Science.gov

Sample records for agricultural return flow

  1. Closing the agricultural water budget: Return flow, ET and the role of laser scintillometry

    NASA Astrophysics Data System (ADS)

    Miller, S. N.; Gordon, B. L.

    2016-12-01

    As one of the western United States' oldest and largest water users, irrigation is of increasing interest as energy development, agricultural production, and population growth alter existing regional dynamics. When irrigation water is applied to agricultural fields, a portion of the applied water is consumed by crops in the process of evapotranspiration. The remaining water eventually makes its way back to adjacent streams and aquifers in the form of return flows. Statewide and regional estimates for both evapotranspiration requirements and return flow vary. Research was conducted in a semi-arid agricultural system adjacent to Bear Creek in northwestern Wyoming. Using an agricultural water balance as a general framework for investigation, we combined hydrological, ecophysiological, and geophysical measurements to quantify total evapotranspiration from agricultural fields. Total return flow contribution from flood irrigation was also quantified using a network of submersible pressure transducers in Bear Creek. The study found that empirical estimates generally over-predict measured evapotranspiration. To quantify the evapotranspiration from the study area we deployed a laser scintillometer over a 664 meter long path representative of the vegetation of the site. Separate totals for measurements taken during unstable periods and during stable/unstable periods were calculated for two reasons: 1) to determine whether comparison during periods of instability were more or less accurate than comparisons over the full day; and 2) to determine whether the inclusion of measurements taken during stable periods drastically altered the seasonal total obtained from the scintillometer. Our results indicated that the inclusion of stable measurements only marginally changed total seasonal ET. The closure in the water balance resulting from using the scintillometer was 94.0% for the 2015 irrigation season water balance. 38.20% of applied water returned to the Bear Creek system and 20

  2. Changes in Soil Chemistry and Agricultural Return Flow in an Integrated Seawater Agriculture System (ISAS) Demonstration in Abu Dhabi

    NASA Astrophysics Data System (ADS)

    Ning, Q.; Matiin, W. A.; Ahmad, F.

    2012-12-01

    Growing halophytes using Integrated Seawater Agriculture Systems (ISAS) offers a sustainable solution for the generation of biomass feedstock for carbon neutral biofuels - halophytes do not enter the foodchain and they do not compete with food-crops for natural resources. A field demonstration of ISAS in the coastal regions of Abu Dhabi, UAE, scheduled to start in 2013, will likely face a number of region-specific challenges not encountered in past demonstrations of ISAS at coastal locations in Mexico and Eritrea. The arid climate, unique soil chemistry (evaporite deposits, especially gypsum), and hypersaline coastal hydrogeology of Abu Dhabi will affect long-term halophyte agricultural productivity when Arabian Gulf seawater is applied to coastal soils as part of ISAS. Therefore, the changes in irrigation return flow quality and soil chemistry must be monitored closely over time to establish transient salt and water balances in order to assess the sustainability of ISAS in the region. As an initial phase of the ISAS demonstration project, numerical modeling of different seawater loadings onto coastal soils was conducted to estimate the chemical characteristics of soil and the irrigation return flow over time. These modeling results will be validated with field monitoring data upon completion of one year of ISAS operation. The results from this study could be used to (i) determine the optimal saline water loading that the soils at the ISAS site can tolerate, (ii) potential for sodicity of the soil with saline water application, (iii) impacts of land application of saline water on underlying coastal groundwater, and (iv) develop strategies to control soil water activities in favor of halophyte agricultural productivity.

  3. River water quality management considering agricultural return flows: application of a nonlinear two-stage stochastic fuzzy programming.

    PubMed

    Tavakoli, Ali; Nikoo, Mohammad Reza; Kerachian, Reza; Soltani, Maryam

    2015-04-01

    In this paper, a new fuzzy methodology is developed to optimize water and waste load allocation (WWLA) in rivers under uncertainty. An interactive two-stage stochastic fuzzy programming (ITSFP) method is utilized to handle parameter uncertainties, which are expressed as fuzzy boundary intervals. An iterative linear programming (ILP) is also used for solving the nonlinear optimization model. To accurately consider the impacts of the water and waste load allocation strategies on the river water quality, a calibrated QUAL2Kw model is linked with the WWLA optimization model. The soil, water, atmosphere, and plant (SWAP) simulation model is utilized to determine the quantity and quality of each agricultural return flow. To control pollution loads of agricultural networks, it is assumed that a part of each agricultural return flow can be diverted to an evaporation pond and also another part of it can be stored in a detention pond. In detention ponds, contaminated water is exposed to solar radiation for disinfecting pathogens. Results of applying the proposed methodology to the Dez River system in the southwestern region of Iran illustrate its effectiveness and applicability for water and waste load allocation in rivers. In the planning phase, this methodology can be used for estimating the capacities of return flow diversion system and evaporation and detention ponds.

  4. Return Flow: a Hydrogeophysical Assessment of Flowpaths

    NASA Astrophysics Data System (ADS)

    Claes, N.; Paige, G. B.; Parsekian, A.

    2016-12-01

    Flood irrigation is one of the most common irrigation methods in the Intermountain West region of the United States. Return flow from flood irrigation to streams is an important component of the eco-hydrological cycle in agricultural areas. Return flow is often assumed to be approximately 50%, however, we need to improve our understanding of the timing and the pathways and processes contributing to return flow, especially when studying the impact on the local eco-hydrological cycle. Return flow is more than just overland run-off back to streams. Two other components of return flow are near-surface return flow and return flow below the vadose zone. To determine how these pathways each contribute to the total amount of return flow and the dynamics behind them, we leverage the advantages of time-lapse ERT, soil moisture measurements and lab analysis. We monitored subsurface flow dynamics using time-lapse ERT and changes in soil moisture under wetting and drying experiments at field scale, similar to those performed during regular field irrigation schedules. The spatially and temporally dense datasets from the time -lapse resistivity observations are combined with the direct and spatially discrete soil moisture measurements along the observed profile and lab analysis. Combination of these datasets captures temporal and spatial variability at which wetting and drying processes occur at the field scale and what pathways are facilitating subsurface flow during different stages of the irrigation cycles. This study allows for a quantitative and qualitative assessment of hydrological fronts at different levels. It furthers, thereby, our knowledge and understanding of the importance of each return flow pathway for the eco-hydrological cycle and provides invaluable data for models that address the impact of flood irrigation on the local environment.

  5. Environmental water incentive policy and return flows

    NASA Astrophysics Data System (ADS)

    Qureshi, M. E.; Schwabe, K.; Connor, J.; Kirby, M.

    2010-04-01

    With increasing urban, industrial, and agricultural water demand and projected reduced supply under climate change, allocations to the environment are critically low in many arid and semiarid basins. Consequently, many governments are striving to augment environmental flows, often through market-oriented mechanisms that involve compensating irrigated agriculture, the largest water user in most basins, for reducing diversions. A widely documented challenge with policies to recover water for the environment arises because part of the water diversion reduction can form the basis for downstream consumptive water rights or environmental flows. This article gives an empirical comparison of two incentive policies to acquire water for environmental flows for a part of the Murray-Darling Basin (MDB), Australia. One policy consists of paying irrigators and water delivery firms to make capital and management investments that improve on-farm irrigation and water-conveyance; the other policy consists of having the government buy water from irrigators on the active MDB water market. The results show that the first option results in relatively larger return flow reduction, while the second option tends to induce significant irrigated land retirement with relatively large reductions in consumptive use and small reductions in return flow. In cases where irrigation losses result in little useful return flow (e.g., evaporative loss reduction or during drought in some instances), efficiency-improving investments may provide some cost-effective opportunities. Where a large portion of loss forms valuable return flow, it is difficult to make a case for the cost-effectiveness of policies involving payments for investments in irrigation and conveyance system upgrades.

  6. Heat Pipe Blocks Return Flow

    NASA Technical Reports Server (NTRS)

    Eninger, J. E.

    1982-01-01

    Metal-foil reed valve in conventional slab-wick heat pipe limits heat flow to one direction only. With sink warmer than source, reed is forced closed and fluid returns to source side through annular transfer wick. When this occurs, wick slab on sink side of valve dries out and heat pipe ceases to conduct heat.

  7. Thermocapillary flow without return flow-linear flow

    NASA Astrophysics Data System (ADS)

    Ospennikov, N. A.; Schwabe, D.

    The experimental realization of thermocapillary flow without return flow is reported. This type of flow (linear flow) was proposed and analyzed theoretically by Smith and Davis (J. Fluid Mech., 132:119-144, 1983). We suppressed the return flow by providing channels and side channels with lower flow resistance compared to that of the return flow. Cooling the layer with linear flow from above results in the Marangoni instability of longitudinal rolls as the most dangerous mode. Strong linear flow stabilizes the system against longitudinal rolls. We report preliminary results on the threshold and on the wavelength of the longitudinal rolls.

  8. Grand valley irrigation return flow case study

    SciTech Connect

    Keys, J.W.

    1981-06-01

    Irrigation water supply is furnished annually to about 71,500 acres of land in the Grand Valley of western Colorado. Return flows from that irrigation contribute about 780,000 tpy of salt to the Colorado River, causing an increase of 77 mg/l in the salinity concentration at Imperial Dam. A case study of water quality in this region is focused on: water quality data for irrigation and return flows/ identification of regulations that affect irrigation and return flows/ and a proposed program for controlling salinity levels. (1 map, 9 references, 8 tables)

  9. Occurrence, distribution, and transport of pesticides in agricultural irrigation-return flow from four drainage basins in the Columbia Basin Project, Washington, 2002-04, and comparison with historical data

    USGS Publications Warehouse

    Wagner, Richard J.; Frans, Lonna M.; Huffman, Raegan L.

    2006-01-01

    Water-quality samples were collected from sites in four irrigation return-flow drainage basins in the Columbia Basin Project from July 2002 through October 2004. Ten samples were collected throughout the irrigation season (generally April through October) and two samples were collected during the non-irrigation season. Samples were analyzed for temperature, pH, specific conductance, dissolved oxygen, major ions, trace elements, nutrients, and a suite of 107 pesticides and pesticide metabolites (pesticide transformation products) and to document the occurrence, distribution, and pesticides transport and pesticide metabolites. The four drainage basins vary in size from 19 to 710 square miles. Percentage of agricultural cropland ranges from about 35 percent in Crab Creek drainage basin to a maximum of 75 percent in Lind Coulee drainage basin. More than 95 percent of cropland in Red Rock Coulee, Crab Creek, and Sand Hollow drainage basins is irrigated, whereas only 30 percent of cropland in Lind Coulee is irrigated. Forty-two pesticides and five metabolites were detected in samples from the four irrigation return-flow drainage basins. The most compounds detected were in samples from Sand Hollow with 37, followed by Lind Coulee with 33, Red Rock Coulee with 30, and Crab Creek with 28. Herbicides were the most frequently detected pesticides, followed by insecticides, metabolites, and fungicides. Atrazine, bentazon, diuron, and 2,4-D were the most frequently detected herbicides and chlorpyrifos and azinphos-methyl were the most frequently detected insecticides. A statistical comparison of pesticide concentrations in surface-water samples collected in the mid-1990s at Crab Creek and Sand Hollow with those collected in this study showed a statistically significant increase in concentrations for diuron and a statistically significant decrease for ethoprophos and atrazine in Crab Creek. Statistically significant increases were in concentrations of bromacil, diuron, and

  10. Return of the Gentleman Farmer?: Conceptualising Gentrification in UK Agriculture

    ERIC Educational Resources Information Center

    Sutherland, Lee-Ann

    2012-01-01

    In this paper, processes of gentrification are assessed in relation to non-commercial farming: the production of agricultural commodities without the intent of earning a living. The author argues that due to the connection between residence and productive assets (particularly land) inherent in farming, agricultural gentrification represents a…

  11. Return of the Gentleman Farmer?: Conceptualising Gentrification in UK Agriculture

    ERIC Educational Resources Information Center

    Sutherland, Lee-Ann

    2012-01-01

    In this paper, processes of gentrification are assessed in relation to non-commercial farming: the production of agricultural commodities without the intent of earning a living. The author argues that due to the connection between residence and productive assets (particularly land) inherent in farming, agricultural gentrification represents a…

  12. Returns to Human and Research Capital, United States Agriculture, 1949-1964.

    ERIC Educational Resources Information Center

    Fishelson, Gideon

    This study estimated rates of return to public investments in human and research capital (formal schooling and extension and vocational agricultural education) in the United States agricultural industry. (Southern states were excluded because of demographic and educational factors that would have biased the variables.) Output per farm was defined…

  13. Importance of return flow as a component of water use

    USGS Publications Warehouse

    Trotta, L.C.; Horn, M.S.

    1990-01-01

    Understanding the relation between the hydrologjc cycle and water use is important for effective water-resources management. The hydrologic cycle is the natural pathway of water from evaporation to precipitation to infiltration or runoff and to storage from which evaporation can again occur. The science of water use is the study of human influences on the hydrologic cycle. Human activities affect the hydrologic cycle by changing the quantity, distribution, and quality of available water. Quantifying return flow is useful to water managers in evaluating such changes. Return flow is often thought of as what runs down the drain, or what is leftover after the water's purpose has been served. As innocuous as that may sound, return flow plays a significant part in the overall water-use picture.

  14. Agricultural Virtual Water Flows in the USA

    NASA Astrophysics Data System (ADS)

    Konar, M.; Dang, Q.; Lin, X.

    2014-12-01

    Global virtual water trade is an important research topic that has yielded several interesting insights. In this paper, we present a comprehensive assessment of virtual water flows within the USA, a country with global importance as a major agricultural producer and trade power. This is the first study of domestic virtual water flows based upon intra-national food flow data and it provides insight into how the properties of virtual water flows vary across scales. We find that both the value and volume of food flows within the USA are roughly equivalent to half that of international flows. However, USA food flows are more water intensive than international food trade, due to the higher fraction of water-intensive meat trade within the USA. The USA virtual water flow network is more social, homogeneous, and equitable than the global virtual water trade network, although it is still not perfectly equitable. Importantly, a core group of U.S. States is central to the network structure, indicating that both domestic and international trade may be vulnerable to disruptive climate or economic shocks in these U.S. States.

  15. Characterization of return flow pathways during flood irrigation

    NASA Astrophysics Data System (ADS)

    Claes, N.; Paige, G. B.; Parsekian, A.; Gordon, B. L.; Miller, S. N.

    2015-12-01

    With a decline in water resources available for private consumption and irrigation, the importance of sustainable water management practices is increasing. Local management decisions, based on models may affect the availability of water both locally and downstream, causing a ripple effect. It is therefore important that the models that these local management decisions are based on, accurately quantify local hydrological processes and the timescales at which they happen. We are focusing on return flow from flood irrigation, which can occur via different pathways back to the streams: overland flow, near-surface return flow and return flow via pathways below the vadose zone. The question addressed is how these different pathways each contribute to the total amount of return flow and the dynamics behind them. We used time-lapse ERT measurements in combination with an ensemble of ERT and seismic lines to answer this question via (1) capturing the process of gradual fragmentation of aqueous environments in the vadose zone during drying stages at field scale; (2) characterization of the formation of preferential flow paths from infiltrating wetting fronts during wetting cycles at field scale. The time-lapse ERT provides the possibility to capture the dynamic processes involved during the occurrence of finger flow or macro-pores when an intensive wetting period during flood irrigation occurs. It elucidates the dynamics of retention in the vadose zone during drying and wetting periods at field scale. This method provides thereby a link to upscale from laboratory experiments to field scale and watershed scale for finger flow and preferential flow paths and illustrates the hysteresis behavior at field scale.

  16. Characteristics and Problems of Older Returning Students. College of Agricultural & Life Sciences Research Report.

    ERIC Educational Resources Information Center

    Flannery, Daniele; Apps, Jerold

    A study examined the barriers encountered by returning adult students and the potential change of those barriers over time. The 43 students constituting the survey population were enrolled in the graduate programs of the College of Agricultural and Life Sciences and the School of Education at the University of Wisconsin-Madison. Students had to be…

  17. Agricultural modifications of hydrological flows create ecological surprises.

    PubMed

    Gordon, Line J; Peterson, Garry D; Bennett, Elena M

    2008-04-01

    Agricultural expansion and intensification have altered the quantity and quality of global water flows. Research suggests that these changes have increased the risk of catastrophic ecosystem regime shifts. We identify and review evidence for agriculture-related regime shifts in three parts of the hydrological cycle: interactions between agriculture and aquatic systems, agriculture and soil, and agriculture and the atmosphere. We describe the processes that shape these regime shifts and the scales at which they operate. As global demands for agriculture and water continue to grow, it is increasingly urgent for ecologists to develop new ways of anticipating, analyzing and managing nonlinear changes across scales in human-dominated landscapes.

  18. Effects of crop residue returning on nitrous oxide emissions in agricultural soils

    NASA Astrophysics Data System (ADS)

    Shan, Jun; Yan, Xiaoyuan

    2013-06-01

    Crop residue returning is a common practice in agricultural system that consequently influences nitrous oxide (N2O) emissions. Much attention has been focused on the effects of crop residue on N2O release. However, no systematic result has yet been drawn because environmental factors among different studies vary. A meta-analysis was described to integrate 112 scientific assessments of crop residue returning on N2O emissions in this study. Results showed that crop residue returning, when averaged across all studies, had no statistically significant effect on N2O release compared with control treatments. However, the range of effects of crop residue returning on N2O emission was significantly affected by synthetic nitrogen (N) fertilizer application, type of crop residue, specific manner in which crop residue has returned, and type of land-use. N2O release was significantly inhibited by 11.7% and 27.1% (P < 0.05) when crop residue was with synthetic N fertilizer and when type of land-use was paddy, respectively. While N2O emissions were significantly enhanced by 42.1% and 23.5% (P < 0.05) when crop residue was applied alone and when type of land-use was upland, respectively. N2O emissions were likewise increased when crop residue with lower C/N ratio was used, mulching of crop residue was performed, and type of land-use was fallow. Our study provides the first quantitative analysis of crop residue returning on N2O emissions, indicating that crop residue returning has no statistically significant effect on N2O release at regional scale, and underlining that the Intergovernmental Panel on Climate Change guidelines should take the opposite effects of crop residue returning on upland and paddy into account when estimating the N2O emission factor of crop residue for different land-use types. Given that most of data are dominated by certain types of crop residue and specific application methods, more field data are required to reduce uncertainty.

  19. Estimates of consumptive use and ground-water return flow using water budgets in Palo Verde Valley, California

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.; Kimsey, Steven L.

    1987-01-01

    Palo Verde Valley, California, is an agricultural area in the flood plain of the Colorado River where irrigation water is diverted from the river and groundwater is discharged to a network of drainage ditches and (or) the river. Consumptive use by vegetation and groundwater return flow were calculated using water budgets. Consumptive use by vegetation was 484,000 acre-ft in 1981, 453,600 acre-ft in 1982, 364,400 acre-ft in 1983, and 374,300 acre-ft in 1984. The consumptive-use estimates are most sensitive to two measured components of the water budget, the diversion at Palo Verde Dam and the discharge from drainage ditches to the river. Groundwater return flow was 31,700 acre-ft in 1981, 24,000 acre-ft in 1982, 2,500 acre-ft in 1983, and 7 ,900 acre-ft in 1984. The return-flow estimates are most sensitive to discharge from drainage ditches; various irrigation requirements and crop areas, particularly alfalfa; the diversion at Palo Verde Dam; and the estimate of consumptive use. During increasing flows in the river, the estimate of groundwater return flow is sensitive also to change in groundwater storage. Change in groundwater storage was estimated to be -5,700 acre-ft in 1981, -12,600 acre-ft in 1982, 5,200 acre-ft in 1983, and 11 ,600 acre-ft in 1984. Changes in storage can be a significant component in the water budget used to estimate groundwater return flow but is negligible in the water budget used to estimate consumptive use. Change in storage was 1 to 3% of annual consumptive use. Change in storage for the area drained by the river ranged from 7 to 96% of annual groundwater return flow during the 4 years studied. Consumptive use calculated as diversions minus return flows was consistently lower than consumptive use calculated in a water budget. Water-budget estimates of consumptive use account for variations in precipitation, tributary inflow, river stage, and groundwater storage. The calculations for diversions minus return flows do not account for these

  20. Contribution of return flows to streamflow in selected stream reaches in Illinois, 1988-89

    USGS Publications Warehouse

    LaTour, J.K.

    1993-01-01

    Water returns by sewage-treatment plants and various water users can be a significant part of streamflow. Knowledge of the effect of return flows on stream- flow is needed for purposes of assessing streamwater quality and water supply. The results of a study by the U.S. Geological Survey, in cooperation with the Illinois Environmental Protection Agency, are presented to describe the contribution of return flows to streamflow for five stream reaches in Illinois during 1988-89. The reaches studied were South Branch Kishwaukee River upstream from De Kaib, Mackinaw River upstream from Congerville, Addison Creek upstream from Bellwood, Flag Creek upstream from Willow Springs, and Thorn Creek upstream from Glenwood. The annual average contributions of return flows to streamflow in each reach ranged from 1 to 99 percent of the annual average streamflow. Return flows significantly affected streamflows in the Flag Creek and Thorn Creek reaches. Significant return flows probably sustained streamflows in the Addison Creek, Flag Creek, and Thorn Creek reaches. Return flows exceeded streamflow during at least 1 month during the 1988 drought at all of the study reaches, except the Thorn Creek reach. Of the amount of return flows that exceeded streamflow, all reaches lost an estimated 0.01 to 0.34 Mgal/d (million gallons per day) to evaporation and 0.36 to 1.33 Mgal/d to infiltration. An analysis-of-variance test indicated that return flows did not differ among seasons. A second analysis indicated that the proportion of return flows to streamflow did differ seasonally. Return flows during July through September 1988-89 constituted a large proportion (67 percent) of the annual streamflows.

  1. Effect of irrigation return flow on groundwater recharge in an overexploited aquifer in Bangladesh

    NASA Astrophysics Data System (ADS)

    Touhidul Mustafa, Syed Md.; Shamsudduha, Mohammad; Huysmans, Marijke

    2016-04-01

    Irrigated agriculture has an important role in the food production to ensure food security of Bangladesh that is home to over 150 million people. However, overexploitation of groundwater for irrigation, particularly during the dry season, causes groundwater-level decline in areas where abstraction is high and surface geology inhibits direct recharge to underlying shallow aquifer. This is causing a number of potential adverse socio-economic, hydrogeological, and environmental problems in Bangladesh. Alluvial aquifers are primarily recharged during monsoon season from rainfall and surface sources. However, return flow from groundwater-fed irrigation can recharge during the dry months. Quantification of the effect of return flow from irrigation in the groundwater system is currently unclear but thought to be important to ensure sustainable management of the overexploited aquifer. The objective of the study is to investigate the effect of irrigation return flow on groundwater recharge in the north-western part of Bangladesh, also known as Barind Tract. A semi-physically based distributed water balance model (WetSpass-M) is used to simulate spatially distributed monthly groundwater recharge. Results show that, groundwater abstraction for irrigation in the study area has increased steadily over the last 29 years. During the monsoon season, local precipitation is the controlling factor of groundwater recharge; however, there is no trend in groundwater recharge during that period. During the dry season, however, irrigation return-flow plays a major role in recharging the aquifer in the irrigated area compared to local precipitation. Therefore, during the dry season, mean seasonal groundwater recharge has increased and almost doubled over the last 29 years as a result of increased abstraction for irrigation. The increase in groundwater recharge during dry season has however no significant effect in the improvement of groundwater levels. The relation between groundwater

  2. The steady-state flow quality in a model of a non-return wind tunnel

    NASA Technical Reports Server (NTRS)

    Mort, K. W.; Eckert, W. T.; Kelly, M. W.

    1972-01-01

    The structural cost of non-return wind tunnels is significantly less than that of the more conventional closed-circuit wind tunnels. However, because of the effects of external winds, the flow quality of non-return wind tunnels is an area of concern at the low test speeds required for V/STOL testing. The flow quality required at these low speeds is discussed and alternatives to the traditional manner of specifying the flow quality requirements in terms of dynamic pressure and angularity are suggested. The development of a non-return wind tunnel configuration which has good flow quality at low as well as at high test speeds is described.

  3. Returns to food and agricultural R&D investments in Sub-Saharan Africa, 1975-2014.

    PubMed

    Pardey, Philip G; Andrade, Robert S; Hurley, Terrance M; Rao, Xudong; Liebenberg, Frikkie G

    2016-12-01

    Research-enabled growth in agricultural productivity is pivotal to sub-Saharan Africa's overall economic growth prospects. Yet, investments in research and development (R&D) targeted to many national food and agricultural economies throughout Africa are fragile and faltering. To gain insight into what could be driving this trend, this article updates, summarizes and reassesses the published evidence on the returns to African agricultural R&D. Based on a compilation of 113 studies published between 1975 and 2014 spanning 25 countries, the reported internal rates of return (IRRs) to food and agricultural research conducted in or of direct consequence for sub-Saharan Africa averaged 42.3%py. In addition to the 376 IRR estimates, the corresponding 129 benefit-cost ratios (BCRs) averaged 30.1. Most (96.5%) of the returns-to-research evaluations are of publicly performed R&D, and the majority (87.6%) of the studies were published in the period 1990-2009. The large dispersion in the reported IRRs and BCRs makes it difficult to discern meaningful patterns in the evidence. Moreover, the distribution of IRRs is heavily (positively) skewed, such that the median value (35.0%py) is well below the mean, like it is for research done elsewhere in the world (mean 62.4%py; median 38.0%py). Around 78.5% of the evaluations relate to the commodity-specific consequences of agricultural research, while 5.5% report on the returns to an "all agriculture" aggregate. The weight of commodity-specific evaluation evidence is not especially congruent with the composition of agricultural production throughout Africa, nor, to the best that can be determined, the commodity orientation of public African agricultural R&D.

  4. Water temperature in irrigation return flow from the Upper Snake Rock watershed

    USDA-ARS?s Scientific Manuscript database

    Water returning to a river from an irrigated watershed could increase the water temperature in the river. The objective of this study was to compare the temperature of irrigation return flow water with the temperature of the diverted irrigation water. Water temperature was measured weekly in the mai...

  5. Entry and return times for semi-flows

    NASA Astrophysics Data System (ADS)

    Marklof, Jens

    2017-02-01

    Haydn, Lacroix and Vaienti (2005 Ann. Probab. 33 2043-50) proved that, for a given ergodic map, the entry time distribution converges in the small target limit, if and only if the corresponding return time distribution converges. The present note explains how entry and return times can be interpreted in terms of stationary point processes and their Palm distribution. This permits a generalization of the results by Haydn et al to non-ergodic maps and continuous-time dynamical systems. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. 291147

  6. Partitioning groundwater recharge between rainfall infiltration and irrigation return flows using stable isotopes: the Crau aquifer.

    NASA Astrophysics Data System (ADS)

    Seraphin, Pierre; Vallet-Coulomb, Christine; Gonçalvès, Julio

    2016-04-01

    Traditional flood irrigation is used since the 16th century in the Crau plain (Southern France) for hay production. To supply this high consuming irrigation practice, water is diverted from the Durance River, originating from the Alps, and the large amount of irrigation return flows constitutes the main recharge of the Crau aquifer, which is in turn largely exploited for domestic, industrial and agricultural water use. A possible reduction of irrigation fluxes due to a need of water saving or to a future land-use change could endanger the groundwater resource. A robust quantification of the groundwater mass balance is thus required to assess a sustainable water management in the region. The high isotopic contrast between these exogenous irrigation waters and local precipitations allows the use of stable isotopes of water as conservative tracers to deduce their contributions to the surface recharge. An extensive groundwater sampling was performed to obtain δ18O and δ2H over the whole aquifer. Based on a new piezometric contour map, combined with a reestimate of the aquifer geometry, the isotopic data are implemented in a geostatistical approach to produce a conceptual equivalent-homogeneous reservoir, in order to apply a simple water and isotope mass balance mixing model. The isotopic composition of the two end-members is assessed, and the quantification of groundwater flows is then used to calculate the two recharge fluxes. Near to steady-state condition, the set of isotopic data treated by geostatistics leads to a recharge by irrigation of 5.20 ± 0.93 m3 s-1 i.e. 1173 ± 210 mm yr-1, and a natural recharge of 2.26 ± 0.91 m3 s-1 i.e. 132 ± 53 mm yr-1. Thus, 70 ± 9% of the effective surface recharge comes from the irrigation return flow, consistent with the literature (between 67% and 78%). This study constitutes a straightforward and independent approach to assess groundwater surface recharges with uncertainties and will help to constrain a future transient

  7. The Influence of Groundwater Depletion from Irrigated Agriculture on the Tradeoffs between Ecosystem Services and Economic Returns

    PubMed Central

    Kovacs, Kent; West, Grant

    2016-01-01

    An irrigated agricultural landscape experiencing groundwater overdraft generates economic returns and a suite of ecosystem services (in particular, groundwater supply, greenhouse gases reduction, and surface water quality). Alternative land cover choices indicate tradeoffs among the value of ecosystem services created and the economic returns. These tradeoffs are explored using efficiency frontiers that determine the least value in ecosystem services that must be given up to generate additional economic returns. Agricultural producers may switch to irrigation with surface water using on-farm reservoirs and tail water recovery systems in response to groundwater overdraft, and this has consequences for the bundle of ecosystem service values and economic returns achievable from the landscape. Planning that accounts for both ecosystem service value and economic returns can achieve more value for society, as does the adoption of reservoirs though lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated GHG emissions from groundwater pumping. Sensitivity analyses of per unit value of ecosystem services, crop prices, and the groundwater and water purification model parameters indicate tradeoff among ecosystems service values, such as the use of a high-end social cost of carbon ultimately lowers groundwater supply and water purification value by more than 15%. PMID:28033405

  8. The Influence of Groundwater Depletion from Irrigated Agriculture on the Tradeoffs between Ecosystem Services and Economic Returns.

    PubMed

    Kovacs, Kent; West, Grant

    2016-01-01

    An irrigated agricultural landscape experiencing groundwater overdraft generates economic returns and a suite of ecosystem services (in particular, groundwater supply, greenhouse gases reduction, and surface water quality). Alternative land cover choices indicate tradeoffs among the value of ecosystem services created and the economic returns. These tradeoffs are explored using efficiency frontiers that determine the least value in ecosystem services that must be given up to generate additional economic returns. Agricultural producers may switch to irrigation with surface water using on-farm reservoirs and tail water recovery systems in response to groundwater overdraft, and this has consequences for the bundle of ecosystem service values and economic returns achievable from the landscape. Planning that accounts for both ecosystem service value and economic returns can achieve more value for society, as does the adoption of reservoirs though lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated GHG emissions from groundwater pumping. Sensitivity analyses of per unit value of ecosystem services, crop prices, and the groundwater and water purification model parameters indicate tradeoff among ecosystems service values, such as the use of a high-end social cost of carbon ultimately lowers groundwater supply and water purification value by more than 15%.

  9. Mean and Turbulent Flow Statistics in a Trellised Agricultural Canopy

    NASA Astrophysics Data System (ADS)

    Miller, Nathan E.; Stoll, Rob; Mahaffee, Walter F.; Pardyjak, Eric R.

    2017-06-01

    Flow physics is investigated in a two-dimensional trellised agricultural canopy to examine that architecture's unique signature on turbulent transport. Analysis of meteorological data from an Oregon vineyard demonstrates that the canopy strongly influences the flow by channelling the mean flow into the vine-row direction regardless of the above-canopy wind direction. Additionally, other flow statistics in the canopy sub-layer show a dependance on the difference between the above-canopy wind direction and the vine-row direction. This includes an increase in the canopy displacement height and a decrease in the canopy-top shear length scale as the above-canopy flow rotates from row-parallel towards row-orthogonal. Distinct wind-direction-based variations are also observed in the components of the stress tensor, turbulent kinetic energy budget, and the energy spectra. Although spectral results suggest that sonic anemometry is insufficient for resolving all of the important scales of motion within the canopy, the energy spectra peaks still exhibit dependencies on the canopy and the wind direction. These variations demonstrate that the trellised-canopy's effect on the flow during periods when the flow is row-aligned is similar to that seen by sparse canopies, and during periods when the flow is row-orthogonal, the effect is similar to that seen by dense canopies.

  10. The variability and causes of organic carbon retention ability of different agricultural straw types returned to soil.

    PubMed

    Wang, Han; Wang, Lei; Zhang, Yannan; Hu, Yu; Wu, Jihua; Fu, Xiaohua; Le, Yiquan

    2017-03-01

    Retaining the organic carbon (C) content of agricultural straw when returned to soil is restricted by rapid decomposition. In order to clarify the difference in returned straw decomposition and the causes, and to develop a straw returning mode with high-efficiency of organic C accumulation, the decomposition processes of corn, soybean, rice and wheat straws were systematically studied in fields. When returned in situ (the original planting area), the C in soybean straw was decomposed most quickly with a decomposition constant of 0.00542 d(-1), but wheat straw showed a longer retention in soil with 0.00303 d(-1). However, for ex situ return of all straw in one area away from in situ return, soybean straw was decomposed most slowly (0.00452 d(-1)) and wheat straw more quickly (0.00652 d(-1)). The sequence of C decomposition rate in 270 d was soybean > corn > rice > wheat (in situ) and corn > wheat > rice > soybean (ex situ). Both surrounding soil and straw nature were important factors influencing the decomposition rate. The farmland with rice and wheat rotation retained more C from returned straws due to its high moisture and low nitrogen (N) content, while the soybean field was a contrast. Soybean straw had a low decomposition rate after ex situ return due to its low N content and high C/N ratio. The farmland of wheat-rice rotation combined with soybean straw ex situ return may develop into a field of higher C retention ability.

  11. The steady-state flow quality of an open return wind tunnel model.

    NASA Technical Reports Server (NTRS)

    Mort, K. W.; Kelly, M. W.; Eckert, W. T.

    1972-01-01

    The structural cost of open return wind tunnels is significantly less than that of the more conventional closed return wind tunnels. However, because of the effects of external winds, the flow quality of open return wind tunnels is an area of concern at the low speeds required for V/STOL testing. The development of a configuration which has good flow quality at low as well as at high test speeds is described. The flow quality required at the low test speeds of interest for V/STOL aircraft is discussed and alternatives to the traditional manner of specifying the flow quality requirements in terms of dynamic pressure and angle of attack are suggested.

  12. Estimating Monthly Water Withdrawals, Return Flow, and Consumptive Use in the Great Lakes Basin

    USGS Publications Warehouse

    Shaffer, Kimberly H.; Stenback, Rosemary S.

    2010-01-01

    Water-resource managers and planners require water-withdrawal, return-flow, and consumptive-use data to understand how anthropogenic (human) water use affects the hydrologic system. Water models like MODFLOW and GSFLOW use calculations and input values (including water-withdrawal and return flow data) to simulate and predict the effects of water use on aquifer and stream conditions. Accurate assessments of consumptive use, interbasin transfer, and areas that are on public supply or sewer are essential in estimating the withdrawal and return-flow data needed for the models. As the applicability of a model to real situations depends on accurate input data, limited or poor water-use data hampers the ability of modelers to simulate and predict hydrologic conditions. Substantial differences exist among the many agencies nationwide that are responsible for compiling water-use data including what data are collected, how the data are organized, how often the data are collected, quality assurance, required level of accuracy, and when data are released to the public. This poster presents water-use information and estimation methods summarized from recent U.S. Geological Survey (USGS) reports with the intent to assist water-resource managers and planners who need estimates of monthly water withdrawals, return flows, and consumptive use. This poster lists references used in Shaffer (2009) for water withdrawals, consumptive use, and return flows. Monthly percent of annual withdrawals and monthly consumptive-use coefficients are used to compute monthly water withdrawals, consumptive use, and return flow for the Great Lakes Basin.

  13. Agricultural virtual water flows within the United States

    NASA Astrophysics Data System (ADS)

    Dang, Qian; Lin, Xiaowen; Konar, Megan

    2015-02-01

    Trade plays an increasingly important role in the global food system, which is projected to be strained by population growth, economic development, and climate change. For this reason, there has been a surge of interest in the water resources embodied in international trade, referred to as "global virtual water trade." In this paper, we present a comprehensive assessment of virtual water flows within the United States (U.S.), a country with global importance as a major agricultural producer and trade power. This is the first study of domestic virtual water flows based upon intranational food transfer empirical data and it provides insight into how the properties of virtual water transfers vary across scales. We find that the volume of virtual water flows within the U.S. is equivalent to 51% of international flows, which is slightly higher than the U.S. food value and mass shares, due to the fact that water-intensive meat commodities comprise a much larger fraction of food transfers within the U.S.. The U.S. virtual water flow network is more social, homogeneous, and equitable than the global virtual water trade network, although it is still not perfectly equitable. Importantly, a core group of U.S. States is central to the network structure, indicating that both domestic and international trade may be vulnerable to disruptive climate or economic shocks in these U.S. States.

  14. Quality of the Arkansas River and irrigation-return flows in the lower Arkansas River Valley, Colorado

    USGS Publications Warehouse

    Cain, Doug

    1985-01-01

    Irrigation-return flows in the lower Arkansas River valley of Colorado were investigated using one-time data at 59 sites, monthly data at 4 sites, and intensive data in a small irrigated area. Specific conductance of return flows increased downstream, paralleling specific conductance of irrigation water. During July 1977, Arkansas River streamflow below Manzanola was mostly irrigation-return flow. A similar situation existed during periods of little precipitation in the early and late irrigation seasons during 1974 to 1978. Irrigation-return flows had a large effect on Arkansas River water quality during these times. (USGS)

  15. Reaping the Return on Agricultural Research and Education in Virginia. Information Series 93-3.

    ERIC Educational Resources Information Center

    Norton, George W.; Paczkowski, Remi

    This report focuses upon the economic and other contributions that agricultural research and education have made to Virginia over the past 40 years. Agricultural research, extension, and classroom instruction contribute in the following ways to Virginia's citizens: increased supplies and reduced costs, improved competitiveness, multiplier effects…

  16. Methods for Estimating Withdrawal and Return Flow by Census Block for 2005 and 2020 for New Hampshire

    USGS Publications Warehouse

    Hayes, Laura; Horn, Marilee A.

    2009-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Department of Environmental Services, estimated the amount of water demand, consumptive use, withdrawal, and return flow for each U.S. Census block in New Hampshire for the years 2005 (current) and 2020. Estimates of domestic, commercial, industrial, irrigation, and other nondomestic water use were derived through the use and innovative integration of several State and Federal databases, and by use of previously developed techniques. The New Hampshire Water Demand database was created as part of this study to store and integrate State of New Hampshire data central to the project. Within the New Hampshire Water Demand database, a lookup table was created to link the State databases and identify water users common to more than one database. The lookup table also allowed identification of withdrawal and return-flow locations of registered and unregistered commercial, industrial, agricultural, and other nondomestic users. Geographic information system data from the State were used in combination with U.S. Census Bureau spatial data to locate and quantify withdrawals and return flow for domestic users in each census block. Analyzing and processing the most recently available data resulted in census-block estimations of 2005 water use. Applying population projections developed by the State to the data sets enabled projection of water use for the year 2020. The results for each census block are stored in the New Hampshire Water Demand database and may be aggregated to larger political areas or watersheds to assess relative hydrologic stress on the basis of current and potential water availability.

  17. Laboratory Evaluation of Air Flow Measurement Methods for Residential HVAC Returns for New Instrument Standards

    SciTech Connect

    Walker, Iain; Stratton, Chris

    2015-08-01

    This project improved the accuracy of air flow measurements used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and efficiency of California residences. The research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to measure return flows used in Title 24 applications. The team developed guidance on performance of current diagnostics as well as a draft test method for use in future evaluations. The study team prepared a draft test method through ASTM International to determine the uncertainty of air flow measurements at residential heating ventilation and air conditioning returns and other terminals. This test method, when finalized, can be used by the Energy Commission and other entities to specify required accuracy of measurement devices used to show compliance with standards.

  18. Spatial estimation of debris flows-triggering rainfall and its dependence on rainfall return period

    NASA Astrophysics Data System (ADS)

    Destro, Elisa; Marra, Francesco; Nikolopoulos, Efthymios I.; Zoccatelli, Davide; Creutin, Jean Dominique; Borga, Marco

    2017-02-01

    Forecasting the occurrence of debris flows is fundamental for issuing hazard warnings, and often focuses on rainfall as a triggering agent and on the use of empirical rainfall thresholds based on rain gauge observations. A recognized component of the uncertainty associated with the use of rainfall thresholds is related to the sampling of strongly varying rainfall variability with sparse rain gauge networks. In this work we examine the spatial distribution of rainfall depth in areas up to 10 km from the debris flow initiation points as a function of return period, and we exploit this information to analyze the errors expected in the estimation of debris flow triggering rainfall when rain gauge data are used. In particular, we investigate the impact of rain gauge density and of the use of different interpolation methods. High-resolution, adjusted radar rainfall estimates, representing the best available spatially-distributed rainfall estimates at the debris flows initiation point and in the surrounding area, are sampled by stochastically generated rain gauge networks characterized by varying densities. Debris flow triggering rainfall is estimated by means of three rainfall interpolation methods: nearest neighbor, inverse distance weighting and ordinary kriging. On average, triggering rainfall shows a local peak corresponding to the debris flow initiation point, with a decay of rainfall with distance which increases with the return period of the triggering rainfall. Interpolation of the stochastically generated rain gauge measurements leads to an underestimation of the triggering rainfall that, irrespective of the interpolation methods, increases with the return period and decreases with the rain gauge density. For small return period events and high rain gauge density, the differences among the methods are minor. With increasing the return period and decreasing the rain gauge density, the nearest neighbor method is less biased, because it makes use only of the

  19. Irrigation efficiency and quality of irrigation return flows in the Ebro River Basin: an overview.

    PubMed

    Causapé, J; Quílez, D; Aragüés, R

    2006-06-01

    The review analysis of twenty two irrigation efficiency (IE) studies carried out in the Ebro River Basin shows that IE is low (average IE)(avg)(= 53%) in surface-irrigated areas with high-permeable and shallow soils inadequate for this irrigation system, high (IE)(avg)(= 79%) in surface-irrigated areas with appropriate soils for this system, and very high (IE)(avg)(= 94%) in modern, automated and well managed sprinkler-irrigated areas. The unitary salt (total dissolved solids) and nitrate loads exported in the irrigation return flows (IRF) of seven districts vary, depending on soil salinity and on irrigation and N fertilization management, between 3-16 Mg salt/ha x year and 23-195 kg NO)(3) (-)-N/ha x year, respectively. The lower nitrate loads exported from high IE districts show that a proper irrigation design and management is a key factor to reduce off-site nitrogen pollution. Although high IE's also reduce off-site salt pollution, the presence of salts in the soil or subsoil may induce relatively high salt loads (>or=14 Mg/ha x year) even in high IE districts. Two important constrains identified in our revision were the short duration of most surveys and the lack of standards for conducting irrigation efficiency and mass balance studies at the irrigation district level. These limitations {emphasize the need for the establishment of a permanent and standardized network of drainage monitoring stations for the appropriate off-site pollution diagnosis and control of irrigated agriculture.

  20. Laboratory Evaluation of Air Flow Measurement Methods for Residential HVAC Returns

    SciTech Connect

    Walker, Iain; Stratton, Chris

    2015-07-01

    This project improved the accuracy of air flow measurements used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and efficiency of California residences. The research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to measure return flows used in Title 24 applications. The team developed guidance on performance of current diagnostics as well as a draft test method for use in future evaluations. The series of tests performed measured air flow using a range of techniques and devices. The measured air flows were compared to reference air flow measurements using inline air flow meters built into the test apparatus. The experimental results showed that some devices had reasonable results (typical errors of 5 percent or less) but others had much bigger errors (up to 25 percent).

  1. Phosphorus removal in a surface-flow constructed wetland treating agricultural runoff.

    PubMed

    Beutel, Marc W; Morgan, Matthew R; Erlenmeyer, Jonathan J; Brouillard, Elaine S

    2014-05-01

    Agricultural runoff is a leading source of phosphorus (P) pollution to lakes and streams. The objective of this study was to evaluate P removal dynamics in a constructed treatment wetland (CTW) treating agricultural irrigation return flows. The CTW included a sedimentation basin (SB) followed by two surface-flow wetlands in parallel. Typical retention times and total P (TP) loading were 1.4 d and 50 to 110 g m yr P, respectively, for the SB and 5 to 6 d and 4 to 10 g m yr P, respectively, for wetlands. On the basis of this multiyear study, concentration removal efficiency in the SB averaged 21% for TP and 32% for reactive phosphorus (RP). Concentration removal efficiency in wetlands averaged 37 and 43% for TP and 22 and 33% for RP. Areal first-order removal rates for TP averaged 22 and 31 m yr in wetlands. Total P removal in wetlands exhibited a strong seasonal pattern, with minimum removal in the summer when high temperatures likely enhanced P release from decaying plant biomass. The performance of the CTW was stochastic, with removal unpredictably poorer in some years in part as a result of muskrat bioturbation and plant harvesting. In years before muskrat impacts, concentration removal efficiencies in wetlands were 50% for TP and 65% for RP. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Crop diversity effects on productivity and economic returns under dryland agriculture

    USDA-ARS?s Scientific Manuscript database

    Increasing crop diversity has been identified as a method to improve agronomic performance of cropping systems and increase provision of ecosystem services. However, there is a need to understand the economic performance of more diverse cropping systems. Crop productivity and economic net returns we...

  3. Effect of High School Completion of the Agricultural Education Program on the Rate of Return on Investment for the Commonwealth of Virginia

    ERIC Educational Resources Information Center

    Bevins, Phillip Scott

    2010-01-01

    This research study sought to determine the effect high school completion of the agricultural career and technical education program has on the rate of return on investment by public schools in Virginia. The research questions guiding this study included: (1) Were students able to find employment related to the agricultural career and technical…

  4. Effect of High School Completion of the Agricultural Education Program on the Rate of Return on Investment for the Commonwealth of Virginia

    ERIC Educational Resources Information Center

    Bevins, Phillip Scott

    2010-01-01

    This research study sought to determine the effect high school completion of the agricultural career and technical education program has on the rate of return on investment by public schools in Virginia. The research questions guiding this study included: (1) Were students able to find employment related to the agricultural career and technical…

  5. Thermocapillary-Driven Convection in a Thin Liquid Layer with a Inclined Temperature Gradient in Linear and Return Flow Fields

    NASA Astrophysics Data System (ADS)

    Kurosawa, Takafumi; Ueno, Ichiro; Kawamura, Hiroshi

    2002-11-01

    Thermocapillary-driven convection in a thin liquid layer of up to 2mm in depth heated from below was experimentally investigated. Temperature gradient inclined to the free surface was applied to the liquid layer. Two different base flows were considered; linear- and return flows. In the case of the return base flow, five stationary flow patterns were observed depending upon the relative magnitude of the perpendicular and parallel temperature gradients; that is, stationary and flowing Benard cellular patterns, streak convection, horizontal circulation without upflow and Stagnation. In the linear flow case, also, quite similar flow patterns were observed despite of the difference in base flow structure. The streak convection indicated the same flow structure as the longitudinal roll predicted by Smith& Davis (1983) in their linear flow case. Flow pattern maps were obtained and compared for the two base flows.

  6. Phosphorus transport by surface and subsurface flow pathways in an upland agricultural watershed

    USDA-ARS?s Scientific Manuscript database

    Improved understanding of phosphorus transport by surface and subsurface flow pathways is critical to protecting water quality in agricultural watersheds. While considerable attention has been devoted to understanding phosphorus losses in overland flow, comparatively limited research has examined ph...

  7. Simulation of non-Newtonian oil-water core annular flow through return bends

    NASA Astrophysics Data System (ADS)

    Jiang, Fan; Wang, Ke; Skote, Martin; Wong, Teck Neng; Duan, Fei

    2017-07-01

    The volume of fluid (VOF) model is used together with the continuum surface force (CSF) model to numerically simulate the non-Newtonian oil-water core annular flow across return bends. A comprehensive study is conducted to generate the profiles of pressure, velocity, volume fraction and wall shear stress for different oil properties, flow directions, and bend geometries. It is revealed that the oil core may adhere to the bend wall under certain operating conditions. Through the analysis of the total pressure gradient and fouling angle, suitable bend geometric parameters are identified for avoiding the risk of fouling.

  8. LABORATORY EVALUATION OF AIR FLOW MEASUREMENT METHODS FOR RESIDENTIAL HVAC RETURNS

    SciTech Connect

    Walker, Iain; Stratton, Chris

    2015-02-01

    This project improved the accuracy of air flow measurements used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and efficiency of California residences. The research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to measure return flows used in Title 24 applications. The team developed guidance on performance of current diagnostics as well as a draft test method for use in future evaluations. The series of tests performed measured air flow using a range of techniques and devices. The measured air flows were compared to reference air flow measurements using inline air flow meters built into the test apparatus. The experimental results showed that some devices had reasonable results (typical errors of 5 percent or less) but others had much bigger errors (up to 25 percent). Because manufacturers’ accuracy estimates for their equipment do not include many of the sources of error found in actual field measurements (and replicated in the laboratory testing in this study) it is essential for a test method that could be used to determine the actual uncertainty in this specific application. The study team prepared a draft test method through ASTM International to determine the uncertainty of air flow measurements at residential heating ventilation and air conditioning returns and other terminals. This test method, when finalized, can be used by the Energy Commission and other entities to specify required accuracy of measurement devices used to show compliance with standards.

  9. Some Aspects of Forecasting Severe Thunderstorms during Cool-Season Return-Flow Episodes.

    NASA Astrophysics Data System (ADS)

    Weiss, Steven J.

    1992-08-01

    Historically, the Gulf of Mexico has been considered a primary source of water vapor that influences the weather for much of the United States east of the Rocky Mountains. Although severe thunderstorms and tornadoes occur most frequently during the spring and summer months, the periodic transport of Gulf moisture inland ahead of traveling baroclinic waves can result in significant severe-weather episodes during the cool season.To gain insight into the short-range skill in forecasting surface synoptic patterns associated with moisture return from the Gulf, operational numerical weather prediction models from the National Meteorological Center were examined. Sea level pressure fields from the Limited-Area Fine-Mesh Model (LFM), Nested Grid Model (NGM), and the aviation (AVN) run of the Global Spectral Model, valid 48 h after initial data time, were evaluated for three cool-season cases that preceded severe local storm outbreaks. The NGM and AVN provided useful guidance in forecasting the onset of return flow along the Gulf coast. There was a slight tendency for these models to be slightly slow in the development of return flow. In contrast the LFM typically overforecasts the occurrence of return flow and tends to `open the Gulf' from west to east too quickly.Although the low-level synoptic pattern may be forecast correctly, the overall prediction process is hampered by a data void over the Gulf. It is hypothesized that when the return-flow moisture is located over the Gulf, model forecasts of stability and the resultant operational severe local storm forecasts are less skillful compared to situations when the moisture has spread inland already. This hypothesis is tested by examining the performance of the initial second-day (day 2) severe thunderstorm outlook issued by the National Severe Storms Forecast Center during the Gulf of Mexico Experiment (GUFMEX) in early 1988.It has been found that characteristically different air masses were present along the Gulf coast

  10. Development and evaluation of a meter for measuring return line fluid flow rates during drilling

    SciTech Connect

    Loeppke, G.E.; Schafer, D.M.; Glowka, D.A.; Scott, D.D.; Wernig, M.D. ); Wright, E.K. )

    1992-06-01

    The most costly problem routinely encountered in geothermal drilling is lost circulation, which occurs when drilling fluid is lost to the formation rather than circulating back to the surface. The successful and economical treatment of lost circulation requires the accurate measurement of drilling fluid flow rate both into and out of the well. This report documents the development of a meter for measuring drilling fluid outflow rates in the return line of a drilling rig. The meter employs a rolling counterbalanced float that rides on the surface of the fluid in the return line. The angle of the float pivot arm is sensed with a pendulum potentiometer, and the height of the float is calculated from this measurement. The float height is closely related to the fluid height and, therefore, the flow rate in the line. The prototype rolling float meter was extensively tested under laboratory conditions in the Wellbore Hydraulics Flow Facility; results from these tests were used in the design of the field prototype rolling float meter. The field prototype meter was tested under actual drilling conditions in August and September 1991 at the Long Valley Exploratory Well near Mammoth Lakes, Ca. In addition, the performance of several other commercially available inflow and outflow meters was evaluated in the field. The tested inflow meters included conventional pump stroke counters, rotary pump speed counters, magnetic flowmeters, and an ultrasonic Doppler flowmeter. On the return flow line, a standard paddlemeter, an acoustic level meter, and the prototype rolling float meter were evaluated for measuring drilling fluid outflow rates.

  11. Hydraulic flow characteristics of agricultural residues for denitrifying bioreactor media

    USDA-ARS?s Scientific Manuscript database

    Denitrifying bioreactors are a promising technology to mitigate agricultural subsurface drainage nitrate-nitrogen losses, a critical water quality goal for the Upper Mississippi River Basin. This study was conducted to evaluate the hydraulic properties of agricultural residues that are potential bio...

  12. Simulated responses of streams and ponds to groundwater withdrawals and wastewater return flows in southeastern Massachusetts

    USGS Publications Warehouse

    Carlson, Carl S.; Walter, Donald A.; Barbaro, Jeffrey R.

    2015-12-21

    The percentages of the total number of ponds affected by pumping with wastewater return flows under long-term average conditions in the modeled areas were 28 percent for the Plymouth-Carver region, 67 percent for western Cape Cod, and 75 percent for eastern Cape Cod. Pond-level alterations ranged from a decrease of 4.6 feet at Great South Pond in the Plymouth Carver region to an increase of 0.9 feet at Wequaquet Lake in western Cape Cod. The magnitudes of monthly alterations to pond water levels were fairly consistent throughout the year.

  13. Numerical analysis and simulation of an assured crew return vehicle flow field

    NASA Technical Reports Server (NTRS)

    Weilmuenster, K. James; Smith, Robert E., Jr.; Greene, Francis A.

    1991-01-01

    A lifting body was proposed as a candidate for the Assured Crew Return Vehicle (ACRV) which will serve as a crew rescue vehicle for the Space Station Freedom. The focus is on body surface definition, both surface and volume grid definition, and the computation of inviscid flow fields about the vehicle at wind tunnel conditions. Very good agreement is shown between the computed aerodynamic characteristics of the vehicle at M(sub infinity) = 10 and those measured in wind tunnel tests at high Reynolds numbers.

  14. Compounding Effects of Agricultural Land Use and Water Use in Free-Flowing Rivers: Confounding Issues for Environmental Flows.

    PubMed

    Hardie, Scott A; Bobbi, Chris J

    2017-03-03

    Defining the ecological impacts of water extraction from free-flowing river systems in altered landscapes is challenging as multiple stressors (e.g., flow regime alteration, increased sedimentation) may have simultaneous effects and attributing causality is problematic. This multiple-stressor context has been acknowledged in environmental flows science, but is often neglected when it comes to examining flow-ecology relationships, and setting and implementing environmental flows. We examined the impacts of land and water use on rivers in the upper Ringarooma River catchment in Tasmania (south-east Australia), which contains intensively irrigated agriculture, to support implementation of a water management plan. Temporal and spatial and trends in river condition were assessed using benthic macroinvertebrates as bioindicators. Relationships between macroinvertebrate community structure and environmental variables were examined using univariate and multivariate analyses, focusing on the impacts of agricultural land use and water use. Structural changes in macroinvertebrate communities in rivers in the catchment indicated temporal and spatial declines in the ecological condition of some stretches of river associated with agricultural land and water use. Moreover, water extraction appeared to exacerbate impairment associated with agricultural land use (e.g., reduced macroinvertebrate density, more flow-avoiding taxa). The findings of our catchment-specific bioassessments will underpin decision-making during the implementation of the Ringarooma water management plan, and highlight the need to consider compounding impacts of land and water use in environmental flows and water planning in agricultural landscapes.

  15. A Stochastic-Dynamic Data Assimilation Strategy Applied to Return Flow over the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Lewis, J. M.

    2013-12-01

    A Lagrangian convective air/sea interaction model is used to make ensemble (Monte Carlo) forecasts of return flow over the Gulf of Mexico. This model is especially appropriate for wintertime conditions over the Gulf when the sea surface temperature is generally 5-10C warmer than the continental air that streams over the Gulf in cold air outflow. In the absence of routine upper-air observations over the Gulf, a premier set of observations collected during the field program GUFMEX is used for the study. Uncertainty in both initial conditions and forcing (turbulence and entrainment parameterization) contribute to the structure of the model's probability density function (pdf). A sequential data assimilation scheme is used to optimally estimate model variables based on a variational principle that incorporates the variance/covariance of model error and error variance of observations.Results indicate that buoy-based measurements of air temperature, vapor mixing ratio, and sea surface temperature in concert with the model pdf serve to give reasonable estimates of the height of the convective layer. This result holds promise for improving the operational forecast of return flow over the Gulf in wintertime.

  16. A numerical simulation of the NFAC (National Full-scale Aerodynamics Complex) open-return wind tunnel inlet flow

    NASA Technical Reports Server (NTRS)

    Kaul, U. K.; Ross, J. C.; Jacocks, J. L.

    1985-01-01

    The flow into an open return wind tunnel inlet was simulated using Euler equations. An explicit predictor-corrector method was employed to solve the system. The calculation is time-accurate and was performed to achieve a steady-state solution. The predictions are in reasonable agreement with the experimental data. Wall pressures are accurately predicted except in a region of recirculating flow. Flow-field surveys agree qualitatively with laser velocimeter measurements. The method can be used in the design process for open return wind tunnels.

  17. Environmental flow deficit at global scale - implication on irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Pastor, Amandine; Ludwig, Fulco; Biemans, Hester; Kabat, Pavel

    2016-04-01

    Freshwater species belong to the most degraded ecosystem on earth. At the beginning of the 21st century, scientists have developed the concept of environmental flow requirements (Brisbane declaration 2003) with the aim of protecting freshwater species in the long term. However, the ecological state of rivers is different across the world depending on their fragmentation, on the presence of dams and reservoirs and on the degree of pollution. To implement new regulations on river flow, it is necessary to evaluate the degree of alteration of rivers which we called "environmental flow deficit". The European water framework directive is still working on evaluating the ecological states of river across Europe. In this study, we calculated monthly environmental flow deficit with the global vegetation dynamic and hydrological model LPJml. Environmental flow requirements were first calculated with the Variable Monthly Flow method (Pastor et al., 2014). Then, we checked in each river basin where and when the actual flow (flow minus abstraction for irrigation) does not satisfy environmental flow requirements. We finally show examples of different river basins such as the Nile and the Amazon to show how climate and irrigation can impact river flow and harm freshwater ecosystems.

  18. Agriculture

    EPA Pesticide Factsheets

    The EPA Agriculture Resource Directory offers comprehensive, easy-to-understand information about environmental stewardship on farms and ranches; commonsense, flexible approaches that are both environmentally protective and agriculturally sound.

  19. Mean and turbulent flow statistics in a trellised agricultural canopy

    USDA-ARS?s Scientific Manuscript database

    The architecture of a trellised agricultural canopy presents many similarities to homogeneous plant canopies, windbreaks, and urban canopies including street canyons. Compared to these other canopies, trellised canopies (e.g. vineyard) present an interesting, complex, two-dimensional environment tha...

  20. Managing material transfer and nutrient flow in an agricultural watershed.

    PubMed

    Nord, E A; Lanyon, L E

    2003-01-01

    Place-based resource management, such as watershed or ecosystem management, is being promoted to replace the media-focused approach for achieving water quality protection. We monitored the agricultural area of a 740-ha watershed to determine the nature and scale of farm material transfers, N and P balances, and farmer decisions that influenced them. Using field data and farmer interviews we found that 3 of 15 farms, emphasizing hog, dairy, or cash crops with poultry production, accounted for more than 80% of the inputs and outputs of N and P for the 362-ha agricultural area (332 ha of managed cropland and animal facilities). Feed for hogs (38% each of total N and P) and manure applied to fields as part of the cash crop and poultry operation (28 and 38% of total N and P, respectively) were the dominant inputs. No crops grown in the watershed were fed to animals in the watershed and more manure nutrients were applied from animals outside than from those in the watershed. A strategic decision by the hog farmer to begin marketing finished hogs changed the material transfers and nutrient balances more than tactical decisions by other farmers in allocating manure to cropland. Since the components of agricultural production were not all interconnected, the fundamental assumption of place-based management programs is not well-suited to this situation. Alternative approaches to managing the effect of agriculture on water quality should consider the organization of agricultural production and the role of strategic decisions in controlling farm nutrient balances.

  1. Estimated water withdrawals and return flows in Vermont in 2005 and 2020

    USGS Publications Warehouse

    Medalie, Laura; Horn, Marilee A.

    2010-01-01

    In 2005, about 12 percent of total water withdrawals (440 million gallons per day (Mgal/d)) in Vermont were from groundwater sources (51 Mgal/d), and about 88 percent were from surface-water sources (389 Mgal/d). Of total water withdrawals, about 78 percent were used for cooling at a power plant, 9 percent were withdrawn by public suppliers, about 5 percent were withdrawn for domestic use, about 3 percent were withdrawn for use at fish hatcheries, and the remaining 5 percent were divided among commercial/industrial, irrigation, livestock, and snowmaking uses. About 49 percent of the population of Vermont was supplied with drinking water by a public supplier, and 51 percent was self supplied. Some of the Minor Civil Divisions (MCDs) that had large self-supplied populations were located near the major cities of St. Albans, Burlington, Montpelier, Barre, and Rutland, where the cities themselves were served largely by public supply, but the surrounding areas were not. Most MCDs where withdrawals by community water systems totaled more than 1 Mgal/d used predominantly surface water, and those where withdrawals by community water systems totaled 1 Mgal/d or less used predominantly groundwater. Withdrawals of groundwater greater than 1 Mgal/d were made in Middlebury, Bethel, Hartford, Springfield, and Bennington, and withdrawals of surface water greater than 2 Mgal/d were made in Grand Isle, Burlington, South Burlington, Mendon, Brattleboro, and Vernon. Increases in groundwater withdrawals greater than 0.1 Mgal/d are projected for 2020 for Fairfax, Hardwick, Middlebury, Sharon, Proctor, Springfield, and Manchester. The largest projected increases in surface-water withdrawals from 2005 to 2020 are located along the center axis of the Green Mountains in the ski-area towns of Stowe, Warren, Mendon, Killington, and Wilmington. In 2005, withdrawals were at least 1 Mgal/d greater than return flows in South Burlington, Waterford, Orange, Mendon, Woodford, and Vernon. Many of

  2. 4D phase-contrast flow cardiovascular magnetic resonance: comprehensive quantification and visualization of flow dynamics in atrial septal defect and partial anomalous pulmonary venous return.

    PubMed

    Valverde, Israel; Simpson, John; Schaeffter, Tobias; Beerbaum, Philipp

    2010-11-01

    The case of an 8-year-old girl with atrial septal defect and associated anomalous pulmonary venous return is presented to illustrate the advantages of four dimensional flow (4D flow) over the current two dimensional flow (2D flow) in terms of time efficiency, easy planning, accurate and individual quantification of the blood sources contributing to the left-to-right shunting from one single acquisition, internal validation of flow measurement accuracy, possibility of reanalysis without rescanning in case of unexpected findings during the postprocessing, and comprehensive understanding of flow insight by use of particle tracing visualization.

  3. Fragipan controls on nitrogen loss by surface and subsurface flow pathways in an upland agricultural watershed

    USDA-ARS?s Scientific Manuscript database

    Improved understanding of nutrient transport by surface and subsurface flow pathways is critical to protecting water quality in agricultural watersheds. We sought to compare nitrogen loss in overland and subsurface flow on two opposing hillslopes (north versus south facing), each with contrasting so...

  4. Water Withdrawals, Use, and Wastewater Return Flows in the Concord River Basin, Eastern Massachusetts, 1996-2000

    USGS Publications Warehouse

    Barlow, Lora K.; Hutchins, Linda M.; DeSimone, Leslie A.

    2009-01-01

    Water withdrawals, use, and wastewater return flows for the Concord River Basin were estimated for the period 1996-2000. The study area in eastern Massachusetts is 400 square miles in area and includes the basins of two major tributaries, the Assabet and Sudbury Rivers, along with the Concord River, which starts at the confluence of the two tributaries. About 400,000 people lived in the basin during the study period, on the basis of an analysis of census data, land use, and population density. Public water systems served an estimated 87 percent of the people in the basin, and public wastewater systems served an estimated 65 percent of the basin population. The estimates of water withdrawals, use, wastewater return flows, and imports and exports for the Concord River Basin and 25 subbasins provide information that can be used in hydrologic analyses such as water budgets and can guide water-resources allocations for human and environmental needs. Withdrawals in the basin were estimated at 12,700 million gallons per year (Mgal/yr) during the study period, of which 10,100 Mgal/yr (about 80 percent) were withdrawn by public water-supply systems and 2,650 Mgal/yr were self-supplied by individual users. Water use in the basin and subbasins was estimated by using water withdrawals, average per capita use rates (about 72 gallons per day per person), land-use data, estimated population densities, and other information. Total water use in the basin, which included imports, was 19,200 Mgal/yr and was provided mostly (86.2 percent) by public supply. Domestic use (11,300 Mgal/yr) was the largest component, accounting for about 60 percent of total water use in the basin. Commercial use (3,770 Mgal/yr), industrial use (1,330 Mgal/yr), and agricultural use (including golf-course irrigation; 562 Mgal/yr) accounted for 19.6, 6.9, and 2.9 percent, respectively, of total use. Water that was unaccounted for in public-supply systems was estimated at 2,260 Mgal/yr, or 11.8 percent of

  5. Multiobjective genetic algorithm conjunctive use optimization for production, cost, and energy with dynamic return flow

    NASA Astrophysics Data System (ADS)

    Peralta, Richard C.; Forghani, Ali; Fayad, Hala

    2014-04-01

    Many real water resources optimization problems involve conflicting objectives for which the main goal is to find a set of optimal solutions on, or near to the Pareto front. E-constraint and weighting multiobjective optimization techniques have shortcomings, especially as the number of objectives increases. Multiobjective Genetic Algorithms (MGA) have been previously proposed to overcome these difficulties. Here, an MGA derives a set of optimal solutions for multiobjective multiuser conjunctive use of reservoir, stream, and (un)confined groundwater resources. The proposed methodology is applied to a hydraulically and economically nonlinear system in which all significant flows, including stream-aquifer-reservoir-diversion-return flow interactions, are simulated and optimized simultaneously for multiple periods. Neural networks represent constrained state variables. The addressed objectives that can be optimized simultaneously in the coupled simulation-optimization model are: (1) maximizing water provided from sources, (2) maximizing hydropower production, and (3) minimizing operation costs of transporting water from sources to destinations. Results show the efficiency of multiobjective genetic algorithms for generating Pareto optimal sets for complex nonlinear multiobjective optimization problems.

  6. On the Pathways of the Return Flow of the Meridional Overturning Circulation in the Tropical Atlantic

    NASA Technical Reports Server (NTRS)

    Jochum, Markus

    2002-01-01

    A numerical model of the tropical Atlantic ocean is used to investigate the upper layer pathways of the Meridional Overturning Circulation (MOC) in the tropical Atlantic. The main focus of this thesis is on those parts of the tropical circulation that are thought to be important for the MOC return flow, but whose dynamics have not been understood yet. It is shown how the particular structure of the tropical gyre and the MOO act to inhibit the flow of North Atlantic water into the equatorial thermocline. As a result, the upper layers of the tropical Atlantic are mainly fed by water from the South Atlantic. The processes that carry the South Atlantic water across the tropical Atlantic into the North Atlantic as part of the MOO are described here, and three processes that were hitherto not understood are explained as follows: The North Brazil Current rings are created as the result of the reflection of Rossby waves at the South American coast. These Rossby waves are generated by the barotropically unstable North Equatorial Countercurrent. The deep structure of the rings can be explained by merger of the wave's anticyclones with the deeper intermediate eddies that are generated as the intermediate western boundary current crosses the equator. The bands of strong zonal velocity in intermediate depths along the equator have hitherto been explained as intermediate currents. Here, an alternative interpretation of the observations is offered: The Eulerian mean flow along the equator is negligible and the observations are the signature of strong seasonal Rossby waves. The previous interpretation of the observations can then be explained as aliasing of the tropical wave field. The Tsuchyia Jets are driven by the Eliassen-Palm flux of the tropical instability waves. The equatorial current system with its strong shears is unstable and generates tropical instability waves.

  7. On the Pathways of the Return Flow of the Meridional Overturning Circulation in the Tropical Atlantic

    NASA Technical Reports Server (NTRS)

    Jochum, Markus

    2002-01-01

    A numerical model of the tropical Atlantic ocean is used to investigate the upper layer pathways of the Meridional Overturning Circulation (MOC) in the tropical Atlantic. The main focus of this thesis is on those parts of the tropical circulation that are thought to be important for the MOC return flow, but whose dynamics have not been understood yet. It is shown how the particular structure of the tropical gyre and the MOO act to inhibit the flow of North Atlantic water into the equatorial thermocline. As a result, the upper layers of the tropical Atlantic are mainly fed by water from the South Atlantic. The processes that carry the South Atlantic water across the tropical Atlantic into the North Atlantic as part of the MOO are described here, and three processes that were hitherto not understood are explained as follows: The North Brazil Current rings are created as the result of the reflection of Rossby waves at the South American coast. These Rossby waves are generated by the barotropically unstable North Equatorial Countercurrent. The deep structure of the rings can be explained by merger of the wave's anticyclones with the deeper intermediate eddies that are generated as the intermediate western boundary current crosses the equator. The bands of strong zonal velocity in intermediate depths along the equator have hitherto been explained as intermediate currents. Here, an alternative interpretation of the observations is offered: The Eulerian mean flow along the equator is negligible and the observations are the signature of strong seasonal Rossby waves. The previous interpretation of the observations can then be explained as aliasing of the tropical wave field. The Tsuchyia Jets are driven by the Eliassen-Palm flux of the tropical instability waves. The equatorial current system with its strong shears is unstable and generates tropical instability waves.

  8. Particulate phosphorus transport within stream flow of an agricultural catchment.

    PubMed

    McDowell, R W; Wilcock, R J

    2004-01-01

    There is interest in quantifying phosphorus (P) loss from intensively grazed dairy landscapes to identify key pathways and target remediation methods. The Bog Burn drains a dairying catchment in Southland, New Zealand, and has been monitored at fortnightly intervals over a 12-mo period at four sites for suspended sediment (SS), dissolved reactive phosphorus (DRP), and total phosphorus (TP). Time-integrated samplers, deployed at 0.6 median water depth at each site (calculated from previous year's flow data), collected sediment samples, which were analyzed for SS, bioavailable phosphorus (BAP), and TP. Mean concentrations of DRP and TP in stream flow and BAP and TP in sediment were generally highest in summer or autumn (0.043 mg DRP L(-1), 0.160 mg TP L(-1), 173 mg BAP kg(-1), 2228 mg TP kg(-1)) and lowest in winter or spring (0.012 mg DRP L(-1), 0.034 mg TP L(-1), 6 mg BAP kg(-1), 711 mg TP kg(-1)), while loads were highest in winter. Analysis of (137)Cs concentrations in trapped sediment, topsoil, subsoil, and stream bed and bank sediment indicated that trapped sediment was derived from topsoil and entered the stream either through tile drainage or, to a lesser extent, overland flow. Because concentrations of DRP and TP in stream flow are in excess of recommended limits for good water quality (>0.01 mg DRP L(-1), 0.033 mg TP L(-1)), management should focus on the topsoil and specifically on decreasing P loss via tile drainage. This is best achieved by decreasing soil Olsen P concentrations, especially because, on average, Olsen P concentrations in the catchment were above the agronomic optimum.

  9. Establishing standards and assessment criteria for ecological instream flow needs in agricultural regions of Canada.

    PubMed

    Peters, Daniel L; Baird, Donald J; Monk, Wendy A; Armanini, David G

    2012-01-01

    Agricultural land use can place heavy demands on regional water resources, strongly influencing the quantity and timing of water flows needed to sustain natural ecosystems. The effects of agricultural practices on streamflow conditions are multifaceted, as they also contribute to the severity of impacts arising from other stressors within the river ecosystem. Thus, river scientists need to determine the quantity of water required to sustain important aquatic ecosystem components and ecological services, to support wise apportionment of water for agricultural use. It is now apparent that arbitrarily defined minimum flows are inadequate for this task because the complex habitat requirements of the biota, which underpin the structure and function of a river ecosystem, are strongly influenced by predictable temporal variations in flow. We present an alternative framework for establishing a first-level, regional ecological instream flow needs standard based on adoption of the Indicators of Hydrologic Alteration/Range of Variability Approach as a broadly applicable hydrological assessment tool, coupling this to the Canadian Ecological Flow Index which assesses ecological responses to hydrological alteration. By explicitly incorporating a new field-based ecological assessment tool for small agricultural streams, we provide a necessary verification of altered hydrology that is broadly applicable within Canada and essential to ensure the continuous feedback between the application of flow management criteria and ecological condition.

  10. [Contribution of Base Flow to Total Nitrogen Loading in Subtropical Agricultural Catchments].

    PubMed

    Ma, Qiu-mei; Li, Wei; Wang, Yi; Liu, Xin-liang; Li, Yong; Wu, Jin-shui

    2016-04-15

    With the fast development of economics and improvement of people's living standard, non-point source pollution of the agricultural catchments in subtropical China has become more and more severe, where water quality deterioration has become a main barrier for sustainable development and ecological restoration. The process of ecohydrology in catchment is greatly influenced by the process of base flow in channel. This study selected the Tuojia and Jianshan catchments located in Changsha County, Hunan Province, to quantify and compare the contribution of base flow to total nitrogen (TN) loading from January 2011 to December 2013, through field observation and model estimation. The results suggested that the Tuojia catchment with higher intensity of rice agriculture had the greater volume of base flow, higher average flow-weighted TN concentration in base flow, and greater monthly TN loading via base flow [15.2 mm · month⁻¹, 4.14 mg · L⁻¹ and 0.54 kg · (hm² · month)⁻¹, respectively] than those in the Jianshan catchment with lower intensity [11.4 mm · month⁻¹, 1.72 mg · L⁻¹ and 0.20 kg · (hm² · month)⁻¹, respectively]. The base flow contribution to TN loading showed an apparently seasonal pattern. During rice-growing seasons, the contributions of base flow to TN loading were 23.2% and 18.6% in the Tuojia and Jianshan catchments, respectively, lower than those in the fallow seasons (46.9% and 40.0% correspondingly. These results suggested that rice agriculture increased the contribution of base flow in the fallow season to TN loading. Therefore, to alleviate the suffering of non-point source pollution in the rice agriculture catchments, reasonable management measure of rice fields should be implemented to decrease contrihution of base flow to TN loading.

  11. The future of irrigated agriculture under environmental flow requirements restrictions

    NASA Astrophysics Data System (ADS)

    Pastor, Amandine; Palazzo, Amanda; Havlik, Petr; Kabat, Pavel; Obersteiner, Michael; Ludwig, Fulco

    2016-04-01

    Water is not an infinite resource and demand from irrigation, household and industry is constantly increasing. This study focused on including global water availability including environmental flow requirements with water withdrawal from irrigation and other sectors at a monthly time-step in the GLOBIOM model. This model allows re-adjustment of land-use allocation, crop management, consumption and international trade. The GLOBIOM model induces an endogenous change in water price depending on water supply and demand. In this study, the focus was on how the inclusion of water resources affects land-use and, in particular, how global change will influence repartition of irrigated and rainfed lands at global scale. We used the climate change scenario including a radiative forcing of 8.5 W/m2 (RCP8.5), the socio-economic scenario (SSP2: middle-of-road), and the environmental flow method based on monthly flow allocation (the Variable Monthly Flow method) with high and low restrictions. Irrigation withdrawals were adjusted to a monthly time-step to account for biophysical water limitations at finer time resolution. Our results show that irrigated land might decrease up to 40% on average depending on the choice of EFR restrictions. Several areas were identified as future hot-spots of water stress such as the Mediterranean and Middle-East regions. Other countries were identified to be in safe position in terms of water stress such as North-European countries. Re-allocation of rainfed and irrigated land might be useful information for land-use planners and water managers at an international level to decide on appropriate legislations on climate change mitigation/adaptation when exposure and sensitivity to climate change is high and/or on adaptation measures to face increasing water demand. For example, some countries are likely to adopt measures to increase their water use efficiencies (irrigation system, soil and water conservation practices) to face water shortages, while

  12. Partitioning groundwater recharge between rainfall infiltration and irrigation return flow using stable isotopes: The Crau aquifer

    NASA Astrophysics Data System (ADS)

    Séraphin, Pierre; Vallet-Coulomb, Christine; Gonçalvès, Julio

    2016-11-01

    This study reports an assessment of the water budget of the Crau aquifer (Southern France), which is poorly referenced in the literature. Anthropogenically controlled by a traditional irrigation practice, this alluvial type aquifer requires a robust quantification of the groundwater mass balance in order to establish sustainable water management in the region. In view of the high isotopic contrast between exogenous irrigation waters and local precipitations, stable isotopes of water can be used as conservative tracers to deduce their contributions to the surface recharge. Extensive groundwater sampling was performed to obtain δ18O and δ2H over the whole aquifer. Based on a new piezometric contour map, combined with an updated aquifer geometry, the isotopic data were implemented in a geostatistical approach to produce a conceptual equivalent homogeneous reservoir. This makes it possible to implement a parsimonious water and isotope mass-balance mixing model. The isotopic compositions of the two end-members were assessed, and the quantification of groundwater flows was then used to calculate the two recharge fluxes (natural and irrigation). Nearly at steady-state, the set of isotopic data treated by geostatistics gave a recharge by irrigation of 4.92 ± 0.89 m3 s-1, i.e. 1109 ± 202 mm yr-1, and a natural recharge of 2.19 ± 0.85 m3 s-1, i.e. 128 ± 50 mm yr-1. Thus, 69 ± 9% of the surface recharge is caused by irrigation return flow. This study constitutes a straightforward and independent approach to assess groundwater surface recharges including uncertainties and will help to constrain future transient groundwater models of the Crau aquifer.

  13. Field Observations Of The 29 September Tsunami In American Samoa: Spatial Variability And Indications Of Strong Return Flow

    NASA Astrophysics Data System (ADS)

    Jaffe, B. E.; Richmond, B. M.; Gelfenbaum, G. R.; Watt, S.; Apotsos, A. A.; Buckley, M. L.; Dudley, W. C.; Peck, B.

    2009-12-01

    The 29 September 2009 tsunami caused 181 fatalities and displaced more than 5000 people on the islands of Samoa, American Samoa, and Tonga. This is the first tsunami to cause significant damage and fatalities on U.S. soil in more than 30 years. Scientists from around the world quickly mobilized to help document the tsunami water levels before this ephemeral data was forever lost as recovery activities and natural processes overtook the effected area. A USGS team collected data in American Samoa from October 6-22 and November 5-12, 2009. The tsunami was large, reaching elevations of greater than 15 m, however wave heights and devastation varied from village to village in American Samoa. Even within villages, some structures were completely destroyed, some flooded and left standing, and others barely touched. Wave heights, flow depths, runup heights, inundation distances, and flow directions were collected for use in ground-truthing inundation models. The team also collected nearshore bathymetry, topography and reef flat elevation, sediment samples, and documented the distribution and characteristics of both sand and boulder deposits. Eyewitness accounts of the tsunami were also videotaped. One striking aspect of this tsunami was the abundance of indicators of strong return flow. For example at Poloa in the northwest of Tutuila, where the runup was greater than 11 m along a 300-m stretch of coast and flow depths exceeded 4 m, the coral reef flat was strewn with debris including chairs, desks, and books from a school. On land, River channels were excavated and new channels formed as return flow scoured sediment and transported it offshore. Possible causes for the strong return flow and the relation between the stength of the return flow, inundation distance, and runup in American Samoa are presented. These relationships and others based on data collected by field survey teams will ultimately reduce loss of life and destruction from tsunamis in the Pacific and

  14. Ensemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic conductivity distribution

    NASA Astrophysics Data System (ADS)

    Bailey, R.; Baã¹, D.

    2010-12-01

    Numerical groundwater models, frequently used to enhance understanding of the hydrologic and chemical processes in local or regional aquifers, are often hindered by an incomplete representation of the parameters which characterize these processes. In this study, we present the use of a data assimilation algorithm that incorporates all past model results and data measurements, an ensemble smoother (ES) to provide enhanced estimates of aquifer hydraulic conductivity (K) through assimilation of hydraulic head (H) and groundwater return flow volume (RFV) measurements into groundwater model simulation results. On the basis of the Kalman filter methodology, residuals between forecasted model results and measurements, together with covariances between model results at measurement locations and nonmeasurement locations, are used to correct model results. Parameter estimation is achieved by incorporating model parameters into the algorithm, thus allowing the correlation between H, RFV, and K to correct the K fields. The applicability of the ES is demonstrated using a synthetic two-dimensional transient groundwater modeling simulation. Sensitivity analyses are carried out to show the performance of the ES in regard to measurement error, number of measurements, number of assimilation times, correlation length of the K fields, and the number of stream gage locations. Results show that the departure of the K fields from a reference K field is greatly reduced through data assimilation and demonstrate that the ES scheme is a promising alternative to other inverse modeling techniques because of low computational burden and the ability to run the algorithm entirely independent of the groundwater model simulation.

  15. Assessment of the natural flow regime in a Mediterranean river impacted from irrigated agriculture.

    PubMed

    Stefanidis, Konstantinos; Panagopoulos, Yiannis; Psomas, Alexandros; Mimikou, Maria

    2016-12-15

    Over the last few decades, the natural flow regime of most rivers has been significantly altered influencing the ecological integrity and functioning of river ecosystems. Especially in the Mediterranean region, irrigated agriculture is considered one of the most important drivers of hydro-morphological modifications in river systems. In this study we employ the Indicators of Hydrologic Alteration (IHA) methodology for the Pinios River and its tributaries, located in a Mediterranean catchment in central Greece, with the purpose to assess the natural flow regime under a simulated no-agriculture scenario and compare with the current situation. The work is based on the use of the SWAT (Soil Water Assessment Tool) model for the simulation of long time series of daily stream flows, which were analyzed under the actual conditions (baseline), and the hypothetical scenario. The key characteristics of the flow regime projected under each model run were assessed through the implementation of the IHA methodology that utilizes a number of indicators to characterize the intra- and inter-annual variability in the hydrologic conditions. The results of this study revealed that without agricultural activities in the catchment, annual and monthly flows would increase, with significant alterations in the flow characteristics of the winter months, and much smaller in summer. However, the analysis showed that the frequency of droughts and low flow summer events would be smaller. The article provides a comprehensive and easy-to-implement methodology that can facilitate the impact assessment of agricultural human activities on river flow variability under the typical Mediterranean conditions, allowing experimentation on setting river flow thresholds required for a good ecological status within the context of the European Water Framework Directive.

  16. The Flow of Agricultural Manpower: Its Vocational and Educational Correlates. Final Report.

    ERIC Educational Resources Information Center

    Marvin, R. Paul; Gilbertson, Osmond

    To determine if rural secondary schools were a feasible source of agricultural manpower flow characteristics, 1,302 farmers from 27 southern Minnesota schools were identified on the basis of 1965-1967 school census data. Questionnaires were sent to a random sample of 279, which was divided into those becoming established, those leaving farming,…

  17. Virtual water flows related to land use in an intensive agriculture in the Fergana Valley, Uzbekistan

    NASA Astrophysics Data System (ADS)

    Klipstein, A.; Schneider, K.; Breuer, L.; Frede, H. G.

    2009-04-01

    Due to low annual precipitation, agricultural production in Uzbekistan is depending on irrigation from the Syrdarya and Amudarya rivers to a great deal. One of the most important cash crops of the country is cotton. Current irrigation management leads to elevated groundwater levels, salinization of soils and to a degradation of soil and water resources. Through export of cotton and other crops, the problems related to water consumption and water management are transported beyond the producing country. The amount of water transported through production and export is referred to as virtual water. To distinguish between productive and unproductive partitioning of water flows, the terms green and blue water have been introduced. Information on virtual water flows due to crop production usually only exist on country level. To reduce uncertainties related to generalization, the effect of land management and environmental factors on the partitioning of water flows needs to be studied on smaller scales. The presented study analyzes water fluxes in an intensively used agricultural area in the Fergana Valley, Uzbekistan. The study aims to a) quantify crop specific water consumption in agricultural production under current management and b) analyze water use efficiency as subject to land use and irrigation management. Based on crop production, irrigation management and environmental conditions in the study area, virtual water flows will be calculated on the level of agricultural collectives (Water Users Associations). In a further step, the partitioning of green and blue water fluxes will be quantified. Alternative scenarios for improved water management will be analyzed in a model study.

  18. MODELING LONG-TERM NITRATE BASE-FLOW LOADING FROM TWO AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    Nitrate contamination of ground water from agricultural practices may be contributing to the eutrophication of the Chesapeake Bay, degrading water quality and aquatic habitats. Groundwater flow and nitrate transport and fate are modeled, using MODFLOW and MT3D computer models, in...

  19. MODELING LONG-TERM NITRATE BASE-FLOW LOADING FROM TWO AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    Nitrate contamination of ground water from agricultural practices may be contributing to the eutrophication of the Chesapeake Bay, degrading water quality and aquatic habitats. Groundwater flow and nitrate transport and fate are modeled, using MODFLOW and MT3D computer models, in...

  20. Puerto Rican Migration: The Return Flow = La Migracion Puertorriquena: El Reflujo a la Isla.

    ERIC Educational Resources Information Center

    Vivo, Paquita, Comp.

    This is a guide to materials and research on Puerto Ricans who have returned to Puerto Rico after living in the United States. Part 1 is an annotated bibliography of books, journal articles, printed documents, doctoral dissertations, master's theses, journalistic accounts, and unpublished papers on characteristics of Puerto Rican return migrants;…

  1. Grassland agriculture

    USDA-ARS?s Scientific Manuscript database

    Agriculture in grassland environments is facing multiple stresses from: shifting demographics, declining and fragmented agricultural landscapes, declining environmental quality, variable and changing climate, volatile and increasing energy costs, marginal economic returns, and globalization. Degrad...

  2. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accordance with the terms of their loan agreement and the following: (1) If there is a positive net cash flow... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment... been taken, borrowers will be required to return any unauthorized ROI. (2) If there is negative cash...

  3. Financial modeling in medicine: cash flow, basic metrics, the time value of money, discount rates, and internal rate of return.

    PubMed

    Lexa, Frank James; Berlin, Jonathan W

    2005-03-01

    In this article, the authors cover tools for financial modeling. Commonly used time lines and cash flow diagrams are discussed. Commonly used but limited terms such as payback and breakeven are introduced. The important topics of the time value of money and discount rates are introduced to lay the foundation for their use in modeling and in more advanced metrics such as the internal rate of return. Finally, the authors broach the more sophisticated topic of net present value.

  4. Computer program for discounted cash flow/rate of return evaluations

    NASA Technical Reports Server (NTRS)

    Robson, W. D.

    1971-01-01

    Technique, incorporated into set of three computer programs, provides economic methodology for reducing all parameters to financially sound common denominator of present worth, and calculates resultant rate of return on new equipment, processes, or systems investments.

  5. Ensemble Forecasting of Return Flow over the Gulf of Mexico: Value of the Single Upper Air Obseration

    NASA Astrophysics Data System (ADS)

    Lewis, J. M.; Lakshmivarahan, S.; Hu, J.; Weiss, S.

    2014-12-01

    Abstract A case study of return flow over the Gulf of Mexico has been conducted with the intention of determining the value of a single upper-air observation. This case study makes use of a set of upper-air observations collected by the U. S. Coast Guard ship Salvia that followed the trajectory of return-flow air parcels—essentially collecting observations in a Lagrangian frame of reference. A mixed layer model is used to make an ensemble forecast during the outflow phase of the phenomenon—that period when surface-driven buoyancy is the dynamical mechanism that transports moisture and heat into the atmospheric boundary layer. With this low-order nonlinear model, the contributions to forecast uncertainty that stem from initial conditions, boundary conditions, and physical/empirical parameters can be determined separately. These uncertainties serve as input to a three-dimensional variational (3D-Var) data assimilation scheme. Results indicate that the uncertainty in initial conditions dominates the full complement of uncertainties. An experiment is conducted to evaluate the value of a single set of upper-air observations over the Gulf (at a point near the onset of return flow). It is clear from this experiment that observations near the initial onset point significantly improves the forecast of mixing ratio and offers hope for improvement in operational forecasting with a modest increase in resources.

  6. Controls of evaporative irrigation return flows in comparison to seawater intrusion in coastal karstic aquifers in northern Sri Lanka: evidence from solutes and stable isotopes

    NASA Astrophysics Data System (ADS)

    Chandrajith, Rohana; Diyabalanage, Saranga; Premathilake, Mahinda; Hanke, Christian; van Geldern, Robert; Barth, Johannes A. C.

    2016-04-01

    region occurs through anthropogenic pollution, and particularly so due to agricultural activities. Extensive groundwater use in the peninsula may also further add concerns of active seawater intrusion after intense abstraction. The area should remain under close monitoring for both quality and quantity in order to protect groundwater as a vulnerable resource. Reference Chandrajith, R., Diyabalanage, S., Premathilake, K.M., Hanke, C., van Geldern, R. and Barth, J.A.C. (2016): Controls of evaporative irrigation return flows in comparison to seawater intrusion in coastal karstic aquifers in northern Sri Lanka: evidence from solutes and stable isotopes. - Science of the Total Environment, in press, [doi:10.1016/j.scitotenv.2016.01.050].

  7. Determinants of Mexico-U.S. Outward and Return Migration Flows: A State-Level Panel Data Analysis.

    PubMed

    Chort, Isabelle; de la Rupelle, Maëlys

    2016-10-01

    Using a unique panel data set of state-to-state outward and return migration flows between Mexico and the United States from 1995 to 2012, this study is the first to analyze Mexico-U.S. migration at the state level and explore simultaneously the effect of economic, environmental, and social factors in Mexico over two decades. Pairing origin and destination states and controlling for a rich structure of fixed effects, we find that income positively impacts migration outflows, especially for Mexican states of origin with a recent migration history and for low-educated migrant flows, suggesting the existence of credit constraints. We find evidence that drought causes more out-migration, while other climatic shocks have no effect. Violence is found to increase out-migration flows from border states and to decrease migration from other Mexican states, especially where violence is directed at migrants. Last, return flows are larger when income growth at destination is lower, consistent with the accumulation of savings as a primary motivation of migrants. Exploring the impact of the crisis, we find evidence of significant changes in the geography of migration flows. Traditional flows are drying up, and new migration corridors are rising, with implications on the composition of the Mexican population in the United States. Although the effect of income on flows in both directions is unchanged by the crisis, the negative effect of violence on out-migration tends to reverse at the end of the period. Overall, this study emphasizes the interest of analyzing disaggregated flows at the infra-country level.

  8. Improving basin water use in linked agricultural, ecological and urban systems: seeking new flow paths and avoiding dead ends.

    PubMed

    Molden, D; Bos, M G

    2005-01-01

    In many river basins, patterns of water withdrawals, deliveries, depletion, return flows, and reuse are prevalent. These cascading systems, often misunderstood, provide opportunities, but also threats to livelihoods and environment. Different ways of thinking about these cascading systems are required.

  9. Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport

    USGS Publications Warehouse

    Stone, W.W.; Wilson, J.T.

    2006-01-01

    Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory. This paper uses chloride concentrations to estimate preferential flow contributions to a tile drain during two storms in May 2004. Chloride, a conservative anion, was selected as the tracer because of differences in chloride concentrations between the two sources of water to the tile drain, preferential and matrix flow. A strong correlation between specific conductance and chloride concentration provided a mechanism to estimate chloride concentrations in the tile drain throughout the storm hydrographs. A simple mixing analysis was used to identify the preferential flow component of the storm hydrograph. During two storms, preferential flow contributed 11 and 51% of total storm tile drain flow; the peak contributions, 40 and 81%, coincided with the peak tile drain flow. Positive relations between glyphosate [N-(phosphonomethyl)glycine] concentrations and preferential flow for the two storms suggest that preferential flow is an important transport pathway to the tile drain. ?? ASA, CSSA, SSSA.

  10. Nitrogen and salt loads in the irrigation return flows of the Ebro River Basin (Spain)

    NASA Astrophysics Data System (ADS)

    Isidoro, Daniel; Balcells, Maria; Clavería, Ignacio; Dechmi, Farida; Quílez, Dolores; Aragüés, Ramón

    2013-04-01

    The conservation of the quality of surface waters demanded by the European Water Framework Directive requires, among others, an assessment of the irrigation-induced pollution. The contribution of the irrigation return flows (IRF) to the pollution of the receiving water bodies is given by its pollutant load, since this load determines the quality status or pollutant concentration in these water bodies. The aim of this work was to quantify the annual nitrogen and salt loads in the IRF of four irrigated catchments within the Ebro River Basin: Violada (2006-10), Alcanadre (2008-10), Valcuerna (2010), and Clamor Amarga (2010). The daily flow (Q), salt (EC) and nitrate concentration (NO3) were measured in the drainage outlets of each basin. The net irrigation-induced salt and nitrogen loads were obtained from these measurements after discounting the salt and nitrogen inputs from outside the catchments and the non-irrigated areas. The N-fertilizer applications were obtained from farmer surveys and animal farming statistical sources. Irrigation water salinity was very low in all catchments (EC < 0.4 dS/m), but IRF salinity was very high in Valcuerna (7.9 dS/m) with underlain saline lutites, high to moderate in Clamor (2.6 dS/m) and Violada (2.1 dS/m) with gypsum-rich soils, and low in Alcanadre (1.0 dS/m) due to dilution in the inefficient traditional flood-irrigation system. Annual salt loads were highest in Valcuerna (11.9 Mg/ha) and lowest in Alcanadre (3.6 Mg/ha) and Clamor (3.3 Mg/ha). Salt load was also high in flood-irrigated Violada (10.3 Mg/ha), but dropped to 2.6 Mg/ha after its modernization to sprinkler irrigation (in 2008-09). N-fertilizer applications ranged from 221 kg/ha in the corn-dominated Valcuerna in 2010 to 63 kg/ha in 2008 in Violada, when farmers barely applied fertilizers due to the irrigation modernization works in progress that year. The highest N applications derived from pig slurry applications by farmers that used their lands as disposal sites

  11. The effects of self-generated and applied magnetic fields on the computation of flow over a Mars return aerobrake

    NASA Technical Reports Server (NTRS)

    Palmer, Grant

    1991-01-01

    A CFD technique is developed to calculate the electromagnetic phenomena simultaneously with the fluid flow in the shock layer over an axisymmetric blunt body in a thermal-equilibrium chemical-nonequilibrium environment. The flowfield is solved using an explicit time-marching, first-order spatially accurate scheme. The electromagnetic phenomena are coupled to the real-gas flow solver through an iterative procedure. The electromagnetic terms introduce a strong stiffness, which was overcome by using significantly smaller time steps for the electromagnetic conservation equation. The technique is applied in calculating the flow over a Mars return aerobrake vehicle entering the Earth's atmosphere. For the case where no external field is applied, the electromagnetic effects have little impact on the flowfield.

  12. Virtual water flows in the international trade of agricultural products of China.

    PubMed

    Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

    2016-07-01

    With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Temporal variability of colloidal material in agricultural storm runoff from managed grassland using flow field-flow fractionation.

    PubMed

    Gimbert, Laura J; Worsfold, Paul J

    2009-12-25

    This paper reports the use of flow field-flow fractionation (FlFFF) to determine the temporal variability of colloidal (<1mum) particle size distributions in agricultural runoff waters in a small managed catchment in SW England during storm events. Three storm events of varying intensity were captured and the colloidal material in the runoff analysed by FlFFF. The technique had sufficient sensitivity to determine directly the changing colloidal profile over the 0.08-1.0mum size range in the runoff waters during these storm events. Rainfall, total phosphorus and suspended solids in the bulk runoff samples were also determined throughout one storm and showed significant correlation (P<0.01) with the amount of colloidal material. Whilst there are some uncertainties in the resolution and absolute calibration of the FlFFF profiles, the technique has considerable potential for the quantification of colloidal material in storm runoff waters.

  14. Migratory Patterns of Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-flowing River Basin

    USGS Publications Warehouse

    Eiler, John H.; Evans, Allison N.; Schreck, Carl B.

    2015-01-01

    Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002–2004. Most (97.5%) of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28–40 km d-1) compared to upper basin stocks (52–62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between “hares” (faster fish becoming slower) and “tortoises” (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation

  15. Ditch network sustains functional connectivity and influences patterns of gene flow in an intensive agricultural landscape

    PubMed Central

    Favre-Bac, L; Mony, C; Ernoult, A; Burel, F; Arnaud, J-F

    2016-01-01

    In intensive agricultural landscapes, plant species previously relying on semi-natural habitats may persist as metapopulations within landscape linear elements. Maintenance of populations' connectivity through pollen and seed dispersal is a key factor in species persistence in the face of substantial habitat loss. The goals of this study were to investigate the potential corridor role of ditches and to identify the landscape components that significantly impact patterns of gene flow among remnant populations. Using microsatellite loci, we explored the spatial genetic structure of two hydrochorous wetland plants exhibiting contrasting local abundance and different habitat requirements: the rare and regionally protected Oenanthe aquatica and the more commonly distributed Lycopus europaeus, in an 83 km2 agricultural lowland located in northern France. Both species exhibited a significant spatial genetic structure, along with substantial levels of genetic differentiation, especially for L. europaeus, which also expressed high levels of inbreeding. Isolation-by-distance analysis revealed enhanced gene flow along ditches, indicating their key role in effective seed and pollen dispersal. Our data also suggested that the configuration of the ditch network and the landscape elements significantly affected population genetic structure, with (i) species-specific scale effects on the genetic neighborhood and (ii) detrimental impact of human ditch management on genetic diversity, especially for O. aquatica. Altogether, these findings highlighted the key role of ditches in the maintenance of plant biodiversity in intensive agricultural landscapes with few remnant wetland habitats. PMID:26486611

  16. Investigating summer flow paths in a Dutch agricultural field using high frequency direct measurements

    NASA Astrophysics Data System (ADS)

    Delsman, J. R.; Waterloo, M. J.; Groen, M. M. A.; Groen, J.; Stuyfzand, P. J.

    2014-11-01

    The search for management strategies to cope with projected water scarcity and water quality deterioration calls for a better understanding of the complex interaction between groundwater and surface water in agricultural catchments. We separately measured flow routes to tile drains and an agricultural ditch in a deep polder in the coastal region of the Netherlands, characterized by exfiltration of brackish regional groundwater flow and intake of diverted river water for irrigation and water quality improvement purposes. We simultaneously measured discharge, electrical conductivity and temperature of these separate flow routes at hourly frequencies, disclosing the complex and time-varying patterns and origins of tile drain and ditch exfiltration. Tile drainage could be characterized as a shallow flow system, showing a non-linear response to groundwater level changes. Tile drainage was fed primarily by meteoric water, but still transported the majority (80%) of groundwater-derived salt to surface water. In contrast, deep brackish groundwater exfiltrating directly in the ditch responded linearly to groundwater level variations and is part of a regional groundwater flow system. We could explain the observed salinity of exfiltrating drain and ditch water from the interaction between the fast-responding pressure distribution in the subsurface that determined groundwater flow paths (wave celerity), and the slow-responding groundwater salinity distribution (water velocity). We found water demand for maintaining water levels and diluting salinity through flushing to greatly exceed the actual sprinkling demand. Counterintuitively, flushing demand was found to be largest during precipitation events, suggesting the possibility of water savings by operational flushing control.

  17. Flow-dependent Export Rates of Phosphorus In Two Small Agricultural Basins In England

    NASA Astrophysics Data System (ADS)

    Withers, P. J. A.; Hodgkinson, R. A.; Hutchins, M. G.

    Eutrophication of surface waters is a major environmental problem and agriculture has been identified as an important and increasingly significant source of phospho- rus (P), the major nutrient limiting eutrophication in sensitive fresh waters. In order to better quantify diffuse P export from agricultural land, two small sub-basins (1.5 and 0.96 km2)of contrasting land uses, land cover, soil types and hydrological con- ditions have been intensively monitored since 1994. The basins are representative of lowland farming systems and were instrumented to monitor flow, suspended solids (SS)and dissolved and particulate P fractions at a number of stations strategically lo- cated in the main stream and at specific drain outfalls. Export rates of P were strongly related to flow, with flow-weighted total P concentrations of ca. 1 and 0.3 mg/l, respec- tively; the difference reflecting the dispersive nature of the soils. The partitioning of flow between surface and sub-surface pathways was considered to be the main factor governing P export rates, with flow rates at individual stations influenced by soil mois- ture conditions within theirdrainage basins. The results suggest that an understanding of hydrological processes and water balance is pre-requisite to developig models of P export from river basins. Whilst there was some indication that individual farm actions (e.g. manure application) may have influenced concentrations of P in land run-off on some days, it was concluded that annual P export rates were governed more by the hydrological interaction between land use and landscape characteristics.

  18. Information flow in networks and the law of diminishing marginal returns: evidence from modeling and human electroencephalographic recordings.

    PubMed

    Marinazzo, Daniele; Wu, Guorong; Pellicoro, Mario; Angelini, Leonardo; Stramaglia, Sebastiano

    2012-01-01

    We analyze simple dynamical network models which describe the limited capacity of nodes to process the input information. For a proper range of their parameters, the information flow pattern in these models is characterized by exponential distribution of the incoming information and a fat-tailed distribution of the outgoing information, as a signature of the law of diminishing marginal returns. We apply this analysis to effective connectivity networks from human EEG signals, obtained by Granger Causality, which has recently been given an interpretation in the framework of information theory. From the distributions of the incoming versus the outgoing values of the information flow it is evident that the incoming information is exponentially distributed whilst the outgoing information shows a fat tail. This suggests that overall brain effective connectivity networks may also be considered in the light of the law of diminishing marginal returns. Interestingly, this pattern is reproduced locally but with a clear modulation: a topographic analysis has also been made considering the distribution of incoming and outgoing values at each electrode, suggesting a functional role for this phenomenon.

  19. Behaviour of a small sedimentary volcanic aquifer receiving irrigation return flows: La Aldea, Gran Canaria, Canary Islands (Spain)

    NASA Astrophysics Data System (ADS)

    Cruz-Fuentes, T.; Heredia, J.; Cabrera, M. C.; Custodio, E.

    2014-06-01

    In many arid and semi-arid areas, intensive cultivation is practiced despite water commonly being a limiting factor. Often, irrigation water is from local aquifers or imported from out-of-area aquifers and surface reservoirs. Irrigation return flows become a significant local recharge source, but they may deteriorate aquifer water quality. La Aldea valley, located in the western sector of Gran Canaria Island (Atlantic Ocean), is a coastal, half-closed depression in altered, low-permeability volcanics with alluvium in the gullies and scree deposits over a large part of the area. This area is intensively cultivated. Irrigation water comes from reservoirs upstream and is supplemented (average 30 %) by local groundwater; supplementation goes up to 70 % in dry years, in which groundwater reserves are used up to exhaustion if the dry period persists. Thus, La Aldea aquifer is key to the water-supply system, whose recharge is mostly from return irrigation flows and the scarce local rainfall recharge on the scree formations, conveyed to the gully deposits. To quantify the hydrogeological conceptual model and check data coherence, a simplified numerical model has been constructed, which can be used as a tool to help in water management.

  20. Energy Vs. Productivity: Diminishing Returns

    ERIC Educational Resources Information Center

    MOSAIC, 1975

    1975-01-01

    Energy invested in corn production is compared with food energy returned in calculations by David Pimentel at Cornell University. The rate of return is falling off sharply in this already energy-intensive agriculture. Increased energy input, in the form of fertilizer, would yield far greater returns where agriculture is less sophisticated.…

  1. Energy Vs. Productivity: Diminishing Returns

    ERIC Educational Resources Information Center

    MOSAIC, 1975

    1975-01-01

    Energy invested in corn production is compared with food energy returned in calculations by David Pimentel at Cornell University. The rate of return is falling off sharply in this already energy-intensive agriculture. Increased energy input, in the form of fertilizer, would yield far greater returns where agriculture is less sophisticated.…

  2. Long-Lasting Science Returns from the Apollo Heat Flow Experiments

    NASA Technical Reports Server (NTRS)

    Nagihara, S.; Taylor, P. T.; Williams, D. R.; Zacny, K.; Hedlund, M.; Nakamura, Y.

    2012-01-01

    The Apollo astronauts deployed geothermal heat flow instruments at landing sites 15 and 17 as part of the Apollo Lunar Surface Experiments Packages (ALSEP) in July 1971 and December 1972, respectively. These instruments continuously transmitted data to the Earth until September 1977. Four decades later, the data from the two Apollo sites remain the only set of in-situ heat flow measurements obtained on an extra-terrestrial body. Researchers continue to extract additional knowledge from this dataset by utilizing new analytical techniques and by synthesizing it with data from more recent lunar orbital missions such as the Lunar Reconnaissance Orbiter. In addition, lessons learned from the Apollo experiments help contemporary researchers in designing heat flow instruments for future missions to the Moon and other planetary bodies. For example, the data from both Apollo sites showed gradual warming trends in the subsurface from 1971 to 1977. The cause of this warming has been debated in recent years. It may have resulted from fluctuation in insolation associated with the 18.6-year-cycle precession of the Moon, or sudden changes in surface thermal environment/properties resulting from the installation of the instruments and the astronauts' activities. These types of reanalyses of the Apollo data have lead a panel of scientists to recommend that a heat flow probe carried on a future lunar mission reach 3 m into the subsurface, approx 0.6 m deeper than the depths reached by the Apollo 17 experiment. This presentation describes the authors current efforts for (1) restoring a part of the Apollo heat flow data that were left unprocessed by the original investigators and (2) designing a compact heat flow instrument for future robotic missions to the Moon. First, at the conclusion of the ALSEP program in 1977, heat flow data obtained at the two Apollo sites after December 1974 were left unprocessed and not properly archived through NASA. In the following decades, heat flow

  3. Long-lasting Science Returns from the Apollo Heat Flow Experiments

    NASA Astrophysics Data System (ADS)

    Nagihara, S.; Taylor, P. T.; Williams, D. R.; Zacny, K.; Hedlund, M.; Nakamura, Y.

    2012-12-01

    The Apollo astronauts deployed geothermal heat flow instruments at landing sites 15 and 17 as part of the Apollo Lunar Surface Experiments Packages (ALSEP) in July 1971 and December 1972, respectively. These instruments continuously transmitted data to the Earth until September 1977. Four decades later, the data from the two Apollo sites remain the only set of in-situ heat flow measurements obtained on an extra-terrestrial body. Researchers continue to extract additional knowledge from this dataset by utilizing new analytical techniques and by synthesizing it with data from more recent lunar orbital missions such as the Lunar Reconnaissance Orbiter. In addition, lessons learned from the Apollo experiments help contemporary researchers in designing heat flow instruments for future missions to the Moon and other planetary bodies. For example, the data from both Apollo sites showed gradual warming trends in the subsurface from 1971 to 1977. The cause of this warming has been debated in recent years. It may have resulted from fluctuation in insolation associated with the 18.6-year-cycle precession of the Moon, or sudden changes in surface thermal environment/properties resulting from the installation of the instruments and the astronauts' activities. These types of re-analyses of the Apollo data have lead a panel of scientists to recommend that a heat flow probe carried on a future lunar mission reach 3 m into the subsurface, ~0.6 m deeper than the depths reached by the Apollo 17 experiment. This presentation describes the authors' current efforts for (1) restoring a part of the Apollo heat flow data that were left unprocessed by the original investigators and (2) designing a compact heat flow instrument for future robotic missions to the Moon. First, at the conclusion of the ALSEP program in 1977, heat flow data obtained at the two Apollo sites after December 1974 were left unprocessed and not properly archived through NASA. In the following decades, heat flow data

  4. Modelling the effects of recent agricultural land use change on catchment flow and sediment generation

    NASA Astrophysics Data System (ADS)

    Escobar Ruiz, Veronica; Smith, Hugh; Blake, William

    2016-04-01

    Intensive agricultural practices can exacerbate runoff and soil erosion leading to detrimental impacts downstream. Physically-based models have previously been used to assess the impacts on flow and sediment transport in response to land use change, but there has been little investigation of the effect shorter-term changes linked to variations in the extent of cultivated land. The aim of this project is to quantify the impacts on flow generation and sediment transport of different catchment conditions related to both actual recent changes in agricultural land use as well as future change scenarios. To this end, a physically-based distributed hydrological model, SHETRAN was applied in the Blackwater catchment (12 km2) located in south-west England. Land cover was simulated on the basis of satellite-derived land cover maps (1990, 2000 and 2007) as well as a catchment-scale field survey (2011). Soils were represented in the model using five layers for five different soil types in which parameter values were varied in accordance with land use and literature values. Rainfall data (15 min) combined with monthly calculations of evapotranspiration using a simple temperature-based PE model were used to represent contemporary climatic conditions spanning 2010-2014. Calibration was undertaken for selected events during 2011 when land use information was concurrent with available flow and suspended sediment yield data. All land use simulations were then completed for the period 2010-2014 to enable the comparison of model outputs. This contribution will present preliminary results from these land use simulations alongside the effect of several future changes scenarios on catchment flow and sediment generation.

  5. Field Evaluation of Preferential Flow in Agricultural Soil of the Mississippi Delta

    NASA Astrophysics Data System (ADS)

    Perkins, K. S.; Nimmo, J. R.; Rose, C. E.; Coupe, R.

    2009-12-01

    In the Bogue Phalia basin in the Delta region of northwestern Mississippi, as in many farmed areas, intensive use of agricultural chemicals raises water quality concerns. The soils are fine textured and often exhibit surface ponding and runoff after irrigation and rainfall. There is extensive surface cracking during extended dry periods. Fields are typically land-formed to promote surface flow into irrigation ditches and streams that feed into larger river ecosystems. Deep percolation below the root zone has been considered to be minimal in this area; however, unsaturated zone processes, including the effects of a declining water table, are not well understood, and there are few measured unsaturated zone data relevant to deep percolation. In this study we assessed solute transport mechanisms within and below the root zone of a fallow soybean field by performing a 2-m ring infiltration experiment. Ponding continued for 67 hours using bromide and rhodamine tracers and subsurface instruments for measuring soil-water content, matric pressure, and solution sampling. Water percolated rapidly below the pond reaching 1 m depth in as little as 30 minutes, indicating preferential flow through the root zone, possibly related to shrink/swell features. Extensive lateral flow of water at shallow depths was apparent as the surface wetted outward to several meters from the pond in all directions with some evidence of preferentiality along slope toward the drainage ditch. Deeper lateral flow was detected at solution samplers 3 m from the pond edge at 5 m depth within a few weeks. Tracer was not detected in the unsaturated zone below 5 m however; the tracer was detected at the water table 12 m below land surface within 10 weeks of the experiment with concentrations increasing over a period of 10 months. A tracer mass balance also suggests the possibility for deep preferential transport of agricultural chemicals within the Bogue Phalia basin.

  6. Exposure Time Distributions reveal Denitrification Rates along Groundwater Flow Path of an Agricultural Unconfined Aquifer

    NASA Astrophysics Data System (ADS)

    Kolbe, T.; Abbott, B. W.; Thomas, Z.; Labasque, T.; Aquilina, L.; Laverman, A.; Babey, T.; Marçais, J.; Fleckenstein, J. H.; Peiffer, S.; De Dreuzy, J. R.; Pinay, G.

    2016-12-01

    Groundwater contamination by nitrate is nearly ubiquitous in agricultural regions. Nitrate is highly mobile in groundwater and though it can be denitrified in the aquifer (reduced to inert N2 gas), this process requires the simultaneous occurrence of anoxia, an electron donor (e.g. organic carbon, pyrite), nitrate, and microorganisms capable of denitrification. In addition to this the ratio of the time groundwater spent in a denitrifying environment (exposure time) to the characteristic denitrification reaction time plays an important role, because denitrification can only occur if the exposure time is longer than the characteristic reaction time. Despite a long history of field studies and numerical models, it remains exceedingly difficult to measure or model exposure times in the subsurface at the catchment scale. To approach this problem, we developed a unified modelling approach combining measured environmental proxies with an exposure time based reactive transport model. We measured groundwater age, nitrogen and sulfur isotopes, and water chemistry from agricultural wells in an unconfined aquifer in Brittany, France, to quantify changes in nitrate concentration due to dilution and denitrification. Field data showed large differences in nitrate concentrations among wells, associated with differences in the exposure time distributions. By constraining a catchment-scale characteristic reaction time for denitrification with water chemistry proxies and exposure times, we were able to assess rates of denitrification along groundwater flow paths. This unified modeling approach is transferable to other catchments and could be further used to investigate how catchment structure and flow dynamics interact with biogeochemical processes such as denitrification.

  7. Contribution of base flow to nonpoint source pollution loads in an agricultural watershed

    USGS Publications Warehouse

    Schilling, K.E.; Wolter, C.F.

    2001-01-01

    Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source pollution from base flow ground water was estimated in the Walnut Creek watershed by measuring chemical loads of atrazine, nitrate, chloride, and sulfate at 18 tributary creeks and 19 tiles. Loads were measured during a stable base flow period at creeks and files that discharged into Walnut Creek between two stream gauges. Chemical concentrations of atrazine (< 0.1-12 ??g/L), nitrate (0.1 to 15 mg/L, and chloride (1.5 to 26 mg/L) in water were similar for creek and tile samples. Water draining predominantly agricultural row crop areas had much higher concentrations than water draining restored prairie areas. Three methods were used to estimate base flow discharge in the watershed: (1) Darcy flux; (2) watershed discharge budget; and (3) discharge-drainage area; each yielded similar results (31.2 L/s to 62.3 L/s). Base flow loads to the main channel were estimated by subtracting the loads from the upstream gauge; creeks and tiles, from the total load measured at the downstream gauge station. Base flow concentration for atrazine ranged from 0.15 to 0.29 ??g/L and sulfate concentration ranged from 32 to 64 mg/L, whereas concentrations for nitrate and chloride were negative (-1 to -4 mg/L). Calculated base flow concentrations of atrazine and sulfate appeared to be reasonable estimates, but negative concentrations of nitrate and chloride imply either loss of chemical mass in the stream from upstream to downstream sampling points or measurement error. Load data suggest little contribution from base flow pollutants to Walnut Creek water quality, with most of the pollutant load derived from major tributary creeks. Results from this study have implications for determining total maximum daily loads in agricultural watersheds where contributions from point sources (creeks and tiles) can he used to

  8. Trading and non-trading period Internet information flow and intraday return volatility

    NASA Astrophysics Data System (ADS)

    Shen, Dehua; Zhang, Wei; Xiong, Xiong; Li, Xiao; Zhang, Yongjie

    2016-06-01

    This paper employs the news appeared in Baidu News as the proxy for Internet information flow, separates them into trading period and non-trading period information and provides alternative evidence for the Mixture of Distribution Hypothesis (MDH). The empirical results show that the contemporary information can effectively reduce the volatility persistence; meanwhile, the lead information and the aggregate information also show some explanatory power. Some future directions are pointed out in the concluding remarks.

  9. Impact of seasonal forecast use on agricultural income in a system with varying crop costs and returns: an empirically-grounded simulation

    NASA Astrophysics Data System (ADS)

    Gunda, T.; Bazuin, J. T.; Nay, J.; Yeung, K. L.

    2017-03-01

    Access to seasonal climate forecasts can benefit farmers by allowing them to make more informed decisions about their farming practices. However, it is unclear whether farmers realize these benefits when crop choices available to farmers have different and variable costs and returns; multiple countries have programs that incentivize production of certain crops while other crops are subject to market fluctuations. We hypothesize that the benefits of forecasts on farmer livelihoods will be moderated by the combined impact of differing crop economics and changing climate. Drawing upon methods and insights from both physical and social sciences, we develop a model of farmer decision-making to evaluate this hypothesis. The model dynamics are explored using empirical data from Sri Lanka; primary sources include survey and interview information as well as game-based experiments conducted with farmers in the field. Our simulations show that a farmer using seasonal forecasts has more diversified crop selections, which drive increases in average agricultural income. Increases in income are particularly notable under a drier climate scenario, when a farmer using seasonal forecasts is more likely to plant onions, a crop with higher possible returns. Our results indicate that, when water resources are scarce (i.e. drier climate scenario), farmer incomes could become stratified, potentially compounding existing disparities in farmers’ financial and technical abilities to use forecasts to inform their crop selections. This analysis highlights that while programs that promote production of certain crops may ensure food security in the short-term, the long-term implications of these dynamics need careful evaluation.

  10. Scaling preferential flow processes in agricultural soils affected by tillage and trafficking at the field scale

    NASA Astrophysics Data System (ADS)

    Filipović, Vilim; Coquet, Yves

    2016-04-01

    There is an accumulation of experimental evidences that agricultural soils, at least the top horizons affected by tillage practices, are not homogeneous and present a structure that is strongly dependent on farming practices like tillage and trafficking. Soil tillage and trafficking can create compacted zones in the soil with hydraulic properties and porosity which are different from those of the non-compacted zones. This spatial variability can strongly influence transport processes and initiate preferential flow. Two or three dimensional models can be used to account for spatial variability created by agricultural practices, but such models need a detailed assessment of spatial heterogeneity which can be rather impractical to provide. This logically raises the question whether and how one dimensional model may be designed and used to account for the within-field spatial variability in soil structure created by agricultural practices. Preferential flow (dual-permeability) modelling performed with HYDRUS-1D will be confronted to classical modelling based on the Richards and convection-dispersion equations using HYDRUS-2D taking into account the various soil heterogeneities created by agricultural practices. Our goal is to derive one set of equivalent 1D soil hydraulic parameters from 2D simulations which accounts for soil heterogeneities created by agricultural operations. A field experiment was carried out in two phases: infiltration and redistribution on a plot by uniform sprinkle irrigation with water or bromide solution. Prior to the field experiment the soil structure of the tilled layer was determined along the face of a large trench perpendicular to the tillage direction (0.7 m depth and 3.1 m wide). Thirty TDR probes and tensiometers were installed in different soil structural zones (Δ compacted soil and Γ macroporous soil) which ensured soil water monitoring throughout the experiment. A map of bromide was constructed from small core samples (4 cm diam

  11. Sediment transport by irrigation return flows on the Yakima Indian Reservation, Washington 1975 and 1976 irrigation seasons

    USGS Publications Warehouse

    Nelson, Leonard M.

    1978-01-01

    As determined from data collected at 10 sites on the Yakima Indian Reservation, Wash., during the 1975 and 1976 irrigation seasons (April-September), seasonal sediment discharges in irrigation return flows ranged from 11,000 tons from Marion Drain and Satus Drain 302 to 400 tons from Coulee Drain. There was little variation between the sediment discharges of the 1975 and 1976 irrigation seasons except those from Satus Drain 302. Due to the lack of natural runoff during those seasons, no distinction could be made between sediment discharges from irrigated and nonirrigated areas. No significant or usable relationships were found between suspend-sediment concentration and concurrent water turbidity or discharges. (Woodard-USGS)

  12. IRIS Observations of Coronal Rain and Prominences: Return Flows of the Chromosphere-Corona Mass Cycle

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Berger, Thomas; Antolin, Patrick; Schrijver, Karel

    2014-06-01

    It has recently been recognized that a mass cycle (e.g., Berger et al. 2011; McIntosh et al. 2012) between the hot, tenuous solar corona and the cool, dense chromosphere underneath it plays an important role in the mass budget and dynamic evolution of the solar atmosphere. Although the corona ultimately loses mass through the solar wind and coronal mass ejections, a fraction of its mass returns to the chromosphere in coronal rain, downflows of prominences, and other as-yet unidentified processes. We present here analysis of joint observations of IRIS, SDO/AIA, and Hinode/SOT of such phenomena. By utilizing the wide temperature coverage (logT: 4 - 7) provided by these instruments combined, we track the coronal cooling sequence (e.g., Schrijver 2001; Liu et al. 2012; Berger et al. 2012) leading to the formation of such material at transition region or chromospheric temperatures (logT: 4 - 5) in the million-degree corona. We compare the cooling times with those expected from the radiative cooling instability. We also measure the kinematics and densities of such downflows and infer their mass fluxes, which are compared to the upward mass fluxes into the corona, e.g., those associated with spicules and flux emergence. Special attention is paid to coronal rain formed near cusp-shaped portions of coronal loops, funnel-shaped prominences at dips of coronal loops, and their respective magnetic environments. With the information about where and when such catastrophic cooling events take place, we discuss the implications for the enigmatic coronal heating mechanisms (e.g., Antolin et al. 2010).

  13. [Energy flow characteristics of the compound agriculture-fruit farming system in Xipo Village, Shaanxi, Northwest China].

    PubMed

    Wu, Fa-Qi; Zhu, Li; Wang, Hong-Hong

    2014-01-01

    Taking the crop-fruit farming system in Xipo Village in Chunhua, Shaanxi Province as a case, the energy flow path, input and output structure, and the indices of energy cycle for the agriculture, fruit, stockbreeding and human subsystems were compared between 2008 and 2010. Results showed that during the study period the total investment to the agriculture-fruit farming system (CAF) decreased by 1.6%, while the total output increased by 56.7%, which led to a 59.4% increase of the output/input ratio. Energy output/input ratio of the agriculture, fruit, stockbreeding, human subsystems increased by 36.6%, 21.0%, 10.0% and 3.8%, respectively. The Xipo Village still needed to stabilize the agriculture, develop stockbreeding and strengthen fruit to upgrade the compound agriculture-fruit farming system.

  14. Modeling water flow in a tile drainage network in glacial clayey tills in an agricultural catchment

    NASA Astrophysics Data System (ADS)

    De Schepper, G.; Therrien, R.; Refsgaard, J.

    2013-12-01

    Tile drainage is a widespread water management practice applied to poorly drained production fields to increase crop productivity and reduce flooding risks. A challenge associated with water resources management in agricultural catchments is to properly understand and quantify the role of tile drainage for the catchment water balance. Only a few studies have been presented where different numerical modeling approaches were tested to simulate tile drainage at the field or catchment scale. These studies suggest that challenges still remainto represent correctly subsurface drainage networks in numerical models while accounting for their influence on water flow and transport. To investigate the impact of tile drains, a variably-saturated flow model has been applied to the Lillebaek agricultural catchment, Denmark. The Lillebaek catchment covers 5 ha and is underlain by about 30 m of Quaternary deposits that consist of a local sandy aquifer with upper and lower clayey till units. A tile drainage network is located in the upper clay till. Water table elevations are recorded daily in a network of piezometers within the catchment, as well as drainage and stream discharge. The control volume finite element HydroGeoSphere model is used to simulate 3D variably-saturated flow in the catchment, coupled with 1D open-channel flow in tile drains and 2D overland flow. That approach requires that the tile drainage network be represented explicitly in the model with 1D elements. The 3D field-scale hydrogeological model was first generated from a national-scale geological model for Denmark combined with available local borehole data. A reference model was then generated for 3D variably-saturated subsurface flow coupled with 2D overland flow. That reference model also incorporates discrete 1D elements to represent the entire drainage network, with a critical depth boundary condition applied to the outlet of the drainage networks. A series of simulation were performed to test the

  15. Rapid decline and recovery of cerebral blood flow on return to upright posture

    NASA Astrophysics Data System (ADS)

    Zuj, Kathryn; Harvey, D.; Wheaton, L.; Hughson, R. L.

    2006-05-01

    We examined cardiovascular and cerebrovascular regulation during standing. Nine women and nine men completed 10 min supine rest followed by 70 s standing. We also studied the effectiveness of the cardiopulmonary baroreflex (CPBR) during three levels of LBNP (-10,-20,-30mmHg). Mean flow velocity (MFVMCA) from the right middle cerebral artery (MCA, transcranial Doppler ultrasound), mean arterial pressure (MAP, Finapres), blood pressure at the level of the MCA (BPMCA), and heart rate (HR) were monitored. An index of cerebrovascular resistance (CVRi) was calculated by CVRi=BPMCA/MFVMCA. Baseline values for MAP, MFVMCA, BPMCA, CVRi, and HR were not statistically different between men and women (P>0.1). The 'stand' tests resulted in initial decreases in MAP (19.6-40.5%), MFVMCA (13.0-51.5%), BPMCA (54.6-81.0%), CVRi (49.3-73.1%) and an increase in HR (30.1-106.3%). A greater decrease in MFVMCA, as a percentage of baseline, was seen for men (P=0.007). Men also showed a greater percentage change in MAP (P<0.004) and BPMCA(P<0.04). In the subjects studied for CPBR gain, the preliminary data revealed a negative correlation between reduction in MAP and CPBR gain (r=-0.648). Thus, it is possible the gender difference of smaller declines in MAP for women might have been related to relatively greater CPBR gains.

  16. Shuttle Return-to-Flight IH-108 Aerothermal Test at CUBRC - Flow Field Calibration and CFD

    NASA Technical Reports Server (NTRS)

    Lau, Kei Y.; Holden, Michael

    2010-01-01

    This paper discusses one specific aspect of the Shuttle Retrun-To-Flight IH-108 Aerothermal Test at CUBRC, the test flow field calibration. It showed the versatility of the CUBRC LENS II wind tunnel for an aerothermal test with unique and demanding requirements. CFD analyses were used effectively to extend the test range at the low end of the Mach range. It demonstrated how ground test facility and CFD synergy can be utilitzed iteratively to enhance the confidence in the fedility of both tools. It addressed the lingering concerns of the aerothermal community on use of inpulse facility and CFD analysis. At the conclusion of the test program, members from the NASA Marshall (MSFC), CUBRC and USA (United Space Alliance) Consultants (The Grey Beards) were asked to independently verify the flight scaling data generated by Boeing for flight certification of the re-designed external tank (ET) components. The blind test comparison showed very good results. A more comprehensive discussion of the topics in this paper can be found in Chapter 6 of Reference [1]. The overall aspect of the test program has been discussed in an AIAA paper by Tim Wadhams [2]. The Shuttle Ascent Stack performance and related issues discussed in the Report [1] are not included in this paper. No ITAR data is included in this paper.

  17. Shuttle Return-to-Flight IH-108 Aerothermal Test at CUBRC - Flow Field Calibration and CFD

    NASA Technical Reports Server (NTRS)

    Lau, Kei Y.; Holden, M. S.

    2011-01-01

    This paper discusses one specific aspect of the Shuttle Retrun-To-Flight IH-108 Aerothermal Test at Calspan-University of Buffalo Research Center (CUBRC), the test flow field calibration. It showed the versatility of the CUBRC Large Energy National Shock Tunnel (LENS) II wind tunnel for an aerothermal test with unique and demanding requirements. CFD analyses were used effectively to extend the test range at the low end of the Mach range. It demonstrated how ground test facility and CFD synergy can be utilitzed iteratively to enhance the confidence in the fedility of both tools. It addressed the lingering concerns of the aerothermal community on use of inpulse facility and CFD analysis. At the conclusion of the test program, members from the NASA Marshall (MSFC), CUBRC and USA (United Space Alliance) Consultants (The Grey Beards) were asked to independently verify the flight scaling data generated by Boeing for flight certification of the re-designed external tank (ET) components. The blind test comparison showed very good results.

  18. A Community Returns to Agriculture

    ERIC Educational Resources Information Center

    Saavedra-Vela, Pilar

    1978-01-01

    Aiming to keep the land in the hands of the people, the Cooperativa del pueblo's first venture of steer grazing on land held communally was abandoned due to financial pressure and the community's social needs. Today its plans include teaching families to grow vegetables for longer periods in an organic manner and developing a marketing…

  19. Characterization of flow and infiltration processes on agricultural plots irrigated by submersion.

    NASA Astrophysics Data System (ADS)

    Alkassem Alosman, Mohamed; Ruy, Stéphane; Olioso, Albert; Bader, Jean Claude; Buis, Samuel; Lecharpentier, Patrice; Charron, Francois

    2015-04-01

    The surface irrigation (flood irrigation, trickle and furrow) is a traditional irrigation system widely used worldwide. This system is recognized as being highly water consumer: high volumes of water are injected to the plot, which generate significant loss of water (drainage and run-off). Although these unused water flows can generate positive externalities (feeding wetlands, groundwater recharge) a decrease of water volume used is sought in a context of limited water resource. In this system of irrigation, the amount of water that is actually brought to the plot surface ("irrigation dose") is insufficiently known because it depends on the interaction between the propagation of water at surface of the plot and its infiltration into the soil. These two processes are conditioned by multiple factors: input flow rate in the plot, irrigation duration, soil properties (hydraulic conductivity, water reserve and depth), geometry of the parcel, hydraulic factors (slope of flow, coefficient of friction hydraulic). A methodology is therefore needed for calculating the doses given on an agricultural plot in order to analyse current practices and to propose ways for optimization. The aim of this study is to develop a methodology to estimate (i) the amount of infiltrated water at the scale of a flood irrigated agricultural field, and (ii) soil properties (permeability, useful water reserve). This work is based on the use of a flood irrigation model (CALHY, model Bader et al., 2010, Hydrol. Sci. J., 55, 177-191) combined with a device for tracking the infiltration and the advancing of water in several fields of hay which are irrigated through submersion. Firstly, a sensitivity analysis was used to define an optimal experimental configuration with respect to the estimation of parameters of interest (hydraulic friction, soil water storage capacity, hydraulic conductivity, soil depth). This analysis was performed on each of the model parameters and for different output variables

  20. Simulation of the Effects of Water Withdrawals, Wastewater Return Flows, and Land-Use Change on Streamflow in the Blackstone River Basin, Massachusetts and Rhode Island

    USGS Publications Warehouse

    Barbaro, Jeffrey R.

    2007-01-01

    Streamflow in many parts of the Blackstone River Basin in south-central Massachusetts and northern Rhode Island is altered by water-supply withdrawals, wastewater-return flows, and land-use change associated with a growing population. Simulations from a previously developed and calibrated Hydrological Simulation Program?FORTRAN (HSPF) precipitation-runoff model for the basin were used to evaluate the effects of water withdrawals, wastewater-return flows, and land-use change on streamflow. Most of the simulations were done for recent (1996?2001) conditions and potential buildout conditions in the future when all available land is developed to provide a long-range assessment of the effects of possible future human activities on water resources in the basin. The effects of land-use change were evaluated by comparing the results of long-term (1960?2004) simulations with (1) undeveloped land use, (2) 1995?1999 land use, and (3) potential buildout land use at selected sites across the basin. Flow-duration curves for these land-use scenarios were similar, indicating that land-use change, as represented in the HSPF model, had little effect on flow in the major tributary streams and rivers in the basin. However, land-use change?particularly increased effective impervious area?could potentially have greater effects on the hydrology, water quality, and aquatic habitat of the smaller streams in the basin. The effects of water withdrawals and wastewater-return flows were evaluated by comparing the results of long-term simulations with (1) no withdrawals and return flows, (2) actual (measured) 1996?2001 withdrawals and wastewater-return flows, and (3) potential withdrawals and wastewater-return flows at buildout. Overall, the results indicated that water use had a much larger effect on streamflow than did land use, and that the location and magnitude of wastewater-return flows were important for lessening the effects of withdrawals on streamflow in the Blackstone River Basin

  1. Seventeenth century organic agriculture in China: II. Energy flows through an agroecosystem in Jiaxing Region

    SciTech Connect

    Dazhong, W.; Pimentel, D.

    1986-03-01

    The energy flows in a seventeenth century agroecosystem in Jiaxing Region of eastern China were analyzed on the basis of historical data. The agroecosystem included cropping, mulberry-silkworm livestock, and fishing systems. In terms of energy, the agroecosystem was sustainable. Human labor provided all the power with inputs of about 3700 hr per hectare of farmland. Most or 70% of the labor was expended in the cropping system. Human and animal manure provided most of the nutrients for crop and mulberry production. About two-thirds of the total manure was used in crop production and one-third in the mulberry plantations. The only fossil energy input was a few hand tools. Approximately 55% of the grain was consumed directly by local residents, about one-third of the grain was used to make an alcohol drink and produce distillers' grains, which was fed to pigs, and only 2% of the grains were exported outside the agroecosystem. About two-thirds of the harvested crop residues were used as household fuel, while the remainder was returned to the field as an organic fertilizer. Pork accounted for 85% and silk cocoons 14% of the total animal products produced. Even though the agroecosystem was generally sustainable in terms of energy, the major environmental problem was that two-thirds of the harvested crop residues were used for household fuel. This reduced nutrient cycling in the system. Insufficient land was available to produce fuelwood; thus, crop residues were the primary source of fuel for the people.

  2. Assessment of nitrogen and phosphorus flows in agricultural and urban systems in a small island under limited data availability.

    PubMed

    Firmansyah, I; Spiller, M; de Ruijter, F J; Carsjens, G J; Zeeman, G

    2017-01-01

    Nitrogen (N) and phosphorus (P) are two essential macronutrients required in agricultural production. The major share of this production relies on chemical fertilizer that requires energy and relies on limited resources (P). Since these nutrients are lost to the environment, there is a need to shift from this linear urban metabolism to a circular metabolism in which N and P from domestic waste and wastewater are reused in agriculture. A first step to facilitate a transition to more circular urban N and P management is to understand the flows of these resources in a coupled urban-agricultural system. For the first time this paper presents a Substance Flow Analysis (SFA) approach for the assessment of the coupled agricultural and urban systems under limited data availability in a small island. The developed SFA approach is used to identify intervention points that can provide N and P stocks for agricultural production. The island of St. Eustatius, a small island in the Caribbean, was used as a case study. The model developed in this study consists of eight sub-systems: agricultural and natural lands, urban lands, crop production, animal production, market, household consumption, soakage pit and open-dump landfill. A total of 26 flows were identified and quantified for a period of one year (2013). The results showed that the agricultural system is a significant source for N and P loss because of erosion/run-off and leaching. Moreover, urban sanitation systems contribute to deterioration of the island's ecosystem through N and P losses from domestic waste and wastewater by leaching and atmospheric emission. Proposed interventions are the treatment of blackwater and greywater for the recovery of N and P. In conclusion, this study allows for identification of potential N and P losses and proposes mitigation measures to improve nutrient management in a small island context.

  3. Phosphorus Geochemistry and Transport along Groundwater Flow paths at Five Agricultural Watersheds, USA

    NASA Astrophysics Data System (ADS)

    Domagalski, J. L.; Johnson, H. M.

    2009-12-01

    Phosphorus chemistry and transport were studied at five agricultural watersheds representing a range of climatic conditions and cropping patterns at five locations within the United States (California, Washington, Nebraska, Indiana, Maryland). Orchards and row crops were the dominant land use at the California and Washington locations, while corn and soybeans were the main crops at the remaining three. Irrigation was required at the California and Washington sites, while rain supplied most or all of the water needs at the remainder. Phosphorus concentrations were assessed within the unsaturated zone, along groundwater flow paths of approximately one kilometer in length and at various depths, and across the sediment water interface of receiving streams in small agricultural basins. Baseflow loadings of phosphorus to some of the streams accounted for up to 20% of the annual load in some locations. Unsaturated zone concentrations tended to be higher than groundwater concentrations because of recently applied fertilizer or manure and the rapid downward movement of irrigation or rainwater. Long residence times in groundwater appeared to result in conditions close to chemical equilibrium. In most cases, sorption onto hydrous iron oxides and differences in major element chemistry explained the variation in observed phosphorus concentrations within and between study units. Concentrations of hydrous iron oxides in the aquifer material also affected the saturation levels of sorbed phosphorus relative to the amount dissolved. Solution pH had a major impact at the location in Maryland. Changes in pH from approximately 7 in the unsaturated zone to less than 5 in groundwater resulted in complete sequestration of phosphorus and under-saturation of the iron oxides along the flow path. Low iron oxide concentrations in the unsaturated zone and the aquifer resulted in uniformly higher concentrations at the Nebraska location. High loadings of phosphorus at an orchard in California

  4. 7 CFR 356.8 - Return procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Return procedure. 356.8 Section 356.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FORFEITURE PROCEDURES § 356.8 Return procedure. If, at the conclusion...

  5. Irrigation-dependent wetlands versus instream flow enhancement: economics of water transfers from agriculture to wildlife uses.

    PubMed

    Peck, Dannele E; McLeod, Doanald M; Hewlett, John P; Lovvorn, James R

    2004-12-01

    Irrigated agriculture throughout western North America faces increasing pressure to transfer water to nonagricultural uses, including instream flows for fish and wildlife management. In an important case, increased instream flows are needed in Nebraska's Platte River for recovery of threatened and endangered fish and wildlife species. Irrigated agriculture in the Laramie Basin of southeast Wyoming is a potential water source for the effort to enhance instream flow. However, flood irrigation of hayfields in the Laramie Basin has created many wetlands, both ephemeral and permanent, over the last century. Attempting to increase Platte River instream flows by purchasing water rights or improving irrigation efficiency in the Laramie Basin would transform irrigated agriculture, causing a substantial fraction of the Laramie Basin's wetlands to be lost. A creative solution is needed to prevent the sacrifice of one ecosystem on behalf of another. A rotating short-term water-leasing program is proposed. The program allows Laramie Basin producers to contribute to instream flows while continuing to support local wetlands. Permanent wetland desiccation is prevented and regional environmental water needs are met without impairing local ecological resources. Budget analysis is used to provide an initial cost estimate for acquiring water from agriculture through the short-term leasing program. The proposed approach is more expensive than traditional programs but allows contribution to instream flows without major wetland loss. Short-term leasing is a more efficient approach if benefits from wetlands exceed the difference in cost between the short-term lease program and programs that do not conserve wetlands.

  6. Gene flow and population structure of a common agricultural wild species (Microtus agrestis) under different land management regimes

    PubMed Central

    Marchi, C; Andersen, L W; Damgaard, C; Olsen, K; Jensen, T S; Loeschcke, V

    2013-01-01

    The impact of landscape structure and land management on dispersal of populations of wild species inhabiting the agricultural landscape was investigated focusing on the field vole (Microtus agrestis) in three different areas in Denmark using molecular genetic markers. The main hypotheses were the following: (i) organic farms act as genetic sources and diversity reservoirs for species living in agricultural areas and (ii) gene flow and genetic structure in the agricultural landscape are influenced by the degree of landscape complexity and connectivity. A total of 443 individual voles were sampled within 2 consecutive years from two agricultural areas and one relatively undisturbed grassland area. As genetic markers, 15 polymorphic microsatellite loci (nuclear markers) and the central part of the cytochrome-b (mitochondrial sequence) were analysed for all samples. The results indicate that management (that is, organic or conventional management) was important for genetic population structure across the landscape, but that landscape structure was the main factor shaping gene flow and genetic diversity. More importantly, the presence of organically managed areas did not act as a genetic reservoir for conventional areas, instead the most important predictor of effective population size was the amount of unmanaged available habitat (core area). The relatively undisturbed natural area showed a lower level of genetic structuring and genetic diversity compared with the two agricultural areas. These findings altogether suggest that political decisions for supporting wildlife friendly land management should take into account both management and landscape structure factors. PMID:23900396

  7. Dynamic Attribution of Global Water Demand to Surface Water and Groundwater Resources: Effects of Abstractions and Return Flows on River Discharge

    NASA Astrophysics Data System (ADS)

    de Graaf, Inge; van Beek, Rens; Wada, Yoshi; Bierkens, Marc

    2013-04-01

    As human water demand is increasing worldwide, groundwater is abstracted at rates that exceed groundwater recharge in many areas, resulting in depletion of existing groundwater stocks. Most studies, that focus on human water consumption and water stress indicate a gap between water demand and availability. However, between studies very different assumptions are made on how water abstraction is divided between surface water, groundwater, and other resources. Moreover, simplified assumptions are used of the interactions between groundwater and surface water. Here, we simulate at the global scale, the dynamic attribution of total water demand to surface water and groundwater resources, based on actual water availability and accounting for return flows and surface water- groundwater interactions. The global hydrological model PCR-GLOBWB is used to simulate water storages, abstractions, and return flows for the model period 1960-2010, with a daily time step at 0.5° x 0.5° spatial resolution. Total water demand is defined as requirements for irrigation, industry, and domestic use. Water abstractions are variably taken from surface water and groundwater resources depending on availability of both resources. Return flows of non-consumed abstracted water contribute to a single source; those of irrigation recharging groundwater, those of industry and domestic use discharging to surface waters. Groundwater abstractions are taken from renewable groundwater, or when exceeding recharge from an alternative unlimited resource. This resource consists of non-renewable groundwater, or non-local water, the former being an estimate of groundwater depletion. Results show that worldwide the effect of water abstractions is evident, especially on the magnitude and frequency of low flows when the contribution of groundwater through baseflow is substantial. River regimes are minimally affected by abstractions in industrial regions because of the high return flows. In irrigated regions the

  8. Modeling fecal bacteria transport and retention in agricultural and urban soils under saturated and unsaturated flow conditions.

    PubMed

    Balkhair, Khaled S

    2017-03-01

    Pathogenic bacteria, that enter surface water bodies and groundwater systems through unmanaged wastewater land application, pose a great risk to human health. In this study, six soil column experiments were conducted to simulate the vulnerability of agricultural and urban field soils for fecal bacteria transport and retention under saturated and unsaturated flow conditions. HYDRUS-1D kinetic attachment and kinetic attachment-detachment models were used to simulate the breakthrough curves of the experimental data by fitting model parameters. Results indicated significant differences in the retention and drainage of bacteria between saturated and unsaturated flow condition in the two studied soils. Flow under unsaturated condition retained more bacteria than the saturated flow case. The high bacteria retention in the urban soil compared to agricultural soil is ascribed not only to the dynamic attachment and sorption mechanisms but also to the greater surface area of fine particles and low flow rate. All models simulated experimental data satisfactorily under saturated flow conditions; however, under variably saturated flow, the peak concentrations were overestimated by the attachment-detachment model and underestimated by the attachment model with blocking. The good match between observed data and simulated concentrations by the attachment model which was supported by the Akaike information criterion (AIC) for model selection indicates that the first-order attachment coefficient was sufficient to represent the quantitative and temporal distribution of bacteria in the soil column. On the other hand, the total mass balance of the drained and retained bacteria in all transport experiments was in the range of values commonly found in the literature. Regardless of flow conditions and soil texture, most of the bacteria were retained in the top 12 cm of the soil column. The approaches and the models used in this study have proven to be a good tool for simulating fecal

  9. Methods to determine transit losses for return flows of transmountain water in Fountain Creek between Colorado Springs and the Arkansas River, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard

    1988-01-01

    Methods were developed by which transit losses could be determined for transmountain return flows in Fountain Creek between Colorado Springs, Colorado, and its confluence with the Arkansas River. The study reach is a complex hydrologic system wherein a substantially variable streamflow interacts with an alluvial aquifer. The study approach included: (1) calibration and verification of a streamflow-routing model that contained a bank-storage-discharge component; (2) use of the model to develop the methods by which transit losses could be calculated; and (3) design of an application method for calculating daily transit loss using the model results. Sources of transit losses that were studied are bank storage, channel storage, and evaporation. Magnitude of bank-storage loss primarily depends on duration of a recovery period during which water lost to bank storage is returned to the stream. Net loss to bank storage can vary from about 50% for a 0-day recovery period to about 2% for a 180-day recovery period. Virtually all water lost to bank storage could be returned to the stream with longer recovery periods. Channel-storage loss was determined to be about 10% of a release quantity. Because the loss on any given day is totally recovered in the form of gains from channel storage on the subsequent day, channel storage is a temporary transit loss. Evaporation loss generally is less than 5% of a given daily transmountain return-flow release, depending on month of year. Evaporation losses are permanently lost from the system. (USGS)

  10. Food, Feed, or Fuel? Phosphorus Flows Embodied in US Agricultural Production and Trade

    NASA Astrophysics Data System (ADS)

    MacDonald, G.; Bennett, E.; Carpenter, S.

    2012-12-01

    Agricultural phosphorus (P) use is integral to sustainable food production and water quality regulation. Globalization of agricultural systems, changing diets, and increasing biofuel production pose new challenges for managing non-renewable P reserves, particularly in key agricultural producing regions such as the US. We used a detailed model of the US agricultural system to assess the quantity of mineral P fertilizers used to produce food crops, livestock, and biofuels relative to the P ultimately consumed in domestic diets. We also quantified linkages in fertilizer use between the US and its trading partners globally via agricultural trade. Feed and livestock production drove by far the largest demand for P fertilizers in the US (56% of all P use for domestic and imported products). Of the total mineral P inputs to US domestic agriculture in 2007 (1905 Gg P), 28% were retained in agricultural soils as surplus P, 40% were lost through processing and waste prior to consumption in human diets, while 10% were diverted directly to biofuel production. One quarter of P fertilizer in the US was required to produce exports, particularly major food and feed crops (corn, soybean, and wheat) that drove a large net P flux out of the country (338 Gg P) with strongly crop-specific effects on soil P imbalances nationally. However, US meat consumption involved considerable reliance on P fertilizer use in other countries to produce red meat imports linked primarily to soil P surpluses abroad. We show that changes in domestic farm management and consumer waste could together reduce the P fertilizer needed to produce food consumed in the US by half, which is comparable to the P fertilizer reduction attainable by cutting domestic meat consumption (44%). More effective distribution of P use for major crops nationally and greater recycling of all agricultural wastes is critical to using US phosphate rock reserves as efficiently as possible while maintaining export-oriented agriculture.

  11. Field tracer investigation of unsaturated zone flow paths and mechanisms in agricultural soils of northwestern Mississippi, USA

    USGS Publications Warehouse

    Perkins, K.S.; Nimmo, J.R.; Rose, C.E.; Coupe, R.H.

    2011-01-01

    In many farmed areas, intensive application of agricultural chemicals and withdrawal of groundwater for irrigation have led to water quality and supply issues. Unsaturated-zone processes, including preferential flow, play a major role in these effects but are not well understood. In the Bogue Phalia basin, an intensely agricultural area in the Delta region of northwestern Mississippi, the fine-textured soils often exhibit surface ponding and runoff after irrigation and rainfall as well as extensive surface cracking during prolonged dry periods. Fields are typically land-formed to promote surface flow into drainage ditches and streams that feed into larger river ecosystems. Downward flow of water below the root zone is considered minimal; regional groundwater models predict only 5% or less of precipitation recharges the heavily used alluvial aquifer. In this study transport mechanisms within and below the root zone of a fallow soybean field were assessed by performing a 2-m ring infiltration test with tracers and subsurface monitoring instruments. Seven months after tracer application, 48 continuous cores were collected for tracer extraction to define the extent of water movement and quantify preferential flow using a mass-balance approach. Vertical water movement was rapid below the pond indicating the importance of vertical preferential flow paths in the shallow unsaturated zone, especially to depths where agricultural disturbance occurs. Lateral flow of water at shallow depths was extensive and spatially non-uniform, reaching up to 10. m from the pond within 2. months. Within 1. month, the wetting front reached a textural boundary at 4-5. m between the fine-textured soil and sandy alluvium, now a potential capillary barrier which, prior to extensive irrigation withdrawals, was below the water table. Within 10. weeks, tracer was detectable at the water table which is presently about 12. m below land surface. Results indicate that 43% of percolation may be through

  12. Analysis of Employment Flow of Landscape Architecture Graduates in Agricultural Universities

    ERIC Educational Resources Information Center

    Yao, Xia; He, Linchun

    2012-01-01

    A statistical analysis of employment flow of landscape architecture graduates was conducted on the employment data of graduates major in landscape architecture in 2008 to 2011. The employment flow of graduates was to be admitted to graduate students, industrial direction and regional distribution, etc. Then, the features of talent flow and factors…

  13. Migratory Patterns of Wild Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-Flowing River Basin.

    PubMed

    Eiler, John H; Evans, Allison N; Schreck, Carl B

    2014-01-01

    Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002-2004. Most (97.5%) of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28-40 km d-1) compared to upper basin stocks (52-62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between "hares" (faster fish becoming slower) and "tortoises" (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation exhibited among

  14. Migratory Patterns of Wild Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-Flowing River Basin

    PubMed Central

    Eiler, John H.; Evans, Allison N.; Schreck, Carl B.

    2015-01-01

    Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002–2004. Most (97.5%) of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28–40 km d-1) compared to upper basin stocks (52–62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between “hares” (faster fish becoming slower) and “tortoises” (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation

  15. Prehistoric Agriculture and Soil Fertility on Lava Flows in Northern Arizona, USA: Results from the San Francisco Volcanic Field REU

    NASA Astrophysics Data System (ADS)

    Broadman, E.; Anderson, K. C.

    2013-12-01

    The San Francisco Volcanic Field in northern Arizona is home to ~600 cinder cones, the youngest of which is Sunset Crater (erupted ~AD 1100). This study documents trends in available phosphate and nitrate content with time, testing whether lowered soil pH from the addition of Sunset cinders increased soil fertility and became a factor in Anasazi agricultural success. Soil fertility is examined both before and after Sunset's eruption in soils of different ages that have developed from eolian deposition on top of lava flows. An increase in phosphate and nitrate levels following acidification would suggest that the presence of Sunset cinders brought the soils to the optimal pH for mobilization of these nutrients. The combined effects of the cinder layer retaining nutrients and water, wetter climates, and increases in phosphate and nitrate (both limiting nutrients for plant growth), would have contributed to Anasazi agricultural success after Sunset's eruption. Samples for this study were taken from eolian-derived soils of different ages atop lava flows in the San Francisco Volcanic Field. OSL data from these soils on Strawberry and SP Craters' lava flows yielded age estimates of ~12.3 ka (Strawberry) and ~32.7 ka (SP), on which a soil chronosequence was based. Results from the chronosequence supported these OSL ages, indicating that soils on the SP flow are older than those on the Strawberry flow. Field descriptions, Harden Development Indices, particle size analysis, and nutrient content analysis were used for this aspect of the project. An experimental acid wash method will be used to simulate the addition of Sunset's acidic cinders, and will yield data for phosphate and nitrate content after Sunset erupted. Preliminary results indicate that phosphate and nitrate accumulate in upper, eolian-derived horizons (Av, Bw) and in more deeply buried carbonate horizons (Bk). Higher concentrations of phosphate and nitrate were found in older (SP) soils than younger

  16. Intra-EU agricultural trade, virtual water flows and policy implications.

    PubMed

    Antonelli, M; Tamea, S; Yang, H

    2017-06-01

    The development of approaches to tackle the European Union (EU) water-related challenges and shift towards sustainable water management and use is one of the main objectives of Horizon 2020, the EU strategy to lead a smart, sustainable and inclusive growth. The EU is an increasingly water challenged area and is a major agricultural trader. As agricultural trade entails an exchange of water embodied in goods as a factor of production, this study investigates the region's water-food-trade nexus by analysing intra-regional virtual water trade (VWT) in agricultural products. The analysed period (1993-2011) comprises the enactment of the Water Framework Directive (WFD) in the year 2000. Aspects of the VWT that are relevant for the WFD are explored. The EU is a net importer of virtual water (VW) from the rest of the world, but intra-regional VWT represents 46% of total imports and 75% of total exports. Five countries account for 60% of total VW imports (Germany, France, Italy, The Netherlands, Belgium) and 65% of total VW exports (The Netherlands, France, Germany, Belgium and Spain). Intra-EU VWT more than doubled over the period considered, while trade with extra-EU countries did not show such a marked trend. In the same period, blue VWT increased significantly within the region and net import from the rest of the world slightly decreased. Water scarce countries, such as Spain and Italy, are major exporters of blue water in the region. The traded volumes of VW have been increasing almost monotonically over the years, and with a substantial increase after 2000. The overall trend in changes in VWT does not seem to be in accordance with the WFD goals. This study demonstrated that VWT analyses can help evaluate intertwining effects of water, agriculture and trade policies which are often made separately in respective sectors. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Stable isotope and groundwater flow dynamics of agricultural irrigation recharge into groundwater resources of the Central Valley, California

    SciTech Connect

    Davisson, M.L.; Criss, R.E.

    1995-01-01

    Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the {delta}{sup 18}O values of groundwater were relatively homogeneous (mostly -7.0 {+-} 0.5{per_thousand}), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high {sup 18}O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low {sup 18}O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in {delta}{sup 18}O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are {approximately}10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for {approximately}40 years, creating cones of depression {approximately}25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low {sup 18}O water (-11.0{per_thousand}) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp {sup 18}O gradients in our groundwater isotope map.

  18. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI) in...

  19. 7 CFR 3560.305 - Return on investment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI) in...

  20. Evaluating ecological effects of small-scale agricultural diversions on stream flow in Coastal California

    NASA Astrophysics Data System (ADS)

    Deitch, M. J.; Kondolf, G. M.; Merenlender, A. M.

    2005-05-01

    In the absence of summer precipitation, grape growers in the California wine country often pump water directly from the stream for frost protection, irrigation, and heat protection. Managers may not be able to evaluate the impacts of the many small diversions on flow or anadromous salmonid habitat because of the uncertainty of human water needs. Building on previous research to predict diversion impacts on streamflow, we monitored flow in Franz Creek (a third-order stream draining 40 km2 in Sonoma County) to evaluate our model, and then measured water coverage in riffles and pools to quantify the change in salmonid habitat that these diversions would cause. Our model reasonably predicted flow decreases from diversion for frost protection: flow decreased by up to 80% on each cold morning, causing 50% riffle loss. Though it was not indicated in our model, the loss of habitat on hot summer days (suggesting diversion for heat protection) was also dramatic: levels dropped suddenly, reducing volume in intermittent pools by over 50%. Both changes in flow led to sudden reductions in habitat, suggesting that diversions are a major impediment to salmonid restoration in the region.

  1. Overland flow transport of pathogens from agricultural land receiving faecal wastes.

    PubMed

    Tyrrel, S F; Quinton, J N

    2003-01-01

    Considerable investment has been made in recent years in improvements to the microbiological quality of urban wastewater discharges to surface waters, particularly in coastal towns, with the aim of reducing the exposure of bathers and surfers to gastrointestinal pathogens. As this source of pollution has come under greater control, attention has started to focus on diffuse catchment sources of faecal contamination which have been shown to be dominant during high river flows associated with storm events. This association with storm events suggests that rapidly responding hydrological pathways such as overland flow are likely to be important. The aim of this paper is to establish the current state of knowledge of pathogen transport processes in overland flow. In addition, the paper will attempt to convey the way that soil erosion science may aid our understanding of this environmental problem. The scale and nature of faecal waste applications to land in the UK is briefly reviewed, with data presented on both livestock slurry and manure, and human sewage sludge. Particular emphasis is placed on factors influencing the likelihood of pathogens making their way from infected livestock and humans to the soil surface, and therefore the chances of them being available for transport by overland flow. The literature relating to pathogen transport in overland flow is reviewed. Existing pathogen transport models treat pathogens as particles and link pathogen transport models to pathogen die-off kinetics. Such models do not attempt to describe the interactions that may occur between pathogens and soil and waste particles. Although conceptual models describing the possible states in which pathogen transport may occur have been proposed, an understanding of the factors controlling the partitioning of the microorganisms between the different states is only just beginning to emerge. The apparent poor performance of overland flow mitigation measures such as grass buffer strips in

  2. Municipal water reuse for urban agriculture in Namibia: Modeling nutrient and salt flows as impacted by sanitation user behavior.

    PubMed

    Woltersdorf, L; Scheidegger, R; Liehr, S; Döll, P

    2016-03-15

    Adequate sanitation, wastewater treatment and irrigation infrastructure often lacks in urban areas of developing countries. While treated, nutrient-rich reuse water is a precious resource for crop production in dry regions, excessive salinity might harm the crops. The aim of this study was to quantify, from a system perspective, the nutrient and salt flows a new infrastructure connecting water supply, sanitation, wastewater treatment and nutrient-rich water reuse for the irrigation of agriculture, from a system perspective. For this, we developed and applied a quantitative assessment method to understand the benefits and to support the management of the new water infrastructure in an urban area in semi-arid Namibia. The nutrient and salt flows, as affected by sanitation user behavior, were quantified by mathematical material flow analysis that accounts for the low availability of suitable and certain data in developing countries, by including data ranges and by assessing the effects of different assumptions in cases. Also the nutrient and leaching requirements of a crop scheme were calculated. We found that, with ideal sanitation use, 100% of nutrients and salts are reclaimed and the slightly saline reuse water is sufficient to fertigate 10 m(2)/cap/yr (90% uncertainty interval 7-12 m(2)/cap/yr). However, only 50% of the P contained in human excreta could be finally used for crop nutrition. During the pilot phase fewer sanitation users than expected used slightly more water per capita, used the toilets less frequently and practiced open defecation more frequently. Therefore, it was only possible to reclaim about 85% of nutrients from human excreta, the reuse water was non-saline and contained less nutrient so that the P was the limiting factor for crop fertigation. To reclaim all nutrients from human excreta and fertigate a larger agricultural area, sanitation user behavior needs to be improved. The results and the methodology of this study can be generalized and

  3. 7 CFR 247.26 - Return of administrative funds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 4 2014-01-01 2014-01-01 false Return of administrative funds. 247.26 Section 247.26 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.26 Return of...

  4. 7 CFR 247.26 - Return of administrative funds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Return of administrative funds. 247.26 Section 247.26 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.26 Return of...

  5. 7 CFR 247.26 - Return of administrative funds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Return of administrative funds. 247.26 Section 247.26 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.26 Return of...

  6. 7 CFR 247.26 - Return of administrative funds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Return of administrative funds. 247.26 Section 247.26 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.26 Return of...

  7. 7 CFR 247.26 - Return of administrative funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Return of administrative funds. 247.26 Section 247.26 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.26 Return of...

  8. Lateral Flow of Carbon From U.S. Agricultural Lands: Carbon Uptake, Consumption, and Respiration

    NASA Astrophysics Data System (ADS)

    Sabesan, A.; West, T. O.; Roddy, A. B.; Marland, G.; Bhaduri, B. L.

    2005-12-01

    Net carbon exchange between biomass and the atmosphere can be estimated and modeled on a regional basis to understand the effects of land-use change on the carbon cycle and on net CO2 emissions to the atmosphere. However, within ecosystems that are managed to produce commodities for consumption (i.e., agriculture and forest lands), carbon can be transported laterally when crops or timber are harvested, in addition to being transported vertically between plants and the atmosphere. The spatial and temporal domain over which carbon uptake, transport, and release occur has implications for regional carbon studies. For example, carbon may be taken up by crops in one region, but released through human consumption in another region. Estimates of lateral transport and release of carbon may therefore contribute another dimension to bottom-up carbon modeling, and may also be used as input for comparison to top-down atmospheric modeling. Our research to date has focused on the uptake, consumption, and respiration of CO2 associated with agricultural crops and related food commodities. We estimate a net uptake of 495 Tg C on U.S. croplands in 2000. This uptake occurs primarily in the Midwestern U.S. Human respiration of CO2 contributed about 31 Tg C and livestock emitted about 77 Tg C as CO2 and CH4 in 2000. Estimates of CO2 from food wastes in municipal landfills and from human excrement in wastewater treatment plants are currently being developed. The spatial distribution of CO2 uptake and release are mapped, respectively, at the county level and at 1km resolution that is commensurate with Landscan USA population data.

  9. 7 CFR 160.82 - Return of security.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) NAVAL STORES REGULATIONS AND STANDARDS FOR NAVAL STORES Loan and Care of United States Standards § 160.82 Return of security....

  10. 7 CFR 160.82 - Return of security.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) NAVAL STORES REGULATIONS AND STANDARDS FOR NAVAL STORES Loan and Care of United States Standards § 160.82 Return of security....

  11. Mechanism and rate of denitrification in an agricultural watershed: Electron and mass balance along groundwater flow paths

    USGS Publications Warehouse

    Tesoriero, A.J.; Liebscher, H.; Cox, S.E.

    2000-01-01

    The rate and mechanism of nitrate removal along and between groundwater flow paths were investigated using a series of well nests screened in an unconfined sand and gravel aquifer. Intensive agricultural activity in this area has resulted in nitrate concentrations in groundwater often exceeding drinking water standards. Both the extent and rate of denitrification varied depending on the groundwater flow path. While little or no denitrification occurred in much of the upland portions of the aquifer, a gradual redox gradient is observed as aerobic upland groundwater moves deeper in the aquifer. In contrast, a sharp shallow redox gradient is observed adjacent to a third-order stream as aerobic groundwater enters reduced sediments. An essentially complete loss of nitrate concurrent with increases in excess N2 provide evidence that denitrification occurs as groundwater enters this zone. Electron and mass balance calculations suggest that iron sulfide (e.g., pyrite) oxidation is the primary source of electrons for denitrification. Denitrification rate estimates were based on mass balance calculations using nitrate and excess N2 coupled with groundwater travel times. Travel times were determined using a groundwater flow model and were constrained by chlorofluorocarbon-based age dates. Denitrification rates were found to vary considerably between the two areas where denitrification occurs. Denitrification rates in the deep, upland portions of the aquifer were found to range from < 0.01 to 0.14 mM of N per year; rates at the redoxcline along the shallow flow path range from 1.0 to 2.7 mM of N per year. Potential denitrification rates in groundwater adjacent to the stream may be much faster, with rates up to 140 mM per year based on an in situ experiment conducted in this zone.The rate and mechanism of nitrate removal along and between groundwater flow paths were investigated using a series of well nests screened in an unconfined sand and gravel aquifer. Intensive

  12. Estimation of water withdrawal and distribution, water use, and wastewater collection and return flow in Cumberland, Rhode Island, 1988

    USGS Publications Warehouse

    Horn, M.A.; Craft, P.A.; Bratton, Lisa

    1994-01-01

    Water-use data collected in Rhode Island by different State agencies or maintained by different public suppliers and wastewater- treatment facilities need to be integrated if these data are to be used in making water- resource management decisions. Water-use data for the town of Cumberland, a small area in northeastern Rhode Island, were compiled and integrated to provide an example of how the procedure could be applied. Integration and reliability assessment of water-use data could be facilitated if public suppliers, wastewater- treatment facilities, and State agencies used a number of standardized procedures for data collection and computer storage. The total surface water and ground water withdrawn in the town of Cumberland during 1988 is estimated to be 15.39 million gallons per day, of which 11.20 million gallons per day was exported to other towns. Water use in Cumberland included 2.51 million gallons per day for domestic use, 0.68 million gallons per day for industrial use, 0.27 million gallons per day for commercial use, and 0.73 million gallons per day for other use, most of which were unmetered use. Disposal of waste- water in Cumberland included 2.03 million gallons per day returned to the hydrologic system and 1.73 million gallons per day exported from Cumberland for wastewater treatment. Consumptive use during 1988 is estimated to be 0.43 million gallons per day.

  13. Hydrologic and biogeochemical controls of river subsurface solutes under agriculturally enhanced ground water flow

    USGS Publications Warehouse

    Wildman, R.A.; Domagalski, J.L.; Hering, J.G.

    2009-01-01

    The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples were collected from 30 drive point locations in March, June, and October 2004. Hydrologic processes, described previously, were verified by observations of bromine concentrations; manganese was used to indicate redox conditions. The separate responses of the minor solutes strontium, barium, uranium, and phosphorus to these influences were examined. Correlation and principal component analyses indicate that hydrologic processes dominate the distribution of trace elements in the ground water. Redox conditions appear to be independent of hydrologic processes and account for most of the remaining data variability. With some variability, major processes are consistent in two sampling transects separated by 100 m. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  14. Flow and geochemistry along shallow ground-water flowpaths in an agricultural area in southeastern Wisconsin

    USGS Publications Warehouse

    Saad, D.A.; Thorstenson, D.C.

    1998-01-01

    Ground water recharging at mid- and downgradient wells is oxic and contains dissolved nitrate, whereas the ground water discharging to the stream is anoxic and contains dissolved ammonium. Redox environments were defined at each well on the basis of relative concentrations of various dissolved redox-active species. Chemically permissible flowpaths inferred from the observed sequence of redox environments at well sites are consistent with flowpaths in the ground-water flow model. The transition from nitrate in recharging ground water to ammonium in ground water discharging to the stream suggests the possibility of nitrate reduction along the flowpath. None of the techniques employed in this study, however, were able to prove the occurrence of this reaction.

  15. Controls of evaporative irrigation return flows in comparison to seawater intrusion in coastal karstic aquifers in northern Sri Lanka: Evidence from solutes and stable isotopes.

    PubMed

    Chandrajith, Rohana; Diyabalanage, Saranga; Premathilake, K M; Hanke, Christian; van Geldern, Robert; Barth, Johannes A C

    2016-04-01

    Groundwater in Miocene karstic aquifers in the Jaffna Peninsula of Sri Lanka is an important resource since no other fresh water sources are available in the region. The subsurface is characterized by highly productive limestone aquifers that are used for drinking and agriculture purposes. A comprehensive hydrogeochemical study was carried out to reveal the processes affecting the groundwater quality in this region. Major and trace element composition and environmental isotope ratios of oxygen and hydrogen (δ(18)OH2O and δ(2)HH2O) were determined in 35 groundwater samples for this investigation. The ion abundance of groundwater in the region was characterized by an anion sequence order with HCO3->Cl->SO4->NO3-. For cations, average Na(+)+K(+) contents in groundwater exceeded those of Ca(2+)+Mg(2+) in most cases. Ionic relationships of major solutes indicated open system calcite dissolution while seawater intrusions are also evident but only close to the coast. The solute contents are enriched by agricultural irrigation returns and associated evaporation. This was confirmed by the stable isotope composition of groundwater that deviated from the local meteoric water line (LMWL) and formed its own regression line denoted as the local evaporation line (LEL). The latter can be described by δ(2)HH2O=5.8×δ(18)OH2O -- 2.9. Increased contents of nitrate-N (up to 5mg/L), sulfate (up to 430mg/L) and fluoride (up to 1.5mg/L) provided evidences for anthropogenic inputs of solutes, most likely from agriculture activities. Among trace elements Ba, Sr, As and Se levels in the Jaffna groundwater were higher compared to that of the dry zone metamorphic aquifers in Sri Lanka. Solute geochemistry and stable isotope evidences from the region indicates that groundwater in the area is mainly derived from local modern precipitation but modified heavily by progressive evaporative concentration rather than seawater intrusion. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Assessing hydrodynamic space use of brown trout, Salmo trutta, in a complex flow environment: a return to first principles.

    PubMed

    Kerr, James R; Manes, Costantino; Kemp, Paul S

    2016-11-01

    It is commonly assumed that stream-dwelling fish should select positions where they can reduce energetic costs relative to benefits gained and enhance fitness. However, the selection of appropriate hydrodynamic metrics that predict space use is the subject of recent debate and a cause of controversy. This is for three reasons: (1) flow characteristics are often oversimplified, (2) confounding variables are not always controlled and (3) there is limited understanding of the explanatory mechanisms that underpin the biophysical interactions between fish and their hydrodynamic environment. This study investigated the space use of brown trout, Salmo trutta, in a complex hydrodynamic flow field created using an array of different sized vertically oriented cylinders in a large open-channel flume in which confounding variables were controlled. A hydrodynamic drag function (D) based on single-point time-averaged velocity statistics that incorporates the influence of turbulent fluctuations was used to infer the energetic cost of steady swimming. Novel hydrodynamic preference curves were developed and used to assess the appropriateness of D as a descriptor of space use compared with other commonly used metrics. Zones in which performance-enhancing swimming behaviours (e.g. Kármán gaiting, entraining and bow riding) that enable fish to hold position while reducing energetic costs (termed 'specialised behaviours') were identified and occupancy was recorded. We demonstrate that energy conservation strategies play a key role in space use in an energetically taxing environment with the majority of trout groups choosing to frequently occupy areas in which specialised behaviours may be adopted or by selecting low-drag regions. © 2016. Published by The Company of Biologists Ltd.

  17. Herbicides and herbicide degradation products in upper midwest agricultural streams during august base-flow conditions

    USGS Publications Warehouse

    Kalkhoff, S.J.; Lee, K.E.; Porter, S.D.; Terrio, P.J.; Thurman, E.M.

    2003-01-01

    Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and Minnesota streams during base-flow conditions in August 1997. Atrazine, the most frequently detected herbicide (94%), was present at relatively low concentrations (median 0.17 μg L−1). Metolachlor was detected in 59% and cyanazine in 37% of the samples. Seven of nine compounds detected in more than 50% of the samples were degradation products. The total concentration of the degradation products (median of 4.4 μg L−1) was significantly greater than the total concentration of parent compounds (median of 0.26 μg L−1). Atrazine compounds were present less frequently and in significantly smaller concentrations in streams draining watersheds with soils developed on less permeable tills than in watersheds with soils developed on more permeable loess. The detection and concentration of triazine compounds was negatively correlated with antecedent rainfall (April–July). In contrast, acetanalide compounds were positively correlated with antecedant rainfall in late spring and early summer that may transport the acetanalide degradates into ground water and subsequently into nearby streams. The distribution of atrazine degradation products suggests regional differences in atrazine degradation processes.

  18. Five year water and nitrogen balance for a constructed surface flow wetland treating agricultural drainage waters.

    PubMed

    Borin, Maurizio; Tocchetto, Davide

    2007-07-15

    The performance of a constructed surface flow wetland in reducing diffuse N pollution coming from croplands is being investigated in an ongoing experiment, begun in 1998 in NE Italy. The 0.32 ha wetland is vegetated with Phragmites australis (Cav.) Trin. and Typha latifolia (L.). It receives drainage water from 6 ha of land managed for an experiment on drainage systems, where maize, sugarbeet, winter wheat and soybean are cultivated. During the period 1998-2002, the wetland received from 4698 to 8412 mm of water per year (on average, about 9 times the environmental rainfall); its water regimen was discontinuous and flooding occurred on a variable number of days per year (from 13 to 126). Nitric nitrogen was the most important form of element load. Its concentration in the inflow water over time was rather discontinuous, with median values ranging from 0.2 (in 2001) to 4.5 (in 2000) mg L(-1). Inflow nitric N concentrations were occasionally in the 5-15 mg L(-1) range. Concentrations reduced passing through the wetland, with a more evident effect in the last year. Over 5 years, the wetland received slightly more than 2000 kg ha(-1) of nitrogen, 87% in nitric form mostly from farmland drainage. The remaining 13% of N was applied as organic slurry directly onto the wetland, with 5 distributions during 1998 to assess wetland performance in treating occasional organic loads. Field drainage loads had a discontinuous time pattern and occurred mostly during autumn-winter, with the exception of the 2001-2002 season which was a very dry. The wetland discharged 206 kg ha(-1) of N, over the 5-year period, with an apparent removal efficiency of about 90%. The disappearance was mostly due to plant uptake (1110 kg ha(-1)) and soil accumulation (570 kg ha(-1)), with the contribution of denitrification being estimated at around 7%.

  19. Evaluation of runoff, peak flow and sediment yield for events simulated by the AnnAGNPS model in a Belgian agricultural watershed

    USDA-ARS?s Scientific Manuscript database

    The AnnAGNPS model, widely utilised as a practical tool in approaching erosion problems and land use planning, was implemented in a small agricultural watershed located in central Belgium, to assess its prediction capacity of runoff, peak flow and sediment yield in humid temperate conditions. Model ...

  20. Storm flow dynamics and loads of fecal bacteria associated with ponds in southern piedmont and coastal plain watersheds with animal agriculture

    USDA-ARS?s Scientific Manuscript database

    Storm events that increase hydrologic flow rates can disturb sediments and produce overland runoff in watersheds with animal agriculture, and, thus, can increase surface water concentrations of fecal bacteria and risk to public health. We tested the hypothesis that strategically placed ponds in wate...

  1. Modelling Water Flow, Heat Transport, Soil Freezing and Thawing, and Snow Processes in a Clayey, Subsurface Drained Agricultural Field

    NASA Astrophysics Data System (ADS)

    Warsta, L.; Turunen, M.; Koivusalo, H. J.; Paasonen-Kivekäs, M.; Karvonen, T.; Taskinen, A.

    2012-12-01

    Simulation of hydrological processes for the purposes of agricultural water management and protection in boreal environment requires description of winter time processes, including heat transport, soil freezing and thawing, and snow accumulation and melt. Finland is located north of the latitude of 60 degrees and has one third to one fourth of the total agricultural land area (2.3 milj. ha) on clay soils (> 30% of clay). Most of the clayey fields are subsurface drained to provide efficient drainage and to enable heavy machines to operate on the fields as soon as possible after the spring snowmelt. Generation of drainflow and surface runoff in cultivated fields leads to nutrient and sediment load, which forms the major share of the total load reaching surface waters at the national level. Water, suspended sediment, and soluble nutrients on clayey field surface are conveyed through the soil profile to the subsurface drains via macropore pathways as the clayey soil matrix is almost impermeable. The objective of the study was to develop the missing winter related processes into the FLUSH model, including soil heat transport, snow pack simulation and the effects of soil freezing and thawing on the soil hydraulic conductivity. FLUSH is an open source (MIT license), distributed, process-based model designed to simulate surface runoff and drainflow in clayey, subsurface drained agricultural fields. 2-D overland flow is described with the diffuse wave approximation of the Saint Venant equations and 3-D subsurface flow with a dual-permeability model. Both macropores and soil matrix are simulated with the Richards equation. Soil heat transport is described with a modified 3-D convection-diffusion equation. Runoff and groundwater data was available from different periods from January 1994 to April 1999 measured in a clayey, subsurface drained field section (3.6 ha) in southern Finland. Soil temperature data was collected in two locations (to a depth of 0.8 m) next to the

  2. Estimation of long-term Ca(2+) loss through outlet flow from an agricultural watershed and the influencing factors.

    PubMed

    Zhang, Wenzhao; Yin, Chunmei; Chen, Chunlan; Chen, Anlei; Xie, Xiaoli; Fu, Xingan; Hou, Haijun; Wei, Wenxue

    2016-06-01

    Soil Ca(2+) loss from agricultural lands through surface runoff can accelerate soil acidification and render soil degradation, but the characteristics of Ca(2+) loss and influencing factors in watershed scale are unclear. This study was carried out in a watershed with various land uses in a subtropical region of China. The outlet flow was automatically monitored every 5 min all year round, and the water samples were collected twice a year from 2001 to 2011. The concentrations of Ca(2+), Mg(2+), K(+), total nitrogen (TN), and total phosphorus (TP) of water samples were measured. The dynamic losses of the nutrients through the outlet flow were estimated, and the relationships between the nutrient losses and rainfall intensity as well as antecedent soil moisture were investigated. The results showed that great variations of nutrient concentrations and losses appeared during the investigation period. The average concentrations of Ca(2+), Mg(2+), K(+), TN, and TP were 0.43, 0.08, 0.10, 0.19, and 0.003 mmol L(-1), respectively. The average Ca(2+) loss reached 1493.79 mol ha(-1) year(-1) and was several times higher than for Mg(2+), K(+), and TN, about 140 times higher than for TP. Rainfall intensity had remarkable effects on Ca(2+) concentration (P < 0.01) and loss (P < 0.05) when it reached rainstorm level (50 mm day(-1)), while a quadratic relationship was observed between antecedent soil moisture and Ca(2+) concentration only when rainfall intensity was less than 50 mm day(-1). In a word, much greater amounts of Ca(2+) were lost from the watershed, and this may be one important contributor to the increasing acidification of acidic soils in subtropical regions.

  3. 7 CFR 160.82 - Return of security.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Return of security. 160.82 Section 160.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) NAVAL STORES REGULATIONS...

  4. Water flowing north of the border: export agriculture and water politics in a rural community in Baja California.

    PubMed

    Zlolniski, Christian

    2011-01-01

    Favored by neoliberal agrarian policies, the production of fresh crops for international markets has become a common strategy for economic development in Mexico and other Latin American countries. But as some scholars have argued, the global fresh produce industry in developing countries in which fresh crops are produced for consumer markets in affluent nations implies “virtual water flows,” the transfer of high volumes of water embedded in these crops across international borders. This article examines the local effects of the production of fresh produce in the San Quintín Valley in northwestern Mexico for markets in the United States. Although export agriculture has fostered economic growth and employment opportunities for indigenous farm laborers, it has also led to the overexploitation of underground finite water resources, and an alarming decline of the quantity and quality of water available for residents’ domestic use. I discuss how neoliberal water policies have further contributed to water inequalities along class and ethnic lines, the hardships settlers endure to secure access to water for their basic needs, and the political protests and social tensions water scarcity has triggered in the region. Although the production of fresh crops for international markets is promoted by organizations such as the World Bank and Inter-American Development Bank as a model for economic development, I argue that it often produces water insecurity for the poorest, threatening the UN goal of ensuring access to clean water as a universal human right.

  5. Tatanka Returns.

    ERIC Educational Resources Information Center

    Simonelli, Richard

    1993-01-01

    Describes efforts of the InterTribal Bison Cooperative (Rapid City, SD) to reintroduce the buffalo for cultural purposes to American Indian reservations. Explains how the buffalo's return is contributing to community wellness. Discusses career opportunities for both Native and non-Native people in buffalo management. (LP)

  6. Declining Returns.

    ERIC Educational Resources Information Center

    Rosen, Gerald H.; Perrin, Robert

    1992-01-01

    The Teachers Insurance and Annuities Association's (TIAA) College Retirement and Equity Fund is criticized for its low returns and its chief executive officer's recent salary raise. It is said to be in need of additional regulation and policyholder involvement. A TIAA vice president responds that the analysis given is inaccurate and misleading.…

  7. Tatanka Returns.

    ERIC Educational Resources Information Center

    Simonelli, Richard

    1993-01-01

    Describes efforts of the InterTribal Bison Cooperative (Rapid City, SD) to reintroduce the buffalo for cultural purposes to American Indian reservations. Explains how the buffalo's return is contributing to community wellness. Discusses career opportunities for both Native and non-Native people in buffalo management. (LP)

  8. MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model; documentation of packages for simulating evapotranspiration with a segmented function (ETS1) and drains with return flow (DRT1)

    USGS Publications Warehouse

    Banta, Edward R.

    2000-01-01

    Two new packages for the U.S. Geological Survey modular finite-difference ground-water-flow model MODFLOW-2000 are documented. The new packages provide flexibility in simulating evapotranspiration and drain features not provided by the MODFLOW-2000 Evapotranspiration (EVT) and Drain (DRN) Packages. The report describes conceptualization of the packages, input instructions, listings and explanations of the source code, and example simulations. The new Evapotranspiration Segments (ETS 1) Package allows simulation of evapotranspiration with a user-defined relation between evapotranspiration rate and hydraulic head. This capability provides a degree of flexibility not supported by the EVT Package, which has been available in MODFLOW since its initial release. In the ETS 1 Package, the relation of evapotranspiration rate to hydraulic head is conceptualized as a segmented line between an evaporation surface, defined as the elevation where the evapotranspiration rate reaches a maximum, and an elevation located at an extinction depth below the evaporation surface, where the evapotranspiration rate reaches zero. The user supplies input to define as many intermediate segment endpoints as desired to define the relation of evapotranspiration rate to head between these two elevations. The EVT Package, in contrast, simulates evapotranspiration with a single linear function. The new Drain Return (DRT1) Package can be used to simulate the return flow of water discharged from a drain feature back into the ground-water system. The DRN Package, which has been available in MODFLOW since its initial release, does not have the capability to simulate return of flow. If the return-flow option of the DRT1 Package is selected, for each cell designated as a drain-return cell, the user has the option of specifying a proportion of the water simulated as leaving the ground-water system through the drain feature that is to be simulated as returning simultaneously to one other cell in the model.

  9. The application of Flow Cytometry to the study of ancient agriculture: Evidence for Mesolithic farming in Northern Britain 7200 Cal yr BP.

    NASA Astrophysics Data System (ADS)

    Jones, Richard; Tennant, Richard; Hatton, Jackie; Lee, Rob; Love, John

    2017-04-01

    The onset of agriculture in the UK, (the Mesolithic-Neolithic transition 6000 - 5500 Cal yr BP), has commonly been viewed as the end point of a cultural and technological wave that began in Eastern Europe on the Hungarian Plain 7500 Cal yr BP. This view is not without its critics, due in part to the uncertainty regarding the timing and rate of expansion and the difficulty in identifying the point at which agriculture first arrived in a particular location. Evidence for potential 'episodes' of Mesolithic agricultural activity in the UK has been identified in the UK pollen record, but this data is very tentative. Cereal pollen is typically present in very low concentrations (requiring very large, time consuming counts) and differentiating early cereal pollen from local grasses is very problematic, particularly in areas where the local grasses were domesticated. We present a multi-proxy record from Mere Tarn (54°8'12.09" N 3°7'24.28"W), 2km from the Morecambe Bay coast in South Cumbria, UK; a region with a long history of human occupation extending back into the Palaeolithic. A lacustrine core spanning the Mesolithic and Neolithic has been analysed using a combination of 'traditional' pollen analysis, Flow Cytometry and ancient DNA (aDNA). Flow Cytometry is employed to increase the concentration of cereal type grains in a sample, whilst also providing a more 'targeted' sample for aDNA analysis. The results so far provide clear evidence for an early phase of 'Mesolithic' agriculture in the catchment, spanning only two centuries ( 7300 to 7100 Cal yr BP). This phase is characterised by the occurrence of large cereal type grains (> 38µm), evidence for woodland clearance and the expansion of key anthropogenic indicators such as P. lanceolata. It occurred over 1600 years before the main transition into permanent and intensive agriculture in the catchment, at a time of significant changes in regional climate and sea-level. The results from Mere Tarn provide the earliest

  10. Preferential flow dynamics in agricultural soils in Navarre (Spain): an experimental approach to gain insight into water connectivity

    NASA Astrophysics Data System (ADS)

    Iturria, Iban; Zubieta, Elena; Giménez, Rafael; Ángel Campo-Bescós, Miguel

    2017-04-01

    To address studies on soil erosion and water quality it is essential to understand and quantify water movements through the soil. The estimation of this movement is usually based on soil texture and structure since it is assumed that the water moves across soil matrix. However, soils prone to the formation of cracks or macropores could trigger rapid flow paths, capable of drastically changing the movement of the water and, therefore, its connectivity across the soil. This would have important consequences both for runoff -and thus for erosion- and for groundwater quality. Local preliminary studies have shown that in many agrarian soils in Navarre (Spain), infiltration rate was mainly determined by this type of preferential flow. On the other hand, the formation of these cracks basically responded to expansion/contraction processes of clays due to changes in soil moisture content caused by rainfall. The aim of this work was to quantify in agricultural soil the presence of cracks/macropores responsible for preferential flow and their temporal variation compared to different soil moisture contents. The work was carried out in experimental plots (150 m2) of the UPNA with different type of conventional tillage: (i) mouldboard plough: (ii) chisel and (iii) mouldboard+Molon rake. Each plot was divided into two halves or subplots. On half was submitted to the action of 4 simulated rainfall (5 days passing between each event); whereas in the other half, no rain was applied. Six subplots were thus defined. After each of the 4 rainfall, and once the 5 days had passed, the following experiments were conducted in each of the 6 subplots. In microplots (0.5 m2) a colourant (aqueous solution of bromide) was applied (Lu and Wu, 2003). To be specific, 8 mm of this solution was applied as intense rain with a sprinkler, but avoiding any waterlogging. Then, vertical cuts of 50-60 cm were made where the cracks/macropores were evidenced by the colourant. Photographs of the profiles were

  11. Peer-Interactions in the Adult Mathematics Classroom and the Flow-On Effect to the Children of Women Returning To Study Mathematics.

    ERIC Educational Resources Information Center

    Brew, Christine R.

    The effects that peer interactions in an adult mathematics classroom have on the children of women returning to study mathematics were explored in a case study of seven Australian mothers who had school-aged children and who had returned to study mathematics in Australia's technical and further education sector. During the 12-month study, the…

  12. Groundwater flow path dynamics and nitrogen transport potential in the riparian zone of an agricultural headwater catchment

    USDA-ARS?s Scientific Manuscript database

    Stream riparian zones are often thought of as areas that provide natural remediation for groundwater contaminants, especially agricultural nitrogen (N). While denitrification and vegetative uptake tend to be efficient N removal processes in slow moving shallow groundwater, these mechanisms decrease ...

  13. Some perspective decisions for the regeneration system equipment of the thermal and nuclear power plants decreasing the probability of water ingress into the turbine and rotor acceleration by return steam flow

    NASA Astrophysics Data System (ADS)

    Trifonov, N. N.; Svyatkin, F. A.; Sintsova, T. G.; Ukhanova, M. G.; Yesin, S. B.; Nikolayenkova, E. K.; Yurchenko, A. Yu.; Grigorieva, E. B.

    2016-03-01

    The regeneration system heaters are one of the sources of possible ingress of the water into the turbine. The water penetrates into the turbine either at the heaters overflow or with the return flow of steam generated when the water being in the heater boils up in the dynamic operation modes or at deenergization of the power-generating unit. The return flow of steam and water is dangerous to the turbine blades and can result in the rotor acceleration. The known protective devices used to prevent the overflow of the low-pressure and high-pressure heaters (LPH and HPH), of the horizontal and vertical heaters of heating-system water (HWH and VWH), as well as of the deaerators and low-pressure mixing heaters (LPMH) were considered. The main protective methods of the steam and water return flows supplied by the heaters in dynamic operation modes or at deenergization of the power-generating unit are described. Previous operating experience shows that the available protections do not fully prevent water ingress into the turbine and the rotor acceleration and, therefore, the development of measures to decrease the possibility of ingress of the water into the turbine is an actual problem. The measures allowing eliminating or reducing the water mass in the heaters are expounded; some of them were designed by the specialists of OAO Polzunov Scientific and Development Association on Research and Design of Power Equipment (NPO CKTI) and are efficiently introduced at heat power plants and nuclear power plants. The suggested technical solutions allow reducing the possibility of the water ingress into the turbine and rotor acceleration by return steam flow in the dynamic operation modes or in the case of power generating unit deenergization. Some of these solutions have been tested in experimental-industrial exploitation and can be used in industry.

  14. Relative Path Impact Index (RPII): a morphometric approach to quantify the effect of anthropogenic features on surface flow processes in agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Tarolli, P.; Prosdocimi, M.; Sofia, G.; Preti, F.; Dalla Fontana, G.

    2014-12-01

    Soil erosion in cultivated land is one of the main critical issue because of its significant economic consequences, especially whether it occurs in hilly and mountainous environments. Among the cultivated lands, vineyards deserve a particular attention. In fact, they not only represent one of the most important crop in terms of income and employment, but they also constitute the form of agricultural land use that causes the highest soil loss. In these cultivated lands, the construction of terraces is one of the most widely used system for soil and water conservation measures. However, while favoring agricultural activities, terraces may cause local instabilities as well, if they are not properly maintained. Terraced fields are also served by agricultural roads and the construction of these anthropogenic features can have deep effects on water flows and instabilities. In fact, the plane surface of roads can intercept the overland and the subsurface flow and can modify the natural flow directions expanding the drainage network. The main objective of this work is to use high-resolution topography derived from lidar technology for a hydro-geomorphological analysis of terraced vineyards. We considered few case studies located in Italy. At first, the Relative Path Impact Index (RPII) is used to identify likely sections of terraces and agricultural roads subject to potential landsliding or erosion. Statistical thresholds of RPII are then defined to label the most critical areas. Afterwards, using the index and the defined thresholds, different scenarios of soil conservation measures are simulated, to establish the optimal solution for erosion reduction. The results prove the effectiveness of high-resolution topography in the analysis of surface erosion in terraced vineyards, when the surface water flow is the main factor triggering the instabilities. This preliminary analysis can help in scheduling a suitable planning to mitigate the consequences of the anthropogenic

  15. Theme: Agricultural Literacy about Agriculture.

    ERIC Educational Resources Information Center

    Frick, Martin J.; And Others

    1996-01-01

    Includes "'Sharing' the Gospel According to Agriculture!" (Frick); "Agricultural Literacy: An Integrated Content and Partnership Approach" (Parmley et al.); "Idaho Agriculture in the Classroom" (Pals, Waitley); "Middle School Agricultural Education" (Moore, Violett); "Agricultural Communication"…

  16. Effect of the submergence, the bed form geometry, and the speed of the surface water flow on the mitigation of pesticides in agricultural ditches

    NASA Astrophysics Data System (ADS)

    Boutron, Olivier; Margoum, Christelle; Chovelon, Jean-Marc; Guillemain, CéLine; Gouy, VéRonique

    2011-08-01

    Pesticides, which have been extensively used in agriculture, have become a major environmental issue, especially regarding surface and groundwater contamination. Of particular importance are vegetated farm drainage ditches, which can play an important role in the mitigation of pesticide contamination by adsorption onto ditch bed substrates. This role is, however, poorly understood, especially regarding the influence of hydrodynamic parameters, which make it difficult to promote best management practice of these systems. We have assessed the influence of three of these parameters (speed of the surface water flow, submergence, and geometrical characteristics of the bed forms) on the transfer and adsorption of selected pesticides (isoproturon, diuron, tebuconazole, and azoxystrobin) into the bed substrate by performing experiments with a tilted experimental flume, using hemp fibers as a standard of natural organic substrates that are found at the bottom of agricultural ditches. Results show the transfer of pesticides from surface water flow into bed substrate is favored, both regarding the amounts transferred into the bed substrate and the kinetics of the transfer, when the surface water speed and the submergence increase and when the bed forms are made of rectangular shapes. Extrapolation of flume data over a distance of several hundred meters suggests that an interesting possibility for improving the mitigation of pesticides in ditches would be to increase the submergence and to favor bed forms that tend to enhance perturbations and subsequent infiltration of the surface water flow.

  17. Variations in Withdrawal, Return Flow, and Consumptive Use of Water in Ohio and Indiana, with Selected Data from Wisconsin, 1999-2004

    USGS Publications Warehouse

    Shaffer, Kimberly H.

    2009-01-01

    This report contains an analysis of water withdrawal and return-flow data for Ohio and withdrawal data for Indiana and Wisconsin to compute consumptive-use coefficients and to describe monthly variability of withdrawals and consumptive use. Concurrent data were available for most water-use categories from 1999 through 2004. Average monthly water withdrawals are discussed for a variety of water-use categories, and average water use per month is depicted graphically for Ohio, Indiana, and Wisconsin (public supply only). For most water-use categories, the summer months were those of highest withdrawal and highest consumptive use. For public supply, average monthly withdrawals ranged from 1,380 million gallons per day (Mgal/d) (November) to 1,620 Mgal/d (July) in Ohio, 621 Mgal/d (December) to 816 Mgal/d (July) in Indiana, and 515 Mgal/d (December) to 694 Mgal/d (July) in Wisconsin. Ohio and Indiana thermoelectric facilities had large increases in average monthly withdrawals in the summer months (5,520 Mgal/d in March to 7,510 Mgal/d in August for Indiana; 7,380 Mgal/d in February to 10,040 Mgal/d in July for Ohio), possibly because of increased electricity production in the summer, a need for additional cooling-water withdrawals when intake-water temperature is high, or use of different types of cooling methods during different times of the year. Average industrial withdrawals ranged from 2,220 Mgal/d (December) to 2,620 Mgal/d (August) in Indiana and from 707 Mgal/d (January) to 787 Mgal/d (August) in Ohio. The Ohio and Indiana irrigation data showed that most withdrawals were in May through October for golf courses, nurseries, and crop irrigation. Commercial water withdrawals ranged from 30.4 Mgal/d (January) to 65.0 Mgal/d (September) in Indiana and from 23.2 Mgal/d (November) to 49.5 Mgal/d (August) in Ohio; commercial facilities that have high water demand in Ohio and Indiana are medical facilities, schools, amusement facilities, wildlife facilities, large stores

  18. Assessing environmental risks for high intensity agriculture using the material flow analysis method--a case study of the Dongting Lake basin in South Central China.

    PubMed

    Yin, Guanyi; Liu, Liming; Yuan, Chengcheng

    2015-07-01

    This study primarily examined the assessment of environmental risk in high intensity agricultural areas. Dongting Lake basin was taken as a case study, which is one of the major grain producing areas in China. Using data obtained from 1989 to 2012, we applied Material Flow Analysis (MFA) to show the material consumption, pollutant output and production storage in the agricultural-environmental system and assessed the environmental risk index on the basis of the MFA results. The results predicted that the status of the environmental quality of the Dongting Lake area is unsatisfactory for the foreseeable future. The direct material input (DMI) declined by 13.9%, the domestic processed output (DPO) increased by 28.21%, the intensity of material consumption (IMC) decreased by 36.7%, the intensity of material discharge (IMD) increased by 10%, the material productivity (MP) increased by 27 times, the environmental efficiency (EE) increased by 15.31 times, and the material storage (PAS) increased by 0.23%. The DMI and DPO was higher at rural places on the edge of cities, whereas the risk of urban agriculture has arisen due to the higher increasing rate of DMI and DPO in cities compared with the counties. The composite environmental risk index increased from 0.33 to 0.96, indicating that the total environmental risk changed gradually but seriously during the 24 years assessed. The driving factors that affect environmental risk in high intensity agriculture can be divided into five classes: social, economic, human, natural and disruptive incidents. This study discussed a number of effective measures for protecting the environment while ensuring food production yields. Additional research in other areas and certain improvements of this method in future studies may be necessary to develop a more effective method of managing and controlling agricultural-environmental interactions.

  19. HYDROGEOLOGIC FOUNDATION IN SUPPORT OF ECOSYSTEM RESTORATION: BASE-FLOW LOADINGS OF NITRATE IN MID-ATLANTIC AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    The study is a consortium between the U.S. Environmental Protection Agency (National Risk Management Research Laboratory) and the U.S. Geological Survey (Baltimore and Dover). The objectives of this study are: (1) to develop a geohydrological database for paired agricultural wate...

  20. Relationship of Stream Flow Rates to Nitrate-N and Pesticide Attenuation in an Agriculturally Impacted First-Order Riparian System, Inner Coastal Plain, Maryland

    NASA Astrophysics Data System (ADS)

    Angier, J. T.; McCarty, G. W.; Rice, C. P.; Prestegaard, K. L.

    2002-05-01

    A valuable function of riparian zones in agricultural settings is the mitigation of contaminants applied to nearby crop fields. This riparian function can be highly variable, both spatially and temporally, within a single ecosystem. Some of this variability may result from hydrological differences, which in turn are influenced by meteorological changes and local geomorphology. The site of this study is part of the USDA-ARS Beltsville Agricultural Research Center in Maryland. It consists of a small, first-order stream and associated riparian zone. The riparian zone receives nutrient and pesticide loads from the neighboring agricultural field. The stream is instrumented with five monitoring/sampling stations for evaluating stream flows and water quality along stream length intervals. Approximately 170 piezometers have been instrumented throughout the site. Three full years of data have been compiled and analyzed. The exportability of some contaminants (nitrate-N and Metolachlor metabolites) appears to be dependent upon stream flow conditions. Higher stream baseflows are strongly linked to higher stream contaminant loads. In the case of nitrate-N, higher stream baseflows tend to yield higher stream nitrate concentrations as well as higher nitrate fluxes, particularly in the downstream sections. There are seasonal patterns in stream nitrate fluxes that suggest in-stream (hyporheic) nitrate processing occurs. Evidence for loss of nitrate within the stream is especially apparent in late Autumn and early Winter, when decaying leaves collect in pools along the stream channel; there is often a downstream increase in stream flow, but a loss of nitrate flux. There is also evidence for stream N processing during Summer. Groundwater quality and delivery patterns vary spatially, and in response to changes in climate, affecting the stream water characteristics as well. Stream nitrate-N and pesticide loads increase with higher stream baseflow conditions because there is more rapid

  1. [Ecological management model of agriculture-pasture ecotone based on the theory of energy and material flow--a case study in Houshan dryland area of Inner Mongolia].

    PubMed

    Fan, Jinlong; Pan, Zhihua; Zhao, Ju; Zheng, Dawei; Tuo, Debao; Zhao, Peiyi

    2004-04-01

    The degradation of ecological environment in the agriculture-pasture ecotone in northern China has been paid more attentions. Based on our many years' research and under the guide of energy and material flow theory, this paper put forward an ecological management model, with a hill as the basic cell and according to the natural, social and economic characters of Houshan dryland farming area inside the north agriculture-pasture ecotone. The input and output of three models, i.e., the traditional along-slope-tillage model, the artificial grassland model and the ecological management model, were observed and recorded in detail in 1999. Energy and material flow analysis based on field test showed that compared with traditional model, ecological management model could increase solar use efficiency by 8.3%, energy output by 8.7%, energy conversion efficiency by 19.4%, N output by 26.5%, N conversion efficiency by 57.1%, P output by 12.1%, P conversion efficiency by 45.0%, and water use efficiency by 17.7%. Among the models, artificial grassland model had the lowest solar use efficiency, energy output and energy conversion efficiency; while the ecological management model had the most outputs and benefits, was the best model with high economic effect, and increased economic benefits by 16.1%, compared with the traditional model.

  2. Gene flow in the green mirid, Creontiades dilutus (Hemiptera: Miridae), across arid and agricultural environments with different host plant species

    PubMed Central

    Hereward, J P; Walter, G H; DeBarro, P J; Lowe, A J; Riginos, C

    2013-01-01

    Creontiades dilutus (Stål), the green mirid, is a polyphagous herbivorous insect endemic to Australia. Although common in the arid interior of Australia and found on several native host plants that are spatially and temporally ephemeral, green mirids also reach pest levels on several crops in eastern Australia. These host-associated dynamics, distributed across a large geographic area, raise questions as to whether (1) seasonal fluctuations in population size result in genetic bottlenecks and drift, (2) arid and agricultural populations are genetically isolated, and (3) the use of different host plants results in genetic differentiation. We sequenced a mitochondrial COI fragment from individuals collected over 24 years and screened microsatellite variation from 32 populations across two seasons. The predominance of a single COI haplotype and negative Tajima D in samples from 2006/2007 fit with a population expansion model. In the older collections (1983 and 1993), a different haplotype is most prevalent, consistent with successive population contractions and expansions. Microsatellite data indicates recent migration between inland sites and coastal crops and admixture in several populations. Altogether, the data suggest that long-distance dispersal occurs between arid and agricultural regions, and this, together with fluctuations in population size, leads to temporally dynamic patterns of genetic differentiation. Host-associated differentiation is evident between mirids sampled from plants in the genus Cullen (Fabaceae), the primary host, and alternative host plant species growing nearby in arid regions. Our results highlight the importance of jointly assessing natural and agricultural environments in understanding the ecology of pest insects. PMID:23610626

  3. A Comparison of Molecular and Isotopic Chemistry of Overland Flow DOM and yPOM to Soil Sources From a Small Mid-western Agricultural Basin

    NASA Astrophysics Data System (ADS)

    Crooker, K.; Filley, T. R.; Six, J.; Frey, J.

    2004-12-01

    In agricultural watersheds, the mobilization of terrestrial organic matter into yaquatic environments has been linked to increased primary productivity and ymicrobial activity in the tributaries of large-order streams and rivers. The yincrease in primary productivity and microbial activity results in downstream ynutrient export which can increase decomposition rates, turbidity, release of ycarbon dioxide to the atmosphere, and reduce the dissolved oxygen levels that yaquatic fauna rely upon to survive. The intensity and frequency of storms is a ycritical factor in determining the mass and chemical character of organic matter ymobilized as overland flow from agricultural watersheds. We will present results yfrom biogeochemical characterization of size fractionated aquatic and soil yorganic matter collected during storm events from a 2.5 Km2 drainage area in ycentral Indiana, part of the U.S. Geological Survey National Water-Quality yAssessment. Molecular and isotopic techniques were applied to size fractions of ysource surface soils and to the resultant dissolved, colloidal, and particulate yaquatic fractions isolated by cross-flow ultra-filtration at the overland flow site and ydown stream. Alkaline CuO oxidation of the size fractions was performed to yrelease lignin and aliphatic biopolymer (cutin and suberin) components. yPreliminary results indicate that dissolved organic components released during ythe storm are more degraded than particulate and colloidal materials. Compound yspecific and bulk carbon isotope analyses of the fractions will help us discern if yselective mobilization and decomposition is a factor in controlling the organic ymatter discharge volume from either the added C3 soybean or C4 corn in this ycorn/soybean rotation system.y

  4. Thresholds of flow-induced bed disturbances and their effects on stream metabolism in an agricultural river

    USGS Publications Warehouse

    O'Connor, Ben L.; Harvey, Judson W.; McPhillips, Lauren E.

    2012-01-01

    Storm-driven flow pulses in rivers destroy and restructure sediment habitats that affect stream metabolism. This study examined thresholds of bed disturbances that affected patch- and reach-scale sediment conditions and metabolism rates. A 4 year record of discharge and diel changes in dissolved oxygen concentrations (ΔDO) was analyzed for disturbances and recovery periods of the ΔDO signal. Disturbances to the ΔDO signal were associated with flow pulses, and the recovery times for the ΔDO signal were found to be in two categories: less than 5 days (30% of the disturbances) or greater than 15 days (70% of the disturbances). A field study was performed during the fall of 2007, which included a storm event that increased discharge from 3.1 to 6.9 m3/s over a 7 h period. During stable flow conditions before the storm, variability in patch-scale stream metabolism values were associated with sediment texture classes with values ranging from −16.4 to 2.3 g O22/d (negative sign indicates net respiration) that bounded the reach-averaged rate of −5.6 g O22/d. Hydraulic modeling of bed shear stresses demonstrated a storm-induced flow pulse mobilized approximately 25% of the bed and reach-scale metabolism rates shifted from −5 to −40 g O22/d. These results suggest that storm-induced bed disturbances led to threshold behavior with respect to stream metabolism. Small flow pulses resulted in partial-bed mobilization that disrupted stream metabolism by increased turbidity with short recovery times. Large flow pulses resulted in full-bed mobilization that disrupted stream metabolism by destroying periphyton habitats with long recovery times.

  5. Amazon river flow regime and flood recessional agriculture: Flood stage reversals and risk of annual crop loss

    NASA Astrophysics Data System (ADS)

    Coomes, Oliver T.; Lapointe, Michel; Templeton, Michael; List, Geneva

    2016-08-01

    The annual flood cycle is an important driver of ecosystem structure and function in large tropical rivers such as the Amazon. Riparian peasant communities rely on river fishing and annual floodplain agriculture, closely adapted to the recession phase of the flood pulse. This article reports on a poorly documented but important challenge facing farmers practicing flood recessional agriculture along the Amazon river: frequent, unpredictable stage reversals (repiquetes) which threaten to ruin crops growing on channel bars. We assess the severity of stage reversals for rice production on exposed river mud bars (barreales) near Iquitos, Peru. Crop loss risk is estimated based on a quantitative analysis of 45 years of daily Amazon stage data and field data from floodplain communities nearby in the Muyuy archipelago, upstream of Iquitos. Rice varieties selected, elevations of silt rich bars where rice is sown, as well as planting and harvest dates are analyzed in the light of the timing, frequencies and amplitudes of observed stage reversals that have the potential to destroy growing rice. We find that unpredictable stage reversals can produce substantial crop losses and shorten significantly the length of average growing seasons on lower elevation river bars. The data reveal that local famers extend planting down to lower bar elevations where the mean probabilities of re-submergence before rice maturity (due to reversals) approach 50%, below which they implicitly consider that the risk of crop loss outweighs the potential reward of planting.

  6. Structural controls on groundwater flow in a fractured bedrock aquifer underlying an agricultural region of northwestern New Brunswick, Canada

    NASA Astrophysics Data System (ADS)

    DesRoches, Aaron; Danielescu, Serban; Butler, Karl

    2014-08-01

    A hydrogeological study was conducted in northwestern New Brunswick, Canada, to improve the predictability of fracture-dominated groundwater flow within folded bedrock composed of fine-grained turbidites. Borehole televiewer logging and outcrop mapping, integrated with hydraulic packer tests revealed enhanced hydraulic conductivity associated with northeasterly striking bedding-plane fractures formed during folding and flexural slip. These fractures impart azimuthal anisotropy to the aquifer because of moderately dipping fold limbs. High-angle fractures form a well-developed non-stratabound network, comprising two open fracture sets striking NNE parallel to the current direction of principal stress, and WNW parallel to the direction of principal stress that dominated during the Acadian orogeny. The subset of fractures showing significant oxidation, deemed most important to the groundwater flow system, is dominated by bedding-plane and high-angle fractures striking near-parallel to the maximum principal stress direction, resulting in extensional opening and enhanced hydraulic conductivities. An equivalent porous media model, incorporating anisotropy and varying hydraulic conductivity with depth, indicates that horizontal flow dominates the aquifer with relatively minor exchange between different model layers. These findings have implications for understanding flow directions in the Black Brook Watershed and elsewhere in the Matapédia Basin where fractures formed under similar stress conditions.

  7. 26 CFR 301.6103(j)(5)-1 - Disclosures of return information reflected on returns to officers and employees of the...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... agriculture. 301.6103(j)(5)-1 Section 301.6103(j)(5)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Returns Returns and Records § 301.6103(j)(5)-1 Disclosures of return information reflected on returns to...) General rule. Pursuant to the provisions of section 6103(j)(5) of the Internal Revenue Code and subject...

  8. Estimates of consumptive use and ground-water return flow and the effect of rising and sustained high river stage on the method of estimation in Cibola Valley, Arizona and California, 1983 and 1984

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1990-01-01

    In Cibola Valley, Arizona, water is pumped from the Colorado River to irrigate crops and to maintain wildlife habitat. Unused water percolates to the water table and, as groundwater, moves downgradient into areas of phreatophytes, into a drainage ditch, out of the flood plain, and back to the river. In 1983 and 1984, groundwater return flow was negligible because in most of Cibola Valley the river lost water to the aquifer. Evapotranspiration was used as an approximation for consumptive use by vegetation. Evapotranspiration was calculated as the sum of the products of the area of vegetation types and water-use rate by vegetation type. Evapotranspiration was estimated to be 70,100 acre-ft in 1983 and 62,600 acre-ft in 1984. These estimates may be in error because of the effect of sustained inundation on the rate of water use by phreatophytes. The effects cannot be quantified and therefore adjustments to rates calculated for dry-surface conditions could not be made. The method of estimating consumptive use of water by vegetation and groundwater return flow is affected by changing conditions during years of rising and sustained high river stage caused by flood-control releases at Parker Dam. Most of the bank storage that will return to the river when the high river stage subsides did not originate as irrigation water. High river stage caused some areas to be flooded directly or raised groundwater levels above the land surface. No crops could be grown in flooded fields. The decreased depth to water and inundation with fresh water resulted in new phreatophyte growth in some areas. In some areas that were flooded, many phreatophytes died. Changes in the inundated and flooded areas throughout the years made it difficult to estimate the evaporation losses from the increased water surface. (USGS)

  9. Cost-Effectiveness Analysis of Surface Flow Constructed Wetlands (SFCW) for Nutrient Reduction in Drainage Discharge from Agricultural Fields in Denmark.

    PubMed

    Gachango, F G; Pedersen, S M; Kjaergaard, C

    2015-12-01

    Constructed wetlands have been proposed as cost-effective and more targeted technologies in the reduction of nitrogen and phosphorous water pollution in drainage losses from agricultural fields in Denmark. Using two pig farms and one dairy farm situated in a pumped lowland catchment as case studies, this paper explores the feasibility of implementing surface flow constructed wetlands (SFCW) based on their cost effectiveness. Sensitivity analysis is conducted by varying the cost elements of the wetlands in order to establish the most cost-effective scenario and a comparison with the existing nutrients reduction measures carried out. The analyses show that the cost effectiveness of the SFCW is higher in the drainage catchments with higher nutrient loads. The range of the cost effectiveness ratio on nitrogen reduction differs distinctively with that of catch crop measure. The study concludes that SFCW could be a better optimal nutrients reduction measure in drainage catchments characterized with higher nutrient loads.

  10. Cost-Effectiveness Analysis of Surface Flow Constructed Wetlands (SFCW) for Nutrient Reduction in Drainage Discharge from Agricultural Fields in Denmark

    NASA Astrophysics Data System (ADS)

    Gachango, F. G.; Pedersen, S. M.; Kjaergaard, C.

    2015-12-01

    Constructed wetlands have been proposed as cost-effective and more targeted technologies in the reduction of nitrogen and phosphorous water pollution in drainage losses from agricultural fields in Denmark. Using two pig farms and one dairy farm situated in a pumped lowland catchment as case studies, this paper explores the feasibility of implementing surface flow constructed wetlands (SFCW) based on their cost effectiveness. Sensitivity analysis is conducted by varying the cost elements of the wetlands in order to establish the most cost-effective scenario and a comparison with the existing nutrients reduction measures carried out. The analyses show that the cost effectiveness of the SFCW is higher in the drainage catchments with higher nutrient loads. The range of the cost effectiveness ratio on nitrogen reduction differs distinctively with that of catch crop measure. The study concludes that SFCW could be a better optimal nutrients reduction measure in drainage catchments characterized with higher nutrient loads.

  11. Developing an Integrated Understanding of the Relationship Between Urban Wastewater Flows and Downstream Reuse in Irrigated Agriculture: A Global Perspective

    NASA Astrophysics Data System (ADS)

    Thebo, A.; Nelson, K.; Drechsel, P.; Lambin, E.

    2015-12-01

    Globally, less than ten percent of collected wastewater receives any form of treatment. This untreated wastewater is discharged to surface waters where it is diluted and reused by farmers and municipalities downstream. Without proper safeguards, the use of these waters can present health risks. However, these same waters also provide a reliable and nutrient rich water source for farmers, often in regions where water is already physically or economically scarce. Case studies show the prevalence and diversity of motivations for indirect reuse, but are difficult to interpret in aggregate at the global scale. This study quantifies the global extent and characteristics of the reuse of wastewater in irrigated agriculture through three main components: Quantifying the global extent of urban and peri-urban irrigated and rainfed croplands; Evaluating the contribution of urban wastewater production to available blue water at the catchment scale; Developing an irrigation water quality indicator and classifying irrigated croplands downstream of cities on the basis of this indicator. Each of these components integrates several global scale spatial datasets including MIRCA2000 (irrigated croplands); GDBD (stream channels and catchments); and compilations of water use, sewerage and wastewater treatment data. All analyses were conducted using spatial analysis tools in ArcGIS and Python. This analysis found that 60 percent of all irrigated croplands (130 Mha) were within 20 km of cities. Urban irrigated croplands were found to be farmed with greater cropping intensity (1.48) as compared to non-urban irrigated croplands. Ten percent of the global catchment area is in catchments where domestic wastewater constitutes greater than five percent of available blue water. In contrast, 25 percent of irrigated croplands are located in catchments where domestic wastewater exceeds five percent of available blue water. Particularly in the water scarce regions of North Africa and East Asia, a

  12. Nitrate pollution from agriculture in different hydrogeological zones of the regional groundwater flow system in the North China Plain

    NASA Astrophysics Data System (ADS)

    Chen, Jianyao; Tang, Changyuan; Sakura, Yasuo; Yu, Jingjie; Fukushima, Yoshihiro

    2005-06-01

    A survey of the quality of groundwater across a broad area of the North China Plain, undertaken in 1998 to 2000, indicates that nitrate pollution is a serious problem affecting the drinking water for a vast population. The use of nitrogen (N)-fertilizer in agriculture has greatly increased over the past 20 years to meet the food needs of the rapidly expanding population. During the study, 295 water samples were collected from wells and springs to determine the water chemistry and the extent of nitrate pollution. High concentrations of nitrate, especially in a recharge area along the western side, but also in the vicinity of Beijing and locally in other parts of the plain, pose a serious problem for the drinking water supply. In places, the nitrate concentration exceeds the maximum for safe drinking water of 45 mg/L. The intense use of N-fertilizer and the widespread use of untreated groundwater for crop irrigation contribute greatly to the problem, but no doubt the disposal of industrial and municipal waste into streams and infiltrating the aquifer also contribute to the problem; however, the lack of data prevents evaluation of those sources. In the recharge area, nitrate is found at depths of as much as 50 m. Near Beijing, relatively high concentrations of nitrate occur at depths of as much as 80 m. In the discharge area, in the vicinity of the Yellow River, high concentrations of nitrate occur at depths of <8 m.

  13. An investigation of used electronics return flows: A data-driven approach to capture and predict consumers storage and utilization behavior

    SciTech Connect

    Sabbaghi, Mostafa; Esmaeilian, Behzad; Raihanian Mashhadi, Ardeshir; Behdad, Sara; Cade, Willie

    2015-02-15

    Highlights: • We analyzed a data set of HDDs returned back to an e-waste collection site. • We studied factors that affect the storage behavior. • Consumer type, brand and size are among factors which affect the storage behavior. • Commercial consumers have stored computers more than household consumers. • Machine learning models were used to predict the storage behavior. - Abstract: Consumers often have a tendency to store their used, old or un-functional electronics for a period of time before they discard them and return them back to the waste stream. This behavior increases the obsolescence rate of used still-functional products leading to lower profitability that could be resulted out of End-of-Use (EOU) treatments such as reuse, upgrade, and refurbishment. These types of behaviors are influenced by several product and consumer-related factors such as consumers’ traits and lifestyles, technology evolution, product design features, product market value, and pro-environmental stimuli. Better understanding of different groups of consumers, their utilization and storage behavior and the connection of these behaviors with product design features helps Original Equipment Manufacturers (OEMs) and recycling and recovery industry to better overcome the challenges resulting from the undesirable storage of used products. This paper aims at providing insightful statistical analysis of Electronic Waste (e-waste) dynamic nature by studying the effects of design characteristics, brand and consumer type on the electronics usage time and end of use time-in-storage. A database consisting of 10,063 Hard Disk Drives (HDD) of used personal computers returned back to a remanufacturing facility located in Chicago, IL, USA during 2011–2013 has been selected as the base for this study. The results show that commercial consumers have stored computers more than household consumers regardless of brand and capacity factors. Moreover, a heterogeneous storage behavior is

  14. Agriculture: Agriculture and Air Quality

    EPA Pesticide Factsheets

    Information on air emissions from agricultural practices, types of agricultural burning, air programs that may apply to agriculture, reporting requirements, and links to state and other federal air-quality information.

  15. An investigation of used electronics return flows: a data-driven approach to capture and predict consumers storage and utilization behavior.

    PubMed

    Sabbaghi, Mostafa; Esmaeilian, Behzad; Raihanian Mashhadi, Ardeshir; Behdad, Sara; Cade, Willie

    2015-02-01

    Consumers often have a tendency to store their used, old or un-functional electronics for a period of time before they discard them and return them back to the waste stream. This behavior increases the obsolescence rate of used still-functional products leading to lower profitability that could be resulted out of End-of-Use (EOU) treatments such as reuse, upgrade, and refurbishment. These types of behaviors are influenced by several product and consumer-related factors such as consumers' traits and lifestyles, technology evolution, product design features, product market value, and pro-environmental stimuli. Better understanding of different groups of consumers, their utilization and storage behavior and the connection of these behaviors with product design features helps Original Equipment Manufacturers (OEMs) and recycling and recovery industry to better overcome the challenges resulting from the undesirable storage of used products. This paper aims at providing insightful statistical analysis of Electronic Waste (e-waste) dynamic nature by studying the effects of design characteristics, brand and consumer type on the electronics usage time and end of use time-in-storage. A database consisting of 10,063 Hard Disk Drives (HDD) of used personal computers returned back to a remanufacturing facility located in Chicago, IL, USA during 2011-2013 has been selected as the base for this study. The results show that commercial consumers have stored computers more than household consumers regardless of brand and capacity factors. Moreover, a heterogeneous storage behavior is observed for different brands of HDDs regardless of capacity and consumer type factors. Finally, the storage behavior trends are projected for short-time forecasting and the storage times are precisely predicted by applying machine learning methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Finding Multiple Internal Rates of Return for a Project with Non-Conventional Cash Flows: Utilizing Popular Financial/Graphing Calculators and Spreadsheet Software

    ERIC Educational Resources Information Center

    Chen, Jeng-Hong

    2008-01-01

    This study demonstrates that a popular graphing calculator among students, TI-83 Plus, has a powerful function to draw the NPV profile and find the accurate multiple IRRs for a project with non-conventional cash flows. However, finance textbooks or related supplementary materials do not provide students instructions for this part. The detailed…

  17. Finding Multiple Internal Rates of Return for a Project with Non-Conventional Cash Flows: Utilizing Popular Financial/Graphing Calculators and Spreadsheet Software

    ERIC Educational Resources Information Center

    Chen, Jeng-Hong

    2008-01-01

    This study demonstrates that a popular graphing calculator among students, TI-83 Plus, has a powerful function to draw the NPV profile and find the accurate multiple IRRs for a project with non-conventional cash flows. However, finance textbooks or related supplementary materials do not provide students instructions for this part. The detailed…

  18. Detecting transition in agricultural systems

    NASA Technical Reports Server (NTRS)

    Neary, P. J.; Coiner, J. C.

    1979-01-01

    Remote sensing of agricultural phenomena has been largely concentrated on analysis of agriculture at the field level. Concern has been to identify crop status, crop condition, and crop distribution, all of which are spatially analyzed on a field-by-field basis. A more general level of abstraction is the agricultural system, or the complex of crops and other land cover that differentiate various agricultural economies. The paper reports on a methodology to assist in the analysis of the landscape elements of agricultural systems with Landsat digital data. The methodology involves tracing periods of photosynthetic activity for a fixed area. Change from one agricultural system to another is detected through shifts in the intensity and periodicity of photosynthetic activity as recorded in the radiometric return to Landsat. The Landsat-derived radiometric indicator of photosynthetic activity appears to provide the ability to differentiate agricultural systems from each other as well as from conterminous natural vegetation.

  19. Detecting transition in agricultural systems

    NASA Technical Reports Server (NTRS)

    Neary, P. J.; Coiner, J. C.

    1979-01-01

    Remote sensing of agricultural phenomena has been largely concentrated on analysis of agriculture at the field level. Concern has been to identify crop status, crop condition, and crop distribution, all of which are spatially analyzed on a field-by-field basis. A more general level of abstraction is the agricultural system, or the complex of crops and other land cover that differentiate various agricultural economies. The paper reports on a methodology to assist in the analysis of the landscape elements of agricultural systems with Landsat digital data. The methodology involves tracing periods of photosynthetic activity for a fixed area. Change from one agricultural system to another is detected through shifts in the intensity and periodicity of photosynthetic activity as recorded in the radiometric return to Landsat. The Landsat-derived radiometric indicator of photosynthetic activity appears to provide the ability to differentiate agricultural systems from each other as well as from conterminous natural vegetation.

  20. 26 CFR 301.6103(j)(5)-1 - Disclosures of return information reflected on returns to officers and employees of the...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... returns to officers and employees of the Department of Agriculture for conducting the census of agriculture. 301.6103(j)(5)-1 Section 301.6103(j)(5)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... officers and employees of the Department of Agriculture for conducting the census of agriculture....

  1. 26 CFR 301.6103(j)(5)-1 - Disclosures of return information reflected on returns to officers and employees of the...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... returns to officers and employees of the Department of Agriculture for conducting the census of agriculture. 301.6103(j)(5)-1 Section 301.6103(j)(5)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... officers and employees of the Department of Agriculture for conducting the census of agriculture....

  2. 26 CFR 301.6103(j)(5)-1 - Disclosures of return information reflected on returns to officers and employees of the...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... returns to officers and employees of the Department of Agriculture for conducting the census of agriculture. 301.6103(j)(5)-1 Section 301.6103(j)(5)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... officers and employees of the Department of Agriculture for conducting the census of agriculture....

  3. 26 CFR 301.6103(j)(5)-1 - Disclosures of return information reflected on returns to officers and employees of the...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... returns to officers and employees of the Department of Agriculture for conducting the census of agriculture. 301.6103(j)(5)-1 Section 301.6103(j)(5)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... officers and employees of the Department of Agriculture for conducting the census of agriculture....

  4. Production of carbonaceous adsorbents from agricultural by-products and novolac resin under a continuous countercurrent flow type pyrolysis operation.

    PubMed

    Ioannou, Z; Simitzis, J

    2013-02-01

    Carbonaceous adsorbents based on novolac resin (N) and olive stone biomass (B) in a proportion of 20/80 and 40/60 w./w. N/O were produced. The specimens were cured (c) and pyrolyzed/carbonized (C) up to 1000 °C under a continuous countercurrent flow type pyrolysis operation (N20B-cC, N40B-cC). Commercial activated carbon (AC) was used for comparison reasons. Methylene blue adsorption from its aqueous solutions onto the adsorbents and kinetic analysis were investigated. The specific surface area of adsorbents and the gross calorific values (GCV) of cured materials were determined. The results show that N40B-cC presents lower weight loss and shrinkage but higher methylene blue adsorption than N20B-cC. Pseudo-second order mechanism describes better methylene blue adsorption onto all adsorbents. The specific surface area of carbonaceous and the gross calorific values of cured materials follow the order: AC>N20B-cC>N40B-cC and N100-c>N40B-c>N20B-c>B respectively. Olive stone biomass may constitute a suitable precursor for the production of carbonaceous materials.

  5. Farming with Grass: Achieving Sustainable Mixed Agricultural Landscapes

    USDA-ARS?s Scientific Manuscript database

    Agriculture in grassland environments is facing multiple stresses from shifting demographics, declining and fragmented agricultural landscapes, declining environmental quality, variable and changing climate, volatile and increasing energy costs, marginal economic returns, and globalization. Grassla...

  6. Why Do Staff Return?

    ERIC Educational Resources Information Center

    Magnuson, Connie

    1992-01-01

    Surveyed 211 returning staff from 25 camps and interviewed 19 returning staff to study factors that influence a counselor's decision to return to camp. Examined the following dimensions of motivation and hygiene factors: (1) stimulation or inspiration; (2) personal; (3) job-related experience; (4) living conditions and camp life; (5) camp…

  7. Martian base agriculture: The effect of low gravity on water flow, nutrient cycles, and microbial biomass dynamics

    NASA Astrophysics Data System (ADS)

    Maggi, Federico; Pallud, Céline

    2010-11-01

    The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen production, and water biofiltration as compared to hydroponics and aeroponics cropping. However, it is still unknown if cropping using soil systems could be sustainable in a Martian greenhouse under a gravity of 0.38 g. The most challenging aspects are linked to the gravity-induced soil water flow; because water is crucial in driving nutrient and oxygen transport in both liquid and gaseous phases, a gravitational acceleration lower than g = 9.806 m s -2 could lead to suffocation of microorganisms and roots, with concomitant emissions of toxic gases. The effect of Martian gravity on soil processes was investigated using a highly mechanistic model previously tested for terrestrial crops that couples soil hydraulics and nutrient biogeochemistry. Net leaching of NO3- solute, gaseous fluxes of NH 3, CO 2, N 2O, NO and N 2, depth concentrations of O 2, CO 2 and dissolved organic carbon (DOC), and pH in the root zone were calculated for a bioregenerative cropping unit under gravitational acceleration of Earth and for its homologous on Mars, but under 0.38 g. The two cropping units were treated with the same fertilizer type and rate, and with the same irrigation regime, but under different initial soil moisture content. Martian gravity reduced water and solute leaching by about 90% compared to Earth. This higher water holding capacity in soil under Martian gravity led to moisture content and nutrient concentrations that favoured the metabolism of various microbial functional groups, whose density increased by 5-10% on Mars as compared to Earth. Denitrification rates became substantially more important than on Earth and ultimately resulted in 60%, 200% and 1200% higher emissions of NO, N 2O and N 2 gases, respectively. Similarly, O 2 and DOC

  8. 9 CFR 355.22 - Designation of place of receipt of returned products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION... management with the approval of the circuit supervisor. Such returned products shall be inspected there...

  9. Agriculture: Newsroom

    EPA Pesticide Factsheets

    Agriculture Newsroom. News releases, reports, and other documents from around EPA that are of interest or direct importance to the environmental management or compliance efforts of the agricultural community.

  10. Understanding Guyton's venous return curves

    PubMed Central

    Feigl, Eric O.

    2011-01-01

    Based on observations that as cardiac output (as determined by an artificial pump) was experimentally increased the right atrial pressure decreased, Arthur Guyton and coworkers proposed an interpretation that right atrial pressure represents a back pressure restricting venous return (equal to cardiac output in steady state). The idea that right atrial pressure is a back pressure limiting cardiac output and the associated idea that “venous recoil” does work to produce flow have confused physiologists and clinicians for decades because Guyton's interpretation interchanges independent and dependent variables. Here Guyton's model and data are reanalyzed to clarify the role of arterial and right atrial pressures and cardiac output and to clearly delineate that cardiac output is the independent (causal) variable in the experiments. Guyton's original mathematical model is used with his data to show that a simultaneous increase in arterial pressure and decrease in right atrial pressure with increasing cardiac output is due to a blood volume shift into the systemic arterial circulation from the systemic venous circulation. This is because Guyton's model assumes a constant blood volume in the systemic circulation. The increase in right atrial pressure observed when cardiac output decreases in a closed circulation with constant resistance and capacitance is due to the redistribution of blood volume and not because right atrial pressure limits venous return. Because Guyton's venous return curves have generated much confusion and little clarity, we suggest that the concept and previous interpretations of venous return be removed from educational materials. PMID:21666119

  11. A Comparison of Methods for Estimating Evapotranspiration (ET) in a Semi-Arid Agricultural System

    NASA Astrophysics Data System (ADS)

    Gordon, B. L.; Claes, N.; Miller, S. N.; Paige, G. B.; Parsekian, A.; Beverly, D.

    2015-12-01

    In the intermountain West, much like the rest of the world, agriculture is the oldest and largest water consumer. Particularly in the arid headwaters states of the intermountain west changing water demands are highlighting the importance of water use efficiency in agriculture. In flood irrigation an area is irrigated until saturation is achieved although crops only consume a portion of the total water applied. The remaining water eventually returns to streams or aquifers. Accurately quantifying the portion of applied water that is consumptively used—and its corollary in the form of return flows—represents an important avenue for potential water use reduction in the face of increasing demands from sundry downstream users. Consumptive use has historically been understood as the difference between the irrigation water applied and irrigation water returned to adjacent surface waters via quick or delayed return flow as well as overland flow. Penman-derived models, which calculate evapotranspiration based on meteorological data, are another widely recognized method for estimating consumptive use. We determined consumptive use on an agricultural field in northeastern Wyoming using both of these two traditional methods as well as a quantitative scintillometer-based estimate, which couples meteorological data with the latent heat flux across a field to measure evapotranspiration for a given area. Since the wider application of the scintillometer is limited by the instrument's complexity and cost, a comparison of the resulting data with these two more customary methods provides critical insight in to where certain methods might under or overestimate consumptive use. The purpose of this comparison is twofold. First, the comparison of these three methods allows for the optimization of a reach-scale water budget that aims to better characterize and quantify return flow processes. Second, the addition of information that couples hydrology, meteorology, geophysics, and heat

  12. Using a physically-based water flow model to explore the dynamics of transit times and mixing in a small agricultural catchment

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Heidbüchel, Ingo; Musolff, Andreas; Fleckenstein, Jan H.

    2017-04-01

    Catchment-scale transit time distributions (TTDs) for discharge and residence time distributions of the water in storage (RTDs) are promising tools to characterize the discharge and mixing behavior of a catchment and can help to interpret the associated solute loads to the stream in a spatially implicit way. TTDs and RTDs are dynamic in time, influenced by dynamic rainfall and evapotranspiration forcing, and changing groundwater storage in the catchment. In order to understand the links between the dynamics of TTDs and groundwater mixing in the small agricultural catchment Schäfertal, in central Germany, a 3D hydrological model was set up for the catchment using the fully coupled surface-subsurface numerical model HydroGeoSphere (HGS). The model is calibrated using discharge and groundwater level measurements, and runs transiently for a period of 10 years from 1997 to 2007. A particle tracking tool was implemented in HGS to track the movement of water parcels in the subsurface, outputting TTDs of channel discharge and RTDs of groundwater storage at daily intervals. Results show that the mean age of the discharge water is significantly younger than that of the water in storage, indicating a poorly mixed subsurface. Discharge preferentially samples faster flowing younger water originating from the more conductive top parts of the aquifer. Spatial variations of the age of water in storage are observed, highly influenced by aquifer heterogeneity. Computed StorAge Selection (SAS) functions [Rinaldo et al. 2015] show clear shifts in the discharge sampling preferences between wet and dry states: during wet states in winter and spring, discharge has a preference for younger water because the shallow flow paths are active due to high groundwater levels and low evapotranspiration. Conversely, during dry states in summer and autumn, discharge has a preference for older water because the shallow flow paths are inactive due to low groundwater levels and stronger

  13. 7 CFR 46.21 - Returns, rejections, or credit memorandums on sales.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... 46.21 Section 46.21 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE MARKETING OF PERISHABLE.... In the event of the rejection and return of any produce sold for or on behalf of another,...

  14. The effects of pumpage, irrigation return, and regional ground-water flow on the water quality at Waiawa water tunnel, Oahu, Hawaii

    USGS Publications Warehouse

    Eyre, P.R.

    1983-01-01

    Waiawa shaft is a 1,700-foot long water tunnel which draws water from the top of the Pearl Harbor Ghyben-Herzberg ground-water lens, Oahu, Hawaii. The application of brackish irrigation water to sugarcane fields overlying Waiawa shaft, combined with relatively low pumping rates at the shaft from 1978 to 1980, caused the chloride concentration of water produced by Waiawa shaft to rise to 290 milligrams per liter. Time-series analyses, pumping tests and analyses of water samples show that a zone of degraded water lies at the top of the lens. This zone is mixed in significantly different proportions with the underlying fresher water depending on the pumping rate at Waiawa shaft. The chloride concentration of water in the Waiawa shaft can generally be kept below 250 milligrams per liter for the next few years, if pumping rates of about 15 million gallons per day are maintained. The use of managed pumping to control the chloride problem over the long term is uncertain owing to the possible increase in chloride concentration of the irrigation water. Based on ground-water flow rates and analogy to nearby wells, the chloride concentration of Waiawa shaft 's water will decrease to less than 100 milligrams per liter in 2 to 3 years if the use of brackish irrigation water is discontinued. (USGS)

  15. Agricultural Waste.

    PubMed

    Xue, Ling; Zhang, Panpan; Shu, Huajie; Chang, Chein-Chi; Wang, Renqing; Zhang, Shuping

    2016-10-01

    In recent years, the quantity of agricultural waste has been rising rapidly all over the world. As a result, the environmental problems and negative impacts of agricultural waste are drawn more and more attention. Therefore, there is a need to adopt proper approaches to reduce and reuse agricultural waste. This review presented about 200 literatures published in 2015 relating to the topic of agricultural waste. The review examined research on agricultural waste in 2015 from the following four aspects: the characterization, reuse, treatment, and management. Researchers highlighted the importance to reuse agricultural waste and investigated the potential to utilize it as biofertilizers, cultivation material, soil amendments, adsorbent, material, energy recycling, enzyme and catalyst etc. The treatment of agricultural waste included carbonization, biodegradation, composting hydrolysis and pyrolysis. Moreover, this review analyzed the differences of the research progress in 2015 from 2014. It may help to reveal the new findings and new trends in this field in 2015 comparing to 2014.

  16. In science communication, why does the idea of a public deficit always return? How do the shifting information flows in healthcare affect the deficit model of science communication?

    PubMed

    Ko, Henry

    2016-05-01

    The healthcare field contains a multitude of opportunities for science communication. Given the many stakeholders dancing together in a multidirectional tango of communication, we need to ask how much does the deficit model apply to the health field? History dictates that healthcare professionals are the holders of all knowledge, and the patients and other stakeholders are the ones that need the scientific information communicated to them. This essay argues otherwise, in part due to the rise of shared decision-making and patients and other stakeholders acting as partners in healthcare. The traditional deficit model in health held that: (1) doctors were experts and patients were consumers, (2) it is impossible for the public to grasp the many disciplines of knowledge in medicine, (3) if experts have trouble keeping up with medical research then the public surely can't keep up, and (4) it is safer for healthcare professionals to communicate to the public using a deficit model. However, with the rise of partnerships with patients in healthcare decision-making, the deficit model might be weakening. Examples of public participation in healthcare decision-making include: (1) crowd-sourcing public participation in systematic reviews, (2) public participation in health policy, (3) public collaboration in health research, and (4) health consumer groups acting as producers of health information. With the challenges to the deficit model in science communication in health, caution is needed with the increasing role of technology and social media, and how these may affect the legitimacy of healthcare information flows away from the healthcare professional. © The Author(s) 2016.

  17. Vocational Agriculture Education. Agricultural Mechanics.

    ERIC Educational Resources Information Center

    Smith, Eddie; And Others

    To assist teachers in agricultural mechanics in providing comprehensive instruction to their students, this curriculum guide treats both the mechanical skills and knowlege necessary for this specialized area. Six sections are included, as follow: orientation and safety; agricultural mechanics skills; agricultural power and machinery; agricultural…

  18. Returning to practice.

    PubMed

    Holland, S

    1994-03-01

    All too often health visitors seeking to return to practice following a career break are met with negative response, writes Stevie Holland. Here she recounts the words and experiences of some of the health visitors who enrolled on the HVA's open learning 'Return to practice' courses in recent years. The health visiting profession needs to encourage the enthusiasm and innovation of returners if it is to survive in today's political climate, she warns.

  19. Surge Driven Return Flow Results in Deposition of Coarse Grain Horizons Archiving a 4000 Year Record of Extreme Storm Events, Cape Cod, Massachusetts

    NASA Astrophysics Data System (ADS)

    Maio, C. V.; Donnelly, J. P.; Sullivan, R.; Weidman, C. R.; Sheremet, V.

    2014-12-01

    The brevity of the instrumental record and lack of detailed historical accounts is a limiting factor in our understanding of the relationship between climate change and the frequency and intensity of extreme storm events. This study applied paleotempestologic and hydrographic methods to identify the mechanisms of storm-induced coarse grain deposition and reconstruct a late Holocene storm record within Waquoit Bay, Massachusetts. Three sediment cores (6.0 m, 8.4 m, and 8.2 m) were collected in 3 m of water using a vibracore system. Grain sizes were measured along core to identify coarse grain anomalies that serve as a proxy for past storm events. An historical age model (1620-2011 AD) was developed based on Pb pollution chronomarkers derived from X-Ray Florescence bulk Pb data, equating to a sedimentation rate of 8-8.3 mm/yr (R2 = 0.99). A long-term (4000 to 275 years before present) sedimentation rate of 1.1-1.4 mm/yr (R2 = 0.89) was calculated based on twenty-four continuous flow atomic mass spectrometry 14C ages of marine bivalves. To determine hydrographic conditions within the embayment during storm events current meters and tide gauges were deployed during Hurricane Irene (2011) which measured a storm surge of 88 cm above mean sea level. The buildup of storm water against the landward shoreline resulted in a measured 10 cm/s seaward moving bottom current capable of transporting coarse sand eroded from the adjacent shoreface into the coring site. Modeled surges for eleven modern and historic storm events ranged in height from 0.37 m (2011) to 3.72 m (1635) above mean high water. The WAQ1, WAQ2, and WAQ3 cores recorded a total of 89, 139, and 137 positive anomalies that exceeded the lower threshold and 15, 34, and 12 that exceeded the upper threshold respectively. Events recorded during the historic period coincide with documented storm events. The mean frequency within the three cores applying the lower threshold was 2.6 events per century, while applying the

  20. Assured crew return vehicle

    NASA Technical Reports Server (NTRS)

    Cerimele, Christopher J. (Inventor); Ried, Robert C. (Inventor); Peterson, Wayne L. (Inventor); Zupp, George A., Jr. (Inventor); Stagnaro, Michael J. (Inventor); Ross, Brian P. (Inventor)

    1991-01-01

    A return vehicle is disclosed for use in returning a crew to Earth from low earth orbit in a safe and relatively cost effective manner. The return vehicle comprises a cylindrically-shaped crew compartment attached to the large diameter of a conical heat shield having a spherically rounded nose. On-board inertial navigation and cold gas control systems are used together with a de-orbit propulsion system to effect a landing near a preferred site on the surface of the Earth. State vectors and attitude data are loaded from the attached orbiting craft just prior to separation of the return vehicle.

  1. Agricultural ecosystems

    SciTech Connect

    Kindscher, K.

    1984-01-01

    The agricultural ecosystem concept promotes a distinctive set of ecological principles that give diversity and stability to the food production process. This system allows people to work more closely with nature and to feel a spiritual connection with the earth. Agricultural ecosystems can be designed to provide numerous advantages. They can be energy conserving, more permanent, make better use of space, reduce and eliminate the need for pesticides, tillage, and chemical fertilizers, and provide food for the local community. The agricultural ecosystem model presented is most suitable for a small-scale farmer or market gardener, but the principles can also be applied on a larger or smaller acreage. The agricultural ecosystem concept is a model-building process that will go through successional stages to a more mature food-producing plant community. The agricultural ecosystem concept expresses permanence and ecology, and is a step toward sustainable agriculture. 55 references, 4 figures.

  2. News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

    NASA Astrophysics Data System (ADS)

    2011-01-01

    Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

  3. Agriculture, summary

    NASA Technical Reports Server (NTRS)

    Baldwin, R.

    1975-01-01

    Applications of remotely sensed data in agriculture are enumerated. These include: predictions of forage for range animal consumption, forest management, soil mapping, and crop inventory and management.

  4. Enhancement of the southward return flow of the Atlantic Meridional Overturning Circulation by data assimilation and its influence in an assimilative ocean simulation forced by CORE-II atmospheric forcing

    NASA Astrophysics Data System (ADS)

    Fujii, Yosuke; Tsujino, Hiroyuki; Toyoda, Takahiro; Nakano, Hideyuki

    2017-08-01

    This paper examines the difference in the Atlantic Meridional Overturning Circulation (AMOC) mean state between free and assimilative simulations of a common ocean model using a common interannual atmospheric forcing. In the assimilative simulation, the reproduction of cold cores in the Nordic Seas, which is absent in the free simulation, enhances the overflow to the North Atlantic and improves AMOC with enhanced transport of the deeper part of the southward return flow. This improvement also induces an enhanced supply of North Atlantic Deep Water (NADW) and causes better representation of the Atlantic deep layer despite the fact that correction by the data assimilation is applied only to temperature and salinity above a depth of 1750 m. It also affects Circumpolar Deep Water in the Southern Ocean. Although the earliest influence of the improvement propagated by coastal waves reaches the Southern Ocean in 10-15 years, substantial influence associated with the arrival of the renewed NADW propagates across the Atlantic Basin in several decades. Although the result demonstrates that data assimilation is able to improve the deep ocean state even if there is no data there, it also indicates that long-term integration is required to reproduce variability in the deep ocean originating from variations in the upper ocean. This study thus provides insights on the reliability of AMOC and the ocean state in the Atlantic deep layer reproduced by data assimilation systems.

  5. Enhancement of the southward return flow of the Atlantic Meridional Overturning Circulation by data assimilation and its influence in an assimilative ocean simulation forced by CORE-II atmospheric forcing

    NASA Astrophysics Data System (ADS)

    Fujii, Yosuke; Tsujino, Hiroyuki; Toyoda, Takahiro; Nakano, Hideyuki

    2015-08-01

    This paper examines the difference in the Atlantic Meridional Overturning Circulation (AMOC) mean state between free and assimilative simulations of a common ocean model using a common interannual atmospheric forcing. In the assimilative simulation, the reproduction of cold cores in the Nordic Seas, which is absent in the free simulation, enhances the overflow to the North Atlantic and improves AMOC with enhanced transport of the deeper part of the southward return flow. This improvement also induces an enhanced supply of North Atlantic Deep Water (NADW) and causes better representation of the Atlantic deep layer despite the fact that correction by the data assimilation is applied only to temperature and salinity above a depth of 1750 m. It also affects Circumpolar Deep Water in the Southern Ocean. Although the earliest influence of the improvement propagated by coastal waves reaches the Southern Ocean in 10-15 years, substantial influence associated with the arrival of the renewed NADW propagates across the Atlantic Basin in several decades. Although the result demonstrates that data assimilation is able to improve the deep ocean state even if there is no data there, it also indicates that long-term integration is required to reproduce variability in the deep ocean originating from variations in the upper ocean. This study thus provides insights on the reliability of AMOC and the ocean state in the Atlantic deep layer reproduced by data assimilation systems.

  6. Agricultural Wastes.

    ERIC Educational Resources Information Center

    Jewell, W. J.; Switzenbaum, M. S.

    1978-01-01

    Presents a literature review of agricultural wastes, covering publications of 1976-77. Some of the areas covered are: (1) water characteristics and impacts; (2) waste treatment; (3) reuse of agricultural wastes; and (4) nonpoint pollution sources. A list of 150 references is also presented. (HM)

  7. Agricultural Wastes.

    ERIC Educational Resources Information Center

    Jewell, W. J.; Switzenbaum, M. S.

    1978-01-01

    Presents a literature review of agricultural wastes, covering publications of 1976-77. Some of the areas covered are: (1) water characteristics and impacts; (2) waste treatment; (3) reuse of agricultural wastes; and (4) nonpoint pollution sources. A list of 150 references is also presented. (HM)

  8. VOCATIONAL AGRICULTURE.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Research Coordinating Unit.

    TO ASSIST THOSE WHO MAKE DECISIONS RELATING TO EDUCATIONAL PROGRAMS IN AGRICULTURE, RECENT RESEARCH IN VOCATIONAL AGRICULTURE IS SUMMARIZED. A 1963 STUDY TREATS THE RELATIONSHIP BETWEEN WORK EXPERIENCE AND STUDENT CHARACTERISTICS, PLANS, AND ASPIRATIONS. STUDIES ON POST-SECONDARY EDUCATION CONCERN GUIDELINES FOR TECHNICIAN PROGRAMS, JUSTIFICATION…

  9. Multifractal analysis of the Korean agricultural market

    NASA Astrophysics Data System (ADS)

    Kim, Hongseok; Oh, Gabjin; Kim, Seunghwan

    2011-11-01

    We have studied the long-term memory effects of the Korean agricultural market using the detrended fluctuation analysis (DFA) method. In general, the return time series of various financial data, including stock indices, foreign exchange rates, and commodity prices, are uncorrelated in time, while the volatility time series are strongly correlated. However, we found that the return time series of Korean agricultural commodity prices are anti-correlated in time, while the volatility time series are correlated. The n-point correlations of time series were also examined, and it was found that a multifractal structure exists in Korean agricultural market prices.

  10. Hydrogeologic framework, ground-water geochemistry, and assessment of nitrogen yield from base flow in two agricultural watersheds, Kent County, Maryland

    USGS Publications Warehouse

    Bachman, L.J.; Krantz, D.E.; Böhlke, John Karl

    2002-01-01

    the ground water contacts the Aquia confining layer.The base-flow discharges of total nitrogen from the two watersheds are of similar magnitude, although Chesterville Branch has somewhat higher loads (29,000 kilograms of nitrogen per year) than Morgan Creek (20,000 kilograms of nitrogen per year), although Morgan Creek has a larger drainage area and a greater discharge of water. The base-flow yield of nitrogen (load per unit area) in Chesterville Branch (median of 0.058 grams per second per square kilometer at the outlet) is more than twice that of Morgan Creek (median of 0.022 grams per second per square kilometer at the outlet), reflecting the higher concentration of nitrate in ground water discharging to Chesterville Branch. Total nitrogen concentrations tend to decrease downstream inChesterville Branch and increase downstream in Morgan Creek. The downstream trend in Chesterville Branch may be affected by instream nitrogen uptake and denitrification, and an increasing proportion of older, denitrified ground water in downstream discharge. The downstream trends in Morgan Creek may be affected by inflow from tributaries, downstream changes in the source of discharge water, and downstream changes in the riparian zone, which could affect the processes and degree of denitrification.Although these two watersheds appear to have landscape features (such as topography, land use, and soils) that would produce similar nitrogen discharges, a more detailed examination of landscape features indicates that Chesterville Branch has soils that are slightly better drained, tributary stream outlets at higher altitudes, and a slightly higher percentage of agricultural land. All of these factors have been related to higher nitrogen yields. Nonetheless, most of the data support the interpretation that hydrostratigraphy has the greatest effect in producing the difference in nitrogen yields between the two watersheds.

  11. Lightning return stroke models

    NASA Technical Reports Server (NTRS)

    Lin, Y. T.; Uman, M. A.; Standler, R. B.

    1980-01-01

    We test the two most commonly used lightning return stroke models, Bruce-Golde and transmission line, against subsequent stroke electric and magnetic field wave forms measured simultaneously at near and distant stations and show that these models are inadequate to describe the experimental data. We then propose a new return stroke model that is physically plausible and that yields good approximations to the measured two-station fields. Using the new model, we derive return stroke charge and current statistics for about 100 subsequent strokes.

  12. Venus Sample Return Mission

    NASA Astrophysics Data System (ADS)

    Whitcomb, G.; Lebreton, J.; Scoon, G.

    The Venus Sample Return (VSR) mission was performed as an in-house activity within the European Space Agency's Science Directorate during a 4-month period. The selected baseline mission scenario involves two launches of the presently available Ariane 5 configuration. The first launch would inject a composite spacecraft consisting of an orbiter and a return capsule into a parking orbit around Venus. The second launch would deliver at Venus a lander composite, consisting of the entry, descent, sampling and ascent modules. The sampling strategy includes returning a surface (with possibly a core) sample and three atmospheric samples at high altitudes. This paper presents the design concept for the mission.

  13. Preparing for the Meteoritic Return of Stardust

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Kontinos, D.; Jordan, D.; Wright, M.; Olejniczak, J.; Raiche, G.; Wercinski, P.; Desai, P. N.; Taylor, M. J., Stenbaek-Nielsen, H. C.; McHarg, M. G.; Abe, S.; Rairden, R. L.; Albers, J.; Winter, M. And, Harms, F.; Wolf, J.; Revelle, D. O.; Gural, P.; Dantowitz, R.; Rietmeijer, F.; Hladiuk, D.; Hildebrand, A. R.

    2007-01-01

    The hypervelocity entry of a sample return capsule on its way back from interplanetary space acts as an artificial meteor, with flow conditions similar to natural m-sized meteoroids. Unlike natural fireballs, a sample return capsule arrives at a known time and its shock emissions and ablation can be studied without the confusion of fragmentation and the obscuring emissions from ablated meteoric metals. The entry of the Stardust Sample Return Capsule (SRC) on Sunday January 15, 2006, was also a real-life test of key risk drivers for future Thermal Protection System (TPS) design, by measuring the amount of radiative heat flux and the ablation response of the TPS. This paper presents results from the calculations made to predict the expected meteoric emissions for the Stardust SRC entry and re-evaluates the surface temperature measurements obtained during a prior mission that observed the Genesis sample return.

  14. Agriculture Education. Agricultural Metal Working.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary agricultural education students enrolled in one or two semester-long courses in agricultural metal working. The guide presents units of study in the following areas: (1) oxyacetylene welding, (2) arc welding, (3) sheet metal, (4) blueprint reading for welders and (5) job…

  15. Agricultural Energy Practices. Agriculture Energy.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with agricultural energy practices. Its objective is for the student to be able to discuss energy use and conservation of resources in the production of agricultural products. Some topics covered are basic uses of direct energy in…

  16. Agriculture Education. Agricultural Metal Working.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary agricultural education students enrolled in one or two semester-long courses in agricultural metal working. The guide presents units of study in the following areas: (1) oxyacetylene welding, (2) arc welding, (3) sheet metal, (4) blueprint reading for welders and (5) job…

  17. Agricultural Energy Practices. Agriculture Energy.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with agricultural energy practices. Its objective is for the student to be able to discuss energy use and conservation of resources in the production of agricultural products. Some topics covered are basic uses of direct energy in…

  18. Old Sunspot Returns

    NASA Image and Video Library

    2017-08-07

    The large sunspot (called AR2665) that rotated out of view about two weeks ago has returned (Aug. 1-2, 2017). Though much reduced in size, it did blast a good-sized coronal mass ejection about a week ago on the far side of the sun. Sunspots can last from days to months, so for it to return again is not an unusual event. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21873

  19. Agricultural Geophysics

    USDA-ARS?s Scientific Manuscript database

    The four geophysical methods predominantly used for agricultural purposes are resistivity, electromagnetic induction, ground penetrating radar (GPR), and time domain reflectometry (TDR). Resistivity and electromagnetic induction methods are typically employed to map lateral variations of apparent so...

  20. Agriculture Sectors

    EPA Pesticide Factsheets

    The Agriculture sectors comprise establishments primarily engaged in growing crops, raising animals, and harvesting fish and other animals. Find information on compliance, enforcement and guidance on EPA laws and regulations on the NAICS 111 & 112 sectors.

  1. Agricultural Microbiology.

    ERIC Educational Resources Information Center

    Brill, Winston J.

    1981-01-01

    Elucidates strategies for applying microbiological techniques to traditional agricultural practices. Discusses the manipulation of microorganisms that live with plants and also the problems involved in the introduction of new genes into crop plants by recombinant DNA methods. (CS)

  2. Agricultural Microbiology.

    ERIC Educational Resources Information Center

    Brill, Winston J.

    1981-01-01

    Elucidates strategies for applying microbiological techniques to traditional agricultural practices. Discusses the manipulation of microorganisms that live with plants and also the problems involved in the introduction of new genes into crop plants by recombinant DNA methods. (CS)

  3. Agricultural Waste.

    PubMed

    Shu, Huajie; Zhang, Panpan; Chang, Chein-Chi; Wang, Renqing; Zhang, Shuping

    2015-10-01

    The management and disposal of agricultural waste are drawn more and more attention because of the increasing yields and negative effects on the environment. However, proper treatments such as converting abundant biomass wastes into biogas through anaerobic digestion technology, can not only avoid the negative impacts, but also convert waste into available resources. This review summarizes the studies of nearly two hundred scholars from the following four aspects: the characterization, reuse, treatment, and management of agricultural waste.

  4. Research on Agriculture Domain Meta-Search Engine System

    NASA Astrophysics Data System (ADS)

    Xie, Nengfu; Wang, Wensheng

    The rapid growth of agriculture web information brings a fact that search engine can not return a satisfied result for users' queries. In this paper, we propose an agriculture domain search engine system, called ADSE, that can obtains results by an advance interface to several searches and aggregates them. We also discuss two key technologies: agriculture information determination and engine.

  5. Research on Agriculture Domain Meta-Search Engine System

    NASA Astrophysics Data System (ADS)

    Xie, Nengfu; Wang, Wensheng

    The rapid growth of agriculture web information brings a fact that search engine can not return a satisfied result for users’ queries. In this paper, we propose an agriculture domain search engine system, called ADSE, that can obtains results by an advance interface to several searches and aggregates them. We also discuss two key technologies: agriculture information determination and engine.

  6. Agriculture: About EPA's National Agriculture Center

    EPA Pesticide Factsheets

    EPA's National Agriculture Center (Ag Center), with the support of the United States Department of Agriculture, serves growers, livestock producers, other agribusinesses, and agricultural information/education providers.

  7. Monitoring and Analysis of Nonpoint Source Pollution - Case study on terraced paddy fields in an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Kai; Jang, Cheng-Shin; Yeh, Chun-Lin

    2013-04-01

    The intensive use of chemical fertilizer has negatively impacted environments in recent decades, mainly through water pollution by nitrogen (N) and phosphate (P) originating from agricultural activities. As a main crop with the largest cultivation area about 0.25 million ha per year in Taiwan, rice paddies account for a significant share of fertilizer consumption among agriculture crops. This study evaluated the fertilization of paddy fields impacting return flow water quality in an agricultural watershed located at Hsinchu County, northern Taiwan. Water quality monitoring continued for two crop-periods in 2012, around subject to different water bodies, including the irrigation water, drainage water, and shallow groundwater. The results indicated that obviously increasing of ammonium-N, nitrate-N and TP concentrations in the surface drainage water were observed immediately following three times of fertilizer applications (including basal, tillering, and panicle fertilizer application), but reduced to relatively low concentrations after 7-10 days after each fertilizer application. Groundwater quality monitoring showed that the observation wells with the more shallow water depth, the more significant variation of concentrations of ammonium-N, nitrate-N and TP could be observed, which means that the contamination potential of nutrient of groundwater is related not only to the impermeable plow sole layer but also to the length of percolation route in this area. The study also showed that the potential pollution load of nutrient could be further reduced by well drainage water control and rational fertilizer management, such as deep-water irrigation, reuse of return flow, the rational application of fertilizers, and the SRI (The System of Rice Intensification) method. The results of this study can provide as an evaluation basis to formulate effective measures for agricultural non-point source pollution control and the reuse of agricultural return flow. Keywords

  8. Modeling the effect of soil structure on water flow and isoproturon dynamics in an agricultural field receiving repeated urban waste compost application.

    PubMed

    Filipović, Vilim; Coquet, Yves; Pot, Valérie; Houot, Sabine; Benoit, Pierre

    2014-11-15

    Transport processes in soils are strongly affected by heterogeneity of soil hydraulic properties. Tillage practices and compost amendments can modify soil structure and create heterogeneity at the local scale within agricultural fields. The long-term field experiment QualiAgro (INRA-Veolia partnership 1998-2013) explores the impact of heterogeneity in soil structure created by tillage practices and compost application on transport processes. A modeling study was performed to evaluate how the presence of heterogeneity due to soil tillage and compost application affects water flow and pesticide dynamics in soil during a long-term period. The study was done on a plot receiving a co-compost of green wastes and sewage sludge (SGW) applied once every 2 years since 1998. The plot was cultivated with a biannual rotation of winter wheat-maize (except 1 year of barley) and a four-furrow moldboard plow was used for tillage. In each plot, wick lysimeter outflow and TDR probe data were collected at different depths from 2004, while tensiometer measurements were also conducted during 2007/2008. Isoproturon concentration was measured in lysimeter outflow since 2004. Detailed profile description was used to locate different soil structures in the profile, which was then implemented in the HYDRUS-2D model. Four zones were identified in the plowed layer: compacted clods with no visible macropores (Δ), non-compacted soil with visible macroporosity (Γ), interfurrows created by moldboard plowing containing crop residues and applied compost (IF), and the plow pan (PP) created by plowing repeatedly to the same depth. Isoproturon retention and degradation parameters were estimated from laboratory batch sorption and incubation experiments, respectively, for each structure independently. Water retention parameters were estimated from pressure plate laboratory measurements and hydraulic conductivity parameters were obtained from field tension infiltrometer experiments. Soil hydraulic

  9. Electrostatic Return of Contaminants

    NASA Technical Reports Server (NTRS)

    Rantanen, R.; Gordon, T.

    2003-01-01

    A Model has been developed capable of calculating the electrostatic return of spacecraft-emitted molecules that are ionized and attracted back to the spacecraft by the spacecraft electric potential on its surfaces. The return of ionized contaminant molecules to charged spacecraft surfaces is very important to all altitudes. It is especially important at geosynchronous and interplanetary environments, since it may be the only mechanism by which contaminants can degrade a surface. This model is applicable to all altitudes and spacecraft geometries. In addition to results of the model will be completed to cover a wide range of potential space systems.

  10. Return to Mt. Makiling

    ERIC Educational Resources Information Center

    Wilson, George C.

    1977-01-01

    The National Arts Center of the Philippines, built to assist in the cultural enrichment of the Philippines through the development of young talents, stands today as the Filipino's tribute to the artist. The author discusses his return to Mt. Makiling comparing the development of the National Arts Center with his first visit in October 1973 at the…

  11. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  12. Sustainable Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  13. Lifting Sample Return Capsule

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Stardust sample return capsule successfully landed at the U.S. Air Force Utah Test and Training Range at 2:10 a.m. Pacific time (3:10 a.m. Mountain time). The capsule contains cometary and interstellar samples gathered by the Stardust spacecraft.

    Here, the capsule is being lifted at the landing site.

  14. Sample Return Capsule

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Stardust sample return capsule successfully landed at the U.S. Air Force Utah Test and Training Range at 2:10 a.m. Pacific time (3:10 a.m. Mountain time). The capsule contains cometary and interstellar samples gathered by the Stardust spacecraft.

  15. Higher Education Endowments Return

    ERIC Educational Resources Information Center

    Bahlmann, David; Walda, John D.; Sedlacek, Verne O.

    2012-01-01

    A new study of endowments by the National Association of College and University Business Officers (NACUBO) and the Commonfund Institute has brought good news to college and universities: While endowment returns dropped precipitously in fiscal year 2009 as a result of the financial crisis and accompanying slide in equity markets, they climbed to an…

  16. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  17. Higher Education Endowments Return

    ERIC Educational Resources Information Center

    Bahlmann, David; Walda, John D.; Sedlacek, Verne O.

    2012-01-01

    A new study of endowments by the National Association of College and University Business Officers (NACUBO) and the Commonfund Institute has brought good news to college and universities: While endowment returns dropped precipitously in fiscal year 2009 as a result of the financial crisis and accompanying slide in equity markets, they climbed to an…

  18. Stardust Sample Return

    NASA Image and Video Library

    2006-01-17

    This image shows the return capsule inside a protective covering. The capsule, which landed at 2:10 a.m. Pacific time 3:10 a.m. Mountain time, contains cometary and interstellar samples gathered by NASA Stardust spacecraft.

  19. Agricultural Biodiversity.

    ERIC Educational Resources Information Center

    Postance, Jim

    1998-01-01

    The extinction of farm animals and crops is rarely brought up during discussions of endangered species and biodiversity; however, the loss of diversity in crops and livestock threatens the sustainability of agriculture. Presents three activities: (1) "The Colors of Diversity"; (2) "Biodiversity among Animals"; and (3) "Heirloom Plants." Discusses…

  20. AGRICULTURAL EXTENSION.

    ERIC Educational Resources Information Center

    FARQUHAR, R.N.

    AUSTRALIAN AGRICULTURAL EXTENSION HAS LONG EMPHASIZED TECHNICAL ADVISORY SERVICE AT THE EXPENSE OF THE SOCIOECONOMIC ASPECTS OF FARM PRODUCTION AND FARM LIFE. ONLY IN TASMANIA HAS FARM MANAGEMENT BEEN STRESSED. DEMANDS FOR THE WHOLE-FARM APPROACH HAVE PRODUCED A TREND TOWARD GENERALISM FOR DISTRICT OFFICERS IN MOST STATES. THE FEDERAL GOVERNMENT,…

  1. Agricultural Biodiversity.

    ERIC Educational Resources Information Center

    Postance, Jim

    1998-01-01

    The extinction of farm animals and crops is rarely brought up during discussions of endangered species and biodiversity; however, the loss of diversity in crops and livestock threatens the sustainability of agriculture. Presents three activities: (1) "The Colors of Diversity"; (2) "Biodiversity among Animals"; and (3) "Heirloom Plants." Discusses…

  2. AGRICULTURAL EDUCATION.

    ERIC Educational Resources Information Center

    STEVENS, GLENN Z.

    FEDERAL LEGISLATION HAS PROVIDED FOR PUBLIC PROGRAMS OF OCCUPATIONAL AGRICULTURE EDUCATION IN LAND GRANT COLLEGES AND UNIVERSITIES, LOCAL SCHOOL DISTRICTS, AND MANPOWER DEVELOPMENT PROGRAMS. PROGRAM OBJECTIVES SHOULD BE TO DEVELOP KNOWLEDGE AND SKILLS, PROVIDE OCCUPATIONAL GUIDANCE AND PLACEMENT, AND DEVELOP ABILITIES IN HUMAN RELATIONS AND…

  3. Agriculture and climate change

    SciTech Connect

    Abelson, P.H.

    1992-07-03

    How will increases in levels of CO{sub 2} and changes in temperature affect food production A recently issued report analyzes prospects for US agriculture 1990 to 2030. The report, prepared by a distinguished Task Force, first projects the evolution of agriculture assuming increased levels of CO{sub 2} but no climate change. Then it deals with effects of climate change, followed by a discussion of how greenhouse emissions might be diminished by agriculture. Economic and policy matters are also covered. How the climate would respond to more greenhouse gases is uncertain. If temperatures were higher, there would be more evaporation and more precipitation. Where would the rain fall That is a good question. Weather in a particular locality is not determined by global averages. The Dust Bowl of the 1930s could be repeated at its former site or located in another region such as the present Corn Belt. But depending on the realities at a given place, farmers have demonstrated great flexibility in choosing what they may grow. Their flexibility has been increased by the numerous varieties of seeds of major crops that are now available, each having different characteristics such as drought resistance and temperature tolerance. In past, agriculture has contributed about 5% of US greenhouse gases. Two large components have involved emissions of CO{sub 2} from farm machinery and from oxidation of organic matter in soil due to tillage. Use of diesel fuel and more efficient machinery has reduced emissions from that source by 40%. In some areas changed tillage practices are now responsible for returning carbon to the soil. The report identifies an important potential for diminishing net US emissions of CO{sub 2} by growth and utilization of biomass. Large areas are already available that could be devoted to energy crops.

  4. Phobos Sample Return mission

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Zakharov, A.; Martynov, M.; Polischuk, G.

    Very mysterious objects of the Solar system are the Martian satellites, Phobos and Deimos. Attempt to study Phobos in situ from an orbiter and from landers have been done by the Russian mission FOBOS in 1988. However, due to a malfunction of the onboard control system the landers have not been delivered to the Phobos surface. A new robotics mission to Phobos is under development now in Russia. Its main goal is the delivery of samples of the Phobos surface material to the Earth for laboratory studies of its chemical, isotopic, mineral composition, age etc. Other goals are in situ studies of Phobos (regolith, internal structure, peculiarities in orbital and proper rotation), studies of Martian environment (dust, plasma, fields). The payload includes a number of scientific instruments: gamma and neutron spectrometers, gaschromatograph, mass spectrometers, IR spectrometer, seismometer, panoramic camera, dust sensor, plasma package. To implement the tasks of this mission a cruise-transfer spacecraft after the launch and the Earth-Mars interplanetary flight will be inserted into the first elliptical orbit around Mars, then after several corrections the spacecraft orbit will be formed very close to the Phobos orbit to keep the synchronous orbiting with Phobos. Then the spacecraft will encounter with Phobos and will land at the surface. After the landing the sampling device of the spacecraft will collect several samples of the Phobos regolith and will load these samples into the return capsule mounted at the returned vehicle. This returned vehicle will be launched from the mother spacecraft and after the Mars-Earth interplanetary flight after 11 monthes with reach the terrestrial atmosphere. Before entering into the atmosphere the returned capsule will be separated from the returned vehicle and will hopefully land at the Earth surface. The mother spacecraft at the Phobos surface carrying onboard scientific instruments will implement the "in situ" experiments during an year

  5. 7 CFR 735.7 - Return of suspended or revoked certificates of licensing or certificates of authorization.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... FOR THE UNITED STATES WAREHOUSE ACT General Provisions § 735.7 Return of suspended or revoked... 7 Agriculture 7 2014-01-01 2014-01-01 false Return of suspended or revoked certificates of licensing or certificates of authorization. 735.7 Section 735.7 Agriculture Regulations of the Department...

  6. 7 CFR 735.7 - Return of suspended or revoked certificates of licensing or certificates of authorization.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... FOR THE UNITED STATES WAREHOUSE ACT General Provisions § 735.7 Return of suspended or revoked... 7 Agriculture 7 2011-01-01 2011-01-01 false Return of suspended or revoked certificates of licensing or certificates of authorization. 735.7 Section 735.7 Agriculture Regulations of the Department...

  7. 7 CFR 735.7 - Return of suspended or revoked certificates of licensing or certificates of authorization.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... FOR THE UNITED STATES WAREHOUSE ACT General Provisions § 735.7 Return of suspended or revoked... 7 Agriculture 7 2012-01-01 2012-01-01 false Return of suspended or revoked certificates of licensing or certificates of authorization. 735.7 Section 735.7 Agriculture Regulations of the Department...

  8. Assured Crew Return Vehicle

    NASA Technical Reports Server (NTRS)

    Stone, D. A.; Craig, J. W.; Drone, B.; Gerlach, R. H.; Williams, R. J.

    1991-01-01

    The developmental status is discussed regarding the 'lifeboat' vehicle to enhance the safety of the crew on the Space Station Freedom (SSF). NASA's Assured Crew Return Vehicle (ACRV) is intended to provide a means for returning the SSF crew to earth at all times. The 'lifeboat' philosophy is the key to managing the development of the ACRV which further depends on matrixed support and total quality management for implementation. The risk of SSF mission scenarios are related to selected ACRV mission requirements, and the system and vehicle designs are related to these precepts. Four possible ACRV configurations are mentioned including the lifting-body, Apollo shape, Discoverer shape, and a new lift-to-drag concept. The SCRAM design concept is discussed in detail with attention to the 'lifeboat' philosophy and requirements for implementation.

  9. STS-120 Crew Return

    NASA Image and Video Library

    2007-11-08

    JSC2007-E-098009 (8 Nov. 2007) --- Astronaut Clay Anderson waves to a crowd of well-wishers on hand Nov. 8 at Houston's Ellington Field to greet the returning STS-120 astronauts following the landing of Space Shuttle Discovery in Florida on Nov. 7. Anderson had been flight engineer onboard the International Space Station approximately five months before the undocking of the shuttle and station earlier this week.

  10. Ground-water flow, geochemistry, and effects of agricultural practices on nitrogen transport at study sites in the Piedmont and Coastal Plain physiographic provinces, Patuxent River basin, Maryland

    USGS Publications Warehouse

    McFarland, E. Randolph

    1997-01-01

    In an effort to improve water quality in Chesapeake Bay, agricultural practices are being promoted that are intended to reduce contaminant transport to the Bay. The effects of agricultural practices on nitrogen transport were assessed at two 10-acre study sites in the Patuxent River basin, Maryland, during 1986-92. Nitrogen load was larger in ground water than in surface runoff at both sites. At the study site in the Piedmont Province, nitrogen load in ground water decreased from 12 to 6 (lb/acre)/yr (pound per acre per year) as corn under no-till cultivation was replaced by no-till soybeans, continuous alfalfa, and contoured strip crops alternated among corn, alfalfa, and soybeans. At the study site in the Coastal Plain Province, no-till soybeans resulted in a nitrogen load in ground water of 12.55 (lb/acre)/yr, whereas conventional-till soybeans resulted in a nitrogen load in ground water of 11.51 (lb/acre)/yr.

  11. A Look at Returning Teachers

    ERIC Educational Resources Information Center

    DeAngelis, Karen J.

    2013-01-01

    Research shows that one-quarter to one-third of teachers who leave the profession return, the majority after only a short absence. Though returning teachers can constitute a substantial share of newly hired teachers in schools each year, little is known about them, the factors associated with their decisions to return, or the schools to which…

  12. Returns to Education in Bangladesh

    ERIC Educational Resources Information Center

    Asadullah, Mohammad Niaz

    2006-01-01

    This paper reports labour market returns to education in Bangladesh using data from recent nationwide household survey. Returns are estimated separately for rural and urban samples, males, females and private-sector employees. Substantial heterogeneity in returns is observed; for example, estimates are higher for urban (than rural sample) and…

  13. Sample Return Science

    NASA Astrophysics Data System (ADS)

    Williford, K. H.; Allwood, A.; Beegle, L. W.; Bhartia, R.; Flannery, D.; Hoffmann, A.; Mora, M. F.; Orbay, J.; Petrizzo, D. A.; Tuite, M. L., Jr.; Willis, P. A.

    2014-12-01

    The first clear identification of an ancient habitable environment on Mars by the Mars Science Laboratory (MSL) rover mission relied on a synthetic analytical approach combining orbital and surface imagery and spectroscopy with sophisticated sample acquisition and handling technology including a rotary percussive drill that provided powdered rock for bulk geochemical analysis [1]. The recent announcement of the instrument package for the proposed NASA Mars2020 rover mission, including micro x-ray fluorescence (PIXL) for elemental mapping as well as scanning ultraviolet laser fluorescence and Raman (SHERLOC) suggests a shift in emphasis of Mars surface science towards spatially resolved geochemical analysis that will support the selection and acquisition of samples for coring, caching, and possible return to Earth for further analysis. During a recent field expedition to investigate Archean and Proterozoic biosignatures in the Pilbara region of Western Australia, we deployed a dry, rotary percussive coring drill with a bit assembly analogous to that being considered for Mars2020. Six targets of varying age and lithology were sampled with the coring drill, and surrounding and adjacent rock samples were collected simultaneously. These samples were subsequently prepared and subsampled for bulk and in situ, spatially resolved analysis using conventional laboratory methods as well as the existing PIXL and SHERLOC platforms currently in development. Here we present new approaches and data from this integrated and ongoing program of "sample return science" designed to simulate, and eventually reduce risk associated with a long-term effort towards Mars sample return. [1] Grotzinger, J.P. et al. 2014. Science 343 DOI: 10.1126/science.1242777.

  14. Stardust Capsule Return

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Stardust Capsule Return as seen from NASA's DC-8 Airborne Laboratory with a mission to explore the conditions during reentry from the light emitted by the fireball caused when the capsule streaked through the sky. The aircraft was located near the end of the trajectory, just outside of UTTR. The participating researchers are from NASA Ames, the SETI Institute, the University of Alaska, Utah State University, Lockheed Martin, U.S. Air Force Academy, the University of Kobe (Japan), and Stuttgart University (Germany).

  15. Titan Science Return Quantification

    NASA Technical Reports Server (NTRS)

    Weisbin, Charles R.; Lincoln, William

    2014-01-01

    Each proposal for a NASA mission concept includes a Science Traceability Matrix (STM), intended to show that what is being proposed would contribute to satisfying one or more of the agency's top-level science goals. But the information traditionally provided cannot be used directly to quantitatively compare anticipated science return. We added numerical elements to NASA's STM and developed a software tool to process the data. We then applied this methodology to evaluate a group of competing concepts for a proposed mission to Saturn's moon, Titan.

  16. Titan Science Return Quantification

    NASA Technical Reports Server (NTRS)

    Weisbin, Charles R.; Lincoln, William

    2014-01-01

    Each proposal for a NASA mission concept includes a Science Traceability Matrix (STM), intended to show that what is being proposed would contribute to satisfying one or more of the agency's top-level science goals. But the information traditionally provided cannot be used directly to quantitatively compare anticipated science return. We added numerical elements to NASA's STM and developed a software tool to process the data. We then applied this methodology to evaluate a group of competing concepts for a proposed mission to Saturn's moon, Titan.

  17. Ground-water flow, geochemistry, and effects of agricultural practices on nitrogen transport at study sites in the Piedmont and Coastal Plain physiographic provinces, Patuxent River Basin, Maryland

    USGS Publications Warehouse

    McFarland, E. Randolph

    1995-01-01

    The effects of agricultural practices on nitrogen transport were assessed at two 10-acre study sites in the Patuxent River Basin, Maryland, during 1986- 92. Nitrogen load was larger in ground water than in surface runoff at both sites. Denitrification and (or) long traveltimes of ground water at the study site in the Piedmont Province resulted in lower concentrations of nitrate than at the site in the Coastal Plain Province. The study period was brief compared to traveltimes of nitrogen in ground water of several decades. Therefore, the effects of agricultural practices were observed only in parts of both sites. At the Piedmont site, nitrate concentration in two springs was 7 mg/L (milligrams per liter) two years after corn was grown under no-till cultivation, and decreased to 3.5 mg/L during 4 years while cultivation practices and crops included no-till soybeans, continuous alfalfa, and contoured strips alternated among corn, alfalfa, and soybeans. Nitrogen load in ground water decreased from 12 to 6 (lb/acre)/yr (pounds per acre per year). At the Coastal Plain site, the concentration of nitrate in ground water decreased from 10 mg/L after soybeans were grown under no-till cultivation for 2 years, to 9 mg/L after soybeans were grown under conventional till cultivation for 3 years. No-till cultivation in 1988 resulted in a greater nitrogen load in ground water (12.55 (lbs/acre)/yr), as well as greater ground-water recharge and discharge, than conventional till cultivation in 1991 (11.51 (lbs/ acre)/yr), even though the amount and timing of precipitation for both years were similar.

  18. Animal Enterprise Record Book. Agricultural Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Agricultural Curriculum Materials Service.

    This record book is intended for use by agricultural education students who have ownership arrangements in animal enterprise experience programs. A major purpose of this book is to aid in separating out or allocating the costs and returns to a specific enterprise. The financial, labor, and management aspects of each enterprise can then be studied…

  19. 7 CFR 1951.15 - Return of paid-in-full or satisfied notes to borrower.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false Return of paid-in-full or satisfied notes to borrower... Servicing Policies § 1951.15 Return of paid-in-full or satisfied notes to borrower. (a) Notes not held in County Office. When the original of the note is not held in the County Office the County Supervisor will...

  20. 7 CFR 1951.15 - Return of paid-in-full or satisfied notes to borrower.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false Return of paid-in-full or satisfied notes to borrower... Servicing Policies § 1951.15 Return of paid-in-full or satisfied notes to borrower. (a) Notes not held in County Office. When the original of the note is not held in the County Office the County Supervisor will...

  1. 7 CFR 1951.15 - Return of paid-in-full or satisfied notes to borrower.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false Return of paid-in-full or satisfied notes to borrower... Servicing Policies § 1951.15 Return of paid-in-full or satisfied notes to borrower. (a) Notes not held in County Office. When the original of the note is not held in the County Office the County Supervisor will...

  2. 7 CFR 273.32 - Households who return to TANF during the transitional period.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS The Transitional Benefits Alternative § 273.32 Households who return to TANF during the transitional period. If a household receiving transitional benefits returns to...

  3. Returning Samples from Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, P.; Kanik, I.; Brownlee, D.; McKay, C.; Anbar, A.; Glavin, D.; Yano, H.

    2012-12-01

    From the first half century of space exploration, we have obtained samples only from the Moon, comet Wild 2, the Solar Wind and the asteroid Itokawa. The in-depth analyses of these samples in terrestrial laboratories have yielded profound knowledge that could not have been obtained without the returned samples. While obtaining samples from Solar System bodies is crucial science, it is rarely done due to cost and complexity. Cassini's discovery of geysers on Enceladus and organic materials, indicate that there is an exceptional opportunity and science rational to do a low-cost flyby sample return mission, similar to what was done by the Stardust. The earliest low cost possible flight opportunity is the next Discovery Mission [Tsou et al 2012]. Enceladus Plume Discovery - While Voyager provided evidence for young surfaces on Enceladus, the existence of Enceladus plumes was discovered by Cassini. Enceladus and comets are the only known solar system bodies that have jets enabling sample collection without landing or surface contact. Cassini in situ Findings -Cassini's made many discoveries at Saturn, including the break up of large organics in the plumes of Enceladus. Four prime criteria for habitability are liquid water, a heat source, organics and nitrogen [McKay et al. 2008, Waite et al. 2009, Postberg et al. 2011]. Out of all the NASA designated habitability targets, Enceladus is the single body that presents evidence for all four criteria. Significant advancement in the exploration of the biological potential of Enceladus can be made on returned samples in terrestrial laboratories where the full power of state-of-the-art laboratory instrumentation and procedures can be used. Without serious limits on power, mass or even cost, terrestrial laboratories provide the ultimate in analytical capability, adaptability, reproducibility and reliability. What Questions can Samples Address? - Samples collected from the Enceladus plume will enable a thorough and replicated

  4. Return to Space

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This video documents the preparations for Shuttle Flight STS-26 with Shuttle Discovery, NASA's return to manned space flight after the Challenger disaster. Footage and descriptions document such changes to the new Shuttle as new joints, improved insulation, and added O-rings to the solid rocket boosters; new safety hardware and procedures such as parachute and sidewire evacuations during liftoff, and new pressure suits; modified landing gear, brakes, and nose wheel steering, as well as a modified landing runway. Also profiled are the 5 member crew of all veteran Shuttle astronauts, the TDRS 3 Satellite to be released from the cargo bay in orbit, and 11 commercial and student experiments to be performed during the mission.

  5. Dealing with returned manuscripts.

    PubMed

    Peh, W C G; Ng, K H

    2009-11-01

    It is useful for authors to learn to deal with returned manuscripts with a rejection decision or a request for revision. Common reasons for rejection include contents outside the scope of the journal or inappropriate for the journal, incomplete submission, poor methodology, faulty experimental design, major flaws in the interpretation of results, extremely poor writing, and duplicated or plagiarised work. Authors should use the editor's and reviewers' comments to improve their manuscripts and resubmit elsewhere. Common reasons for revision requests include minor faults in the methodology, minor inaccuracies in data, inconsistencies among different sections of the manuscript, faulty deductions, data that do not support the conclusions, excessive data or text, poor or excessive illustrations, and poor but salvageable writing. A request for revision should be viewed positively, as it means that there is a possibility that the manuscript may still be potentially publishable, provided that all the editor's and reviewers' comments are addressed.

  6. Awaiting Halley's Return

    NASA Astrophysics Data System (ADS)

    Heyn, Herman M.

    2004-01-01

    When Comet Halley perihelioned in early 1986, there were people still around who had witnessed its previous, 1910 apparition. )Then there is Mark Twain, who was born under the comet in 1835, wished for his demise upon its return, and died one day after it perihelioned in 1910!( I so enjoyed my 1986 view of Halley, that I decided I would like to be among those who see it again when it perihelions in 2061. The big problem with this ambition is that I would need to live to a Guinness Book of World's Records age of 131 years. Now, thanks to Randy Showstack's In Brief news note, ``Farthest, faintest detection of a comet'' (Eos, 16 September 2003), I have been handed a fallback position which, literally, I may be able to live with: a telescopic photo of Halley at aphelion.

  7. Expedition 8 Returns Home

    NASA Image and Video Library

    2004-04-30

    JSC2004-E-21252 (30 April 2004) --- Astronaut C. Michael Foale, Expedition 8 commander and NASA ISS science officer, is carried in a chair from the Soyuz landing site to an inflatable medical tent after he and his crewmates, cosmonaut Alexander Y. Kaleri (out of frame), Soyuz flight engineer representing Russia’s Federal Space Agency, and European Space Agency (ESA) astronaut Andre Kuipers (out of frame) of the Netherlands, successfully landed in north central Kazakhstan on April 30, 2004, in their Soyuz TMA-3 capsule. Foale and Kaleri completed 195 days in space aboard the International Space Station (ISS), while Kuipers returned after an 11-day research mission as part of a commercial agreement between ESA and Russia’s Federal Space Agency. Photo Credit: NASA/Bill Ingalls

  8. A RESEARCH STUDY OF AGRICULTURAL TRAINING NEEDS IN VENTURA COUNTY.

    ERIC Educational Resources Information Center

    RODRIGUES, DONALD F.

    QUESTIONNAIRE RETURNS FROM 103 EMPLOYERS IN AGRICULTURE AND RELATED INDUSTRIES WERE COMBINED WITH 50 INTERVIEWS WITHIN THE SAME GROUP TO PROVIDE INFORMATION ABOUT AGRICULTURAL TRAINING NEEDS IN VENTURA COUNTY. MOST FIRMS EMPLOYED FEWER THAN 15 WORKERS ON A PERMANENT BASIS, SUPPLEMENTED BY LARGE MEMBERS OF SEASONAL WORKERS, ESPECIALLY IN THE…

  9. Trophic relationships of small nonnative fishes in a natural creek and several agricultural drains flowing into the Salton Sea, and their potential, effects on the endangered desert pupfish

    USGS Publications Warehouse

    Martin, Barbara A.; Saiki, Michael K.

    2009-01-01

    This study was conducted to characterize trophic relationships of small nonnative fishes and to determine if predation by these fishes contributes to the decline of desert pupfish (Cyprinodon macularius), an endangered cyprinodont on the verge of extinction. We sampled 403 hybrid Mozambique tilapias (Oreochromis mossambica by O. urolepis), 107 redbelly tilapias (Tilapia zillii), 32 longjaw mudsuckers (Gillkhthys mirabilis), 182 western mosquitofish (Gambusia affinis), 222 sailfin mollies (Poecilia latipinna), 63 shortfin mollies (Poecilia mexicana), and 235 porthole livebearers (Poecilurpsis gracilis) from a natural creek and four agricultural drains during September 1999- December 2001. Evidence of piscivory was in gastrointestinal contents of 14 hybrid Mozambique tilapias, 3 redbelly tilapias, 10 longjaw mudsuckers, 8 western mosquitofish, 2 sailfin mollies, and 8 porthole livebearers. Although digestion often was too advanced for identification of fishes consumed by nonnative fishes, remains of desert pupfish were in gastrointestinal contents of a longjaw mudsucker. Our findings, along with Field evidence from other studies that inverse relationships exist between abundances of desert pupfish and nonnative species, are consistent with the hypothesis that predation by nonnative species is contributing to decline of desert pupfish. We suspect that competitive interactions with nonnative fishes might also adversely affect abundance of desert pupfish.

  10. Returning to freud.

    PubMed

    Chessick, Richard D

    2010-01-01

    In this article I attempt to renew interest in the importance of Freud's work for both the practice of psychoanalysis and in the training of psychoanalysts. I hope to stimulate readers to return to Freud's writings in detail, which seem to be increasingly neglected these days both in training and in the many conflicting contemporary models of psychoanalysis. I propose that the identity of psychoanalysis can still be based on Freud's work, and his approach can form a fundamental center from which there are various channels of divergence that may be useful when the patient seems to need them. But the centerpiece of our training and our orientation, I suggest, should be the basic principles spelled out in Freud's numerous volumes, in spite of the many changes and contradictions and even outright mistakes and cultural blindness he displays in some instances. I proceed to review some of these basic principles in the hope of persuading the reader to return to Freud again. I present these with some commentary from my own 50 years of clinical experience. I briefly review the clinical cornerstones of Freud's approach as developed in his early books, his controversial papers on technique, and his later emendations, which constitute the actual reality of Freud at work in psychoanalysis (that sometimes--and sometimes wisely--violates his papers on technique), and I discuss his notion of curative factors in psychoanalysis. All of this is to revive an interest in Freud's thought and to emphasize the lasting value of his work, both in its contemporary clinical relevance and as the proposed foundation stone of our identity as psychoanalysts.

  11. Mars Rover Sample Return mission delivery and return challenges

    NASA Technical Reports Server (NTRS)

    Cohen, Aaron

    1988-01-01

    The Mars Rover Sample Return mission is a robotic exploration mission culminating in the return of atmospheric and surface samples from Mars to Earth. To accomplish this complex mission requires sophisticated autonomous systems for many time-critical operations associated with the delivery and return phases, since the round trip light times preclude Earth-based control of these operations. In addition, there are significant engineering and technology challenges to be addressed to meet the mission science and exploration objectives.

  12. Stable water isotopes and Rn-222 to determine dam and groundwater contribution to baseflow and event flow in a small agricultural catchment

    NASA Astrophysics Data System (ADS)

    Hughes, C. E.; Scarff, S. A.; Morrison, T.; Fischer, M. J.; Adams, G. A.; Hart, M. R.

    2009-04-01

    In order to improve local water managers understanding of nutrient inputs into Sydney's drinking water catchments, a detailed study of nutrients in streamflow has been carried out in the headwaters of Kellys Ck in the New South Wales southern highlands, Australia. One component of this study attempted to determine the flow pathways contributing to baseflow and to runoff generation during a rainfall event over a 128 ha catchment area. Rainfall, stream, shallow groundwater, spring and dam samples were collected during baseflow (pre-event), flow event and post event periods around a 4 day rainfall event in July 2008. Samples were analysed for stable water isotopes, Rn-222, DOC, nutrients and major ions. Hydrograph separation and transit time distribution modelling were used to examine the contribution of event water, dam water and pre-event water to streamflow for a 9 day period encompassing the rain event. The results show that pre-event and event water contribute equally to streamflow with the pre-event contribution dominated by evaporated water (pre-event dam storage and soil water) rather than the more depleted shallow groundwater and spring water. Rn-222 was also used to understand the spatial variation of groundwater contribution during baseflow conditions.

  13. Agricultural land management options following large-scale environmental contamination - evaluation for Fukushima affected agricultural land

    SciTech Connect

    Vandenhove, Hildegarde

    2013-07-01

    The accident at the Fukushima Daiichi Nuclear Power Plant has raised questions about the accumulation of radionuclides in soils, the transfer in the food chain and the possibility of continued restricted future land use. This paper summarizes what is generally understood about the application of agricultural countermeasures as a land management option to reduce the radionuclides transfer in the food chain and to facilitate the return of potentially affected soils to agricultural practices in areas impacted by a nuclear accident. (authors)

  14. FLOW SYSTEM FOR REACTOR

    DOEpatents

    Zinn, W.H.

    1963-06-11

    A reactor is designed with means for terminating the reaction when returning coolant is below a predetermined temperature. Coolant flowing from the reactor passes through a heat exchanger to a lower reservoir, and then circulates between the lower reservoir and an upper reservoir before being returned to the reactor. Means responsive to the temperature of the coolant in the return conduit terminate the chain reaction when the temperature reaches a predetermined minimum value. (AEC)

  15. 17. Internal view of boiler in steam space above return ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Internal view of boiler in steam space above return flues. View looks forward in ship toward fireboxes; tubes (flues) below carry hot combustion gases from return chamber to smoke chamber. From thence gasses flow through vertical pipe at left into steam stack, and eventually to ship's smokestack. Inclined and radiating straps are stays used to reinforce boiler plates against distortion under pressure. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

  16. 26 CFR 31.6011(a)-1 - Returns under Federal Insurance Contributions Act.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Employers of agricultural workers. Every employer who pays wages for agricultural labor with respect to... make a return of income tax withheld from wages. (3) Employers of domestic workers. Schedule H (Form... Insurance Contributions Act, paid by the employer in any calendar year for domestic service as defined...

  17. 26 CFR 31.6011(a)-1 - Returns under Federal Insurance Contributions Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Employers of agricultural workers. Every employer who pays wages for agricultural labor with respect to... make a return of income tax withheld from wages. (3) Employers of domestic workers. Schedule H (Form... Insurance Contributions Act, paid by the employer in any calendar year for domestic service as defined...

  18. Return to Rhea

    NASA Image and Video Library

    2015-03-30

    After a couple of years in high-inclination orbits that limited its ability to encounter Saturn's moons, NASA's Cassini spacecraft returned to Saturn's equatorial plane in March 2015. As a prelude to its return to the realm of the icy satellites, the spacecraft had its first relatively close flyby of an icy moon (apart from Titan) in almost two years on Feb. 9. During this encounter Cassini's cameras captured images of the icy moon Rhea, as shown in these in two image mosaics. The views were taken about an hour and a half apart as Cassini drew closer to Rhea. Images taken using clear, green, infrared and ultraviolet spectral filters were combined to create these enhanced color views, which offer an expanded range of the colors visible to human eyes in order to highlight subtle color differences across Rhea's surface. The moon's surface is fairly uniform in natural color. The image at right represents one of the highest resolution color views of Rhea released to date. A larger, monochrome mosaic is available in PIA07763. Both views are orthographic projections facing toward terrain on the trailing hemisphere of Rhea. An orthographic view is most like the view seen by a distant observer looking through a telescope. The views have been rotated so that north on Rhea is up. The smaller view at left is centered at 21 degrees north latitude, 229 degrees west longitude. Resolution in this mosaic is 450 meters (1,476 feet) per pixel. The images were acquired at a distance that ranged from about 51,200 to 46,600 miles (82,100 to 74,600 kilometers) from Rhea. The larger view at right is centered at 9 degrees north latitude, 254 degrees west longitude. Resolution in this mosaic is 300 meters (984 feet) per pixel. The images were acquired at a distance that ranged from about 36,000 to 32,100 miles (57,900 to 51,700 kilometers) from Rhea. The mosaics each consist of multiple narrow-angle camera (NAC) images with data from the wide-angle camera used to fill in areas where NAC

  19. 11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS WERE NUCLEAR WEAPONS SHIPPED TO THE ROCKY FLATS PLANT FROM THE NUCLEAR WEAPON STOCKPILE FOR RETIREMENT, TESTING, OR UPGRADING. FISSILE MATERIALS (PLUTONIUM, URANIUM, ETC.) AND RARE MATERIALS (BERYLLIUM) WERE RECOVERED FOR REUSE, AND THE REMAINDER WAS DISPOSED. (8/7/62) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  20. Christmas Island birds returning

    NASA Astrophysics Data System (ADS)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  1. The Fertile Grounds Initiative: A new way to close nutrient flows at regional level resulting in better agricultural productivity and less environmental losses

    NASA Astrophysics Data System (ADS)

    van Beek, Christy; van Duivenbooden, Niek; Noij, Gert-Jan

    2014-05-01

    The threat of declining soil fertility levels is well known. Yet, and despite numerous efforts, we seem incapable of changing the current situation of sink areas in developed countries and depletion areas in developing countries. With negative consequences (i.e. loss in productive capacity and loss in environmental quality) in both areas. Moreover, due to globalization and urbanization nutrient flows become increasingly disconnected. Soil nutrient depletion cannot simply be compensated for with mineral fertilisers, for the following reasons: • mineral fertilisers are often not affordable for smallholders and fertiliser subsidy systems are not always successful • mineral fertilisers do not contain organic matter and therefore do not halt the degradation of the soil • mineral fertilisers work best in combination with organic sources of nutrients (compost, farm yard manure, etc.) • To halt soil degradation an integrated approach is needed, including reducing losses of nutrients and organic matter from soils at risk. Presently, more actors are getting involved in reallocation of nutrients, especially in the energy and waste sector. Time has come for a new approach to bring together demands and supplies for nutrients. We therefore present the Fertile Grounds Initiative: a broker for nutrient supply and demand in the region. The Fertile Grounds Initiative is based on the findings that: • Organic ánd mineral nutrients are required for increased and sustainable production; • Nutrients have a value and should be treated as such; • Due to globalization and urbanization nutrient flows are ever more polarized between depletion and concentration areas; • The demand for energy poses new threats and opportunities for nutrient management. In the Fertile Grounds Initiative nutrient suppliers from the energy sector, waste management, fertilizer companies, etc. and demands for nutrients from farmers are brought together in a dynamic platform. This platform acts as a

  2. The Point of No Return

    PubMed Central

    Logan, Gordon D.

    2015-01-01

    Bartlett (1958) described the point of no return as a point of irrevocable commitment to action, which was preceded by a period of gradually increasing commitment. As such, the point of no return reflects a fundamental limit on the ability to control thought and action. I review the literature on the point of no return, taking three perspectives. First, I consider the point of no return from the perspective of the controlled act, as a locus in the architecture and anatomy of the underlying processes. I review experiments from the stop-signal paradigm that suggest that the point of no return is located late in the response system. Then I consider the point of no return from the perspective of the act of control that tries to change the controlled act before it becomes irrevocable. From this perspective, the point of no return is a point in time that provides enough “lead time” for the act of control to take effect. I review experiments that measure the response time to the stop signal as the lead time required for response inhibition in the stop-signal paradigm. Finally, I consider the point of no return in hierarchically controlled tasks, in which there may be many points of no return at different levels of the hierarchy. I review experiments on skilled typing that suggest different points of no return for the commands that determine what is typed and the countermands that inhibit typing, with increasing commitment to action the lower the level in the hierarchy. I end by considering the point of no return in perception and thought as well as action. PMID:25633089

  3. Mars Sample Return Mission Planning

    NASA Technical Reports Server (NTRS)

    Beaty, David

    2001-01-01

    This presentation considers the decisions which go into planning the Mars Sample Return Mission (i.e. spacecraft design) and how these choices affect concerns about the safe handling of any sample returns. Topics covered include: 'being there' trades, 'getting home' trades, quantitative functions and risk assessments.

  4. Capital Structure and Stock Returns

    ERIC Educational Resources Information Center

    Welch, Ivo

    2004-01-01

    U.S. corporations do not issue and repurchase debt and equity to counteract the mechanistic effects of stock returns on their debt-equity ratios. Thus over one- to five-year horizons, stock returns can explain about 40 percent of debt ratio dynamics. Although corporate net issuing activity is lively and although it can explain 60 percent of debt…

  5. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA-WPI Sample Return Robot Centennial Challenge teams, NASA management, and challenge organizers pose for a group photograph on Saturday, June 16, 2012 at Worcester Polytechnic Institute (WPI) in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  6. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Chief Technologist Mason Peck talks at the kick off of the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  7. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    A judge for the NASA-WPI Sample Return Robot Centennial Challenge follows a robot on the playing field during the challenge on Saturday, June 16, 2012 in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  8. [Return to the family].

    PubMed

    Ouaidou, N G

    1993-08-01

    Sahelian countries occupy an inglorious place in the global list of human development. The human development index is superior to the gross national product (GNP) at measuring the progress of a country in terms of development, because it includes income, longevity, and educational level. The highest ranked Sahelian country holds the 114th position out of a 173 countries. The low human development index scores for the Sahel reflects the socioeconomic crisis which has overcome these countries. In 1991, only 3 of 9 Sahelian countries had a mean GP equal or superior to US$500. Just 2 countries had a life expectancy greater than 50 years. In fact, the Sahel had a lower life expectancy than all of Africa (50 years) and much lower than Asia (64 years) and Latin America (67 years). The economic crisis is worse than the cold statistics show. It destabilizes the most disadvantaged populations. The pressure it exerts often leads public authorities to adopt unpopular measures. It depreciates some sociocultural values and disintegrates traditional social structures. It is accentuated by the effects of war and drought. Internal and external migration increases even as urban hope is uncertain. For most people, the family (the traditional framework of individual development) is ready to break apart, leaving only a disincarnate nuclear entity to subsist. Yet, African history is built around the extended family: the place of reproduction, production, distribution, formation, management, perpetuation of demographic behavior, and social control. Senegal and Mali have created ministries which invest in families. The Third African Conference on Population, in 1992, chose its theme to be the relationship between family, population, and sustainable development. It is important to return to the natural or primordial framework--family--as a refuge against the economic crisis.

  9. Vocational Agriculture Handbook for Agriculture Cooperative Training.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Vocational Instructional Services.

    This handbook was designed to assist school administrators, vocational administrators, vocational agricultural teachers, and area consultants of vocational agriculture in developing, implementing, and improving an agricultural cooperative training program (especially in Texas). The handbook, which presents information in a narrative format,…

  10. Agricultural SWOT analysis and wisdom agriculture design of chengdu

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Chen, Xiangyu; Du, Shaoming; Yin, Guowei; Yu, Feng; Liu, Guicai; Gong, Jin; Han, Fujun

    2017-08-01

    According to the status of agricultural information, this paper analyzed the advantages, opportunities and challenges of developing wisdom agriculture in Chengdu. By analyzed the local characteristics of Chengdu agriculture, the construction program of Chengdu wisdom agriculture was designed, which was based on the existing agricultural informatization. The positioning and development theme of Chengdu agriculture is leisure agriculture, urban agriculture and quality agriculture.

  11. National animal health surveillance: Return on investment.

    PubMed

    Scott, Aaron E; Forsythe, Kenneth W; Johnson, Cynthia L

    2012-08-01

    A weighted benefit-cost analysis (BCA) supports prioritization of animal health surveillance activities to safeguard animal agriculture industries and reduce the impact of disease on the national economy. We propose to determine the value of investment in surveillance by assessing benefits from: avoiding disease incursion and expansion modified by the probability of occurrence of the disease event, the sensitivity of systems to detect it, and the degree to which we can mitigate disease impact when detected. The weighted benefit-cost ratio is the modified value of surveillance as laid out above divided by the cost of surveillance. We propose flexible, stream-based surveillance that capitalizes on combining multiple streams of information from both specific pathogen based and non-pathogen based surveillance. This stream-based type of system provides high value with lower costs and will provide a high return for the funds invested in animal health surveillance. Published by Elsevier B.V.

  12. Agricultural production and stability of settlement systems in Upper Mesopotamia during the Early Bronze Age (third millennium BCE)

    NASA Astrophysics Data System (ADS)

    Kalayci, Tuna

    This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system. The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production cycle, further discussions on the forces that shaped and sustained urban settlement systems will be lacking. While large scale fluctuations in the flow of agricultural products between settlements are not the only determinants of hierarchical structures, the total available agricultural yield for each urban settlement in a hierarchy must have influenced settlement relations. As for the methodology, first, Early Bronze Age precipitation levels are estimated by using modern day associations between the eastern Mediterranean coastal areas and the inner regions of Upper Mesopotamia. Next, these levels are integrated into a remote-sensing based biological growth model. Also, a CORONA satellite imagery based archaeological survey is conducted in order to map the Early Bronze Age settlement system in its entirety as well as the ancient markers of agricultural intensification. Finally, ancient agricultural production landscapes are modeled in a GIS. The study takes a critical position towards the traditionally held assumption that large urban settlements (cities) in Upper Mesopotamia were in a state of constant demand for food. The results from this study also suggest that when variations in ancient precipitation levels are translated into the variations in production levels, the impact of climatic aridification on ancient

  13. Agricultural Research Service

    MedlinePlus

    ... Protection Natural Resources and Sustainable Agricultural Systems Nutrition, Food Safety, and Quality Overseas Biological Control Laboratories Office of International Research Programs National Agricultural Library Research Locations (Map) ...

  14. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Chief Technologist Mason Peck, left, NASA Deputy Administrator Lori Garver, and Worcester Polytechnic Institute (WPI) President Dennis Berkey, third from left, talk with WPI Robotics Resource Center Director and NASA-WPI Sample Return Robot Centennial Challenge Judge Ken Stafford at the edge of the playing field during the robotic challenge on Saturday, June 16, 2012 in Worcester, Mass. Teams in the NASA-WPI Sample Return Robot Centennial Challenge were tasked with building autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  15. Curtailing Agricultural Pumping in an Era of Extended Drought: Infusing Science and Leagality into a Common Hydrologic Framework

    NASA Astrophysics Data System (ADS)

    Carroll, R. W. H.; Pohll, G.; Benedict, J.; Felling, R.

    2016-12-01

    Many arid and semi-arid agricultural systems of the Great Basin in the western United States depend on supplemental groundwater pumping to augment diminished surface water flows during periods of drought. As droughts become longer and more severe in the region, unprecedented drawdown in these aquifer systems has occurred with legal and environmental implications on both surface and groundwater. The Walker River in the Great Basin supports extensive agriculture in the region and is the sole perennial stream to one of the few desert terminal lakes in North America. Continuous declines in the lake have spurred extensive research into management options to balance demands of agriculture and increase water deliveries to the lake. Smith and Mason Valleys are important agricultural centers within the Walker Basin. In 2015 the region entered its fifth year of drought and both valleys were the focus of curtailment orders to restrict the use of supplemental groundwater rights. To aid management decisions, hydrologic models were developed that simulate complex feedbacks between surface diversions, crop consumptive needs, groundwater recharge, return flow, and groundwater-surface water interactions. Demand-driven pumping that incorporates priority dates and maximum duty allocations are directly input to the hydrologic model to allow an assessment of groundwater curtailment options under a variety of drought scenarios to meet targeted water levels and downstream conveyance of surface water in a legally defensible framework. Hydrologic results using a sliding scale approach to priority based curtailment are presented in the arena of stakeholder participation and response.

  16. FRS Geospatial Return File Format

    EPA Pesticide Factsheets

    The Geospatial Return File Format describes format that needs to be used to submit latitude and longitude coordinates for use in Envirofacts mapping applications. These coordinates are stored in the Geospatail Reference Tables.

  17. Total anomalous pulmonary venous return

    MedlinePlus

    ... atrial septal defect (ASD) or patent foramen ovale (passage between the left and right atria) must exist ... heart disease - TAPVR Images Heart, section through the middle Totally anomalous pulmonary venous return, x-ray Totally ...

  18. Endeavour Return to Flight Maintenance

    NASA Image and Video Library

    2003-10-10

    In the Orbiter Processing Facility, David Sanborn and Rick Cady, with United Space Alliance, check tiles on the underside of Endeavour. Tile check is part of routine maintenance and return to flight activities on the orbiter fleet.

  19. Another Kind of Returning Student.

    ERIC Educational Resources Information Center

    Chandler, Judith B.

    1984-01-01

    Discusses the needs of women who are returning to school for adult basic education. Provides suggestions for meeting the needs of this group in terms of professional action, counselor education, teacher training, grants, financial support, publication, and volunteerism. (JAC)

  20. Endeavour Return to Flight Maintenance

    NASA Image and Video Library

    2003-10-10

    In the Orbiter Processing Facility, Tim Chastain (left) and John Peterson (right), with United Space Alliance, prepare to remove the body flap actuator from the orbiter Endeavour. The work is part of return to flight activities on the orbiter fleet.

  1. Sample Return Challenges and Technologies

    NASA Astrophysics Data System (ADS)

    Bouilly, J.-M.; Scheer, H.; Pisseloup, A.

    2014-06-01

    During the last ten years, Airbus Defence and Space contributed to several Earth Return Capsules projects. The scope of this paper is to present an overview of main results and achievements obtained through mission studies and technology maturation.

  2. Another Kind of Returning Student.

    ERIC Educational Resources Information Center

    Chandler, Judith B.

    1984-01-01

    Discusses the needs of women who are returning to school for adult basic education. Provides suggestions for meeting the needs of this group in terms of professional action, counselor education, teacher training, grants, financial support, publication, and volunteerism. (JAC)

  3. Theme: Agricultural Literacy.

    ERIC Educational Resources Information Center

    Deeds, Jacquelyn P.; And Others

    1991-01-01

    Six theme articles attempt to define and advocate agricultural literacy, review the status of K-8 agricultural literacy programs in states, discuss an Oklahoma study of agricultural literacy, clarify the meaning of sustainable agriculture, and describe the Future Farmers of America's Food for America program for elementary students. (SK)

  4. Handbook of Agricultural Geophysics

    USDA-ARS?s Scientific Manuscript database

    Geophysical methods continue to show great promise for use in agriculture. The term “agricultural geophysics” denotes a subdiscipline of geophysics that is focused only on agricultural applications. The Handbook of Agricultural Geophysics was compiled to include a comprehensive overview of the geoph...

  5. Theme: Agricultural Literacy.

    ERIC Educational Resources Information Center

    Deeds, Jacquelyn P.; And Others

    1991-01-01

    Six theme articles attempt to define and advocate agricultural literacy, review the status of K-8 agricultural literacy programs in states, discuss an Oklahoma study of agricultural literacy, clarify the meaning of sustainable agriculture, and describe the Future Farmers of America's Food for America program for elementary students. (SK)

  6. Vocational Agriculture Computer Handbook.

    ERIC Educational Resources Information Center

    Kentucky State Dept. of Education, Frankfort.

    This document is a catalog of reviews of computer software suitable for use in vocational agriculture programs. The reviews were made by vocational agriculture teachers in Kentucky. The reviews cover software on the following topics: farm management, crop production, livestock production, horticulture, agricultural mechanics, general agriculture,…

  7. Vocational Agriculture Computer Handbook.

    ERIC Educational Resources Information Center

    Kentucky State Dept. of Education, Frankfort.

    This document is a catalog of reviews of computer software suitable for use in vocational agriculture programs. The reviews were made by vocational agriculture teachers in Kentucky. The reviews cover software on the following topics: farm management, crop production, livestock production, horticulture, agricultural mechanics, general agriculture,…

  8. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    "Harry" a Goldendoodle is seen wearing a NASA backpack during the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  9. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Worcester Polytechnic Institute (WPI) President Dennis Berkey, left, walks with NASA Deputy Administrator Lori Garver to the competition field for the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  10. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Worcester Polytechnic Institute (WPI) President Dennis Berkey talks to NASA Deputy Administrator Lori Garver prior to the kick off of the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 at WPI in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  11. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Posters for the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event are seen posted around the campus on Saturday, June 16, 2012 at WPI in Worcester, Mass. The TouchTomorrow event was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  12. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-14

    A University of Waterloo Robotics Team member tests their robot on the practice field two days prior to the NASA-WPI Sample Return Robot Centennial Challenge, Thursday, June 14, 2012 at the Worcester Polytechnic Institute in Worcester, Mass. Teams will compete for a $1.5 million NASA prize to build an autonomous robot that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  13. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Panoramic of some of the exhibits available on the campus of the Worcester Polytechnic Institute (WPI) during their "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Anthony Shrout)

  14. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    University of Waterloo (Canada) Robotics Team members test their robot on the practice field one day prior to the NASA-WPI Sample Return Robot Centennial Challenge, Friday, June 15, 2012 at the Worcester Polytechnic Institute in Worcester, Mass. Teams will compete for a $1.5 million NASA prize to build an autonomous robot that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  15. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Deputy Administrator Lori Garver, left, listens as Worcester Polytechnic Institute (WPI) Robotics Resource Center Director and NASA-WPI Sample Return Robot Centennial Challenge Judge Ken Stafford points out how the robots navigate the playing field during the challenge on Saturday, June 16, 2012 in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  16. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Team members of "Survey" drive their robot around the campus on Saturday, June 16, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. The Survey team was one of the final teams participating in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  17. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Deputy Administrator Lori Garver, right, listens as Worcester Polytechnic Institute (WPI) Robotics Resource Center Director and NASA-WPI Sample Return Robot Centennial Challenge Judge Ken Stafford points out how the robots navigate the playing field during the challenge on Saturday, June 16, 2012 in Worcester, Mass. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  18. Derivation of low flow frequency distributions under human activities and its implications

    NASA Astrophysics Data System (ADS)

    Gao, Shida; Liu, Pan; Pan, Zhengke; Ming, Bo; Guo, Shenglian; Xiong, Lihua

    2017-06-01

    Low flow, refers to a minimum streamflow in dry seasons, is crucial to water supply, agricultural irrigation and navigation. Human activities, such as groundwater pumping, influence low flow severely. In order to derive the low flow frequency distribution functions under human activities, this study incorporates groundwater pumping and return flow as variables in the recession process. Steps are as follows: (1) the original low flow without human activities is assumed to follow a Pearson type three distribution, (2) the probability distribution of climatic dry spell periods is derived based on a base flow recession model, (3) the base flow recession model is updated under human activities, and (4) the low flow distribution under human activities is obtained based on the derived probability distribution of dry spell periods and the updated base flow recession model. Linear and nonlinear reservoir models are used to describe the base flow recession, respectively. The Wudinghe basin is chosen for the case study, with daily streamflow observations during 1958-2000. Results show that human activities change the location parameter of the low flow frequency curve for the linear reservoir model, while alter the frequency distribution function for the nonlinear one. It is indicated that alter the parameters of the low flow frequency distribution is not always feasible to tackle the changing environment.

  19. Return to work following ileostomy.

    PubMed

    Whates, P D; Irving, M

    1984-08-01

    The experiences of 1033 members of the 51 English divisions of the Ileostomy Association of Great Britain and Ireland have been analysed in respect of their return to work after construction of an ileostomy. Although there was a fall in the number of patients returning to work after operation this was often for reasons unrelated to surgery. The majority of those returning to work resumed work with the same employer and usually in the same post. Fifty-nine (5.7 per cent) patients began work for the first time after operation, including 33 (3.2 per cent) who were previously inactive although of working age. Analysis of occupational class shows that, although a number of patients initially resumed work within a lower class, once established in employment successful career advancement was possible. Problems in the gaining or resumption of employment were reported by 56 (5.4 per cent) patients. In 22 (2.1 per cent) patients, almost all approaching or above retirement age, successful surgery resulted in a decision not to return to employment. An ileostomy is no barrier to successful return to work in nearly all occupations, and is accomplished by the majority of patients without major difficulty.

  20. Agricultural Chartbook 1988. Agriculture Handbook No. 673.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    These charts present an overview of the current economic health of American agriculture. The charts move from the national and international arenas to farm economic health measures and crop and livestock trends. A small amount of descriptive narrative accompanies most of the charts. Charts depicting the economic picture of U.S. agriculture include…

  1. 1986 Agricultural Chartbook. Agriculture Handbook No. 663.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    This book contains 310 charts, tables, and graphs containing statistical information about agriculture-related commodities and services, primarily in the United States, in 1986. The book is organized in seven sections that cover the following topics: (1) the farm (farm income, farm population, farm workers, food and fiber system, agriculture and…

  2. 1986 Agricultural Chartbook. Agriculture Handbook No. 663.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    This book contains 310 charts, tables, and graphs containing statistical information about agriculture-related commodities and services, primarily in the United States, in 1986. The book is organized in seven sections that cover the following topics: (1) the farm (farm income, farm population, farm workers, food and fiber system, agriculture and…

  3. Removal of human pathogenic viruses in a down-flow hanging sponge (DHS) reactor treating municipal wastewater and health risks associated with utilization of the effluent for agricultural irrigation.

    PubMed

    Kobayashi, Naohiro; Oshiki, Mamoru; Ito, Toshihiro; Segawa, Takahiro; Hatamoto, Masashi; Kato, Tsuyoshi; Yamaguchi, Takashi; Kubota, Kengo; Takahashi, Masanobu; Iguchi, Akinori; Tagawa, Tadashi; Okubo, Tsutomu; Uemura, Shigeki; Harada, Hideki; Motoyama, Toshiki; Araki, Nobuo; Sano, Daisuke

    2017-03-01

    A down-flow hanging sponge (DHS) reactor has been developed as a cost-effective wastewater treatment system that is adaptable to local conditions in low-income countries. A pilot-scale DHS reactor previously demonstrated stable reduction efficiencies for chemical oxygen demand (COD) and ammonium nitrogen over a year at ambient temperature, but the pathogen reduction efficiency of the DHS reactor has yet to be investigated. In the present study, the reduction efficiency of a pilot-scale DHS reactor fed with municipal wastewater was investigated for 10 types of human pathogenic viruses (norovirus GI, GII and GIV, aichivirus, astrovirus, enterovirus, hepatitis A and E viruses, rotavirus, and sapovirus). DHS influent and effluent were collected weekly or biweekly for 337 days, and concentrations of viral genomes were determined by microfluidic quantitative PCR. Aichivirus, norovirus GI and GII, enterovirus, and sapovirus were frequently detected in DHS influent, and the log10 reduction (LR) of these viruses ranged from 1.5 to 3.7. The LR values for aichivirus and norovirus GII were also calculated using a Bayesian estimation model, and the average LR (±standard deviation) values for aichivirus and norovirus GII were estimated to be 1.4 (±1.5) and 1.8 (±2.5), respectively. Quantitative microbial risk assessment was conducted to calculate a threshold reduction level for norovirus GII that would be required for the use of DHS effluent for agricultural irrigation, and it was found that LRs of 2.6 and 3.7 for norovirus GII in the DHS effluent were required in order to not exceed the tolerable burden of disease at 10(-4) and 10(-6) disability-adjusted life years loss per person per year, respectively, for 95% of the exposed population during wastewater reuse for irrigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. FGD gypsum's place in American agriculture

    SciTech Connect

    Haynes, C.

    2007-07-01

    Surface cracks and soil clumps form when saline-sodic, high-clay soil dries out. Treatment with FGD gypsum and irrigation water flowing into these cracks leaches salts until the aggregates swell and the cracks close up. The article describes research projects to develop agricultural uses of FGD gypsum from coal-fired power plants that have been conducted by university researchers and USDA-Agricultural Research Service scientists.

  5. Sustainable intensification in agricultural systems

    PubMed Central

    Pretty, Jules; Bharucha, Zareen Pervez

    2014-01-01

    Background Agricultural systems are amended ecosystems with a variety of properties. Modern agroecosystems have tended towards high through-flow systems, with energy supplied by fossil fuels directed out of the system (either deliberately for harvests or accidentally through side effects). In the coming decades, resource constraints over water, soil, biodiversity and land will affect agricultural systems. Sustainable agroecosystems are those tending to have a positive impact on natural, social and human capital, while unsustainable systems feed back to deplete these assets, leaving fewer for the future. Sustainable intensification (SI) is defined as a process or system where agricultural yields are increased without adverse environmental impact and without the conversion of additional non-agricultural land. The concept does not articulate or privilege any particular vision or method of agricultural production. Rather, it emphasizes ends rather than means, and does not pre-determine technologies, species mix or particular design components. The combination of the terms ‘sustainable’ and ‘intensification’ is an attempt to indicate that desirable outcomes around both more food and improved environmental goods and services could be achieved by a variety of means. Nonetheless, it remains controversial to some. Scope and Conclusions This review analyses recent evidence of the impacts of SI in both developing and industrialized countries, and demonstrates that both yield and natural capital dividends can occur. The review begins with analysis of the emergence of combined agricultural–environmental systems, the environmental and social outcomes of recent agricultural revolutions, and analyses the challenges for food production this century as populations grow and consumption patterns change. Emergent criticisms are highlighted, and the positive impacts of SI on food outputs and renewable capital assets detailed. It concludes with observations on policies and

  6. Evaluation of the returned traveler.

    PubMed Central

    Hill, D. R.

    1992-01-01

    Recognition of clinical syndromes in returned travelers is an important part of providing care to international travelers. The first step is to take a history with attention to pre-travel preventive measures, the patient's itinerary, and potential exposure to infectious agents. The patient should then be examined to document physical signs, such as fever, rash, or hepatosplenomegaly, and to have basic laboratory data obtained. This evaluation will provide most physicians with the necessary information to generate a differential diagnosis. Each diagnosis should be matched against the incubation period of the disease, the geographic location of illness, the frequency of illness in returned travelers, and the pre-travel preventive measures. Careful attention to these aspects of patient care should result in the appropriate diagnosis and therapeutic intervention for the ill returned traveler. PMID:1290276

  7. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Visitors, some with their dogs, line up to make their photo inside a space suit exhibit during the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  8. Sample Return Primer and Handbook

    NASA Technical Reports Server (NTRS)

    Barrow, Kirk; Cheuvront, Allan; Faris, Grant; Hirst, Edward; Mainland, Nora; McGee, Michael; Szalai, Christine; Vellinga, Joseph; Wahl, Thomas; Williams, Kenneth; hide

    2007-01-01

    This three-part Sample Return Primer and Handbook provides a road map for conducting the terminal phase of a sample return mission. The main chapters describe element-by-element analyses and trade studies, as well as required operations plans, procedures, contingencies, interfaces, and corresponding documentation. Based on the experiences of the lead Stardust engineers, the topics include systems engineering (in particular range safety compliance), mission design and navigation, spacecraft hardware and entry, descent, and landing certification, flight and recovery operations, mission assurance and system safety, test and training, and the very important interactions with external support organizations (non-NASA tracking assets, landing site support, and science curation).

  9. Sample Return Primer and Handbook

    NASA Technical Reports Server (NTRS)

    Barrow, Kirk; Cheuvront, Allan; Faris, Grant; Hirst, Edward; Mainland, Nora; McGee, Michael; Szalai, Christine; Vellinga, Joseph; Wahl, Thomas; Williams, Kenneth; Lee, Gentry; Duxbury, Thomas

    2007-01-01

    This three-part Sample Return Primer and Handbook provides a road map for conducting the terminal phase of a sample return mission. The main chapters describe element-by-element analyses and trade studies, as well as required operations plans, procedures, contingencies, interfaces, and corresponding documentation. Based on the experiences of the lead Stardust engineers, the topics include systems engineering (in particular range safety compliance), mission design and navigation, spacecraft hardware and entry, descent, and landing certification, flight and recovery operations, mission assurance and system safety, test and training, and the very important interactions with external support organizations (non-NASA tracking assets, landing site support, and science curation).

  10. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Children visiting the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event try to catch basketballs being thrown by a robot from FIRST Robotics at Burncoat High School (Mass.) on Saturday, June 16, 2012 at WPI in Worcester, Mass. The TouchTomorrow event was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  11. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    A visitor to the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event helps demonstrate how a NASA rover design enables the rover to climb over obstacles higher than it's own body on Saturday, June 16, 2012 at WPI in Worcester, Mass. The event was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  12. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Deputy Administrator Lori Garver and NASA Chief Technologist Mason Peck stop to look at the bronze statue of the goat mascot for Worcester Polytechnic Institute (WPI) named "Gompei" that is wearing a staff t-shirt for the "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  13. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    NASA Program Manager for Centennial Challenges Sam Ortega help show a young visitor how to drive a rover as part of the interactive NASA Mars rover exhibit during the Worcester Polytechnic Institute (WPI) "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The NASA-WPI challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  14. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    Intrepid Systems Team member Mark Curry, left, talks with NASA Deputy Administrator Lori Garver and NASA Chief Technologist Mason Peck, right, about his robot named "MXR - Mark's Exploration Robot" on Saturday, June 16, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Curry's robot team was one of the final teams participating in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams were challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  15. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    Wunderkammer Laboratory Team leader Jim Rothrock, left, answers questions from 8th grade Sullivan Middle School (Mass.) students about his robot named "Cerberus" on Friday, June 15, 2012, at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Rothrock's robot team will compete for a $1.5 million NASA prize in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams have been challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  16. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    Intrepid Systems Team member Mark Curry, right, answers questions from 8th grade Sullivan Middle School (Mass.) students about his robot named "MXR - Mark's Exploration Robot" on Friday, June 15, 2012, at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Curry's robot team will compete for a $1.5 million NASA prize in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams have been challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  17. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    Intrepid Systems robot, foreground, and the University of Waterloo (Canada) robot, take to the practice field on Friday, June 15, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Robot teams will compete for a $1.5 million NASA prize in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams have been challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  18. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    Intrepid Systems robot "MXR - Mark's Exploration Robot" takes to the practice field and tries to capture the white object in the foreground on Friday, June 15, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Intrepid Systems' robot team will compete for a $1.5 million NASA prize in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams have been challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  19. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-16

    The bronze statue of the goat mascot for Worcester Polytechnic Institute (WPI) named "Gompei" is seen wearing a staff t-shirt for the "TouchTomorrow" education and outreach event that was held in tandem with the NASA-WPI Sample Return Robot Centennial Challenge on Saturday, June 16, 2012 in Worcester, Mass. The challenge tasked robotic teams to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  20. Sample Return Robot Centennial Challenge

    NASA Image and Video Library

    2012-06-15

    SpacePRIDE Team members Chris Williamson, right, and Rob Moore, second from right, answer questions from 8th grade Sullivan Middle School (Mass.) students about their robot on Friday, June 15, 2012 at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. SpacePRIDE's robot team will compete for a $1.5 million NASA prize in the NASA-WPI Sample Return Robot Centennial Challenge at WPI. Teams have been challenged to build autonomous robots that can identify, collect and return samples. NASA needs autonomous robotic capability for future planetary exploration. Photo Credit: (NASA/Bill Ingalls)

  1. Agricultural biotechnology in developing countries.

    PubMed

    Dookun, A

    2001-01-01

    After a slow start many developing countries are now investing in agricultural biotechnology. Although these countries face several constraints, efforts are being made to promote biotechnology that requires high investment with long term returns. A number of donor agencies are providing incentives to stimulate biotechnology in the developing countries. There is however a major debate towards the development of biotechnology, especially genetically modified organisms, in the developing countries and there is a need for them to address biosafety issues and proper monitoring systems. The concern of intellectual property rights is a major issue in the developing countries in order to have access to the technologies that are often owned by multinational corporations in the industrialized countries.

  2. The Genesis Solar Wind Sample Return Mission

    NASA Technical Reports Server (NTRS)

    Wiens, Roger C.; Burnett, Donald S.; Neugebauer, Marcia; Sasaki, Chester; Sevilla, Donald; Stansbery, Eileen; Clark, Ben; Smith, Nick; Oldham, Lloyd

    1990-01-01

    The Genesis spacecraft was launched on August 8 from Cape Canaveral on a journey to become the first spacecraft to return from interplanetary space. The fifth in NASA's line of low-cost Discovery-class missions, its goal is to collect samples of solar wind and return them to Earth for detailed isotopic and elemental analysis. The spacecraft is to collect solar wind for over two years, while circling the L1 point 1.5 million km sunward of the earth, before heading back for a capsule-style re-entry in September, 2004. After parachute deployment, a mid-air helicopter recovery will be used to avoid a hard landing. The mission has been in the planning stages for over ten years. Its cost, including development, mission operations, and sample analysis, is approximately $209M. The Genesis science team, headed by principal investigator Donald Burnett of Caltech, consists of approximately 20 co-investigators from universities and science centers around the country and internationally. The spacecraft consists of a relatively flat spacecraft bus containing most of the subsystem components, situated below a sample return capsule (SRC) which holds the solar-wind collection substrates and an electrostatic solar wind concentrator. Some of the collectors are exposed throughout the collection period, for a sample of bulk solar wind, while others are exposed only to certain solar wind regimes, or types of flow. Ion and electron spectrometers feed raw data to the spacecraft control and data-handling (C&DH) unit, which determines ion moments and electron flux geometries in real time. An algorithm is used to robotically decide between interstream (IS), coronal hole (CH), and coronal mass ejection (CME) regimes, and to control deployment of the proper arrays to sample these wind regimes independently. This is the first time such a solar-wind decision algorithm has been used on board a spacecraft.

  3. Agriculture: Land Use

    EPA Pesticide Factsheets

    Land Use and agriculture. Information about land use restrictions and incentive programs.Agricultural operations sometimes involve activities regulated by laws designed to protect water supplies, threatened or endangered plants and animals, or wetlands.

  4. Traditional Agriculture and Permaculture.

    ERIC Educational Resources Information Center

    Pierce, Dick

    1997-01-01

    Discusses benefits of combining traditional agricultural techniques with the concepts of "permaculture," a framework for revitalizing traditions, culture, and spirituality. Describes school, college, and community projects that have assisted American Indian communities in revitalizing sustainable agricultural practices that incorporate…

  5. Vocational Agriculture in Ponape

    ERIC Educational Resources Information Center

    Dayrit, Ruben S.

    1975-01-01

    The general objectives of agriculture education in both the elementary and secondary schools in Ponape District are to develop interest in agriculture among students and to provide practical and technical skills in growing crops and raising domestic animals. (Author)

  6. Traditional Agriculture and Permaculture.

    ERIC Educational Resources Information Center

    Pierce, Dick

    1997-01-01

    Discusses benefits of combining traditional agricultural techniques with the concepts of "permaculture," a framework for revitalizing traditions, culture, and spirituality. Describes school, college, and community projects that have assisted American Indian communities in revitalizing sustainable agricultural practices that incorporate…

  7. Agriculture: Climate Change

    EPA Pesticide Factsheets

    Climate change affects agricultural producers because agriculture and fisheries depend on specific climate conditions. Temperature changes can cause crop planting dates to shift. Droughts and floods due to climate change may hinder farming practices.

  8. Strategies for Agriculture.

    ERIC Educational Resources Information Center

    Crosson, Pierre R.; Rosenberg, Norman J.

    1989-01-01

    Discusses the change of agricultural methods with human population growth. Describes the trends of world food production, changes in farmland, use of fertilizer, and 13 agricultural research institutions. Lists 5 references for further reading. (YP)

  9. Strategies for Agriculture.

    ERIC Educational Resources Information Center

    Crosson, Pierre R.; Rosenberg, Norman J.

    1989-01-01

    Discusses the change of agricultural methods with human population growth. Describes the trends of world food production, changes in farmland, use of fertilizer, and 13 agricultural research institutions. Lists 5 references for further reading. (YP)

  10. Uncertain Educational Returns in a Developing Economy

    ERIC Educational Resources Information Center

    Mohapatra, Sandeep; Luckert, Martin K.

    2012-01-01

    This paper estimates the distribution of educational returns by gender for India. While previous studies focus on mean returns, the variance of educational returns has important implications for policy-making and micro-level decision making with respect to education. If the variance of educational returns is large, it can leave large sections of…

  11. Uncertain Educational Returns in a Developing Economy

    ERIC Educational Resources Information Center

    Mohapatra, Sandeep; Luckert, Martin K.

    2012-01-01

    This paper estimates the distribution of educational returns by gender for India. While previous studies focus on mean returns, the variance of educational returns has important implications for policy-making and micro-level decision making with respect to education. If the variance of educational returns is large, it can leave large sections of…

  12. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Returned mail. 540.24 Section 540.24... PERSONS IN THE COMMUNITY Correspondence § 540.24 Returned mail. Staff shall open and inspect for contraband all undelivered mail returned to an institution by the Post Office before returning it to...

  13. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Returned mail. 540.24 Section 540.24... PERSONS IN THE COMMUNITY Correspondence § 540.24 Returned mail. Staff shall open and inspect for contraband all undelivered mail returned to an institution by the Post Office before returning it to...

  14. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Returned mail. 540.24 Section 540.24... PERSONS IN THE COMMUNITY Correspondence § 540.24 Returned mail. Staff shall open and inspect for contraband all undelivered mail returned to an institution by the Post Office before returning it to...

  15. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Returned mail. 540.24 Section 540.24... PERSONS IN THE COMMUNITY Correspondence § 540.24 Returned mail. Staff shall open and inspect for contraband all undelivered mail returned to an institution by the Post Office before returning it to...

  16. 28 CFR 540.24 - Returned mail.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Returned mail. 540.24 Section 540.24... PERSONS IN THE COMMUNITY Correspondence § 540.24 Returned mail. Staff shall open and inspect for contraband all undelivered mail returned to an institution by the Post Office before returning it to...

  17. Advanced agricultural biotechnologies and sustainable agriculture.

    PubMed

    Lyson, Thomas A

    2002-05-01

    Agricultural biotechnologies are anchored to a scientific paradigm rooted in experimental biology, whereas sustainable agriculture rests on a biological paradigm that is best described as ecological. Both biotechnology and sustainable agriculture are associated with particular social science paradigms: biotechnology has its foundation in neoclassical economics, but sustainability is framed by an emerging community-centered, problem-solving perspective. Fundamentally, biotechnology and neoclassical economics are reductionist in nature. Sustainability and community problem-solving, however, are nonreductionist. Given these differences, we might see the development of two rather distinct systems of food production in the near future.

  18. Information for Agricultural Development.

    ERIC Educational Resources Information Center

    Kaungamno, E. E.

    This paper describes the major international agricultural information services, sources, and systems; outlines the existing information situation in Tanzania as it relates to problems of agricultural development; and reviews the improvements in information provision resources required to support the process of agricultural development in Tanzania.…

  19. African Americans and Agriculture.

    ERIC Educational Resources Information Center

    Morgan, Joan

    2000-01-01

    Reviews the opportunities available in the field of agriculture for African American students and notes efforts of the 136 colleges of agriculture to publicize their offerings and recruit students. Profiles six black leaders in agriculture, highlighting their achievements in research and aid to developing countries. A table provides data on annual…

  20. Agricultural Structures, Volume II.

    ERIC Educational Resources Information Center

    Linhardt, Richard E.; Burhoe, Steve

    This guide to a curriculum unit in agricultural structures is designed to expand the curriculum materials available in vocational agriculture in Missouri. It and Agricultural Structures I (see note) provide reference materials to systematize the curriculum. The six units cover working with concrete (19 lessons, 2 laboratory exercises), drawing and…

  1. Biotechnology and Agriculture.

    ERIC Educational Resources Information Center

    Kenney, Martin

    Even at this early date in the application of biotechnology to agriculture, it is clear that agriculture may provide the largest market for new or less expensive biotechnologically manufactured products. The chemical and pharmaceutical industries that hold important positions in agricultural inputs are consolidating their positions by purchasing…

  2. Agriculture Business and Management.

    ERIC Educational Resources Information Center

    Seperich, George; And Others

    This curriculum guide is intended for vocational agriculture teachers who deliver agricultural business and management programs at the secondary or postsecondary level. It is based on the Arizona validated occupational competencies and tasks for management and supervisory positions in agricultural business. The competency/skill and task list…

  3. Chapter 3: Cropland Agriculture

    USDA-ARS?s Scientific Manuscript database

    In 2013, cropland agriculture resulted in total emissions of approximately 209 MMT CO2 eq. of greenhouse gases (GHG). Cropland agriculture is responsible for almost half (46%) of all emissions from the agricultural sector. Nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) emissions from c...

  4. Agricultural Structures, Volume II.

    ERIC Educational Resources Information Center

    Linhardt, Richard E.; Burhoe, Steve

    This guide to a curriculum unit in agricultural structures is designed to expand the curriculum materials available in vocational agriculture in Missouri. It and Agricultural Structures I (see note) provide reference materials to systematize the curriculum. The six units cover working with concrete (19 lessons, 2 laboratory exercises), drawing and…

  5. Agriculture, Environmental Education Guide.

    ERIC Educational Resources Information Center

    Project I-C-E, Green Bay, WI.

    This agriculture guide, for use at the secondary level, is one of a series of guides, K-12, which were developed by teachers to help introduce environmental education into the total curriculum. Environmental problems are present in every community where agriculture education is offered, and therefore many agriculture teachers have included some…

  6. Dutch Agricultural Education.

    ERIC Educational Resources Information Center

    Netherlands Ministry of Agriculture and Fisheries, The Hauge.

    Agricultural Education in the Netherlands is categorized as Scientific, Higher Secondary, Middle Secondary, and Lower Secondary. Scientific education is given at the agricultural university which has a 6- or 7-year curriculum. Higher secondary education is given at agricultural and horticultural colleges with a 3- to 4-year curriculum. Middle…

  7. Agriculture Business and Management.

    ERIC Educational Resources Information Center

    Seperich, George; And Others

    This curriculum guide is intended for vocational agriculture teachers who deliver agricultural business and management programs at the secondary or postsecondary level. It is based on the Arizona validated occupational competencies and tasks for management and supervisory positions in agricultural business. The competency/skill and task list…

  8. 7 CFR 58.521 - Pasteurization and product flow.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Pasteurization and product flow. 58.521 Section 58.521 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.521 Pasteurization and product flow. (a) The skim milk used for the manufacture of cottage...

  9. 7 CFR 58.521 - Pasteurization and product flow.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Pasteurization and product flow. 58.521 Section 58.521 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.521 Pasteurization and product flow. (a) The skim milk used for the manufacture of cottage...

  10. The Returns to Community College

    ERIC Educational Resources Information Center

    Agan, Amanda Yvonne

    2013-01-01

    Almost half of postsecondary students are currently enrolled in community colleges. These institutions imply that even amongst students with the same degree outcome there is considerable heterogeneity in the path taken to get there. I estimate the life-cycle private and social returns to the different postsecondary paths and sequential decisions…

  11. Comet coma sample return instrument

    NASA Astrophysics Data System (ADS)

    Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

    The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

  12. Analysing Enterprise Returns on Training.

    ERIC Educational Resources Information Center

    Moy, Janelle; McDonald, Rod

    Recent Australian and overseas studies on evaluation of enterprises' return on training investment (ROTI) were reviewed to identify key issues in encouraging increased evaluation of training benefits by enterprises and successful approaches that may inform future "enterprise-friendly" studies of ROTI. It was concluded that more…

  13. Comet coma sample return instrument

    NASA Technical Reports Server (NTRS)

    Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

    1994-01-01

    The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

  14. The Returns to Community College

    ERIC Educational Resources Information Center

    Agan, Amanda Yvonne

    2013-01-01

    Almost half of postsecondary students are currently enrolled in community colleges. These institutions imply that even amongst students with the same degree outcome there is considerable heterogeneity in the path taken to get there. I estimate the life-cycle private and social returns to the different postsecondary paths and sequential decisions…

  15. Analysing Enterprise Returns on Training.

    ERIC Educational Resources Information Center

    Moy, Janelle; McDonald, Rod

    Recent Australian and overseas studies on evaluation of enterprises' return on training investment (ROTI) were reviewed to identify key issues in encouraging increased evaluation of training benefits by enterprises and successful approaches that may inform future "enterprise-friendly" studies of ROTI. It was concluded that more…

  16. Language Skills and Economic Returns

    ERIC Educational Resources Information Center

    Garrouste, Christelle

    2008-01-01

    This article focuses on the contributions from the emerging positivist epistemological approach, endorsed by the economics of language and the economics of education, to study the returns to language skills, assuming that language competencies constitute key components of human capital. It presents initial results from a study on economic returns…

  17. Endeavour Return to Flight Maintenance

    NASA Image and Video Library

    2003-10-10

    (Clockwise from left), in the Orbiter Processing Facility, Tim Chastain, John Peterson and Sang Huynh, with United Space Alliance, work at removing the body flap actuator from the orbiter Endeavour. The work is part of return to flight activities on the orbiter fleet.

  18. Endeavour Return to Flight Maintenance

    NASA Image and Video Library

    2003-10-10

    In the Orbiter Processing Facility, (from left) Tim Chastain, Sang Huynh and John Peterson, with United Space Alliance, work at removing the body flap actuator from the orbiter Endeavour. The work is part of return to flight activities on the orbiter fleet.

  19. Neurocognitive Performance: Returning to Competition

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; McIntire, Kyle

    2010-01-01

    Athletes who suffer from concussions under report their symptoms in order to expedite their return to competition. Athletic trainers and coaches must be aware of what is going on with athletes, even if it means requiring them to refrain from competition. Ninety percent of concussions are minor and can be difficult to diagnosis. There is a lack of…

  20. Phobos Sample Return: Next Approach

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

    The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

  1. Surface Force Strategy: Return to Sea Control

    DTIC Science & Technology

    2016-01-01

    trategy orce urfaceS F S Return to Sea Control Surface Force Strategy Return to Sea Control 14 Return to Sea Control Return to Sea Control A quarter...Responding to the call to “strengthen naval power at and from the sea,” the U.S. Naval Surface Force submits this “Surface Force Strategy .” The... strategy describes the return to sea control and implementation of Distributed Lethality as an operational and organizational principle for achieving

  2. Flow of Talent at Zhongguancun

    ERIC Educational Resources Information Center

    Hansheng, Li; Ruixin, Kang

    2004-01-01

    This article reports the flow of talent at Zhongguancun. Zhongguancun, with its many enterprise opportunities, high returns, and concentration of large corporations, is an ideal place for talent to seek employment, and the flow of talent here is more lively than in other regions. The talent flow rate in Zhongguancun is 20 percent, but the flow…

  3. Geomorphological characterization of conservation agriculture

    NASA Astrophysics Data System (ADS)

    Tarolli, Paolo; Cecchin, Marco; Prosdocimi, Massimo; Masin, Roberta

    2017-04-01

    characterise the surface morphology. For each of derived Digital Elevation Model, seven morphometric indexes, such as slope, curvature, flow direction, contributing area, roughness, and connectivity was calculated. We showed then the variations of the morphology in the areas converted to the conservation agriculture, and, consequently, a possible modification of processes such as erosion and runoff. The results suggested that the agricultural surfaces interested by no-tillage practices are different from those tilled with conventional systems. The topography is rougher, with chaotic flow directions, and more concave areas, thus resulting in potential water storages, mitigating the intensity of soil erosion and runoff processes. On the other hand, the topography of traditional tillage area is more regular and smooth, with flow directions that tend to follow the same direction on the surface. These results are a novelty in the Earth Science and Agronomy: we demonstrated and quantified, from the geomorphological point of view, the potential role of conservative agriculture in mitigating, not only land degradation phenomena, but also the distribution of pollutants, and rainfall-runoff processes. References Prosdocimi, M., Tarolli, P., Cerdà, A. (2016). Mulching practice for reducing soil water erosion: A review. Earth-Science Reviews, 161, 191-203. Prosdocimi, M., Burguet, M., Di Prima, S., Sofia, G., Terol, E, Rodrigo Comino J., Cerdà, A., Tarolli, P. (2017). Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards. Science of the Total Environment, 574, 204-215. Tarolli, P., Sofia G. (2016). Human topographic signatures and derived geomorphic processes across landscapes, Geomorphology, 255, 140-161.

  4. Return to nursing home investment: Issues for public policy

    PubMed Central

    Baldwin, Carliss Y.; Bishop, Christine E.

    1984-01-01

    Because Government policy does much to determine the return available to nursing home investment, the profitability of the nursing home industry has been a subject of controversy since Government agencies began paying a large portion of the Nation's nursing home bill. Controversy appears at several levels. First is the rather narrow concern, often conceived in accounting terms, of the appropriate reimbursement of capital-related expense under Medicaid and Medicare. Second is the concern about how return to capital affects the flow of investment into nursing homes, leading either to inadequate access to care or to over-capacity. Third is the concern about how-sources of return to nursing home investment affect the pattern of nursing home ownership and the amount of equity held by owners since the pattern of ownership and amount of equity have been linked to quality of care. PMID:10310945

  5. Landscape irrigation management for maintaining an aquifer and economic returns.

    PubMed

    Kovacs, Kent Forrest; Mancini, Mattia; West, Grant

    2015-09-01

    Expanding irrigated agriculture and dryer climatic conditions has led to large-scale withdrawals of groundwater and the decline in shallow aquifers. Policy makers must wrestle with the challenge of maintaining economic growth while conserving the groundwater resource. A spatially explicit landscape level model analyzes consequences of optimally chosen crop mix patterns on an aquifer and economic returns. The model of the groundwater use incorporates irrigation needs of the crops grown, initial aquifer thickness, hydro-conductivity of the aquifer, and distance to surrounding grid cells. The economic model incorporates the site specific yield, crop mix, and irrigation practice investments to predict economic returns. A tradeoff occurs between the volume of the aquifer and economic returns due to groundwater withdrawal for irrigation, but the farm's ability to grow profitable lower irrigation crops dampens the intensity of this tradeoff. Allowing for multiple unconventional irrigation practices that are yield increasing and water conserving significantly increases the economic returns of a given crop mix while maintaining the aquifer.

  6. Removal of Nitrogen and Pathogens in Agricultural or Urban Channles using Engineered Streambeds

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Herzog, S.; Higgins, C. P.

    2015-12-01

    Treating non-point source pollution is one of our greatest challenges in environmental hydrology. Previous efforts in agricultural or urban settings have focused on removing sources or implementing distributed best management practices (BMPs) throughout a watershed. However, for stream pollution, the most efficient point of treatment would be within the stream itself, which integrates flows from the entire watershed. Engineered streambed modifications in urban or agricultural streams and constructed channels have the potential to mitigate nonpoint source pollution. Geomedia designed to treat water pollutants and achieve an optimal residence time via hydraulic conductivity modifications are termed biohydrochemical enhancement structures for stream water treatment (BEST). BEST modules can efficiently drive interchange, attenuating nutrients and pathogens (and can be designed to remove other pollutants such as phosphorus, metals or trace organics). Numerical models, combined with data from bench-top and 2D experiments, demonstrate effective contaminant removal potential for practical applications. Nitrogen and pathogens could be attenuated within a series of BEST on the order of 50 m of stream length, and at a favorable cost compared to traditional BMPs, suggesting that BEST could be an effective best management practice for constructed stormwater channels (particularly outlets of detention ponds) or channels carrying irrigation return flows. New results from a constructed stream demonstrate the real-world applicability of the BEST system.

  7. [Agricultural migration has changed face].

    PubMed

    Ouedraogo, D

    1991-04-01

    decertification of the Sahel. Rural population transfers sponsored by the government have also entailed high costs and met with only partial success. Local populations displaced by dams, large reforestation projects, and other large projects have not always been compensated and relocated adequately. The more significant type of government population transfer program involves relocation at greater distances of residents of relatively poor and overpopulated regions to managed zones where agricultural intensification makes better returns and incomes possible. Large resettlement projects based on improved agricultural techniques including irrigation have yielded disappointing results since the 1960s due to high cost, inadequate management of irrigation, and difficult recruitment of settlers. Results of these projects should be kept in mind when plan for rural population redistribution are made.

  8. Returning forests analyzed with the forest identity

    PubMed Central

    Kauppi, Pekka E.; Ausubel, Jesse H.; Fang, Jingyun; Mather, Alexander S.; Sedjo, Roger A.; Waggoner, Paul E.

    2006-01-01

    Amid widespread reports of deforestation, some nations have nevertheless experienced transitions from deforestation to reforestation. In a causal relationship, the Forest Identity relates the carbon sequestered in forests to the changing variables of national or regional forest area, growing stock density per area, biomass per growing stock volume, and carbon concentration in the biomass. It quantifies the sources of change of a nation's forests. The Identity also logically relates the quantitative impact on forest expanse of shifting timber harvest to regions and plantations where density grows faster. Among 50 nations with extensive forests reported in the Food and Agriculture Organization's comprehensive Global Forest Resources Assessment 2005, no nation where annual per capita gross domestic product exceeded $4,600 had a negative rate of growing stock change. Using the Forest Identity and national data from the Assessment report, a single synoptic chart arrays the 50 nations with coordinates of the rates of change of basic variables, reveals both clusters of nations and outliers, and suggests trends in returning forests and their attributes. The Forest Identity also could serve as a tool for setting forest goals and illuminating how national policies accelerate or retard the forest transitions that are diffusing among nations. PMID:17101996

  9. Returning forests analyzed with the forest identity.

    PubMed

    Kauppi, Pekka E; Ausubel, Jesse H; Fang, Jingyun; Mather, Alexander S; Sedjo, Roger A; Waggoner, Paul E

    2006-11-14

    Amid widespread reports of deforestation, some nations have nevertheless experienced transitions from deforestation to reforestation. In a causal relationship, the Forest Identity relates the carbon sequestered in forests to the changing variables of national or regional forest area, growing stock density per area, biomass per growing stock volume, and carbon concentration in the biomass. It quantifies the sources of change of a nation's forests. The Identity also logically relates the quantitative impact on forest expanse of shifting timber harvest to regions and plantations where density grows faster. Among 50 nations with extensive forests reported in the Food and Agriculture Organization's comprehensive Global Forest Resources Assessment 2005, no nation where annual per capita gross domestic product exceeded 4,600 dollars had a negative rate of growing stock change. Using the Forest Identity and national data from the Assessment report, a single synoptic chart arrays the 50 nations with coordinates of the rates of change of basic variables, reveals both clusters of nations and outliers, and suggests trends in returning forests and their attributes. The Forest Identity also could serve as a tool for setting forest goals and illuminating how national policies accelerate or retard the forest transitions that are diffusing among nations.

  10. Field variability and vulnerability index to identify precision agriculture opportunity

    USDA-ARS?s Scientific Manuscript database

    Innovations in precision agriculture (PA) have created opportunities to achieve a greater understanding of within-field variability. However, PA adoption has been hindered due to uncertainty about field-specific performance and return on investment. Uncertainty could be better addressed by analyzing...

  11. Supervised Occupational Experience Programs in Vocational Agriculture. Bulletin No. 705.

    ERIC Educational Resources Information Center

    Pals, Douglas A.; Slocombe, John W.

    A 1985 study examined the quality and quantity of Idaho supervised occupational experience (SOE) programs as perceived by a sample of 38 instructors and 1,198 students who returned questionnaires sent to all vocational agriculture students and teachers throughout the state. Data on the value of SOE as perceived by parents, employers, and…

  12. The returning traveler with fever.

    PubMed

    Saxe, S E; Gardner, P

    1992-06-01

    The febrile returning traveler tests a clinician's knowledge of tropical medicine as well as skills in differential diagnosis. A thorough history with special emphasis placed on the patient's travel itinerary and knowledge of the geographic location and incubation times of certain tropical diseases will narrow the diagnostic possibilities. This will allow the clinician to focus the diagnostic work-up and make wise choices of laboratory tests and procedures.

  13. Asteroid Return Mission Feasibility Study

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Gershman, Robert; Landau, Damon; Polk, James; Porter, Chris; Yeomans, Don; Allen, Carlton; Williams, Willie; Asphaug, Erik

    2011-01-01

    This paper describes an investigation into the technological feasibility of finding, characterizing, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the International Space Station (ISS) for scientific investigation, evaluation of its resource potential, determination of its internal structure and other aspects important for planetary defense activities, and to serve as a testbed for human operations in the vicinity of an asteroid. Reasonable projections suggest that several dozen candidates NEAs in the size range of interest (approximately 2-m diameter) will be known before the end of the decade from which a suitable target could be selected. The conceptual mission objective is to return an approximately 10,000-kg asteroid to the ISS in a total flight time of approximately 5 years using a single Evolved Expendable Launch Vehicle. Preliminary calculations indicate that this could be accomplished using a solar electric propulsion (SEP) system with high-power Hall thrusters and a maximum power into the propulsion system of approximately 40 kW. The SEP system would be used to provide all of the post-launch delta V. The asteroid would have an unrestricted Earth return Planetary Protection categorization, and would be curated at the ISS where numerous scientific and resource utilization experiments would be conducted. Asteroid material brought to the ground would be curated at the NASA Johnson Space Center. This preliminary study identified several areas where additional work is required, but no show stoppers were identified for the approach that would return an entire 10,000-kg asteroid to the ISS in a mission that could be launched by the end of this decade.

  14. STS-32 Return to KSC

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Space Shuttle Columbia, returning to KSC after the successful STS-32 mission, is poised atop the Shuttle Carrier Aircraft (SCA) as the duo fly by the Vehicle Assembly Building (VAB) at KSC January 26. Columbia, carrying the Long Duration Exposure Facility (LDEF) in its payload bay, was compleitng a two-day ferry flight from Edwards Air Force Base, California. Landing at the Shuttle Landing Facility occurred a few moments later at 3:30 p.m.

  15. Sustainable intensification in agricultural systems.

    PubMed

    Pretty, Jules; Bharucha, Zareen Pervez

    2014-12-01

    Agricultural systems are amended ecosystems with a variety of properties. Modern agroecosystems have tended towards high through-flow systems, with energy supplied by fossil fuels directed out of the system (either deliberately for harvests or accidentally through side effects). In the coming decades, resource constraints over water, soil, biodiversity and land will affect agricultural systems. Sustainable agroecosystems are those tending to have a positive impact on natural, social and human capital, while unsustainable systems feed back to deplete these assets, leaving fewer for the future. Sustainable intensification (SI) is defined as a process or system where agricultural yields are increased without adverse environmental impact and without the conversion of additional non-agricultural land. The concept does not articulate or privilege any particular vision or method of agricultural production. Rather, it emphasizes ends rather than means, and does not pre-determine technologies, species mix or particular design components. The combination of the terms 'sustainable' and 'intensification' is an attempt to indicate that desirable outcomes around both more food and improved environmental goods and services could be achieved by a variety of means. Nonetheless, it remains controversial to some. This review analyses recent evidence of the impacts of SI in both developing and industrialized countries, and demonstrates that both yield and natural capital dividends can occur. The review begins with analysis of the emergence of combined agricultural-environmental systems, the environmental and social outcomes of recent agricultural revolutions, and analyses the challenges for food production this century as populations grow and consumption patterns change. Emergent criticisms are highlighted, and the positive impacts of SI on food outputs and renewable capital assets detailed. It concludes with observations on policies and incentives necessary for the wider adoption of

  16. On the return current of the equatorial electrojet

    NASA Astrophysics Data System (ADS)

    Onwumechili, C. A.

    In practically all cases, investigators have found it compelling to include westward currents on the flanks of the dip equator in order to fit well the observed dip equatorial magnetic variation profiles. There are three sources of the return currents: the geometry of field lines in the dynamo region, the polarization at the boundaries of enhanced conductivity at the dip equator, and the local neutral winds varying with height. These combine constructively, taking advantage of the peaks of conductivities around 5-deg-dip latitude, to provide for the return currents of practically all the eastward electrojet current. The return currents flow on the flanks of the dip equator for about 3.5 deg to about 20-deg-dip latitude, in any case not extending beyond the Sq focus. The negative correlation between the width and the intensity of the equatorial electrojet has been confirmed with data derived from physical model, indicating its origin in the return currents. The ionospheric current system so far detected by rockets is essentially in two layers. The intense lower layer including the return currents peaking around 5-deg-dip latitude may be associated with the equatorial electrojet; and the weak upper layer that maintains fairly steady altitude characteristics everywhere may be associated with the worldwide part of the Sq currents.

  17. Combination valance and conditioned air admission and return ducts

    SciTech Connect

    Sprout, F.C. Sr.

    1987-06-16

    This patent describes an improved air treatment system for a dwelling comprising: an air diffusion chamber associated with the ceiling and having at least a portion in a position of close proximity to an outer wall of the dwelling; an opening formed in the chamber faces downwardly in close proximity to the wall and parallels the wall for venting the chamber to the room; a conditioning unit having integral fan means generates a flow of conditioned air to the chamber; means conducts the air from the generating means to the chamber; means returns the air vented into the room to the air generating means; a suspended valance member associated with and extends below the chamber for concealment of the opening from view within the room; an auxiliary fan located in the air returning means to cause the returned air to be drawn through the air returning means and be forced into the integral fan means of the conditioning unit; the air return means comprises a network of interconnected concrete channels constructed directly in the ground to extend beneath each of the rooms of the structure and are concealed by the floor of the structure; and apertures extend through the flooring to communicate with the network of channels, the apertures are positioned to provide at least one aperture in each of the major rooms of the structure; and the network of interconnected channels additionally forms to receive service utilities for the structure.

  18. Tick size and stock returns

    NASA Astrophysics Data System (ADS)

    Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo

    2009-02-01

    Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.

  19. Challenging Return to Play Decisions

    PubMed Central

    Asplund, Chad A.; O’Connor, Francis G.

    2015-01-01

    Context: Sports medicine providers frequently return athletes to play after sports-related injuries and conditions. Many of these conditions have guidelines or medical evidence to guide the decision-making process. Occasionally, however, sports medicine providers are challenged with complex medical conditions for which there is little evidence-based guidance and physicians are instructed to individualize treatment; included in this group of conditions are exertional heat stroke (EHS), exertional rhabdomyolysis (ER), and exertional collapse associated with sickle cell trait (ECAST). Evidence Acquisition: The MEDLINE (2000-2015) database was searched using the following search terms: exertional heat stroke, exertional rhabdomyolysis, and exertional collapse associated with sickle cell trait. References from consensus statements, review articles, and book chapters were also utilized. Study Design: Clinical review. Level of Evidence: Level 4. Results: These entities are unique in that they may cause organ system damage capable of leading to short- or long-term detriments to physical activity and may not lend to complete recovery, potentially putting the athlete at risk with premature return to play. Conclusion: With a better understanding of the pathophysiology of EHS, ER, and ECAST and the factors associated with recovery, better decisions regarding return to play may be made. PMID:26896216

  20. The Mars Sample Return Project.

    PubMed

    O'Neil, W J; Cazaux, C

    2000-01-01

    The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles. c 2000 American Institute of Aeronautics and Astronautics, Inc. Published by Elsevier Science Ltd.

  1. The Mars Sample Return Project

    NASA Technical Reports Server (NTRS)

    O'Neil, W. J.; Cazaux, C.

    2000-01-01

    The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles. c 2000 American Institute of Aeronautics and Astronautics, Inc. Published by Elsevier Science Ltd.

  2. Comet nucleus sample return mission

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A comet nucleus sample return mission in terms of its relevant science objectives, candidate mission concepts, key design/technology requirements, and programmatic issues is discussed. The primary objective was to collect a sample of undisturbed comet material from beneath the surface of an active comet and to preserve its chemical and, if possible, its physical integrity and return it to Earth in a minimally altered state. The secondary objectives are to: (1) characterize the comet to a level consistent with a rendezvous mission; (2) monitor the comet dynamics through perihelion and aphelion with a long lived lander; and (3) determine the subsurface properties of the nucleus in an area local to the sampled core. A set of candidate comets is discussed. The hazards which the spacecraft would encounter in the vicinity of the comet are also discussed. The encounter strategy, the sampling hardware, the thermal control of the pristine comet material during the return to Earth, and the flight performance of various spacecraft systems and the cost estimates of such a mission are presented.

  3. Modeling agriculture in the Community Land Model

    NASA Astrophysics Data System (ADS)

    Drewniak, B.; Song, J.; Prell, J.; Kotamarthi, V. R.; Jacob, R.

    2013-04-01

    The potential impact of climate change on agriculture is uncertain. In addition, agriculture could influence above- and below-ground carbon storage. Development of models that represent agriculture is necessary to address these impacts. We have developed an approach to integrate agriculture representations for three crop types - maize, soybean, and spring wheat - into the coupled carbon-nitrogen version of the Community Land Model (CLM), to help address these questions. Here we present the new model, CLM-Crop, validated against observations from two AmeriFlux sites in the United States, planted with maize and soybean. Seasonal carbon fluxes compared well with field measurements for soybean, but not as well for maize. CLM-Crop yields were comparable with observations in countries such as the United States, Argentina, and China, although the generality of the crop model and its lack of technology and irrigation made direct comparison difficult. CLM-Crop was compared against the standard CLM3.5, which simulates crops as grass. The comparison showed improvement in gross primary productivity in regions where crops are the dominant vegetation cover. Crop yields and productivity were negatively correlated with temperature and positively correlated with precipitation, in agreement with other modeling studies. In case studies with the new crop model looking at impacts of residue management and planting date on crop yield, we found that increased residue returned to the litter pool increased crop yield, while reduced residue returns resulted in yield decreases. Using climate controls to signal planting date caused different responses in different crops. Maize and soybean had opposite reactions: when low temperature threshold resulted in early planting, maize responded with a loss of yield, but soybean yields increased. Our improvements in CLM demonstrate a new capability in the model - simulating agriculture in a realistic way, complete with fertilizer and residue management

  4. Agricultural Occupations Program Planning Guide.

    ERIC Educational Resources Information Center

    Hemp, Paul E.; Mayer, Leon

    The major program objectives of agricultural occupations courses are (1) to develop agricultural competencies needed by individuals engaged in or preparing to engage in production agriculture, and in agricultural occupations other than production agriculture; (2) to develop an understanding of the career opportunities in agriculture; (3) to…

  5. Agricultural Occupations Programs Planning Guides

    ERIC Educational Resources Information Center

    Stitt, Thomas R.; And Others

    1977-01-01

    A set of program planning guides that include seven areas (1) Agricultural Production, (2) Agricultural Supplies and Services, (3) Agricultural Mechanics, (4) Agricultural Products, (5) Ornamental Horticulture, (6) Agricultural Resources, and (7) Forestry, were developed and introduced to high school applied biological and agricultural occupations…

  6. Receipts. Agricultural Record Keeping. Supplementary Units.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    Eight supplementary units are included in these instructional materials for agricultural recordkeeping: (1) receipts; (2) expenditures; (3) cash flow; (4) inventory; (5) financial statement; (6) business agreements; (7) ownership business agreements; and (8) placement training agreements. Each unit contains an introduction, lesson objectives, and…

  7. Receipts. Agricultural Record Keeping. Supplementary Units.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    Eight supplementary units are included in these instructional materials for agricultural recordkeeping: (1) receipts; (2) expenditures; (3) cash flow; (4) inventory; (5) financial statement; (6) business agreements; (7) ownership business agreements; and (8) placement training agreements. Each unit contains an introduction, lesson objectives, and…

  8. Integrated Systems Mitigate Land Degradation and Improve Agricultural System Sustainability

    NASA Astrophysics Data System (ADS)

    Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Brevik, Eric

    2017-04-01

    Rain-fed agricultural production supported by exogenous inputs is not sustainable because a continuous influx of expensive inputs (fertilizer, chemicals, fossil fuel, labor, tillage, and other) is required. Alternatives to traditional management allow natural occurring dynamic soil processes to provide the necessary microbial activity that supports nutrient cycling in balance with nature. Research designed to investigate the potential for integrated systems to replace expensive inputs has shown that healthy soils rich in soil organic matter (SOM) are the foundation upon which microbial nutrient cycling can reduce and eventually replace expensive fertilizer. No-till seed placement technology effectively replaces multiple-pass cultivation conserving stored soil water in semi-arid farming systems. In multi-crop rotations, cool- and warm-season crops are grown in sequence to meet goals of the integrated farming and ranching system, and each crop in the rotation complements the subsequent crop by supplying a continuous flow of essential SOM for soil nutrient cycling. Grazing animals serve an essential role in the system's sustainability as non-mechanized animal harvesters that reduce fossil fuel consumption and labor, and animal waste contributes soil nutrients to the system. Integrated systems' complementarity has contributed to greater soil nutrient cycling and crop yields, fertilizer reduction or elimination, greater yearling steer grazing net return, reduced cow wintering costs grazing crop residues, increased wildlife sightings, and reduced environmental footprint. Therefore, integrating crop and animal systems can reverse soil quality decline and adopting non-traditional procedures has resulted in a wider array of opportunities for sustainable agriculture and profitability.

  9. Dynamics of the return distribution in the Korean financial market

    NASA Astrophysics Data System (ADS)

    Yang, Jae-Suk; Chae, Seungbyung; Jung, Woo-Sung; Moon, Hie-Tae

    2006-03-01

    In this paper, we studied the dynamics of the log-return distribution of the Korean Composition Stock Price Index (KOSPI) from 1992 to 2004. Based on the microscopic spin model, we found that while the index during the late 1990s showed a power-law distribution, the distribution in the early 2000s was exponential. This change in distribution shape was caused by the duration and velocity, among other parameters, of the information that flowed into the market.

  10. 26 CFR 31.6011(a)-4 - Returns of income tax withheld.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... wages—(1) For further guidance, see § 31.6011(a)-4T(a)(1). (2) Wages paid for domestic service. Schedule... under section 3402(p), from wages paid for domestic service as defined in section 3510. Schedule H (Form... § 301.6361-1(d)(3)(iv). (3) Wages paid for agricultural labor. Every person shall make a return...

  11. 7 CFR 1786.161 - Return of Qualified Notes and release of lien.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Return of Qualified Notes and release of lien. 1786... Qualified Notes and release of lien. Upon payment to RUS at closing of the full amount specified in the...(e)), RUS will deliver to the borrower at closing those Qualified Notes which have been paid in full...

  12. 7 CFR 1786.161 - Return of Qualified Notes and release of lien.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Return of Qualified Notes and release of lien. 1786... Qualified Notes and release of lien. Upon payment to RUS at closing of the full amount specified in the...(e)), RUS will deliver to the borrower at closing those Qualified Notes which have been paid in full...

  13. 7 CFR 1786.161 - Return of Qualified Notes and release of lien.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Return of Qualified Notes and release of lien. 1786... Qualified Notes and release of lien. Upon payment to RUS at closing of the full amount specified in the...(e)), RUS will deliver to the borrower at closing those Qualified Notes which have been paid in full...

  14. Agricultural aviation research

    NASA Technical Reports Server (NTRS)

    Chevalier, H. L. (Compiler); Bouse, L. F. (Compiler)

    1977-01-01

    A compilation of papers, comments, and results is provided during a workshop session. The purpose of the workshop was to review and evaluate the current state of the art of agricultural aviation, to identify and rank potentially productive short and long range research and development areas, and to strengthen communications between research scientists and engineers involved in agricultural research. Approximately 71 individuals actively engaged in agricultural aviation research were invited to participate in the workshop. These were persons familiar with problems related to agricultural aviation and processing expertise which are of value for identifying and proposing beneficial research.

  15. Modeling the impacts of regulatory frameworks on self-organization in dryland agricultural systems

    NASA Astrophysics Data System (ADS)

    Gower, D.; Caylor, K. K.; McCord, P. F.; Evans, T. P.

    2015-12-01

    The climatological conditions that characterize dryland environments - high potential evapotranspiration combined with low and variable total rainfall - pose challenges for farmers deciding when and how much to irrigate. These challenges are greater in developing countries where the absence of sufficient storage infrastructure means that irrigation water is sometimes applied to agricultural fields directly from rivers. Because soil moisture and river flow both depend on recent rainfall, high irrigation demand often coincides with low river flow, limiting access to water when it is most needed. These feedbacks can constrain the yield increases expected from irrigation in such settings. Scaled up to the catchment level, irrigation water availability varies spatially as well as temporally. Irrigators in upstream areas of the catchment have first access to river water but rely on a smaller drainage network while those in downstream areas are affected by the opposite conditions. During periods of high rainfall, downstream users have the greatest access to water while upstream users are then favored during drought intervals. In the absence of rules governing water access, these flow dynamics will constrain the distribution of potential agricultural yields within the catchment. A simple numerical model simulating catchment and irrigation processes was constructed in order to better understand how climate and geomorphologic characteristics affect crop yield, economic returns and the spatial distribution of irrigated areas. By assuming a statistically representative river network structure, the model was first used to explore the effect of unregulated irrigation withdrawals on these variables. Multiple water management programs, including withdrawal limits, rotational systems and flow minima, were then simulated and the results compared to the unregulated case. This analysis shows the potential for simple models to provide insight into complex irrigation systems and to make

  16. Returning to sports after a back injury

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000518.htm Returning to sports after a back injury To use the sharing ... Back pain - returning to sports Which Type of Sport is Best? In deciding when and if to ...

  17. Calculating the financial return on educational programs.

    PubMed

    DeSilets, Lynore D

    2010-04-01

    Calculating the financial returns from educational activities can be accomplished by using either benefit-cost ratio (BCR) or return on investment (ROI) methodologies. Examples of each are presented in this column. Copyright 2010, SLACK Incorporated.

  18. 26 CFR 50.7 - Returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... part. (b) Content of return. The return shall show: (1) The identity of the particular dam or other works restraining debris from the mine; (2) The name and location of the mine; (3) The name and address...

  19. Assured crew return capability Crew Emergency Return Vehicle (CERV) avionics

    NASA Technical Reports Server (NTRS)

    Myers, Harvey Dean

    1990-01-01

    The Crew Emergency Return Vehicle (CERV) is being defined to provide Assured Crew Return Capability (ACRC) for Space Station Freedom. The CERV, in providing the standby lifeboat capability, would remain in a dormat mode over long periods of time as would a lifeboat on a ship at sea. The vehicle must be simple, reliable, and constantly available to assure the crew's safety. The CERV must also provide this capability in a cost effective and affordable manner. The CERV Project philosophy of a simple vehicle is to maximize its useability by a physically deconditioned crew. The vehicle reliability goes unquestioned since, when needed, it is the vehicle of last resort. Therefore, its systems and subsystems must be simple, proven, state-of-the-art technology with sufficient redundancy to make it available for use as required for the life of the program. The CERV Project Phase 1'/2 Request for Proposal (RFP) is currently scheduled for release on October 2, 1989. The Phase 1'/2 effort will affirm the existing project requirements or amend and modify them based on a thorough evaluation of the contractor(s) recommendations. The system definition phase, Phase 2, will serve to define CERV systems and subsystems. The current CERV Project schedule has Phase 2 scheduled to begin October 1990. Since a firm CERV avionics design is not in place at this time, the treatment of the CERV avionics complement for the reference configuration is not intended to express a preference with regard to a system or subsystem.

  20. An assessment of flow data from Klamath River sites between Link River Dam and Keno Dam, south-central Oregon

    USGS Publications Warehouse

    Risley, John C.; Hess, Glen W.; Fisher, Bruce J.

    2006-01-01

    Records of diversion and return flows for water years 1961?2004 along a reach of the Klamath River between Link River and Keno Dams in south-central Oregon were evaluated to determine the cause of a water-balance inconsistency in the hydrologic data. The data indicated that the reach was losing flow in the 1960s and 1970s and gaining flow in the 1980s and 1990s. The absolute mean annual net water-balance difference in flows between the first and second half of the 44-year period (1961-2004) was approximately 103,000 acre-feet per year (acre-ft/yr). The quality of the diversion and return-flow records used in the water balance was evaluated using U.S. Geological Survey (USGS) criteria for accuracy. With the exception of the USGS Klamath River at Keno record, which was rated as 'good' or 'excellent,' the eight other flow records, all from non-USGS flow-measurement sites, were rated as 'poor' by USGS standards due to insufficient data-collection documentation and a lack of direct discharge measurements to verify the rating curves. The record for the Link River site, the most upstream in the study area, included both river and westside power canal flows. Because of rating curve biases, the river flows might have been overestimated by 25,000 acre-ft/yr on average from water years 1961 to 1982 and underestimated by 7,000 acre-ft/yr on average from water years 1983 to 2004. For water years 1984-2004, westside power canal flows might have been underestimated by 11,000 acre-ft/yr. Some diversion and return flows (for mostly agricultural, industrial, and urban use) along the Klamath River study reach, not measured continuously and not included in the water-balance equation, also were evaluated. However, the sum of these diversion and return flows was insufficient to explain the water-balance inconsistency. The possibility that ground-water levels in lands adjacent to the river rose during water years 1961-2004 and caused an increase in ground-water discharge to the river

  1. 5 CFR 1650.5 - Returned funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Returned funds. 1650.5 Section 1650.5 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD METHODS OF WITHDRAWING FUNDS FROM THE THRIFT SAVINGS PLAN General § 1650.5 Returned funds. If a withdrawal is returned as undeliverable, the TSP...

  2. Heterogeneity in Schooling Rates of Return

    ERIC Educational Resources Information Center

    Henderson, Daniel J.; Polachek, Solomon W.; Wang, Le

    2011-01-01

    This paper relaxes the assumption of homogeneous rates of return to schooling by employing nonparametric kernel regression. This approach allows us to examine the differences in rates of return to education both across and within groups. Similar to previous studies we find that on average blacks have higher returns to education than whites,…

  3. Teaching Materials for Environmental Related Courses in Agriculture Occupations Programs.

    ERIC Educational Resources Information Center

    Bohning, Kermit B.; Stitt, Thomas R.

    The lesson plans were designed to provide the practicing applied biological and agricultural occupations teacher with a series of units setting down a basic foundation in Environmental Education. Nine lesson plans cover (1) ecosystems and agriculture, (2) biotic communities and food chains, (3) energy and nutrient flow, (4) land use and supply,…

  4. Modules in Agricultural Education for Agricultural Resources.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Occupational and Career Curriculum Development.

    Each of the 31 curriculum modules in this packet for agricultural resources instruction contains a brief description of the module content, a list of the major division or units, the overall objective, objectives by units, content outline and suggested teaching methods, student application activities, and evaluation procedures. A list of resource…

  5. Modules in Agricultural Education for Agricultural Mechanics.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Occupational and Career Curriculum Development.

    Each of the 38 curriculum modules in this packet for agricultural mechanics instruction contains a brief description of the module content, a list of the major divisions or units, the overall objectives, objectives by unit, content outline and suggested teaching methods, student application activities, and evaluation procedures. A listing of…

  6. VOCATIONAL AGRICULTURE RECORD BOOK FOR PRODUCTION AGRICULTURE.

    ERIC Educational Resources Information Center

    1966

    FORMS ARE PROVIDED FOR RECORDING FINANCIAL INFORMATION ABOUT SUPERVISED FARM PROGRAM ENTERPRISES BY INDIVIDUAL VOCATIONAL AGRICULTURE STUDENTS. THE BOOK IS DESIGNED ON AN ENTERPRISE BASIS AND PROVIDES SPACE FOR AGREEMENTS, INVENTORIES, EXPENSES, INCOME, SUMMARIES, AND ANALYSES. ASSISTANCE FOR TEACHERS USING THIS RECORD BOOK IS AVAILABLE IN "GUIDE…

  7. Department of Agriculture

    MedlinePlus

    ... in Conservation Innovation Grants Digitally discover your public lands using the new Forest Service Visitor Map Returning ... Natural Resources and Environment Forestry, conservation, damage prevention, land management, sustainable land management... Research, Education and Economics ...

  8. Hematospermia in a returned traveler

    PubMed Central

    Lang, Raynell; Minion, Jessica; Wong, Alexander

    2017-01-01

    Hematospermia is a common complaint among patients seen in outpatient urology clinics. The differential diagnosis is broad and includes inflammatory, infectious, neoplastic, structural, systemic, and traumatic causes. The most common infectious causes are uropathogens and sexually transmitted infections. However, with increasing global travel, physicians must maintain a high clinical suspicion for pathogens not endemic to their region, including Echinococcus, Mycobacterium tuberculosis, and Schistosoma.1 We present a case of hematospermia in a traveler returning from Eastern Africa with exposure to Lake Malawi. The patient’s microscopic analysis of semen was positive for Schistosoma haematobium, revealing a rare presentation of S. haematobium infection. PMID:28163813

  9. Orbiter Atlantis returns to KSC

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Shuttle Carrier Aircraft gently lands its piggyback cargo - - orbiter Atlantis -- at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999.

  10. Mars 2005 Sample Return Workshop

    NASA Technical Reports Server (NTRS)

    Gulick, V. C. (Editor)

    1997-01-01

    Convened at the request of Dr. Jurgen Rahe of the NASA Office of Space Science, the purpose of this workshop was to reexamine the science issues that will determine how an optimum sample return mission would be carried out in 2005 given the new context that has emerged for Mars exploration since the last such workshop was held (in 1987). The results and summary of discussion that took place at the meeting are contained in this volume. The community was invited to participate in the preparation of the final written report by browsing through the agenda and reading the text and viewgraphs provided by workshop participants and submitting comments for that section.

  11. Return to Flight Task Group

    NASA Technical Reports Server (NTRS)

    2005-01-01

    It has been 29 months since Columbia was lost over East Texas in February 2003. Seven months after the accident, the Columbia Accident Investigation Board (CAIB) released the first volume of its final report, citing a variety of technical, managerial, and cultural issues within NASA and the Space Shuttle Program. To their credit, NASA offered few excuses, embraced the report, and set about correcting the deficiencies noted by the accident board. Of the 29 recommendations issued by the CAIB, 15 were deemed critical enough that the accident board believed they should be implemented prior to returning the Space Shuttle to flight. Some of these recommendations were relatively easy, most were straightforward, a few bordered on the impossible, and others were largely overcome by events, particularly the decision by the President to retire the Space Shuttle by 2010. The Return to Flight Task Group (RTF TG, or simply, the Task Group) was chartered by the NASA Administrator in July 2003 to provide an independent assessment of the implementation of the 15 CAIB return-to-flight recommendations. An important observation must be stated up-front: neither the CAIB nor the RTF TG believes that all risk can be eliminated from Space Shuttle operations; nor do we believe that the Space Shuttle is inherently unsafe. What the CAIB and RTF TG do believe, however, is that NASA and the American public need to understand the risks associated with space travel, and that NASA must make every reasonable effort to minimize such risk. Since the release of the CAIB report, NASA and the Space Shuttle Program expended enormous effort and resources toward correcting the causes of the accident and preparing to fly again. Relative to the 15 specific recommendations that the CAIB indicated should be implemented prior to returning to flight, NASA has met or exceeded most of them the Task Group believes that NASA met the intent of the CAIB for 12 of these recommendations. The remaining three

  12. Hematospermia in a returned traveler.

    PubMed

    Lang, Raynell; Minion, Jessica; Wong, Alexander

    2017-01-01

    Hematospermia is a common complaint among patients seen in outpatient urology clinics. The differential diagnosis is broad and includes inflammatory, infectious, neoplastic, structural, systemic, and traumatic causes. The most common infectious causes are uropathogens and sexually transmitted infections. However, with increasing global travel, physicians must maintain a high clinical suspicion for pathogens not endemic to their region, including Echinococcus, Mycobacterium tuberculosis, and Schistosoma.1 We present a case of hematospermia in a traveler returning from Eastern Africa with exposure to Lake Malawi. The patient's microscopic analysis of semen was positive for Schistosoma haematobium, revealing a rare presentation of S. haematobium infection.

  13. Radiative driving of shallow return flows from the ITCZ

    NASA Astrophysics Data System (ADS)

    Nishant, N.; Sherwood, S. C.; Geoffroy, O.

    2016-06-01

    The tropical overturning circulation over the central-east Pacific not only extends through the troposphere but also includes a shallow component outflowing from the ITCZ near the planetary boundary layer (PBL) top, the Shallow Meridional Circulation (SMC). Idealized simulations with the Weather Research and Forecasting (WRF) model, which qualitatively reproduce this two-component circulation, are used to investigate the mechanism driving the SMC by altering model parameterization schemes (PBL, cumulus and radiation), the solar heating rate, and the SST gradient. A radiative-driving model for subsidence is tested and found to quantitatively predict the altitude and strength of the SMC in all experiments. This includes experiments with a changed SST gradient, in which the changes in temperature profile and clouds near PBL top in the subsiding region altered radiative cooling so as to make the SMC vary in proportion to the SST gradient. These results indicate that the SMC is strongly controlled by radiative cooling rather than independently by SST patterns or convective processes, at least in this model setup. Experiments with altered solar heating of the atmosphere affected the strength of the SMC strongly, while changes in cumulus parameterization had a weaker effect. Parameterization changes influenced the SMC mainly by altering shallow cloud amount and humidity in subsidence regions, but vertical gradients of temperature also affect the radiative driving of the SMC in at least one case. The results highlight that atmospheric radiative heating is of prime importance for determining the character of deep and shallow overturning.

  14. Agricultural Technology Opportunities.

    ERIC Educational Resources Information Center

    North Carolina State Board of Education, Raleigh. Agricultural Technology Education Section.

    Agricultural education programs available through North Carolina's newly created system of industrial education center, technical institutes, and community colleges are described. The information is for use by administrators, and teachers of adult agricultural courses and counselors of high school dropouts and graduates. It describes the need for…

  15. USSR Report Agriculture

    DTIC Science & Technology

    2007-11-02

    the last century one of the first Russian agronomists, M. G. Pavlov , in speaking about efficient agriculture, was asked the question, is agriculture...three are agronomists in enterprises--Nikolay Georgiyevich Kovalev, Fedor Akimovich Ivashchenko and Ivan Kirillovich Okhrimenko. All three work under the

  16. Theme: Urban Agriculture.

    ERIC Educational Resources Information Center

    Ellibee, Margaret; And Others

    1990-01-01

    On the theme of secondary agricultural education in urban areas, this issue includes articles on opportunities, future directions, and implications for the profession; creative supervised experiences for horticulture students; floral marketing, multicultural education; and cultural diversity in urban agricultural education. (JOW)

  17. Vocational Agriculture I.

    ERIC Educational Resources Information Center

    Patton, Bob; Harp, Keith

    These course materials are designed to provide a foundation of basic knowledge in production agriculture as a prelude to further education in vocational agriculture. The guide contains 6 sections and 22 units of instruction. Each unit includes all or most of eight basic components: performance objectives, suggested activities for the teacher,…

  18. Agricultural Technology Opportunities.

    ERIC Educational Resources Information Center

    North Carolina State Board of Education, Raleigh. Agricultural Technology Education Section.

    Agricultural education programs available through North Carolina's newly created system of industrial education center, technical institutes, and community colleges are described. The information is for use by administrators, and teachers of adult agricultural courses and counselors of high school dropouts and graduates. It describes the need for…

  19. Invasive species in agriculture

    USDA-ARS?s Scientific Manuscript database

    Agricultural production of food, feed, fiber or fuel is a local human activity with global ecological impacts, including the potential to foster invasions. Agriculture plays an unusual role in biological invasions, in that it is both a source of non-indigenous invasive species (NIS) and especially s...

  20. Revisiting Supervised Agricultural Experience.

    ERIC Educational Resources Information Center

    Camp, William G.; Clarke, Ariane; Fallon, Maureen

    2000-01-01

    A Delphi panel of 40 agricultural educators unanimously agreed that supervised agricultural experience should remain an integral component of the curriculum; a name change is not currently warranted. Categories recommended were agribusiness entrepreneurship, placement, production, research, directed school lab, communications, exploration, and…

  1. Agricultural Education in Yugoslavia.

    ERIC Educational Resources Information Center

    Buila, Theodore

    A study was made, during 1965-68, of the development and current operation of programs of agricultural education and manpower development in Yugoslavia. Data were also gathered on occupational patterns of graduates, occupational migration, off-job satisfaction and dissatisfaction, hiring plans of agricultural firms, and manpower planning. The rise…

  2. Agriculture Power and Machinery.

    ERIC Educational Resources Information Center

    Rogers, Tom

    This guide is intended to assist vocational agriculture teachers who are teaching secondary- or postsecondary-level courses in agricultural power and machinery. The materials presented are based on the Arizona validated occupational competencies and tasks for the following occupations: service manager, shop foreman, service technician, and tractor…

  3. Vocational Agriculture I.

    ERIC Educational Resources Information Center

    Patton, Bob; Harp, Keith

    These course materials are designed to provide a foundation of basic knowledge in production agriculture as a prelude to further education in vocational agriculture. The guide contains 6 sections and 22 units of instruction. Each unit includes all or most of eight basic components: performance objectives, suggested activities for the teacher,…

  4. Theme: Marketing Agricultural Education.

    ERIC Educational Resources Information Center

    Staller, Bernie L.; And Others

    1988-01-01

    Consists of six articles on marketing agricultural education. Topics include (1) being consumer conscious, (2) cooperating with agribusiness, (3) preparing students for postsecondary education, (4) allowing concurrent enrollments, (5) saving the failing agricultural program, and (6) refocusing the curriculum toward agrimarketing. (CH)

  5. Agricultural Occupations Handbook.

    ERIC Educational Resources Information Center

    Lark, Floyd J.; Henderson, Billie

    This agricultural occupations handbook was developed from the Dictionary of Occupational Titles (DOT) and the U.S. Departments of Health, Education, and Welfare, and Labor publication, Vocational Education and Occupations. It includes the U.S. Office of Education coding for the instructional area of agriculture and the cluster coding for the…

  6. Theme: Marketing Agricultural Education.

    ERIC Educational Resources Information Center

    Staller, Bernie L.; And Others

    1988-01-01

    Consists of six articles on marketing agricultural education. Topics include (1) being consumer conscious, (2) cooperating with agribusiness, (3) preparing students for postsecondary education, (4) allowing concurrent enrollments, (5) saving the failing agricultural program, and (6) refocusing the curriculum toward agrimarketing. (CH)

  7. Agriculture in the Midwest

    USDA-ARS?s Scientific Manuscript database

    Agriculture in the Midwest United States (Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin) represents one of the most intense areas of agriculture in the world. This area is not only critically important for the United States, but also for world exports of grain and meat for the Un...

  8. Agriculture Power and Machinery.

    ERIC Educational Resources Information Center

    Rogers, Tom

    This guide is intended to assist vocational agriculture teachers who are teaching secondary- or postsecondary-level courses in agricultural power and machinery. The materials presented are based on the Arizona validated occupational competencies and tasks for the following occupations: service manager, shop foreman, service technician, and tractor…

  9. Global Transformations and Agriculture.

    ERIC Educational Resources Information Center

    Campbell, Rex R.

    1990-01-01

    Examines worldwide political, economic, and social transformations and their impact on agriculture, focusing on biotechnology. Discusses rise of international corporations and accompanying constraints on government power. Sees trend toward increasing agribusiness role in world food and agricultural sectors. Calls for broader views and research in…

  10. Precision agricultural systems

    USDA-ARS?s Scientific Manuscript database

    Precision agriculture is a new farming practice that has been developing since late 1980s. It has been variously referred to as precision farming, prescription farming, site-specific crop management, to name but a few. There are numerous definitions for precision agriculture, but the central concept...

  11. Revisiting Supervised Agricultural Experience.

    ERIC Educational Resources Information Center

    Camp, William G.; Clarke, Ariane; Fallon, Maureen

    2000-01-01

    A Delphi panel of 40 agricultural educators unanimously agreed that supervised agricultural experience should remain an integral component of the curriculum; a name change is not currently warranted. Categories recommended were agribusiness entrepreneurship, placement, production, research, directed school lab, communications, exploration, and…

  12. Global Transformations and Agriculture.

    ERIC Educational Resources Information Center

    Campbell, Rex R.

    1990-01-01

    Examines worldwide political, economic, and social transformations and their impact on agriculture, focusing on biotechnology. Discusses rise of international corporations and accompanying constraints on government power. Sees trend toward increasing agribusiness role in world food and agricultural sectors. Calls for broader views and research in…

  13. Agricultural Occupations Handbook.

    ERIC Educational Resources Information Center

    Lark, Floyd J.; Henderson, Billie

    This agricultural occupations handbook was developed from the Dictionary of Occupational Titles (DOT) and the U.S. Departments of Health, Education, and Welfare, and Labor publication, Vocational Education and Occupations. It includes the U.S. Office of Education coding for the instructional area of agriculture and the cluster coding for the…

  14. The Agricultural Origins of Time Preference*

    PubMed Central

    Galor, Oded; Özak, Ömer

    2017-01-01

    This research explores the origins of observed differences in time preference across countries and regions. Exploiting a natural experiment associated with the expansion of suitable crops for cultivation in the course of the Columbian Exchange, the research establishes that pre-industrial agro-climatic characteristics that were conducive to higher return to agricultural investment, triggered selection, adaptation and learning processes that generated a persistent positive effect on the prevalence of long-term orientation in the contemporary era. Furthermore, the research establishes that these agro-climatic characteristics have had a culturally embodied impact on economic behavior such as technological adoption, education, saving, and smoking. PMID:28781375

  15. Agricultural sustainability: concepts, principles and evidence.

    PubMed

    Pretty, Jules

    2008-02-12

    Concerns about sustainability in agricultural systems centre on the need to develop technologies and practices that do not have adverse effects on environmental goods and services, are accessible to and effective for farmers, and lead to improvements in food productivity. Despite great progress in agricultural productivity in the past half-century, with crop and livestock productivity strongly driven by increased use of fertilizers, irrigation water, agricultural machinery, pesticides and land, it would be over-optimistic to assume that these relationships will remain linear in the future. New approaches are needed that will integrate biological and ecological processes into food production, minimize the use of those non-renewable inputs that cause harm to the environment or to the health of farmers and consumers, make productive use of the knowledge and skills of farmers, so substituting human capital for costly external inputs, and make productive use of people's collective capacities to work together to solve common agricultural and natural resource problems, such as for pest, watershed, irrigation, forest and credit management. These principles help to build important capital assets for agricultural systems: natural; social; human; physical; and financial capital. Improving natural capital is a central aim, and dividends can come from making the best use of the genotypes of crops and animals and the ecological conditions under which they are grown or raised. Agricultural sustainability suggests a focus on both genotype improvements through the full range of modern biological approaches and improved understanding of the benefits of ecological and agronomic management, manipulation and redesign. The ecological management of agroecosystems that addresses energy flows, nutrient cycling, population-regulating mechanisms and system resilience can lead to the redesign of agriculture at a landscape scale. Sustainable agriculture outcomes can be positive for food

  16. Holistic assessment of occurrence and fate of metolachlor within environmental compartments of agricultural watersheds

    USGS Publications Warehouse

    Rose, Claire E.; Coupe, Richard H.; Capel, Paul D.; Webb, Richard M.

    2017-01-01

    Background: Metolachlor [(RS)-2-Chloro-N-(2-ethyl-6-methyl-phenyl)-N-(1-methoxypropan-2-yl)acetamide] and two degradates (metolachlor ethane-sulfonic acid and metolachlor oxanilic acid) are commonly observed in surface and groundwater. The behavior and fate of these compounds were examined over a 12-year period in seven agricultural watersheds in the United States. They were quantified in air, rain, streams, overland flow, groundwater, soil water, subsurface drain water, and water at the stream/groundwater interface. The compounds were frequently detected in surface and groundwater associated with agricultural areas. A mass budget approach, based on all available data from the study and literature, was used to determine a percentage-wise generalized distribution and fate of applied parent metolachlor in typical agricultural environments.Results: In these watersheds, about 90% of applied metolachlor was taken up by plants or degraded, 10% volatilized, and 0.3% returned as rainfall. One percent was transported to surface water, while an equal amount infiltrated into the unsaturated zone soil water. < 0.02% reached the groundwater. Subsurface flow paths resulted in greater degradation of metolachlor because degradation reactions had more time to proceed.Conclusions: An understanding of the residence times of water in the different environmental compartments, and the important processes affecting metolachlor as it is transported along flowpaths among the environmental compartments allows for a degree of predictability of metolachlor's fate. Degradates with long half-lives can be used (in a limited capacity) as tracers of metolachlor, because of their persistence and widespread occurrence in the environment.

  17. Identifying International Agricultural Concepts for Secondary Agricultural Education Curriculum

    ERIC Educational Resources Information Center

    Conner, Nathan W.; Gates, Hailey; Stripling, Christopher T.

    2017-01-01

    The globalization of the agriculture industry has created an emerging need for agricultural education in the United States to take a more globalized approach to prepare students for future careers in agriculture. The purpose of this study was to identify international agricultural concepts for secondary agricultural education curriculum. A Delphi…

  18. Return to sport following amputation.

    PubMed

    Matthews, D; Sukeik, M; Haddad, F

    2014-08-01

    Amputation in athletes has a substantial impact on lifestyle and sporting activity, as well as self-perception and quality of life. The impact of limb loss on athletic ability will vary depending on the cause of amputation and the anatomical location of the amputation. The use of sporting activity for rehabilitation of amputees was first introduced in 1944 at Stoke Mandeville Hospital. The first international paralympic games were founded in 1960. Following these events the opportunity to participate in sport following limb loss has increased significantly. Sport participation has been aided by the development of sporting prostheses, however multiple factors will determine the exact prosthesis used. These include the nature of the sporting activity as well as the level of the amputation. The biomechanics involved in walking and running are altered following the loss of a limb or part thereof. This can cause subsequent degenerative changes within the remaining joints on the amputated limb as well as the contralateral limb. Factors affecting return to sporting activity are multivariate and inter-related, including patient factors, surgical factors, nature and level of the sporting activity and prosthetic factors. The authors review current literature, detail predictive factors of return to sport and the physical and psychosocial impact on patients following limb amputation.

  19. Returning to work while breastfeeding.

    PubMed

    Biagioli, Frances

    2003-12-01

    Mothers who work outside the home initiate breastfeeding at the same rate as mothers who stay at home. However, the breastfeeding continuance rate declines sharply in mothers who return to work. While the work environment may be less than ideal for the breastfeeding mother, obstacles can be overcome. Available breast pump types include manual pumps, battery-powered pumps, electric diaphragm pumps, electric piston pumps, and hospital-grade electric piston pumps. Electric piston pumps may be the most suitable type for mothers who work outside the home for more than 20 hours per week; however, when a mother is highly motivated, any pump type can be successful in any situation. Conservative estimates suggest that breast milk can be stored at room temperature for eight hours, refrigerated for up to eight days, and frozen for many months. A breastfeeding plan can help the working mother anticipate logistic problems and devise a practical pumping schedule. A mother's milk production usually is well established by the time her infant is four weeks old; it is best to delay a return to work until at least that time, and longer if possible.

  20. Technical concepts related to conservation of irrigation and rainwater in agricultural systems

    NASA Astrophysics Data System (ADS)

    Clemmens, A. J.; Allen, R. G.; Burt, C. M.

    2008-07-01

    Forty percent of freshwater withdrawals in the United States are for irrigated agriculture, which contribute more than $50 billion to the economy. Increasing diversions of water for urban, environmental, and other uses will likely decrease water available to agriculture. Water conservation in agriculture is touted as a good method for minimizing the impact of reduced agricultural diversions on production. Because "wasted" water is often reused until it reaches the ocean, there are limitations to the true water savings that result from programs that aim to increase irrigation efficiency. True water savings can come from four areas: reduction of unnecessary evaporation and transpiration, more effective use of rainfall, reduction of deep percolation water that becomes severely degraded in quality, and reduction of runoff from fields that is not reusable downstream. Any other reduction in net water consumption must come from reductions in evapotranspiration from the crops grown, which requires either reduction in acreage or reduction in crop yield brought on by intentional plant water stress. Other benefits of field or district-level water conservation may include increased in-stream flows (due to lower diversions) and energy conservation due to less pumping or more hydroelectric production, but not result in true water savings, since unconsumed water returns as a usable water resource. Understanding the hydrologic settings is critical to determining true water savings from conservation practices. On-farm water conservation practices that provide true water savings at one location may be ineffective at another. In large irrigation projects, water delivery limitations often present obstacles to on-farm water conservation efforts.

  1. The dynamics of health and return migration.

    PubMed

    Davies, Anita A; Borland, Rosilyne M; Blake, Carolyn; West, Haley E

    2011-06-01

    The increasing importance and complexity of migration globally also implies a global increase in return migration, and thus an increased interest in the health of returning migrants. The health of returning migrants is impacted by the cumulative exposure to social determinants and risk factors of health during the migration process, during the return movement, and following return. Circular migration often occurs among the diaspora, which can result in the transfer of knowledge and skills that contribute to development, including health system strengthening. Migrants with dual nationality often return to countries with better health services than their country of origin when they are sick and can not get care at home. To maintain and improve the health of returning migrants, multi-sectoral policies at global and national levels should facilitate access to appropriate and equitable health services, social services, and continuity of care across and within borders.

  2. Simulation of ground-water flow in the basin-fill aquifer of the Tularosa Basin, south-central New Mexico, predevelopment through 2040

    USGS Publications Warehouse

    Huff, Glenn F.

    2005-01-01

    The hydrology of the basin-fill aquifer in the Tularosa Basin was evaluated through construction and calibration of steady-state and transient three-dimensional ground-water-flow simulations. Simulations were made using the U.S. Geological Survey finite-difference modular ground-water-flow computer software MODFLOW-96. The transient simulation covered 1948-2040. Both steady-state and transient simulations were calibrated by matching simulation output to available ground-water-level measurements. The root-mean-square error of the steady-state calibration in the well-calibrated area of the ground-water-flow simulation was 6.3 meters, and root-mean-square errors of individual transient-calibration points ranged from 0.8 to 17.0 meters. The areal distribution of water-level measurements used in the steady-state and transient calibrations restricts the well-calibrated area of the model to the eastern side of the Tularosa Basin. Water levels in the La Luz Creek subbasin area were underestimated by both the steady-state and transient models, suggesting that the hydrology of this area is not well represented in the model. About 143,000 cubic meters per day of recharge is estimated to enter the basin-fill aquifer from subbasins that rim the Tularosa Basin. The estimated recharge is about 4-5 percent of total precipitation in most subbasins. Approximately 88 percent of total recharge left the basin-fill aquifer as evapotranspiration under predevelopment conditions. Water levels were simulated for 1948, 1995, and 2040 under scenarios of zero and maximum return flows. Estimated return flows from municipalities were calculated on the basis of data in the Tularosa Basin Regional Water Plan for 2000-2040. Agricultural return flows were estimated primarily on the basis of ground-water-withdrawal, ground-water-depletion, surface-water-withdrawal, and surface-water-depletion data for the Tularosa Basin. The ground-water-flow simulation was sensitive to the return-flow scenario in

  3. Issues of sustainable irrigated agriculture in the San Joaquin Valley of California in a changing regulatory environment concerning water quality and protection of wildlife

    SciTech Connect

    Quinn, N.W.T.; Delamore, M.L.

    1994-06-01

    Since the discovery of selenium toxicosis in the Kesterson Reservoir in the San Joaquin Valley, California, public perception of irrigated agriculture as a benign competitor for California`s developed water supply has been changed irrevocably. Subsurface return flows from irrigated agriculture were implicated as the source of selenium which led to incidents of reproductive failure in waterfowl and threatened survival of other fish and wildlife species. Stringent water quality objectives were promulgated to protect rivers, tributaries, sloughs and other water bodies receiving agricultural discharges from selenium contamination. Achieving these objectives was left to the agricultural water districts, federal and state agencies responsible for drainage and water quality enforcement in the San Joaquin Basin. This paper describes some of the strategies to improve management of water resources and water quality in response to these new environmental objectives. Similar environmental objectives will likely be adopted by other developed and developing countries with large regions of arid zone agriculture and susceptible wildlife resources. A series of simulation models have been developed over the past four years to evaluate regional drainage management strategies such as: irrigation source control; drainage recycling; selective retirement of agricultural land; regional shallow ground water pumping; coordination of agricultural drainage, wetland and reservoir releases; and short-term ponding of drainage water. A new generation of Geographic Information Service-based software is under development to bridge the gap between planning and program implementation. Use of the decision support system will allow water districts and regulators to continuously monitor drainage discharges to the San Joaquin River in real-time and to assess impacts of management strategies that have been implemented to take advantage of the River`s assimilative capacity for trace elements and salts.

  4. Population age structure and asset returns: an empirical investigation.

    PubMed

    Poterba, J M

    1998-10-01

    "This paper investigates the association between population age structure, particularly the share of the population in the 'prime saving years' 45-60, and the returns on stocks and bonds. The paper is motivated by the claim that the aging of the 'Baby Boom' cohort in the United States is a key factor in explaining the recent rise in asset values. It also addresses the associated claim that asset prices will decline when this large cohort reaches retirement age and begins to reduce its asset holdings. This paper begins by considering household age-asset accumulation profiles. Data from the Survey of Consumer Finances suggest that while cross-sectional age-wealth profiles peak for households in their early 60s, cohort data on the asset ownership of the same households show a much less pronounced peak.... The paper then considers the historical relationship between demographic structure and real returns on Treasury bills, long-term government bonds, and corporate stock. The results do not suggest any robust relationship between demographic structure and asset returns.... The paper concludes by discussing factors such as international capital flows and forward-looking behavior on the part of market participants that could weaken the relationship between age structure and asset returns in a single nation." excerpt

  5. Melioidosis in a returning traveller

    PubMed Central

    Ismail, Alaa; Buckley, Adam; Dubrey, Simon William

    2013-01-01

    A 66-year-old man returned to the UK from Thailand with a 2-week history of new confusion, hallucinations, fever with rigours and productive cough. He had not responded to (unspecified) antibiotic treatment in Thailand. On examination he was afebrile, with an abbreviated mental test score of 8/10 and no other findings on systemic examination. He was treated with ceftriaxone in response to discovery of a Gram-negative organism in blood. This was converted to meropenem on the clinical suspicion of our microbiologist, on the basis of a history of contact with surface water in the Far East. A blood culture subsequently confirmed Burkholderia pseudomallei. His condition remained stable for approximately 4 days, but then deteriorated over the course of the next 2 weeks with pneumonia and subsequent formation of disseminated abscesses. Treatment was withdrawn as his condition deteriorated to the point at which survival was deemed impossible and he subsequently died. PMID:23605844

  6. Orbiter Atlantis returns to KSC

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Shuttle Carrier Aircraft rolls to a stop with its piggyback cargo -- orbiter Atlantis -- at the Shuttle Landing Facility. In the background is the Vehicle Assembly Building. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999.

  7. Orbiter Atlantis returns to KSC

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Stairs are rolled to the forward opening of the Shuttle Carrier Aircraft -- with its piggyback cargo, the orbiter Atlantis -- after it rolls to a stop at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999.

  8. Partial Return Yoke for MICE

    SciTech Connect

    Witte H.; Plate, S

    2013-05-03

    The international Muon Ionization Cooling Experiment (MICE) is a large scale experiment which is presently assembled at the Rutherford Appleton Laboratory in Didcot, UK. The purpose of MICE is to demonstrate the concept of ionization cooling experimentally. Ionization cooling is an important accelerator concept which will be essential for future HEP experiments such as a potential Muon Collider or a Neutrino Factory. The MICE experiment will house up to 18 superconducting solenoids, all of which produce a substantial amount of magnetic flux. Recently it was realized that this magnetic flux leads to a considerable stray magnetic field in the MICE hall. This is a concern as technical equipment in the MICE hall may may be compromised by this. In July 2012 a concept called partial return yoke was presented to the MICE community, which reduces the stray field in the MICE hall to a safe level. This report summarizes the general concept, engineering considerations and the expected shielding performance.

  9. Feeding and healing the world: through regenerative agriculture and permaculture.

    PubMed

    Rhodes, Christopher J

    2012-01-01

    The study of soil is a mature science, whereas related practical methods of regenerative agriculture and permaculture are not. However, despite a paucity of detailed peer reviewed research published on these topics, there is overwhelming evidence both that the methods work and they may offer the means to address a number of prevailing environmental challenges, e.g. peak oil, climate change, carbon capture, unsustainable agriculture and food shortages, peak phosphorus (phosphate), water shortages, environmental pollution, desert reclamation, and soil degradation. What is lacking is a proper scientific study, made in hand with actual development projects. By elucidating the scientific basis of these remarkable phenomena, we may obtain the means for solving some of the otherwise insurmountable problems confronting humanity, simply by observing, and working with, the patterns and forces of nature. This article is intended as a call to arms to make serious investment in researching and actualising these methods on a global scale. Despite claims that peak oil is no longer a threat because vast resources of gas and shale oil (tight oil) can now be recovered by fracking (hydraulic fracturing) combined with horizontal drilling, the reality is that proven actual reserves are only adequate to delay the peak by a few years. Furthermore, because of the rapid depletion rates of flow from gas wells and oil wells that are accessed by fracking, it will be necessary to drill continuously and relentlessly to maintain output, and there are material limits of equipment, technology and trained personnel to do this. Moreover, to make any sensible difference to the liquid fuel crisis, which is the most immediate consequence of peak oil, it would be necessary to convert the worlds one billion vehicles to run on natural gas rather than liquid fuels refined from crude oil, and this would take some considerable time and effort. The loss of widespread personalised transportation is thus

  10. Efficient phosphorus management practices in the Everglades Agricultural Area

    NASA Astrophysics Data System (ADS)

    Bhadha, J. H.; Lang, T. A.; Daroub, S. H.; Alvarez, O.; Tootoonchi, M.; Capasso, J.

    2016-12-01

    In the 450,000 acres of the Everglades Agricultural Area (EAA) of South Florida, farming practices have long been mindful of phosphorus (P) management as it relates to sufficiency and efficiency of P utilization. Over two decades of P best management practices have resulted in 3001 metric-ton of P load reduction from the EAA to downstream ecosystems. During the summer, more than 50,000 acres of fallow sugarcane land is available for rice production. The net value of growing flooded rice in the EAA as a rotational crop with sugarcane far exceeds its monetary return. Soil conservation, improvement in tilth and P load reduction are only some of the benefits. With no P fertilizer applied, a two-year field trial on flooded rice showed improved outflow P concentrations by up to 40% as a result of particulate setting and plant P uptake. Harvested whole grain rice can effectively remove a significant amount of P from a rice field per growing season. In parts of the EAA where soils are sandy, the application of using locally derived organic amendments as potential P fertilizer has gained interest over the past few years. The use of local agricultural and urban organic residues as amendments in sandy soils of South Florida provide options to enhance soil properties and improve sugarcane yields, while reducing waste and harmful effects of agricultural production on the environment. A lysimeter study conducted to determine the effect of mill ash and three types of biochar (rice hulls, yard waste, horse bedding) on sugarcane yields, soil properties, and drainage water quality in sandy soils showed that mill ash and rice hull biochar increased soil TP, Mehlich 3-P (M3-P), and cation exchange capacity (CEC) compared to the control. TP and M3-P content remained constant after 9 months, CEC showed a significant increase over time with rich hull biochar addition. Future projects include the utilization of aquatic vegetation, such as chara and southern naiad as bio-filters in farm

  11. Aerothermodynamic Environment Definition for the Genesis Sample Return Capsule

    NASA Technical Reports Server (NTRS)

    Cheatwood, F. McNeil; Merski, N. Ronald, Jr.; Riley, Christopher J.; Mitcheltree, Robert A.

    2001-01-01

    NASA's Genesis sample return mission will be the first to return material from beyond the Earth-Moon system. NASA Langley Research Center supported this mission with aerothermodynamic analyses of the sample return capsule. This paper provides an overview of that effort. The capsule is attached through its forebody to the spacecraft bus. When the attachment is severed prior to Earth entry, forebody cavities remain. The presence of these cavities could dramatically increase the heating environment in their vicinity and downstream. A combination of computational fluid dynamics calculations and wind tunnel phosphor thermography tests were employed to address this issue. These results quantify the heating environment in and around the cavities, and were a factor in the decision to switch forebody heat shield materials. A transition map is developed which predicts that the flow aft of the penetrations will still be laminar at the peak heating point of the trajectory. As the vehicle continues along the trajectory to the peak dynamic pressure point, fully turbulent flow aft of the penetrations could occur. The integrated heat load calculations show that a heat shield sized to the stagnation point levels will be adequate for the predicted environment aft of the penetrations.

  12. From theoretical fixed return period events to real flooding impacts: a new approach to set flooding scenarios, thresholds and alerts

    NASA Astrophysics Data System (ADS)

    Parravicini, Paola; Cislaghi, Matteo; Condemi, Leonardo

    2017-04-01

    allows to give a return period for each scenario. The return period may vary along the river course according to the discharges associated with the scenario. The values of return period may show the areas characterized by higher risk and can be an important basis for civil protection emergency planning and river monitoring. For example, considering the Lambro River, the red scenario (major flood) shows a return period of 50 years in the northern rural part of the catchment. When the river crosses the city of Milan, the return period drops to 4 years. Afterwards it goes up to more than 100 years when the river flows in the agricultural areas in the southern part of the catchment. In addition, the knowledge gained with event-based analysis allows evaluating the compliance of the monitoring network with early warning requirements and represents the starting point for further development of the network itself.

  13. Direct flow crystal growth system

    SciTech Connect

    Montgomery, K.E.; Milanovich, F.P.

    1989-10-30

    A crystal is grown in a constantly filtered solution which is flowed directly into the growing face of a crystal. In a continuous flow system, solution at its saturation temperature is removed from a crystal growth tank, heated above its saturation temperatue, filtered, cooled back to its saturation temperature, and returned to the tank. 2 figs.

  14. Direct flow crystal growth system

    DOEpatents

    Montgomery, Kenneth E.; Milanovich, Fred P.

    1992-01-01

    A crystal is grown in a constantly filtered solution which is flowed directly into the growing face of a crystal. In a continuous flow system, solution at its saturation temperature is removed from a crystal growth tank, heated above its saturation temperature, filtered, cooled back to its saturation temperature, and returned to the tank.

  15. Serving Agriculture's "Big Business"

    ERIC Educational Resources Information Center

    Schake, L. M.

    1970-01-01

    A new dimension and challenge in Extension activities is emerging as some phases of agriculture evolve from small operations to multimillion dollar agribusiness ventures; the beef cattle commercial feedlot industry in the Southwest is a good example. (EB)

  16. Agricultural Credit Expansion Act

    THOMAS, 112th Congress

    Sen. Gillibrand, Kirsten E. [D-NY

    2011-09-21

    Senate - 09/21/2011 Read twice and referred to the Committee on Agriculture, Nutrition, and Forestry. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  17. Collaboration in Agricultural Education.

    ERIC Educational Resources Information Center

    Peterson, Roland L.; And Others

    1995-01-01

    Theme articles discuss environment, food, agriculture, and renewal resources as they relate to science education, learning partnerships, collaboration in Kyrghyzstan, leadership development, opportunities for collaboration, networking, and the creation of a shared course between agribusiness and biology. (JOW)

  18. Agricultural Education and OSHA

    ERIC Educational Resources Information Center

    Brown, Ronald A.

    1974-01-01

    Agriculture teachers should be interested in and become familiar with the implications of the Williams-Steiger Occupational Safety and Health Act of 1970 for their own benefit, for their students, and for their students' future employers. (AG)

  19. Collaboration in Agricultural Education.

    ERIC Educational Resources Information Center

    Peterson, Roland L.; And Others

    1995-01-01

    Theme articles discuss environment, food, agriculture, and renewal resources as they relate to science education, learning partnerships, collaboration in Kyrghyzstan, leadership development, opportunities for collaboration, networking, and the creation of a shared course between agribusiness and biology. (JOW)

  20. Serving Agriculture's "Big Business"

    ERIC Educational Resources Information Center

    Schake, L. M.

    1970-01-01

    A new dimension and challenge in Extension activities is emerging as some phases of agriculture evolve from small operations to multimillion dollar agribusiness ventures; the beef cattle commercial feedlot industry in the Southwest is a good example. (EB)