Science.gov

Sample records for potential water harvesting

  1. Spatial assessment of conjunctive water harvesting potential in watershed systems

    NASA Astrophysics Data System (ADS)

    Sekar, I.; Randhir, T. O.

    2007-02-01

    SummaryWater harvesting can be used to minimize water loss and to augment water supplies in watershed systems. This effort is increasingly being recognized as critical in regions experiencing urbanization and facing uneven water supplies. Water harvesting requires a careful assessment of geographic locations in a watershed and evaluation of surface and groundwater hydrology. In this paper, we develop a spatially explicit method to evaluate costs of harvesting and potential benefits in water harvesting in the Taunton River Watershed in Eastern Massachusetts, USA. A spatial analysis is used to assess surface storage and groundwater recharge potentials in developed and undeveloped regions of the watershed. Distributed parameters used in the analysis include runoff coefficients, land use, soil properties, precipitation, aquifer, and land price. Prioritization maps were developed to characterize conjunctive harvesting potential that is based on benefits and costs. The results demonstrate that a spatially variable harvesting strategy can be used to minimize runoff loss and to augment water supplies. The potential harvest areas were clustered in specific locations that satisfy feasibility and economic criteria. In some subwatersheds, potential harvest locations were dispersed. A spatially variable approach that incorporates economic criteria to hydrologic assessment can be used to enhance efficiency related to water harvest and supply management. Given the increasing demand for clean water, a distributed and conjunctive harvesting strategy could be effective in several urbanizing watersheds. The model has potential for further extension into complex situations of biophysical and socioeconomic conditions at watershed level.

  2. Developing index maps of water-harvest potential in Africa

    USGS Publications Warehouse

    Senay, G.B.; Verdin, J.P.

    2004-01-01

    The food security problem in Africa is tied to the small farmer, whose subsistence farming relies heavily on rain-fed agriculture. A dry spell lasting two to three weeks can cause a significant yield reduction. A small-scale irrigation scheme from small-capacity ponds can alleviate this problem. This solution would require a water harvest mechanism at a farm level. In this study, we looked at the feasibility of implementing such a water harvest mechanism in drought prone parts of Africa. A water balance study was conducted at different watershed levels. Runoff (watershed yield) was estimated using the SCS curve number technique and satellite derived rainfall estimates (RFE). Watersheds were delineated from the Africa-wide HYDRO-1K digital elevation model (DEM) data set in a GIS environment. Annual runoff volumes that can potentially be stored in a pond during storm events were estimated as the product of the watershed area and runoff excess estimated from the SCS Curve Number method. Estimates were made for seepage and net evaporation losses. A series of water harvest index maps were developed based on a combination of factors that took into account the availability of runoff, evaporation losses, population density, and the required watershed size needed to fill a small storage reservoir that can be used to alleviate water stress during a crop growing season. This study presents Africa-wide water-harvest index maps that could be used for conducting feasibility studies at a regional scale in assessing the relative differences in runoff potential between regions for the possibility of using ponds as a water management tool. ?? 2004 American Society of Agricultural Engineers.

  3. Increasing the potential of agricultural water harvesting in Africa

    NASA Astrophysics Data System (ADS)

    Irvine, Brian; Kirkby, Mike; Woldearegay, Kifle

    2014-05-01

    The WAHARA project aims to increase the potential of water harvesting in Africa. The WAHARA project draws on expertise and field data from four study sites in Ethiopia, Tunisia, Burkina Faso and Zambia. The project is transdisciplinary working closely with stakeholders to ensure that the water harvesting technologies selected and tested meet their needs. The effectiveness of WH technologies will be assessed under different environmental and socio-economic conditions. Each study site offers a number of WH technologies and aim to trial technologies from other study sites. The results from the study sites will inform the adaptation of the PESERA model and the potential of WH for the whole of Africa This presentation highlights the climate range in which the field trials are being carried out and the technologies being trialed in northern Ethiopia. Conceptual models for each technology are considered and incorporated into the PESERA model. The model is applied for the study site with both field based and catchment based technologies being assessed. The transferability and potential of individual and combined technologies will be considered across climate gradients and soil type for Africa. A quick assessment tool has been developed and offers an initial assessment of water harvesting potential. The tool can be used to quickly assess which kinds of WHT could be used in specific areas in Africa and is available to interested parties.

  4. Snow Harvesting: A Potential Water Source for Afghanistan

    DTIC Science & Technology

    2009-08-01

    storage capabilities, with many regions suffering recurring drought. A widespread drought occurred from 1997 to 2002, causing a significant decrease ...supply using snow fences depends not only upon the ability to capture the snow but also the effect that introducing a new water source has upon the...

  5. Networks of triboelectric nanogenerators for harvesting water wave energy: a potential approach toward blue energy.

    PubMed

    Chen, Jun; Yang, Jin; Li, Zhaoling; Fan, Xing; Zi, Yunlong; Jing, Qingshen; Guo, Hengyu; Wen, Zhen; Pradel, Ken C; Niu, Simiao; Wang, Zhong Lin

    2015-03-24

    With 70% of the earth's surface covered with water, wave energy is abundant and has the potential to be one of the most environmentally benign forms of electric energy. However, owing to lack of effective technology, water wave energy harvesting is almost unexplored as an energy source. Here, we report a network design made of triboelectric nanogenerators (TENGs) for large-scale harvesting of kinetic water energy. Relying on surface charging effect between the conventional polymers and very thin layer of metal as electrodes for each TENG, the TENG networks (TENG-NW) that naturally float on the water surface convert the slow, random, and high-force oscillatory wave energy into electricity. On the basis of the measured output of a single TENG, the TENG-NW is expected to give an average power output of 1.15 MW from 1 km(2) surface area. Given the compelling features, such as being lightweight, extremely cost-effective, environmentally friendly, easily implemented, and capable of floating on the water surface, the TENG-NW renders an innovative and effective approach toward large-scale blue energy harvesting from the ocean.

  6. Geo - hydrological investigations and impact of water harvesting structures on groundwater potential in Anantapur District, Andhra Pradesh, India.

    PubMed

    Suryanarayana, K V; Krishnaiah, S; Khokalay, Murthy Rao V

    2010-10-01

    In this paper, the data pertaining to the rainfall, its departure from normal, moving mean rainfall, depth of water levels in pre-monsoon and post-monsoon seasons, groundwater availability, groundwater utilization and impact of storage of water in large water bodies are analyzed graphically. The results indicate that the groundwater is over exploited in many places in Anantapur District (India). The groundwater levels found fluctuating, when compared the observations in pre-monsoon and post-monsoon seasons. Hence, it is concluded that the construction of water harvesting structures at suitable locations will have a definite impact on the groundwater potential in Anantapur District.

  7. Nanoparticles: potential biomarker harvesters.

    PubMed

    Geho, David H; Jones, Clinton D; Petricoin, Emanuel F; Liotta, Lance A

    2006-02-01

    A previously untapped bank of information resides within the low molecular weight proteomic fraction of blood. Intensive efforts are underway to harness this information so that it can be used for early diagnosis of diseases such as cancer. The physicochemical malleability and high surface areas of nanoparticle surfaces make them ideal candidates for developing biomarker harvesting platforms. Given the variety of engineering strategies afforded through nanoparticle technologies, a significant goal is to tailor nanoparticle surfaces to selectively bind a subset of biomarkers, sequestering them for later study using high sensitivity proteomic tests. To date, applications of nanoparticles have largely focused on imaging systems and drug delivery vectors. As such, biomarker harvesting is an underutilized application of nanoparticle technology and is an area of nanotechnology research that will likely undergo substantial growth.

  8. SCS-CN and GIS-based approach for identifying potential water harvesting sites in the Kali Watershed, Mahi River Basin, India

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, D.; Bandyopadhyay, A.; Kusuma, K. N.

    2009-08-01

    The Kali sub-watershed is situated in the semi-arid region of Gujarat, India and forms a part of the Mahi River Watershed. This watershed receives an average annual rainfall of 900mm mainly between July and September. Due to high runoff potential, evapo-transpiration and poor infiltration, drought like situation prevails in this area from December to June almost every year. In this paper, augmentation of water resource is proposed by construction of runoff harvesting structures like check dam, percolation pond, farm pond, well and subsurface dyke. The site suitability for different water harvesting structures is determined by considering spatially varying parameters like runoff potential, slope, fracture pattern and micro-watershed area. GIS is utilised as a tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage and fracture. The runoff derived by SCS-CN method is a function of runoff potential which can be expressed in terms of runoff coefficient (ratio between the runoff and rainfall) which can be classified into three classes, viz., high (>40%), moderate (20-40%) and low (<20%). In addition to IMSD, FAO specifications for water harvesting/recharging structures, parameters such as effective storage, rock mass permeability are herein considered to augment effective storage. Using the overlay and decision tree concepts in GIS, potential water harvesting sites are identified. The derived sites are field investigated for suitability and implementation. In all, the accuracy of the site selection at implementation level varies from 80-100%.

  9. Water Harvesting II: Working toward Being Green

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Ness, Daniel; Craven, John A.

    2008-01-01

    As you have read in the previous "After the Bell" column, water harvesting is a process of diverting and collecting rainwater. One of the main reasons to harvest rainwater is to reduce the demand on local sources of water. The objective of the harvesting procedure is to gather water from a weather event that is usually lost as runoff and either…

  10. System for harvesting water wave energy

    DOEpatents

    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.

  11. Assessing the biophysical and socio-economic potential of Sustainable Land Management and Water Harvesting Technologies for rainfed agriculture across semi-arid Africa.

    NASA Astrophysics Data System (ADS)

    Irvine, Brian; Fleskens, Luuk; Kirkby, Mike

    2016-04-01

    Stakeholders in recent EU projects identified soil erosion as the most frequent driver of land degradation in semi-arid environments. In a number of sites, historic land management and rainfall variability are recognised as contributing to the serious environmental impact. In order to consider the potential of sustainable land management and water harvesting techniques stakeholders and study sites from the projects selected and trialled both local technologies and promising technologies reported from other sites . The combined PESERA and DESMICE modelling approach considered the regional effects of the technologies in combating desertification both in environmental and socio-economical terms. Initial analysis was based on long term average climate data with the model run to equilibrium. Current analysis, primarily based on the WAHARA study sites considers rainfall variability more explicitly in time series mode. The PESERA-DESMICE approach considers the difference between a baseline scenario and a (water harvesting) technology scenario, typically, in terms of productivity, financial viability and scope for reducing erosion risk. A series of 50 year rainfall realisations are generated from observed data to capture a full range of the climatic variability. Each realisation provides a unique time-series of rainfall and through modelling can provide a simulated time-series of crop yield and erosion risk for both baseline conditions and technology scenarios. Subsequent realisations and model simulations add to an envelope of the potential crop yield and cost-benefit relations. The development of such envelopes helps express the agricultural and erosional risk associated with climate variability and the potential for conservation measures to absorb the risk, highlighting the probability of achieving a given crop yield or erosion limit. Information that can directly inform or influence the local adoption of conservation measures under the climatic variability in semi

  12. Bioinspired Breathable Architecture for Water Harvesting

    PubMed Central

    von Spreckelsen, Rowan M.; Harris, Matthew T.; Wigzell, James M.; Fraser, Rebekah C.; Carletto, Andrea; Mosquin, Daniel P. K.; Justice, Douglas; Badyal, Jas Pal S.

    2015-01-01

    Thuja plicata is a coniferous tree which displays remarkable water channelling properties. In this article, an easily fabricated mesh inspired by the hierarchical macro surface structure of Thuja plicata branchlets is described which emulates this efficient water collection behaviour. The key parameters are shown to be the pore size, pore angle, mesh rotation, tilt angle (branch droop) and layering (branch overlap). Envisaged societal applications include water harvesting and low cost breathable architecture for developing countries. PMID:26577768

  13. Water flow energy harvesters for autonomous flowmeters

    NASA Astrophysics Data System (ADS)

    Boisseau, Sebastien; Duret, Alexandre-Benoit; Perez, Matthias; Jallas, Emmanuel; Jallas, Eric

    2016-11-01

    This paper reports on a water flow energy harvester exploiting a horizontal axis turbine with distributed magnets of alternate polarities at the rotor periphery and air coils outside the pipe. The energy harvester operates down to 1.2L/min with an inlet section of 20mm of diameter and up to 25.2mW are provided at 20L/min in a 2.4V NiMH battery through a BQ25504 power management circuit. The pressure loss induced by the insertion of the energy harvester in the hydraulic circuit and by the extraction of energy has been limited to 0.05bars at 30L/min, corresponding to a minor loss coefficient of KEH=3.94.

  14. Potential Rainwater Harvesting Improvement Using Advanced Remote Sensing Applications

    PubMed Central

    Elhag, Mohamed; Bahrawi, Jarbou A.

    2014-01-01

    The amount of water on earth is the same and only the distribution and the reallocation of water forms are altered in both time and space. To improve the rainwater harvesting a better understanding of the hydrological cycle is mandatory. Clouds are major component of the hydrological cycle; therefore, clouds distribution is the keystone of better rainwater harvesting. Remote sensing technology has shown robust capabilities in resolving challenges of water resource management in arid environments. Soil moisture content and cloud average distribution are essential remote sensing applications in extracting information of geophysical, geomorphological, and meteorological interest from satellite images. Current research study aimed to map the soil moisture content using recent Landsat 8 images and to map cloud average distribution of the corresponding area using 59 MERIS satellite imageries collected from January 2006 to October 2011. Cloud average distribution map shows specific location in the study area where it is always cloudy all the year and the site corresponding soil moisture content map came in agreement with cloud distribution. The overlay of the two previously mentioned maps over the geological map of the study area shows potential locations for better rainwater harvesting. PMID:25114973

  15. Rainwater harvesting potentials for drought mitigation in Iran.

    PubMed

    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. Environmental and socioeconomic benefits and limitations of water harvesting techniques in semiarid regions

    NASA Astrophysics Data System (ADS)

    Díaz-Pereira, Elvira; Asunción Romero-Díaz, María; de Vente, Joris

    2016-04-01

    water harvesting are increased crop yield and farm income. Their implementation also leads to an improved food security and knowledge of soil erosion and conservation and to strengthening of social networks. Their main environmental benefits include an increased soil moisture content and water availability, reduced soil loss and reduced downstream flooding and siltation. These impacts have positive implications for a range of regulating (flood control), provisioning (food production), supporting (nutrient cycling) and cultural (aesthetic value) ecosystem services. Despite their many perceived potential benefits, the main constraints for local implementation of water harvesting techniques are due to labour constraints, implementation costs and the loss of productive land. This highlights the need for political solutions including incentives for implementation for most effective water harvesting techniques adapted to local environmental and socioeconomic conditions.

  17. Harvesting energy from water flow over graphene?

    PubMed

    Yin, Jun; Zhang, Zhuhua; Li, Xuemei; Zhou, Jianxin; Guo, Wanlin

    2012-03-14

    It is reported excitingly in a previous letter (Nano Lett. 2011, 11, 3123) that a small piece of graphene sheet about 30 × 16 μm(2) immersed in flowing water with 0.6 M hydrochloric acid can produce voltage ~20 mV. Here we find that no measurable voltage can be induced by the flow over mono-, bi- and trilayered graphene samples of ~1 × 1.5 cm(2) in size in the same solution once the electrodes on graphene are isolated from interacting with the solution, mainly because the H(3)O(+) cations in the water adsorb onto graphene by strong covalent bonds as revealed by our first-principles calculations. When both the graphene and its metal electrodes are exposed to the solution as in the previous work, water flow over the graphene-electrode system can induce voltages from a few to over a hundred millivolts. In this situation, the graphene mainly behaves as a load connecting between the electrodes. Therefore, the harvested energy is not from the immersed carbon nanomaterials themselves in ionic water flow but dominated by the exposed electrodes.

  18. Assessment of the toxic potential of polycyclic aromatic hydrocarbons (PAHs) affecting Gulf menhaden (Brevoortia patronus) harvested from waters impacted by the BP Deepwater Horizon Spill.

    PubMed

    Olson, Gregory M; Meyer, Buffy M; Portier, Ralph J

    2016-02-01

    Approximately 4.9 million barrels of crude oil and gas were released into the Gulf of Mexico (GoM) from April to July 2010 during the Deepwater Horizon (DWH) spill. This resulted in the possible contamination of marine organisms with polycyclic aromatic hydrocarbons (PAHs), USEPA identified constituents of concern. To determine the impact of the DWH oil spill, Gulf menhaden (Brevoortia patronus), a commercially harvested and significant trophic grazing species, was sampled from two Louisiana coastal regions between the years 2011-2013. Tissue extraction and GC/MS analysis demonstrated measurable concentrations of PAH within menhaden. Analysis yielded total PAHs, carcinogenic equivalents (BaP-TEQ), and mutagenic equivalents (BaP-MEQ) which provided an initial toxic potential assessment of this GoM Fishery. Gulf menhaden contained less total PAH concentrations in 2012 and significantly less in 2013 as compared to 2011 (p < 0.05) ranging from 7 ug/g tissue dry weight to 3 ng/g tissue dry weight. Carcinogenic and mutagenic PAHs were also significantly reduced (p < 0.05) over the three year period. The reduction of total PAH concentrations and the reduction of BaP-TEQs and MEQs between 2011 and 2013 indicates a diminished input of new source PAHs along with a reduction of carcinogenic and mutagenic PAHs in menhaden populations. The use of Gulf menhaden was successful in determining the acute toxic potential of PAHs contaminating the GoM in the years directly following the DWH spill event.

  19. Potentiality of rainwater harvesting for an urban community in Bangladesh

    NASA Astrophysics Data System (ADS)

    Akter, Aysha; Ahmed, Shoukat

    2015-09-01

    Due to cost effectiveness, rainwater harvesting (RWH) systems are practicing already in some rural parts of Bangladesh but very few in urban areas. This paper aimed to evaluate the potentiality of RWH systems in the South Agrabad in Chittagong city with an average annual precipitation of 3000 mm, experiencing both water scarcity and urban flooding in the same year. The adopted approach was Analytic Hierarchy Process (AHP) based multicriteria decision analysis technique, and the evaluation criteria were roof area, slope, drainage density and runoff coefficient. Geospatial Hydrologic Modeling Extension supported hydrologic model viz. HEC-HMS used to simulate the precipitation-runoff process, the model outcomes showed RWH potentiality which could minimize stagnant storm water up to 26% through supplementing city water supply annually up to 20 liter/person/day. Then, assigning suitable weightage to the evaluation criteria with their associated features in ArcGIS 9.3, the study area was reasonably divided into three potential zones i.e. good, moderate and poor covering 19%, 64% and 17% of the total area respectively. Thus, this is envisaged AHP using HEC-HMS could provide important guidance to the decision supporting system not only for urban areas but also for the wide sub-basin/basin context.

  20. Assessment of the performance of water harvesting systems in semi-arid regions

    NASA Astrophysics Data System (ADS)

    Lasage, Ralph

    2016-04-01

    Water harvesting is widely practiced and has the potential to improve water availability for domestic and agricultural use in semi-arid regions. New funds are becoming available to stimulate the implementation of water harvesting projects, for meeting the Sustainable Development Goals and to help communities to adapt to climate change. For this, it is important to understand which factors determine the success of water harvesting techniques under different conditions. For this, we review the literature, including information on the crop yield impacts of water harvesting projects in semi-arid Africa and Asia. Results show that large water harvesting structures (> 500 m3) are less expensive than small structures, when taking into account investment costs, storage capacity and lifetimes. We also find that water harvesting improves crop yields significantly, and that the relative impact of water harvesting on crop yields is largest in low rainfall years. We also see that the governance, technical knowledge and initial investment are more demanding for the larger structures than for smaller structures, which may affect their spontaneous adoption and long term sustainability when managed by local communities. To support the selection of appropriate techniques, we present a decision framework based on case specific characteristics. This framework can also be used when reporting and evaluating the performance of water harvesting techniques, which is up to now quite limited in peer reviewed literature. Based on Bouma, J., Hegde, S.E., Lasage, R., (2016). Assessing the returns to water harvesting: A meta-analysis. Agricultural Water Management 163, 100-109. Lasage, R., Verburg P.H., (2015). Evaluation of small scale water harvesting techniques for semi-arid environments. Journal of Arid Environments 118, 48-57.

  1. Water quality management of rooftop rainwater harvesting systems.

    PubMed

    Abbasi, Tasneem; Abbasi, S A

    2009-10-01

    The ancient technique of harvesting rainwater falling on rooftops, which had been forgotten after the advent of large-scale centralized water resource systems like dam-based reservoirs, has staged a global comeback in the post-modern era. It is expected that in the near future all dwellings everywhere will be equipped to harvest and use rainwater. Such widespread use of rooftop rainwater harvesting makes it very important that the water quality aspects associated with it are clearly understood and managed. The present paper addresses the related issues. The pathways by which pollutants can enter in a rainwater harvest have been traced and the strategies to manage the water quality, at pre-harvest as well as post-harvest stages, have been discussed.

  2. Enhancing ability of harvesting energy from random vibration by decreasing the potential barrier of bistable harvester

    NASA Astrophysics Data System (ADS)

    Lan, Chunbo; Qin, Weiyang

    2017-02-01

    When a bistable energy harvester (BEH) is driven by weak random excitation, its harvesting efficiency will decrease due to the seldom occurrence of interwell motion. To overcome this defect, we developed an improved bistable energy harvester (IBEH) from BEH by adding a small magnet at the middle of two fixed magnets. It is proved that the attractive force originated from the additional magnet can pull down the potential barrier and shallow the potential well, but still keep the middle position of beam unstable. This can make jumping between potential wells easier. Thus IBEH can realize snap-through even at fairly weak excitation. The magnetic potential energy is given and the electromechanical equations are derived. Then the harvesting performance of IBEH under random excitation is studied. Validation experiments are designed and carried out. Comparisons prove that IBEH is preferable to BEH in harvesting random energy and can give out a high output voltage even at weak excitation. The size of additional magnet can be optimized to reach the best performance of IBEH.

  3. Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

    PubMed

    Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

    2015-11-01

    Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests.

  4. Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

    PubMed Central

    Dobrowsky, P. H.; De Kwaadsteniet, M.; Cloete, T. E.

    2014-01-01

    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. PMID:24487540

  5. Desert water harvesting to benefit wildlife: a simple, cheap, and durable sub-surface water harvester for remote locations.

    PubMed

    Rice, William E

    2004-12-01

    A sub-surface desert water harvester was constructed in the sagebrush steppe habitat of south-central Idaho, U.S.A. The desert water harvester utilizes a buried micro-catchment and three buried storage tanks to augment water for wildlife during the dry season. In this region, mean annual precipitation (MAP) ranges between about 150-250 mm (6"-10"), 70% of which falls during the cold season, November to May. Mid-summer through early autumn, June through October, is the dry portion of the year. During this period, the sub-surface water harvester provides supplemental water for wildlife for 30-90 days, depending upon the precipitation that year. The desert water harvester is constructed with commonly available, "over the counter" materials. The micro-catchment is made of a square-shaped, 20 mL. "PERMALON" polyethylene pond liner (approximately 22.9 m x 22.9 m = 523 m2) buried at a depth of about 60 cm. A PVC pipe connects the harvester with two storage tanks and a drinking trough. The total capacity of the water harvester is about 4777 L (1262 U.S. gallons) which includes three underground storage tanks, a trough and pipes. The drinking trough is refined with an access ramp for birds and small animals. The technology is simple, cheap, and durable and can be adapted to other uses, e.g. drip irrigation, short-term water for small livestock, poultry farming etc. The desert water harvester can be used to concentrate and collect water from precipitation and run-off in semi-arid and arid regions. Water harvested in such a relatively small area will not impact the ground water table but it should help to grow small areas of crops or vegetables to aid villagers in self-sufficiency.

  6. Energy harvesting potential of tuned inertial mass electromagnetic transducers

    NASA Astrophysics Data System (ADS)

    Asai, Takehiko; Araki, Yoshikazu; Ikago, Kohju

    2017-02-01

    The demand for developing renewable energy technologies has been growing in today's society. As one of promising renewable energy sources, large-scale energy harvesting from structural vibrations employing electromagnetic transducers has recently been proposed and considerable effort has been devoted to increase the power generation capability. In this paper, we introduce the mechanism of a tuned inertial mass electromagnetic transducer (TIMET), which can absorb vibratory energy more efficiently by tuning the parameters to adjust the system. Then we propose a new vibratory energy harvester with the TIMET and determine the parameter values for the device with a simple static admittance (SA) control law to maximize the energy harvested from a stationary stochastic disturbance. To investigate the energy harvesting potential of the TIMET further, the performance-guaranteed (PG) control and the LQG control proposed in the literature are applied as well. Then the numerical simulation studies are carried out and the effectiveness of the proposed energy harvester is examined by comparing the traditional electromagnetic transducers.

  7. Harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Fog-harvesting potential of lubricant-impregnated electrospun nanomats.

    PubMed

    Lalia, Boor Singh; Anand, Sushant; Varanasi, Kripa K; Hashaikeh, Raed

    2013-10-22

    Hydrophobic PVDF-HFP nanowebs were fabricated by a facile electrospinning method and proposed for harvesting fog from the atmosphere. A strong adhesive force between the surface and a water droplet has been observed, which resists the water being shed from the surface. The water droplets on the inhomogeneous nanomats showed high contact angle hysteresis. The impregnation of nanomats with lubricants (total quartz oil and Krytox 1506) decreased the contact angle hysteresis and hence improved the roll off of water droplets on the nanomat surface. It was found that water droplets of 5 μL size (diameter = 2.1 mm) and larger roll down on an oil-impregnated surface, held vertically, compared to 38 μL (diameter = 4.2 mm) on a plain nanoweb. The contact angle hysteresis decreased from ~95 to ~23° with the Krytox 1506 impregnation.

  9. Harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spindle picker and brush-roll stripper are the two machines used to harvest cotton produced in the United States. Adoption of each harvester type is dictated by regional differences in regard to production environment, production practices, cultivar, and yield. The spindle picker is a selectiv...

  10. Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating.

    PubMed

    Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-03-13

    Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m(2). Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

  11. Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating

    NASA Astrophysics Data System (ADS)

    Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-03-01

    Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

  12. Water harvesting techniques for small communities in arid areas.

    PubMed

    Yuen, E; Anda, M; Mathew, K; Ho, G

    2001-01-01

    Limited water resources exist in numerous remote indigenous settlements around Australia. Indigenous people in these communities are still living in rudimentary conditions while their urban counterparts have full amenities, large scale water supplies and behavioral practices which may not be appropriate for an arid continent but are supported by extensive infrastructure in higher rainfall coastal areas. As remote indigenous communities continue to develop, their water use will increase, and in some cases, costly solutions may have to be implemented to augment supplies. Water harvesting techniques have been applied in settlements on a small scale for domestic and municipal purposes, and in the large, broadacre farm setting for productive use of the water. The techniques discussed include swales, infiltration basins, infiltration trenches and "sand dam" basins. This paper reviews the applications of water harvesting relevant to small communities for land rehabilitation, landscaping and flood control. Landscaping is important in these communities as it provides shelter from the sun and wind, reduces soil erosion and hence reduced airborne dust, and in some cases provides food and nutrition. Case studies of water harvesting systems applied in the Pilbara Region, Western Australia for landscaping around single dwellings in Jigalong and Cheeditha, in a permaculture garden in Wittenoon and at a college and carpark in Karratha are described.

  13. Applicability of ERTS to Antarctic iceberg resources. [harvesting sea ice for fresh water

    NASA Technical Reports Server (NTRS)

    Hult, J. L. (Principal Investigator); Ostrander, N. C.

    1973-01-01

    The author has identified the following significant results. This investigation explorers the applicability of ERTS to (1) determine the Antarctic sea ice and environmental behavior that may influence the harvesting of icebergs, and (2) monitor iceberg locations, characteristics, and evolution. Imagery has shown that the potential applicability of ERTS to the research, planning, and harvesting operations can contribute importantly to the glowing promise derived from broader scope studies for the use of Antarctic icebergs to relieve a growing global thirst for fresh water. Several years of comprehensive monitoring will be necessary to characterize sea ice and environmental behavior and iceberg evolution. Live ERTS services will assist harvesting control and claiming operations and offer a means of harmonizing entitlements of iceberg resources. The valuable ERTS services will be more cost effective than other means will be easily justified and borne by the iceberg harvesting operations.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Light-harvesting photocatalysis for water oxidation using mesoporous organosilica.

    PubMed

    Takeda, Hiroyuki; Ohashi, Masataka; Goto, Yasutomo; Ohsuna, Tetsu; Tani, Takao; Inagaki, Shinji

    2014-07-14

    An organic-based photocatalysis system for water oxidation, with visible-light harvesting antennae, was constructed using periodic mesoporous organosilica (PMO). PMO containing acridone groups in the framework (Acd-PMO), a visible-light harvesting antenna, was supported with [Ru(II)(bpy)3(2+)] complex (bpy = 2,2'-bipyridyl) coupled with iridium oxide (IrO(x)) particles in the mesochannels as photosensitizer and catalyst, respectively. Acd-PMO absorbed visible light and funneled the light energy into the Ru complex in the mesochannels through excitation energy transfer. The excited state of Ru complex is oxidatively quenched by a sacrificial oxidant (Na2S2O8) to form Ru(3+) species. The Ru(3+) species extracts an electron from IrO(x) to oxidize water for oxygen production. The reaction quantum yield was 0.34 %, which was improved to 0.68 or 1.2 % by the modifications of PMO. A unique sequence of reactions mimicking natural photosystem II, 1) light-harvesting, 2) charge separation, and 3) oxygen generation, were realized for the first time by using the light-harvesting PMO.

  16. Flared natural gas-based onsite atmospheric water harvesting (AWH) for oilfield operations

    NASA Astrophysics Data System (ADS)

    Wikramanayake, Enakshi D.; Bahadur, Vaibhav

    2016-03-01

    Natural gas worth tens of billions of dollars is flared annually, which leads to resource waste and environmental issues. This work introduces and analyzes a novel concept for flared gas utilization, wherein the gas that would have been flared is instead used to condense atmospheric moisture. Natural gas, which is currently being flared, can alternatively power refrigeration systems to generate the cooling capacity for large scale atmospheric water harvesting (AWH). This approach solves two pressing issues faced by the oil-gas industry, namely gas flaring, and sourcing water for oilfield operations like hydraulic fracturing, drilling and water flooding. Multiple technical pathways to harvest atmospheric moisture by using the energy of natural gas are analyzed. A modeling framework is developed to quantify the dependence of water harvest rates on flared gas volumes and ambient weather. Flaring patterns in the Eagle Ford Shale in Texas and the Bakken Shale in North Dakota are analyzed to quantify the benefits of AWH. Overall, the gas currently flared annually in Texas and North Dakota can harvest enough water to meet 11% and 65% of the water consumption in the Eagle Ford and the Bakken, respectively. Daily harvests of upto 30 000 and 18 000 gallons water can be achieved using the gas currently flared per well in Texas and North Dakota, respectively. In fifty Bakken sites, the water required for fracturing or drilling a new well can be met via onsite flared gas-based AWH in only 3 weeks, and 3 days, respectively. The benefits of this concept are quantified for the Eagle Ford and Bakken Shales. Assessments of the global potential of this concept are presented using data from countries with high flaring activity. It is seen that this waste-to-value conversion concept offers significant economic benefits while addressing critical environmental issues pertaining to oil-gas production.

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

    PubMed

    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.

  18. Structural Optimization of Triboelectric Nanogenerator for Harvesting Water Wave Energy.

    PubMed

    Jiang, Tao; Zhang, Li Min; Chen, Xiangyu; Han, Chang Bao; Tang, Wei; Zhang, Chi; Xu, Liang; Wang, Zhong Lin

    2015-12-22

    Ocean waves are one of the most abundant energy sources on earth, but harvesting such energy is rather challenging due to various limitations of current technologies. Recently, networks formed by triboelectric nanogenerator (TENG) have been proposed as a promising technology for harvesting water wave energy. In this work, a basic unit for the TENG network was studied and optimized, which has a box structure composed of walls made of TENG composed of a wavy-structured Cu-Kapton-Cu film and two FEP thin films, with a metal ball enclosed inside. By combination of the theoretical calculations and experimental studies, the output performances of the TENG unit were investigated for various structural parameters, such as the size, mass, or number of the metal balls. From the viewpoint of theory, the output characteristics of TENG during its collision with the ball were numerically calculated by the finite element method and interpolation method, and there exists an optimum ball size or mass to reach maximized output power and electric energy. Moreover, the theoretical results were well verified by the experimental tests. The present work could provide guidance for structural optimization of wavy-structured TENGs for effectively harvesting water wave energy toward the dream of large-scale blue energy.

  19. Semi-Arid Water Resource Challenges - Can Water Harvesting Close the Gap?

    NASA Astrophysics Data System (ADS)

    Meixner, T.; Niraula, R.; Norman, L.; Pivo, G.; Gerlak, A.; Pavao-Zuckerman, M.; Henry, A.

    2015-12-01

    Water resource availability restricts development in arid and semi-arid regions of world. Past observations show that urban areas can increase stream discharge at least on a local scale. These results suggest that urbanization may increase the availability of wet water capable of being used by urban society. Here we present a combination of observational work demonstrating the increase of available water in urban areas of southern Arizona; and a modelling study demonstrating that future land use change may significantly increase river discharge across the Santa Cruz watershed which is ~12% urban. The observational data comes from over 30 watersheds varying in cover from undeveloped to highly urban and in spatial scale from a few square meters to thousands of square kilometers. The modelling study includes a conservation (~35% urban), megalopolitan (~34% urban) and business as usual scenario (~38% urban) for land use change due to regional population growth. All land use change scenarios result in significant increases in watershed streamflow. Depending upon pattern of urbanization, streamflow increased as much 88% in some watershed locations; demonstrating the potential to partially meet water resources demands in the region with water produced by the urbanization process. This water could be used regionally or locally, and significant efforts at implementing water harvesting in the region have been pursued. However, the ability to scale such implementation and overcome the physical, and social barriers to implementation are currently unquantified.

  20. Potential Ambient Energy-Harvesting Sources and Techniques

    ERIC Educational Resources Information Center

    Yildiz, Faruk

    2009-01-01

    Ambient energy harvesting is also known as energy scavenging or power harvesting, and it is the process where energy is obtained from the environment. A variety of techniques are available for energy scavenging, including solar and wind powers, ocean waves, piezoelectricity, thermoelectricity, and physical motions. For example, some systems…

  1. Maintaining antioxidant potential of fresh fruits and vegetables after harvest.

    PubMed

    Villa-Rodriguez, Jose A; Palafox-Carlos, H; Yahia, Elhadi M; Ayala-Zavala, J Fernando; Gonzalez-Aguilar, Gustavo A

    2015-01-01

    The consumption of fruits and vegetables has increased in the past few years, not only because of their attractive sensorial properties, but also for their nutritional and health benefits. Antioxidants are compounds found in fresh fruits and vegetables, and evidence of their role in the prevention of degenerative diseases is continuously emerging. However, the antioxidants in some fruits and vegetables can be lost during handling after harvest, even during minimal processing and storage. In this sense, postharvest treatments are needed to preserve the quality and antioxidant potential of fresh produce. Postharvest treatments and technologic strategies (including ultraviolet light, controlled and modified atmospheres, heat treatments, and application of natural compounds, such as edible coatings, active packaging, microencapsulation, and nanoemulsion) have shown positive and promising results to maintain fruit and vegetable antioxidant potential. The purpose of this review is to analyze and propose the application of postharvest strategies to maintain, or even improve, the antioxidant status of fruits and vegetables, thus offering options to maximize health benefits to consumers.

  2. Effects of mechanical harvest plus chipping and prescribed fire on Sierran runoff water quality.

    PubMed

    Loupe, T M; Miller, W W; Johnson, D W; Sedinger, J S; Carroll, E M; Walker, R F; Murphy, J D; Stein, C M

    2009-01-01

    Fire suppression in Sierran ecosystems creates a substantial wildfire hazard and may exacerbate nutrient inputs into Lake Tahoe by allowing the buildup of O horizon material, which serves as a source for high N and P concentrations in runoff water. The purpose of this study was to evaluate the effects of biomass reduction using cut-to-length mechanical harvest followed by chipping and controlled burning on surface runoff volume and water quality. Based on previous findings regarding N and P leaching flux and soil solution concentrations, we hypothesized that controlled burning and/or mechanical harvest with residue chipping does not increase inorganic N, P, and S concentrations in overland flow. Runoff, snowmelt, and rainfall were collected, volume measurements were taken, and samples were analyzed for NO(3)-N, NH(4)-N, PO(4)-P, and SO(4). Runoff volume, season, and year were identified as important parameters influencing overland flow nutrient concentrations and loads. Higher nutrient concentrations were commonly associated with summer rather than winter runoff, but the opposite was true for nutrient loads due to the higher runoff volumes. Treatment (unharvested, harvested, unburned, burned) effect was a strong predictor for discharge loads of NO(3)-N and SO(4) but was a weak predictor for PO(4)-P. Discharge loads of NO(3)-N and SO(4) were greater for the unburned harvested and the burned unharvested treatments than for the unburned, unharvested control sites or the burned and harvested combined treatment. Although mechanical harvest and/or controlled burning had a small initial impact on increased nutrient loading, the effects were minimal compared with background levels. Hence, these management practices may have the potential to improve forest health without the danger of large-magnitude nutrient mobilization and degradation of runoff water quality found with wildfire.

  3. Water harvest- and storage- location assessment model using GIS and remote sensing

    NASA Astrophysics Data System (ADS)

    Weerasinghe, H.; Schneider, U. A.; Löw, A.

    2011-04-01

    This study describes a globally applicable method to determine the local suitability to implement water supply management strategies within the context of a river catchment. We apply this method, and develop a spatial analysis model named Geographic Water Management Potential (GWAMP). We retrieve input data from global data repositories and rescale these data to 1km spatial resolution to obtain a set of manageable input data. Potential runoff is calculated as an intermediate input using the Soil Conservation Service Curve Number (SCS-CN) equation. Multi Criteria Evaluation techniques are used to determine the suitability levels and relative importance of input parameters for water supply management. Accordingly, the model identifies, potential water harvesting- and storage sites for on-farm water storage, regional dams, and soil moisture conservation. We apply the model to two case-study locations, the Sao-Francisco and Nile catchments, which differ in their geographic and climatic conditions. The model results are validated against existing data on hydrologic networks, reservoir capacities and runoff. On average, GWAMP predictions of sites with high rain water storage suitability correlate well (83%) with the locations of existing regional dams and farm tanks. According to the results from testing and validation of the GWAMP we point out that the GWAMP can be used identify potential sites for rain water harvesting and storage technologies in a given catchment.

  4. Comparison of the microbiological and chemical characterization of harvested rainwater and reservoir water as alternative water resources.

    PubMed

    Lee, Ju Young; Yang, Jung-Seok; Han, Mooyoung; Choi, Jaeyoung

    2010-01-15

    Rainwater harvesting (RWH) offers considerable potential as an alternative water supply. In this study, all of the harvested rainwater samples met the requirements for grey water but not for drinking water. In terms of microbiological parameters, total coliform (TC) and Escherichia coli (EC) were measured in 91.6% and 72%, respectively, of harvested rainwater samples at levels exceeding the guidelines for drinking water, consistent with rainfall events. In the case of the reservoir water samples, TC and EC were detected in 94.4% and 85.2%, respectively, of the samples at levels exceeding the guidelines for drinking water. Both indicators gradually increased in summer and fall. The highest median values of both TC and EC were detected during the fall. Chemical parameters such as common anions and major cations as well as metal ions in harvested rainwater were within the acceptable ranges for drinking water. By contrast, Al shows a notable increase to over 200mugL(-1) in the spring due to the intense periodic dust storms that can pass over the Gobi Desert in northern China. In terms of statistical analysis, the harvested rainwater quality showed that TC and EC exhibit high positive correlations with NO(3)(-) (rho(TC)=0.786 and rho(EC)=0.42) and PO(4)(-) (rho(TC)=0.646 and rho(EC)=0.653), which originally derive from catchment contamination, but strong negative correlations with Cl(-) (rho(TC)=-0.688 and rho(EC)=-0.484) and Na(+) (rho(TC)=-0.469 and rho(EC)=-0.418), which originate from seawater.

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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.

  7. Water harvesting using a conducting polymer: A study by molecular dynamics simulation

    SciTech Connect

    Ostwal, Mayur M.; Sahimi, Muhammad; Tsotsis, Theodore T.

    2009-06-15

    The results of extensive molecular simulations of adsorption and diffusion of water vapor in polyaniline, made conducting by doping it with HCl or HBr over a broad range of temperatures, are reported. The atomistic model of the polymers was generated using energy minimization, equilibrium molecular dynamics simulations, and two different force fields. The computed sorption isotherms are in excellent agreement with the experimental data. The computed activation energies for the diffusion of water molecules in the polymers also compare well with what has been reported in the literature. The results demonstrate the potential of conducting polyaniline for water harvesting from air.

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:24701186

  10. The water factor in harvest-sprouting of hard red spring wheat

    NASA Technical Reports Server (NTRS)

    Bauer, A.; Black, A. L. (Principal Investigator)

    1983-01-01

    Sprouting in unthreshed, ripe, hard red spring wheat (Triticum aestivum L.) is induced by rain, but sprouting does not necessarily occur because the crop is wetted. The spike and grain water conditions conducive to sprouting were determined in a series of laboratory experiments. Sprouting did not occur in field growing wheat wetted to 110% water concentration until the spike water concentration was reduced to 12% and maintained at this concentration for 2 days before wetting. When cut at growth stage 11.3, Feekes scale, Saratovskaya 20 (USSR) sprouted after 4 days drying, Olaf and Alex between 7 and 15 days drying and Columbus, recognized for its resistance to harvest time sprouting, after more than 15 days drying. Sprouting potential was enhanced after 4 wetting drying cycles in which any wetted interval was too brief to permit sufficient water imbibition to initiate sprouting. At harvest ripeness, grain water concentration exceeded spike water concentration by 0.7 percentage units. Following 6 months storage, 20% of the kernels in 300 spike bundles (simulating windrows) sprouted within 28 hrs after initiation of wetting to saturation (150% water concentration). Ninety percent sprouting occurred within 8 days in bundles maintained at 75% water concentration and higher, but less sprouting occurred in bundles dried to 50% water concentration before resaturation.

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

    PubMed

    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.

  12. Suspended onion particles and potential corneal injury in onion harvesters.

    PubMed

    Hwang, Yaw-Huei; Chou, En-Ju; Chang, Ching-Wen; Chen, Chih-Chieh; Ho, Chi-Kung; Chou, Chih-Liang; Lee, Zhih-Young; Tseng, Chi-Ting

    2002-01-01

    The authors suspected that suspended onion particles contributed to corneal ulcers in onion harvesters in southern Taiwan. In the present study, the authors used manikins to study suspended onion particles in fields in an effort to simulate typical conditions experienced by onion harvesters. An animal eye-exposure simulation study was also performed by the authors, who impacted suspended soil grains or onion particles onto the corneas of guinea pigs via aerosol generated from the Palas dispersion nozzle. The average size of 25.9 pm for suspended particles collected during the digging of onions was the largest one of those for various harvesting activities. Some onion skin flakes were found in samples obtained from gathering and packing activities; the typical flake size was approximately 3.5 x 2.5 mm2. The results of the animal study indicated that the size of soil grains has a demonstrable effect on the severity of corneal injury (p = .009). With respect to onion skin flakes, wind velocity was also associated significantly with the occurrence of corneal injury (p = .0004). A wind velocity threshold of 7 m/sec is recommended for the maintenance of safety, and if the wind speed exceeds this threshold level, workers should not engage in harvesting activities. Furthermore, use of appropriately designed goggles is necessary for the protection of onion harvesters who work in high-wind conditions.

  13. Improving crop yield and water productivity by ecological sanitation and water harvesting in South Africa.

    PubMed

    Andersson, Jafet C M; Zehnder, Alexander J B; Wehrli, Bernhard; Jewitt, Graham P W; Abbaspour, Karim C; Yang, Hong

    2013-05-07

    This study quantifies the potential effects of a set of technologies to address water and fertility constraints in rain-fed smallholder agriculture in South Africa, namely in situ water harvesting (WH), external WH, and ecological sanitation (Ecosan, fertilization with human urine). We used the Soil and Water Assessment Tool to model spatiotemporally differentiated effects on maize yield, river flow, evaporation, and transpiration. Ecosan met some of the plant nitrogen demands, which significantly increased maize yields by 12% and transpiration by 2% on average across South Africa. In situ and external WH did not significantly affect the yield, transpiration or river flow on the South Africa scale. However, external WH more than doubled the yields for specific seasons and locations. WH particularly increased the lowest yields. Significant water and nutrient demands remained even with WH and Ecosan management. Additional fertility enhancements raised the yield levels but also the yield variability, whereas soil moisture enhancements improved the yield stability. Hence, coupled policies addressing both constraints will likely be most effective for improving food security.

  14. Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating

    PubMed Central

    Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-01-01

    Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system. PMID:25765205

  15. Relative performance of a vibratory energy harvester in mono- and bi-stable potentials

    NASA Astrophysics Data System (ADS)

    Masana, Ravindra; Daqaq, Mohammed F.

    2011-11-01

    Motivated by the need for broadband vibratory energy harvesting, many research studies have recently proposed energy harvesters with nonlinear characteristics. Based on the shape of their potential function, such devices are classified as either mono- or bi-stable energy harvesters. This paper aims to investigate the relative performance of these two classes under similar excitations and electric loading conditions. To achieve this goal, an energy harvester consisting of a clamped-clamped piezoelectric beam bi-morph is considered. The shape of the harvester's potential function is altered by applying a static compressive axial load at one end of the beam. This permits operation in the mono-stable (pre-buckling) and bi-stable (post-buckling) configurations. For the purpose of performance comparison, the axial load is used to tune the harvester's oscillation frequencies around the static equilibria such that they have equal values in the mono- and bi-stable configurations. The harvester is subjected to harmonic base excitations of different magnitudes and a slowly varying frequency spanning a wide band around the tuned oscillation frequency. The output voltage measured across a purely resistive load is compared over the frequency range considered. Two cases are discussed; the first compares the performance when the bi-stable harvester has deep potential wells, while the second treats a bi-stable harvester with shallow wells. Both numerical and experimental results demonstrate the essential role that the potential shape plays in conjunction with the base acceleration to determine whether the bi-stable harvester can outperform the mono-stable one and for what range of frequencies. Results also illustrate that, for a bi-stable harvester with shallow potential wells, super-harmonic resonances can activate the inter-well dynamics even for a small base acceleration, thereby producing large voltages in the low frequency range.

  16. Potential soil quality impact of harvesting crop residues for biofuels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Humankind is in the midst of one of the greatest technological, environmental and social transitions since the industrial revolution, as we strive to replace fossil energy with renewable biomass resources. This presentation will (1) briefly review increased public interest in harvesting crop residue...

  17. Harvesting broadband kinetic impact energy from mechanical triggering/vibration and water waves.

    PubMed

    Wen, Xiaonan; Yang, Weiqing; Jing, Qingshen; Wang, Zhong Lin

    2014-07-22

    We invented a triboelectric nanogenerator (TENG) that is based on a wavy-structured Cu-Kapton-Cu film sandwiched between two flat nanostructured PTFE films for harvesting energy due to mechanical vibration/impacting/compressing using the triboelectrification effect. This structure design allows the TENG to be self-restorable after impact without the use of extra springs and converts direct impact into lateral sliding, which is proved to be a much more efficient friction mode for energy harvesting. The working mechanism has been elaborated using the capacitor model and finite-element simulation. Vibrational energy from 5 to 500 Hz has been harvested, and the generator's resonance frequency was determined to be ∼100 Hz at a broad full width at half-maximum of over 100 Hz, producing an open-circuit voltage of up to 72 V, a short-circuit current of up to 32 μA, and a peak power density of 0.4 W/m(2). Most importantly, the wavy structure of the TENG can be easily packaged for harvesting the impact energy from water waves, clearly establishing the principle for ocean wave energy harvesting. Considering the advantages of TENGs, such as cost-effectiveness, light weight, and easy scalability, this approach might open the possibility for obtaining green and sustainable energy from the ocean using nanostructured materials. Lastly, different ways of agitating water were studied to trigger the packaged TENG. By analyzing the output signals and their corresponding fast Fourier transform spectra, three ways of agitation were evidently distinguished from each other, demonstrating the potential of the TENG for hydrological analysis.

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

    PubMed

    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.

  19. Conservation of water for washing beef heads at harvest.

    PubMed

    DeOtte, R E; Spivey, K S; Galloway, H O; Lawrence, T E

    2010-03-01

    The objective of this research was to develop methods to conserve water necessary to cleanse beef heads prior to USDA-FSIS inspection. This was to be accomplished by establishing a baseline for the minimum amount of water necessary to adequately wash a head and application of image analysis to provide an objective measure of head cleaning. Twenty-one beef heads were manually washed during the harvest process. An average 18.75 L (2.49 SD) and a maximum of 23.88 L were required to cleanse the heads to USDA-FSIS standards. Digital images were captured before and after manual washing then evaluated for percentage red saturation using commercially available image analysis software. A decaying exponential curve extracted from these data indicated that as wash water increased beyond 20 L the impact on red saturation decreased. At 4 sigma from the mean of 18.75 L, red saturation is 16.0 percent, at which logistic regression analysis indicates 99.994 percent of heads would be accepted for inspection, or less than 1 head in 15,000 would be rejected. Reducing to 3 sigma would increase red saturation to 27.6 percent, for which 99.730 percent of heads likely would be accepted (less than 1 in 370 would be rejected).

  20. Potential of light-harvesting proton pumps for bioenergy applications.

    PubMed

    Walter, Jessica M; Greenfield, Derek; Liphardt, Jan

    2010-06-01

    Concerns about the security and longevity of traditional energy sources have increased interest in alternative methods of energy production, particularly those which utilize abundantly available solar energy. Solar energy can be harvested either indirectly through the conversion of plant or algal byproducts into biofuels or directly using engineered microorganisms. Here we summarize the main features of light-harvesting proton pumps, which may provide a relatively simple way to boost the efficiency of energy-limited biological processes in fuel production. This family of proton pumps, which includes bacteriorhodopsin and proteorhodopsin, directly uses light energy to create a proton motive force (pmf) which can be used by other enzymes to facilitate active transport, regulate transmembrane proteins, or to generate ATP and NADH.

  1. Can macrophyte harvesting from eutrophic water close the loop on nutrient loss from agricultural land?

    PubMed

    Quilliam, Richard S; van Niekerk, Melanie A; Chadwick, David R; Cross, Paul; Hanley, Nick; Jones, Davey L; Vinten, Andy J A; Willby, Nigel; Oliver, David M

    2015-04-01

    Eutrophication is a major water pollution issue and can lead to excessive growth of aquatic plant biomass (APB). However, the assimilation of nutrients into APB provides a significant target for their recovery and reuse, and harvesting problematic APB in impacted freshwater bodies offers a complementary approach to aquatic restoration, which could potentially deliver multiple wider ecosystem benefits. This critical review provides an assessment of opportunities and risks linked to nutrient recovery from agriculturally impacted water-bodies through the harvesting of APB for recycling and reuse as fertilisers and soil amendments. By evaluating the economic, social, environmental and health-related dimensions of this resource recovery from 'waste' process we propose a research agenda for closing the loop on nutrient transfer from land to water. We identify that environmental benefits are rarely, if ever, prioritised as essential criteria for the exploitation of resources from waste and yet this is key for addressing the current imbalance that sees environmental managers routinely undervaluing the wider environmental benefits that may accrue beyond resource recovery. The approach we advocate for the recycling of 'waste' APB nutrients is to couple the remediation of eutrophic waters with the sustainable production of feed and fertiliser, whilst providing multiple downstream benefits and minimising environmental trade-offs. This integrated 'ecosystem services approach' has the potential to holistically close the loop on agricultural nutrient loss, and thus sustainably recover finite resources such as phosphorus from waste.

  2. The Potential for Harvesting Energy from the Movement of Trees

    PubMed Central

    McGarry, Scott; Knight, Chris

    2011-01-01

    Over the last decade, wireless devices have decreased in size and power requirements. These devices generally use batteries as a power source but can employ additional means of power, such as solar, thermal or wind energy. However, sensor networks are often deployed in conditions of minimal lighting and thermal gradient such as densely wooded environments, where even normal wind energy harvesting is limited. In these cases a possible source of energy is from the motion of the trees themselves. We investigated the amount of energy and power available from the motion of a tree in a sheltered position, during Beaufort 4 winds. We measured the work performed by the tree to lift a mass, we measured horizontal acceleration of free movement, and we determined the angular deflection of the movement of the tree trunk, to determine the energy and power available to various types of harvesting devices. We found that the amount of power available from the tree, as demonstrated by lifting a mass, compares favourably with the power required to run a wireless sensor node. PMID:22163695

  3. The potential for harvesting energy from the movement of trees.

    PubMed

    McGarry, Scott; Knight, Chris

    2011-01-01

    Over the last decade, wireless devices have decreased in size and power requirements. These devices generally use batteries as a power source but can employ additional means of power, such as solar, thermal or wind energy. However, sensor networks are often deployed in conditions of minimal lighting and thermal gradient such as densely wooded environments, where even normal wind energy harvesting is limited. In these cases a possible source of energy is from the motion of the trees themselves. We investigated the amount of energy and power available from the motion of a tree in a sheltered position, during Beaufort 4 winds. We measured the work performed by the tree to lift a mass, we measured horizontal acceleration of free movement, and we determined the angular deflection of the movement of the tree trunk, to determine the energy and power available to various types of harvesting devices. We found that the amount of power available from the tree, as demonstrated by lifting a mass, compares favourably with the power required to run a wireless sensor node.

  4. Non-resonant energy harvesting via an adaptive bistable potential

    NASA Astrophysics Data System (ADS)

    Haji Hosseinloo, Ashkan; Turitsyn, Konstantin

    2016-01-01

    Narrow bandwidth and easy detuning, inefficiency in broadband and non-stationary excitations, and difficulties in matching a linear harvester’s resonance frequency to low-frequency excitations at small scales, have convinced researchers to investigate nonlinear, and in particular bistable, energy harvesters in recent years. However, bistable harvesters suffer from co-existing low and high energy orbits, and sensitivity to initial conditions, and have recently been proven inefficient when subjected to many real-world random and non-stationary excitations. Here, we propose a novel non-resonant buy-low-sell-high strategy that can significantly improve the harvester’s effectiveness at low frequencies in a much more robust fashion. This strategy could be realized by a passive adaptive bistable system. Simulation results confirm the high effectiveness of the adaptive bistable system following a buy-low-sell-high logic when subjected to harmonic and random non-stationary walking excitations compared to its conventional bistable and linear counterparts.

  5. Feasibility studies for water harvesting from fog and atmospheric moisture in Hormozgan coastal zone (south of Iran)

    NASA Astrophysics Data System (ADS)

    Esfandiarnejad, A.; Ahangar, R.; Kamalian, U. R.; Sangchouli, T.

    2010-07-01

    The level of precipitation in the coastal towns & islands of the Hormozgan province is very low, but the relative humidity so high that wets the soil at below dew point temperatures and could therefore be utilized for relieving the water shortage, to some extents by employing water harvesting systems from fog & air moisture. The inhabitants of Qeshm Island have made efforts from the ancient times to collect air moisture along rainwater gathering. The reminders of these efforts are 366 small wells drilled in stone, which are now a tourist attraction. This method is also applied today in a less elaborate manner. This research has been carried out to study the feasibility of water harvesting from fog and air moisture in the coastal towns and islands of the Hormozgan province of Iran on the northern shores of the Persian Gulf. To examine the potential water in the atmosphere, the data from Bandar Abbass synoptic station with a statistical period of 1961-2005 was reviewed and the humidity values of over 70% and wind speed less than 5m/s were analyzed. The average water content of each cubic meter of air in Bandar Abbas in its most dry condition is 16.2g which amounts to 19.5g in its most humid state. The maximum water yield by applying this method could be harvested from 22 June until 22 September. The recorded data show that highest rate of moisture in each cubic meter of air occurred in 1961 while the highest extractable water potential was in 1995. Mentioning these facts, somehow indicate the importance of parameters effecting water harvesting such as wind speed and direction and the amount of moisture in the air. More details have been presented in the paper. Field observations and archeological artifacts approve the results obtained by the conducted estimations showing the feasibility of water harvesting from fog & air moisture in this region and its rates in the different seasons.

  6. 50 CFR 622.415 - Limited exemption regarding harvest in waters of a foreign nation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic... a vessel that has legally harvested spiny lobsters in the waters of a foreign nation and possesses spiny lobster, or separated tails, in the EEZ incidental to such foeign harvesting is exempt from...

  7. 50 CFR 622.415 - Limited exemption regarding harvest in waters of a foreign nation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic... a vessel that has legally harvested spiny lobsters in the waters of a foreign nation and possesses spiny lobster, or separated tails, in the EEZ incidental to such foeign harvesting is exempt from...

  8. Bioinspired Special Wettability Surfaces: From Fundamental Research to Water Harvesting Applications.

    PubMed

    Zhang, Songnan; Huang, Jianying; Chen, Zhong; Lai, Yuekun

    2017-01-01

    Nowadays, the pollution of water has become worse in many parts of the world, which causes a severe shortage of clean water and attracts widespread attention worldwide. Bioinspired from nature, i.e. spider silk, cactus, Namib desert beetle, Nepenthes alata, special wettability surfaces have attracted great interest from fundamental research to water-harvesting applications. Here, recently published literature about creatures possessing water-harvesting ability are reviewed, with a focus on the corresponding water-harvesting mechanisms of creatures in dry or arid regions, consisting of the theory of wetting and transporting. Then a detailed account of the innovative fabrication technologies and bionic water-harvesting materials with special wetting are summarized, i.e. bio-inspired artificial spider silk, bio-inspired artificial cactus-like structures, and bio-inspired artificial Namib desert beetle-like surfaces. Special attentions are paid to the discussion of the advantages and disadvantages of the technologies, as well as factors that affect the amount of water-harvesting. Finally, conclusions, future outlooks and the current challenges for future development of the water-harvesting technology are presented and discussed.

  9. Enhanced drinking water supply through harvested rainwater treatment

    NASA Astrophysics Data System (ADS)

    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.

  10. Economic feasibility analysis of water-harvesting techniques for mined-land reclamation

    SciTech Connect

    Nieves, L.A.; Marti, M.H.

    1981-07-01

    A water harvesting, agricultural production system, field tested as a means of reclaiming strip-mined land is described. Though the technical feasibility of the system is becoming increasingly apparent, economic feasibility and legal issues may determine its potential application. The purpose of this study is to explore the economic feasibility of the system and to provide information for use in assessing whether further investigation of water harvesting reclamation techniques is warranted. The economic feasibility of the PNL reclamation system hinges on whether its net benefits exceed those of conventional reclamation. This preliminary feasibility study assesses the net private benefits of each system using data for the Peabody Coal Company's Kayenta mine on the Black Mesa in Arizona. To compare the alternative reclamation systems, the present value of direct net benefits (income minus production and reclamation costs) is calculated for grazing (conventional reclamation) or for cropping (PNL reclamation). Three of the PNL system slope treatments have lower estimated total costs than conventional reclamation. The difference is $3895/acre for compacted slope, $3025/acre for salt-compacted slope and $2310/acre for crop-on-slope. These differences constitute a substantial cost advantage for the system on the basis of the present value of land reclamation and maintenance costs. The system also has advantages based on the estimated value of agricultural production capacity. Even the lowest yield levels considered for alfalfa, corn, and pinto beans had higher net present values than grazing.

  11. Modelling surface runoff and water productivity in small dryland watersheds with water-harvesting interventions, an application from Jordan

    NASA Astrophysics Data System (ADS)

    Bruggeman, A.; Akroush, S.; Mudabber, M.; Ziadat, F.; Oweis, T.

    2009-04-01

    Vast areas of the rangelands (badia) of West Asia and North Africa are severely degraded due to over-grazing, cutting of shrubs and ploughing. Because of the scarce vegetation cover and the often dense soil surface crust, a large part of the limited rainfall runs off to wadis or evaporates back to the atmosphere with little local benefit. To develop and evaluate techniques for rehabilitation of the degraded lands an integrated research project was implemented with two communities in the badia of Jordan. The average annual rainfall in the research area is approximately 150 mm/yr. The project tested different micro-catchment water-harvesting techniques (earthen dikes planted with fodder shrubs) to capture the runoff and improve plant survival and growth in the watersheds. To estimate the long-term benefits of these water-harvesting systems and to assist with watershed-level planning and design a model is needed. However, current models can not capture the spatially variable runoff and water-harvesting processes in these environments. The objective of the research was to develop a model for estimating the runoff and biomass production of small badia watersheds with and without water-harvesting interventions. The basic spatial unit of the model is a square grid cell. Each cell is assigned to a specific land use unit, based on the characteristics of the soil and surface that affect the runoff, infiltration, and biomass production potential of the land. The model computes infiltration and runoff for each cell from daily rainfall with a curvilinear equation, based on data from plot studies. The runoff is routed using a 10-m digital elevation model and can infiltrate in downstream cells. The water infiltrated in each cell is summed for the August-September hydrologic year; and the annual biomass production is computed based on the water productivity potential of the cell. The model was applied to a 119-ha watershed, where 11 ha of micro-catchments were implemented, using a

  12. Harvesting energy from a water flow through ionic polymer metal composites' buckling

    NASA Astrophysics Data System (ADS)

    Cellini, Filippo; Cha, Youngsu; Porfiri, Maurizio

    2014-03-01

    This study seeks to investigate the feasibility of energy harvesting from mechanical buckling of ionic polymer metal composites (IPMCs) induced by a steady fluid flow. In particular, we propose a harvesting device composed of a paddle wheel, a slider-crank mechanism, and two IPMCs clamped at both their ends. We test the system in a water tunnel to estimate the effects of the flow speed and the shunting resistance on power harvesting. The classical post-buckling theory of inextensible rods is utilized, in conjunction with a black-box model for IPMC sensing, to interpret experimental results.

  13. Life Cycle Assessment of Domestic and Agricultural Rainwater Harvesting Systems

    EPA Science Inventory

    To further understanding of the environmental implications of rainwater harvesting and its water savings potential relative to conventional U.S. water delivery infrastructure, we present a method to perform life cycle assessment of domestic rainwater harvesting (DRWH) and agricul...

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Recycling harvest water to cultivate Chlorella zofingiensis under nutrient limitation for biodiesel production.

    PubMed

    Zhu, L D; Takala, J; Hiltunen, E; Wang, Z M

    2013-09-01

    Harvest water recycling for Chlorella zofingiensis re-cultivation under nutrient limitation was investigated. Using 100% harvest water, four cultures were prepared: Full medium, P-limited medium, N-limited medium and N- and P-limited medium, while another full medium was also prepared using 50% harvest water. The results showed that the specific growth rate and biomass productivity ranged from 0.289 to 0.403 day(-1) and 86.30 to 266.66 mg L(-1) day(-1), respectively. Nutrient-limited cultures witnessed much higher lipid content (41.21-46.21% of dry weight) than nutrient-full cultures (26% of dry weight). The N- and P-limited medium observed the highest FAME yield at 10.95% of dry weight, while the N-limited culture and P-limited culture shared the highest biodiesel productivity at 20.66 and 19.91 mg L(-1) day(-1), respectively. The experiment on harvest water recycling times demonstrated that 100% of the harvest water could be recycled twice with the addition of sufficient nutrients.

  16. Effects of seedbed preparation, irrigation, and water harvesting on seedling emergence at the Nevada Test Site

    SciTech Connect

    Winkel, V.K.; Ostler, W.K.; Gabbert, W.D.; Lyon, G.E.

    1993-10-01

    Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with plutonium. As part of a cleanup effort, both the indigenous vegetation and the top 5--10 cm of soil may be removed, and the soil may or may not be replaced. Technologies must be developed to stabilize and revegetate these lands. A study was developed to determine adaptable plant species, methods to prepare seedbeds for direct seeding and water harvesting, and proper irrigation rates. Plots were cleared of indigenous vegetation, and then prepared with various seedbed/water harvesting treatments including, pitting, land imprinting, and mulching. Other plots were treated with large water harvesting structures. Three irrigation treatments were superimposed over the seedbed/water harvesting treatments. Seedling emergence data was collected, and the treatment combinations compared. Supporting meteorological and soil data were collected with an automatic data-logger. Specific data included soil water data from all treatment combinations, precipitation, and air temperature. Irrigation did extend the period of available water approximately two to three weeks, but in a year of above average precipitation, this extension did not generally aid germination and emergence of seeded species, and only slightly increased densities of species from the native seedbank. With the exception of increased shrub seedling densities in desert strips, there were no strong seedbed preparation/water harvesting treatment effects. In years of above-average rainfall, mulching and water harvesting treatments, and irrigation may not be necessary to insure adequate germination and emergence of adapted perennial grasses, forbs, and shrubs in the Mojave/Great Basin Transition Desert.

  17. Effects of seedbed preparation, irrigation, and water harvesting of seedling emergence at the Nevada Test Site

    SciTech Connect

    Winkel, V.K.; Ostler, W.K.; Gabbert, W.D.; Lyon, G.E.

    1994-02-01

    Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with plutonium. As part of a cleanup effort, both the indigenous vegetation and the top 5--10 cm of soil may be removed, and the soil may or may not be replaced. Technologies must be developed to stabilize and revegetate these lands. A study was developed to determine adaptable plant species, methods to prepare seedbeds for direct seeding and water harvesting, and proper irrigation rates. Plots were cleared of indigenous vegetation, and then prepared with various seedbed/water harvesting treatments including, pitting, land imprinting, and mulching. Other plots were treated with large water harvesting structures. Three irrigation treatments were superimposed over the seedbed/water harvesting treatments. Seedling emergence data was collected, and the treatment combinations compared. Supporting meteorological and soil data were collected with an automatic data-logger. Specific data included precipitation, and air temperature. In a year of above-average precipitation, irrigation did not generally aid germination and emergence of seeded species, and only slightly increased densities of species from the native seedbank. With the exception of increased shrub seedling densities in desert strips, there were no strong seedbed preparation/water harvesting treatment effects. In years of above-average rainfall, mulching and water harvesting treatments, irrigation may not be necessary to insure adequate germination and emergence of adapted perennial grasses, forbs, and shrubs in the Mojave/Great Basin Transition Desert. Future collection of survival data will determine whether a maintenance irrigation program is necessary to ensure establishmnent of native plants.

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

    PubMed

    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.

  19. Potential impact of harvesting on the population dynamics of two epiphytic bromeliads

    NASA Astrophysics Data System (ADS)

    Toledo-Aceves, Tarin; Hernández-Apolinar, Mariana; Valverde, Teresa

    2014-08-01

    Large numbers of epiphytes are extracted from cloud forests for ornamental use and illegal trade in Latin America. We examined the potential effects of different harvesting regimes on the population dynamics of the epiphytic bromeliads Tillandsia multicaulis and Tillandsia punctulata. The population dynamics of these species were studied over a 2-year period in a tropical montane cloud forest in Veracruz, Mexico. Prospective and retrospective analyses were used to identify which demographic processes and life-cycle stages make the largest relative contribution to variation in population growth rate (λ). The effect of simulated harvesting levels on population growth rates was analysed for both species. λ of both populations was highly influenced by survival (stasis), to a lesser extent by growth, and only slightly by fecundity. Vegetative growth played a central role in the population dynamics of these organisms. The λ value of the studied populations did not differ significantly from unity: T. multicaulis λ (95% confidence interval) = 0.982 (0.897-1.060) and T. punctulata λ = 0.967 (0.815-1.051), suggesting population stability. However, numerical simulation of different levels of extraction showed that λ would drop substantially even under very low (2%) harvesting levels. Matrix analysis revealed that T. multicaulis and T. punctulata populations are likely to decline and therefore commercial harvesting would be unsustainable. Based on these findings, management recommendations are outlined.

  20. A literature based study of stormwater harvesting as a new water resource.

    PubMed

    Hamdan, Sami M

    2009-01-01

    Rainwater harvesting is an important new water resource that participates in bridging the deficit in the water resources in water scarce countries. It is not a new technology but it has been practiced in many countries for many years. From a quantitative point of view it makes a positive contribution to the water resources balance. However, the quality of this new water resource was under the subject of this study in addition to the historical and international experiences carried out in stormwater management. Rainwater harvested from rooftops was noted to be much cleaner than that coming from urban stormwater runoff. The water quality parameters in stormwater were examined with a focus on heavy metals such as Cd, Zn, Pb and Cu which are released in low pH values. Fortunately, heavy metals like other ionic bounds and metal oxide bounds are removed by precipitation or co-precipitation at high values of pH.

  1. Influence of combined fundamental potentials in a nonlinear vibration energy harvester

    PubMed Central

    Podder, Pranay; Mallick, Dhiman; Amann, Andreas; Roy, Saibal

    2016-01-01

    Ambient mechanical vibrations have emerged as a viable energy source for low-power wireless sensor nodes aiming the upcoming era of the ‘Internet of Things’. Recently, purposefully induced dynamical nonlinearities have been exploited to widen the frequency spectrum of vibration energy harvesters. Here we investigate some critical inconsistencies between the theoretical formulation and applications of the bistable Duffing nonlinearity in vibration energy harvesting. A novel nonlinear vibration energy harvesting device with the capability to switch amidst individually tunable bistable-quadratic, monostable-quartic and bistable-quartic potentials has been designed and characterized. Our study highlights the fundamentally different large deflection behaviors of the theoretical bistable-quartic Duffing oscillator and the experimentally adapted bistable-quadratic systems, and underlines their implications in the respective spectral responses. The results suggest enhanced performance in the bistable-quartic potential in comparison to others, primarily due to lower potential barrier and higher restoring forces facilitating large amplitude inter-well motion at relatively lower accelerations. PMID:27874033

  2. Influence of combined fundamental potentials in a nonlinear vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Podder, Pranay; Mallick, Dhiman; Amann, Andreas; Roy, Saibal

    2016-11-01

    Ambient mechanical vibrations have emerged as a viable energy source for low-power wireless sensor nodes aiming the upcoming era of the ‘Internet of Things’. Recently, purposefully induced dynamical nonlinearities have been exploited to widen the frequency spectrum of vibration energy harvesters. Here we investigate some critical inconsistencies between the theoretical formulation and applications of the bistable Duffing nonlinearity in vibration energy harvesting. A novel nonlinear vibration energy harvesting device with the capability to switch amidst individually tunable bistable-quadratic, monostable-quartic and bistable-quartic potentials has been designed and characterized. Our study highlights the fundamentally different large deflection behaviors of the theoretical bistable-quartic Duffing oscillator and the experimentally adapted bistable-quadratic systems, and underlines their implications in the respective spectral responses. The results suggest enhanced performance in the bistable-quartic potential in comparison to others, primarily due to lower potential barrier and higher restoring forces facilitating large amplitude inter-well motion at relatively lower accelerations.

  3. Conservation of water for washing beef heads at harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to develop methods to conserve water necessary to cleanse beef heads prior to USDA–FSIS inspection. This was to be accomplished by establishing a baseline for the minimum amount of water necessary to adequately wash a head and application of image analysis to provi...

  4. Pine straw harvesting effects on water content of a forest soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study addresses concerns that harvesting pine straw from forests may decrease timber productivity by accelerating evaporation of soil water. Pine needles that accumulate on the forest floor help to conserve soil moisture, protect the soil surface against erosion, moderate soil temperature, inh...

  5. Water quality in hybrid catfish ponds after partial fish harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensification of United States catfish aquaculture involves hybrid catfish ('channel catfish Ictalurus punctatus x ' blue catfish I. furcatus) grown in ponds with abundant aeration and high feeding rates. High feeding rates cause water quality deterioration because most of the nitrogen, phosphorus...

  6. Harvesting river water through small dams promote positive environmental impact.

    PubMed

    Agoramoorthy, Govindasamy; Chaudhary, Sunita; Chinnasamy, Pennan; Hsu, Minna J

    2016-11-01

    While deliberations relating to negative consequences of large dams on the environment continue to dominate world attention, positive benefits provided by small dams, also known as check dams, go unobserved. Besides, little is known about the potential of check dams in mitigating global warming impacts due to less data availability. Small dams are usually commissioned to private contractors who do not have clear mandate from their employers to post their work online for public scrutiny. As a result, statistics on the design, cost, and materials used to build check dams are not available in public domain. However, this review paper presents data for the first time on the often ignored potential of check dams mitigating climate-induced hydrological threats. We hope that the scientific analysis presented in this paper will promote further research on check dams worldwide to better comprehend their eco-friendly significance serving society.

  7. Fundamental measure theory for the electric double layer: implications for blue-energy harvesting and water desalination

    NASA Astrophysics Data System (ADS)

    Härtel, Andreas; Janssen, Mathijs; Samin, Sela; van Roij, René

    2015-05-01

    Capacitive mixing (CAPMIX) and capacitive deionization (CDI) are promising candidates for harvesting clean, renewable energy and for the energy efficient production of potable water, respectively. Both CAPMIX and CDI involve water-immersed porous carbon (supercapacitors) electrodes at voltages of the order of hundreds of millivolts, such that counter-ionic packing is important for the electric double layer (EDL) which forms near the surfaces of these porous materials. Thus, we propose a density functional theory (DFT) to model the EDL, where the White-Bear mark II fundamental measure theory functional is combined with a mean-field Coulombic and a mean spherical approximation-type correction to describe the interplay between dense packing and electrostatics, in good agreement with molecular dynamics simulations. We discuss the concentration-dependent potential rise due to changes in the chemical potential in capacitors in the context of an over-ideal theoretical description and its impact on energy harvesting and water desalination. Compared to less elaborate mean-field models our DFT calculations reveal a higher work output for blue-energy cycles and a higher energy demand for desalination cycles.

  8. Potential effect of atmospheric warming on grapevine phenology and post-harvest heat accumulation across a range of climates

    NASA Astrophysics Data System (ADS)

    Hall, Andrew; Mathews, Adam J.; Holzapfel, Bruno P.

    2016-09-01

    Carbohydrates are accumulated within the perennial structure of grapevines when their production exceeds the requirements of reproduction and growth. The period between harvest and leaf-fall (the post-harvest period) is a key period for carbohydrate accumulation in relatively warmer grape-growing regions. The level of carbohydrate reserves available for utilisation in the following season has an important effect on canopy growth and yield potential and is therefore an important consideration in vineyard management. In a warming climate, the post-harvest period is lengthening and becoming warmer, evidenced through studies in wine regions worldwide that have correlated recent air temperature increases with changing grapevine phenology. Budbreak, flowering, veraison, and harvest have all been observed to be occurring earlier than in previous decades. Additionally, the final stage of the grapevine phenological cycle, leaf-fall, occurs later. This study explored the potential for increased post-harvest carbohydrate accumulation by modelling heat accumulation following harvest dates for the recent climate (1975-2004) and two warmer climate projections with mean temperature anomalies of +1.26 and +2.61 °C. Summaries of post-harvest heat accumulation between harvest and leaf-fall were produced for each of Australia's Geographical Indications (wine regions) to provide comparisons from the base temperatures to projected warmer conditions across a range of climates. The results indicate that for warmer conditions, all regions observe earlier occurring budbreak and harvest as well as increasing post-harvest growing degree days accumulation before leaf-fall. The level of increase varies depending upon starting climatic condition, with cooler regions experiencing the greatest change.

  9. Assessment of water quality of first-flush roof runoff and harvested rainwater

    NASA Astrophysics Data System (ADS)

    Gikas, Georgios D.; Tsihrintzis, Vassilios A.

    2012-10-01

    SummarySix pilot rainwater harvesting systems were installed in five urban, suburban and rural houses, and on a university campus. The systems consist of horizontal gutters to collect roof drainage, and downdrains which end into one or two plastic storage tanks. Devices were also provided to remove first-flush water. Water quality was monitored in the storage tanks and the first-flush devices during the 2-year period from October 2006 to November 2008. Water samples were collected at a frequency of once every 10 days, and analyzed according to potable water specifications to determine major anions (e.g., SO42-, NO3-, NO2-, F-, Cl-) and cations (e.g., NH4+, Na+, K+, Ca2+, Mg2+), total suspended solids, alkalinity, total phosphorus and microbiological indicators (e.g., total coliforms, Escherichia coli, Streptococcus, Clostridium perfrigens, Pseudomonas syringae and total viable counts at 22 °C and 37 °C). Furthermore, temperature, pH, dissolved oxygen and electrical conductivity were measured in situ. The mean concentrations of chemical parameters in harvested rainwater (with the exception of NH4+) were below the limits set by the 98/93/EU directive for drinking water. Total coliforms were detected in 84.4-95.8% of the collected rainwater samples in the six tanks. E. coli, Streptococcus, C. perfrigens, P. syringae and total viable counts at 22 °C and 37 °C were found at low counts in samples of collected rainwater. The collected rainwater quality was found satisfactory regarding its physicochemical parameters, but not regarding its sanitary quality. Therefore, rainwater harvesting systems in this area could only supply water appropriate for use as gray water.

  10. Energy Autonomous Wireless Water Meter with Integrated Turbine Driven Energy Harvester

    NASA Astrophysics Data System (ADS)

    Becker, P.; Folkmer, B.; Goepfert, R.; Hoffmann, D.; Willmann, A.; Manoli, Y.

    2013-12-01

    Accurate meter reading is the fundamental task of the home water system for the handling of payments. Meters need to be read correctly, to avoid an effect of adding events that increase unnecessary cost and create customer dissatisfaction. This paper presents a fully integrated wireless, energy autonomous water metering system based on the European Standard EN 13757 "Communication systems for meters and remote reading of meters". The system can be used in multiple water metering scenarios. No maintenance will be required and the system will provide precise and secure data transmission as well as timely and accurate recording of the consumption of water. The identification of any leakages will be improved through the analysis of the actual quantity supplied and recorded by the meters. The system is powered by an energy harvester, based on a water driven turbine wheel that is directly coupled to an electromagnetic energy transducer. The power delivered by the generator is dependent of the amount of flowing water and the pressure in the water pipes. Therefor the power is commonly non-continuous, fluctuant and unstable in the voltage amplitude. To be able to report the meter readings at all times, the system needs to be powered not only in times when the energy harvester delivers energy. Therefor an energy buffer, that stores the harvested energy, is installed to compensate the energy requirement between the actual generator output and the energy consumption of the application. Besides a complete system overview, the presentation will focus on the power management and energy aware battery charging circuitry. The design, fabrication, measuring results and the preparations for field tests in rural and urban environment will be presented and discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Highly efficient nonradiative energy transfer mediated light harvesting in water using aqueous CdTe quantum dot antennas.

    PubMed

    Mutlugun, Evren; Samarskaya, Olga; Ozel, Tuncay; Cicek, Neslihan; Gaponik, Nikolai; Eychmüller, Alexander; Demir, Hilmi Volkan

    2010-05-10

    We present light harvesting of aqueous colloidal quantum dots to nonradiatively transfer their excitonic excitation energy efficiently to dye molecules in water, without requiring ligand exchange. These as-synthesized CdTe quantum dots that are used as donors to serve as light-harvesting antennas are carefully optimized to match the electronic structure of Rhodamine B molecules used as acceptors for light harvesting in aqueous medium. By varying the acceptor to donor concentration ratio, we measure the light harvesting factor, along with substantial lifetime modifications of these water-soluble quantum dots, from 25.3 ns to 7.2 ns as a result of their energy transfer with efficiency levels up to 86%. Such nonradiative energy transfer mediated light harvesting in aqueous medium holds great promise for future quantum dot multiplexed dye biodetection systems.

  13. Quantifying health improvements from water quantity enhancement: an engineering perspective applied to rainwater harvesting in West Africa.

    PubMed

    Fry, Lauren M; Cowden, Joshua R; Watkins, David W; Clasen, Thomas; Mihelcic, James R

    2010-12-15

    Knowledge of potential benefits resulting from technological interventions informs decision making and planning of water, sanitation, and hygiene programs. The public health field has built a body of literature showing health benefits from improvements in water quality. However, the connection between improvements in water quantity and health is not well documented. Understanding the connection between technological interventions and water use provides insight into this problem. We present a model predicting reductions in diarrhea disease burden when the water demands from hygiene and sanitation improvements are met by domestic rainwater harvesting (DRWH). The model is applied in a case study of 37 West African cities. For all cities, with a total population of over 10 million, we estimate that DRWH with 400 L storage capacity could result in a 9% reduction in disability-affected life years (DALYs). If DRWH is combined with point of use (POU) treatment, this potential impact is nearly doubled, to a 16% reduction in DALYs. Seasonal variability of diarrheal incidence may have a small to moderate effect on the effectiveness of DRWH, depending on the storage volume used. Similar predictions could be made for other interventions that improve water quantity in other locations where disease burden from diarrhea is known.

  14. Seasonal variation of bacterial communities in shellfish harvesting waters: preliminary study before applying phage therapy.

    PubMed

    Pereira, C; Santos, L; Silva, A P; Silva, Y J; Cunha, A; Romalde, J L; Nunes, M L; Almeida, A

    2015-01-15

    The recurrent emergence of infections outbreaks associated with shellfish consumption is an important health problem, which results in substantial economic losses to the seafood industry. Even after depuration, shellfish is still involved in outbreaks caused by pathogenic bacteria, which increases the demand for new efficient strategies to control the shellfish infection transmission. Phage therapy during the shellfish depuration is a promising approach, but its success depends on a detailed understanding of the dynamics of bacterial communities in the harvesting waters. This study intends to evaluate the seasonal dynamics of the overall bacterial communities, disease-causing bacterial populations and bacterial sanitary quality indicators in two authorized harvesting-zones at Ria de Aveiro. During the hot season, the total bacterial community presented high complexity and new prevalent populations of the main shellfish pathogenic bacteria emerged. These results indicate that the spring/summer season is a critical period during which phage therapy should be applied.

  15. Charging System Optimization of Triboelectric Nanogenerator for Water Wave Energy Harvesting and Storage.

    PubMed

    Yao, Yanyan; Jiang, Tao; Zhang, Limin; Chen, Xiangyu; Gao, Zhenliang; Wang, Zhong Lin

    2016-08-24

    Ocean waves are one of the most promising renewable energy sources for large-scope applications due to the abundant water resources on the earth. Triboelectric nanogenerator (TENG) technology could provide a new strategy for water wave energy harvesting. In this work, we investigated the charging characteristics of utilizing a wavy-structured TENG to charge a capacitor under direct water wave impact and under enclosed ball collision, by combination of theoretical calculations and experimental studies. The analytical equations of the charging characteristics were theoretically derived for the two cases, and they were calculated for various load capacitances, cycle numbers, and structural parameters such as compression deformation depth and ball size or mass. Under the direct water wave impact, the stored energy and maximum energy storage efficiency were found to be controlled by deformation depth, while the stored energy and maximum efficiency can be optimized by the ball size under the enclosed ball collision. Finally, the theoretical results were well verified by the experimental tests. The present work could provide strategies for improving the charging performance of TENGs toward effective water wave energy harvesting and storage.

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

    PubMed

    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.

  17. Harvesting fresh water and marine algae by magnetic separation: screening of separation parameters and high gradient magnetic filtration.

    PubMed

    Cerff, Martin; Morweiser, Michael; Dillschneider, Robert; Michel, Aymeé; Menzel, Katharina; Posten, Clemens

    2012-08-01

    In this study, the focus is on magnetic separation of fresh water algae Chlamydomonas reinhardtii and Chlorella vulgaris as well as marine algae Phaeodactylum tricornutum and Nannochloropsis salina by means of silica-coated magnetic particles. Due to their small size and low biomass concentrations, harvesting algae by conventional methods is often inefficient and cost-consuming. Magnetic separation is a powerful tool to capture algae by adsorption to submicron-sized magnetic particles. Hereby, separation efficiency depends on parameters such as particle concentration, pH and medium composition. Separation efficiencies of >95% were obtained for all algae while maximum particle loads of 30 and 77 g/g were measured for C. reinhardtii and P. tricornutum at pH 8 and 12, respectively. This study highlights the potential of silica-coated magnetic particles for the removal of fresh water and marine algae by high gradient magnetic filtration and provides critical discussion on future improvements.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    feasibility and optimum scales and designs of rainwater-harvesting schemes in areas under changing precipitation patterns and coastal sea-level rise. We present preliminary results based on changing rainfall patterns, water budget analysis, and rainwater harvesting potential.

  19. Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in Eastern Canadian Boreal Shield lakes

    NASA Astrophysics Data System (ADS)

    Glaz, P.; Gagné, J.-P.; Archambault, P.; Sirois, P.; Nozais, C.

    2015-06-01

    Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a three-year period in eight Eastern Boreal Shield lakes: four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering one year before and one year after the perturbation only. At one year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~15 mg C L-1 compared to 12.5 mg C L-1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterised with spectroscopic techniques. Multivariate statistical analysis showed lakes to be significantly different one year after the perturbation. These results confirm an impact of forestry activities one year after the perturbation. However, this effect seems to be mitigated two years after, indicating that the system shows high resilience and may be able to return to its original condition.

  20. Phase-dependent dynamic potential of magnetically coupled two-degree-of-freedom bistable energy harvester

    PubMed Central

    Kim, Pilkee; Nguyen, Minh Sang; Kwon, Ojin; Kim, Young-Jin; Yoon, Yong-Jin

    2016-01-01

    A system of magnetically coupled oscillators has been recently considered as a promising compact structure to integrate multiple bistable energy harvesters (BEHs), but its design is not straightforward owing to its varying potential energy pattern, which has not been understood completely yet. This study introduces the concept of phase-dependent dynamic potential in a magnetically coupled BEH system with two degrees of freedom (DOFs) to explain the underlying principle of the complicated dynamics of the system. Through theoretical simulations and analyses, two distinct dynamic regimes, called the out-of-phase and in-phase mode regimes in this report, are found to exist in the frequency regions of the 1st and 2nd primary intrawell resonances. For the out-of-phase mode regime, the frequency displacement (and output power) responses of the 2-DOF BEH system exhibit typical double-well dynamics, whereas for the in-phase mode regime, only single-well dynamics is observed though the system is statically bistable. These dynamic regimes are also revealed to be caused by the difference in the dynamic potential energy trajectories propagating on a high-dimensional potential energy surface. The present approach to the dynamics of the 2-DOF BEH system can be extended and applied to higher-DOF systems, which sheds light on compact and efficient designs of magnetically coupled BEH chain structures. PMID:27677356

  1. Phase-dependent dynamic potential of magnetically coupled two-degree-of-freedom bistable energy harvester

    NASA Astrophysics Data System (ADS)

    Kim, Pilkee; Nguyen, Minh Sang; Kwon, Ojin; Kim, Young-Jin; Yoon, Yong-Jin

    2016-09-01

    A system of magnetically coupled oscillators has been recently considered as a promising compact structure to integrate multiple bistable energy harvesters (BEHs), but its design is not straightforward owing to its varying potential energy pattern, which has not been understood completely yet. This study introduces the concept of phase-dependent dynamic potential in a magnetically coupled BEH system with two degrees of freedom (DOFs) to explain the underlying principle of the complicated dynamics of the system. Through theoretical simulations and analyses, two distinct dynamic regimes, called the out-of-phase and in-phase mode regimes in this report, are found to exist in the frequency regions of the 1st and 2nd primary intrawell resonances. For the out-of-phase mode regime, the frequency displacement (and output power) responses of the 2-DOF BEH system exhibit typical double-well dynamics, whereas for the in-phase mode regime, only single-well dynamics is observed though the system is statically bistable. These dynamic regimes are also revealed to be caused by the difference in the dynamic potential energy trajectories propagating on a high-dimensional potential energy surface. The present approach to the dynamics of the 2-DOF BEH system can be extended and applied to higher-DOF systems, which sheds light on compact and efficient designs of magnetically coupled BEH chain structures.

  2. Phase-dependent dynamic potential of magnetically coupled two-degree-of-freedom bistable energy harvester.

    PubMed

    Kim, Pilkee; Nguyen, Minh Sang; Kwon, Ojin; Kim, Young-Jin; Yoon, Yong-Jin

    2016-09-28

    A system of magnetically coupled oscillators has been recently considered as a promising compact structure to integrate multiple bistable energy harvesters (BEHs), but its design is not straightforward owing to its varying potential energy pattern, which has not been understood completely yet. This study introduces the concept of phase-dependent dynamic potential in a magnetically coupled BEH system with two degrees of freedom (DOFs) to explain the underlying principle of the complicated dynamics of the system. Through theoretical simulations and analyses, two distinct dynamic regimes, called the out-of-phase and in-phase mode regimes in this report, are found to exist in the frequency regions of the 1(st) and 2(nd) primary intrawell resonances. For the out-of-phase mode regime, the frequency displacement (and output power) responses of the 2-DOF BEH system exhibit typical double-well dynamics, whereas for the in-phase mode regime, only single-well dynamics is observed though the system is statically bistable. These dynamic regimes are also revealed to be caused by the difference in the dynamic potential energy trajectories propagating on a high-dimensional potential energy surface. The present approach to the dynamics of the 2-DOF BEH system can be extended and applied to higher-DOF systems, which sheds light on compact and efficient designs of magnetically coupled BEH chain structures.

  3. Strategies for cooler cities? Ecophysiological responses of semi-arid street trees to storm water harvesting

    NASA Astrophysics Data System (ADS)

    DeMets, C. M.; Pavao-zuckerman, M.; Barron-Gafford, G.

    2013-12-01

    As the southwestern U.S. moves into an uncertain future in terms of water supply and climate, communities are seeking creative ways to harvest urban runoff. One such solution is to implement water-sensitive urban design features such as rain basins, which are designed to capture and facilitate infiltration of precipitation and storm water as it runs off impermeable surfaces like streets and sidewalks. Rain basins essentially act as temporary cisterns, allowing a given rain event to have a much larger impact in recharging soil water profiles. In this sense, even a 'small' rain may yield a more saturated soil profile and stimulate plant physiological activity well beyond plants that lack this additional moisture input. However, the impacts of rain basins on plant function remain unquantified. Therefore, the purpose of our research is to characterize the performance of native mesquite trees in basins relative to non-basin native mesquites. To answer our question, we randomly sampled basin and non-basin native mesquites in two different neighborhoods in Tucson, AZ, and characterized their response to precipitation events. We measured stomatal conductance, a proxy for transpiration, on the first and third days following rain events in 2013. Numerous environmental factors, such as photosynthetically available radiation (PAR), temperature, relative humidity, and soil moisture, were also measured in order to explore relationships with conductance. These measurements were conducted before and during monsoon season in order to determine the significance of water in basin performance, enabling us to better characterize plant response to medium (6 to 12 mm) rain events. Findings from this study indicate that basin and non-basin mesquites have similar pre-monsoon conductance rates, with a mean basin value of 70 +/-10 mmol/(m2*s) and a mean non-basin value of 57 +/-6 mmol/(m2*s) at peak conductance. In contrast, during the monsoon, basin mesquites showed significantly higher

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

    PubMed

    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.

  5. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    PubMed Central

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang

    2011-01-01

    Summary Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water. PMID:21977432

  6. Ethephon As a Potential Abscission Agent for Table Grapes: Effects on Pre-Harvest Abscission, Fruit Quality, and Residue

    PubMed Central

    Ferrara, Giuseppe; Mazzeo, Andrea; Matarrese, Angela M. S.; Pacucci, Carmela; Trani, Antonio; Fidelibus, Matthew W.; Gambacorta, Giuseppe

    2016-01-01

    Some plant growth regulators, including ethephon, can stimulate abscission of mature grape berries. The stimulation of grape berry abscission reduces fruit detachment force (FDF) and promotes the development of a dry stem scar, both of which could facilitate the production of high quality stemless fresh-cut table grapes. The objective of this research was to determine how two potential abscission treatments, 1445 and 2890 mg/L ethephon, affected FDF, pre-harvest abscission, fruit quality, and ethephon residue of Thompson Seedless and Crimson Seedless grapes. Both ethephon treatments strongly induced abscission of Thompson Seedless berries causing >90% pre-harvest abscission. Lower ethephon rates, a shorter post-harvest interval, or berry retention systems such as nets, would be needed to prevent excessive pre-harvest losses. The treatments also slightly affected Thompson Seedless berry skin color, with treated fruit being darker, less uniform in color, and with a more yellow hue than non-treated fruit. Ethephon residues on Thompson Seedless grapes treated with the lower concentration of ethephon were below legal limits at harvest. Ethephon treatments also promoted abscission of Crimson Seedless berries, but pre-harvest abscission was much lower (≅49%) in Crimson Seedless compared to Thompson Seedless. Treated fruits were slightly darker than non-treated fruits, but ethephon did not affect SSC, acidity, or firmness of Crimson Seedless, and ethephon residues were below legal limits. PMID:27303407

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

    NASA Astrophysics Data System (ADS)

    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

  8. Water harvesting experience in sub-Saharan Africa - lessons for sustainable intensification of rainfed agriculture and the influence of available soils and rainfall data

    NASA Astrophysics Data System (ADS)

    Gowin, John; Bunclark, Lisa

    2013-04-01

    Africa is seen by many as the continent with the greatest potential for agricultural growth, but land degradation and environmental change threaten the African soil resource more severely than in many other regions of the planet. Achieving future food security will depend mainly on increasing production from rainfed agriculture. The challenge of delivering the required sustainable intensification in rainfed agriculture is most acute in the drylands - the semi-arid and dry sub-humid climatic regions. There are two broad strategies for increasing yields under these circumstances: (1) capturing more rainwater and storing it (increasing water availability), and (2) using the available water more effectively by increasing the plant growth and/or reducing non-productive soil evaporation (increasing water productivity). We focus on the first of these options - water harvesting, which is defined as, "the collection and concentration of rainfall runoff, or floodwaters, for plant production". The benefits of water harvesting have been documented from small scale experimental plot studies, but evidence of successful adoption and impact is weak. As a contribution to improving the evidence base, we present results from an investigation conducted in SSA to gather information on progress with efforts to promote adoption of water harvesting. The intention was to investigate in detail the processes and outcomes on a large enough sample area to draw some common conclusions. This was not a comprehensive analysis of all that is happening in each country, nor was it a random sample; this was a purposive sample guided by available baseline information to permit comparative analysis. Water harvesting seems to have made the most progress where techniques can be adopted by individual farmers: in Burkina Faso and Niger micro- scale zaï /tassa and demi-lune systems; in Sudan and Tanzania meso-scale majaruba and teras systems. Macro-scale systems requiring social organisation may offer

  9. The relation of harvesting intensity to changes in soil, soil water, and stream chemistry in a northern hardwood forest, Catskill Mountains, USA

    USGS Publications Warehouse

    Siemion, Jason; Burns, Douglas A.; Murdoch, Peter S.; Germain, Rene H.

    2011-01-01

    Previous studies have shown that clearcutting of northern hardwood forests mobilizes base cations, inorganic monomeric aluminum (Alim), and nitrate (NO3--N) from soils to surface waters, but the effects of partial harvests on NO3--N have been less frequently studied. In this study we describe the effects of a series of partial harvests of varying proportions of basal area removal (22%, 28% and 68%) on Alim, calcium (Ca2+), and NO3--N concentrations in soil extracts, soil water, and surface water in the Catskill Mountains of New York, USA. Increases in NO3--N concentrations relative to pre-harvest values were observed within a few months after harvest in soils, soil water, and stream water for all three harvests. Increases in Alim and Ca2+ concentrations were also evident in soil water and stream water over the same time period for all three harvests. The increases in Alim, Ca2+, and NO3--N concentrations in the 68% harvest were statistically significant as measured by comparing the 18-month pre-harvest period with the 18-month post-harvest period, with fewer significant responses in the two harvests of lowest intensity. All three solutes returned to pre-harvest concentrations in soil water and stream water in the two lowest intensity harvests in 2–3 years compared to a full 3 years in the 68% harvest. When the results of this study were combined with those of a previous nearby clearcut and 40% harvest, the post-harvest increases in NO3--N concentrations in stream water and soil water suggest a harvesting level above which the relation between concentration and harvest intensity changes; there was a greater change in concentration per unit change in harvest intensity when basal area removal was greater than 40%. These results indicate that the deleterious effects on aquatic ecosystems previously demonstrated for intensive harvests in northern hardwood forests of northeastern North America that receive high levels of atmospheric N deposition can be greatly

  10. Potential losses of macro and micronutrients by removal of sugarcane post-harvest crop residue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Green-cane harvest of sugarcane (Saccharum spp.) deposits large amounts of leaf residue onto the soil. Decomposition of crop residue recycles nutrients into the soil and maintains soil health. However, with the establishment of the bioenergy industry, crop residues may be harvested as feedstock for ...

  11. Measurement of the Water Potential of Stored Potato Tubers 1

    PubMed Central

    Bland, William L.; Tanner, Champ B.

    1985-01-01

    A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential. Pressure chamber measurements, while useful for tubers with functional stolons, cannot be made on stored tubers. Measurements could be made on excised tissue pieces in a hygrometer chamber and with hygrometers implanted into tubers. We report here our evaluation of these hygrometric methods using a comparison with the pressure chamber on tubers harvested with stolons intact. In tubers of high water potential, measurements on excised tissue were as much as 0.5 megapascals lower than the pressure chamber, probably due to turgor-driven expansion of the sample when freed from constraints imposed by surrounding tissue. Good agreement (±0.05 megapascals) was found between the implanted hygrometer and the pressure chamber at potentials higher than −0.5 megapascals. At lower water potentials, both hygrometer measurements were higher than the pressure chamber. Respirational heating of the tissue contributed to the increase in the excised tissue samples, but not with the implanted hygrometers because of the hygrometer design. The osmotic pressure balanced the pressure chamber measurement of potential at −0.7 megapascals, but was too small to do so at lower potentials. At most, 25% of this discrepancy can be accounted for by dilution by apoplastic water. We believe that the pressure chamber measurement is too low at low water potentials and that the error is associated with air bubbles in the xylem. At low potentials air emerged from xylem vessels along with sap, and fewer xylem emitted sap as potentials decreased. PMID:16664511

  12. Measurement of the water potential of stored potato tubers.

    PubMed

    Bland, W L; Tanner, C B

    1985-11-01

    A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential. Pressure chamber measurements, while useful for tubers with functional stolons, cannot be made on stored tubers. Measurements could be made on excised tissue pieces in a hygrometer chamber and with hygrometers implanted into tubers. We report here our evaluation of these hygrometric methods using a comparison with the pressure chamber on tubers harvested with stolons intact.In tubers of high water potential, measurements on excised tissue were as much as 0.5 megapascals lower than the pressure chamber, probably due to turgor-driven expansion of the sample when freed from constraints imposed by surrounding tissue. Good agreement (+/-0.05 megapascals) was found between the implanted hygrometer and the pressure chamber at potentials higher than -0.5 megapascals. At lower water potentials, both hygrometer measurements were higher than the pressure chamber. Respirational heating of the tissue contributed to the increase in the excised tissue samples, but not with the implanted hygrometers because of the hygrometer design. The osmotic pressure balanced the pressure chamber measurement of potential at -0.7 megapascals, but was too small to do so at lower potentials. At most, 25% of this discrepancy can be accounted for by dilution by apoplastic water. We believe that the pressure chamber measurement is too low at low water potentials and that the error is associated with air bubbles in the xylem. At low potentials air emerged from xylem vessels along with sap, and fewer xylem emitted sap as potentials decreased.

  13. Urban stormwater harvesting and reuse: a probe into the chemical, toxicology and microbiological contaminants in water quality.

    PubMed

    Chong, Meng Nan; Sidhu, Jatinder; Aryal, Rupak; Tang, Janet; Gernjak, Wolfgang; Escher, Beate; Toze, Simon

    2013-08-01

    Stormwater is one of the last major untapped urban water resources that can be exploited as an alternative water source in Australia. The information in the current Australian Guidelines for Water Recycling relating to stormwater harvesting and reuse only emphasises on a limited number of stormwater quality parameters. In order to supply stormwater as a source for higher value end-uses, a more comprehensive assessment on the potential public health risks has to be undertaken. Owing to the stochastic variations in rainfall, catchment hydrology and also the types of non-point pollution sources that can provide contaminants relating to different anthropogenic activities and catchment land uses, the characterisation of public health risks in stormwater is complex, tedious and not always possible through the conventional detection and analytical methods. In this study, a holistic approach was undertaken to assess the potential public health risks in urban stormwater samples from a medium-density residential catchment. A combined chemical-toxicological assessment was used to characterise the potential health risks arising from chemical contaminants, while a combination of standard culture methods and quantitative polymerase chain reaction (qPCR) methods was used for detection and quantification of faecal indicator bacteria (FIB) and pathogens in urban stormwater. Results showed that the concentration of chemical contaminants and associated toxicity were relatively low when benchmarked against other alternative water sources such as recycled wastewater. However, the concentrations of heavy metals particularly cadmium and lead have exceeded the Australian guideline values, indicating potential public health risks. Also, high numbers of FIB were detected in urban stormwater samples obtained from wet weather events. In addition, qPCR detection of human-related pathogens suggested there are frequent sewage ingressions into the urban stormwater runoff during wet weather events

  14. Microbial source tracking in shellfish harvesting waters in the Gulf of Nicoya, Costa Rica.

    PubMed

    Symonds, E M; Young, S; Verbyla, M E; McQuaig-Ulrich, S M; Ross, E; Jiménez, J A; Harwood, V J; Breitbart, M

    2017-03-15

    Current microbial water quality monitoring is generally limited to culture-based measurements of fecal indicator bacteria (FIB). Given the many possible sources of fecal pollution within a watershed and extra-intestinal FIB reservoirs, it is important to determine source(s) of fecal pollution as a means to improve water quality and protect public health. The principal objective of this investigation was to characterize the microbial water quality of shellfish harvesting areas in the Gulf of Nicoya, Costa Rica during 2015. In order to achieve this objective, the specificity and sensitivity of 11 existing microbial source tracking (MST) PCR assays, associated with cows (BacCow), dogs (BacCan, DogBac), domestic wastewater (PMMoV), general avian (GFD), gulls (Gull2), horses (HorseBac, HoF), humans (HF183, HPyV), and pigs (PF), were evaluated using domestic wastewater and animal fecal samples collected from the region. The sensitivity of animal-associated assays ranged from 13 to 100%, while assay specificity ranged from 38 to 100%. The specificity of pepper mild mottle virus (PMMoV) and human polyomavirus (HPyV) was 100% for domestic wastewater, as compared to 94% specificity of the HF183 Bacteroidales marker. PMMoV was identified as a useful domestic wastewater-associated marker, with concentrations as high as 1.1 × 10(5) copies/ml and 100% sensitivity and specificity. Monthly surface water samples collected from four shellfish harvesting areas were analyzed using culture-based methods for Escherichia coli as well as molecular methods for FIB and a suite of MST markers, which were selected for their specificity in the region. While culturable E. coli results suggested possible fecal pollution during the monitoring period, the absence of human/domestic wastewater-associated markers and low FIB concentrations determined using molecular methods indicated sufficient microbial water quality for shellfish harvesting. This is the first study to our knowledge to test the

  15. Hydroelastic response and energy harvesting potential of flexible piezoelectric beams in viscous flow

    NASA Astrophysics Data System (ADS)

    Akcabay, Deniz Tolga; Young, Yin Lu

    2012-05-01

    Electroactive polymers such as piezoelectric elements are able to generate electric potential differences from induced mechanical deformations. They can be used to build devices to harvest ambient energy from natural flow-induced deformations, e.g., as flapping flags subject to flowing wind or artificial seaweed subject to waves or underwater currents. The objectives of this study are to (1) investigate the transient hydroelastic response and energy harvesting potential of flexible piezoelectric beams fluttering in incompressible, viscous flow, and (2) identify critical non-dimensional parameters that govern the response of piezoelectric beams fluttering in viscous flow. The fluid-structure interaction response is simulated using an immersed boundary approach coupled with a finite volume solver for incompressible, viscous flow. The effects of large beam deformation, membrane tension, and coupled electromechanical responses are all considered. Validation studies are shown for the motion of a flexible filament in uniform flow, and for a piezoelectric beam subject to base vibration. The predicted flutter velocities and frequencies also compared well with published experimental and numerical data over a range of Reynolds numbers for varying fluid and solid combinations. The results showed that for a heavy beam in a light fluid (i.e., high βρ regime), flutter incepts at a lower critical speed with a lower reduced frequency than for a light beam in a heavy fluid (i.e., low βρ regime). In the high βρ regime, flutter develops at the second mode and is only realized when the fluid inertial forces are in balance with the solid elastic restoring forces, which leads to large amplitude oscillations and complex wake patterns; the flutter speed is practically independent of the Reynolds number (Re) and solid to fluid mass ratio (βρ), because the response is dominated by the solid inertial forces. In the low βρ regime, fluid inertial forces dominate, flutter develops at

  16. Cell water balance of white button mushrooms (Agaricus bisporus) during its post-harvest lifetime studied by quantitative magnetic resonance imaging.

    PubMed

    Donker, H C; Van As, H

    1999-04-19

    A combination of quantitative water density and T2 MRI and changes therein observed after infiltration with 'invisible' Gd-DTPA solution was used to study cell water balances, cell water potentials and cell integrity. This method was applied to reveal the evolution and mechanism of redistribution of water in harvested mushrooms. Even when mushrooms did not lose water during the storage period, a redistribution of water was observed from stipe to cap and gills. When the storage condition resulted in a net loss of water, the stipe lost more water than the cap. The water density in the gill increased, probably due to development of spores. Deterioration effects (i.e. leakage of cells, decrease in osmotic water potential) were found in the outer stipe. They were not found in the cap, even at prolonged storage at 293 K and R.H.=70%. The changes in osmotic potential were partly accounted for by changes in the mannitol concentration. Changes in membrane permeability were also indicated. Cells in the cap had a constant low membrane (water) permeability. They developed a decreasing osmotic potential (more negative), whereas the osmotic potential in the outer stipe increased, together with the permeability of cells.

  17. Design Considerations and Economics of Water Harvesting System for Crop Production

    NASA Astrophysics Data System (ADS)

    Pali, A. K.

    2016-06-01

    By and large, the design of water harvesting pond is generally based on thumb rules and needs to be upgraded on scientific and engineering principles. In this study, the design procedure of on-farm water harvesting pond has been discussed and two farm ponds of circular, rectangular and square shapes were designed for 50, 60, 75 and 80 % probability of occurrence of rainfall and runoff. Though, the circular shape resulted in the least mean water surface area, but due to not being practicable for agricultural operations, it was discarded. The square shaped ponds resulted in giving least water surface areas as 0.761 ha for the micro watershed of 8.19 ha and as 0.246 ha for the micro watershed of 1.7 ha at 80 % probability level of rainfall and runoff at 80 % level of probability. The storage capacity of the first pond was found as 32,314 m3 and it was 12,962 m3 for the second farm pond. The area to be occupied by the two ponds was worked out as about 11 % of the total land area (8.19 ha) of the first micro watershed and about 18-22 % of the area (1.7 ha) of second micro watershed. Results indicated that the designed size of the first farm pond can be acceptable for construction. The economics of farm pond based agricultural production showed that the highest B/C ratio of 2 and 1.9 were possible for the farm pond designed at 80 and 75 % probability of occurrence of rainfall and runoff respectively.

  18. Hygrometric Measurement of Soil Water Potential

    NASA Astrophysics Data System (ADS)

    Butler, C. D.; Tyner, J. S.

    2004-12-01

    Knowledge of soil water potential as a function of water content is required to make unsaturated flow and transport predictions. Although numerous methods are available to measure soil water potential, they are largely difficult and time consuming procedures. The goal of the research is to develop a hygrometric method that will perform satisfactorily with minimal required hardware or technician time. The volume of a drop of saline water will change due to evaporation or condensation until its salinity, and hence osmotic potential, is equal to the water potential in the adjacent gas phase. This relationship is exploited by our method to measure soil moisture potential. To begin, a drop of KCl solution with known mass and KCL concentration is placed adjacent to a soil sample with known water content inside a hermetically sealed container. The mass of the KCl drop is recorded over time with an electronic balance. As thermodynamic equilibrium is achieved, the mass of water within the KCl drop changes until its osmotic potential is equal to the capillary potential of water within the soil sample. After the mass of the KCl drop reaches equilibrium, the KCl concentration is calculated, which enables direct determination of the water potential within the soil sample. Unlike transient hygrometric measurements of water potential using psychrometers, no calibration is required.

  19. Modeling of a water vapor selective membrane unit to increase the energy efficiency of humidity harvesting

    NASA Astrophysics Data System (ADS)

    Bergmair, D.; Metz, S. J.; de Lange, H. C.; van Steenhoven, A. A.

    2012-11-01

    Air humidity is a promising source of clean and safe drinking water. However, in conventional systems a lot of energy is wasted on the production of cold air, rather than the condensation of water vapor. This study examines the possibility of using a hollow fiber membrane module to make this process more energy efficient, by separating the vapor from other gases, prior to the cooling process with the help of selective membranes. The water vapor concentration within a fiber has been modeled using a random walker approach, and the membrane permeability has been implemented as a re-bounce probability for simulation particles interacting with the membrane. Considering the additional work requirement for driving a feed flow through the membrane section and the computed water vapor permeation it could be shown that the energy demand per unit water is lowest for slow flow speeds and favors short and thin fibers. The total energy requirement was estimated to be less than half of the conventional one. Comparison with other CFD simulations and a real life module has shown a good level of agreement, indicating that a membrane section could improve the energy efficiency of humidity harvesting significantly.

  20. Living off-grid in an arid environment without a well : can residential and commercial/industrial water harvesting help solve water supply problems?

    SciTech Connect

    Axness, Carl L.; Ferrando, Ana

    2010-08-01

    Our family of three lives comfortably off-grid without a well in an arid region ({approx}9 in/yr, average). This year we expect to achieve water sustainability with harvested or grey water supporting all of our needs (including a garden and trees), except drinking water (about 7 gallons/week). We discuss our implementation and the implication that for an investment of a few thousand dollars, many single family homes could supply a large portion of their own water needs, significantly reducing municipal water demand. Generally, harvested water is very low in minerals and pollutants, but may need treatment for microbes in order to be potable. This may be addressed via filters, UV light irradiation or through chemical treatment (bleach). Looking further into the possibility of commercial water harvesting from malls, big box stores and factories, we ask whether water harvesting could supply a significant portion of potable water by looking at two cities with water supply problems. We look at the implications of separate municipal water lines for potable and clean non-potable uses. Implications on changes to future building codes are explored.

  1. Floating microbial fuel cells as energy harvesters for signal transmission from natural water bodies

    NASA Astrophysics Data System (ADS)

    Schievano, Andrea; Colombo, Alessandra; Grattieri, Matteo; Trasatti, Stefano P.; Liberale, Alessandro; Tremolada, Paolo; Pino, Claudio; Cristiani, Pierangela

    2017-02-01

    A new type of floating microbial fuel cell (fMFC) was developed for power supply of remote environmental sensors and data transmission. Ten operating fMFCs generated a cell potential in the range 100-800 mV depending on the external resistance applied. Power production peaked around 3-3.5 mW (power density of 22-28 mW m-2 cathode) after about 20-30 days of start-up period. The average of daily electrical energy harvested ranged between 10 and 35 mWh/d. Long-term performances were ensured in the presence of dense rice plants (Oryza Sativa). A power management system, based on a step-up DC/DC converter and a low-power data transmission system via SIGFOX™ technology, have been set up for the fMFCs. The tested fMFCs systems allowed to: i) harvest produced energy, ii) supply electronic devices (intermittent LED-light and a buzzer); iii) transmit remote data at low speed (three message of 12 bites each, in 6 s). Several 'floating garden' MFCs were set in the context of demonstrative events at EXPO2015 world exposition held in Milan between May-October 2015. Some of the 'floating garden' MFCs were operating for more than one year.

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

    PubMed

    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

  3. Timber Harvest Effects on Sediment and Water Yields and Analysis of Sediment Load Calculation Methods in the Interior Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Elverson, C.; Karwan, D. L.

    2015-12-01

    Timber harvest practices have a long-standing association with changes in water and sediment yields. We quantify the trends in water and sediment yields in the Mica Creek Experimental Watershed (MCEW) in relation to management practices with linear regression and analysis of covariance (ANCOVA). From 1991 to 2013, an increase in water yield resulted from both clearcutting and thinning treatments, with monthly water yield rate increases of 13-57% and annual water yield increases up to 210 mm (40%) in the clearcut watershed. Following treatment, annual sediment yields increased in the clearcut watershed by 40-131% and the thinned watershed by 33-163%, both relative to the control watershed, with statistically-significant monthly load increases in the year immediately following treatment. Water and sediment yield changes do not follow the same post-treatment patterns. Water yields increased immediately following treatment and, over time, gradually dropped towards pre-harvest levels. Annual sediment yields increased in some years after the harvest, but in some cases the increase was years after treatment. Monthly sediment yields increased in the first year following the clearcut harvest, but elevated monthly loads following the partial cut harvest came years later. Hence, we investigate the changes in sediment yield through an examination of water yield and sediment concentration and in response to events. We test the sensitivity of our results to different methods for computing sediment yields based on total suspended solids concentration and continuous discharge measurements. Flow-weighted sediment yield averaged 24% higher than sediment yield computed from linear-interpolated total suspended solids concentration values. During typical summer and fall conditions, flow-weighting was found to overweight storm measurements and produce large sediment yield estimates. Further work is suggested to test methods of calculating monthly sediment yields with irregularly

  4. Geotechnology and landscape ecology applied to the selection of potential forest fragments for seed harvesting.

    PubMed

    Santos, Alexandre Rosa Dos; Antonio Alvares Soares Ribeiro, Carlos; de Oliveira Peluzio, Telma Machado; Esteves Peluzio, João Batista; de Queiroz, Vagner Tebaldi; Figueira Branco, Elvis Ricardo; Lorenzon, Alexandre Simões; Domingues, Getulio Fonseca; Marcatti, Gustavo Eduardo; de Castro, Nero Lemos Martins; Teixeira, Thaisa Ribeiro; Dos Santos, Gleissy Mary Amaral Dino Alves; Santos Mota, Pedro Henrique; Ferreira da Silva, Samuel; Vargas, Rozimelia; de Carvalho, José Romário; Macedo, Leandro Levate; da Silva Araújo, Cintia; de Almeida, Samira Luns Hatum

    2016-12-01

    The Atlantic Forest biome is recognized for its biodiversity and is one of the most threatened biomes on the planet, with forest fragmentation increasing due to uncontrolled land use, land occupation, and population growth. The most serious aspect of the forest fragmentation process is the edge effect and the loss of biodiversity. In this context, the aim of this study was to evaluate the dynamics of forest fragmentation and select potential forest fragments with a higher degree of conservation for seed harvesting in the Itapemirim river basin, Espírito Santo State, Brazil. Image classification techniques, forest landscape ecology, and multi-criteria analysis were used to evaluate the evolution of forest fragmentation to develop the landscape metric indexes, and to select potential forest fragments for seed harvesting for the years 1985 and 2013. According to the results, there was a reduction of 2.55% of the occupancy of the fragments in the basin between the years 1985 and 2013. For the years 1985 and 2013, forest fragment units 2 and 3 were spatialized with a high potential for seed harvesting, representing 6.99% and 16.01% of the total fragments, respectively. The methodology used in this study has the potential to be used to support decisions for the selection of potential fragments for seed harvesting because selecting fragments in different environments by their spatial attributes provides a greater degree of conservation, contributing to the protection and conscious management of the forests. The proposed methodology can be adapted to other areas and different biomes of the world.

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

    NASA Astrophysics Data System (ADS)

    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

  6. Hetero-type dual photoanodes for unbiased solar water splitting with extended light harvesting.

    PubMed

    Kim, Jin Hyun; Jang, Ji-Wook; Jo, Yim Hyun; Abdi, Fatwa F; Lee, Young Hye; van de Krol, Roel; Lee, Jae Sung

    2016-12-14

    Metal oxide semiconductors are promising photoelectrode materials for solar water splitting due to their robustness in aqueous solutions and low cost. Yet, their solar-to-hydrogen conversion efficiencies are still not high enough for practical applications. Here we present a strategy to enhance the efficiency of metal oxides, hetero-type dual photoelectrodes, in which two photoanodes of different bandgaps are connected in parallel for extended light harvesting. Thus, a photoelectrochemical device made of modified BiVO4 and α-Fe2O3 as dual photoanodes utilizes visible light up to 610 nm for water splitting, and shows stable photocurrents of 7.0±0.2 mA cm(-2) at 1.23 VRHE under 1 sun irradiation. A tandem cell composed with the dual photoanodes-silicon solar cell demonstrates unbiased water splitting efficiency of 7.7%. These results and concept represent a significant step forward en route to the goal of >10% efficiency required for practical solar hydrogen production.

  7. Relationship between antibiotic- and disinfectant-resistance profiles in bacteria harvested from tap water.

    PubMed

    Khan, Sadia; Beattie, Tara K; Knapp, Charles W

    2016-06-01

    Chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What is concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population. Here, we investigated the relationship between chlorine- and antibiotic-resistances by harvesting 148 surviving bacteria from chlorinated drinking-water systems and compared their susceptibilities against chlorine disinfectants and antibiotics. Twenty-two genera were isolated, including members of Paenibacillus, Burkholderia, Escherichia, Sphingomonas and Dermacoccus species. Weak (but significant) correlations were found between chlorine-tolerance and minimum inhibitory concentrations against the antibiotics tetracycline, sulfamethoxazole and amoxicillin, but not against ciprofloxacin; this suggest that chlorine-tolerant bacteria are more likely to also be antibiotic resistant. Further, antibiotic-resistant bacteria survived longer than antibiotic-sensitive organisms when exposed to free chlorine in a contact-time assay; however, there were little differences in susceptibility when exposed to monochloramine. Irrespective of antibiotic-resistance, spore-forming bacteria had higher tolerance against disinfection compounds. The presence of chlorine-resistant bacteria surviving in drinking-water systems may carry additional risk of antibiotic resistance.

  8. Assessing the implications of water harvesting intensification on upstream-downstream ecosystem services: A case study in the Lake Tana basin.

    PubMed

    Dile, Yihun Taddele; Karlberg, Louise; Daggupati, Prasad; Srinivasan, Raghavan; Wiberg, David; Rockström, Johan

    2016-01-15

    Water harvesting systems have improved productivity in various regions in sub-Saharan Africa. Similarly, they can help retain water in landscapes, build resilience against droughts and dry spells, and thereby contribute to sustainable agricultural intensification. However, there is no strong empirical evidence that shows the effects of intensification of water harvesting on upstream-downstream social-ecological systems at a landscape scale. In this paper we develop a decision support system (DSS) for locating and sizing water harvesting ponds in a hydrological model, which enables assessments of water harvesting intensification on upstream-downstream ecosystem services in meso-scale watersheds. The DSS was used with the Soil and Water Assessment Tool (SWAT) for a case-study area located in the Lake Tana basin, Ethiopia. We found that supplementary irrigation in combination with nutrient application increased simulated teff (Eragrostis tef, staple crop in Ethiopia) production up to three times, compared to the current practice. Moreover, after supplemental irrigation of teff, the excess water was used for dry season onion production of 7.66 t/ha (median). Water harvesting, therefore, can play an important role in increasing local- to regional-scale food security through increased and more stable food production and generation of extra income from the sale of cash crops. The annual total irrigation water consumption was ~4%-30% of the annual water yield from the entire watershed. In general, water harvesting resulted in a reduction in peak flows and an increase in low flows. Water harvesting substantially reduced sediment yield leaving the watershed. The beneficiaries of water harvesting ponds may benefit from increases in agricultural production. The downstream social-ecological systems may benefit from reduced food prices, reduced flooding damages, and reduced sediment influxes, as well as enhancements in low flows and water quality. The benefits of water

  9. Conservation potential of agricultural water conservation subsidies

    NASA Astrophysics Data System (ADS)

    Huffaker, Ray

    2008-07-01

    A current policy subsidizes farmers to invest in improved on-farm irrigation efficiency, expecting water to be conserved off farm. Contrary to expectation, water has been increasingly depleted in some regions after such improvements. This paper investigates the policy's failure to conserve water consistently by (1) formulating an economic model of irrigated crop production to determine a profit-maximizing irrigator's range of responses to a subsidy and (2) embedding these responses into hypothetical streamflow diagrams to ascertain their potential to conserve water under various hydrologic regimes. Testable hypotheses are developed to predict the conservation potential of a subsidy in real-world application.

  10. The efficiency of trenches as runoff water harvesting systems and the role of their design in minimizing water losses

    NASA Astrophysics Data System (ADS)

    Berliner, Pedro; Carmi, Gennady; Agam, Nurit; Leake, Solomon

    2016-04-01

    Water is a primary limiting factor to agricultural development in many arid and semi-arid regions. In these regions, much of the annual rainfall occurs as a result of a few intensive convective storms. Only a small fraction of the rain is absorbed by the soil, does not penetrate deeply into the soil profile and is mostly lost by direct evaporation into the atmosphere shortly after the rain event. Usually the fraction that is not absorbed by the soil, flows as the runoff to the lower laying parts of the land and is thus lost for plant production. The technique of collecting the runoff and conveying it to areas, in which it can be ponded, is known as runoff harvesting. This technique may be used for food, fuel production, flood and erosion control, as well as for landscape development. In terms of combating desertification and degradation, water harvesting appears to be a viable solution. Microcatchments are one of the primary techniques used for collecting, storing and conserving local surface runoff for growing trees/shrubs. In this system, runoff water is collected close-by the area in which it was generated, and trees/shrubs may utilize the water during the next dry season. The main objective of the present research was to estimate the effect the shape of the micro-catchment collection area (shallow basin and deep trench) has on the efficiency of the water conservation in the soil profile The study was carried out using regular micro-catchments (three replicates) with a surface area of 9 m2 (3 x 3 m) and a depth of 0.1 m and trenches (three replicates) with a surface area of 12 m2 (12 x 1 m) and 1 m depth. One and three olive trees were planted inside the trenches and micro-catchments, respectively. Access tubes for neutron probe were installed in micro-catchments and trenches (four and seven, respectively) to depths of 3 m. Soil water content in the soil profile was monitored. Sap flow in trees was measured by PS-TDP8 Granier sap flow system every 0.5 hour and

  11. Temperature dependence of soil water potential

    SciTech Connect

    Mohamed, A.M.O.; Yong, R.N. ); Cheung, S.C.H. )

    1992-12-01

    To understand the process of coupled heat and water transport, the relationship between temperature and soil water potential must be known. Two clays, Avonlea bentonite and Lake Agassiz clay, are being considered as the clay-based sealing materials for the Canadian nuclear fuel waste disposal vault. Avonlea bentonite is distinguished from Lake Agassiz clay by its high sealing potential in water. A series of experiments was performed in which the two clays were mixed with equal amounts of sand and were compacted to a dry density of 1.67 Mg/m[sup 3] under various moisture contents and temperatures. A psychrometer was placed within the compacted clay-sand to measure the soil water potential based on the electromotive force measured by the psychrometer. The results indicate that the soil water potential at a particular temperature is higher for both clay-sand mixtures than predicted by the change in the surface tension of water; this effect is much more prominent in the Avonlea bentonite and at low moisture contents. The paper presents empirical equations relating the soil water potential with the moisture content and temperature of the two clay-sand mixtures. 24 refs., 8 figs., 2 tabs.

  12. Comparison of soil water potential sensors

    NASA Astrophysics Data System (ADS)

    Degre, Aurore; van der Ploeg, Martine; Caldwell, Todd; Gooren, Harm

    2015-04-01

    Temporal and spatial monitoring of soil water potential and soil water content are necessary for quantifying water flow in the domains of hydrology, soil science and crop production as knowledge of the soil water retention curve is important for solving Richards' equation. Numerous measurement techniques exist nowadays that use various physical properties of the soil-water complex to record changes in soil water content or soil water potential. Laboratory techniques are very useful to determine static properties of the soil water retention curve, and have been used to show the impacts of hysteresis. Yet, other spatiotemporal dynamics resulting from for example growing root systems, biological activity, periodic tillage and their impact on the soil structure cannot satisfactory be quantified in static setups in the laboratory. ). To be able to quantify the influence of soil heterogeneity, and spatiotemporal dynamics on the soil water retention curve, an in situ approach combining soil moisture and soil water potential measurements could provide useful data. Such an in situ approach would require sensors that can measure a representative part of the soil water retention curve. The volumetric soil water content is often measured using time domain reflectometry, and has gained widespread acceptance as a standard electronic means of volumetric water content measurement. To measure the soil water potential, water filled tensiometers are used in most studies. Unfortunately, their range remains limited due to cavitation. Recently, several new sensors for use under in situ conditions have been proposed to cover a wider range of pressure head: Polymer tensiometers, MPS (Decagon) and pF-meter (ecoTech). In this study, we present the principles behind each measurement technique. Then we present the results of a fully controlled experiment where we compared two MPS sensors, two pF-meter sensors and two POT sensors in the same repacked soil. It allows us to discuss advantages

  13. Water quality effects of clearcut harvesting and forest fertilization with best management practices.

    PubMed

    McBroom, Matthew W; Beasley, R Scott; Chang, Mingteh; Ice, George G

    2008-01-01

    Nine small (2.5 ha) and four large (70-135 ha) watersheds were instrumented in 1999 to evaluate the effects of silvicultural practices with application of best management practices (BMPs) on stream water quality in East Texas, USA. Two management regimes were implemented in 2002: (i) conventional, with clearcutting, herbicide site preparation, and BMPs and (ii) intensive, which added subsoiling, aerial broadcast fertilization, and an additional herbicide application. Watershed effects were compared with results from a study on the same small watersheds in 1981, in which two combinations of harvesting and mechanical site preparation without BMPs or fertilization were evaluated. Clearcutting with conventional site preparation resulted in increased nitrogen losses on the small watersheds by about 1 additional kg ha(-1) each of total Kjeldahl nitrogen (TKN) and nitrate-nitrogen (NO(3)-N) in 2003. First-year losses were not significantly increased on the large watershed with a conventional site preparation with BMPs. Fertilization resulted in increased runoff losses in 2003 on the intensive small watersheds by an additional 0.77, 2.33, and 0.36 kg ha(-1) for NO(3)-N, TKN, and total phosphorus, respectively. Total loss rates of ammonia nitrogen (NH(4)-N) and NO(3)-N were low overall and accounted for only approximately 7% of the applied N. Mean loss rates from treated watersheds were much lower than rainfall inputs of about 5 kg ha(-1) TKN and NO(3)-N in 2003. Aerial fertilization of the 5-yr-old stand on another large watershed did not increase nutrient losses. Intensive silvicultural practices with BMPs did not significantly impair surface water quality with N and P.

  14. Leaf cuticular wax amount and crystal morphology regulate post-harvest water loss in mulberry (Morus species).

    PubMed

    Mamrutha, H M; Mogili, T; Jhansi Lakshmi, K; Rama, N; Kosma, Dylan; Udaya Kumar, M; Jenks, Matthew A; Nataraja, Karaba N

    2010-08-01

    Mulberry leaves are the sole source of food for silkworms (Bombyx mori), and moisture content of the detached leaves fed to silkworms determines silkworm growth and cocoon yield. Since leaf dehydration in commercial sericulture is a serious problem, development of new methods that minimize post-harvest water loss are greatly needed. In the present study, variability in moisture retention capacity (MRC, measured as leaf relative water content after one to 5 h of air-drying) was examined by screening 290 diverse mulberry accessions and the relationship between MRC and leaf surface (cuticular) wax amount was determined. Leaf MRC varied significantly among accessions, and was found to correlate strongly with leaf wax amount. Scanning electron microscopic analysis indicated that leaves having crystalline surface waxes of increased facet size and density were associated with high MRC accessions. Leaf MRC at 5 h after harvest was not related to other parameters such as specific leaf weight, and stomatal frequency and index. This study suggests that mulberry accessions having elevated leaf surface wax amount and crystal size and density exhibit reduced leaf post-harvest water loss, and could provide the foundation for selective breeding of improved cultivars.

  15. Continuous Monitoring of Plant Water Potential

    PubMed Central

    Schaefer, Nick L.; Trickett, Edward S.; Ceresa, Anthony; Barrs, Henry D.

    1986-01-01

    Plant water potential was monitored continuously with a Wescor HR-33T dewpoint hygrometer in conjunction with a L51 chamber. This commercial instrument was modified by replacing the AC-DC mains power converter with one stabilized by zener diode controlled transistors. The thermocouple sensor and electrical lead needed to be thermally insulated to prevent spurious signals. For rapid response and faithful tracking a low resistance for water vapor movement between leaf and sensor had to be provided. This could be effected by removing the epidermis either by peeling or abrasion with fine carborundum cloth. A variety of rapid plant water potential responses to external stimuli could be followed in a range of crop plants (sunflower (Helianthus annuus L., var. Hysun 30); safflower (Carthamus tinctorious L., var. Gila); soybean (Glycine max L., var. Clark); wheat (Triticum aestivum L., var. Egret). These included light dark changes, leaf excision, applied pressure to or anaerobiosis of the root system. Water uptake by the plant (safflower, soybean) mirrored that for water potential changes including times when plant water status (soybean) was undergoing cyclical changes. PMID:16664805

  16. Continuous monitoring of plant water potential.

    PubMed

    Schaefer, N L; Trickett, E S; Ceresa, A; Barrs, H D

    1986-05-01

    Plant water potential was monitored continuously with a Wescor HR-33T dewpoint hygrometer in conjunction with a L51 chamber. This commercial instrument was modified by replacing the AC-DC mains power converter with one stabilized by zener diode controlled transistors. The thermocouple sensor and electrical lead needed to be thermally insulated to prevent spurious signals. For rapid response and faithful tracking a low resistance for water vapor movement between leaf and sensor had to be provided. This could be effected by removing the epidermis either by peeling or abrasion with fine carborundum cloth. A variety of rapid plant water potential responses to external stimuli could be followed in a range of crop plants (sunflower (Helianthus annuus L., var. Hysun 30); safflower (Carthamus tinctorious L., var. Gila); soybean (Glycine max L., var. Clark); wheat (Triticum aestivum L., var. Egret). These included light dark changes, leaf excision, applied pressure to or anaerobiosis of the root system. Water uptake by the plant (safflower, soybean) mirrored that for water potential changes including times when plant water status (soybean) was undergoing cyclical changes.

  17. Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer

    NASA Astrophysics Data System (ADS)

    Glaz, P.; Gagné, J.-P.; Archambault, P.; Sirois, P.; Nozais, C.

    2015-12-01

    Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L-1 compared to 12.5 mgC L-1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.

  18. Triple-well potential with a uniform depth: Advantageous aspects in designing a multi-stable energy harvester

    NASA Astrophysics Data System (ADS)

    Kim, Pilkee; Son, Dowung; Seok, Jongwon

    2016-06-01

    Analytical expressions for the bi- and tri-stable conditions of a multi-stable energy harvester (MEH) are derived on the basis of bifurcation analyses, and the associated multi-stable regions are characterized in a 2-D parametric space. It is found that a special boundary condition exists for a triple-well with a uniform depth (TU boundary condition), originating from a degenerate pitchfork bifurcation (DPF) point. Interestingly, the outermost well-to-well distance of the triple-well potential, when subjected to the condition that the maximum well depth is kept constant, becomes widest when the well depth is uniform. Accordingly, instead of investigating all possible parametric conditions, the design parameters for the optimal well configuration of the MEH can be sought most efficiently by simply tracing them on the TU boundary. A detailed examination of the potential well configurations along the TU boundary reveals that the most efficient energy harvesting from low-intensity ambient vibrations can be achieved on a TU boundary point, near the DPF point but inevitably a certain distance apart, by inducing an enlarged interwell motion. This investigation is experimentally validated.

  19. Reviving the Ganges Water Machine: potential

    NASA Astrophysics Data System (ADS)

    Amarasinghe, Upali Ananda; Muthuwatta, Lal; Surinaidu, Lagudu; Anand, Sumit; Jain, Sharad Kumar

    2016-03-01

    The Ganges River basin faces severe water challenges related to a mismatch between supply and demand. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3-4 months (June-September) of the monsoon season. Yet, the highest demands occur during the 8-9 months (October-May) of the non-monsoon period. Addressing this mismatch, which is likely to increase with increasing demand, requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River basin is problematic. A range of interventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface-subsurface water exchange, has long been known as the Ganges Water Machine (GWM). The approach of the GWM for providing such SSS is through additional pumping and depleting of the groundwater resources prior to the onset of the monsoon season and recharging the SSS through monsoon surface runoff. An important condition for creating such SSS is the degree of unmet water demand. The paper shows that the potential unmet water demand ranging from 59 to 124 Bm3 year-1 exists under two different irrigation water use scenarios: (i) to increase irrigation in the Rabi (November-March) and hot weather (April-May) seasons in India, and the Aman (July-November) and Boro (December-May) seasons in Bangladesh, to the entire irrigable area, and (ii) to provide irrigation to Rabi and the hot weather season in India and the Aman and Boro seasons in Bangladesh to the entire cropped area. However, the potential for realizing the unmet irrigation demand is high only in 7 sub-basins in the northern and eastern parts, is moderate to low in 11 sub-basins in the middle, and has little or no potential in 4 sub

  20. Suitability of giant reed (Arundo donax L.) for anaerobic digestion: effect of harvest time and frequency on the biomethane yield potential.

    PubMed

    Ragaglini, Giorgio; Dragoni, Federico; Simone, Marco; Bonari, Enrico

    2014-01-01

    This study aimed to investigate the potential of giant reed for biomethane production by examining the influence of harvest time and frequency on the Biochemical Methane Potential (BMP), the kinetics of biomethane accumulation in batch reactors and the expected methane yield per hectare. The crop was cut at five different times, regrowths from early cuts were harvested in autumn and BMP of each cut was assessed. The highest BMP (392 NL kg VS(-1)) and the best kinetics of methane production were associated to juvenile traits of the crop. By coupling the early cuts with the corresponding regrowths (double harvest), the dry biomass (from 35 to 40 Mg ha(-1)) equaled that obtained by a single cut at end of the season (38 Mg ha(-1)), while the methane yield per hectare (11,585-12,981 Nm(3) ha(-1)) exceeded up to 35% the methane produced with a single harvest at crop maturity (9452 Nm(3) ha(-1)).

  1. Fruit cuticle lipid composition and fruit post-harvest water loss in an advanced backcross generation of pepper (Capsicum sp.).

    PubMed

    Parsons, Eugene P; Popopvsky, Sigal; Lohrey, Gregory T; Lü, Shiyou; Alkalai-Tuvia, Sharon; Perzelan, Yaacov; Paran, Ilan; Fallik, Elazar; Jenks, Matthew A

    2012-09-01

    To understand the role of fruit cuticle lipid composition in fruit water loss, an advanced backcross population, the BC(2)F(2) , was created between the Capsicum annuum (PI1154) and the Capsicum chinense (USDA162), which have high and low post-harvest water loss rates, respectively. Besides dramatic differences in fruit water loss, preliminary studies also revealed that these parents exhibited significant differences in both the amount and composition of their fruit cuticle. Cuticle analysis of the BC(2)F(2) fruit revealed that although water loss rate was not strongly associated with the total surface wax amount, there were significant correlations between water loss rate and cuticle composition. We found a positive correlation between water loss rate and the amount of total triterpenoid plus sterol compounds, and negative correlations between water loss and the alkane to triterpenoid plus sterol ratio. We also report negative correlations between water loss rate and the proportion of both alkanes and aliphatics to total surface wax amount. For the first time, we report significant correlations between water loss and cutin monomer composition. We found positive associations of water loss rate with the total cutin, total C(16) monomers and 16-dihydroxy hexadecanoic acid. Our results support the hypothesis that simple straight-chain aliphatic cuticle constituents form more impermeable cuticular barriers than more complex isoprenoid-based compounds. These results shed new light on the biochemical basis for cuticle involvement in fruit water loss.

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

    PubMed

    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.

  3. Technology assessment of solar energy systems: Potential soil erosion effects of harvesting crop residues for energy production

    NASA Astrophysics Data System (ADS)

    Torpy, M. F.; Habegger, L. J.; Snider, M. A.; Surles, T.

    1981-01-01

    An evaluation is presented of the potential increase in erosion that could result from removal of the ground cover that the residues provide. The study indicates that removal of crop residues sufficient to produce 0.13 and 0.42 x 10 to the 15th power Btu of end-use energy (as specified, respectively, in the two scenarios addressed by the Technology Assessment of Solar Energy Program) would have little effect on soil erosion except in a few areas. An alternative scenario is addressed in which all reasonably available crop residues would be harvested to produce 1.5 x 10 to the 15th power Btu of end-use energy. The approach used in evaluating erosion due to removal of residue is also described.

  4. Microalgae cultivation in urban wastewater: Coelastrum cf. pseudomicroporum as a novel carotenoid source and a potential microalgae harvesting tool.

    PubMed

    Úbeda, Bárbara; Gálvez, José Ángel; Michel, Mónica; Bartual, Ana

    2017-03-01

    The aim of this work was to study the optimal growth and high value-added production of the microalgae Coelastrum cf. pseudomicroporum Korshikov cultivated in urban wastewater. It was observed that C. cf. pseudomicroporum grew ideally in this medium, acting as an efficient nutrient starver. Additionally, the obtained biomass increased carotenoid cell content after saltwater stress. The effects of light intensity and salt stress on its growth rate were analysed. The results showed that this alga can grow very fast using wastewater as culture medium, reaching maximum growth rates of 1.61±0.05day(-1), and tolerating strong irradiances. It was also found that under salt-stress this species could accumulate carotenoids (range 1.73-91.2pgcell(-1)). Moreover, a good harvesting efficiency (96.84%) was observed using Coelastrum exudates as bioflocculant of Scenedesmus sp., so Coelastrum exudates could act as a potential bioflocculant for other species.

  5. Decreased growth-induced water potential: A primary cause of growth inhibition at low water potentials

    SciTech Connect

    Nonami, Hiroshi; Wu, Yajun; Boyer, J.S.

    1997-06-01

    Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of soybean seedlings and the growth and potential difference were monitored in the stems. In water-limited plants, the inhibited stem growth increased when the roots were pressurized and it reverted to the previous rate when the pressure was released. The pressure around the roots was perceived as an increased turgor in the stem in small cells next to the xylem, but not in outlying cortical cells. This local effect implied that water transport was impeded by the small cells. The diffusivity for water was much less in the small cells than in the outlying cells. The small cells thus were a barrier that caused the growth-induced potential difference to be large during rapid growth, but to reverse locally during the early part of a water deficit. Such a barrier may be a frequent property of meristems. Because stem growth responded to the pressure-induced recovery of the potential difference across this barrier, we conclude that a decrease in the growth-induced potential difference was a primary cause of the inhibition.

  6. Wave power potential in Malaysian territorial waters

    NASA Astrophysics Data System (ADS)

    Asmida Mohd Nasir, Nor; Maulud, Khairul Nizam Abdul

    2016-06-01

    Up until today, Malaysia has used renewable energy technology such as biomass, solar and hydro energy for power generation and co-generation in palm oil industries and also for the generation of electricity, yet, we are still far behind other countries which have started to optimize waves for similar production. Wave power is a renewable energy (RE) transported by ocean waves. It is very eco-friendly and is easily reachable. This paper presents an assessment of wave power potential in Malaysian territorial waters including waters of Sabah and Sarawak. In this research, data from Malaysia Meteorology Department (MetMalaysia) is used and is supported by a satellite imaginary obtained from National Aeronautics and Space Administration (NASA) and Malaysia Remote Sensing Agency (ARSM) within the time range of the year 1992 until 2007. There were two types of analyses conducted which were mask analysis and comparative analysis. Mask analysis of a research area is the analysis conducted to filter restricted and sensitive areas. Meanwhile, comparative analysis is an analysis conducted to determine the most potential area for wave power generation. Four comparative analyses which have been carried out were wave power analysis, comparative analysis of wave energy power with the sea topography, hot-spot area analysis and comparative analysis of wave energy with the wind speed. These four analyses underwent clipping processes using Geographic Information System (GIS) to obtain the final result. At the end of this research, the most suitable area to develop a wave energy converter was found, which is in the waters of Terengganu and Sarawak. Besides that, it was concluded that the average potential energy that can be generated in Malaysian territorial waters is between 2.8kW/m to 8.6kW/m.

  7. Processes driving the episodic flux of faecal indicator organisms in streams impacting on recreational and shellfish harvesting waters.

    PubMed

    Wilkinson, Jeremy; Kay, David; Wyer, Mark; Jenkins, Alan

    2006-01-01

    Understanding the process controls on episodic fluxes of faecal indicator organisms (FIOs) is becoming increasingly important for the sustainable management and accurate modelling of water quality in both recreational and shellfish harvesting waters. Both environments exhibit transitory non-compliance with microbiological standards after rainfall episodes despite significant expenditures on control of sewage derived pollutant loadings in recent years. This paper demonstrates the role of wave propagation in the entrainment of FIOs from river channel beds as a contributor to episodes of poor microbial water quality. Previously reported data is reviewed in the light of relationships between wave and mean water travel velocities. High flows and rapid changes in river flow, driven by releases of bacterially pure reservoir water, resulted in elevated FIO concentrations and transient peaks in concentration. The new interpretation of these data suggest three modes of entrainment: (i) immediate wave-front disturbance, (ii) wave propagation lift and post-wave transport at mean flow velocity, and (iii) stochastic erosional mechanisms that maintain elevated bacterial concentrations under steady high flow conditions. This is a significant advance on the previously proposed mechanisms. Understanding these mechanisms provides an aid to managing streams intended for recreational use and emphasises the need to control the timing of high flow generation prior to use of the water body for e.g. canoeing events. In addition the processes highlighted have relevance for the protection of shellfish nurseries, drinking water supply intakes and episodes of poor bathing water quality, and associated health risks.

  8. The Erosive Potential of Some Flavoured Waters

    PubMed Central

    Rees, Jeremy; Loyn, Theresa; Hunter, Lindsay; Sadaghiani, Leili; Gilmour, Alan

    2007-01-01

    Objectives To assess the erosive potential of a number of readily available flavoured waters in the laboratory. Methods The erosive potential was assessed by measuring the pH, neutralisable acidity and ability to erode enamel. These were compared to an orange juice positive control. Results The pH of the flavoured waters ranged from 2.64–3.24 with their neutralisable acidity ranging from 4.16–16.30 mls of 0.1M NaOH. The amount of enamel removed following 1-hour immersion in the drinks ranged from 1.18–6.86 microns. In comparison, the orange juice control had a pH of 3.68, a neutralisable acidity of 19.68 mls of 0.1 M NaOH and removed 3.24 microns of enamel. Conclusions Many of the flavoured waters tested were found to be as erosive as orange juice. This information will be of use to clinicians when counselling patients with tooth surface loss. (Eur J Dent 2007;1:5–9) PMID:19212489

  9. Self-organized multi-species vegetation patterns: the role of connectivity of environmental niches in natural water harvesting ecosystems

    NASA Astrophysics Data System (ADS)

    Callegaro, Chiara; Ursino, Nadia

    2016-04-01

    Self-organizing vegetation patterns are natural water harvesting systems in arid and semi-arid regions of the world and should be imitated when designing man-managed water-harvesting systems for rain-fed crop. Disconnected vegetated and bare zones, functioning as a source-sink system of resources, sustain vegetation growth and reduce water and soil losses. Mechanisms such as soil crusting over bare areas and soil loosening in vegetated areas feed back to the local net facilitation effect and contribute to maintain the patterned landscape structure. Dis-connectivity of run-off production and run-on infiltration sites reduces runoff production at the landscape scale, and increases water retention in the vegetated patches. What is the effect of species adaptation to different resource niches on the landscape structure? A minimal model for two coexisting species and soil moisture balance was formulated, to improve our understanding of the effects of species differentiation on the dynamics of plants and water at single-pattern and landscape scale within a tiger bush type ecosystem. A basic assumption of our model was that soil moisture availability is a proxy for the environmental niche of plant species. Connectivity and dis-connectivity of specific niches of adaptation of two differing plant species was an input parameter of our model, in order to test the effect of coexistence on the ecosystem structure. The ecosystem structure is the model outcome, including: patterns persistence of coexisting species; patterns persistence of one species with exclusion of the other; patterns decline with just one species surviving in a non organized structure; bare landscape with loss of both species. Results suggest that pattern-forming-species communities arise as a result of complementary niche adaptation (niche dis-connecivity), whereas niche superposition (niche connectivity) may lead to impoverishment of environmental resources and loss of vegetation cover and diversity.

  10. Biofilters for stormwater harvesting: understanding the treatment performance of key metals that pose a risk for water use.

    PubMed

    Feng, Wenjun; Hatt, Belinda E; McCarthy, David T; Fletcher, Tim D; Deletic, Ana

    2012-05-01

    A large-scale stormwater biofilter column study was conducted to evaluate the impact of design configurations and operating conditions on metal removal for stormwater harvesting and protection of aquatic ecosystems. The following factors were tested over 8 months of operation: vegetation selection (plant species), filter media type, filter media depth, inflow volume (loading rate), and inflow pollutant concentrations. Operational time was also integrated to evaluate treatment performance over time. Vegetation and filter type were found to be significant factors for treatment of metals. A larger filter media depth resulted in increased outflow concentrations of iron, aluminum, chromium, zinc, and lead, likely due to leaching and mobilization of metals within the media. Treatment of all metals except aluminum and iron was generally satisfactory with respect to drinking water quality standards, while all metals met standards for irrigation. However, it was shown that biofilters could be optimized for removal of iron to meet the required drinking water standards. Biofilters were generally shown to be resilient to variations in operating conditions and demonstrated satisfactory removal of metals for stormwater-harvesting purposes.

  11. Harnessing Potential Evaporation as a Renewable Energy Resource With Water-Saving Benefits

    NASA Astrophysics Data System (ADS)

    Cavusoglu, A. H.; Chen, X.; Gentine, P.; Sahin, O.

    2015-12-01

    Water's large latent heat of vaporization makes evaporation a critical component of the energy balance at the Earth's surface. An immense amount of energy drives the hydrological cycle and is an important component of various weather and climate patterns. However, the potential of harnessing evaporation has received little attention as a renewable energy resource compared to wind and solar energy. Here, we investigate the potential of harvesting energy from naturally evaporating water. Using weather data across the contiguous United States and a modified model of potential evaporation, we estimate the power availability, intermittency, and the changes in evaporation rates imposed by energy conversion. Our results indicate that natural evaporation can deliver power densities similar to existing renewable energy platforms and require little to no energy storage to match the varying power demands of urban areas. This model also predicts additional, and substantial, water savings by reducing evaporative losses. These findings suggest that evaporative energy harvesting can address significant challenges with water/energy interactions that could be of interest to the hydrology community.

  12. Effects of Forest Harvesting on Ecosystem Health in the Headwaters of the New York City Water Supply, Catskill Mountains, New York

    USGS Publications Warehouse

    McHale, Michael R.; Murdoch, Peter S.; Burns, Douglas A.; Baldigo, Barry P.

    2008-01-01

    The effects of forest clearcutting and selective harvesting on forest soils, soil and stream water chemistry, forest regrowth, and aquatic communities were studied in four small headwater catchments. This research was conducted to identify the sensitivity of forested ecosystems to forest disturbance in the northeastern United States. The study area was in the headwaters of the Neversink Reservoir watershed, part of the New York City water supply system, in the Catskill Mountains of southeastern New York. Two sub-catchments of the Shelter Creek watershed were selectively harvested, one in its northern half and one more heavily in its southern half in 1995?96, the Dry Creek watershed was clearcut in the winter of 1996?97, and the Clear Creek watershed was left undisturbed and monitored as a control site. Monitoring was conducted from 4 years before the harvests until 4 years after the harvests. Clearcutting caused a large release of nitrate (NO3-) from watershed soils and a concurrent release of inorganic monomeric aluminum (Alim), which is toxic to some aquatic biota. The increased soil NO3- concentrations measured after the harvest could be completely accounted for by the decrease in nitrogen (N) uptake by watershed trees, rather than an increase in N mineralization and nitrification. The large increase in stream water NO3- and Alim concentrations caused 100-percent mortality of caged brook trout (Salvelinus fontinalis) during the first year after the clearcut and adversely affected macroinvertebrate communities for 2 years after the harvest. Nutrient uptake and biomass accumulation increased in uncut mature trees after the two selective harvests. There was no increase in stream-water NO3- or Alim concentrations, and so there were no adverse affects on macroinvertebrate or trout communities. The amount of tree biomass that can be removed without causing a sharp increase in stream-water NO3- and Alim stream-water concentrations is unknown, but probably depends on

  13. Potential of Cerbera odollam as a bio-fungicide for post-harvest pathogen Penicilium digitatum

    NASA Astrophysics Data System (ADS)

    Singh, Harbant; Yin-Chu, Sue; Al-Samarrai, Ghassan; Syarhabil, Muhammad

    2015-05-01

    Postharvest diseases due to fungal infection contribute to economic losses in agriculture industry during storage, transportation or in the market. Penicillium digitatum is one of the common pathogen responsible for the postharvest rot in fruits. This disease is currently being controlled by synthetic fungicides such as Guazatine and Imazalil. However, heavy use of fungicides has resulted in environmental pollution, such as residue in fruit that expose a significant risk to human health. Therefore, there is a strong need to develop alternatives to synthetic fungicide to raise customer confidence. In the current research, different concentrations (500 to 3000 ppm) of ethanol extract of Cerbera odollam or commonly known as Pong-pong were compared with Neem and the controls (Positive control/Guazatine; Negative control/DMSO) for the anti-fungicide activity in PDA media contained in 10 cm diameter Petri dishes, using a modification of Ruch and Worf's method. The toxicity (Lc50) of the C.odollam extract was determined by Brine-shrimp test (BST). The results of the research indicated that crude extraction from C.odollam showed the highest inhibition rate (93%) and smallest colony diameter (0.63 cm) at 3000 ppm in vitro compared with Neem (inhibition rate: 88%; colony diameter: 1.33 cm) and control (Positive control/Guazatine inhibition rate: 79%, colony diameter: 1.9 cm; Negative control/DMSO inhibition rate: 0%, colony diameter: 9.2 cm). C.odollam recorded Lc50 value of 5 µg/ml which is safe but to be used with caution (unsafe level: below 2 µg/ml). The above anti-microbial activity and toxicity value results indicate that C.odollam has a potential of being a future bio-fungicide that could be employed as an alternative to synthetic fungicide.

  14. Dual-mode triboelectric nanogenerator for harvesting water energy and as a self-powered ethanol nanosensor.

    PubMed

    Lin, Zong-Hong; Cheng, Gang; Wu, Wenzhuo; Pradel, Ken C; Wang, Zhong Lin

    2014-06-24

    When water is passing through the air or an insulating tube, it will contain not only the mechanical energy but also the electrostatic energy due to the existence of triboelectric charges on its surface as a result of contact with the air/solid surface. In this paper, a hybrid triboelectric nanogenerator (TENG) is designed to simultaneously harvest the electrostatic and mechanical energies of flowing water. Water-TENG, mainly constructed by a superhydrophobic TiO2 layer with hierarchical micro/nanostructures, is used to collect the electrostatic energy of water (Output 1). Contact-TENG, composed by a polytetrafluoroethylene film and a layer of assembled SiO2 nanoparticles, is used to collect the mechanical energy of water (Output 1 and Output 2). Using TiO2 nanomaterials in water-TENG provides the advantages of photocatalytic activity and antibacterial property for water purification. Under the impact of a water stream from a household faucet at a flowing rate of 40 mL s(-1), the generated short-circuit current from Output 1 and Output 2 of dual-mode TENG can reach 43 and 18 μA, respectively. The instantaneous output power densities from Output 1 and Output 2 of dual-mode TENG are 1.31 and 0.38 W m(-2), respectively, when connecting to a load resistor of 44 MΩ. The rectified outputs have been applied to drive light-emitting diodes and charge commercial capacitors. Besides, the water-TENG has also been demonstrated as a self-powered nanosensor for ethanol detection.

  15. Water quality . . . potential sources of pollution

    USGS Publications Warehouse

    Vandas, Stephen; Farrar, Frank

    1996-01-01

    What is water quality? To most students, water quality may suggest only "clean" water for drinking, swimming, and fishing. But to the farmer or manufacturer, water quality may have an entirely different meaning. One of the most important issues concerning the quality of water is how that water will be used. Water that is perfectly fine for irrigation might not be suitable for drinking or swimming.

  16. Stripper harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton produced in the High Plains of Texas, Oklahoma, and Kansas and the Blackland, Coastal bend, and Rolling Plains regions of Texas is harvested using brush roll stripper type harvesters. These machines were developed to harvest cotton characterized by low yield, tight boll conformation, and shor...

  17. An ecosystem-based assessment of hairtail ( Trichiurus lepturus) harvested by multi-gears and management implications in Korean waters

    NASA Astrophysics Data System (ADS)

    Kang, Hee Joong; Zhang, Chang Ik; Lee, Eun Ji; Seo, Young Il

    2015-06-01

    Hairtail ( Trichiurus lepturus) has been traditionally harvested by multi-gear types in the Yellow Sea and the East China Sea, except for the East Sea (Sea of Japan) in Korean waters. Six different fishery types such as offshore stownet fishery, offshore longline fishery, large pair-trawl fishery, large purse seine fishery, large otter trawl fishery and offshore angling fishery target to harvest the hairtail stock accounting for about 90% of the total annual catch. We attempted to develop an ecosystem-based fisheries assessment approach, which determines the optimal allocation of catch quotas and fishing efforts for major fisheries. We conducted standardization of fishing effort for six types of hairtail fisheries using a general linear model (GLM), and then estimated maximum sustainable yield (MSY) and maximum economic yield (MEY). Estimated MSY and MEY for the hairtail stock were estimated as 100,151 mt and 97,485 mt, respectively. In addition, we carried out an ecosystem-based risk analysis to obtain species risk index (SRI), which was applied to adjusting the optimal proportion of fishing effort for six hairtail fisheries as a penalty or an incentive. As a result, fishing effort ratios were adjusted by SRI for the six fisheries types. Also, the total allowable catch (TAC) was estimated as 97,485 mt and the maximum net profit at TAC by the hairtail fisheries was estimated as 778 billion won (USD 765 million).

  18. Identification of Suitable Water Harvesting Zones Based on Geomorphic Resources for Drought Areas: A Case Study of Una District, Himachal Pradesh, India.

    NASA Astrophysics Data System (ADS)

    Prakasam, D. C., Jr.; Zaman, B.

    2014-12-01

    Water is one of the most vital natural resource and its availability and quality determine ecosystem productivity, both for agricultural and natural systems. Una district is one of the major potential agricultural districts in Himachal Pradesh, India. More than 70% of the population of this district is engaged in agriculture and allied sectors and major crops grown are maize, wheat, rice, sugarcane, pulses and vegetables. The region faces drought every year and about 90 per cent of the area is water stressed. This has resulted in crop loss and shortage of food and fodder. The sources of drinking water, small ponds and bowlies dry-up during summer season resulting in scarcity of drinking water. Una district receives rainfall during monsoons from June to September and also during non-monsoon period (winter). The annual average rainfall in the area is about 1040 mm with 55 average rainy days. But due to heavy surface run-off the farmers not able to cultivate the crops more than once in a year. Past research indicate that the geomorphology of the Una district might be responsible for such droughts as it controls the surface as well as ground water resources. The research proposes to develop a water stress model for Una district using the geomorphic parameters, water resource and land use land cover data of the study area. Using Survey of India topographical maps (1:50000), the geomorphic parameters are extracted. The spatial layers of these parameters i.e. drainage density, slope, relative relief, ruggedness index, surface water body's frequency are created in GIS. A time series of normalized remotely sensed data of the study area is used for land use land cover classification and analyses. Based on the results from the water stress model, the drought/water stress areas and water harvesting zones are identified and documented. The results of this research will help the general population in resolving the drinking water problem to a certain extent and also the

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

    PubMed

    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.

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

    PubMed

    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.

  1. Estimating water consumption of potential natural vegetation on global dry lands: building an LCA framework for green water flows.

    PubMed

    Núñez, Montserrat; Pfister, Stephan; Roux, Philippe; Antón, Assumpció

    2013-01-01

    This study aimed to provide a framework for assessing direct soil-water consumption, also termed green water in the literature, in life cycle assessment (LCA). This was an issue that LCA had not tackled before. The approach, which is applied during the life cycle inventory phase (LCI), consists of quantifying the net change in the evapo(transpi)ration of the production system compared to the natural reference situation. Potential natural vegetation (PNV) is used as the natural reference situation. In order to apply the method, we estimated PNV evapotranspiration adapted to local biogeographic conditions, on global dry lands, where soil-water consumption impacts can be critical. Values are reported at different spatial aggregation levels: 10-arcmin global grid, ecoregions (501 units), biomes (14 units), countries (124 units), continents, and a global average, to facilitate the assessment for different spatial information detail levels available in the LCI. The method is intended to be used in rain-fed agriculture and rainwater harvesting contexts, which includes direct soil moisture uptake by plants and rainwater harvested and then reused in production systems. The paper provides the necessary LCI method and data for further development of impact assessment models and characterization factors to evaluate the environmental effects of the net change in evapo(transpi)ration.

  2. Hybrid energy harvesting using active thermal backplane

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  3. Orientation-Induced Effects of Water Harvesting on Humps-on-Strings of Bioinspired Fibers

    NASA Astrophysics Data System (ADS)

    Chen, Yuan; Li, Dan; Wang, Ting; Zheng, Yongmei

    2016-01-01

    Smart water-collecting functions are naturally endowed on biological surfaces with unique wettable microstructures, e.g., beetle back with “alternate hydrophobic, hydrophilic micro-regions”, and spider silk with wet-rebuilt “spindle-knot, joint” structures. Enlightened by the creature features, design of bio-inspired surfaces becomes the active issue in need of human beings for fresh water resource. Recently, as observed from spider web in nature, the net of spider silk is usually set in different situations and slopes in air, thus spider silks can be placed in all kinds of orientations as capturing water. Here, we show the styles and orientations of hump-on-string to control the ability of water collection as bioinspired silks are fabricated successfully. As different strings, sizes (height, length, pitch) of humps can become the controlling on volumes of extreme water drops. It is related to the different solid/liquid contact regions resulting in the as-modulated wet adhesion due to orientations of humps-on-strings. The conversion of high-low adhesion can be achieved to rely on orientations for the effect of capturing water drops. These studies offer an insight into enhancement of water collection efficiency and are helpful to design smart materials for controlled water drop capture and release via conversions of high-low adhesion.

  4. Orientation-Induced Effects of Water Harvesting on Humps-on-Strings of Bioinspired Fibers

    PubMed Central

    Chen, Yuan; Li, Dan; Wang, Ting; Zheng, Yongmei

    2016-01-01

    Smart water-collecting functions are naturally endowed on biological surfaces with unique wettable microstructures, e.g., beetle back with “alternate hydrophobic, hydrophilic micro-regions”, and spider silk with wet-rebuilt “spindle-knot, joint” structures. Enlightened by the creature features, design of bio-inspired surfaces becomes the active issue in need of human beings for fresh water resource. Recently, as observed from spider web in nature, the net of spider silk is usually set in different situations and slopes in air, thus spider silks can be placed in all kinds of orientations as capturing water. Here, we show the styles and orientations of hump-on-string to control the ability of water collection as bioinspired silks are fabricated successfully. As different strings, sizes (height, length, pitch) of humps can become the controlling on volumes of extreme water drops. It is related to the different solid/liquid contact regions resulting in the as-modulated wet adhesion due to orientations of humps-on-strings. The conversion of high-low adhesion can be achieved to rely on orientations for the effect of capturing water drops. These studies offer an insight into enhancement of water collection efficiency and are helpful to design smart materials for controlled water drop capture and release via conversions of high-low adhesion. PMID:26812942

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

    NASA Astrophysics Data System (ADS)

    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. GROUND WATER CONTAMINATION POTENTIAL FROM STORMWATER INFILTRATION

    EPA Science Inventory

    Prior to urbanization, ground water recharge resulted from infiltration of precipitation through pervious surfaces, including grasslands and woods. This infiltration water was relatively uncontaminated. With urbanization, the permeable soil surface area through which recharge by...

  7. Global potential to increase crop production through water management in rainfed agriculture

    NASA Astrophysics Data System (ADS)

    Rost, Stefanie; Gerten, Dieter; Hoff, Holger; Lucht, Wolfgang; Falkenmark, Malin; Rockström, Johan

    2009-12-01

    This modeling study explores—spatially explicitly, for current and projected future climate, and for different management intensity levels—the potential for increasing global crop production through on-farm water management strategies: (a) reducing soil evaporation ('vapor shift') and (b) collecting runoff on cropland and using it during dry spells ('runoff harvesting'). A moderate scenario, implying both a 25% reduction in evaporation and a 25% collection of runoff, suggests that global crop production can be increased by 19%, which is comparable with the effect of current irrigation (17%). Climate change alone (three climate models, SRES A2r emissions and population, constant land use) will reduce global crop production by 9% by 2050, which could be buffered by a vapor shift level of 50% or a water harvesting level of 25%. Even if realization of the beneficial effects of rising atmospheric CO2 concentration upon plants was ensured (by fertilizer use) in tandem with the above moderate water management scenario, the water available on current cropland will not meet the requirements of a world population of 9-10 billion.

  8. Comparing the levels of trace metal from two fish species harvested from treated waste water in Pretoria, South Africa.

    PubMed

    Olowoyo, J O; Mdakane, S T R; Okedeyi, O O

    2011-06-15

    The persistent problem of water scarcity with the ever increasing demand of water has necessitated the reuse of effluent in agriculture. The present study evaluated the reuse of treated waste water and bioaccumulation properties of two fish species from a manmade lake. Trace metals content of two fish species: Clarias gariepinus and Cyprinus carpio and levels of trace metals from waste water in the lake where the fish species were harvested were determined by Inductive Couple Plasma-Optical Emission Spectrometer (ICP-OES). The trace metal values from fish samples ranged between 0.45-4.41 microg g(-1) for Cu, 16.45-72.23 microg g(-1) for Zn, 1.92-4.71 microg g(-1) for Cr, 2.45-5.65 microg g(-1) for Ni, 10.23-44.31 microg g(-1) for Mn, 9.67-46.59 microg g(-1) for Fe and 0.12-0.56 microg g(-1) for Pb. The carp exhibited a significantly higher concentration for the trace metals for all the parts analyzed (p<0.01). The levels of trace metals concentration from Cyprinus carpio was in the order liver>gill>muscle>bone and metal accumulation was in the order Zn>Fe>Mn>Cr>Ni >Cu>Pb. The concentration of trace metals such as zinc, iron, chromium and nickel were higher than the recommended legal limits for human consumption. The result revealed that properly treated waste water could be used for the purpose of aquaculture. Clarias gariepinus bio accumulated more trace metals from the lake when compared with Cyprinus carpio.

  9. Design and testing of large fog collectors for water harvesting in Asir region, Kingdom of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Abualhamayel, H. I.; Gandhidasan, P.

    2010-07-01

    The region of Asir is located in the southwestern part of the Kingdom of Saudi Arabia between longitudes 41 - 45 E and latitudes 17 - 21 N. Known for its natural beauty and cool climate delight the visitors and the region has become a destination for tourists. One of the main problems in the Asir region is the high demand for water during tourism seasons especially in view of the rapidly growing tourism sector. Flourishing tourism in the region is challenged by the scarcity of water resources and there is urgent need to identify alternative sources of potable water. It is found that fog water collection is a viable resource and Asir region is the most suitable location for fog water harvesting. An operational fog water collection project was initiated in 2007 to provide fresh water supply. Al-Sooda, situated at an altitude of about 3,000 m, was identified as the most suitable experimental site and two large fog collectors measuring 20 m by 2 m each were erected in 2009. The distance between the two sites is about 2 km. This paper gives the methods used to select the experimental site and the design of the large fog collection system. The fog collectors are flat rectangular nets supported by a post at both ends and arranged perpendicular to the direction of the prevailing wind. The collection surface, comprising two layers of black polypropylene mesh net, is fastened laterally to the posts with a set of fastening bars. The aluminum trough located below the mesh net catches the water that runs down the net and carries it to a pipe connected to the storage tank. Because the fog collectors are long and require space for guy wires for the posts, the basic site consideration is that at least 25 m of horizontal land available for the erection. Meteorological instruments and the portable weather station are used to measure the climatic data which are recorded three times a day, namely at 7:00, 14:00 and 19:00 h. On average, yields of about 5 to 6 L/m2 per day are collected

  10. Potential of water surface-floating microalgae for biodiesel production: Floating-biomass and lipid productivities.

    PubMed

    Muto, Masaki; Nojima, Daisuke; Yue, Liang; Kanehara, Hideyuki; Naruse, Hideaki; Ujiro, Asuka; Yoshino, Tomoko; Matsunaga, Tadashi; Tanaka, Tsuyoshi

    2017-03-01

    Microalgae have been accepted as a promising feedstock for biodiesel production owing to their capability of converting solar energy into lipids through photosynthesis. However, the high capital and operating costs, and high energy consumption, are hampering commercialization of microalgal biodiesel. In this study, the surface-floating microalga, strain AVFF007 (tentatively identified as Botryosphaerella sudetica), which naturally forms a biofilm on surfaces, was characterized for use in biodiesel production. The biofilm could be conveniently harvested from the surface of the water by adsorbing onto a polyethylene film. The lipid productivity of strain AVFF007 was 46.3 mg/L/day, allowing direct comparison to lipid productivities of other microalgal species. The moisture content of the surface-floating biomass was 86.0 ± 1.2%, which was much lower than that of the biomass harvested using centrifugation. These results reveal the potential of this surface-floating microalgal species as a biodiesel producer, employing a novel biomass harvesting and dewatering strategy.

  11. Evaluation of rotary, slapper, and sway blueberry mechanical harvesters for potential fruit impact points using a miniature instrumented sphere

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry production in the United States has expanded to more than 63,000 acres, a 55 percent increase over the past decade. Blueberries are prone to bruise damages and the vast majority of the fruit destined for the fresh market is hand-harvested. Bruising leads to a rapid increase in the amount...

  12. Corn stover harvest increases herbicide movement to subsurface drains – Root Zone Water Quality Model simulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Removal of crop residues for bioenergy production can alter soil hydrologic properties, but there is little information on its impact on transport of herbicides and their degradation products to subsurface drains. The Root Zone Water Quality Model, previously calibrated using measured fl...

  13. Tree harvesting

    SciTech Connect

    Badger, P.C.

    1995-12-31

    Short rotation intensive culture tree plantations have been a major part of biomass energy concepts since the beginning. One aspect receiving less attention than it deserves is harvesting. This article describes an method of harvesting somewhere between agricultural mowing machines and huge feller-bunchers of the pulpwood and lumber industries.

  14. Potential Health Impacts of Hard Water

    PubMed Central

    Sengupta, Pallav

    2013-01-01

    In the past five decades or so evidence has been accumulating about an environmental factor, which appears to be influencing mortality, in particular, cardiovascular mortality, and this is the hardness of the drinking water. In addition, several epidemiological investigations have demonstrated the relation between risk for cardiovascular disease, growth retardation, reproductive failure, and other health problems and hardness of drinking water or its content of magnesium and calcium. In addition, the acidity of the water influences the reabsorption of calcium and magnesium in the renal tubule. Not only, calcium and magnesium, but other constituents also affect different health aspects. Thus, the present review attempts to explore the health effects of hard water and its constituents. PMID:24049611

  15. Water required, water used, and potential water sources for rice irrigation, north coast of Puerto Rico

    USGS Publications Warehouse

    Roman-Mas, A. J.

    1988-01-01

    A 3-yr investigation was conducted to determine the water required and used (both consumed and applied) for irrigation in the rice-growing areas of Vega Baja, Manati, and Arecibo along the north coast. In addition, the investigation evaluated the water resources of each area with regard to the full development of rice farming areas. Based on experiments conducted at selected test farms, water required ranged from 3.13 to 5.25 acre-ft/acre/crop. The amount of water required varies with the wet and dry seasons. Rainfall was capable of supplying from 31 to 70% of the water required for the measured crop cycles. Statistical analyses demonstrated that as much as 95% of rainfall is potentially usable for rice irrigation. The amount of water consumed differed from the quantity required at selected test farms. The difference between the amount of water consumed and that required was due to unaccounted losses or gains, seepage to and from the irrigation and drainage canals, and lateral leakage through levees. Due to poor water-management practices, the amount of water applied to the farms was considerably larger than the sum of the water requirement and the unaccounted losses or gains. Rivers within the rice growing areas constitute the major water supply for rice irrigation. Full development of these areas will require more water than the rivers can supply. Efficient use of rainfall can significantly reduce the water demand from streamflow. The resulting water demand, however, would still be in excess of the amount available from streamflow. Groundwater development in the area is limited because of seawater intrusion in the aquifers underlying the rice-growing areas. Capture of seepage to the aquifers using wells located near streams, artificial recharge, and development of the deep artesian system can provide additional water for rice irrigation. (Author 's abstract)

  16. Spatial multi-criteria analysis for selecting potential sites for aquifer recharge via harvesting and infiltration of surface runoff in north Jordan

    NASA Astrophysics Data System (ADS)

    Steinel, Anke; Schelkes, Klaus; Subah, Ali; Himmelsbach, Thomas

    2016-11-01

    In (semi-)arid regions, available water resources are scarce and groundwater resources are often overused. Therefore, the option to increase available water resources by managed aquifer recharge (MAR) via infiltration of captured surface runoff was investigated for two basins in northern Jordan. This study evaluated the general suitability of catchments to generate sufficient runoff and tried to identify promising sites to harvest and infiltrate the runoff into the aquifer for later recovery. Large sets of available data were used to create regional thematic maps, which were then combined to constraint maps using Boolean logic and to create suitability maps using weighted linear combination. This approach might serve as a blueprint which could be adapted and applied to similar regions. The evaluation showed that non-committed source water availability is the most restricting factor for successful water harvesting in regions with <200 mm/a rainfall. Experiences with existing structures showed that sediment loads of runoff are high. Therefore, the effectiveness of any existing MAR scheme will decrease rapidly to the point where it results in an overall negative impact due to increased evaporation if maintenance is not undertaken. It is recommended to improve system operation and maintenance, as well as monitoring, in order to achieve a better and constant effectiveness of the infiltration activities.

  17. Effects of harvesting forest biomass on water and climate regulation services: A synthesis of long-term ecosystem experiments in eastern North America

    USGS Publications Warehouse

    Caputo, Jesse; Beier, Colin D; Groffman, Peter M; Burns, Douglas A.; Beall, Frederick D; Hazlett, Paul W.; Yorks, Thad E

    2016-01-01

    Demand for woody biomass fuels is increasing amidst concerns about global energy security and climate change, but there may be negative implications of increased harvesting for forest ecosystem functions and their benefits to society (ecosystem services). Using new methods for assessing ecosystem services based on long-term experimental research, post-harvest changes in ten potential benefits were assessed for ten first-order northern hardwood forest watersheds at three long-term experimental research sites in northeastern North America. As expected, we observed near-term tradeoffs between biomass provision and greenhouse gas regulation, as well as tradeoffs between intensive harvest and the capacity of the forest to remediate nutrient pollution. In both cases, service provision began to recover along with the regeneration of forest vegetation; in the case of pollution remediation, the service recovered to pre-harvest levels within 10 years. By contrast to these two services, biomass harvesting had relatively nominal and transient impacts on other ecosystem services. Our results are sensitive to empirical definitions of societal demand, including methods for scaling societal demand to ecosystem units, which are often poorly resolved. Reducing uncertainty around these parameters can improve confidence in our results and increase their relevance for decision-making. Our synthesis of long-term experimental studies provides insights on the social-ecological resilience of managed forest ecosystems to multiple drivers of change.

  18. Stormwater harvesting for irrigation purposes: an investigation of chemical quality of water recycled in pervious pavement system.

    PubMed

    Nnadi, Ernest O; Newman, Alan P; Coupe, Stephen J; Mbanaso, Fredrick U

    2015-01-01

    Most available water resources in the world are used for agricultural irrigation. Whilst this level of water use is expected to increase due to rising world population and land use, available water resources are expected to become limited due to climate change and uneven rainfall distribution. Recycled stormwater has the potential to be used as an alternative source of irrigation water and part of sustainable water management strategy. This paper reports on a study to investigate whether a sustainable urban drainage system (SUDS) technique, known as the pervious pavements system (PPS) has the capability to recycle water that meets irrigation water quality standard. Furthermore, the experiment provided information on the impact of hydrocarbon (which was applied to simulate oil dripping from parked vehicles onto PPS), leaching of nutrients from different layers of the PPS and effects of nutrients (applied to enhance bioremediation) on the stormwater recycling efficiency of the PPS. A weekly dose of 6.23 × 10(-3) L of lubricating oil and single dose of 17.06 g of polymer coated controlled-release fertilizer granules were applied to the series of 710 mm × 360 mm model pervious pavement structure except the controls. Rainfall intensity of 7.4 mm/h was applied to the test models at the rate of 3 events per week. Analysis of the recycled water showed that PPS has the capability to recycle stormwater to a quality that meets the chemical standards for use in agricultural irrigation irrespective of the type of sub-base used. There is a potential benefit of nutrient availability in recycled water for plants, but care should be taken not to dispose of this water in natural water courses as it might result in eutrophication problems.

  19. The potential of electrical impedance on the performance of galloping systems for energy harvesting and control applications

    NASA Astrophysics Data System (ADS)

    Abdelmoula, H.; Abdelkefi, A.

    2016-05-01

    Performances of galloping-based piezoelectric systems for energy harvesting and control applications when considering complex electrical impedance are investigated. The aeroelastic system is composed of a unimorph piezoelectric cantilever beam with a square cylinder attached at its tip and subjected to a uniform flow speed. A quasi-steady representation is used to model the aerodynamic force. A nonlinear distributed-parameter model is developed when considering various scenarios of connections between electrical resistance, capacitance, and inductance. Theoretical strategies are developed in order to determine the relation between the onset speed of galloping and the components of the electrical impedance. The results show that the presence of the electrical capacitance and inductance is not beneficial in terms of improving the levels of the harvested power crossing the load resistance. On the other hand, it is shown that the inclusion of these electrical components may be useful for energy harvesting purposes when charging/discharging batteries. One of the important findings of this research study is that including an electrical inductance in connection to a load resistance is very beneficial for control purposes because a significant increase in the onset speed of instability can be obtained for well-defined values of the electrical components. Analytical predictions of these optimum values of the electrical inductance and resistance are determined and compared with numerical simulations. It is also demonstrated that supercritical Hopf bifurcations take place at this controlled optimal configuration without having any hysteresis and jumps when increasing and decreasing the wind speeds.

  20. The Recovery of Net Ecosystem Productivity and Water Use Efficiency of a Harvested Aspen Forest in the Western Boreal Plain, Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Petrone, R. M.; Giroux, K.; Brown, S. M.; Devito, K. J.; Chasmer, L. E.

    2011-12-01

    The Utikuma Region Study Area (URSA) is located in north-central Alberta, Canada, in a region where aspen (Populus Tremuloides Michx.) dominate the upland vegetation of the Western Boreal Plain (WBP). Due to the heterogeneity of the surficial geology as well as the sub-humid climate where the water balance is dominated by evapotranspiration, the carbon balance across this landscape is highly variable. Moreover, the upland aspen regions represent significant stores of carbon. More recently, aspen stands have become valuable commercial resources for pulp and paper processing. These stands are harvested through clear cutting and are generally left to regenerate on their own, a process which occurs rapidly in clonal species like aspen. At URSA, three eddy covariance towers were setup during the length of the growing seasons of 2005-2009 to investigate the CO2 exchange under natural conditions and the rate of recovery after harvest. In 2007, the south facing slope of URSA was harvested and the north facing slope in 2008. This study examines the inter-annual variability and recovery (after harvest) of net ecosystem productivity (NEP) and water use efficiency (WUE) as controlled by environmental variables such as air temperature, precipitation, soil moisture, growing season length and LAI.

  1. [Determination of the redox potential of water saturated with hydrogen].

    PubMed

    Piskarev, I M; Ushkanov, V A; Aristova, N A; Likhachev, P P; Myslivets, T C

    2010-01-01

    It has been shown that the redox potential of water saturated with hydrogen is -500--700 mV. The time of the establishment of the potential is 24 h. The potential somewhat increases with increasing volume of hydrogen introduced to a reservoir with water and practically does not depend on the presence of additions in water, provided these additions are not reduced by hydrogen. The pH value of water does not change after the addition of water. In a glass vessel with a metallic cover resting on the side, no decrease in potential during the 2.5-month storage was observed. In plastic bottles, the content of hydrogen decreased; on storage for more than two weeks, it disappeared almost completely, and as a result, the potential increased after storage for three to four weeks to a level near zero. In an open vessel, the potential remained negative for two days.

  2. A water-powered Energy Harvesting system with Bluetooth Low Energy interface

    NASA Astrophysics Data System (ADS)

    Kroener, M.; Allinger, K.; Berger, M.; Grether, E.; Wieland, F.; Heller, S.; Woias, P.

    2016-11-01

    This paper reports the design, and testing of a water turbine generator system for typical flow rates in domestic applications, with an integrated power management and a Bluetooth low energy (BLE) based RF data transmission interface. It is based on a commercially available low cost hydro generator. The generator is built into a housing with optimized reduced fluidic resistance to enable operation with flow rates as low as 6 l/min. The power management combines rectification, buffering, defined start-up, and circuit protection. An MSP430FR5949 microcontroller is used for data acquisition and processing. The data are transmitted via RF, using a Bluegiga BLE112 module in advertisement mode, to a PC where the measured flow rate is stored and displayed. The transmission rate of the wireless sensor node (WSN) is set to 1 Hz if enough power is available, which is the case for flow rates above 5.5 l/min. The electronics power demand is calculated to be 340 μW in average, while the generator is capable of delivering more than 200 mW for flow rates above 15 l/min.

  3. Preliminary Study on Norovirus, Hepatitis A Virus, Escherichia coli and their Potential Seasonality in Shellfish from Different Growing and Harvesting Areas in Sardinia Region

    PubMed Central

    Fattaccio, Maria Caterina; Salza, Sara; Canu, Antonella; Marongiu, Edoardo; Pisanu, Margherita

    2014-01-01

    Edible lamellibranch molluscs can be involved in foodborne disease and infections of varying severity. They are filter feeding animals able to retain and concentrate in their organism bacteria, parasites, viruses and biotoxins marine algae present in their external environment. Major shellfish harvesting and relaying areas from different areas in Sardinia region were defined and studied by analysing different physicochemical parameters in the water and the levels of Escherichia coli (E. coli), Norovirus (NoVs) genogroup I (NoVGI), NoVs genogroup II (NoVGII) and hepatitis A virus (HAV) in the shellfish harvested and farmed from 2009 to 2011. During that period the identification of the viral agents was carried out by one step real-time reverse transcriptase-polymerase chain reaction and Escherichia coli according to ISO TS 16649-3:2005 standard method. A total of 1266 shellfish samples were tested for NoVGI, NoVGII, HAV and faecal indicators. Norovirus contamination was found in 337 samples (26.6%); only one sample of mussels was positive for HAV (0.08%); while E. coli prevalence was 3.8% in shellfish. The probability of observing shellfish samples positive for NoVs, HAV and E. coli presence was associated with harvesting, growing and relaying areas, period of sampling, environmental parameters, animal species (P<0.05). Although the higher prevalence rate of human enteropathogenic viruses was found in the winter period, we did not observe a significant relationship between the effect of seawater temperature (seasonality) and NoVs presence all over the study period; in fact, according to statistical analysis, the presence of human enteric viruses does not appear to be related to water temperature. PMID:27800328

  4. Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: effects of frond harvesting regimes and arsenic levels in refill water.

    PubMed

    Natarajan, Seenivasan; Stamps, Robert H; Ma, Lena Q; Saha, Uttam K; Hernandez, Damaris; Cai, Yong; Zillioux, Edward J

    2011-01-30

    A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater using Pteris vittata (Chinese brake fern) was successfully tested in a field. In this 30-wk study, three frond-harvesting regimes (all, mature, and senescing fronds) and two water-refilling schemes to compensate for evapotranspiration (high-As water of 140-180 μg/L and low-As water of <7 μg/L) were investigated. Two experiments (Cycle 1 and Cycle 2) were conducted using the same plants in 24 tanks with each containing 600 L of arsenic-contaminated groundwater and 32 ferns. During Cycle 1 and with initial As of 140 μg/L, As in tanks refilled with low-As water was reduced to <10 μg/L in 8 wks compared to <10 μg/L in 17 wks in tanks refilled with high-As water. During Cycle 2 and with initial As of 180 μg/L, the remediation time was reduced by 2-5 wks, indicating that more established ferns were more efficient. In areas where clean water is limiting, refilling high-As water coupled with harvesting senescing fronds is recommended for more effective As phytoremediation.

  5. Nicotine exposure and decontamination on tobacco harvesters' hands.

    PubMed

    Curwin, Brian D; Hein, Misty J; Sanderson, Wayne T; Nishioka, Marcia G; Buhler, Wayne

    2005-07-01

    Green tobacco sickness is an illness associated with nicotine exposures among tobacco harvesters. Agricultural workers manually harvest tobacco and thus have the potential for skin exposure to nicotine, particularly on the hands. Often gloves are not worn as it hinders the harvesters' ability to harvest the tobacco leaves. The purposes of this study were to measure the concentration of nicotine residue on the hands of tobacco harvesters and the effectiveness of hand washing at removing the residue. Wipe samples from the hands of 12 tobacco harvesters were collected at the end of morning and afternoon work periods over two consecutive days. Each harvester had one hand wiped before washing his hands, and the other hand wiped after washing his hands with soap and water. Eight samples per worker were collected over the two days for a total of 96 samples collected. In addition to the hand-wipe samples, leaf-wipe samples were collected from 15 tobacco plants to estimate the amount of nicotine residue on the plants. The average nicotine level in leaf-wipe samples was 1.0 microg cm(-2). The geometric mean pre-wash and post-wash nicotine levels on the hands were 10 and 0.38 microg cm(-2), respectively. Nicotine leaf-wipe level, right or left hand and time of sampling did not significantly influence exposure. Job position-working on the bottom versus the top of the tobacco harvesting machine-was associated with nicotine levels. Pre-wash nicotine levels were higher for workers on the bottom of the harvester but not significantly higher (P = 0.17). Post-wash nicotine levels were significantly higher for workers on the bottom of the harvester (P = 0.012). A substantial amount of nicotine was transferred to the hands, but washing with soap and water in the field significantly reduced nicotine levels by an average of 96% (P < 0.0001).

  6. [Effects of ridge and furrow rain harvesting with supplemental irrigation on winter wheat photosynthetic characteristics, yield and water use efficiency in Guanzhong irrigation district].

    PubMed

    Zhang, Yu; Han, Qing-fang; Cheng, Xue-feng; Yang, Shan-shan; Jia, Zhi-kuan; Ding, Rui-xia; Ren, Xiao-long; Nie, Jun-feng

    2015-05-01

    A field experiment was conducted to determine the regulation of crop photosynthesis and output and water saving effect under ridge and furrow rain harvesting with supplemental irrigation in Guanzhong irrigation district. The experiment was set with 5 treatments with irrigation at returning green stage, and the widths of both ridge and furrow being 60 cm. T1, T2 and T3 were in the ridge and furrow rain harvesting planting pattern, with the irrigation volumes being 0, 375 and 750 m3 · hm(-2) respectively, T4 was flat planting with irrigation (border irrigation) of 750 m3 · hm(-2) and CK was flat planting without irrigation. Effects on winter wheat photosynthetic organs, photosynthetic rate, yield and water use efficiency, etc. were tested. The results showed that compared with T4, T1, T2 and T3 treatments increased the grain yield by 2.8%, 9.6% and 18.9%, improved the harvest index by 2.0% to 8.5%, advanced the flag leaf chlorophyll content by 41.9% to 64.4% significantly, and improved the 0-40 cm layer soil moisture content by 0.1%-4.6% during the whole growth period. Photosynthetic rates at the flowering and filling stages also increased by 22.3% to 54.2% and -4.3% to 67.2%, respectively. Total water use efficiencies (WUEy) were 17.9%, 10.4% and 15.4% higher than that of T4, and 69.3%, 58.6% and 65.7% higher than that of CK (P < 0.05), respectively, and enhanced precipitation utilization efficiency ( PUE ) by 94.3%-124.5% than CK. Leaf areas of T2 and T3 treatments at each growth stage were significantly higher than that of T4 and CK, irrigation water use efficiencies (IUE) were 119.1% and 18.8% higher than that of T4, respectively. Therefore, it was concluded that ridge and furrow rain harvesting cultivation could maintain higher grain yield than border irrigation without irrigation or with irrigation reduction by 50%. The utilization efficiency of irrigation water under the condition of irrigation reduction by 50% was improved significantly, and the ridge and

  7. Influence of temperature gradients on leaf water potential.

    PubMed

    Wiebe, H H; Prosser, R J

    1977-02-01

    Water potential was monitored at nine locations along single maize (Zea mays L.) leaf blades with aluminum block in situ thermocouple hygrometers. Water potential showed a continuous decrease toward the tip, with a 2- to 4-bar difference between leaf base and tip under both moist and dry soil conditions. The water potential difference between the soil and the leaf base was about 4 bars. Water potentials decreased during the day and during a drying cycle, and increased at night and after irrigation. Heating a band of a leaf to 40 C or cooling it to 7 C had no influence on the water potential of the affected portion when this was corrected for hygrometer output over standard calibrating solutions at the respective temperatures. Heating or cooling a portion of a leaf had neither short nor long term effects on water potential of more distal leaf portions continuously monitored by hygrometers in dew point readout. Water potential fluctuated with an amplitude of about 1.5 bars and an irregular period of 10 to 30 minutes. Measurements with silver foil in situ psychrometers gave similar results.

  8. A hydrostatic pressure-cycle energy harvester

    NASA Astrophysics Data System (ADS)

    Shafer, Michael W.; Hahn, Gregory; Morgan, Eric

    2015-04-01

    There have been a number of new applications for energy harvesting with the ever-decreasing power consumption of microelectronic devices. In this paper we explore a new area of marine animal energy harvesting for use in powering tags known as bio-loggers. These devices record data about the animal or its surroundings, but have always had limited deployment times due to battery depletion. Reduced solar irradiance below the water's surface provides the impetus to explore other energy harvesting concepts beyond solar power for use on marine animals. We review existing tag technologies in relation to this application, specifically relating to energy consumption. Additionally, we propose a new idea for energy harvesting, using hydrostatic pressure changes as a source for energy production. We present initial testing results of a bench-top model and show that the daily energy harvesting potential from this technology can meet or exceed that consumed by current marine bio-logging tags. The application of this concept in the arena of bio-logging technology could substantially increase bio-logger deployment lifetimes, allowing for longitudinal studies over the course of multiple breeding and/or migration cycles.

  9. Correlation between nitrate contamination and ground water pollution potential.

    PubMed

    Chowdhury, Shafiul H; Kehew, Alan E; Passero, Richard N

    2003-01-01

    AQUIPRO, a PC-based method, was used to assess aquifer vulnerability using digital water well logs. The AQUIPRO model is a parameter/factor weighting system for rating the pollution potential of an aquifer. This method uses the well depth, as well as the clay and partial clay thickness in a well, to generate pollution potential scores. In this model, aquifer protection increases as the AQUIPRO vulnerability scores increase and ground water pollution potential decreases. Computerized water well records of 2435 domestic wells with partial chemistry data were used to determine the ground water pollution potential of Kalamazoo County, Michigan. Theoretically, low AQUIPRO pollution potential scores should have more frequent occurrences of ground water contamination events than areas with high AQUIPRO scores with similar land-use, well construction, and well densities. The relative AQUIPRO scores were compared with the frequency of occurrences of nitrate-N in ground water wells. The average nitrate-N concentrations within each relative AQUIPRO vulnerability scores category were also compared. The results indicate that domestic wells containing 5 mg/L or more nitrate-N showed a positive correlation between the frequency of occurrences of nitrate-N and relative decrease of AQUIPRO (r2 = 0.99) vulnerability scores. In other words, as the ground water pollution potential increases, the occurrence frequency of nitrate-N also increases. Furthermore, the results show that as the relative AQUIPRO (r2 = 0.96) vulnerability scores decrease, the mean nitrate-N concentrations also increase.

  10. Earth observing data and methods for advancing water harvesting technologies in the semi-arid rain-fed environments of India

    USGS Publications Warehouse

    Sharma, C.; Thenkabail, P.; Sharma, R. R.

    2011-01-01

    The paper develops approaches and methods of modeling and mapping land and water productivity of rain-fed crops in semi-arid environments of India using hyperspectral, hyperspatial, and advanced multispectral remote sensing data and linking the same to field-plot data and climate station data. The overarching goal is to provide information to advance water harvesting technologies in the agricultural croplands of the semi-arid environments of India by conducting research in a representative pilot site in Jodhpur, Rajasthan, India. ?? 2011 IEEE.

  11. Potential of mixed microalgae to harness biodiesel from ecological water-bodies with simultaneous treatment.

    PubMed

    Mohan, S Venkata; Devi, M Prathima; Mohanakrishna, G; Amarnath, N; Babu, M Lenin; Sarma, P N

    2011-01-01

    Biodiesel as an eco-friendly fuel is gaining much acceptance in recent years. This communication provides an overview on the possibility of using mixed microalgae existing in ecological water-bodies for harnessing biodiesel. Microalgal cultures from five water-bodies are cultivated in domestic wastewater in open-ponds and the harvested algal-biomass was processed through acid-catalyzed transesterification. Experiments evidenced the potential of using mixed microalgae for harnessing biodiesel. Presence of palmitic acid (C16:0) in higher fraction and physical properties of algal oil correlated well with the biodiesel properties. Functional characteristics of water-bodies showed to influence both species diversity and lipid accumulation. Microalgae from stagnant water-bodies receiving domestic discharges documented higher lipid accumulation. Algal-oil showed to consist 33 types of saturated and unsaturated fatty acids having wide food and fuel characteristics. Simultaneous wastewater treatment was also noticed due to the syntrophic association in the water-body microenvironment. Diversity studies visualized the composition of algae species known to accumulate higher lipids.

  12. The potential of nanofibers and nanobiocides in water purification.

    PubMed

    Botes, Marelize; Cloete, Thomas Eugene

    2010-01-01

    Electrospun nanofibers and nanobiocides show potential in the improvement of water filtration membranes. Biofouling of membranes caused by the bacterial load in water reduces the quality of drinking water and has become a major problem. Several studies showed inhibition of these bacteria after exposure to nanofibers with functionalized surfaces. Nanobiocides such as metal nanoparticles and engineered nanomaterials are successfully incorporated into nanofibers showing high antimicrobial activity and stability in water. Research on the applications of nanofibers and nanobiocides in water purification, the fabrication thereof and recently published patents are reviewed in this article.

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

    PubMed

    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.

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

    SciTech Connect

    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.

  15. Assessment of atmospheric moisture harvesting by direct cooling

    NASA Astrophysics Data System (ADS)

    Gido, Ben; Friedler, Eran; Broday, David M.

    2016-12-01

    The enormous amount of water vapor present in the atmosphere may serve as a potential water resource. An index is proposed for assessing the feasibility and energy requirements of atmospheric moisture harvesting by a direct cooling process. A climate-based analysis of different locations reveals the global potential of this process. We demonstrate that the Moisture Harvesting Index (MHI) can be used for assessing the energy requirements of atmospheric moisture harvesting. The efficiency of atmospheric moisture harvesting is highly weather and climate dependent, with the smallest estimated energy requirement found at the tropical regions of the Philippines (0.23 kW/L). Less favorable locations have much higher energy demands for the operation of an atmospheric moisture harvesting device. In such locations, using the MHI to select the optimal operation time periods (during the day and the year) can reduce the specific energy requirements of the process dramatically. Still, using current technology the energy requirement of atmospheric moisture harvesting by a direct air cooling process is significantly higher than of desalination by reverse osmosis.

  16. Cotton Harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton harvesting is performed in the US using either a spindle picker or brush-roll stripper. This presentation discusses the environmental, economic, geographic, and cultivar specific reasons behind a grower's choice to use either machine. The development of each machine system was discussed. A...

  17. Determination of estrogenic potential in waste water without sample extraction.

    PubMed

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Uranjek-Ževart, Nataša; Heath, Ester

    2013-09-15

    This study describes the modification of the ER-Calux assay for testing water samples without sample extraction (NE-(ER-Calux) assay). The results are compared to those obtained with ER-Calux assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux) to "real" influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux) assay gave higher values compared to ER-Calux assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was potential was 92-98%. Daytime estrogenic potential values varied significantly.

  18. Algae harvesting for biofuel production: influences of UV irradiation and polyethylenimine (PEI) coating on bacterial biocoagulation.

    PubMed

    Agbakpe, Michael; Ge, Shijian; Zhang, Wen; Zhang, Xuezhi; Kobylarz, Patricia

    2014-08-01

    There is a pressing need to develop efficient and sustainable separation technologies to harvest algae for biofuel production. In this work, two bacterial species (Escherichia coli and Rhodococus sp.) were used as biocoagulants to harvest Chlorella zofingiensis and Scenedesmus dimorphus. The influences of UV irradiation and polyethylenimine (PEI)-coating on the algal harvesting efficiency were investigated. Results showed that the UV irradiation could slightly enhance bacteria-algae biocoagulation and algal harvesting efficiency. In contrast, the PEI-coated E. coli cells noticeably increased the harvesting efficiencies from 23% to 83% for S. dimorphus when compared to uncoated E. coli cells. Based on the soft-particle Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, an energy barrier existed between uncoated E. coli cells and algal cells, whereas the PEI coating on E. coli cells eliminated the energy barrier, thereby the biocoagulation was significantly improved. Overall, this work presented groundwork toward the potential use of bacterial biomass for algal harvesting from water.

  19. 25 CFR 163.12 - Harvesting restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Harvesting restrictions. 163.12 Section 163.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.12 Harvesting restrictions. (a) Harvesting timber on commercial forest...

  20. 25 CFR 163.12 - Harvesting restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Harvesting restrictions. 163.12 Section 163.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.12 Harvesting restrictions. (a) Harvesting timber on commercial forest...

  1. 25 CFR 163.12 - Harvesting restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Harvesting restrictions. 163.12 Section 163.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.12 Harvesting restrictions. (a) Harvesting timber on commercial forest...

  2. 25 CFR 163.12 - Harvesting restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Harvesting restrictions. 163.12 Section 163.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.12 Harvesting restrictions. (a) Harvesting timber on commercial forest...

  3. 25 CFR 163.12 - Harvesting restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Harvesting restrictions. 163.12 Section 163.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.12 Harvesting restrictions. (a) Harvesting timber on commercial forest...

  4. A Split-Root Technique for Measuring Root Water Potential

    PubMed Central

    Adeoye, Kingsley B.; Rawlins, Stephen L.

    1981-01-01

    Water encounters various resistances in moving along a path of decreasing potential energy from the soil through the plant to the atmosphere. The reported relative magnitudes of these pathway resistances vary widely and often these results are conflicting. One reason for such inconsistency is the difficulty in measuring the potential drop across various segments of the soil-plant-atmosphere continuum. The measurement of water potentials at the soil-root interface and in the root xylem of a transpiring plant remains a challenging problem. In the divided root experiment reported here, the measured water potential of an enclosed, nonabsorbing branch of the root system of young corn (Bonanza) plants to infer the water potential of the remaining roots growing in soil was used. The selected root branch of the seedling was grown in a specially constructed Teflon test tube into which a screen-enclosed thermocouple psychrometer was inserted and sealed to monitor the root's water potential. The root and its surrounding atmosphere were assumed to be in vapor equilibrium. Images PMID:16661886

  5. The Oil-Water Interface: Mapping the Solvation Potential

    SciTech Connect

    Bell, Richard C.; Wu, Kai; Iedema, Martin J.; Schenter, Gregory K.; Cowin, James P.

    2009-01-06

    Ions moving across the oil water interface are strongly impacted by the continuous changes in solvation. The solvation potential for Cs+ is directly measured as they approach the oil-water interface (“oil” = 3-methylpentane), from 0.4 to 4 nm away. The oil-water interfaces are created at 40K using molecular beam epitaxy and a softlanding ion beam, with pre-placed ions. The solvation potential slope was determined at each distance by balancing it against an increasing electrostatic potential made by increasing the number of imbedded ions at that distance, and monitoring the resulting ion motion. The potential approaches the Born model for greater than z>0.4nm, and shows the predicted reduction of the polarizability at z<0.4nm.

  6. Identification and assessment of potential water quality impact factors for drinking-water reservoirs.

    PubMed

    Gu, Qing; Deng, Jinsong; Wang, Ke; Lin, Yi; Li, Jun; Gan, Muye; Ma, Ligang; Hong, Yang

    2014-06-10

    Various reservoirs have been serving as the most important drinking water sources in Zhejiang Province, China, due to the uneven distribution of precipitation and severe river pollution. Unfortunately, rapid urbanization and industrialization have been continuously challenging the water quality of the drinking-water reservoirs. The identification and assessment of potential impacts is indispensable in water resource management and protection. This study investigates the drinking water reservoirs in Zhejiang Province to better understand the potential impact on water quality. Altogether seventy-three typical drinking reservoirs in Zhejiang Province encompassing various water storage levels were selected and evaluated. Using fifty-two reservoirs as training samples, the classification and regression tree (CART) method and sixteen comprehensive variables, including six sub-sets (land use, population, socio-economy, geographical features, inherent characteristics, and climate), were adopted to establish a decision-making model for identifying and assessing their potential impacts on drinking-water quality. The water quality class of the remaining twenty-one reservoirs was then predicted and tested based on the decision-making model, resulting in a water quality class attribution accuracy of 81.0%. Based on the decision rules and quantitative importance of the independent variables, industrial emissions was identified as the most important factor influencing the water quality of reservoirs; land use and human habitation also had a substantial impact on water quality. The results of this study provide insights into the factors impacting the water quality of reservoirs as well as basic information for protecting reservoir water resources.

  7. The water environment as a source of potentially pathogenic mycobacteria.

    PubMed

    Makovcova, Jitka; Slany, Michal; Babak, Vladimir; Slana, Iva; Kralik, Petr

    2014-06-01

    Nontuberculous mycobacteria (NTM) are ubiquitous organisms of a wide variety of environmental reservoirs, including natural and municipal water, soil, aerosols, protozoans, animals and humans. Several of these species are potential pathogens which affect human health. The aim of this study was to determine the occurrence of NTM in the water environment. Samples were taken from 13 water-related facilities including fish ponds, storage ponds, drinking water reservoirs and an experimental recirculation system. Altogether, 396 samples of water, sediment and aquatic plants were collected and analysed. All samples were examined using conventional culture methods. Suspected microbial isolates were subjected to polymerase chain reaction analysis and identified using partial sequence analysis of the 16S rDNA gene. The culture revealed 94/396 samples (23.7%) that contained mycobacteria. Among known NTM we identified potentially pathogenic mycobacteria isolated from the fresh water environment for the first time: Mycobacterium asiaticum, M. chimaera, M. interjectum, M. kumamotonense, M. lentiflavum, M. montefiorense, M. nebraskense, M. paraffinicum and M. simiae. Epidemiologic studies suggest that the natural water environment is the principal source of human exposure. Our results indicate that besides the well-known potentially pathogenic mycobacteria it is important to observe occurrence, proliferation and persistence of newly discovered mycobacterial species.

  8. Investigating the potential for "water piracy" in North East Greenland

    NASA Astrophysics Data System (ADS)

    Karlsson, Nanna B.; Dahl-Jensen, Dorthe

    2013-04-01

    The incorporation of subglacial processes in ice flow models remains a challenge while at the same time observational evidence increasingly underscores the important role liquid water plays in ice flow dynamics. One of the many problems ice flow models face (that also includes scarcity of data at the bed and the deformational properties of water-saturated sediments) is the different time-scales on which the processes operate. For example, observations indicate that subglacial water may be re-routed to a neighbouring ice stream in response to changes in surface elevation. This implies that ice flow models have to allow for changes in ice flow mode where, depending on the basal properties, the flow may be dominated by deformation or basal sliding. The re-routing of water between neighbouring ice streams is often termed "water piracy" and in this study we demonstrate that the potential for water piracy exists even in regions with very small surface elevation changes. We use a simple, vertically integrated, 2D-plane ice flow model based on the shallow ice flow approximation to model the large-scale changes in surface elevation of North East Greenland in response to gravity and mass balance. Considering time-scales of 100-500 years the model predicts changes in elevation of less than a metre per year which is in agreement with data from remote sensing. We then calculate the corresponding changes in hydrological pressure potential and use evidence from radio-echo sounding data to identify areas with basal melting and thus potential liquid water production. The corresponding change in hydrological pressure potential in response to the surface elevation changes is sufficient to divert the subglacial water to different pathways. This change in subglacial water pathways could be sufficient to change the ice flow mode from deformation to sliding and might initiate speed-up and/or slow-down of the ice streams at the margins of the basin.

  9. Evaluating the growth potential of pathogenic bacteria in water.

    PubMed

    Vital, Marius; Stucki, David; Egli, Thomas; Hammes, Frederik

    2010-10-01

    The degree to which a water sample can potentially support the growth of human pathogens was evaluated. For this purpose, a pathogen growth potential (PGP) bioassay was developed based on the principles of conventional assimilable organic carbon (AOC) determination, but using pure cultures of selected pathogenic bacteria (Escherichia coli O157, Vibrio cholerae, or Pseudomonas aeruginosa) as the inoculum. We evaluated 19 water samples collected after different treatment steps from two drinking water production plants and a wastewater treatment plant and from ozone-treated river water. Each pathogen was batch grown to stationary phase in sterile water samples, and the concentration of cells produced was measured using flow cytometry. In addition, the fraction of AOC consumed by each pathogen was estimated. Pathogen growth did not correlate with dissolved organic carbon (DOC) concentration and correlated only weakly with the concentration of AOC. Furthermore, the three pathogens never grew to the same final concentration in any water sample, and the relative ratio of the cultures to each other was unique in each sample. These results suggest that the extent of pathogen growth is affected not only by the concentration but also by the composition of AOC. Through this bioassay, PGP can be included as a parameter in water treatment system design, control, and operation. Additionally, a multilevel concept that integrates the results from the bioassay into the bigger framework of pathogen growth in water is discussed. The proposed approach provides a first step for including pathogen growth into microbial risk assessment.

  10. Ecohydrological implications of runoff harvesting in the headwaters of the Thukela River basin, South Africa

    NASA Astrophysics Data System (ADS)

    De Winnaar, Gary; Jewitt, Graham

    Hydrological regimes have an important influence on biodiversity, structure, and functioning of aquatic ecosystems. Unforeseen circumstances, both hydrologically and ecologically, caused by potential adoption and expansion of runoff harvesting innovations is of particular concern to water resource planners, as downstream river systems are likely to be adversely affected. This paper provides methods for determining the influence that large-scale adoption of runoff harvesting could have on downstream flow regimes by using a scenario-based approach, with the ACRU Agrohydrological model, to simulate the potential alteration of streamflow regimes due to runoff harvesting. Scenarios were based entirely on the spatial extent of impervious surfaces associated with rural homesteads, estimates of which were taken from current population data and used to establish the density of hypothetical runoff harvesting systems within a catchment setup. Daily streamflow simulation from nine Quaternary Catchments in the Thukela River basin provided suitable data series’ for analysis using the Indicators of Hydrological Alteration method to compute ecologically relevant hydrological parameters. The outcome of this ecohydrological study demonstrated that a relatively simple modelling exercise offers the potential to assess impacts that may arise from large-scale runoff harvesting. Results established that magnitudes of high and low flows of river flow regimes were most affected by runoff harvesting. Flow reduction was found to be most significant with low flows (up to 29%) in the case where the maximum runoff harvesting scenario was used. However, the majority of the IHA hydrological flow parameters revealed only slight impacts, even under circumstances where modelling scenarios were based on unrealistically high proportions of runoff harvesting. Increasing the spatial extent of runoff harvesting is thus expected to have a much greater impact at smaller spatial scales; water resources of

  11. Approaches to automated protein crystal harvesting

    SciTech Connect

    Deller, Marc C. Rupp, Bernhard

    2014-01-28

    Approaches to automated and robot-assisted harvesting of protein crystals are critically reviewed. While no true turn-key solutions for automation of protein crystal harvesting are currently available, systems incorporating advanced robotics and micro-electromechanical systems represent exciting developments with the potential to revolutionize the way in which protein crystals are harvested.

  12. Evaluation Of Biocides for Potential Treatment of Ballast Water

    DTIC Science & Technology

    2004-10-01

    in sewage effluent (Haas and Gould, 1980). Sodium azide is ineffective at removing dinoflagellate cysts at doses up to 500 milligrams per liter (mg...water treatment agents for marine and freshwater use. Copper, bromine, iodine, sodium chlorite, chloramines, ozone, formaldehyde, ethylene oxide, and...as potential agents for ballast water treatment in both marine and freshwater environments; • Copper, bromine, iodine, sodium chlorite, chloramines

  13. Potential for biofilm development in drinking water distribution systems.

    PubMed

    van der Kooij, D

    1998-12-01

    Regrowth of micro-organisms in drinking water distribution systems is caused by the utilisation of biodegradable compounds which are either present in treated water or originate from materials in contact with drinking water. In the Netherlands most drinking water is distributed without disinfectant residual and regrowth is limited by achieving biostable drinking water. A combination of methods is used to assess the biostability of drinking water. These methods are: (1) determination of the concentration of easily assimilable organic carbon (AOC); and (2) assessment of the biofilm formation rate (BFR). Assimilated organic carbon concentrations in drinking water in the Netherlands range from a few μg C/l in slow sand filtrates and in ground water supplies to values of ∼ 50 μg C/l in supplies using ozonation in water treatment. Biofilm formation rate values were found to range from < 1 pg ATP/cm(2)/d in supplies using anaerobic ground water as the source. Increase of heterotrophic plate counts is limited at AOC values below 10 μg C/l. At BFR values below 10 pg ATP/cm(2)/d the risk of exceeding the guideline value for aeromonads (90 percentile < 200 c.f.u./100 ml) is less than 20%. Calculations based on the decrease of the AOC concentration observed in distributions systems confirm that very low concentrations of AOC can cause considerable biofilm formation on the pipe wall. The methods for assessing the biostability of drinking water combine with the assessment of the Biofilm Formation Potential of materials in contact with drinking water, thus providing a framework, the Unified Biofilm Approach, for evaluating the biostability of drinking water and materials.

  14. A microtensiometer capable of measuring water potentials below -10 MPa.

    PubMed

    Pagay, Vinay; Santiago, Michael; Sessoms, David A; Huber, Erik J; Vincent, Olivier; Pharkya, Amit; Corso, Thomas N; Lakso, Alan N; Stroock, Abraham D

    2014-08-07

    Tensiometers sense the chemical potential of water (or water potential, Ψw) in an external phase of interest by measuring the pressure in an internal volume of liquid water in equilibrium with that phase. For sub-saturated phases, the internal pressure is below atmospheric and frequently negative; the liquid is under tension. Here, we present the initial characterization of a new tensiometer based on a microelectromechanical pressure sensor and a nanoporous membrane. We explain the mechanism of operation, fabrication, and calibration of this device. We show that these microtensiometers operate stably out to water potentials below -10 MPa, a tenfold extension of the range of current tensiometers. Finally, we present use of the device to perform an accurate measurement of the equation of state of liquid water at pressures down to -14 MPa. We conclude with a discussion of outstanding design considerations, and of the opportunities opened by the extended range of stability and the small form factor in sensing applications, and in fundamental studies of the thermodynamic properties of water.

  15. Potential microbial bioinvasions via ships' ballast water, sediment, and biofilm.

    PubMed

    Drake, Lisa A; Doblin, Martina A; Dobbs, Fred C

    2007-01-01

    A prominent vector of aquatic invasive species to coastal regions is the discharge of water, sediments, and biofilm from ships' ballast-water tanks. During eight years of studying ships arriving to the lower Chesapeake Bay, we developed an understanding of the mechanisms by which invasive microorganisms might arrive to the region via ships. Within a given ship, habitats included ballast water, unpumpable water and sediment (collectively known as residuals), and biofilms formed on internal surfaces of ballast-water tanks. We sampled 69 vessels arriving from foreign and domestic ports, largely from Western Europe, the Mediterranean region, and the US East and Gulf coasts. All habitats contained bacteria and viruses. By extrapolating the measured concentration of a microbial metric to the estimated volume of ballast water, biofilm, or residual sediment and water within an average vessel, we calculated the potential total number of microorganisms contained by each habitat, thus creating a hierarchy of risk of delivery. The estimated concentration of microorganisms was greatest in ballast water>sediment and water residuals>biofilms. From these results, it is clear microorganisms may be transported within ships in a variety of ways. Using temperature tolerance as a measure of survivability and the temperature difference between ballast-water samples and the water into which the ballast water was discharged, we estimated 56% of microorganisms could survive in the lower Bay. Extrapolated delivery and survival of microorganisms to the Port of Hampton Roads in lower Chesapeake Bay shows on the order of 10(20) microorganisms (6.8 x 10(19) viruses and 3.9 x 10(18) bacteria cells) are discharged annually to the region.

  16. A review of initial investigations to utilize ERTS-1 data in determining the availability and distribution of living marine resources. [harvest and management of fisheries resources in Mississippi Sound and Gulf waters

    NASA Technical Reports Server (NTRS)

    Stevenson, W. H.; Kemmerer, A. J.; Atwell, B. H.; Maughan, P. M.

    1974-01-01

    The National Marine Fisheries Service has been studying the application of aerospace remote sensing to fisheries management and utilization for many years. The 15-month ERTS study began in July 1972 to: (1) determine the reliability of satellite and high altitude sensors to provide oceanographic parameters in coastal waters; (2) demonstrate the use of remotely-sensed oceanographic information to predict the distribution and abundance of adult menhaden; and (3) demonstrate the potential use of satellites for acquiring information for improving the harvest and management of fisheries resources. The study focused on a coastal area in the north-central portion of the Gulf of Mexico, including parts of Alabama, Mississippi, and Louisiana. The test area used in the final analysis was the Mississippi Sound and the area outside the barrier islands to approximately the 18-meter (10-fathom) curve.

  17. Electrochemically driven mechanical energy harvesting

    PubMed Central

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-01

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress–voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition–voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities. PMID:26733282

  18. Electrochemically driven mechanical energy harvesting.

    PubMed

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-06

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress-voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition-voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities.

  19. Electrochemically driven mechanical energy harvesting

    NASA Astrophysics Data System (ADS)

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-01

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress-voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition-voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities.

  20. Influence of Water Table Depth on Pore Water Chemistry and Trihalomethane Formation Potential in Peatlands.

    PubMed

    Gough, Rachel; Holliman, Peter J; Fenner, Nathalie; Peacock, Mike; Freeman, Christopher

    2016-02-01

    Drained peatland catchments are reported to produce more colored, dissolved organic carbon (DOC)-rich water, presenting problems for potable water treatment. The blocking of peatland drainage ditches to restore the water table is increasingly being considered as a strategy to address this deterioration in water quality. However, the effect of ditch blocking on the potential of DOC to form trihalomethanes (THMs) has not been assessed. In this study, the effect of peat rewetting on pore water DOC concentration and characteristics (including THM formation potential [THMFP]) was assessed over 12 months using peat cores collected from two drained peatland sites. The data show little evidence of differences in DOC concentration or characteristics between the different treatments. The absence of any difference in the THMFP of pore water between treatments suggests that, in the short term at least, ditch blocking may not have an effect on the THMFP of waters draining peatland catchments.

  1. Potential health impacts of consuming desalinated bottled water.

    PubMed

    Rowell, Candace; Kuiper, Nora; Shomar, Basem

    2015-06-01

    This study compared physicochemical properties, anion and carbon content and major and trace elements in desalinated and non-desalinated bottled water available in Qatar, and assessed the potential health risks associated with prolonged consumption of desalinated water. Results indicate that Qatar's population is not at elevated risk of dietary exposure to As (mean = 666 ng/L), Ba (48.0 μg/L), Be (9.27 ng/L), Cd (20.1 ng/L), Cr (874 ng/L), Pb (258 ng/L), Sb (475 ng/L) and U (533 ng/L) from consumption of both desalinated and non-desalinated bottled water types available in the country. Consumers who primarily consume desalinated water brands further minimize risk of exposure to heavy metals as levels were significantly lower than in non-desalinated bottled water. Desalinated bottled water was not a significant contributor to recommended daily intakes for Ca, Mg and F(-) for adults and children and may increase risk of deficiencies. Desalinated bottled water accounted for only 3% of the Institute of Medicine (IOM) adequate intake (AI) for Ca, 5-6% of the recommended daily allowance for Mg and 4% of the AI for F among adults. For children desalinated water contributed 2-3% of the IOM AICa, 3-10% of the RDA(Mg) and 3-9% of the AIF.

  2. Potential perchlorate exposure from Citrus sp. irrigated with contaminated water.

    PubMed

    Sanchez, C A; Krieger, R I; Khandaker, N R; Valentin-Blasini, L; Blount, B C

    2006-05-10

    Citrus produced in the southwestern United States is often irrigated with perchlorate-contaminated water. This irrigation water includes Colorado River water which is contaminated with perchlorate from a manufacturing plant previously located near the Las Vegas Wash, and ground water from wells in Riverside and San Bernardino counties of California which are affected by a perchlorate plume associated with an aerospace facility once located near Redlands, California. Studies were conducted to evaluate the uptake and distribution of perchlorate in citrus irrigated with contaminated water, and estimate potential human exposure to perchlorate from the various citrus types including lemon (Citrus limon), grapefruit (Citrus paradise), and orange (Citrus sinensis) produced in the region. Perchlorate concentrations ranged from less than 2-9 microg/L for Colorado River water and from below detection to approximately 18 microg/L for water samples from wells used to irrigate citrus. Destructive sampling of lemon trees produced with Colorado River water show perchlorate concentrations larger in the leaves (1835 microg/kg dry weight (dw)) followed by the fruit (128 microg/kg dw). Mean perchlorate concentrations in roots, trunk, and branches were all less than 30 microg/kg dw. Fruit pulp analyzed in the survey show perchlorate concentrations ranged from below detection limit to 38 microg/kg fresh weight (fw), and were related to the perchlorate concentration of irrigation water. Mean hypothetical exposures (mug/person/day) of children and adults from lemons (0.005 and 0.009), grapefruit (0.03 and 0.24), and oranges (0.51 and 1.20) were estimated. These data show that potential perchlorate exposures from citrus in the southwestern United States are negligible relative to the reference dose recommended by the National Academy of Sciences.

  3. Leaf water potential, stomatal resistance, and photosynthetic response to water stress in peach seedlings.

    PubMed

    Hand, J M; Young, E; Vasconcelos, A C

    1982-05-01

    Individual groups of peach (Prunus persica [L.] Batsch) seedlings stressed to -17, -26 and -36 bars recovered to control levels within 1, 3, and 4 days, respectively. Stomatal resistance was significantly correlated with both leaf water potential and net photosynthesis. In seedlings stressed to -52 bars, leaf water potential and stomatal resistance recovered sooner than net photosynthesis, despite recovery of 0(2) evolution at a rate similar to leaf water potential. Therefore, some nonstomatal factor other than reduction in photochemical activity must be responsible for the lag in recovery of CO(2) assimilation following irrigation.

  4. Fishery induces sperm depletion and reduction in male reproductive potential for crab species under male-biased harvest strategy.

    PubMed

    Pardo, Luis Miguel; Rosas, Yenifer; Fuentes, Juan Pablo; Riveros, Marcela Paz; Chaparro, Oscar Roberto

    2015-01-01

    Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI) were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the current management of

  5. Fishery Induces Sperm Depletion and Reduction in Male Reproductive Potential for Crab Species under Male-Biased Harvest Strategy

    PubMed Central

    Pardo, Luis Miguel; Rosas, Yenifer; Fuentes, Juan Pablo; Riveros, Marcela Paz; Chaparro, Oscar Roberto

    2015-01-01

    Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI) were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the current management of

  6. Potential contamination of drinking water with Toxoplasma gondii oocysts.

    PubMed Central

    Aramini, J. J.; Stephen, C.; Dubey, J. P.; Engelstoft, C.; Schwantje, H.; Ribble, C. S.

    1999-01-01

    The world's first documented toxoplasmosis outbreak associated with a municipal water supply was recognized in 1995 in Victoria, British Columbia, Canada. It was hypothesized that domestic cat (Felis catus) or cougar (Felis concolor) faeces contaminated a surface water reservoir with Toxoplasma gondii oocysts. An extensive investigation of the Victoria watershed 1 year following the outbreak documented the presence of an endemic T. gondii cycle involving the animals inhabiting the area. Cats and cougars were observed throughout the watershed. Serological evidence of T. gondii infection was demonstrated among domestic cats living in the Victoria area. Cougars were found to shed T. gondii oocysts. Serological evidence of T. gondii infection in deer mice living in the riparian environments of the watershed suggested that T. gondii oocysts were being shed near the water edge. Contamination of Victoria's water supply with T. gondii oocysts potentially occurred during the study period and future waterborne toxoplasmosis outbreaks in this and other communities are possible. PMID:10355797

  7. Potential impacts of changing supply-water quality on drinking water distribution: A review.

    PubMed

    Liu, Gang; Zhang, Ya; Knibbe, Willem-Jan; Feng, Cuijie; Liu, Wentso; Medema, Gertjan; van der Meer, Walter

    2017-03-19

    Driven by the development of water purification technologies and water quality regulations, the use of better source water and/or upgraded water treatment processes to improve drinking water quality have become common practices worldwide. However, even though these elements lead to improved water quality, the water quality may be impacted during its distribution through piped networks due to the processes such as pipe material release, biofilm formation and detachment, accumulation and resuspension of loose deposits. Irregular changes in supply-water quality may cause physiochemical and microbiological de-stabilization of pipe material, biofilms and loose deposits in the distribution system that have been established over decades and may harbor components that cause health or esthetical issues (brown water). Even though it is clearly relevant to customers' health (e.g., recent Flint water crisis), until now, switching of supply-water quality is done without any systematic evaluation. This article reviews the contaminants that develop in the water distribution system and their characteristics, as well as the possible transition effects during the switching of treated water quality by destabilization and the release of pipe material and contaminants into the water and the subsequent risks. At the end of this article, a framework is proposed for the evaluation of potential transition effects.

  8. A "First Principles" Potential Energy Surface for Liquid Water from VRT Spectroscopy of Water Clusters

    SciTech Connect

    Goldman, N; Leforestier, C; Saykally, R J

    2004-05-25

    We present results of gas phase cluster and liquid water simulations from the recently determined VRT(ASP-W)III water dimer potential energy surface. VRT(ASP-W)III is shown to not only be a model of high ''spectroscopic'' accuracy for the water dimer, but also makes accurate predictions of vibrational ground-state properties for clusters up through the hexamer. Results of ambient liquid water simulations from VRT(ASP-W)III are compared to those from ab initio Molecular Dynamics, other potentials of ''spectroscopic'' accuracy, and to experiment. The results herein represent the first time that a ''spectroscopic'' potential surface is able to correctly model condensed phase properties of water.

  9. Understanding the physiological effects of UV-C light and exploiting its agronomic potential before and after harvest.

    PubMed

    Urban, Laurent; Charles, Florence; de Miranda, Maria Raquel Alcântara; Aarrouf, Jawad

    2016-08-01

    There is an abundant literature about the biological and physiological effects of UV-B light and the signaling and metabolic pathways it triggers and influences. Much less is known about UV-C light even though it seems to have a lot of potential for being effective in less time than UV-B light. UV-C light is known since long to exert direct and indirect inhibitory and damaging effects on living cells and is therefore commonly used for disinfection purposes. More recent observations suggest that UV-C light can also be exploited to stimulate the production of health-promoting phytochemicals, to extent shelf life of fruits and vegetables and to stimulate mechanisms of adaptation to biotic and abiotic stresses. Clearly some of these effects may be related to the stimulating effect of UV-C light on the production of reactive oxygen species (ROS) and to the stimulation of antioxidant molecules and mechanisms, although UV-C light could also trigger and regulate signaling pathways independently from its effect on the production of ROS. Our review clearly underlines the high potential of UV-C light in agriculture and therefore advocates for more work to be done to improve its efficiency and also to increase our understanding of the way UV-C light is perceived and influences the physiology of plants.

  10. Crop modeling: Studying the effect of water stress on the driving forces governing plant water potential

    NASA Astrophysics Data System (ADS)

    van Emmerik, T. H. M.; Mirfenderesgi, G.; Bohrer, G.; Steele-Dunne, S. C.; Van De Giesen, N.

    2015-12-01

    Water stress is one of the most important environmental factors that influence plant water dynamics. To prevent excessive water loss and physiological damage, plants can regulate transpiration by adjusting the stomatal aperture. This enhances survival, but also reduced photosynthesis and productivity. During periods of low water availability, stomatal regulation is a trade-off between optimization of either survival or production. Water stress defence mechanisms lead to significant changes in plant dynamics, e.g. leaf and stem water content. Recent research has shown that water content in a corn canopy can change up to 30% diurnally as a result of water stress, which has a considerable influence on radar backscatter from a corn canopy [1]. This highlighted the potential of water stress detection using radar. To fully explore the potential of water stress monitoring using radar, we need to understand the driving forces governing plant water potential. For this study, the recently developed the Finite-Element Tree-Crown Hydrodynamic model version 2 (FETCH2) model is applied to a corn canopy. FETCH2 is developed to resolve the hydrodynamic processes within a plant using the porous media analogy, allowing investigation of the influence of environmental stress factors on plant dynamics such as transpiration, photosynthesis, stomatal conductance, and leaf and stem water content. The model is parameterized and evaluated using a detailed dataset obtained during a three-month field experiment in Flevoland, the Netherlands, on a corn canopy. [1] van Emmerik, T., S. Steele-Dunne, J. Judge and N. van de Giesen: "Impact of Diurnal Variation in Vegetation Water Content on Radar Backscatter of Maize During Water Stress", Geosciences and Remote Sensing, IEEE Transactions on, vol. 52, issue 7, doi: 10.1109/TGRS.2014.2386142, 2015.

  11. Notepad-like triboelectric generator for efficiently harvesting low-velocity motion energy by interconversion between kinetic energy and elastic potential energy.

    PubMed

    Liu, Guanlin; Leng, Qiang; Lian, Jiawei; Guo, Hengyu; Yi, Xi; Hu, Chenguo

    2015-01-21

    Great attention has been paid to nanogenerators that harvest energy from ambient environments lately. In order to give considerable output current, most nanogenerators require high-velocity motion that in most cases can hardly be provided in our daily life. Here we report a notepad-like triboelectric generator (NTEG), which uses simple notepad-like structure to generate elastic deformation so as to turn a low-velocity kinetic energy into high-velocity kinetic energy through the conversion of elastic potential energy. Therefore, the NTEG can achieve high current output under low-velocity motion, which completely distinguishes it from tribogenerators previously reported. The factors that may affect the output performance are explored, including the number of slices, active length of slice, press speed, and vertical displacement. In addition, the working mechanism is systematically studied, indicating that the efficiency of the generator can be greatly enhanced by interconversion between kinetic energy and elastic potential energy. The short-circuit current, the open-circuit voltage, and power density are 205 μA and 470 V and 9.86 W/m(2), respectively, which is powerful enough to light up hundreds of light-emitting diodes (LEDs) and charge a commercial capacitor. Besides, NTEGs have been successfully applied to a self-powered door monitor.

  12. Chemical characteristics of dissolved organic matter (DOM) in relation to heavy metal concentrations in soil water from boreal peatlands after clear-cut harvesting

    NASA Astrophysics Data System (ADS)

    Kiikkilä, O.; Nieminen, T.; Starr, M.; Ukonmaanaho, L.

    2012-04-01

    Boreal peatlands form an important terrestrial carbon reserve and are a major source of dissolved organic matter (DOM) to surface waters, particularly when disturbed through forestry practices such as draining or timber harvesting. Heavy metals show a strong affinity to organic matter and so, along with DOM, heavy metals can be mobilized and transported from the soil to surface waters and sediments where they may become toxic to aquatic organisms and pass up the food chain. The complexation of heavy metals with DOM can be expected to be related and determined by the chemical characteristics of DOM and oxidation/reducing conditions in the peat. We extracted interstitial water from peat samples and determined the concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and Al, Cu, Zn and Fe in various fractions of DOM isolated by adsorption properties (XAD-8 fractionation) and molecular-weight (ultrafiltration). The peat samples were taken from 0-30 and 30-50 cm depth in drained peatland catchments two years after whole-tree or stem-only clear-cut harvesting (Scots pine or Norway spruce) had been carried out. The samples from the upper layer had been subject to alternating saturation/aeration conditions while the deeper layer had been continuously under the water table. The fractionation of DOC and DON according to both adsorption properties and molecular-weight fractions clearly differed between the upper and lower peat layers. While the hydrophobic acid fraction contained proportionally more DOC and DON than the hydrophilic acid fraction in the upper peat layer the results were vice versa in the lower peat layer. High-molecular-weight compounds (> 100 kDa) were proportionally more abundant in the upper and low-molecular-weight compounds (< 1 kDa) in the lower peat layer. These differences are assumed to reflect differences in the aerobic/ anaerobic conditions and degree of decomposition between the two layers. The concentrations of Zn, Al

  13. A transferable classical potential for the water molecule.

    PubMed

    Baranyai, András; Kiss, Péter T

    2010-10-14

    We developed a new model for the water molecule which contains only three Gaussian charges. Using the gas-phase geometry the dipole moment of the molecule matches, the quadrupole moment closely approximates the experimental values. The negative charge is connected by a harmonic spring to its gas-phase position. The polarized state is identified by the equality of the intermolecular electrostatic force and the spring force acting on the negative charge. In each timestep the instantaneous position of the massless negative charge is determined by iteration. Using the technique of Ewald summation, we derived expressions for the potential energy, the forces, and the pressure for Gaussian charges. The only properties to be fitted are the half-width values of the Gaussian charge distributions and the parameters of the nonelectrostatic repulsion-attraction potential. We determined the properties of gas-phase clusters up to six molecules, the internal energy and density of ambient water and hexagonal ice. We calculated the equilibrium density of ice VII as a function of pressure. As an additional test, we calculated the pair-correlation function, the isotherm compressibility, the heat capacity, and the self-diffusion coefficients for ambient water. As far as we know, this is the first classical model of water which is able to estimate both ends of the phase diagram, the high pressure ice VII, and the gas clusters of water with excellent accuracy.

  14. Performance evaluation of TDT soil water content and watermark soil water potential sensors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the performance of digitized Time Domain Transmissometry (TDT) soil water content sensors (Acclima, Inc., Meridian, ID) and resistance-based soil water potential sensors (Watermark 200, Irrometer Company, Inc., Riverside, CA) in two soils. The evaluation was performed by compar...

  15. Potential Nitrous Oxide Emissions from Municipal Drinking Water

    NASA Astrophysics Data System (ADS)

    Anderson, D. E.; Thienelt, T.; Tindall, J.; McMahon, P.

    2005-12-01

    Nitrous oxide (N2O) is a potent greenhouse gas, having a global warming potential 280 times larger than carbon dioxide. Although the bulk of N2O emissions appear to be related to agricultural activity, various industrial and transportation related emissions exist as well. This study reports the discovery of a new and significant source of potential N2O emissions related to its presence in purified municipal water supplies worldwide. Multiple drinking water samples were obtained from 86 cities in the United States (US) and 44 cities in 16 countries in the Americas, Europe, Asia, and Africa. Samples ranged from 0.004 to 2μmol/L or the equivalent of 60% unsaturated to 200 times supersaturated with respect to ambient atmospheric concentration (320 ppb). Highest N2O contents were from southern US cities. Suspecting nitrification as the cause for the presence of N2O in drinking water, correlation statistics were calculated between N2O concentration and city size, geographical location, mean annual temperature, nitrate, and ammonia concentrations for the total population of samples as well as subsets based on country, water purification method, and raw water source (ground, surface, combination). The highest correlation (r=0.66, p<0.05, N=73) found was between latitude and N2O content for the subset group of large US cities using chloramines to purify water. Continuous year long sampling from a major US city indicated that variance in N2O content is remarkably low through the year within a water supply district. The annual US emission, based on this preliminary analysis, is 8x106 moles or 3.5X108 g N2O. Annual global emissions may be five times larger.

  16. Radio frequency heating: a new potential means of post-harvest pest control in nuts and dry products.

    PubMed

    Wang, Shao-jin; Tang, Ju-ming

    2004-10-01

    The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applications. There is an urgent need to develop effective and economically viable alternative treatments to replace current phytosanitary and quarantine practices in order to maintain the competitiveness of US agriculture in domestic and international markets. With the reliable heating block system, the thermal death kinetics for fifth-instar codling moth, Indianmeal moth, and navel orangeworm were determined at a heating rate of 18 degrees C/min. A practical process protocol was developed to control the most heat resistant insect pest, fifth-instar navel orangeworm, in in-shell walnuts using a 27 MHz pilot scale radio frequency (RF) system. RF heating to 55 degrees C and holding in hot air for at least 5 min resulted in 100% mortality of the fifth-instar navel orangeworm. Rancidity, sensory qualities and shell characteristics were not affected by the treatments. If this method can be economically integrated into the handling process, it should have excellent potential as a disinfestation method for in-shell walnuts.

  17. Health risk from the use of roof-harvested rainwater in Southeast Queensland, Australia, as potable or nonpotable water, determined using quantitative microbial risk assessment.

    PubMed

    Ahmed, W; Vieritz, A; Goonetilleke, A; Gardner, T

    2010-11-01

    A total of 214 rainwater samples from 82 tanks were collected in urban Southeast Queensland (SEQ) in Australia and analyzed for the presence and numbers of zoonotic bacterial and protozoal pathogens using binary PCR and quantitative PCR (qPCR). Quantitative microbial risk assessment (QMRA) analysis was used to quantify the risk of infection associated with the exposure to potential pathogens from roof-harvested rainwater used as potable or nonpotable water. Of the 214 samples tested, 10.7%, 9.8%, 5.6%, and 0.4% were positive for the Salmonella invA, Giardia lamblia β-giardin, Legionella pneumophila mip, and Campylobacter jejuni mapA genes, respectively. Cryptosporidium parvum oocyst wall protein (COWP) could not be detected. The estimated numbers of Salmonella, G. lamblia, and L. pneumophila organisms ranged from 6.5 × 10¹ to 3.8 × 10² cells, 0.6 × 10⁰ to 3.6 × 10⁰ cysts, and 6.0 × 10¹ to 1.7 × 10² cells per 1,000 ml of water, respectively. Six risk scenarios were considered for exposure to Salmonella spp., G. lamblia, and L. pneumophila. For Salmonella spp. and G. lamblia, these scenarios were (i) liquid ingestion due to drinking of rainwater on a daily basis, (ii) accidental liquid ingestion due to hosing twice a week, (iii) aerosol ingestion due to showering on a daily basis, and (iv) aerosol ingestion due to hosing twice a week. For L. pneumophila, these scenarios were (i) aerosol inhalation due to showering on a daily basis and (ii) aerosol inhalation due to hosing twice a week. The risk of infection from Salmonella spp., G. lamblia, and L. pneumophila associated with the use of rainwater for showering and garden hosing was calculated to be well below the threshold value of one extra infection per 10,000 persons per year in urban SEQ. However, the risk of infection from ingesting Salmonella spp. and G. lamblia via drinking exceeded this threshold value and indicated that if undisinfected rainwater is ingested by drinking, then the incidences of

  18. Streaming Potential In Rocks Saturated With Water And Oil

    NASA Astrophysics Data System (ADS)

    Tarvin, J. A.; Caston, A.

    2011-12-01

    Fluids flowing through porous media generate electrical currents. These currents cause electric potentials, called "streaming potentials." Streaming potential amplitude depends on the applied pressure gradient, on rock and fluid properties, and on the interaction between rock and fluid. Streaming potential has been measured for rocks saturated with water (1) and with water-gas mixtures. (2) Few measurements (3) have been reported for rocks saturated with water-oil mixtures. We measured streaming potential for sandstone and limestone saturated with a mixture of brine and laboratory oil. Cylindrical samples were initially saturated with brine and submerged in oil. Saturation was changed by pumping oil from one end of a sample to the other and then through the sample in the opposite direction. Saturation was estimated from sample resistivity. The final saturation of each sample was determined by heating the sample in a closed container and measuring the pressure. Measurements were made by modulating the pressure difference (of oil) between the ends of a sample at multiple frequencies below 20 Hz. The observed streaming potential is a weak function of the saturation. Since sample conductivity decreases with increasing oil saturation, the electro-kinetic coupling coefficient (Pride's L (4)) decreases with increasing oil saturation. (1) David B. Pengra and Po-zen Wong, Colloids and Surfaces, vol., p. 159 283-292 (1999). (2) Eve S. Sprunt, Tony B. Mercer, and Nizar F. Djabbarah, Geophysics, vol. 59, p. 707-711 (1994). (3) Vinogradov, J., Jackson, M.D., Geophysical Res. L., Vol. 38, Article L01301 (2011). (4) Steve Pride, Phys. Rev. B, vol. 50, pp. 15678-15696 (1994).

  19. Life cycle assessment of domestic and agricultural rainwater harvesting systems.

    PubMed

    Ghimire, Santosh R; Johnston, John M; Ingwersen, Wesley W; Hawkins, Troy R

    2014-04-01

    To further understanding of the environmental implications of rainwater harvesting and its water savings potential relative to conventional U.S. water delivery infrastructure, we present a method to perform life cycle assessment of domestic rainwater harvesting (DRWH) and agricultural rainwater harvesting (ARWH) systems. We also summarize the design aspects of DRWH and ARWH systems adapted to the Back Creek watershed, Virginia. The baseline design reveals that the pump and pumping electricity are the main components of DRWH and ARWH impacts. For nonpotable uses, the minimal design of DRWH (with shortened distribution distance and no pump) outperforms municipal drinking water in all environmental impact categories except ecotoxicity. The minimal design of ARWH outperforms well water in all impact categories. In terms of watershed sustainability, the two minimal designs reduced environmental impacts, from 58% to 78% energy use and 67% to 88% human health criteria pollutants, as well as avoiding up to 20% blue water (surface/groundwater) losses, compared to municipal drinking water and well water. We address potential environmental and human health impacts of urban and rural RWH systems in the region. The Building for Environmental and Economic Sustainability (BEES) model-based life cycle inventory data were used for this study.

  20. Impacts of partial harvesting on the carbon and water balance of a mixed conifer forest attacked by the mountain pine beetle

    NASA Astrophysics Data System (ADS)

    Mathys, A.; Black, T. A.; Brown, M.; Nesic, Z.; Nishio, G.; Burton, P.; Spittlehouse, D.; Fredeen, A.; Trofymow, T.; Grant, N.; Lessard, D.; Bowler, R.

    2011-12-01

    The mountain pine beetle (MPB) outbreak has had a major impact on the carbon (C) and water balances of forests in Interior BC, Canada. As a management response, the forest sector has increased the annual allowable cut to enable partial harvesting in the timber supply areas. Protecting the non-pine secondary structure provides opportunities for mid-term (15-30 years) timber harvest, while providing habitat for wildlife, reducing run-off to rivers and streams and retaining stand biomass. This study investigates the effects of partial cutting on the CO2 and H2O fluxes and also compares it to clearcut harvesting. The study area is an MPB-attacked forest located near Summit Lake (54°13'N, 122°37'W) about 40 km north of Prince George, BC. In February and March 2009, the beetle-killed lodgepole pine trees (Pinus contorta var. latifolia) were removed, leaving 49% of secondary structure consisting mainly of black spruce (Picea mariana), white hybrid spruce (Picea engelmannii x glauca) and subalpine fir trees (Abies lasiocarpa) with a canopy height of ~16 m and a stand density of 535 stems ha-1. Net ecosystem productivity (NEP) has been continuously measured since October 2009 with the eddy-covariance technique using an ultrasonic anemometer and an open-path infrared gas analyzer mounted 26 m above the ground. This poster reports results for 2010, which was a relatively normal year in central BC with respect to solar radiation, precipitation and air temperature. During the growing season the stand was a C sink, with monthly total NEP values of up to 23.1 g C m-2 in June. Midday evapotranspiration rates did not exceed 0.3 mm h-1 with Bowen ratios usually greater than 1.5. By the end of the year the stand was a weak C source with an annual NEP of -50 g C m-2. In comparison, clearcuts in the region remain C sources for many years during the growing season. Results for 2011 will also be presented and compared to flux measurements in part of the stand that was clearcut

  1. Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

    NASA Astrophysics Data System (ADS)

    Misra, R. K.; Patel, J. H.; Baxi, V. R.

    2010-05-01

    SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

  2. Global terrestrial water storage capacity and flood potential using GRACE

    NASA Astrophysics Data System (ADS)

    Reager, J. T.; Famiglietti, J. S.

    2009-12-01

    Terrestrial water storage anomaly from the Gravity Recovery and Climate Experiment (GRACE) and precipitation observations from the Global Precipitation Climatology Project (GPCP) are applied at the regional scale to show the usefulness of a remotely sensed, storage-based flood potential method. Over the GRACE record length, instances of repeated maxima in water storage anomaly that fall short of variable maxima in cumulative precipitation suggest an effective storage capacity for a given region, beyond which additional precipitation must be met by marked increases in runoff or evaporation. These saturation periods indicate the possible transition to a flood-prone situation. To investigate spatially and temporally variable storage overflow, a monthly storage deficit variable is created and a global map of effective storage capacity is presented for possible use in land surface models. To highlight a flood-potential application, we design a monthly global flood index and compare with Dartmouth Flood Observatory flood maps.

  3. (Metabolic mechanisms of plant growth at low-water potentials)

    SciTech Connect

    Boyer, J.S.

    1989-01-01

    For the year 1989, the progress made on this DOE sponsored research will be described by considering the questions presented in the original proposal and describing the work on each one. We used soybean seedlings grown in vermiculite in a dark, humid environment because they are convenient to grow, undergo most of the physiological changes induced by low water potentials in large plants, and have exposed growing regions on which molecular experiments can be done.

  4. Transpiration- and growth-induced water potentials in maize

    SciTech Connect

    Westgate, M.E.; Boyer, J.S.

    1984-01-01

    Recent evidence from leaves and stems indicates that gradients in water potential (psi/sub w/) necessary for water movement through growing tissues are larger than previously assumed. Because growth is sensitive to tissue psi/sub w/ and the behavior of these gradients has not been investigated in transpiring plants, the authors examined the water status of all the growing and mature vegetative tissues of maize (Zea mays L.) during high and low rates of transpiration. The psi/sub w/ measured in the mature regions of the plant responded primarily to transpiration, while the psi/sub w/ in the growing regions was affected both by transpiration and growth. The transpiration-induced potentials of the mature tissue formed a gradient of decreasing psi/sub w/ along the transpiration stream while the growth-induced potentials formed a gradient of decreasing psi/sub w/ from the transpiration stream to the expanding cells in the growing tissue. The growth-induced gradient in psi/sub w/ within the leaf remained fairly constant as the xylem psi/sub w/ decreased during the day and was associated with a decreased osmotic potential (psi/sub s/) of the growing region (osmotic adjustment). The growth-induced gradient in psi/sub w/ was not caused by excision of the tissue because intact maize stems exhibited a similar psi/sub w/. These observations support the concept that large gradients in psi/sub w/ are required to maintain water flow to expanding cells within all the vegetative tissues and suggest that the maintenance of a favorable gradient in psi/sub w/ for cell enlargement may be an important role for osmotic adjustment. 33 references, 7 figures, 1 table.

  5. Use of models to map potential capture of surface water

    USGS Publications Warehouse

    Leake, Stanley A.

    2006-01-01

    The effects of ground-water withdrawals on surface-water resources and riparian vegetation have become important considerations in water-availability studies. Ground water withdrawn by a well initially comes from storage around the well, but with time can eventually increase inflow to the aquifer and (or) decrease natural outflow from the aquifer. This increased inflow and decreased outflow is referred to as “capture.” For a given time, capture can be expressed as a fraction of withdrawal rate that is accounted for as increased rates of inflow and decreased rates of outflow. The time frames over which capture might occur at different locations commonly are not well understood by resource managers. A ground-water model, however, can be used to map potential capture for areas and times of interest. The maps can help managers visualize the possible timing of capture over large regions. The first step in the procedure to map potential capture is to run a ground-water model in steady-state mode without withdrawals to establish baseline total flow rates at all sources and sinks. The next step is to select a time frame and appropriate withdrawal rate for computing capture. For regional aquifers, time frames of decades to centuries may be appropriate. The model is then run repeatedly in transient mode, each run with one well in a different model cell in an area of interest. Differences in inflow and outflow rates from the baseline conditions for each model run are computed and saved. The differences in individual components are summed and divided by the withdrawal rate to obtain a single capture fraction for each cell. Values are contoured to depict capture fractions for the time of interest. Considerations in carrying out the analysis include use of realistic physical boundaries in the model, understanding the degree of linearity of the model, selection of an appropriate time frame and withdrawal rate, and minimizing error in the global mass balance of the model.

  6. Hydrologic resilience of a Canadian Foothills watershed to forest harvest

    NASA Astrophysics Data System (ADS)

    Goodbrand, Amy; Anderson, Axel

    2016-04-01

    Recent investigations of long-term hydrometeorological, groundwater, and streamflow data from watersheds on the eastern slopes of the Canadian Rocky Mountains showed the streamflow regime was resilient to forest harvest. These watersheds had low levels of harvest relative to their size and a large area of sparsely vegetated alpine talus slopes and exposed bedrock; an area shown to generate the majority of runoff for streamflow. In contrast, watersheds located in the foothills of the Rocky Mountains are of lower relief and typically have harvestable timber throughout the watershed; therefore, these watersheds may be more sensitive to forest disturbance and have increased potential for streamflow response. This project assesses the hydrologic resilience of an Alberta Foothills watershed to forest harvest using a 23-year dataset from the Tri-Creeks Experimental Watershed (Tri-Creeks). Tri-Creeks has been the site of intensive streamflow, groundwater, snow accumulation, and precipitation observations from 1967 - 1990. During the early 1980s, forestry experiments were conducted to compare the effects of timber harvest and riparian buffers, and the effectiveness of timber harvesting ground rules in protecting fisheries and maintaining water resources within three sub-watersheds: Eunice (16.8 km2; control); Deerlick (15.2 km2; 36% streamside timber removal); and, Wampus (28.3 km2; 37% clear-cut). Statistical analyses were used to compare the pre-and post-harvest ratios of treatment to control sub-watershed runoff for: water year, monthly (April - October), snowmelt peak flow, and low flow (10th percentile streamflow) periods as an assessment of hydrologic resilience to forest harvest. The only significant post-harvest change was an increase in water yield during May at Wampus (Mann-Whitney (MW), p<0.05) and Deerlick (MW, p<0.1) Creeks. The lack of change in snowmelt peak flow timing or magnitude was not expected, particularly in Deerlick, which had 36% streamside timber

  7. Evaluations of membrane fouling potential in water treatment applications

    SciTech Connect

    Tu, S.C.; Ravindran, V.; Pirbazari, M.

    1999-07-01

    Membrane processes such as ultrafiltration, nanofiltration, and reverse osmosis are becoming increasingly popular in water treatment utilities because of their ability to produce high finished water quality. A major problem affecting the economics of these processes is permeate flux decline due to membrane fouling. The types of membrane fouling can be broadly categorized as follows: organic fouling, biofouling, colloidal fouling, inorganic fouling, and precipitation scaling. The membrane performance with respect to resistance to fouling as well as rejection characteristics is an important consideration. Selection of appropriate membranes for performance improvement in water treatment applications mandates the evaluation of the fouling potential, an aspect related to the membrane material, membrane type, nature of feed solution, and interactions between membranes and solutes. In the present study, the membrane fouling potential is evaluated by membrane performance tests with respect to permeate flux and solute rejections, and by membrane surface characterization techniques including measurements of membrane sorption, zeta potential, contact angles, and membrane surface morphology. These surface characterization techniques are intended to evaluate membrane sorption characteristics (with respect to foulants), membrane surface hydrophobicity, membrane surface charge under different solution conditions, and changes on membrane surface topography on the clean and fouled membranes.

  8. Planetary opportunities in crop water management: Potential to outweigh cropland expansion

    NASA Astrophysics Data System (ADS)

    Jägermeyr, Jonas; Gerten, Dieter; Lucht, Wolfgang; Heinke, Jens

    2014-05-01

    Global available land and water resources probably cannot feed projected future human populations under current productivity levels. Moreover, the planetary boundaries of both land use change and water consumption are being approached rapidly, and at the same time competition between food production, bioenergy plantations and biodiversity conservation is increasing. Global cropland is expected to expand to meet future demands, while considerable yield gaps remain in many world regions. Yield increases in Sub-Saharan Africa, for example, are currently mainly based on expansion of arable land into currently non-agricultural areas - while small-scale irrigation and water conservancy methods are considered very promising to boost yields there. In the here presented modeling study we investigate, at global scale, to what degree different on-farm options to better manage green and blue water might contribute to a global crop yield increase under conditions of current climate and projected future climate change. We consider methods aiming for a maximization of crops' water use efficiency and an optimal use of available on-farm water (precipitation): reducing unproductive soil evaporation (vapor shift, VS), collecting surface runoff after rain events to mitigate subsequent dry-spells (rain-water harvesting, RWH), increasing irrigation efficiency, and expanding irrigated area into rain-fed cropland (based on water savings from higher efficiencies). Global yield simulations based on hypothetical scenarios of these management opportunities are performed with the LPJmL ecohydrological modeling framework driven by reanalysis data and GCM ensemble simulations. We consider a range of about 20 climate change projections to cover respective uncertainties, and we analyze the effects of increasing CO2 concentration on the crops and their water demand. Crops are represented in a process-based and dynamic way by 12 crop functional types, each for rain-fed and irrigated areas, with

  9. Fundamental Limits to Nonlinear Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Haji Hosseinloo, Ashkan; Turitsyn, Konstantin

    2015-12-01

    Linear and nonlinear vibration energy harvesting has been the focus of considerable research in recent years. However, fundamental limits on the harvestable energy of a harvester subjected to an arbitrary excitation force and different constraints is not yet fully understood. Understanding these limits is not only essential for an assessment of the technology potential, but it also provides a broader perspective on the current harvesting mechanisms and guidance in their improvement. Here, we derive the fundamental limits on the output power of an ideal energy harvester for arbitrary excitation waveforms and build on the current analysis framework for the simple computation of this limit for more sophisticated setups. We show that the optimal harvester maximizes the harvested energy through a mechanical analog of a buy-low-sell-high strategy. We also propose a nonresonant passive latch-assisted harvester to realize this strategy for an effective harvesting. It is shown that the proposed harvester harvests energy more effectively than its linear and bistable counterparts over a wider range of excitation frequencies and amplitudes. The buy-low-sell-high strategy also reveals why the conventional bistable harvester works well at low-frequency excitation.

  10. RNA Sequencing of Contaminated Seeds Reveals the State of the Seed Permissive for Pre-Harvest Aflatoxin Contamination and Points to a Potential Susceptibility Factor

    PubMed Central

    Clevenger, Josh; Marasigan, Kathleen; Liakos, Vasileios; Sobolev, Victor; Vellidis, George; Holbrook, Corley; Ozias-Akins, Peggy

    2016-01-01

    Pre-harvest aflatoxin contamination (PAC) is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus, Aspergillus flavus, aflatoxin is the most naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and breeding for PAC resistance has been slow. It has been shown that aflatoxin production can be induced by applying drought stress as peanut seeds mature. We have implemented an automated rainout shelter that controls temperature and moisture in the root and peg zone to induce aflatoxin production. Using polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC), seeds meeting the following conditions were selected: infected with Aspergillus flavus and contaminated with aflatoxin; and not contaminated with aflatoxin. RNA sequencing analysis revealed groups of genes that describe the transcriptional state of contaminated vs. uncontaminated seed. These data suggest that fatty acid biosynthesis and abscisic acid (ABA) signaling are altered in contaminated seeds and point to a potential susceptibility factor, ABR1, as a repressor of ABA signaling that may play a role in permitting PAC. PMID:27827875

  11. Acephate exposure and decontamination on tobacco harvesters' hands.

    PubMed

    Curwin, Brian D; Hein, Misty J; Sanderson, Wayne T; Nishioka, Marcia; Buhler, Wayne

    2003-05-01

    Agricultural workers manually harvesting tobacco have the potential for high dermal fexposure to pesticides, particularly on the hands. Often gloves are not worn as it hinders the harvesters' ability to harvest the tobacco leaves. To enable harvesters to remove pesticide residue on the hands and decrease absorbed doses, the EPA Worker Protection Standard requires growers to have hand-wash stations available in the field. The purpose of this study was to measure the concentration of acephate residue on the hands of tobacco harvesters, and the effectiveness of hand washing in reducing the acephate residue. Hand-wipes from the hands of 12 tobacco harvesters were collected at the end of the morning and at the end of the afternoon over 2 consecutive days. Each harvester had one hand-wiped prior to washing his hands, and the other hand-wiped after washing his hands with soap and water. In addition to the hand-wipe samples, leaf-wipe samples were collected from 15 tobacco plants to determine the amount of acephate residue on the plants. The average acephate level in leaf-wipe samples was 1.4 ng/cm(2). The geometric mean prewash and postwash acephate levels on the hands were 10.5 and 0.4 ng/cm(2), respectively. Both prewash (P-value=0.0009) and postwash hand (P-value=0.01) samples were positively correlated with leaf-wipe concentrations. Tobacco harvester position tended to influence hand exposure. Hand washing significantly reduced acephate levels on the hand, after adjusting for sampling period, hand sampled, job position, and leaf-wipe concentration (P-value< or =0.0001) with levels reduced by 96%. A substantial amount of acephate was transferred to the hands, and while hand washing significantly reduced the amount of residue on the hands, not all residue was removed.

  12. Restoration of surface-mined lands with rainfall harvesting

    SciTech Connect

    Sauer, R.H.; Rickard, W.H.

    1982-12-01

    Strip mining for coal in the arid western US will remove grazing land as energy demands are met. Conventional resotration usually includes leveling the spoil banks and covering them with top soil, fertilizing, seeding and irrigation with well or river water. An overview of research on an alternate method of restoring this land is reported. From 1976 through 1981 studies were conducted on the use of water harvesting, the collection and use of rainfall runoff, to restore the vegetative productivity of strip mined lands in arid regions. These studies tested the technical and economic feasibility of using partially leveled spoil banks at strip mines as catchment areas to collect and direct runoff to the topsoiled valley floor where crops were cultivated. Information was collected on the efficiency of seven treatments to increase runoff from the catchment areas and on the productivity of seven crops. The experiments were conducted in arid areas of Washington, Arizona, and Colorado. It was concluded that water harvesting can replace or augment expensive and inadequate supplies of well and river water in arid regions with a suitable climate. These studies showed that some treatments provided adequate runoff to produce a useful crop in the valleys, thus making this alternative approach to restoration technically feasible. This approach was also potentially economically feasible where the treatment costs of the catchment areas were low, the treatment was effective, the crop was productive and valuable, and earthmoving costs were lower than with conventional restoration involving complete leveling of spoil banks. It was also concluded that water harvesting can be made more effective with further information on catchment area treatments, which crops are most adaptable to water harvesting, the optimum incline of the catchment areas and climatic influences on water harvesting.

  13. In(1-x)Ga(x)N@ZnO: a rationally designed and quantum dot integrated material for water splitting and solar harvesting applications.

    PubMed

    Rajaambal, Sivaraman; Mapa, Maitri; Gopinath, Chinnakonda S

    2014-09-07

    The highly desirable combination of the visible light absorption properties of In1-xGaxN Quantum dots (QD) along with the multifunctionality of ZnO into a single integrated material was prepared for solar harvesting. This is the first report on InGaN QD integrated with ZnO (InGaN@ZnO), synthesized by a highly reproducible, simple combustion method in 15 min. Structural, microstructural and electronic integration of the nitride and oxide components of InGaN@ZnO was demonstrated by appropriate characterization methods. Self-assembly of InGaN QD is induced in growing nascent zinc oxo nanoclusters taking advantage of the common wurtzite structure and nitrogen incorporation at the expense of oxygen vacancies. Direct integration brings about a single phase structure exhibiting extensive visible light absorption and high photostability. InGaN@ZnO suggests synergistic operation of light harvesting and charge conducting components for solar H2 generation without using any co-catalyst or sacrificial agent, and a promising photocurrent generation at 0 V under visible light illumination. The present study suggests a direct integration of QD with the host matrix and is a potential method to realize the advantages of QDs.

  14. Measurements of water potential and water content in unsaturated crystalline rock

    NASA Astrophysics Data System (ADS)

    Schneebeli, Martin; Flühler, Hannes; Gimmi, Thomas; Wydler, Hannes; LäSer, Hans-Peter; Baer, Toni

    1995-08-01

    A water desaturation zone develops around a tunnel in water-saturated rock when the evaporative water loss at the rock surface is larger than the water flow from the surrounding saturated region of restricted permeability. We describe the methods with which such water desaturation processes in rock materials can be quantified. The water retention characteristic θ (ψ) of crystalline rock samples was determined with a pressure membrane apparatus. The negative water potential, identical to the capillary pressure, ψ, below the tensiometric range (ψ < -0.1 MPa) can be measured with thermocouple psychrometers (TP), and the volumetric water contents, θ, by means of time domain reflectometry (TDR). These standard methods were adapted for measuring the water status in a macroscopically unfissured granodiorite with a total porosity of approximately 0.01. The measured water retention curve of granodiorite samples from the Grimsel test site (central Switzerland) exhibits a shape which is typical for bimodal pore size distributions. The measured bimodality is probably an artifact of a large surface ratio of solid/voids. The thermocouples were installed without a metallic screen using the cavity drilled into the granodiorite as a measuring chamber. The water potentials observed in a cylindrical granodiorite monolith ranged between -0.1 and -3.0 MPa; those near the wall in a ventilated tunnel between -0.1 and -2.2 MPa. Two types of three-rod TDR probes were used, one as a depth probe inserted into the rock, the other as a surface probe using three copper stripes attached to the surface for detecting water content changes in the rock-to-air boundary. The TDR signal was smoothed with a low-pass filter, and the signal length determined based on the first derivative of the trace. Despite the low porosity of crystalline rock these standard methods are applicable to describe the unsaturated zone in solid rock and may also be used in other consolidated materials such as concrete.

  15. A GIS based screening tool for locating and ranking of suitable stormwater harvesting sites in urban areas.

    PubMed

    Inamdar, P M; Cook, S; Sharma, A K; Corby, N; O'Connor, J; Perera, B J C

    2013-10-15

    There is the need to re-configure current urban water systems to achieve the objective of sustainable water sensitive cities. Stormwater represents a valuable alternative urban water source to reduce pressure on fresh water resources, and to mitigate the environmental impact of urban stormwater runoff. The selection of suitable urban stormwater harvesting sites is generally based on the judgement of water planners, who are faced with the challenge of considering multiple technical and socio-economic factors that influence the site suitability. To address this challenge, the present study developed a robust GIS based screening methodology for identifying potentially suitable stormwater harvesting sites in urban areas as a first pass for then more detailed investigation. The study initially evaluated suitability based on the match between harvestable runoff and demand through a concept of accumulated catchments. Drainage outlets of these accumulated catchments were considered as potential stormwater harvesting sites. These sites were screened and ranked under screening parameters namely demand, ratio of runoff to demand and weighted demand distance. The methodology described in this paper was successfully applied to a case study in Melbourne, Australia in collaboration with the local water utility. The methodology was found to be effective in supporting the selection of priority sites for stormwater harvesting schemes, as it provided the basis to identify, short-list and rank sites for further detailed investigation. The rapid identification of suitable sites for stormwater harvesting can assist planners in prioritising schemes in areas that will have the most impact on reducing potable water demand.

  16. Water savings potentials of irrigation systems: dynamic global simulation

    NASA Astrophysics Data System (ADS)

    Jägermeyr, J.; Gerten, D.; Heinke, J.; Schaphoff, S.; Kummu, M.; Lucht, W.

    2015-04-01

    Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatio-temporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of global agricultural water use, and of water saving and water productivity potentials constrained by biophysical processes and also non-trivial downstream effects, we incorporated a dynamic representation of the three major irrigation systems (surface, sprinkler, and drip) into a process-based bio- and agrosphere model, LPJmL. Based on this enhanced model we provide a gridded worldmap of dynamically retrieved irrigation efficiencies reflecting differences in system types, crop types, climatic and hydrologic conditions, and overall crop management. We find pronounced regional patterns in beneficial irrigation efficiency (a refined irrigation efficiency indicator accounting for crop-productive water consumption only), due to differences in these features, with lowest values (< 30%) in South Asia and Sub-Saharan Africa and highest values (> 60%) in Europe and North America. We arrive at an estimate of global irrigation water withdrawal of 2396 km3 (2004-2009 average); irrigation water consumption is calculated to be 1212 km3, of which 511 km3 are non-beneficially consumed, i.e. lost through evaporation, interception, and conveyance. Replacing surface systems by sprinkler or drip systems could, on average across the world's river basins, reduce the non-beneficial consumption at river basin level by 54 and 76%, respectively, while maintaining the current level of crop yields. Accordingly, crop water productivity would increase by 9 and 15%, respectively, and by much more in specific regions such as in the Indus basin. This study significantly advances the global quantification of

  17. Excess chemical potential of small solutes across water--membrane and water--hexane interfaces

    NASA Technical Reports Server (NTRS)

    Pohorille, A.; Wilson, M. A.

    1996-01-01

    The excess chemical potentials of five small, structurally related solutes, CH4, CH3F, CH2F2, CHF3, and CF4, across the water-glycerol 1-monooleate bilayer and water-hexane interfaces were calculated at 300, 310, and 340 K using the particle insertion method. The excess chemical potentials of nonpolar molecules (CH4 and CF4) decrease monotonically or nearly monotonically from water to a nonpolar phase. In contrast, for molecules that possess permanent dipole moments (CH3F, CH2F, and CHF3), the excess chemical potentials exhibit an interfacial minimum that arises from superposition of two monotonically and oppositely changing contributions: electrostatic and nonelectrostatic. The nonelectrostatic term, dominated by the reversible work of creating a cavity that accommodates the solute, decreases, whereas the electrostatic term increases across the interface from water to the membrane interior. In water, the dependence of this term on the dipole moment is accurately described by second order perturbation theory. To achieve the same accuracy at the interface, third order terms must also be included. In the interfacial region, the molecular structure of the solvent influences both the excess chemical potential and solute orientations. The excess chemical potential across the interface increases with temperature, but this effect is rather small. Our analysis indicates that a broad range of small, moderately polar molecules should be surface active at the water-membrane and water-oil interfaces. The biological and medical significance of this result, especially in relation to the mechanism of anesthetic action, is discussed.

  18. Efficient fog harvesting by Stipagrostis sabulicola (Namib dune bushman grass)

    NASA Astrophysics Data System (ADS)

    Roth-Nebelsick, A.; Ebner, M.; Miranda, T.

    2010-07-01

    Stipagrostis sabulicola is an endemic species of the central Namib Desert which settles on extremely arid dune fields. Due to its ability to persistence even during exceptionally dry years it is generally assumed that water supply of this species is substantially based on fog water. In this contribution, the results of a study investigating the capability of S. sabulicola for fog harvesting are presented. For this purpose, stem flow rates of S. sabulicola during fog events, spatial gradient of soil water content (SWC) close to mounds of S. sabulicola and its leaf water potential (LWP) before and after fog events were monitored together with climate parameters. According to the data obtained during this study, S. sabulicola is able to harvest substantial amounts of water by fog catchment from nocturnal fog events. Since culms of S. sabulicola are often stiff with an upright habitus, fog harvesting occurs via stemflow that conducts water directly towards the root zone of a plant. According to this mechanism, the stem runoff is concentrated within the area of the mound. A medium-sized mound of S. sabulicola is able to collect an amount of about 4 l per fog night. This fog harvesting leads to a considerable spatial gradient of soil water content with values decreasing with increasing distance from the mound. As a result of the water input by fog drip, SWC within the mound increases significantly, particularly close to the culm bases where SWC values increased to 2.2 % after a fog event. Due to the uneven distribution of water by stemflow, SWC within a mound shows high spatial heterogeneity which is also illustrated by the numerous outliers and extreme values of SWC within the mound region. This heterogeneity is also due to the fact that several sagging leaves are always present causing fog drip which more or less irregularly scatters moisture. For bare soil outside of a mound, the water content is not substantially increased, amounting to 0.78 % on average during dry

  19. Contamination of community water sources by potentially pathogenic vibrios following sea water inundation.

    PubMed

    Kanungo, Reba; Shashikala; Karunasagar, I; Srinivasan, S; Sheela, Devi; Venkatesh, K; Anitha, P

    2007-12-01

    Potentially pathogenic members of the Vibrionaceae family including Vibrio cholerae and Vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in Southern India. Phenotypic and genotypic studies were done to confirm the identity and detection of toxins. Vibrio-gyr (gyrase B gene) was detected in all sixteen vibrio isolates. Toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not detected in any of the strains, thereby ruling out presence of toxins which could endanger human life. Other potentially pathogenic bacteria Aeromonas and Plesiomonas were also isolated from hand pumps and wells, in a few localities. There was no immediate danger in the form of an outbreak or sporadic gastroenteritis at the time of the study. Timely chlorination and restoration of potable water supply to the flood affected population by governmental and nongovernmental agencies averted waterborne gastroenteritis. Assessment of quality of water and detection of potential virulent organisms is an important public health activity following natural disasters. This work highlights the importance of screening water sources for potentially pathogenic microorganisms after natural disasters to avert outbreaks of gastroenteritis and other infectious diseases.

  20. BOREAS TE-12 SSA Leaf Water Potential Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.; Chen, L.; Yang, Litao

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-12 (Terrestrial Ecology) team collected water potential data in 1993 and 1994 from aspen, jack pine, and black spruce leaves/needles. Collections were made at the Southern Study Area Nipawin Fen Site (SSA FEN), Young Jack Pine (YJP), Young Aspen (YA), Old Aspen (OA), and Old Black Spruce (OBS) sites. Measurements were made using a pressure chamber on a platform in the field. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  1. An Approach to the Teaching of Cell Water Relations in Biology at A-Level Using the Water Potential Concept.

    ERIC Educational Resources Information Center

    Hutchinson, Colin S.; Sutcliffe, James F.

    1983-01-01

    The existence of several different approaches to teaching water relations is noted, arguing that the concept of water potential is the most useful basis for this approach. The meaning of water potential is discussed, and a means of introducing it and using it to explain cell water relations is outlined. (Author/JN)

  2. Potential Health Benefits of Deep Sea Water: A Review

    PubMed Central

    Jaafar, A. B.; Mahdzir, A.; Musa, M. N.

    2016-01-01

    Deep sea water (DSW) commonly refers to a body of seawater that is pumped up from a depth of over 200 m. It is usually associated with the following characteristics: low temperature, high purity, and being rich with nutrients, namely, beneficial elements, which include magnesium, calcium, potassium, chromium, selenium, zinc, and vanadium. Less photosynthesis of plant planktons, consumption of nutrients, and organic decomposition have caused lots of nutrients to remain there. Due to this, DSW has potential to become a good source for health. Research has proven that DSW can help overcome health problems especially related to lifestyle-associated diseases such as cardiovascular disease, diabetes, obesity, cancer, and skin problems. This paper reviews the potential health benefits of DSW by referring to the findings from previous researches. PMID:28105060

  3. Ab initio water pair potential with flexible monomers.

    PubMed

    Jankowski, Piotr; Murdachaew, Garold; Bukowski, Robert; Akin-Ojo, Omololu; Leforestier, Claude; Szalewicz, Krzysztof

    2015-03-26

    A potential energy surface for the water dimer with explicit dependence on monomer coordinates is presented. The surface was fitted to a set of previously published interaction energies computed on a grid of over a quarter million points in the 12-dimensional configurational space using symmetry-adapted perturbation theory and coupled-cluster methods. The present fit removes small errors in published fits, and its accuracy is critically evaluated. The minimum and saddle-point structures of the potential surface were found to be very close to predictions from direct ab initio optimizations. The computed second virial coefficients agreed well with experimental values. At low temperatures, the effects of monomer flexibility in the virial coefficients were found to be much smaller than the quantum effects.

  4. Thermodynamic properties of liquid water from a polarizable intermolecular potential.

    PubMed

    Yigzawe, Tesfaye M; Sadus, Richard J

    2013-01-28

    Molecular dynamics simulation results are reported for the pressure, isothermal pressure coefficient, thermal expansion coefficient, isothermal and adiabatic compressibilities, isobaric and isochoric heat capacities, Joule-Thomson coefficient and speed of sound of liquid water using a polarizable potential [Li et al., J. Chem. Phys. 127, 154509 (2007)]. These properties were obtained for a wide range of temperatures and pressures at a common liquid density using the treatment of Lustig [J. Chem. Phys. 100, 3048 (1994)] and Meier and Kabelac [J. Chem. Phys. 124, 064104 (2006)], whereby thermodynamic state variables are expressible in terms of phase-space functions determined directly from molecular dynamics simulations. Comparison with experimental data indicates that the polarizable potential can be used to predict most thermodynamic properties with a very good degree of accuracy.

  5. Potential Health Benefits of Deep Sea Water: A Review.

    PubMed

    Mohd Nani, Samihah Zura; Majid, F A A; Jaafar, A B; Mahdzir, A; Musa, M N

    2016-01-01

    Deep sea water (DSW) commonly refers to a body of seawater that is pumped up from a depth of over 200 m. It is usually associated with the following characteristics: low temperature, high purity, and being rich with nutrients, namely, beneficial elements, which include magnesium, calcium, potassium, chromium, selenium, zinc, and vanadium. Less photosynthesis of plant planktons, consumption of nutrients, and organic decomposition have caused lots of nutrients to remain there. Due to this, DSW has potential to become a good source for health. Research has proven that DSW can help overcome health problems especially related to lifestyle-associated diseases such as cardiovascular disease, diabetes, obesity, cancer, and skin problems. This paper reviews the potential health benefits of DSW by referring to the findings from previous researches.

  6. Potential for Quantifying Expression of the Geobacteraceae Citrate Synthase Gene To Assess the Activity of Geobacteraceae in the Subsurface and on Current-Harvesting Electrodes

    PubMed Central

    Holmes, Dawn E.; Nevin, Kelly P.; O'Neil, Regina A.; Ward, Joy E.; Adams, Lorrie A.; Woodard, Trevor L.; Vrionis, Helen A.; Lovley, Derek R.

    2005-01-01

    The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transcription-PCR studies with mRNA extracted from cultures of Geobacter sulfurreducens grown in chemostats with Fe(III) as the electron acceptor or in batch with electrodes as the electron acceptor indicated that transcript levels of the citrate synthase gene, gltA, increased with increased rates of growth/Fe(III) reduction or current production, whereas the expression of the constitutively expressed housekeeping genes recA, rpoD, and proC remained relatively constant. Analysis of mRNA extracted from groundwater collected from a U(VI)-contaminated site undergoing in situ uranium bioremediation revealed a remarkable correspondence between acetate levels in the groundwater and levels of transcripts of gltA. The expression of gltA was also significantly greater in RNA extracted from groundwater beneath a highway runoff recharge pool that was exposed to calcium magnesium acetate in June, when acetate concentrations were high, than in October, when the levels had significantly decreased. It was also possible to detect gltA transcripts on current-harvesting anodes deployed in freshwater sediments. These results suggest that it is possible to monitor the in situ metabolic rate of Geobacteraceae by tracking the expression of the citrate synthase gene. PMID:16269721

  7. Potential for quantifying expression of the Geobacteraceae citrate synthase gene to assess the activity of Geobacteraceae in the subsurface and on current-harvesting electrodes

    USGS Publications Warehouse

    Holmes, Dawn E.; Nevin, Kelly P.; O'Neil, Regina A.; Ward, Joy E.; Adams, Lorrie A.; Woodard, Trevor L.; Vrionis, Helen A.; Lovely, Derek R.

    2005-01-01

    The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transcription-PCR studies with mRNA extracted from cultures of Geobacter sulfurreducens grown in chemostats with Fe(III) as the electron acceptor or in batch with electrodes as the electron acceptor indicated that transcript levels of the citrate synthase gene, gltA, increased with increased rates of growth/Fe(III) reduction or current production, whereas the expression of the constitutively expressed housekeeping genes recA, rpoD, and proC remained relatively constant. Analysis of mRNA extracted from groundwater collected from a U(VI)-contaminated site undergoing in situ uranium bioremediation revealed a remarkable correspondence between acetate levels in the groundwater and levels of transcripts of gltA. The expression of gltA was also significantly greater in RNA extracted from groundwater beneath a highway runoff recharge pool that was exposed to calcium magnesium acetate in June, when acetate concentrations were high, than in October, when the levels had significantly decreased. It was also possible to detect gltA transcripts on current-harvesting anodes deployed in freshwater sediments. These results suggest that it is possible to monitor the in situ metabolic rate of Geobacteraceae by tracking the expression of the citrate synthase gene.

  8. Polarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer potential energy surface

    NASA Astrophysics Data System (ADS)

    Bukowski, Robert; Szalewicz, Krzysztof; Groenenboom, Gerrit C.; van der Avoird, Ad

    2008-03-01

    A six-dimensional interaction potential for the water dimer has been fitted to ab initio interaction energies computed at 2510 dimer configurations. These energies were obtained by combining the supermolecular second-order energies extrapolated to the complete basis set limit from up to quadruple-zeta quality basis sets with the contribution from the coupled-cluster method including single, double, and noniterative triple excitations computed in a triple-zeta quality basis set. All basis sets were augmented by diffuse functions and supplemented by midbond functions. The energies have been fitted using an analytic form with the induction component represented by a polarizable term, making the potential directly transferable to clusters and the bulk phase. Geometries and energies of stationary points on the potential surface agree well with the results of high-level ab initio geometry optimizations.

  9. An Ab Initio Based Potential Energy Surface for Water

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Schwenke, David W.; Langhoff, Stephen R. (Technical Monitor)

    1996-01-01

    We report a new determination of the water potential energy surface. A high quality ab initio potential energy surface (PES) and dipole moment function of water have been computed. This PES is empirically adjusted to improve the agreement between the computed line positions and those from the HITRAN 92 data base. The adjustment is small, nonetheless including an estimate of core (oxygen 1s) electron correlation greatly improves the agreement with experiment. Of the 27,245 assigned transitions in the HITRAN 92 data base for H2(O-16), the overall root mean square (rms) deviation between the computed and observed line positions is 0.125/cm. However the deviations do not correspond to a normal distribution: 69% of the lines have errors less than 0.05/cm. Overall, the agreement between the line intensities computed in the present work and those contained in the data base is quite good, however there are a significant number of line strengths which differ greatly.

  10. Acclimation of photosynthesis to low leaf water potentials

    SciTech Connect

    Matthews, M.A.; Boyer, J.S.

    1984-01-01

    Photosynthesis is reduced at low leaf water potentials (PSI/sub l/) but repeated water deficits can decrease this reduction, resulting in photosynthetic acclimation. The contribution of the stomata and the chloroplasts to this acclimation is unknown. The authors evaluated stomatal and chloroplast contributions when soil-grown sunflower (Helianthus annuus L.) plants were subjected to water deficit pretreatments for 2 weeks. The relationship between photosynthesis and PSI/sub l/, determined from gas-exchange and isopiestic thermocouple psychometry, was shifted 3 to 4 bars towards lower PSI/sub l/ in pretreated plants. Leaf diffusive resistance was similarly affected. Chloroplast activity, demonstrated in situ with measurements of quantum yield and the capacity to fix CO/sub 2/ at all partial pressures of CO/sub 2/, and in vitro by photosystem II activity of isolated organelles, was inhibited at low PSI/sub l/ but less in pretreated plants than in control plants. The magnitude of this inhibition indicated that decreases in chloroplast activity contributed more than closure of stomata both to losses in photosynthesis and to the acclimation of photosynthesis to low PSI/sub l/. 32 references, 8 figures.

  11. Emerging and potentially emerging viruses in water environments.

    PubMed

    La Rosa, Giuseppina; Fratini, Marta; della Libera, Simonetta; Iaconelli, Marcello; Muscillo, Michele

    2012-01-01

    Among microorganisms, viruses are best fit to become emerging pathogens since they are able to adapt not only by mutation but also through recombination and reassortment and can thus become able to infect new hosts and to adjust to new environments. Enteric viruses are among the commonest and most hazardous waterborne pathogens, causing both sporadic and outbreak-related illness. The main health effect associated with enteric viruses is gastrointestinal illness, but they can also cause respiratory symptoms, conjunctivitis, hepatitis, central nervous system infections, and chronic diseases. Non-enteric viruses, such as respiratory and epitheliotrophic viruses are not considered waterborne, as they are not readily transmitted to water sources from infected individuals. The present review will focus on viral pathogens shown to be transmitted through water. It will also provide an overview of viruses that had not been a concern for waterborne transmission in the past, but that may represent potentially emerging waterborne pathogens due to their occurrence and persistence in water environments.

  12. A comparison of the spatial distribution of vadose zone water in forested and agricultural floodplains a century after harvest.

    PubMed

    Kellner, Elliott; Hubbart, Jason A

    2016-01-15

    To improve quantitative understanding of the long-term impact of historic forest removal on floodplain vadose zone water regime, a study was implemented in fall 2010, in the Hinkson Creek Watershed, Missouri, USA. Automated, continuously logging capacitance-frequency probes were installed in a grid-like formation (n=6) and at depths of 15, 30, 50, 75, and 100 cm within a historic agricultural field (Ag) and a remnant bottomland hardwood forest (BHF). Data were logged at thirty minute intervals for the duration of the 2011, 2012, and 2013 hydrologic years. Results showed volumetric water content (VWC) to be significantly different between sites (p<0.01) during the study, with site averages of 33.1 and 32.8% at the Ag and BHF sites, respectively. Semi-variogram analyses indicate the presence of strong (<25%) horizontal and vertical spatial correlation of VWC at the Ag site, and a relatively short-range (25 cm) vertical spatial correlation at the BHF, but only indicate horizontal VWC spatial correlation in the top 30 cm of the BHF profile. Likely mechanisms contributing to patterns of observed differences are contrasting rates and depths of plant water use, and the presence of preferential flow paths in the below ground BHF. Results suggest historic forest removal and cultivation of the Ag site lead to an effective homogenization of the upper soil profile, and facilitated the development of strong VWC spatial dependency. Conversely, higher hydraulic conductivity of the more heterogeneous BHF subsurface likely results in a wetting of the deeper profile (75 cm) during climatically wet periods, and thus a more effective processing of hydrologic inputs. Collective results highlight the greater extent and degree to which forest vegetation impacts subsurface hydrology, relative to grassland/agricultural systems, and point to the value of reestablishing floodplain forests for fresh water routing, water quality, and flood mitigation in mixed-land-use watersheds.

  13. SARAL/Altika for inland water: current and potential applications

    NASA Astrophysics Data System (ADS)

    Tarpanelli, Angelica; Brocca, Luca; Barbetta, Silvia; Moramarco, Tommaso; Santos da Silva, Joécila; Calmant, Stephane

    2015-04-01

    Although representing less than 1% of the total amount of water on Earth the freshwater is essential for terrestrial life and human needs. Over one third of the world's population is not served by adequate supplies of clean water and for this reason freshwater wars are becoming one of the most pressing environmental issues exacerbating the already difficult tensions between the riparian nations. Notwithstanding the foregoing, we have surprisingly poor knowledge of the spatial and temporal dynamics of surface discharge. In-situ gauging networks quantify the instantaneous water volume in the main river channels but provide few information about the spatial dynamics of surface water extent, such as floodplain flows and the dynamics of wetlands. The growing reduction of hydrometric monitoring networks over the world, along with the inaccessibility of many remote areas and the difficulties for data sharing among developing countries feed the need to develop new procedures for river discharge estimation based on remote sensing technology. The major challenge in this case is the possibility of using Earth Observation data without ground measurements. Radar altimeters are a valuable tool to retrieve hydrological information from space such as water level of inland water. More than a decade of research on the application of radar altimetry has demonstrated its advantages also for monitoring continental water, providing global coverage and regular temporal sampling. The high accuracy of altimetry data provided by the latest spatial missions and the convincing results obtained in the previous applications suggest that these data may be employed for hydraulic/hydrological applications as well. If used in synergy with the modeling, the potential benefits of the altimetry measurements can grow significantly. The new SARAL French-Indian mission, providing improvements in terms of vertical accuracy and spatial resolution of the onboard altimeter Altika, can offer a great

  14. Influence of harvesting site on chemical composition and potential protein value of Acacia erioloba, A. nilotica and Ziziphus mucronata leaves for ruminants.

    PubMed

    Mnisi, C M; Mlambo, V

    2016-07-21

    This study was designed to evaluate the chemical composition, buffer N solubility, in vitro ruminal N degradation and in vitro ruminal biological activity of condensed tannins in Acacia erioloba, Acacia nilotica and Ziziphus mucronata leaves harvested from two sites (Masuthle communal grazing land and Molelwane private farm). Leaves were harvested, dried at 60 °C and milled. The highest crude protein (CP) content was found in leaves of Z. mucronata (177.7 g/kg DM). Leaves harvested from Masuthle had higher (p < 0.05) soluble phenolics (SPh) (44.6 g TAE/kg DM) compared to those harvested from Molelwane (29.8 g TAE/kg DM). In both Molelwane and Masuthle, leaves of A. nilotica had higher levels of condensed tannins (CT) (0.76 AU550/200 mg and 0.52 AU550/200 mg respectively) followed by A. erioloba and Z. mucronata, which did not differ (p > 0.05). Nitrogen degradability at 24 h was the same (p > 0.05) for all tree species but not at 12 and 36 h. No linear association (p > 0.05) was found between buffer-soluble N and in vitro ruminal N degradability in leaves with high SPh content. The largest polyethylene glycol (PEG) effect was in leaves of A. nilotica (448%) harvested from Masuthle after 36 h of incubation. Ziziphus mucronata leaves harvested from Molelwane had the least PEG effect at 48 h. There was no linear association (p > 0.05) between PEG effect and SPh for all incubation periods, but a positive relationship was observed between PEG effect and condensed tannins content. There was no linear association between solubility index (SI) and in vitro ruminal N degradability for tannin-rich leaves. It was concluded that higher browsing pressure in Masuthle communal rangeland resulted in leaves with higher levels of condensed tannins, which had higher in vitro ruminal biological activity, compared to those harvested from Molelwane.

  15. Crumb rubber filtration: a potential technology for ballast water treatment.

    PubMed

    Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

    2006-05-01

    The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between removal efficiency and filter depth. Higher filtration rate resulted in lower removal efficiency and higher head loss. Compared with conventional granular media filters, crumb rubber filters required less backwash, and developed lower head loss. Consequently crumb rubber filters could be run for a longer time or allow a higher filtration rate. The results also indicate that the crumb rubber filtration alone did not achieve the target removal of invasive species. However, crumb rubber filtration could potentially be used as a primary treatment technology to enhance the efficiency of a secondary treatment process (e.g., disinfection).

  16. Black Phosphorus: Critical Review and Potential for Water Splitting Photocatalyst

    PubMed Central

    Lee, Tae Hyung; Kim, Soo Young; Jang, Ho Won

    2016-01-01

    A century after its first synthesis in 1914, black phosphorus has been attracting significant attention as a promising two-dimensional material in recent years due to its unique properties. Nowadays, with the development of its exfoliation method, there are extensive applications of black phosphorus in transistors, batteries and optoelectronics. Though, because of its hardship in mass production and stability problems, the potential of the black phosphorus in various fields is left unexplored. Here, we provide a comprehensive review of crystal structure, electronic, optical properties and synthesis of black phosphorus. Recent research works about the applications of black phosphorus is summarized. Among them, the possibility of black phosphorous as a solar water splitting photocatalyst is mainly discussed and the feasible novel structure of photocatalysts based on black phosphorous is proposed. PMID:28335322

  17. Black Phosphorus: Critical Review and Potential for Water Splitting Photocatalyst.

    PubMed

    Lee, Tae Hyung; Kim, Soo Young; Jang, Ho Won

    2016-10-29

    A century after its first synthesis in 1914, black phosphorus has been attracting significant attention as a promising two-dimensional material in recent years due to its unique properties. Nowadays, with the development of its exfoliation method, there are extensive applications of black phosphorus in transistors, batteries and optoelectronics. Though, because of its hardship in mass production and stability problems, the potential of the black phosphorus in various fields is left unexplored. Here, we provide a comprehensive review of crystal structure, electronic, optical properties and synthesis of black phosphorus. Recent research works about the applications of black phosphorus is summarized. Among them, the possibility of black phosphorous as a solar water splitting photocatalyst is mainly discussed and the feasible novel structure of photocatalysts based on black phosphorous is proposed.

  18. MODELING POTENTIAL PATHOGEN INFECTED WATERS UTILIZING LANDSCAPE INDICES

    EPA Science Inventory

    The federal Clean Water Act (CWA) requires states, territories and tribal lands to assess their waters on a biennial schedule and identify, list and prioritize impaired waters not meeting water quality standards. Once a water body is listed, the state is required to develop Tota...

  19. Hydrogen-Bonding Polarizable Intermolecular Potential Model for Water.

    PubMed

    Jiang, Hao; Moultos, Othonas A; Economou, Ioannis G; Panagiotopoulos, Athanassios Z

    2016-12-08

    A polarizable intermolecular potential model with short-range directional hydrogen-bonding interactions was developed for water. The model has a rigid geometry, with bond lengths and angles set to experimental gas-phase values. Dispersion interactions are represented by the Buckingham potential assigned to the oxygen atom, whereas electrostatic interactions are modeled by Gaussian charges. Polarization is handled by a Drude oscillator site, using a negative Gaussian charge attached to the oxygen atom by a harmonic spring. An explicit hydrogen-bonding term is included in the model to account for the effects of charge transfer. The model parameters were optimized to density, configurational energy, pair correlation function, and the dielectric constant of water under ambient conditions, as well as the minimum gas-phase dimer energy. Molecular dynamics and Gibbs ensemble Monte Carlo simulations were performed to evaluate the new model with respect to the thermodynamic and transport properties over a wide range of temperature and pressure conditions. Good agreement between model predictions and experimental data was found for most of the properties studied. The new model yields better performance relative to the majority of existing models and outperforms the BK3 model, which is one of the best polarizable models, for vapor-liquid equilibrium properties, whereas the new model is not better than the BK3 model for representation of other properties. The model can be efficiently simulated with the thermalized Drude oscillator algorithm, resulting in computational costs only 3 times higher than those of the nonpolarizable TIP4P/2005 model, whereas having significantly improved properties. Because it involves only a single Drude oscillator site, the new model is significantly faster than polarizable models with multiple sites. With the explicit inclusion of hydrogen-bond interactions, the model may provide a better description of the phase behavior of aqueous mixtures.

  20. Water quality and plankton communities in hybrid catfish (female channel catfish, Ictalurus punctatus x male blue catfish, I. furcatus) ponds after partial fish harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve, 0.4-ha ponds were stocked with 10,000 hybrid catfish fingerlings in March 2015. Six ponds were partially harvested in August to remove fish larger than ~ 0.57 kg. All remaining fish were removed in October and November. Partial harvest of faster-growing fish removed ~26% of fish initially st...

  1. Potential risk of microplastics transportation into ground water

    NASA Astrophysics Data System (ADS)

    Huerta, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A.; Geissen, Violette

    2016-04-01

    Microplastics, are plastics particles with a size smaller than 5mm. They are formed by the fragmentation of plastic wastes. They are present in the air, soil and water. But only in aquatic systems (ocean and rivers) are studies over their distribution, and the effect of microplastics on organisms. There is a lack of information of what is the distribution of microplastics in the soil, and in the ground water. This study tries to estimate the potential risk of microplastics transportation into the ground water by the activity of earthworms. Earthworms can produce burrows and/or galleries inside the soil, with the presence of earthworms some ecosystem services are enhanced, as infiltration. In this study we observed after 14 days with 5 treatments (0, 7, 28 and 60% w/w microplastics mixed with Populus nigra litter) and the anecic earthworm Lumbricus terrestris, in microcosms (3 replicas per treatment) that macroplastics are indeed deposit inside earthworms burrows, with 7% microplastics on the surface is possible to find 1.8 g.kg-1 microplastics inside the burrows, with a bioaumentation factor of 0.65. Burrows made by earthworms under 60% microplastics, are significant bigger (p<0.05) than the burrows of those earthworms without microplastics in their soil surface. The amount of litter that is deposit inside the burrows is significant higher (p<0.05) with the presence of microplastics on the surface than without microplastics. The microplastics size distribution is smaller inside the burrows than on the surface, with an abundance of particles under 63 μm.

  2. Transient streaming potentials under varying pore-water ionic strength

    NASA Astrophysics Data System (ADS)

    Malama, B.

    2014-12-01

    Streaming potentials (SP) are generated when polar fluids such as groundwater flow through porous media that have charged mineral surfaces. This is due to the flow-shearing of the diffuse layer of the electric double layer (EDL), which is known to form in the fluid phase at the fluid-rock interface. Previous works have suggested that the EDL vanishes at high pore-fluid ionic strengths resulting in vanishing SP signals. However, recent observations in sea-water intrusion applications by Jackson and coworkers indicate that measurable SP signals are obtainable in flows of fluids with high ionic strengths through silica sand. We demonstrate the repeatability of these observations through a series of laboratory flow experiments performed on 98% silica sand in a falling-head permeameter with brines of concentrations ranging from 0.001M to about 5 M NaCl. The results of the experiments, which clearly show measurable SP signals even at the highest concentration of 5 M NaCl, are reported. They are also used to estimate the hydraulic conductivity and electrokinetic coupling coefficient. The linearity assumption for the relation between pressure and SP differentials is evaluated for high pore-water NaCl concentrations. Additionally, displacement of one brine by another of different NaCl concentration yields dramatic transient SP responses that may be harnessed in the development of early-detection/warning technologies for sea-water intrusion applications. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. This research is funded by WIPP programs administered by the Office of Environmental Management (EM) of the U.S Department of Energy.

  3. Water potential and starvation stress in deep subsurface microorganisms

    SciTech Connect

    Kieft, T.L.; Rosacker, L.L.; Willcox, D.; Franklin, A.J.

    1990-12-31

    Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (ATP assay), and low microbial activities (measured as respiration), suggesting that low metric waterpotentials in these strata are limiting factors to microorganisms. An Acinetobacter sp. isolated from the 324 m depth was found to maintain viability under starvation conditions in sterilized aquifer material, even when subjected to severe desiccation ({minus}22 MPa). A Pseudomonas sp., with the ability to oxidize thiosulfate to sulfate, was isolated from the 378 m Middendorf clay sample. This organism survived nutrient deprivation reasonably well; however, the presence of thiosulfate appeared to interfere with its normal ability to maintain viability by endogenous metabolism. Cells cultured in the presence of thiosulfate did not undergo dwarfing and cell viability declines. These are two examples of indigenous subsurface microorganisms, each with different adaptations for long-term survival under conditions of desiccation and/or starvation.

  4. Water potential and starvation stress in deep subsurface microorganisms

    SciTech Connect

    Kieft, T.L.; Rosacker, L.L.; Willcox, D.; Franklin, A.J.

    1990-01-01

    Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (ATP assay), and low microbial activities (measured as respiration), suggesting that low metric waterpotentials in these strata are limiting factors to microorganisms. An Acinetobacter sp. isolated from the 324 m depth was found to maintain viability under starvation conditions in sterilized aquifer material, even when subjected to severe desiccation ({minus}22 MPa). A Pseudomonas sp., with the ability to oxidize thiosulfate to sulfate, was isolated from the 378 m Middendorf clay sample. This organism survived nutrient deprivation reasonably well; however, the presence of thiosulfate appeared to interfere with its normal ability to maintain viability by endogenous metabolism. Cells cultured in the presence of thiosulfate did not undergo dwarfing and cell viability declines. These are two examples of indigenous subsurface microorganisms, each with different adaptations for long-term survival under conditions of desiccation and/or starvation.

  5. 77 FR 36260 - Proposed Information Collection; Comment Request; Puget Sound Recreational Shellfish Harvesting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... recreational shellfish harvesting through statistical estimation of models; and (3) the potential changes in... Sound Recreational Shellfish Harvesting Project AGENCY: National Oceanic and Atmospheric Administration..., affecting local growers and restricting commercial and recreational harvest opportunities. The Puget...

  6. Molecular-dynamics simulation of liquid water with an ab initio flexible water-water interaction potential

    NASA Astrophysics Data System (ADS)

    Lie, G. C.; Clementi, E.

    1986-04-01

    The Matsuoka-Clementi-Yoshimine (MCY) configuration interaction potential for rigid water-water interactions has been extended to include the intramolecular vibrations. The extended potential (MCYL), using no empirical parameters other than the atomic masses, electron charge, and Planck constant, is used in a molecular-dynamics simulation study of the static and dynamic properties of liquid water. Among the properties studied are internal energy, heat capacity, pressure, radial distribution functions, dielectric constant, static structure factor, velocity autocorrelation functions, self-diffusion coefficients, dipole autocorrelation function, and density and current fluctuations. Comparison with experiments is made whenever possible. Most of these properties are found to improve slightly relative to the MCY model. The simulated high-frequency sound mode seems to support the results and interpretation of a recent coherent inelastic neutron scattering experiment.

  7. An overview of water disinfection in developing countries and the potential for solar thermal water pasteurization

    SciTech Connect

    Burch, J.; Thomas, K.E.

    1998-01-01

    This study originated within the Solar Buildings Program at the U.S. Department of Energy. Its goal is to assess the potential for solar thermal water disinfection in developing countries. In order to assess solar thermal potential, the alternatives must be clearly understood and compared. The objectives of the study are to: (a) characterize the developing world disinfection needs and market; (b) identify competing technologies, both traditional and emerging; (c) analyze and characterize solar thermal pasteurization; (d) compare technologies on cost-effectiveness and appropriateness; and (e) identify research opportunities. Natural consequences of the study beyond these objectives include a broad knowledge of water disinfection problems and technologies, introduction of solar thermal pasteurization technologies to a broad audience, and general identification of disinfection opportunities for renewable technologies.

  8. OXIDATION-REDUCTION POTENTIAL MEASUREMENTS OF IMPORTANT OXIDANTS IN DRINKING WATER

    EPA Science Inventory

    Oxidation-reduction (redox) reactions are important in drinking water treatment and distribution. Oxidation-reduction potential (ORP) measurements of water reflect the tendency of major constituents in the water to accept or lose electrons. Although ORP measurements are valuable...

  9. Hydraulic fracturing water use variability in the United States and potential environmental implications.

    PubMed

    Gallegos, Tanya J; Varela, Brian A; Haines, Seth S; Engle, Mark A

    2015-07-01

    A U.S. map of water volumes used to hydraulically fracture oil and gas wells, 2011-2014Hydraulic fracturing water volumes differ regionally across the U.S.Discussion of variation in water use and potential environmental implications.

  10. Changes in water quality and climate after forest harvest in central Washington state. Forest Service research paper

    SciTech Connect

    Fowler, W.B.; Anderson, T.D.; Helvey, J.D.

    1988-01-01

    Chemical output of nitrate, calcium, magnesium, sodium, potassium, and organic nitrogen were determined on a grams-per-hectare-per-day basis for five treatment watersheds and a control watershed. Water samples were collected from April to October during 3 pretreatment and 3 post-treatment years (1978 to 1983). Except for increased calcium and sodium in several streams, regression equations comparing treatment with control showed significant difference for pretreatment and posttreatment output. Output generally declined in the post-treatment years. Cyclic changes in output from these and other streams in the eastern Cascade Range in Washington appeared to occur regardless of treatment and were probably related to precipitation. Mean maximum air temperature increased during the posttreatment period in all the small watersheds, but stream temperatures were relatively unaffected.

  11. FLUORESCENCE EMISSION SPECTRA OF MARINE AND BRACKISH-WATER ECOTYPES OF FUCUS VESICULOSUS AND FUCUS RADICANS (PHAEOPHYCEAE) REVEAL DIFFERENCES IN LIGHT-HARVESTING APPARATUS(1).

    PubMed

    Maria Gylle, Anna; Rantamäki, Susanne; Ekelund, Nils G A; Tyystjärvi, Esa

    2011-02-01

    The Bothnian Sea in the northerly part of the Baltic Sea is a geologically recent brackish-water environment, and rapid speciation is occurring in the algal community of the Bothnian Sea. We measured low-temperature fluorescence emission spectra from the Bothnian Sea and the Norwegian Sea ecotypes of Fucus vesiculosus L., a marine macroalga widespread in the Bothnian Sea. Powdered, frozen thallus was used to obtain undistorted emission spectra. The spectra were compared with spectra measured from the newly identified species Fucus radicans Bergström et L. Kautsky, which is a close relative of F. vesiculosus and endemic to the Bothnian Sea. The spectrum of variable fluorescence was used to identify fluorescence peaks originating in PSI and PSII in this chl c-containing alga. The spectra revealed much higher PSII emission, compared to PSI emission, in the Bothnian Sea ecotype of F. vesiculosus than in F. radicans or in the Norwegian Sea ecotype of F. vesiculosus. The results suggest that more light-harvesting chl a/c proteins serve PSII in the Bothnian Sea ecotype of F. vesiculosus than in the two other algal strains. Treatment of the Bothnian Sea ecotype of F. vesiculosus in high salinity (10, 20, and 35 practical salinity units) for 1 week did not lead to spectral changes, indicating that the measured features of the Bothnian Sea F. vesiculosus are stable and not simply a direct result of exposure to low salinity.

  12. Potential Seasonal Predictability of the Global Water Cycle

    NASA Astrophysics Data System (ADS)

    Feng, X.; DelSole, T. M.; Houser, P. R.

    2011-12-01

    The potential predictability of seasonal means of water cycle components, specifically precipitation and evaporation, are estimated using recently developed methods based on Analysis of Covariance (ANOCOVA) and the bootstrap, and the previous methods proposed by Katz (KZ), Shukla-Gutzler (SG) and Madden (MN). The ANOCOVA method has the advantage of not only taking into account autocorrelation structure in the daily time series but also accounting for the uncertainty of the estimated parameters in the significance test. This method tests whether interannual variability of seasonal means exceeds that due to weather noise under the null hypothesis that seasonal means are identical every year. The second method is based on the bootstrap technique that makes few assumptions about physical process, model structure and underlying distribution. The essence of the bootstrap is to randomly resample the daily time series to build up an empirical distribution of the variance of seasonal means under the null hypothesis that seasonal mean is independent of year. The predictability of the observed precipitation estimated by ANOCOVA, the bootstrap and KZ reveals similar spatial distribution patterns: large fraction of predictable variance (FPV) in tropics and low FPV over extatropics where interannual variability is not significantly distinguished from the weather noise. There are more regions identified potentially predictable in December-January-February (DJF) and March-April-May (MAM) than in June-July-August (JJA) and September-October-November (SON). The ANOCOVA method exhibits the highest predictability of the three methods and is close to the bootstrap, while KZ shows the smallest FPV due to the dominance of noise. Seasonal evaporation over global land from ANOCOVA, bootstrap, SG and MN indicates that high predictability occurs predominately over tropical and southern mid-latitude land areas, and modest predictability occurs over North America and Europe. The potential

  13. The effects of harvest on waterfowl populations

    USGS Publications Warehouse

    Cooch, Evan G.; Guillemain, Matthieu; Boomer, G Scott; Lebreton, Jean-Dominique; Nichols, James D.

    2014-01-01

    Overall, there is substantial uncertainty about system dynamics, about the impacts of potential management and conservation decisions on those dynamics, and how to optimise management decisions in the presence of such uncertainties. Such relationships are unlikely to be stationary over space or time, and selective harvest of some individuals can potentially alter life history allocation of resources over time – both of which will potentially influence optimal harvest strategies. These sources of variation and uncertainty argue for the use of adaptive approaches to waterfowl harvest management.

  14. Phytoplankton biomass, production and potential export in the North Water

    NASA Astrophysics Data System (ADS)

    Klein, Bert; LeBlanc, Bernard; Mei, Zhi-Ping; Beret, Rachel; Michaud, Josée; Mundy, C.-J.; von Quillfeldt, Cecilie H.; Garneau, Marie-Ève; Roy, Suzanne; Gratton, Yves; Cochran, J. Kirk; Bélanger, Simon; Larouche, Pierre; Pakulski, J. Dean; Rivkin, Richard B.; Legendre, Louis

    The seasonal patterns of phytoplankton biomass and production were determined in the North Water, located between Greenland and Ellesmere Island (Canadian Arctic), in August 1997, April-July 1998, and August-September 1999. The patterns differed among the four defined regions of this large polynya, i.e. North (>77.5°N), East (>75°W), West (<75°W), and South (<76°N). Phytoplankton biomass and production were low during April throughout the North Water. Biomass first increased in the East during April. From there, the biomass spread north- and westwards during May-June, when the bloom culminated (chlorophyll a concentrations up to 19.8 mg m -3). The large-sized (>5 μm) fraction dominated the biomass and production during the bloom. During July, August, and September, biomass and production decreased over the whole region, with the highest biomass, dominated by large cells, occurring in the North. The annual particulate and dissolved phytoplankton production were the highest ever reported for the high Arctic, reaching maximum values of 254 and 123 g C m -2 yr -1, respectively, in the East. Rates in the North and West were considerably lower than in the East (ca. two- and three-fold, respectively). The f-ratios (i.e. ratio of new to total production), derived from the size structure of phytoplankton, were high north of 76°N (0.4-0.7). Regionally, this indicated a high potential export of particulate organic carbon ( EPOC) from the phytoplankton community to other trophic compartments and/or downwards in the East (155 g C m -2 yr -1), with lower values in the North and West (i.e. 77 and 42 g C m -2 yr -1, respectively). The seasonal and spatial patterns of EPOC were consistent with independent estimates of potential carbon export. Phytoplankton biomass and production were generally dominated by the large size fraction, whereas EPOC seemed to be dominated by the large size fraction early in the season and by the small size fraction (<5 μm) from June until the end

  15. Harvesting of Chlorella sorokiniana by co-culture with the filamentous fungus Isaria fumosorosea: A potential sustainable feedstock for hydrothermal gasification.

    PubMed

    Mackay, Stephen; Gomes, Eduardo; Holliger, Christof; Bauer, Rolene; Schwitzguébel, Jean-Paul

    2015-06-01

    Despite recent advances in down-stream processing, production of microalgae remains substantially limited because of economical reasons. Harvesting and dewatering are the most energy-intensive processing steps in their production and contribute 20-30% of total operational cost. Bio-flocculation of microalgae by co-cultivation with filamentous fungi relies on the development of large structures that facilitate cost effective harvesting. A yet unknown filamentous fungus was isolated as a contaminant from a microalgal culture and identified as Isaria fumosorosea. Blastospores production was optimized in minimal medium and the development of pellets, possibly lichens, was followed when co-cultured with Chlorella sorokiniana under strict autotrophic conditions. Stable pellets (1-2mm) formed rapidly at pH 7-8, clearing the medium of free algal cells. Biomass was harvested with large inexpensive filters, generating wet slurry suitable for hydrothermal gasification. Nutrient rich brine from the aqueous phase of hydrothermal gasification supported growth of the fungus and may increase the process sustainability.

  16. Potential Chemical Effects of Changes in the Source of Water Supply for the Albuquerque Bernalillo County Water Utility Authority

    USGS Publications Warehouse

    Bexfield, Laura M.; Anderholm, Scott K.

    2008-01-01

    Chemical modeling was used by the U.S. Geological Survey, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (henceforth, Authority), to gain insight into the potential chemical effects that could occur in the Authority's water distribution system as a result of changing the source of water used for municipal and industrial supply from ground water to surface water, or to some mixture of the two sources. From historical data, representative samples of ground-water and surface-water chemistry were selected for modeling under a range of environmental conditions anticipated to be present in the distribution system. Mineral phases calculated to have the potential to precipitate from ground water were compared with the compositions of precipitate samples collected from the current water distribution system and with mineral phases calculated to have the potential to precipitate from surface water and ground-water/surface-water mixtures. Several minerals that were calculated to have the potential to precipitate from ground water in the current distribution system were identified in precipitate samples from pipes, reservoirs, and water heaters. These minerals were the calcium carbonates aragonite and calcite, and the iron oxides/hydroxides goethite, hematite, and lepidocrocite. Several other minerals that were indicated by modeling to have the potential to precipitate were not found in precipitate samples. For most of these minerals, either the kinetics of formation were known to be unfavorable under conditions present in the distribution system or the minerals typically are not formed through direct precipitation from aqueous solutions. The minerals with potential to precipitate as simulated for surface-water samples and ground-water/surface-water mixtures were quite similar to the minerals with potential to precipitate from ground-water samples. Based on the modeling results along with kinetic considerations, minerals that appear most likely to

  17. Eggs under pressure: components of water potential of chameleon eggs during incubation.

    PubMed

    Adams, Geoffrey K; Andrews, Robin M; Noble, Lydia M

    2010-01-01

    Water exchange of squamate eggs is driven by the difference between the water potentials of eggs and of their nest environment. While osmotic potential is generally assumed to dominate the net water potential of eggs, resistance of the eggshell to stretching also affects egg water potential. We therefore determined osmotic potentials and pressure potentials (mechanical pressure) of eggs of the veiled chameleon Chamaeleo calyptratus over the course of incubation. Because embryos are diapausing gastrulae when eggs are laid and diapause persists several months, the water potential of eggs can be evaluated before it is influenced by the developing embryo. Water uptake during the first 2 wk of incubation was rapid as a result of the large difference between the total water potential of the egg (-848 kPa) and that of its incubation substrate. After about 2 wk, water potential of the egg stabilized at -460 kPa. By day 80 of incubation, the developing embryo and allantois affected water exchange of the egg. The allantoic fluid was initially very dilute, but its osmotic potential decreased to about -200 kPa by the end of incubation. Pressure potential of the egg averaged 25 kPa, with no systematic trend during incubation. The pressure potential exerted by the eggshell reduced the difference between the water potential of the egg and the water potential of the environment, that is, the ability of eggs to take up water. At the time of oviposition, this effect was relatively small, producing a 4%-6% reduction in water potential difference. Once the yolk osmotic potential stabilized, however, the reduction was 12% or more. This observation means that the dynamics of water uptake by squamate eggs cannot be fully understood without consideration of the pressure that is exerted on the contents of eggs by their shells.

  18. Momentum harvesting techniques for solar system travel

    NASA Technical Reports Server (NTRS)

    Willoughby, Alan J.

    1990-01-01

    Astronomers are lately estimating there are 400,000 Earth visiting asteroids larger than 100 meters in diameter. These asteroids are accessible sources of building materials, propellants, oxygen, water, and minerals which 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 extraction of the momentum wanted must be learned. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to the destination are discussed. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether will determine the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As it plays out of its reel, drag on the tether steadily accelerates the spacecraft. A variety of concepts for riding and using the asteroid after capture are discussed. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroidal materials. The chemist and the hijacker go further, they process the asteroid into propellant. Or, an 'asteroid railway system' could evolve with each hijacked asteroid becoming a scheduled train. Travelers could board the space railway system assured that water, oxygen, and propellants await them.

  19. (Metabolic mechanisms of plant growth at low-water potentials): Progress report

    SciTech Connect

    Boyer, J.S.

    1988-01-01

    We used soybean seedlings grown in vermiculite in a dark, humid environment because they are convenient to grow, undergo most of the physiological changes induced by low water potentials in large plants, and have exposed growing regions. We studied how growth-induced water potentials originate; which of the parameters regulating cell enlargement are the cause of the decreased rate of stem growth observed at low water potentials; molecular changes that occur in the cell wall at low water potentials; and the mechanism of differential root and shoot growth at low water potential.

  20. Potential of mosquito fern (Azolla caroliniana Willd.) plants as a biofilter for cadmium removal from waste water

    SciTech Connect

    Sajwam, K.S.; Ornes, W.H. |

    1995-12-31

    The aquatic vascular Mosquito Fern (Azolla Caroliania Willd.) was investigated as a potential biological filter for removal of Cd from waste water. Mosquito Fern plants were grown in and harvested weekly from 0.10 M Hoagland nutrient solutions containing 0.01, 0.04, and 1.03 {mu}g Cd mL{sup -1} or 0.50 M Hoagland nutrient solutions containing 0.02, 1.0, and 9.14,{mu}g Cd mL{sup -1}. Dry weights of plants significantly increased when exposed to all three Cd concentrations in 0. 10 M Hoagland solution through week three then decreased thereafter. However, in plants exposed to Cd treatments in 0.50 M Hoagland solution, dry weights increased through week one and decreased thereafter. Tissue Cd concentrations in plants grown in 0.10 M Hoagland solution increased during the first two weeks followed by decreases in week 3 and 4. However, tissue Cd increased through week 3 in plants grown in 0.50 M Hoagland solutions. Cadmium exposure to plants grown in 0.10 M Hoagland solution seemed to increase the tissue P concentrations in plants exposed to the lowest concentration of Cd. Tissue P in both control and treated plants in 0.50 M Hoagland solution seemed to increase over time with exception of the medium level (1 {mu}g Cd mL{sup -1}). These results suggest that Mosquito Fern would be useful for absorbing Cd from nutrient-rich water when the solution concentration was in the range of as low as 0.01 and as high as 9.14 {mu}g Cd mL{sup -1}. However, the harvest regime would have to be every one or two weeks to sustain plant vigor and realize maximum uptake of Cd from solution.

  1. A systematic development of a polarizable potential of water.

    PubMed

    Kiss, Péter T; Baranyai, András

    2013-05-28

    Based on extensive studies of existing potentials we propose a new molecular model for water. The new model is rigid and contains three Gaussian charges. Contrary to other models, all charges take part in the polarization of the molecule. They are connected by harmonic springs to their gas-phase positions: the negative charge to a prescribed point on the main axis of the molecule; the positive charges to the hydrogens. The mechanical equilibrium between the electrostatic forces and the spring forces determines the polarization of the molecule which is established by iteration at every timestep. The model gives excellent estimates for ambient liquid properties and reasonably good results from high-pressure solids to gas-phase clusters. We present a detailed description of the development of this model and a large number of calculated properties compared to the estimates of the nonpolarizable TIP4P∕2005 [J. L. F. Abascal and C. Vega, J. Chem. Phys. 123, 234505 (2005)], the polarizable GCPM [P. Paricaud, M. Predota, A. A. Chialvo, and P. T. Cummings, J. Chem. Phys. 122, 244511 (2005)], and our earlier BKd3 model [P. T. Kiss and A. Baranyai, J. Chem. Phys. 137, 084506 (2012)]. The best overall performance is shown by the new model.

  2. Timing of harvest of Phragmites australis (CAV.) Trin. ex Steudel affects subsequent canopy structure and nutritive value of roughage in subtropical highland.

    PubMed

    Tanaka, Takashi S T; Irbis, Chagan; Kumagai, Hajime; Inamura, Tatsuya

    2016-01-15

    In recent decades, constructed wetlands dominated by common reeds [Phragmites australis (CAV.) Trin. ex Steudel] have been utilized for treating nitrogen-rich wastewaters. Although plant harvest is a vegetation management in constructed wetlands for the purpose of improving nutrient removal, harvested biomass has become a problem in many places. The reed has attracted increasing interest for its potential as high-quality roughage for ruminants. Therefore, it is crucial to understand the effect of reed harvest timing on subsequent regrowth, reconstruction of canopy structure, and nutritive value of regrown biomass for roughage when defining an appropriate vegetation management in constructed wetlands. The shoots of common reeds were harvested in January (winter), March (spring), and May (early summer) in a free-water surface constructed wetland in southwest China. Harvesting in winter enhanced the shoot regrowth and concentrations of total digestible nutrients (TDN), probably due to vigorous translocations of nonstructural carbohydrates from rhizomes. Harvesting in spring and early summer decreased aboveground biomass, nitrogen (N) standing stock, and concentrations of TDN. From fifty to 110 days after harvest, the TDN had sharply declined to values similar to non-harvested stands. Thus, to obtain high-quality roughage, it is recommended that regrown shoots be harvested again within a year in the early growing stage after the first harvest in winter.

  3. Quantifying blue and green virtual water contents in global crop production as well as potential production losses without irrigation

    NASA Astrophysics Data System (ADS)

    Siebert, Stefan; Döll, Petra

    2010-04-01

    SummaryCrop production requires large amounts of green and blue water. We developed the new global crop water model GCWM to compute consumptive water use (evapotranspiration) and virtual water content (evapotranspiration per harvested biomass) of crops at a spatial resolution of 5' by 5', distinguishing 26 crop classes, and blue versus green water. GCWM is based on the global land use data set MIRCA2000 that provides monthly growing areas for 26 crop classes under rainfed and irrigated conditions for the period 1998-2002 and represents multi-cropping. By computing daily soil water balances, GCWM determines evapotranspiration of blue and green water for each crop and grid cell. Cell-specific crop production under both rainfed and irrigated conditions is computed by downscaling average crop yields reported for 402 national and sub-national statistical units, relating rainfed and irrigated crop yields reported in census statistics to simulated ratios of actual to potential crop evapotranspiration for rainfed crops. By restricting water use of irrigated crops to green water only, the potential production loss without any irrigation was computed. For the period 1998-2002, the global value of total crop water use was 6685 km 3 yr -1, of which blue water use was 1180 km 3 yr -1, green water use of irrigated crops was 919 km 3 yr -1 and green water use of rainfed crops was 4586 km 3 yr -1. Total crop water use was largest for rice (941 km 3 yr -1), wheat (858 km 3 yr -1) and maize (722 km 3 yr -1). The largest amounts of blue water were used for rice (307 km 3 yr -1) and wheat (208 km 3 yr -1). Blue water use as percentage of total crop water use was highest for date palms (85%), cotton (39%), citrus fruits (33%), rice (33%) and sugar beets (32%), while for cassava, oil palm and cocoa, almost no blue water was used. Average crop yield of irrigated cereals was 442 Mg km -2 while average yield of rainfed cereals was only 266 Mg km -2. Average virtual water content of cereal

  4. Water saving at the field scale with Irrig-OH, an open-hardware environment device for soil water potential monitoring and irrigation management

    NASA Astrophysics Data System (ADS)

    Masseroni, Daniele; Facchi, Arianna; Gandolfi, Claudio

    2015-04-01

    Sustainability of irrigation practices is an important objective which should be pursued in many countries, especially in areas where water scarcity causes strong conflicts among the different water uses. The efficient use of water is a key factor in coping with the food demand of an increasing world population and with the negative effects of the climate change on water resources availability in many areas. In this complex context, it is important that farmers adopt instruments and practices that enable a better management of water at the field scale, whatever the irrigation method they adopt. This work presents the hardware structure and the functioning of an open-hardware microstation based on the Arduino technology, called Irrig-OH, which allows the continuous and low-cost monitoring of the soil water potential (SWP) in the root zone for supporting the irrigation scheduling at the field scale. In order to test the microstation, an experiment was carried out during the agricultural season 2014 at Lodi (Italy), with the purpose of comparing the farmers' traditional management of irrigation of a peach variety and the scheduling based on the SWP measurements provided by the microstation. Additional measurements of leaf water potential (LWP), stomatal resistance, transpiration (T), crop water stress index (CWSI) and fruit size evolution were performed respectively on leafs and fruits for verifying the plant physiological responses on different SWP levels in soil. At the harvesting time, the peach production in term of quantity and quality (sucrose content was measured by a rifractometer over a sample of one hundred fruits) of the two rows were compared. Irrigation criteria was changed with respect to three macro-periods: up to the endocarp hardening phase (begin of May) soil was kept well watered fixing the SWP threshold in the first 35 cm of the soil profile at -20 kPa, during the pit hardening period (about the entire month of May) the allowed SWP threshold was

  5. Water hyacinth a potential source for value addition: An overview.

    PubMed

    Sindhu, Raveendran; Binod, Parameswaran; Pandey, Ashok; Madhavan, Aravind; Alphonsa, Jose Anju; Vivek, Narisetty; Gnansounou, Edgard; Castro, Eulogio; Faraco, Vincenza

    2017-04-01

    Water hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Hence conversion of this problematic weed to value added chemicals and fuels helps in the self-sustainability especially for developing countries. The present review discusses the various value added products and fuels which can be produced from water hyacinth, the recent research and developmental activities on the bioconversion of water hyacinth for the production of fuels and value added products as well as its possibilities and challenges in commercialization.

  6. Harvesting in seasonal environments.

    PubMed

    Xu, Cailin; Boyce, Mark S; Daley, Daryl J

    2005-06-01

    Most harvest theory is based on an assumption of a constant or stochastic environment, yet most populations experience some form of environmental seasonality. Assuming that a population follows logistic growth we investigate harvesting in seasonal environments, focusing on maximum annual yield (M.A.Y.) and population persistence under five commonly used harvest strategies. We show that the optimal strategy depends dramatically on the intrinsic growth rate of population and the magnitude of seasonality. The ordered effectiveness of these alternative harvest strategies is given for different combinations of intrinsic growth rate and seasonality. Also, for piecewise continuous-time harvest strategies (i.e., open/closed harvest, and pulse harvest) harvest timing is of crucial importance to annual yield. Optimal timing for harvests coincides with maximal rate of decline in the seasonally fluctuating carrying capacity. For large intrinsic growth rate and small environmental variability several strategies (i.e., constant exploitation rate, linear exploitation rate, and time-dependent harvest) are so effective that M.A.Y. is very close to maximum sustainable yield (M.S.Y.). M.A.Y. of pulse harvest can be even larger than M.S.Y. because in seasonal environments population size varies substantially during the course of the year and how it varies relative to the carrying capacity is what determines the value relative to optimal harvest rate. However, for populations with small intrinsic growth rate but subject to large seasonality none of these strategies is particularly effective with M.A.Y. much lower than M.S.Y. Finding an optimal harvest strategy for this case and to explore harvesting in populations that follow other growth models (e.g., involving predation or age structure) will be an interesting but challenging problem.

  7. A novel investigation on carbon nanotube/ZnO, Ag/ZnO and Ag/carbon nanotube/ZnO nanowires junctions for harvesting piezoelectric potential on textile

    SciTech Connect

    Khan, Azam Edberg, Jesper; Nur, Omer; Willander, Magnus

    2014-07-21

    In the present work, three junctions were fabricated on textile fabric as an alternative substrate for harvesting piezoelectric potential. First junction was formed on ordinary textile as (textile/multi-walled carbon nanotube film/zinc oxide nanowires (S1: T/CNTs/ZnO NWs)) and the other two were formed on conductive textile with the following layer sequence: conductive textile/zinc oxide nanowires (S2: CT/ZnO NWs) and conductive textile/multi-walled carbon nanotubes film/zinc oxide nanowires (S3: CT/CNTs/ZnO NWs). Piezoelectric potential was harvested by using atomic force microscopy in contact mode for the comparative analysis of the generated piezoelectric potential. ZnO NWs were synthesized by using the aqueous chemical growth method. Surface analysis of the grown nanostructures was performed by using scanning electron microscopy and transmission electron microscopy. The growth orientation and crystalline size were studied by using X-ray diffraction technique. This study reveals that textile as an alternative substrate have many features like cost effective, highly flexible, nontoxic, light weight, soft, recyclable, reproducible, portable, wearable, and washable for nanogenerators fabrication with acceptable performance and with a wide choice of modification for obtaining large amount of piezoelectric potential.

  8. A novel investigation on carbon nanotube/ZnO, Ag/ZnO and Ag/carbon nanotube/ZnO nanowires junctions for harvesting piezoelectric potential on textile

    NASA Astrophysics Data System (ADS)

    Khan, Azam; Edberg, Jesper; Nur, Omer; Willander, Magnus

    2014-07-01

    In the present work, three junctions were fabricated on textile fabric as an alternative substrate for harvesting piezoelectric potential. First junction was formed on ordinary textile as (textile/multi-walled carbon nanotube film/zinc oxide nanowires (S1: T/CNTs/ZnO NWs)) and the other two were formed on conductive textile with the following layer sequence: conductive textile/zinc oxide nanowires (S2: CT/ZnO NWs) and conductive textile/multi-walled carbon nanotubes film/zinc oxide nanowires (S3: CT/CNTs/ZnO NWs). Piezoelectric potential was harvested by using atomic force microscopy in contact mode for the comparative analysis of the generated piezoelectric potential. ZnO NWs were synthesized by using the aqueous chemical growth method. Surface analysis of the grown nanostructures was performed by using scanning electron microscopy and transmission electron microscopy. The growth orientation and crystalline size were studied by using X-ray diffraction technique. This study reveals that textile as an alternative substrate have many features like cost effective, highly flexible, nontoxic, light weight, soft, recyclable, reproducible, portable, wearable, and washable for nanogenerators fabrication with acceptable performance and with a wide choice of modification for obtaining large amount of piezoelectric potential.

  9. Rainwater harvesting in South Africa: Challenges and opportunities

    NASA Astrophysics Data System (ADS)

    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.

  10. EDITORIAL Solar harvest Solar harvest

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-12-01

    The first observations of the photoelectric effect date back to the early 19th century from work by Alexandre Edmond Becquerel, Heinrich Hertz, Wilhelm Hallwachs and J J Thomson. The theory behind the phenomena was clarified in a seminal paper by Einstein in 1905 and became an archetypical feature of the wave-particle description of light. A different manifestation of quantised electron excitation, whereby electrons are not emitted but excited into the valence band of the material, is what we call the photoconductive effect. As well as providing an extension to theories in fundamental physics, the phenomenon has spawned a field with enormous ramifications in the energy industry through the development of solar cells. Among advances in photovoltaic technology has been the development of organic photovoltaic technology. These devices have many benefits over their inorganic counterparts, such as light-weight, flexible material properties, as well as versatile materials' synthesis and low-cost large-scale production—all highly advantageous for manufacturing. The first organic photovoltaic systems were reported over 50 years ago [1], but the potential of the field has escalated in recent years in terms of efficiency, largely through band offsetting. Since then, great progress has been made in studies for optimising the efficiency of organic solar cells, such as the work by researchers in Germany and the Netherlands, where investigations were made into the percentage composition and annealing effects on composites of poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) [2]. Hybrid devices that aim to exploit the advantages of both inorganic and organic constituents have also proven promising. One example of this is the work reported by researchers in Tunisia and France on a systematic study for optimising the composition morphology of TiO2 nanoparticles in poly(N-vinylcarbazole) (PVK), which also led to insights

  11. An effective technique of scrotal harvest.

    PubMed

    Sheridan, R L; Ryan, C M; Tompkins, R G

    1993-01-01

    In male patients with extensive burns, the scrotum is often spared and is potentially a very useful donor site. We describe a technique that simplifies scrotal harvest and facilitates the procurement of clinically useful amounts of split-thickness skin.

  12. Broadband pendulum energy harvester

    NASA Astrophysics Data System (ADS)

    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.

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

    DTIC Science & Technology

    2010-06-01

    potable water source Result – reduces overall demand for municipal water US Army Corps of Engineers® Engineer Research and Development Center Why...reduction, reduction of sewage from potable water Most water used on installations does not have to be of drinking water quality. Beneficially use water...harvesting in potable or stormwater sections causing confusion • Definitions – UPC • Harvested rainwater – Conveyed from a building roof, stored in a

  14. Development of EEM based silicon-water and silica-water wall potentials for non-reactive molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Kim, Junghan; Iype, Eldhose; Frijns, Arjan J. H.; Nedea, Silvia V.; van Steenhoven, Anton A.

    2014-07-01

    Molecular dynamics simulations of heat transfer in gases are computationally expensive when the wall molecules are explicitly modeled. To save computational time, an implicit boundary function is often used. Steele's potential has been used in studies of fluid-solid interface for a long time. In this work, the conceptual idea of Steele's potential was extended in order to simulate water-silicon and water-silica interfaces. A new wall potential model is developed by using the electronegativity-equalization method (EEM), a ReaxFF empirical force field and a non-reactive molecular dynamics package PumMa. Contact angle simulations were performed in order to validate the wall potential model. Contact angle simulations with the resulting tabulated wall potentials gave a silicon-water contact angle of 129°, a quartz-water contact angle of 0°, and a cristobalite-water contact angle of 40°, which are in reasonable agreement with experimental values.

  15. Concentration of Mercury in Cockles (Anadara granosa and A. antiquata) Harvested from Estuaries of Western Lombok, Indonesia, and Potential Risks to Human Health.

    PubMed

    Rahayu, Rachmawati Noviana; Irawan, Bambang; Soegianto, Agoes

    2016-01-01

    This study measured the levels of total mercury (tHg) in the whole tissues of cockles (Anadara granosa and A. antiquata) harvested from three estuaries of Western Lombok Island (WLI), Indonesia. This paper also evaluated the hazard level posed by the mercury in relation to the maximum residual limit for human consumption and to estimate the weekly intake and compare it with the provisional tolerable weekly intake (PTWI). The tHg concentrations in A. granosa ranged from 0.020 to 0.070 mg kg(-1), and those in A. antiquata were between 0.032 and 0.077 mg kg(-1) at all locations. All samples of cockles harvested from WLI contain tHg below the permissible limit for human consumption. The maximum weekly intakes for total mercury by coastal people range from 0.28 to 1.08 µg kg(-1) b.w., and they are below the recommended values of PTWI (5.6 µg kg(-1) b.w.). If it is assumed that 100% of the Hg in cockles is methyl mercury (MeHg), consumption of the indicated amounts at the measured values wouldn't exceed the MeHg PTWI (1.6 µg kg(-1) b.w.).

  16. Evaluation of potential water conservation using site-specific irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the advent of site-specific variable-rate irrigation (VRI) systems, irrigation can be spatially managed within sub-field-sized zones. Spatial irrigation management can optimize spatial water use efficiency and may conserve water. Spatial VRI systems are currently being managed by consultants ...

  17. Multilayer ferroelectret-based energy harvesting insole

    NASA Astrophysics Data System (ADS)

    Luo, Z.; Zhu, D.; Beeby, S. P.

    2015-12-01

    This paper reports a flexible energy harvesting insole made of multilayer ferroelectrets, and demonstrates that this insole can power a wireless signal transmission. We have previously studied the energy harvesting characteristics of single and 10-layer ferroelectrets under compressive forces with quantified amplitudes and frequencies. In this work, we fabricate a flexible insole using multilayer ferroelectrets, and increase the number of layers from 10 up to 80, then use this insole to harvest energy from footsteps. We use this insole to power a commercial ZigBee wireless transmitter, and successfully demonstrate that an 8-bit data transmission can be solely powered by the energy harvested from this insole for every 3 to 4 footsteps. It confirms the anticipation from our previous work that the multilayer ferroelectrets are capable of powering the start-up and transmission of a low-power chipset, and shows a potential of using this energy harvesting insole in wearable applications.

  18. Evaluation of the impact of water harvesting techniques on the evolution of piezometric head of Ain El Bidha groundwater in Kairouan at the Central part of Tunisia

    NASA Astrophysics Data System (ADS)

    Mechergui, M. Mohamed; Henda Saoudi, Mme

    2016-04-01

    This study aims to assess the impact of water harvesting constructed hydraulic structures (big and small dams, terraces, seuils for recharge…) on the evolution of piezometric head of Ain El Beidha groundwater table. The measurements of depth of water table, taken at the end of rain season and at the end of irrigation season, in many piezometers and monitoring wells, for a long period of observation before and after implementation of all the hydraulic structures, were used with the cumulative rain to the highest water table to diagnostic the effect of natural recharge and constructed hydraulic structures. According to the analysis of curves illustrating the evolution of piezometric head and rainfall over time, it was shown that despite the fact that the same amount of rain fall on the total area in the limits of Ain El Beidha groundwater table, the piezometers respond differently. This is because there are many sources of recharge and many factors affecting the recharge. First of all, the aquifer is divided in four compartments (the calcareous formation of Djebel El Houyareb, the plio-quaternary formation, the Miocene formation: Baglia and Saouaf). All those respond differently to the recharge by their capacity of infiltration and their hydrodynamic characteristics. The recharge of the groundwater table was increased by the implementation of small soil and water conservation structures, artificial lakes, El Haouareb Dam, run off in the natural Oued bads and seuils for recharge installed in the bads of oueds. The different piezometric drown maps were used to determine the flow direction and hydraulic gradient in order to identify the recharge areas, while tracking maps for three equal piezometric heads 210 m 300 m and 370 m established over different years made it possible to assess the impact of hydraulic structures, namely the effect of SWC and Ben Zitoun Lake. To illustrate the impact of El Houareb dam on the groundwater, the piezometric maps and local values

  19. Source rock potential of shallow-water evaporitic settings

    SciTech Connect

    Warren, J.K.

    1986-05-01

    In the major evaporitic environments on the world's surface today, most organic matter accumulates in shallow subaqueous to seasonally subaerially exposed, algal-mat sediments. Given the present depositional setting, this organic matter probably could not be preserved to form source rocks. However, if the authors place such evaporite deposition into a geologic context, source rocks could have formed in shallow-water settings in the past. Such settings were characterized by hydrologic conditions that allowed the retention of hypersaline, anoxic pore water to depths where the organic material was buried deep enough to generate hydrocarbons. When deep-basin, shallow-water, evaporite successions were laid down in basins such as the Mediterranean during the late Miocene, the Michigan basin during the Silurian, and in other large saline giants, conditions were right for source rocks to form within shallow-water and salt-flat evaporitic environments. The evaporites in these saline giants were deposited under conditions of relatively shallow water (< 50 m); the basin never appears to have dried out, but water levels changed quickly (approx. 10,000 years) from shallow to deep. Continual water saturation coupled with saline pore fluids prevented the inflow of fresh, oxidizing ground water into the basin center of shallow-water organic-rich evaporites. Immature hydrocarbons derived from such rocks today drip from the 5.5-m.y. old evaporites of Sicily in active salt and sulfur mines. Organic-rich sediments could also be preserved to generate hydrocarbons in rapidly subsiding rift basins. In such basins, rapid burial has prevented the entrance of fresher oxygenated waters and the associated degradation and destruction of the organic matter. The early continental rift stage generates the source rocks; the ephemeral streams, wadis, and dune fields become the reservoirs, and the subsequent evaporite stage seals the reservoir.

  20. A multisector analysis of urban irrigation and water savings potential

    NASA Astrophysics Data System (ADS)

    Bijoor, N.; Kim, H.; Famiglietti, J. S.

    2014-12-01

    Urban irrigation strains limited water supplies in semi-arid areas such as Orange County, CA, yet the quantity and controlling factors of urban irrigation are not well understood. The goals of this research are to (1) quantify and compare landscape irrigation applied by residential and commercial sectors in various retail agencies at a parcel scale (2) determine over- and under-irrigation compared to theoretical need (3) determine the climatic and socioeconomic controls on landscape irrigation. A research partnership was established between six water retail agencies in Orange County, CA representing a wide range of climatic and economic conditions. These agencies contributed between 3 and 13 years of water use data on a monthly/bimonthly basis. Irrigation depth (mm) was estimated using the "minimum month method," and landscape evapotranspiration was calculated using the Hargreaves equation for 122,345 parcels. Multiple regressions of water use were conducted with climatic and socioeconomic variables as possible explanatory variables. Single family residences accounted for the majority of urban water use. Findings from 112,192 single family residences (SFRs) show that total and indoor water use declined, though irrigation did not significantly change. Average irrigation for SFRs was 94 L/day, and a large proportion (42%) of irrigation was applied in excess to landscapes. Air temperature was found to be the primary driver of irrigation. We mapped over-irrigation relative to plant water demand to highlight areas that can be targeted for water conservation efforts. We also show the water savings that would be gained by improving the efficiency of irrigation systems. The information gained in this study would be useful for developing water use efficiency policies and/or educational programs to promote sustainable irrigation practices at the individual parcel scale.

  1. Metabolic mechanisms of plant growth at low water potentials. Progress report

    SciTech Connect

    Boyer, J.S.

    1986-01-01

    Experiments were conducted to identify primary and secondary factors that cause cell enlargement to be inhibited in the stems of soybean seedlings exposed to low water potentials. The factors that were analyzed are wall extensibility, yield threshold of the walls, hydraulic conductance of the tissue, turgor, osmotic potential, and growth-induced water potentials.

  2. POTENTIAL Use of Digital Computer Ground Water Models.

    DTIC Science & Technology

    1978-04-01

    Corps of Engineers, Albuquerque, New Mexico , as part of a water supply study of the Albuquerque Greater Urban Area (AGUA). Although the material...Engineers, Albuquerque, New Mexico , as part of a water supply study of the Albuquerque Greater Urban Area (AGUA). Although the m terial pre- sented herein...Albuquerque Area, Bernalillo ard Sandoval Counties, New Mexico : New Mexico State Engineer Technical Report 21, 117 p. Holcomb Research Institute , June

  3. Options for modeling ground water pollution potential by dissolved chemicals

    NASA Astrophysics Data System (ADS)

    Jury, William A.; Tseng, Peng-Hsiang

    A common characteristic of virtually all forms of non-point source pollutants is that they move downward through the soil under the influence of erratic and generally unsaturated water flow. As a consequence, both soil-water flow and solute-transport properties must be known to model the event on a field or larger scale. The extensive spatial variability of these properties make deterministic modeling unfeasible at this scale, necessitating some form of approximate stochastic approach that extrapolates from limited samples of properties and input parameters. There are a number of options for exercising this strategy, but most of them involve using a local-model representation that is averaged over the spatial domain in a statistical sense, by using a number of discrete one-dimensional simulations in parallel. With this strategy, the important question becomes what type of local model to use, and how complex to make it. This paper explores options for local representation in modeling the water flow regime, ranging from full simulation using the Richards flow equation, to steady flow using only the field-capacity estimate of water content. Simulations of flow and transport to ground water are run on a hypothetical field with variable climatic data and properties generated by geometric scaling theory, using data from 20 sites averaged in parallel to represent field-scale movement to ground water for a conservative and reactive chemical pulse. Although the transient-flow model is necessary to achieve accurate representation of the position of the pulse within the profile, mass loading of ground water was represented quite accurately with a simple flow regime assuming steady-state flow and uniform, water content. The field-capacity estimate was greatly out of agreement with the other methods, however.

  4. Rooftop level rainwater harvesting system

    NASA Astrophysics Data System (ADS)

    Traboulsi, Hayssam; Traboulsi, Marwa

    2015-05-01

    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.

  5. The Potential Role of Neglected and Underutilised Crop Species as Future Crops under Water Scarce Conditions in Sub-Saharan Africa.

    PubMed

    Chivenge, Pauline; Mabhaudhi, Tafadzwanashe; Modi, Albert T; Mafongoya, Paramu

    2015-05-26

    Modern agricultural systems that promote cultivation of a very limited number of crop species have relegated indigenous crops to the status of neglected and underutilised crop species (NUCS). The complex interactions of water scarcity associated with climate change and variability in sub-Saharan Africa (SSA), and population pressure require innovative strategies to address food insecurity and undernourishment. Current research efforts have identified NUCS as having potential to reduce food and nutrition insecurity, particularly for resource poor households in SSA. This is because of their adaptability to low input agricultural systems and nutritional composition. However, what is required to promote NUCS is scientific research including agronomy, breeding, post-harvest handling and value addition, and linking farmers to markets. Among the essential knowledge base is reliable information about water utilisation by NUCS with potential for commercialisation. This commentary identifies and characterises NUCS with agronomic potential in SSA, especially in the semi-arid areas taking into consideration inter alia: (i) what can grow under water-scarce conditions, (ii) water requirements, and (iii) water productivity. Several representative leafy vegetables, tuber crops, cereal crops and grain legumes were identified as fitting the NUCS category. Agro-biodiversity remains essential for sustainable agriculture.

  6. The Potential Role of Neglected and Underutilised Crop Species as Future Crops under Water Scarce Conditions in Sub-Saharan Africa

    PubMed Central

    Chivenge, Pauline; Mabhaudhi, Tafadzwanashe; Modi, Albert T.; Mafongoya, Paramu

    2015-01-01

    Modern agricultural systems that promote cultivation of a very limited number of crop species have relegated indigenous crops to the status of neglected and underutilised crop species (NUCS). The complex interactions of water scarcity associated with climate change and variability in sub-Saharan Africa (SSA), and population pressure require innovative strategies to address food insecurity and undernourishment. Current research efforts have identified NUCS as having potential to reduce food and nutrition insecurity, particularly for resource poor households in SSA. This is because of their adaptability to low input agricultural systems and nutritional composition. However, what is required to promote NUCS is scientific research including agronomy, breeding, post-harvest handling and value addition, and linking farmers to markets. Among the essential knowledge base is reliable information about water utilisation by NUCS with potential for commercialisation. This commentary identifies and characterises NUCS with agronomic potential in SSA, especially in the semi-arid areas taking into consideration inter alia: (i) what can grow under water-scarce conditions, (ii) water requirements, and (iii) water productivity. Several representative leafy vegetables, tuber crops, cereal crops and grain legumes were identified as fitting the NUCS category. Agro-biodiversity remains essential for sustainable agriculture. PMID:26016431

  7. Two degrees of freedom piezoelectric vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Liu, Shengsheng; Cao, Junyi; Zhou, Shengxi; Lin, Jing

    2016-04-01

    Recently, vibration energy harvesting from surrounding environments to power wearable devices and wireless sensors in structure health monitoring has received considerable interest. Piezoelectric conversion mechanism has been employed to develop many successful energy harvesting devices due to its simple structure, long life span, high harvesting efficiency and so on. However, there are many difficulties of microscale cantilever configurations in energy harvesting from low frequency ambient. In order to improve the adaptability of energy harvesting from ambient vibrations, a two degrees of freedom (2-DOF) magnetic-coupled piezoelectric energy harvester is proposed in this paper. The electromechanical governing models of the cantilever and clamped hybrid energy harvester are derived to describe the dynamic characteristics for 2-DOF magnetic-coupled piezoelectric vibration energy harvester. Numerical simulations based on Matlab and ANSYS software show that the proposed magnetically coupled energy harvester can enhance the effective operating frequency bandwidth and increase the energy density. The experimental voltage responses of 2-DOF harvester under different structure parameters are acquired to demonstrate the effectiveness of the lumped parameter model for low frequency excitations. Moreover, the proposed energy harvester can enhance the energy harvesting performance over a wider bandwidth of low frequencies and has a great potential for broadband vibration energy harvesting.

  8. Harvest prediction in `Algerie' loquat

    NASA Astrophysics Data System (ADS)

    Hueso, Juan J.; Pérez, Mercedes; Alonso, Francisca; Cuevas, Julián

    2007-05-01

    Plant phenology is in great measure driven by air temperature. To forecast harvest time for ‘Algerie’ loquat accurately, the growing degree days (GDD) needed from bloom to ripening were determined using data from nine seasons. The methods proposed by Zalom et al. (Zalom FG, Goodell PB, Wilson LT, Barnett WW, Bentley W, Degree-days: the calculation and use of heat units in pest management, leaflet no 21373, Division Agriculture and Natural Resources, University of California 10 pp, 1983) were compared as regards their ability to estimate heat summation based on hourly records. All the methods gave remarkably similar results for our cultivation area, although the double-sine method showed higher performance when temperatures were low. A base temperature of 3°C is proposed for ‘Algerie’ loquat because it provides a coefficient of variation in GDD among seasons of below 5%, and because of its compatibility with loquat growth. Based on these determinations, ‘Algerie’ loquat requires 1,715 GDD from bloom to harvest; under our conditions this heat is accumulated over an average of 159 days. Our procedure permits the ‘Algerie’ harvest date to be estimated with a mean error of 4.4 days (<3% for the bloom-harvest period). GDD summation did not prove superior to the use of the number of calendar days for predicting ‘Algerie’ harvest under non-limiting growing conditions. However, GDD reflects the developmental rate in water-stressed trees better than calendar days. Trees under deficit irrigation during flower development required more time and more heat to ripen their fruits.

  9. Harvest prediction in 'Algerie' loquat.

    PubMed

    Hueso, Juan J; Pérez, Mercedes; Alonso, Francisca; Cuevas, Julián

    2007-05-01

    Plant phenology is in great measure driven by air temperature. To forecast harvest time for 'Algerie' loquat accurately, the growing degree days (GDD) needed from bloom to ripening were determined using data from nine seasons. The methods proposed by Zalom et al. (Zalom FG, Goodell PB, Wilson LT, Barnett WW, Bentley W, Degree-days: the calculation and use of heat units in pest management, leaflet no 21373, Division Agriculture and Natural Resources, University of California 10 pp, 1983) were compared as regards their ability to estimate heat summation based on hourly records. All the methods gave remarkably similar results for our cultivation area, although the double-sine method showed higher performance when temperatures were low. A base temperature of 3 degrees C is proposed for 'Algerie' loquat because it provides a coefficient of variation in GDD among seasons of below 5%, and because of its compatibility with loquat growth. Based on these determinations, 'Algerie' loquat requires 1,715 GDD from bloom to harvest; under our conditions this heat is accumulated over an average of 159 days. Our procedure permits the 'Algerie' harvest date to be estimated with a mean error of 4.4 days (<3% for the bloom-harvest period). GDD summation did not prove superior to the use of the number of calendar days for predicting 'Algerie' harvest under non-limiting growing conditions. However, GDD reflects the developmental rate in water-stressed trees better than calendar days. Trees under deficit irrigation during flower development required more time and more heat to ripen their fruits.

  10. Steady state method to determine unsaturated hydraulic conductivity at the ambient water potential

    DOEpatents

    HUbbell, Joel M.

    2014-08-19

    The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision. The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision.

  11. The Potential for Forecasting Water Cycle Extremes with GRACE

    NASA Astrophysics Data System (ADS)

    Rodell, M.; Zaitchik, B. F.; Getirana, A.; Li, B.; Kumar, S.; Beaudoing, H. K.; Save, H.; Bettadpur, S. V.

    2015-12-01

    GRACE is able to quantify changes in terrestrial water storage (the sum of groundwater, soil moisture, surface waters, and snow), which makes it well suited for identifying both hydrological droughts, when terrestrial water storage is low, and floods, when terrestrial water storage is high. Several recent studies have explored the use of GRACE data for quantifying water cycle trends and extremes. In particular, fields of soil moisture and groundwater storage variations are being generated through the assimilation of GRACE data into a land surface model, and those results are used to produce wetness index maps that have been distributed from the U.S. National Drought Mitigation Center's data portal since 2011. The objectives of this presentation are (1) to characterize wet and dry extremes around the world during the GRACE period (i.e., since 2002) in the context of other information on major floods and droughts; (2) to explore how data assimilation can be used to overcome GRACE's low spatial and temporal resolutions (relative to other hydrological observations) and data latency, to make GRACE relevant for worldwide drought and flood monitoring; and (3) to outline steps now being taken to extrapolate the GRACE data assimilation results into the future in order to improve seasonal forecasts of regional droughts and floods in the continental U.S.

  12. Effective harvesting of microalgae: Comparison of different polymeric flocculants.

    PubMed

    Gerchman, Yoram; Vasker, Barak; Tavasi, Mordechai; Mishael, Yael; Kinel-Tahan, Yael; Yehoshua, Yaron

    2017-03-01

    Microalgae harvesting is a major hurdle in the use of microalgae for oil production. Here we describe the use of a standard cationic polymer used for water treatment, Polydiallyldimethylammonium chloride (PDADMAC), for sedimentation of Chlorella vulgaris and comparison of its flocculation properties with two other polymers, chitosan and Superfloc®. We found PDADMAC to be the most effective flocculant with 90% of the algae flocculating at concentrations as low as 5mg/L within 60min, and good activity even at pH=10. Interestingly, with both PDADMAC and chitosan maximum flocculation was achieved much before zeroing of zeta potential. PDADMAC flocculation was also very effective in enhancing harvest by filtration and somewhat at flocculation and sedimentation of marine algae, Nannochloropsis salina.

  13. Primary events regulating stem growth at low water potentials. [Glycine max (L. )

    SciTech Connect

    Nonami, Hiroshi; Boyer, J.S. )

    1990-08-01

    Cell enlargement is inhibited by inadequate water. As a first step toward understanding the mechanism, all the physical parameters affecting enlargement were monitored to identify those that changed first, particularly in coincidence with the inhibition. The osmotic potential, turgor, yield threshold turgor, growth-induced water potential, wall extensibility, and conductance to water were measured in the elongating region, and the water potential was measured in the xylem of stems of dark-grown soybean (Glycine max (L.) Merr.) seedlings. The results indicate that the primary event during the growth inhibition was the change in the growth-induced water potential. Because the growth limitation subsequently shifted to the low wall extensibility and tissue conductance for water, the initial change in potential may have set in motion subsequent metabolic changes that altered the characteristics of the wall and cell membranes.

  14. 50 CFR 300.132 - Lobster harvest limitations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not...

  15. 50 CFR 300.132 - Lobster harvest limitations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not...

  16. 50 CFR 300.132 - Lobster harvest limitations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 11 2014-10-01 2014-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not...

  17. 50 CFR 300.132 - Lobster harvest limitations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 11 2012-10-01 2012-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not...

  18. 50 CFR 300.132 - Lobster harvest limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not...

  19. Soil Water Potential Measurement by Tensiometers -- Encyclopedia Publication

    SciTech Connect

    Hubbell, Joel Michael; Sisson, James Buckley

    2003-08-01

    Tensiometers, which are used to indicate when plants should be irrigated, are widely used in agricultural and research applications. Research applications include characterizing and monitoring disposal sites to evaluate the presence of recharge, determining the direction of moisture flow, and estimating the water content and unsaturated hydraulic conductivity of the geologic materials at a site.

  20. Phosphorus fertilization, soil stratification and potential water quality impacts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water quality experts have suggested that no-till induces phosphorus stratification, which may exacerbate soluble P runoff from agricultural fields, leading to eutrophication. The objectives of this study were to explore P fertilization strategies on P stratification and P runoff from a corn-soybea...

  1. Evaluation of acute toxicity potential of water hyacinth leaves.

    PubMed

    Wu, Wenbiao; Guo, Xiaoguang; Huang, Mingliang

    2014-06-01

    Although higher protein yield per hectare of water hyacinth than that of soy, high protein content of its leaves and good essential amino acid pattern have been proven, its dietary toxicity for human or animal consumption has not yet been evaluated. Therefore, the acute toxicity of water hyacinth leaves has been evaluated by an animal feeding test. The concentrations of common toxic metals including cadmium, lead, platinum, palladium, tin, mercury, barium, silver, stibium and aluminum in the water hyacinth leaf powder (WHLP) used for the animal feeding test were within their maximum limits in food additives as reported by the World Health Organization. The median lethal dose (LD50) of WHLP was more than 16 g kg(-1) body weight. In the study, after feeding for 7 and 28 days, the body weight of all the mice increased. The results of hematological analysis, clinical biochemical analysis, histopathological evaluation, general dissection or investigations of internal organs, appearance and behavior observations did not indicate any adverse effects from the diet containing WHLP. It is therefore concluded that water hyacinth leaves are not acutely toxic.

  2. Potential Relationships Between Hydraulic Fracturing and Drinking Water Resources

    EPA Science Inventory

    The conferees urge the Agency to carry out a study on the relationship between hydraulic fracturing and drinking water, using a credible approach that relies on the best available science, as well as independent sources of information. The conferees expect the study to be conduct...

  3. Seed germination of five Poa species at negative water potentials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under field conditions water is often inadequate for satisfactory seed germination. An experiment was conducted to determine the effects of simulated dry conditions on germination and seedling growth of five bluegrass (Poa) species including: Texas, P. arachnifera Torr.; annual, P. annua L.; mutto...

  4. Effects of irrigation deprivation during the harvest period on yield determinants in mature almond trees.

    PubMed

    Esparza, G; DeJong, T M; Weinbaum, S A; Klein, I

    2001-09-01

    Effects of irrigation deprivation during the harvest period on yield determinants in mature almond (Prunus dulcis (Mill.) D.A. Webb cv. Nonpareil) trees were investigated during a 3-year field experiment. Return bloom and fruit set were measured on 2185 individually tagged spurs. Water stress resulting from irrigation deprivation during the harvest period, which purportedly coincides with the time of flower initiation, had no effect on the percentage of spurs that flowered or set fruit during subsequent years. Although water stress had no apparent effect on spur mortality, 66% of the tagged spurs died within 3 years. In addition, many spurs were vegetative by the third year, indicating the importance of spur renewal for sustained fruit production. Reductions in nut yield were evident after two successive years of irrigation deprivation during the harvest period. Regression analysis indicated a loss in yield of 7.7 kg tree(-1) in response to each 1 MPa decrease in stem water potential below -1.2 MPa during the previous seasons. The number of fruiting positions per tree (estimated indirectly for whole trees based on weight of current-year shoots > 5 cm in length) was negatively associated with water stress. Yield reduction in response to water stress during harvest appears to be a compound, multiyear effect, associated with reduced annual growth and renewal of fruiting positions.

  5. Studies of liquid water by computer simulations. V. Equation of state of fluid water with Carravetta-Clementi potential

    NASA Astrophysics Data System (ADS)

    Kataoka, Yosuke

    1987-07-01

    The pressure of liquid water at normal density is obtained by molecular dynamics simulations based on four intermolecular potential functions derived from quantum chemical calculations of the water dimer; Matsuoka-Clementi-Yoshimine, Carravetta-Clementi, Clementi-Habitz, Yoon-Morokuma-Davidson. Among them, the Carravetta-Clementi potential gives the most reasonable temperature-dependence of pressure, although the absolute value is large compared with the experimental one. The fluid state is surveyed over a wide range of temperature and density with the Carravetta-Clementi potential. The equation of state of fluid water is determined by a least-square fitting of the calculated energies and pressures at 347 state points. The anomalous properties of liquid water observed experimentally are nonempirically reproduced on a semiquantitative level. The calculated equation of state of liquid water is consistent with the Speedy-Angell conjecture on the limit of stability of the liquid phase.

  6. Development of a "First Principles" Water Potential with Flexible Monomers: Dimer Potential Energy Surface, VRT Spectrum, and Second Virial Coefficient.

    PubMed

    Babin, Volodymyr; Leforestier, Claude; Paesani, Francesco

    2013-12-10

    The development of a "first principles" water potential with flexible monomers (MB-pol) for molecular simulations of water systems from gas to condensed phases is described. MB-pol is built upon the many-body expansion of the intermolecular interactions, and the specific focus of this study is on the two-body term (V2B) representing the full-dimensional intermolecular part of the water dimer potential energy surface. V2B is constructed by fitting 40,000 dimer energies calculated at the CCSD(T)/CBS level of theory and imposing the correct asymptotic behavior at long-range as predicted from "first principles". The comparison of the calculated vibration-rotation tunneling (VRT) spectrum and second virial coefficient with the corresponding experimental results demonstrates the accuracy of the MB-pol dimer potential energy surface.

  7. Ocean Thermal Energy Conversion: the potential impact on microphytoplankton of bottom water discharge at subsurface in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Giraud, Mélanie; Boye, Marie; Garçon, Véronique; L'Helguen, Stéphane; Donval, Anne; De la Broise, Denis

    2015-04-01

    Part of the solar energy can be harvested and used in different processes. Taking advantage of the natural temperature gradient between the surface and deep ocean, the Ocean Thermal Energy Conversion (OTEC) process fulfills this goal. The IMPALA project (Impacts of artificial upwelling on microplankton) aims to study the potential environmental impacts of releasing, below the surface, deep seawater flowing out of a scheduled OTEC pilot plant offshore the Martinique Island in the Caribbean Sea. Biogeochemical processes involved in the artificial upwelling generated by the use of an Ocean Thermal Energy Conversion (OTEC) plant were studied in this poor nutrient environment. The biogeochemical and physical ecosystem structure and functioning on the OTEC site were described and deep seawater discharge using in situ microcosm experiments was carried out off Martinique. Surface seawater was collected in ultra-clean conditions at two depths (corresponding to the maximum of chlorophyll a concentration and bottom of nutricline) and mixed in different proportions with deep seawater (2% and 10%). Pigments determination, picophytoplankton abundance, macro-nutrients (silicates, nitrates, and phosphates), particular organic carbon and nitrogen concentrations and primary production were documented to assess the variability between the natural environment and within the microcosms. The latter were immersed for 6 days on a 250 meters mooring. Variations observed in microcosms experiments and in the surrounding waters were compared in order to evaluate the natural variability of the phytoplankton assemblage and the potential shifts induced by deep water supply. Results obtained during two fields campaigns conducted off Martinique at the onset of the dry (November-December 2013) and wet seasons (June 2014), respectively, will be presented and discussed. Incubating mixtures of subsurface and deep waters at two ratios and at two depths, allows evaluating the potential impact of a deep

  8. Uranium mine waste water: potential source of ground water in northwestern New Mexico

    USGS Publications Warehouse

    Hiss, W.L.

    1977-01-01

    Substantial quantities of water are being pumped from the Morrison Formation of Late Jurassic age in uranium mines in the Grants mineral belt in northwestern New Mexico. The water often contains unacceptable amounts of dissolved uranium, radium, iron, and selenium and suspended solids, but with treatment it can be made suitable for municipal and industrial purposes. Water salvaged from current and projected mining operations constitutes the most readily available water in this otherwise water-deficient area.

  9. A new water-based liquid scintillator and potential applications

    NASA Astrophysics Data System (ADS)

    Yeh, M.; Hans, S.; Beriguete, W.; Rosero, R.; Hu, L.; Hahn, R. L.; Diwan, M. V.; Jaffe, D. E.; Kettell, S. H.; Littenberg, L.

    2011-12-01

    In this paper we describe a new type of scintillating liquid based on water. We describe the concept, preparation, and properties of this liquid, and how it could be used for a very large, but economical detector. The applications of such a detector range from fundamental physics such as nucleon decay and neutrino physics to physics with broader application such as neutron detection. We briefly describe the scientific requirements of these applications, and how they can be satisfied by the new material.

  10. 2011 High Plains and Northern Rolling Plains Cotton Harvest-Aid Guide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvest-aid chemicals are generally applied to hasten harvest of a mature crop and to reduce potential preharvest losses of lint yield and fiber quality. Proper use of harvest aids can result in earlier harvest, preservation of fiber quality, and fewer seed quality reductions due to field exposure. ...

  11. 2009 High plains and northern rolling plains cotton harvest-aid guide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvest-aid chemicals are generally applied to hasten harvest of a mature crop, and to reduce potential preharvest losses of lint yield and fiber quality. Proper use of harvest aids can result in earlier harvest, preservation of fiber quality, and fewer seed quality reductions due to field exposure....

  12. 2012 High Plains and Northern Rolling Plains Cotton harvest aid-guide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvest-aid chemicals are generally applied to hasten harvest of a mature crop, and to reduce potential preharvest losses of lint yield and fiber quality. Proper use of harvest aids can result in earlier harvest, preservation of fiber quality, and fewer seed quality reductions due to field exposure....

  13. Organic hydrogels as potential sorbent materials for water purification

    NASA Astrophysics Data System (ADS)

    Linardatos, George; Bekiari, Vlasoula; Bokias, George

    2014-05-01

    Hydrogels are three-dimensional, hydrophilic, polymeric networks capable to adsorb large amounts of water or biological fluids. The networks are composed of homopolymers or copolymers and are insoluble due to the presence of chemical or physical cross-links. Depending on the nature of the structural units, swelling or shrinking of these gels can be activated by several external stimuli, such as solvent, heat, pH, electric stimuli. As a consequence, these materials are attractive for several applications in a variety of fields: drug delivery, muscle mimetic soft linear actuators, hosts of nanoparticles and semiconductors, regenerative medicine etc. Of special interest is the application of hydrogels for water purification, since they can effectively adsorb several water soluble pollutants such as metal ions, inorganic or organic anions, organic dyestaff, etc. In the present work, anionic hydrogels bearing negatively charged -COO- groups were prepared and investigated. These are based on the anionic monomer sodium acrylate (ANa) and the nonionic one N,N-dimethylacrylamide (DMAM). A series of copolymeric hydrogels (P(DMAM-co-ANax) were synthesized. The molar content x of ANa units (expressing the molar charged content of the hydrogel) varies from 0 (nonionic poly(N,N-dimethylacrylamide), PDMAM, hydrogel) up to 1 (fully charged poly(sodium acrylate), PANa, hydrogel). The hydrogels were used to extract organic or inorganic solutes from water. Cationic and anionic model dyes, as well as multivalent inorganic ions, have been studied. It is found that cationic dyes are strongly adsorbed and retained by the hydrogels, while adsorbance of anionic dyes was negligible. Both maximum adsorption and equilibrium binding constant depend on the chemical structure of the dye, the presence of functional chemical groups and the hydrophobic-hydrophilic balance. In the case of metal cations, adsorption depends mostly on the charge of the cation. In addition, crucial factors controlling

  14. The Water Regime of Ceres and its Potential Habitability

    NASA Astrophysics Data System (ADS)

    Li, J. Y.; Sykes, M. V.; Castillo, J. C.; McFadden, L. A.

    2014-12-01

    The Lunar Reconnaissance Orbiter (LRO) and LCROSS have provided an avalanche of new data regarding the lunar poles: LCROSS directly detected water vapor and other volatiles in its impact plume; LRO LAMP has detected surface frost using UV ratios; LEND has refined understanding of the distribution of hydrogen; LOLA and LAMP have showed that the spectral properties of permanently shadowed regions (PSR) are anomalous and may be due to unusual surface texture or altered space weathering; Diviner shows both where the coldest portions of the poles exist, and its quantitative results show where temperatures are low enough to preserve water ice at depth, well outside the PSRs. Yet while we are data rich, our understanding of the lunar poles is maddeningly poor. Our poverty of understanding is made even more baffling by the MESSENGER results from Mercury. At Mercury's poles the distribution of volatiles is dictated by temperature: where subsurface temperatures inferred from topography are consistent with long term preservation of water ice, radar anomalies indicating thick ice are present; where surface temperatures are consistent with preservation of surface frost, high reflectance anomalies indicating surface frost are revealed by laser reflectance. The distribution of water ice on Mercury is well understood. In contrast, temperature is only a weak indicator of the presence of volatiles at the lunar poles; there is little ability to predict the location and abundance of hydrogen or water. The difference may in the age of the volatile deposits on the two planets. Turn the clock forward a few billion years on Mercury and the deposits may appear more lunar. Surface lag deposits may have long ago succumbed to impact gardening, as has much of the shallow buried ice. Ice retained could be patchy, and confined to the coldest places that may tend to preserve it more effectively, even when finely comminuted. Lunar polar volatiles, a possible relic of an ancient, Mercury

  15. RELATIONSHIPS BETWEEN OXIDATION-REDUCTION POTENTIAL, OXIDANT, AND PH IN DRINKING WATER

    EPA Science Inventory

    Oxidation and reduction (redox) reactions are very important in drinking water. Oxidation-reduction potential (ORP) measurements reflect the redox state of water. Redox measurements are not widely made by drinking water utilities in part because they are not well understood. The ...

  16. An examination of the potential added value of water safety plans to the United States national drinking water legislation.

    PubMed

    Baum, Rachel; Amjad, Urooj; Luh, Jeanne; Bartram, Jamie

    2015-11-01

    National and sub-national governments develop and enforce regulations to ensure the delivery of safe drinking water in the United States (US) and countries worldwide. However, periodic contamination events, waterborne endemic illness and outbreaks of waterborne disease still occur, illustrating that delivery of safe drinking water is not guaranteed. In this study, we examined the potential added value of a preventive risk management approach, specifically, water safety plans (WSPs), in the US in order to improve drinking water quality. We undertook a comparative analysis between US drinking water regulations and WSP steps to analyze the similarities and differences between them, and identify how WSPs might complement drinking water regulations in the US. Findings show that US drinking water regulations and WSP steps were aligned in the areas of describing the water supply system and defining monitoring and controls. However, gaps exist between US drinking water regulations and WSPs in the areas of team procedures and training, internal risk assessment and prioritization, and management procedures and plans. The study contributes to understanding both required and voluntary drinking water management practices in the US and how implementing water safety plans could benefit water systems to improve drinking water quality and human health.

  17. Analyzing the potential for water quality externalities as the result of market water transfers

    NASA Astrophysics Data System (ADS)

    Connor, Jeffery D.; Perry, Gregory M.

    1999-09-01

    This article presents a comparative static framework for predicting the water quality outcomes of water trade. The focus is on a comprehensive treatment of water quality processes. Previous work has assumed that reductions in agriculturally induced water quality externalities are an increasing function of irrigation application rates. The comparative static framework used here allows for the possibility that water transfer can result in both positive and negative water quality externalities as the result of dilution, even when the rate of loading decreases. We apply our model to the Owyhee aquifer of eastern Oregon, an area where nitrate concentrations exceeded the EPA standard of 10 ppm in over 30% of area test wells in 1991. In conclusion, we describe conditions when water trade is most likely to generate positive versus negative water quality externalities. We also draw policy conclusions about the kinds of institutional rules best suited to balance trade-offs between gains to trade, water quality externalities, and transactions costs.

  18. Big bluestem and switchgrass feedstock harvest timing: Nitrous oxide response to feedstock harvest timing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks. Feedstock storage limitations, labor constraints for harvest, and environmental benefits provided by perennials are rationales for developing localized perennial feedstock as an alter...

  19. Phenotypic plasticity of stem water potential correlates with crop load in horticultural trees.

    PubMed

    Sadras, Victor O; Trentacoste, Eduardo R

    2011-05-01

    Conceptual models accounting for the influence of source:sink ratio on water relations of trees are theoretically relevant from a physiological perspective and practically important for irrigation scheduling. Midday stem water potential of horticultural trees often declines with increasing crop load but the actual response depends on environmental, management and plant factors. Here we advance a quantitative synthesis of the response of stem water potential to crop load from the perspective of phenotypic plasticity, defined as 'the amount by which the expression of individual characteristics of a genotype are changed by different environments'. Data sets of stem water potential for contrasting crop loads were compiled for apple (Malus domestica L. Borkh.), olive (Olea europea L.), peach (Prunus persica L.), pear (Pyrus communis L.) and plum (Prunus domestica L.). Phenotypic plasticity of stem water potential was calculated as the slope of the linear regression between stem water potential for each crop load and the environmental mean of stem water potential across crop loads. Regression lines for trees with different crop load diverged with decreasing environmental mean stem water potential. For the pooled data, plasticity of stem water potential was a linear function of relative crop load. This represents a significant shift in perspective: the effect of crop load on the trait per se (stem water potential) is environmentally contingent, but the effect of crop load on the plasticity of the trait is not. We conclude that research on the effects of crop load on tree water relations would return more robust results if plant traits are considered from the dual perspective of the trait per se and its plasticity.

  20. Principles of thermoacoustic energy harvesting

    NASA Astrophysics Data System (ADS)

    Avent, A. W.; Bowen, C. R.

    2015-11-01

    Thermoacoustics exploit a temperature gradient to produce powerful acoustic pressure waves. The technology has a key role to play in energy harvesting systems. A time-line in the development of thermoacoustics is presented from its earliest recorded example in glass blowing through to the development of the Sondhauss and Rijke tubes to Stirling engines and pulse-tube cryo-cooling. The review sets the current literature in context, identifies key publications and promising areas of research. The fundamental principles of thermoacoustic phenomena are explained; design challenges and factors influencing efficiency are explored. Thermoacoustic processes involve complex multi-physical coupling and transient, highly non-linear relationships which are computationally expensive to model; appropriate numerical modelling techniques and options for analyses are presented. Potential methods of harvesting the energy in the acoustic waves are also examined.

  1. Potential Interference from Wireless Water Tank Transmitters at Goldstone

    NASA Astrophysics Data System (ADS)

    Ho, C.

    2008-02-01

    The Deep Space Network (DSN) facility in the Goldstone, California, area is considering installation of a new type of wireless transmitter (M2400S) within the facility. The transmitters will be used to monitor the water levels in several water tanks. Then these water-level signals will be transmitted to the nearby DSN facilities using transmitters operating in the UHF band (900-MHz) or S-band (2.4-GHz). This study is to evaluate the interference effects from the transmitters in adjacent DSN receiving stations. First we perform a terrain profile analysis to identify if there is a line of sight between each transmitter and the nearby DSN stations. After taking into account terrain shielding using high-resolution data, total propagation losses are calculated along each path. Then we perform the link analysis for each site to identify if the interference power exceeds the protection threshold of DSN receiving stations. As a result, we find that, because there is no bandpass filter installed in the transmitter system, interference power from the new transmitter at S-band will greatly exceed the protection criteria of broadband radio astronomy services (RAS) at S-band, such as Deep Space Station (DSS) 12 and DSS 28, by about 50 dB. The interference may also cause problems on all deep-space research stations at S-band, such as the Mars, Apollo, Venus, and Gemini sites. Without a sharp bandpass filter to suppress the out-of-band emissions in the frequency bands that the DSN station and RAS use, the author recommends not installing this type of transmitter within the Goldstone DSN facility area.

  2. Estimating Leaf Water Potential of Giant Sequoia Trees from Airborne Hyperspectral Imagery

    NASA Astrophysics Data System (ADS)

    Francis, E. J.; Asner, G. P.

    2015-12-01

    Recent drought-induced forest dieback events have motivated research on the mechanisms of tree survival and mortality during drought. Leaf water potential, a measure of the force exerted by the evaporation of water from the leaf surface, is an indicator of plant water stress and can help predict tree mortality in response to drought. Scientists have traditionally measured water potentials on a tree-by-tree basis, but have not been able to produce maps of tree water potential at the scale of a whole forest, leaving forest managers unaware of forest drought stress patterns and their ecosystem-level consequences. Imaging spectroscopy, a technique for remote measurement of chemical properties, has been used to successfully estimate leaf water potentials in wheat and maize crops and pinyon-pine and juniper trees, but these estimates have never been scaled to the canopy level. We used hyperspectral reflectance data collected by the Carnegie Airborne Observatory (CAO) to map leaf water potentials of giant sequoia trees (Sequoiadendron giganteum) in an 800-hectare grove in Sequoia National Park. During the current severe drought in California, we measured predawn and midday leaf water potentials of 48 giant sequoia trees, using the pressure bomb method on treetop foliage samples collected with tree-climbing techniques. The CAO collected hyperspectral reflectance data at 1-meter resolution from the same grove within 1-2 weeks of the tree-level measurements. A partial least squares regression was used to correlate reflectance data extracted from the 48 focal trees with their water potentials, producing a model that predicts water potential of giant sequoia trees. Results show that giant sequoia trees can be mapped in the imagery with a classification accuracy of 0.94, and we predicted the water potential of the mapped trees to assess 1) similarities and differences between a leaf water potential map and a canopy water content map produced from airborne hyperspectral data, 2

  3. Occurrence of Potential Pathogens in Water Containing Ornamental Fishes

    PubMed Central

    Trust, T. J.; Bartlett, K. H.

    1974-01-01

    The bacterial population of the water supplied with ornamental fish purchased from retail outlets was examined qualitatively and quantitatively. As many as 109 viable aerobic organisms per 100 ml were present, with fecal coliform counts as high as 105 per 100 ml. Citrobacter, Escherichia, Pseudomonas, and Vibrio were isolated from 75% or more of the samples, whereas Aeromonas, Alcaligenes, Enterobacter, Flavobacterium, and Streptococcus were isolated from 45 to 65% of the samples. Pseudomonas aeruginosa, Edwardsiella tarda, and Klebsiella pneumoniae were also isolated. PMID:4602309

  4. Measurement of the matric potential of soil water in the rhizosphere.

    PubMed

    Whalley, W R; Ober, E S; Jenkins, M

    2013-10-01

    The availability of soil water, and the ability of plants to extract it, are important variables in plant research. The matric potential has been a useful way to describe water status in a soil-plant system. In soil it is the potential that is derived from the surface tension of water menisci between soil particles. The magnitude of matric potential depends on the soil water content, the size of the soil pores, the surface properties of the soil particles, and the surface tension of the soil water. Of all the measures of soil water, matric potential is perhaps the most useful for plant scientists. In this review, the relationship between matric potential and soil water content is explored. It is shown that for any given soil type, this relationship is not unique and therefore both soil water content and matric potential need to be measured for the soil water status to be fully described. However, in comparison with water content, approaches for measuring matric potential have received less attention until recently. In this review, a critique of current methods to measure matric potential is presented, together with their limitations as well as underexploited opportunities. The relative merits of both direct and indirect methods to measure matric potential are discussed. The different approaches needed in wet and dry soil are outlined. In the final part of the paper, the emerging technologies are discussed in so far as our current imagination allows. The review draws upon current developments in the field of civil engineering where the measurement of matric potential is also important. The approaches made by civil engineers have been more imaginative than those of plant and soil scientists.

  5. Roots of Pisum sativum L. exhibit hydrotropism in response to a water potential gradient in vermiculite.

    PubMed

    Tsuda, Shogo; Miyamoto, Naoko; Takahashi, Hideyuki; Ishihara, Kuni; Hirasawa, Tadashi

    2003-12-01

    In the present study, root hydrotropism in an agravitropic mutant of Pisum sativum L. grown in vermiculite with a steep water potential gradient was examined. When wet and dry vermiculite were placed side by side, water diffused from the wet (-0.04 MPa) to the dry (-1.2 MPa) and a steep water potential gradient became apparent in the dry vermiculite close to the boundary between the two. The extent and location of the gradient remained stable between the fourth and sixth day after filling a box with vermiculite, and the steepest gradient (approx. 0.02 MPa mm-1) was found in the initially dry vermiculite between 60 and 80 mm from the boundary. When seedlings with 25-35 mm long roots were planted in the initially dry vermiculite near where the gradient had been established, each of the main roots elongated toward the wet vermiculite, i.e. toward the high water potential. Control roots elongated without curvature in both the wet and the dry vermiculite, in which no water potential gradient was detectable. These results show that pea roots respond to the water potential gradient around them and elongate towards the higher water potential. Therefore, positive hydrotropism occurs in vermiculite just as it does in air. Hydrotropism in soil may be significant when a steep water potential gradient is apparent, such as when drip irrigation is applied.

  6. {zeta}-potentials of silica in water-alcohol mixtures

    SciTech Connect

    Kosmulski, M.; Matijevic, E.

    1992-04-01

    Two effects of 1-alcohols (up to 30% w/w) on electrokinetic properties of silica in the presence of different concentrations of KCl (1 x 10{sup -3}-1 x 1-{sup -1} mol dm{sup -3}) are described. The isoelectric point shifts toward more basic pH, while the negative {zeta}-potentials decrease with higher concentrations of the alcohol and the electrolyte. The change in the pH{sub iep} is explained in terms of the complexation of protonated surface hydroxyl groups by alcohol molecules. The lower negative {zeta}-potentials are due to an increase in cation activity in mixed solvents and, thus, an enhanced counterion adsorption in the Stern layer. 15 refs., 8 figs., 1 tab.

  7. Exploring the potential of magnetic antimicrobial agents for water disinfection.

    PubMed

    Pina, Ana S; Batalha, Iris L; Fernandes, Cláudia S M; Aoki, Matheus A; Roque, Ana C A

    2014-12-01

    Industrial and urban activities yield large amounts of contaminated groundwater, which present a major health issue worldwide. Infectious diseases are the most common health risk associated with drinking-water and wastewater remediation is a major concern of our modern society. The field of wastewater treatment is being revolutionized by new nano-scale water disinfection devices which outperform most currently available technologies. In particular, iron oxide magnetic nanoparticles (MNPs) have been widely used in environmental applications due to their unique physical-chemical properties. In this work, poly(ethylene) glycol (PEG)-coated MNPs have been functionalized with (RW)3, an antimicrobial peptide, to yield a novel magnetic-responsive support with antimicrobial activity against Escherichia coli K-12 DSM498 and Bacillus subtilis 168. The magnetic-responsive antimicrobial device showed to be able to successfully disinfect the surrounding solution. Using a rapid high-throughput screening platform, the minimal inhibitory concentration (MIC) was determined to be 500 μM for both strains with a visible bactericidal effect.

  8. Potential water saving through changes in European diets.

    PubMed

    Vanham, D; Hoekstra, A Y; Bidoglio, G

    2013-11-01

    This study quantifies the water footprint of consumption (WFcons) regarding agricultural products for three diets - the current diet (REF), a healthy diet (HEALTHY) and a vegetarian diet (VEG) - for the four EU zones WEST, NORTH, SOUTH and EAST. The WFcons related to the consumption of agricultural products (4265l per capita per day or lcd) accounts for 89% of the EU's total WFcons (4815lcd). The effect of diet has therefore an essential impact on the total WFcons. The current zonal WFcons regarding agricultural products is: 5875lcd (SOUTH), 4053lcd (EAST), 3761lcd (WEST) and 3197lcd (NORTH). These differences are the result of different consumption behaviours as well as different agricultural production methods and conditions. From the perspective of a healthy diet based on regional dietary guidelines, the intake of several product groups (sugar, crop oils, animal fats and meat) should be decreased and increased for others (vegetables, fruit). The WFcons regarding agricultural products for the alternative diets are the following: HEALTHY 4110lcd (-30%) and VEG 3476lcd (-41%) for SOUTH; HEALTHY 3606lcd (-11%) and VEG 2956lcd (-27%) for EAST; HEALTHY 2766lcd (-26%) and VEG 2208lcd (-41%) for WEST; HEALTHY 3091lcd (-3%) and VEG 2166lcd (-32%) for NORTH. Both the healthy and vegetarian diets thus result - consistent for all zones - in substantial WFcons reductions. The largest reduction takes place for the vegetarian diet. Indeed, a lot of water can be saved by EU citizens by a change in their diet.

  9. The vibrational proton potential in bulk liquid water and ice.

    PubMed

    Burnham, C J; Anick, D J; Mankoo, P K; Reiter, G F

    2008-04-21

    We present an empirical flexible and polarizable water model which gives an improved description of the position, momentum, and dynamical (spectroscopic) distributions of H nuclei in water. We use path integral molecular dynamics techniques in order to obtain momentum and position distributions and an approximate solution to the Schrodinger equation to obtain the infrared (IR) spectrum. We show that when the calculated distributions are compared to experiment the existing empirical models tend to overestimate the stiffness of the H nuclei involved in H bonds. Also, these models vastly underestimate the enormous increase in the integrated IR intensity observed in the bulk over the gas-phase value. We demonstrate that the over-rigidity of the OH stretch and the underestimation of intensity are connected to the failure of existing models to reproduce the correct monomer polarizability surface. A new model, TTM4-F, is parametrized against electronic structure results in order to better reproduce the polarizability surface. It is found that TTM4-F gives a superior description of the observed spectroscopy, showing both the correct redshift and a much improved intensity. TTM4-F also has a somewhat improved dielectric constant and OH distribution function. It also gives an improved match to the experimental momentum distribution, although some discrepancies remain.

  10. Relation of electrochemical potentials and iron content to ground-water flow patterns

    USGS Publications Warehouse

    Back, William; Barnes, Ivan

    1965-01-01

    This study was undertaken to develop means of measuring oxidation potentials in aquifer systems and to use the measured values in interpreting the behavior of iron in ground water. Anne Arundel County, Md., was selected as the area of study because of the wide range of concentration of iron-nearly zero to about 35 ppm-in the ground water and the rather complete information on the geology and hydrology. The regional geology consists of coastal plain sediments ranging in age from Early Cretaceous through the Recent. Most of the pH and oxidation-potential measurements were made in nonmarine Cretaceous deposits, only a few in the marine Eocene. Iron-bearing minerals in the area are primarily hematite or limonite and glauconite with a small amount of pyrite. Equipment was developed that permits the measurement of oxidation potentials by use of saturated calomel and platinum electrodes in ground-water samples uncontaminated by oxygen of the atmosphere. Measured Eh values range from about +700 mv to -40 mv. Approximately 2 to 3 hours are required to measure a stable or nearly stable oxidation potential. The mineralogy and organic content of the deposits and the ground-water flow pattern are the primary controls on the oxidation potential and pH of the water. A correlation exists between the oxidation potential and the concentration of iron in ground water; the higher concentrations occur in waters with the lowest values of Eh. The concentration of iron in the water tested shows little correlation with the pH of the water. The highest oxidation potentials were measured in water produced from shallow wells and those wells in recharge areas. The lowest potentials were measured farthest downgradient in water associated with gray and green sediments. The Eh values measured in the field are between values predicted from the solubility of Fe(OH)2(c) and values predicted from the solubility of hematite.

  11. Momentum harvesting techniques for solar system travel

    NASA Technical Reports Server (NTRS)

    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.

  12. (Metabolic mechanisms of plant growth at low water potentials)

    SciTech Connect

    Not Available

    1990-01-01

    The work supported by DOE showed that water-limitation inhibits plant growth first by imposing a physical limitation that is followed in a few h by metabolic changes leading to reduced wall extensibility in the enlarging cells. After the wall extensibility decreased, a 28kD protein accumulated particularly in the walls of the growth-affected cells. Antibodies were used to identify cDNA for the protein. The base sequence of the cDNA was typical of an enzyme rather than known structural components of walls. The sequence was identical to one published by another laboratory at the same time and encoding a protein that accumulates in vacuoles of depodded soybean plants.

  13. Looking for Water in the Woods: Quantifying the Potential for Forest Management to Increase Regional Water Yield

    NASA Astrophysics Data System (ADS)

    Acharya, S.; Kaplan, D. A.; Mclaughlin, D. L.; Cohen, M. J.

    2014-12-01

    Water scarcity presents a crucial challenge for water resource managers charged with maintaining hydrologic resources for domestic, industrial, and agricultural use while protecting natural systems. Forest lands are critical to the functioning of the hydrologic cycle in many watersheds, affecting the quantity, quality, and timing of water delivered to surface and groundwater systems. While the hydrologic impacts of forest growth and removal have been shown to be substantial in watersheds around the globe, data and models connecting forest management to water use and regional hydrology are generally lacking. We propose that water-focused forest management has the potential to deliver a "new" source of water to surface and groundwater resources. To test this hypothesis, we developed a statistical model of water yield in southeastern US pine stands as a function of forest stand structure and ecosystem water use. Model results suggest a potential increase in water yield of up to 64% for pine stands managed at lower basal areas relative to those managed according to standard silvicultural practices. At the watershed scale, the magnitude of this potential water yield enhancement is driven by existing land use and forest management; evaluated for a large watershed in NE Florida, this potential increase is in excess of 200 million gallons per day (equivalent to 20% of the anthropogenic water use in the watershed). While useful for exploration, our statistical model also highlighted critical sources of uncertainty, including the effects of climatic variation, between-site variability, water use in young pine stands, and prescribed fire. Thus, in ongoing work we are comparing the effects of specific land management actions (e.g., thinning, clearcutting, and fire) on water yield across a gradient of environmental conditions (soil type, aquifer confinement, and climate) using a novel combination of in-situ soil moisture and groundwater monitoring. These data are being used to

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Power Harvesting from Rotation?

    ERIC Educational Resources Information Center

    Chicone, Carmen; Feng, Z. C.

    2008-01-01

    We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics. (Contains 2 figures.)

  16. Occurrence and potential causes of androgenic activities in source and drinking water in China.

    PubMed

    Hu, Xinxin; Shi, Wei; Wei, Si; Zhang, Xiaowei; Feng, Jianfang; Hu, Guanjiu; Chen, Sulan; Giesy, John P; Yu, Hongxia

    2013-09-17

    The increased incidences of disorders of male reproductive tract as well as testicular and prostate cancers have been attributed to androgenic pollutants in the environment. Drinking water is one pathway of exposure through which humans can be exposed. In this study, both potencies of androgen receptor (AR) agonists and antagonists were determined in organic extracts of raw source water as well as finished water from waterworks, tap water, boiled water, and poured boiled water in eastern China. Ten of 13 samples of source water exhibited detectable AR antagonistic potencies with AR antagonist equivalents (Ant-AR-EQs) ranging from <15.3 (detection limit) to 140 μg flutamide/L. However, no AR agonistic activity was detected in any source water. All finished water from waterworks, tap water, boiled water, and poured boiled water exhibited neither AR agonistic nor antagonistic activity. Although potential risks are posed by source water, water treatment processes effectively removed AR antagonists. Boiling and pouring of water further removed these pollutants. Phthalate esters (PAEs) including diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP) were identified as major contributors to AR antagonistic potencies in source waters. Metabolites of PAEs exhibited no AR antagonistic activity and did not increase potencies of PAEs when they coexist.

  17. Simulating soybean canopy temperature as affected by weather variables and soil water potential

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.

    1982-01-01

    Hourly weather data for several clear sky days during summer at Phoenix and Baltimore which covered a wide range of variables were used with a plant atmosphere model to simulate soybean (Glycine max L.) leaf water potential, stomatal resistance and canopy temperature at various soil water potentials. The air and dew point temperatures were found to be the significant weather variables affecting the canopy temperatures. Under identical weather conditions, the model gives a lower canopy temperature for a soybean crop with a higher rooting density. A knowledge of crop rooting density, in addition to air and dew point temperatures is needed in interpreting infrared radiometric observations for soil water status. The observed dependence of stomatal resistance on the vapor pressure deficit and soil water potential is fairly well represented. Analysis of the simulated leaf water potentials indicates overestimation, possibly due to differences in the cultivars.

  18. Elimination of disinfection byproduct formation potential in reclaimed water during solar light irradiation.

    PubMed

    Qian-Yuan, Wu; Chao, Li; Ye, Du; Wen-Long, Wang; Huang, Huang; Hong-Ying, Hu

    2016-05-15

    Ecological storage of reclaimed water in ponds and lakes is widely applied in water reuse. During reclaimed water storage, solar light can degrade pollutants and improve water quality. This study investigated the effects of solar light irradiation on the disinfection byproduct formation potential in reclaimed water, including haloacetonitriles (HANs), trichloronitromethane (TCNM), trihalomethanes (THMs), haloketones (HKs) and chloral hydrate (CH). Natural solar light significantly decreased the formation potential of HANs, TCNM, and HKs in reclaimed water, but had a limited effect on the formation potential of THMs and CH. Ultraviolet (UV) light in solar radiation played a dominant role in the decrease of the formation potential of HANs, TCNM and HKs. Among the disinfection byproducts, the removal kinetic constant of dichloroacetonitrile (DCAN) with irradiation dose was much larger than those for dichloropropanone (1,1-DCP), trichloropropanone (1,1,1-TCP) and TCNM. During solar irradiation, fluorescence spectra intensities of reclaimed water also decreased significantly. The removal of tyrosine (Tyr)-like and tryptophan (Trp)-like protein fluorescence spectra intensity volumes was correlated to the decrease in DCAN formation potential. Solar irradiation was demonstrated to degrade Trp, Tyr and their DCAN formation potential. The photolysis products of Trp after solar irradiation were detected as kynurenine and tryptamine, which had chloroform, CH and DCAN formation potential lower than those of Trp.

  19. A National Assessment of the Potential Impacts of Hydraulic Fracturing Activities on Drinking Water Resources

    NASA Astrophysics Data System (ADS)

    Ridley, C.; Burden, S.; Fleming, M. M.; Knightes, C. D.; Koplos, J.; LeDuc, S. D.; Ring, S.; Stanek, J.; Tuccillo, M. E.; Weaver, J.; Frithsen, J.

    2015-12-01

    The U.S. Environmental Protection Agency recently released a draft assessment of the potential impacts of hydraulic fracturing on drinking water resources. As part of the draft assessment, we reviewed, analyzed, and synthesized information from over 950 sources and concluded that there are above and below ground mechanisms by which hydraulic fracturing activities have the potential to impact drinking water resources. These mechanisms include: Water withdrawals in times of, or in areas with, low water availability; Spills of hydraulic fracturing fluids and produced water; Fracturing directly into underground drinking water resources; Below ground migration of liquids and gases; and Inadequate treatment and discharge of wastewater. Of the potential mechanisms identified in this report, we found specific instances where one or more mechanisms led to impacts on drinking water resources, including contamination of drinking water wells. The number of identified cases, however, was small compared to the number of hydraulically fractured wells. This finding could reflect a rarity of effects on drinking water resources, but may also be due to other limiting factors. These factors include: insufficient pre- and post-fracturing data on the quality of drinking water resources; the paucity of long-term systematic studies; the presence of other sources of contamination precluding a definitive link between hydraulic fracturing activities and an impact; and the inaccessibility of some information on hydraulic fracturing activities and potential impacts. Disclaimer: The views expressed are those of the authors and do not necessarily reflect the views or polices of the EPA.

  20. Ecological impacts of energy-wood harvests: lessons from whole-tree harvesting and natural disturbance

    USGS Publications Warehouse

    Berger, Alaina L.; Palik, Brian; D'Amato, Anthony W.; Fraver, Shawn; Bradford, John B.; Nislow, Keith H.; King, David; Brooks, Robert T.

    2013-01-01

    Recent interest in using forest residues and small-diameter material for biofuels is generating a renewed focus on harvesting impacts and forest sustainability. The rich legacy of research from whole-tree harvesting studies can be examined in light of this interest. Although this research largely focused on consequences for forest productivity, in particular carbon and nutrient pools, it also has relevance for examining potential consequences for biodiversity and aquatic ecosystems. This review is framed within a context of contrasting ecosystem impacts from whole-tree harvesting because it represents a high level of biomass removal. Although whole-tree harvesting does not fully use the nonmerchantable biomass available, it indicates the likely direction and magnitude of impacts that can occur through energy-wood harvesting compared with less-intensive conventional harvesting and to dynamics associated with various natural disturbances. The intent of this comparison is to gauge the degree of departure of energy-wood harvesting from less intensive conventional harvesting. The review of the literature found a gradient of increasing departure in residual structural conditions that remained in the forest when conventional and whole-tree harvesting was compared with stand-replacing natural disturbance. Important stand- and landscape-level processes were related to these structural conditions. The consequence of this departure may be especially potent because future energy-wood harvests may more completely use a greater range of forest biomass at potentially shortened rotations, creating a great need for research that explores the largely unknown scale of disturbance that may apply to our forest ecosystems.

  1. Measurement of water potential in low-level waste management. [Shallow Land Burial

    SciTech Connect

    Jones, T. L.; Gee, G. W.; Kirkham, R. R.; Gibson, D. D.

    1982-08-01

    The measurement of soil water is important to the shallow land burial of low-level waste. Soil water flow is the principle mechanism of radionuclide transport, allows the establishment of stabilizing vegetation and also governs the dissolution and release rates of the waste. This report focuses on the measurement of soil water potential and provides an evaluation of several field instruments that are available for use to monitor waste burial sites located in arid region soils. The theoretical concept of water potential is introduced and its relationship to water content and soil water flow is discussed. Next, four major areas of soils research are presented in terms of their dependence on the water potential concept. There are four basic types of sensors used to measure soil water potential. These are: (1) tensiometers; (2) soil psychrometers; (3) electrical resistance blocks; and (4) heat dissipation probes. Tensiometers are designed to measure the soil water potential directly by measuring the soil water pressure. Monitoring efforts at burial sites require measurements of soil water over long time periods. They also require measurements at key locations such as waste-soil interfaces and within any barrier system installed. Electrical resistance blocks are well suited for these types of measurements. The measurement of soil water potential can be a difficult task. There are several sensors commercially available; however, each has its own limitations. It is important to carefully select the appropriate sensor for the job. The accuracy, range, calibration, and stability of the sensor must be carefully considered. This study suggests that for waste management activities, the choice of sensor will be the tensiometer for precise soil characterization studies and the electrical resistance block for long term monitoring programs. (DMC)

  2. [Accidents affecting potato harvesters].

    PubMed

    Hansen, J U

    1993-09-27

    During industrialization in agriculture, many farming machines have been introduced. It is well-known that farming is a dangerous workplace and that farm machinery cause many serious accidents every year. Four cases of accidents with potato harvesters are discussed. In three of four cases the farmers were injured while cleaning the machine without stopping it, which probably was the main cause of the accidents. Farmers are in general not careful enough when using farm machinery. Every year, farmers in Denmark are severely invalided in accidents with potato harvesters. A strategy to lower the accidents is proposed: 1. Information of farmers, farmer schools, machine constructors and importers about mechanisms of injury. 2. A better education of farmers in using potato harvesters (and other farming machines). 3. Better fencing of the potato harvesters. 4. If possibly constructional changes in the potato harvesters so things will not get stuck, or so that the machine will stop if things stuck. 5. Installation of switches on potato harvesters, which can be reached from all positions, stopping the machines immediately, or a remote switch control carried by the farmer.

  3. Reproductive Biology of the Blue Swimming Crab Portunus pelagicus (Brachyura: Portunidae) in East Lampung Waters, Indonesia: Fecundity and Reproductive Potential

    PubMed Central

    Zairion; Wardiatno, Yusli; Boer, Mennofatria; Fahrudin, Achmad

    2015-01-01

    The blue swimming crab Portunus pelagicus is an important catch species for many coastal villages along the Java Sea coastline, but little is known regarding its reproductive biology or stock status. We examined the batch fecundity of female crabs that were collected monthly at landing sites from June 2011 to May 2012, calculated the relationships with body size, egg mass and month of the year, and determined the size at which females became potentially reproductive in the population inhabiting East Lampung waters (western Java Sea). Fecundity values ranged from 229,468 to 2,236,355 (mean = 926,638±30,975 [±SE]). The fecundity was positively and linearly correlated with carapace width (CW), but the relationships with body weight and egg mass were best described by logarithmic regression. A peaked, temporally cyclical pattern in fecundity was observed, with a peak period that was significantly different (F = 226.36; df = 22, p<0.05) from March to May 2012. Reproductive females were within the 111.0–155.9 mm CW size range; significantly higher reproductive potentials (F = 14.59; df = 30, p<0.05) were found in females within the 126.0–130.9 mm CW size group. The current minimum legal size (MLS = 100 mm CW) is not an appropriate limit reference point, and a precautionary approach is needed for a sustainable harvesting strategy. Resetting the MLS to 115 mm CW would potentially provide adequate protection for spawning females and increase total egg production, thereby maintaining population productivity and enhancing resilience in the face of current fishing pressures. PMID:26019748

  4. Reproductive Biology of the Blue Swimming Crab Portunus pelagicus (Brachyura: Portunidae) in East Lampung Waters, Indonesia: Fecundity and Reproductive Potential.

    PubMed

    Zairion; Wardiatno, Yusli; Boer, Mennofatria; Fahrudin, Achmad

    2015-04-01

    The blue swimming crab Portunus pelagicus is an important catch species for many coastal villages along the Java Sea coastline, but little is known regarding its reproductive biology or stock status. We examined the batch fecundity of female crabs that were collected monthly at landing sites from June 2011 to May 2012, calculated the relationships with body size, egg mass and month of the year, and determined the size at which females became potentially reproductive in the population inhabiting East Lampung waters (western Java Sea). Fecundity values ranged from 229,468 to 2,236,355 (mean = 926,638±30,975 [±SE]). The fecundity was positively and linearly correlated with carapace width (CW), but the relationships with body weight and egg mass were best described by logarithmic regression. A peaked, temporally cyclical pattern in fecundity was observed, with a peak period that was significantly different (F = 226.36; df = 22, p<0.05) from March to May 2012. Reproductive females were within the 111.0-155.9 mm CW size range; significantly higher reproductive potentials (F = 14.59; df = 30, p<0.05) were found in females within the 126.0-130.9 mm CW size group. The current minimum legal size (MLS = 100 mm CW) is not an appropriate limit reference point, and a precautionary approach is needed for a sustainable harvesting strategy. Resetting the MLS to 115 mm CW would potentially provide adequate protection for spawning females and increase total egg production, thereby maintaining population productivity and enhancing resilience in the face of current fishing pressures.

  5. Response of the water status of soybean to changes in soil water potentials controlled by the water pressure in microporous tubes

    NASA Technical Reports Server (NTRS)

    Steinberg, S. L.; Henninger, D. L.

    1997-01-01

    Water transport through a microporous tube-soil-plant system was investigated by measuring the response of soil and plant water status to step change reductions in the water pressure within the tubes. Soybeans were germinated and grown in a porous ceramic 'soil' at a porous tube water pressure of -0.5 kpa for 28 d. During this time, the soil matric potential was nearly in equilibrium with tube water pressure. Water pressure in the porous tubes was then reduced to either -1.0, -1.5 or -2.0 kPa. Sap flow rates, leaf conductance and soil, root and leaf water potentials were measured before and after this change. A reduction in porous tube water pressure from -0.5 to -1.0 or -1.5 kPa did not result in any significant change in soil or plant water status. A reduction in porous tube water pressure to -2.0 kPa resulted in significant reductions in sap flow, leaf conductance, and soil, root and leaf water potentials. Hydraulic conductance, calculated as the transpiration rate/delta psi between two points in the water transport pathway, was used to analyse water transport through the tube-soil-plant continuum. At porous tube water pressures of -0.5 to-1.5 kPa soil moisture was readily available and hydraulic conductance of the plant limited water transport. At -2.0 kPa, hydraulic conductance of the bulk soil was the dominant factor in water movement.

  6. Response of the water status of soybean to changes in soil water potentials controlled by the water pressure in microporous tubes.

    PubMed

    Steinberg, S L; Henninger, D L

    1997-12-01

    Water transport through a microporous tube-soil-plant system was investigated by measuring the response of soil and plant water status to step change reductions in the water pressure within the tubes. Soybeans were germinated and grown in a porous ceramic 'soil' at a porous tube water pressure of -0.5 kpa for 28 d. During this time, the soil matric potential was nearly in equilibrium with tube water pressure. Water pressure in the porous tubes was then reduced to either -1.0, -1.5 or -2.0 kPa. Sap flow rates, leaf conductance and soil, root and leaf water potentials were measured before and after this change. A reduction in porous tube water pressure from -0.5 to -1.0 or -1.5 kPa did not result in any significant change in soil or plant water status. A reduction in porous tube water pressure to -2.0 kPa resulted in significant reductions in sap flow, leaf conductance, and soil, root and leaf water potentials. Hydraulic conductance, calculated as the transpiration rate/delta psi between two points in the water transport pathway, was used to analyse water transport through the tube-soil-plant continuum. At porous tube water pressures of -0.5 to-1.5 kPa soil moisture was readily available and hydraulic conductance of the plant limited water transport. At -2.0 kPa, hydraulic conductance of the bulk soil was the dominant factor in water movement.

  7. Antioxidant and enzymatic responses to oxidative stress induced by pre-harvest water supply reduction and ripening on mango (Mangifera indica L. cv. 'Cogshall') in relation to carotenoid content.

    PubMed

    Rosalie, Rémy; Joas, Jacques; Deytieux-Belleau, Christelle; Vulcain, Emmanuelle; Payet, Bertrand; Dufossé, Laurent; Léchaudel, Mathieu

    2015-07-20

    The effects of a reduction in water supply during fruit development and postharvest fruit ripening on the oxidative status and the antioxidant defense system were studied in the mango fruit (Mangifera indica L.) cv. Cogshall. Changes in non-enzymatic (ascorbate) and enzymatic (SOD, CAT, APX, MDHAR, DHAR and GR) antioxidants, as well as oxidative parameters (H2O2 and MDA) and major carotenoids, were measured in unripe and ripe fruits from well-irrigated and non-irrigated trees. Under non-limiting water supply conditions, ripening induced oxidation as a result of the production of ROS and decreased ascorbate content. Antioxidant enzymatic systems were activated to protect fruit tissues and to regenerate the ascorbate pool. The carotenoid pool, mainly represented by β-carotene and esterified violaxanthine isomers, accumulated naturally during mango ripening. The suppression of irrigation decreased fruit size and induced accumulation of ABA and of its storage form, ABA-GE, in fruit pulp from the earliest harvest. It also increased oxidation, which was observable by the high levels of ascorbate measured at the early stages at harvest, and by the delay in the time it took to reach the pseudo constant carotene-to-xanthophyll ratio in ripe fruits. Nevertheless, differences between the irrigation treatments on the antioxidant system in ripe fruits were not significant, mainly because of the drastic changes in this system during ripening.

  8. Vibrational energy harvesting by exploring structural benefits and nonlinear characteristics

    NASA Astrophysics Data System (ADS)

    Wei, Chongfeng; Jing, Xingjian

    2017-07-01

    Traditional energy harvesters are often of low efficiency due to very limited energy harvesting bandwidth, which should also be enough close to the ambient excitation frequency. To overcome this difficulty, some attempts can be seen in the literature typically with the purposes of either increasing the energy harvesting bandwidth with a harvester array, or enhancing the energy harvesting bandwidth and peak with nonlinear coupling effect etc. This paper presents an alternative way which can achieve tuneable resonant frequency (from high frequency to ultralow frequency) and improved energy harvesting bandwidth and peak simultaneously by employing special structural benefits and advantageous displacement-dependent nonlinear damping property. The proposed energy harvesting system employs a lever systems combined with an X-shape supporting structure and demonstrates very adjustable stiffness and unique nonlinear damping characteristics which are very beneficial for energy harvesting. It is shown that the energy harvesting performance of the proposed system is directly determined by several easy-to-tune structural parameters and also by the relative displacement in a special nonlinear manner, which provides a great flexibility and/or a unique tool for tuning and improving energy harvesting efficiency via matching excitation frequencies and covering a broader frequency band. This study potentially provides a new insight into the design of energy harvesting systems by employing structural benefits and geometrical nonlinearities.

  9. Growth of the Maize Primary Root at Low Water Potentials 1

    PubMed Central

    Sharp, Robert E.; Hsiao, Theodore C.; Silk, Wendy Kuhn

    1990-01-01

    Primary roots of maize (Zea mays L. cv WF9 × Mo17) seedlings growing in vermiculite at various water potentials exhibited substantial osmotic adjustment in the growing region. We have assessed quantitatively whether the osmotic adjustment was attributable to increased net solute deposition rates or to slower rates of water deposition associated with reduced volume expansion. Spatial distributions of total osmotica, soluble carbohydrates, potassium, and water were combined with published growth velocity distributions to calculate deposition rate profiles using the continuity equation. Low water potentials had no effect on the rate of total osmoticum deposition per unit length close to the apex, and caused decreased deposition rates in basal regions. However, rates of water deposition decreased more than osmoticum deposition. Consequently, osmoticum deposition rates per unit water volume were increased near the apex and osmotic potentials were lower throughout the growing region. Because the stressed roots were thinner, osmotic adjustment occurred without osmoticum accumulation per unit length. The effects of low water potential on hexose deposition were similar to those for total osmotica, and hexose made a major contribution to the osmotic adjustment in middle and basal regions. In contrast, potassium deposition decreased at low water potentials in close parallel with water deposition, and increases in potassium concentration were small. The results show that growth of the maize primary root at low water potentials involves a complex pattern of morphogenic and metabolic events. Although osmotic adjustment is largely the result of a greater inhibition of volume expansion and water deposition than solute deposition, the contrasting behavior of hexose and potassium deposition indicates that the adjustment is a highly regulated process. PMID:16667622

  10. Isolating the non-polar contributions to the intermolecular potential for water-alkane interactions

    NASA Astrophysics Data System (ADS)

    Ballal, Deepti; Venkataraman, Pradeep; Fouad, Wael A.; Cox, Kenneth R.; Chapman, Walter G.

    2014-08-01

    Intermolecular potential models for water and alkanes describe pure component properties fairly well, but fail to reproduce properties of water-alkane mixtures. Understanding interactions between water and non-polar molecules like alkanes is important not only for the hydrocarbon industry but has implications to biological processes as well. Although non-polar solutes in water have been widely studied, much less work has focused on water in non-polar solvents. In this study we calculate the solubility of water in different alkanes (methane to dodecane) at ambient conditions where the water content in alkanes is very low so that the non-polar water-alkane interactions determine solubility. Only the alkane-rich phase is simulated since the fugacity of water in the water rich phase is calculated from an accurate equation of state. Using the SPC/E model for water and TraPPE model for alkanes along with Lorentz-Berthelot mixing rules for the cross parameters produces a water solubility that is an order of magnitude lower than the experimental value. It is found that an effective water Lennard-Jones energy ɛW/k = 220 K is required to match the experimental water solubility in TraPPE alkanes. This number is much higher than used in most simulation water models (SPC/E—ɛW/k = 78.2 K). It is surprising that the interaction energy obtained here is also higher than the water-alkane interaction energy predicted by studies on solubility of alkanes in water. The reason for this high water-alkane interaction energy is not completely understood. Some factors that might contribute to the large interaction energy, such as polarizability of alkanes, octupole moment of methane, and clustering of water at low concentrations in alkanes, are examined. It is found that, though important, these factors do not completely explain the anomalously strong attraction between alkanes and water observed experimentally.

  11. Isolating the non-polar contributions to the intermolecular potential for water-alkane interactions.

    PubMed

    Ballal, Deepti; Venkataraman, Pradeep; Fouad, Wael A; Cox, Kenneth R; Chapman, Walter G

    2014-08-14

    Intermolecular potential models for water and alkanes describe pure component properties fairly well, but fail to reproduce properties of water-alkane mixtures. Understanding interactions between water and non-polar molecules like alkanes is important not only for the hydrocarbon industry but has implications to biological processes as well. Although non-polar solutes in water have been widely studied, much less work has focused on water in non-polar solvents. In this study we calculate the solubility of water in different alkanes (methane to dodecane) at ambient conditions where the water content in alkanes is very low so that the non-polar water-alkane interactions determine solubility. Only the alkane-rich phase is simulated since the fugacity of water in the water rich phase is calculated from an accurate equation of state. Using the SPC/E model for water and TraPPE model for alkanes along with Lorentz-Berthelot mixing rules for the cross parameters produces a water solubility that is an order of magnitude lower than the experimental value. It is found that an effective water Lennard-Jones energy ε(W)/k = 220 K is required to match the experimental water solubility in TraPPE alkanes. This number is much higher than used in most simulation water models (SPC/E-ε(W)/k = 78.2 K). It is surprising that the interaction energy obtained here is also higher than the water-alkane interaction energy predicted by studies on solubility of alkanes in water. The reason for this high water-alkane interaction energy is not completely understood. Some factors that might contribute to the large interaction energy, such as polarizability of alkanes, octupole moment of methane, and clustering of water at low concentrations in alkanes, are examined. It is found that, though important, these factors do not completely explain the anomalously strong attraction between alkanes and water observed experimentally.

  12. Simulating sunflower canopy temperatures to infer root-zone soil water potential

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Idso, S. B.

    1983-01-01

    A soil-plant-atmosphere model for sunflower (Helianthus annuus L.), together with clear sky weather data for several days, is used to study the relationship between canopy temperature and root-zone soil water potential. Considering the empirical dependence of stomatal resistance on insolation, air temperature and leaf water potential, a continuity equation for water flux in the soil-plant-atmosphere system is solved for the leaf water potential. The transpirational flux is calculated using Monteith's combination equation, while the canopy temperature is calculated from the energy balance equation. The simulation shows that, at high soil water potentials, canopy temperature is determined primarily by air and dew point temperatures. These results agree with an empirically derived linear regression equation relating canopy-air temperature differential to air vapor pressure deficit. The model predictions of leaf water potential are also in agreement with observations, indicating that measurements of canopy temperature together with a knowledge of air and dew point temperatures can provide a reliable estimate of the root-zone soil water potential.

  13. Water-soluble platinum phthalocyanines as potential antitumor agents.

    PubMed

    Bologna, Giuseppina; Lanuti, Paola; D'Ambrosio, Primiano; Tonucci, Lucia; Pierdomenico, Laura; D'Emilio, Carlo; Celli, Nicola; Marchisio, Marco; d'Alessandro, Nicola; Santavenere, Eugenio; Bressan, Mario; Miscia, Sebastiano

    2014-06-01

    Breast cancer represents the second cause of death in the European female population. The lack of specific therapies together with its high invasive potential are the major problems associated to such a tumor. In the last three decades platinum-based drugs have been considered essential constituents of many therapeutic strategies, even though with side effects and frequent generation of drug resistance. These drugs have been the guide for the research, in last years, of novel platinum and ruthenium based compounds, able to overcome these limitations. In this work, ruthenium and platinum based phthalocyanines were synthesized through conventional techniques and their antiproliferative and/or cytotoxic actions were tested. Normal mammary gland (MCF10A) and several models of mammarian carcinoma at different degrees of invasiveness (BT474, MCF-7 and MDA-MB-231) were used. Cells were treated with different concentrations (5-100 μM) of the above reported compounds, to evaluate toxic concentration and to underline possible dose-response effects. The study included growth curves made by trypan blue exclusion test and scratch assay to study cellular motility and its possible negative modulation by phthalocyanine. Moreover, we investigated cell cycle and apoptosis through flow cytometry and AMNIS Image Stream cytometer. Among all the tested drugs, tetrasulfonated phthalocyanine of platinum resulted to be the molecule with the best cytostatic action on neoplastic cell lines at the concentration of 30 μM. Interestingly, platinum tetrasulfophtalocyanine, at low doses, had no antiproliferative effects on normal cells. Therefore, such platinum complex, appears to be a promising drug for mammarian carcinoma treatment.

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

    NASA Astrophysics Data System (ADS)

    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

  15. Water footprint of European cars: potential impacts of water consumption along automobile life cycles.

    PubMed

    Berger, Markus; Warsen, Jens; Krinke, Stephan; Bach, Vanessa; Finkbeiner, Matthias

    2012-04-03

    Due to global increase of freshwater scarcity, knowledge about water consumption in product life cycles is important. This study analyzes water consumption and the resulting impacts of Volkswagen's car models Polo, Golf, and Passat and represents the first application of impact-oriented water footprint methods on complex industrial products. Freshwater consumption throughout the cars' life cycles is allocated to material groups and assigned to countries according to import mix shares or location of production sites. Based on these regionalized water inventories, consequences for human health, ecosystems, and resources are determined by using recently developed impact assessment methods. Water consumption along the life cycles of the three cars ranges from 52 to 83 m(3)/car, of which more than 95% is consumed in the production phase, mainly resulting from producing iron, steel, precious metals, and polymers. Results show that water consumption takes place in 43 countries worldwide and that only 10% is consumed directly at Volkswagen's production sites. Although impacts on health tend to be dominated by water consumption in South Africa and Mozambique, resulting from the production of precious metals and aluminum, consequences for ecosystems and resources are mainly caused by water consumption of material production in Europe.

  16. [ASSESSMENT OF POTENTIAL RISK FOR CONTAMINATION OF SURFACE WATER RESERVOIRS BY PATHOGENS OF HUMAN PARASITIC DISEASES].

    PubMed

    Khromenkova, E P; Dimidova, L L; Dumbadze, O S; Aidinov, G T; Shendo, G L; Agirov, A Kh; Batchaev, Kh Kh

    2015-01-01

    Sanitary and parasitological studies of the waste effluents and surface reservoir waters were conducted in the south of Russia. The efficiency of purification of waste effluents from the pathogens of parasitic diseases was investigated in the region's sewage-purification facilities. The water of the surface water reservoirs was found to contain helminthic eggs and larvae and intestinal protozoan cysts because of the poor purification and disinfection of service fecal sewage waters. The poor purification and disinvasion of waste effluents in the region determine the potential risk of contamination of the surface water reservoirs and infection of the population with the pathogens of human parasitic diseases.

  17. The potential of solar water disinfection as a household water treatment method in peri-urban Zimbabwe

    NASA Astrophysics Data System (ADS)

    Murinda, Sharon; Kraemer, Silvie

    The potential for reducing diarrhoea morbidity and improving the health status of children in developing countries using solar water disinfection (SODIS) has been demonstrated in past research. A baseline survey was conducted to explore the feasibility and necessity of introducing SODIS in peri-urban communities of Zimbabwe. The survey sought to establish drinking water quality in these areas and to determine the health and hygiene beliefs as well as practices related to water handling in the household. Microbiological water quality tests and personal interviews were carried out in Epworth township and Hopley farm, two peri-urban areas near the capital of Zimbabwe, Harare. These two areas are among the poorest settlements around Harare with 80% of inhabitants being informal settlers. Community meetings were held to introduce solar water disinfection prior to the survey. This was followed by administration of questionnaires, which aimed to investigate whether the community had ever heard about SODIS, whether they were practicing it, other means that were being used to treat drinking water as well as health and hygiene beliefs and practices. It was found out that most households cannot afford basic water treatment like boiling as firewood is expensive. People generally reported that the water was not palatable due to objectionable odour and taste. Microbiological water quality tests proved that drinking water was contaminated in both areas, which makes the water unsafe for drinking and shows the necessity of treatment. Although the majority of people interviewed had not heard of SODIS prior to the interview, attitudes towards its introduction were very positive and the intention to do SODIS in the future was high. Amongst the ones who had heard about SODIS before the study, usage was high. Plastic PET bottles, which were used for the SODIS experiments are currently unavailable and this has been identified as a potential hindrance to the successful implementation of

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

    PubMed

    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.

  19. Piezomagnetoelastic broadband energy harvester: Nonlinear modeling and characterization

    NASA Astrophysics Data System (ADS)

    Aravind Kumar, K.; Ali, S. F.; Arockiarajan, A.

    2015-11-01

    Piezomagnetoelastic energy harvesters are one among the widely explored configurations to improve the broadband characteristics of vibration energy harvesters. Such nonlinear harvesters follow a Moon beam model with two magnets at the base and one at the tip of the beam. The present article develops a geometric nonlinear mathematical model for the broadband piezomagnetoelastic energy harvester. The electromechanical coupling and the nonlinear magnetic potential equations are developed from the dimensional system parameters to describe the nonlinear dynamics exhibited by the system. The developed model is capable of characterizing the monostable, bistable and tristable operating regimes of the piezomagnetoelastic energy harvester, which are not explicit in the Duffing representation of the system. Bifurcations and attractor motions are analyzed as nonlinear functions of the distance between base magnets and the field strength of the tip magnet. The model is further used to characterize the potential wells and stable states, with due focus on the performance of the system in broadband energy harvesting.

  20. Change of water consumption and its potential influential factors in Shanghai: A cross-sectional study

    PubMed Central

    2012-01-01

    Background Different water choices affect access to drinking water with different quality. Previous studies suggested social-economic status may affect the choice of domestic drinking water. The aim of this study is to investigate whether recent social economic changes in China affect residents’ drinking water choices. Methods We conducted a cross-sectional survey to investigate residents’ water consumption behaviour in 2011. Gender, age, education, personal income, housing condition, risk perception and personal preference of a certain type of water were selected as potential influential factors. Univariate and backward stepwise logistic regression analyses were performed to analyse the relation between these factors and different drinking water choices. Basic information was compared with that of a historical survey in the same place in 2001. Self-reported drinking-water-related diarrhoea was found correlated with different water choices and water hygiene treatment using chi-square test. Results The percentage of tap water consumption remained relatively stable and a preferred choice, with 58.99% in 2001 and 58.25% in 2011. The percentage of bottled/barrelled water consumption was 36.86% in 2001 and decreased to 25.75% in 2011. That of household filtrated water was 4.15% in 2001 and increased to 16.00% in 2011. Logistic regression model showed strong correlation between one’s health belief and drinking water choices (P < 0.001). Age, personal income, education, housing condition, risk perception also played important roles (P < 0.05) in the models. Drinking-water-related diarrhoea was found in all types of water and improper water hygiene behaviours still existed among residents. Conclusions Personal health belief, housing condition, age, personal income, education, taste and if worm ever founded in tap water affected domestic drinking water choices in Shanghai. PMID:22708830

  1. EPA Releases Draft Assessment on the Potential Impacts to Drinking Water Resources from Hydraulic Fracturing Activities

    EPA Pesticide Factsheets

    WASHINGTON-The Environmental Protection Agency (EPA) is releasing a draft assessment today on the potential impacts of hydraulic fracturing activities on drinking water resources in the United States. The assessment, done at the request of Congress, shows

  2. WATER QUALITY AND OYSTER HEALTH (CRASSOSTREA VIRGINICA): AN INTEGRATED APPROACH TO DETERMINING HABITAT RESTORATION POTENTIAL

    EPA Science Inventory

    Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2001. Water Quality and Oyster Health (Crassostrea virginica): An Integrated Approach to Determining Habitat Restoration Potential (Abstract). Presented at the 5th International Conference on Shellfish Restoration, 18-21...

  3. High volume hydraulic fracturing operations: potential impacts on surface water and human health.

    PubMed

    Mrdjen, Igor; Lee, Jiyoung

    2016-08-01

    High volume, hydraulic fracturing (HVHF) processes, used to extract natural gas and oil from underground shale deposits, pose many potential hazards to the environment and human health. HVHF can negatively affect the environment by contaminating soil, water, and air matrices with potential pollutants. Due to the relatively novel nature of the process, hazards to surface waters and human health are not well known. The purpose of this article is to link the impacts of HVHF operations on surface water integrity, with human health consequences. Surface water contamination risks include: increased structural failure rates of unconventional wells, issues with wastewater treatment, and accidental discharge of contaminated fluids. Human health risks associated with exposure to surface water contaminated with HVHF chemicals include increased cancer risk and turbidity of water, leading to increased pathogen survival time. Future research should focus on modeling contamination spread throughout the environment, and minimizing occupational exposure to harmful chemicals.

  4. An investigation of the relationship between tree water potential and dielectric constant

    NASA Technical Reports Server (NTRS)

    Mcdonald, Kyle C.; Zimmermann, Reiner; Way, Jobea; Oren, Ram

    1992-01-01

    An experiment that has been performed to verify the relationship between the dielectric constant of several tree species and their respective water potentials is described. The water potential, xylem flow and dielectric properties of five tree species were continuously monitored while simultaneously manipulating canopy transpiration and water status. An analysis of the data recorded during these manipulations is presented. Results of this analysis demonstrate a clear coincidence of change in dielectric constant and water status. The implication of this relationship for the utilization of remotely sensed data to study canopy water relations is explored. Preliminary backscatter modeling results demonstrate that the changes in dielectric constant that occur as a result of changes in water status are significant enough to be observable with microwave radar.

  5. Water and bioterrorism: preparing for the potential threat to U.S. water supplies and public health.

    PubMed

    Meinhardt, Patricia L

    2005-01-01

    Water supplies and water distribution systems represent potential targets for terrorist activity in the United States because of the critical need for water in every sector of our industrialized society. Even short-term disruption of water service can significantly impact a community, and intentional contamination of a municipal water system as part of a terrorist attack could lead to serious medical, public health, and economic consequences. Most practicing physicians and public health professionals in the United States have received limited training in the recognition and evaluation of waterborne disease from either natural or intentional contamination of water. Therefore, they are poorly prepared to detect water-related disease resulting from intentional contamination and may not be adequately trained to respond appropriately to a terrorist assault on water. The purpose of this review is to address this critical information gap and present relevant epidemiologic and clinical information for public health and medical practitioners who may be faced with addressing the recognition, management, and prevention of water terrorism in their communities.

  6. Harvesting Vibrational Energy Using Material Work Functions

    PubMed Central

    Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

    2014-01-01

    Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

  7. 25 CFR 163.26 - Forest product harvesting permits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Forest product harvesting permits. 163.26 Section 163.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.26 Forest product harvesting permits. (a) Except as provided...

  8. 25 CFR 163.26 - Forest product harvesting permits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Forest product harvesting permits. 163.26 Section 163.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.26 Forest product harvesting permits. (a) Except as provided...

  9. 25 CFR 163.26 - Forest product harvesting permits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Forest product harvesting permits. 163.26 Section 163.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.26 Forest product harvesting permits. (a) Except as provided...

  10. 25 CFR 163.26 - Forest product harvesting permits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Forest product harvesting permits. 163.26 Section 163.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.26 Forest product harvesting permits. (a) Except as provided...

  11. 25 CFR 163.26 - Forest product harvesting permits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Forest product harvesting permits. 163.26 Section 163.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.26 Forest product harvesting permits. (a) Except as provided...

  12. Natural organic matter and DBP formation potential in Alaskan water supplies.

    PubMed

    White, Daniel M; Garland, D Sarah; Narr, Jasprit; Woolard, Craig R

    2003-02-01

    Disinfection by-products (DBP) are formed when natural organic matter (NOM) in water reacts with a disinfectant, usually chlorine. DBPs are a health risk element and regulated under the Safe Drinking Water Act. A study was conducted to evaluate the characteristics of NOM that contribute to DBPs in 17 different drinking water systems in Alaska. In order to determine the nature of the organic matter contributing to DBPs, DBP formation potential was compared with standard water quality parameters such as UV-254, color and dissolved organic carbon (DOC), as well as pyrolysis-gas chromatography/mass spectrometry (GC/MS). Results showed strong correlations between UV-254 and DBP formation potential for all waters studied. DOC, on the other hand, was less strongly correlated to DBP formation potential. Unlike previous studies, the total trihalomethane and haloacetic acid formation potentials were equal on a mass concentration basis for the waters studied. Pyrolysis-GC/MS indicated that NOM contributing to DBPs were primarily phenolic compounds. This finding was consistent with previous studies; however, unlike other studies, no correlation was found between aliphatic compounds in the raw waters and DBP formation potential.

  13. Cavitation and water fluxes driven by ice water potential in Juglans regia during freeze-thaw cycles.

    PubMed

    Charra-Vaskou, Katline; Badel, Eric; Charrier, Guillaume; Ponomarenko, Alexandre; Bonhomme, Marc; Foucat, Loïc; Mayr, Stefan; Améglio, Thierry

    2016-02-01

    Freeze-thaw cycles induce major hydraulic changes due to liquid-to-ice transition within tree stems. The very low water potential at the ice-liquid interface is crucial as it may cause lysis of living cells as well as water fluxes and embolism in sap conduits, which impacts whole tree-water relations. We investigated water fluxes induced by ice formation during freeze-thaw cycles in Juglans regia L. stems using four non-invasive and complementary approaches: a microdendrometer, magnetic resonance imaging, X-ray microtomography, and ultrasonic acoustic emissions analysis. When the temperature dropped, ice nucleation occurred, probably in the cambium or pith areas, inducing high water potential gradients within the stem. The water was therefore redistributed within the stem toward the ice front. We could thus observe dehydration of the bark's living cells leading to drastic shrinkage of this tissue, as well as high tension within wood conduits reaching the cavitation threshold in sap vessels. Ultrasonic emissions, which were strictly emitted only during freezing, indicated cavitation events (i.e. bubble formation) following ice formation in the xylem sap. However, embolism formation (i.e. bubble expansion) in stems was observed only on thawing via X-ray microtomography for the first time on the same sample. Ultrasonic emissions were detected during freezing and were not directly related to embolism formation. These results provide new insights into the complex process and dynamics of water movements and ice formation during freeze-thaw cycles in tree stems.

  14. The potential of the fresh-water fern Azolla in aquatic farming systems

    NASA Astrophysics Data System (ADS)

    Bijl, Peter K.; Werf, vd, Adrie; Schluepmann, Henriette; Reichart, Gert-Jan; Brouwer, Paul; Nierop, Klaas G. J.; Hellgardt, Klaus; Brinkhuis, Henk

    2014-05-01

    With aquatic farming systems a new avenue in agriculture is explored, in which the competition with conventional arable land is avoided. The aquatic, ubiquitous, floating fern Azolla is not yet widely explored as potential crop in such farming systems, despite its high potential because it grows in many natural systems under low-light intensities, has an enormous annual yield, and has special biomass qualities for applications in food, feed and specialty chemical industries. But, what makes Azolla particularly interesting as cost-effective crop is its capability to take up atmospheric nitrogen through symbiosis with nitrogen-fixing bacteria Anabaena azollae. This makes Azolla independent of nitrogen fertilization. In order to explore the potential of Azolla as a crop for a suite of applications, we have assembled a team of expertise: AZOFAST, consisting of agricultural engineers, plant physiologists, chemical engineers and organic chemists. Our growth experiments reveal high annual production yields with constant harvest. We are developing a germination and spore collecting/preservation protocol as a first step to domestication. Finally we have explored the biomass quality of different species of extant Azolla. We performed organic chemical analyses on lipid and tannin extracts, and quantified yields of specific compounds within these fractions. In our presentation we will present some of our results to show the potential of Azolla as a new, sustainable aquatic crop serving all kinds of industrial streams from protein feed to platform chemicals.

  15. Technology transfer potential of an automated water monitoring system. [market research

    NASA Technical Reports Server (NTRS)

    Jamieson, W. M.; Hillman, M. E. D.; Eischen, M. A.; Stilwell, J. M.

    1976-01-01

    The nature and characteristics of the potential economic need (markets) for a highly integrated water quality monitoring system were investigated. The technological, institutional and marketing factors that would influence the transfer and adoption of an automated system were studied for application to public and private water supply, public and private wastewater treatment and environmental monitoring of rivers and lakes.

  16. Final Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources

    EPA Science Inventory

    The overall purpose of this study is to elucidate the relationship, if any, between hydraulic fracturing and drinking water resources. More specifically, the study has been designed to assess the potential impacts of hydraulic fracturing on drinking water resources and to identif...

  17. Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources (Monterey, CA)

    EPA Science Inventory

    A summary of EPA's research relating to potential impacts of hydraulic fracturing on drinking water resources will be presented. Background about the study plan development will be presented along with an analysis of the water cycle as it relates to hydraulic fracturing processe...

  18. Potential impacts of global warming on water resources in southern California.

    PubMed

    Beuhler, M

    2003-01-01

    Global warming will have a significant impact on water resources within the 20 to 90-year planning period of many water projects. Arid and semi-arid regions such as Southern California are especially vulnerable to anticipated negative impacts of global warming on water resources. Long-range water facility planning must consider global climate change in the recommended mix of new facilities needed to meet future water requirements. The generally accepted impacts of global warming include temperature, rising sea levels, more frequent and severe floods and droughts, and a shift from snowfall to rain. Precipitation changes are more difficult to predict. For Southern California, these impacts will be especially severe on surface water supplies. Additionally, rising sea levels will exacerbate salt-water intrusion into freshwater and impact the quality of surface water supplies. Integrated water resources planning is emerging as a tool to develop water supplies and demand management strategies that are less vulnerable to the impacts of global warming. These tools include water conservation, conjunctive use of surface and groundwater and desalination of brackish water and possibly seawater. Additionally, planning for future water needs should include explicit consideration of the potential range of global warming impacts through techniques such as scenario planning.

  19. 50 CFR 640.21 - Harvest limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF COMMERCE SPINY LOBSTER FISHERY OF THE GULF OF MEXICO AND SOUTH ATLANTIC Management Measures § 640.21 Harvest limitations. (a) Berried lobsters. A berried (egg-bearing) spiny lobster or slipper lobster in or from the EEZ must be returned immediately to the water unharmed. If found in a trap in...

  20. 50 CFR 640.21 - Harvest limitations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE SPINY LOBSTER FISHERY OF THE GULF OF MEXICO AND SOUTH ATLANTIC Management Measures § 640.21 Harvest limitations. (a) Berried lobsters. A berried (egg-bearing) spiny lobster or slipper lobster in or from the EEZ must be returned immediately to the water unharmed. If found in a...

  1. Experimentally probing the libration of interfacial water: the rotational potential of water is stiffer at the air/water interface than in bulk liquid.

    PubMed

    Tong, Yujin; Kampfrath, Tobias; Campen, R Kramer

    2016-07-21

    Most properties of liquid water are determined by its hydrogen-bond network. Because forming an aqueous interface requires termination of this network, one might expect the molecular level properties of interfacial water to markedly differ from water in bulk. Intriguingly, much prior experimental and theoretical work has found that, from the perspective of their time-averaged structure and picosecond structural dynamics, hydrogen-bonded OH groups at an air/water interface behave the same as hydrogen-bonded OH groups in bulk liquid water. Here we report the first experimental observation of interfacial water's libration (i.e. frustrated rotation) using the laser-based technique vibrational sum frequency spectroscopy. We find this mode has a frequency of 834 cm(-1), ≈165 cm(-1) higher than in bulk liquid water at the same temperature and similar to bulk ice. Because libration frequency is proportional to the stiffness of water's rotational potential, this increase suggests that one effect of terminating bulk water's hydrogen bonding network at the air/water interface is retarding rotation of water around intact hydrogen bonds. Because in bulk liquid water the libration plays a key role in stabilizing reaction intermediates and dissipating excess vibrational energy, we expect the ability to probe this mode in interfacial water to open new perspectives on the kinetics of heterogeneous reactions at aqueous interfaces.

  2. Differing Sensitivity of Photosynthesis to Low Leaf Water Potentials in Corn and Soybean 1

    PubMed Central

    Boyer, J. S.

    1970-01-01

    Rates of net photosynthesis were studied in soil-grown corn (Zea mays) and soybean (Glycine max) plants having various leaf water potentials. Soybean was unaffected by desiccation until leaf water potentials were below −11 bars. Rates of photosynthesis in corn were inhibited whenever leaf water potentials dropped below −3.5 bars. The differences in photosynthetic behavior could be attributed solely to differences in stomatal behavior down to leaf water potentials of −16 bars in soybean and −10 bars in corn. Below these potentials, other factors in addition to stomatal closure caused inhibition, although their effect was relatively small. Corn, which has the C4-dicarboxylic acid pathway for carbon fixation, generally had a higher rate of photosynthesis than soybean during desiccation. Nevertheless, since inhibition of photosynthesis began at higher potentials than in soybean, and since corn was less able to withstand severe desiccation without tissue death, it was concluded that the C4 pathway confers no particular ability to withstand low leaf water potentials. PMID:16657442

  3. Molecular simulation of aqueous electrolytes: water chemical potential results and Gibbs-Duhem equation consistency tests.

    PubMed

    Moučka, Filip; Nezbeda, Ivo; Smith, William R

    2013-09-28

    This paper deals with molecular simulation of the chemical potentials in aqueous electrolyte solutions for the water solvent and its relationship to chemical potential simulation results for the electrolyte solute. We use the Gibbs-Duhem equation linking the concentration dependence of these quantities to test the thermodynamic consistency of separate calculations of each quantity. We consider aqueous NaCl solutions at ambient conditions, using the standard SPC/E force field for water and the Joung-Cheatham force field for the electrolyte. We calculate the water chemical potential using the osmotic ensemble Monte Carlo algorithm by varying the number of water molecules at a constant amount of solute. We demonstrate numerical consistency of these results in terms of the Gibbs-Duhem equation in conjunction with our previous calculations of the electrolyte chemical potential. We present the chemical potential vs molality curves for both solvent and solute in the form of appropriately chosen analytical equations fitted to the simulation data. As a byproduct, in the context of the force fields considered, we also obtain values for the Henry convention standard molar chemical potential for aqueous NaCl using molality as the concentration variable and for the chemical potential of pure SPC/E water. These values are in reasonable agreement with the experimental values.

  4. Energy harvesting using ionic electro-active polymer thin films with Ag-based electrodes

    NASA Astrophysics Data System (ADS)

    Anand, S. V.; Arvind, K.; Bharath, P.; Mahapatra, D. Roy

    2010-04-01

    In this paper we employ the phenomenon of bending deformation induced transport of cations via the polymer chains in the thickness direction of an electro-active polymer (EAP)-metal composite thin film for mechanical energy harvesting. While EAPs have been applied in the past in actuators and artificial muscles, promising applications of such materials in hydrodynamic and vibratory energy harvesting are reported in this paper. For this, functionalization of EAPs with metal electrodes is the key factor in improving the energy harvesting efficiency. Unlike Pt-based electrodes, Ag-based electrodes have been deposited on an EAP membrane made of Nafion. The developed ionic metal polymer composite (IPMC) membrane is subjected to a dynamic bending load, hydrodynamically, and evaluated for the voltage generated against an external electrical load. An increase of a few orders of magnitude has been observed in the harvested energy density and power density in air, deionized water and in electrolyte solutions with varying concentrations of sodium chloride (NaCl) as compared to Pt-based IPMC performances reported in the published literature. This will have potential applications in hydrodynamic and residual environmental energy harvesting to power sensors and actuators based on micro-and nano-electro-mechanical systems (MEMS and NEMS) for biomedical, aerospace and oceanic applications.

  5. Sizing a rainwater harvesting cistern by minimizing costs

    NASA Astrophysics Data System (ADS)

    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.

  6. Evidence from Amazonian forests is consistent with isohydric control of leaf water potential.

    PubMed

    Fisher, Rosie A; Williams, Mathew; Do Vale, Raquel Lobo; Da Costa, Antonio Lola; Meir, Patrick

    2006-02-01

    Climate modelling studies predict that the rain forests of the Eastern Amazon basin are likely to experience reductions in rainfall of up to 50% over the next 50-100 years. Efforts to predict the effects of changing climate, especially drought stress, on forest gas exchange are currently limited by uncertainty about the mechanism that controls stomatal closure in response to low soil moisture. At a through-fall exclusion experiment in Eastern Amazonia where water was experimentally excluded from the soil, we tested the hypothesis that plants are isohydric, that is, when water is scarce, the stomata act to prevent leaf water potential from dropping below a critical threshold level. We made diurnal measurements of leaf water potential (psi 1), stomatal conductance (g(s)), sap flow and stem water potential (psi stem) in the wet and dry seasons. We compared the data with the predictions of the soil-plant-atmosphere (SPA) model, which embeds the isohydric hypothesis within its stomatal conductance algorithm. The model inputs for meteorology, leaf area index (LAI), soil water potential and soil-to-leaf hydraulic resistance (R) were altered between seasons in accordance with measured values. No optimization parameters were used to adjust the model. This 'mechanistic' model of stomatal function was able to explain the individual tree-level seasonal changes in water relations (r2 = 0.85, 0.90 and 0.58 for psi 1, sap flow and g(s), respectively). The model indicated that the measured increase in R was the dominant cause of restricted water use during the dry season, resulting in a modelled restriction of sap flow four times greater than that caused by reduced soil water potential. Higher resistance during the dry season resulted from an increase in below-ground resistance (including root and soil-to-root resistance) to water flow.

  7. An autoparametric energy harvester

    NASA Astrophysics Data System (ADS)

    Kecik, K.; Borowiec, M.

    2013-09-01

    This paper presents a numerical study of an autoparametric system composed of two elements: a pendulum and an excited nonlinear oscillator. Owing to an inertial coupling between the two elements, different types of motion are possible, from periodic to chaotic. This study examines a linear induction of an energy harvester depending on the pendulum motion. The harvester consists of a cylindrical permanent magnet mounted on a rotor and of four windings fixed to the housing as a stator. When the pendulum is rotating or swinging, the converter is generating energy due to magnetic induction. In this paper, a method utilizing parametrical resonance for harvesting energy from low frequency vibrations is studied. The authors compare energy induced by different types of pendulum motion: swinging, rotation and chaotic dynamics. Additionally, voltage values for different parameters of excitation are estimated.

  8. Characterizing the effective bandwidth of tri-stable energy harvesters

    NASA Astrophysics Data System (ADS)

    Panyam, Meghashyam; Daqaq, Mohammed F.

    2017-01-01

    Recently, it has been shown that nonlinear vibratory energy harvesters possessing a tri-stable potential function are capable of harvesting energy efficiently over a wider range of frequencies in comparison to harvesters with a double-well potential function. However, the effect of the design parameters of the harvester on the dynamic response and the effective bandwidth of such devices remains uninvestigated. To fill this void, this paper establishes an analytical approach to characterize the effective frequency bandwidth of harvesters that possess a hexic potential energy function. To achieve this goal, the method of multiple scales is utilized to construct analytical solutions describing the amplitude and stability of the intra- and inter-well dynamics of the harvester. Using these solutions, critical bifurcations in the parameter's space are identified and used to define an effective frequency bandwidth of the harvester. The influence of the electric parameters, namely, the time constant ratio (ratio between the period of the mechanical system and the time constant of the harvesting circuit) and the electromechanical coupling, on the effective frequency bandwidth is analyzed. Experimental studies performed on the harvester are presented to validate some of the theoretical findings.

  9. Potential of Nanotechnology based water treatment solutions for the improvement of drinking water supplies in developing countries

    NASA Astrophysics Data System (ADS)

    Dutta, Joydeep; Bhattacharya, Prosun; Bundschuh, Jochen

    2016-04-01

    Over the last decades explosive population growth in the world has led to water scarcity across the globe putting additional pressure already scarce ground water resources and is pushing scientists and researchers to come up with new alternatives to monitor and treat water for use by mankind and for food security. Nearly 4 billion people around the world are known to lack access to clean water supply. Systematic water quality data is important for the assessment of health risks as well as for developing appropriate and affordable technologies for waste and drinking water treatments, and long-term decision making policy against water quality management. Traditional water treatment technologies are generally chemical-intensive processes requiring extremely large infrastructural support thus limiting their effective applications in developing nations which creates an artificial barrier to the application of technological solutions for the provision of clean water. Nanotechnology-based systems are in retrospect, smaller, energy and resource efficient. Economic impact assessment of the implementation of nanotechnology in water treatment and studies on cost-effectiveness and environmental and social impacts is of key importance prior to its wide spread acceptance. Government agencies and inter-governmental bodies driving research and development activities need to measure the effective potential of nanotechnology as a solution to global water challenges in order to effectively engage in fiscal, economic and social issues at national and international levels for different types of source waters with new national and international initiatives on nanotechnology and water need to be launched. Environmental pollution and industrialization in global scale is further leading to pollution of available water sources and thus hygienically friendly purification technologies are the need of the hour. Thus cost-effective treatment of pollutants for the transformation of hazardous

  10. Investigating the Potential of Single-Walled Aluminosilicate Nanotubes in Water Desalination.

    PubMed

    Liou, Kai-Hsin; Kang, Dun-Yen; Lin, Li-Chiang

    2017-01-18

    Water shortage has become a critical issue. To facilitate the large-scale deployment of reverse-osmosis water desalination to produce fresh water, discovering novel membranes is essential. Here, we computationally demonstrate the great potential of single-walled aluminosilicate nanotubes (AlSiNTs), materials that can be synthesized through scalable methods, in desalination. State-of-the-art molecular dynamics simulations were employed to investigate the desalination performance and structure-performance relationship of AlSiNTs. Free energy profiles, passage time distribution, and water density map were also analyzed to further understand the dependence of transport properties on diameter and water dynamics in the nanotubes. AlSiNTs with an inner diameter of 0.86 nm were found to fully reject NaCl ions while allowing orders of magnitude higher water fluxes compared to currently available reverse osmosis membranes, providing opportunities in water desalination.

  11. Zeta potential in oil-water-carbonate systems and its impact on oil recovery during controlled salinity water-flooding

    NASA Astrophysics Data System (ADS)

    Jackson, Matthew D.; Al-Mahrouqi, Dawoud; Vinogradov, Jan

    2016-11-01

    Laboratory experiments and field trials have shown that oil recovery from carbonate reservoirs can be increased by modifying the brine composition injected during recovery in a process termed controlled salinity water-flooding (CSW). However, CSW remains poorly understood and there is no method to predict the optimum CSW composition. This work demonstrates for the first time that improved oil recovery (IOR) during CSW is strongly correlated to changes in zeta potential at both the mineral-water and oil-water interfaces. We report experiments in which IOR during CSW occurs only when the change in brine composition induces a repulsive electrostatic force between the oil-brine and mineral-brine interfaces. The polarity of the zeta potential at both interfaces must be determined when designing the optimum CSW composition. A new experimental method is presented that allows this. Results also show for the first time that the zeta potential at the oil-water interface may be positive at conditions relevant to carbonate reservoirs. A key challenge for any model of CSW is to explain why IOR is not always observed. Here we suggest that failures using the conventional (dilution) approach to CSW may have been caused by a positively charged oil-water interface that had not been identified.

  12. Zeta potential in oil-water-carbonate systems and its impact on oil recovery during controlled salinity water-flooding.

    PubMed

    Jackson, Matthew D; Al-Mahrouqi, Dawoud; Vinogradov, Jan

    2016-11-23

    Laboratory experiments and field trials have shown that oil recovery from carbonate reservoirs can be increased by modifying the brine composition injected during recovery in a process termed controlled salinity water-flooding (CSW). However, CSW remains poorly understood and there is no method to predict the optimum CSW composition. This work demonstrates for the first time that improved oil recovery (IOR) during CSW is strongly correlated to changes in zeta potential at both the mineral-water and oil-water interfaces. We report experiments in which IOR during CSW occurs only when the change in brine composition induces a repulsive electrostatic force between the oil-brine and mineral-brine interfaces. The polarity of the zeta potential at both interfaces must be determined when designing the optimum CSW composition. A new experimental method is presented that allows this. Results also show for the first time that the zeta potential at the oil-water interface may be positive at conditions relevant to carbonate reservoirs. A key challenge for any model of CSW is to explain why IOR is not always observed. Here we suggest that failures using the conventional (dilution) approach to CSW may have been caused by a positively charged oil-water interface that had not been identified.

  13. Zeta potential in oil-water-carbonate systems and its impact on oil recovery during controlled salinity water-flooding

    PubMed Central

    Jackson, Matthew D.; Al-Mahrouqi, Dawoud; Vinogradov, Jan

    2016-01-01

    Laboratory experiments and field trials have shown that oil recovery from carbonate reservoirs can be increased by modifying the brine composition injected during recovery in a process termed controlled salinity water-flooding (CSW). However, CSW remains poorly understood and there is no method to predict the optimum CSW composition. This work demonstrates for the first time that improved oil recovery (IOR) during CSW is strongly correlated to changes in zeta potential at both the mineral-water and oil-water interfaces. We report experiments in which IOR during CSW occurs only when the change in brine composition induces a repulsive electrostatic force between the oil-brine and mineral-brine interfaces. The polarity of the zeta potential at both interfaces must be determined when designing the optimum CSW composition. A new experimental method is presented that allows this. Results also show for the first time that the zeta potential at the oil-water interface may be positive at conditions relevant to carbonate reservoirs. A key challenge for any model of CSW is to explain why IOR is not always observed. Here we suggest that failures using the conventional (dilution) approach to CSW may have been caused by a positively charged oil-water interface that had not been identified. PMID:27876833

  14. KINETIC CONTROL OF OXIDATION STATE AT THERMODYNAMICALLY BUFFERED POTENTIALS IN SUBSURFACE WATERS

    EPA Science Inventory

    Dissolved oxygen (DO) and organic carbon (Corg) are among the highest- and lowest-potential reactants, respectively, of redox couples in natural waters. When DO and Corg are present in subsurface settings, other couples are drawn toward potentials imposed by them, generating a b...

  15. Piezoelectric monolayers as nonlinear energy harvesters.

    PubMed

    López-Suárez, Miquel; Pruneda, Miguel; Abadal, Gabriel; Rurali, Riccardo

    2014-05-02

    We study the dynamics of h-BN monolayers by first performing ab-initio calculations of the deformation potential energy and then solving numerically a Langevine-type equation to explore their use in nonlinear vibration energy harvesting devices. An applied compressive strain is used to drive the system into a nonlinear bistable regime, where quasi-harmonic vibrations are combined with low-frequency swings between the minima of a double-well potential. Due to its intrinsic piezoelectric response, the nonlinear mechanical harvester naturally provides an electrical power that is readily available or can be stored by simply contacting the monolayer at its ends. Engineering the induced nonlinearity, a 20 nm2 device is predicted to harvest an electrical power of up to 0.18 pW for a noisy vibration of 5 pN.

  16. A Five-Year Assessment of Corn Stover Harvest in Central Iowa, USA

    SciTech Connect

    Douglas L. Karlen; Stuart J. Birell; J. Richard Hess

    2011-11-01

    , presumably because soil-test P was again in the low range. A soil quality analysis using the Soil Management Assessment Framework (SMAF) with six indicators showed that soils at the continuous corn and rotated sites were functioning at an average of 93 and 83% of their inherent potential, respectively. With good crop management practices, including routine soil-testing, adequate fertilization, maintenance of soil organic matter, sustained soil structure, and prevention of wind, water or tillage erosion, a portion of the corn stover being produced in central Iowa, USA can be harvested in a sustainable manner.

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

    PubMed

    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 (P<0.05). At one case study site, results suggested that piping and tap material can contribute to contaminant loads of harvested rainwater. 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 (P<0.05). Similarly, zinc, lead, arsenic, strontium and molybdenum were significantly elevated in samples collected from a polyvinyl chloride pipe sampling point that does not supply household uses, compared with corresponding roof runoff samples (P<0.05). Elemental composition was also found to vary significantly between the tank tap and an internal cold tap at one of the sites investigated, with several elements fluctuating significantly between the two outlets of interest at this site, including potassium, zinc, manganese, barium, copper, vanadium, chromium and arsenic. These results highlighted the variability in the elemental composition of collected 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.

  18. Review of the application of energy harvesting in buildings

    NASA Astrophysics Data System (ADS)

    Matiko, J. W.; Grabham, N. J.; Beeby, S. P.; Tudor, M. J.

    2014-01-01

    This review presents the state of the art of the application of energy harvesting in commercial and residential buildings. Electromagnetic (optical and radio frequency), kinetic, thermal and airflow-based energy sources are identified as potential energy sources within buildings and the available energy is measured in a range of buildings. Suitable energy harvesters are discussed and the available and the potential harvested energy calculated. Calculations based on these measurements, and the technical specifications of state-of-the-art harvesters, show that typical harvested powers are: (1) indoor solar cell (active area of 9 cm2, volume of 2.88 cm3): ˜300 µW from a light intensity of 1000 lx; (2) thermoelectric harvester (volume of 1.4 cm3): 6 mW from a thermal gradient of 25 °C (3) periodic kinetic energy harvester (volume of 0.15 cm3): 2 µW from a vibration acceleration of 0.25 m s-2 at 45 Hz (4) electromagnetic wave harvester (13 cm antenna length and conversion efficiency of 0.7): 1 µW with an RF source power of -25 dBm; and (5) airflow harvester (wind turbine blade of 6 cm diameter and generator efficiency of 0.41): 140 mW from an airflow of 8 m s-1. These results highlight the high potential of energy harvesting technology in buildings and the relative attractions of various harvester technologies. The harvested power could either be used to replace batteries or to prolong the life of rechargeable batteries for low-power (˜1 mW) electronic devices.

  19. Common mycorrhizal networks provide a potential pathway for the transfer of hydraulically lifted water between plants.

    PubMed

    Egerton-Warburton, Louise M; Querejeta, José Ignacio; Allen, Michael F

    2007-01-01

    Plant roots may be linked by shared or common mycorrhizal networks (CMNs) that constitute pathways for the transfer of resources among plants. The potential for water transfer by such networks was examined by manipulating CMNs independently of plant roots in order to isolate the role(s) of ectomycorrhizal (EM) and arbuscular mycorrhizal fungal (AMF) networks in the plant water balance during drought (soil water potential -5.9 MPa). Fluorescent tracer dyes and deuterium-enriched water were used to follow the pathways of water transfer from coastal live oak seedlings (Quercus agrifolia Nee; colonized by EM and AMF) conducting hydraulic lift (HL) into the roots of water-stressed seedlings connected only by EM (Q. agrifolia) or AMF networks (Q. agrifolia, Eriogonum fasciculatum Benth., Salvia mellifera Greene, Keckiella antirrhinoides Benth). When connected to donor plants by hyphal linkages, deuterium was detected in the transpiration flux of receiver oak plants, and dye-labelled extraradical hyphae, rhizomorphs, mantles, and Hartig nets were observed in receiver EM oak roots, and in AMF hyphae of Salvia. Hyphal labelling was scarce in Eriogonum and Keckiella since these species are less dependent on AMF. The observed patterns of dye distribution also indicated that only a small percentage of mycorrhizal roots and extraradical hyphae were involved with water transfer among plants. Our results suggest that the movement of water by CMNs is potentially important to plant survival during drought, and that the functional ecophysiological traits of individual mycorrhizal fungi may be a component of this mechanism.

  20. Acclimation of photosynthesis in Zea mays to low water potentials involves alterations in protoplast volume reduction.

    PubMed

    Berkowitz, G A; Kroll, K S

    1988-09-01

    Effects of water-stress treatment of Zea mays L. plants on protoplast volume and photosynthesis in leaf slices exposed to solutions of different osmotic potential (Ψ s) were studied. Decreased photosynthetic capacity in the leaf slices at low tissue Ψ w was associated with dehydration-induced protoplast-volume reduction. Leaf slices from plants exposed to in-situ water deficits exhibited greater photosynthetic capacity and relative protoplast volume at low water potential (Ψ w) invitro than tissue from control plants.In-situ water stress induced osmotic adjustment of the leaf tissue as determined by pressure/volume analysis. It is concluded that plant acclimation to low leaf Ψ w may involve a reduced degree of cell shrinkage at a given Ψ w. This acclimation would allow for the maintenance of relatively higher photosynthetic capacity at low water protentials.

  1. Kenaf harvest decision matrix or how should I harvest kenaf?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The correct harvest method for kenaf (Hibiscus cannabinus L., Malvaceae) is dependent on many factors, including production location, equipment availability, storage options, processing plans, plant utilization, and economics. Since its first domestication, kenaf has consistently been hand-harveste...

  2. Prediction of water content at different potentials from soil property data in Jazan region

    NASA Astrophysics Data System (ADS)

    Alturki, Ali; Ibrahim, Hesham

    2016-04-01

    In dry regions effective irrigation management is crucial to maintain crop production and sustain limited water resources. Effective irrigation requires good knowledge of soil water content in the root zone. However, measurement of soil water in the root zone over time is extremely expensive and time consuming. On the other hand, weather and basic soil property data are more available, either from existing databases or by direct measurement in the field. Simulation models can be used to efficiently and accurately estimate soil water content and subsequent irrigation requirements based on the available weather and soil data. In this study we investigated three hierarchical approaches to predict water content at variable potentials (0, 10, 33, 60, 100, 300, 500, 800, 1000, and 1500 kPa) using the Rosetta model: soil texture class (STC); percent of sand, silt, and clay (SSC); bulk density, percent of sand, silt, and clay, and water content measurements at 33 and 1500 kPa (SSC+WC). Estimation of soil water content at 43 locations in Jazan region using the three hierarchical approaches was compared with gravimetric water content. Results showed that the three approaches failed to describe water content accurately at saturation conditions (<10kPa). At water potentials lower than 10 kPa, good agreement was obtained, in general, between measured and simulated soil water content indicating that soil property data can be used to provide adequate estimates of the average soil water content in the root zone. The third approach gave the best results as indicated by an average NSCE value of 0.75 as compared to 0.16 and 0.18 for the first and second approaches, respectively. The ability to predict the amount of available water in the soil profile will facilitate the accurate estimate of irrigation requirements and achieve effective irrigation scheduling especially in locations where only limited weather and soil date are available.

  3. Comparison of Water Potentials Measured by In Situ Psychrometry and Pressure Chamber in Morphologically Different Species 1

    PubMed Central

    Turner, Neil C.; Spurway, R. A.; Schulze, E.-D.

    1984-01-01

    Leaf water potentials measured by in situ psychrometry were compared with leaf water potentials measured by the pressure chamber technique at various values of water potential in Helianthus annuus, Helianthus nuttallii, Vigna unguiculata, Nerium oleander, Pistacia vera, and Corylus avellana. In V. unguiculata, the leaf water potentials measured by the in situ psychrometer oscillated at the same periodicity as, and proportional to, the leaf conductance. In all species, potentials measured by in situ psychrometers operating in the psychrometric mode were linearly correlated with potentials measured with the pressure chamber. However, the in situ psychrometers underestimated the leaf water potential in the two Helianthus species at low water potentials and overestimated the water potential in P. vera, N. oleander, and C. avellana. The underestimation in the two Helianthus species at low water potentials resulted from differences in water potential across the leaf. The overestimation in P. vera, N. oleander, and C. avellana was considered to arise from low epidermal conductances in these species even after abrasion of the cuticle. Pressure-volume studies with Lycopersicon esculentum showed that less water was expressed from distal than proximal leaflets when the whole leaf was slowly pressurized. The implication of this for water relations characteristics obtained by pressure-volume techniques is discussed. We conclude that in situ psychrometers are suitable for following dynamic changes in leaf water potential, but should be used with caution on leaves with low epidermal conductances. PMID:16663415

  4. Evaluating energy sorghum harvest thresholds and tillage cropping systems to offset negative environmental impacts and harvesting equipment-induced soil compaction

    NASA Astrophysics Data System (ADS)

    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

  5. Hydraulic fracturing water use variability in the United States and potential environmental implications

    NASA Astrophysics Data System (ADS)

    Gallegos, Tanya J.; Varela, Brian A.; Haines, Seth S.; Engle, Mark A.

    2015-07-01

    Until now, up-to-date, comprehensive, spatial, national-scale data on hydraulic fracturing water volumes have been lacking. Water volumes used (injected) to hydraulically fracture over 263,859 oil and gas wells drilled between 2000 and 2014 were compiled and used to create the first U.S. map of hydraulic fracturing water use. Although median annual volumes of 15,275 m3 and 19,425 m3 of water per well was used to hydraulically fracture individual horizontal oil and gas wells, respectively, in 2014, about 42% of wells were actually either vertical or directional, which required less than 2600 m3 water per well. The highest average hydraulic fracturing water usage (10,000-36,620 m3 per well) in watersheds across the United States generally correlated with shale-gas areas (versus coalbed methane, tight oil, or tight gas) where the greatest proportion of hydraulically fractured wells were horizontally drilled, reflecting that the natural reservoir properties influence water use. This analysis also demonstrates that many oil and gas resources within a given basin are developed using a mix of horizontal, vertical, and some directional wells, explaining why large volume hydraulic fracturing water usage is not widespread. This spatial variability in hydraulic fracturing water use relates to the potential for environmental impacts such as water availability, water quality, wastewater disposal, and possible wastewater injection-induced earthquakes.

  6. Hydraulic fracturing water use variability in the United States and potential environmental implications

    USGS Publications Warehouse

    Gallegos, Tanya J.; Varela, Brian A.; Haines, Seth S.; Engle, Mark A.

    2015-01-01

    Until now, up-to-date, comprehensive, spatial, national-scale data on hydraulic fracturing water volumes have been lacking. Water volumes used (injected) to hydraulically fracture over 263,859 oil and gas wells drilled between 2000 and 2014 were compiled and used to create the first U.S. map of hydraulic fracturing water use. Although median annual volumes of 15,275 m3 and 19,425 m3 of water per well was used to hydraulically fracture individual horizontal oil and gas wells, respectively, in 2014, about 42% of wells were actually either vertical or directional, which required less than 2600 m3 water per well. The highest average hydraulic fracturing water usage (10,000−36,620 m3 per well) in watersheds across the United States generally correlated with shale-gas areas (versus coalbed methane, tight oil, or tight gas) where the greatest proportion of hydraulically fractured wells were horizontally drilled, reflecting that the natural reservoir properties influence water use. This analysis also demonstrates that many oil and gas resources within a given basin are developed using a mix of horizontal, vertical, and some directional wells, explaining why large volume hydraulic fracturing water usage is not widespread. This spatial variability in hydraulic fracturing water use relates to the potential for environmental impacts such as water availability, water quality, wastewater disposal, and possible wastewater injection-induced earthquakes.

  7. Hydraulic fracturing water use variability in the United States and potential environmental implications

    PubMed Central

    Varela, Brian A.; Haines, Seth S.; Engle, Mark A.

    2015-01-01

    Abstract Until now, up‐to‐date, comprehensive, spatial, national‐scale data on hydraulic fracturing water volumes have been lacking. Water volumes used (injected) to hydraulically fracture over 263,859 oil and gas wells drilled between 2000 and 2014 were compiled and used to create the first U.S. map of hydraulic fracturing water use. Although median annual volumes of 15,275 m3 and 19,425 m3 of water per well was used to hydraulically fracture individual horizontal oil and gas wells, respectively, in 2014, about 42% of wells were actually either vertical or directional, which required less than 2600 m3 water per well. The highest average hydraulic fracturing water usage (10,000−36,620 m3 per well) in watersheds across the United States generally correlated with shale‐gas areas (versus coalbed methane, tight oil, or tight gas) where the greatest proportion of hydraulically fractured wells were horizontally drilled, reflecting that the natural reservoir properties influence water use. This analysis also demonstrates that many oil and gas resources within a given basin are developed using a mix of horizontal, vertical, and some directional wells, explaining why large volume hydraulic fracturing water usage is not widespread. This spatial variability in hydraulic fracturing water use relates to the potential for environmental impacts such as water availability, water quality, wastewater disposal, and possible wastewater injection‐induced earthquakes. PMID:26937056

  8. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    PubMed Central

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-01-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing. PMID:27063149

  9. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces.

    PubMed

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-04-11

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions-dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  10. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    NASA Astrophysics Data System (ADS)

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-04-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  11. Pepper harvest technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peppers (Capsicum spp.) include a diverse collection of cultivars produced for a wide variety of end uses. This specialty crop and its processing industry are in the midst of a dual transition driven by labor cost and unavailability. Production and post-harvest processing is either converting to m...

  12. PEPPER HARVESTER DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peppers (Capsicum spp.) include a diverse collection of cultivars produced for a wide variety of end uses. This specialty crop and its processing industry are in the midst of a transition driven by labor cost and unavailability. Production and post-harvest processing is either converting to mechan...

  13. Comprehensive Screening of Cell Surface Markers Expressed by Adult-Derived Human Liver Stem/Progenitor Cells Harvested at Passage 5: Potential Implications for Engraftment

    PubMed Central

    Sokal, Etienne

    2016-01-01

    Mesenchymal stromal cells (MSCs) are known to have potential therapeutic benefits for a number of diseases. However, many studies report low engraftment levels, regardless of the target organ. One possible explanation could be that MSCs do not express the necessary receptors for engraftment. Indeed, MSCs appear to use a similar mechanism to leukocytes to engraft into injured organs, relying on various receptors for rolling, firm adhesion, and transmigration. In this study, we conducted an extensive surface molecule screening of adult-derived human liver stem/progenitor cells (ADHLSC) in an attempt to shed some light on this subject. We observed that ADHLSCs lack expression of most of the costimulatory molecules tested. Furthermore, study of the adhesion molecule profile of ADHLSCs revealed that they do not express selectin ligands or LFA-1 which are, respectively, involved in the rolling process and the firm adhesion. In addition, ADHLSCs slightly express VLA-4 and lose expression of CXCR4 altogether on their surface during culture expansion. However, ADHLSCs express all the integrin couples and matrix metalloproteinases needed to bind and integrate the extracellular matrix once the endothelial barrier is crossed. Collectively, these results suggest that binding to the endothelium may be the critical weak point in the engraftment process. PMID:27956903

  14. Piezoelectric energy harvesting: State-of-the-art and challenges

    NASA Astrophysics Data System (ADS)

    Toprak, Alperen; Tigli, Onur

    2014-09-01

    Piezoelectric energy harvesting has attracted wide attention from researchers especially in the last decade due to its advantages such as high power density, architectural simplicity, and scalability. As a result, the number of studies on piezoelectric energy harvesting published in the last 5 years is more than twice the sum of publications on its electromagnetic and electrostatic counterparts. This paper presents a comprehensive review on the history and current state-of-the art of piezoelectric energy harvesting. A brief theory section presents the basic principles of piezoelectric energy conversion and introduces the most commonly used mechanical architectures. The theory section is followed by a literature survey on piezoelectric energy harvesters, which are classified into three groups: (i) macro- and mesoscale, (ii) MEMS scale, and (iii) nanoscale. The size of a piezoelectric energy harvester affects a variety of parameters such as its weight, fabrication method, achievable power output level, and potential application areas. Consequently, size-based classification provides a reliable and effective basis to study various piezoelectric energy harvesters. The literature survey on each scale group is concluded with a summary, potential application areas, and future directions. In a separate section, the most prominent challenges in piezoelectric energy harvesting and the studies focusing on these challenges are discussed. The conclusion part summarizes the current standing of piezoelectric energy harvesters as possible candidates for various applications and discusses the issues that need to be addressed for realization of practical piezoelectric energy harvesting devices.

  15. Theoretical and Experimental Errors for In Situ Measurements of Plant Water Potential 1

    PubMed Central

    Shackel, Kenneth A.

    1984-01-01

    Errors in psychrometrically determined values of leaf water potential caused by tissue resistance to water vapor exchange and by lack of thermal equilibrium were evaluated using commercial in situ psychrometers (Wescor Inc., Logan, UT) on leaves of Tradescantia virginiana (L.). Theoretical errors in the dewpoint method of operation for these sensors were demonstrated. After correction for these errors, in situ measurements of leaf water potential indicated substantial errors caused by tissue resistance to water vapor exchange (4 to 6% reduction in apparent water potential per second of cooling time used) resulting from humidity depletions in the psychrometer chamber during the Peltier condensation process. These errors were avoided by use of a modified procedure for dewpoint measurement. Large changes in apparent water potential were caused by leaf and psychrometer exposure to moderate levels of irradiance. These changes were correlated with relatively small shifts in psychrometer zero offsets (−0.6 to −1.0 megapascals per microvolt), indicating substantial errors caused by nonisothermal conditions between the leaf and the psychrometer. Explicit correction for these errors is not possible with the current psychrometer design. PMID:16663701

  16. Potential impacts of climate change on water quality in a shallow reservoir in China.

    PubMed

    Zhang, Chen; Lai, Shiyu; Gao, Xueping; Xu, Liping

    2015-10-01

    To study the potential effects of climate change on water quality in a shallow reservoir in China, the field data analysis method is applied to data collected over a given monitoring period. Nine water quality parameters (water temperature, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total nitrogen, total phosphorus, chemical oxygen demand, biochemical oxygen demand and dissolved oxygen) and three climate indicators for 20 years (1992-2011) are considered. The annual trends exhibit significant trends with respect to certain water quality and climate parameters. Five parameters exhibit significant seasonality differences in the monthly means between the two decades (1992-2001 and 2002-2011) of the monitoring period. Non-parametric regression of the statistical analyses is performed to explore potential key climate drivers of water quality in the reservoir. The results indicate that seasonal changes in temperature and rainfall may have positive impacts on water quality. However, an extremely cold spring and high wind speed are likely to affect the self-stabilising equilibrium states of the reservoir, which requires attention in the future. The results suggest that land use changes have important impact on nitrogen load. This study provides useful information regarding the potential effects of climate change on water quality in developing countries.

  17. Nutrient abatement potential and abatement costs of waste water treatment plants in the Baltic Sea region.

    PubMed

    Hautakangas, Sami; Ollikainen, Markku; Aarnos, Kari; Rantanen, Pirjo

    2014-04-01

    We assess the physical potential to reduce nutrient loads from waste water treatment plants in the Baltic Sea region and determine the costs of abating nutrients based on the estimated potential. We take a sample of waste water treatment plants of different size classes and generalize its properties to the whole population of waste water treatment plants. Based on a detailed investment and operational cost data on actual plants, we develop the total and marginal abatement cost functions for both nutrients. To our knowledge, our study is the first of its kind; there is no other study on this issue which would take advantage of detailed data on waste water treatment plants at this extent. We demonstrate that the reduction potential of nutrients is huge in waste water treatment plants. Increasing the abatement in waste water treatment plants can result in 70 % of the Baltic Sea Action Plan nitrogen reduction target and 80 % of the Baltic Sea Action Plan phosphorus reduction target. Another good finding is that the costs of reducing both nutrients are much lower than previously thought. The large reduction of nitrogen would cost 670 million euros and of phosphorus 150 million euros. We show that especially for phosphorus the abatement costs in agriculture would be much higher than in waste water treatment plants.

  18. [Effects of water content on redox potential and carbon mineralization of wetland sediments].

    PubMed

    Yang, Gai-ren; Tong, Cheng-li; Xiao, He-ai; Wu, Jin-shui

    2009-08-15

    To better understand the effect of soil water contents on redox potential (Eh), and their impacts on C mineralization in natural wetland, sediment samples from 3 types of wetlands (fen, humus marsh and marshy meadow) in the San-jiang Plate region of North China were incubated (25 degrees C) for 155 d under a range of reducing and oxidizing conditions by controlling water contents (varied from 24% to 232% of water holding capacity) (WHC). CO2-C evolved during incubation was measured at different time intervals. Results showed that Eh of sediments decreased significantly as water content increased from 24% WHC (lighted moisturized) to about 100% WHC, then decreased slightly as water content increased further to a level of submersed (about 2 cm water-depths). The accumulative amount of CO2-C evolved from the sediments indicated that the optimum water contents for mineralization of organic C are 32%, 48% and 76%-100% WHC for sediments of fen, humus marsh, and marshy meadow, respectively. The relationship between mineralization rates and redox potentials (Eh) were well fitted with second order parabola equations (p < 0.05). Mineralization rates and accumulative amount of organic C displayed a positive correlation with Eh up to 300 mV. However, a significant negative correlation was observed when Eh increased above 300 mV. Results demonstrated that low redox potential is the controlling factor of carbon accumulation of wetland in San-jiang Plate region.

  19. Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia.

    PubMed

    Hristovski, Kiril D; Pacemska-Atanasova, Tatjana; Olson, Larry W; Markovski, Jasmina; Mitev, Trajce

    2016-08-01

    Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955-2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in surface water hydrology over the last half century, which caused the surface waters in Macedonia to be frequently dominated by >50% of untreated sewage discharges. The surface water quality deterioration is further supported by an increasing trend in modeled biochemical oxygen demand trends, which correspond well with the scarce and intermittent water quality data that are available. Facilitated by the climate change trends, the increasing number of severe weather events is already triggering flooding of the sewage-dominated rivers into urban and non-urban areas. If efforts to develop a comprehensive sewage collection and treatment infrastructure are not implemented, such events have the potential to increase public health risks and cause epidemics, as in the 2015 case of a tularemia outbreak.

  20. Bioavailability of the Nano-Unit 14C-Agrochemicals Under Various Water Potential.

    PubMed

    Jung, S C; Kim, H G; Kuk, Y I; Ahn, H G; Senseman, S A; Lee, D J

    2015-08-01

    The study was conducted to investigate the effects of water potential on bioavailability of the nano-unit 14C-cafenstrole, 14C-pretilachlor, 14C-benfuresate, 14C-simetryn and 14C-oxyfluorfen applied with or without dimepiperate or daimuron under various water potential conditions. The highest bioavailable concentration in soil solution (BCSS) was found at 60% soil moisture, while the lowest occurred at 50% soil moisture for soil-applied alone or in combination. All water potential conditions differed significantly from each other with variations in total bioavailable amount in soil solution (TBSS) when either dimepiperate or daimuron were added to the soil, and changes were directly proportional to variations in water potential. Across all treatments, TBSS at 80% soil moisture was three to four times greater than that at 50% soil moisture when applied alone or in combination with dimepiperate or daimuron. Cafenstrole and simetryn had distribution coefficient (Kd) values <64 ml g-1 and a TBSS ranging from 10 to 44 ng g-1 soil, regardless of water potential conditions applied alone or in combination. Pretilachlor and benfuresate had Kd values <15 ml g-1 and a TBSS range of 38 to 255 ng g-1 soil when applied with or without dimepiperate or daimuron.

  1. Universal scaling of potential energy functions describing intermolecular interactions. II. The halide-water and alkali metal-water interactions

    SciTech Connect

    Werhahn, Jasper C.; Akase, Dai; Xantheas, Sotiris S.

    2014-08-14

    The scaled versions of the newly introduced [S. S. Xantheas and J. C. Werhahn, J. Chem. Phys.141, 064117 (2014)] generalized forms of some popular potential energy functions (PEFs) describing intermolecular interactions – Mie, Lennard-Jones, Morse, and Buckingham exponential-6 – have been used to fit the ab initio relaxed approach paths and fixed approach paths for the halide-water, X-(H2O), X = F, Cl, Br, I, and alkali metal-water, M+(H2O), M = Li, Na, K, Rb, Cs, interactions. The generalized forms of those PEFs have an additional parameter with respect to the original forms and produce fits to the ab initio data that are between one and two orders of magnitude better in the χ2 than the original PEFs. They were found to describe both the long-range, minimum and repulsive wall of the respective potential energy surfaces quite accurately. Overall the 4-parameter extended Morse (eM) and generalized Buckingham exponential-6 (gBe-6) potentials were found to best fit the ab initio data for these two classes of ion-water interactions. Finally, the fitted values of the parameter of the (eM) and (gBe-6) PEFs that control the repulsive wall of the potential correlate remarkably well with the ionic radii of the halide and alkali metal ions.

  2. 75 FR 78973 - Proposed Information Collection; Comment Request; Special Subsistence Permits and Harvest Logs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ... Subsistence Permits and Harvest Logs for Pacific Halibut in Waters Off Alaska AGENCY: National Oceanic and... Response: Permit applications, 10 minutes; Community harvest log, 30 minutes; Ceremonial or educational harvest log, 30 minutes; Appeal for permit denial, 4 hours. Estimated Total Annual Burden Hours:...

  3. Economics of Condensing Gas Furnaces and Water Heaters Potential in Residential Single Family Homes

    SciTech Connect

    Lekov, Alex; Franco, Victor; Meyers, Steve

    2010-05-14

    Residential space and water heating accounts for over 90percent of total residential primary gas consumption in the United States. Condensing space and water heating equipment are 10-30percent more energy-efficient than conventional space and water heating. Currently, condensing gas furnaces represent 40 percent of shipments and are common in the Northern U.S. market. Meanwhile, manufacturers are planning to develop condensing gas storage water heaters to qualify for Energy Star? certification. Consumers, installers, and builders who make decisions about installing space and water heating equipment generally do not perform an analysis to assess the economic impacts of different combinations and efficiencies of space and water heating equipment. Thus, equipment is often installed without taking into consideration the potential life-cycle economic and energy savings of installing space and water heating equipment combinations.