份量最小仅为361.8 m3,6月份量最大为729.6 m3;同期可收集屋面雨水总量为2179.3 m3,并据雨水径流总量与初期弃流量产生的径流量设计蓄水池容量为131 m3;将收集雨水全部用于屋顶花园绿地灌溉,能节省61.88%灌溉用水;据此,采用工程技术为屋顶花园设计雨水收集系统及自动灌溉系统,对屋顶花园雨水收集量与灌溉量的水量平衡分析结果表明:利用该自动灌溉系统可节约灌溉用水67.20%,雨水利用率可达54.55%,该设计对北方干旱地区屋顶花园雨水回用技术设计具一定的实用价值和应用前景。%In recent years, urban landscape has changed from ground greening to the roof three-dimensional greening with the rapid development of landscaping in China, and a lot of roof gardens have been built to open up the new development space for the landscape in cities. Shortage of water exists in many cities, and the city water stress will turn out because of the increasing roof gardens. To solve these problem, taking the roof garden of Beidahuang group hotel as an example, we would intend to discuss the feasibility of using roof rainwater for irrigating roof garden, and design the collection and utilization of the roof rainwater following the plant evapotranspiration (ET), the rainwater collection quantity, the reservoir capacity and rainwater collection systems. Firstly, the plant water requirement in roof garden was calculated using Penman-Monteith formula and garden coefficient methods. The results showed that the

  3. Harvesting of short rotation coppice. Harvesting trials with a cut and storage system in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schweier, J.; Becker, G.

    2012-11-01

    Short rotation coppice (SRC) harvesting techniques are available in Germany, but broad experience and knowledge about machine performance and the related effective costs of harvesting operations are still missing. This information is crucial, as harvesting costs strongly influence the economic performance of the overall supply chain. Therefore, it was the aim of this study to collect and analyze productivity data of different harvesting systems for SRC. The combined cut and chip system on the one hand and the cut and storage system on the other hand were studied by literature review. Several studies analyze the combined cut and chip systems and the reported machine productivities showed great variations. The average was 30 green tons per scheduled machine hour (gt smh{sup -1}). Few studies are analysing the cut and storage system. They report that machines still are under development and that further research is needed. Therefore, time studies of harvesting operations using the cut and storage system were carried out. Five trials were performed with the harvesting machine 'Stemster MK III' developed by Nordic Biomass. The share of productive working time was 85% and the average productivity was 21 gt smh{sup -1}. These results were compared with values from the literature. Resulting harvesting costs were calculated per oven dry ton (Euro odt{sup -1}). The advantages and disadvantages of both harvesting systems are highlighted. (orig.)

  4. Assessing Marginalized Communities in Mexico for Implementation of Rainwater Catchment Systems

    Directory of Open Access Journals (Sweden)

    Gerardo Sámano-Romero

    2016-04-01

    Full Text Available Mexico contains a high percentage of marginalized communities, as well as geographic areas with high annual precipitation (approximately 2000 mm. This study uses regional water access and precipitation data to determine municipalities that would most benefit from the installation of Domestic Rain Water Harvesting Systems (DRWHS. The main objective was to find a relationship between local conditions (marginalization, expected level of service, and precipitation and the physical components of DRWHS. First, monthly precipitation and the number of inhabitants per household were determined for each municipality. Catchment area and tank size were then calculated for a single dwelling by municipality using water demand, run-off coefficient, monthly precipitation, and number of inhabitants per household. In general, municipalities with very low access to municipal water and very high precipitation were found in the southern area of the country. A curve that estimates catchment area based on annual precipitation was developed using the selected municipalities, which produced an average catchment area of 113.3 m2 for a water demand of 100 L/capita/day. While any DRWHS must be designed specific to local conditions, this study has determined that a regional approximation can be used to select ideal communities for these systems, which can in turn facilitate national implementation.

  5. Effects of leaching salt on irrigation with harvested rainwater in accumulating salt orchards in semiarid regions%半干旱山区积盐果园集雨灌溉洗盐效果研究

    Institute of Scientific and Technical Information of China (English)

    郭全恩; 马忠明; 王益权; 郭天文; 刘军; 南丽丽; 伏耀龙; 吕军峰

    2009-01-01

    The object of study was the orchard soil in Zhengchuan Village of Xingguo Town in Qin'an County of Gansu Province under salt stress, with which a field irrigation experiment using harvested rainwater was carried out to de-termine effects of irrigation with harvested rainwater on salt and ions content in orchard soil profile and apple tree growth. The results show that there was a very marked difference between before leaching and after leaching on soil total salt(P = 0.001 < 0.01) and water-solubility sodium(P = 0.000 < 0.01), and there was a marked difference on chlorine ion ( P = 0.040 < 0.05) and water-solubility calcium(P = 0.045 < 0.05). But there was little difference on water-solubility K~+, Mg~(2+), HCO_3~-, CO_3~(2-) and SO_4~(2-) between before leaching and after leaching. The leaves that had withered marginally recovered gradually after leaching salt.%以甘肃省秦安县兴国镇郑川村盐分胁迫果园土壤为研究对象,研究了集雨灌溉对果园土壤剖面盐分离子和果树生长的影响.结果表明:在淋洗前后全盐(P=0.001<0.01)和水溶性Na+(P=0.000<0.01)有极显著的差异,Cl~-(P=0.040<0.05)和水溶性Ca~(2+)(P=0.045<0.05)有显著的差异,而K~+、Mg~(2+)、HCO_3~-、CO_3~(2-)和SO_4~(2-)在淋洗前后差异不显著.通过果园土壤淋洗,能够明显改善树体的生长状况,叶缘焦枯的叶片逐渐恢复正常.

  6. Specialized Planning of Rainwater Drainage System for Coastal Cities%某沿海城市雨水排水系统专项规划

    Institute of Scientific and Technical Information of China (English)

    刘巧红

    2016-01-01

    The drainage region was divided and drainage pattern was determined according to the principles of safety, energy efficiency,cost efficiency,scientificness and innovativeness for solving current problems of rainwater drainage system.In addition,present pipes,terrain and topography,receiving waterbody and the susceptibility of coastal cities to storm surge were also taken into consideration.Correspondingly,measures for rebuilding and using of the current rainwater drainage system and for moisture protection were proposed,which closely combine traditional rainwater pipe systems,low impact development rainwater systems and super standard rainwater discharge systems.These approaches may give full play to the guiding function of the specialized planning for engineering construction,protecting people’s life and social produc-tion from waterlog.%针对雨水排水系统存在的问题,遵循安全、节能、经济、科学和创新的原则,考虑沿海城市易遭受风暴潮灾害的特殊情况,结合现状管渠、地形地势和受纳水体,划分排水分区,确定排水方式,提出对现状雨水系统的改造利用措施和防潮措施,将传统的雨水管渠系统、低影响开发雨水系统和超标雨水径流排放系统紧密结合,充分发挥规划对工程建设的指导作用,保护人民生活和社会生产免受洪涝灾害影响。

  7. Electrochemical systems configured to harvest heat energy

    Science.gov (United States)

    Lee, Seok Woo; Yang, Yuan; Ghasemi, Hadi; Chen, Gang; Cui, Yi

    2017-01-31

    Electrochemical systems for harvesting heat energy, and associated electrochemical cells and methods, are generally described. The electrochemical cells can be configured, in certain cases, such that at least a portion of the regeneration of the first electrochemically active material is driven by a change in temperature of the electrochemical cell. The electrochemical cells can be configured to include a first electrochemically active material and a second electrochemically active material, and, in some cases, the absolute value of the difference between the first thermogalvanic coefficient of the first electrochemically active material and the second thermogalvanic coefficient of the second electrochemically active material is at least about 0.5 millivolts/Kelvin.

  8. 基于低影响开发(LID)的可持续城市雨水系统%Sustainable Urban Rainwater System Based on Low Impact Development

    Institute of Scientific and Technical Information of China (English)

    邢薇; 赵冬泉; 陈吉宁; 王浩正

    2011-01-01

    城市内涝多发、水环境污染和雨水资源大量流失等已成为制约城市可持续发展的关键问题.低影响开发(Low Impact Development,LID)是美国提出的一种雨水管理体系,其核心理念是通过源头控制维持城市水文循环.基于LID理念,构建将雨水源头控制措施、雨水排除管网和雨水集中处理设施统一结合的可持续城市雨水系统,既可控制降雨径流引起的负面影响,又可有效利用雨水资源,从整体上提高城市排水安全,减轻下游防洪压力,控制城市非点源污染,更好地体现了我国的雨水管理要求.针对可持续城市雨水系统,建立科学的动态评估方法,并开发界面友好、行之有效的评估工具,是其在工程应用中的核心问题.%Urban waterlogging, water environment pollution, and rainwater resource loss have been recognized as key problems restricting sustainable development of cities. Low impact development (LID) , with a core conception of maintaining urban hydrological recycle through source control, is a rainwater management strategy developed in the USA. Based on the conception of LID, a sustainable urban rainwater system was constructed by combining source control techniques, pipe networks and centralized treatment facilities of rainwater. This system can efficiently control the negative impacts caused by rainfall runoff and utilize the rainwater resource. As a result, the security of urban drainage can be enhanced, the pressure of downstream flood control can be alleviated, and the urban non-point pollution can be controlled, which are in accordance with the demand of rainwater management in China. Aiming at the sustainable urban rainwater system, scientific dynamic assessment methods and effective evaluation tools with friendly interfaces are key issues in its practical application.

  9. Energy harvesting autonomous sensor systems design, analysis, and practical implementation

    CERN Document Server

    Tan, Yen Kheng

    2013-01-01

    This book is the considered the first to describe sensor-oriented energy harvesting issues. Its content is derived from the author's research on the development of a truly self-autonomous and sustainable energy harvesting wireless sensor network (EH-WSN). This network harvests energy from a variety of ambient energy sources and converts it into electrical energy to power batteries. The book discusses various types of energy harvesting (EH) systems and their respective main components.

  10. Design optimization of harvester head and actuation system of forest harvester

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael R.; Mouritsen, Ole Ø.

    2005-01-01

    This paper is on the analysis and subsequent efficiency optimization of a forrest harvester. As basis for the optimization the existing machine has undergone substantial experimental testing with a view to determine the loading that the harvester head is subjected to and also the corresponding ef...... efficiency of the hydraulic actuation system during a typical working cycle....

  11. Photovoltaic Energy Harvester with Power Management System

    Directory of Open Access Journals (Sweden)

    M. Ferri

    2010-01-01

    Full Text Available We present a photovoltaic energy harvester, realized in 0.35-μm CMOS technology. The proposed system collects light energy from the environment, by means of 2-mm2 on-chip integrated microsolar cells, and accumulates it in an external capacitor. While the capacitor is charging, the load is disconnected. When the energy in the external capacitor is enough to operate the load for a predefined time slot, the load is connected to the capacitor by a power management circuit. The choice of the value of the capacitance determines the operating time slot for the load. The proposed solution is suitable for discrete-time-regime applications, such as sensor network nodes, or, in general, systems that require power supply periodically for short time slots. The power management circuit includes a charge pump, a comparator, a level shifter, and a linear voltage regulator. The whole system has been extensively simulated, integrated, and experimentally characterized.

  12. Momentum harvesting techniques for solar system travel

    Science.gov (United States)

    Willoughby, Alan J.

    1991-01-01

    Astronomers are lately estimating there are 400,000 earth visiting asteroids larger than 100 meters in diameter. These asteroids are uniquely accessible sources of building materials, propellants, oxygen, water, and minerals. They also constitute a huge momentum reserve, potentially usable for travel throughout the solar system. To use this momentum, these stealthy objects must be tracked and the ability to extract the desired momentum obtained. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to its destination is discussed. The purpose is neither to quantify nor justify the momentum exchange processes, but to stimulate collective imaginations with some intriguing possibilities which emerge when momentum as well as material is considered. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether determines the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As the tether plays out of its reel, drag on the tether steadily accelerates the spacecraft and dilutes, in time, the would-be collision. A variety of concepts for riding and using asteroids after capture are introduced. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroid materials. The chemist and the hijacker go further, they process the asteroid into propellants. Or, an asteroid railway system could be constructed with each hijacked asteroid becoming a scheduled train. Travelers could board this space railway system assured that water, oxygen propellants, and shielding await them. Austere space travel could give way to comforts, with a speed and economy impossible without nature's gift of earth visiting asteroids.

  13. Urban rainwater runoff quantity and quality - A potential endogenous resource in cities?

    Science.gov (United States)

    Angrill, Sara; Petit-Boix, Anna; Morales-Pinzón, Tito; Josa, Alejandro; Rieradevall, Joan; Gabarrell, Xavier

    2017-03-15

    Rainwater harvesting might help to achieve self-sufficiency, but it must comply with health standards. We studied the runoff quantity and quality harvested from seven urban surfaces in a university campus in Barcelona according to their use (pedestrian or motorized mobility) and materials (concrete, asphalt and slabs). An experimental rainwater harvesting system was used to collect the runoff resulting from a set of rainfall events. We estimated the runoff coefficient and initial abstraction of each surface and analyzed the physicochemical and microbiological properties, and hydrocarbon and metal content of the samples. Rainfall intensity, surface material and state of conservation were essential parameters. Because of low rainfall intensity and surface degradation, the runoff coefficient was variable, with a minimum of 0.41. Concrete had the best quality, whereas weathering and particulate matter deposition led to worse quality in asphalt areas. Physicochemical runoff quality was outstanding when compared to superficial and underground water. Microorganisms were identified in the samples (>1 CFU/100 mL) and treatment is required to meet human consumption standards. Motorized traffic mostly affects the presence of metals such as zinc (31.7 μg/L). In the future, sustainable mobility patterns might result in improved rainwater quality standards.

  14. Treatment Solutions for Rainwater Contaminated with Various Pollutants

    Directory of Open Access Journals (Sweden)

    Adriana Tokar

    2015-07-01

    Full Text Available This study presents aspects on the environmental pollution with contaminants difficult to manage from sources such as car parking, roads and roofs in crowded areas that have deficient wastewater harvesting urban networks. The contaminants washed by the rainwater that are not collected and treated can reach directly into the natural environment. Thus, rainwater which falls on rough surfaces, especially in car parking and roads without drainage channels carries out various pollutants directly into the soil and water. In order to control environmental pollution there are presented solutions for contaminated rainwater depollution.

  15. A low frequency rotational energy harvesting system

    Science.gov (United States)

    Febbo, M.; Machado, S. P.; Ramirez, J. M.; Gatti, C. D.

    2016-11-01

    This paper presents a rotary power scavenging unit comprised of two systems of flexible beams connected by two masses which are joined by means of a spring, considering a PZT (QP16N, Midé Corporation) piezoelectric sheet mounted on one of the beams. The energy harvesting (EH) system is mounted rigidly on a rotating hub. The gravitational force on the masses causes sustained oscillatory motion in the flexible beams as long as there is rotary motion. The intention is to use the EH system in the wireless autonomous monitoring of wind turbines under different wind conditions. Specifically, the development is oriented to monitor the dynamic state of the blades of a wind generator of 30 KW which rotates between 50 and 150 rpm. The paper shows a complete set of experimental results on three devices, modifying the amount of beams in the frame supporting the system. The results show an acceptable sustained voltage generation for the expected range, in the three proposed cases. Therefore, it is possible to use this system for generating energy in a low-frequency rotating environment. As an alternative, the system can be easily adapted to include an array of piezoelectric sheets to each of the beams, to provide more power generation.

  16. Task Scheduling in Energy Harvesting Real-time Embedded Systems

    OpenAIRE

    Chetto, Maryline

    2012-01-01

    International audience; Harvesting energy from the environment is very desirable for many emerging applications that use embedded devices. Energy harvesting also known as energy scavenging enables us to guarantee quasi-perpetual system operation for wireless sensors, medical implants, etc. without requiring human intervention which is normally necessary for recharging batteries in classical battery-operated systems. Nevertheless, energy harvesting calls for solving numerous technological prob...

  17. Research and simulation on the rollover system of corn harvester

    Science.gov (United States)

    Li, Shizhuang; Cao, Shukun

    2017-01-01

    The structural characteristics of our country's corn harvester are narrow-track, high centroid and existence of eccentric distance, so rollover accident is easily to occur when driving in mountainous and hilly regions. In order to improve the design quality of corn harvester and enhance the security of operation, it is of great significance to research the rollover prevention system of the corn harvester. Hydro-pneumatic suspension has powerful function of adjusting the balance of automobile body and good shock absorption function. In this paper, hydro-pneumatic suspension is applied to the rollover prevention system of the corn harvester to improve the ability of anti-rollover. At last using ADAMS simulation technology to simulate the roll stability of traditional corn harvester and the corn harvester with hydro pneumatic suspension, then calculating the heeling angle in both cases.

  18. Energy harvesting solar, wind, and ocean energy conversion systems

    CERN Document Server

    Khaligh, Alireza

    2009-01-01

    Also called energy scavenging, energy harvesting captures, stores, and uses ""clean"" energy sources by employing interfaces, storage devices, and other units. Unlike conventional electric power generation systems, renewable energy harvesting does not use fossil fuels and the generation units can be decentralized, thereby significantly reducing transmission and distribution losses. But advanced technical methods must be developed to increase the efficiency of devices in harvesting energy from environmentally friendly, ""green"" resources and converting them into electrical energy.Recognizing t

  19. Study of micro-flocculation/disc filter for rainwater reuse system%微絮凝/盘式过滤器用于雨水回用处理的研究

    Institute of Scientific and Technical Information of China (English)

    王慧莉; 归谈纯; 顾海玲; 杨俊

    2015-01-01

    At present,water scarcity has become the serious crisis facing human being.Rain water harvesting and reuse is one of the effective measures to solve the contradiction between water resource and water consumption.Rainwater on architecture roof could be used as the grey water af-ter collection and treatment,which would decrease the requirements on tap water and save the pre-cious water resource.Micro-flocculation/disc filter could be used in rainwater reclamation system and its performance showed satisfying removal on SS,turbidity,TP and iron.In the experiment, when the PAC dosge was 1 5 mg/L,effluent from micro-flocculation/disc filter could meet the re-quirements of water quality of reuse.%水资源匮乏已经成为人们目前面临的严重危机之一,水资源的供需矛盾日益突出,雨水的收集利用则是缓解这一问题的有效措施之一。建筑屋面的雨水经收集处理后可用于水质要求较低的城市杂用水,从而大大减少自来水的用量,节约宝贵的饮用水资源。微絮凝/盘式过滤器工艺用于雨水回用处理系统,对SS、浊度、TP和铁都有较好的处理效果。在试验水质条件下,PAC 投加量为15 mg/L时,微絮凝/盘式过滤工艺的出水水质基本满足回用水水质要求。

  20. Relevance of hydrological variables in water-saving efficiency of domestic rainwater tanks: Multivariate statistical analysis

    Science.gov (United States)

    Andrade, Leonardo Rosa; Maia, Adelena Gonçalves; Lucio, Paulo Sérgio

    2017-02-01

    This research investigated the relevance of four hydrological variables in the performance of a domestic rainwater harvesting (DRWH) system. The hydrological variables investigated are average annual rainfall (P), precipitation concentration degree (PCD), antecedent dry weather period (ADWP), and ratio of dry days to rainy days (nD/nR). Principal component analyses are used to group the water-saving efficiency into a select set of variables, and the relevance of the hydrological variables in a water-saving efficiency system was studied using canonical correlation analysis. The P associated with PCD, ADWP, or nD/nR attained a better correlation with water-saving efficiency than single P. We conclude that empirical models that represent a large combinations of roof-surface areas, rainwater-tank sizes, water demands, and rainfall regimes should also consider a variable for precipitation temporal variability, and treat it as an independent variable.

  1. Rainwater tank drowning.

    Science.gov (United States)

    Byard, Roger W

    2008-11-01

    Drowning remains a significant cause of accidental death in young children. The site of drowning varies among communities and is influenced by cultural and geographic factors, including the availability of particular water sources. The drowning deaths of a twin two-year-old brother and sister in a rainwater tank are reported to demonstrate specific issues that may arise. Ladders, vegetation and trellises may provide access to tanks and should be removed. Secure child-proof access points should also be installed, particularly on in-ground tanks (given the ready accessibility of the latter). As there has been a recent trend in Australia to install more domestic rainwater tanks, the number of childhood rainwater tank drownings and near-drownings will need to be monitored by forensic pathologists and child death review committees to ensure that this has not led to the introduction of a new hazard into the home environment.

  2. Short rotation forestry harvesting - systems and costs

    Science.gov (United States)

    Bruce R. Hartsough; Bryce J. Stokes

    1997-01-01

    Single stem short rotation plantations in the United States are largely dedicated to pulp production, with fuel as a secondary product. There are very limited plantings for fuel production, and others where the primary purpose is treatment of various wastewater's. All production harvesting of single stem plantations is conducted with conventional forestry...

  3. Controls on the redox potential of rainwater.

    Science.gov (United States)

    Willey, Joan D; Mullaugh, Katherine M; Kieber, Robert J; Avery, G Brooks; Mead, Ralph N

    2012-12-18

    Hydrogen peroxide acting as a reductant affects the redox potential of rainwater collected at the Bermuda Atlantic Time Series Station, the South Island of New Zealand, the contiguous USA, and the primary study site in Wilmington, NC. Analytical measurements of both halves of redox couples for dissolved iron, mercury, and the nitrate-nitrite-ammonium system can predict the rainwater redox potential measured directly by a platinum electrode. Measurements of these redox couples along with the pH in rain yields pe⁻ between 8 and 11; the half reaction for hydrogen peroxide acting as a reductant using typical rainwater conditions of 15 μM H₂O₂ at pH 4.7 gives pe⁻ = 9.12, where pe⁻ = negative log of the activity of hydrated electrons. Of the six rainwater redox systems investigated, only manganese speciation appeared to be controlled by molecular oxygen (pe⁻ = 15.90). Copper redox speciation was consistent with superoxide acting as a reductant (pe⁻ = 2.7). The concentration of H₂O₂ in precipitation has more than doubled over the preceding decade due to a decrease in SO₂ emissions, which suggests the redox chemistry of rainwater is dynamic and changing, potentially altering the speciation of many organic compounds and trace metals in atmospheric waters.

  4. Using Weather Radar to Optimise Operation of an Urban Drainage System with Distributed Rainwater Storage

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Thorndahl, Søren Liedtke; Bentzen, Thomas Ruby

    2012-01-01

    The perspective of controlling the local rain water storage tanks for a small catchment is investigated to evaluate if a predictive control reduces the CSO from the storm drainage system. A weather radar based nowcast system is used to predict the actual precipitation two hours ahead. In case...

  5. Mammary artery harvesting using the Da Vinci Si robotic system

    Directory of Open Access Journals (Sweden)

    Leonardo Secchin Canale

    2014-03-01

    Full Text Available Internal mammary artery harvesting is an essential part of any coronary artery bypass operation. Totally endoscopic coronary artery bypass graft surgery has become reality in many centers as a safe and effective alternative to conventional surgery in selected patients. Internal mammary artery harvesting is the initial part of the procedure and should be performed equally safely if one wants to achieve excellence in patency rates for the bypass. We here describe the technique for mammary harvesting with the Da Vinci Si robotic system.

  6. RAINWATER MANAGEMENT IN PROTECTED AREAS

    Directory of Open Access Journals (Sweden)

    Wioletta Żarnowiec

    2017-03-01

    Full Text Available The aim of the study was to find out whether the climate of the southern Poland allows for removing rainwater from industrial areas by evaporation from roof surfaces. The study covered the premises of a Logistics Centre with an approximate area of 34 hectares, located in the catchment of the Wedonka stream and in the region of water intake for Kraków at the Rudawa river. In the future, the Centre will comprise nine large warehouses. Road traffic associated with the project will cause potential risks for groundwater and surface water of this protected area. Therefore, the Centre’s investor decided to evaporate rainwater from the premises. To establish advisability of this plan, the study team designed and built a unique experimental station consisting of experimental roof, tank for collecting water for the sprinkler system, system for delivering, distributing and discharging water from the roof, measuring tilt tray, automatic meteorological station, and electronic devices for recording measurement data. The research on the experimental station was carried out from April to October in 2011 and 2012 and included continuous measurements of the volume of water supplied to and discharged from the roof. Moreover, the temperature of the roof and water in the tank and a number of important meteorological parameters were measured. The difference between supplied and discharged water, divided by the wetted surface of the roof, helped to determine thickness of the evaporation layer in millimeters. The study confirmed the possibility of removing potentially contaminated rainwater by evaporating it from roof surfaces of the Logistics Centre located near Kraków at an average rate of 5.9 dm3·m–2.d–1. However, due to high seasonal variability of rainfall and air temperature, it is necessary to temporarily collect water in an expansion tank of suitable capacity.

  7. Hybrid energy harvesting/transmission system for embedded devices

    Science.gov (United States)

    Hehr, Adam; Park, Gyuhae; Farinholt, Kevin

    2012-04-01

    In most energy harvesting applications the need for a reliable long-term energy supply is essential in powering embedded sensing and control electronics. The goal of many harvesters is to extract energy from the ambient environment to power hardware; however in some applications there may be conditions in which the harvester's performance cannot meet all of the demands of the embedded electronics. One method for addressing this shortfall is to supplement harvested power through the transmission of wireless energy, a concept that has successfully been demonstrated by the authors in previous studies. In this paper we present our findings on the use of a single electromagnetic coil to harvest kinetic energy in a solenoid configuration, as well as background and directed wireless energy in the 2.4 GHz radio frequency (RF) bands commonly used in WiFi and cellular phone applications. The motivation for this study is to develop a compact energy harvester / receiver that conserves physical volume, while providing multi-modal energy harvesting capabilities. As with most hybrid systems there are performance trade-offs that must be considered when capturing energy from different physical sources. As part of this paper, many of the issues related to power transmission, physical design, and potential applications are addressed for this device.

  8. System for harvesting water wave energy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhong Lin; Su, Yanjie; Zhu, Guang; Chen, Jun

    2016-07-19

    A generator for harvesting energy from water in motion includes a sheet of a hydrophobic material, having a first side and an opposite second side, that is triboelectrically more negative than water. A first electrode sheet is disposed on the second side of the sheet of a hydrophobic material. A second electrode sheet is disposed on the second side of the sheet of a hydrophobic material and is spaced apart from the first electrode sheet. Movement of the water across the first side induces an electrical potential imbalance between the first electrode sheet and the second electrode sheet.

  9. Discussion on the Quality Supervision of Rainwater Reuse System for Green Buildings in Nanjing%浅谈南京地区绿建项目雨水回用系统的质量监督

    Institute of Scientific and Technical Information of China (English)

    周若涵

    2016-01-01

    The mode and key point of rainwater reuse system was creatively proposed in this paper by combining construction with quality supervision of rainwater reuse system,which was based on laws and regulations. Meanwhile,the requirement for rainwater reuse system test and acceptance was put forward to serve as reference for numerous quality supervisory workers.%结合南京地区雨水回用系统建设和监督管理的现状,依据相关政策法规和标准规范,创新性地提出了雨水回用系统的质量监督方式和重点,并提出了系统检验和验收的要求。

  10. CMOS indoor light energy harvesting system for wireless sensing applications

    CERN Document Server

    Ferreira Carvalho, Carlos Manuel

    2016-01-01

    This book discusses in detail the CMOS implementation of energy harvesting.  The authors describe an integrated, indoor light energy harvesting system, based on a controller circuit that dynamically and automatically adjusts its operation to meet the actual light circumstances of the environment where the system is placed.  The system is intended to power a sensor node, enabling an autonomous wireless sensor network (WSN). Although designed to cope with indoor light levels, the system is also able to work with higher levels, making it an all-round light energy harvesting system.  The discussion includes experimental data obtained from an integrated manufactured prototype, which in conjunction with a photovoltaic (PV) cell, serves as a proof of concept of the desired energy harvesting system.  ·         Discusses several energy sources which can be used to power energy harvesting systems and includes an overview of PV cell technologies  ·         Includes an introduction to voltage step-...

  11. Deliberation on Design Strategies of Automatic Harvesting Systems: A Survey

    Directory of Open Access Journals (Sweden)

    Shivaji Bachche

    2015-06-01

    Full Text Available In Asia, decreasing farmer and labor populations due to various factors is a serious problem that leads to increases in labor costs, higher harvesting input energy consumption and less resource utilization. To solve these problems, researchers are engaged in providing long term and low-tech alternatives in terms of mechanization and automation of agriculture by way of efficient, low cost and easy to use solutions. This paper reviews various design strategies in recognition and picking systems, as well as developments in fruit harvesting robots during the past 30 years in several countries. The main objectives of this paper are to gather all information on fruit harvesting robots; focus on the technical developments so far achieved in picking devices; highlight the problems still to be solved; and discuss the future prospects of fruit harvesting robots.

  12. Multiphysics Simulation in the Development of Thermoelectric Energy Harvesting Systems

    Science.gov (United States)

    Nesarajah, Marco; Frey, Georg

    2016-03-01

    This contribution presents a model-based development process for thermoelectric energy harvesting systems. Such systems convert thermal energy into electrical energy and produce enough energy to supply low-power devices. Realizations require three main challenges to be solved: to guarantee optimal thermal connection of the thermoelectric generators, to find a good design for the energy harvesting system, and to find an optimal electrical connection. Therefore, a development process is presented here. The process is divided into different steps and supports the developer in finding an optimal thermoelectric energy harvesting system for a given heat source and given objectives (technical and economical). During the process, several steps are supported by simulation models. Based on developed model libraries in Modelica®/Dymola®, thermal, thermoelectrical, electrical, and control components can be modeled, integrated into different variants, and verified step by step before the system is physically built and finally validated. The process is illustrated by an example through all the steps.

  13. Design of Rainwater and Sewage Separation System at Valley-type Landfill Site%山谷型生活垃圾填埋场库区雨污分流设计

    Institute of Scientific and Technical Information of China (English)

    苟剑锋; 曾正中; 徐燕; 郭浩磊

    2012-01-01

    以甘肃省肃南县城区生活垃圾填埋场为例,对山谷型生活垃圾填埋场库区的雨污分流措施进行了探讨,提出了一种填埋场雨污分流设计方案,以实现渗滤液的减量化,为山谷型生活垃圾填埋场工程的雨污分流设计提供了借鉴.%The rainwater and sewage separation measures at the valley-type municipal solid waste landfill site in Sunan County, Gansu Province are discussed. A design scheme for rainwater and sewage separation is proposed to achieve the reduction of leachate, which provides reference for design of the rainwater and sewage separation system at the valley-type municipal solid waste landfill site.

  14. Passively Self-Tuning Piezoelectric Energy Harvesting System

    Science.gov (United States)

    Gregg, C. G.; Pillatsch, P.; Wright, P. K.

    2014-11-01

    Real world systems that are candidates for vibrational energy harvesting rarely vibrate at a single frequency, nor are these frequencies constant over time. This necessitates that vibration harvesters operate over a wide bandwidth or tune their resonance. Most tunable devices require additional energy or active control to achieve resonance over various frequencies. This work presents a passively self-tuning energy harvester that autonomously adapts its resonant frequency to the input without requiring additional energy. The system consists of a clamped- clamped beam, a movable proof mass, and a piezoelectric patch bonded to the underside of the beam. It demonstrated an open-circuit voltage output of 668 mVrms at 160Hz, 0.65g input excitation. Discrepancies between displacement and voltage magnification factors upon tuning at higher frequencies are discussed, as well as instabilities of the system and sensitivity to proof mass characteristics.

  15. Evaluation of a load measurement system for cotton harvesters

    Science.gov (United States)

    The objective of this work is to develop and characterize the performance of a system used onboard a cotton harvester for obtaining seed cotton weight data. This system can be used to measure seed cotton weight on a load by load basis, thereby enhancing the ability for a producer to conduct on-farm ...

  16. A harvester based calibration system for cotton yield monitors

    Science.gov (United States)

    The objective of this work was to develop a system for measuring seed cotton weight on a cotton harvester to facilitate on-farm research efforts and provide information for use in semi-real-time calibration of yield monitors. The system tested in 2014 was improved from the original design developed...

  17. MIMO Precoding for Networked Control Systems with Energy Harvesting Sensors

    Science.gov (United States)

    Cai, Songfu; Lau, Vincent K. N.

    2016-09-01

    In this paper, we consider a MIMO networked control system with an energy harvesting sensor, where an unstable MIMO dynamic system is connected to a controller via a MIMO fading channel. We focus on the energy harvesting and MIMO precoding design at the sensor so as to stabilize the unstable MIMO dynamic plant subject to the energy availability constraint at the sensor. Using the Lyapunov optimization approach, we propose a closed-form dynamic energy harvesting and dynamic MIMO precoding solution, which has an event-driven control structure. Furthermore, the MIMO precoding solution is shown to have an eigenvalue water-filling structure, where the water level depends on the state estimation covariance, energy queue and the channel state, and the sea bed level depends on the state estimation covariance. The proposed scheme is also compared with various baselines and we show that significant performance gains can be achieved.

  18. Using DNA nanostructures to harvest light and create energy transfer and harvesting systems

    Science.gov (United States)

    Díaz, Sebastián. A.; Buckhout-White, Susan; Brown, Carl W.; Samanta, Anirban; Klein, William P.; Ancona, Mario G.; Dwyer, Chris L.; Goldman, Ellen R.; Melinger, Joseph S.; Cunningham, Paul D.; Spillmann, Chris M.; Medintz, Igor L.

    2016-12-01

    DNA is a biocompatible scaffold that allows for the design of a variety of nanostructures, from straightforward double stranded DNA to more complex DNA origami and 3-D structures. By modifying the structures, with dyes, nanoparticles, or enzymes, they can be used to create light harvesting and energy transfer systems. We have focused on using Förster resonance energy transfer (FRET) between organic fluorophores separated with nanometer precision based on the DNAs defined positioning. Using FRET theory we can control the direction of the energy flow and optimize the design parameters to increase the systems efficiency. The design parameters include fluorophore selection, separation, number, and orientation among others. Additionally the use of bioluminescence resonance energy transfer (BRET) allowed the use of chemical energy, as opposed to photonic, to activate the systems. Here we discuss a variety of systems, such as the longest reported DNA-based molecular photonic wires (> 30 nm), dendrimeric light harvesting systems, and semiconductor nanocrystals integrated systems where they act as both scaffold and antennae for the original excitation. Using a variety of techniques, a comparison of different types of structures as well as heterogeneous vs. homogenous FRET was realized.

  19. Global Positioning System (GPS) and Geographic Information System (GIS) analysis of mobile harvesting equipment and sediment delivery to streams during forest harvest operations on steep terrain: Experimental design

    Science.gov (United States)

    Daniel Bowker; Jeff Stringer; Chris Barton; Songlin. Fei

    2011-01-01

    Sediment mobilized by forest harvest machine traffic contributes substantially to the degradation of headwater stream systems. This study monitored forest harvest machine traffic to analyze how it affects sediment delivery to stream channels. Harvest machines were outfitted with global positioning system (GPS) dataloggers, recording machine movements and working status...

  20. Which is better, electrostatic or piezoelectric energy harvesting systems?

    Science.gov (United States)

    Elliott, A. D. T.; Miller, L. M.; Halvorsen, E.; Wright, P. K.; Mitcheson, P. D.

    2015-12-01

    This paper answers the often asked, and until now inadequately answered, question of which MEMS compatible transducer type achieves the best power density in an energy harvesting system. This question is usually poorly answered because of the number of variables which must be taken into account and the multi-domain nature of the modelling and optimisation. The work here includes models of the mechanics, transducer and the power processing circuits (e.g. rectification and battery management) which in turn include detailed semiconductor models. It is shown that electrostatic harvesters perform better than piezoelectric harvesters at low accelerations, due to lower energy losses, and the reverse is generally true at high accelerations. At very high accelerations using MEMS-scale devices the dielectric breakdown limit in piezoelectric energy harvesters severely decreases their performance thus electrostatics are again preferred. Using the insights gained in this comparison, the optimal transduction mechanism can be chosen as a function of harvesting operating frequency, acceleration and device size.

  1. Harvesting and Conversation in a Predator-Prey System

    NARCIS (Netherlands)

    Hoekstra, Jeljer; Bergh, van den Jeroen C.J.M.

    2001-01-01

    Optimal harvesting of prey in a predator-prey ecosystem is studiedunder the condition that the existence of the predator has value. Predators (birds) and humans (fishers) compete for prey (shellfish). The behavior of the system is studied and conditions for optimal control are deduced. Various optim

  2. Simulation and optimization of biomass harvest and transport system

    Energy Technology Data Exchange (ETDEWEB)

    Busato, Patricia; Berruto, Remigio; Piccarolo, Pietro [University of Turin (Italy). Dipt. di Economia e Ingegneria Agraria, Forestale e Ambientale (DEIAFA)], E-mail: patrizia.busato@unito.it

    2008-07-01

    The implementation of a biomass supply chain needs the delivery of good feasibility studies. Since biomass is characterized by low value and low energy density, the logistic costs is an important component in order to assess this feasibility. To design the logistics and estimate the costs is a complex task because the process consists of multiple work processes intensively interlinked. Bottlenecks within transport or unloading operations can reduce system capacity below the capacity of the harvester. A well-matched system can lower the cost of producing forages. The overall goal of this study was to present the combined use of both the simulation and linear programming models to optimize the flow of biomass from field to a power plant. The simulation predicted the overall system performance. The results from the simulation model were then used as input in the linear programming model, which chosen the best combination of equipment for each field distance and yield, in order to minimize the logistic costs, while satisfying some constraint like the number of hours available for harvest and the area to be harvested. The presented case study refers to corn silage harvest of an area of 4000 ha (72000 tDM). The logistic operation costs ranged from 17.00 Euros.tDM{sup -1} for 10 km to 31.86 Euros.tDM{sup -1} for 40 km biomass collection radius. The average unitary costs were respectively of 306 Euros.ha{sup -1} and 574 Euros.ha{sup -1}. (author)

  3. 压力流虹吸式屋面雨水排水系统的设计与应用探讨%Discussion on Design and Application of Siphon Roof Rainwater Drainage System

    Institute of Scientific and Technical Information of China (English)

    潘俊杰; 何蓉

    2011-01-01

    Based on analysis of working principle of siphon roof rainwater drainage system, the siphon drainage system is compared with the gravity rainwater drainage system. The characteristics and advantages of siphon roof rainwater drainage system are discussed. Some problems in design and application of this system are explored. It is concluded that although the siphon roof rainwater drainage system is one of the effective ways to solve the problems of roof rainwater drainage of industrial and public buildings with large area and large span, it should be prudently used for high-rise buildings.%在分析压力流虹吸式屋面雨水排水系统工作原理的基础上,对该排水方式与传统重力流雨水排水方式进行了比较,讨论了压力流虹吸式屋面雨水排水系统的特点和优势,并对压力流虹吸式屋面雨水排水系统的设计与应用中的几个问题进行了探讨和分析.压力流虹吸式屋面雨水排水系统虽然是解决大面积、大跨度的工业厂房与公共建筑物的屋面雨水排水问题最有效的方式之一,但在高层建筑中应审慎采用.

  4. Microbiological investigations of rainwater and graywater collected for toilet flushing

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen

    2002-01-01

    Seven Danish rainwater systems were investigated with respect to the microbial water quality. The general microbiological quality (total numbers of bacteria (AODC)), and heterotrophic plate counts on R2A and Plate Count Agar in the toilets supplied with rainwater were approximately the same as in...... and hand wash basin was reused. The graywater systems gave more problems in terms of bad smell and substantially higher numbers of E. coli and Enterococcus in some toilet bowls supplied with graywater....

  5. Experimental tests on a new harvesting system for Burley tobacco

    Directory of Open Access Journals (Sweden)

    Salvatore Faugno

    2013-09-01

    Full Text Available The globalization of the tobacco production has led to a drop in competitiveness of the Italian tobacco on the world market. Burley is the main variety of tobacco cropped in Campania region of Southern Italy. Its leaves have to be sewn, in the curing phase. Aim of this work is to show the results of the implementation of a new harvest machine prototype. Basically, the machine used for Bright tobacco, totally mechanical harvested, which doesn’t need to be sewn because it requires an indirect-fire treatment into the curing furnaces. The machine was modified in order to mechanize harvesting of Burley tobacco, and tested on four cultivars of Burley tobacco under three different planting layouts. The Burley tobacco leaves can be harvested mechanically by pulling individual leaves off the stalk; leaves are then sorted and tied in bundles prior to sewing. A mechanical burley tobacco harvesting system was evaluated. This machine consists in realizing a leaves orientation system based on the different weight between the leaf blade and the stalk enhanced by an air flow. The measurements taken were harvest timing, work capacity, and quality standards of the work carried out. The results, in terms of user time, range from 6.67 h/ha to 7.80 h/ha while in terms of operational efficiency are between 88% and 89%. The average user capacity recorded for the four cultivars is equal to 0.14 ha/h, a value far from the one recorded for the same harvesting machine used for Bright tobacco (0.25 ha/h. The harvest timing capacity, range from 0.51 t/h to 0.99 t/h. The work productivity goes from 0.17 t to 0.33 t per hour of human unit respectively. The average number of detached leaves, depending on the cultivar, has been between 523 and 744. Concerning the leaf orientation, a general percentage of 73% was achieved.

  6. Electrodynamic energy harvester for electrical transformer's temperature monitoring system

    Indian Academy of Sciences (India)

    Farid Khan; Shadman Razzaq

    2015-10-01

    The development of an electrodynamic energy harvester (EDEH) for operating a wireless temperature monitoring system for electrical transformer is reported in this work. Analytical modeling, fabrication and characterization of EDEH prototype are performed. The developed EDEH consists of a mild steel core, a wound copper coil and Teflon housing. COMSOL Multiphysics software is used to optimize the design of the harvester. The split-cylindrical design of the developed EDEH permitted the harvester to be wrapped around the output power cable of the electrical transformer without shutting-off the power or disconnecting the power cable. From the electrical transformer, at current levels of 27, 72 and 155 A in the main power line, the energy harvester produced maximum RMS load voltages of 0.356, 1.09 and 2.58 V respectively, when connected to 100 load resistance. However, at matching impedance of 24 (resistance of the coil), the EDEH produced the maximum power levels of 2.99, 19.66 and 112.03 mW for a cable currents of 27, 72 and 155 A respectively. The simulation results of the devised analytical model of the harvester are in good agreement with the experimental results. Moreover, at a cable current of 93 A, when the harvester is connected to the rectifying circuit, the optimum impedance shifted to 185 and the maximum power of 19 mW is generated at that load. The reduction in power generation is attributed to the power consumption of the rectifying circuit. When the rectified DC voltage is used to charge a 3.8 V, Nickel–Cadmium (Ni–Cd) rechargeable battery, it took 3 h to completely charge the battery from 1 to 3.85 V. With the charged battery a wireless temperature sensor node is successfully operated for monitoring the temperature of the electrical transformer.

  7. Study on Drive System of Hybrid Tree Harvester

    Directory of Open Access Journals (Sweden)

    Shen Rong-feng

    2017-01-01

    Full Text Available Hybrid tree harvester with a 60 kW diesel engine combined with a battery pile could be a “green” forest harvesting and transportation system. With the new design, the diesel engine maintains a constant engine speed, keeping fuel consumption low while charging the batteries that drive the forwarder. As an additional energy saving method, the electric motors work as generators to charge the battery pile when the vehicle moves downhill. The vehicle is equipped with six large wheels providing high clearance over uneven terrain while reducing ground pressure. Each wheel is driven via a hub gear by its own alternating current motor, and each of the three wheel pairs can be steered independently. The combination of the diesel engine and six electric motors provides plenty of power for heavy lifting and pulling. The main component parameters of the drive system are calculated and optimized with a set of dynamics and simulated with AVL Cruise software. The results provide practical insights for the fuel tree harvester and are helpful to reduce the structure and size of the tree harvester. Advantage Environment provides information about existing and future products designed to reduce environmental impacts.

  8. A STAGE-STRUCTURED AND HARVESTING PREDATOR-PREY SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A predator-prey system with independent harvesting in either species and BeddingtonDeAngelis functional response is investigated. By analyzing characteristic equations and using an iterative technique,we obtain a set of easily verifiable sufficient conditions,which ensure the local and global stability of the nonnegative equilibria of the system. It is also shown that the time delay can cause a stable equilibrium to become unstable and even a switching of stabilities. Numerical simulations are carried out t...

  9. Introduction to rainwater management in Australia and suggestions for China's water problems

    Institute of Scientific and Technical Information of China (English)

    CHEN Duan; Roger ATTWATER; LUO Min

    2008-01-01

    Australia is one of the world leaders in water management. The country meets the challenge of water shortage with established integrated water management in which rainwater is taken as a too precious resource to be just drained off. In Australia, rainwater is extensively harvested and polished to provide cheaper supply for potable and non-potable domestic uses, irrigation, landscaping, refilling aquifers and other uses. Implementing dual management over the quantity and quality of storm water and practicing water sensitive urban design (WSUD) in urban areas effectively control non-point-source pollution of waterways by pollutants carried with runoffs, reduce the discharge of rainwater and thus protect properties and lives from damage by floods. These achievements are attributed to constant reinforcement by govenments from federal to local levels in policy, financial, legal and educational aspects, and also to the lasting efforts of professional communities and water industry in developing requisite techniques, demonstrating the benefits and fostering public credence of rainwater reuse. The successful rainwater management practices in Australia suggest rainwater harvesting can be a complimentary means for the South-to-North Water Transfer Scheme to solve the water shortage in China's northern regions, and thus release to a degree the pressure on the Yangtze water resources. Best management practices of rainwater can be an effective controlling strategy for flooding and non-point-source water pollution of waterways. Such in-site source control initiatives have particular significance to protecting slow waterways of weak self-purification ability, like the Three Gorges Reservior.

  10. Harvesting Intelligence in Multimedia Social Tagging Systems

    Science.gov (United States)

    Giannakidou, Eirini; Kaklidou, Foteini; Chatzilari, Elisavet; Kompatsiaris, Ioannis; Vakali, Athena

    As more people adopt tagging practices, social tagging systems tend to form rich knowledge repositories that enable the extraction of patterns reflecting the way content semantics is perceived by the web users. This is of particular importance, especially in the case of multimedia content, since the availability of such content in the web is very high and its efficient retrieval using textual annotations or content-based automatically extracted metadata still remains a challenge. It is argued that complementing multimedia analysis techniques with knowledge drawn from web social annotations may facilitate multimedia content management. This chapter focuses on analyzing tagging patterns and combining them with content feature extraction methods, generating, thus, intelligence from multimedia social tagging systems. Emphasis is placed on using all available "tracks" of knowledge, that is tag co-occurrence together with semantic relations among tags and low-level features of the content. Towards this direction, a survey on the theoretical background and the adopted practices for analysis of multimedia social content are presented. A case study from Flickr illustrates the efficiency of the proposed approach.

  11. Validation of energy harvest modeling for X14 system

    Science.gov (United States)

    Finot, Marc; MacDonald, Bob; Lance, Tamir

    2012-10-01

    Skyline Solar has developed a second generation medium concentration photovoltaic system with an optical concentration of around 14. The energy harvest model based on the first generation system has been updated and improved using field data. The model combines a bottom-up modeling approach based on performance of subcomponents such as mirrors and cells with a top-down approach based on measuring the system output under different environmental conditions. Improvement of the model includes the effect of non-uniformity of the light on the panel. The predicted energy ratio (ratio between the observed energy and expected energy) has been measured over a 10-month period and shows monthly variability below 2%, resulting in high confidence level for the mean of the expected energy harvest.

  12. Development of Vibration-Based Piezoelectric Raindrop Energy Harvesting System

    Science.gov (United States)

    Wong, Chin Hong; Dahari, Zuraini

    2017-01-01

    The trend of finding new means to harvest energy has triggered numerous researches to explore the potential of raindrop energy harvesting. This paper presents an investigation on raindrop energy harvesting which compares the performance of polyvinylidene fluoride (PVDF) cantilever and bridge structure transducers and the development of a raindrop energy harvesting system. The parameters which contribute to the output voltage such as droplet size, droplets released at specific heights and dimensions of PVDF transducers are analyzed. Based on the experimental results, the outcomes have shown that the bridge structure transducer generated a higher voltage than the cantilever. Several dimensions have been tested and it was found that the 30 mm × 4 mm × 25 μm bridge structure transducer generated a relatively high AC open-circuit voltage, which is 4.22 V. The power generated by the bridge transducer is 18 μW across a load of 330 kΩ. The transducer is able to drive up a standard alternative current (AC) to direct current (DC) converter (full-wave bridge rectifier). It generated a DC voltage, V DC of 8.7 mV and 229 pW across a 330 kΩ resistor per drop. It is also capable to generate 9.3 nJ in 20 s from an actual rain event.

  13. Consequences to water suppliers of collecting rainwater on housing estates

    OpenAIRE

    Gires, Auguste; De Gouvello, Bernard

    2009-01-01

    International audience; The collection, storage and use of rainwater from roofs reduce the need for potable water. However if water suppliers are to decrease their infrastructure costs as well as their operational costs (due to water savings), the rainwater system has to provide most of the time a significant percentage of the water demand. This paper adopts the view point of the water suppliers and investigates how reliable this source of water is in the case of a housing estate, considering...

  14. Particle behaviour consideration to maximize the settling capacity of rainwater storage tanks.

    Science.gov (United States)

    Han, M Y; Mun, J S

    2007-01-01

    Design of a rainwater storage tank is mostly based on the mass balance of rainwater with respect to the tank, considering aspects such as rainfall runoff, water usage and overflow. So far, however, little information is available on the quality aspects of the stored rainwater, such as the behavior of particles, the effect of retention time of the water in the tank and possible influences of system configuration on water quality in the storage tank. In this study, we showed that the performance of rainwater storage tanks could be maximized by recognizing the importance of water quality improvement by sedimentation and the importance of the system configuration within the tank, as well as the efficient collection of runoff. The efficiency of removal of the particles was increased by there being a considerable distance between the inlet and the outlet in the rainwater storage tank. Furthermore, it is recommended that the effective water depth in a rainwater tank be designed to be more than 3 m and that the rainwater be drawn from as close to the water surface as possible by using a floating suction device. An operation method that increases the retention time by stopping rainwater supply when the turbidity of rainwater runoff is high will ensure low turbidity in the rainwater collected from the tank.

  15. Optimal Energy Transfer in Light-Harvesting Systems

    Directory of Open Access Journals (Sweden)

    Lipeng Chen

    2015-08-01

    Full Text Available Photosynthesis is one of the most essential biological processes in which specialized pigment-protein complexes absorb solar photons, and with a remarkably high efficiency, guide the photo-induced excitation energy toward the reaction center to subsequently trigger its conversion to chemical energy. In this work, we review the principles of optimal energy transfer in various natural and artificial light harvesting systems. We begin by presenting the guiding principles for optimizing the energy transfer efficiency in systems connected to dissipative environments, with particular attention paid to the potential role of quantum coherence in light harvesting systems. We will comment briefly on photo-protective mechanisms in natural systems that ensure optimal functionality under varying ambient conditions. For completeness, we will also present an overview of the charge separation and electron transfer pathways in reaction centers. Finally, recent theoretical and experimental progress on excitation energy transfer, charge separation, and charge transport in artificial light harvesting systems is delineated, with organic solar cells taken as prime examples.

  16. Optimal Energy Transfer in Light-Harvesting Systems.

    Science.gov (United States)

    Chen, Lipeng; Shenai, Prathamesh; Zheng, Fulu; Somoza, Alejandro; Zhao, Yang

    2015-08-20

    Photosynthesis is one of the most essential biological processes in which specialized pigment-protein complexes absorb solar photons, and with a remarkably high efficiency, guide the photo-induced excitation energy toward the reaction center to subsequently trigger its conversion to chemical energy. In this work, we review the principles of optimal energy transfer in various natural and artificial light harvesting systems. We begin by presenting the guiding principles for optimizing the energy transfer efficiency in systems connected to dissipative environments, with particular attention paid to the potential role of quantum coherence in light harvesting systems. We will comment briefly on photo-protective mechanisms in natural systems that ensure optimal functionality under varying ambient conditions. For completeness, we will also present an overview of the charge separation and electron transfer pathways in reaction centers. Finally, recent theoretical and experimental progress on excitation energy transfer, charge separation, and charge transport in artificial light harvesting systems is delineated, with organic solar cells taken as prime examples.

  17. Natural Light Harvesting Systems: Unraveling the quantum puzzles

    CERN Document Server

    Thilagam, A

    2013-01-01

    In natural light harvesting systems, the sequential quantum events of photon absorption by specialized biological antenna complexes, charge separation, exciton formation and energy transfer to localized reaction centers culminates in the conversion of solar to chemical energy. A notable feature in these processes is the exceptionally high efficiencies (> 95 %) at which excitation is transferred from the illuminated protein complex site to the reaction centers. Such high exciton propagation rates within a system of interwoven biomolecular network structures, is yet to be replicated in artificial light harvesting complexes. A clue to unraveling the quantum puzzles of nature may lie in the observation of long lived coherences lasting several picoseconds in the electronic spectra of photosynthetic complexes, even in noisy environmental baths. A number of experimental and theoretical studies have been devoted to unlocking the links between quantum processes and information protocols, in the hope of finding answers...

  18. PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Niederman, Robert A. [Rutgers Univ., New Brunswick, NJ (United States); Blankenship, Robert E. [Washington Univ., St. Louis, MO (United States); Frank, Harry A. [Univ. of Connecticut, Storrs, CT (United States)

    2015-02-07

    These funds were used for partial support of the PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems, that was held on 8-11 August, 2013, at Washington University, St. Louis, MO. This conference, held in conjunction with the 16th International Congress on Photosynthesis/St. Louis, continued a long tradition of light-harvesting satellite conferences that have been held prior to the previous six international photosynthesis congresses. In this Workshop, the basis was explored for the current interest in replacing fossil fuels with energy sources derived form direct solar radiation, coupled with light-driven electron transport in natural photosynthetic systems and how they offer a valuable blueprint for conversion of sunlight to useful energy forms. This was accomplished through sessions on the initial light-harvesting events in the biological conversion of solar energy to chemically stored energy forms, and how these natural photosynthetic processes serve as a guide to the development of robust bio-hybrid and artificial systems for solar energy conversion into both electricity or chemical fuels. Organized similar to a Gordon Research Conference, a lively, informal and collegial setting was established, highlighting the exchange of exciting new data and unpublished results from ongoing studies. A significant amount of time was set aside for open discussion and interactive poster sessions, with a special session devoted to oral presentations by talented students and postdoctoral fellows judged to have the best posters. This area of research has seen exceptionally rapid progress in recent years, with the availability of a number of antenna protein structures at atomic resolution, elucidation of the molecular surface architecture of native photosynthetic membranes by atomic force microscopy and the maturing of ultrafast spectroscopic and molecular biological techniques for the investigation and manipulation of photosynthetic systems. The conferees

  19. Trip report Rainwater Basin Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a summary a trip to Rainwater Basin Wetland Management District in 1991, and focuses on the hydrology and soil habitat types. It is part of the...

  20. Energy-driven computing for energy-harvesting embedded systems

    OpenAIRE

    Merrett, Geoff V.

    2016-01-01

    There has been increasing interest over the last decade in the powering of embedded systems from ‘harvested’ energy, and this has been further fuelled by the promise and vision of IoT. Energy harvesting systems present numerous challenges, although some of these are also posed by their battery-powered counterparts: e.g. ultra-low power consumption. However, a significant challenge not witnessed in battery-powered systems is a requirement to manage the combination of a highly unpredictable and...

  1. Risk of gastrointestinal illness associated with the consumption of rainwater: a systematic review.

    Science.gov (United States)

    Dean, Jonathan; Hunter, Paul R

    2012-03-06

    The collection of rainwater for human consumption is a practice well established in many parts of the world. Much of the research to date regarding this inexpensive and sustainable source has focused on its microbiological or chemical quality and there have been no reviews of epidemiological evidence regarding actual health risks associated with rainwater consumption. Electronic bibliographic databases were searched for epidemiological studies that attempted to quantify the risk of gastrointestinal disease linked to the consumption of harvested rainwater. Online databases were searched from the oldest date up to January 2011. Both observational and experimental studies were included. In addition, reference sections of key articles were searched and authors of previous studies were contacted where appropriate. Studies were assessed for relevance independently and in duplicate. Searches returned a total of 764 articles, 13 met inclusion criteria, 5 of these were outbreak reports, and 9 were studies of other design types. Pooled subgroup analysis suggests that rainwater is associated with reduced risk of illness compared to unimproved supplies (relative risk 0.57 95% CI 0.42, 0.77). There was no significant difference in risk in the pooled analysis of studies that compared rainwater to improved water supplies (relative risk 0.82 95% CI 0.38, 1.73). However, there was heterogeneity with one study showing an excess risk of campylobacteriosis. Classification of outbreak reports determined that 4 reports were "strongly associated with rainwater" while 1 report was "probably associated with rainwater". We conclude that the evidence suggests that rainwater is safer than water from unimproved water supplies. Where feasible rainwater harvesting should be encouraged as a step toward achieving millennium development targets.

  2. Research of Rainwater Infiltration in Eastern Slovakia

    Directory of Open Access Journals (Sweden)

    Hudáková Gabriela

    2015-11-01

    Full Text Available Today precipitation water in the majority of built up and other sealed surface areas no longer reach the water circulation system via natural routes. This can lead to long-term changes to the soil and water resources, reduce the natural local regeneration of the groundwater and have effects on the chemical and biological conditions above and below the ground surface. Reasonable rainwater management leads to maintain or recover a sound and sustainable water cycle. The purpose of this paper is to present objectives and monitoring of a drainage project in Eastern Slovakia, in Kosice city. The paper focuses on percolation facilities in the research area of campus of Technical University and measurements connected with rainwater infiltration.

  3. Vibration properties of and power harvested by a system of electromagnetic vibration energy harvesters that have electrical dynamics

    Science.gov (United States)

    Cooley, Christopher G.

    2017-09-01

    This study investigates the vibration and dynamic response of a system of coupled electromagnetic vibration energy harvesting devices that each consist of a proof mass, elastic structure, electromagnetic generator, and energy harvesting circuit with inductance, resistance, and capacitance. The governing equations for the coupled electromechanical system are derived using Newtonian mechanics and Kirchhoff circuit laws for an arbitrary number of these subsystems. The equations are cast in matrix operator form to expose the device's vibration properties. The device's complex-valued eigenvalues and eigenvectors are related to physical characteristics of its vibration. Because the electrical circuit has dynamics, these devices have more natural frequencies than typical electromagnetic vibration energy harvesters that have purely resistive circuits. Closed-form expressions for the steady state dynamic response and average power harvested are derived for devices with a single subsystem. Example numerical results for single and double subsystem devices show that the natural frequencies and vibration modes obtained from the eigenvalue problem agree with the resonance locations and response amplitudes obtained independently from forced response calculations. This agreement demonstrates the usefulness of solving eigenvalue problems for these devices. The average power harvested by the device differs substantially at each resonance. Devices with multiple subsystems have multiple modes where large amounts of power are harvested.

  4. Application of Grey Fuzzy Comprehensive Evaluation Method in Urban Rainwater Utilization System%灰色模糊综合评价法在城市雨水利用系统中的应用

    Institute of Scientific and Technical Information of China (English)

    赵玲萍; 雷春生; 张凤娥; 董良飞; 涂保华

    2011-01-01

    In order to make clear the comprehensive benefits of urban rainwater utilization system to promote its application in the cit y, the urban rainwater ulilization system is needed to be evaluated objectively and accurately. An evaluation index system for urban rainwater ulilization system is presented , and an evaluation model is established by adopting Analysis Hierarchy Process to ascertain right weight and combining fuzzy comprehensive evaluation method with the Grey System Theory. Example study is conducted and the result validates the accuracy , validity and certain practical value of using grey fuzzy comprehensive evaluation method to analyze the rainwater utilization system solution.%为明确城市雨水利用系统的综合效益,以促进其在城市的推广应用,需要客观、准确地评价城市雨水利用系统。提出了城市雨水利用系统的评价指标体系,利用层次分析法确定权重,并采用模糊综合评价法结合灰色系统理论,建立了灰色模糊综合评价模型,并结合雨水利用实例进行了研究。结果表明运用灰色模糊综合评价法来分析、解决雨水利用系统方案具有准确性和有效性,有一定的应用价值。

  5. 浅析上海市城镇排水系统的防汛能力%A Brief Analysis of Flood Control Ability for Urban Rainwater Drainage System in Shanghai City

    Institute of Scientific and Technical Information of China (English)

    储小英

    2014-01-01

    Based on the survey data on existed rainwater pipes,pumping stations and tunnel drainage of Shanghai Drainage System, the current situation and main problems in Shanghai infrastructure of drainage pipe network were analyzed. The targeted improvement measures and operation management optimization were suggested. The system-wide compliance and the idea of rainwater utilization were raised.%该文从上海市排水系统已建雨水管、泵站及地道排水等调查数据,分析了上海市基础设施排水管网的现状和存在的一些主要问题,提出了具有针对性改善措施、运行管理优化建议及排水管网系统建设全系统达标,雨水综合利用的思路。

  6. 下穿式道路立交雨水泵站排水设计参数探讨%Probe into design parameters of undercrossing grade separation drainage system for rainwater pump station

    Institute of Scientific and Technical Information of China (English)

    张建新; 吕锐; 贺田富

    2012-01-01

    城市下穿式立交道路地势较低且其周边地形特殊,立交雨水泵站和下游雨水排水系统较复杂,每遇暴雨较易发生积水,严重影响正常的交通出行.以武汉市新华下路铁路立交排水为例探讨积水原因.按照常用的计算方法校核立交泵站的抽排规模,讨论设计参数取值的合理性,优化立交雨水排除系统,核算抵御极端雨季排涝能力,为国内城市立交排水提供依据.%The terrain of the undercrossing grade separation road in the city is relatively low and the topography around is complicated. As a result, the grade separation rainwater pump station and down-stream rainwater drainage system is complicated and the rainwater will easily be congested during storm, which might obstruct the normal transportation seriously. Taking the Xinhua Down road undercrossing railway grade separation drainage system in Wuhan as a case study, the reasons for water congestion were analyzed. According to the normal calculation method, the drainage capability of the grade separation pump station was checked, the reasonability of design parameters selection was discussed, the grade separation rainwater drainage system was optimized, and the extreme drainage ability was also checked, which would offer references for urban grade separation drainage system in China.

  7. Hybrid energy harvesting systems, using piezoelectric elements and dielectric polymers

    Science.gov (United States)

    Cornogolub, Alexandru; Cottinet, Pierre-Jean; Petit, Lionel

    2016-09-01

    Interest in energy harvesting applications has increased a lot during recent years. This is especially true for systems using electroactive materials like dielectric polymers or piezoelectric materials. Unfortunately, these materials despite multiple advantages, present some important drawbacks. For example, many dielectric polymers demonstrated high energy densities; they are cheap, easy to process and can be easily integrated in many different structures. But at the same time, dielectric polymer generators require an external energy supply which could greatly compromise their autonomy. Piezoelectric systems, on the other hand, are completely autonomous and can be easily miniaturized. However, most common piezoelectric materials present a high rigidity and are brittle by nature and therefore their integration could be difficult. This paper investigates the possibility of using hybrid systems combining piezoelectric elements and dielectric polymers for mechanical energy harvesting applications and it is focused mainly on the problem of electrical energy transfer. Our objective is to show that such systems can be interesting and that it is possible to benefit from the advantages of both materials. For this, different configurations were considered and the problem of their optimization was addressed. The experimental work enabled us to prove the concept and identify the main practical limitations.

  8. Energy Harvesting Systems and Methods of Assembling Same

    Science.gov (United States)

    Cepeda-Rizo, Juan (Inventor); Ganapathi, Gani B. (Inventor)

    2013-01-01

    A method of assembling an energy harvesting system is provided. The method includes coupling at least one energy storage device in flow communication with at least one apparatus that is configured to generate thermal energy and to transfer the thermal energy into at least one fluid stream. The energy storage device is configured to store the fluid stream. Moreover, the method includes coupling at least one fluid transfer device downstream from the energy storage device. The fluid transfer device receives the fluid stream from the energy storage device. A bladeless turbine is coupled in flow communication with the fluid transfer device, wherein the bladeless turbine receives the fluid stream to generate power.

  9. The early rainwater collection and processing bases on Low impact development (LID) rainwater system In the background of Sponge City%基于“海绵城市”低影响开发(LID)雨水系统下初期雨水的收集及处理--以郑州航空港区市政道路初期雨水的收集及处理为例

    Institute of Scientific and Technical Information of China (English)

    刘文涛; 张楠

    2016-01-01

    Rainwater is an important part of natural water system, all kinds of Water use on land use are rain. Currently rainwater are discharged directly into natural water bodies, Rainwater carries significant concentrations of pollutants, resulting in the pollution of water bodies. This article discusses the collection and discharge of rainwater issues In the background of Sponge City.%雨水是自然界水循环系统中的重要环节。陆地上一切形式的水资源利用都是雨水利用。目前国内雨水均是直接排放入天然水体,鉴于初期雨水携带相当浓度的污染物质,造成了对水体的污染。本文主要是在海绵城市大背景下对初期雨水的收集及排放问题提出了一些讨论。

  10. Planning of Urban Rainwater Drainage System for Pollution Control in Ningbo City%基于污染控制的宁波市雨水系统规划研究

    Institute of Scientific and Technical Information of China (English)

    叶晓东

    2014-01-01

    快速城市化带来的城市雨水系统污染日趋严重,系统的应用性研究缺失是制约污染控制措施实施的重要因素。本文以宁波为例,调研分析了雨水系统的污染状况,提出推广普及屋顶绿化、低势绿地、植被浅沟、闸门井和小型调蓄池等控制措施,并编制了不同类型的雨水系统设计优化方案;指出应在控规编制时将控制措施建设要求纳入法定文件,并建议从法规、管理、资金等方面保障雨水系统污染的控制。%The pollution of urban rainwater drainage system caused by rapid urbanization is becoming more and more serious. The absence of systematic application research is the key factor, which restricts the enforcement of pollution control. Taking Ningbo as an example, this study investigated and analyzed the current situation of rainwater pollution, proposed to promote the control measures such as roof greening, low elevation greenbelt, gate shaft, detention tank and so on, composed the prioritization scheme of different rainwater drainage systems, indicated that the requirements of control measures should be brought into statutory instruments, and suggested to ensure the pollution control of rainwater drainage system from the aspects of legislation, management, capital.

  11. Smart metacomposite-based systems for transient elastic wave energy harvesting

    Science.gov (United States)

    Yi, K.; Monteil, M.; Collet, M.; Chesne, S.

    2017-03-01

    In this paper, novel harvesting systems are proposed and studied to obtain enhanced energy from transient waves. Each of these systems contains a piezo-lens to focus waves and a harvester to yield energy from the induced focused waves. The piezo-lens comprises a host plate and piezoelectric patches bonded on the plate surfaces. The piezoelectric patches are shunted with negative capacitance (NC) circuits in order to control the spatial variation of the effective refractive index inside the piezo-lens domain. The harvester is placed at the designed focal point of the piezo-lens, two different synchronized switch harvesting on inductor (SSHI) based harvesters are analyzed in the studies. Corrected reduced models are developed to predict the transient responses of the harvesting systems. The performances of the systems incorporating SSHI-based harvesters in transient wave energy harvesting are studied and compared with the system using a standard DC harvester. The focusing effect of the piezo-lens on transient waves and its capability to improve the harvested energy are verified. Since the NC circuits are active elements, an energy balance analysis is performed. Applicability of the harvesting systems is also discussed.

  12. 国内外城市雨水资源化利用与管理体系比较%Compare urban rainwater utilization and management system between domestic and abroad

    Institute of Scientific and Technical Information of China (English)

    杨劲松; 彭湃; 赵芳

    2012-01-01

    对比分析了最佳管理措施、低影响开发、可持续排水系统、水敏感性城市设计4种国外城市雨水资源化利用与管理体系,以及我国《建筑与小区雨水利用工程技术规范》《绿色建筑评价标准》和《中国生态住区技术评估手册》在雨水资源化利用方面的管理与技术,进而提出了我国城市雨水资源化利用与管理体系的发展思路。%Compared and analyzed 4 kinds of urban rainwater utilization and management systems: Best Management Practices,Low Impact Development,Sustainable Discharge System and Water Sensitive Urban Design abroad,and rainwater utilization management and technology of Engineering Technical Code for Rain Utilization in Building and Sub-district Evaluation Standard for Green Building and Technical Evaluation Manual for Ecological Sub-district in China domestic,the paper puts forward the developing ideas of urban rainwater utilization and management system in our country.

  13. Power Management Integrated Circuit for Indoor Photovoltaic Energy Harvesting System

    Science.gov (United States)

    Jain, Vipul

    In today's world, power dissipation is a main concern for battery operated mobile devices. Key design decisions are being governed by power rather than area/delay because power requirements are growing more stringent every year. Hence, a hybrid power management system is proposed, which uses both a solar panel to harvest energy from indoor lighting and a battery to power the load. The system tracks the maximum power point of the solar panel and regulates the battery and microcontroller output load voltages through the use of an on-chip switched-capacitor DC-DC converter. System performance is verified through simulation at the 180nm technology node and is made to be integrated on-chip with 0.25 second startup time, 79% efficiency, --8/+14% ripple on the load, an average 1micro A of quiescent current (3.7micro W of power) and total on-chip area of 1.8mm2 .

  14. Dynamic analysis of a fractional order delayed predator-prey system with harvesting.

    Science.gov (United States)

    Song, Ping; Zhao, Hongyong; Zhang, Xuebing

    2016-06-01

    In the study, we consider a fractional order delayed predator-prey system with harvesting terms. Our discussion is divided into two cases. Without harvesting, we investigate the stability of the model, as well as deriving some criteria by analyzing the associated characteristic equation. With harvesting, we investigate the dynamics of the system from the aspect of local stability and analyze the influence of harvesting to prey and predator. Finally, numerical simulations are presented to verify our theoretical results. In addition, using numerical simulations, we investigate the effects of fractional order and harvesting terms on dynamic behavior. Our numerical results show that fractional order can affect not only the stability of the system without harvesting terms, but also the switching times from stability to instability and to stability. The harvesting can convert the equilibrium point, the stability and the stability switching times.

  15. 雨水花园在整个雨水处理系统的作用%The Role of Rain-garden in the Whole Rain-water Dispose System

    Institute of Scientific and Technical Information of China (English)

    杜无名; 邓薇; 李晶源

    2015-01-01

    雨水是重要的自然资源,雨水收集对于缓解水资源紧张起到重要的作用。文章简要的介绍了雨水处理系统,并着重说明雨水花园在雨水处理环节所起到作用,并对他的构造原理以及在与景观设计相结合的过程中形式的灵活性作了介绍。%Rain-water is the important natural resources, and rain-water collection plays an important role in releasing the water stress. This paper briefly introduces the rain-water dispose system, emphasizes the role of "rain-garden" in rain-water dispose link, and also introduces its structure principle and the flexibility formed in the process of combining with landscape design.

  16. Energy harvesting from hydroelectric systems for remote sensors

    Directory of Open Access Journals (Sweden)

    Joaquim Azevedo

    2016-10-01

    Full Text Available Hydroelectric systems are well-known for large scale power generation. However, there are virtually no studies on energy harvesting with these systems to produce tens or hundreds of milliwatts. The goal of this work was to study which design parameters from large-scale systems can be applied to small-scale systems. Two types of hydro turbines were evaluated. The first one was a Pelton turbine which is suitable for high heads and low flow rates. The second one was a propeller turbine used for low heads and high flow rates. Several turbine geometries and nozzle diameters were tested for the Pelton system. For the propeller, a three-bladed turbine was tested for different heads and draft tubes. The mechanical power provided by these turbines was measured to evaluate the range of efficiencies of these systems. A small three-phase generator was developed for coupling with the turbines in order to evaluate the generated electric power. Selected turbines were used to test battery charging with hydroelectric systems and a comparison between several efficiencies of the systems was made.

  17. Microbiological investigations of rainwater and graywater collected for toilet flushing

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen

    2002-01-01

    Seven Danish rainwater systems were investigated with respect to the microbial water quality. The general microbiological quality (total numbers of bacteria (AODC)), and heterotrophic plate counts on R2A and Plate Count Agar in the toilets supplied with rainwater were approximately the same...... as in the reference toilets supplied with drinking water. However, in 12 of the 27 analysed samples one or more pathogens were observed (Aeromonas sp., Pseudomonas aeruginosa, Legionella non-pneumophila, Campylobacter jejuni, Mycobacterium avium, and Cryptosporidium sp.). These pathogens were not found in any...... of the reference toilets (32 toilets). This means that the use of rainwater introduced new, potentially pathogenic microorganisms into the households which would normally not occur in toilets supplied with water from waterworks. Furthermore, four graywater systems were investigated where water from the shower...

  18. Analysis and experimental verification of electroacoustic wave energy harvesting in a coupled piezoelectric plate-harvester system

    Science.gov (United States)

    Darabi, Amir; Leamy, Michael J.

    2017-03-01

    This paper introduces an analytical framework for predicting wave energy harvested by a circular piezoelectric disk attached to a thin plate. An harmonic point source excitation generates waves that are then incident on a piezoelectric disk—summing responses due to all such excitation enables general forcing profiles to be considered. The analysis approach decomposes the coupled system into two subdomains, one being the piezoelectric disk, and the other an infinite plate for which a Green's function is readily available. Interaction forces between the two subdomains couple the problems and lead to a closed-form solution for the propagation, transmission, and reflection of waves over the entire domain. In addition, the voltage generated by the harvester is calculated using coupled electromechanical equations. The analysis approach is first validated by comparing predicted response quantities to those computed using numerical simulations, documenting good agreement. The system is then studied in the frequency domain and the optimum harvester resistance is found for generating the most electrical power. Representative experiments are carried out to demonstrate the validity of the analytical approach and verify the harvested power versus resistance trend.

  19. CH2 Energy Harvesting Systems: Economic Use and Efficiency

    Directory of Open Access Journals (Sweden)

    Chun Cheung

    2012-11-01

    Full Text Available This paper looks at the City of Melbourne's new office development CH2 as a case study of world class energy performance. In particular, the integrated design of conventionally independent systems has led to the potential to deliver significant savings to the Council and to deliver better environmental conditions to building occupants that in turn may contribute to satisfaction, well-being and productivity. It is concluded that this project has the potential to be an iconic example of effective implementation of ESD (environmental sustainable design principles and therefore act as a demonstration project to others. Energy efficiency of more than 50% of current benchmarks for Melbourne is effected. Energy harvesting is defined as arising from squander, waste and nature, which is a new concept introduced in this paper to better describe the design decision process.

  20. An Effective Power Management Circuit system for Energy Harvesting Applications

    Directory of Open Access Journals (Sweden)

    Chun-Chang Wu

    2014-05-01

    Full Text Available A high-efficiency power management circuit is realized using TSMC 0.35μm CMOS process to convert energy harvested from the environment for battery storage as a suitable power supply for application circuitry. A high conversion efficiency (74% switching voltage regulator is designed to serve as a digital control circuit with greater tolerance to power noise. For noise-sensitive analog circuits such as amplifiers and the analog-to-digital converters, a linear low dropout (LDO regulator is also designed to provide a cleaner and more stable power supply. In addition, a microcontroller which can effectively control the power switching of each circuit block is also implemented. To prevent power waste, the system blocks normally stay in standby mode with extremely low power consumption. Each block will be turned on only when instructed to activate.

  1. Hidden symmetries enhance quantum transport in Light Harvesting systems

    CERN Document Server

    Zech, Tobias; Wellens, Thomas; Buchleitner, Andreas

    2012-01-01

    For more than 50 years we have known that photosynthetic systems harvest solar energy with almost unit {\\it quantum efficiency}. However, recent experimental evidence of {\\it quantum coherence} during the excitonic energy transport in photosynthetic organisms challenges our understanding of this fundamental biological function. Currently, and despite numerous efforts, the causal connection between coherence and efficiency is still a matter of debate. We show, through the study of extensive simulations of quantum coherent transport on networks, that three dimensional structures characterized by centro-symmetric Hamiltonians are statistically more efficient than random arrangements. Moreover, we demonstrate that the experimental data available for the electronic Hamiltonians of the Fenna-Mathew-Olson (FMO) complex of sulfur bacteria and of the crypophyte PC645 complex of marine algae are consistent with this strong correlation of centro-symmetry with quantum efficiency. These results show that what appears to b...

  2. Rainwater Collection and Purification Heating Roofing System%雨水收集净化加热屋面系统研究

    Institute of Scientific and Technical Information of China (English)

    谷胜利

    2014-01-01

    Roof areas become larger and larger with the development of cities. The utility of roofs is one fo-cus issue in architecture field. Using the roof to collect and heat rainwater is a reasonable approach. In this paper,a new member that uses glasses and ceramics collect rainwater is introduced. The member is composed by four layers. The glasses are used to collect rainwater and form greenhouse. The ceramic plates with black surface are used to collection sunlight and heat the rainwater. Water vapor is condensate and collected by the bottom ceramic plate. This member with high capacity of collecting rainwater and sun-light absorption is a hopeful roof member.%介绍了一种新型的在钢筋混凝土屋面上利用玻璃和陶瓷材料收集、净化以及加热雨水的新型屋面构造。它由玻璃板面层、黑色陶瓷吸光层、普通陶瓷冷却层构成。其中,玻璃板用来收集雨水,并构成温室;黑色陶瓷板则用来接受太阳能辐射,并将其背面的雨水加热;底层陶瓷用来冷凝和收集水蒸气。南四湖区的应用实验数据分析表明,该构造具有较高的吸收阳光、雨水收集和净化能力,应用前景广阔。

  3. Analysis of environmentally friendly harvesting systems for integrated stump fuel and roundwood production

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Simon [Swedish Univ. of Agricultural Sciences, Dept. of Forest Resource Management, Umeaa (Sweden)], e-mail: Simon.Berg@slu.se

    2012-11-01

    Tree stumps could potentially make a significant contribution to the transition from reliance on foreign fossil to renewable domestic energy sources in Sweden, but harvesting them can have unintended negative environmental consequences, largely due to ground disturbance. One way to reduce the ground disturbance is to only harvest the central part of the stump, but this is not profitable using current systems. A possible solution is to integrate stump-centre and roundwood harvests. In the presented study the work, productivity and costs of a conventional, separate stem and stump harvesting system were compared in simulations to an integrated system for simultaneously harvesting stem and stump centre. The conventional system involves use of a harvester, a forwarder, a stump harvester and a stump forwarder, while the integrated system consists of a feller-puller that fells trees with the stump centre attached, a processor and a forwarder. The results indicate that integrated harvests could produce stump wood more cheaply than the current stump harvesting system at sites dominated by trees with breast height diameters exceeding 200 mm, which includes about 80% of the clear-cutting sites in Sweden. The study is not yet complete, the results are thus preliminary and require further validation, but such integrated supply systems are promising and warrant further research.

  4. A Dual-Band Antenna for RF Energy Harvesting Systems in Wireless Sensor Networks

    OpenAIRE

    A. Bakkali; Pelegri-Sebastia, J.; Sogorb, T.; V. Llario; Bou-Escriva, A.

    2016-01-01

    In this paper, we focus on ambient radio frequency energy available from commercial broadcasting stations in order to provide a system based on RF energy harvesting using a new design of receiving antenna. Several antenna designs have been proposed for use in RF energy harvesting systems, as a pertinent receiving antenna design is highly required since the antenna features can affect the amount of energy harvested. The proposed antenna is aimed at greatly increasing the energy harves...

  5. Thin Thermoelectric Generator System for Body Energy Harvesting

    Science.gov (United States)

    Settaluri, Krishna T.; Lo, Hsinyi; Ram, Rajeev J.

    2012-06-01

    Wearable thermoelectric generators (TEGs) harvest thermal energy generated by the body to generate useful electricity. The performance of these systems is limited by (1) the small working temperature differential between the body and ambient, (2) the desire to use natural air convection cooling on the cold side of the generator, and (3) the requirement for thin, lightweight systems that are comfortable for long-term use. Our work has focused on the design of the heat transfer system as part of the overall thermoelectric (TE) system. In particular, the small heat transfer coefficient for natural air convection results in a module thermal impedance that is smaller than that of the heat sink. In this heat-sink-limited regime, the thermal resistance of the generator should be optimized to match that of the heat sink to achieve the best performance. In addition, we have designed flat (1 mm thickness) copper heat spreaders to realize performance surpassing splayed pin heat sinks. Two-dimensional (2-D) heat spreading exploits the large surface area available in a wristband and allows patterned copper to efficiently cool the TE. A direct current (DC)/DC converter is integrated on the wristband. The system generates up to 28.5 μW/cm2 before the converter and 8.6 μW/cm2 after the converter, with 30% efficiency. It generates output of 4.15 V with overall thickness under 5 mm.

  6. Brief analysis on rainwater regulation and storage for pressure alleviation of municipal drainage system%结合规范浅析建筑小区内雨水调蓄对缓解市政排水压力的作用

    Institute of Scientific and Technical Information of China (English)

    彭志刚; 马达

    2014-01-01

    为了在不改变排水管网路径和不加大排水管网规模的同时优化雨水排水系统的性能,提升排水系统能力,在排水管网路径中设置雨水调蓄设施。通过梳理、比对雨水调蓄在实际工程中对雨水排水系统的优化应用,并通过列表对比在不同城市中雨水调蓄在现行的暴雨强度计算公式中对优化排水系统的改善作用。结果表明:分散地在排水路径上设置雨水调蓄设施可以降低排水管网设计的暴雨强度,其效果等同于延长雨水排水管网设计中的降雨历时。因此在建筑小区雨水排水管网设计时采用分散地在排水路径上设置雨水调蓄设施是优化系统的有效措施。该做法既可降低建筑小区排水管网规模又可提高市政雨水排水的安全。%Rainwater plays an important role in the improvement of the drainage performance while leaving the drainage network structure and capacity unchanged.Based on the comparison of rainwater storage performance in projected rainwater drainage systems it shows that the rainwater storage facilities based on the current rainfall intensity computing formulation can improve the drainage system.The results show that the decentralized rainwater drainage network in municipal drainage helps to reduce the designed rainfall intensity capacity in the drainage network.Thus the effect can be equal to increasing the rainfall duration in the rainwater drainage network design.Therefore the rainwater storage facilities in decentralized networks optimize the rainwater drainage network in community rainwater drainage design.It also reduces the capacity of the drainage network and improves the safety of the municipal rainwater drainage system in residential areas.

  7. An energy harvesting system surveyed for a variety of unattended electronic applications

    Science.gov (United States)

    Zhao, Wei; Choi, Kwangsik; Bauman, Scott; Salter, Thomas; Lowy, Daniel A.; Peckerar, Martin; Khandani, Mehdi Kalantari

    2013-01-01

    All energy-harvesting schemes require some form of "intermediate" storage - batteries or capacitors that reservoir energy harvested from the environment. There are a number of reasons for this requirement. Ambient energy fluctuates and intermediate storage smoothes out the impact of these fluctuations on the power delivered to a load. In addition, energy must be "conditioned" to be useful in a given application. It must be set to a certain voltage or made capable of delivering a desired current to load. In this article, a complete energy harvesting system including storage and conditioning electronics is described with a concentration on radio frequency (RF) harvesting. The system is capable of harvesting energy from a commercially available hand-held communication device, and exhibits an overall energy harvesting efficiency of 13.2%. Several potential applications have been investigated based on the performance of this system. Highlighted example applications include power sources for nodes in an architectural structural integrity monitor, and limb prosthesis.

  8. Performance Analysis and Modelling of a Radio Frequency Energy Harvesting System

    Directory of Open Access Journals (Sweden)

    CIRSTEA, C.

    2013-02-01

    Full Text Available The development of autonomous battery powered systems which can be deployed in inaccessible locations for sensing applications has determined the development of various energy harvesting systems. Such an energy harvester is the one developed by Powercast which can convert the energy of radio frequency signals into useful power. A model of the harvested power can prove to be a useful tool for simulation purposes as it can provide, to some extent, prior knowledge of available energy resources when optimally deploying sensor networks. To obtain an accurate model of the harvested energy we have developed an experimental setup which has been used to determine the harvested power in two different environments, a hallway and a parking lot. We have developed the experimental setup to determine the amount of power available at the output of the radio frequency harvester which consists of a current measurement system and a data acquisition system. We have also modeled through simulations the harvested power based on the characteristics of the transmitter and receiver antennas and those of the environment. We have compared the results obtained through in field measurement with the ones obtained through simulation and we have shown that within certain margins of error of maximum 2 dBm one can successfully predict the amount of energy the system can harvest. However the RF-DC and Boost converter efficiency are also key factors in the quantity of harvested energy.

  9. 建筑垃圾受纳场雨污分流系统的措施探讨%Discussion on Separate System of Rainwater and Sewage in Construction Waste Landfill Site

    Institute of Scientific and Technical Information of China (English)

    林伯伟

    2011-01-01

    以深圳某建筑垃圾受纳场为例,对其雨污分流系统进行了论述.分别就场地平整、永久性截洪沟、排水系统等进行分类、探讨,并提出了解决方案.%Taking a construction waste landfill site in Shenzhen as a case, the separate system of rainwater and sewage is described. The area leveling, permanent flood intercepting trench and drainage system are classified and discussed, and some specific schemes are proposed.

  10. Field trials of a short-rotation biomass feller buncher and selected harvesting systems

    Science.gov (United States)

    Bryce J. Stokes; Douglas J. Frederick; Dennis T. Curtin

    1986-01-01

    A continuous-speed felling and bunching prototype machine was evaluated in harvesting a three-year-old, short-rotation sycamore plantation. A small tractor, grapple skidder, and large chipper were evaluate along with the prototype machine as complete harvesting systems. Prediction equations, production rates, and costs were developed for each component of the systems....

  11. Camber Effects on the Power Harvesting from Piezoaeroelastic Systems

    Directory of Open Access Journals (Sweden)

    Hajj Muhammad R

    2012-07-01

    Full Text Available We investigate the effects of the aerodynamic loads on the performance of piezoaeroelastic energy harvesters. The harvester consists of a rigid airfoil having a pitch and plunge degrees of freedom with a piezoelectric coupling attached to the plunge degree of freedom. The Unsteady Vortex Lattice Method is used to model the unsteady flow and predict the loads. An iterative scheme based on Humming’s fourth order predictor-corrector method is employed to solve simultaneously and interactively the governing equations. The effects of varying the airfoil camber coeffcient are determined. We demonstrate that increasing the camber does not necessarily increase the level of the harvested power.

  12. Biomass removal, retention, and costs associated with biomass harvesting in the partial harvest systems of Ontario's Great Lakes-Saint Lawrence forest region : preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, D. [Toronto Univ., ON (Canada). Faculty of Forestry

    2010-07-01

    Recent bioenergy policy developments in Ontario have increased interest in forest biomass supply research. Biomass harvested from clearcut and partial harvest system in the Great Lakes-Saint Lawrence (GLSL) region can be used to supply centralized pellet plants or directly to forest mill-based conversion facilities for electricity generation. Preliminary results from a biomass harvesting trial conducted in the GLSL have confirmed that whole-tree harvesting (WTH) and the removal of skid trail results in increased biomass removal and improved operational productivity relative to conventional cut-to-length methods. Biomass removals can be increased through the imposition of smaller minimum topping diameters and the harvesting of unmerchantable trees. The results of a study conducted to evaluate the difference between conventional and biomass harvesting in a shelterwood and selection system in the GLSL has indicated that increases in the amount of firewood and small, irregular blocks of wood recovered from biomass harvests are negligible compared with conventional harvesting practices. Biomass harvesting trials are currently being conducted to determine biomass removal and operational productivity calculations for determining the overall economic feasibility of biomass harvesting for energy in the region.

  13. Excitation migration in fluctuating light-harvesting antenna systems.

    Science.gov (United States)

    Chmeliov, Jevgenij; Trinkunas, Gediminas; van Amerongen, Herbert; Valkunas, Leonas

    2016-01-01

    Complex multi-exponential fluorescence decay kinetics observed in various photosynthetic systems like photosystem II (PSII) have often been explained by the reversible quenching mechanism of the charge separation taking place in the reaction center (RC) of PSII. However, this description does not account for the intrinsic dynamic disorder of the light-harvesting proteins as well as their fluctuating dislocations within the antenna, which also facilitate the repair of RCs, state transitions, and the process of non-photochemical quenching. Since dynamic fluctuations result in varying connectivity between pigment-protein complexes, they can also lead to non-exponential excitation decay kinetics. Based on this presumption, we have recently proposed a simple conceptual model describing excitation diffusion in a continuous medium and accounting for possible variations of the excitation transfer pathways. In the current work, this model is further developed and then applied to describe fluorescence kinetics originating from very diverse antenna systems, ranging from PSII of various sizes to LHCII aggregates and even the entire thylakoid membrane. In all cases, complex multi-exponential fluorescence kinetics are perfectly reproduced on the entire relevant time scale without assuming any radical pair equilibration at the side of the excitation quencher, but using just a few parameters reflecting the mean excitation energy transfer rate as well as the overall average organization of the photosynthetic antenna.

  14. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems.

    Science.gov (United States)

    de Azevedo, Lucas Carvalho Basilio; Stürmer, Sidney Luiz; Lambais, Marcio Rodrigues

    2014-01-01

    Sugarcane (Saccharum spp.) is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF) and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning). Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development.

  15. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems

    Science.gov (United States)

    de Azevedo, Lucas Carvalho Basilio; Stürmer, Sidney Luiz; Lambais, Marcio Rodrigues

    2014-01-01

    Sugarcane (Saccharum spp.) is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF) and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning). Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development. PMID:25477936

  16. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems

    Directory of Open Access Journals (Sweden)

    Lucas Carvalho Basilio de Azevedo

    2014-09-01

    Full Text Available Sugarcane (Saccharum spp. is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning. Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development.

  17. Mechanical harvesting of aquatic plants. Report 3. Evaluation of the Limnos System

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.L.

    1984-05-01

    The Limnos Mechanical Harvesting System consists of a separate cutter machine; a harvester, which includes a gathering and conveyor pickup unit and a processor; and two transport tank barges. System operational tests were conducted on the Withlacoochee River in central Florida during the summer of 1979. Plants harvested were primarily topped-out hydrilla with small amounts of waterhyacinth. Productivity of the cutter unit was evaluated separately and in conjunction with the harvester. Tests were conducted with the harvester with the tank barges to remove the plant material from the water and also without the barges, which allowed the processed plant materials to be discharged directly into the water body. High productivity of the harvester in dense hydrilla (and water-hyacinth mixtures) required reducing the width of cut of the plant material or using 18-ft cuts at two depths (3 and 6 ft). This procedure limited the mass of material that had to be handled by the harvester. Several potential areas requiring additional research were identified as a result of these tests: improved procedures for evaluating mechanical harvesting machines, and possible improvements to the Limnos harvester system to allow higher productivity. 5 figures, 4 tables.

  18. PVC-M管材在高层建筑雨水管道中的应用%Application of PVC-M pipes in high-building rainwater drainage system

    Institute of Scientific and Technical Information of China (English)

    李福灿; 陈建春; 陈蓉

    2013-01-01

    介绍了高层建筑雨水管道(HRS )的特点、应用现状,PVC-M管材在HRS中应用的优点及现状,并比较了HRS专用PVC-M管材的配方。%The characteristics and present situation of high-building rainwater drainage system (HRS ) ,the advantages and present situation of applying PVC-M pipes in HRS were introduced . The formulas of the PVC-M pipe special for HRS were compared .

  19. Remote Fault Information Acquisition and Diagnosis System of the Combine Harvester Based on LabVIEW

    Science.gov (United States)

    Chen, Jin; Wu, Pei; Xu, Kai

    Most combine harvesters have not be equipped with online fault diagnosis system. A fault information acquisition and diagnosis system of the Combine Harvester based on LabVIEW is designed, researched and developed. Using ARM development board, by collecting many sensors' signals, this system can achieve real-time measurement, collection, displaying and analysis of different parts of combine harvesters. It can also realize detection online of forward velocity, roller speed, engine temperature, etc. Meanwhile the system can judge the fault location. A new database function is added so that we can search the remedial measures to solve the faults and also we can add new faults to the database. So it is easy to take precautions against before the combine harvester breaking down then take measures to service the harvester.

  20. Consequences to water suppliers of collecting rainwater on housing estates.

    Science.gov (United States)

    Gires, Auguste; de Gouvello, Bernard

    2009-01-01

    The collection, storage and use of rainwater from roofs reduce the need for potable water. However, if water suppliers are to decrease their infrastructure costs as well as their operational costs (due to water savings), the rainwater system has to provide most of the time a significant percentage of the water demand. This paper adopts the viewpoint of the water suppliers and investigates how reliable this source of water is in the case of a housing estate, considering WC flushing as the only water demand. A housing estate was modelled and different realistic input scenarios (water demand for WC flushing, storage capacity, roof area, and rainfall) were defined. Three indicators were exhibited. The variability generated by each input on the indicators was evaluated. The indicators were estimated for 63 homogeneously distributed French cities. Among the indicators exhibited in this paper, the most relevant one is the percentage of water supplied from the tank that is secured during 95% of the days of the simulation. The main conclusion is that the optimum way of determining the storage capacity of the rainwater collection system is not the same from the viewpoint of the users than from the viewpoint of the water suppliers. Indeed, water suppliers tend to require bigger tanks in order to take into account the rainwater collection systems in their management plan.

  1. Thermal effects in exciton harvesting in biased one-dimensional systems

    NARCIS (Netherlands)

    Vlaming, S. M.; Malyshev, V.A.; Knoester, J.

    2008-01-01

    The study of energy harvesting in chain-like structures is important due to its relevance to a variety of interesting physical systems. Harvesting is understood as the combination of exciton transport through intra-band exciton relaxation (via scattering on phonon modes) and subsequent quenching by

  2. Chaos control applied to piezoelectric vibration-based energy harvesting systems

    Science.gov (United States)

    Barbosa, W. O. V.; De Paula, A. S.; Savi, M. A.; Inman, D. J.

    2015-11-01

    Chaotic behavior presents intrinsic richness due to the existence of an infinity number of unstable periodic orbits (UPOs). The possibility of stabilizing these periodic patterns with a small amount of energy makes this kind of response interesting to various dynamical systems. Energy harvesting has as a goal the use of available mechanical energy by promoting a conversion into electrical energy. The combination of these two approaches may establish autonomous systems where available environmental mechanical energy can be employed for control purposes. Two different goals can be defined as priority, allowing a change between them: vibration reduction and energy harvesting enhancement. This work deals with the use of harvested energy to perform chaos control. Both control actuation and energy harvesting are induced employing piezoelectric materials, in a simultaneous way. A bistable piezomagnetoelastic structure subjected to harmonic excitations is investigated as a case study. Numerical simulations show situations where it is possible to perform chaos control using only the energy generated by the harvesting system.

  3. Improving collected rainwater quality in rural communities.

    Science.gov (United States)

    Garrido, S; Aviles, M; Ramirez, A; Gonzalez, A; Montellano, L; Gonzalez, B; de la Paz, J; Ramirez, R M

    2011-01-01

    The country of Mexico is facing serious problems with water quality and supply for human use and consumption in rural communities, mainly due to topographic and isolation. In Mexico the average annual precipitation is 1,500 cubic kilometers of water, if 3% of that amount were used, 13 million Mexicans could be supplied with drinking water that they currently do not have access. Considering the limited infrastructure and management in rural communities, which do not receive services from the centralized systems of large cities, a modified pilot multi-stage filtration (MMSF) system was designed, developed, and evaluated for treating collected rainwater in three rural communities, Ajuchitlan and Villa Nicolas Zapata (Morelos State) and Xacxamayo (Puebla State). The efficiencies obtained in the treatment system were: colour and turbidity >93%. It is worth mentioning that the water obtained for human use and consumption complies with the Mexican Standard NOM-127-SSA1-1994.

  4. Energy harvesting using parametric resonant system due to time-varying damping

    Science.gov (United States)

    Scapolan, Matteo; Tehrani, Maryam Ghandchi; Bonisoli, Elvio

    2016-10-01

    In this paper, the problem of energy harvesting is considered using an electromechanical oscillator. The energy harvester is modelled as a spring-mass-damper, in which the dissipated energy in the damper can be stored rather than wasted. Previous research provided the optimum damping parameter, to harvest maximum amount of energy, taking into account the stroke limit of the device. However, the amount of the maximum harvested energy is limited to a single frequency in which the device is tuned. Active and semi-active strategies have been suggested, which increases the performance of the harvester. Recently, nonlinear damping in the form of cubic damping has been proposed to extend the dynamic range of the harvester. In this paper, a periodic time-varying damper is introduced, which results in a parametrically excited system. When the frequency of the periodic time-varying damper is twice the excitation frequency, the system internal energy increases proportionally to the energy already stored in the system. Thus, for certain parametric damping values, the system can become unstable. This phenomenon can be exploited for energy harvesting. The transition curves, which separate the stable and unstable dynamics are derived, both analytically using harmonic balance method, and numerically using time simulations. The design of the harvester is such that its response is close to the transition curves of the Floquet diagram, leading to stable but resonant system. The performance of the parametric harvester is compared with the non-parametric one. It is demonstrated that performances and the frequency bandwidth in which the energy can be harvested can be both increased using time-varying damping.

  5. SandTraps are efficient, scalable, and mild systems for harvesting, washing and concentrating cells.

    Science.gov (United States)

    Frauenstein, Danny; Seidel, Katja; Adrian, Lorenz

    2017-01-01

    Microbial cells vary widely in size, specific density, shearing resistance, oxygen sensitivity and abundance so that differential harvesting and washing procedures are needed to efficiently recover cells from dilute suspensions. We here describe a mild, simple, variable and cost-efficient method to harvest cells on columns packed with silica beads. The method collects and concentrates 40-98% of the cells preserving enzymatic activity and cell viability. The method can be applied for strictly anaerobic microorganisms, is scalable to different culture volumes and can be multiplexed in standardized systems. We see major application potential in harvesting small cells leaking through 0.2μm filters, for harvesting strictly anaerobic cells and for differential harvesting of cells according to cell size using a gradient system.

  6. A piezoelectric spring-mass system as a low-frequency energy harvester.

    Science.gov (United States)

    Hu, Hongping; Hu, Lin; Yang, Jiashi; Wang, Hairen; Chen, Xuedong

    2013-04-01

    We propose a new structure consisting of a piezoelectric spring-mass system as a low-frequency piezoelectric energy harvester. A theoretical model is developed for the system from the theory of piezoelectricity. An analysis is performed to demonstrate the low-frequency nature of the system. Other basic characteristics of the energy harvester, including the output power, voltage, and efficiency, are also calculated and examined.

  7. Combine harvester monitor system based on wireless sensor network

    Science.gov (United States)

    A measurement method based on Wireless Sensor Network (WSN) was developed to monitor the working condition of combine harvester for remote application. Three JN5139 modules were chosen for sensor data acquisition and another two as a router and a coordinator, which could create a tree topology netwo...

  8. The Rainwater Utilization and Integration Solutions of Landscape Water System in Dongguan Institute%东莞某学院雨水利用及景观水体系统综合解决方案

    Institute of Scientific and Technical Information of China (English)

    钟丽

    2013-01-01

    This paper designs the use of rainwater col ection and landscape water system taking Dongguan Col ege as an example. In order to ensure the water quality of the lake, the need for recycling treatment of landscape water, to prevent the occurrence of eutrophication. Through the use of rainwater, anti-seepage lake landscape and other measures, reduce the amount of supplementary water landscape water. Surplus wat-er used for water supply in the green school.%  本文以东莞某学院为例进行雨水收集利用和中心景观水系统的方案设计。为保证湖水水质,需要对景观水进行循环处理,防止水体富营养化的发生。通过雨水利用、景观湖防渗处理等措施,减少景观水体的补充水量。富余雨水则用于学院内的绿化给水。

  9. Research and Design of Rainwater Recycling and Greenbelt Irrigation Distributed Control System%雨水回收与绿化灌溉集散控制系统的研究与设计

    Institute of Scientific and Technical Information of China (English)

    徐亮; 王辉

    2014-01-01

    介绍了一个运用集散控制技术实现对小区雨水回收与绿化灌溉综合管理的方案。通过分析雨水回收利用的工艺流程,设计了相应的控制系统硬件构成,制定了控制方案,编写了监控计算机程序。经试验证实该方案能够稳定运行且便于管理。%This paper introduced a project of applying distributed control technology to realize the integrated management of rainwater recycling and greenbelt irrigation for a residential area. Through analyzing the process of rainwater recycling and utilization, the corresponding hardware construction of control system was designed,the control scheme was made,the monitor program was written. The experiment proved the project could run stably and manageable.

  10. Optimal Harvesting and Stability for a Predator-prey System with Stage Structure

    Institute of Scientific and Technical Information of China (English)

    Xin-yu Song; Lan-sun Chen

    2002-01-01

    The dynamics of a predator-prey system, where prey population has two stages, an immature stage and a mature stage with harvesting, the growth of predator population is of Lotka-Volterra nature, are modelled by a system of retarded functional differential equations. We obtain conditions for global asymptotic stability of three nonnegative equilibria and a threshold of harvesting for the mature prey population. The effect of delay on the population at positive equilibrium and the optimal harvesting of the mature prey population are also considered.

  11. Fecal indicators and zoonotic pathogens in household drinking water taps fed from rainwater tanks in Southeast Queensland, Australia.

    Science.gov (United States)

    Ahmed, W; Hodgers, L; Sidhu, J P S; Toze, S

    2012-01-01

    In this study, the microbiological quality of household tap water samples fed from rainwater tanks was assessed by monitoring the numbers of Escherichia coli bacteria and enterococci from 24 households in Southeast Queensland (SEQ), Australia. Quantitative PCR (qPCR) was also used for the quantitative detection of zoonotic pathogens in water samples from rainwater tanks and connected household taps. The numbers of zoonotic pathogens were also estimated in fecal samples from possums and various species of birds by using qPCR, as possums and birds are considered to be the potential sources of fecal contamination in roof-harvested rainwater (RHRW). Among the 24 households, 63% of rainwater tank and 58% of connected household tap water (CHTW) samples contained E. coli and exceeded Australian drinking water guidelines of tanks and 83% of CHTW samples also contained enterococci. In all, 21%, 4%, and 13% of rainwater tank samples contained Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% of rainwater tank and 13% of CHTW samples contained Campylobacter spp. and G. lamblia, respectively. The number of E. coli (P = 0.78), Enterococcus (P = 0.64), Campylobacter (P = 0.44), and G. lamblia (P = 0.50) cells in rainwater tanks did not differ significantly from the numbers observed in the CHTW samples. Among the 40 possum fecal samples tested, Campylobacter spp., Cryptosporidium parvum, and G. lamblia were detected in 60%, 13%, and 30% of samples, respectively. Among the 38 bird fecal samples tested, Campylobacter spp., Salmonella spp., C. parvum, and G. lamblia were detected in 24%, 11%, 5%, and 13% of the samples, respectively. Household tap water samples fed from rainwater tanks tested in the study appeared to be highly variable. Regular cleaning of roofs and gutters, along with pruning of overhanging tree branches, might also prove effective in reducing animal fecal contamination of rainwater tanks.

  12. Bacterial abundance and viability in rainwater associated with cyclones, stationary fronts and typhoons in southwestern Japan

    Science.gov (United States)

    Hu, Wei; Murata, Kotaro; Toyonaga, Satoshi; Zhang, Daizhou

    2017-10-01

    The abundance and viability of bacterial cells in rainwater at a suburban site in southwestern Japan between October 2014 and September 2015 were measured and their distinctiveness, according to synoptic weather systems, i.e., cyclones (cold fronts), stationary fronts (including Meiyu and non-Meiyu fronts) and typhoons, was examined. On average, the cell concentration of bacteria in the rainwater was 2.3 ± 1.5 × 104 cells mL-1, and bacterial viability, the ratio of viable cells to total cells, was 80 ± 10%. In the rainwater of cyclones when clouds were induced by the intrusion of continental air, the bacterial concentration was higher (3.5 ± 1.6 × 104 cells mL-1) and the viability was lower (75 ± 8%) than in the rainwater of other types. In the rainwater of Meiyu fronts and typhoons when clouds were significantly influenced by marine air, bacterial concentrations were 1.5 ± 0.5 × 104 and 1.2 ± 0.3 × 104 cells mL-1, and bacterial viabilities were 84 ± 7% and 85 ± 7%, respectively. In the rainwater of non-Meiyu stationary fronts, the bacterial concentration was 2.4 ± 1.6 × 104 cells mL-1, and the viability was 78 ± 14%. Abundant bacteria were associated with ions nss-SO42-, nss-Ca2+, and NO3- in rainwater, but bacterial concentrations did not correlate with the ratios of airborne particle concentrations to the precipitation amounts. Further investigations with correlation and principal component analysis combining bacteria and ion species revealed that bacteria in the rainwater were likely enclosed in clouds at the stage of cloud formation in addition to below-cloud removal, and bacteria involved in the rainwater did not show confirmable growth.

  13. Development of a Telemetry and Yield-Mapping System of Olive Harvester

    Directory of Open Access Journals (Sweden)

    Francisco J. Castillo-Ruiz

    2015-02-01

    Full Text Available Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD and super-high-density (SHD olive orchards. A GNSS (Global Navigation Satellite System and GSM (Global System for Mobile Communications device was installed to track these harvesters. The GNSS receiver did not affect the driver’s work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yields.

  14. Development of a telemetry and yield-mapping system of olive harvester.

    Science.gov (United States)

    Castillo-Ruiz, Francisco J; Pérez-Ruiz, Manuel; Blanco-Roldán, Gregorio L; Gil-Ribes, Jesús A; Agüera, Juan

    2015-02-10

    Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD) and super-high-density (SHD) olive orchards. A GNSS (Global Navigation Satellite System) and GSM (Global System for Mobile Communications) device was installed to track these harvesters. The GNSS receiver did not affect the driver's work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yields.

  15. A frequency up-converting harvester based on internal resonance in 2-DOF nonlinear systems

    Science.gov (United States)

    Wu, Yipeng; Qiu, Jinhao; Ji, Hongli

    2016-11-01

    This paper reports the design and experimental testing of a novel frequency up- converting piezoelectric energy harvester. The harvester is firstly approximated as a 2-degree- of-freedom cubic nonlinear system instead of the general Duffing systems. A 1:3 internal resonance innovatively applied in the frequency up-conversion approach is thoroughly investigated. Finally, the theoretical dynamic model confirmed by the experimental results clearly shows the effect of the frequency up-conversion.

  16. Translocation and Transformation of Phosphorus in Rainwater Runoff in the Bio-Retention System%生物滞留系统中径流雨水磷的迁移转化规律

    Institute of Scientific and Technical Information of China (English)

    冯萃敏; 蔡志文; 米楠; 张雅君; 钱宏亮

    2016-01-01

    基于生物滞留系统对雨水的处理效果,对其进行模拟径流雨水进水试验,通过连续提取法检测生物滞留系统土壤渗滤介质不同深度(0、5、15、35 cm)处交换态无机磷(Ex⁃P)、铝磷(Al⁃P)、铁磷(Fe⁃P)含量,并监测系统出水TP。结果表明,土壤渗滤介质对Ex⁃P、Al⁃P、Fe⁃P的吸附是从上至下逐层进行、逐层减弱的,Ex⁃P转化为Al⁃P、Fe⁃P ,同时Al⁃P转化为Fe⁃P ,因此Ex⁃P含量逐层减少,而Al⁃P、Fe⁃P逐层累积。系统对径流雨水中TP的去除率在90%以上,其中未被植物利用的TP体现为水-土壤-根系-生物系统内磷的动态平衡。%Based on effects of a bio⁃retention system on rainwater, a simulation test on rainwater runoff was carried out. With the sequential extraction method, contents of exchangeable inorganic phosphorus(Ex⁃P), aluminum phosphate(Al⁃P) and iron phosphorus(Fe⁃P) in the filtration medium or soil of the bioretention system at different depth (0, 5, 15 and 35 cm) were determined and TP in the effluent of bio⁃retention system was also monitored. Results show that the adsorp⁃tion of Ex⁃P, Al⁃P and Fe⁃P by the soil medium decreased with the depth, layer by layer from the top to the bottom. Dur⁃ing the process of adsorption, Ex⁃P gradually transformed into Al⁃P and Fe⁃P, while, Al⁃P did into Fe⁃P. As a result, Ex⁃P decreased in concentration while Al⁃P and Fe⁃P increased with the depth. About 90% of the TP in the runoff rainwater was intercepted and removed by the system. The phosphorus, not absorbed by plants, remained in the system, being a part of the dynamic TP balance of the water⁃soil⁃root⁃biome system.

  17. Comparison of four harvesting systems in a loblolly pine plantation

    Science.gov (United States)

    J. Klepac; Dana Mitchell

    2016-01-01

    Felling and skidding operations were monitored while clearcut harvesting a 12-acre area of a 14-year old loblolly pine (Pinus taeda) plantation. The study area contained 465 trees per acre for trees 2.0 inches Diameter at Breast Height (DBH) and larger with a Quadratic Mean Diameter (QMD) of 7.26 inches. Two feller-bunchers (tracked and rubber-tired) and two skidders (...

  18. Dual-Hop VLC/RF Transmission System with Energy Harvesting Relay under Delay Constraint

    KAUST Repository

    Rakia, Tamer

    2017-02-09

    In this paper, we introduce a dual-hop visible light communication (VLC) / radio frequency (RF) transmission system to extend the coverage of indoor VLC systems. The relay between the two hops is able to harvest light energy from different artificial light sources and sunlight entering the room. The relay receives data packet over a VLC channel and uses the harvested energy to retransmit it to a mobile terminal over an RF channel. We develop a novel statistical model for the harvested electrical power and analyze the probability of data packet loss. We define a system design parameter (α ∈ [0, 1)) that controls the time dedicated for excess energy harvesting and data packet retransmission. It was found that the parameter has an optimal value which minimizes the packet loss probability. Further more, this optimal value is independent of the RF channel path loss. However, optimal showed inverse dependence on the packet size.

  19. 乌鲁木齐城市小区雨水收集回用系统设计建议——以晨光-佳苑为例%The Design of Rainwater Collection and Reuse system in Urumqi——Taking the Chenguang-Jiayuan Block as an Example

    Institute of Scientific and Technical Information of China (English)

    郭锦怡

    2012-01-01

    Using of urban residential rainwater collection and reuse system is a new way to save water resource in the city.Based on analyzing the original situation of rainwater collection and reuse in Chenguang-Jiayuan block in Urumqi,it suggested that the old system is remade by adopting the technique of rain infiltration,and the new system of rainwater collection and reuse is added.At the same time,the feasibility of remaking rainwater collection and reuse system was discussed,and the proposal about perfecting the newly added system was put forward.%运用城市小区雨水资源收集回用系统成为了城市节约水资源新的途径。分析了乌鲁木齐晨光-佳苑住宅小区原有雨水收集回用状况,建议采用雨水入渗技术,对原有设计系统进行改造,增加新的雨水收集回用系统,探讨改造小区雨水收集回用系统的可行性,提出完善新增雨水收集回用系统的建议。

  20. Giant reed (Arundo donax L. harvesting system, an economic and technical evaluation

    Directory of Open Access Journals (Sweden)

    M. Bentini

    2013-09-01

    Full Text Available The giant reed is a herbaceous energy crop that demonstrates a good adaptability for areas of central-northern Italy. However, its size and stem resistance to cutting pose problems for harvesting in relation both to the availability of suitable machinery and costs of the operation. A technical and economic evaluation has been conducted of a harvesting system based on an experimental machine, the biotriturator, developed by University of Bologna in collaboration with the Nobili Company (Bologna, Italy and adapted to field operating conditions. The harvesting system consists of cutting-shredding and baling in a single pass. The system was evaluated by performing a winter harvest when the crop was in quiescence and had a low moisture content. The total harvesting costs were evaluated as 11.6 € Mg-1 dry biomass. Given that the estimated area that can be covered by the harvesting system was 123 hectares per year the system represents an effective solution for not very large areas and is therefore suitable for the Italian environment where average farm sizes are slightly over seven hectares (ISTAT, 2011.

  1. 施工废水和雨水收集净化利用系统设计与施工技术%Design and Construction Technology of Construction Waste Water and Rainwater Collection and Utilization System

    Institute of Scientific and Technical Information of China (English)

    刘淑敏; 马广生; 亓志刚; 刘春远

    2016-01-01

    In order to take the construction waste water and rainwater used for the project,firstly, it should design collection pipe network,three tanks,and sedimentation sand filtration water purification tank nitrogen removal and purification of water supply pumping station,water system,then according to the construction sequence of system and main methods of the provisions of the organization construction, the construction of waste water and rainwater collection and purification to construction water quality standards,so as to solve the past construction waste water and rainwater collection without purification, which cannot be used for mixing mortar and flushing water problems of pipeline engineering. The system has reasonable design,simple construction,strong applicability,and could be reused,which could provide the design and construction of the construction enterprises according to different conditions.%为使施工废水和雨水利用于工程,需先设计收集管网、三级沉淀中和储罐、砂滤水除氮净化槽、净化水供应泵站、水利用等系统,再按照规定的系统施工顺序及主要方法组织施工,可将施工废水和雨水收集、净化达到施工用水的质量标准,从而解决过去施工废水和雨水收集后未经净化,不能用于搅拌砂浆和管道冲洗等工程用水的问题。本系统设计合理,施工简便,适用性强,设备还可重复利用,可提供广大施工企业根据不同工况参照设计与施工。

  2. Vacuum-packaged piezoelectric vibration energy harvesters: damping contributions and autonomy for a wireless sensor system

    Science.gov (United States)

    Elfrink, R.; Renaud, M.; Kamel, T. M.; de Nooijer, C.; Jambunathan, M.; Goedbloed, M.; Hohlfeld, D.; Matova, S.; Pop, V.; Caballero, L.; van Schaijk, R.

    2010-10-01

    This paper describes the characterization of thin-film MEMS vibration energy harvesters based on aluminum nitride as piezoelectric material. A record output power of 85 µW is measured. The parasitic-damping and the energy-harvesting performances of unpackaged and packaged devices are investigated. Vacuum and atmospheric pressure levels are considered for the packaged devices. When dealing with packaged devices, it is found that vacuum packaging is essential for maximizing the output power. Therefore, a wafer-scale vacuum package process is developed. The energy harvesters are used to power a small prototype (1 cm3 volume) of a wireless autonomous sensor system. The average power consumption of the whole system is less than 10 µW, and it is continuously provided by the vibration energy harvester.

  3. A Self-Powered Hybrid Energy Scavenging System Utilizing RF and Vibration Based Electromagnetic Harvesters

    Science.gov (United States)

    Uluşan, H.; Gharehbaghi, K.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

    2015-12-01

    This study presents a novel hybrid system that combines the power generated simultaneously by a vibration-based Electromagnetic (EM) harvester and a UHF band RF harvester. The novel hybrid scavenger interface uses a power management circuit in 180 nm CMOS technology to step-up and to regulate the combined output. At the first stage of the system, the RF harvester generates positive DC output with a 7-stage threshold compensated rectifier, while the EM harvester generates negative DC output with a self-powered AC/DC negative doubler circuit. At the second stage, the generated voltages are serially added, stepped-up with an on-chip charge pump circuit, and regulated to a typical battery voltage of 3 V. Test results indicate that the hybrid operation enables generation of 9 μW at 3 V output for a wide range of input stimulations, which could not be attained with either harvesting mode by itself. Moreover the hybrid system behaves as a typical battery, and keeps the output voltage stable at 3 V up to 18 μW of output power. The presented system is the first battery-like harvester to our knowledge that generates energy from two independent sources and regulates the output to a stable DC voltage.

  4. Comparison of Energy Harvesting Systems for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    James M. Gilbert; Farooq Balouchi

    2008-01-01

    Wireless sensor networks (WSNs) offer an attractive solution to many environmental, security, and process monitoring problems. However, one barrier to their fuller adoption is the need to supply electrical power over extended periods of time without the need for dedicated wiring. Energy harvesting provides a potential solution to this problem in many applications. This paper reviews the characteristics and energy requirements of typical sensor network nodes, assesses a range of potential ambient energy sources, and outlines the characteristics of a wide range of energy conversion devices. It then proposes a method to compare these diverse sources and conversion mechanisms in terms of their normalised power density.

  5. Stability and Hopf Bifurcation of Delayed Predator-Prey System Incorporating Harvesting

    Directory of Open Access Journals (Sweden)

    Fengying Wei

    2014-01-01

    Full Text Available A kind of delayed predator-prey system with harvesting is considered in this paper. The influence of harvesting and delay is investigated. Our results show that Hopf bifurcations occur as the delay τ passes through critical values. By using of normal form theory and center manifold theorem, the direction of Hopf bifurcation and the stability of the bifurcating periodic solutions are obtained. Finally, numerical simulations are given to support our theoretical predictions.

  6. Development and Deployment of a Short Rotation Woody Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header

    Energy Technology Data Exchange (ETDEWEB)

    Eisenbies, Mark [SUNY ESF; Volk, Timothy [SUNY ESF

    2014-10-03

    Demand for bioenergy sourced from woody biomass is projected to increase; however, the expansion and rapid deployment of short rotation woody crop systems in the United States has been constrained by high production costs and sluggish market acceptance due to problems with quality and consistency from first-generation harvesting systems. The objective of this study was to evaluate the effect of crop conditions on the performance of a single-pass, cut and chip harvester based on a standard New Holland FR-9000 series forage harvester with a dedicated 130FB short rotation coppice header, and the quality of chipped material. A time motion analysis was conducted to track the movement of machine and chipped material through the system for 153 separate loads over 10 days on a 54-ha harvest. Harvester performance was regulated by either ground conditions, or standing biomass on 153 loads. Material capacities increased linearly with standing biomass up to 40 Mgwet ha-1 and plateaued between 70 and 90 Mgwet hr-1. Moisture contents ranged from 39 to 51% with the majority of samples between 43 and 45%. Loads produced in freezing weather (average temperature over 10 hours preceding load production) had 4% more chips greater than 25.4 mm (P < 0.0119). Over 1.5 Mgdry ha-1 of potentially harvested material (6-9% of a load) was left on site, of which half was commercially undesirable meristematic pieces. The New Holland harvesting system is a reliable and predictable platform for harvesting material over a wide range of standing biomass; performance was consistent overall in 14 willow cultivars.

  7. 虹吸式雨水排水系统施工技术和质量控制%On construction technique of hydrocone rainwater drainage system and its quality control

    Institute of Scientific and Technical Information of China (English)

    王俊

    2014-01-01

    The paper introduces the working principle and craft procedure of the roof hydrocone rainwater drainage system,illustrates the con-struction techniques for the measurement and calculation,pipeline prefabrication,positioning and lining,and manufacturing and installation of support,and indicates its quality control measures,so as to provide some reference for similar constructions and projects.%介绍了屋面虹吸式雨水排水系统的工作原理及工艺流程,着重对测量计算、管道预制、定位放线、支架制作安装等施工技术进行了阐述,并说明了其质量控制措施,对其他类似工程施工具有借鉴作用。

  8. 增城某安置区--雨水收集系统的计算%The Calculation Of The Rainwater Reuse System For The Settlement Site In Zeng Cheng City

    Institute of Scientific and Technical Information of China (English)

    朱文忠

    2014-01-01

    Now we are in promoting green building al across the country, And water saving is one of the most important part of it. This paper introduces the design process in more detail about the rainwater reuse system calculation problem. At the same time, For similar project also has certain reference value.%现在全国各地都在大力倡导绿色建筑,而节水是其中最重要的一部分,本文比较详细地介绍了在设计过程中雨水收集利用系统的水量计算问题,对类似项目有一定的参考价值。

  9. Design of Outdoor Rainwater System for National Academy for Performing Arts in Port of Spain, Trinidad and Tobago%特立尼达和多巴哥西班牙港国家艺术中心雨水系统设计

    Institute of Scientific and Technical Information of China (English)

    张留霞; 胡明

    2011-01-01

    在特立尼达和多巴哥西班牙港国家艺术中心室外雨水系统的设计中,根据当地排水部门的要求,项目建成前后的基地雨水排放不能增加市政排放系统的流量,为此根据当地暴雨强度公式,对比了项目建成前后的雨水排放量,通过设置雨水调节池的方式调蓄了洪峰径流量,并就如何确定调节池的容积进行了探讨.%In the design of outdoor rainwater system for National Academy for Performing Arts in Port of Spain, Trinidad and Tobago, according to the requirement of local drainage department, the rainwater drainage from the site could not increase the capacity of municipal drainage system.So, the rainwater drainage volume before and after building the National Academy was compared based on local rainfall intensity equation.Rainwater detention tank was applied in this project to intercept peak flood.A discussion is given on how to determine the tank volume.

  10. Powering-up Wireless Sensor Nodes Utilizing Rechargeable Batteries and an Electromagnetic Vibration Energy Harvesting System

    Directory of Open Access Journals (Sweden)

    Salar Chamanian

    2014-10-01

    Full Text Available This paper presents a wireless sensor node (WSN system where an electromagnetic (EM energy harvester is utilized for charging its rechargeable batteries while the system is operational. The capability and the performance of an in-house low-frequency EM energy harvester for charging rechargeable NiMH batteries were experimentally verified in comparison to a regular battery charger. Furthermore, the power consumption of MicaZ motes, used as the WSN, was evaluated in detail for different operation conditions. The battery voltage and current were experimentally monitored during the operation of the MicaZ sensor node equipped with the EM vibration energy harvester. A compact (24.5 cm3 in-house EM energy harvester provides approximately 65 µA charging current to the batteries when excited by 0.4 g acceleration at 7.4 Hz. It has been shown that the current demand of the MicaZ mote can be compensated for by the energy harvester for a specific low-power operation scenario, with more than a 10-fold increase in the battery lifetime. The presented results demonstrate the autonomous operation of the WSN, with the utilization of a vibration-based energy harvester.

  11. Development and application of remote video monitoring system for combine harvester based on embedded Linux

    Science.gov (United States)

    Chen, Jin; Wang, Yifan; Wang, Xuelei; Wang, Yuehong; Hu, Rui

    2017-01-01

    Combine harvester usually works in sparsely populated areas with harsh environment. In order to achieve the remote real-time video monitoring of the working state of combine harvester. A remote video monitoring system based on ARM11 and embedded Linux is developed. The system uses USB camera for capturing working state video data of the main parts of combine harvester, including the granary, threshing drum, cab and cut table. Using JPEG image compression standard to compress video data then transferring monitoring screen to remote monitoring center over the network for long-range monitoring and management. At the beginning of this paper it describes the necessity of the design of the system. Then it introduces realization methods of hardware and software briefly. And then it describes detailedly the configuration and compilation of embedded Linux operating system and the compiling and transplanting of video server program are elaborated. At the end of the paper, we carried out equipment installation and commissioning on combine harvester and then tested the system and showed the test results. In the experiment testing, the remote video monitoring system for combine harvester can achieve 30fps with the resolution of 800x600, and the response delay in the public network is about 40ms.

  12. Performance Evaluation of Yield Monitoring System for Rice Combine Harvester in Selangor, Malaysia

    Directory of Open Access Journals (Sweden)

    Renny Eka Putri

    2016-01-01

    Full Text Available Yield monitoring system constructed for combine harvester was able to monitor and store required, measured attributes during field tests. A rugged, wireless crop yield monitoring instrumentation system was employed on a rice combine harvester to measure instantaneous rice yield in this study.  A mild steel chute mounted with SWR SolidFlow microwave type flow sensor and SWR M-Sens 2 microwave type moisture sensor were located at the end top of the clean grain auger of the combine harvester to the flow rate of the dropped grain into the grain storage tank and measure the moisture content of the grain transferred by the auger. The objective of conducted performance test was to check both the operational and robustness of the instrumentation system under the actual harvesting operation with the combine in the paddy field.  During harvesting, the embedded system, DGPS, router and all sensors within the instrumentation system functioned reliable. Instrumentation system records combined multiple data by following moisture content (%, cutting width (mm, elevator rotation speed (RPM and combine speed (km/hr. Through yield monitoring and yield mapping, the rice farmers could correct soil nutrient defiencies as indicated by the yield variabilities within the plot for the next cropping season

  13. Design and optimization of an RF energy harvesting system from multiple sources

    Science.gov (United States)

    Ali, Mai; Albasha, Lutfi; Qaddoumi, Nasser

    2013-05-01

    This paper presents the design and optimization of an RF energy harvesting system from multiple sources. The RF power is harvested from four frequency bands representing five wireless systems, namely GSM, UMTS, DTV, Wi-Fi, and road tolling system. A Schottky diode model was developed based on which an RF-DC rectifier joined with a voltage multiplier circuits were designed. The simulation results of the complete RF harvesting system showed superior performance to similar state of the art systems. To further optimize the design, and to eliminate use of a non-standard CMOS process associated with Schottky diodes, the Schottky diode based rectifier was replaced by diode connected transistor configuration based on self-threshold cancellation (SVC) technique.

  14. Energy harvesting from a DE-based dynamic vibro-impact system

    Science.gov (United States)

    Yurchenko, D.; Val, D. V.; Lai, Z. H.; Gu, G.; Thomson, G.

    2017-10-01

    Dielectric elastomer (DE) generators may be used in harvesting energy from ambient vibrations. Based on existing research on the mechanical properties of a circular DE membrane, a DE-based dynamic vibro-impact system is proposed in this paper to convert vibrational energy into electrical one. The dimensional, electrical and dynamic parameters of the DE membrane are analysed and then used to numerically estimate the output voltage of the proposed system. The system output performances under harmonic excitation are further discussed. At last, the comparison study has been conducted with an electromagnetic energy harvesting system, served as a ‘shaking’ flashlight.

  15. Modelling the potential of rainwater harvesting in western Kenya ...

    African Journals Online (AJOL)

    Samuel

    The Kakamega area in western Kenya is known for plenty of rainfall. (around ..... I and II, Ministry of Finance and Planning, Central Bureau of Statistics, Nairobi, .... growing season for western Kenya', Agricultural and Forest Meteorology, vol.

  16. Quality assessment and primary uses of harvested rainwater in ...

    African Journals Online (AJOL)

    2013-08-08

    Aug 8, 2013 ... Results indicated that the tank water quality was within all the chemical standards (cations and ... operation and maintenance; (iii) whether the user would be .... drinking, washing clothes, cleaning the house and/or bathing.

  17. Adoption of Rainwater Harvesting Technologies 'by Farmers in ...

    African Journals Online (AJOL)

    the decisions made by fanners to use that par- ticular technology ... land in Tanzania is located in arid and semi- arid lands ... standing the relative importance ·of.factors 'and. 'cons'traints ...... 1985 'Theory and P,uctice oj Economet-. "rics New ...

  18. Rainwater Utilization Technology Demonstrated in London Case Hall of Shanghai World Expo 2010%上海世博会伦敦案例馆展示的雨水利用技术案例分析

    Institute of Scientific and Technical Information of China (English)

    徐钟骏; 刘晋民

    2012-01-01

    为实现雨水资源化,满足节约用水的要求,雨水利用技术越来越多地被有节水要求的新建及改建项目所采用,相关雨水利用系统的设计运用越来越广泛.2010年上海世博会伦敦案例馆是单体建筑节能、降耗的典范,雨水利用技术是该项目的节能措施之一,该项目建成已有两年,雨水利用系统运行良好,收集及净化的雨水量大于建筑消耗的水资源耗量,充分发挥了预期的节水的作用,很好地回应了参展方“零能耗”的主题.该文对雨水利用技术在该项目中的具体实施及运用进行了详细介绍,阐述了雨水利用系统的工艺流程、系统组成及设计要点,说明了此类项目在工程具体实施时需注意的要点,对雨水利用系统在单个节能建筑中的设计有着很好的借鉴作用.%Rainwater utilization technology is used more widely by water—saving requirements of new and renovation projects,and the design of the rainwater utilization system is widely applied in water-saving projects. 2010 Shanghai World Expo London case is a model for building energy efficiency. The rainwater harvesting technology is one of the energy-saving methods in this project. The project has been completed for two years, rainwater utilization system runs well, water-saving effect is significant. By introducing the appliement and operation processes of the rainwater utilization system in details, the process parameters, system components and design key points were pointed out. Most important things of how to run the system in engineering project was also concluded, which will be a good reference for applying the rainwater utilization system in building energy efficiency.

  19. Evaluation of the on-board module building cotton harvest systems

    Science.gov (United States)

    The "on-board" module building systems from Case IH (Module Express 625 [ME 625]) and a system under final testing by John Deere (7760) represent the most radical change in the seed cotton handling and harvest system since the module builder was introduced over 30 years ago. The Module Express 625 c...

  20. Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration

    Energy Technology Data Exchange (ETDEWEB)

    Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

    2013-07-01

    Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing

  1. Optimal Design of Dual-Hop VLC/RF Communication System With Energy Harvesting

    KAUST Repository

    Rakia, Tamer

    2016-07-28

    In this letter, we consider a dual-hop heterogeneous visible light communication (VLC)/radio frequency (RF) communication system to extend the coverage of VLC systems. Besides detecting the information over VLC link, the relay is able to harvest energy from the first-hop VLC link, by extracting the direct current component of the received optical signal, and uses the harvested energy to retransmit the data to a mobile terminal over the second-hop RF link. We investigate the optimal design of the hybrid system in terms of data rate maximization.

  2. Production system and harvesting stage influence on nitrate content and quality of butterhead lettuce

    Directory of Open Access Journals (Sweden)

    Siti Fairuz Yosoff

    2015-01-01

    Full Text Available Leafy vegetables such as lettuce grown under different production systems may accumulate different concentrations of nitrate which may reach to the levels potentially toxic to humans. Moreover, nitrate accumulation varies in various plant parts and physiological age of the plant. Therefore, to determine the effect of production system and harvesting stage on nitrate accumulation and quality of butterhead lettuce, a study was conducted considering two lettuce production systems namely hydroponic and organic, and four different harvesting stages such as 35, 38, 41 and 44 days after transplanting (DAT. The experimental design was complete randomized design (CRD with four replications. Hydroponic and organic systems performed similar in terms of yield, quality and nitrate content of butterhead lettuce. Delaying harvesting can not only increase yield but also can minimize nitrate accumulation and health hazard risk as well. Delay in harvesting stage may result in quality deterioration of lettuce and increased production cost. Thus, a compromise is necessary to consider 41 DAT as the optimum stage to harvest butterhead lettuce with significantly higher reduction of nitrate content in both outer adult leaf blades and young leaves of hydroponic lettuce. Fresh weight, firmness and color of butterhead lettuce at this stage were still acceptable.

  3. A System for Harvesting Eggs from the Pink-Spotted Lady Beetle

    Directory of Open Access Journals (Sweden)

    Margaret L. Allen

    2012-01-01

    Full Text Available We describe a system for harvesting eggs from a predatory insect, the pink-spotted lady beetle, Coleomegilla maculata De Geer (Coleoptera: Coccinellidae. Adult beetles placed in square, transparent containers that included oviposition substrates hanging from the top of the cage deposited eggs on the materials provided. We harvested eggs from these substrates in quantities sufficient for either destructive sampling or synchronous development of larvae. We evaluated effects of crowding inside cages; effects of a chemical attractant on oviposition behavior; egg cannibalism. Females preferred a textured surface rather than a smooth, waxy one for laying eggs. Crowding inhibited oviposition of beetles. Presence of a chemical attractant (methyl salicylate did not significantly improve oviposition. This paper describes an inexpensive system for harvesting eggs from C. maculata. Refinement of this system should improve oviposition and reduce cannibalism.

  4. A Dual-Band Antenna for RF Energy Harvesting Systems in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    A. Bakkali

    2016-01-01

    Full Text Available In this paper, we focus on ambient radio frequency energy available from commercial broadcasting stations in order to provide a system based on RF energy harvesting using a new design of receiving antenna. Several antenna designs have been proposed for use in RF energy harvesting systems, as a pertinent receiving antenna design is highly required since the antenna features can affect the amount of energy harvested. The proposed antenna is aimed at greatly increasing the energy harvesting efficiency over Wi-Fi bands: 2.45 GHz and 5 GHz. This provides a promising alternative energy source in order to power sensors located in harsh environments or remote places, where other energy sources are impracticable. The dual-band antenna can be easily integrated with RF energy harvesting system on the same circuit board. Simulations and measurements were carried out to evaluate the antenna performances and investigate the effects of different design parameters on the antenna performance. The receiving antenna meets the required bandwidth specification and provides peak gain of more than 4 dBi across the operating band.

  5. Design and Implementation of RF Energy Harvesting System for Low-Power Electronic Devices

    Science.gov (United States)

    Uzun, Yunus

    2016-08-01

    Radio frequency (RF) energy harvester systems are a good alternative for energizing of low-power electronics devices. In this work, an RF energy harvester is presented to obtain energy from Global System for Mobile Communications (GSM) 900 MHz signals. The energy harvester, consisting of a two-stage Dickson voltage multiplier circuit and L-type impedance matching circuits, was designed, simulated, fabricated and tested experimentally in terms of its performance. Simulation and experimental works were carried out for various input power levels, load resistances and input frequencies. Both simulation and experimental works have been carried out for this frequency band. An efficiency of 45% is obtained from the system at 0 dBm input power level using the impedance matching circuit. This corresponds to the power of 450 μW and this value is sufficient for many low-power devices. The most important parameters affecting the efficiency of the RF energy harvester are the input power level, frequency band, impedance matching and voltage multiplier circuits, load resistance and the selection of diodes. RF energy harvester designs should be optimized in terms of these parameters.

  6. Systems-Level Energy Audit for Main Complex, Construction Engineering Research Laboratory

    Science.gov (United States)

    2003-08-01

    months. Minimiz- ing water overflow with active monitoring could result in water conservation. • Consider reusing the paint test tank effluent (10 kgal...Waterless urinals and low-flow toilets (FY04) 5. Process water control (FY05/6) 6. Harvest rainwater for greywater system for flushing (FY06) 7

  7. RELIABILITY TESTING OF AN ON-HARVESTER COTTON WEIGHT MEASUREMENT SYSTEM

    Science.gov (United States)

    A system for weighing seed cotton onboard stripper harvesters was developed and installed on several producer owned and operated machines. The weight measurement system provides critical information to producers when in the process of calibrating yield monitors or conducting on-farm research. The ...

  8. Optimized Design of Thermoelectric Energy Harvesting Systems for Waste Heat Recovery from Exhaust Pipes

    Directory of Open Access Journals (Sweden)

    Marco Nesarajah

    2017-06-01

    Full Text Available With the increasing interest in energy efficiency and resource protection, waste heat recovery processes have gained importance. Thereby, one possibility is the conversion of the heat energy into electrical energy by thermoelectric generators. Here, a thermoelectric energy harvesting system is developed to convert the waste heat from exhaust pipes, which are very often used to transport the heat, e.g., in automobiles, in industrial facilities or in heating systems. That is why a mockup of a heating is built-up, and the developed energy harvesting system is attached. To build-up this system, a model-based development process is used. The setup of the developed energy harvesting system is very flexible to test different variants and an optimized system can be found in order to increase the energy yield for concrete application examples. A corresponding simulation model is also presented, based on previously developed libraries in Modelica®/Dymola®. In the end, it can be shown—with measurement and simulation results—that a thermoelectric energy harvesting system on the exhaust pipe of a heating system delivers extra energy and thus delivers a contribution for a more efficient usage of the inserted primary energy carrier.

  9. Fixed Priority Scheduling Strategies for Ambient Energy-Harvesting Embedded systems

    OpenAIRE

    Chetto, Maryline; Masson, Damien; Midonnet, Serge

    2011-01-01

    International audience; The new generation of embedded systems will have the capability to harvest energy from the environment. The electrical energy which is available to power these devices changes over time and is limited by the size of the energy storage unit such as battery or capacitor and the size of the harvester such as a solar panel. In order to cope with this limitation, the system has to dynamically decide when to be active and when to sleep in order to provide the best quality of...

  10. Hopf Bifurcation Analysis of a Predator-Prey Biological Economic System with Nonselective Harvesting

    OpenAIRE

    Biwen Li; Zhenwei Li; Boshan Chen; Gan Wang

    2015-01-01

    A modified predator-prey biological economic system with nonselective harvesting is investigated. An important mathematical feature of the system is that the economic profit on the predator-prey system is investigated from an economic perspective. By using the local parameterization method and Hopf bifurcation theorem, we analyze the Hopf bifurcation of the proposed system. In addition, the modified model enriches the database for the predator-prey biological economic system. Finally, numeric...

  11. Water harvesting for improved water productivity in dry environments of the Mediterranean region case study

    DEFF Research Database (Denmark)

    Yazar, A.; Kuzucu, M.; Çelik, I.

    2014-01-01

    (negarim) under a typical arid environment in Turkey as a case study. In the negarim case study, we analysed rainfall, runoff, catchment area, soil water storage and crop evapotranspiration. The microcatchment area (36 m2) included five surface treatment methods (natural, plastic cover, stone cover, hay......Low rainfall, water scarcity and land degradation severely intimidate the production capacities of the rangelands in the arid environments. Water harvesting focuses on improving the productive use of rainwater on the local scale (field to subcatchment scale) before the runoff water leaves...... the geographical unit in question. The aim is to mitigate the effects of temporal water shortages to cover both domestic and agricultural needs. This paper provides a review on water harvesting techniques focusing on microcatchment methods, and information on performance of a small-basin water harvesting system...

  12. 南宁青秀山雨水收集利用设计%Design on Rainwater Collection and Utilization of Qingxiushan in Nanning

    Institute of Scientific and Technical Information of China (English)

    李杨璐; 廖秋林; 胡磊; 胡振华

    2013-01-01

    南宁青秀山森林公园年雨水收集量为43.40×105m3,为总需水量的77.74%,雨水是园区内最直接、最经济的水资源.根据园区的气候、地形地貌等条件,将青秀山分为天池雨水区、北坡雨水区、蜡烛湾雨水区、清水麓雨水区、玫瑰湾雨水区和瓦窑雨水区6个区并对雨水进行收集,分别设计了集雨系统、净化系统及存储系统,旨在能够较为充分地利用雨水资源,达到缓解用水压力、节约经济成本、调蓄雨洪、改善水环境等目的.%The annual amount of rainwater collection of Qingxiushan Forest Park is 43.40×105 m3,account for 77.74 percent of total water requirements,which is the most direct and economical water resource.According to the condition of weather and landform,the system of Rainwater Collection and Utilization of Qingxiushan has been designed.The system is consist of rainwater collected system,water-purifying system and water storage system.The rainwater collected mainly come from six districts,which are Tianchi rainwater district,Beipo rainwater district,Lazhuwan rainwater district,Qingshuilu rainwater district,Meiguiwan rainwater district and Wayao rainwater district.The system can make the best use of rainwater resource and achieves the objectives such as releasing water-using stress,saving economic costs and balancing water and flood.

  13. Harvesting-aware and Quality-aware Energy Management for Solar-powered Embedded Systems

    OpenAIRE

    Dang, Nga

    2015-01-01

    Embedded system market growth is fast in the last couple of decades, especially with the current demand for embedded processing to support IoT services. However, to power billions of IoT devices and embedded systems is a challenge. Energy harvesting has emerged as a promising power supply alternative for embedded systems, enabling systems to convert renewable energy sources in the surrounding environment (solar, wind, thermal, kinetic energy, etc.) to electrical energy. Nevertheless, these re...

  14. Application of Initial Rainwater Storage Tanks in Urban Drainage System%初期雨水调蓄池在城市排水系统中的应用

    Institute of Scientific and Technical Information of China (English)

    王肖军

    2012-01-01

    The initial rainwater has been controlled in many cities because of the emphasis on the ecological environment. The initial rainwater storage tanks were built in the construction of rainwater pumping stations, which could reduce pollution caused by direct discharge of initial rainwater into rivers. In combination with the construction of a pumping station in Shanghai, the layout form, volume calculation , wash method and operation mode of initial rainwater storage tanks were analyzed to provide reference for application of initial rainwater storage tanks in similar projects.%随着对生态环境的重视,很多城市已经对初期雨水进行了控制,在建设雨水泵房的同时设置初期雨水调蓄池,可减少初期雨水直接排河造成的污染.结合上海某泵站的建设实例,介绍了城市排水系统中初期雨水调蓄池的布置形式、容积计算、冲洗方式、运行模式等,对今后同类项目初期雨水调蓄池的应用具有借鉴意义.

  15. The increasing role of epidermal grafting utilizing a novel harvesting system in chronic wounds.

    Science.gov (United States)

    Serena, Thomas E

    2015-02-01

    Skin grafting techniques range from harvesting full-thickness to split-thickness grafts to grafts containing only epidermis. All of these autologous tissues have their place on the reconstructive ladder. However, the use of full-thickness and split-thickness grafts as coverage over chronic wounds remains limited by a number of factors, including the need for anesthesia, a surgically trained physician, and an operating room in which to perform the procedure; pain and damage associated with the donor site; and severe patient comorbidities. Epidermal grafting offers an option for autografts and uses only a minimal amount of superficial epidermis from the donor site. Although successful use of epidermal grafting has been reported in pigmentation disorders, as well as burns and chronic wounds, previous harvesting methods have been described as cumbersome and time consuming. An automated epidermal harvesting system is now commercially available and involves a tool that applies both heat and suction concurrently to normal skin to induce epidermal micrograft formation. The new tool allows quick harvest and transfer of the epidermal micrografts at the bedside without anesthesia, with minimal donor site healing time and patient discomfort. The use of epidermal grafts in chronic wounds and the harvesting technique are reviewed here.

  16. Devices, systems, and methods for harvesting energy and methods for forming such devices

    Science.gov (United States)

    Kotter, Dale K.; Novack, Steven D.

    2012-12-25

    Energy harvesting devices include a substrate coupled with a photovoltaic material and a plurality of resonance elements associated with the substrate. The resonance elements are configured to collect energy in at least visible and infrared light spectra. Each resonance element is capacitively coupled with the photovoltaic material, and may be configured to resonate at a bandgap energy of the photovoltaic material. Systems include a photovoltaic material coupled with a feedpoint of a resonance element. Methods for harvesting energy include exposing a resonance element having a resonant electromagnetic radiation having a frequency between approximately 20 THz and approximately 1,000 THz, absorbing at least a portion of the electromagnetic radiation with the resonance element, and resonating the resonance element at a bandgap energy of an underlying photovoltaic material. Methods for forming an energy harvesting device include forming resonance elements on a substrate and capacitively coupling the resonance elements with a photovoltaic material.

  17. A Nonlinear Suspended Energy Harvester for a Tire Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    Yu-Jen Wang

    2015-02-01

    Full Text Available The objective of this study is to develop and analyze a nonlinear suspended energy harvester (NSEH that can be mounted on a rotating wheel. The device comprises a permanent magnet as a mass in the kinetic system, two springs, and two coil sets. The mass vibrates along the transverse direction because of the variations in gravitational force. This research establishes nonlinear vibration equations based on the resonance frequency variation of the energy harvester; these equations are used for analyzing the power generation and vibration of the harvester. The kinetic behaviors can be determined according to the stiffness in the two directions of the two suspended springs. Electromagnetic damping is examined to estimate the power output and effect of the kinematic behaviors on NSEH. The power output of the NSEH with a 52 Ω resistor connected in series ranged from approximately 30 to 4200 μW at wheel speeds that ranged from nearly 200 to 900 rpm.

  18. An energy harvester combining a piezoelectric cantilever and a single degree of freedom elastic system

    Institute of Scientific and Technical Information of China (English)

    Hong-yan WANG; Xiao-biao SHAN; Tao XIE

    2012-01-01

    This paper presents a type of vibration energy harvester combining a piezoelectric cantilever and a single degree of freedom (SDOF) elastic system.The main function of the additional SDOF elastic system is to magnify vibration displacement of the piezoelectric cantilever to improve the power output.A mathematical model of the energy harvester is developed based on Hamilton's principle and Rayleigh-Ritz method.Furthermore,the effects of the structural parameters of the SDOF elastic system on the electromechanical outputs of the energy harvester are analyzed numerically.The accuracy of the output performance in the numerical solution is identified from the finite element method (FEM).A good agreement is found between the numerical results and FEM results.The results show that the power output can be increased and the frequency bandwidth can be improved when the SDOF elastic system has a larger lumped mass and a smaller damping ratio.The numerical results also indicate that a matching load resistance under the short circuit resonance condition can obtain a higher current output,and so is more suitable for application to the piezoelectric energy harvester.

  19. Quantum coherence controls the charge separation in a prototypical artificial light harvesting system

    Directory of Open Access Journals (Sweden)

    Schramm H.

    2013-03-01

    Full Text Available Ultrafast spectroscopy and quantum-dynamics simulations of an artificial supramolecular light-harvesting system — a supramolecular triad - provide strong evidence that the quantum-correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds governs the ultrafast electronic charge transfer.

  20. Multireference excitation energies for bacteriochlorophylls A within light harvesting system 2

    DEFF Research Database (Denmark)

    Anda, Andre; Hansen, Thorsten; De Vico, Luca

    2016-01-01

    Light-harvesting system 2 (LH2) of purple bacteria is one of the most popular antenna complexes used to study Nature's way of collecting and channeling solar energy. The dynamics of the absorbed energy is probed by ultrafast spectroscopy. Simulation of these experiments relies on fitting a range...

  1. Four positive periodic solutions of a discrete time Lotka-Volterra competitive system with harvesting terms

    Directory of Open Access Journals (Sweden)

    Xinggui Liu

    2011-01-01

    Full Text Available In this paper, by using Mawhin's continuation theorem of coincidence degree theory, we establish the existence of at least four positive periodic solutions for a discrete time Lotka-Volterra competitive system with harvesting terms. An example is given to illustrate the effectiveness of our results.

  2. A system for harvesting eggs from the pink-spotted lady beetle

    Science.gov (United States)

    We describe a system for harvesting eggs from a predatory insect, the pink spotted lady beetle. Coleomegilla maculata De Geer (Coleoptera: Coccinellidae). Adult beetles placed in square transparent containers that included oviposition substrates hanging from the top of the cage deposited eggs on t...

  3. Hybrid artificial photosynthetic systems comprising semiconductors as light harvesters and biomimetic complexes as molecular cocatalysts.

    Science.gov (United States)

    Wen, Fuyu; Li, Can

    2013-11-19

    Solar fuel production through artificial photosynthesis may be a key to generating abundant and clean energy, thus addressing the high energy needs of the world's expanding population. As the crucial components of photosynthesis, the artificial photosynthetic system should be composed of a light harvester (e.g., semiconductor or molecular dye), a reduction cocatalyst (e.g., hydrogenase mimic, noble metal), and an oxidation cocatalyst (e.g., photosystem II mimic for oxygen evolution from water oxidation). Solar fuel production catalyzed by an artificial photosynthetic system starts from the absorption of sunlight by the light harvester, where charge separation takes place, followed by a charge transfer to the reduction and oxidation cocatalysts, where redox reaction processes occur. One of the most challenging problems is to develop an artificial photosynthetic solar fuel production system that is both highly efficient and stable. The assembly of cocatalysts on the semiconductor (light harvester) not only can facilitate the charge separation, but also can lower the activation energy or overpotential for the reactions. An efficient light harvester loaded with suitable reduction and oxidation cocatalysts is the key for high efficiency of artificial photosynthetic systems. In this Account, we describe our strategy of hybrid photocatalysts using semiconductors as light harvesters with biomimetic complexes as molecular cocatalysts to construct efficient and stable artificial photosynthetic systems. We chose semiconductor nanoparticles as light harvesters because of their broad spectral absorption and relatively robust properties compared with a natural photosynthesis system. Using biomimetic complexes as cocatalysts can significantly facilitate charge separation via fast charge transfer from the semiconductor to the molecular cocatalysts and also catalyze the chemical reactions of solar fuel production. The hybrid photocatalysts supply us with a platform to study the

  4. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    Directory of Open Access Journals (Sweden)

    Hanif SedighNejad

    2014-01-01

    Full Text Available In this paper a new concept for control and performance assessment of compressed air energy storage (CAES systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI, measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated community with significant wind energy resource. A case study reveals the usefulness of the proposed criterion in design, control and implementation of a small CAES system in a hybrid power system (HPM for an isolated community. Energy harvested index and its effectiveness in increasing the wind penetration rate in the total energy production is discussed.

  5. Harvesting software systems for MDA-based reengineering

    NARCIS (Netherlands)

    Reus, T.; Geers, H.; Van Deursen, A.

    2006-01-01

    In this paper we report on a feasibility study in reengineering legacy systems towards a model-driven architecture (MDA). Steps in our approach consist of (1) parsing the source code of the legacy system according to a grammar; (2) mapping the abstract syntax trees thus obtained to a grammar model t

  6. Simulation of harvest operations in a static rose cultivation system

    NARCIS (Netherlands)

    Ooster, van 't A.; Bontsema, J.; Henten, van E.; Hemming, S.

    2014-01-01

    Labour is the most dominant cost factor in Dutch cut-rose production. To improve crop production systems and labour management, a generic process modelling approach was developed enabling the impact of different scenarios on labour productivity to be assessed. The crop production system with crop ha

  7. Environmental Risk Prevention and Control Measures of Rainwater Drainage System in Chemical Industry Park%化工园区雨排系统环境风险防控对策

    Institute of Scientific and Technical Information of China (English)

    冯鸣凤; 谢志成; 田顺; 贺立争

    2016-01-01

    In terms of chemical industry park, rainwater drainage system is an important infrastructure. Reviewing the water environment pollution accident of chemical industrial park, it was found that the main carrier of pollutant diffusion to the external environment was park rain drainage pipe and flood channel, so there were environmental security concerns about the park rain drainage system. At present in our country's chemical industrial park, mandatory measures, corresponding standards and technical specifications were lacking in the prevention and control of the environmental risk, this resulted in lacking of effective daily supervision means in the environmental protection department, and the imperfect coordination mechanism of park planning stage also increased the difficulty of the post supervision. In order to effectively prevent and control the environmental risk of chemical industrial park, it was recommended that the state and local administrations formulated the mandatory and uniform regulatory standards as soon as possible, optimized the rainwater drainage system, and strengthened the supervision of the park and corporate.%雨排系统是化工园区重要的基础设施。回顾近年化工园区水环境污染事故发现,污染物扩散至外环境的主要载体为园区的雨排管渠及防洪排涝河道,园区雨排系统存在环境安全隐患。目前,我国对化工园区雨排系统的环境风险防控缺少强制性的措施要求和相应的标准、技术规范,导致环保部门缺乏行之有效的日常监管手段,园区规划阶段协同机制的不健全也增加了后期监管的难度。为有效防控化工园区雨排系统的环境风险,建议国家和地方尽快出台强制性和统一性法规标准,优化园区雨排系统,同时加强园区及企业的监管。

  8. Thermoelectric energy harvesting system for demonstrating autonomous operation of a wireless sensor node enabled by a multipurpose interface

    Science.gov (United States)

    Leicht, Joachim; Heilmann, Peter; Hehn, Thorsten; Li, Xiaoming; Maurath, Dominic; Moranz, Christian; Thewes, Marcell; Scholl, Gerd; Manoli, Yiannos

    2013-12-01

    This paper demonstrates the autonomous operation of a wireless sensor node exclusively powered by thermoelectric energy harvesting. Active operation of a wireless sensor system is demonstrated successfully by means of an on-line programmable emulation kit that enables various thermoelectric energy harvesting scenarios. Moreover, this emulation kit accomplishes autonomous wireless sensor node operation by interfacing a small-scaled thermogenerator via a CMOS integrated autonomous multipurpose energy harvesting interface circuit performing maximum power point tracking.

  9. Systems and methods for harvesting and storing materials produced in a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Heinold, Mark R.; Dayal, Yogeshwar; Brittingham, Martin W.

    2016-04-05

    Systems produce desired isotopes through irradiation in nuclear reactor instrumentation tubes and deposit the same in a robust facility for immediate shipping, handling, and/or consumption. Irradiation targets are inserted and removed through inaccessible areas without plant shutdown and placed in the harvesting facility, such as a plurality of sealable and shipping-safe casks and/or canisters. Systems may connect various structures in a sealed manner to avoid release of dangerous or unwanted matter throughout the nuclear plant, and/or systems may also automatically decontaminate materials to be released. Useable casks or canisters can include plural barriers for containment that are temporarily and selectively removable with specially-configured paths inserted therein. Penetrations in the facilities may limit waste or pneumatic gas escape and allow the same to be removed from the systems without over-pressurization or leakage. Methods include processing irradiation targets through such systems and securely delivering them in such harvesting facilities.

  10. Development and Deployment of a Short Rotation Woody Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header

    Energy Technology Data Exchange (ETDEWEB)

    Eisenbies, Mark [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Volk, Timothy [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Abrahamson, Lawrence [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Shuren, Richard [GreenWood Resources, Inc., Portland, OR (United States); Stanton, Brian [GreenWood Resources, Inc., Portland, OR (United States); Posselius, John [Case New Holland, New Holland, PA (United States); McArdle, Matt [Mesa Reduction Engineering and Processing, Inc., Auburn, NY (United States); Karapetyan, Samvel [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Patel, Aayushi [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Shi, Shun [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Zerpa, Jose [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States)

    2014-10-03

    Biomass for biofuels, bioproducts and bioenergy can be sourced from forests, agricultural crops, various residue streams, and dedicated woody or herbaceous crops. Short rotation woody crops (SRWC), like willow and hybrid poplar, are perennial cropping systems that produce a number of environmental and economic development benefits in addition to being a renewable source of biomass that can be produced on marginal land. Both hybrid poplar and willow have several characteristics that make them an ideal feedstock for biofuels, bioproducts, and bioenergy; these include high yields that can be obtained in three to four years, ease of cultivar propagation from dormant cuttings, a broad underutilized genetic base, ease of breeding, ability to resprout after multiple harvests, and feedstock composition similar to other sources of woody biomass. Despite the range of benefits associated with SRWC systems, their deployment has been restricted by high costs, low market acceptance associated with inconsistent chip quality (see below for further explanation), and misperceptions about other feedstock characteristics (see below for further explanation). Harvesting of SRWC is the largest single cost factor (~1/3 of the final delivered cost) in the feedstock supply system. Harvesting is also the second largest input of primary fossil energy in the system after commercial N fertilizer, accounting for about one third of the input. Therefore, improving the efficiency of the harvesting system has the potential to reduce both cost and environmental impact. At the start of this project, we projected that improving the overall efficiency of the harvesting system by 25% would reduce the delivered cost of SRWC by approximately $0.50/MMBtu (or about $7.50/dry ton). This goal was exceeded over the duration of this project, as noted below.

  11. Evaluating energy sorghum harvest thresholds and tillage cropping systems to offset negative environmental impacts and harvesting equipment-induced soil compaction

    Science.gov (United States)

    Meki, M. N.; Snider, J. L.; Kiniry, J. R.; Raper, R. L.; Rocateli, A. C.

    2011-12-01

    Energy sorghum (Sorghum bicolor L. Moench) could be the ideal feedstock for the cellulosic ethanol industry because of its robust establishment, broader adaptability and drought tolerance, water and nutrient use efficiency, and the relatively high annual biomass yields. Of concern, however, is the limited research data on harvest thresholds, subsequent environmental impacts and the potential cumulative effects of harvesting equipment-induced soil compaction. Indiscriminate harvests of the high volume wet energy sorghum biomass, coupled with repeated field passes, could cause irreparable damage to the soil due to compaction. Furthermore, biomass harvests result in lower soil organic matter returns to the soil, making the soil even more susceptible to soil compaction. Compacted soils result in poor root zone aeration and drainage, more losses of nitrogen from denitrification, and restricted root growth, which reduces yields. Given the many positive attributes of conservation tillage and crop residue retention, our research and extension expectations are that sustainable energy sorghum cropping systems ought to include some form of conservation tillage. The challenge is to select cropping and harvesting systems that optimize feedstock production while ensuring adequate residue biomass to sustainably maintain soil structure and productivity. Producers may have to periodically subsoil-till or plow-back their lands to alleviate problems of soil compaction and drainage, weeds, insects and disease infestations. Little, however, is known about the potential impact of these tillage changes on soil productivity, environmental integrity, and sustainability of bioenergy agro-ecosystems. Furthermore, 'safe' energy sorghum feedstock removal thresholds have yet to be established. We will apply the ALMANAC biophysical model to evaluate permissible energy sorghum feedstock harvest thresholds and the effects of subsoil tillage and periodically plowing no-tilled (NT) energy sorghum

  12. Design and Experimental Evaluation on an Advanced Multisource Energy Harvesting System for Wireless Sensor Nodes

    Directory of Open Access Journals (Sweden)

    Hao Li

    2014-01-01

    Full Text Available An effective multisource energy harvesting system is presented as power supply for wireless sensor nodes (WSNs. The advanced system contains not only an expandable power management module including control of the charging and discharging process of the lithium polymer battery but also an energy harvesting system using the maximum power point tracking (MPPT circuit with analog driving scheme for the collection of both solar and vibration energy sources. Since the MPPT and the power management module are utilized, the system is able to effectively achieve a low power consumption. Furthermore, a super capacitor is integrated in the system so that current fluctuations of the lithium polymer battery during the charging and discharging processes can be properly reduced. In addition, through a simple analog switch circuit with low power consumption, the proposed system can successfully switch the power supply path according to the ambient energy sources and load power automatically. A practical WSNs platform shows that efficiency of the energy harvesting system can reach about 75–85% through the 24-hour environmental test, which confirms that the proposed system can be used as a long-term continuous power supply for WSNs.

  13. Design and experimental evaluation on an advanced multisource energy harvesting system for wireless sensor nodes.

    Science.gov (United States)

    Li, Hao; Zhang, Gaofei; Ma, Rui; You, Zheng

    2014-01-01

    An effective multisource energy harvesting system is presented as power supply for wireless sensor nodes (WSNs). The advanced system contains not only an expandable power management module including control of the charging and discharging process of the lithium polymer battery but also an energy harvesting system using the maximum power point tracking (MPPT) circuit with analog driving scheme for the collection of both solar and vibration energy sources. Since the MPPT and the power management module are utilized, the system is able to effectively achieve a low power consumption. Furthermore, a super capacitor is integrated in the system so that current fluctuations of the lithium polymer battery during the charging and discharging processes can be properly reduced. In addition, through a simple analog switch circuit with low power consumption, the proposed system can successfully switch the power supply path according to the ambient energy sources and load power automatically. A practical WSNs platform shows that efficiency of the energy harvesting system can reach about 75-85% through the 24-hour environmental test, which confirms that the proposed system can be used as a long-term continuous power supply for WSNs.

  14. Methodology for choice of harvesting system for energy wood from early thinning

    Energy Technology Data Exchange (ETDEWEB)

    Laitila, J.

    2012-11-01

    The primary aim of the present study was to develop a methodology for estimating the procurement cost of forest chips from early thinnings. The most common logging systems and supply chains of forest chips used in early thinnings in Finland were compared at stand and regional level using productivity models and cost parameters obtained mainly from the substudies of this thesis. Furthermore, a decision tree was constructed for selecting harvesting method for energy wood originating from early thinnings. Forwarding productivity following mechanised cutting was significantly higher compared to productivity after motor-manual cutting. Mechanised cutting by the harvester enables felling and bunching of whole trees into large grapple loads close to strip roads, which facilitates increasing forwarding output and reducing costs. The two-machine system comprised of a harvester and a forwarder was the most cost-efficient logging system due to higher efficiency in cutting and especially in the forwarding phase. The cost of motor-manual whole-tree cutting was equal to mechanised whole-tree cutting, while forwarding cost after motor-manual cutting was almost double that after mechanised cutting. Using a forwarderbased harwarder resulted in the highest logging costs. However, with large tree volumes and removals its costs were almost equal to those of motor-manual-based logging. In order to achieve a breakthrough for the harwarder system, costs must be reduced by improving both machine technology and working techniques. Available volumes and procurement costs of fuel chips made of small-diameter trees were compared at regional level. The trees were harvested either by the multi-stem delimbed shortwood or whole-tree method and chipped by a truck-mounted drum chipper at the roadside. Based on the availability analysis, delimbing reduced regional cutting recovery by 42% compared to whole tree harvesting, when the minimum concentration of energy wood was set at 25 m{sup 3} ha{sup -1

  15. Excitation migration in fluctuating light-harvesting antenna systems

    NARCIS (Netherlands)

    Chmeliov, J.; Trinkunas, G.; Amerongen, van H.; Valkunas, L.

    2016-01-01

    Complex multi-exponential fluorescence decay kinetics observed in various photosynthetic systems like photosystem II (PSII) have often been explained by the reversible quenching mechanism of the charge separation taking place in the reaction center (RC) of PSII. However, this description does not ac

  16. 基于雨水收集利用的高校景观设计研究--以西北大学长安校区为例%Research of Campus Landscape Design Based on The Rainwater Collection and Utilization--- A Case Study of Changan Campus of Northwest University

    Institute of Scientific and Technical Information of China (English)

    吴欣; 崔鹏

    2015-01-01

    The sustainable development has become a social consensus, the future of the campus will be towards the "low-carbon, energy saving, human nature" direction of development. This paper analyzes the landscape design theory of rainwater har-vesting and utilization, discusses the methods and ways of collecting rainwater resources in campus landscape design. And this pa-per take Northwest University as the practice field of the university landscape combined with the rainwater collection and utilization, suggests the reasonable landscape renovation in campus district, explore the landscape way of rainwater resource collection and utili-zation in campus planning. Finally come to the conclusion that is suitable for the campus landscape design of rainwater utilization system, provide good ideas for the future of the campus landscape design.%可持续发展已成为社会的共识,未来校园也必定会朝着“低碳、节能、人性化”的方向发展。文章通过分析雨水收集利用的景观设计理论,探讨高校校园景观设计过程中雨水资源收集利用的方式与途径,以西北大学作为雨水收集利用与高校景观结合的实践场地,提出合理的校园教学区景观改造建议,探索雨水资源收集利用在高校校园规划中的景观化途径,总结适用于校园景观设计的雨水利用系统,为今后的校园景观设计提供良好的思路。

  17. State-dependent resource harvesting with lagged information about system states

    Science.gov (United States)

    Johnson, Fred A.; Fackler, Paul L.; Boomer, G Scott; Zimmerman, Guthrie; Williams, Byron K.; Nichols, James; Dorazio, Robert

    2016-01-01

    Markov decision processes (MDPs), which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos) in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest) even in the face of an uncertain system state at the time of a decision.

  18. Object-Oriented Modeling of an Energy Harvesting System Based on Thermoelectric Generators

    Science.gov (United States)

    Nesarajah, Marco; Frey, Georg

    This paper deals with the modeling of an energy harvesting system based on thermoelectric generators (TEG), and the validation of the model by means of a test bench. TEGs are capable to improve the overall energy efficiency of energy systems, e.g. combustion engines or heating systems, by using the remaining waste heat to generate electrical power. Previously, a component-oriented model of the TEG itself was developed in Modelica® language. With this model any TEG can be described and simulated given the material properties and the physical dimension. Now, this model was extended by the surrounding components to a complete model of a thermoelectric energy harvesting system. In addition to the TEG, the model contains the cooling system, the heat source, and the power electronics. To validate the simulation model, a test bench was built and installed on an oil-fired household heating system. The paper reports results of the measurements and discusses the validity of the developed simulation models. Furthermore, the efficiency of the proposed energy harvesting system is derived and possible improvements based on design variations tested in the simulation model are proposed.

  19. State-Dependent Resource Harvesting with Lagged Information about System States.

    Directory of Open Access Journals (Sweden)

    Fred A Johnson

    Full Text Available Markov decision processes (MDPs, which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest even in the face of an uncertain system state at the time of a decision.

  20. Performance Testing of Thermal Cutting Systems for Sweet Pepper Harvesting Robot in Greenhouse Horticulture

    Science.gov (United States)

    Bachche, Shivaji; Oka, Koichi

    2013-03-01

    This paper proposes design of end-effector and prototype of thermal cutting system for harvesting sweet peppers. The design consists of two parallel gripper bars mounted on a frame connected by specially designed notch plate and operated by servo motor. Based on voltage and current, two different types of thermal cutting system prototypes; electric arc and temperature arc respectively were developed and tested for performance. In electric arc, a special electric device was developed to obtain high voltage to perform cutting operation. At higher voltage, electrodes generate thermal arc which helps to cut stem of sweet pepper. In temperature arc, nichrome wire was mounted between two electrodes and current was provided directly to electrodes which results in generation of high temperature arc between two electrodes that help to perform cutting operation. In both prototypes, diameters of basic elements were varied and the effect of this variation on cutting operation was investigated. The temperature arc thermal system was found significantly suitable for cutting operation than electric arc thermal system. In temperature arc thermal cutting system, 0.5 mm nichrome wire shows significant results by accomplishing harvesting operation in 1.5 seconds. Also, thermal cutting system found suitable to increase shelf life of fruits by avoiding virus and fungal transformation during cutting process and sealing the fruit stem. The harvested sweet peppers by thermal cutting system can be preserved at normal room temperature for more than 15 days without any contamination.

  1. Electrical Transport in Thin Film Systems for Energy Harvesting

    Science.gov (United States)

    Huang, Bingyuan

    Many energy conversion technologies rely on the function and properties of thin films. In many cases, the fundamental physics underlying the structure-property-performance interrelationship is not completely understood. So it is not possible to fully exploit the true capabilities of these systems. Therefore, investigating and understanding such interrelationships in different systems is of both scientific and technological importance. In this dissertation, both conjugated polymer systems for photovoltaic application and strained silicon system for thermoelectric application are investigated in order to develop a clearer understanding of the effect of film thickness and microstructural features on electrical transport. Morphological features such as domain size, phase purity are investigated in the polymers in order to understand the effects on charge mobility, recombination and further on device performance. With regard to silicon, the effects of lattice strain on electrical conductivity and thermopower are studied. The out-of-plane hole mobility was investigated in regioregular P3HT thin films. It was shown that the hole mobilities monotonically increased an order of magnitude when film thickness increased from 80 nm to 700 nm. Based on X-ray diffraction, spectroscopic ellipsometry and simulations, this thickness-dependent mobility is associated with substrate induced anisotropies of the P3HT film structure. The role of microstructural features on the performance characteristics of the archetypal P3HT:PCBM (1:1) bulk heterojunction solar cell was investigated. It is demonstrated that small domain sizes and correspondingly large interfacial areas accommodated a high initial carrier density. However in these materials, non-geminate recombination of carriers could be significant, leading to low open circuit voltages and low fill factors. The purity of the domains also influenced the charge carrier mobilities and non-germinate recombination. One important finding from

  2. Rainwater utilization and storm pollution control based on urban runoff characterization.

    Science.gov (United States)

    Zhang, Mulan; Chen, Hao; Wang, Jizhen; Pan, Gang

    2010-01-01

    The characteristics of urban runoffs and their impact on rainwater utilization and storm pollution control were investigated in three different functional areas of Zhengzhou City, China. The results showed that in the same rain event the pollutant loads (chemical oxygen demand (COD) and total suspended solids (TSS)) in the sampling areas were in the order of industrial area > commercial area > residential area, and within the same area the COD and TSS concentrations of road runoffs were higher than those of roof runoffs. The first flush effects in roof and road runoffs were observed, hence the initial rainwater should be treated separately to reduce rainwater utilization cost and control storm pollution. The initial roof rainfall of 2 mm in residential area, 5 mm in commercial area and 10 mm in industrial area, and the initial road rainfall of 4 mm in residential area and all the road rainfall in commercial and industrial areas should be collected and treated accordingly before direct discharge or utilization. Based on the strong correlation between COD and TSS (R2, 0.87-0.95) and the low biodegradation capacity (biochemical oxygen demand BOD5/COD system composed of soil and slag were designed to treat the initial rainwater, which could remove over 90% of the pollutant loads. The above results may help to develop better rainwater utilization and pollution control strategies for cities with water shortages.

  3. Hydrogen based energy storage for energy harvesting systems

    Energy Technology Data Exchange (ETDEWEB)

    Bretthauer, Christian

    2011-07-01

    This thesis presents the development of a novel type of silicon integrated alkaline fuel cell - electrolyser device as on-chip energy storage. The alkaline environment allows not only a facilitated water management compared to state-of-the-art acidic integrated fuel cell systems, it further allows the usage of non-precious metal catalysts and hydrogen storage materials, for the first time. Additionally, a button cell shaped version of the accumulator is presented that incorporates a photoactive SrTiO{sub 3} ceramic for solar recharge. The solar charging mechanism is shown to be inherently self-regulating such that the cell depicts essentially a Micro Hydrogen Economy including energy conversion, energy management and energy storage in a single device. (orig.)

  4. Research on Grey Sliding Mode Control of Motor System of Fruit Harvesting Manipulator Joint

    Directory of Open Access Journals (Sweden)

    Jueping Bu

    2015-03-01

    Full Text Available The sliding mode control algorithm based on grey prediction theory is proposed in this study, aiming at the uncertainties in the servo system of fruit harvesting robot and the external disturbances that may affect the control quality of conventional sliding mode control algorithm. The proposed algorithm uses the grey theory ability to unknown information data to establish the grey model to the uncertainty and real-time compensate the unmodeled dynamics and the interference signal of system. Meanwhile, an improved reaching law direction is proposed to resist chattering and improve control accuracy. The simulation results show that the proposed sliding mode control algorithm effectively predicts and compensates the unmodeled dynamics and disturbances signal in the DC motor servo system of the fruit harvesting robot and improves the control precision of controller which provides the theoretical basis for the industrial application based on the grey prediction theory of sliding mode control algorithm.

  5. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Harel, Elad [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

    2012-05-07

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  6. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    Science.gov (United States)

    Harel, Elad

    2012-05-01

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  7. USE THE METHOD OF DIMENSIONING OF INFILTRATION-RETENTION BASINS FOR MANAGEMENT OF RAINWATER

    Directory of Open Access Journals (Sweden)

    Ewa Suchanek

    2015-01-01

    Full Text Available The easiest way to “use” rainwater is its detention in places where it falls, and referral to the ground. Systems of rainwater utilization system can be implemented in different variants. In the simplest configuration it is a tank, with a runoff from the roof. The principle of operation of the tank (basin is a method for rain water management. The article presents a practical application of methods of dimensioning infiltration basins by performing calculations showing how to alter the dimensions of the basin when changing the ground conditions while maintaining the same filling.

  8. Optimization of contour ridge water harvesting systems for arid zones.

    Science.gov (United States)

    Berliner, Pedro; Arazi, Adit

    2017-04-01

    Runoff is generated along slopes in semi-arid regions during rainfall events and flows into the lower lying areas, usually ephemeral streams. Depending on the slope and volume of water involved, the flow can become turbulent and cause the detachments of soil particles (erosion). The purpose of the system under investigation is to capture the water after a relatively short flow distance and allow it to be absorbed by the soil. This action accomplishes two objectives: erosion is averted and the stored water can be used for plant production. Depending on the ratio of contributing to receiving areas and storm characteristics the stored water can be significantly higher than the precipitation. The objective of the present project was to develop a simple model that describes the above biomass production in such a system and allows to determine the optimum distribution of structures along a given slope in order to meet one criteria (e.g. minimize variance, maximize production, maximize lowest production, etc.) or a suite of them. The basic assumption is that tree above ground biomass production is linearly related to transpired water, the latter driven by an external force (potential evaporation) and modulated by water availability in the soil. PET is computed using the standard Penman-Monteith formulation for evaporation from open water bodies, if the latter is not available. Four water fluxes are computed: Evaporation, Transpiration, Runoff and Drainage, the first two not interacting directly. All of the above mentioned fluxes and rates are daily lumped values and water content in the profile is updated daily, assuming that rainfall events happen after the computation of fluxes. Daily water inputs are estimated from rainfall data and computed runoff. A dynamic runoff coefficient (=cumulative generated runoff generated/cumulative precipitation) was derived from measurements carried out in the area and used in order to estimate runoff volumes from total recorded

  9. Thermodynamic limits to information harvesting by sensory systems

    Science.gov (United States)

    Bo, Stefano; Del Giudice, Marco; Celani, Antonio

    2015-01-01

    In view of the relation between information and thermodynamics we investigate how much information about an external protocol can be stored in the memory of a stochastic measurement device given an energy budget. We consider a layered device with a memory component storing information about the external environment by monitoring the history of a sensory part coupled to the environment. We derive an integral fluctuation theorem for the entropy production and a measure of the information accumulated in the memory device. Its most immediate consequence is that the amount of information is bounded by the average thermodynamic entropy produced by the process. At equilibrium no entropy is produced and therefore the memory device does not add any information about the environment to the sensory component. Consequently, if the system operates at equilibrium the addition of a memory component is superfluous. Such a device can be used to model the sensing process of a cell measuring the external concentration of a chemical compound and encoding the measurement in the amount of phosphorylated cytoplasmic proteins.

  10. Harvesting Energy from Random Mechanical Vibrations Using Linear and Nonlinear Electromechanical Systems: Comparison of Different Noises

    Directory of Open Access Journals (Sweden)

    Zahra Etesami

    2017-05-01

    Full Text Available We investigate harvesting electrical energy from Gaussian white, Gaussian colored, telegraph and random phase-random amplitude (RARP noises, using linear and nonlinear electromechanical systems. We show that the output power of the linear system with one or two degrees of freedom, is maximum for the Gaussian white noise. The response of the system with two degrees of freedom is widened in a larger frequency domain compared to that of a single degree of freedom system. A nonlinear system generates more power than a linear one.

  11. 构建城市绿色集雨系统的途径与对策—以济南市为例%Ways and countermeasures of building green rainwater-collecting system:A case study on Jinan City

    Institute of Scientific and Technical Information of China (English)

    鲁敏; 康文凤; 李东和

    2012-01-01

    充分利用降水资源是缓解当今水资源危机的战略思想和必然要求.建设城市绿色集雨系统,是现代城市建设不可缺少的一部分,是走可持续发展道路建设生态城市的必由之路.文章阐述了国内外集雨利用的现状及存在的问题;分析了济南市集雨利用的现状和潜力;提出了济南市构建绿色集雨系统的途径与策略.%To make full use of precipitation resources is the strategic thinking and inevitable requirement to alleviate current water crisis. Construction of urban green system is an indispensable part of modern city construction and the route of sustainable development one must take in the construction of ecological city. The paper expounds the present situation and the existing problems of rainwater-collection and utilization at home and abroad, analyzes the present situation and potential of Jinan rainwater-collection and utilization and puts forward the ways and strategies of the construction of green rainwater-collecting system in Jinan city.

  12. Design of Pervious Concrete Pavement and Constructed Wetland System for Rainwater Collection and Treatment%透水混凝土路面/人工湿地雨水收集处理系统的设计

    Institute of Scientific and Technical Information of China (English)

    吴文伶; 宋中南; 石云兴; 罗兰; 王珂; 戢文占; 张涛; 冯建华; 李艳稳

    2011-01-01

    Pervious concrete pavement for rainwater collection and constructed wetland for rainwater treatment are used in a rainwater collection and utilization project in Lisui town of Shunyi District, Beijing City. The design methods of pervious concrete pavement, detention tank and constructed wetland are introduced. Furthermore, the technology advantages, process flow and structure design are discussed.%北京市顺义区李遂镇某雨水收集利用工程采用透水混凝土路面收集雨水并应用人工湿地进行雨水处理,详细介绍了透水混凝土路面、调节池、人工湿地的设计方法,并对该技术的优势、工艺流程、结构设计等进行了详细探讨.

  13. A High-Efficiency Wind Energy Harvester for Autonomous Embedded Systems

    Directory of Open Access Journals (Sweden)

    Davide Brunelli

    2016-03-01

    Full Text Available Energy harvesting is currently a hot research topic, mainly as a consequence of the increasing attractiveness of computing and sensing solutions based on small, low-power distributed embedded systems. Harvesting may enable systems to operate in a deploy-and-forget mode, particularly when power grid is absent and the use of rechargeable batteries is unattractive due to their limited lifetime and maintenance requirements. This paper focuses on wind flow as an energy source feasible to meet the energy needs of a small autonomous embedded system. In particular the contribution is on the electrical converter and system integration. We characterize the micro-wind turbine, we define a detailed model of its behaviour, and then we focused on a highly efficient circuit to convert wind energy into electrical energy. The optimized design features an overall volume smaller than 64 cm3. The core of the harvester is a high efficiency buck-boost converter which performs an optimal power point tracking. Experimental results show that the wind generator boosts efficiency over a wide range of operating conditions.

  14. A High-Efficiency Wind Energy Harvester for Autonomous Embedded Systems.

    Science.gov (United States)

    Brunelli, Davide

    2016-03-04

    Energy harvesting is currently a hot research topic, mainly as a consequence of the increasing attractiveness of computing and sensing solutions based on small, low-power distributed embedded systems. Harvesting may enable systems to operate in a deploy-and-forget mode, particularly when power grid is absent and the use of rechargeable batteries is unattractive due to their limited lifetime and maintenance requirements. This paper focuses on wind flow as an energy source feasible to meet the energy needs of a small autonomous embedded system. In particular the contribution is on the electrical converter and system integration. We characterize the micro-wind turbine, we define a detailed model of its behaviour, and then we focused on a highly efficient circuit to convert wind energy into electrical energy. The optimized design features an overall volume smaller than 64 cm³. The core of the harvester is a high efficiency buck-boost converter which performs an optimal power point tracking. Experimental results show that the wind generator boosts efficiency over a wide range of operating conditions.

  15. Study on fault diagnosis and load feedback control system of combine harvester

    Science.gov (United States)

    Li, Ying; Wang, Kun

    2017-01-01

    In order to timely gain working status parameters of operating parts in combine harvester and improve its operating efficiency, fault diagnosis and load feedback control system is designed. In the system, rotation speed sensors were used to gather these signals of forward speed and rotation speeds of intermediate shaft, conveying trough, tangential and longitudinal flow threshing rotors, grain conveying auger. Using C8051 single chip microcomputer (SCM) as processor for main control unit, faults diagnosis and forward speed control were carried through by rotation speed ratio analysis of each channel rotation speed and intermediate shaft rotation speed by use of multi-sensor fused fuzzy control algorithm, and these processing results would be sent to touch screen and display work status of combine harvester. Field trials manifest that fault monitoring and load feedback control system has good man-machine interaction and the fault diagnosis method based on rotation speed ratios has low false alarm rate, and the system can realize automation control of forward speed for combine harvester.

  16. Past and present status of runoff harvesting systems in dryland peninsular India: a critical review.

    Science.gov (United States)

    Gunnell, Yanni; Krishnamurthy, Anupama

    2003-06-01

    Many modern agricultural systems are structured around one dominant form of water storage and distribution, usually large reservoirs. In contrast, in peninsular India, small reservoirs (tanks), predominantly supplied by surface runoff as opposed to river canals have for centuries been the trademark of an entire agrarian civilization, with no equivalent elsewhere in the semiarid tropics. This article focuses on the physical and socioeconomic conditions that underlie the success of an indigenous technology which has for centuries exploited the potential for runoff harvesting by i) optimizing water management for agriculture; and ii) minimizing soil loss. Today, siltation of reservoirs, privatization of water resources, and generalized mining of groundwater, pose a threat to the sustainability of these water-harvesting systems. The ongoing transformation of this common resource pool is critically assessed.

  17. Power electronics and control techniques for maximum energy harvesting in photovoltaic systems

    CERN Document Server

    Femia, Nicola

    2012-01-01

    Incentives provided by European governments have resulted in the rapid growth of the photovoltaic (PV) market. Many PV modules are now commercially available, and there are a number of power electronic systems for processing the electrical power produced by PV systems, especially for grid-connected applications. Filling a gap in the literature, Power Electronics and Control Techniques for Maximum Energy Harvesting in Photovoltaic Systems brings together research on control circuits, systems, and techniques dedicated to the maximization of the electrical power produced by a photovoltaic (PV) so

  18. Note on the Stability Property of a Cooperative System Incorporating Harvesting

    Directory of Open Access Journals (Sweden)

    Xiangdong Xie

    2014-01-01

    Full Text Available The stability of a kind of cooperative model incorporating harvesting is revisited in this paper. By using an iterative method, the global attractivity of the interior equilibrium point of the system is investigated. We show that the condition which ensures the existence of a unique positive equilibrium is enough to ensure the global attractivity of the positive equilibrium. Our results significantly improve the corresponding results of Wei and Li (2013.

  19. Solving Ratio-Dependent Predator-Prey System with Constant Effort Harvesting Using Homotopy Perturbation Method

    Directory of Open Access Journals (Sweden)

    Abdoul R. Ghotbi

    2008-01-01

    Full Text Available Due to wide range of interest in use of bioeconomic models to gain insight into the scientific management of renewable resources like fisheries and forestry, homotopy perturbation method is employed to approximate the solution of the ratio-dependent predator-prey system with constant effort prey harvesting. The results are compared with the results obtained by Adomian decomposition method. The results show that, in new model, there are less computations needed in comparison to Adomian decomposition method.

  20. Design and fabrication of self-powered micro-harvesters rotating and vibrated micro-power systems

    CERN Document Server

    Pan, C T; Lin, Liwei; Chen, Ying-Chung

    2013-01-01

    Presents the latest methods for designing and fabricating self-powered micro-generators and energy harvester systems Design and Fabrication of Self-Powered Micro-Harvesters introduces the latest trends of self-powered generators and energy harvester systems, including the design, analysis and fabrication of micro power systems. Presented in four distinct parts, the authors explore the design and fabrication of: vibration-induced electromagnetic micro-generators; rotary electromagnetic micro-generators; flexible piezo-micro-generator with various widths; and PVDF electrospunpiezo-energy with

  1. Nitrification inhibitors can increase post-harvest nitrous oxide emissions in an intensive vegetable production system

    Science.gov (United States)

    Scheer, Clemens; Rowlings, David; Firrell, Mary; Deuter, Peter; Morris, Stephen; Riches, David; Porter, Ian; Grace, Peter

    2017-01-01

    To investigate the effect of nitrification inhibitors (NIs) 3,4-dimethylpyrazole phosphate (DMPP) and 3-methylpyrazole 1,2,4-triazole (3MP + TZ), on N2O emissions and yield from a typical vegetable rotation in sub-tropical Australia we monitored soil N2O fluxes continuously over an entire year using an automated greenhouse gas measurement system. The temporal variation of N2O fluxes showed only low emissions over the vegetable cropping phases, but significantly higher emissions were observed post-harvest accounting for 50–70% of the annual emissions. NIs reduced N2O emissions by 20–60% over the vegetable cropping phases; however, this mitigation was offset by elevated N2O emissions from the NIs treatments over the post-harvest fallow period. Annual N2O emissions from the conventional fertiliser, the DMPP treatment, and the 3MP + TZ treatment were 1.3, 1.1 and 1.6 (sem = 0.2) kg-N ha−1 year−1, respectively. This study highlights that the use of NIs in vegetable systems can lead to elevated N2O emissions by storing N in the soil profile that is available to soil microbes during the decomposition of the vegetable residues. Hence the use of NIs in vegetable systems has to be treated carefully and fertiliser rates need to be adjusted to avoid an oversupply of N during the post-harvest phase. PMID:28266551

  2. Nitrification inhibitors can increase post-harvest nitrous oxide emissions in an intensive vegetable production system.

    Science.gov (United States)

    Scheer, Clemens; Rowlings, David; Firrell, Mary; Deuter, Peter; Morris, Stephen; Riches, David; Porter, Ian; Grace, Peter

    2017-03-07

    To investigate the effect of nitrification inhibitors (NIs) 3,4-dimethylpyrazole phosphate (DMPP) and 3-methylpyrazole 1,2,4-triazole (3MP + TZ), on N2O emissions and yield from a typical vegetable rotation in sub-tropical Australia we monitored soil N2O fluxes continuously over an entire year using an automated greenhouse gas measurement system. The temporal variation of N2O fluxes showed only low emissions over the vegetable cropping phases, but significantly higher emissions were observed post-harvest accounting for 50-70% of the annual emissions. NIs reduced N2O emissions by 20-60% over the vegetable cropping phases; however, this mitigation was offset by elevated N2O emissions from the NIs treatments over the post-harvest fallow period. Annual N2O emissions from the conventional fertiliser, the DMPP treatment, and the 3MP + TZ treatment were 1.3, 1.1 and 1.6 (sem = 0.2) kg-N ha(-1) year(-1), respectively. This study highlights that the use of NIs in vegetable systems can lead to elevated N2O emissions by storing N in the soil profile that is available to soil microbes during the decomposition of the vegetable residues. Hence the use of NIs in vegetable systems has to be treated carefully and fertiliser rates need to be adjusted to avoid an oversupply of N during the post-harvest phase.

  3. Nitrification inhibitors can increase post-harvest nitrous oxide emissions in an intensive vegetable production system

    Science.gov (United States)

    Scheer, Clemens; Rowlings, David; Firrell, Mary; Deuter, Peter; Morris, Stephen; Riches, David; Porter, Ian; Grace, Peter

    2017-03-01

    To investigate the effect of nitrification inhibitors (NIs) 3,4-dimethylpyrazole phosphate (DMPP) and 3-methylpyrazole 1,2,4-triazole (3MP + TZ), on N2O emissions and yield from a typical vegetable rotation in sub-tropical Australia we monitored soil N2O fluxes continuously over an entire year using an automated greenhouse gas measurement system. The temporal variation of N2O fluxes showed only low emissions over the vegetable cropping phases, but significantly higher emissions were observed post-harvest accounting for 50-70% of the annual emissions. NIs reduced N2O emissions by 20-60% over the vegetable cropping phases; however, this mitigation was offset by elevated N2O emissions from the NIs treatments over the post-harvest fallow period. Annual N2O emissions from the conventional fertiliser, the DMPP treatment, and the 3MP + TZ treatment were 1.3, 1.1 and 1.6 (sem = 0.2) kg-N ha-1 year-1, respectively. This study highlights that the use of NIs in vegetable systems can lead to elevated N2O emissions by storing N in the soil profile that is available to soil microbes during the decomposition of the vegetable residues. Hence the use of NIs in vegetable systems has to be treated carefully and fertiliser rates need to be adjusted to avoid an oversupply of N during the post-harvest phase.

  4. Optimal component sizing in a two-reservoir passive energy harvesting system

    Science.gov (United States)

    Munsing, E.; Cowell, M.; Moura, S.; Wright, P.

    2016-11-01

    We utilize particle swarm optimization to reduce the size of the energy management components in an energy harvesting system, allowing us to eliminate the need for voltage regulators or DC-DC converters without affecting system performance. Prior literature on optimal power management in microelectronics [1, 2] has relied on engineering estimates or exhaustive parameter searches to optimize system design. No prior literature has considered the optimal design of a device with only passive components [3]. By using particle swarm optimization, we demonstrate a 55% reduction in device size relative to conventional engineering calculations of an optimal device design.

  5. Simple and Efficient System for Combined Solar Energy Harvesting and Reversible Hydrogen Storage.

    Science.gov (United States)

    Li, Lu; Mu, Xiaoyue; Liu, Wenbo; Mi, Zetian; Li, Chao-Jun

    2015-06-24

    Solar energy harvesting and hydrogen economy are the two most important green energy endeavors for the future. However, a critical hurdle to the latter is how to safely and densely store and transfer hydrogen. Herein, we developed a reversible hydrogen storage system based on low-cost liquid organic cyclic hydrocarbons at room temperature and atmospheric pressure. A facile switch of hydrogen addition (>97% conversion) and release (>99% conversion) with superior capacity of 7.1 H2 wt % can be quickly achieved over a rationally optimized platinum catalyst with high electron density, simply regulated by dark/light conditions. Furthermore, the photodriven dehydrogenation of cyclic alkanes gave an excellent apparent quantum efficiency of 6.0% under visible light illumination (420-600 nm) without any other energy input, which provides an alternative route to artificial photosynthesis for directly harvesting and storing solar energy in the form of chemical fuel.

  6. Modelling and Testing of the Piezoelectric Beam as Energy Harvesting System

    Directory of Open Access Journals (Sweden)

    Koszewnik Andrzej

    2016-12-01

    Full Text Available The paper describes modelling and testing of the piezoelectric beam as energy harvesting system. The cantilever beam with two piezo-elements glued onto its surface is considered in the paper. As result of carried out modal analysis of the beam the natural frequencies and modes shapes are determined. The obtained results in the way mentioned above allow to estimate such location of the piezo-actuator on the beam where the piezo generates maximal values of modal control forces. Experimental investigations carried out in the laboratory allow to verify results of natural frequencies obtained during simulation and also testing of the beam in order to obtain voltage from vibration with help of the piezo-harvester. The obtained values of voltage stored on the capacitor C0 shown that the best results are achieved for the beam excited to vibration with third natural frequency, but the worst results for the beam oscillating with the first natural frequency.

  7. Design and Simulation of Two Robotic Systems for Automatic Artichoke Harvesting

    Directory of Open Access Journals (Sweden)

    Domenico Longo

    2013-12-01

    Full Text Available The target of this research project was a feasibility study for the development of a robot for automatic or semi-automatic artichoke harvesting. During this project, different solutions for the mechanical parts of the machine, its control system and the harvesting tools were investigated. Moreover, in cooperation with the department DISPA of University of Catania, different field structures with different kinds of artichoke cultivars were studied and tested. The results of this research could improve artichoke production for preserves industries. As a first step, an investigation on existing machines has been done. From this research, it has been shown that very few machines exist for this purpose. Based also on previous experiences, some proposals for different robotic systems have been done, while the mobile platform itself was developed within another research project. At the current stage, several different configurations of machines and harvesting end-effectors have been designed and simulated using a 3D CAD environment interfaced with Matlab®. Moreover, as support for one of the proposed machines, an artificial vision algorithm has been developed in order to locate the artichokes on the plant, with respect to the robot, using images taken with a standard webcam.

  8. Investigation of an energy harvesting MR damper in a vibration control system

    Science.gov (United States)

    Sapiński, Bogdan; Rosół, Maciej; Węgrzynowski, Marcin

    2016-12-01

    In this paper the authors investigate the performance of an energy harvesting MR damper (EH-MRD) employed in a semi-active vibration control system (SVCS) and used in a single DOF mechanical structure configuration. Main components of the newly proposed SCVS include the MR damper and an electromagnetic vibration energy harvester based on the Faraday’s law (EVEH) that converts vibration energy into electrical energy and delivers electrical power supplying the MR damper. The main objective of the study is to indicate that the SVCS, controlled by the specially designed embedded system, is feasible and presents good performance at the present stage of the research. The work describes investigation the unique features of the EH-MRD, i.e. its self-powering and self-sensing capabilities. Two cases were considered and the testing was done accordingly. In the case 1, only the self-powered capability was investigated. It was found out that harvested energy is sufficient to power the EH-MRD damper and to adjust it to structural vibration. The results confirmed the adequacy of the SVCS and demonstrated a significant reduction of the resonance peak. In the case 2, both the self-powering and self-sensing capabilities were investigated. Due to the self-sensing capability, the SCVS does not require any sensor. It appeared that thus harvested energy is sufficient to power the EH-MRD and enables self-sensing action since the signal of voltage induced by EVEH agrees with the relative velocity signal across the device. Similar to case 1, the resonance peak is significantly reduced.

  9. Analysis of first flush to improve the water quality in rainwater tanks.

    Science.gov (United States)

    Kus, B; Kandasamy, J; Vigneswaran, S; Shon, H K

    2010-01-01

    Although most Australians receive their domestic supply from reticulated mains or town water, there are vast areas with very low population densities and few reticulated supplies. In many of these areas rainwater collected in tanks is the primary source of drinking water. Heavy metals have recently become a concern as their concentration in rain water tanks was found to exceed recommended levels suitable for human consumption. Rainwater storage tanks also accumulate contaminants and sediments that settle to the bottom. Although not widely acknowledged, small amounts of contaminants such as lead found in rain water (used as drinking water) may have a cumulative and poisonous effect on human health over a life time. This is true for certain factors that underlie many of the chronic illnesses that are becoming increasingly common in contemporary society. The paper reports on a study which is part of a project that aims to develop a cost effective in-line filtration system to improve water quality in rainwater tanks. To enable this, the characteristics of rainwater need to be known. One component of this characterization is to observe the effects of the first flush on a rainwater tank. Samples of the roof runoff collected from an urban residential roof located in the Sydney Metropolitan Area in the initial first few millimetres of rain were analysed. The results show that bypassing the first 2 mm of rainfall gives water with most water quality parameters compliant with the Australian Drinking Water Guidelines (ADWG) standards. The parameters that did not comply were lead and turbidity, which required bypassing approximately the first 5 mm of rainfall to meet ADWG standards. Molecular weight distribution (MWD) analysis showed that the concentration of rainwater organic matter (RWOM) decreased with increasing amount of roof runoff.

  10. MULTIPLE PERIODIC SOLUTIONS TO A MICHAELIS-MENTEN-TYPE PREDATOR-PREY SYSTEM WITH DELAY AND HARVESTING

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In this paper,the existence of eight periodic solutions to a Michaelis-Menten-type predator-prey system with delay and harvesting in patch environment is established using the analytical techniques and Mawhin's coincidence degree theory.

  11. Carbon dioxide emissions under different soil tillage systems in mechanically harvested sugarcane

    Science.gov (United States)

    Silva-Olaya, A. M.; Cerri, C. E. P.; La Scala, N., Jr.; Dias, C. T. S.; Cerri, C. C.

    2013-03-01

    Soil tillage and other methods of soil management may influence CO2 emissions because they accelerate the mineralization of organic carbon in the soil. This study aimed to quantify the CO2 emissions under conventional tillage (CT), minimum tillage (MT) and reduced tillage (RT) during the renovation of sugarcane fields in southern Brazil. The experiment was performed on an Oxisol in the sugarcane-planting area with mechanical harvesting. An undisturbed or no-till (NT) plot was left as a control treatment. The CO2 emissions results indicated a significant interaction (p residues to the adoption of green cane harvesting. The CO2 emissions in the CT system could respond to a loss of 80% of the potential soil C accumulated over one year as result of the adoption of mechanized sugarcane harvesting. Meanwhile, soil tillage during the renewal of the sugar plantation using RT and MT methods would result in low impact, with losses of 12% and 2% of the C that could potentially be accumulated during a one year period.

  12. Harvesting microalgal biomass using a magnetically induced membrane vibration (MMV) system: filtration performance and energy consumption.

    Science.gov (United States)

    Bilad, M R; Discart, V; Vandamme, D; Foubert, I; Muylaert, K; Vankelecom, Ivo F J

    2013-06-01

    This study was performed to investigate the effectiveness of submerged microfiltration to harvest both a marine diatom Phaeodactylum tricornutum and a Chlorella vulgaris in a recently developed magnetically induced membrane vibrating (MMV) system. We assess the filtration performance by conducting the improved flux step method (IFM), fed-batch concentration filtrations and membrane fouling autopsy using two lab-made membranes with different porosity. The full-scale energy consumption was also estimated. Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive. By combining the membrane filtration (15× concentration) with centrifugation to reach a final concentration of 25% w/v, the energy consumption to harvest P. tricornutum and C. vulgaris was, respectively, as low as 0.84 and 0.77kWh/m(3), corresponding to 1.46 and 1.39 kWh/kg of the harvested biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. An Enhanced Piezoelectric Vibration Energy Harvesting System with Macro Fiber Composite

    Directory of Open Access Journals (Sweden)

    Shuwen Zhang

    2015-01-01

    Full Text Available Self-power supply is a promising project in various applied conditions. Among this research area, piezoelectric material-based energy harvesting (EH method has been researched in recent years due to its advantages. With the limitation of energy form acceptance range of EH circuit system, a sum of energy is not accessible to be obtained. To enlarge the EH quantity from the vibration, an enhanced piezoelectric vibration EH structure with piezoelectric film is developed in this work. Piezoelectric-based energy harvesting mechanism is primarily proposed in this work. The special-designed electric circuit for EH from macro fiber composite (MFC is proposed and then analyzed. When the structure vibrates in its modes of frequencies, the experiments are developed to measure the EH effect. The energy harvested from the vibrating structure is analyzed and the enhanced effect is presented. The results indicate that, with the enhanced EH structure in this work, vibration energy from structure is obtained in a larger range, and the general EH quantity is enlarged.

  14. Micro electro-mechanical system piezoelectric cantilever array for a broadband vibration energy harvester.

    Science.gov (United States)

    Chun, Inwoo; Lee, Hyun-Woo; Kwon, Kwang-Ho

    2014-12-01

    Limited energy sources of ubiquitous sensor networks (USNs) such as fuel cells and batteries have grave drawbacks such as the need for replacements and re-charging owing to their short durability and environmental pollution. Energy harvesting which is converting environmental mechanical vibration into electrical energy has been researched with some piezoelectric materials and various cantilever designs to increase the efficiency of energy-harvesting devices. In this study, we focused on an energy-harvesting cantilever with a broadband vibration frequency. We fabricated a lead zirconate titanate (PZT) cantilever array with various Si proof masses on small beams (5.5 mm x 0.5 mm x 0.5 mm). We obtained broadband resonant frequencies ranging between 127 Hz and 136 Hz using a micro electro-mechanical system (MEMS) process. In order to obtain broadband resonant characteristics, the cantilever array was comprised of six cantilevers with different resonant frequencies. We obtained an output power of about 2.461 μW at an acceleration of 0.23 g and a resistance of 4 kΩ. The measured bandwidth of the resonant frequency was approximately 9 Hz (127-136 Hz), which is about six times wider than the bandwidth of a single cantilever.

  15. Maquet Vasoview Hemopro VH-3000 vessel harvesting system may self-activate or fail to deactivate, potentially resulting in injury.

    Science.gov (United States)

    2011-05-01

    The Harvesting Tool component of the Maquet Vasoview Hemopro VH-3000 vessel harvesting system may self-activate or may fail to deactivate, increasing the chance of thermal injury to the patient or staff, or of igniting a fire. Users of this product must be aware of the potential for either of the unintended activation problems to occur and must be familiar with Maquet's recommendations for dealing with the issue, which are provided in the system's instructions for use.

  16. Rectifier Design Challenges for RF Wireless Power Transfer and Energy Harvesting Systems

    Directory of Open Access Journals (Sweden)

    A. Collado

    2017-06-01

    Full Text Available The design of wireless power transfer (WPT and energy harvesting (EH solutions poses different challenges towards achieving maximum RF-DC conversion efficiency in these systems. This paper covers several selected challenges when developing WPT and electromagnetic EH solutions, such as the design of multiband and broadband rectifiers, the minimization of the effect that load and input power variations may have on the system performance and finally the most optimum power combining mechanisms that can be used when dealing with multi-element rectifiers.

  17. Design of control system of combine harvester louver sieve angle based on ARM

    Science.gov (United States)

    Chen, Jin; Cai, Yangyang; Chen, Xuan; Wang, Xuelei; Wang, Shuqing

    2017-01-01

    In view of the disadvantages of the traditional control methods of combine harvester louver sieve, an electronic control system of louver sieve is designed to replace the traditional mechanical regulation structure, and it changes the old way of manipulating louver sieve. In order to achieve the goal control effect more accurately and quickly, the fuzzy adaptive PID control method and the key control design method based on the finite state machine is proposed during the control process. The tests show that the control system can reach louver sieve electric control goals, and can obtain accurate and stable control effect.

  18. Rainwater collection and management from roofs at the Edison Environmental Center

    Science.gov (United States)

    In the past, the EPA’s Edison Environmental Center, a 200 acre federal run facility, directed all rainwater from roofed areas to the existing stormwater conveyance system. Over the last several years, modifications have been made to the practice of discharging stormwater to the e...

  19. Rainwater Channelization and Infiltration in Granular Media

    Science.gov (United States)

    Cejas, Cesare; Wei, Yuli; Barrois, Remi; Durian, Douglas; Dreyfus, Remi; Compass Team

    2013-03-01

    We investigate the formation of fingered flow in dry granular media under simulated rainfall using a quasi-2D experimental set-up composed of a random close packing of mono-disperse glass beads. We determine effects of grain diameter and surface wetting properties on the formation and infiltration of water channels. For hydrophilic granular media, rainwater initially infiltrates a shallow top layer of soil creating a uniform horizontal wetting front before instabilities occur and grow to form water channels. For hydrophobic media, rainwater ponds on the soil surface rather than infiltrates and water channels may still occur at a later time when the hydraulic pressure of the ponding water exceeds the capillary repellency of the soil. We probe the kinetics of the fingering instabilities that serve as precursors for the growth and drainage of water channels. We also examine the effects of several different methods on improving rainwater channelization such as varying the level of pre-saturation, modifying the soil surface flatness, and adding superabsorbent hydrogel particles.

  20. Power flow in a small electromagnetic energy harvesting system excited by mechanical motion

    CERN Document Server

    Helseth, Lars Egil

    2014-01-01

    In this study the power flow in a coupled mechanical and electromagnetic harvesting system in presence of both positional and electrical fluctuations is analyzed. Explicit expressions for the power into and out of the mechanical and electrical parts of the system are found in the case of weak coupling, and it is shown how the power flows between the domains consistent with energy conservation. The case of thermal fluctuations is considered in particular, and use of the fluctuation-dissipation theorem explicitly demonstrates that the power delivered to the mechanical system from the electrical system is the same as the power delivered to the electrical system from the mechanical system. On the other hand, the power dissipated in the electrical circuit is not the same as the power transferred from the mechanical domain if the electrical circuit contains its own current fluctuations. The electrical noise power dissipated in a load resistor is calculated, and found to consist of a component due to electromagnetic...

  1. Piezoelectric business optimization for use in energy systems harvesting; Optimizacion de piezoelectricos comerciales para su uso en sistemas de Energy Harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Martinez, F. J.; Frutos, J. de; Alonso, D.; Vazquez, M.

    2015-07-01

    In this work, commercial piezoelectric materials are electro mechanically characterized, in different configurations for potential use in harvesting devices of mechanical energy, in order to store and use in the feeding of low power electronic systems. Optimization models considering two different types of mechanical energy are proposed: one for capture energy from continuous vibration, even low intensity and other for capture energy from impacts. Different configurations are discussed, and the feasibility of the models presented is analyzed by frequency vibration systems controlled and a test simulation of passing vehicles, designed and patented by POEMMA R and D group. Everyday applications in which devices in the configurations described may be used are listed. (Author)

  2. System monitoring feedback in cinemas and harvesting energy of the air conditioning condenser

    Science.gov (United States)

    Pop, P. P.; Pop-Vadean, A.; Barz, C.; Latinovic, T.; Chiver, O.

    2017-05-01

    Our article monitors the degree of emotional involvement of the audience in the action film in theaters by measuring the concentration of CO2. The software performs data processing obtained dispersion sensors and displays data during the film. The software will also trigger the start of the air conditioning condenser where we can get harvesting energy by installing a piezoelectric device. Useful energy can be recovered from various waste produced in cinema. The time lag between actions and changes in environmental systems determines that decisions made now will affect subsequent generations and the future of our environment.

  3. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Tien-Kan Chung

    2016-02-01

    Full Text Available An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers, criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence. Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  4. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring.

    Science.gov (United States)

    Chung, Tien-Kan; Yeh, Po-Chen; Lee, Hao; Lin, Cheng-Mao; Tseng, Chia-Yung; Lo, Wen-Tuan; Wang, Chieh-Min; Wang, Wen-Chin; Tu, Chi-Jen; Tasi, Pei-Yuan; Chang, Jui-Wen

    2016-02-23

    An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  5. Briquetting of wastes from coffee plants conducted in zero harvest system

    Directory of Open Access Journals (Sweden)

    Oberdan Everton Zerbinatti

    2014-06-01

    Full Text Available The briquetting process consists of lignocellulosic residues densification in solid biofuel with high calorific value denominated briquette. Coffee crop is one of the most important Brazilian commodities and according to the cultural practices produces plant residues in different amounts. The zero harvest system in coffee crop is based in pruning of plagiotropic branches in alternated years to make possible to concentrate the harvest and to avoid coffee biannual production. The aim of the present work was to verify the viability of briquette production using the biomass waste obtained by zero harvest system. The treatments were composed of briquetting process: 1 coffee rind; 2 mixture of branches and leaves; 3 25% of coffee rind + 75% of branches and leaves; 4 75% of coffee rind + 25% of branches and leaves; 5 50% of coffee rind + 50% of branches and leaves; 6 40% of coffee rind + 60% of branches and leaves. The mixtures were realized in v/v base, milled to produce 5-10 mm particles and were briqueted with 12% of humidity. The C-teor of briquettes produced ranged from 41.85 to 43. 84% and sulphur teor was below 0.1%. The calorific value of briquettes produced ranged from 3,359 to 4, 028 Kcal/ kg and the ashes were below 6%. The isolated use of coffee rind or branches and leaves, as well the mixtures of coffee rind with 50% or more of branches and leaves allow the production of briquettes with calorific value around 4,000 Kcal/ kg which is within the quality parameters. The briquetting of coffee crop wastes is viable and sustainable energetically.

  6. Separating annihilation and excitation energy transfer dynamics in light harvesting systems.

    Science.gov (United States)

    Vengris, Mikas; Larsen, Delmar S; Valkunas, Leonas; Kodis, Gerdenis; Herrero, Christian; Gust, Devens; Moore, Thomas; Moore, Ana; van Grondelle, Rienk

    2013-09-26

    The dependence of excitation energy transfer kinetics on the electronic state of the acceptor (ground vs excited) has been resolved with a novel multipulse prePump-Pump-Probe spectroscopy. The primary energy transfer and annihilation dynamics in two model light-harvesting systems were explored: an artificially synthesized carotenoid-zinc-phthalocyanine dyad and a naturally occurring light-harvesting peridinin-chlorophyll protein complex from Amphidinium carterae. Both systems use carotenoid as the primary excitation energy donor with porphyrin chromophores as the acceptor molecules. The prePump-Pump-Probe transient signals were analyzed with Monte Carlo modeling to explicitly address the underlying step-by-step kinetics involved in both excitation migration and annihilation processes. Both energy transfer and annihilation dynamics were demonstrated to occur with approximately the same rate in both systems, regardless of the excitation status of the acceptor pigments. The possible reasons for these observations are discussed in the framework of the Förster energy transfer model.

  7. Evaluation of reinitialization-free nonvolatile computer systems for energy-harvesting Internet of things applications

    Science.gov (United States)

    Onizawa, Naoya; Tamakoshi, Akira; Hanyu, Takahiro

    2017-08-01

    In this paper, reinitialization-free nonvolatile computer systems are designed and evaluated for energy-harvesting Internet of things (IoT) applications. In energy-harvesting applications, as power supplies generated from renewable power sources cause frequent power failures, data processed need to be backed up when power failures occur. Unless data are safely backed up before power supplies diminish, reinitialization processes are required when power supplies are recovered, which results in low energy efficiencies and slow operations. Using nonvolatile devices in processors and memories can realize a faster backup than a conventional volatile computer system, leading to a higher energy efficiency. To evaluate the energy efficiency upon frequent power failures, typical computer systems including processors and memories are designed using 90 nm CMOS or CMOS/magnetic tunnel junction (MTJ) technologies. Nonvolatile ARM Cortex-M0 processors with 4 kB MRAMs are evaluated using a typical computing benchmark program, Dhrystone, which shows a few order-of-magnitude reductions in energy in comparison with a volatile processor with SRAM.

  8. Analysis of tristable energy harvesting system having fractional order viscoelastic material

    Energy Technology Data Exchange (ETDEWEB)

    Oumbé Tékam, G. T.; Woafo, P. [Laboratory of Modelling and Simulation in Engineering, Biomimetics and Prototypes, Department of Physics, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé (Cameroon); Kitio Kwuimy, C. A. [Center for Nonlinear Dynamics and Control, Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, Pennsylvania 19085 (United States)

    2015-01-15

    A particular attention is devoted to analyze the dynamics of a strongly nonlinear energy harvester having fractional order viscoelastic flexible material. The strong nonlinearity is obtained from the magnetic interaction between the end free of the flexible material and three equally spaced magnets. Periodic responses are computed using the KrylovBogoliubov averaging method, and the effects of fractional order damping on the output electric energy are analyzed. It is obtained that the harvested energy is enhanced for small order of the fractional derivative. Considering the order and strength of the fractional viscoelastic property as control parameter, the complexity of the system response is investigated through the Melnikov criteria for horseshoes chaos, which allows us to derive the mathematical expression of the boundary between intra-well motion and bifurcations appearance domain. We observe that the order and strength of the fractional viscoelastic property can be effectively used to control chaos in the system. The results are confirmed by the smooth and fractal shape of the basin of attraction as the order of derivative decreases. The bifurcation diagrams and the corresponding Lyapunov exponents are plotted to get insight into the nonlinear response of the system.

  9. Stationary distribution and periodic solution for stochastic predator-prey systems with nonlinear predator harvesting

    Science.gov (United States)

    Zuo, Wenjie; Jiang, Daqing

    2016-07-01

    In this paper, we investigate the dynamics of the stochastic autonomous and non-autonomous predator-prey systems with nonlinear predator harvesting respectively. For the autonomous system, we first give the existence of the global positive solution. Then, in the case of persistence, we prove that there exists a unique stationary distribution and it has ergodicity by constructing a suitable Lyapunov function. The result shows that, the relatively weaker white noise will strengthen the stability of the system, but the stronger white noise will result in the extinction of one or two species. Particularly, for the non-autonomous periodic system, we show that there exists at least one nontrivial positive periodic solution according to the theory of Khasminskii. Finally, numerical simulations illustrate our theoretical results.

  10. OPTIMAL DYNAMICAL BALANCE HARVESTING FOR A CLASS OF RENEWABLE RESOURCES SYSTEM

    Institute of Scientific and Technical Information of China (English)

    何泽荣; 王绵森; 王峰

    2004-01-01

    An optimal utilization problem for a class of renewable resources system is investigated. Firstly, a control problem was proposed by introducing a new utility function which depends on the harvesting effort and the stock of resources.Secondly, the existence of optimal solution for the problem was discussed. Then, using a maximum principle for infinite horizon problem, a nonlinear four-dimensional differential equations system was attained. After a detailed analysis of the unique positive equilibrium solution, the existence of limit cycles for the system is demonstrated. Next a reduced system on the central manifold is carefully derived, which assures the stability of limit cycles. Finally significance of the results in bioeconomics is explained.

  11. Dissolved organic carbon in rainwater from areas heavily impacted by sugar cane burning

    Science.gov (United States)

    Coelho, C. H.; Francisco, J. G.; Nogueira, R. F. P.; Campos, M. L. A. M.

    This work reports on rainwater dissolved organic carbon (DOC) from Ribeirão Preto (RP) and Araraquara over a period of 3 years. The economies of these two cities, located in São Paulo state (Brazil), are based on agriculture and related industries, and the region is strongly impacted by the burning of sugar cane foliage before harvesting. Highest DOC concentrations were obtained when air masses traversed sugar cane fields burned on the same day as the rain event. Significant increases in the DOC volume weighted means (VWM) during the harvest period, for both sites, and a good linear correlation ( r = 0.83) between DOC and K (a biomass burning marker) suggest that regional scale organic carbon emissions prevail over long-range transport. The DOC VWMs and standard deviations were 272 ± 22 μmol L -1 ( n = 193) and 338 ± 40 μmol L -1 ( n = 80) for RP and Araraquara, respectively, values which are at least two times higher than those reported for other regions influenced by biomass burning, such as the Amazon. These high DOC levels are discussed in terms of agricultural activities, particularly the large usage of biogenic fuels in Brazil, as well as the analytical method used in this work, which includes volatile organic carbon when reporting DOC values. Taking into account rainfall volume, estimated annual rainwater DOC fluxes for RP (4.8 g C m -2 yr -1) and Araraquara (5.4 g C m -2 yr -1) were close to that previously found for the Amazon region (4.8 g C m -2 yr -1). This work also discusses whether previous calculations of the global rainwater carbon flux may have been underestimated, since they did not consider large inputs from biomass combustion sources, and suffered from a possible analytical bias.

  12. On energy harvesting module for scalable cognitive autonomous nondestructive sensing network (SCANSn) system for bridge health monitoring

    Science.gov (United States)

    Turner, John; Cartwright, Justin; Ha, Dong Sam; Zhang, David; Banerjee, Sourav

    2011-04-01

    The SCANSn is a structural health monitoring (SHM) system is being developed by Acellent Technologies to monitor steel bridges. The required voltage of the system is 14.4 V for active scanning, and the power consumption is approximately 8 W. The investigated energy harvesting from both solar and thermal sources to recharge the lithium-ion battery of the system. A solar panel and a Thermal Electric Generator (TEG) are used to harvest ambient energy. The thermoelectric device is placed in a Fresnel dome to maximize the temperature gradient of the TEG. During shading of the solar panel, the TEG continues to supply power to the battery charger. Since the output voltages and currents of the solar and thermal energy harvesters vary significantly, the energy harvesting module is constructed by two buck-boost converters operating in parallel. Maximal Power Point Tracking (MPPT) is employed for the buck-boost converter for the solar panel, while a fixed duty cycle converter is used for the TEG due to substantially lower power compared with the solar panel. The system design and measured results of a prototype system are presented. Our prototype system successfully demonstrates that the SCANSn system can be powered by the energy harvested from solar and thermal.

  13. Optimized MPPT-based converter for TEG energy harvester to power wireless sensor and monitoring system in nuclear power plant

    Science.gov (United States)

    Xing, Shaoxu; Anakok, Isil; Zuo, Lei

    2017-04-01

    Accidents like Fukushima Disasters push people to improve the monitoring systems for the nuclear power plants. Thus, various types of energy harvesters are designed to power these systems and the Thermoelectric Generator (TEG) energy harvester is one of them. In order to enhance the amount of harvested power and the system efficiency, the power management stage needs to be carefully designed. In this paper, a power converter with optimized Maximum Power Point Tracking (MPPT) is proposed for the TEG Energy Harvester to power the wireless sensor network in nuclear power plant. The TEG Energy Harvester is installed on the coolant pipe of the nuclear plant and harvests energy from its heat energy while the power converter with optimized MPPT can make the TEG Energy Harvester output the maximum power, quickly response to the voltage change and provide sufficient energy for wireless sensor system to monitor the operation of the nuclear power plant. Due to the special characteristics of the Single-Ended Primary Inductor Converter (SEPIC) when it is working in the Discontinuous Inductor Current Mode (DICM) and Continuous Conduction Mode (CCM), the MPPT method presented in this paper would be able to control the converter to achieve the maximum output power in any working conditions of the TEG system with a simple circuit. The optimized MPPT algorithm will significantly reduce the cost and simplify the system as well as achieve a good performance. Experiment test results have shown that, comparing to a fixed- duty-cycle SEPIC which is specifically designed for the working on the secondary coolant loop in nuclear power plant, the optimized MPPT algorithm increased the output power by 55%.

  14. Simulation and testing of a micro electromagnetic energy harvester for self-powered system

    Directory of Open Access Journals (Sweden)

    Yiming Lei

    2014-01-01

    Full Text Available This paper describes a low cost and efficient electromagnetic vibration energy harvester (EVEH for a self-powered system. The EVEH consists of a resistant (copper spring, a permanent magnet (NdFeB35 and a wire-wound copper coil. The copper spring was fabricated by the laser precision cutting technology. A numerical model was adopted to analyze magnetic field distribution of a rectangle permanent magnet. The finite element (FEM soft ANSYS was used to simulate the mechanical properties of the system. The testing results show that the micro electromagnetic vibration energy harvester can generate the maximal power 205.38 μW at a resonance frequency of 124.2 Hz with an acceleration of 0.5 g (g = 9.8 ms−2 across a load the 265 Ω and a superior normalized power density (NPD of 456.5 μW cm−3 g−2. The magnetic field distribution of the permanent magnet was calculated to optimize geometric parameters of the coil. The proposed EVEH has a high efficiency with the lower cost.

  15. A miniature batteryless health and usage monitoring system based on hybrid energy harvesting

    Science.gov (United States)

    Huang, Chenling; Chakrabartty, Shantanu

    2011-04-01

    The cost and size of the state-of-the-art health and usage monitoring systems (HUMS) are determined by capacity of on-board energy storage which limits their large scale deployment. In this paper, we present a miniature low-cost mechanical HUMS integrated circuit (IC) based on the concept of hybrid energy harvesting where continuous monitoring is achieved by self-powering, where as the programming, localization and communication with the sensor is achieved using remote RF powering. The self-powered component of the proposed HUMS is based on our previous result which used a controllable hot electron injection on floatinggate transistor as an ultra-low power signal processor. We show that the HUMS IC can seamlessly switch between different energy harvesting modes based on the availability of ambient RF power and that the configuration, programming and communication functions can be remotely performed without physically accessing the HUMS device. All the measured results presented in this paper have been obtained from prototypes fabricated in a 0.5 micron standard CMOS process and the entire system has been successfully integrated on a 1.5cm x 1.5cm package.

  16. Multireference Excitation Energies for Bacteriochlorophylls A within Light Harvesting System 2.

    Science.gov (United States)

    Anda, André; Hansen, Thorsten; De Vico, Luca

    2016-03-08

    Light-harvesting system 2 (LH2) of purple bacteria is one of the most popular antenna complexes used to study Nature's way of collecting and channeling solar energy. The dynamics of the absorbed energy is probed by ultrafast spectroscopy. Simulation of these experiments relies on fitting a range of parameters to reproduce the spectra. Here, we present a method that can determine key parameters to chemical accuracy. These will eliminate free variables in the modeling, thus reducing the problem. Using MS-RASPT2/RASSCF calculations, we compute excitation energies and transition dipole moments of all bacteriochlorophylls in LH2. We find that the excitation energies vary among the bacteriochlorophyll monomers and that they are regulated by the curvature of the macrocycle ring and the dihedral angle of an acetyl moiety. Increasing the curvature lifts the ground state energy, which causes a red shift of the excitation energy. Increasing the torsion of the acetyl moiety raises the excited state energy, resulting in a blue shift of the excitation energy. The obtained results mark a giant leap for multiconfigurational multireference quantum chemical methods in the photochemistry of biological systems, which can prove instrumental in exposing the underlying physics of photosynthetic light-harvesting.

  17. A resonant electromagnetic vibration energy harvester for intelligent wireless sensor systems

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jing, E-mail: jingqiu@cqu.edu.cn; Wen, Yumei; Li, Ping; Liu, Xin; Chen, Hengjia; Yang, Jin [Sensors and Instruments Research Center, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044 (China)

    2015-05-07

    Vibration energy harvesting is now receiving more interest as a means for powering intelligent wireless sensor systems. In this paper, a resonant electromagnetic vibration energy harvester (VEH) employing double cantilever to convert low-frequency vibration energy into electrical energy is presented. The VEH is made up of two cantilever beams, a coil, and magnetic circuits. The electric output performances of the proposed electromagnetic VEH have been investigated. With the enhancement of turns number N, the optimum peak power of electromagnetic VEH increases sharply and the resonance frequency deceases gradually. When the vibration acceleration is 0.5 g, we obtain the optimum output voltage and power of 9.04 V and 50.8 mW at frequency of 14.9 Hz, respectively. In a word, the prototype device was successfully developed and the experimental results exhibit a great enhancement in the output power and bandwidth compared with other traditional electromagnetic VEHs. Remarkably, the proposed resonant electromagnetic VEH have great potential for applying in intelligent wireless sensor systems.

  18. The effect of management systems and ecosystem types on bark regeneration in Himatanthus drasticus (Apocynaceae): recommendations for sustainable harvesting.

    Science.gov (United States)

    Baldauf, Cristina; Maës dos Santos, Flavio Antonio

    2014-01-01

    Bark and exudates are widely commercialized non-timber forest products. However, the ecological impacts of the harvesting of these products have seldom been studied. The aim of this study is to investigate the relationship of tree resilience to harvesting intensity in Himatanthus drasticus, a tree that is highly exploited in the Brazilian savanna (Cerrado) for its medicinal latex. Although the traded product is the latex, the traditional harvesting systems involve the removal of the bark of the trees to allow exploitation. A 3-year experiment was conducted in two different Cerrado ecosystems (open savanna and savanna woodland). Trees were debarked at four debarking intensities to simulate the effects of traditional management systems. Measurements of bark growth were taken every 6 months, and quantitative and qualitative indexes of bark regeneration were obtained. The mortality of the debarked trees was low and could not be related to the intensity of harvesting. No signs of attack by fungi or insects were recorded. Compared with other species exploited for bark, H. drasticus is very resilient to harvesting; however, bark regeneration is relatively slow. In both analyzed ecosystems, the regeneration indexes showed higher values in the controls than in the treatments, indicating that 3 years is not sufficient for total recovery of the rhytidome. Bark regeneration occurred primarily by sheet growth and was more rapid in open savanna than in savanna woodland. No differences in the rate of bark recovery were found among management treatments. Based on the results, sustainable harvesting guidelines are suggested for the species.

  19. The cost of silage harvest and transport systems for herbaceous crops

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow, A.; Downing, M.; Butler, J.

    1996-12-31

    Some of the highest yielding herbaceous biomass crops are thick-stemmed species such as energy cane (Saccharum ssp.), Napiergrass (Pennisetum purpureum), and forage sorghum (Sorghum bicolor). Their relatively high moisture content necessitates they be handled and stored as silage rather than hay bales or modules. This paper presents estimated costs of harvesting and transporting herbaceous crops as silage. Costs are based on an engineering-economic approach. Equipment costs are estimated by combining per-hour costs with the hours required to complete the operation. Harvest includes severing, chopping, and blowing stalks into a wagon or track. For 50% moisture content, in-field costs using trucks in the field (options 0 and 1) are $3.72-$5.99/dry Mg ($3.37-$5.43/dt) for a farmer and $3.09-$3.64/dry Mg ($2.81- $3.30/dt) for custom operators. However, slopes and wet field conditions may not permit trucks to enter the field. Direct-cut harvest systems using wagons to haul silage to trucks waiting at the field edge (option 2) are $8.52-$11.94/dry Mg ($7.73-$10.83/dt) for farmers and $7.20-$7.36/dry Mg ($6.53-$6.68/dt) for custom operators. Based on four round trips per 8-hour day, 50% and 70% moisture silage, truck transport costs are $8.37/dry Mg ($ 7.60/dt) and $13.98/dry Mg ($12.68/dt), respectively. Lower yields, lower hours of machine use, or a higher discount rate result in higher costs.

  20. Lowest of AC-DC power output for electrostrictive polymers energy harvesting systems

    Science.gov (United States)

    Meddad, Mounir; Eddiai, Adil; Hajjaji, Abdelowahed; Guyomar, Daniel; Belkhiat, Saad; Boughaleb, Yahia; Chérif, Aida

    2013-11-01

    Advances in technology led to the development of electronic circuits and sensors with extremely low electricity consumption. At the same time, structural health monitoring, technology and intelligent integrated systems created a need for wireless sensors in hard to reach places in aerospace vehicles and large civil engineering structures. Powering sensors with energy harvesters eliminates the need to replace batteries on a regular basis. Scientists have been forced to search for new power source that are able to harvested energy from their surrounding environment (sunlight, temperature gradients etc.). Electrostrictive polymer belonging to the family of electro-active polymers, offer unique properties for the electromechanical transducer technology has been of particular interest over the last few years in order to replace conventional techniques such as those based on piezoelectric or electromagnetic, these materials are highly attractive for their low-density, with large strain capability that can be as high as two orders of magnitude greater than the striction-limited, rigid and fragile electroactive ceramics. Electrostrictive polymers sensors respond to vibration with an ac output signal, one of the most important objectives of the electronic interface is to realize the required AC-DC conversion. The goal of this paper is to design an active, high efficiency power doubler converter for electrostrictive polymers exclusively uses a fraction of the harvested energy to supply its active devices. The simulation results show that it is possible to obtain a maximum efficiency of the AC-DC converter equal to 80%. Premiliminary experimental measurements were performed and the results obtained are in good agreement with simulations.

  1. Avian cholera in Nebraska's Rainwater Basin

    Science.gov (United States)

    Windingstad, R.M.; Hurt, J.J.; Trout, A.K.; Cary, J.

    1984-01-01

    The first report of avian cholera in North America occurred in northwestern Texas in winter 1944 (Quortrup et al. 1946). In 1975, mortality from avian cholera occurred for the first time in waterfowl in the Rainwater Basin of Nebraska when an estimated 25,000 birds died (Zinkl et al. 1977). Avian cholera has continued to cause mortality in wild birds in specific areas of the Basin each spring since. Losses of waterfowl from avian cholera continue to be much greater in some of the wetlands in the western part of the Basin than in the east. Several wetlands in the west have consistently higher mortality and are most often the wetlands where initial mortality is noticed each spring (Figure 1). The establishment of this disease in Nebraska is of considerable concern because of the importance of the Rainwater Basin as a spring staging area for waterfowl migrating to their breeding grounds. The wetlands in this area are on a major migration route used by an estimated 5 to 9 million ducks and several hundred thousand geese. A large portion of the western mid-continental greater white-fronted goose (Anser albifrons) population stage in the Basin each spring. Occasionally, whooping cranes (Grus americana) use these wetlands during migration, and lesser sandhill cranes (Grus canadensis) staging on the nearby Platte River sometimes use wetlands where avian cholera occurs (Anonymous 1981). Our objectives were to determine whether certain water quality variables in the Rainwater Basin differed between areas of high and low avian cholera incidence. These results would then be used for laboratory studies involving the survivability of Pasteurella multocida, the causative bacterium of avian cholera. Those studies will be reported elsewhere.

  2. An efficient start-up circuitry for de-energized ultra-low power energy harvesting systems

    Science.gov (United States)

    Hörmann, Leander B.; Berger, Achim; Salzburger, Lukas; Priller, Peter; Springer, Andreas

    2015-05-01

    Cyber-physical systems often include small wireless devices to measure physical quantities or control a technical process. These devices need a self-sufficient power supply because no wired infrastructure is available. Their operational time can be enhanced by energy harvesting systems. However, the convertible power is often limited and discontinuous which requires the need of an energy storage unit. If this unit (and thus the whole system) is de-energized, the start-up process may take a significant amount of time because of an inefficient energy harvesting process. Therefore, this paper presents a system which enables a safe and fast start-up from the de-energized state.

  3. Design & Implementation of a Mobile Phone Charging System Based on Solar Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Qutaiba I. Ali

    2011-06-01

    Full Text Available The ability to harvest energy from the environment represents an important technology area that promises to eliminate wires and battery maintenance for many important applications and permits deploying self powered devices. This paper suggests the use of a solar energy harvester to charge mobile phone devices. In the beginning, a comprehensive overview to the energy harvesting concept and technologies is presented. Then the design procedure of our energy harvester was detailed. Our prototype solar energy harvester proves its efficiency to charge the aimed batteries under sunlight or an indoor artificial light.

  4. Self-Assembly Strategies for Integrating Light Harvesting and Charge Separation in Artificial Photosynthetic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wasielewski, Michael R. (NWU)

    2017-02-15

    In natural photosynthesis, organisms optimize solar energy conversion through organized assemblies of photofunctional chromophores and catalysts within proteins that provide specifically tailored environments for chemical reactions. As with their natural counterparts, artificial photosynthetic systems for practical solar fuels production must collect light energy, separate charge, and transport charge to catalytic sites where multielectron redox processes will occur. While encouraging progress has been made on each aspect of this complex problem, researchers have not yet developed self-ordering and self-assembling components and the tailored environments necessary to realize a fully-functional artificial system. Previously researchers have used complex, covalent molecular systems comprised of chromophores, electron donors, and electron acceptors to mimic both the light-harvesting and the charge separation functions of photosynthetic proteins. These systems allow for study of the dependencies of electron transfer rate constants on donor?acceptor distance and orientation, electronic interaction, and the free energy of the reaction. The most useful and informative systems are those in which structural constraints control both the distance and the orientation between the electron donors and acceptors. Self-assembly provides a facile means for organizing large numbers of molecules into supramolecular structures that can bridge length scales from nanometers to macroscopic dimensions. The resulting structures must provide pathways for migration of light excitation energy among antenna chromophores, and from antennas to reaction centers. They also must incorporate charge conduits, that is, molecular 'wires' that can efficiently move electrons and holes between reaction centers and catalytic sites. The central scientific challenge is to develop small, functional building blocks with a minimum number of covalent linkages, which also have the appropriate molecular

  5. Smart nanogrid systems for disaster mitigation employing deployable renewable energy harvesting devices

    Science.gov (United States)

    Ghasemi-Nejhad, Mehrdad N.; Menendez, Michael; Minei, Brenden; Wong, Kyle; Gabrick, Caton; Thornton, Matsu; Ghorbani, Reza

    2016-04-01

    This paper explains the development of smart nanogrid systems for disaster mitigation employing deployable renewable energy harvesting, or Deployable Disaster Devices (D3), where wind turbines and solar panels are developed in modular forms, which can be tied together depending on the needed power. The D3 packages/units can be used: (1) as a standalone unit in case of a disaster where no source of power is available, (2) for a remote location such as a farm, camp site, or desert (3) for a community that converts energy usage from fossil fuels to Renewable Energy (RE) sources, or (4) in a community system as a source of renewable energy for grid-tie or off-grid operation. In Smart D3 system, the power is generated (1) for consumer energy needs, (2) charge storage devices (such as batteries, capacitors, etc.), (3) to deliver power to the network when the smart D3 nano-grid is tied to the network and when the power generation is larger than consumption and storage recharge needs, or (4) to draw power from the network when the smart D3 nano-grid is tied to the network and when the power generation is less than consumption and storage recharge needs. The power generated by the Smart D3 systems are routed through high efficiency inverters for proper DC to DC or DC to AC for final use or grid-tie operations. The power delivery from the D3 is 220v AC, 110v AC and 12v DC provide proper power for most electrical and electronic devices worldwide. The power supply is scalable, using a modular system that connects multiple units together. This are facilitated through devices such as external Input-Output or I/O ports. The size of the system can be scaled depending on how many accessory units are connected to the I/O ports on the primary unit. The primary unit is the brain of the system allowing for smart switching and load balancing of power input and smart regulation of power output. The Smart D3 systems are protected by ruggedized weather proof casings allowing for operation

  6. Survival and Transfer of Murine Norovirus within a Hydroponic System during Kale and Mustard Microgreen Harvesting.

    Science.gov (United States)

    Wang, Qing; Kniel, Kalmia E

    2015-11-13

    Hydroponically grown microgreens are gaining in popularity, but there is a lack of information pertaining to their microbiological safety. The potential risks associated with virus contamination of crops within a hydroponic system have not been studied to date. Here a human norovirus (huNoV) surrogate (murine norovirus [MNV]) was evaluated for its ability to become internalized from roots to edible tissues of microgreens. Subsequently, virus survival in recirculated water without adequate disinfection was assessed. Kale and mustard seeds were grown on hydroponic pads (for 7 days with harvest at days 8 to 12), edible tissues (10 g) were cut 1 cm above the pads, and corresponding pieces (4 cm by 4 cm) of pads containing only roots were collected separately. Samples were collected from a newly contaminated system (recirculated water inoculated with ∼3 log PFU/ml MNV on day 8) and from a previously contaminated system. (A contaminated system without adequate disinfection or further inoculation was used for production of another set of microgreens.) Viral titers and RNA copies were quantified by plaque assay and real-time reverse transcription (RT)-PCR. The behaviors of MNV in kale and mustard microgreens were similar (P > 0.05). MNV was detected in edible tissues and roots after 2 h postinoculation, and the levels were generally stable during the first 12 h. Relatively low levels (∼2.5 to ∼1.5 log PFU/sample of both edible tissues and roots) of infectious viruses were found with a decreasing trend over time from harvest days 8 to 12. However, the levels of viral RNA present were higher and consistently stable (∼4.0 to ∼5.5 log copies/sample). Recirculated water maintained relatively high levels of infectious MNV over the period of harvest, from 3.54 to 2.73 log PFU/ml. Importantly, cross-contamination occurred easily; MNV remained infectious in previously contaminated hydroponic systems for up to 12 days (2.26 to 1.00 PFU/ml), and MNV was detected in both

  7. Design and parametric study on energy harvesting from bridge vibration using tuned dual-mass damper systems

    Science.gov (United States)

    Takeya, Kouichi; Sasaki, Eiichi; Kobayashi, Yusuke

    2016-01-01

    A bridge vibration energy harvester has been proposed in this paper using a tuned dual-mass damper system, named hereafter Tuned Mass Generator (TMG). A linear electromagnetic transducer has been applied to harvest and make use of the unused reserve of energy the aforementioned damper system absorbs. The benefits of using dual-mass systems over single-mass systems for power generation have been clarified according to the theory of vibrations. TMG parameters have been determined considering multi-domain parameters, and TMG has been tuned using a newly proposed parameter design method. Theoretical analysis results have shown that for effective energy harvesting, it is essential that TMG has robustness against uncertainties in bridge vibrations and tuning errors, and the proposed parameter design method for TMG has demonstrated this feature.

  8. Modeling stump biomass of stands using harvester measurements for adaptive energy wood procurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Vesa, Lauri [ForestCalc Consulting Oy Ltd., 80230 Joensuu (Finland); Palander, Teijo [School of Forest Sciences, University of Eastern Finland, 80100 Joensuu (Finland)

    2010-09-15

    The value and volumes of industrial stump fuel supply are increasing for energy production. Accurate estimates of aboveground and belowground biomass of trees are important when estimating the potential of stumps as a bioenergy source. In this study two stump biomass equations were adapted and tested using them as calibrated stump biomass models computed as the cumulative sum by a local stand. In addition, variables derived from stem measurements of the forest harvester data were examined to predict stump biomass of a stand by applying regression analysis. The true stump yield (dry weight) was used as the reference data in the study. Both biomass models performed well (adjusted R{sup 2} {proportional_to} 0.84) and no advance was found in using other stem dimensions as independent variables in the model. The stand-level model can be used in innovative stump biomass prediction tools for increasing efficiency of energy wood procurement planning to stands within a certain area. In practice, wood procurement managers would need to adapt developed system and decide whether the degree of accuracy/precision provided by the models is acceptable in their local stand harvesting conditions. (author)

  9. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    Directory of Open Access Journals (Sweden)

    Dongxu Su

    2014-11-01

    Full Text Available Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation.

  10. Forster Energy Transfer Theory as Reflected in the Structures of Photosynthetic Light-Harvesting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sener, Melih [Univ. of Illinois, Urbana-Champaign, IL (United States); Strumpfer, Johan [Univ. of Illinois, Urbana-Champaign, IL (United States); Hsin, Jen [Univ. of Illinois, Urbana-Champaign, IL (United States); Chandler, Danielle [Univ. of Illinois, Urbana-Champaign, IL (United States); Scheuring, Simon [Institut National de la Sante Et Recherche Medicale, Paris (France); Hunter, C. Neil [Univ. of Sheffield (United Kingdom); Schulten, Klaus [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2011-02-22

    Förster's theory of resonant energy transfer underlies a fundamental process in nature, namely the harvesting of sunlight by photosynthetic life forms. The theoretical framework developed by Förster and others describes how electronic excitation migrates in the photosynthetic apparatus of plants, algae, and bacteria from light absorbing pigments to reaction centers where light energy is utilized for the eventual conversion into chemical energy. The demand for highest possible efficiency of light harvesting appears to have shaped the evolution of photosynthetic species from bacteria to plants which, despite a great variation in architecture, display common structural themes founded on the quantum physics of energy transfer as described first by Förster. Herein, Förster’s theory of excitation transfer is summarized, including recent extensions, and the relevance of the theory to photosynthetic systems as evolved in purple bacteria, cyanobacteria, and plants is demonstrated. Förster's energy transfer formula, as used widely today in many fields of science, is also derived.

  11. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    Energy Technology Data Exchange (ETDEWEB)

    Su, Dongxu, E-mail: sudx@iis.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Tokyo 1538505 (Japan); Zheng, Rencheng; Nakano, Kimihiko [Institute of Industrial Science, The University of Tokyo, Tokyo 1538505 (Japan); Cartmell, Matthew P [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2014-11-15

    Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation.

  12. Design of a Wildlife Avoidance Planning System for Autonomous Harvesting Operations

    Directory of Open Access Journals (Sweden)

    Dionysis D. Bochtis

    2014-01-01

    Full Text Available Harvesting and mowing operations are among the main potential stressors affecting wildlife within agricultural landscapes, leading to large animal losses. A number of studies have been conducted on harvesting practices to address the problem of wildlife mortality, providing a number of management actions or field area coverage strategies. Nevertheless, these are general rules limited to simple-shaped fields, and which are not applicable to more complex operational situations. The objectives of the present study were to design a system capable of deriving a wildlife avoidance driving pattern for any field shape complexity and field boundary conditions (in terms of escape and non-escape areas and applicable to different animal behaviours. The assumed animal escape reactions are the result of the parameterization of a series of developed behavioural functions. This parameterization will be able to adapt any knowledge that is or might become available as a result of dedicated future experiments on animal behaviour for different species or different animal ages.

  13. Multireference excitation energies for bacteriochlorophylls A within light harvesting system 2

    DEFF Research Database (Denmark)

    Anda, Andre; Hansen, Thorsten; De Vico, Luca

    2016-01-01

    of the excitation energy. Increasing the torsion of the acetyl moiety raises the excited state energy, resulting in a blue shift of the excitation energy. The obtained results mark a giant leap for multiconfigurational multireference quantum chemical methods in the photochemistry of biological systems, which can......Light-harvesting system 2 (LH2) of purple bacteria is one of the most popular antenna complexes used to study Nature's way of collecting and channeling solar energy. The dynamics of the absorbed energy is probed by ultrafast spectroscopy. Simulation of these experiments relies on fitting a range...... of parameters to reproduce the spectra. Here, we present a method that can determine key parameters to chemical accuracy. These will eliminate free variables in the modeling, thus reducing the problem. Using MS-RASPT2/RASSCF calculations, we compute excitation energies and transition dipole moments of all...

  14. Performance of magnetoelectric PZT/Ni multiferroic system for energy harvesting application

    Science.gov (United States)

    Gupta, Reema; Tomar, Monika; Kumar, Ashok; Gupta, Vinay

    2017-03-01

    Magnetoelectric (ME) coefficient of Lead Zirconium Titanate (PZT) thin films has been probed for possible energy harvesting applications. Single phase PZT thin films have been deposited on nickel substrate (PZT/Ni) using pulsed laser deposition (PLD) technique. The effect of PLD process parameters on the ME coupling coefficient in the prepared systems has been investigated. The as grown PZT films on Ni substrate were found to be polycrystalline with improved ferroelectric and ferromagnetic properties. The electrical switching behavior of the PZT thin films were verified using capacitance voltage measurements, where well defined butterfly loops were obtained. The ME coupling coefficient was estimated to be in the range of 94.5 V cm‑1 Oe‑1–130.5 V cm‑1 Oe‑1 for PZT/Ni system, which is large enough for harnessing electromagnetic energy for subsequent applications.

  15. Dynamics of a Ivlev-type predator-prey system with constant rate harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Ling Li [Institute of Nonlinear Analysis, College of Mathematics and Information Science, Wenzhou University, Wenzhou 325035 (China); Wang Weiming [Institute of Nonlinear Analysis, College of Mathematics and Information Science, Wenzhou University, Wenzhou 325035 (China)], E-mail: weimingwang2003@163.com

    2009-08-30

    In this paper, by using the analysis of qualitative method and bifurcation theory, we investigate the dynamical properties of the Ivlev-type predator-prey model with nonzero constant prey harvesting and with or without time delay, respectively. It is shown that the system we considered can exhibit the subcritical and supercritical Hopf bifurcation. We also study the effect of the time delay on the dynamics of the system. By choosing the delay {tau} as a bifurcation parameter, we show that Hopf bifurcation can occur as the delay {tau} crosses some critical values. The direction and stability of the Hopf bifurcation are investigated by following the procedure of deriving normal form given by Faria and Magalhaes. Finally, numerical simulations are performed to illustrate the obtained results.

  16. Periodic Solutions and Homoclinic Bifurcations of Two Predator-Prey Systems with Nonmonotonic Functional Response and Impulsive Harvesting

    Directory of Open Access Journals (Sweden)

    Mingzhan Huang

    2014-01-01

    Full Text Available Two predator-prey models with nonmonotonic functional response and state-dependent impulsive harvesting are formulated and analyzed. By using the geometry theory of semicontinuous dynamic system, we obtain the existence, uniqueness, and stability of the periodic solution and analyse the dynamic phenomenon of homoclinic bifurcation of the first system by choosing the harvesting rate β as control parameter. Besides, we also study the homoclinic bifurcation of the second system about parameter δ on the basis of the theory of rotated vector field. Finally, numerical simulations are presented to illustrate the results.

  17. Controlling factors of rainwater and water vapor isotopes at Bangalore, India: Constraints from observations in 2013 Indian monsoon

    Science.gov (United States)

    Rahul, P.; Ghosh, Prosenjit; Bhattacharya, S. K.; Yoshimura, Kei

    2016-12-01

    Isotopic ratios of rainwaters are believed to decrease with the amount of rainfall. However, analyses of the isotopic composition of rainwater and water vapor samples collected from Bangalore during the monsoon period of 2013 fail to show any simple relationship with the local meteorological parameters whereas show good correlation with the regional integrated convective activity. The correlation is particularly high when the averaging is done over the preceding 8 to 15 days, showing the influence of mixing or residence time scale of atmospheric moisture. This observation emphasizes the role of regional atmospheric circulation driving the isotopic values. A comparison between observed isotope ratios in water vapor and rainwater with Isotope-enabled Global Spectral Model shows discrepancies between the two. The observed values are relatively enriched, indicating a systematic bias in the model values. The higher observed values suggest underestimation of the evaporation in the model, which we estimate to be about 28 ± 15% on average. Simultaneous analyses of rainwater and water vapor isotopic composition again show definitive presence of raindrop evaporation (31 ± 14%). We also documented a distinct pattern of isotopic variation in six samples collected at Bangalore due to mixing of vapor from a cyclonic system in close proximity that originated from the Bay of Bengal. It seems that large-scale isotopic depletion occurs during cyclones caused by Rayleigh fractionation due to massive rainout. These results demonstrate the power of rainwater and water vapor isotope monitoring to elucidate the genesis and dynamics of water recycling within synoptic-scale monsoon systems.

  18. Using Landscape Metrics Analysis and Analytic Hierarchy Process to Assess Water Harvesting Potential Sites in Jordan

    Directory of Open Access Journals (Sweden)

    Abeer Albalawneh

    2015-09-01

    Full Text Available Jordan is characterized as a “water scarce” country. Therefore, conserving ecosystem services such as water regulation and soil retention is challenging. In Jordan, rainwater harvesting has been adapted to meet those challenges. However, the spatial composition and configuration features of a target landscape are rarely considered when selecting a rainwater-harvesting site. This study aimed to introduce landscape spatial features into the schemes for selecting a proper water-harvesting site. Landscape metrics analysis was used to quantify 10 metrics for three potential landscapes (i.e., Watershed 104 (WS 104, Watershed 59 (WS 59, and Watershed 108 (WS 108 located in the Jordanian Badia region. Results of the metrics analysis showed that the three non–vegetative land cover types in the three landscapes were highly suitable for serving as rainwater harvesting sites. Furthermore, Analytic Hierarchy Process (AHP was used to prioritize the fitness of the three target sites by comparing their landscape metrics. Results of AHP indicate that the non-vegetative land cover in the WS 104 landscape was the most suitable site for rainwater harvesting intervention, based on its dominance, connectivity, shape, and low degree of fragmentation. Our study advances the water harvesting network design by considering its landscape spatial pattern.

  19. Early Changes in Soil Metabolic Diversity and Bacterial Community Structure in Sugarcane under Two Harvest Management Systems

    Directory of Open Access Journals (Sweden)

    Lucas Carvalho Basilio Azevedo

    2015-06-01

    Full Text Available Preharvest burning is widely used in Brazil for sugarcane cropping. However, due to environmental restrictions, harvest without burning is becoming the predominant option. Consequently, changes in the microbial community are expected from crop residue accumulation on the soil surface, as well as alterations in soil metabolic diversity as of the first harvest. Because biological properties respond quickly and can be used to monitor environmental changes, we evaluated soil metabolic diversity and bacterial community structure after the first harvest under sugarcane management without burning compared to management with preharvest burning. Soil samples were collected under three sugarcane varieties (SP813250, SP801842 and RB72454 and two harvest management systems (without and with preharvest burning. Microbial biomass C (MBC, carbon (C substrate utilization profiles, bacterial community structure (based on profiles of 16S rRNA gene amplicons, and soil chemical properties were determined. MBC was not different among the treatments. C-substrate utilization and metabolic diversity were lower in soil without burning, except for the evenness index of C-substrate utilization. Soil samples under the variety SP801842 showed the greatest changes in substrate utilization and metabolic diversity, but showed no differences in bacterial community structure, regardless of the harvest management system. In conclusion, combined analysis of soil chemical and microbiological data can detect early changes in microbial metabolic capacity and diversity, with lower values in management without burning. However, after the first harvest, there were no changes in the soil bacterial community structure detected by PCR-DGGE under the sugarcane variety SP801842. Therefore, the metabolic profile is a more sensitive indicator of early changes in the soil microbial community caused by the harvest management system.

  20. [Determination of hydrogen peroxide in rainwater by fluorometry].

    Science.gov (United States)

    Fang, Yan-Fen; Huang, Ying-Ping; Luo, Guang-Fu; Li, Rui-Ping

    2008-04-01

    The present paper introduces a new method using spectrofluorimetric analysis to determine the concentration of hydrogen peroxide in rainwater. In this method, an oxidation reaction is conducted between o-phenylenediamine (OPDA) and hydrogen peroxide in the buffer medium of NaAc-HAc at pH 4. 48 to form a new product 2,3-diaminophenazine (DAPN). Then the fluorescence intensity of DAPN is measured and 426 and 554 nm are chosen as the excitation and emission wavelengths. Therefore, with the foreknown concentration of input hydrogen peroxide, a series of fluorescence intensities of DAPN are acquired according to a series of different concentration of hydrogen peroxide as input, greatly improving the selectivity and sensibility of the system. A relationship between the input concentration of hydrogen peroxide and the fluorescence intensity of DAPN is then obtained using a linear regression. Results show that fluorescence intensity of DAPN is in proportion to the increase in the concentration of hydrogen peroxide in the range of 9.0 x 10(-7) -3.56 x 10(-5) mol x L(-1) almost linearly. The linear equation is F = 1.15c (micromol x L(-1))+398.6 (r = 0.999 1) and the detection limit is 2.7 x10(-7) mol x L(-1) (n = 11). The relative standard deviation of 11 parallel measurements with the concentration of H2O2 at 7.5 x 10(-6) and 3.0 x 10(-5) mol x L(-1), is 2.2 and 1.0%, respectively. Results from DPD method was used to verify this method. The interference of foreign iron was studied. Compared to the traditional methods, this binary system has a simplified operation and high sensitivity. The proposed method has been successfully applied to determine the concentration of hydrogen peroxide in rainwater.

  1. Evaluation of different mechanical fruit harvesting systems and oil quality in very large size olive trees

    Directory of Open Access Journals (Sweden)

    Franco Famiani

    2014-11-01

    Full Text Available In 2006 and 2009, trials were carried out in the Apulia region in Southern Italy to evalu-ate the possibility of mechanizing olive harvesting in groves of old and very large trees. The trees belonged to the cultivars ‘Cellina di Nardò’ and ‘Ogliarola Salentina’. They were 60-100 years old and 7-9 m tall with a canopy volume of 140-360 m3. In the first half of November 2006, with a mechanical beater mounted on a tractor plus hand-held pneumatic combs, the harvesting yield was close to 90% of the total olives present in the canopy, and the harvesting working productivity was around 60 kg of harvested olives h-1 worker-1. With a self-propelled shaker attached to the main branches the harvesting yield was about 73% in ‘Cellina di Nardò’, and 40% in ‘Ogliarola Salentina’, while the harvesting working productivities were around 103 and 85 kg of harvested olives h-1 worker-1, respectively. In the second half of No-vember 2009, in ‘Cellina di Nardò’, with a mechanical beater mounted on a tractor plus nets on the ground or a catching frame (reversed umbrella mounted on another tractor, the harvesting yield was about 97%. The working productivity was about 98 kg of harvested olives h-1 worker-1 with the mechanical beater plus nets and around 133 kg of harvested olives h-1 worker-1 when the mechanical beater was combined with a reversed umbrella. The oil obtained from the mechanically harvested olives was always of high quality. A basic economic evaluation of the harvesting costs is also reported.

  2. Primary light harvesting system: phycobilisomes and associated membranes. Progress report, January 1, 1978--December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Gantt, E.

    1978-01-01

    Phycobilisomes, attached to photosynthetic membranes of the red and blue-green algae, function as the major light harvesters for photosynthesis. They represent one of the most efficient energy transfer systems in photosynthetic organisms. Allophycocyanin is the terminal pigment in the transfer chain. One of the far emitting allophycocyanin forms has been under study because it is the probable bridging pigment between the phycobilisomes and the photosynthetic membrane. Vesicles with attached phycobilisomes from Anabaena variabilis have been isolated and shown to transfer excitation energy from phycobiliproteins to photosystem II chlorophy11 and to actively evolving oxygen. With the availability of such conditions, and with the capability of being able to isolate phycobilisomes from any algae, probes for the phycobilisome attachment site can now be undertaken. Our isolation, characterization, and in vitro recombination of a phycocyanin and phycoerythrin complex represents the first crucial step in being able to explore the in vitro formation of phycobilisomes.

  3. The fundamental role of localised vibrations in excitation dynamics in photosynthetic light-harvesting systems

    CERN Document Server

    Kolli, Avinash; Scholes, Gregory D; Olaya-Castro, Alexandra

    2012-01-01

    The importance of fast vibrations in enhancing and controlling energy transfer and conversion in biomolecules is an issue of current debate. In this article we show that coupling between localised high-frequency vibrations and electronic degrees of freedom is fundamental for efficient excitation transport in photosynthetic light-harvesting systems with high degree of disorder. We consider the cryptophyte antennae protein phycoerythrin 545 and discuss how the balance between electronic interactions and coupling to fast vibronic modes supports the biological function of these antennae by generating a non-cascaded transport that leads to a rapid, directed and wider spatial distribution of excitation energy across the complex. Furthermore, we illustrate signatures of vibronic influence in the beating of excitonic coherences and show that mechanisms supporting coherent evolution of excitons also assist coupling to selected modes that enhance energy transfer to preferential sites in the complex. We therefore argue ...

  4. Energy harvesting from a multifrequency response of a tuned bending-torsion system

    Science.gov (United States)

    Abdelkefi, A.; Nayfeh, A. H.; Hajj, M. R.; Najar, F.

    2012-07-01

    We investigate the benefits of tuning the frequencies of an energy harvester to extract more energy from a base excitation that comprises three frequency components. The energy harvester is composed of a unimorph cantilever beam with asymmetric tip masses. By adjusting the asymmetry of the tip masses, we can tune this beam-mass structure to harvest energy from multifrequency components of a base excitation. We model the beam using the Euler-Bernoulli beam theory and use the first three global mode shapes of the harvester in a Galerkin procedure to derive a reduced-order model describing its response. We derive an exact analytical solution for the tip deflection, twisting angle, voltage output, and harvested electrical power. Using this solution, we investigate the advantages of harvesting energy from a response that contains multifrequencies in comparison to a response that contains a single frequency by tuning only the fundamental frequency. The advantages of this bending-torsion energy harvester and the effect of its tuning are investigated for different short- and open-circuit configurations. The results show that, through a proper tuning of this bending-torsion harvester, the harvested power can be increased significantly and it can be made to cover a wide range of electrical load resistances.

  5. Broadband pendulum energy harvester

    Science.gov (United States)

    Liang, Changwei; Wu, You; Zuo, Lei

    2016-09-01

    A novel electromagnetic pendulum energy harvester with mechanical motion rectifier (MMR) is proposed and investigated in this paper. MMR is a mechanism which rectifies the bidirectional swing motion of the pendulum into unidirectional rotation of the generator by using two one-way clutches in the gear system. In this paper, two prototypes of pendulum energy harvester with MMR and without MMR are designed and fabricated. The dynamic model of the proposed MMR pendulum energy harvester is established by considering the engagement and disengagement of the one way clutches. The simulation results show that the proposed MMR pendulum energy harvester has a larger output power at high frequencies comparing with non-MMR pendulum energy harvester which benefits from the disengagement of one-way clutch during pendulum vibration. Moreover, the proposed MMR pendulum energy harvester is broadband compare with non-MMR pendulum energy harvester, especially when the equivalent inertia is large. An experiment is also conducted to compare the energy harvesting performance of these two prototypes. A flywheel is attached at the end of the generator to make the disengagement more significant. The experiment results also verify that MMR pendulum energy harvester is broadband and has a larger output power at high frequency over the non-MMR pendulum energy harvester.

  6. Rainfall Harvesting as Resources of Self Watering Fertigation System with Various Growing Medias

    Directory of Open Access Journals (Sweden)

    Nurpilihan Bafdal

    2016-10-01

    Full Text Available The climate condition in Indonesia determinate by tropical monsoons, in normal years the rainy season extend about 6 months, from November to April and the dry season prevails from May to September. The annual rainfall is more less 2000mm, of which more than 80% occur in rainy season. In dry season has a critical water deficit to crops while during the wet season, water from rainfall is able to collect it to storage and applied as irrigation water especially in the dry season. The problem is could the rainfall harvesting roof top of the greenhouse good enough for crop water requirement with various growing medias during dry and wet seasons. Self watering fertigation is a system was water irrigation mixed with fertilizer and applied it to the autopots simultaneously through the closed channel.The study of rainfall harvesting as a resources of self water fertigation with various growing medias were the first year from 4 years of  the main research with topic supply and demand water management on self watering fertigation system. The research funding born from Academic Leadership Grant (ALG 1.1.6. The objective of the first research were to find out conducted for each three treatments of growing medias and consumptive used. The experiment was conducted in Jatinangor, West Java Indonesia with treatments were water requirement efficiency and three growing medias i.e. (1 paddy skin charcoal with compos; (2 paddy skin charcoal with organic matter and (3 paddy skin charcoal with coco peat. Cherry tomato and paprika were planted. The results show that water requirement efficiency with growing media of paddy skin charcoal with compos gave growth and production for cherry tomato and paprika.

  7. Electronic coherence and the kinetics of inter-complex energy transfer in light-harvesting systems.

    Science.gov (United States)

    Huo, Pengfei; Miller, Thomas F

    2015-12-14

    We apply real-time path-integral dynamics simulations to characterize the role of electronic coherence in inter-complex excitation energy transfer (EET) processes. The analysis is performed using a system-bath model that exhibits the essential features of light-harvesting networks, including strong intra-complex electronic coupling and weak inter-complex coupling. Strong intra-complex coupling is known to generate both static and dynamic electron coherences, which delocalize the exciton over multiple chromophores and potentially influence the inter-complex EET dynamics. With numerical results from partial linearized density matrix (PLDM) real-time path-integral calculations, it is found that both static and dynamic coherence are correlated with the rate of inter-complex EET. To distinguish the impact of these two types of intra-complex coherence on the rate of inter-complex EET, we use Multi-Chromophore Förster Resonance Energy Transfer (MC-FRET) theory to map the original parameterization of the system-bath model to an alternative parameterization for which the effects of static coherence are preserved while the effects of dynamic coherence are largely eliminated. It is then shown that both parameterizations of the model (i.e., the original that supports dynamic coherence and the alternative that eliminates it), exhibit nearly identical EET kinetics and population dynamics over a wide range of parameters. These observations are found to hold for cases in which either the EET donor or acceptor is a dimeric complex and for cases in which the dimeric complex is either symmetric or asymmetric. The results from this study suggest that dynamic coherence plays only a minor role in the actual kinetics of inter-complex EET, whereas static coherence largely governs the kinetics of incoherent inter-complex EET in light-harvesting networks.

  8. The Integration Design of Residential Area Landscape and Rainwater Resources in Harbin%哈尔滨市居住区雨水资源化与景观整合设计

    Institute of Scientific and Technical Information of China (English)

    李爽; 刘慧民; 许文婷

    2015-01-01

    Selecting the Yiyuan Courtyard in Harbin as an example ,through the following three aspects:Potential analysis of rainwater resource ,the direct and indirect used landscape approaches of residential rainwater resources ,which detail the integrated design strat-egy of residential area landscape and rainwater resources.The results showed that:From May to October ,the total amounts of rainwa-ter recycled and reused is 14023.55 m3 and the total water consumption is about 20129.54 m3.The recycled and reused rainwater can meet the part of water consumption of the residential area ,which offers the possibility of reference for the implementation of rainwater collection and utilization of resources.By building “rainwater gardens” and “parterre rainwater harvesting mode”, roads, green spaces rainwater resources 7786.08 m3 and rooftop rainwater resources 6985.03 m3 can be collected separately in Yiyuan Courtyard residential area.In considering settlements rainwater resources while the rich settlements landscape is else built ,attempting to urban residential area rainwater resource management and the integration of landscape design provides reference .%以哈尔滨市“颐源庭院”居住区景观设计为例,从雨水资源潜力分析、居住区雨水资源直接、间接利用景观途径3个方面详述了居住区景观与雨水资源化的整合设计策略。结果表明:颐源庭院5—10月可回收利用的雨水总量为14023.55 m3、总消耗用水量为20129.54 m3,收集回用雨水量能够满足该居住区的部分用水;通过构建“雨水花园”及“花坛雨水收集利用模式”,颐源庭院居住区可分别收集道路、绿地雨水资源7786.08 m3,屋顶雨水资源6985.03 m3。在居住区雨水资源化的同时打造出丰富的居住区景观,可为城市居住区雨水资源管理与景观的整合设计提供借鉴。

  9. Vacuum-packaged piezoelectric vibration energy harvesters: Damping contributions and autonomy for a wireless sensor system

    NARCIS (Netherlands)

    Elfrink, R.; Renaud, M.; Kamel, T.M.; Nooijer, C. de; Jambunathan, M.; Goedbloed, M.; Hohlfeld, D.; Matova, S.; Pop, V.; Caballero, L.; Schaijk, R. van

    2010-01-01

    This paper describes the characterization of thin-film MEMS vibration energy harvesters based on aluminum nitride as piezoelectric material. A record output power of 85 μW is measured. The parasitic-damping and the energy-harvesting performances of unpackaged and packaged devices are investigated. V

  10. Effect of various shapes and materials on the generated power for piezoelectric energy harvesting system

    Science.gov (United States)

    Kaur, Sarabjeet; Graak, Pinki; Gupta, Ankita; Chhabra, Priya; Kumar, Dinesh; Shetty, Arjun

    2016-04-01

    Piezoelectric energy harvesting systems are used to convert vicinity vibrations into useful electrical energy. Effect of various shapes and materials open the gateway towards the choice of maximum power generation for the micro and nano world. Comsol Multiphysics was used to simulate the four designed shapes named as Pi, E, Rectangular and T in the size range of less than 1mm but greater than 1 micron. Designed shapes worked under the impact of ambient vibrations using few piezoelectric materials for the maximum power generation so that traditional power sources can be replaced with such piezoelectric energy harvester. A layer of piezoelectric material (PZT-5H, AlN, BaTiO3) of thickness 0.5 µm is added to the cantilever and the base material is silicon of thickness 1.5 µm. Simulations were performed using the piezoelectric device module of Comsol Multiphysics. All three materials were studied for the all four cantilever geometries. The generated power was observed maximum as 382.5 µW in case of the barium titanate material with rectangular shape geometry but the displacement is 0.132 µm which is very less whereas E shape cantilever shows the maximum displacement of 0.6078 µm in case of PZT-5H, Hence rectangular shape with barium titanate material is concluded to be good for maximum power generation but the displacement factor cannot be neglected, hence the cantilever with E shape geometry is considered as the best with a generated power of 49.005 µW and a displacement of 0.6078 µm.

  11. Dynamical Analysis of a Delayed Predator-Prey System with Birth Pulse and Impulsive Harvesting at Different Moments