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Sample records for tuwayq pivot irrigation

  1. Performance evaluation of a center pivot variable rate irrigation system

    Science.gov (United States)

    Variable Rate Irrigation (VRI) for center pivots offers potential to match specific application rates to non-uniform soil conditions along the length of the lateral. The benefit of such systems is influenced by the areal extent of these variations and the smallest scale to which the irrigation syste...

  2. Identifying and locating land irrigated by center-pivot irrigation systems using satellite imagery

    Science.gov (United States)

    Hoffman, R. O.

    1980-01-01

    A methodology for using Landsat imagery for the identification and location of land irrigated by center-pivot irrigation systems is presented. The procedure involves the use of sets of Landsat band 5 imagery taken separated in time by about three weeks during the irrigation season, a zoom transfer scope and mylar base maps to record the locations of center pivots. Further computer processing of the data has been used to obtain plots of center-pivot irrigation systems and tables indicating the distribution and growth of systems by county for the state of Nebraska, and has been found to be in 95% agreement with current high-altitude IR photography. The information obtainable can be used for models of ground-water aquifers or resource planning.

  3. Optimal irrigation water allocation for a center pivot using remotely sensed data

    Science.gov (United States)

    Hassan Esfahani, L.; McKee, M.

    2013-12-01

    Efficient irrigation can help avoid crop water stress, undesirable leaching of nutrients, and yield reduction due to water shortage, and runoff and soil erosion due to over irrigation. Gains in water use efficiency can be achieved when water application is precisely matched to the spatially distributed crop water demand. This is important to produce high quality crops and otherwise conserve water for greatest efficiency of use. Irrigation efficiency is a term which defines irrigation performance based on indicators such as irrigation uniformity, crop production, economic return and water resources sustainability. The present paper introduces a modeling approach for optimal water allocation to a center pivot irrigation unit in consideration of these types of indicators. Landsat images, weather data and field measurements were used to develop a soil water balance model using Artificial Neural Networks (ANN). The model includes two main modules, one for soil water forecasting and one for optimization of water allocation. The optimization module uses Genetic Algorithms (GA) to identify optimal crop water application rates based on the crop type, growing stage and sensitivity to water stress. The forecasting module allocates water through time across the area covered by the center pivot considering the results from the previous period of irrigation and the operational limitations of the center pivot irrigation system. The model was tested for a farm equipped with a modern sprinkler irrigation system in Scipio, Utah. The solution obtained from the model used up to 30 percent less water without reducing the benefits realized by the irrigator than traditional operating procedures.

  4. Integration of wireless sensor networks into automatic irrigation scheduling of a center pivot

    Science.gov (United States)

    A six-span center pivot system was used as a platform for testing two wireless sensor networks (WSN) of infrared thermometers. The cropped field was a semi-circle, divided into six pie shaped sections of which three were irrigated manually and three were irrigated automatically based on the time tem...

  5. Droplet kinetic energy of moving spray-plate center-pivot irrigation sprinklers

    Science.gov (United States)

    The kinetic energy of discrete water drops impacting a bare soil surface generally leads to a drastic reduction in water infiltration rate due to formation of a seal on the soil surface. Under center-pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development ...

  6. Characterizing droplet kinetic energy applied by moving spray-plate center pivot irrigation sprinklers

    Science.gov (United States)

    The kinetic energy of discrete drops impacting a bare soil surface is generally observed to lead to a drastic reduction in water infiltration rate due to soil surface seal formation. Under center pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can...

  7. Potential for Photovoltaic Solar Installation in Non-Irrigated Corners of Center Pivot Irrigation Fields in the State of Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, B.

    2011-07-01

    The State of Colorado expressed an interest in assessing the potential for photovoltaic (PV) solar installations on non-irrigated corners of center-pivot irrigation (CPI) fields throughout the state. Using aerial imagery and irrigated land data available from the Colorado Water Conservation Board, an assessment of potentially suitable sites was produced. Productivity estimates were calculated from that assessment. The total area of non-irrigated corners of CPI fields in Colorado was estimated to be 314,674 acres, which could yield 223,418 acres of installed PV panels assuming 71% coverage in triangular plots. The total potential annual electricity production for the state was estimated to be 56,821 gigawatt hours (GWH), with an average of 1.3 GWH per available plot.

  8. Economic feasibility of converting center pivot irrigation to subsurface drip irrigation

    Science.gov (United States)

    Advancements in irrigation technology have increased water use efficiency. However, producers can be reluctant to convert to a more efficient irrigation system when the initial investment costs are high. This study examines the economic feasibility of replacing low energy precision application (LEPA...

  9. Evaluation of water distribution under pivot irrigation systems using remote sensing imagery in eastern Nile delta

    Directory of Open Access Journals (Sweden)

    E. Farg

    2017-04-01

    Full Text Available Traditional methods for center pivot evaluation depend on the water depth distribution along the pivot arm. Estimation and mapping the water depth under pivot irrigation systems using remote sensing data is essential for calculating the coefficient of uniformity (CU of water distribution. This study focuses on estimating and mapping water depth using Landsat OLI 8 satellite data integrated with Heerman and Hein (1968 modified equation for center pivot evaluation. Landsat OLI 8 image was geometrically and radiometrically corrected to calculate the vegetation and water indices (NDVI and NDWI in addition to land surface temperature. Results of the statistical analysis showed that the collected water depth in catchment cans is also highly correlated negatively with NDVI. On the other hand water, depth was positively correlated with NDWI and LST. Multi-linear regression analysis using stepwise selection method was applied to estimate and map the water depth distribution. The results showed R2 and adjusted R2 0.93 and 0.88 respectively. Study area or field level verification was applied for estimation equation with correlation 0.93 between the collected water depth and estimated values.

  10. Effects of two types of sprinklers and height in the irrigation of sugar beet with a centre pivot

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J. N.; Tarjuelo, J. M.; Juan, J. A. de

    2012-11-01

    The main objective of this paper is to analyse the effects of sprinkler type and height above the ground on soil water uniformity (CUs) and sugar beet yield. Irrigation was performed with a centre pivot operating under field conditions with two types of sprinklers, one with a stationary plate (SPS) and the other with a moving plate (MPS), at two heights (1 and 2.5 m). The average coefficient of uniformity (CU) of water application of individual irrigation events with SPS ranged from 74 to 81%, compared to nearly 90% from MPS. The value of the cumulative coefficient of uniformity for the set of irrigation events (CUa) for all sprinkler-height combinations exceeded 90%, a value similar to that obtained for CUS. Results do not show a clear advantage in the final crop response by using sprinklers with MPS or SPS. However, MPS, and especially those located at 1 m in height with a spacing of 1.5 m, have higher water application uniformity, achieving higher yield and yield indexes, as well as higher water use efficiency. The final yield of sugar beet was more influenced by the amount of soil water available for the crop than the small differences in soil water uniformity obtained with the centre pivot. (Author) 62 refs.

  11. Manejo da irrigação em pastagem irrigada por pivô-central Irrigated pasture: water management under center pivot irrigation

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    Alexandre C. Xavier

    2004-12-01

    Full Text Available A aplicação de lâminas de irrigação em pastagem irrigada sob pivô-central é, de maneira geral, realizada sem um critério técnico pertinente ao sistema, pois se deve considerar que para um mesmo período a pastagem se encontra em diferentes estádios de desenvolvimento em cada parcela, apresentando taxas de evapotranspiração diferenciadas dentro da área irrigada; todavia, usualmente se aplica uma única lâmina para toda a área. Neste trabalho foi desenvolvido um modelo para aplicação de lâminas de irrigação distinta para cada parcela do pivô o qual, de modo geral, considera: i a capacidade do pivô-central de aplicar lâminas distintas na área; ii o nível de desenvolvimento da cultura em cada parcela; iii o período de retorno do gado a determinada parcela (ciclo de pastejo; e iv o potencial de desenvolvimento da pastagem de certa região. Para modelar o coeficiente de cultura (Kc foram utilizadas duas metodologias, a primeira com taxa de variação do Kc constante com o número de dias em que a parcela está em descanso (k, e a segunda, com taxa de variação do Kc na forma senoidal com k. O modelo foi aplicado para pastagens hipotéticas nas regiões de Piracicaba e Pereira Barreto, para avaliação e, como resultado, observou-se que o modelo se mostrou sensível ao nível de desenvolvimento de cada parcela e às condições de variação do clima de cada região.The application of irrigation depths in irrigated pasture under center pivot machines, in a general way, is accomplished without a pertinent technical criterion, because it should be considered that for any time period, the pasture plots are at different development stages (rotary pasture, presenting different evapotranspiration rates inside the irrigated area. Furthermore, farmers usually apply a single irrigation depth for the whole area. In this study a model was developed for the application of different irrigation depths in each portion of the pivot (pizza

  12. Development of a methodology for the evaluation of energy efficiency of central irrigation pivots; Desenvolvimento de uma metodologia para a avaliacao da eficiencia energetica de pivos centrais de irrigacao

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Aureo Cezar de [Centro Federal de Educacao Tecnologica de Petrolina (CEFET-Pet), PE (Brazil); Guimaraes Junior, Sebastiao Camargo; Camacho, Jose Roberto; Salerno, Carlos Henrique [Universidade Federal de Uberlandia (NERFAE/UFU), MG (Brazil). Fac. de Engenharia Eletrica. Nucleo de Eletricidade Rural e Fontes Alternativas de Energia

    2006-07-01

    It will be presented in this work a methodology for the evaluation of the energy efficiency of irrigation center systems by central pivot. Integrating water efficiency application with the energy associated to the sprinklers, adduction pipeline, pivot arm and pump systems, the proposed indexes make possible to evaluate the energy income of each component of the irrigation system, contributing for the increase of the global efficiency of the irrigated agriculture. (author)

  13. Evaluation and analysis of the energetic efficiency of center pivot irrigation systems; Avaliacao e analise da eficiencia energetica na irrigacao em sistemas pivo central

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Aureo C. de [Universidade Federal da Grande Dourados (UFGD), Dourados, MS (Brazil). Unidade II], email: aureolima@ufgd.edu.br; Guimaraes Junior, Sebastiao C.; Camacho, Jose R. [Universidade Federal de Uberlandia (UFU), MG (Brazil). Nucleo de Energia Rural e Fontes Alternativas de Energia], emails: scguimaes@ufu.br, jrcamacho@ufu.br; Fietz, Carlos R. [EMBRAPA Agropecuaria Oeste, Dourados, MS (Brazil)], email: fietz@cpao.embrapa.br

    2009-07-01

    With an irrigated area of approximately 710,500 ha in Brazil, it is possible to estimate an annual electricity consumption of 1,928 G Wh per year due to center pivot systems. Considering the need of optimization of the irrigated agricultural production, the energies that are dissipated in the suction pipes, water supply, lateral lines and sprinkler systems are analyzed in this study and an equation is proposed to determine the useful power of center pivot irrigation systems. Three center pivot systems located in Itamarati I (a Government settlement for the landless in the city of Ponta Pora, State of Mato Grosso do Sul, Brazil) were evaluated and measures of energetic efficiency were simulated in order to determine a viable economic configuration to meet the life span of the equipment. The systems were characterized by the energy use and results show that the average irrigation energetic efficiency may be raised from 14.9 to 25.9% leading to a possible reduction of R$ 118,800 per year over 7,200 ha, equivalent to 11% of the yearly expenses with electricity of the whole area. (author)

  14. Cost of electric energy in irrigated dry bean for center pivot, affected by the irrigation management and tillage systems; Custo de energia eletrica em cultura do feijoeiro irrigado por pivo central, afetado pelo manejo da irrigacao e sistemas de cultivo

    Energy Technology Data Exchange (ETDEWEB)

    Turco, Jose E.P.; Rizzatti, Gilcileia dos S.; Pavani, Luiz C. [UNESP/FCAV, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias

    2009-04-15

    The objective of this work was to analyze the consumption and cost of electric energy in dry bean crop, IAC-Carioca, irrigated by center pivot, submitted to two irrigation managements: tensiometry and climatological water balance with Class A pan, under conventional and no-tillage systems, grown in Oxisol, in the year of 2002. The research was developed at the Demonstrative and Experimental Area of Irrigation - ADEI, of FCAV/UNESP, Campus of Jaboticabal - SP, Brazil. The irrigation system electric energy consumption was monitored for two tariff groups: A and B. The prices of kWh of the tariff systems of electric energy had been gotten in the CPFL (Sao Paulo Company of Force and Light). The treatments where the irrigation management was carried through the method of the Class A pan showed higher consumption and cost of electric energy, in relation to the treatments where the management was carried through tensiometry; for the tillage systems it had not been observed differences. The green and/or blue tariff with discount was the best option for the four treatments. (author)

  15. Qualidade da irrigação controlada por tensiômetros em pivô central Quality of center pivot irrigation controlled by tensiometers

    Directory of Open Access Journals (Sweden)

    A.M. Saad

    1994-12-01

    Full Text Available A qualidade da irrigação foi avaliada durante a safra de inverno do ano de 1988 na cultura do feijoeiro (Phaseolus vulgaris L., irrigado por pivô central, em área de ocorrência de Latossolo Roxo (A moderado, textura argilosa a muito argilosa, distrófico, em Guaíra, SP. Os critérios utilizados para esta avaliação foram a eficiência do uso da água pela cultura e a efetividade da irrigação, esta última representada pela eficiência de aplicação da água, a uniformidade de distribuição da água sobre o solo e a eficiência de armazenagem da água no solo. O monitoramento das irrigações foi realizado através da instalação de 20 baterias de tensiômetros e 60 coletores de água de chuva e irrigação ao longo de uma transeção de 300 metros na direção radial do pivô. Os tensiômetros de cada bateria foram instalados a 15 cm e 30 cm de profundidade e espaçados entre si de 15 metros. Os coletores foram instalados a uma altura de 50 cm da superfície do terreno e distanciados entre si de 5 metros. O controle da irrigação foi feito com base na média ponderada dos 20 valores diários de potencial mátrico a 15 cm de profundidade, tendo como fator de ponderação a área representativa de cada tensiômetro. O valor mínimo de potencial mátrico estabelecido para a definição do momento da irrigação foi -0,06 MPa à profundidade de 15 cm e o valor da lâmina de água a ser aplicada em cada irrigação, calculado tendo-se em conta o valor de -0,008 MPa para o potencial mátrico a capacidade de campo. Os resultados obtidos mostraram que as irrigações efetuadas foram de alta qualidade uma vez que foram elevados os valores da eficiência de aplicação (80% e dos coeficientes de uniformidade de distribuição (94 e 91% calculados a partir das 16 irrigações acumuladas, o mesmo ocorrendo com a eficiência de armazenagem (95% e a eficiência de uso da água (0,8 kg/m³.The irrigation quality was evaluated for a center pivot

  16. Desempenho e uniformidade da distribuição de água de um pivô central Performance of a center pivot irrigation system and irrigation distribution uniformity

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Cainelli

    1998-03-01

    Full Text Available O objetivo deste experimento foi avaliar as características de desempenho de um equipamento de irrigação pivô central, de baixa pressão, bem como determinar a uniformidade de distribuição de água, tanto abaixo como acima da superfície do solo. Para a avaliação do desempenho do sistema utilizaram-se os coeficientes de uniformidade de Christiansen (CUC e de distribuição (CUD, calculados a partir de dados da precipitação dos aspersores. O pivô central foi ensaiado nas velocidades de 25%, 50%, 75% e 100% da velocidade máxima de deslocamento do equipamento. Utilizou-se quatro linhas de coletores, uniformemente espaçados. Os valores encontrados do CUC e o CUD foram superiores ao mínimo recomendado para a cultura do milho, confirmando o bom desempenho do pivô central. Em todas as profundidades do solo estudadas os coeficientes de uniformidade foram superiores aos obtidos acima do solo, ocorrendo um aumento nos valores dos coeficientes de uniformidade abaixo da superfície do solo com o tempo.The objective of this work was to evaluate some characteristics of a center pivot irrigation system equipament, as well as to determine the water distribuition uniformity, under and over the soil surface. The Christiansen uniformity coefficient (CUC and distribuition (CUD were used to evaluate the system. A low pressure center pivot was tested in four different speeds: 25%, 50%, 75% and 100% of the timer sensor, and in four collectors Unes spaced. Results indicated that both coeficients presented good performance. The values of CUC and CUD were above the minimum recommended for na irrigated corn field. The uniformity coefficients in all depths of the soil were higher than the above the soil surface. Howerer, the uniformity under soil surface increased with the time in all depths.

  17. Circles of live buffer strips in a center pivot to improve multiple ecosystem services and sustainability of irrigated agriculture in the southern great plains

    Science.gov (United States)

    Declining Ogallala Aquifer has threatened sustainability of highly productive irrigated agriculture in the region. The region, known for the dust bowl of thirties, is scared of its return. Lower well outputs and increasing pumping costs have compelled farmers to adapt alternative conservation strate...

  18. Parâmetros de desempenho de dezesseis equipamentos de irrigação por pivô central Parameters of performance of sixteen center-pivot irrigation equipments

    Directory of Open Access Journals (Sweden)

    Delvio Sandri

    2009-02-01

    Full Text Available O tempo de uso de sistemas de irrigação por pivô central pode resultar em alteração de suas características hidráulicas, necessitando de avaliações periódicas para manter a uniformidade de distribuição de água em níveis aceitáveis. Objetivou-se, neste trabalho, avaliar as condições de funcionamento e desempenho de dezesseis pivôs centrais, localizados em onze municípios de Goiás e no Distrito Federal. Estimou-se o coeficiente de uniformidade de Heermann & Hein - CUH e uniformidade de distribuição - CUD, variação da lâmina coletada em relação à projetada e os fatores que interferem no desempenho dos equipamentos. Dos pivôs avaliados, quatro (25% apresentaram CUH inadequado (The time of use of the center-pivot irrigation system may result in alteration of the hydraulic characteristics, frequent evaluations being needed to maintain the efficiency of water distribution at acceptable levels. The aim of this work was to evaluate the conditions of the use and the performance of sixteen center pivots, located in eleven municipal districts of Goiás State and Federal District, Brazil. The Heermann & Hein - CUH coefficient of uniformity and coefficient of distribution - CUD, variation between the collected and projected depth and verification of the main factors that influenced the performance were evaluated. Among the evaluated pivots, four (25% presented inadequate CUH (< 80% and three (18.75% presented inadequate CUD (< 70%. The average depth applied was higher than the projected in three and lower in thirteen pivots, with the difference higher than 10% in only one pivot. Most of the evaluated pivots need maintenance to solve the following problems: emitters with flow rate different from the flow considered appropriate for some intervals of the equipments; emitters totally or partially clogged or damaged; absence of suspension strings; damaged pressure regulators; leaks in several points and speed displacement different

  19. Irrigation System

    Science.gov (United States)

    1984-01-01

    Under contract with Marshall Space Flight Center, Midwest Research Institute compiled a Lubrication Handbook intended as a reference source for designers and manufacturers of aerospace hardware and crews responsible for maintenance of such equipment. Engineers of Lindsay Manufacturing Company learned of this handbook through NASA Tech Briefs and used it for supplemental information in redesigning gear boxes for their center pivot agricultural irrigation system.

  20. Economic viability of retrofiting emitters in center pivot irrigation systems Viabilidade econômica da troca de emissores em sistemas de irrigação tipo pivô central

    Directory of Open Access Journals (Sweden)

    Cornélio A. Zolin

    2012-06-01

    Full Text Available Although several studies have been conducted to evaluate the uniformity of water application under center pivot irrigation systems, there are few studies concerning the economic perspective of such coefficient. The aim of this study is to present a methodology to accomplish an economic analysis as support for the decision-making to retrofit emitters in center pivot irrigation systems, and to attribute an economic meaning to the uniformity coefficient of water application taking into account the response function productivity to the amount of water applied and the sale price of the crops. In the hypothetic calculation example considering the variation of revenue of potato crop under center pivot irrigation system, it was verified that the area with uniformity coefficient of water application of 90% brought an income increase of BR$ 1,992.00, considering an area about 1,0 ha. Thus, it can be concluded that the methodology presented has met the objectives proposed in the study and made it possible to attribute an economical meaning to the coefficient of water uniformity application.Embora vários estudos tenham sido conduzidos para a avaliação da uniformidade de aplicação de água por equipamentos de irrigação do tipo pivô central, são escassos os trabalhos que tenham analisado de um ponto de vista econômico o significado de tal coeficiente. Objetivou-se com o presente trabalho apresentar uma metodologia de análise econômica como auxílio na tomada de decisão para troca de emissores de sistemas de irrigação tipo pivô central e atribuir um significado econômico ao coeficiente de uniformidade de aplicação de água, levando-se em consideração a função de resposta da cultura à lâmina de água aplicada e o preço de venda dos produtos agrícolas. No exemplo hipotético de cálculo, considerando-se a diferença na renda obtida com a cultura da batata irrigada com coeficiente de uniformidade de 90% e 70%, respectivamente, verificou

  1. Produtividade e rendimento do cafeeiro nas cinco primeiras safras irrigado por pivô central em Lavras, MG Coffee yield and production during the initial five harvests under irrigation with center pivot in Lavras, MG

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    Luiz Antônio Lima

    2008-12-01

    foi de 225,6 sc e a média anual de 45,12 sc ha-1, com acréscimo de 119% na produtividade do cafeeiro quando comparada ao tratamento não irrigado, que produziu, em média, 24 sc ha-1 ano-1. O grau de maturação, no momento da colheita, influenciou o rendimento dos tratamentos, sendo os frutos nos estádios cereja e seco, os que mais interferiram no rendimento.Search for sustainability on agricultural exploration and incorporation of new technologies impose the necessity for knowledge and management of main factors related to production, such as irrigation. This experiment evaluated the irrigation effect on yield and production efficiency (amount of beans to produce a bag of 60Kg of coffee irrigated by center pivot in Lavras-MG, Brazil. The experiment was planted with the cultivar Rubi MG-1192, planted on March, 1999. spaced 3.5 meters between rows and 0.8 meters between plants. The experimental design was the one of randomized blocks, with six treatment levels and three replicates. The irrigation was applied at intervals of 2 or 3 days, on Mondays, Wednesdays and Fridays, based on the amount estimated by the water blance considering the class A pan evaporation (ECA and rain depths. The irrigation was calculated as 0% of the difference between ECA and rain depth - 0% ECA (T1, non irrigated, 60% ECA (T2, 80% ECA (T3, 100% ECA (T4, 120% ECA (T5 and 140% ECA (T6. After harvesting the coffee grains from the experimental plots, coffee samples were packed in ventilated plastic bags and dried on wood benches exposed to air long enough to decrease its moisture content between 11 and 12%, gravimetric water content. After drying, the beans were unpeeled and weighed to calculate the yield and production efficiency. Irrigation increased the yield of irrigated plots compared to non irrigated. Although non significant difference was statistically observed when comparing annual yields, the differences were statistically significant when the total production was compared among

  2. Variabilidade espacial de micronutrientes em solo sob pivô central no sul do Estado de Mato Grosso Spatial variability of microelements in soil under center pivot irrigation system in southern Mato Grosso State, Brazil

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    Eduardo Guimarães Couto

    1999-12-01

    Full Text Available Este estudo foi desenvolvido para identificar, caracterizar e comparar a estrutura da dependência espacial dos micronutrientes boro, cobre, ferro, manganês e zinco solúveis em um Latossolo Vermelho-Escuro sob pivô central após 14 anos de uso intensivo, no sul do Estado de Mato Grosso. O esquema de amostragem consistiu de coletas de 132 amostras com espaçamento regular de 167 m, especialmente idealizado para determinar a variabilidade espacial em distância de até 1 m. Com exceção do zinco, o uso intensivo propiciou um aumento significativo nas concentrações desses nutrientes na camada mais afetada pelo manejo (0-20 cm, mesmo assim insuficientes para atingir o nível crítico estabelecido para a região. Cerca de 95% das amostras de boro, 75% das amostras de cobre, 95% das amostras de manganês e 1,5% das amostras de zinco apresentaram valores abaixo do nível crítico, distribuídos diferentemente pelos quadrantes, o que mostra que as práticas de fertilização e/ou as operações de preparo de solo não foram eficientes na distribuição e homogeneização dos fertilizantes.This study was carried out to identify, characterize and compare spatial structures of boron, copper, iron, manganese and zinc in a Dark-Red Latosol under crop field intensively managed for 14 years with a center pivot irrigation system in the Southern Mato Grosso State, Brazil. The soil sampling scheme, consisting of 132 systematic sampling, in which sampling points were located at regular intervals of 167 m, in such a way that it was possible to determine the soil variability at 1 m distance. The result showed that, with exception of the zinc, the intensive land use increased significantly the nutrients concentration in the upper layer, however it was insufficient to reach the critical level established for the region. About 95% of boron samples, 75% of copper samples, 95% of manganese samples and 1.5% of zinc samples presented values below the critical level

  3. Desenvolvimento de software e hardware para irrigação de precisão usando pivô central Development of software and hardware for precision irrigation using the center pivot

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    Tadeu M. de Queiroz

    2008-03-01

    Full Text Available O presente trabalho teve por objetivo desenvolver softwares e hardwares para aplicação ao monitoramento e controle automático para a irrigação de precisão usando sistemas do tipo pivô central. O trabalho foi desenvolvido no Departamento de Engenharia Rural - LER, da Escola Superior de Agricultura "Luiz de Queiroz" - ESALQ, da Universidade de São Paulo - USP, em Piracicaba - SP. Foram utilizados componentes eletrônicos discretos, circuitos integrados diversos, módulos de radiofreqüência, microcontroladores da família Basic Step e um microcomputador. Foram utilizadas as linguagens Delphi e TBasic. O hardware é constituído de dois circuitos eletrônicos, sendo um deles para "interface" com o computador e o outro para monitoramento e transmissão da leitura de tensiômetros para o computador via radiofreqüência. Foram feitas avaliações do alcance e da eficiência na transmissão de dados dos módulos de radiofreqüência e do desempenho do software e do hardware. Os resultados mostraram que tanto os circuitos quanto os aplicativos desenvolvidos apresentaram funcionamento satisfatório. Os testes de comunicação dos rádios indicaram que esses possuem alcance máximo de 50 m. Concluiu-se que o sistema desenvolvido tem grande potencial para utilização em sistemas de irrigação de precisão usando pivô central, bastando para isso que o alcance dos rádios seja aumentado.The objective of this work was to develop softwares and hardwares applied to the management and automatic control for precision irrigation using center pivot systems. They were developed in the Rural Engineering Department - LER, at the "Luiz de Queiroz" College of Agriculture - ESALQ, of São Paulo University - USP, in Piracicaba, SP-Brazil. It was used discrete electronic components, several integrated circuits, radio frequency modules, microcontrollers from the Basic Step family and a microcomputer. The computer software was developed in Delphi language, and

  4. Uso de motores monofásicos acoplados mecanicamente em série, em irrigação por pivô central Utilization of mechanically coupled single phase motors in series in central pivot irrigation system

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    Delly Oliveira Filho

    2005-03-01

    Full Text Available A utilização de sistemas de irrigação por pivô central requer elevada potência elétrica, o que, em geral, implica em alto investimento inicial. No Brasil, a maioria das fazendas é eletrificada no sistema monofásico, devido ao fato de sua implantação requerer cerca de 40% do investimento inicial exigido pelo sistema trifásico. Salienta-se que a maior potência disponível no mercado de motores monofásicos no Brasil é de 9,2 kW (12,5 cv. Para suprir demanda de potência acima desta com sistema monofásico, propõe-se acoplar os motores monofásicos mecanicamente em série. Este trabalho teve como objetivo estimar o rendimento de um sistema de acoplamento e sua viabilidade técnico-econômica, comparado-o com outras formas de fornecimento de energia, diesel e sistema elétrico trifásico.The utilization of central pivot irrigation system requires in most cases high electric power which imply in high initial investment. Most of the Brazilian farms are electrified in the single phase electrical system, due to the fact that their implementation requires only about 40% of the initial investment as compared to three phase system. In Brazilian market the highest available power of single phase motors is 9.2 kW (12.5 hp. To supply power demand above this limit with single phase system one could couple mechanically the single phase motors in series. The objective of this work was to estimate the efficiency of such coupling system and to evaluate the economic and technical feasibility compared with other forms of energy supply such as diesel and three phase electrical system.

  5. Comprender: propuesta de pivotes

    Directory of Open Access Journals (Sweden)

    Santiago Alonso

    2011-06-01

    Full Text Available How do we understand? A pivot proposalThe basic question is what it is needed to understand. The proposal is that understanding requires pivots, a useful word to integrate findings in different areas. In that sense, a pivot can be understood as a mental model. It can also be the body, an idea based on embodied cognition. But more fundamentally, our biology and brain are the central pivots for understanding. Therefore, this essay can be seen as a brief travel through three different subjects: Mental Models, Embodied Cognition and Cognitive Neuroscience, all of which are necessary to understand how a person understands.

  6. Spatial variability of soil texture in pivot irrigated area in different landscape positions = Variabilidade espacial da textura do solo em área irrigada por pivô central em diferentes posições na paisagem

    Directory of Open Access Journals (Sweden)

    Guilherme Adalberto Ferreira Castione

    2015-10-01

    Full Text Available The landscape configuration favors the understanding of the behavior of textural attributes being influenced to a lesser extent by the strand segments because the migration of sediments, water and nutrients meet the surface geological processes and to weathering. This study aim to characterize the spatial variability of texture in an irrigated area by center pivot in different positions in the landscape in the Crystalline, state GO region. Soil samples were taken at regular intervals of 10 m, shaped mesh, totaling 180 sampling points in different positions in the landscape. Samples were collected at depths of 0.00 to 0.10 m, 0.10-0.20 0.20-0.30 m me for the determination of clay, silt and sand. The data were submitted to descriptive statistics, geostatistics and kriging interpolation. The results demonstrate that migration occurred particles followed the flow of water present in causing the selective transport of sediment, which would imply higher erosion sediments, water and nutrients. The shed forms conditioned the movement and concentration of soil particles. The migration of clay to subsurface soil layers is related to the genesis of the soil and carrying of. = A configuração da paisagem favorece o entendimento do comportamento dos atributos texturais, sendo influenciada em menor escala pelos segmentos de vertente, pois a migração de sedimentos, água e nutrientes obedecem aos processos geológicos superficiais e ao intemperismo. Diante disso, objetivou-se com esse trabalho caracterizar a variabilidade espacial da textura em uma área irrigada por pivô central em diferentes posições na paisagem da região de Cristalina-GO. Foram realizadas amostragens do solo em intervalos regulares de 10 m, em forma de malha, totalizando 180 pontos, em diferentes posições da paisagem. As amostras foram coletadas s nas profundidades de 0,00-0,10 m, 0,10-0,20 m e 0,20-0,30 m para a determinação dos teores de argila, silte e areia. Os dados foram

  7. Determination of kinetic energy applied by center pivot sprinklers

    Science.gov (United States)

    The kinetic energy of discrete drops impacting a bare soil surface is generally observed to lead to a drastic reduction in water infiltration rate due to soil surface seal formation. Under center pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can...

  8. Droplet Kinetic Energy from Center-Pivot Sprinklers

    Science.gov (United States)

    The kinetic energy of discrete water drops impacting a bare soil surface is generally observed to lead to a drastic reduction in water infiltration rate due to soil surface seal formation. Under center-pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy developmen...

  9. en los pivotes centrales

    Directory of Open Access Journals (Sweden)

    Reynaldo Roque Rodés

    2005-01-01

    Full Text Available Se hace una revisión y comentarios sobre las ventajas y limitantes del empleo del LEPA (Low Enery Precision Aplication en los sistemas de riego de pivotes centrales. Estos sistemas o filosofía de manejo del agua para condiciones de escasez o mala calidad del líquido es una alternativa viable para la producción de alimentos. Introducida en la década del 80 en las planicies del sur de Texas, donde la alta evaporación del agua y la necesidad de regar grandes áreas con pivotes centrales obligaba a la búsqueda de una alternativa para incrementar al máximo la eficiencia de aplicación del riego. Aún en fase de estudio e introducción en Cuba para áreas específicas, puede ser una solución de incremento de los rendimientos de los cultivos, empleando menos agua y aguas con calidad limitada

  10. Automation of a center pivot using the temperature-time-threshold method of irriation scheduling

    Science.gov (United States)

    A center pivot was completely automated using the temperature-time-threshold (TTT) method of irrigation scheduling. An array of infrared thermometers was mounted on the center pivot and these were used to remotely determine the crop leaf temperature as an indicator of crop water stress. We describ...

  11. Analysis of Pivot Sampling in Dual-Pivot Quicksort

    DEFF Research Database (Denmark)

    Nebel, Markus E.; Wild, Sebastian; Martinez, Conrado

    2016-01-01

    The new dual-pivot Quicksort by Vladimir Yaroslavskiy—used in Oracle’s Java runtime library since version 7—features intriguing asymmetries. They make a basic variant of this algorithm use less comparisons than classic single-pivot Quicksort. In this paper, we extend the analysis to the case where...

  12. Fertigation - Injecting soluble fertilizers into the irrigation system

    Science.gov (United States)

    Thomas D. Landis; Jeremy R. Pinto; Anthony S. Davis

    2009-01-01

    Fertigation (fertilization + irrigation) is the newest way for nursery managers to apply fertilizer, and has become a standard practice in container nurseries. Because of the inherent inefficient water distribution patterns in field irrigation systems, fertigation has not been widely used in bareroot nurseries. However, a bareroot nursery with a center-pivot irrigation...

  13. Technical descriptions of ten irrigation technologies for conserving energy

    Energy Technology Data Exchange (ETDEWEB)

    Harrer, B.J.; Wilfert, G.L.

    1983-05-01

    Technical description of ten technologies which were researched to save energy in irrigated agriculture are presented. These technologies are: well design and development ground water supply system optimization, column and pump redesign, variable-speed pumping, pipe network optimization, reduced-pressure center-pivot systems, low-energy precision application, automated gated-pipe system, computerized irrigation scheduling, and instrumented irrigation scheduling. (MHR)

  14. Efficient irrigation management with conventional and VRI sprinkler systems

    Science.gov (United States)

    In Alabama, there is a ploitical push towards irrigated agriculture, as reduction in water resources for agriculture in the West becomes more limited. Some farmers have invested in center pivot systems but have little experience with irrigation scheduling methods. ARS scientists at Bushland have e...

  15. How Good Is Multi-Pivot Quicksort?

    DEFF Research Database (Denmark)

    Aumüller, Martin; Dietzfelbinger, Martin; Klaue, Pascal

    2016-01-01

    Multi-Pivot Quicksort refers to variants of classical quicksort where in the partitioning step k pivots are used to split the input into k + 1 segments. For many years, multi-pivot quicksort was regarded as impractical, but in 2009 a two-pivot approach by Yaroslavskiy, Bentley, and Bloch was chosen...... for multi-pivot quicksort are devised and analyzed. The analysis shows that the benefits of using multiple pivots with respect to the average comparison count are marginal and these strategies are inferior to simpler strategies such as the well-known median-of-k approach. A substantial part...

  16. A review of mechanical move sprinkler irrigation control and automation technologies

    Science.gov (United States)

    Electronic sensors, equipment controls, and communication protocols have been developed to meet the growing interest in site-specific irrigation using center pivot and lateral move irrigation systems. Onboard and field-distributed sensors can collect data necessary for real-time irrigation manageme...

  17. HPC s Pivot to Data

    Energy Technology Data Exchange (ETDEWEB)

    Parete-Koon, Suzanne [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Caldwell, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Canon, Richard Shane [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Dart, Eli [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Sciences Network (ESnet); Hick, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Hill, Jason J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Layton, Chris [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Pelfrey, Daniel S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Shipman, Galen M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Skinner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Nam, Hai Ah [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Wells, Jack C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Zurawski, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Sciences Network (ESnet)

    2014-05-03

    Computer centers such as NERSC and OLCF have traditionally focused on delivering computational capability that enables breakthrough innovation in a wide range of science domains. Accessing that computational power has required services and tools to move the data from input and output to computation and storage. A ''pivot to data'' is occurring in HPC. Data transfer tools and services that were previously peripheral are becoming integral to scientific workflows. Emerging requirements from high-bandwidth detectors, high-throughput screening techniques, highly concur- rent simulations, increased focus on uncertainty quantification, and an emerging open-data policy posture toward published research are among the data-drivers shaping the networks, file systems, databases, and overall compute and data environment. In this paper we explain the pivot to data in HPC through user requirements and the changing resources provided by HPC with particular focus on data movement. For WAN data transfers we present the results of a study of network performance between centers.

  18. Pivotal Response Treatment: Case Reports.

    Science.gov (United States)

    Ventola, Pamela; Friedman, Hannah; Oosting, Devon

    2015-01-01

    The current paper provides an overview of an evidence-based treatment, Pivotal Response Treatment (PRT), for autism spectrum disorder (ASD). The paper describes PRT principles and then illustrates the approach using two case reports. The children are preschool-aged children with high-functioning ASD. They were participating in a four-month clinical trial of PRT. At the start of treatment, they presented with significant social communication impairments, including a minimal understanding of reciprocity, limited play skills, and repetitive behaviors and speech. The paper outlines how behavioral treatment goals were identified and then how activities were designed, using principles of PRT, to target skill acquisition. Following the treatment course, both children made substantial and meaningful gains in social communication skill development.

  19. Novel approach to evaluate the dynamic variation of wind drift and evaporation losses under moving irrigation systems

    Science.gov (United States)

    Sayed-Hossein Sadeghi; Troy R. Peters; Mohammad Z. Amini; Sparkle L. Malone; Hank W. Loescher

    2015-01-01

    The increased need for water and food security requires the development of new approaches to save water through irrigation management strategies, particularly for center pivot irrigation. To do so entails monitoring of the dynamic variation in wind drift and evaporation losses (WDELs) of irrigation systems under different weather conditions and for relatively long time...

  20. Extending Teach and Repeat to Pivoting Wheelchairs

    Directory of Open Access Journals (Sweden)

    Guillermo Del Castillo

    2003-02-01

    Full Text Available The paper extends the teach-and-repeat paradigm that has been successful for the control of holonomic robots to nonholonomic wheelchairs which may undergo pivoting action over the course of their taught movement. Due to the nonholonomic nature of the vehicle kinematics, estimation is required -- in the example given herein, based upon video detection of wall-mounted cues -- both in the teaching and the tracking events. In order to accommodate motion that approaches pivoting action as well as motion that approaches straight-line action, the estimation equations of the Extended Kalman Filter and the control equations are formulated using two different definitions of a nontemporal independent variable. The paper motivates the need for pivoting action in real-life settings by reporting extensively on the abilities and limitations of estimation-based teach-and-repeat action where pivoting and near-pivoting action is disallowed. Following formulation of the equations in the near-pivot mode, the paper reports upon experiments where taught trajectories which entail a seamless mix of near-straight and near-pivot action are tracked.

  1. Developing wind and/or solar powered crop irrigation systems for the Great Plains

    Science.gov (United States)

    Some small scale, off-grid irrigation systems (less than 2.5 ha) that are powered by wind or solar energy are cost effective, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. It was found that partitioning t...

  2. Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains

    Science.gov (United States)

    Some small scale irrigation systems (powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind...

  3. Climate Change Impacts of Irrigation on the Central High Plains

    Science.gov (United States)

    Cotterman, K. A.; Kendall, A. D.; Basso, B.; Hyndman, D. W.

    2015-12-01

    Since the 1940s, the High Plains Aquifer (HPA) has been pivotal for irrigation over the Central High Plains (CHP), a region spanning parts of five states in the central U.S.. Today after decades of over-pumping, many areas of the CHP are no longer able to irrigate due to localized depletion of the HPA. With a range of global climate models predicting an increase in temperature and decrease in growing-season precipitation for the CHP, demand for irrigation is likely to increase and exacerbate drawdown and depletion of the aquifer. Here we apply the Landscape Hydrology Model (LHM) coupled with the crop simulation model SALUS to simulate irrigation water use in response to historical climate and land use. This model is validated using historical groundwater levels. We then simulate future climate scenarios to predict how irrigation demand and water availability will alter the hydrology of the CHP. This study provides a predictive relationship of future irrigation demand linked to both climate change and agricultural management, and presents a modeling approach to answer two questions: How will future climate change affect irrigation demand? How will climate change and irrigation demand affect groundwater availability for the future? Different climate scenarios based on the representative concentration pathways (RCPs) are used to simulate the impact of different projected future climate conditions through the year 2100. By examining predicted groundwater levels along with saturated thickness we analyze where irrigation is likely to be viable in the future and compare this to current irrigation extent.

  4. Using Cotton Model Simulations to Estimate Optimally Profitable Irrigation Strategies

    Science.gov (United States)

    Mauget, S. A.; Leiker, G.; Sapkota, P.; Johnson, J.; Maas, S.

    2011-12-01

    In recent decades irrigation pumping from the Ogallala Aquifer has led to declines in saturated thickness that have not been compensated for by natural recharge, which has led to questions about the long-term viability of agriculture in the cotton producing areas of west Texas. Adopting irrigation management strategies that optimize profitability while reducing irrigation waste is one way of conserving the aquifer's water resource. Here, a database of modeled cotton yields generated under drip and center pivot irrigated and dryland production scenarios is used in a stochastic dominance analysis that identifies such strategies under varying commodity price and pumping cost conditions. This database and analysis approach will serve as the foundation for a web-based decision support tool that will help producers identify optimal irrigation treatments under specified cotton price, electricity cost, and depth to water table conditions.

  5. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  6. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  7. Developing a Simple Unique Head-Discharge Equation for Pivot Weirs with Different Side Contractions

    Directory of Open Access Journals (Sweden)

    neda Sheikh Rezazadeh Nikou

    2016-10-01

    Full Text Available Introduction: Pivot weirs (sharp crested inclined weirs, Fig. 1-a is frequently used for discharge measurement, controlling water surface and flow diversion. Some typical features of pivot weirs are: (a overshot design for better water level control, (b Their application as head gates, turnout or check structure which requiring low head loss and high accuracy, (c ease of removing sediment deposit behind the weir, and (d ability to manage and monitor on-site or operating remotely when connected to a supervisory control and data acquisition (SCADA network. Kindsvater and Carter (8 derived a weir discharge equation based on energy and continuity equations. Hulsing (4 determined head-discharge relationship of inclined suppressed sharp crested weir with the slope of 3:3, 2:3 and 1:3 toward downstream and compared them with the equivalent normal sharp crested weir. In the USBR report on pivot weirs (regarding The Boulder Canyon Project,1948 the head discharge data of the suppressed pivot weir were presented in a channel with 5.5m length, 2.9m depth and 0.61m width. Some field experiments were also carried out in the IID (Imperial Irrigation District on a trapezoidal cross-section (0.61 m bottom width channel with pivot weir of 1.7m length, and two different widths of 1.63m. The flow rate (350-880 lit/s was held constant and different angles (15-50° calibrated instead of holding the angle constant and varying the flow rate. Some other laboratory tests were performed with Wahlin and Replogle (1994 on two pivot weirs with 1.2 m and 1.14 m width for the 0.61 m and 0.46 m length of blade and contraction factor of 0.925. RUBICON Company established an extensive operation on the application and automation of pivot weirs in irrigation channels in Australia (Www.rubicon.com. All previous studies concentrated on modifying the normal rectangular weir head-discharge equation so that it can be used for the pivot weirs. In this study, it is trying to derive a

  8. Learning to Pivot with Adversarial Networks

    CERN Document Server

    Louppe, Gilles; Cranmer, Kyle

    2016-01-01

    Many inference problems involve data generation processes that are not uniquely specified or are uncertain in some way. In a scientific context, the presence of several plausible data generation processes is often associated to the presence of systematic uncertainties. Robust inference is possible if it is based on a pivot -- a quantity whose distribution is invariant to the unknown value of the (categorical or continuous) nuisance parameters that parametrizes this family of generation processes. In this work, we introduce a flexible training procedure based on adversarial networks for enforcing the pivotal property on a predictive model. We derive theoretical results showing that the proposed algorithm tends towards a minimax solution corresponding to a predictive model that is both optimal and independent of the nuisance parameters (if that models exists) or for which one can tune the trade-off between power and robustness. Finally, we demonstrate the effectiveness of this approach with a toy example and an...

  9. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

  10. WATER REQUIREMENT OF IRRIGATED GARLIC

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  11. Water Requirements Of Irrigated Garlic

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  12. Multi-Pivot Quicksort: an Experiment with Single, Dual, Triple, Quad, and Penta-Pivot Quicksort Algorithms in Python

    Science.gov (United States)

    Budiman, M. A.; Zamzami, E. M.; Rachmawati, D.

    2017-03-01

    Dual-pivot quicksort, which was proposed by Yaroslavsky, has been experimentally proven to be more efficient than the classical single-pivot quicksort under the Java Virtual Machine [6]. Moreover, Kushagara, López-Ortiz, and Munro [4] has shown that triple-pivot quicksort runs 7-8% faster than dual-pivot quicksort in C, mutatis mutandis. In this research, we implement and experiment with single, dual, triple, quad, and penta-pivot quicksort algorithms in Python. Our experimental results are as follows. Firstly, the quicksort with single pivot is the slowest among the five variants. Secondly, at least until five (penta) pivots are being used, it is proven that the more pivots are used in a quicksort algorithm, the faster its performance becomes. Thirdly, the increase of speed resulted by adding more pivots tends to decrease gradually.

  13. 76 FR 53425 - Pivotal LNG, Inc.; Notice of Application

    Science.gov (United States)

    2011-08-26

    ... Energy Regulatory Commission Pivotal LNG, Inc.; Notice of Application Take notice that on August 8, 2011, Pivotal LNG, Inc. (Pivotal), Ten Peachtree Place, Suite 1000, Atlanta, Georgia 30309, filed with the... transportation of natural gas as a by-product of the operation of non-jurisdictional liquefied natural gas...

  14. Evaluation system of water ecological civilization of irrigation area in China

    Science.gov (United States)

    Liu, Z.; Chen, J.; Chen, D.; Zhang, S.; Li, X. C.; Zhu, Y.; Li, Y.

    2016-08-01

    Irrigation area is an important carrier, and also has a pivotal role in the construction of water ecological civilization in China, as well as worldwide. This work extracted the five basic characteristics of water ecological civilization of irrigated area, namely "resource saving, efficient production, ecological nature, beautiful environment, and civilized consciousness". Further, based on the frequency analysis of indicators related to the evaluation of irrigation area, we proposed the evaluation system of water ecological civilization of irrigated area. Taking an irrigation district of Huaian City, Jiangsu Province, China as an example, we carried out the case evaluation in use of the fuzzy comprehensive evaluation method. Thus, we provide the theoretical and technical reference for the construction and assessment of water ecological civilization of irrigation district to both China and abroad.

  15. Root canal irrigants.

    Science.gov (United States)

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-10-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were 'root canal irrigants' and 'endodontic irrigants.' The reference lists of each article were manually checked for additional articles of relevance.

  16. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  17. Sequential pivotal mechanisms for public project problems

    CERN Document Server

    Apt, Krzysztof R

    2008-01-01

    It is well-known that for several natural decision problems no budget balanced Groves mechanisms exist. This motivated recent research on designing variants of feasible Groves mechanisms (termed as `redistribution of VCG (Vickrey-Clarke-Groves) payments') that generate reduced deficit. With this in mind, we study sequential Groves mechanisms and consider optimal strategies that can lower the taxes that the players would have to pay under the simultaneous mechanism. We show that in the sequential pivotal mechanism for several variants of public project problems such strategies do exist. These strategies differ from truth-telling. In particular we exhibit an optimal strategy with the property that when each player follows it a maximal social welfare is generated.

  18. Intervention patterns of pivot nurses in oncology.

    Science.gov (United States)

    Skrutkowski, Myriam; Saucier, Andréanne; Ritchie, Judith A; Tran, Ngoc; Smith, Kevin

    2011-01-01

    The Pivot Nurse in Oncology (PNO) is a health care professional dedicated to providing patients with cancer and their families with continuing and consistent supportive care throughout the care trajectory. The purpose of this paper is to describe the variation and frequency of nursing interventions delivered by 12 PNOs at our health centre. An administrative analysis over a three-year period revealed a total of 43,906 interventions that were grouped into 10 categories. This analysis provided a description of the intervention frequency and these interventions were further collapsed into the four role functions of the PNO. Coordination/continuity of care and the assessment of needs and symptoms were identified as the dominant practice domains of the PNO in the professional cancer navigator role.

  19. Assessment of irrigation performance: contribution to improve water management in a small catchment in the Brazilian savannas

    Science.gov (United States)

    Rodrigues, Lineu; Marioti, Juliana; Steenhuis, Tammo; Wallender, Wesley

    2010-05-01

    Irrigated agriculture is the major consumer of surface water in Brazil using over 70% of the total supply. Due to the growing competition for water among different sectors of the economy, sustainable water use can only be achieved by decreasing the portion of water used by the irrigated agriculture. Thus, in order to maintain yield, farmers need to irrigate more efficiently. There is little known on irrigation efficiency in Brazil. Therefore a study was carried out in the Buriti Vermelho basin to assess the irrigation performance of existing system. The experimental basin has a drainage area of 940 hectares and is located in the eastern part of the Federal District, in the Brazilian savanna region. Agriculture is the main activity. There is a dominance of red latosols. Several types of land use and crop cover are encountered in the basin. Conflicts among farmers for water are increasing. As water, in quality and quantity, is crucial to maintain the livelihood of the population in the basin, concern about risk of water lack due to climatic and land use change is in place. Once irrigation is the main water user in the basin, to increase water availability and reduce conflicts a water resource management plan has to be established. For this purpose, irrigation system performance has to be understood. The objective of this work was to assess the performance and the management of irrigation (small and big) that has been carried out by farmers in the Buriti Vermelho experimental watershed. A survey undertaken in 2007 was used to identify the irrigation systems in the basin. It was verified that irrigation is practiced by both small (area up to 6 hectare) and big farmers. Small farmers usually crop limes and vegetables and use micro-irrigation, drip, sprinkler, guns or furrow to irrigate them. Big farmers plant annual crops and use center pivot as irrigation system. In this first assessment 13 irrigation systems were evaluated: five conventional sprinklers, four drip

  20. Irrigation water quality assessments

    Science.gov (United States)

    Increasing demands on fresh water supplies by municipal and industrial users means decreased fresh water availability for irrigated agriculture in semi arid and arid regions. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require co...

  1. Irrigation Systems. Student's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by individuals preparing for a career in commercial and residential irrigation. The materials included are geared toward students who have had some experience in the irrigation business; they are intended to be presented in 10 six-hour sessions. The first two sections deal with using this guide and preparing for the…

  2. Irrigation Systems. Instructor's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by licensed irrigators who wish to teach others how to design and install residential and commercial irrigation systems. The materials included in the guide have been developed under the assumption that the instructors who use it have little or no formal training as teachers. The first section presents detailed…

  3. Irrigation Without Waste

    Science.gov (United States)

    Shea, Kevin P.

    1975-01-01

    A new means of irrigation, called the drip or trickle system, has been proven more efficient and less wasteful than the current system of flood irrigation. As a result of this drip system, fertilizer-use efficiency is improved and crop yield, though never decreased, is sometimes increased in some crops. (MA)

  4. Excel PivotTables and PivotCharts Your Visual Blueprint for Creating Dynamic Spreadsheets

    CERN Document Server

    McFedries, Paul

    2010-01-01

    Master two of the most powerful features of Excel. Even if you use Excel all the time, you may not be up to speed on two of Excel's most useful features. PivotTable and PivotChart turn long lists of unreadable data into dynamic, easy-to-read tables and charts that highlight the information you need most; you can tweak results with a click or easily fuse data from several sources into one document. Now you can learn how to tap these powerful Excel tools with this practical guide. Using a series of step-by-step tutorials and easy-to-follow screenshots, this book shows you in a visual way how to

  5. Irrigation in endodontics.

    Science.gov (United States)

    Haapasalo, M; Shen, Y; Wang, Z; Gao, Y

    2014-03-01

    Irrigation is a key part of successful root canal treatment. It has several important functions, which may vary according to the irrigant used: it reduces friction between the instrument and dentine, improves the cutting effectiveness of the files, dissolves tissue, cools the file and tooth, and furthermore, it has a washing effect and an antimicrobial/antibiofilm effect. Irrigation is also the only way to impact those areas of the root canal wall not touched by mechanical instrumentation. Sodium hypochlorite is the main irrigating solution used to dissolve organic matter and kill microbes effectively. High concentration sodium hypochlorite (NaOCl) has a better effect than 1 and 2% solutions. Ethylenediaminetetraacetic acid (EDTA) is needed as a final rinse to remove the smear layer. Sterile water or saline may be used between these two main irrigants, however, they must not be the only solutions used. The apical root canal imposes a special challenge to irrigation as the balance between safety and effectiveness is particularly important in this area. Different means of delivery are used for root canal irrigation, from traditional syringe-needle delivery to various machine-driven systems, including automatic pumps and sonic or ultrasonic energy.

  6. Pivotal Response Training. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2016

    2016-01-01

    This intervention report presents findings from a systematic review of "pivotal response training" conducted using the What Works Clearinghouse Procedures and Standards Handbook (version 3.0) and the Children and Students with an Autism Spectrum Disorder review protocol (version 3.0). "Pivotal response training"…

  7. The Discharge Coefficient of a Centre-Pivot Roof Window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza; Nielsen, Peter V.

    2012-01-01

    value of discharge coefficient is used. The constant value of discharge coefficient leads to deceptive airflow estimation in the cases of centre-pivot roof windows. The object of this paper is to study and evaluate the discharge coefficient of the centre pivot roof window. Focus is given...

  8. Vision of irrigation

    Directory of Open Access Journals (Sweden)

    Fernando Braz-Tangerino

    2014-08-01

    Full Text Available Irrigation not only has been a key factor for the development and maintenance of human societies but it still plays this role now and it is foreseen that in the future as well. Its evolution has been constrained to the advance in knowledge on matters regarding Agronomy and Water Engineering and in technology however, many challenges deserve further research. It is worth to note that Brazil has strongly promoted irrigation in the last decade. Within the limited extension of this article, some current topics in irrigation, some of them are innovative such us the research line studying water flow in soil-plant in Mediterranean plants and its consequences on water use,. and future challenges are presented with the purpose of stimulate publication of Irrigation papers in the journal “Ingeniería del Agua” among Portuguese and Spanish language communities.

  9. Evaluating a Pivot-Based Approach for Bilingual Lexicon Extraction

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Kim

    2015-01-01

    Full Text Available A pivot-based approach for bilingual lexicon extraction is based on the similarity of context vectors represented by words in a pivot language like English. In this paper, in order to show validity and usability of the pivot-based approach, we evaluate the approach in company with two different methods for estimating context vectors: one estimates them from two parallel corpora based on word association between source words (resp., target words and pivot words and the other estimates them from two parallel corpora based on word alignment tools for statistical machine translation. Empirical results on two language pairs (e.g., Korean-Spanish and Korean-French have shown that the pivot-based approach is very promising for resource-poor languages and this approach observes its validity and usability. Furthermore, for words with low frequency, our method is also well performed.

  10. Advances in Irrigation

    Science.gov (United States)

    Gardner, W. R.

    This is the first volume of Advances in Irrigation, a new serial publication by the publishers of Advances in Agronomy and Advances in Hydroscience and designed to follow the same format. The editor is a well-known researcher and writer on irrigation and related subjects and has assembled a collection of highly regarded and respected authors for the initial volume. The readership for this volume will probably be mainly specialists and students interested in irrigation and an occasional design engineer.The seven contributions in this volume fall roughly into two classes: research and practice. Three papers (“Conjunctive Use of Rainfall and Irrigation in Semi-arid Regions,” by Stewart and Musik, “Irrigation Scheduling Using Soil Moisture Measurements: Theory and Practice,” by G. S. and M. D. Campbell, and “Use of Solute Transport Models to Estimate Salt Balance Below Irrigated Cropland,” by Jury) cover topics that have been the subject of a number of reviews. The contributions here provide brief, well-written, and authoritative summaries of the chosen topics and serve as good introductions or reviews. They should lend themselves well to classroom use in various ways. They also should be helpful to the nonspecialist interested in getting a sense of the subject without going into great detail.

  11. Fiducial inference in the pivotal family of distributions

    Institute of Scientific and Technical Information of China (English)

    XU; Xingzhong; LI; Guoying

    2006-01-01

    In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is given.The method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four applications of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods.

  12. Geospatial compilation and digital map of centerpivot irrigated areas in the mid-Atlantic region, United States

    Science.gov (United States)

    Finkelstein, Jason S.; Nardi, Mark R.

    2015-01-01

    To evaluate water availability within the Northern Atlantic Coastal Plain, the U.S. Geological Survey, in cooperation with the University of Delaware Agricultural Extension, created a dataset that maps the number of acres under center-pivot irrigation in the Northern Atlantic Coastal Plain study area. For this study, the extent of the Northern Atlantic Coastal Plain falls within areas of the States of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The irrigation dataset maps about 271,900 acres operated primarily under center-pivot irrigation in 57 counties. Manual digitizing was performed against aerial imagery in a process where operators used observable center-pivot irrigation signatures—such as irrigation arms, concentric wheel paths through cropped areas, and differential colors—to identify and map irrigated areas. The aerial imagery used for digitizing came from a variety of sources and seasons. The imagery contained a variety of spatial resolutions and included online imagery from the U.S. Department of Agriculture National Agricultural Imagery Program, Microsoft Bing Maps, and the Google Maps mapping service. The dates of the source images ranged from 2010 to 2012 for the U.S. Department of Agriculture imagery, whereas maps from the other mapping services were from 2013.

  13. TIPOLOGI GRAMATIKAL DAN SISTEM PIVOT BAHASA PAKPAK-DAIRI

    Directory of Open Access Journals (Sweden)

    Ida Basaria

    2013-07-01

    The pivot testing shows that the deletion of a nominal phrase in PDL can be directly made if it functions as a subject or adverbial. If a nominal phrase functions as a predicate, the deletion cannot be directly made; one of the clauses must be made passive or topicalized first. Based on such a pattern, in can be concluded that PDL belongs to the accusative language typology with a pivot pattern of S/A.

  14. A NEW PRINCIPAL PIVOTING SCHEME FOR BOX LINEAR COMPLEMENTARITY PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    WANGZHEMIN

    1997-01-01

    Judice and Pires developed in recent years principal pivoting methods for the solving ofthe so-called box linear complementarity problems (BLCPs) where the constraint matrices are restrictedly supposed to be of P-matrices. This paper aims at presenting a new principal pivoting scheme for BLCPs where the constraint matrices are loosely supposed to be row sufficient. This scheme can be applied to the solving of convex quadratic programs subject to linear constraints and arbitrary upper and lower bound constraints on variables.

  15. SEDIMENT CONTROL FOR IRRIGATION INTAKES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The analysis of the sediment problems in irrigation engineeringwas carried out, and the layout, the method as well as the effect of sediment control for irrigation intake structures in China were briefly introduced.

  16. Topic-aware pivot language approach for statistical machine translation

    Institute of Scientific and Technical Information of China (English)

    Jin-song SU; Xiao-dong SHI; Yan-zhou HUANG; Yang LIU; Qing-qiang WU; Yi-dong CHEN; Huai-lin DONG

    2014-01-01

    The pivot language approach for statistical machine translation (SMT) is a good method to break the resource bottleneck for certain language pairs. However, in the implementation of conventional approaches, pivot-side context information is far from fully utilized, resulting in erroneous estimations of translation probabilities. In this study, we propose two topic-aware pivot language approaches to use different levels of pivot-side context. The fi rst method takes advantage of document-level context by assuming that the bridged phrase pairs should be similar in the document-level topic distributions. The second method focuses on the effect of local context. Central to this approach are that the phrase sense can be refl ected by local context in the form of probabilistic topics, and that bridged phrase pairs should be compatible in the latent sense distributions. Then, we build an interpolated model bringing the above methods together to further enhance the system performance. Experimental results on French-Spanish and French-German translations using English as the pivot language demonstrate the effectiveness of topic-based context in pivot-based SMT.

  17. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  18. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  19. Study of Investments in Irrigation Water Sector in Khyber Pakhtunkhwa, Pakistan

    Directory of Open Access Journals (Sweden)

    Shah Fahad

    2015-04-01

    Full Text Available Irrigation water sector is playing pivotal role in agricultural production and have prominent contribution to GDP (Gross Domestic Product both at provincial and country level. Many of the stakeholders including different ministries/department of Federal and Provincial governments, private sectors, farmers, and NGOs (Non-Government Organizations are investing in this sector. Although that the data and data analysis tools are present in most of the countries, yet a comprehensive information base on investments in irrigation water sector is missing. This has led to duplication at resources and beneficiaries? level on one side, as well as gaps in technical, infrastructural, institutional and managerial strategies of the irrigation water sector projects on the other. This paper analyzes investments in irrigation water sector made by government of KPK (Khyber Pakhtunkhwa during the last 10 fiscal years? time period (2003-2013 and identifies gaps. Besides recommendations are also made in order to overcome the identified gaps/issues.

  20. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    Directory of Open Access Journals (Sweden)

    Hussein M. Al-Ghobari

    2016-12-01

    Full Text Available Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  1. Review on Trickle Irrigation Application in Groundwater Irrigation Schemes

    Directory of Open Access Journals (Sweden)

    Prastowo

    2006-04-01

    Full Text Available The Government of Indonesia has developed groundwater irrigation schemes in some province e.g. East Java, Central Java, Yogyakarta, Wast Java, Bali, West Nusa Tenggara and East Nusa Tenggara. However, not all regions were able to optimally utilize it. The irrigation effeciency of groundwater irrigation scheme was about 59%, while the wells-pumping efficiencies were varied from 28 to 98 %. In thefuture, the irrigation effieciency should be increased to anticipate water deficit during dry season. The application of trickle irrigation in indonesia has not been widely developed. Although trickle system has been used, however, it is still limited for few commercial agribusinesses. Trickle irrigation systems have a prospect to be developed in some regions having limited water resources. For preliminary stage, the systems could be applied in groundwater irrigation schemes that have been developed either by farmers or government.

  2. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  3. A case study of field-scale maize irrigation patterns in western Nebraska: implications for water managers and recommendations for hyper-resolution land surface modeling

    Science.gov (United States)

    Gibson, Justin; Franz, Trenton E.; Wang, Tiejun; Gates, John; Grassini, Patricio; Yang, Haishun; Eisenhauer, Dean

    2017-02-01

    In many agricultural regions, the human use of water for irrigation is often ignored or poorly represented in land surface models (LSMs) and operational forecasts. Because irrigation increases soil moisture, feedback on the surface energy balance, rainfall recycling, and atmospheric dynamics is not represented and may lead to reduced model skill. In this work, we describe four plausible and relatively simple irrigation routines that can be coupled to the next generation of hyper-resolution LSMs operating at scales of 1 km or less. The irrigation output from the four routines (crop model, precipitation delayed, evapotranspiration replacement, and vadose zone model) is compared against a historical field-scale irrigation database (2008-2014) from a 35 km2 study area under maize production and center pivot irrigation in western Nebraska (USA). We find that the most yield-conservative irrigation routine (crop model) produces seasonal totals of irrigation that compare well against the observed irrigation amounts across a range of wet and dry years but with a low bias of 80 mm yr-1. The most aggressive irrigation saving routine (vadose zone model) indicates a potential irrigation savings of 120 mm yr-1 and yield losses of less than 3 % against the crop model benchmark and historical averages. The results of the various irrigation routines and associated yield penalties will be valuable for future consideration by local water managers to be informed about the potential value of irrigation saving technologies and irrigation practices. Moreover, the routines offer the hyper-resolution LSM community a range of irrigation routines to better constrain irrigation decision-making at critical temporal (daily) and spatial scales (< 1 km).

  4. Investigation into rainwater use by cotton under multiple irrigation management conditions in the Texas High Plains

    Science.gov (United States)

    Goebel, T.; Lascano, R. J.

    2012-12-01

    Irrigation management practices in the Texas High Plains (THP) might be improved if we could ascertain the proportion of rainfall utilized by the crop in any given rainfall event. For instance, the primary source of irrigation water in the THP is pumped from the Ogallala Aquifer (OA), and can be enriched in 18O compared to rainfall-captured water. Given this expected difference, it should be possible to determine if the crop is utilizing the water from a rainfall event. To this end, cotton was grown using three irrigation management practices: subsurface drip, center pivot, and no irrigation (dry land). The water used for irrigation was pumped from the Ogallala aquifer, and rainfall was gathered in a rain gauge with mineral oil to prevent evaporation. Additionally, plant and soil samples were collected following each precipitation event every two hours and every eight hours respectively. Water was then extracted from the soil and plant samples using cryogenic vacuum distillation, and analyzed for 18O/16O ratios using the DLT-100 Liquid-Water Isotope Analyzer from Los Gatos Research Inc. The difference in isotope concentrations in the extracts from soils was used to determine infiltration depth into the soil profile at each location. The isotopic composition of the plant water was used to determine if the was used to compare rainwater use across the different irrigation management practices. Results might suggest changes to the way in which we apply irrigation water that would improve root growth and distribution to enhance the capture of rainfall.

  5. PowerPivot for advanced reporting and dashboards

    CERN Document Server

    Bosco, Robert

    2013-01-01

    A step-by-step tutorial with focused examples that builds progressively from basic to advanced topics and helps you create business intelligence reports and dashboards quickly and efficiently using the PowerPivot add-in.This book is ideal for data analysts, reporting and MIS professionals, business analysts, managers, dashboard makers, business intelligence professionals, self-service business intelligence personnel, and students. It is assumed that you have basic data analysis skills and intermediate level Excel skills. Familiarity with Pivot Tables as well as basic knowledge of VBA scripting

  6. Spectrophotometric determination of irrigant extrusion using passive ultrasonic irrigation, EndoActivator, or syringe irrigation.

    Science.gov (United States)

    Rodríguez-Figueroa, Carolina; McClanahan, Scott B; Bowles, Walter R

    2014-10-01

    Sodium hypochlorite (NaOCl) irrigation is critical to endodontic success, and several new methods have been developed to improve irrigation efficacy (eg, passive ultrasonic irrigation [PUI] and EndoActivator [EA]). Using a novel spectrophotometric method, this study evaluated NaOCl irrigant extrusion during canal irrigation. One hundred fourteen single-rooted extracted teeth were decoronated to leave 15 mm of the root length for each tooth. Cleaning and shaping of the teeth were completed using standardized hand and rotary instrumentation to an apical file size #40/0.04 taper. Roots were sealed (not apex), and 54 straight roots (n = 18/group) and 60 curved roots (>20° curvature, n = 20/group) were included. Teeth were irrigated with 5.25% NaOCl by 1 of 3 methods: passive irrigation with needle, PUI, or EA irrigation. Extrusion of NaOCl was evaluated using a pH indicator and a spectrophotometer. Standard curves were prepared with known amounts of irrigant to quantify amounts in unknown samples. Irrigant extrusion was minimal with all methods, with most teeth showing no NaOCl extrusion in straight or curved roots. Minor NaOCl extrusion (1-3 μL) in straight roots or curved roots occurred in 10%-11% of teeth in all 3 irrigant methods. Two teeth in both the syringe irrigation and the EA group extruded 3-10 μL of NaOCl. The spectrophotometric method used in this study proved to be very sensitive while providing quantification of the irrigant levels extruded. Using the PUI or EA tip to within 1 mm of the working length appears to be fairly safe, but apical anatomy can vary in teeth to allow extrusion of irrigant. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Irrigation mitigates against heat extremes

    Science.gov (United States)

    Thiery, Wim; Fischer, Erich; Visser, Auke; Hirsch, Annette L.; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2017-04-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use gridded observations and ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on hot extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Finally we find that present-day irrigation is partly masking GHG-induced warming of extreme temperatures, with particularly strong effects in South Asia. Our results overall underline that irrigation substantially reduces our exposure to hot temperature extremes and highlight the need to account for irrigation in future climate projections.

  8. Asian irrigation, African rain: Remote impacts of irrigation

    Science.gov (United States)

    Vrese, Philipp; Hagemann, Stefan; Claussen, Martin

    2016-04-01

    Irrigation is not only vital for global food security but also constitutes an anthropogenic land use change, known to have strong effects on local hydrological and energy cycles. Using the Max Planck Institute for Meteorology's Earth System Model, we show that related impacts are not confined regionally but that possibly as much as 40% of the present-day precipitation in some of the arid regions in Eastern Africa are related to irrigation-based agriculture in Asia. Irrigation in South Asia also substantially influences the climate throughout Southeast Asia and China via the advection of water vapor and by altering the Asian monsoon. The simulated impact of irrigation on remote regions is sensitive to the magnitude of the irrigation-induced moisture flux. Therefore, it is likely that a future extension or decline of irrigated areas due to increasing food demand or declining fresh water resources will also affect precipitation and temperatures in remote regions.

  9. Effect of low‐cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    National Research Council Canada - National Science Library

    Keraita, Bernard; Konradsen, Flemming; Drechsel, Pay; Abaidoo, Robert C

    2007-01-01

    Objective  To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water...

  10. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  11. Classroom Pivotal Response Teaching for Children with Autism

    Science.gov (United States)

    Stahmer, Aubyn C.; Suhrheinrich, Jessica; Reed, Sarah; Schreibman, Laura; Bolduc, Cynthia

    2011-01-01

    This practical manual and accompanying DVD-ROM present a research-supported behavioral intervention for children with autism that teachers can easily integrate into their existing classroom curriculum. Classroom Pivotal Response Teaching (CPRT) enhances children's motivation and participation in learning; increases the number of learning…

  12. Pivotal Teaching Moments in Technology-Intensive Secondary Geometry Classrooms

    Science.gov (United States)

    Cayton, Charity; Hollebrands, Karen; Okumus, Samet; Boehm, Ethan

    2017-01-01

    This study investigates three teachers' uses of a dynamic geometry program (The Geometer's Sketchpad) in their high school geometry classes over a 2-year period. The researchers examine teachers' actions and questions during pivotal teaching moments to characterize mathematics instruction that utilizes technology. Findings support an association…

  13. Distraction osteogenesis with pivot plate in the treatment of scaphocephaly.

    Science.gov (United States)

    Nam, Seung Min; Kim, Yong Bae; Shin, Ho Seong; Park, Eun Soo; Jung, Sung Gyun

    2011-01-01

    In scaphocephaly, traditional distraction osteogenesis increases only the bitemporal width. We describe distraction osteogenesis with a pivot plate for scaphocephaly, which not only increases the bitemporal width but also decreases the anteroposterior length. Three patients with scaphocephaly were treated using distraction osteogenesis with a pivot plate between January 2005 and June 2006. These children underwent cranial reshaping by gradual distraction using an external distraction device and pivot plate. The distraction rate was 1 mm/d, and the latency period was 5 days. The follow-up period after distraction osteogenesis ranged from 16 to 24 months. No specific complications, such as accidental removal of the distraction devices, infection, or neurologic problems in any patient, occurred. The mean distraction was 45 mm. The mean cranial index was 73.6. Distraction osteogenesis for scaphocephaly is still in the development stage, but it is becoming accepted as a useful method because of its many advantages. Distraction osteogenesis with a pivot plate for scaphocephaly is better than other distraction osteogenesis techniques because it induces increased bitemporal width and decreased anteroposterior length synchronously.

  14. Sediment transport in irrigation canals

    OpenAIRE

    Méndez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high crop production. Irrigation has been the largest recipient of public agricultural investment in the developing world. Hence, continued investment in irrigation along with reforms in institutional a...

  15. Biophysical indicators based on satellite images in an irrigated area at the São Francisco River Basin, Brazil

    Science.gov (United States)

    Leivas, Janice F.; Teixeira, Antônio Heriberto C.; Bayma-Silva, Gustavo; Ronquim, Carlos Cesar; Ribeiro da Silva Reis, João. Batista

    2016-10-01

    The Jaíba Irrigated Perimeter is a large irrigated agriculture area, located in the region Forest Jaíba between the São Francisco and Verde Grande rivers, in the Brazilian semi-arid region. In 2014, irrigators this the region face losses in the interruption of new plantings in irrigated areas due to water scarcity. The objective of this study is combine the model to estimate the Monteith BIO with the SAFER algorithm in the case of obtaining ET, to analyze the dynamics of natural vegetation and irrigated crops in water scarcity period. For application of the model are necessary data from meteorological stations and satellite images. Were used 23 satellite images of MODIS with spatial resolution of 250m and temporal 16 days, of 2014 year. For analyze the results, we used central pivots irrigation mask of Minas Gerais state, Brazil. In areas with irrigated agriculture with central pivot, the mean values of BIO over the year 2014 were 88.96 kg.ha-1.d-1. The highest values occurred between April 23 and May 8, with BIO 139 kg.ha-1.d-1. For areas with natural vegetation, the average BIO was 88.34 kg.ha-1.d-1 with lower values in September. Estimates of ET varied with the lowest values of ET observed in natural vegetation 1.91+/-1.22 mm.d-1 and the highest values in irrigated area is observed 3.51+/-0.97 mm.d-1. Results of this study can assist in monitoring of river basins, contributing to the management irrigated agriculture, with the trend of scarcity of water resources and increasing conflicts for the water use.

  16. Irrigation trends in Kansas, 1991–2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This fact sheet examines trends in total reported irrigation water use and acres irrigated as well as irrigation water use by crop type and system type in Kansas for...

  17. Soil Water Distribution and Irrigation Uniformity Under Alternative Furrow Irrigation

    Institute of Scientific and Technical Information of China (English)

    PAN Ying-hua; KANG Shao-zhong; DU Tai-sheng; YANG Xiu-ying

    2003-01-01

    Field experiments were conducted to investigate the spatial-temporal distribution and the uni-formity of soil water under alternative furrow irrigation in spring maize field in Gansu Province. Resultsshowed that during the crop growing season, alternative drying and wetting furrows could incur crops to en-dure a water stress, thus the adsorptive ability of root system could be enhanced. As there was no zero fluxplane between irrigated furrows and non-irrigated furrows under alternative furrow irrigation, lateral infiltra-tion of water was obviously increased, thus decreasing the deep percolation. Compared with the conventionalirrigation, although the water consumption in alternative furrow irrigation was reduced, the uniformity of soilwater was not obviously affected.

  18. Irrigation management in organic greenhouse

    NARCIS (Netherlands)

    Voogt, W.; Balendonck, J.; Berkelmans, R.; Enthoven, N.

    2017-01-01

    Irrigation in protected cultivation is essential due to the absence of natural precipitation. High evapotranspiration, due to higher temperature and prolonged cropping period, requires ample an adequate supply of water. The water supply in a greenhouse is solely carried out by irrigation and thus

  19. CROP UNDER DEFICIT IRRIGATION SCHEDULING

    African Journals Online (AJOL)

    This study presents crop coefficient (Kc) values of TMV 1 -ST maize variety ... given time from planting to the time it is harvested. ... real time irrigation scheduling for high frequent and non-fiequent water .... 10 m, and the average soil bulk density was 1420 kg/m'. ...... Performance Evaluation of Fadama Irrigation Practice.

  20. Remote pivot decoupler pylon: Wing/store flutter suppressor

    Science.gov (United States)

    Hassler, J. M., Jr. (Inventor)

    1986-01-01

    A device for suspending a store from an aerodynamic support surface, such an an aircraft wing, and more specifically, for improving upon singlet pivot decoupler pylons by reducing both frequency of active store, alignment, and alignment system space and power requirements. Two links suspend a lower pylon/rack section and releasable attached store from an upper pylon section mounted under the wing. The links allow the lower pylon section to rotate in pitch about a remote pivot point. A leaf spring connected between the lower section and electrical alignment system servomechanism provides pitch alignment of the lower section/store combination. The servomechanism utilizes an electric servomotor to drive the gear train and reversibly move the leaf spring, thereby maintaining the pitch attitude of the store within acceptable limits. The damper strokes when the lower section rotates to damp large oscillations of store.

  1. An Analysis and Implementation of a Parallel Ball Pivoting Algorithm

    Directory of Open Access Journals (Sweden)

    Julie Digne

    2014-07-01

    Full Text Available The problem of surface reconstruction from a set of 3D points given by their coordinates andoriented normals is a difficult problem, which has been tackled with many different approaches.In 1999, Bernardini and colleagues introduced a very elegant and efficient reconstruction methodthat uses a ball pivoting around triangle edges and adds new triangles if the ball is incidentto three points and contains no other points. This paper details an implementation and parallelization of this algorithm.

  2. Towards a pivotal-based approach for business process alignment

    OpenAIRE

    Ulmer, Jean-Stéphane; Belaud, Jean-Pierre; Le Lann, Jean-Marc

    2011-01-01

    This article focuses on business process engineering, especially on alignment between business analysis and implementation. Through a business process management approach, different transformations interfere with process models in order to make them executable. To keep the consistency of process model from business model to IT model, we propose a pivotal metamodel-centric methodology. It aims at keeping or giving all requisite structural and semantic data needed to perform such transformation...

  3. Gyroscope Pivot Bearing Dimension and Surface Defect Detection

    OpenAIRE

    2011-01-01

    Because of the perceived lack of systematic analysis in illumination system design processes and a lack of criteria for design methods in vision detection a method for the design of a task-oriented illumination system is proposed. After detecting the micro-defects of a gyroscope pivot bearing with a high curvature glabrous surface and analyzing the characteristics of the surface detection and reflection model, a complex illumination system with coaxial and ring lights is proposed. The illumin...

  4. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  5. Soil management and conservation: Irrigation: Methods

    Science.gov (United States)

    Irrigation applies water to soil to improve crop production. The three main methods of irrigation are surface, sprinkler and micro. Surface irrigation is used on 85% of the irrigated land in the world. It generally requires lower capital investment because the soil conveys water within the field, ra...

  6. Wireless sensor networks for irrigation management

    Science.gov (United States)

    Sustaining an adequate food supply for the world's population will require advancements in irrigation technology and improved irrigation management. Site-specific irrigation and automatic irrigation scheduling are examples of strategies to deal with declining arable land and limited fresh water reso...

  7. 76 FR 20971 - Turlock Irrigation District and Modesto Irrigation District; Notice of Intent To File License...

    Science.gov (United States)

    2011-04-14

    ... Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice of..., 2011. d. Submitted By: Turlock Irrigation District and Modesto Irrigation District. e. Name of Project... Regulatory Affairs, Turlock Irrigation District, P.O. Box 949, Turlock, California 95381, 209-883-8241...

  8. New insights into muscle function during pivot feeding in seahorses.

    Directory of Open Access Journals (Sweden)

    Sam Van Wassenbergh

    Full Text Available Seahorses, pipefish and their syngnathiform relatives are considered unique amongst fishes in using elastic recoil of post-cranial tendons to pivot the head extremely quickly towards small crustacean prey. It is known that pipefish activate the epaxial muscles for a considerable time before striking, at which rotations of the head and the hyoid are temporarily prevented to allow energy storage in the epaxial tendons. Here, we studied the motor control of this system in seahorses using electromyographic recordings of the epaxial muscles and the sternohyoideus-hypaxial muscles with simultaneous high-speed video recordings of prey capture. In addition we present the results from a stimulation experiment including the muscle hypothesised to be responsible for the locking and triggering of pivot feeding in seahorses (m. adductor arcus palatini. Our data confirmed that the epaxial pre-activation pattern observed previously for pipefish also occurs in seahorses. Similar to the epaxials, the sternohyoideus-hypaxial muscle complex shows prolonged anticipatory activity. Although a considerable variation in displacements of the mouth via head rotation could be observed, it could not be demonstrated that seahorses have control over strike distance. In addition, we could not identify the source of the kinematic variability in the activation patterns of the associated muscles. Finally, the stimulation experiment supported the previously hypothesized role of the m. adductor arcus palatini as the trigger in this elastic recoil system. Our results show that pre-stressing of both the head elevators and the hyoid retractors is taking place. As pre-activation of the main muscles involved in pivot feeding has now been demonstrated for both seahorses and pipefish, this is probably a generalized trait of Syngnathidae.

  9. Long-term outcomes following Medtronic Open Pivot valved conduit.

    Science.gov (United States)

    Naidoo, Rishendran; Pearse, Bronwyn; Tesar, Peter J; Yap, Su-Ann; Barnett, Adrian G; Fayers, Trevor

    2014-01-01

    Aortic root replacement is a complex procedure, though subsequent modifications of the original Bentall procedure have made surgery more reproducible. The study aim was to examine the outcomes of a modified Bentall procedure, using the Medtronic Open PivotTM valved conduit. Whilst short-term data on the conduit and long-term data on the valve itself are available, little is known of the long-term results with the valved conduit. Patients undergoing aortic root replacement between February 1999 and February 2010, using the Medtronic Open Pivot valved conduit were identified from the prospectively collected Cardiothoracic Register at The Prince Charles Hospital, Brisbane, Australia. All patients were followed up echocardiographically and clinically. The primary end-point was death, and a Cox proportional model was used to identify factors associated.with survival. Secondary end-points were valve-related morbidity (as defined by STS guidelines) and postoperative morbidity. Predictors of morbidity were identified using logistic regression. A total of 246 patients (mean age 50 years) was included in the study. The overall mortality was 12%, with actuarial 10-year survival 79% and a 10-year estimate of valve-related death of 0.04 (95% CI: 0.004, 0.07). Preoperative myocardial infarction (p = 0.004, HR 4.74), urgency of operation (p = 0.038, HR 2.8) and 10% incremental decreases in ejection fraction (p = 0.046, HR 0.69) were predictive of mortality. Survival was also affected by the valve gradients, with a unit increase in peak gradient reducing mortality (p = 0.021, HR 0.93). Valve-related morbidity occurred in 11 patients. Urgent surgery (p Medtronic Open Pivot valved conduit is a safe and durable option for aortic root replacement, and is associated with low morbidity and 10-year survival of 79%. However, further studies are required to determine the effect of valve gradient on survival.

  10. Pivotal Technology Research of Grid Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-wei; WANG Ru-chuan

    2004-01-01

    Grid Based on Mobile Agent is a new grid scheme. The purpose of the paper is to solve the pivotal technology of Grid Based on Mobile Agent ( GBMA) combined with thought of Virtual Organization ( VO). In GBMA, virtual organization is viewed as the basic management unit of the grid, and mobile agent is regarded as an important interactive means. Grid architecture, grid resource management and grid task management are the core technology problem of GBMA. The simulation results show that Inter- VO pattern has the obvious advantage because it can make full use of resources from other virtual organizations in GBMA environment.

  11. Irrigation Controllers Specification and Certification

    Science.gov (United States)

    WaterSense labeled irrigation controllers, which act like a thermostat for your sprinkler system telling it when to turn on and off, use local weather and landscape conditions to tailor watering schedules to actual conditions on the site.

  12. Irrigation Sprinklers Notice of Intent

    Science.gov (United States)

    High-efficiency irrigation sprinklers aim to deliver water more evenly to the landscape than traditional sprinklers and/or regulate outlet pressure to ensure a constant flow rate over a range of supply pressures.

  13. Swing Set Irrigation System

    Directory of Open Access Journals (Sweden)

    Ambe Verma

    2015-05-01

    Full Text Available ABSTRACT India is a vast country based on agriculture and irrigation is the most important factor for agriculture. In India there are many sources provide for irrigation. Every day new technologies are emerged in the world which brings a revolutionary change in the nature of this world. day by day the energy resources used by the large population of this world are coming on the last stage This project give the idea that how the other different form of energy can be used and implemented efficiently to overcome from this problem The aim of this project is to achieve the objective of energy lasting problem which is likely to be faced over in coming decades. Energy lasting is a big problem in India. This is faced by every people who live in the country. Swing energy is the form of energy. In this paper we have represented the methodology of swing energy using for rural area of application. This paper is all about Swing Set Water Pump in which the water pump will execute with the help of a swing set of canopy type. As we need a motor to operate the water pump but in this project we use the swing in the place of motor and we use oscillatory motion of swing in the place of rotating motion of a motor. Everybody has needed the energy at an increasing rate ever since he came on the Earth. Because of this lot of energy has been exhausted and wasted. All the member are dedicated the amount of their important time to participate in multiple meetings read and research for making the content to the report. We would especially like to thanks for the efficient condition of the entire Advisory member and their experiences. This study was initial and performed within the BUDDHA INSTITUTE OF TECHNOLOGY GIDA Gorakhpur the final report represents the labour and interest of the entire member working for this project. Finally we would like to thanks to all the member of our college workshop who helped us in manufacturing of this project model.

  14. 78 FR 3892 - Turlock Irrigation District and Modesto Irrigation District; Notice Clarifying Party Status

    Science.gov (United States)

    2013-01-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice Clarifying Party Status On January 9, 2013, the Modesto Irrigation District (Modesto) filed a motion...

  15. Gyroscope Pivot Bearing Dimension and Surface Defect Detection

    Directory of Open Access Journals (Sweden)

    Xudong Li

    2011-03-01

    Full Text Available Because of the perceived lack of systematic analysis in illumination system design processes and a lack of criteria for design methods in vision detection a method for the design of a task-oriented illumination system is proposed. After detecting the micro-defects of a gyroscope pivot bearing with a high curvature glabrous surface and analyzing the characteristics of the surface detection and reflection model, a complex illumination system with coaxial and ring lights is proposed. The illumination system is then optimized based on the analysis of illuminance uniformity of target regions by simulation and grey scale uniformity and articulation that are calculated from grey imagery. Currently, in order to apply the Pulse Coupled Neural Network (PCNN method, structural parameters must be tested and adjusted repeatedly. Therefore, this paper proposes the use of a particle swarm optimization (PSO algorithm, in which the maximum between cluster variance rules is used as fitness function with a linearily reduced inertia factor. This algorithm is used to adaptively set PCNN connection coefficients and dynamic threshold, which avoids algorithmic precocity and local oscillations. The proposed method is used for pivot bearing defect image processing. The segmentation results of the maximum entropy and minimum error method and the one described in this paper are compared using buffer region matching, and the experimental results show that the method of this paper is effective.

  16. Gyroscope pivot bearing dimension and surface defect detection.

    Science.gov (United States)

    Ge, Wenqian; Zhao, Huijie; Li, Xudong

    2011-01-01

    Because of the perceived lack of systematic analysis in illumination system design processes and a lack of criteria for design methods in vision detection a method for the design of a task-oriented illumination system is proposed. After detecting the micro-defects of a gyroscope pivot bearing with a high curvature glabrous surface and analyzing the characteristics of the surface detection and reflection model, a complex illumination system with coaxial and ring lights is proposed. The illumination system is then optimized based on the analysis of illuminance uniformity of target regions by simulation and grey scale uniformity and articulation that are calculated from grey imagery. Currently, in order to apply the Pulse Coupled Neural Network (PCNN) method, structural parameters must be tested and adjusted repeatedly. Therefore, this paper proposes the use of a particle swarm optimization (PSO) algorithm, in which the maximum between cluster variance rules is used as fitness function with a linearily reduced inertia factor. This algorithm is used to adaptively set PCNN connection coefficients and dynamic threshold, which avoids algorithmic precocity and local oscillations. The proposed method is used for pivot bearing defect image processing. The segmentation results of the maximum entropy and minimum error method and the one described in this paper are compared using buffer region matching, and the experimental results show that the method of this paper is effective.

  17. Wave Energy, Lever Operated Pivoting Float LOPF Study

    DEFF Research Database (Denmark)

    Margheritini, Lucia

    University in Denmark. The model size was 60cm W x 90cm L x 21cm H. The 60 cm width pointed towards the wave front. The LOPF buoy is characterized by a simple mechanical design with few moving parts and direct electrical output and it is taut moored to the sea bed, so all forces are referenced to the seabed......The fully instrumented Resen Waves Lever Operated Pivoting Float LOPF wave energy buoy model has gone through the first stage of testing in regular waves in scale 1:25 of the North Sea wave conditions, in the 3D deep wave basin at the Hydraulic and Coastal Engineering Laboratory of Aalborg...... for maximum energy output in regular as well as irregular waves. During storms the buoy pivots and streamlines itself to minimize loads on the mooring line. A conservative estimate shows that a full scale system for North Sea conditions has a float size width of 15 m that will, with 60% generator efficiency...

  18. Significant impacts of irrigation water sources and methods on modeling irrigation effects in the ACME Land Model

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong; Leung, Lai-Yung; Huang, Maoyi

    2017-07-01

    An irrigation module that considers both irrigation water sources and irrigation methods has been incorporated into the ACME Land Model (ALM). Global numerical experiments were conducted to evaluate the impacts of irrigation water sources and irrigation methods on the simulated irrigation effects. All simulations shared the same irrigation soil moisture target constrained by a global census dataset of irrigation amounts. Irrigation has large impacts on terrestrial water balances especially in regions with extensive irrigation. Such effects depend on the irrigation water sources: surface-water-fed irrigation leads to decreases in runoff and water table depth, while groundwater-fed irrigation increases water table depth, with positive or negative effects on runoff depending on the pumping intensity. Irrigation effects also depend significantly on the irrigation methods. Flood irrigation applies water in large volumes within short durations, resulting in much larger impacts on runoff and water table depth than drip and sprinkler irrigations. Differentiating the irrigation water sources and methods is important not only for representing the distinct pathways of how irrigation influences the terrestrial water balances, but also for estimating irrigation water use efficiency. Specifically, groundwater pumping has lower irrigation water use efficiency due to enhanced recharge rates. Different irrigation methods also affect water use efficiency, with drip irrigation the most efficient followed by sprinkler and flood irrigation. Our results highlight the importance of explicitly accounting for irrigation sources and irrigation methods, which are the least understood and constrained aspects in modeling irrigation water demand, water scarcity and irrigation effects in Earth System Models.

  19. Comparison and analysis of empirical equations for soil heat flux for different cropping systems and irrigation methods

    Science.gov (United States)

    Irmak, A.; Singh, R.K.; Walter-Shea, Elizabeth; Verma, S.B.; Suyker, A.E.

    2011-01-01

    We evaluated the performance of four models for estimating soil heat flux density (G) in maize (Zea mays L.) and soybean (Glycine max L.) fields under different irrigation methods (center-pivot irrigated fields at Mead, Nebraska, and subsurface drip irrigated field at Clay Center, Nebraska) and rainfed conditions at Mead. The model estimates were compared against measurements made during growing seasons of 2003, 2004, and 2005 at Mead and during 2005, 2006, and 2007 at Clay Center. We observed a strong relationship between the G and net radiation (Rn) ratio (G/Rn) and the normalized difference vegetation index (NDVI). When a significant portion of the ground was bare soil, G/Rn ranged from 0.15 to 0.30 and decreased with increasing NDVI. In contrast to the NDVI progression, the G/Rn ratio decreased with crop growth and development. The G/Rn ratio for subsurface drip irrigated crops was smaller than for the center-pivot irrigated crops. The seasonal average G was 13.1%, 15.2%, 10.9%, and 12.8% of Rn for irrigated maize, rainfed maize, irrigated soybean, and rainfed soybean, respectively. Statistical analyses of the performance of the four models showed a wide range of variation in G estimation. The root mean square error (RMSE) of predictions ranged from 15 to 81.3 W m-2. Based on the wide range of RMSE, it is recommended that local calibration of the models should be carried out for remote estimation of soil heat flux.

  20. Teaching transanal irrigation for functional bowel disorders.

    Science.gov (United States)

    Coggrave, Maureen; Norton, Christine

    Transanal irrigation of the bowel in the management of functional bowel disorders is currently receiving increased attention following the recent introduction of the Peristeen irrigation kit (Coloplast Ltd) in April 2007. Irrigation provides a welcome additional choice in the limited range of available interventions for the management of these patients. However, evidence to support clinical practice around irrigation is limited and nursing knowledge and experience of irrigation is only just developing. This paper reports a series of master classes conducted to support and develop the use of irrigation in the UK, and demonstrates the value of the master class as an educational tool when introducing a novel therapy.

  1. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  2. Perturb and Observe Control for an Embedded Point Pivoted Absorber

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-11-01

    Full Text Available Marine energy sources represent an attractive and inexhaustible reservoir able to contribute to the fulfillment of the world energy demand in accordance with climate/energy regulatory frameworks. Wave energy converter (WEC integration into the main grid requires both the maximization of the harvested energy and the proper management of the generation variability. The present paper focuses on both these mentioned issues. More specifically, it presents an embedded point pivoted absorber (PPA and its related control strategy aimed at maximizing the harvested energy. Experimental and numerical investigations have been carried out in a wave/towing tank facility in order to derive the design characteristics of the full-scale model and demonstrate the validity and effectiveness of the proposed control strategy.

  3. Astrocyte glutamine synthetase: pivotal in health and disease.

    Science.gov (United States)

    Rose, Christopher F; Verkhratsky, Alexei; Parpura, Vladimir

    2013-12-01

    The multifunctional properties of astrocytes signify their importance in brain physiology and neurological function. In addition to defining the brain architecture, astrocytes are primary elements of brain ion, pH and neurotransmitter homoeostasis. GS (glutamine synthetase), which catalyses the ATP-dependent condensation of ammonia and glutamate to form glutamine, is an enzyme particularly found in astrocytes. GS plays a pivotal role in glutamate and glutamine homoeostasis, orchestrating astrocyte glutamate uptake/release and the glutamate-glutamine cycle. Furthermore, astrocytes bear the brunt of clearing ammonia in the brain, preventing neurotoxicity. The present review depicts the central function of astrocytes, concentrating on the importance of GS in glutamate/glutamine metabolism and ammonia detoxification in health and disease.

  4. Characteristics of pivotal trials and FDA review of innovative devices.

    Science.gov (United States)

    Rising, Joshua P; Moscovitch, Ben

    2015-01-01

    When patients lack sufficient treatment options for serious medical conditions, they rely on the prompt approval and development of new therapeutic alternatives, such as medical devices. Understanding the development of innovative medical devices, including the characteristics of premarket clinical trials and length of Food and Drug Administration (FDA) review, can help identify ways to expedite patient access to novel technologies and inform recent efforts by FDA to more quickly get these products to patients and physicians. We analyzed publicly available information on clinical trials and premarket FDA review for innovative medical devices that fill an unmet medical need. In this first-of-its-kind study focusing on these products, we extracted data on the length of the pivotal trials, primary study endpoint and FDA review; number of patients enrolled in trials; and in what country the device was available first. We identified 27 approved priority review devices from January 2006 through August 2013. The median duration of pivotal clinical trials was 3 years, ranging from 3 months to approximately 7 years. Trials had a median primary outcome measure evaluation time of one year and a median enrollment of 297 patients. The median FDA review time was 1 year and 3 months. Most priority review devices were available abroad before they were approved in the United States. Our study indicates that addressing the length of clinical studies--and contributing factors, such as primary outcome measures and enrollment--could expedite patient access to innovative medical devices. FDA, manufacturers, Congress and other stakeholders should identify the contributing factors to the length of clinical development, and implement appropriate reforms to address those issues.

  5. Characteristics of pivotal trials and FDA review of innovative devices.

    Directory of Open Access Journals (Sweden)

    Joshua P Rising

    Full Text Available When patients lack sufficient treatment options for serious medical conditions, they rely on the prompt approval and development of new therapeutic alternatives, such as medical devices. Understanding the development of innovative medical devices, including the characteristics of premarket clinical trials and length of Food and Drug Administration (FDA review, can help identify ways to expedite patient access to novel technologies and inform recent efforts by FDA to more quickly get these products to patients and physicians. We analyzed publicly available information on clinical trials and premarket FDA review for innovative medical devices that fill an unmet medical need. In this first-of-its-kind study focusing on these products, we extracted data on the length of the pivotal trials, primary study endpoint and FDA review; number of patients enrolled in trials; and in what country the device was available first. We identified 27 approved priority review devices from January 2006 through August 2013. The median duration of pivotal clinical trials was 3 years, ranging from 3 months to approximately 7 years. Trials had a median primary outcome measure evaluation time of one year and a median enrollment of 297 patients. The median FDA review time was 1 year and 3 months. Most priority review devices were available abroad before they were approved in the United States. Our study indicates that addressing the length of clinical studies--and contributing factors, such as primary outcome measures and enrollment--could expedite patient access to innovative medical devices. FDA, manufacturers, Congress and other stakeholders should identify the contributing factors to the length of clinical development, and implement appropriate reforms to address those issues.

  6. Wave energy, lever operated pivoting float LOPF study

    Energy Technology Data Exchange (ETDEWEB)

    Margheritini, L.

    2012-11-01

    The fully instrumented Resen Waves Lever Operated Pivoting Float LOPF wave energy buoy model has gone through the first stage of testing in regular waves in scale 1:25 of the North Sea wave conditions, in the 3D deep wave basin at the Hydraulic and Coastal Engineering Laboratory of Aalborg University in Denmark. The model size was 60cm W x 90cm L x 21cm H. The 60 cm width pointed towards the wave front. The LOPF buoy is characterized by a simple mechanical design with few moving parts and direct electrical output and it is taut moored to the sea bed, so all forces are referenced to the seabed for maximum energy output in regular as well as irregular waves. During storms the buoy pivots and streamlines itself to minimize loads on the mooring line. A conservative estimate shows that a full scale system for North Sea conditions has a float size width of 15 m that will, with 60% generator efficiency, produce 610 MWh/y (609.497 kWh/y) with an average power output of 69.6 kW, which requires a generator capacity of 700 kW. It is expected the generator efficiency can be increased to 90% in the future. More specific calculations (from EnergiNet) show that with one generator of 695 kW the expected power production is 585 MWh/y; with a generator of 250 kW and 100 kW, the expected power production is 481 MWh/y and 182 MWh/y respectively. In addition there are several areas for future improvements for increased power production. (Author)

  7. Estimating actual irrigation application by remotely sensed evapotranspiration observations

    NARCIS (Netherlands)

    Droogers, P.; Immerzeel, W.W.; Lorite, I.J.; SWAP, PEST

    2010-01-01

    Water managers and policy makers need accurate estimates of real (actual) irrigation applications for effective monitoring of irrigation and efficient irrigation management. However, this information is not readily available at field level for larger irrigation areas. An innovative inverse modeling

  8. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  9. AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

    Directory of Open Access Journals (Sweden)

    Leszek Łabędzki

    2016-05-01

    Full Text Available The paper is a review of the so far used in Poland methods and criteria for assessing the needs of irrigation for planning purposes, the assessment because of the agroclimatic conditions and taking into account the soil water retention. Irrigation needs of the most are determined taking into account crop water deficits. This is the factor that is characterized by a shortage of precipitation in relation to the water requirements of crops. Some methods use only the meteorological parameters that determine the state of the atmosphere-soil-plant system, and some also take into account soil water retention and its availability for plants.

  10. Ground-water use, locations of production wells, and areas irrigated using ground water in 1998, middle Humboldt River basin, north-central Nevada

    Science.gov (United States)

    Plume, Russell W.

    2003-01-01

    In 1998, ground water was being pumped from about 420 production wells in the middle Humboldt River Basin for a variety of uses. Principal uses were for agriculture, industry, mining, municipal, and power plant purposes. This report presents a compilation of the number and types of production wells, areas irrigated by ground water, and ground-water use in 14 hydrographic areas of the middle Humboldt River Basin in 1998. Annual pumping records for production wells usually are reported to the Nevada Division of Water Resources. However, operators of irrigation wells are not consistently required to report annual pumpage. Daily power-consumption and pump-discharge rates measured at 20 wells during the 1998 irrigation season and total power use at each well were used to estimate the amount of water, in feet of depth, applied to 20 alfalfa fields. These fields include about 10 percent of the total area, 36,700 acres, irrigated with ground water in the middle Humboldt River Basin. In 1998 an average of 2.0 feet of water was applied to 14 fields irrigated using center-pivot sprinkler systems, and an average of 2.6 feet of water was applied to 6 fields irrigated using wheel-line sprinkler systems. A similar approach was used to estimate the amount of water pumped at three wells using pumps powered by diesel engines. The two fields served by these three wells received 3.9 feet of water by flood irrigation during the 1998 irrigation season. The amount of water applied to the fields irrigated by center-pivot and wheel-line irrigation systems during the 1998 irrigation season was less than what would have been applied during a typical irrigation season because late winter and spring precipitation exceeded long-term monthly averages by as much as four times. As a result, the health of crops was affected by over-saturated soils, and most irrigation wells were only used sporadically in the first part of the irrigation season. Power consumption at 19 of the 20 wells in the 1994

  11. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  12. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  13. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands

  14. 75 FR 43958 - Turlock Irrigation District and Modesto Irrigation District; Notice of Application for Amendment...

    Science.gov (United States)

    2010-07-27

    ... Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice of...: May 24, 2010. d. Applicant: Turlock Irrigation District and Modesto Irrigation District. e. Name of.... g. Filed Pursuant to: Federal Power Act, 16 USC 791a-825r. h. Applicant Contact: Turlock...

  15. Cotton irrigation timing with variable seasonal irrigation capacities in the Texas south plains.

    Science.gov (United States)

    Within the Ogallala Aquifer Region of Texas, the irrigation capacity (IC) for a given field often changes within a growing season due to seasonal depletion of the aquifer, in season changes in crop irrigation needs in dry years, or consequences of irrigation volume limits imposed by irrigation distr...

  16. 75 FR 35778 - Modesto Irrigation District and Turlock Irrigation District; Notice of Preliminary Permit...

    Science.gov (United States)

    2010-06-23

    ... Energy Regulatory Commission Modesto Irrigation District and Turlock Irrigation District; Notice of... Competing Applications June 16, 2010. On February 1, 2010, Modesto Irrigation District and Turlock Irrigation District filed an application for a preliminary permit, pursuant to section 4(f) of the...

  17. SURDEV: surface irrigation software; design, operation, and evaluation of basin, border, and furrow irrigation

    NARCIS (Netherlands)

    Jurriëns, M.; Zerihun, D.; Boonstra, J.; Feyen, J.

    2001-01-01

    SURDEV is a computer package for the design, operation, and evaluation of surface irrigation. SURDEV combines three sub-programs: BASDEV (for basin irrigation), FURDEV (for furrow irrigation), and BORDEV for (border irrigation). This combination enables the user to simulate many of the problems invo

  18. Modernisation Strategy for National Irrigation Systems in the Philippines: Balanac and Sta. Maria River Irrigation Systems

    NARCIS (Netherlands)

    Delos Reyes, M.L.F.

    2017-01-01

    This book examines the nature and impact of irrigation system rehabilitation on increasing the actual area irrigated by the publicly funded canal irrigation systems of the Philippines. It proposes a system diagnosis approach for the development of a more appropriate and climate-smart irrigation

  19. SURDEV: surface irrigation software; design, operation, and evaluation of basin, border, and furrow irrigation

    NARCIS (Netherlands)

    Jurriëns, M.; Zerihun, D.; Boonstra, J.; Feyen, J.

    2001-01-01

    SURDEV is a computer package for the design, operation, and evaluation of surface irrigation. SURDEV combines three sub-programs: BASDEV (for basin irrigation), FURDEV (for furrow irrigation), and BORDEV for (border irrigation). This combination enables the user to simulate many of the problems

  20. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  1. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  2. Laboratory evaluation of the pivot-shift phenomenon with use of kinetic analysis: a preliminary study.

    Science.gov (United States)

    Sanchis-Alfonso, Vicente; Baydal-Bertomeu, José-María; Castelli, Andrea; Montesinos-Berry, Erik; Marín-Roca, Susana; Garrido-Jaén, José-David

    2011-07-06

    Currently, a suitable and reliable noninvasive method to evaluate rotational stability in vivo in anterior cruciate ligament-deficient knees, particularly during sports movements, does not exist. We speculated that if there is a rotational instability, the patient would avoid reaching a high pivoting moment during pivoting activities as a defense mechanism, and that the ground reaction moment, as registered by dynamometric platforms, would be reduced. On the basis of this hypothesis, we developed a study using kinetic analysis to evaluate rotational stability under dynamic loading. Thirty recreationally active athletes, including fifteen healthy subjects and fifteen with an anterior cruciate ligament-deficient knee, were recruited for this study. Patients performed jumping with pivoting with internal tibial rotation and external tibial rotation on the dynamometric platform with both the healthy and the injured limb. The quantitative results were graphically plotted, and the following parameters were evaluated: loading moment, pivoting moment, torque amplitude, loading slope, pivoting slope, percentage of pivoting with load, loading impulse, pivoting impulse, and maximum body rotation angle. There were no significant differences between the dominant and nondominant knees in the control group during the jumping with pivoting and external tibial rotation test with regard to the pivoting moment (p = 0.805), pivoting slope (p = 0.716), pivoting impulse 2 (p = 0.858), and pivoting impulse 3 (p = 0.873). In patients with a chronic tear of the anterior cruciate ligament, there was a significant decrease of the pivoting moment (p = 0.02), pivoting slope (p = 0.005), pivoting impulse 2 (p = 0.006), and pivoting impulse 3 (p = 0.035) during the jumping with pivoting and external tibial rotation test in the anterior cruciate ligament-deficient knee compared with the healthy, contralateral knee. Kinetic analysis with use of a dynamic platform can objectively detect alterations

  3. Sediment transport in irrigation canals.

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high

  4. Sediment transport in irrigation canals

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to

  5. Position paper : Whole bowel irrigation

    NARCIS (Netherlands)

    2004-01-01

    Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that W

  6. Plant hormone cross-talk: the pivot of root growth.

    Science.gov (United States)

    Pacifici, Elena; Polverari, Laura; Sabatini, Sabrina

    2015-02-01

    Root indeterminate growth and its outstanding ability to produce new tissues continuously make this organ a highly dynamic structure able to respond promptly to external environmental stimuli. Developmental processes therefore need to be finely tuned, and hormonal cross-talk plays a pivotal role in the regulation of root growth. In contrast to what happens in animals, plant development is a post-embryonic process. A pool of stem cells, placed in a niche at the apex of the meristem, is a source of self-renewing cells that provides cells for tissue formation. During the first days post-germination, the meristem reaches its final size as a result of a balance between cell division and cell differentiation. A complex network of interactions between hormonal pathways co-ordinates such developmental inputs. In recent years, by means of molecular and computational approaches, many efforts have been made aiming to define the molecular components of these networks. In this review, we focus our attention on the molecular mechanisms at the basis of hormone cross-talk during root meristem size determination. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Pivot and cluster strategy: a preventive measure against diagnostic errors

    Directory of Open Access Journals (Sweden)

    Shimizu T

    2012-11-01

    Full Text Available Taro Shimizu,1 Yasuharu Tokuda21Rollins School of Public Health, Emory University, Atlanta, GA, USA; 2Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, JapanAbstract: Diagnostic errors constitute a substantial portion of preventable medical errors. The accumulation of evidence shows that most errors result from one or more cognitive biases and a variety of debiasing strategies have been introduced. In this article, we introduce a new diagnostic strategy, the pivot and cluster strategy (PCS, encompassing both of the two mental processes in making diagnosis referred to as the intuitive process (System 1 and analytical process (System 2 in one strategy. With PCS, physicians can recall a set of most likely differential diagnoses (System 2 of an initial diagnosis made by the physicians’ intuitive process (System 1, thereby enabling physicians to double check their diagnosis with two consecutive diagnostic processes. PCS is expected to reduce cognitive errors and enhance their diagnostic accuracy and validity, thereby realizing better patient outcomes and cost- and time-effective health care management.Keywords: diagnosis, diagnostic errors, debiasing

  8. Graph reductions, binary rank, and pivots in gene assembly

    CERN Document Server

    Pflueger, Nathan

    2011-01-01

    In this paper, we describe a graph reduction operation, generalizing three combinatorial graph reduction rules related to gene assembly in ciliates. We study these reductions and their relation to the binary rank of a graph, which is the rank of the adjacency matrix over the finite field with two elements, and relate them to the graph pivot operation. We use these methods to solve two open problems posed by Harju, Li, and Petre regarding a graph formalization of gene assembly in ciliates. The graph formalization of gene assembly considers three reduction rules, called the positive, double, and negative rule, each of which removes one or two vertices from the graph. The graph reductions we define consist precisely of all compositions of these rules. We give algebraic criteria describing those subsets of vertices that can be removed by graph reductions, characterize the number of times the negative rule is applied to remove a given set of vertices, and show that such reductions are path invariant, in the sense ...

  9. Quantification of the impacts of coalmine water irrigation on the underlying aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, D.; Usher, B.; van Tonder, G. [University of Free State, Bloemfontein (South Africa). Institute of Groundwater Studies

    2009-07-15

    It is predicted that vast volumes of affected mine water will be produced by mining activities in the Mpumalanga coalfields of South Africa, The potential environmental impact of this excess water is of great concern in a water-scarce country like South Africa. Research over a period of more than 10 years has shown that this water can be used successfully for the irrigation of a range of crops. There is, however, continuing concern from the local regulators regarding the long-term impact that large-scale mine water irrigation may have on groundwater quality and quantity. Detailed research has been undertaken over the last three years to supplement the groundwater monitoring programme at five different pilot sites, on both virgin soils (greenfields) and in coalmining spoils. These sites range from sandy soils to very clayey soils. The research has included soil moisture measurements, collection of in situ soil moisture over time, long-term laboratory studies of the leaching and attenuation properties of different soils and the impact of irrigation on acid rock drainage processes, and in depth determination of the hydraulic properties of the subsurface at each of these sites, including falling head tests, pumping tests and point dilution tests. This has been supported by geochemical modelling of these processes to quantify the impacts. The results indicate that many of the soils have considerable attenuation capacities and that in the period of irrigation, a large proportion of the salts have been contained in the upper portions of the unsaturated zones below each irrigation pivot. The volumes and quality of water leaching through to the aquifers have been quantified at each site. From this mixing ratios have been calculated in order to determine the effect of the irrigation water on the underlying aquifers.

  10. A Fuzzy Control Irrigation System For Cottonfield

    Science.gov (United States)

    Zhang, Jun; Zhao, Yandong; Wang, Yiming; Li, Jinping

    A fuzzy control irrigation system for cotton field is presented in this paper. The system is composed of host computer, slave computer controller, communication module, soil water sensors, valve controllers, and system software. A fuzzy control model is constructed to control the irrigation time and irrigation quantity for cotton filed. According to the water-required rules of different cotton growing periods, different irrigation strategies can be carried out automatically. This system had been used for precision irrigation of the cotton field in Langfang experimental farm of Soil and Fertilizer Institute, Chinese Academy of Agricultural Sciences in 2006. The results show that the fuzzy control irrigation system can improve cotton yield and save much water quantity than the irrigation system based on simple on-off control algorithm.

  11. Pivotal response treatment for autism spectrum disorder: current perspectives

    Directory of Open Access Journals (Sweden)

    Lei J

    2017-06-01

    Full Text Available Jiedi Lei, Pamela Ventola Yale Child Study Center, Yale University School of Medicine, New Haven, CT, USA Abstract: Pivotal response treatment (PRT is an evidence-based behavioral intervention based on applied behavior analysis principles aimed to improve social communication skills in individuals with autism spectrum disorder (ASD. PRT adopts a more naturalistic approach and focuses on using a number of strategies to help increase children’s motivation during intervention. Since its conceptualization, PRT has received much empirical support for eliciting therapeutic gains in greater use of functional social communication skills in individuals with ASD. Building upon the empirical evidence supporting PRT, recent advancements have increasingly turned to using interdisciplinary research integrating neuroimaging techniques and behavioral measures to help identify objective biomarkers of treatment, which have two primary purposes. First, neuroimaging results can help characterize how PRT may elicit change, and facilitate partitioning of the heterogeneous profiles of neural mechanisms underlying similar profile of behavioral changes observed over PRT. Second, neuroimaging provides an objective means to both map and track how biomarkers may serve as reliable and sensitive predictors of responder profiles to PRT, assisting clinicians to identify who will most likely benefit from PRT. Together, a better understanding of both mechanisms of change and predictors of responder profile will help PRT to serve as a more precise and targeted intervention for individuals with ASD, thus moving towards the goal of precision medicine and improving quality of care. This review focuses on the recent emerging neuroimaging evidences supporting PRT, offering current perspectives on the importance of interdisciplinary research to help clinicians better understand how PRT works and predict who will respond to PRT. Keywords: PRT, ASD, biomarkers, neuroimaging

  12. Present-day irrigation mitigates heat extremes

    Science.gov (United States)

    Thiery, Wim; Davin, Edouard L.; Lawrence, David M.; Hirsch, Annette L.; Hauser, Mathias; Seneviratne, Sonia I.

    2017-02-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. An evaluation of the model performance reveals that irrigation has a small yet overall beneficial effect on the representation of present-day near-surface climate. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Our results underline that irrigation has substantially reduced our exposure to hot temperature extremes in the past and highlight the need to account for irrigation in future climate projections.

  13. Pivotal behavior as the mediator of the relationship between parental responsiveness and children's symbolic behavior.

    Science.gov (United States)

    Chiu, Chun-Hao; Lin, Chu-Sui; Mahoney, Gerald; Cheng, Shu-Fen; Chang, Shu-Hui

    2017-08-01

    Previous research with parents and children with developmental disabilities indicated that the relationship between mothers' responsive style of interaction and children's rate of development was mediated by the simultaneous relationship between mothers' responsiveness and children's social engagement, or pivotal behavior. In this study, we attempted to determine whether children's pivotal behavior might also mediate the relationship between responsiveness and child development in a sample of 165 typically developing toddlers and their Taiwanese parents. Child development was assessed with a parent report measure of children's symbolic behavior. Parental responsiveness and children's pivotal behavior were assessed from observations of parent-child play. Results indicated that parental responsiveness was correlated with children's pivotal behavior, and that both of these variables were correlated with children's symbolic behavior. Structural equation models indicated that the relationship between responsiveness and children's symbolic behavior was fully mediated by children's pivotal behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. IRRIGATION OF ORNAMENTAL PLANT NURSERY

    Directory of Open Access Journals (Sweden)

    Eduardo de Aguiar do Couto

    2013-01-01

    Full Text Available Airports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessar y. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irri gation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year a nd the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli we re analyzed. Removal efficiencies of 85% and 91% were achieved for C OD and solids, respectively. Removal efficiencies for ammonia nitrogen a nd total phosphorus were 77% and 59%, respectively. In terms of E. coli concen tration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evalua ted. The experiment showed that reuse can enhance plant growth without signi ficantly affecting leaf tissue and soil characteristics. This study highlighted th e importance of simple technologies for sewage treatment especially in count ries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.

  15. Hevin plays a pivotal role in corneal wound healing.

    Directory of Open Access Journals (Sweden)

    Shyam S Chaurasia

    with exogenous administration of rhHevin. Thus, hevin plays a pivotal role in the corneal wound healing.

  16. Effects of Irrigation in India on the Atmospheric Water Budget

    NARCIS (Netherlands)

    Tuinenburg, O.A.; Hutjes, R.W.A.; Stacke, T.; Wiltshire, A.; Lucas-Picher, P.

    2014-01-01

    The effect of large-scale irrigation in India on the moisture budget of the atmosphere was investigated using three regional climate models and one global climate model, all of which performed an irrigated run and a natural run without irrigation. Using a common irrigation map, year-round irrigation

  17. The Role of Windbreaks in Reducing Water Resources Use in Irrigated Agriculture

    Science.gov (United States)

    Cochrane, T. A.; de Vries, T. T.

    2014-12-01

    Windbreaks are common features in flat agricultural landscapes around the world. The reduction in wind speed afforded by windbreaks is dictated by their porosity, location, height, and distance from the windbreak. The reduction in wind speeds not only reduces potential wind erosion; it also reduces crop evapotranspiration (ET) and provides shelter for livestock and crops. In the Canterbury plains of New Zealand there are over 300,000 km of windbreaks which were first implemented as a soil conservation strategy to reduce wind erosion of prime agricultural land. Agriculture in the region has since changed to irrigated pasture cultivation for dairy production and windbreaks are being cut down or reduced to heights of 2 m to allow for large scale centre-pivot irrigation schemes. Although soil erosion is no longer a major concern due to permanent pasture cover, irrigation water is sourced from limited supplies of ground and surface water and thus the effects of wind on irrigation losses due to spray drift and increased ET are of significant concern. The impact of reducing windbreaks needs to be understood in terms of water resources use. Experimental and theoretical work was conducted to quantify the reduction in wind speeds by windbreaks and in spray evaporation losses. A temporal and spatial model was also developed and validated to quantify the impact of single and multiple windbreaks on irrigation water losses. Initial modelling results show that for hot windy dry conditions in Canterbury, ET can increase by up to 1.4 mm/day when windbreaks are reduced to 2 m in height and on average wind days ET can increase by up to 0.5 mm/day. ET can be reduced by up to 30% in the windbreak leeward zone relative to ET in areas not protected by windbreaks. Wind speed, air temperature and relative humidity all had a considerable impact on spray evaporation losses, but the extent is determined by the droplet size. Estimated losses range from only 0.07% to 67% for 5 and 0.2 mm

  18. Evaluating regional water scarcity: Irrigated crop water budgets for groundwater management in the Wisconsin Central Sands

    Science.gov (United States)

    Nocco, M. A.; Kucharik, C. J.; Kraft, G.

    2013-12-01

    recharge) and by inferring ET through difference, modeling, and gas exchange. In April 2013 prior to planting, we installed 10 passive capillary wick lysimeters below the effective rooting zone (z=100 cm) in potato (n=6) and maize (n=4) cropping systems to collect drainage at a 10-minute time-step under cultivation on Isherwood Farms, a sixth-generation family farm in the Wisconsin Central Sands region. Lysimeters were also instrumented to measure soil moisture and temperature at depth (z=10, 20, 40, 80 cm). Farm operators initiated center-pivot irrigation when soil moisture dropped to approximately 50% of plant available water content. Results show that drainage for May-July 2013 was 43 × 53 mm and 48 × 41 mm in irrigated potato and maize cropping systems, respectively, despite 320 mm of precipitation received during the experimental period, which was 15% above average for this region. Soil moisture consistently fluctuated in response to precipitation/irrigation events at the 10 and 20 cm soil depths, but rarely fluctuated in response to precipitation/irrigation events at the 40 and 80 cm soil depths, supporting the low drainage observed during the growing season. Future work will couple these drainage data to ongoing phenological, micrometeorological, and gas exchange observations in order to infer ET and calculate crop water budgets on a seasonal basis.

  19. Senegal - Irrigation and Water Resource Management

    Data.gov (United States)

    Millennium Challenge Corporation — IMPAQ: This evaluation report presents findings from the baseline data collected for the Irrigation and Water Resources Management (IWRM) project, which serves as...

  20. Automation of irrigation systems to control irrigation applications and crop water use efficiency

    Science.gov (United States)

    Agricultural irrigation management to slow water withdrawals from non-replenishing quality water resources is a global endeavor and vital to sustaining irrigated agriculture and dependent rural economies. Research in site-specific irrigation management has shown that water use efficiency, and crop p...

  1. 78 FR 37538 - Idaho Irrigation District; New Sweden Irrigation District; Notice of Preliminary Permit...

    Science.gov (United States)

    2013-06-21

    ... Energy Regulatory Commission Idaho Irrigation District; New Sweden Irrigation District; Notice of... Competing Applications On April 19, 2013, the Idaho and New Sweden Irrigation Districts, filed a joint... Street, Idaho Falls, Idaho 83404; phone: (208) 522-2356. Mr. Louis Thiel, Chairman, New Sweden...

  2. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Ken

  3. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; Sluis, van der L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  4. The simulation of cropping pattern to improve the performance of irrigation network in Cau irrigation area

    Science.gov (United States)

    Wahyuningsih, Retno; Rintis Hadiani, RR; Sobriyah

    2017-01-01

    Cau irrigation area located in Madiun district, East Java Province, irrigates 1.232 Ha of land which covers Cau primary channel irrigation network, Wungu Secondary channel irrigation network, and Grape secondary channel irrigation network. The problems in Cau irrigation area are limited availability of water especially during the dry season (planting season II and III) and non-compliance to cropping patterns. The evaluation of irrigation system performance of Cau irrigation area needs to be done in order to know how far the irrigation system performance is, especially based on planting productivity aspect. The improvement of irrigation network performance through cropping pattern optimization is based on the increase of water necessity fulfillment (k factor), the realization of planting area and rice productivity. The research method of irrigation system performance is by analyzing the secondary data based on the Regulation of Ministry of Public Work and State Minister for Public Housing Number: 12/PRT/M/2015. The analysis of water necessity fulfillment (k factor) uses Public Work Plan Criteria Method. The performance level of planting productivity aspect in existing condition is 87.10%, alternative 1 is 93.90% dan alternative 2 is 96.90%. It means that the performance of the irrigation network from productivity aspect increases 6.80% for alternative 1 and 9.80% for alternative 2.

  5. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  6. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

  7. 77 FR 16828 - Turlock Irrigation District, & Modesto Irrigation District; Notice of Dispute Resolution Process...

    Science.gov (United States)

    2012-03-22

    ... Energy Regulatory Commission Turlock Irrigation District, & Modesto Irrigation District; Notice of... and the Modesto Irrigation District (collectively, the Districts), are co-licensees for the Don Pedro... Steelhead Full Life-Cycle Population Models; and Request 9--Effects of the Project and Related Facilities on...

  8. Evaluation of an Indigenously Prepared Herbal Extract (EndoPam) as an Antimicrobial Endodontic Irrigant: An Ex Vivo Study

    Science.gov (United States)

    Mathew, Jain; Pathrose, Sonia; Kottoor, Jojo; Karaththodiyil, Ranjith; Alani, Mathew; Mathew, Joy

    2015-01-01

    Backgroundg: Root canal irrigation plays a pivotal role in endodontics. Constant increase in antibiotic resistance and side effects caused by synthetic irrigants has shifted the research toward developing herbal alternatives. The current study aims to assess the ex vivo effectiveness of an indigenously prepared herbal extract “EndoPam” and compare it with the conventional endodontic irrigants for disinfection of root canals infected with Enterococcus faecalis. Materials and Methods: As a preliminary study of the antimicrobial efficacy of the test irrigants, an Agar diffusion study was conducted, and zone of inhibition measured. Forty extracted mandibular premolars with straight root canals were selected and standardized to 12 ± 1 mm in length. Root canals were prepared using rotary ProTaper system until F3 instrument and were infected with the culture of E. faecalis for three weeks. Specimens were divided into four groups (n = 10). Group 1: EndoPam ( Ingredients: Syzigium aromaticum, Eucalyptus globulus, Cinnamomum zeylanicum and Mentha piperita), Group 2: 2% chlorhexidine, Group 3: 5.25% Sodium hypochlorite, Group 4: Normal Saline. Irrigation was performed for each group. Samples were inoculated and incubated for 24 h at 37°C for qualitative analysis qualitative analysis. Results: In the preliminary Agar diffusion study, EndoPam exhibited a zone of inhibition comparable to that of sodium hypochrorite. The diameter of the inhibition zone was in the following order: 2% chlorhexidine gluconate > EndoPam > 5.25% NaOCl > Normal Saline. The qualitative assay done by culturing the bacteria after a period of 3 weeks showed no bacterial growth in any of the tested irrigants, except in normal saline. Conclusion: It was found that the experimental product was as effective as conventional irrigants in reducing the microbial count. PMID:26124607

  9. Irrigation-based livelihood trends in river basins: theory and policy implications for irrigation development

    Science.gov (United States)

    Lankford, Bruce

    This paper examines irrigation development and policy in Tanzania utilising a livelihoods and river basin perspective. On the basis of observations, the author argues that river basins theoretically exhibit a sigmoid curve of irrigation development in three stages; proto-irrigation, irrigation-momentum and river basin management. This model arises from two governing factors. Firstly, irrigation is a complex livelihood activity that, although has benefits, also has costs, risks and alternatives that integrate across many systems; farmers implicitly understand this and enter into or keep out of irrigation accordingly. In the proto-irrigation stage, irrigators are less common, and irrigation is felt to be a relatively unattractive livelihood. In the irrigation-momentum stage, irrigators are drawn very much to irrigation in providing livelihood needs. Hence, given both of these circumstances, governments should be cautious about policies that call for the need to ‘provide irrigation’ (when farmers may not wish to irrigate) or to further increase it (when farmers already have the means and will to do so). Second, irrigation consumes water, generating externalities. Thus if irrigation momentum proceeds to the point when water consumption directly impacts on other sectors and livelihoods, (e.g. pastoralists, downstream irrigation, the environment) decision-makers should focus not necessarily on irrigation expansion, but on water management, allocation and conflict mediation. This three-stage theoretical model reminds us to take a balanced ‘livelihoods river-basin’ approach that addresses real problems in each given stage of river basin development and to develop policy accordingly. The paper contains a discussion on livelihood factors that affect entry into irrigation. It ends with a series of recommendations on policy; covering for example new large-scale systems; problems solving; and the use of an irrigation-river basin livelihoods approach. The recommendations

  10. Irrigation as an Historical Climate Forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2014-01-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  11. Irrigation as an historical climate forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2015-03-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  12. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Directory of Open Access Journals (Sweden)

    A. D. Chukalla

    2015-07-01

    Full Text Available Consumptive water footprint (WF reduction in irrigated crop production is essential given the increasing competition for fresh water. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET and yield (Y and thus the consumptive WF of crops (ET/Y. The management practices are: four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD; four irrigation strategies (full (FI, deficit (DI, supplementary (SI and no irrigation; and three mulching practices (no mulching, organic (OML and synthetic (SML mulching. Various cases were considered: arid, semi-arid, sub-humid and humid environments; wet, normal and dry years; three soil types; and three crops. The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching. The average reduction in the consumptive WF is: 8–10 % if we change from the reference to drip or SSD; 13 % when changing to OML; 17–18 % when moving to drip or SSD in combination with OML; and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

  13. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  14. Identifying the potential for irrigation development in Mozambique: Capitalizing on the drivers behind farmer-led irrigation expansion

    NARCIS (Netherlands)

    Beekman, P.W.; Veldwisch, G.J.A.; Bolding, J.A.

    2014-01-01

    Smallholder irrigation in Central Mozambique predominantly takes place in an informal setting. This renders these smallholders and their activities invisible for policy purposes. Identification efforts of smallholder irrigation as well as the potential for new irrigation development are often the

  15. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen

    2012-01-01

    Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

  16. Pivotal response treatment for children with autism spectrum disorders: A systematic review

    NARCIS (Netherlands)

    Verschuur, R.; Didden, H.C.M.; Lang, R.; Sigafoos, J.; Huskens, B.E.B.M.

    2014-01-01

    Intervention studies evaluating pivotal response treatment (PRT) were systematically identified and analyzed. Forty-three studies were summarized in terms of (a) participant characteristics, (b) dependent variables, (c) intervention procedures, (d) intervention outcomes, and (e) certainty of evidenc

  17. 78 FR 66941 - Design Considerations for Pivotal Clinical Investigations for Medical Devices; Guidance for...

    Science.gov (United States)

    2013-11-07

    ... for Medical Devices; Guidance for Industry, Clinical Investigators, Institutional Review Boards and... entitled ``Design Considerations for Pivotal Clinical Investigations for Medical Devices.'' This document... premarket submissions for medical devices and for FDA staff who review those submissions. This...

  18. A study of shallow water’s effect on a ship’s pivot point

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Carreño

    2012-12-01

    Full Text Available Information regarding a turning ship’s pivot point has been collected, taking practical notes and ship maneuvering manuals into account as well as experimental data and simulated results, together revealing consistent behaviour when varying water depth or some ship’s particulars. Results from studies already carried out using the Colombian Navy’s River Support Patrol Vessel (RSPV are included here to estimate the pivot point and contrast results with theory and available observations. Linear manoeuvrability theory was tested and the results revealed poor agreement with kinematic equations. As to the depth variation effect, full-scale experiments confirmed that the pivot point’s position, when in shallow water, always varied in the same way, thereby agreeing with available pivot point information.

  19. The Polynomial Pivots as Initial Values for a New Root-Finding Iterative Method

    Directory of Open Access Journals (Sweden)

    Mario Lázaro

    2015-01-01

    Full Text Available A new iterative method for polynomial root-finding based on the development of two novel recursive functions is proposed. In addition, the concept of polynomial pivots associated with these functions is introduced. The pivots present the property of lying close to some of the roots under certain conditions; this closeness leads us to propose them as efficient starting points for the proposed iterative sequences. Conditions for local convergence are studied demonstrating that the new recursive sequences converge with linear velocity. Furthermore, an a priori checkable global convergence test inside pivots-centered balls is proposed. In order to accelerate the convergence from linear to quadratic velocity, new recursive functions together with their associated sequences are constructed. Both the recursive functions (linear and the corrected (quadratic convergence are validated with two nontrivial numerical examples. In them, the efficiency of the pivots as starting points, the quadratic convergence of the proposed functions, and the validity of the theoretical results are visualized.

  20. A scintigraphic study of colostomy irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige (Nara Medical Univ., Kashihara (Japan))

    1991-09-01

    Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with {sup 99m}Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author).

  1. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    C. Boutsioukis; L.W.M. van der Sluis

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  2. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, C.; van der Sluis, L.W.M.; Basrani, B.

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  3. Using Automation to Improve Surface Irrigation Management

    Science.gov (United States)

    In the Lower Mississippi Water Resource Area (WRA 08), also called the Mid-South, 2 million ha of cropland (80% of the irrigated farmland) employ surface irrigation, almost equally divided between furrow (52%) and controlled flooding (48%). Because Mid-South farmers experience less-than-optimal surf...

  4. Soil Enzyme Activities with Greenhouse Subsurface Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-Long; WANG Yao-Sheng

    2006-01-01

    Various environmental conditions determine soil enzyme activities, which are important indicators for changes of soil microbial activity, soil fertility, and land quality. The effect of subsurface irrigation scheduling on activities of three soil enzymes (phosphatase, urease, and catalase) was studied at five depths (0-10, 10-20, 20-30, 30-40, and 40-60 cm) of a tomato greenhouse soil. Irrigation was scheduled when soil water condition reached the maximum allowable depletion(MAD) designed for different treatments (-10, -16, -25, -40, and -63 kPa). Results showed that soil enzyme activities had significant responses to the irrigation scheduling during the period of subsurface irrigation. The neutral phosphatase activity and the catalase activity were found to generally increase with more frequent irrigation (MAD of -10 and -16kPa). This suggested that a higher level of water content favored an increase in activity of these two enzymes. In contrast,the urease activity decreased under irrigation, with less effect for MAD of -40 and -63 kPa. This implied that relatively wet soil conditions were conducive to retention of urea N, but relatively dry soil conditions could result in increasing loss of urea N. Further, this study revealed that soil enzyme activities could be alternative natural bio-sensors for the effect of irrigation on soil biochemical reactions and could help optimize irrigation management of greenhouse crop production.

  5. CROP DENSITY AND IRRIGATION WITH SALINE WATER

    OpenAIRE

    Feinerman, Eli

    1983-01-01

    The economic implications of plant density for irrigation water use under saline conditions are investigated, utilizing the involved physical and biological relationships. The analysis considers a single crop and is applied to cotton data. The results suggest that treating plant density as an endogenous control variable has substantial impact on profits and the optimal quantities and qualities of the applied irrigation water.

  6. Tomato Root Response to Subsurface Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Yu-Ping; ZHANG Xu-Dong; ZHANG Yu-Long; LI Jun; YANG Li-Juan; HUANG Yi; LIU Ming-Da

    2004-01-01

    Four depth treatments of subsurface drip irrigation pipes were designated as 1) at 20,2) 30 and 3) 40 cm depths all with a drip-proof flumes underneath,and 4) at 30 cm without a drip-proof flume to investigate the responses of a tomato root system to different technical parameters of subsurface drip irrigation in a glass greenhouse,to evaluate tomato growth as affected by subsurface drip irrigation,and to develop an integrated subsurface drip irrigation method for optimal tomato yield and water use in a glass greenhouse. Tomato seedlings were planted above the subsurface drip irrigation pipe. Most of the tomato roots in treatment 1 were found in the top 0-20 cm soil depth with weak root activity but with yield and water use efficiency (WUE) significantly less (P ---- 0.05) than treatment 2; root activity and tomato yield were significantly higher (P = 0.05) with treatment 3 compared to treatment 1; and with treatment 2 the tomato roots and shoots grew harmoniously with root activity,nutrient uptake,tomato yield and WUE significantly higher (P= 0.05) or as high as the other treatments. These findings suggested that subsurface drip irrigation with pipes at 30 cm depth with a drip-proof flume placed underneath was best for tomato production in greenhouses. In addition,the irrigation interval should be about 7-8 days and the irrigation rate should be set to 225 m3 ha-1 per event.

  7. Water Resources Impacts on Tribal Irrigation Projects

    Science.gov (United States)

    Minihane, M.

    2015-12-01

    The Bureau of Indian Affairs (BIA) Branch of Irrigation and Power provides oversight and technical support to select irrigation projects and systems on tribal lands. The BIA provides operations and maintenance support for 16 irrigation systems. To make the best use of limited resources, the BIA must incorporate climate change impacts on hydrology and water management for these irrigation systems in the coming decades. The 16 irrigation projects discussed here are divided into three climatological regions: the Pacific Northwest Region, the Greater Rocky Mountain Region, and the Western, Southwest, & Navajo Region. Significant climate projections that impact irrigation systems in one or more of these regions include increased temperatures and evaporative demand, earlier snowmelt and runoff, an increase in floods, an increase in heavy precipitation events, an increase in the frequency and intensity of droughts, and declining water supplies. Some irrigation projects are particularly vulnerable to these climate impacts because they are in already water-stressed areas or areas in which water resources are over-allocated. Other irrigation projects will have to adjust their storage and water management strategies to accommodate changes in the timing of streamflow. Overall, though, the BIA will be better able to assist tribal nations by incorporating expected climate impacts into their water resources management practices.

  8. Effect of low-cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, P.

    2007-01-01

    without caps from a height >1 m. CONCLUSION: Simple, cheap and easily adoptable irrigation methods have great potential to reduce crop contamination in low-income areas. When used in combination with other on-farm and post-harvest risk reduction measures, these will help to comprehensively reduce public......OBJECTIVE: To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water in urban farming in Ghana. METHODS: Trials on drip kits, furrow irrigation and watering...... cans were conducted with urban vegetable farmers. Trials were arranged in a completely randomised block design with each plot having all three irrigation methods tested. This was conducted in both dry and wet seasons. Three hundred and ninety-six lettuce, 72 soil, 15 poultry manure and 32 water samples...

  9. Reclaimed Water for Turfgrass Irrigation

    Directory of Open Access Journals (Sweden)

    Xunzhong Zhang

    2010-09-01

    Full Text Available Sustainable irrigation of turfgrass grown on coarse-textured soils with reclaimed water must avoid detrimental effects of soluble salts on plant growth and soil quality and groundwater enrichment of nitrogen (N and phosphorus (P. The purpose of this study was (1 to investigate the effects of irrigating with municipal reclaimed water containing higher concentrations of soluble salts than potable water on turfgrass growth and quality and (2 to compare the effects of reclaimed and potable water on turfgrass assimilation and leaching of N and P. A sand-based medium plumbed to supply potable and reclaimed water and instrumented with lysimeters to collect leachate was planted with hybrid bermudagrass (Cynodon dactylon x Cynodon transvaalensis var. Tifsport and creeping bentgrass (Agrostis stolonifera var. L-93. Both species produced high quality turfgrass with the reclaimed water. Although both grasses are moderately or highly salt tolerant when fully established, the bermudagrass growth and quality were reduced by the reclaimed water upon breaking dormancy, and its N use during this period was reduced. Continuous use of reclaimed water of the quality used in the study poses a potential soil Na accumulation problem. Both turfgrasses assimilated high amounts of N and P with minimal potential losses to groundwater.

  10. Setting efficiency indicators for center pivots Ajuste de indicadores de eficiência para pivôs centrais

    Directory of Open Access Journals (Sweden)

    Ricardo L. Schons

    2012-06-01

    Full Text Available In this study, it was discussed the efficiency criteria in each of the elements that compose a central pivot, and this analysis was applied to two sets of systems located in regions of Cruz Alta and Santo Augusto, state of Rio Grande do Sul, Brazil. The methodology used combines water and energy assessment through an indicator called Normalized Specific Consumption in Irrigation (C ENI, allowing thus a comparison between equipment and projects. The C ENI in Cruz Alta region showed 72% of the equipment above the standard (8.68 kWh mm-1 ha-1 100m-1, and in Santo Augusto region 64.28% with consumption above the standard. The mean irrigation efficiency for Cruz Alta region was 29.85%, with standard deviation of 5.41%, and for Santo Augusto region, it was 29.02%, with standard deviation of 5.15%.Neste trabalho, são discutidos critérios de eficiência em cada um dos elementos que compõem um pivô central, sendo esta análise aplicada a dois conjuntos de sistemas localizados, nas regiões de Cruz Alta e Santo Augusto, Rio Grande do Sul. A metodologia utilizada associa as avaliações hídrica e energética por meio de um indicador denominado Consumo Específico Normalizado na Irrigação (C ENI, possibilitando, desta forma, uma comparação entre equipamentos e entre projetos. O C ENI na região de Cruz Alta apresentou 72% dos equipamentos acima do padrão (8,68 kWh mm-1 ha-1 100m-1, e na região de Santo Augusto, 64,28% com o consumo acima do padrão. A eficiência de irrigação média para a região de Cruz Alta foi de 29,85%, com desvio-padrão de 5,41%; e para a Região de Santo Augusto foi de 29,02%, com desvio padrão de 5,15%.

  11. [Irrigants and intracanal medicaments in endodontics].

    Science.gov (United States)

    Zehnder, Matthias; Lehnert, Birgit; Schönenberger, Kathrin; Waltimo, Tuomas

    2003-01-01

    Modern, biologic root canal therapy should be performed with suitable irrigating solutions and intracanal medicaments. The goal of endodontic treatment is to free the treated tooth from infection and prevent reinfection as thoroughly as possible by means which do not put the organism at risk. In this review of the literature, an evidence-based concept for irrigation and medication of root canal systems is presented. Irrigants and medicaments are discussed with respect to their antimicrobial, tissue-dissolving and endotoxin-decontaminating capacity in relation to their systemic toxicity. Recent findings pertaining to interactions of root canal medicaments and irrigating solutions and their impact on a sound irrigating and medicating concept are discussed.

  12. A sustainable model for training teachers to use pivotal response training.

    Science.gov (United States)

    Suhrheinrich, Jessica

    2015-08-01

    The increase in the rate of autism diagnoses has created a growing demand for teachers who are trained to use effective interventions. The train-the-trainer model, which involves training supervisors to train others, may be ideal for providing cost-effective training and ongoing support to teachers. Although research supports interventions, such as pivotal response training, as evidence-based, dissemination to school environments has been problematic. This study assessed the benefits of using the train-the-trainer model to disseminate pivotal response training to school settings. A multiple-baseline design was conducted across three training groups, each consisting of one school staff member (trainer), three special education teachers, and six students. Trainers conducted the teacher-training workshop with high adherence to training protocol and met mastery criteria in their ability to implement pivotal response training, assess implementation of pivotal response training, and provide feedback to teachers. Six of the nine teachers mastered all components of pivotal response training. The remaining three teachers implemented 89% of the pivotal response training components correctly. The majority of trainers and teachers maintained their abilities at follow-up. These results support the use of the train-the-trainer model as an effective method of disseminating evidence-based practices in school settings. © The Author(s) 2014.

  13. Efficient Execution Methods of Pivoting for Bulk Extraction of Entity-Attribute-Value-Modeled Data.

    Science.gov (United States)

    Luo, Gang; Frey, Lewis J

    2016-03-01

    Entity-attribute-value (EAV) tables are widely used to store data in electronic medical records and clinical study data management systems. Before they can be used by various analytical (e.g., data mining and machine learning) programs, EAV-modeled data usually must be transformed into conventional relational table format through pivot operations. This time-consuming and resource-intensive process is often performed repeatedly on a regular basis, e.g., to provide a daily refresh of the content in a clinical data warehouse. Thus, it would be beneficial to make pivot operations as efficient as possible. In this paper, we present three techniques for improving the efficiency of pivot operations: 1) filtering out EAV tuples related to unneeded clinical parameters early on; 2) supporting pivoting across multiple EAV tables; and 3) conducting multi-query optimization. We demonstrate the effectiveness of our techniques through implementation. We show that our optimized execution method of pivoting using these techniques significantly outperforms the current basic execution method of pivoting. Our techniques can be used to build a data extraction tool to simplify the specification of and improve the efficiency of extracting data from the EAV tables in electronic medical records and clinical study data management systems.

  14. Reconciling irrigated food production with environmental flows for Sustainable Development Goals implementation

    Science.gov (United States)

    Jägermeyr, Jonas; Pastor, Amandine; Biemans, Hester; Gerten, Dieter

    2017-07-01

    Safeguarding river ecosystems is a precondition for attaining the UN Sustainable Development Goals (SDGs) related to water and the environment, while rigid implementation of such policies may hamper achievement of food security. River ecosystems provide life-supporting functions that depend on maintaining environmental flow requirements (EFRs). Here we establish gridded process-based estimates of EFRs and their violation through human water withdrawals. Results indicate that 41% of current global irrigation water use (997 km3 per year) occurs at the expense of EFRs. If these volumes were to be reallocated to the ecosystems, half of globally irrigated cropland would face production losses of >=10%, with losses of ~20-30% of total country production especially in Central and South Asia. However, we explicitly show that improvement of irrigation practices can widely compensate for such losses on a sustainable basis. Integration with rainwater management can even achieve a 10% global net gain. Such management interventions are highlighted to act as a pivotal target in supporting the implementation of the ambitious and seemingly conflicting SDG agenda.

  15. Historical influence of irrigation on climate extremes

    Science.gov (United States)

    Thiery, Wim; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2016-04-01

    Land irrigation is an essential practice sustaining global food production and many regional economies. During the last decades, irrigation amounts have been growing rapidly. Emerging scientific evidence indicates that land irrigation substantially affects mean climate conditions in different regions of the world. However, a thorough understanding of the impact of irrigation on extreme climatic conditions, such as heat waves, droughts or intense precipitation, is currently still lacking. In this context, we aim to assess the historical influence of irrigation on the occurrence of climate extremes. To this end, two simulations are conducted over the period 1910-2010 with a state-of-the-art global climate model (the Community Earth System Model, CESM): a control simulation including all major anthropogenic and natural external forcings except for irrigation and a second experiment with transient irrigation enabled. The two simulations are evaluated for their ability to represent (i) hot, dry and wet extremes using the HadEX2 and ERA-Interim datasets as a reference, and (ii) latent heat fluxes using LandFlux-EVAL. Assuming a linear combination of climatic responses to different forcings, the difference between both experiments approximates the influence of irrigation. We will analyse the impact of irrigation on a number of climate indices reflecting the intensity and duration of heat waves. Thereby, particular attention is given to the role of soil moisture changes in modulating climate extremes. Furthermore, the contribution of individual biogeophysical processes to the total impact of irrigation on hot extremes is quantified by application of a surface energy balance decomposition technique to the 90th and 99th percentile surface temperature changes.

  16. Determination of Water Use Effectiveness in Hayrabolu Irrigation Scheme

    Directory of Open Access Journals (Sweden)

    A.N.Yuksel

    2005-05-01

    Full Text Available This study was conducted to determine the effectiveness of irrigation water use in HayraboluIrrigation Scheme, established in 1987 and transferred to irrigation cooperative. The study was completed intwo years in order to minimize the meteorological and environmental effects on evapotranspiration andirrigation water requirement. Irrigation application efficiency and sufficiency of farmer irrigation applicationwere investigated at 20 different farmers’ fields.Pressurized irrigation was prevailed (51 % and irrigation efficiency for sprinkler and surfaceirrigation methods were 61 and 62 %, respectively. Irrigation water losses on the scheme basis was 11,91 %.It was further determined that farmers irrigated their crops according to the phonological observation, did nottake the permissible consumption level of water content and applied insufficient water to satisfy the fieldcapacity. Among the predominantly grown crops, wheat and sunflower were not irrigated assuming that theprecipitation was sufficient to meet their demand while onion and corn were under-supplied. Generally, aneffective irrigation programme was not realised.

  17. Mediterranean irrigation under climate change: more efficient irrigation needed to compensate for increases in irrigation water requirements

    Science.gov (United States)

    Fader, M.; Shi, S.; von Bloh, W.; Bondeau, A.; Cramer, W.

    2016-03-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 concentrations may affect irrigation requirements in the Mediterranean region by 2080-2090. Future demographic change and technological improvements in irrigation systems are taken into account, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL (Lund-Potsdam-Jena managed Land) after an extensive development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries such as Syria, Egypt and Turkey have a higher savings potential than others. Currently some crops, especially sugar cane and agricultural trees, consume on average more irrigation water per hectare than annual crops. Different crops show different magnitudes of changes in net irrigation requirements due to climate change, the increases being most pronounced in agricultural trees. The Mediterranean area as a whole may face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (4 and 18 % with 2 °C global warming combined with the full CO2-fertilization effect and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the southern and eastern Mediterranean. However, improved irrigation technologies and conveyance systems have a large water saving potential, especially in the eastern Mediterranean, and may be able to

  18. Debris and irrigant extrusion potential of 2 rotary systems and irrigation needles.

    Science.gov (United States)

    Altundasar, Emre; Nagas, Emre; Uyanik, Ozgur; Serper, Ahmet

    2011-10-01

    The purpose of this study was to compare the amount of apically extruded irrigant using 2 Ni-Ti rotary systems. Forty mandibular premolars with single canals were randomly assigned into 4 groups. Flower arrangement foam cubes were weighed with a precision balance before being attached to the apical portions of all teeth. In group 1, preparation was completed with ProTaper files. In group 2 canals were prepared with RaCe files. In groups 1 and 2, the irrigant was delivered with a 30-gauge conventional dental needle. In groups 3 and 4, teeth were prepared as in groups 1 and 2 with the exception that the irrigant was delivered with a side-vented irrigation needle. The weight of the extruded material (irrigant and debris) for each group was calculated by comparing the pre- and postinstrumentation weights of the foams used for periapical modeling. Obtained data were analyzed by Kruskal-Wallis and Mann-Whitney U tests, with P equals .05 as the level for statistical significance. ProTaper files used with regular needle irrigation had the highest fluid extrusion. The lowest irrigant extrusion was observed with the RaCe system combined with a side-vented irrigation needle. Within the limitations of this study, it can be concluded that irrigation needle and rotary instruments have an effect on the amount of extruded root canal irrigant.

  19. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions.

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen; Forner, Leopoldo

    2012-05-01

    Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layers and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation.

  20. Biological degradation of chernozems under irrigation

    Directory of Open Access Journals (Sweden)

    Oksana Naydyonova

    2014-12-01

    Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

  1. Irrigation Water Management in Latin America

    Directory of Open Access Journals (Sweden)

    Aureo S de Oliveira

    2009-12-01

    Full Text Available Latin American countries show a great potential for expanding their irrigated areas. Irrigation is important for strengthening local and regional economy and for enhancing food security. The present paper aimed at providing a brief review on key aspects of irrigation management in Latin America. Poor irrigation management can have great impact on crop production and on environment while good management reduces the waste of soil and water and help farmers maximizing their profits. It was found that additional research is needed to allow a better understanding of crop water requirements under Latin American conditions as well as to provide farmers with local derived information for irrigation scheduling. The advantages of deficit irrigation practices and the present and future opportunities with the application of remote sensing tools for water management were also considered. It is clear that due to the importance of irrigated agriculture, collaborative work among Latin American researchers and institutions is of paramount importance to face the challenges imposed by a growing population, environment degradation, and competition in the global market.

  2. Stress optimization of leaf-spring crossed flexure pivots for an active Gurney flap mechanism

    Science.gov (United States)

    Freire Gómez, Jon; Booker, Julian D.; Mellor, Phil H.

    2015-04-01

    The EU's Green Rotorcraft programme is pursuing the development of a functional and airworthy Active Gurney Flap (AGF) for a full-scale helicopter rotor blade. Interest in the development of this `smart adaptive rotor blade' technology lies in its potential to provide a number of aerodynamic benefits, which would in turn translate into a reduction in fuel consumption and noise levels. The AGF mechanism selected employs leaf-spring crossed flexure pivots. These provide important advantages over bearings as they are not susceptible to seizing and do not require maintenance (i.e. lubrication or cleaning). A baseline design of this mechanism was successfully tested both in a fatigue rig and in a 2D wind tunnel environment at flight-representative deployment schedules. For full validation, a flight test would also be required. However, the severity of the in-flight loading conditions would likely compromise the mechanical integrity of the pivots' leaf-springs in their current form. This paper investigates the scope for stress reduction through three-dimensional shape optimization of the leaf-springs of a generic crossed flexure pivot. To this end, a procedure combining a linear strain energy formulation, a parametric leaf-spring profile definition and a series of optimization algorithms is employed. The resulting optimized leaf-springs are proven to be not only independent of the angular rotation at which the pivot operates, but also linearly scalable to leaf-springs of any length, minimum thickness and width. Validated using non-linear finite element analysis, the results show very significant stress reductions relative to pivots with constant cross section leaf-springs, of up to as much as 30% for the specific pivot configuration employed in the AGF mechanism. It is concluded that shape optimization offers great potential for reducing stress in crossed flexure pivots and, consequently, for extending their fatigue life and/or rotational range.

  3. Irrigation of treated wastewater in Braunschweig, Germany

    DEFF Research Database (Denmark)

    Ternes, T.A.; Bonerz, M.; Herrmann, N.

    2007-01-01

    In this study the fate of pharmaceuticals and personal care products which are irrigated on arable land with treated municipal waste-water was investigated. In Braunschweig, Germany, wastewater has been irrigated continuously for more than 45 years. In the winter time only the effluent...... of digested sludge, because many polar compounds do not sorb to sludge and lipophilic compounds are not mobile in the soil-aquifer. Most of the selected PPCPs were never detected in any of the lysimeter or groundwater samples, although they were present in the treated wastewater irrigated onto the fields...

  4. Irrigation water use in Kansas, 2013

    Science.gov (United States)

    Lanning-Rush, Jennifer L.

    2016-03-22

    This report, prepared by the U.S. Geological Survey in cooperation with the Kansas Department of Agriculture, Division of Water Resources, presents derivative statistics of 2013 irrigation water use in Kansas. The published regional and county-level statistics from the previous 4 years (2009–12) are shown with the 2013 statistics and are used to calculate a 5-year average. An overall Kansas average and regional averages also are calculated and presented. Total reported irrigation water use in 2013 was 3.3 million acre-feet of water applied to 3.0 million irrigated acres.

  5. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation. Thre

  6. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation.

  7. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    OpenAIRE

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Kennedy published his channel-forming discharge theory in 1895. Subsequently different theories have been developed and are used around the world. All of them assume uniform and steady flow conditions ...

  8. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development. In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment. Field dye staining experiments were conducted at different soils with various irrigation amount. Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency. Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage efficiency, and uniformity. Under the same irrigation condition, soil chemical distributions were more heterogeneous than soil water distributions. The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount. Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount. Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uniformity, which resulted in high environmental risks of groundwater pollution.

  9. Analysis of Irrigation Water Quality at Kadawa Irrigation Project for Improved Productivity

    Directory of Open Access Journals (Sweden)

    AR Sanda

    2014-09-01

    Full Text Available In the face of water scarcity and the several negative consequences, such as water wastage, flooding, water logging, soil losses and production losses, conserving the finite amount of fresh water is a must. The quality of irrigation water must therefore be ascertained. The chemical quality of three sources of irrigation water from canal and drainage water, namely drainage water, fresh irrigation water from canal, and drainage/irrigation water mixture, were analyzed from Kadawa irrigation Project for year 2013 and 2014 cropping seasons, with the view to evaluating the potential risks associated with their use in irrigation and hence their suitability or otherwise for irrigation purposes. The analysis revealed that the use of drainage water alone for irrigation may result in problems associated with salinity, while a blend of drainage/irrigation water in the ratio of 1:1 is a viable means of water conservation and a good means of crop production. DOI: http://dx.doi.org/10.3126/ije.v3i3.11082 International Journal of Environment Vol.3(3 2014: 235-240

  10. Farmers’ Willingness to Pay for Irrigation Water: A Case of Tank Irrigation Systems in South India

    Directory of Open Access Journals (Sweden)

    Karthikeyan Chandrasekaran

    2009-08-01

    Full Text Available The economic value of tank irrigation water was determined through Contingency Valuation Method by analyzing farmers’ willingness to pay for irrigation water under improved water supply conditions during wet and dry seasons of paddy cultivation. Quadratic production function was also used to determine the value of irrigation water. The comparison of the economic value of water estimated using different methods strongly suggests that the present water use pattern will not lead to sustainable use of the resource in the tank command areas. Policy options for sustainable use of irrigation water and management of tanks in India were suggested.

  11. Strategic irrigation against apple scab (Venturia inaequalis)

    DEFF Research Database (Denmark)

    Korsgaard, Maren

    2012-01-01

    In Denmark there are several organic orchards, that do not spray at all, and they seek non-spraying methods to prevent apple scab. In this pilot trial, irrigation with water at strategic moments was tested to prevent scab-infection. In April-June 2011 in five organic orchards we irrigated...... the orchard floor, to force the ascospores to be released. We irrigated with at least 0.2 mm of water in dry periods, at least 12 hours before rain forecast. The idea was to empty the stock of ascospores during dry spells, so they would dry out without infecting the leaves. To find the best strategic times...... for irrigation, we used the local weather forecast and the scab-warning programme Rimpro based on data from climate stations located in the orchards. In this first year of trial we experienced difficulties in spreading the water evenly. A water wagon turned out to work better than sprinklers. We found...

  12. Estimated Irrigated Agricultural Water Use In 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a 100-meter cell resolution raster dataset of estimated use of irrigated agricultural water use data for the southwestern U.S. The dataset was...

  13. Pivotal surfaces in inverse hexagonal and cubic phases of phospholipids and glycolipids.

    Science.gov (United States)

    Marsh, Derek

    2011-03-01

    Data on the location and dimensions of the pivotal surfaces in inverse hexagonal (H(II)) and inverse cubic (Q(II)) phases of phospholipids and glycolipids are reviewed. This includes the H(II) phases of dioleoyl phosphatidylethanolamine, 2:1 mol/mol mixtures of saturated fatty acids with the corresponding diacyl phosphatidylcholine, and glucosyl didodecylglycerol, and also the Q(II)(230/G) gyroid inverse cubic phases of monooleoylglycerol and glucosyl didodecylglycerol. Data from the inverse cubic phases are largely compatible with those from inverse hexagonal H(II)-phases. The pivotal plane is located in the hydrophobic region, relatively close to the polar-apolar interface. The area per lipid at the pivotal plane is similar in size to lipid cross-sectional areas found in the fluid lamellar phase (L(α)) of lipid bilayers. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Single-sided natural ventilation through a centre-pivot roof window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Nielsen, Peter V.; Gunner, Amalie

    2014-01-01

    The characteristics of centre pivot roof windows for wind driven single-sided ventilation has not been studied before. These types of windows are dominating roof windows in Europe. Knowledge of flow characteristics of this kind of window is essential for accurate designing of natural ventilation...... systems. In this study, numerical methods were used to characterise a centre-pivot roof window for wind-driven single-sided ventilation. A 1:20 scale model house of the Energy Flex House (Denmark) was used in this study. The roof slope was 36o. It was found that the single-sided ventilation through...... the centre-pivot roof window can be characterised by a factor called the flow factor. The flow factor was a function of the sash opening-angle and wind direction. The flow factor increased with increase in opening-angle and decreased with increase in wind direction....

  15. Proceedings of the solar irrigation workshop

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-06-01

    The ERDA Solar Irrigation Workshop was structured to be a major vehicle for information dissemination and technology transfer. It covered a wide range of subject matter related to crop irrigation including current hardware, economics, experiments, and international requirements. Speakers represented manufacturers, ranchers, governmental entities, universities and research firms. The proceedings consist of one page abstracts for each presentation, a brief biographical sketch of each speaker and sources for further information on each subject.

  16. Smart Water Conservation System for Irrigated Landscape

    Science.gov (United States)

    2016-05-01

    by the Energy Independence and Security Act (EISA). Reducing potable water demand for landscape irrigation correlates to lower energy costs necessary...irrigation is necessary. Typically, timer-based systems are adjusted higher than needed to account for consecutive hot days that stress turf beyond the...implementation at sports field, parade grounds, and/or landscape near buildings. Appendix C details the life cycle cost for the smart water

  17. Irrigation enhances precipitation at the mountains downwind

    Directory of Open Access Journals (Sweden)

    J. Jódar

    2010-05-01

    Full Text Available Atmospheric circulation models predict an irrigation-rainfall feedback. However, actual field evidences are very weak. We present strong field evidence about an increase in rainfall at the mountains located downwind of irrigated zones. We chose two regions, located in semiarid southern Spain, where irrigation started at a well defined date, and we analyzed rainfall statistics before and after the beginning of irrigation. Analyzed statistics include the variation of (1 mean rainfall Δ P, (2 ratio of monthly precipitation to annual precipitation Δ r, and (3 number of months with minimum rainfall episodes Δ Pmin after a transition period from unirrigated to irrigated conditions. All of them show statistically significant increases. Δ P and Δ r show larger and more statistically significant variations in June and July. Their variation is proportional to the mean annual water volume applied in the neighboring upwind irrigation lands. Variations in Δ Pmin are statistically significant in the whole summer. That is, the number of months with some rain displays a relevant increase after irrigation. However, increase in rainfall while statistically significant is distributed over a broad region, so that it is of little relevance from a water resources perspective. The joint increment in Δ P and Δ Pmin after the irrigation transition period denotes a net increase in the number of months having a minimum cumulated precipitation in summer.

  18. Irrigation et paludisme : un couple infernal?

    OpenAIRE

    Mergeai, G.

    2016-01-01

    Irrigation and Malaria - a Terrible Combination?. Increasing agricultural productivity is a priority in most of the developing countries and using irrigation is one of the most efficient ways of achieving this goal. Almost half a billion people in the world contract malaria every year and approximately one million die as a result. The majority of these victims are farmers or members of their families. In infected areas, malaria continues to have major negative impacts on agricultural producti...

  19. Grower demand for sensor-controlled irrigation

    Science.gov (United States)

    Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

    2015-01-01

    Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

  20. Steps towards commercialization of new power buoy with pivoting arm LOPF

    DEFF Research Database (Denmark)

    2013-01-01

    direct measurements from the model device are: voltage output, the torque on the generator, the arm bending moment produced by the mooring line and the absolute angle of the pivoting float. These allowed to follow the conversion of power in the power train from mechanic to electric power......The fully instrumented Lever Operated Pivoting Float LOPF wave energy buoy model has gone through the first stage of testing in regular waves in scale 1:25 of the North Sea wave conditions, in the 3D deep wave basin at the Hydraulic and Coastal Engineering Laboratory of Aalborg University. Some...

  1. Excel Data Analysis your visual blueprint for creating and analyzing data, charts and PivotTables

    CERN Document Server

    Etheridge, Denise

    2010-01-01

    Advanced techniques for Excel power users. Crunch and analyze Excel data the way the professionals do with this clean, uncluttered, visual guide to advanced Excel techniques. Using numerous screenshots and easy-to-follow numbered steps, this book clearly shows you how to perform professional-level modeling, charting, data access, data slicing, and other functions. You'll find super techniques for getting the most out of Excel's statistical and financial functions, Excel PivotTables and PivotCharts, Excel Solver and BackSolver, and more.: Provides a clear look at power-using Excel, the world's

  2. Improvement of effective solid angle using virtual-pivot holder and large EDS detector.

    Science.gov (United States)

    Koshiya, Shogo; Kimoto, Koji

    2017-02-01

    This paper describes the effective solid angle improvement achieved using a large-area silicon drift detector together with a virtual-pivot double-tilt specimen holder. The virtual-pivot mechanism enables various designs of specimen-retaining and can reduce the shadowing effect. Energy-dispersive X-ray spectra were measured and converted into effective solid angles using different types of specimen holders and specimens. The investigated shadowing-free mechanical system yielded effective solid angles approaching the nominal solid angle of 0.464sr. In addition, we have demonstrated the availability of the plastic (polyetheretherketone) specimen holder for low system noise.

  3. Experimental Evaluation of the Discharge Coefficient of a Centre-Pivot Roof Window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza; Heiselberg, Per

    2013-01-01

    Windows are a component of naturally ventilated buildings. The scientific knowledge of how to estimate of airflow rates through windows is limited, especially in the case of centre-pivot roof windows. The flow through this type of windows is traditionally characterized by the orifice plate flow...... equation. This equation involves a discharge coefficient of the window. The value of the discharge coefficient is the major cause of erroneous estimation of airflow rates. This paper focuses on the experimental study of the discharge coefficient (CD) of a centre-pivot roof window. The measurements were...

  4. Mediterranean agriculture: More efficient irrigation needed to compensate increases in future irrigation water requirements

    Science.gov (United States)

    Fader, Marianela; Shi, Sinan; von Bloh, Werner; Bondeau, Alberte; Cramer, Wolfgang

    2016-04-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. Our research shows that, at present, Mediterranean region could save 35% of water by implementing more efficient irrigation and conveyance systems. Some countries like Syria, Egypt and Turkey have higher saving potentials than others. Currently some crops, especially sugar cane and agricultural trees, consume in average more irrigation water per hectare than annual crops (1). Also under climate change, more efficient irrigation is of vital importance for counteracting increases in irrigation water requirements. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4% and 18% from climate change alone by the end of the century if irrigation systems and conveyance are not improved. Population growth increases these numbers to 22% and 74%, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean, and may be able to compensate to some degree the increases due to climate change and population growth. Both subregions would need around 35% more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect (1). However, in some scenarios (in this case as combinations of climate change, irrigation technology, influence of population growth and CO2-fertilization effect) water scarcity may constrain the supply of the irrigation water needed in future in Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain (1). In this study, vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL ("Lund-Potsdam-Jena managed Land") after a

  5. A Real-time Irrigation Forecasting System in Jiefangzha Irrigation District, China

    Science.gov (United States)

    Cong, Z.

    2015-12-01

    In order to improve the irrigation efficiency, we need to know when and how much to irrigate in real time. If we know the soil moisture content at this time, we can forecast the soil moisture content in the next days based on the rainfall forecasting and the crop evapotranspiration forecasting. Then the irrigation should be considered when the forecasting soil moisture content reaches to a threshold. Jiefangzha Irrigation District, a part of Hetao Irrigation District, is located in Inner Mongolia, China. The irrigated area of this irrigation district is about 140,000 ha mainly planting wheat, maize and sunflower. The annual precipitation is below 200mm, so the irrigation is necessary and the irrigation water comes from the Yellow river. We set up 10 sites with 4 TDR sensors at each site (20cm, 40cm, 60cm and 80cm depth) to monitor the soil moisture content. The weather forecasting data are downloaded from the website of European Centre for Medium-Range Weather Forecasts (ECMWF). The reference evapotranspiration is estimated based on FAO-Blaney-Criddle equation with only the air temperature from ECMWF. Then the crop water requirement is forecasted by the crop coefficient multiplying the reference evapotranspiration. Finally, the soil moisture content is forecasted based on soil water balance with the initial condition is set as the monitoring soil moisture content. When the soil moisture content reaches to a threshold, the irrigation warning will be announced. The irrigation mount can be estimated through three ways: (1) making the soil moisture content be equal to the field capacity; (2) making the soil moisture saturated; or (3) according to the irrigation quota. The forecasting period is 10 days. The system is developed according to B2C model with Java language. All the databases and the data analysis are carried out in the server. The customers can log in the website with their own username and password then get the information about the irrigation forecasting

  6. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Artificial Drainage (1992) and Irrigation (1997)

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data sets were derived from tabular National Resource Inventory (NRI) data sets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 2000). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, U.S. Geological Survey, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others, 2007). The MRB_E2RF1 catchments are based on a modified

  7. Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

    NARCIS (Netherlands)

    Kooij, van der S.

    2016-01-01

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems

  8. Reducing microbial contamination on wastewater-irrigated lettuce by cessation of irrigation before harvesting

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, Pay;

    2007-01-01

    OBJECTIVE: To assess the effectiveness of cessation of irrigation before harvesting in reducing microbial contamination of lettuce irrigated with wastewater in urban vegetable farming in Ghana. METHODS: Assessment was done under actual field conditions with urban vegetable farmers in Ghana. Trials...

  9. Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

    NARCIS (Netherlands)

    Kooij, van der S.

    2016-01-01

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems (FMI

  10. Irrigation Requirement Estimation Using Vegetation Indices and Inverse Biophysical Modeling

    Science.gov (United States)

    Bounoua, Lahouari; Imhoff, Marc L.; Franks, Shannon

    2010-01-01

    We explore an inverse biophysical modeling process forced by satellite and climatological data to quantify irrigation requirements in semi-arid agricultural areas. We constrain the carbon and water cycles modeled under both equilibrium, balance between vegetation and climate, and non-equilibrium, water added through irrigation. We postulate that the degree to which irrigated dry lands vary from equilibrium climate conditions is related to the amount of irrigation. The amount of water required over and above precipitation is considered as an irrigation requirement. For July, results show that spray irrigation resulted in an additional amount of water of 1.3 mm per occurrence with a frequency of 24.6 hours. In contrast, the drip irrigation required only 0.6 mm every 45.6 hours or 46% of that simulated by the spray irrigation. The modeled estimates account for 87% of the total reported irrigation water use, when soil salinity is not important and 66% in saline lands.

  11. Irrigation Analysis Based on Long-Term Weather Data

    Directory of Open Access Journals (Sweden)

    James R. Mahan

    2016-08-01

    Full Text Available Irrigation management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET using weather data. In 1994, an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. Though producers used the ET-network, by 2010 public access was discontinued. Why did producers allow a valuable irrigation-management tool to be eliminated? Our objective was to analyze the effect of declining well capacities on the usefulness of cotton ET (ETc for irrigation. Thirty years (1975–2004 of daily ETc data were used to compare irrigation demand vs. irrigation responses at four locations, analyzed for multiple years and range of well capacities for three irrigation-intervals. Results indicated that when well capacities declined to the point that over-irrigation was not possible, the lower well capacities reduced the value of ETc in terms of the number of irrigations and total amount of water applied. At well capacities <1514 L·min−1 the fraction of irrigations for which ETc information was used to determine the irrigation amount was <35% across years and irrigation intervals. The value of an ETc-based irrigation may fall into disuse when irrigation-water supplies decline.

  12. Irrigation Training Manual. Planning, Design, Operation, and Management of Small-Scale Irrigation Systems [and] Irrigation Reference Manual. A Technical Reference to Be Used with the Peace Corps Irrigation Training Manual T0076 in the Selection, Planning, Design, Operation, and Management of Small-Scale Irrigation Systems.

    Science.gov (United States)

    Salazar, LeRoy; And Others

    This resource for trainers involved in irrigated agriculture training for Peace Corps volunteers consists of two parts: irrigation training manual and irrigation reference manual. The complete course should fully prepare volunteers serving as irrigation, specialists to plan, implement, evaluate and manage small-scale irrigation projects in arid,…

  13. ASPECTS OF DRIP IRRIGATION ON SLOPES

    Directory of Open Access Journals (Sweden)

    Oprea Radu

    2010-01-01

    Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

  14. Using Pivotal Response Training and Technology to Engage Preschoolers with Autism in Conversations

    Science.gov (United States)

    Stockall, Nancy; Dennis, Lindsay R.

    2014-01-01

    It is well known that children with autism spectrum disorder (ASD) demonstrate a significant delay in language development that impacts their ability to engage in robust conversations. In this article the authors discuss two specific elements of pivotal response training--motivation and self-initiations--for children with ASD. Specific…

  15. Improving Question-Asking Initiations in Young Children with Autism Using Pivotal Response Treatment

    Science.gov (United States)

    Koegel, Robert L.; Bradshaw, Jessica L.; Ashbaugh, Kristen; Koegel, Lynn Kern

    2014-01-01

    Social initiations make up a core deficit for children with autism spectrum disorder (ASD). In particular, initiated questions during social interactions are often minimal or absent in this population. In the context of a multiple baseline design, the efficacy of using the motivational procedures of Pivotal Response Treatment to increase social…

  16. Pivotal Response Treatment for Children with Autism: Core Principles and Applications for School Psychologists

    Science.gov (United States)

    Renshaw, Tyler L.; Kuriakose, Sarah

    2011-01-01

    During the past 2 decades, pivotal response treatment (PRT) has emerged as an evidence-based methodology for intervening with the behavioral, communicative, social, and academic impairments of children with autism. Unlike other highly structured behavioral interventions for autism, PRT emphasizes principles over procedures and focuses on enhancing…

  17. Peer-Mediated Pivotal Response Treatment for Young Children with Autism Spectrum Disorders: A Systematic Review

    Science.gov (United States)

    Boudreau, Ainsley M.; Corkum, Penny; Meko, Katelyn; Smith, Isabel M.

    2015-01-01

    This review examined the effectiveness of peer-mediated pivotal response treatment (PM-PRT) to increase social-communication skills for children with autism spectrum disorders (ASD). A systematic review was conducted of all published studies examining PM-PRT in school-aged children with ASD, based on an established rubric. Five PM-PRT studies…

  18. From Pivot to Symmetry Integrating Africa in the Rebalance to Asia

    Science.gov (United States)

    2014-02-13

    could be worse than any kind of pivot. Notes 1 Aaron Friedberg , "The Future of U.S.-China Relations: Is Conflict Inevitable... Friedberg , p. 7. 3 Stephen M. Walt, “Dealing With a Chinese Monroe Doctrine,” New York Times, 26 August 2013, http://www.nytimes.com/roomfordebate/2012/05

  19. Effect of Opening the Sash of a Centre-Pivot Roof Window on Wind Pressure Coefficients

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Wigö, Hans; Heiselberg, Per

    2014-01-01

    This paper describes the effect of outward opening the sash of a window on local and overall wind pressures. Wind tunnel experiments were used for the purpose of evaluation. A centre-pivot roof window on a pitched roof in a modelled scaled building was used in the analysis of wind pressures...

  20. Neural Mechanisms of Improvements in Social Motivation after Pivotal Response Treatment: Two Case Studies

    Science.gov (United States)

    Voos, Avery C.; Pelphrey, Kevin A.; Tirrell, Jonathan; Bolling, Danielle Z.; Vander Wyk, Brent; Kaiser, Martha D.; McPartland, James C.; Volkmar, Fred R.; Ventola, Pamela

    2013-01-01

    Pivotal response treatment (PRT) is an empirically validated behavioral treatment that has widespread positive effects on communication, behavior, and social skills in young children with autism spectrum disorder (ASD). For the first time, functional magnetic resonance imaging was used to identify the neural correlates of successful response to…

  1. Subexponential lower bounds for randomized pivoting rules for the simplex algorithm

    DEFF Research Database (Denmark)

    Friedmann, Oliver; Hansen, Thomas Dueholm; Zwick, Uri

    2011-01-01

    The simplex algorithm is among the most widely used algorithms for solving linear programs in practice. With essentially all deterministic pivoting rules it is known, however, to require an exponential number of steps to solve some linear programs. No non-polynomial lower bounds were known, prior...

  2. Desenvolvimento de um sistema de pulverização acoplável a pivô central Development of a spray system attached to center pivot

    Directory of Open Access Journals (Sweden)

    Luis A. A. Vilela

    2004-12-01

    Full Text Available Com o objetivo de se aplicar produtos químicos às culturas, desenvolveu-se um sistema de pulverização acoplável a pivô central e também um protótipo do equipamento. Durante a aplicação, a estrutura aérea do pivô central se desloca sem irrigar, apenas transportando o sistema de pulverização sobre a área. O sistema é composto de duas barras de pulverização instaladas em cada vão do pivô. O regime intermitente da pulverização, responsável pela redução da calda aplicada, foi feito por meio de um circuito eletrônico, sincronizado ao acionamento dos motorredutores, que aciona uma válvula solenóide localizada na entrada da barra de pulverização. O sistema desenvolvido possibilita aplicar-se volume de pulverização de até 246 L ha-1. Os diâmetros de gotas atenderam às recomendações técnicas para aplicação de defensivos agrícolas. Tempos ligado-desligado da válvula solenóide de 0,4 - 2,5, 0,5 - 2,5, 0,3 - 3,5 e 0,4 - 3,5 s resultaram em valores de coeficiente de variação inferiores a 15%, aceitáveis para pulverizações por meio terrestre.For the application of chemical products a equipment attached to center pivots was developed. During application, the aerial structure of the center pivot system moves, without accomplishing irrigation, just transporting the spray system around the area. In order to compensate different speeds two spray bars were installed in each pivot span. Intermittent spraying was achieved by means of solenoid valves controlled by electronic circuit synchronized with electric motor gears. The system is able to apply a minimum volume of 246 L ha-1. Drop diameters obtained were compatible with the requirements of application of chemical products. On/off time sequences of 0.4 - 2.5, 0.5 - 2.5, 0.3 - 3.5 and 0.4 - 3.5 s resulted in coefficients of variation under 15%, that are acceptable for ground based applications.

  3. Loss of surface horizon of an irrigated soil detected by radiometric images of normalized difference vegetation index.

    Science.gov (United States)

    Fabian Sallesses, Leonardo; Aparicio, Virginia Carolina; Costa, Jose Luis

    2017-04-01

    The use of the soil in the Humid Pampa of Argentina has changed since the mid-1990s from agricultural-livestock production (that included pastures with direct grazing) to a purely agricultural production. Also, in recent years the area under irrigation by central pivot has been increased to 150%. The waters used for irrigation are sodium carbonates. The combination of irrigation and rain increases the sodium absorption ratio of soil (SARs), consequently raising the clay dispersion and reducing infiltration. This implies an increased risk of soil loss. A reduction in the development of white clover crop (Trifolium repens L.) was observed at an irrigation plot during 2015 campaign. The clover was planted in order to reduce the impact of two maize (Zea mays L.) campaigns under irrigation, which had increased soil SAR and deteriorated soil structure. SPOT-5 radiometric normalized difference vegetation index (NDVI) images were used to determine two zones of high and low production. In each zone, four random points were selected for further geo-referenced field sampling. Two geo-referenced measures of effective depth and surface soil sampling were carried out in each point. Texture of soil samples was determined by Pipette Method of Sedimentation Analysis. Data exploratory analysis showed that low production zone had a media effective depth = 80 cm and silty clay loam texture, while high production zone had a media effective depth > 140 cm and silt loam texture. The texture class of the low production zone did not correspond to prior soil studies carried out by the INTA (National Institute of Agricultural Technology), which showed that those soil textures were silt loam at surface and silty clay loam at sub-surface. The loss of the A horizon is proposed as a possible explanation, but further research is required. Besides, the need of a soil cartography actualization, which integrates new satellite imaging technologies and geo-referenced measurements with soil sensors is

  4. Efficient Storage and Querying of Horizontal Tables Using a PIVOT Operation in Commercial Relational DBMSs

    Science.gov (United States)

    Shin, Sung-Hyun; Moon, Yang-Sae; Kim, Jinho; Kim, Sang-Wook

    In recent years, a horizontal table with a large number of attributes is widely used in OLAP or e-business applications to analyze multidimensional data efficiently. For efficient storing and querying of horizontal tables, recent works have tried to transform a horizontal table to a traditional vertical table. Existing works, however, have the drawback of not considering an optimized PIVOT operation provided (or to be provided) in recent commercial RDBMSs. In this paper we propose a formal approach that exploits the optimized PIVOT operation of commercial RDBMSs for storing and querying of horizontal tables. To achieve this goal, we first provide an overall framework that stores and queries a horizontal table using an equivalent vertical table. Under the proposed framework, we then formally define 1) a method that stores a horizontal table in an equivalent vertical table and 2) a PIVOT operation that converts a stored vertical table to an equivalent horizontal view. Next, we propose a novel method that transforms a user-specified query on horizontal tables to an equivalent PIVOT-included query on vertical tables. In particular, by providing transformation rules for all five elementary operations in relational algebra as theorems, we prove our method is theoretically applicable to commercial RDBMSs. Experimental results show that, compared with the earlier work, our method reduces storage space significantly and also improves average performance by several orders of magnitude. These results indicate that our method provides an excellent framework to maximize performance in handling horizontal tables by exploiting the optimized PIVOT operation in commercial RDBMSs.

  5. Effects of irrigation fluid in shoulder arthroscopy

    Science.gov (United States)

    Gupta, Surbhi; Manjuladevi, M; Vasudeva Upadhyaya, KS; Kutappa, AM; Amaravathi, Rajkumar; Arpana, J

    2016-01-01

    Background and Aims: Extravasation of irrigation fluid used in shoulder arthroscopy can lead to life-threatening airway and systemic complications. This study was conducted to assess the effect of irrigation fluid absorption on measurable anthropometric parameters and to identify whether these parameters predict airway/respiratory compromise. Methods: Thirty six American Society of Anaesthesiologists physical status one or two patients aged 15–60 years undergoing shoulder arthroscopy under general anaesthesia were recruited. Measured variables preoperatively (baseline) and at the end of surgery were neck, chest, midarm and midthigh circumferences, weight, haemoglobin and serum sodium. Temperature, endotracheal tube cuff pressure, airway pressure, duration of surgery, amount of irrigation fluid and intravenous fluid used were also noted. Measured parameters were correlated with the duration of surgery and the amount of irrigation fluid used. Results: Postoperatively, the changes in variables showed a significant increase in the mean values (cm) for neck, chest, midarm and midthigh circumference (mean ± standard deviation: 2.35 ± 1.9, P cm, P compared to the baseline. No significant change was found in the serum sodium levels (P = 0.92). No patient experienced airway/respiratory compromise. Conclusion: Regional and systemic absorption of irrigation fluid in arthroscopic shoulder surgery is reflected in the degree of change in the measured anthropometric variables. However, this change was not significant enough to cause airway/respiratory compromise. PMID:27053783

  6. Municipal Treated Wastewater Irrigation: Microbiological Risk Evaluation

    Directory of Open Access Journals (Sweden)

    Antonio Lonigro

    2008-06-01

    Full Text Available Municipal wastewater for irrigation, though treated, can contain substances and pathogens toxic for humans and animals. Pathogens, although not harmful from an agronomical aspect, undoubtedly represent a major concern with regards to sanitary and hygienic profile. In fact, vegetable crops irrigated with treated wastewater exalt the risk of infection since these products can also be eaten raw, as well as transformed or cooked. Practically, the evaluation of the microbiological risk is important to verify if the microbial limits imposed by law for treated municipal wastewater for irrigation, are valid, thus justifying the treatments costs, or if they are too low and, therefore, they don’ t justify them. Different probabilistic models have been studied to assess the microbiological risk; among these, the Beta-Poisson model resulted the most reliable. Thus, the Dipartimento di Scienze delle Produzioni Vegetali of the University of Bari, which has been carrying out researches on irrigation with municipal filtered wastewater for several years, considered interesting to verify if the microbial limits imposed by the italian law n.185/03 are too severe, estimating the biological risk by the probabilistic Beta-Poisson model. Results of field trials on vegetable crops irrigated by municipal filtered wastewater, processed by the Beta-Poisson model, show that the probability to get infection and/or illness is extremely low, and that the actual italian microbial limits are excessively restrictive.

  7. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  8. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  9. The impact of irrigation on the quality of drainage water in a new irrigation district

    Directory of Open Access Journals (Sweden)

    J.M. Villar Mir

    2015-10-01

    Full Text Available The water quality of two agricultural drainage systems was monitored over two irrigation seasons in order to determine the sustainability of a new area of irrigated land (the Algerri-Balager irrigation district located in the northeast of Spain. The average electrical conductivity of the drainage water was around 4 dS·m-1, and the waters were enriched with boron, phosphorous and nitrate. Drainage represented 17% of total applied irrigation water (measured leached fraction and is considered necessary to minimize the risk of soil salinization in semiarid environments. The most common ions in the drainage waters were magnesium, sulphate, and calcium and others related with dissolved soil minerals present in the area. The presence of Fe, Cu, Mn, Zn and pesticides was negligible. The information provided by this research was very useful for the irrigation district, and it’s transferable to other irrigation districts, as it could help to improve agricultural practices and be used to control the quality and quantity of irrigation drainage.

  10. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  11. Irrigation methods for efficient water application: 40 years of South ...

    African Journals Online (AJOL)

    Irrigation methods for efficient water application: 40 years of South African ... to a specific situation rather than by calculating various performance indicators. ... of Irrigation Water Use covers 4 levels of water-management infrastructure: the ...

  12. Effects of ten years treated wastewater drip irrigation on soil ...

    African Journals Online (AJOL)

    Effects of ten years treated wastewater drip irrigation on soil microbiological properties under ... Water shortage in most countries of the southern Mediterranean basin has led to the reuse of municipal wastewater for irrigation. ... Article Metrics.

  13. Impact of Methods of Administering Growth-Stage Deficit Irrigation ...

    African Journals Online (AJOL)

    Impact of Methods of Administering Growth-Stage Deficit Irrigation on Yield and Soil Water ... study reveal that at vegetative growth stage of the maize crop, it is better to skip weekly irrigation (to ..... Treatment Class. ..... middle Egypt conditions.

  14. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... root per cm3 soil) compared with root development in fully irrigated (FI) potatoes. Highest RLD existed in the top 30–40cm of the ridge below which it decreased sharply. The RLD was distributed homogenously along the ridge and furrow but heterogeneously across the ridge and furrow with highest root...

  15. Wireless sensor networks for canopy temperature sensing and irrigation management

    Science.gov (United States)

    For researchers, canopy temperature measurements have proven useful in characterizing crop water stress and developing protocols for irrigation management. Today, there is heightened interest in using remote canopy temperature measurements for real-time irrigation scheduling. However, without the us...

  16. Strategy of Irrigation Branch in Russia

    Science.gov (United States)

    Zeyliger, A.; Ermolaeva, O.

    2012-04-01

    At this moment, at the starting time of the program on restoration of a large irrigation in Russia till 2020, the scientific and technical community of irrigation branch does not have clear vision on how to promote a development of irrigated agriculture and without repeating of mistakes having a place in the past. In many respects absence of a vision is connected to serious backlog of a scientific and technical and informational and technological level of development of domestic irrigation branch from advanced one. Namely such level of development is necessary for the resolving of new problems in new conditions of managing, and also for adequate answers to new challenges from climate and degradation of ground & water resources, as well as a rigorous requirement from an environment. In such important situation for irrigation branch when it is necessary quickly generate a scientific and technical politics for the current decade for maintenance of translation of irrigated agriculture in the Russian Federation on a new highly effective level of development, in our opinion, it is required to carry out open discussion of needs and requirements as well as a research for a adequate solutions. From political point of view a framework organized in FP6 DESIRE 037046 project is an example of good practice that can serve as methodical approach how to organize and develop such processes. From technical point of view a technology of operational management of irrigation at large scale presents a prospective alternative to the current type of management based on planning. From point of view ICT operational management demands creation of a new platform for the professional environment of activity. This platform should allow to perceive processes in real time, at their partial predictability on signals of a straight line and a feedback, within the framework of variability of decision making scenarious, at high resolution and the big ex-awning of sensor controls and the gauges

  17. Genotoxicity of vegetables irrigated by industrial wastewater

    Institute of Scientific and Technical Information of China (English)

    Nupur Mathur; Pradeep Bhatnagar; Hemraj Verma

    2006-01-01

    Wastewater effluents from textile dyeing and printing industries of Sanganer are discharged directly, without any treatment,into Amani Shah Nallah drainage. The drainage water takes the dissolved toxicants to flora and fauna, including crops and seasonal vegetables, being grown in the land adjoining the Nallah drainage. Thus mutagenic potential of vegetables irrigated by the water of Amani Shah Nallah drainage was investigated in the present study. The vegetables irrigated by ground water from Sanganer have also been analyzed to determine possible adverse effects of these wastewater effluents on aqua duct.

  18. An Assessment of Global Net Irrigation Water Requirements from Various Water Supply Sources to Sustain Irrigation

    Science.gov (United States)

    Yoshikawa, Sayaka; Cho, Jail; Yamada, Hannah; Khajuria, Anupam; Hanasaki, Naota; Kanae, Shinjiro

    2014-05-01

    Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependence of irrigation water requirements from water supply sources, with a particular focus on variations in irrigation area during the period 1960-2050 using the global water resources model, H08. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0° . The sources of irrigation water requirements in the past simulations were specified using four categories: rivers (RIV), large reservoirs (LR) with a storage capacity greater than 1.0 km3, medium-size reservoirs (MSR) with storage capacities ranging from 1.0 km3 to 3.0 M m3, and non-local non-renewable blue water (NNBW). We also estimated future irrigation water requirements from the above four water supply sources and an additional water supply source (ADD) in three future simulation designs; irrigation area change, climate change, and changes in both irrigation area and climate. ADD was defined as the difference between NNBW in the 1990s and NNBW in the 2040s, because it was difficult to distinguish the types of future water supply sources except for RIV. The simulated results showed that RIV, MSR, and NNBW increased significantly through the 1960s to the early 1990s globally, but LR increased at a relatively low rate. After the early 1990s, RIV approached a critical limit due to the continued expansion of the irrigation area. Furthermore, MSR and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of the medium-size reservoirs. After the 2020s, MSR could be expected to approach the critical limit without the construction of medium-size reservoirs. ADD would account for 11-23% of the total requirements in the 2040s. We found that an expansion of

  19. The Pivot to Asia: Can It Serve as the Foundation for American Grand Strategy in the 21st Century

    Science.gov (United States)

    noting the growing importance of India and Chinas efforts to expand their influence into Central Asia, Europe, Africa , and Latin America. Dr. Stuart...complicated its efforts to keep its focus on the pivot strategy in the IAP region . He concludes with some lessons for strategists, derived from the Obama teams experience with the pivot.

  20. Two independent pivotal statistics that test location and misspecification and add-up to the Anderson-Rubin statistic

    NARCIS (Netherlands)

    Kleibergen, F.R.

    2002-01-01

    We extend the novel pivotal statistics for testing the parameters in the instrumental variables regression model. We show that these statistics result from a decomposition of the Anderson-Rubin statistic into two independent pivotal statistics. The first statistic is a score statistic that tests loc

  1. Mapping Irrigation Potential in the Upper East Region of Ghana

    Science.gov (United States)

    Akomeah, E.; Odai, S. N.; Annor, F. O.; Adjei, K. A.; Barry, B.

    2009-04-01

    The Upper East Region together with the other two regions in Northern Ghana (Upper West and Northern Region) is seen as the locus of perennial food deficit (GPRS, 2003). Despite, the provision of over 200 small scale dams and various mechanisms aimed at poverty alleviation, the region is still plagued with poverty and yearly food shortages. To achieve food security and alleviate poverty in the region however, modernization of agriculture through irrigation is deemed inevitable. While it is true that considerable potential still exists for future expansion of irrigation, it cannot be refuted that water is becoming scarcer in the regions where the need for irrigation is most important, hence mapping the irrigation potential of the region will be the first step toward ensuring sound planning and sustainability of the irrigation developments. In this study, an attempt has been made to map out the irrigation potential of the Upper East Region. The river basin approach was used in assessing the irrigation potential. The catchments drained by The White Volta river, Red volta river, River Sissili and River Kulpawn were considered in the assessment. The irrigation potential for the sub basins was computed by combining information on gross irrigation water requirements for the selected cash crops, area of soil suitable for irrigation and available water resources. The capacity of 80%, 70%, 60% and 50% time of exceedance flow of the available surface water resources in the respective sub basins was estimated. The area that can be irrigated with this flow was computed with selected cropping pattern. Combining the results of the potential irrigable areas and the land use map of the respective sub basins, an irrigation potential map has been generated showing potential sites in the upper east region that can be brought under irrigation. Keywords: Irrigation potential, irrigation water requirement, land evaluation, dependable flow

  2. The management perspective on the performance of the irrigation subsector

    OpenAIRE

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the performance of irrigation investments was far below its potential. The size of this underperformance is well represented by Seckler's alarming conclusion that the average irrigation investment costs twi...

  3. A management perspective on the performance of the irrigation subsector.

    OpenAIRE

    Nijman, Ch.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the performance of irrigation investments was far below its potential. The size of this underperformance is well represented by Seckler's alarming conclusion that the average irrigation investment costs twi...

  4. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NARCIS (Netherlands)

    Chukalla, A.D.; Krol, M.S; Hoekstra, A.Y.

    2015-01-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thu

  5. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NARCIS (Netherlands)

    Chukalla, Abebe Demissie; Krol, Martinus S.; Hoekstra, Arjen Ysbert

    2015-01-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and

  6. An Analysis of the R327Z Center P Irrigation Machine Hydraulic Performance Test%R327 Z型中心支轴式喷灌机部分水力性能试验分析

    Institute of Scientific and Technical Information of China (English)

    李铁男; 李美娟

    2015-01-01

    以 R327Z型中心支轴式喷灌机为研究对象,对其水量分布、喷灌均匀度进行现场试验。结果表明:R327Z型中心支轴式喷灌机的灌水均匀性良好,喷灌均匀系数平均为94.6%,能够很好的满足灌溉要求;当机组行走速度为80%时测得的喷洒均匀系数大于行走速度为40%时的喷洒均匀系数。%By taking the R327Z center pivot irrigation system as the research object ,the water distribution and the irrigation uniform‐ity are tested .The results show that the uniformity of the R327Z center pivot irrigation system is good ,which is 94 .6% on average , can well meet the requirements of irrigation .The spraying uniformity coefficient is greater when the walking speed is 80% .

  7. Assessment of FAO AquaCrop Model for Simulating Maize Growth and Productivity under Deficit Irrigation in a Tropical Environment

    Directory of Open Access Journals (Sweden)

    Geneille E. Greaves

    2016-11-01

    Full Text Available Crop simulation models have a pivotal role to play in evaluating irrigation management strategies for improving agricultural water use. The objective of this study was to test and validate the AquaCrop model for maize under deficit irrigation management. Field observations from three experiments consisting of four treatments were used to evaluate model performance in simulating canopy cover (CC, biomass (B, yield (Y, crop evapotranspiration (ETc, and water use efficiency (WUE. Statistics for root mean square error, model efficiency (E, and index of agreement for B and CC suggest that the model prediction is good under non-stressed and moderate stress environments. Prediction of final B and Y under these conditions was acceptable, as indicated by the high coefficient of determination and deviations <10%. In severely stressed conditions, low E and deviations >11% for B and 9% for Y indicate a reduction in the model reliability. Simulated ETc and WUE deviation from observed values were within the range of 9.5% to 22.2% and 6.0% to 32.2%, respectively, suggesting that AquaCrop prediction of these variables is fair, becoming unsatisfactory as plant water stress intensifies. AquaCrop can be reliably used for evaluating the effectiveness of proposed irrigation management strategies for maize; however, the limitations should be kept in mind when interpreting the results in severely stressed conditions.

  8. Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

    Science.gov (United States)

    Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

    2014-08-01

    Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity.

  9. Nitrogen Effects on Onion Yield Under Drip and Furrow Irrigation

    Science.gov (United States)

    Onion (Allium cepa L.) is a high cash value crop with a very shallow root system that is frequently irrigated and fertilized with high N rates to maximize yield. Converting from furrow-irrigated to drip-irrigated onion production may reduce N fertilizer needs, water inputs, and NO3-N leaching poten...

  10. Sustainable Irrigation Development in the White Volta Sub-Basin

    NARCIS (Netherlands)

    Ofosu, E.A.

    2011-01-01

    This study on sustainable irrigation development identified growing markets for irrigated products as an important driving force behind the expansion of irrigation which has given rise to new technologies. The new technologies have spread because they gave farmers direct control over water sources.

  11. Irrigation system management assisted by thermal imagery and spatial statistics

    Science.gov (United States)

    Thermal imaging has the potential to assist with many aspects of irrigation management including scheduling water application, detecting leaky irrigation canals, and gauging the overall effectiveness of water distribution networks used in furrow irrigation. Many challenges exist for the use of therm...

  12. A land suitability system for spate irrigation schemes in Eritrea

    NARCIS (Netherlands)

    Tesfai, M.H.

    2002-01-01

    Spate irrigation is a system used for wetting land prior to planting. Use is made of seasonal rivers (wadis) producing flash floods in the uplands, which are directed by structures to irrigate fields in the lowlands. A land suitability system for spate irrigation schemes in Eritrea was studied in th

  13. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  14. 21 CFR 876.5220 - Colonic irrigation system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Colonic irrigation system. 876.5220 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5220 Colonic irrigation system. (a) Identification. A colonic irrigation system is a device intended to instill water into the...

  15. 21 CFR 872.6510 - Oral irrigation unit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oral irrigation unit. 872.6510 Section 872.6510...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6510 Oral irrigation unit. (a) Identification. An oral irrigation unit is an AC-powered device intended to provide a pressurized stream of water...

  16. In Vitro Durability - Pivot bearing with Diamond Like Carbon for Ventricular Assist Devices

    CERN Document Server

    de Sá, Rosa Corrêa Leoncio; Leão, Tarcísio Fernandes; da Silva, Evandro Drigo; da Fonseca, Jeison Willian Gomes; da Silva, Bruno Utiyama; Leal, Edir Branzoni; Moro, João Roberto; de Andrade, Aron José Pazin; Bock, Eduardo Guy Perpétuo

    2015-01-01

    Institute Dante Pazzanese of Cardiology (IDPC) develops Ventricular Assist Devices (VAD) that can stabilize the hemodynamics of patients with severe heart failure before, during and/or after the medical practice; can be temporary or permanent. The ADV's centrifugal basically consist of a rotor suspended for system pivoting bearing; the PIVOT is the axis with movement of rotational and the bearing is the bearing surface. As a whole system of an implantable VAD should be made of long-life biomaterial so that there is no degradation or deformation during application time; surface modification techniques have been widely studied and implemented to improve properties such as biocompatibility and durability of applicable materials. The Chemical Vapour Deposition technique allows substrates having melting point higher than 300 {\\deg}C to be coated, encapsulated, with a diamond like carbon film (DLC); The test simulated the actual conditions in which the system of support remains while applying a ADV. The results hav...

  17. Pivotal temperature and sexual dimorphism of Podocnemis expansa hatchlings (Testudines: Podocnemididae from Bananal Island, Brazil

    Directory of Open Access Journals (Sweden)

    Adélio Lubiana

    2009-09-01

    Full Text Available A common problem when trying to identify the sex of hatchling turtles is that juveniles are not obviously externally dimorphic and current techniques to identify sex are often invasive. In this paper, 300 eggs of Podocnemis expansa from Bananal Island, state of Tocantins (Brazil, were incubated at constant temperatures. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis. The hatchlings were subsequently euthanized and had their gonads removed for sex determination. The pivotal temperature of P. expansa was 33.5ºC, confirming that this species has the highest pivotal temperature among reptiles. Geometric morphometric analysis of the shape of the carapace proved efficient in differentiating the sex of the hatchlings and confirmed that this methodology can be efficient for studies that need to ascertain the sex ratio in P. expansa hatchlings.

  18. Safer and More Efficient Ship Handling with the Pivot Point Concept

    Directory of Open Access Journals (Sweden)

    Seong-Gi Seo

    2016-12-01

    Full Text Available The concept of the pivot point of a turning ship has been in existence for more than two centuries. It was not, however, properly understood from the beginning, and thus some misconceptions developed. This in turn caused it to be viewed as something mystical, thus preventing ship handling from scientific approach. The concept is expounded in a fresh light, deriving an equation for the definition and others for the calculation of the pivot point location both in general and for specific examples in an idealized condition. The implications of the derived equations are discussed. The results of a verification experiment are presented, which proved centuries’ of teachings and learnings to have been incorrect. A number of exercises for both steady and unsteady cases have been suggested for the training of the practitioners in the light of these new findings.

  19. U.S.“Pivot to Asia" Faces Numerous Problems Ahead

    Institute of Scientific and Technical Information of China (English)

    Hong; Yuan

    2014-01-01

    <正>It is generally believed that U.S.pivot to Asia or the rebalancing in Asia-Pacific derives from its psychology,which is more fear of China’s rise than China’s wish to challenge America.So far there is no effective evidence showing that China is challenging the United States,but fear of China can be seen everywhere in the United States.Therefore,the biggest global objective of the United States is

  20. The Akt-mTOR axis is a pivotal regulator of eccentric hypertrophy during volume overload

    OpenAIRE

    Masataka Ikeda; Tomomi Ide; Takeo Fujino; Yuka Matsuo; Shinobu Arai; Keita Saku; Takamori Kakino; Yasuhiro Oga; Akiko Nishizaki; Kenji Sunagawa

    2015-01-01

    The heart has two major modalities of hypertrophy in response to hemodynamic loads: concentric and eccentric hypertrophy caused by pressure and volume overload (VO), respectively. However, the molecular mechanism of eccentric hypertrophy remains poorly understood. Here we demonstrate that the Akt-mammalian target of rapamycin (mTOR) axis is a pivotal regulator of eccentric hypertrophy during VO. While mTOR in the heart was activated in a left ventricular end-diastolic pressure (LVEDP)-depende...

  1. Fruit yield and quality of drip-irrigated tomato under deficit irrigation ...

    African Journals Online (AJOL)

    African Journal of Food, Agriculture, Nutrition and Development ... The competition for limited amount of world fresh water is increasing at a fast rate. ... The two tomato cultivars were exposed to four irrigation water deficit levels expressed as ...

  2. Time-Resolved Micro PIV in the Pivoting Area of the Triflo Mechanical Heart Valve.

    Science.gov (United States)

    Vennemann, Bernhard M; Rösgen, Thomas; Carrel, Thierry P; Obrist, Dominik

    2016-09-01

    The Lapeyre-Triflo FURTIVA valve aims at combining the favorable hemodynamics of bioprosthetic heart valves with the durability of mechanical heart valves (MHVs). The pivoting region of MHVs is hemodynamically of special interest as it may be a region of high shear stresses, combined with areas of flow stagnation. Here, platelets can be activated and may form a thrombus which in the most severe case can compromise leaflet mobility. In this study we set up an experiment to replicate the pulsatile flow in the aortic root and to study the flow in the pivoting region under physiological hemodynamic conditions (CO = 4.5 L/min / CO = 3.0 L/min, f = 60 BPM). It was found that the flow velocity in the pivoting region could reach values close to that of the bulk flow during systole. At the onset of diastole the three valve leaflets closed in a very synchronous manner within an average closing time of 55 ms which is much slower than what has been measured for traditional bileaflet MHVs. Hot spots for elevated viscous shear stresses were found at the flanges of the housing and the tips of the leaflet ears. Systolic VSS was maximal during mid-systole and reached levels of up to 40 Pa.

  3. Plant responses, climate pivot points, and trade-offs in water-limited ecosystems

    Science.gov (United States)

    Munson, Seth M.

    2013-01-01

    Plant species in dryland ecosystems are limited by water availability and may be vulnerable to increases in aridity. Methods are needed to monitor and assess the rate of change in plant abundance and composition in relation to climate, understand the potential for degradation in dryland ecosystems, and forecast future changes in plant species assemblages. I employ nearly a century of vegetation monitoring data from three North American deserts to demonstrate an approach to determine plant species responses to climate and critical points over a range of climatic conditions at which plant species shift from increases to decreases in abundance (climate pivot points). I assess these metrics from a site to regional scale and highlight how these indicators of plant performance can be modified by the physical and biotic environment. For example, shrubs were more responsive to drought and high temperatures on shallow soils with limited capacity to store water and fine-textured soils with slow percolation rates, whereas perennial grasses were more responsive to precipitation in sparse shrublands than in relatively dense grasslands and shrublands, where competition for water is likely more intense. The responses and associated climate pivot points of plant species aligned with their lifespan and structural characteristics, and the relationship between responses and climate pivot points provides evidence of the trade-off between the capacity of a plant species to increase in abundance when water is available and its drought resistance.

  4. Irrigation frequency and timing influence pepper yields

    Science.gov (United States)

    Information on how fertilizer and irrigation affect production of vegetables can help growers improve resource use efficiency and profitability. Fertilizer was applied at the recommended rate and twice the recommended rate to bell and non-pungent jalapeno peppers, both Capsicum annuum L., in 2009 a...

  5. Using a System Model for Irrigation Management

    Science.gov (United States)

    de Souza, Leonardo; de Miranda, Eu; Sánchez-Román, Rodrigo; Orellana-González, Alba

    2014-05-01

    When using Systems Thinking variables involved in any process have a dynamic behavior, according to nonstatic relationships with the environment. In this paper it is presented a system dynamics model developed to be used as an irrigation management tool. The model involves several parameters related to irrigation such as: soil characteristics, climate data and culture's physiological parameters. The water availability for plants in the soil is defined as a stock in the model, and this soil water content will define the right moment to irrigate and the water depth required to be applied. The crop water consumption will reduce soil water content; it is defined by the potential evapotranspiration (ET) that acts as an outflow from the stock (soil water content). ET can be estimated by three methods: a) FAO Penman-Monteith (ETPM), b) Hargreaves-Samani (ETHS) method, based on air temperature data and c) Class A pan (ETTCA) method. To validate the model were used data from the States of Ceará and Minas Gerais, Brazil, and the culture was bean. Keyword: System Dynamics, soil moisture content, agricultural water balance, irrigation scheduling.

  6. Irrigation performance assessment in Crimea, Ukraine

    NARCIS (Netherlands)

    Pavlov, S.S.; Roerink, G.J.; Hellegers, P.J.G.J.; Popovych, V.F.

    2006-01-01

    After the collapse of the Soviet Union the performance of irrigated agriculture decreased drastically in Ukraine, due to problems related to the transition from a centrally planned economy to a market economy. Before formulating recommendations on required actions to modify this problematic situatio

  7. SANITARY SEWAGE REUSE IN AGRICULTURAL CROP IRRIGATION

    Directory of Open Access Journals (Sweden)

    Lidiane Bittencourt Barroso

    2011-10-01

    Full Text Available The water availability was exceeded by demand, becoming a limiting factor in irrigated agriculture. This study aimed to provide a general theoretical framework on the issue of water reuse for agricultural purposes. This is due to the fact that we need a prior knowledge of the state of the art concerning the matter. To that end, we performed a review of irrigated agriculture, the effects on cultivated land and the development of agricultural crops as well as aspects of security to protect groups at risk. The amount of macro and micronutrients in the effluent may reduce or eliminate the use of commercial fertilizers. And this addition of organic matter acts as a soil conditioner, increasing its capacity to retain water. Depending on the characteristics of sewage, the practice of irrigation for long periods may lead to accumulation of toxic compounds and the significant increase of salinity. The inhibition of plant growth by salinity may be due to osmotic effect, causing drought and / or specific effects of ions, which can cause toxicity or nutritional imbalance. The minimization of human exposure to the practice of agricultural reuse is based on a set of mitigation measures that must be implemented by the authorities responsible for operating and monitoring systems for water recycling. It is concluded that the use of sewage depends on management of irrigation, monitoring of soil characteristics and culture.

  8. COMMUNITY IRRIGATION DAMS IN THE UPPER EAST

    African Journals Online (AJOL)

    such as Unit Committee members, Assembly members or higher government authori- .... entails some system of rotation of irrigable land ownership between the ... work and the management procedures institutionalized and the outcomes. .... WUA has also been able to generate revenue through its membership registration.

  9. Irrigation performance assessment in Crimea, Ukraine

    NARCIS (Netherlands)

    Pavlov, S.S.; Roerink, G.J.; Hellegers, P.J.G.J.; Popovych, V.F.

    2006-01-01

    After the collapse of the Soviet Union the performance of irrigated agriculture decreased drastically in Ukraine, due to problems related to the transition from a centrally planned economy to a market economy. Before formulating recommendations on required actions to modify this problematic

  10. Cytotoxic effect of endodontic irrigants in vitro.

    Science.gov (United States)

    Bajrami, Donika; Hoxha, Veton; Gorduysus, Omer; Muftuoglu, Sevda; Zeybek, Nacije Dilara; Küçükkaya, Selen

    2014-03-10

    Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. The aim of this study was to assess the cytotoxic effect of NaOCl 3%, Chx 2%, and MTAD on rat periodontal ligament fibroblasts, at 0.1 and 100 µl/mL, using WST-1 colorimetric method. Rat ligamental fibroblasts were exposed to the irrigants and their viability was assessed after 1, 24, 48, and 72 h. The measurements were determined using WST-1 assay, using a micro ELISA reader. At 100 ml/L all 3 irrigants were strongly cytotoxic, although CHX was less so than NaOCl and MTAD. At the 0.1 ml/L concentration, NaOCl and MTAD were only moderately cytotoxic, whereas Chx was highly deleterious to cell viability at all time points. There was a significant influence of the dilution rate of the substance, because the odds ratio for cell viability being over 50% was increased 51 times between the 100 ml/L and 0.1 ml/L dilutions. It seems that irrigating solutions should be used at lower concentrations to enhance cell viability.

  11. Precision agriculture approach for improving cotton irrigation

    Science.gov (United States)

    Cotton is a vital part of the southeast Missouri economy and while we’re not currently facing problems with groundwater decline, it’s still important to apply the right amount of irrigation at the proper time. We currently have several projects at the Fisher Delta Research Center with that aim. For ...

  12. Reuse of drainage water from irrigated areas

    NARCIS (Netherlands)

    Willardson, L.S.; Boels, D.; Smedema, L.K.

    1997-01-01

    Increasing competition for water of good quality and the expectation that at least half of the required increase in food production in the near-future decades must come from the world's irrigated land requires to produce more food by converting more of the diverted water into food. Reuse of the

  13. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  14. Decision support for optimised irrigation scheduling

    NARCIS (Netherlands)

    Anastasiou, A.; Sawas, D.; Pasgianos, G.; Sigrimis, N.; Stanghellini, C.; Kempkes, F.L.K.

    2009-01-01

    The system, developed under the FLOW-AID (an FP6 project), is a farm level water management system of special value in situations where the water availability and quality is limited. This market-ready precision irrigation management system features new models, hardware and software. The hardware pla

  15. Irrigation timing and fertilizer rate in peppers

    Science.gov (United States)

    Excessive rain fall might leach nutrients from the soil or cause producers to not supply irrigation to pepper (Capsicum sp.). Fertilizer at 150 or 300 lb/acre of triple 17 NPK, the lower rate is the recommended rate, was supplied to either bell, cv. Jupiter, or non-pungent jalapeno, cv. Pace 105, pe...

  16. Philippines : PPP Options in Irrigation Sector

    OpenAIRE

    World Bank

    2013-01-01

    This study proposes an analytical framework to determine the extent to which Public-Private Partnership (PPP) is a viable and effective business option for developing and modernizing the irrigation sector in the Philippines. It focuses on: (a) assessing and providing recommendations to address the policy, regulatory and institutional constraints that limit the recourse to PPP as a tool to ...

  17. Comparative inflammatory effect of antiseptic irrigating solutions against conventional irrigation with sodium chloride in rats.

    OpenAIRE

    Rodríguez Alfaro, Miguel; Profesor Asociado del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Chumpitaz Cerrate, Víctor; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Burga Sánchez, Jonny; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Medicina de la UCSUR.; Arroyo Acevedo, Jorge; Profesor Principal del Departamento Académico de Ciencias Básicas de la Facultad de Medicina de la UNMSM.; Ramón Rosales, Jorge; Profesor Auxiliar del departamento Académico de Ciencias Básicas de la Facultad de Estomatología de la UCSUR.; Aguirre Siancas, Elías; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Cabrejos Álvarez, José; Profesor de la Catedra de Cirugia Bucal y Máxilofacial de la Facultad de Estomatología de la UIGV.; Zegarra Cuya, Juan; Ex-Profesor del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.

    2014-01-01

    The aim of this study was to demonstrate that the use of irrigating solutions in surgical procedures does not alter both inflammation processes and tissue repair. Four (04) groups were formed containing 15 rats each. After being dosed with general anaesthesia, they underwent osteotomy in the tibia with tungsten carbide burs and irrigation for 15 seconds, using the following solutions in each group: A) 0,12 % chlorhexidine with cetylpyridinium 0,05 %, B) 0,12 % chlorhexidine with aspartame; C)...

  18. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system,

  19. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system, wh

  20. Irrigation et paludisme : un couple infernal?

    Directory of Open Access Journals (Sweden)

    Mergeai, G.

    2016-01-01

    Full Text Available Irrigation and Malaria - a Terrible Combination?. Increasing agricultural productivity is a priority in most of the developing countries and using irrigation is one of the most efficient ways of achieving this goal. Almost half a billion people in the world contract malaria every year and approximately one million die as a result. The majority of these victims are farmers or members of their families. In infected areas, malaria continues to have major negative impacts on agricultural productivity. For example, in the Equateur province of the DRC, after access to production means, fevers are considered the second biggest obstacle to the development of agricultural activities. In the Ivory Coast, a study has shown that growers suffering from malaria were about half as productive as their healthy colleagues. The disease often strikes at the start of the rainy season when work begins again in the fields. It reduces the amount of land cultivated and affects the amount of care taken with crops. Agricultural practices influence the risk of contracting malaria. Irrigation, in particular, can encourage the proliferation of vectors of the disease and make it more likely to spread. This tendency can be observed in many locations where irrigated rice production is on the increase. Paradoxically, however, an increased number of mosquitoes does not systematically result in more malaria. In Ethiopia, malaria is more prevalent close to the micro-dams sponsored by the government, whereas, in Tanzania, there is less malaria in irrigated areas. Various theories can be put forward in order to explain this paradox. In particular, increased income due to higher rice yields enables farmers to purchase insecticide-treated mosquito nets. It also allows them to eat better, which strengthens their immune systems. It also appears that the negative impact of irrigation systems is greater in areas, in which immunity levels were low in the population prior to the creation of

  1. The role of energy audits in irrigated areas. The case of Fuente Palmera irrigation district (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Cobo, M. T.; Rodriguez-Diaz, J. A.; Camacho-Poyato, E.

    2010-07-01

    In recent years, energy consumption for irrigation has grown rapidly. Actually, nowadays energy represents a significant percentage on the total water costs in irrigation districts using energy to pressurize water. With the aim of improving energy efficiency in the Fuente Palmera irrigation district, was applied the protocol for conducting energy audits in irrigation districts developed by Spanish Institute for Diversification and Energy Savings (IDAE). The irrigated area organized in two independent sectors according to a homogeneous elevation criterion is analyzed and simulated. The potential energy savings derived from this measure was evaluated. For this purpose, a model based on the hydraulic simulator EPANET has been carried out. Its energy demand was estimated in 1,360 kWh ha-1 and its overall energy efficiency in 56%. The district was globally classified in group C (normal). Results show potential energy savings of up to 12% were obtained when the network was divided in sectors and farmers organized in two irrigation shifts. Further energy savings could be achieved by improving the hydraulic structures, such as the pumping station or the network layout and dimensions. (Author) 26 refs.

  2. Glyphosate transport through weathered granite soils under irrigated and non-irrigated conditions--Barcelona, Spain.

    Science.gov (United States)

    Candela, Lucila; Caballero, Juan; Ronen, Daniel

    2010-05-15

    The transport of Glyphosate ([N-phosphonomethyl] glycine), AMPA (aminomethylphosphonic acid, CH(6)NO(3)P), and Bromide (Br(-)) has been studied, in the Mediterranean Maresme area of Spain, north of Barcelona, where groundwater is located at a depth of 5.5m. The unsaturated zone of weathered - granite soils was characterized in adjacent irrigated and non-irrigated experimental plots where 11 and 10 boreholes were drilled, respectively. At the non irrigated plot, the first half of the period was affected by a persistent and intense rainfall. After 69 days of application residues of Glyphosate up to 73.6 microgg(-1) were detected till a depth of 0.5m under irrigated conditions, AMPA, analyzed only in the irrigated plot was detected till a depth of 0.5m. According to the retardation coefficient of Glyphosate as compared to that of Br(-) for the topsoil and subsoil (80 and 83, respectively) and the maximum observed migration depth of Br(-) (2.9 m) Glyphosate and AMPA should have been detected till a depth of 0.05 m only. Such migration could be related to the low content of organic matter and clays in the soils; recharge generated by irrigation and heavy rain, and possible preferential solute transport and/or colloidal mediated transport. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Simulated errors in deep drainage beneath irrigated settings: Partitioning vegetation, texture and irrigation effects using Monte Carlo

    Science.gov (United States)

    Gibson, J. P.; Gates, J. B.; Nasta, P.

    2014-12-01

    Groundwater in irrigated regions is impacted by timing and rates of deep drainage. Because field monitoring of deep drainage is often cost prohibitive, numerical soil water models are frequently the main method of estimation. Unfortunately, few studies have quantified the relative importance of likely error sources. In this study, three potential error sources are considered within a Monte Carlo framework: water retention parameters, rooting depth, and irrigation practice. Error distributions for water retention parameters were determined by 1) laboratory hydraulic measurements and 2) pedotransfer functions. Error distributions for rooting depth were developed from literature values. Three irrigation scheduling regimes were considered: one representing pre-scheduled irrigation ignoring preceding rainfall, one representing pre-scheduled irrigation that was altered based on preceding rainfall, and one representing algorithmic irrigation scheduling informed by profile matric potential sensors. This approach was applied to an experimental site in Nebraska with silt loam soils and irrigated corn for 2002-2012. Results are based on Six Monte-Carlo simulations, each consisting of 1000 Hydrus 1D simulations at daily timesteps, facilitated by parallelization on a 12-node computing cluster. Results indicate greater sensitivity to irrigation regime than to hydraulic or vegetation parameters (median values for prescheduled irrigation, prescheduled irrigation altered by rainfall, and algorithmic irrigation were 310 ,100, and 110 mm/yr, respectively). Error ranges were up to 700% higher for pedotransfer functions than for laboratory-measured hydraulic functions. Deep drainage was negatively correlated with alpha and maximum root zone depth and, for some scenarios, positively correlated with n. The relative importance of error sources differed amongst the irrigation scenarios because of nonlinearities amongst parameter values, profile wetness, and deep drainage. Compared to pre

  4. Biochar enhances yield and quality of tomato under reduced irrigation

    DEFF Research Database (Denmark)

    Saleem Akhtar, Saqib; Li, Guitong; Andersen, Mathias Neumann

    2014-01-01

    tBiochar is an amendment that can be used for enhancing soil water storage which may increase cropproductivity. The objective of this study was to investigate the effects of biochar on physiology, yield andquality of tomato under different irrigation regimes. From early flowering to fruit maturity...... stages, theplants were subjected to full irrigation (FI), deficit irrigation (DI) and partial root-zone drying irrigation(PRD) and two levels of biochar (0% and 5% by weight). In FI, the plants were irrigated daily to pot waterholding capacity while in DI and PRD, 70% of FI was irrigated on either...... the whole or one side of the pots,respectively. In PRD, irrigation was switched between sides when the soil water content of the dry sidedecreased to 15%. The results showed that addition of biochar increased the soil moisture contents in DIand PRD, which consequently improved physiology, yield, and quality...

  5. Sediment and nutrient losses from an irrigated watershed.

    Science.gov (United States)

    Bjorneberg, D.; Ippolito, J.

    2011-12-01

    Irrigated agriculture is an essential part of stable food and fiber production. However, water returning from irrigated watersheds can contain excess sediment, nutrients and salts. Applying polyacrylamide to furrow irrigated fields reduces erosion 60 to 90%. Converting from furrow irrigation to sprinkler irrigation eliminates planned irrigation runoff necessary for uniform water application. Installing sediment ponds removes 50 to 80% of the suspended sediment from water before it flows back to major water bodies. In southern Idaho, irrigation watershed monitoring showed that implementing these conservation practices has reduced average suspended sediment loss from 460 kg/ha in 1970 to less than 100 kg/ha in 2005. These practices, however, have had less effect on soluble nutrients. Median nitrate concentrations have almost doubled from 1970 to 2005. Current research is focusing on identifying practices to reduce soluble nutrient losses.

  6. ASSESSMENT OF IRRIGATION EFFICIENCIES UNDER CENTRAL ANATOLIA CONDITIONS

    Directory of Open Access Journals (Sweden)

    Yusuf Ersoy Yildirim

    2016-12-01

    Full Text Available Turkey is located within semi-arid climate zone and large portion of the country experience water deficits. Thus, efficient water use has become a significand issue in agricultural practices. Current global warming and climate change have aggravated such deficiencies. Konya province is located right at the center of Central Anatolia region and mostly groundwater is used in irrigations. Excessive groundwater withdrawals drop groundwaters levels and also increase energy costs. Although farmers pay quite high sums for energy, they were not using water efficiently and thus were not able to get desired benefits from the irrigations. In this study, irrigation practices of an irrigation cooperative were assessed and compared with optimum irrigation programs created through IRSIS irrigation scheduling software. It was concluded that all irrigation practices of the region were wrong and way behind the optimum ones.

  7. Seismic Risk Management of Irrigation System in an Earthquake

    Science.gov (United States)

    Kobayashi, Akira; Hayashi, Takuma; Yamamoto, Kiyohito; Kiyama, Shoichi

    A risk analysis method of an irrigation system in an earthquake is proposed. The irrigation system consists of irrigation tanks and canals. The damage probability of the irrigation tanks and canals was obtained from both numerical simulation and actual disaster data from the Mid Niigata prefecture earthquake. The losses due to reduced crop yield, restoration and secondary disaster were considered in the risk assessment. The probability of annual peak ground acceleration was introduced from the earthquake records in Niigata prefecture. To reduce the damage probability, an enhanced foundation of canals on flat land and widening of the embankment were applied. It was found that the countermeasures for the irrigation tanks were more effective than those for the canals. In the case of a large secondary disaster of the irrigation system on flat land, the countermeasures for the irrigation system were very effective.

  8. Two challenges for U.S. irrigation due to climate change: increasing irrigated area in wet states and increasing irrigation rates in dry states.

    Directory of Open Access Journals (Sweden)

    Robert I McDonald

    Full Text Available Agricultural irrigation practices will likely be affected by climate change. In this paper, we use a statistical model relating observed water use by U.S. producers to the moisture deficit, and then use this statistical model to project climate changes impact on both the fraction of agricultural land irrigated and the irrigation rate (m³ ha⁻¹. Data on water withdrawals for US states (1985-2005 show that both quantities are highly positively correlated with moisture deficit (precipitation--PET. If current trends hold, climate change would increase agricultural demand for irrigation in 2090 by 4.5-21.9 million ha (B1 scenario demand: 4.5-8.7 million ha, A2 scenario demand: 9.1-21.9 million ha. Much of this new irrigated area would occur in states that currently have a wet climate and a small fraction of their agricultural land currently irrigated, posing a challenge to policymakers in states with less experience with strict regulation of agriculture water use. Moreover, most of this expansion will occur in states where current agricultural production has relatively low market value per hectare, which may make installation of irrigation uneconomical without significant changes in crops or practices by producers. Without significant increases in irrigation efficiency, climate change would also increase the average irrigation rate from 7,963 to 8,400-10,415 m³ ha⁻¹ (B1 rate: 8,400-9,145 m³ ha⁻¹, A2 rate: 9,380-10,415 m³ ha⁻¹. The irrigation rate will increase the most in states that already have dry climates and large irrigation rates, posing a challenge for water supply systems in these states. Accounting for both the increase in irrigated area and irrigation rate, total withdrawals might increase by 47.7-283.4 billion m³ (B1 withdrawal: 47.7-106.0 billion m³, A2 withdrawal: 117.4-283.4 billion m³. Increases in irrigation water-use efficiency, particularly by reducing the prevalence of surface irrigation, could eliminate the

  9. Groundwater use for irrigation – a global inventory

    Directory of Open Access Journals (Sweden)

    S. Siebert

    2010-10-01

    Full Text Available Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha, China (19 million ha and the USA (17 million ha. Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.

  10. Groundwater use for irrigation – a global inventory

    Directory of Open Access Journals (Sweden)

    S. Siebert

    2010-06-01

    Full Text Available Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1 277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha, China (19 million ha and the United States of America (17 million ha. Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.

  11. The fluid mechanics of root canal irrigation.

    Science.gov (United States)

    Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

    2010-12-01

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  12. Comparison of a continuous ultrasonic irrigation device and conventional needle irrigation in the removal of root canal debris.

    Science.gov (United States)

    Curtis, Tyson O; Sedgley, Christine M

    2012-09-01

    The purpose of this in vitro study was to compare a continuous ultrasonic irrigation device (VPro StreamClean System [VSS], Vista Dental Products, Racine, WI) with conventional needle irrigation when used as a final irrigation procedure to debride the apical region of the root canal. The null hypothesis that there is no difference was tested. Root canals of matched pairs (N = 20) of extracted human teeth were prepared to an apical size of 36/.04 using Profile series 29/.04 rotary files (Dentsply Tulsa Dental, Tulsa, OK) with 6% sodium hypochlorite (NaOCl) irrigation. One tooth of each pair was randomly assigned to receive final irrigation with either VSS or conventional needle irrigation. The gauge of the needle (#30), the irrigation cycles (ie, 5 mL NaOCl, 5 mL 15% EDTA, and 5 mL NaOCl), the irrigant flow rate (5 mL/min), and needle depth placement (1 mm from the working length [WL]) were experimental constants. Serial sections were obtained at 1 and 3 mm from the WL, stained with hematoxylin-eosin, and viewed at 100× magnification for the presence of debris. The percentage of debris in the canal lumen after VSS or conventional needle irrigation was compared by using the Wilcoxon matched pairs test. There was significantly less debris in the VSS group compared with the conventional needle irrigation group at the 1-mm level (1.50% [VSS] vs 9.90% [conventional needle irrigation], P = .0001) and the 3-mm level (0.45% [VSS] vs 5.16% [conventional needle irrigation], P = .0014). The null hypothesis was rejected. Final irrigation with the VSS compared with conventional needle irrigation delivery resulted in significantly less debris present in root canals at 1 and 3 mm from the WL. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Kalman Filter-based Single-baseline GNSS Data Processing without Pivot Satellite Changing

    Directory of Open Access Journals (Sweden)

    ZHANG Baocheng

    2015-09-01

    Full Text Available Single-baseline global navigation satellite system (GNSS data are able to be processed into a batch of parameters such as positions, timing information as well as atmospheric delays. The applications of relevance, therefore, consist of relative positioning, time and frequency transfer and so forth. To achieve real-time capability, these parameters are usually estimated by means of Kalman-filter. Moreover, the reliability of these parameters can be further strengthened by forming and then successfully fixing a set of independent double-differenced (DD integer ambiguities. For this purpose, the filter function model is commonly set up based on the DD observation equations (DD filter model. In order to preserve the continuity of the filter, DD filter model needs to explicitly refer to another pivot satellite once the previous one becomes invisible. This thereby implies that, before being predicted to the next epoch, the former filtered DD ambiguity vector has to be “mapped” with respect to the newly-defined pivot satellite. In addition to that, the estimated receiver phase clocks using DD filter model may soak up distinct between-receiver single-differenced (SD ambiguities belonging to different pivot satellites and would thereby be subject to apparent “integer jumps”. In this contribution, SD observation equations involving estimable DD ambiguity parameters are alternatively selected as the filter function model (SD filter model. Our analyses suggest that, both DD and SD filter models are equivalent in theory, but differ from each other as far as their implementations are concerned. Typically, for SD filter model, no effort should be made to map DD ambiguities, thus implying less intensive computational burden and better flexibility than DD filter model. At the same time, receiver phase clocks determined by SD filter model are free from “integer jumps” and thus are particularly beneficial for frequency transfer.

  14. Motion within the unstable cervical spine during patient maneuvering: the neck pivot-shift phenomenon.

    Science.gov (United States)

    Lador, Ran; Ben-Galim, Peleg; Hipp, John A

    2011-01-01

    Cervical extrication collars are applied to millions of blunt trauma victims despite the lack of any evidence that a collar can protect against secondary injuries to the cervical spine. Cadaver studies support that in the presence of a dissociative injury, substantial motion can occur within the occipitocervical spine with collar application or during patient transfers. Little is known about the biomechanics of cervical stabilization; hence, it is difficult to develop and test improved immobilization strategies. Severe unstable injuries were created in seven fresh whole human cadavers. Rigid collars were applied with the body in a neutral position. Computed tomographic examinations were obtained before and after tilting the body or backboard as would be done during patient transport or to inspect the back. Relative displacements between vertebrae at the site of the injury were measured from the Computed tomographic examinations. The overall relative alignment between body and collar was assessed to understand the mechanisms that may facilitate motion at the injury site. Intervertebral motion averaged 7.7 mm±6.8 mm in the axial plain and 2.9 mm±2.5 mm in the cranial-caudal direction. The rigid collars appeared to create pivot points where the collar contacts the head in the region under the ear and where the collar contacts the shoulders. Rigid cervical collars appear to create pivot points that shift the center of rotation lateral to the spine and contribute to the intervertebral motions that were measured. Immobilization strategies that avoid these neck pivot-shift phenomena may help to reduce secondary injuries to the cervical spine. The whole cadaver model with simulation of patient maneuvers may provide an effective test method for cervical immobilization.

  15. Development of Strategies for Sustainable Irrigation Water Management in Russia

    Science.gov (United States)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2013-04-01

    During 1960 - 1990 years irrigated areas in Russia have increased rapidly, helping to boost agricultural output. Although the impressive achievements of irrigation in this period its large experience indicates problems and failures of irrigation water management. In addition to large water use and low irrigation water efficiency, environmental concerns (excessive water depletion, water quality reduction, water logging, soil degradation) are usually considered like the most significant problem of the irrigation sector. Despite of considerable shrinking of irrigated areas in Russia and decreasing of water withdrawal for irrigation purposes during two last decades a degradation of environment as well as degradation of soil and water resources in irrigated areas was prolonged and will probably continue if current irrigation practices are maintained. Nowadays, in different regions of Russia there are societal demand to restore agricultural irrigation in Russia as answer to challenges from climate pattern changes and degradation of land & water resources. In the respect of these demands there is a need to develop strategies for sustainability of agricultural irrigation in Russia that should be based on three main societal objectives: costeffective use of water in irrigated agriculture at farm level, and satisfactory preserving the natural environment. Therefore sustainable irrigation water management is not only an objective at farm level but also an overall goal at the local and regional as well. A way to achieve sustainability in irrigation water management is to solve the local conflicts arising from the interactions between water use at irrigation areas and surrounding environment. Thus should be based on the development of irrigation framework program including on the irrigation water management issues, policies & decisions making at federal and regional levels should be based on the indicators of environment & irrigation water efficiency monitoring promoting the

  16. Online decision support system for surface irrigation management

    Science.gov (United States)

    Wang, Wenchao; Cui, Yuanlai

    2017-04-01

    Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

  17. Experimental analysis of single sided ventilation through a centre pivot roof window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza; Heiselberg, Per

    2015-01-01

    In the present study bidirectional airflow characteristics of a centre-pivot roof window were analysed in-situ. Both wind and temperature differences were present at the time of measurements. Tracer gas technique using N2O gas was used to estimate the air change rates in the experimental space....... Leakages through the experimental space were estimated using the blower door tests. Air-change rates increased with increase in the window sash opening angle. When the window was open all the way, with an average wind speed of 4 m/s, the average air-change rate was 2. Flow factor was used to characterise...

  18. Clusters and pivots for evaluating a large numberof alternatives in AHP

    Directory of Open Access Journals (Sweden)

    Alessio Ishizaka

    2012-04-01

    Full Text Available AHP has been successful in many cases but it has a major limitation: a larger number of alternatives requires a high number of judgements in the comparison matrices. In order to reduce this problem,we present a method with clusters and pivots. This method also helps with a further four problems of the Analytic Hierarchy Process. It enlarges the comparison scale, facilitates the construction of a consistent or near consistent matrix, eliminates the problem of the choice of the priorities derivation method and allows the use of incomparable alternatives.

  19. Tropical grasslands: A pivotal place for a more multi-functional agriculture.

    Science.gov (United States)

    Boval, Maryline; Angeon, Valérie; Rudel, Tom

    2017-02-01

    Tropical grasslands represent a pivotal arena for the sustainable intensification of agriculture in the coming decades. The abundant ecosystem services provided by the grasslands, coupled with the aversion to further forest destruction, makes sustainable intensification of tropical grasslands a high policy priority. In this article, we provide an inventory of agricultural initiatives that would contribute to the sustainable intensification of the tropical grassland agro-ecosystem, and we recommend a shift in the scientific priorities of animal scientists that would contribute to realization of a more agro-ecological and multi-functional agriculture in the world's tropical grasslands.

  20. Genetic base of Brazilian irrigated rice cultivars

    Directory of Open Access Journals (Sweden)

    Hudson de Oliveira Rabelo

    2015-08-01

    Full Text Available The aim of this study was to estimate the genetic base of Brazilian irrigated rice cultivars released in the period from 1965 to 2012. The genealogies of the cultivars were obtained based on information from marketing folders, websites, crossings records, and scientific articles. The following factors were calculated: relative genetic contribution (RGC, accumulated genetic contribution (AGC, frequency (in percentage of each ancestor in the genealogy (FAG, number of ancestors that constitute each cultivar (NAC,number of ancestors responsible for 60%, 70%, 80% and 90% of the genetic base (NAGB, and average number of ancestor per cultivar (ANAC. The cultivars were also grouped based on the period of release (1965-1980, 1981-1990, 1991-2000 and 2001-2012. For each grouping, the previously described factors were also estimated. A total of 110 cultivars were studied and it was concluded that the genetic base of Brazilian irrigated rice cultivars is narrow.

  1. Irrigants in non-surgical endodontic treatment.

    Science.gov (United States)

    Regan, John D; Fleury, Alex A P

    2006-01-01

    This paper highlights that one of the main goals of root canal treatment is the elimination of microorganisms from the contaminated root canal system. Instrumentation alone will not allow for adequate debridement and disinfection of the complex and diverse root canal system. Chemomechanical debridement is required. The importance of the use of irrigants during non-surgical root canal treatment has frequently been neglected both during instruction of dental students and later in the clinical practice of endodontics. The article highlights 'shape, clean and fill' vs. 'clean, shape and fill' to enable chemomechanical debridement. Our protocol advises mechanical debridement and copious irrigation for a minimum of twenty minutes with 2.5% to 6% solutions of sodium hypochlorite, followed by a rinse with a 17% solution of ethylenediaminetetraacetic acid and a final rinse with 2% chlorhexidine. The canals are dried with high volume aspirators and sterile paper points.

  2. DEVELOPMENT OF WATER CIRCULATION MODEL INCLUDING IRRIGATION

    Science.gov (United States)

    Kotsuki, Shunji; Tanaka, Kenji; Kojiri, Toshiharu; Hamaguchi, Toshio

    It is well known that since agricultural water withdrawal has much affect on water circulation system, accurate analysis of river discharge or water balance are difficult with less regard for it. In this study, water circulation model composed of land surface model and distributed runoff model is proposed at 10km 10km resolution. In this model, irrigation water, which is estimated with land surface model, is introduced to river discharge analysis. The model is applied to the Chao Phraya River in Thailand, and reproduced seasonal water balance. Additionally, the discharge on dry season simulated with the model is improved as a result of including irrigation. Since the model, which is basically developed from global data sets, simulated seasonal change of river discharge, it can be suggested that our model has university to other river basins.

  3. Saline water irrigation of quinoa and chickpea

    DEFF Research Database (Denmark)

    Hirich, A.; Jelloul, A.; Choukr-Allah, R.

    2014-01-01

    A pot experiment was conducted in the south of Morocco to evaluate the response of chickpea and quinoa to different irrigation water salinity treatments (1, 4, 7 and 10 dS m-1 for chickpea and 1, 10, 20 and 30 dS m-1 for quinoa). Increasing salinity affected significantly (P ... and height and caused delay and reduction in seed emergence, quinoa was shown to be more resistant than chickpea. Dry biomass, seed yield, harvest index and crop water productivity were affected significantly (P ... and seed yield for both quinoa and chickpea while increasing salinity resulted in increase - in the case of quinoa - and decrease - in the case of chickpea - in harvest index and crop water productivity. Na+ and Na+/K+ ratio increased with increasing irrigation water salinity, while K+ content decreased...

  4. Review of root canal irrigant delivery techniques and devices

    Directory of Open Access Journals (Sweden)

    Yeon-Jee Yoo

    2011-05-01

    Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

  5. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    WANG Kang; ZHANG RenDuo; SHENG Feng

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development.In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment.Field dye staining experiments were conducted at different soils with various irrigation amount.Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency.Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage effi-ciency, and uniformity.Under the same irrigation condition, soil chemical distributions were more het-erogeneous than soil water distributions.The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount.Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount.Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uni-formity, which resulted in high environmental risks of groundwater pollution.

  6. Rice photosynthetic productivity and PSII photochemistry under nonflooded irrigation.

    Science.gov (United States)

    He, Haibing; Yang, Ru; Jia, Biao; Chen, Lin; Fan, Hua; Cui, Jing; Yang, Dong; Li, Menglong; Ma, Fu-Yu

    2014-01-01

    Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM), furrow irrigation with nonmulching (FIN), and drip irrigation with plastic mulching (DI). Compared with the conventional flooding (CF) treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN), lower maximum quantum yield (Fv/Fm), and lower effective quantum yield of PSII photochemistry (ΦPSII). And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC). Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA) were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  7. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    Directory of Open Access Journals (Sweden)

    Jochen Hemming

    2009-04-01

    Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

  8. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    Directory of Open Access Journals (Sweden)

    Haibing He

    2014-01-01

    Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  9. Effect of three different irrigation solutions applied by passive ultrasonic irrigation

    Directory of Open Access Journals (Sweden)

    Carmen Llena

    2015-05-01

    Full Text Available Objectives This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI. Materials and Methods Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl, 2% chlorhexidine (Group B, CHX and saline solution (Group C, control group were applied with Irrisafe 20 tips (Acteon and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM. The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. Results In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05, but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. Conclusions NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.

  10. Comparative anti-microbial efficacy of Azadirachta indica irrigant with standard endodontic irrigants: A preliminary study

    Directory of Open Access Journals (Sweden)

    Arindam Dutta

    2014-01-01

    Full Text Available Objective: The anti-microbial efficacy of 2.5% sodium hypochlorite (SHC and 0.2% chlorhexidine gluconate were compared with an experimental irrigant formulated from the Neem tree, Azadirachta indica A. Juss. Materials and Methods: A sample of 36 single rooted anterior teeth with periapical radiolucency and absence of response to vitality tests that required root canal treatment were selected for this study. The test irrigants and their combinations were assigned to five different groups and saline served as the control. Access cavities were prepared using an aseptic technique and samples collected for both anaerobic culture and Gram stained smears, followed by irrigation and sample collection again. The number of organisms were expressed in colony forming units/ml after 72 h of incubation; the smears were analyzed for their microbial loads and tissue clearance and assessed as per defined criteria. Results: Our results found the maximum reduction in microbial loads, when analyzed by culture method, with a combination of SHC and the experimental neem irrigant. Maximum tissue clearance on the Gram Stained smears was also found with the same combination. Conclusion: Neem irrigant has anti-microbial efficacy and can be considered for endodontic use.

  11. EFFECT OF GROUNDWATER TABLE CONTROL ON WATER SAVING IRRIGATION STRATEGIES IN THE QINGTONGXIA IRRIGATION DISTRICT

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-gui; HOLLANDERS P. H. J.

    2004-01-01

    This paper focuses on the analysis of the effects of groundwater table control under different irrigation water amounts on the water and salinity balance and on crop yield. Two experimental areas, the Pingluo and Huinong experimental sites, were selected to collect the required data.The agro-hydrological model Soil-Water Atmosphere-Plant(SWAP) was used to analyse the water flows and salt transport processes for different groundwater levels and irrigation scenarios. Six scenarios, which resulted from different groundwater table regimes combined with different irrigation amounts, were simulated. The results show that high groundwater tables due to the excessive irrigation are the main cause of the large amount of drainage water and low crop yield;reducing irrigation water without a lower groundwater table will not lead to a large reduction of the drainage water, and will reduce the crop yield even more; to lower the groundwater table is a good measure to control the drainage water and increase crop yield.

  12. Solar Energy Based Automated Irrigation System

    Directory of Open Access Journals (Sweden)

    Prof. Lodhi A. K.

    2013-09-01

    Full Text Available In the field of agriculture, use of proper method of irrigation is important because the main reason is the lack of rains {&} scarcity of land reservoir water. The continuous extraction of water from earth is reducing the water level due to which lot of land is coming slowly in the zones of un-irrigated land. Another very important reason of this is due to unplanned use of water due to which a significant amount of water goes waste. For this purpose; we use this automatic plant irrigation system. In this project we use solar energy which is used to operate the irrigation pump. The circuit comprises of sensor parts built using op-amp IC LM358. Op-amp are configured here as a comparator. Two stiff copper wires are inserted in the soil to sense whether the soil is wet or dry. The Microcontroller is used to control the whole system by monitoring the sensors and when sensors sense the dry condition then the microcontroller will send command to relay driver IC the contacts of which are used to switch on the motor and it will switch off the motor when all the sensors are in wet condition. The microcontroller does the above job as it receives the signal from the sensors through the output of the comparator, and these signals operate under the control of software which is stored in ROM of the Microcontroller. The condition of the pump i.e., ON/OFF is displayed on a 16X2 LCD

  13. Phosphorus losses in furrow irrigation runoff.

    Science.gov (United States)

    Westermann, D T; Bjorneberg, D L; Aase, J K; Robbins, C W

    2001-01-01

    Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff. We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface-irrigated with Snake River water. Water-soluble P, Olsen P (inorganic and organic P), and iron-oxide impregnated paper-extractable P (FeO-Ps) were determined on a 0.03-m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999. Dissolved reactive phosphorus (DRP) in a 0.45-microm filtered runoff sample, and iron-oxide impregnated paper-extractable P (FeO-Pw), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4-h irrigation on 18.3-m field plots. The 1998 and 1999 data sets were combined because there were no significant differences. Flow-weighted average runoff DRP and FeO-Pw concentrations increased linearly as all three soil P test concentrations increased. The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration. Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration. The average runoff total P concentration was 1.08 mg L(-1) at a soil Olsen P concentration of 10 mg kg(-1). Soil erosion control will be necessary to reduce P losses in surface irrigation runoff.

  14. Pivotal connection for articulated column of sea-bed working structure. Leddforbindelse for en soeyle for arbeide paa havbunnen

    Energy Technology Data Exchange (ETDEWEB)

    Tuson, S.; Chilardi, J.P.

    1984-08-20

    The invention relates to a pivotal connecting device of the kind forming a universal Cardan joint coupling in particular for a compliant or articulated column of a sea-bed working structure, said column being pivotally connected to a base member, wherein said universal Cardan joint coupling is associated with one or more rigid connecting ducts for conveying the flow of at least one fluid between said base member and said column. 4 drawings.

  15. Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

    Science.gov (United States)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2016-04-01

    The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

  16. Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

    NARCIS (Netherlands)

    Kissawike, K.

    2008-01-01

    This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to understand how irrigation and agricultural technologies have interacted with local society to transform production, paying particular attention to gender relations and changes for women farmers. The thesis seeks to

  17. Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

    NARCIS (Netherlands)

    Kissawike, K.

    2008-01-01

    This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to understand how irrigation and agricultural technologies have interacted with local society to transform production, paying particular attention to gender relations and changes for women farmers. The thesis seeks to c

  18. Impacts of Irrigation on the Heat Fluxes and Near-Surface Temperature in an Inland Irrigation Area of Northern China

    Directory of Open Access Journals (Sweden)

    Li Jiang

    2014-03-01

    Full Text Available Irrigated agriculture has the potential to alter regional to global climate significantly. We investigate how irrigation will affect regional climate in the future in an inland irrigation area of northern China, focusing on its effects on heat fluxes and near-surface temperature. Using the Weather Research and Forecasting (WRF model, we compare simulations among three land cover scenarios: the control scenario (CON, the irrigation scenario (IRR, and the irrigated cropland expansion scenario (ICE. Our results show that the surface energy budgets and temperature are sensitive to changes in the extent and spatial pattern of irrigated land. Conversion to irrigated agriculture at the contemporary scale leads to an increase in annual mean latent heat fluxes of 12.10 W m−2, a decrease in annual mean sensible heat fluxes of 8.85 W m−2, and a decrease in annual mean temperature of 1.3 °C across the study region. Further expansion of irrigated land increases annual mean latent heat fluxes by 18.08 W m−2, decreases annual mean sensible heat fluxes by 12.31 W m−2, and decreases annual mean temperature by 1.7 °C. Our simulated effects of irrigation show that changes in land use management such as irrigation can be an important component of climate change and need to be considered together with greenhouse forcing in climate change assessments.

  19. Apical Extrusion of Irrigants in Immature Permanent Teeth by Using EndoVac and Needle Irrigation: An In Vitro Study.

    Directory of Open Access Journals (Sweden)

    N Velmurugan

    2014-08-01

    Full Text Available Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation.Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20: EndoVac Microcannula (group I, EndoVac Macrocannula (group II, NaviTip irrigation needle (group III and Max-i-Probe Irrigating needle (group IV; 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically.Group I, group III and group IV showed 100% extrusion (20/20 but group II showed only 40% extrusion (8/20. The difference in this respect between group II and other groups was statistically significant (P<0.001. With regards to the volume of extrusion, group II had only 0.23 ml of extruded irrigant. Group I extruded 7.53ml of the irrigant. Group III and group IV extruded the entire volume of irrigant delivered.EndoVac Macrocannula resulted in the least extrusion of irrigant in immature teeth when compared to EndoVac Microcannula and conventional needle irrigation.

  20. Where Does the Irrigation Water Go? An Estimate of the Contribution of Irrigation to Precipitation Using MERRA

    Science.gov (United States)

    Wei, Jiangfeng; Dirmeyer, Paul A.; Wisser, Dominik; Bosilovich, Michael G.; Mocko, David M.

    2013-01-01

    Irrigation is an important human activity that may impact local and regional climate, but current climate model simulations and data assimilation systems generally do not explicitly include it. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) shows more irrigation signal in surface evapotranspiration (ET) than the Modern-Era Retrospective Analysis for Research and Applications (MERRA) because ERA-Interim adjusts soil moisture according to the observed surface temperature and humidity while MERRA has no explicit consideration of irrigation at the surface. But, when compared with the results from a hydrological model with detailed considerations of agriculture, the ET from both reanalyses show large deficiencies in capturing the impact of irrigation. Here, a back-trajectory method is used to estimate the contribution of irrigation to precipitation over local and surrounding regions, using MERRA with observation-based corrections and added irrigation-caused ET increase from the hydrological model. Results show substantial contributions of irrigation to precipitation over heavily irrigated regions in Asia, but the precipitation increase is much less than the ET increase over most areas, indicating that irrigation could lead to water deficits over these regions. For the same increase in ET, precipitation increases are larger over wetter areas where convection is more easily triggered, but the percentage increase in precipitation is similar for different areas. There are substantial regional differences in the patterns of irrigation impact, but, for all the studied regions, the highest percentage contribution to precipitation is over local land.

  1. Traditional Irrigation Management in Betmera-Hiwane, Ethiopia: The Main Peculiarities for the Persistence of Irrigation Practices

    Institute of Scientific and Technical Information of China (English)

    Solomon Habtu; Kitamura Yoshinobu

    2006-01-01

    Traditional irrigation, as part of the ancient agricultural practices in northern Ethiopia (Tigray), has persisted for long time since 500 B.C.,while many newly introduced irrigation projects have usually failed there. The main objective of this study is thus to investigate the peculiarities pertinent to irrigation management and those having contributed for the persistence of traditional irrigation practices for a long period of time. The experience gained from such areas can definitely help make irrigation management system of new irrigation schemes sustainable. Betmera-Hiwane, one of the ancient traditional irrigation areas in Tigray region, was selected for the field study. Direct observations through field visits accompanied by interviews to farmers, local officials, local knowledgeable individuals and higher officials were made. After analyzing the collected primary and secondary information, the main peculiarities that contributed to the persistence of traditional irrigation areas were identified, and they are: the presence of communally constructed local rules, locally designed hydraulic control structures, ownership feeling of the irrigators and accountability of water distributors to the irrigation management, the culture for mobilizing communal resources and the culture of self-initiating local water management strategies.

  2. Energy performance of sprinkler irrigated maize, wheat and sunflower in Vigia irrigation district

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Sandra; Rodrigues, Goncalo Caleia; Paredes, Paula; Pereira, Luis S. [Centro de Engenharia dos Biossistemas (CEER/ISA), Lisboa (Portugal)], E-mail: lspereira@isa.utl.pt

    2008-07-01

    The energy potential of a crop may be evaluated through life cycle assessment methodologies. These refer to the computation of the crop's energy balance and other related indicators, such as the energy ratio and the energetic efficiency, that may be used as to assess how a given irrigated crop may be used for production of biofuel. This study concerns sprinkler irrigated sunflower, wheat and maize crops using data relative to the campaign of 2007 in the Vigia Irrigation District, Alentejo. A model was developed and various scenarios were considered. The modelling results lead to the conclusion that the maize crop is the most efficient in producing energy and sunflower is the least one for all the alternative scenarios considered. (author)

  3. Effect of Opening the Sash of a Centre-Pivot Roof Window on Wind Pressure Coefficients

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Wigö, Hans; Heiselberg, Per

    2014-01-01

    This paper describes the effect of outward opening the sash of a window on local and overall wind pressures. Wind tunnel experiments were used for the purpose of evaluation. A centre-pivot roof window on a pitched roof in a modelled scaled building was used in the analysis of wind pressures. The ...... pressure distribution nearby the window. The use of wind pressure coefficients from the analysis of sealed plain surface may lead to erroneous estimation of airflow rate.......This paper describes the effect of outward opening the sash of a window on local and overall wind pressures. Wind tunnel experiments were used for the purpose of evaluation. A centre-pivot roof window on a pitched roof in a modelled scaled building was used in the analysis of wind pressures....... The wind pressures were defined in terms of wind pressure coefficients. Traditionally wind pressure coefficients are extracted from the analysis of sealed plain surface. These wind pressure coefficients are used to estimate the natural ventilation rate through windows/openings due to wind effect. Surface...

  4. Resilience Pivots: Stability and Identity in a Social-Ecological-Cultural System

    Directory of Open Access Journals (Sweden)

    Stephanie J. Rotarangi

    2014-03-01

    Full Text Available How is cultural resilience achieved in the face of significant social and ecological change? Is resilience compatible with changed structures, functions, and feedbacks as long as identity is maintained? The concept of cultural resilience has been less explored than its older siblings ecological resilience, social resilience, and social-ecological resilience. We seek to redress the balance, drawing from resilience thinking to examine how a New Zealand Māori tribal group of landowners retained strong cultural identity and connectedness to their land despite enduring significant changes in land use, economy, tenure, and governance. The landowners negotiated radical transformations in the ecology and land use of their home lands on terms that supported matters of cultural importance. The key resilience concepts of adaptation and transformation were helpful in analyzing the trajectory of change, but fell short of representing the elements of stability that supported the cultural resilience of the landowners. The concept of resilience pivots was designed to address this conceptual gap, and to offer another heuristic to resilience thinking by focusing on stability rather than change. Resilience pivots are those elements of a resilient system that remain stable despite adaptation or even transformation of other elements of that system, and in doing so support the maintenance of the system's distinctive identity.

  5. Reservoir storage and irrigation in Arequipa, Peru

    Science.gov (United States)

    Ertsen, Maurits; Swiech, Theoclea; Machicao Pererya, Carlos

    2010-05-01

    In countries such as Peru, irrigated agriculture is not only vital for the subsistence of many but can also be a factor of economic development and by extent social improvement. To answer the local demand and respond to the water scarcity in the sub-basin of Yarabamba, near city of Arequipa, the government decided the construction of a dam for irrigation. The irrigation systems are affected by the lack of water during the dry season for lack of storage and of water distribution between downstream and upstream sectors, among other issues. Water scarcity is the main issue in the basin, leading to poor yields and the inability of growing crops with a high commercial value. Rainfall is available only from November to April, the rest of the year being very dry. Furthermore, the lowest areas of Yarabamba, Sogay and Quequeña are disadvantaged compared to the highest area of Polobaya. By creating a large storage area to regulate the variations of water availability through the year, the dam would allow to at least palliate the lack of water in existing lands, and at best to extend agricultural lands. Farmers would then be able to shift toward higher value crops more easily than without this extra storage. The main focus of the research was the dam which was supposed to improve the water distribution and availability in the sub-basin. From the results of the study, it can be concluded that other factors, related to the irrigation system itself, are involved in the efficiency of the new structure. The farmers, the main stakeholders, believe that more could be done to improve the system and their standard of living. Most of all, the main issue that should be resolved is the fair distribution of water. However, this is not possible without a strong cooperation between sectors, and a potential change in diversion structures. The competition between the districts should be reduced, otherwise the benefits of the dam would not give the expected results. This example shows that

  6. WATER MANAGEMENT STRATEGIES UNDER DEFICIT IRRIGATION

    Directory of Open Access Journals (Sweden)

    Antonino Capra

    2008-12-01

    Full Text Available Deficit irrigation (DI is an optimization strategy whereby net returns are maximized by reducing the amount of irrigation water; crops are deliberated allowed to sustain some degree of water deficit and yield reduction. Although the DI strategy dates back to the 1970s, this technique is not usually adopted as a practical alternative to full irrigation by either academics or practitioners. Furthermore, there is a certain amount of confusion regarding its concept. In fact, a review of recent literature dealing with DI has shown that only a few papers use the concept of DI in its complete sense (e.g. both the agronomic and economic aspects. A number of papers only deal with the physiological and agronomical aspects of DI or concern techniques such as Regulated Deficit Irrigation (RDI and Partial Root Drying (PRD. The paper includes two main parts: i a review of the principal water management strategies under deficit conditions (e.g. conventional DI, RDI and PRD; and ii a description of a recent experimental research conducted by the authors in Sicily (Italy that integrates agronomic, engineering and economic aspects of DI at farm level. Most of the literature reviewed here showed, in general, quite positive effects from DI application, mostly evidenced when the economics of DI is included in the research approach. With regard to the agronomic effects, total fresh mass and total production is generally reduced under DI, whereas the effects on dry matter and product quality are positive, mainly in crops for which excessive soil water availability can cause significant reductions in fruit size, colour or composition (grapes, tomatoes, mangos, etc.. The experimental trial on a lettuce crop in Sicily, during 2005 and 2006, shows that the highest mean marketable yield of lettuce (55.3 t ha-1 in 2005 and 51.9 t ha-1 in 2006 was recorded in plots which received 100% of ET0-PM (reference evapotranspiration by the Penman- Monteith method applied water. In

  7. Irrigation and avifaunal change in coastal Northwest Mexico: has irrigated habit attracted threatened migratory species?

    Directory of Open Access Journals (Sweden)

    Sievert Rohwer

    2015-08-01

    Full Text Available Irrigation in desert ecosystems can either reduce or increase species diversity. Groundwater pumping often lowers water tables and reduces natural wetlands, whereas canal irrigation often creates mesic habitat, resulting in great increases in avian diversity from irrigation. Here we compare a dataset of potential natural vegetation to recent datasets from areal and satellite imagery to show that 60% of the land in the coastal plain of southern Sonora and northern Sinaloa lying below 200 m elevation has been converted by irrigation to more mesic habitats. We then use the record of bird specimens in the world’s museums from this same region of Mexico to examine the avian community before and after the development of extensive irrigation. In general these museum records show an increase in the abundance and diversity of breeding birds associated with mesic habitats. Although thorn forest birds have likely decreased in total numbers, most are common enough in the remaining thorn forest that collection records did not indicate their probable decline. Four migrants having most of their breeding ranges in the US or Canada, Yellow-billed Cuckoo, Cliff Swallow, Bell’s Vireo, and Orchard Oriole, apparently have increased dramatically as breeders in irrigated habitats of NW Mexico. Because these species have decreased or even largely disappeared as breeding birds in parts of the US or Canada, further research should assess whether their increases in new mesic habitats of NW Mexico are linked to their declines as breeding birds in Canada and the US For Bell’s Vireo recent specimens from Sinaloa suggest its new breeding population in NW Mexico may be composed partly of the endangered Least Bell’s Vireo.

  8. Improvement of sustainability of irrigation in olive by the accurate management of regulated deficit irrigation

    Science.gov (United States)

    Memmi, Houssem; Moreno, Marta M.; Gijón, M. Carmen; Pérez-López, David

    2015-04-01

    Regulated Deficit Irrigation (RDI) is a useful tool to balance the improvement of productivity and water saving. This methodology is based in keeping the maximum yield with deficit irrigation. The key consists in setting water deficit during a non-sensitive phenological period. In olive, this phenological period is pit hardening, although, the accurate delimitation of the end of this period is nowadays under researching. Another interesting point in this methodology is how deep can be the water stress during the non-sensitive period. In this assay, three treatments were used in 2012 and 2013. A control treatment (T0), irrigated following FAO methodology, without water stress during the whole season and two RDI treatments in which water stress was avoided only during stage I and III of fruit growth. During stage II, widely considered as pit hardening, irrigation was ceased until trees reach the stated water stress threshold. Water status was monitored by means of stem water potential (ψs) measurements. When ψs value reached -2 MPa in T1 treatment, trees were irrigated but with a low amount of water with the aim of keeping this water status for the whole stage II. The same methodology was used for T2 treatment, but with a threshold of -3 MPa. Water status was also controlled by leaf conductance measurements. Fruit size and yield were determined at the end of each season. The statistically design was a randomized complete blocks with four repetitions. The irrigation amount in T1 and T2 was 50% and 65% less than T0 at the end of the study. There were no significant differences among treatments in terms of yield in 2012 (year off) and 2013 (year on).

  9. Optimizing preplant irrigation for maize under limited water in the high plains

    Science.gov (United States)

    Due to inadequate irrigation capacity, some farmers in the United States High Plains apply preplant irrigation to buffer the crop between irrigation events during the cropping season. The purpose of the study was to determine preplant irrigation amount and irrigation capacity combinations that optim...

  10. 25 CFR 171.415 - Can I place an obstruction on a BIA irrigation project?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I place an obstruction on a BIA irrigation project... IRRIGATION OPERATION AND MAINTENANCE Irrigation Facilities § 171.415 Can I place an obstruction on a BIA irrigation project? No. You may not place obstructions on BIA irrigation projects. (a) If you do so, we will...

  11. In vitro disinfection of dentinal tubules by various endodontics irrigants.

    Science.gov (United States)

    Buck, R; Eleazer, P D; Staat, R H

    1999-12-01

    Effectiveness of endodontic irrigants within dentinal tubules of human teeth was evaluated. Mid-sections of single-rooted teeth were prepared into dentin wedges. The pulpal sides of the sections were exposed to Micrococcus luteus or Bacillus megaterium that grew into the tubules. Irrigants used in the study included: 0.525% NaOCl, 0.12% chlorhexidine, RC Prep, 0.5% betadine iodine, and sterile H2O (as a control). Pulpal surfaces were exposed to an irrigant and then rinsed in sterile water. The samples were then cracked, exposing a fresh surface. Culture of the exposed dentin surfaces showed that selected irrigants reached to the far ends of the dentinal tubules in a concentration sufficient to kill 100% of the M. luteus. However B. megaterium was neither killed nor apparently inhibited by any irrigant. We conclude that endodontic irrigants permeate throughout dentinal tubules, but their effectiveness is dependent on the type of bacteria found within the tubules.

  12. Comparison of Manual and Automatic Irrigation of Pot Experiments

    DEFF Research Database (Denmark)

    Haahr, Vagner

    1975-01-01

    An air-lift principle for transport of water was adapted for automatic irrigation of experimental pots originally constructed for manual irrigation by the weighing method. The two irrigation techniques were compared in an experiment with increasing amounts of nitrogen fertilizer to spring barley....... Productions of grain and straw and chemical composition were almost the same after the two irrigation methods, and it was concluded that the laborious manual watering could be replaced by automatic irrigation. Comparison of the yield from individual plants in the pots showed a large difference between centre...... plants and border plants independent of irrigation principle. The increase in yield per pot with increasing N fertilization was at the highest N level caused only by an increase in yield of the border plants....

  13. Reform of irrigation management and investment policy in African development

    Directory of Open Access Journals (Sweden)

    KW Easter

    2015-01-01

    Full Text Available This paper examines the reform of water and irrigation management in Africa and compares it with similar reforms in Asia.  Several things are evident from the review.  First, Sub-Saharan Africa (SSA is at an earlier stage of irrigation development and reform than Asia.  Second, the articulated need for reform is much stronger in Asia than it is in SSA.  Third, the productivity of small-scale irrigated farms is significantly lower in SSA compared to Asia.  Thus any irrigation investment strategy in SSA should be different from Asia and focus on increasing small-farm productivity as well as small-scale irrigation projects.  Finally, all direct government irrigation investments should be done jointly with decisions regarding the type of project management.

  14. Irrigation Optimization by Modeling of Plant-Soil Interaction

    OpenAIRE

    2011-01-01

    Irrigation scheduling is an important issue for crop management, in a general context of limited water resources and increasing concern about agricultural productivity. Methods to optimize crop irrigation should take into account the impact of water stress on plant growth and the water balance in the plant-soil-atmosphere system. In this article, we propose a methodology to solve the irrigation scheduling problem. For this purpose, a plant-soil interaction model is used to simulate the struct...

  15. Water Supply Planning for Landscape Irrigation in Virginia

    OpenAIRE

    Tucker, Adrienne Janel LaBranche

    2009-01-01

    A water supply plan approach was used to investigate irrigation application on landscaped areas in Virginia with a focus on turfgrass. The economically-important turfgrass industry in Virginia should be proactive in conserving drinking water supplies to meet human consumption needs, especially in drought times. This thesis investigates current irrigation water supplies, water supply sustainability, and alternative water sources to meet irrigation demands and offers an insight on how potable w...

  16. 75 FR 29577 - Rate Adjustments for Indian Irrigation Projects

    Science.gov (United States)

    2010-05-26

    ... acre 68.00 70.00 Wapato Irrigation Project--Additional Works Minimum Charge per tract...... 63.00 65.00... Others Basic-per acre 20.50 22.50 (includes Bighorn, Soap Creek, and Pryor Units) *. Crow Irrigation Two... 86.00 feet (Ranch 5). San Carlos Irrigation Project (Joint Works) Basic per acre 21.00 21.00 (See...

  17. MANAGEMENT OF IRRIGATION AND NITROGEN FERTILIZERS TO REDUCE AMMONIA VOLATILIZATION

    Directory of Open Access Journals (Sweden)

    Fernando Viero

    2015-12-01

    Full Text Available ABSTRACT Nitrogen losses by ammonia (NH3 volatilization can be reduced by appropriate irrigation management or by alternative N sources, replacing urea. The objective of this study was to evaluate the efficiency of irrigation management and N source combinations in decreasing NH3 volatilization from an Argissolo Vermelho Distrófico típico cultivated for 28 years with black oat (Avena strigosa and maize (Zea mays, under no-tillage in the region of Depressão Central, Rio Grande do Sul, Brazil. The experiment was arranged in a randomized block design with split plots with three replications, where the main plots consisted of irrigation systems: no irrigation; irrigation immediately before and irrigation immediately after fertilization. The subplots were treated with different N sources: urea, urea with urease inhibitor and slow-release fertilizer, at an N rate of 180 kg ha-1, broadcast over maize, plus a control treatment without N fertilization. Ammonia volatilization was assessed using semi-open static collectors for 1, 2, 4, 6, and 10 days after N fertilization. In general, more than 90 % of total NH3-N losses occurred until three days after N fertilization, with peaks up to 15.4 kg ha-1 d-1. The irrigation was efficient to reduce NH3 losses only when applied after N fertilization. However, reductions varied according to the N fertilizer, and were higher for urea (67 % and slightly lower for urea with urease inhibitor (50 % and slow-release fertilizer (40 %, compared with the mean of the treatments without irrigation and irrigation before fertilization. The use of urea with urease inhibitor instead of urea was only promising under volatilization-favorable conditions (no irrigation or irrigation before N fertilization. Compared to urea, slow-release fertilizer did not reduce ammonia volatilization in any of the rainfed or irrigated treatments.

  18. Evaluation of Wetland Hydrology in Formerly Irrigated Areas

    Science.gov (United States)

    2017-07-01

    ER D C/ EL T R- 17 -1 3 Wetlands Regulatory Assistance Program Evaluation of Wetland Hydrology in Formerly Irrigated Areas En vi ro nm...EL TR-17-13 July 2017 Evaluation of Wetland Hydrology in Formerly Irrigated Areas Jacob F. Berkowitz, Jason P. Pietroski, and Steven J. Currie...of hydrology , and the distribution of plant communities. As a result, the identification of wetlands in irrigated areas remains challenging. The

  19. Influence of Irrigation Scheduling Using Thermometry on Peach Tree Water Status and Yield under Different Irrigation Systems

    Directory of Open Access Journals (Sweden)

    Huihui Zhang

    2017-02-01

    Full Text Available Remotely-sensed canopy temperature from infrared thermometer (IRT sensors has long been shown to be effective for detecting plant water stress. A field study was conducted to investigate peach tree responses to deficit irrigation which was controlled using canopy to air temperature difference (ΔT during the postharvest period at the USDA-ARS (U.S. Department of Agriculture, Agricultural Research Service San Joaquin Valley Agricultural Sciences Center in Parlier, California, USA. The experimental site consisted of a 1.6 ha early maturing peach tree orchard. A total of 18 IRT sensors were used to control six irrigation treatments including furrow, micro-spray, and surface drip irrigation systems with and without postharvest deficit irrigation. During the postharvest period in the 2012–2013 and 2013–2014 growing seasons, ΔT threshold values at mid-day was tested to trigger irrigation in three irrigation systems. The results showed that mid-day stem water potentials (ψ for well irrigated trees were maintained at a range of −0.5 to −1.2 MPa while ψ of deficit irrigated trees dropped to lower values. Soil water content in deficit surface drip irrigation treatment was higher compared to deficit furrow and micro-spray irrigation treatments in 2012. The number of fruits and fruit weight from peach trees under postharvest deficit irrigation treatment were less than those well-watered trees; however, no statistically significant (at the p < 0.05 level reduction in fruit size or quality was found for trees irrigated by surface drip and micro-spray irrigation systems by deficit irrigation. Beside doubles, we found an increased number of fruits with deep sutures and dimples which may be a long-term (seven-year postharvest regulated deficit irrigation impact of deficit irrigation on this peach tree variety. Overall, deployment of IRT sensors provided real-time measurement of canopy water status and the information is valuable for making irrigation

  20. Filtration, Treatment, and Maintenance Considerations for Micro-Irrigation Systems

    OpenAIRE

    Benham, Brian Leslie, 1960-; Ross, B. Blake

    2009-01-01

    Causes and Prevention of Emitter Plugging, Water Quality Analysis, Physical plugging hazards, Biological plugging hazards, Chemical plugging hazards, Flushing, Injecting chemicals into Micro-irrigation system

  1. The relationship between irrigation water demand and drought in the Yellow River basin

    Science.gov (United States)

    Wang, Yu; Wang, Weihao; Peng, Shaoming; Jiang, Guiqin; Wu, Jian

    2016-10-01

    In order to organize water for drought resistance reasonably, we need to study the relationship between irrigation water demand and meteorological drought in quantitative way. We chose five typical irrigation districts including the Qingtongxia irrigation district, Yellow River irrigation districts of Inner Mongolia in the upper reaches of the Yellow River, the Fen river irrigation district and the Wei river irrigation district in the middle reaches of the Yellow River and the irrigation districts in the lower reaches of the Yellow River as research area. Based on the hydrology, meteorology, groundwater and crop parameters materials from 1956 to 2010 in the Yellow River basin, we selected reconnaissance drought index (RDI) to analyze occurrence and evolution regularity of drought in the five typical irrigation districts, and calculated the corresponding irrigation water demand by using crop water balance equation. The relationship of drought and irrigation water demand in each typical irrigation district was studied by using grey correlation analysis and relevant analysis method, and the quantitative relationship between irrigation water demand and RDI was established in each typical irrigation district. The results showed that the RDI can be applied to evaluate the meteorological drought in the typical irrigation districts of the Yellow River basin. There is significant correlation between the irrigation water demand and RDI, and the grey correlation degree and correlation coefficient increased with increasing crops available effective rainfall. The irrigation water demand of irrigation districts in the upstream, middle and downstream of the Yellow River basin presented different response degrees to drought. The irrigation water demand increased 105 million m3 with the drought increasing one grade (RDI decreasing 0.5) in the Qingtongxia irrigation district and Yellow River irrigation districts of Inner Mongolia. The irrigation water demand increased 219 million m3

  2. Distribuição espacial de pivôs centrais no Brasil: I - região sudeste Spatial distribution of center pivots in Brazil: I - southeast region

    Directory of Open Access Journals (Sweden)

    Wulf Schmidt

    2004-12-01

    Full Text Available Quando se buscam, em literatura, dados sobre a irrigação no Brasil, o que se encontra disponível é a área irrigada por estado e por método de irrigação. A distribuição dentro dos estados, o número de equipamentos e seu tamanho são de difícil obtenção, mesmo junto às indústrias. No entanto, essas são informações fundamentais quando se pretende estudar a disponibilidade hídrica ou o potencial de crescimento da área irrigada de uma região, por exemplo, temas esses bastante atuais com a crescente demanda por água potável em nível mundial e nacional. Com o presente trabalho objetivou-se coletar essas informações utilizando-se de imagens do satélite Landsat com base na característica intrínseca do sistema de pivô central de marcar com um círculo o local onde está instalado. Em função do referenciamento cartesiano das imagens e da sua articulação com os mapas do IBGE, foi possível desenhar os mapas estaduais com as áreas de concentração desse tipo de equipamento que, quando comparados com outras fontes, permitiram concluir-se pela validade da metodologia para obtenção dessas informações.Irrigated areas by state and by irrigation method is the available information about irrigation in Brazil. Distribution inside the states, number or size is not easily found even through the industry. These data are very important when one intends to study water availability or growth potencial of irrigated areas for a specific site due to the increasing concern about drinking water worldwide and nationally. The present study had the objective to collect such information using satellite images from Landsat based on the intrinsic characteristic of the center pivot equipments, the circular mark on landscape easily visible. With comparison the geo-referenced images and its articulation with the official IBGE maps, it was possible to draw the state maps with the equipment density distribution, which, when compared to other

  3. Apical Extrusion of Irrigants in Immature Permanent Teeth by Using EndoVac and Needle Irrigation: An In Vitro Study

    Science.gov (United States)

    Velmurugan, N; Sooriaprakas, C; Jain, Preetham

    2014-01-01

    Objective: Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation. Materials and Methods: Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20): EndoVac Microcannula (group I), EndoVac Macrocannula (group II), NaviTip irrigation needle (group III) and Max-i-Probe Irrigating needle (group IV); 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically. Results: Group I, group III and group IV showed 100% extrusion (20/20) but group II showed only 40% extrusion (8/20). The difference in this respect between group II and other groups was statistically significant (Pirrigant. Group I extruded 7.53ml of the irrigant. Group III and group IV extruded the entire volume of irrigant delivered. Conclusion: EndoVac Macrocannula resulted in the least extrusion of irrigant in immature teeth when compared to EndoVac Microcannula and conventional needle irrigation. PMID:25584055

  4. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques.

    Science.gov (United States)

    Spoorthy, E; Velmurugan, N; Ballal, S; Nandini, S

    2013-09-01

    To evaluate the effect of an apical negative pressure system, a passive ultrasonic irrigation system and a combination of both apical negative pressure and passive ultrasonic irrigation on the penetration of the irrigating contrast solution (ICS) up to working length and into simulated lateral canals. The root canals of 64 single-rooted teeth were instrumented using the ProTaper rotary system. In each sample, three simulated lateral canals were created at 2, 4 and 6 mm levels from the root apex using a 06-size C+ file (Dentsply Maillefer, Ballaigues, Switzerland). Samples were randomly assigned into 4 experimental groups (n = 16): group I - conventional needle irrigation, group II - passive ultrasonic irrigation, group III - apical negative irrigation system and group IV - combination of passive ultrasonic irrigation and apical negative pressure irrigation system. To examine irrigating solution penetration, Indian ink was mixed with 5.25% NaOCl and delivered into the root canals. Samples were then assessed by direct observation of the images taken using Canon EOS rebel T3. The depth of penetration of ICS up to the working length and into the simulated lateral canals was analysed using chi-squared tests. The combination (ANP and PUI) and ANP group had significantly deeper ICS penetration up to the working length (P Endodontic Journal. Published by John Wiley & Sons Ltd.

  5. Comparison of sealer penetration using the EndoVac irrigation system and conventional needle root canal irrigation.

    Science.gov (United States)

    Kara Tuncer, Aysun; Unal, Bayram

    2014-05-01

    The aim of this study was to compare the effect of the EndoVac irrigation system (SybronEndo, Orange, CA) and conventional endodontic needle irrigation on sealer penetration into dentinal tubules. Forty single-rooted, recently extracted human maxillary central incisors were randomly divided into 2 groups according to the irrigation technique used: conventional endodontic needle irrigation and EndoVac irrigation. All teeth were instrumented using the ProFile rotary system (Dentsply Maillefer, Ballaigues, Switzerland) and obturated with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) labeled with fluorescent dye. Transverse sections at 1, 3, and 5 mm from the root apex were examined using confocal laser scanning microscopy. The total percentage and maximum depth of sealer penetration were then measured. Mann-Whitney test results showed that EndoVac irrigation resulted in a significantly higher percentage of sealer penetration than conventional irrigation at both the 1- and 3-mm levels (P irrigation system significantly improved the sealer penetration at the 1- to 3-mm level over that of conventional endodontic needle irrigation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Appropriate designs and appropriating irrigation systems : irrigation infrastructure development and users' management capability in Bolivia

    NARCIS (Netherlands)

    Gutierrez Pérez, Z.

    2005-01-01

    The objectives of this book are to explore and demonstrate the 'divorce' that is taking place in how critical actors think about irrigation infrastructure design and management, and in how designers often impose their own narrow preferences in infrastructure composition and performance without refle

  7. Irrigation and fertigation with drip and alternative micro irrigation systems in northern highbush blueberry

    Science.gov (United States)

    The effects of nitrogen (N) fertigation using conventional drip and alternative micro irrigation systems were evaluated in six cultivars of northern highbush blueberry. The drip system consisted of two laterals of drip tubing, with 2 L/h in-line emitters (point source) spaced every 0.45 m, on each s...

  8. Laser assisted irrigation and hand irrigation for root canal decontamination: a comparison

    Science.gov (United States)

    Olivi, M.; Stefanucci, M.; Todea, C.

    2014-01-01

    Aim: to compare the bactericidal efficiency of conventional method and LAI for root canal decontamination. Material and method: 22 human single root teeth, extracted for periodontal problems, mechanically prepared up to ISO 25 at the working lenght were divided in 2 groups: after sterilization, the teeth were infected with enterococcus faecalis and incubated for 4 weeks. Group A: 10 teeth were irrigated with conventional hand technique (CI): 3ml of 5% NaClO were used for two times of 30s each and after washing with sterile bi-distilled water for 20s, a final irrigation was performed with 3ml of 17% EDTA. Group B: 10 teeth were irrigated with 3ml of NaClO and activated by erbium laser, two cycles of 30s; also the final irrigation with 3ml of 17% EDTA was activated by erbium laser. In both the groups a resting time of 30s was used between the two sessions to allow the reaction rate of NaClO. The Erbium laser 2940 nm (LightWalker AT, Fotona; Lublijana, Slovenia) was used with 50microsecond pulse duration, at 15Hz, 20mJ, with a 600micron PIPS tip. Two samples were used as positive and negative control.

  9. Irrigating lives : Development intervention and dynamics of social relationships in an irrigation project

    NARCIS (Netherlands)

    Magadlela, D.

    2000-01-01

    This study is about rural agricultural development and social processes of change in rural Zimbabwe. It is aimed at understanding how irrigation intervention in a remote rural context changed the cultural, social, political and farming lives of people. It is a study of people coping with changes in

  10. Irrigating lives : development intervention and dynamics of social relationships in an irrigation project

    NARCIS (Netherlands)

    Magadlela, D.

    2000-01-01

    This study is about rural agricultural development and social processes of change in rural Zimbabwe. It is aimed at understanding how irrigation intervention in a remote rural context changed the cultural, social, political and farming lives of people. It is a study of people coping with ch

  11. Effects of Irrigation Practices on Some Soil Chemical Properties on OMI Irrigation Scheme

    Directory of Open Access Journals (Sweden)

    M.A. Adejumobi

    2014-10-01

    Full Text Available Irrigation practices have been observed to impact scheme soil properties and other parameters negatively. These could be as a result of irrigation water quality, method of application and nature of scheme soil. This study was therefore conducted to study the effects of irrigation practices on the soils of Omi irrigation scheme Kogi state, Nigeria after 13years of operation. Soil samples were taken at depths 0 – 20 cm (A1, 20 – 80 cm (A2 and 80 – 120 cm (A3 from two operating lands (OL; OL 5 and OL 18 of the study area. The samples were analysed for chemical parameters (pH, CEC, ESP, Mg2+, Ca2+, OM, and OC. The soil pH which was in the neutral range (pH=6.65 to 7.00 at inception of scheme, has become slightly acidic (pH=6.53 to 6.60. Cation exchange capacity (CEC levels have also increased from 10cmol+kg-1 to 35cmol+kg-1. While Organic matter (OM and Organic carbon (OC also have marked increase in their levels (baseline as 0.93 to 1.08; for year 2013 as 9.52 to 9.79. Generally, the analysis indicated a need for proper monitoring of the scheme soil to prevent further deterioration.

  12. Intervention Processes and Irrigation Institutions: Sustainability of Farmer Managed Irrigation Systems in Nepal

    NARCIS (Netherlands)

    Pant, D.R.

    2000-01-01

    With the support from various donors, His Majesty's Government of Nepal has implemented support programmes with a view to transform water availability, improve production, and increase the institutional capabilities of farmers to develop and sustain efficient, fair and reliable irrigation management

  13. 77 FR 21556 - Don Pedro Hydroelectric Project: Turlock Irrigation District; Modesto Irrigation District...

    Science.gov (United States)

    2012-04-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Don Pedro Hydroelectric Project: Turlock Irrigation District; Modesto... Tuolumne Habitats for Anadromous Fish; Request 8--Salmon and Steelhead Full Life-Cycle Population Models...

  14. 76 FR 58249 - Notice of Availability of Proposed Low Effect Habitat Conservation Plan for Tumalo Irrigation...

    Science.gov (United States)

    2011-09-20

    ... Effect Habitat Conservation Plan for Tumalo Irrigation District's Tumalo Conservation Project AGENCY... Tumalo Irrigation District's (TID) application for an incidental take permit, pursuant to the Endangered... Columbia River Steelhead in the Deschutes River basin that may occur from irrigation activities...

  15. Off-design performance loss model for radial turbines with pivoting, variable-area stators

    Science.gov (United States)

    Meitner, P. L.; Glassman, A. J.

    1980-01-01

    An off-design performance loss model was developed for variable stator (pivoted vane), radial turbines through analytical modeling and experimental data analysis. Stator loss is determined by a viscous loss model; stator vane end-clearance leakage effects are determined by a clearance flow model. Rotor loss coefficient were obtained by analyzing the experimental data from a turbine rotor previously tested with six stators having throat areas from 20 to 144 percent of design area and were correlated with stator-to-rotor throat area ratio. An incidence loss model was selected to obtain best agreement with experimental results. Predicted turbine performance is compared with experimental results for the design rotor as well as with results for extended and cutback versions of the rotor. Sample calculations were made to show the effects of stator vane end-clearance leakage.

  16. Impact of Functional Electrical Stimulation of Lower Limbs during Sitting Pivot Transfer Motion for Paraplegic People

    Directory of Open Access Journals (Sweden)

    Jovana Jovic

    2013-01-01

    Full Text Available Individuals with Spinal Cord Injury (SCI, perform Sitting Pivot Transfer (SPT motion around fifteen times a day using upper extremities. It can lead to upper limbs pain and often shoulder complications. In this paper, we investigate the influence of Functional Electrical Stimulation (FES on SPT motion of a paraplegic person. First, we proposed to develop a dynamic optimization method in order to predict SPT motion of an able‐bodied subject. This approach has been validated by comparing the computed SPT trajectories with the ones measured during the experiment with an able‐bodied subject. Then, we used the optimization tool to analyze the influence of FES on the SPT maneuver of paraplegic persons. Our results suggest that FES can decrease arm participation during the transfer motion of a paraplegic person.

  17. Frequency domain wave equation forward modeling using gaussian elimination with static pivoting

    Science.gov (United States)

    Jian-Yong, Song; Xiao-Dong, Zheng; Yan, Zhang; Ji-Xiang, Xu; Zhen, Qin; Xue-Juan, Song

    2011-03-01

    Frequency domain wave equation forward modeling is a problem of solving large scale linear sparse systems which is often subject to the limits of computational efficiency and memory storage. Conventional Gaussian elimination cannot resolve the parallel computation of huge data. Therefore, we use the Gaussian elimination with static pivoting (GESP) method for sparse matrix decomposition and multi-source finite-difference modeling. The GESP method does not only improve the computational efficiency but also benefit the distributed parallel computation of matrix decomposition within a single frequency point. We test the proposed method using the classic Marmousi model. Both the single-frequency wave field and time domain seismic section show that the proposed method improves the simulation accuracy and computational efficiency and saves and makes full use of memory. This method can lay the basis for waveform inversion.

  18. Impact of Functional Electrical Stimulation of Lower Limbs during Sitting Pivot Transfer Motion for Paraplegic People

    Directory of Open Access Journals (Sweden)

    Jovana Jovic

    2013-01-01

    Full Text Available Individuals with Spinal Cord Injury (SCI, perform Sitting Pivot Transfer (SPT motion around fifteen times a day using upper extremities. It can lead to upper limbs pain and often shoulder complications. In this paper, we investigate the influence of Functional Electrical Stimulation (FES on SPT motion of a paraplegic person. First, we proposed to develop a dynamic optimization method in order to predict SPT motion of an able-bodied subject. This approach has been validated by comparing the computed SPT trajectories with the ones measured during the experiment with an able-bodied subject. Then, we used the optimization tool to analyze the influence of FES on the SPT maneuver of paraplegic persons. Our results suggest that FES can decrease arm participation during the transfer motion of a paraplegic person.

  19. Formalin irrigation for hemorrhagic chronic radiation proctitis.

    Science.gov (United States)

    Ma, Teng-Hui; Yuan, Zi-Xu; Zhong, Qing-Hua; Wang, Huai-Ming; Qin, Qi-Yuan; Chen, Xiao-Xia; Wang, Jian-Ping; Wang, Lei

    2015-03-28

    To assess the efficacy and safety of a modified topical formalin irrigation method in refractory hemorrhagic chronic radiation proctitis (CRP). Patients with CRP who did not respond to previous medical treatments and presented with grade II-III rectal bleeding according to the Common Terminology Criteria for Adverse Events were enrolled. Patients with anorectal strictures, deep ulcerations, and fistulas were excluded. All patients underwent flexible endoscopic evaluation before treatment. Patient demographics and clinical data, including primary tumor, radiotherapy and previous treatment options, were collected. Patients received topical 4% formalin irrigation in a clasp-knife position under spinal epidural anesthesia in the operating room. Remission of rectal bleeding and related complications were recorded. Defecation, remission of bleeding, and other symptoms were investigated at follow-up. Endoscopic findings in patients with rectovaginal fistulas were analyzed. Twenty-four patients (19 female, 5 male) with a mean age of 61.5 ± 9.5 years were enrolled. The mean time from the end of radiotherapy to the onset of bleeding was 11.1 ± 9.0 mo (range: 2-24 mo). Six patients (25.0%) were blood transfusion dependent. The median preoperative Vienna Rectoscopy Score (VRS) was 3 points. Nineteen patients (79.2%) received only one course of topical formalin irrigation, and five (20.8%) required a second course. No side effects were observed. One month after treatment, bleeding cessation was complete in five patients and obvious in 14; the effectiveness rate was 79.1% (19/24). For long-term efficacy, 5/16, 1/9 and 0/6 patients complained of persistent bleeding at 1, 2 and 5 years after treatment, respectively. Three rectovaginal fistulas were found at 1 mo, 3 mo and 2 years after treatment. Univariate analysis showed associations of higher endoscopic VRS and ulceration score with risk of developing rectovaginal fistula. Modified formalin irrigation is an effective and safe

  20. Irrigation and fertigation frequencies with nitrogen in the watermelon culture

    Directory of Open Access Journals (Sweden)

    Carlos Newdmar Vieira Fernandes

    2014-06-01

    Full Text Available This study evaluates the influence of different irrigation frequencies and different nitrogen fertigation frequencies on the growth performance of the watermelon (Citrullus lanatus culture. Two experiments were conducted at the Paraguay farm in the Cruz municipality, Ceará, Brazil. They was randomized blocks design with six treatments and four replications. The irrigation frequency experiment consisted of the application of different irrigation frequencies. The treatments were: DM - daily irrigation in the morning with 100% daily dosage; DT - daily irrigation in the afternoon, with 100% daily dosage; DMT - twice daily irrigation, with 50% daily dosage in the morning and 50% daily dosage in the afternoon; 2D - irrigation every two days; 3D - irrigation every three days and 4D - irrigation every four days. To the experiment with different nitrogen fertigation frequencies, the treatments used were: 2F - 2 fertigations in a cycle; 4F - 4 fertigations in a cycle; 8F - 8 fertigations in a cycle; 16F - 16 fertigations in a cycle; 32F - 32 fertigations in a cycle and 64F - 64 fertigations in a cycle. We evaluated the marketable yield (PC, fruit weight (M, polar diameter (DP, equatorial diameter (DE, shell thickness (EC and soluble solids (SS. The irrigation frequency treatments influenced all variables significantly, with twice daily irrigation (DMT, 50% in the morning and the 50% in the afternoon promoting the highest productivity (69.79 t ha-1. The different frequencies of fertigation also significantly influenced all variables, except for the shell thickness, the highest yield (80.69 t ha-1 being obtained with treatment 64 fertigations in a cycle.

  1. Derivation of irrigation requirements for radiological impact assessments.

    Science.gov (United States)

    Almahayni, Talal; Crout, Neil M J

    2016-11-01

    When assessing the radiological impacts of radioactive waste disposal, irrigation using groundwater contaminated with releases from the disposal system is a principal means of crop and soil contamination. In spite of their importance for radiological impact assessments, irrigation data are scarce and often associated with considerable uncertainty for several reasons including limited obligation to measure groundwater abstraction and differences in measuring methodologies. Further uncertainty arises from environmental (e.g. climate and landscape) change likely to occur during the assessment long time frame. In this paper, we derive irrigation data using the crop growth AquaCrop model relevant to a range of climates, soils and crops for use in radiological impact assessments. The AquaCrop estimates were compared with actual irrigation data reported in the literature and with estimates obtained from simple empirical methods proposed for use in radiological impact assessments. Further, the AquaCrop irrigation data were analysed using mixed effects modelling to investigate the effects of climate, soil and crop type on the irrigation requirement. Irrigation estimates from all models were within a reasonable range of the measured values. The AquaCrop estimates, however, were at the higher end of the range and higher than those from the empirical methods. Nevertheless, they may be more appropriate for conservative radiological assessments. The use of mixed effects modelling allowed for the characterisation of crop-specific variability in the irrigation data, and in contrast to the empirical methods, the AquaCrop and the mixed effects models accounted for the soil effect on the irrigation requirement. The approach presented in this paper is relevant for obtaining irrigation data for a specific site under different climatic conditions as well as for generic dose assessments. To the best of our knowledge, this is one of the most comprehensive analyses of irrigation data in

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

    Science.gov (United States)

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

    2015-04-01

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

  3. Effects of global irrigation on the near-surface climate

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, William J. [University of Wisconsin-Madison, Center for Sustainability and the Global Environment, Madison, WI (United States); Cook, Benjamin I. [Lamont-Doherty Earth Observatory, Ocean and Climate Physics, Palisades, NY (United States); NASA Goddard Institute for Space Studies, New York, NY (United States); Buenning, Nikolaus [University of Colorado-Boulder, Department of Atmospheric and Oceanic Sciences and Cooperative Institute for Research in Environmental Sciences, Boulder, CO (United States); Levis, Samuel [National Center for Atmospheric Research, Climate and Global Dynamics Division, Boulder, CO (United States); Helkowski, Joseph H. [Earth Tech, Miami, FL (United States)

    2009-08-15

    Irrigation delivers about 2,600 km{sup 3} of water to the land surface each year, or about 2% of annual precipitation over land. We investigated how this redistribution of water affects the global climate, focusing on its effects on near-surface temperatures. Using the Community Atmosphere Model (CAM) coupled to the Community Land Model (CLM), we compared global simulations with and without irrigation. To approximate actual irrigation amounts and locations as closely as possible, we used national-level census data of agricultural water withdrawals, disaggregated with maps of croplands, areas equipped for irrigation, and climatic water deficits. We further investigated the sensitivity of our results to the timing and spatial extent of irrigation. We found that irrigation alters climate significantly in some regions, but has a negligible effect on global-average near-surface temperatures. Irrigation cooled the northern mid-latitudes; the central and southeast United States, portions of southeast China and portions of southern and southeast Asia cooled by {proportional_to}0.5 K averaged over the year. Much of northern Canada, on the other hand, warmed by {proportional_to}1 K. The cooling effect of irrigation seemed to be dominated by indirect effects like an increase in cloud cover, rather than by direct evaporative cooling. The regional effects of irrigation were as large as those seen in previous studies of land cover change, showing that changes in land management can be as important as changes in land cover in terms of their climatic effects. Our results were sensitive to the area of irrigation, but were insensitive to the details of irrigation timing and delivery. (orig.)

  4. Achieving numerical accuracy and high performance using recursive tile LU factorization with partial pivoting

    KAUST Repository

    Dongarra, Jack

    2013-09-18

    The LU factorization is an important numerical algorithm for solving systems of linear equations in science and engineering and is a characteristic of many dense linear algebra computations. For example, it has become the de facto numerical algorithm implemented within the LINPACK benchmark to rank the most powerful supercomputers in the world, collected by the TOP500 website. Multicore processors continue to present challenges to the development of fast and robust numerical software due to the increasing levels of hardware parallelism and widening gap between core and memory speeds. In this context, the difficulty in developing new algorithms for the scientific community resides in the combination of two goals: achieving high performance while maintaining the accuracy of the numerical algorithm. This paper proposes a new approach for computing the LU factorization in parallel on multicore architectures, which not only improves the overall performance but also sustains the numerical quality of the standard LU factorization algorithm with partial pivoting. While the update of the trailing submatrix is computationally intensive and highly parallel, the inherently problematic portion of the LU factorization is the panel factorization due to its memory-bound characteristic as well as the atomicity of selecting the appropriate pivots. Our approach uses a parallel fine-grained recursive formulation of the panel factorization step and implements the update of the trailing submatrix with the tile algorithm. Based on conflict-free partitioning of the data and lockless synchronization mechanisms, our implementation lets the overall computation flow naturally without contention. The dynamic runtime system called QUARK is then able to schedule tasks with heterogeneous granularities and to transparently introduce algorithmic lookahead. The performance results of our implementation are competitive compared to the currently available software packages and libraries. For example

  5. Pivotal response treatment for preschoolers with autism spectrum disorder: Defining a predictor profile.

    Science.gov (United States)

    Fossum, Kristin-Lee; Williams, Loriann; Garon, Nancy; Bryson, Susan E; Smith, Isabel M

    2017-08-31

    Behavioral characteristics of children with autism spectrum disorder (ASD) who respond positively to Pivotal Response Treatment (PRT) have been described previously, based on single-subject design research. The present study examined several such characteristics, as well as positive affect, as predictors of expressive language (EL) gains in a representative sample of preschoolers with ASD (n = 57) enrolled in a PRT-based community early intervention program. Children's cognitive ability, positive affect, and levels of appropriate toy contact measured at the start of intervention each contributed significantly to the prediction of EL outcomes. Together these variables accounted for 40% of the total outcome variance. In addition, a profile of increased EL ability, positive affect and appropriate toy contact, and decreased social avoidance and stereotyped and repetitive vocalizations was associated with greater gains during intervention. Results are discussed in relation to their implications for understanding both the variable treatment response documented in children with ASD and how to tailor treatment to optimize individual benefit. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. The study examined behavior of 57 preschoolers who made the greatest and least gains from 1 year of a community Pivotal Response Treatment program. Using pre-treatment videos, we saw that children who made the most progress showed more language, positive affect, and appropriate interactions with toys, also less avoidance of people and fewer repetitive vocalizations. Behavior profiles can be used to match treatment to individual children's needs. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

  6. Berry morphology and composition in irrigated and non-irrigated grapevine (Vitis vinifera L.).

    Science.gov (United States)

    Sofo, Adriano; Nuzzo, Vitale; Tataranni, Giuseppe; Manfra, Michele; De Nisco, Mauro; Scopa, Antonio

    2012-07-15

    The present study was carried out in a 5-year-old vineyard (Vitis vinifera L., cv. Aglianico) located in Southern Italy. Half of the plants (IRR) were fully irrigated, whereas the other half were not irrigated (NIRR). In both of the treatments, plant water status, gas exchange, photosynthetic efficiency and productive performance were determined. The arid conditions resulted in significant decreases in stem water potential in NIRR (minimum values of -1.34 and -1.52 MPa in IRR and NIRR, respectively). The values of yield per plant, cluster weight and total berry weight were significantly higher in IRR. Grape berries were separated into four weight classes, and morphometric and microscopic analyses were carried out to measure and calculate berry skin characteristics. Irrigation determined a marked shift toward heavier (+23% in the class ≥ 1.25 g) and bigger (336.35 mm³ vs 299.15 mm³) berries, and induced significant changes in other morphometric berry parameters. No differences among berry weight classes and irrigation treatments were observed for berry skin thickness. In all of the berry weight classes, total anthocyanins extracted from berry skins were significantly higher in NIRR than in IRR (12301.53 and 9585.52 mg kg⁻¹ fresh berry skin, respectively), and appeared to be positively related to berry weight, whereas total flavonols were not significantly different between the two treatments. Qualitative changes in the levels of single anthocyanin and flavonol compounds were detected between IRR and NIRR. In addition, iron, copper and zinc, whose high concentration can negatively affect wine quality, were significantly higher in the IRR treatment. The results highlighted that the absence of irrigation did not determine decreases in grape quality. Such data can be of primary importance in environments where water availability is by far the most important limiting factor for plant growth.

  7. Distillation irrigation: a low-energy process for coupling water purification and drip irrigation

    Science.gov (United States)

    Constantz, J.

    1989-01-01

    A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply the distillate to a widely spaced row crop. To predict the performance of the proposed device, an empirical equation for distillate production, dp, is developed from reported solar still production rates, and a modified Jensen-Haise equation is used to calculate the potential evapotranspiration, et, for a row crop. Monthly values for et and dp are calculated by using a generalized row crop at five locations in the Western United States. Calculated et values range from 1 to 22 cm month-1 and calculated dp values range from 2 to 11 cm month-1, depending on the location, the month, and the crop average. When the sum of dp plus precipitation, dp + P, is compared to et for the case of 50% distillation irrigation system coverage, the results indicate that the crop's et is matched by dp + P, at the cooler locations only. However, when the system coverage is increased to 66%, the crop's et is matched by dp + P even at the hottest location. Potential advantages of distillation irrigation include the ability: (a) to convert impaired water resources to water containing no salts or sediments; and (b) to efficiently and automatically irrigate crops at a rate that is controlled primarily by radiation intensities. The anticipated disadvantages of distillation irrigation include: (a) the high costs of a system, due to the large amounts of sheeting required, the short lifetime of the sheeting, and the physically cumbersome nature of a system; (b) the need for a widely spaced crop to reduce shading of the system by the crop; and (c) the production of a concentrated brine or precipitate, requiring proper off-site disposal. ?? 1989.

  8. Winter Irrigation Effects in Cotton Fields in Arid Inland Irrigated Areas in the North of the Tarim Basin, China

    Directory of Open Access Journals (Sweden)

    Pengnian Yang

    2016-02-01

    Full Text Available Winter irrigation is one of the water and salt management practices widely adopted in arid irrigated areas in the Tarim Basin located in the Xinjiang Uygur Autonomous Region in the People’s Republic of China. A winter irrigation study was carried out from November 2013 to March 2014 in Korla City. A cotton field was divided into 18 plots with a size of 3 m × 3 m and five winter irrigation treatments (1200 m3/ha, 1800 m3/ha, 2400 m3/ha, 3000 m3/ha, and 3600 m3/ha and one non-irrigation as a control were designed. The results showed that the higher winter irrigation volumes allowed the significant short-term difference after the irrigation in the fields with the higher soil moisture content. Therefore, the soil moisture in the next sowing season could be maintained at the level which was slightly lower than field capacity and four times that in the non-irrigation treatment. The desalination effect of winter irrigation increased with the increase of water irrigation volume, but its efficiency decreased with the increase of water irrigation volume. The desalination effect was characterized by short-term desalination, long-term salt accumulation, and the time-dependent gradually decreasing trend. During the winter irrigation period, air temperature was the most important external influencing factor of the soil temperature. During the period of the decrease in winter temperatures from December to January, soil temperature in the 5-cm depth showed no significant difference in all the treatments and the control. However, during the period of rising temperatures from January to March, soil temperature in the control increased significantly, faster than that in all treatments. Under the same irrigation volume, the temperature difference between the upper soil layer and the lower soil layer increased during the temperature drop period and decreased during the temperature rise period. In this paper, we proposed the proper winter irrigation volume of 1800

  9. More efficient irrigation may compensate for increases in irrigation water requirements due to climate change in the Mediterranean area

    Science.gov (United States)

    Fader, Marianela; Shi, Sinan; von Bloh, Werner; Bondeau, Alberte; Cramer, Wolfgang

    2017-04-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. We will present a recently published study1 that estimates the current level of water demand for Mediterranean agriculture and simulates the potential impacts of climate change, population growth and transitions to water-saving irrigation and conveyance technologies. The results indicate that, at present, Mediterranean region could save 35% of water by implementing more efficient irrigation and conveyance systems, with large differences in the saving potentials across countries. Under climate change, more efficient irrigation is of vital importance for counteracting increases in irrigation water requirements. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4% and 18% from climate change alone by the end of the century if irrigation systems and conveyance are not improved. Population growth increases these numbers to 22% and 74%, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean. Both the Eastern and the Southern Mediterranean would need around 35% more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect. However, in some scenarios water scarcity may constrain the supply of the irrigation water needed in future in Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain. In this study, vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL ("Lund-Potsdam-Jena managed Land") after a large development2 that comprised the improved representation of Mediterranean crops.

  10. The effects of deifcit irrigation on nitrogen consumption, yield, and quality in drip irrigated grafted and ungrafted watermelon

    Institute of Scientific and Technical Information of China (English)

    Seluk zmen; Rza Kanber; Nebahat Sar; Mustafa nl

    2015-01-01

    The aim of this study is to determine the effects of deifcit irrigation on nitrogen consumption, yield, and quality in grafted and ungrafted watermelon. The study was conducted in Çukurova region, Eastern Mediterranean, Turkey, between 2006 and 2008, and employed 3 irrigation rates (ful irrigation (I100) with no stress, moderate irrigation (DI70), and low irrigation (DI50);DI70 and DI50 were considered deifcit irrigation) on grafted (CTJ, Crimson Tide+Jumbo) and the ungrafted (CT, Crim-son Tide) watermelon. The amount of irrigation water (IR) applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals. Nitrogen consumption was 16%lower in CTJ plants than in CT plants. On the other hand, consumption of nitrogen was 28%higher in DI50 plants than in DI70 plants while it was 23%higher in DI50 plants than in I100 plants. By grafting, the average amount of nitrogen content in seeds, pulps and peels for CTJ was 30, 43 and 56%more than those of CT, respectively. The yield and the quality were not signiifcantly affected by the deifcit irrigation. In this respect, grafting of watermelon gave higher yield, but, it had a slight effect on fruit quality. The highest yield values of 16.90 and 19.32 kg plant–1 in 2008 were obtained with I100 and in CTJ plants, respectively. However, DI50 treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited. Additional y, the yield increased by applying CTJ treatment to the watermelon production.

  11. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    NARCIS (Netherlands)

    Pardossi, A.; Incrocci, L.; Incrocci, G.; Marlorgio, F.; Battista, P.; Bacci, L.; Rapi, B.; Marzialetti, P.; Hemming, J.; Balendonck, J.

    2009-01-01

    Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of effici

  12. Impact of drought genetics on irrigated corn production

    Science.gov (United States)

    Corn is the major irrigated crop in the High Plains of Colorado, Nebraska, and Kansas. Declining water levels in the High Plains Aquifer have reduced well capacity such that limited irrigation strategies must be employed. Crop breeding advances have led to the introduction of drought resistant hybri...

  13. A management perspective on the performance of the irrigation subsector.

    NARCIS (Netherlands)

    Nijman, Ch.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the perfo

  14. Alfalfa response to irrigation from limited water supplies

    Science.gov (United States)

    A five-year field study (2007-2011) of irrigated alfalfa production with a limited water supply was conducted in southwest Kansas with two years of above-average precipitation, one year of average precipitation, and two years of below-average precipitation. The irrigation treatments were designed to...

  15. Irrigation Alternatives to Meet Army Net Zero Water Goals

    Science.gov (United States)

    2012-05-01

    Up to 100 Rain Barrel Catchment Up to...US Army Corps of Engineers BUILDING STRONG® Irrigation Alternatives to Meet Army Net Zero Water Goals Richard J. Scholze Dick L. Gebhart H...TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Irrigation Alternatives to Meet Army Net Zero Water Goals 5a. CONTRACT

  16. Small private irrigation: Enhancing benefits and managing trade-offs

    NARCIS (Netherlands)

    Giordano, M.; Fraiture, de C.M.S.

    2014-01-01

    Millions of smallholder farmers in sub-Saharan Africa and South Asia benefit from readily available and affordable irrigation technologies. The rapid uptake of small private irrigation in South Asia had a proven positive effect on poverty alleviation. In sub-Saharan Africa similar trends are emergin

  17. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha

  18. Diagnosing Trouble Spots Caused by an Irrigation System

    Science.gov (United States)

    John R. Scholtes

    2002-01-01

    I discuss a testing procedure to determine the water distribution pattern of a sprinkler irrigation system and steps that may be taken to improve uniformity of application. All irrigation systems require testing and maintenance to assure that water application is as uniform as possible. Even new systems installed to a manufacturer's specifications should be "...

  19. SPRINKLER IRRIGATION AS A VOC SEPARATION AND DISPOSAL METHOD

    Science.gov (United States)

    Sprinkler irrigation is a common farming practice in those states where the semi-arid climate and lack of sufficient rainfall during critical growing periods necessitate the use of supplemental water. The source of most irrigation water is groundwater which can be contaminated wi...

  20. Phosphorus as a limiting factor on sustainable greywater irrigation.

    Science.gov (United States)

    Turner, Ryan D R; Will, Geoffrey D; Dawes, Les A; Gardner, Edward A; Lyons, David J

    2013-07-01

    Water reuse through greywater irrigation has been adopted worldwide and has been proposed as a potential sustainable solution to increased water demands. Despite widespread adoption, there is limited domestic knowledge of greywater reuse. There is no pressure to produce low-level phosphorus products and current guidelines and legislation, such as those in Australia, may be inadequate due to the lack of long-term data to provide a sound scientific basis. Research has clearly identified phosphorus as a potential environmental risk to waterways from many forms of irrigation. To assess the sustainability of greywater irrigation, this study compared four residential lots that had been irrigated with greywater for four years and adjacent non-irrigated lots that acted as controls. Each lot was monitored for the volume of greywater applied and selected physic-chemical water quality parameters and soil chemistry profiles were analysed. The non-irrigated soil profiles showed low levels of phosphorus and were used as controls. The Mechlich3 Phosphorus ratio (M3PSR) and Phosphate Environmental Risk Index (PERI) were used to determine the environmental risk of phosphorus leaching from the irrigated soils. Soil phosphorus concentrations were compared to theoretical greywater irrigation loadings. The measured phosphorus soil concentrations and the estimated greywater loadings were of similar magnitude. Sustainable greywater reuse is possible; however incorrect use and/or lack of understanding of how household products affect greywater can result in phosphorus posing a significant risk to the environment.

  1. The SRFR 5 modeling system for surface irrigation

    Science.gov (United States)

    The SRFR program is a modeling system for surface irrigation. It is a central component of WinSRFR, a software package for the hydraulic analysis of surface irrigation systems. SRFR solves simplified versions of the equations of unsteady open channel flow coupled to a user selected infiltration mod...

  2. Effects of different irrigation programs on yield and quality ...

    African Journals Online (AJOL)

    Jane

    2011-07-11

    Jul 11, 2011 ... This indicated that when irrigation water and ET increased, yield also increased to a certain point. However ... need irrigation water during the all growing period and get adequate benefit ... season is cold and snowy. In Isparta ...

  3. Bureaucratic designs : the paradox of irrigation management transfer in Indonesia

    NARCIS (Netherlands)

    Suhardiman, D.

    2008-01-01

    Irrigation Management Transfer (IMT) policy has been formulated and implemented worldwide, relying on three basic assumptions: that the irrigation agency are motivated to adapt their role in the sector's development; that farmers are willing to take over the system management; and that the process

  4. Remote sensing, GIS and hydrological modelling for irrigation management

    NARCIS (Netherlands)

    Menenti, M.; Azzali, S.; Urso, d' G.

    1996-01-01

    This paper gives an overview of literature and of work done by the authors between 1988 and 1993. It was presented at a NATO expert meeting on sustainability of irrigated agriculture in 1994. The paper deals with crop water requirements and crop waterstress, assessing irrigation performance with

  5. The implication of irrigation in climate change impact assessment

    NARCIS (Netherlands)

    Zhao, Gang; Webber, Heidi; Hoffmann, Holger; Wolf, Joost; Siebert, Stefan; Ewert, Frank

    2015-01-01

    This study evaluates the impacts of projected climate change on irrigation requirements and yields of six crops (winter wheat, winter barley, rapeseed, grain maize, potato, and sugar beet) in Europe. Furthermore, the uncertainty deriving from consideration of irrigation, CO2 effects on

  6. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to accu

  7. Treadle pump irrigation in Malawi: adoption, gender and benefits

    NARCIS (Netherlands)

    Kamwamba-Mtethiwa, J.; Namara, R.; Fraiture, de C.M.S.; Mangisoni, J.; Owusu, E.

    2012-01-01

    As part of their irrigation strategy, the government and non-governmental organizations (NGOs) in Malawi are actively promoting the use of treadle pumps in smallholder irrigation. The positive impact of treadle pumps on food security and poverty reduction in Malawi and elsewhere in sub-Saharan Afric

  8. Infrared thermometry for deficit irrigation of peach trees

    Science.gov (United States)

    Water shortage has been a major concern for crop production in the western states of the USA and other arid regions in the world. Deficit irrigation can be used in some cropping systems as a potential water saving strategy to alleviate water shortage, however, the margin of error in irrigation manag...

  9. Yield Response and Economics of Shallow Subsurface Drip Irrigation Systems

    Science.gov (United States)

    Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

  10. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to accu

  11. Status and migration of irrigation in the USA

    Science.gov (United States)

    Irrigated agriculture produces 49% of crop market value on 18% of cropped lands in the USA. Irrigation is essential to the most highly productive, intensely managed, and internationally competitive sectors of our agricultural economy, which play a key role in meeting growing global food, fiber, and ...

  12. Irrigation Management in the Pamirs in Tajikistan: A Man's Domain?

    NARCIS (Netherlands)

    Bossenbroek, L.; Zwarteveen, M.Z.

    2014-01-01

    Families living in Gorno-Badakhshan—situated in the Pamir Mountains in Tajikistan—depend on irrigated agriculture to meet their subsistence needs. Because men predominate, and are most visible in, the operation and management of irrigation systems in this region, water-related activities are often l

  13. Peanut canopy temperature and NDVI response to varying irrigation rates

    Science.gov (United States)

    Variable rate irrigation (VRI) systems have the potential to conserve water by spatially allocating limited water resources. In this study, peanut was grown under a VRI system to evaluate the impact of differential irrigation rates on peanut yield. Additionally, we evaluated the impact of differenti...

  14. NUTRIENT CONTENT IN SUNFLOWERS IRRIGATED WITH OIL EXPLORATION WATER

    Directory of Open Access Journals (Sweden)

    ADERVAN FERNANDES SOUSA

    2016-01-01

    Full Text Available Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil - produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW, reverse osmosis - treated produced water (OPW, or ground water (GW. At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis - treated produced water in agriculture. However, more long - term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.

  15. The politics of policy : participatory irrigation management in Andhra Pradesh

    NARCIS (Netherlands)

    Nikku, B.R.

    2006-01-01

    This thesis studies the emergence, process and politics of the Andhra Pradesh reform policy of Participatory Irrigation Management (PIM). The reform has been labeled as the 'A? model' of irrigation reforms and supported by external aid agencies like World Bank. Within a short span of time Andhra

  16. Atmospheric effects of irrigation in monsoon climate: the Indian subcontinent

    NARCIS (Netherlands)

    Tuinenburg, O.A.

    2013-01-01

    During the 20th century, an increasing population increased the demand for food.  As a consequence, agricultural activity has expanded and become more intense. A  part of this intensification is the use of irrigation systems to water crops. Due to this  irrigation, dams and channeling

  17. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    2012-01-01

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha (G

  18. land evaluation for improved rice production in watari irrigation ...

    African Journals Online (AJOL)

    DR. AMINU

    directly related to quality and suitability of soil, and as ... mapping and monitoring land use changes. ... the consequences of land use/land cover changes is ... The ecology of the Watari Irrigation project is Sudan ... mapping units identified as suitable for irrigation by .... adequate rice production, sufficient quantity of water.

  19. Groundwater Suitability for Irrigation: a Case Study from Debre ...

    African Journals Online (AJOL)

    Bheema

    irrigation water quality, the groundwater is suitable for irrigation with some minor ... specific toxicity effect on vegetables and field crops, however, there are ... alone cannot sustain the practice, the issues like ecological and social are to be taken in to ... particularly for crops that are sensitive to changes in quality (Bohn et al., ...

  20. Development of guidance for sustainable irrigation use of greywater ...

    African Journals Online (AJOL)

    as ecological sanitation (EcoSan) have arisen to address this .... be long-term effects, while effects on plant growth and yield .... in food crops irrigated with mixed domestic greywater (Rodda ..... of E0 in place of point estimates, or using the SAPWAT model ..... STANDEN R and McGUCKIAN R (2000) Developing irrigation.

  1. The management perspective on the performance of the irrigation subsector

    NARCIS (Netherlands)

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the perfo

  2. Irrigation analysis based on long-term weather data

    Science.gov (United States)

    Irrigation-management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET) using weather data. In 1994 an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. ...

  3. Bureaucratic designs : the paradox of irrigation management transfer in Indonesia

    NARCIS (Netherlands)

    Suhardiman, D.

    2008-01-01

    Irrigation Management Transfer (IMT) policy has been formulated and implemented worldwide, relying on three basic assumptions: that the irrigation agency are motivated to adapt their role in the sector's development; that farmers are willing to take over the system management; and that the process o

  4. Next generation sequencing of oomycete communities in nursery irrigation water

    Science.gov (United States)

    Joyce Eberhart; Fumiaki Funahashi; Zachary S.L. Foster; Jennifer Parke

    2017-01-01

    Horticultural nurseries are under increasing pressure to reduce, remediate, and recycle irrigation water. A major constraint for reusing irrigation water is contamination by waterborne plant pathogenic Phytophthora and Pythium species. Current research is focused on helping plant nurseries monitor oomycete pathogens in...

  5. Irrigation and the demand for electricity. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Maddigan, R. J.; Chern, W. S.; Gallagher, C. A.

    1980-03-01

    In order to anticipate the need for generating capacity, utility planners must estimate the future growth in electricity demand. The need for demand forecasts is no less important for the nation's Rural Electric Cooperatives (RECs) than it is for the investor-owned utilities. The RECs serve an historically agrarian region; therefore, the irrigation sector accounts for a significant portion of the western RECs' total demand. A model is developed of the RECs' demand for electricity used in irrigation. The model is a simultaneous equation system which focuses on both the short-run utilization of electricity in irrigation and the long-run determination of the number of irrigators using electricity. Irrigation demand is described by a set of equations in which the quantity of electricity demanded, the average electricity price, the number of irrigation customers, and the ratio of electricity to total energy used for irrigation are endogenous. The structural equations are estimated using pooled state-level data for the period 1961-1977. In light of the model's results, the impact of changes in relative energy prices on irrigation can be examined.

  6. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to

  7. The management perspective on the performance of the irrigation subsector

    NARCIS (Netherlands)

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the

  8. Technology transfer: Promoting irrigation progress and best management practices

    Science.gov (United States)

    Educational efforts promoting irrigation best management practices are designed to increase adoption of these practices and increase public understanding of the importance of irrigation. They increase visibility and the impact of the Ogallala Aquifer Program and promote affiliated research and exten...

  9. The politics of policy : participatory irrigation management in Andhra Pradesh

    NARCIS (Netherlands)

    Nikku, B.R.

    2006-01-01

    This thesis studies the emergence, process and politics of the Andhra Pradesh reform policy of Participatory Irrigation Management (PIM). The reform has been labeled as the 'A? model' of irrigation reforms and supported by external aid agencies like World Bank. Within a short span of time Andhra Pra

  10. Consumptive Water Use and Crop Coefficients of Irrigated Sunflower

    Science.gov (United States)

    In semi-arid environments, the use of irrigation is necessary for sunflower production to reach its maximum potential. The aim of this study was to quantify the consumptive water use and crop coefficients of irrigated sunflower (Helianthus annuus L.) without soil water limitations during two growing...

  11. Micro-irrigation systems, automation and fertigation in citrus

    Directory of Open Access Journals (Sweden)

    Parameshwar Sidramappa Shirgure

    2012-11-01

    Full Text Available Citrus is number one group of fruits grown in more than 140 countries in the world. Micro-irrigation systems and fertigation management is one of the main concerns of the modem citrus fruit production irrespective of availability of soil, water and fertilizer resources. A variety of recommendations have emerged world over on irrigation systems and fertigation based on soil and leaf analysis of the nutrients, evapo-transpiration and water use pattern. The research review of literature has revealed best promising results on irrigation scheduling based on depletion pattern of soil available water content, irrigation systems and fertigation. Various micro-irrigation systems have established their superiority over traditionally used flood irrigation with micro-jets having little edge over rest of the others. Similarly, fertigation has shown good responses on growth, yield, quality and uniform distribution pattern of applied nutrients within the plant rootzone compared to band placement involving comparatively localized fertilization. Automated fertigation in citrus orchards is a new concept, which would be the only solitary choice amongst many irrigation monitoring methods in near future. The present status of the review on micro-irrigation and fertigation in citrus cultivars is clearly indicated in this article.

  12. Size and stochasticity in irrigated social-ecological systems

    Science.gov (United States)

    Puy, Arnald; Muneepeerakul, Rachata; Balbo, Andrea L.

    2017-01-01

    This paper presents a systematic study of the relation between the size of irrigation systems and the management of uncertainty. We specifically focus on studying, through a stylized theoretical model, how stochasticity in water availability and taxation interacts with the stochastic behavior of the population within irrigation systems. Our results indicate the existence of two key population thresholds for the sustainability of any irrigation system: or the critical population size required to keep the irrigation system operative, and N* or the population threshold at which the incentive to work inside the irrigation system equals the incentives to work elsewhere. Crossing irretrievably leads to system collapse. N* is the population level with a sub-optimal per capita payoff towards which irrigation systems tend to gravitate. When subjected to strong stochasticity in water availability or taxation, irrigation systems might suffer sharp population drops and irreversibly disintegrate into a system collapse, via a mechanism we dub ‘collapse trap’. Our conceptual study establishes the basis for further work aiming at appraising the dynamics between size and stochasticity in irrigation systems, whose understanding is key for devising mitigation and adaptation measures to ensure their sustainability in the face of increasing and inevitable uncertainty. PMID:28266656

  13. SMART IRRIGATION TECHNIQUE USING VOCAL COMMANDS

    Directory of Open Access Journals (Sweden)

    V.Divya

    2013-02-01

    Full Text Available In this wireless communication era, mobile phones have become a necessity in the common man’s life. Besides being capable of making calls and sending messages, the latest advancements in mobile phones facilitate them to connect to the internet also. With these capabilities, there has been an unprecedented use of mobile phones in many areas of automation. One such area where mobile phone can help with the automation is irrigation process. The main aim of the work is to simplify the method of irrigation using vocal commands through the mobile phone. The Farmer just needs to call a fixed number and utter the control commands through his phone. The control system at the field involves a PIC microcontroller interfaced with GSM modem to receive the command from the farmer and a voice recognition unit which decodes it. The motor is turned on/off according to the decoded commands by the controller. In addition, the system also sends back a message to the farmer’s mobile about the action that has taken place. The power detection and battery backup unit helps in detecting the power availability in the field and inform the farmer about the same, even if the there is no supply at the field. The moisture sensor attached to the system helps in collecting the moisture content of the soil and switch off the motor after it reaches the required value.

  14. PRODUCTION OF TOMATO SEEDLINGS UNDER SALINE IRRIGATION

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Brasiliano Campos

    2007-01-01

    Full Text Available Processing tomato is the most important vegetable crop of the Brazilian agribusiness and few researches have been conducted to evaluate the tolerance of this crop to saline stress. In this study, the effects of five levels of salinity of the irrigation water (1, 2, 3, 4 and 5 dS m-1 and three equivalent proportions of Na:Ca:Mg (1:1:0.5, 4:1:0.5 and 7:1:0.5 were tested on the emergence and vigor of processing tomato, cultivar IPA 6. Seeds were sowed in expanded polystyrene tray (128 cells and each tray received 1 L of water after sowing. The trays were piled and, four days after sowing, they were placed on suspended supports in a greenhouse. Irrigation was accomplished daily from the fifth day after sowing. Only dry weight of shoot and root was affected by sodium proportions, while linear reductions of the speed of emergence, stem length and the dry weight of shoot and root were observed with increasing salinity. Root was more affected than shoot by salinity and relative growth ratioincreased with salinity levels on the 14-21 days after sowing period, indicating that the crop showed a certain increase of salinity tolerance with the time of exposure to salts.

  15. Estimates of Savings Achievable from Irrigation Controller

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Alison; Fuchs, Heidi; Whitehead, Camilla Dunham

    2014-03-28

    This paper performs a literature review and meta-analysis of water savings from several types of advanced irrigation controllers: rain sensors (RS), weather-based irrigation controllers (WBIC), and soil moisture sensors (SMS).The purpose of this work is to derive average water savings per controller type, based to the extent possible on all available data. After a preliminary data scrubbing, we utilized a series of analytical filters to develop our best estimate of average savings. We applied filters to remove data that might bias the sample such as data self-reported by manufacturers, data resulting from studies focusing on high-water users, or data presented in a non-comparable format such as based on total household water use instead of outdoor water use. Because the resulting number of studies was too small to be statistically significant when broken down by controller type, this paper represents a survey and synthesis of available data rather than a definitive statement regarding whether the estimated water savings are representative.

  16. Experience with irrigation analgesia after abdominal hysterectomy

    Directory of Open Access Journals (Sweden)

    R. V. Garyaev

    2012-01-01

    Full Text Available A prospective randomized clinical trial was performed in 100 patients who underwent abdominal hysterectomy under endotracheal anesthesia based on sevoflurane and fentanyl. Intraoperatively, ketorolac 30 mg was administered intramuscularly after induction of anesthesia and paracetamol 1 g was injected intravenously 30–40 minutes prior to surgical termination in a control group (n = 25. For postoperative anal- gesia, promedol, tramadol, and ketorolac were used intramuscularly and paracetamol was given intravenously. Three study groups (n = 2 in each differed from the control group in that during wound suturing a multiperforated catheter was placed above the peritoneum over a length of 15 cm, through which a 10-ml bolus of 0.75 % ropivacaine was first administered, followed by continuous infusion of 0.2 % ropivacaine at a rate of 8 ml/hour for 36 hours. In one irrigation group, ketorolac 30 mg was injected intramuscularly t.i.d. for 2 days; in another group, the agent was added to a ropivacaine solution calculated with reference to 180 mg for 2 days; in the third group, ketoprofen 100 mg instead of ketorolac was used b.i.d. for 2 days. Pain level (by digital rating scale, 0–10 and the need for analgesics were measured. There was no sta- tistical significant difference in the level of pain and the need for analgesics between the wound irrigation and control groups.

  17. Non-sustainable groundwater sustaining irrigation - a global assessment

    Science.gov (United States)

    Wada, Y.; van Beek, L. P. H.; Bierkens, M. F. P.

    2012-04-01

    Irrigated crops play a vital role in securing global food production. It is estimated that 17% of agricultural lands are irrigated, yet they account for 40% of the global food production, sustaining the livelihood of billions of people (Abdullah, 2006). At the same time, water used by irrigated crops (i.e., crop water demand) and irrigation water demand are responsible for about 70% of the global water withdrawal and account for about 90% of the global water consumption, i.e. water withdrawal minus return flow respectively. Water demand for irrigated crops can be met by three different sources: 1) green water, being water from local precipitation that is temporarily stored in the soil, 2) blue water, being surface freshwater available in rivers, lakes, reservoirs and wetlands, and renewable groundwater, and 3) non-renewable or non-sustainable groundwater and non-local water resources. Here, we quantify globally the amount of non-renewable groundwater abstraction to sustain current irrigation practice. We use the global hydrological model PCR-GLOBWB to simulate gross crop water demand for irrigated crops and available blue and green water to meet this demand. We downscale country statistics of groundwater abstraction by considering the part of net total water demand that cannot be met by surface freshwater. We subsequently confront these with simulated groundwater recharge including return flow from irrigation to estimate non-renewable groundwater abstraction. Results show that non-renewable groundwater abstraction contributes approximately 20% to the global gross irrigation water demand for the year 2000. The contribution of non-renewable groundwater abstraction to irrigation is largest in India (68 km3 yr-1) followed by Pakistan (35 km3/yr), USA (30 km3/yr), Iran (20 km3/yr), China (20 km3/yr), Mexico (10 km3/yr) and Saudi Arabia (10 km3/yr). Results also show that globally this contribution more than tripled from 75 to 234 km3/yr over the period 1960-2000. These

  18. Sustainable Irrigation with Brackish Groundwater in Heilonggang Region, China

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of significance to resolve water shortage, slow down environmental degradation and support the sustainable development of the local agriculture. Four key points are proposed to be managed by comprehensive measures: (1) adapting salt-resistant ability; (2) reducing salt input; (3) decreasing soil surface evaporation and salt accumulation in the root zone, and (4) washing away salt from the root zone. Experiments and farming practices demonstrated that brackish water with TDS (total dissolved solids) of 2-5 g/l can be used for crop irrigation. For example, winter wheat can be sustainably irrigated by brackish water with a water limitation of 120 mm every year. Irrigation in combination with different comprehensive measures can increase the efficiency of saline water irrigation.

  19. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    leaching without compromising profits. Four replicate plots of each treatment with varying predefined and model-based (Daisy and Aquacrop crop model) irrigation and N fertilization levels were used in the study. Two experiments were conducted. In experiment-I, treatments consisted of one drip......The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P...

  20. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

  1. Irrigated lands assessment for water management: Technique test. [California

    Science.gov (United States)

    Wall, S. L.; Brown, C. E.; Eriksson, M.; Grigg, C. A.; Thomas, R. W.; Colwell, R. N.; Estes, J. E.; Tinney, L. R.; Baggett, J. O.; Sawyer, G.

    1981-01-01

    A procedure for estimating irrigated land using full frame LANDSAT imagery was demonstrated. Relatively inexpensive interpretation of multidate LANDSAT photographic enlargements was used to produce a map of irrigated land in California. The LANDSAT and ground maps were then linked by regression equations to enable precise estimation of irrigated land area by county, basin, and statewide. Land irrigated at least once in California in 1979 was estimated to be 9.86 million acres, with an expected error of less than 1.75% at the 99% level of confidence. To achieve the same level of error with a ground-only sample would have required 3 to 5 times as many ground sample units statewide. A procedure for relatively inexpensive computer classification of LANDSAT digital data to irrigated land categories was also developed. This procedure is based on ratios of MSS band 7 and 5, and gave good results for several counties in the Central Valley.

  2. Comparison of water distribution mechanisms under two localized irrigation techniques (Drip Irrigation & Buried Diffuser) for one week irrigation period in a sandy soil of southeastern Tunisia

    Science.gov (United States)

    Gasmi, Ines; Kodešová, Radka; Mechergui, Mohamed; Nikodem, Antonín; Moussa, Mohamed

    2017-04-01

    The majority of agricultural ecosystems in the Mediterranean basin of northern Africa suffer from water shortage and positions these regions in a highly vulnerable to climate change. In arid regions of Tunisia and exactly in the Southeastern part, during each growing season, plant productivity in sandy-loamy soils is dramatically reduced by limited availability of soil water and nutrients. Thus, highly permeable soils are unable to retain adequate water and nutrient resource in the plant root zone. Moreover, the investments of supplemental irrigation and agricultural amendments of additional fertilization are not sustainable due to the leaching of water supplies and nutrients, which severely limit agricultural productivity. In addition, inadequate soil water distribution, costly irrigation and fertilization leads to negative responses to plant nutrients added to highly permeable soils. That's why we should use irrigation techniques with high water use efficiency. This paper focuses on the comparison between two localized irrigation techniques which are the Drip Irrigation (DI) and the Buried Diffuser (BD) that has the same flow rates (4 l/h). The BD is buried at 15 cm depths. Experimental data was obtained from Smar-Médenine located in South-East of Tunisia. The water distribution at the soil surface for BD is very important about 195 cm2 while for the DI is about 25.12 cm2. The HYDRUS 2D/3D model helped to evaluate the water distribution and compare the water balance obtained with those two irrigation techniques for one week irrigation period. There is a rapid kinetic which has a duration of 3 hours (irrigation time) and a slow kinetic which is the result of the water distribution in the soil, the plant uptake and the effect of climatic condition. There are two mechanisms that affect the two irrigation techniques: the water distribution and the position of irrigation system. As a result, irrigation with BD goes dipper in the soil. The transmission zone for this

  3. Irrigation water policy analysis using a business simulation game

    Science.gov (United States)

    Buchholz, M.; Holst, G.; Musshoff, O.

    2016-10-01

    Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

  4. Greywater reuse for irrigation: effect on soil properties.

    Science.gov (United States)

    Travis, Micheal J; Wiel-Shafran, Alit; Weisbrod, Noam; Adar, Eilon; Gross, Amit

    2010-05-15

    A controlled study of the effect of greywater (GW) irrigation on soil properties was conducted. Containers of sand, loam and loess soils were planted with lettuce, and irrigated with fresh water, raw artificial GW or treated artificial GW. Greywater was treated using a recirculating vertical-flow constructed wetland. Soil samples were collected every 10 days for the 40-day duration of the study, and plant growth was measured. Soils were analysed for physicochemical and biological parameters to determine changes caused by the different treatments. It was demonstrated that raw artificial GW significantly increased the development of hydrophobicity in the sand and loam soils, as determined by water droplet penetration time. No significant changes were observed for the loess soil under all treatments. Observed hydrophobicity was correlated with increased oil and grease and surfactant concentrations in the soil. Zeta (zeta) potential of the soils was measured to determine changes in the soil particle surface properties as a result of GW irrigation. A significant change in zeta-potential (less negative) was observed in the raw artificial GW-irrigated sand, whereas no difference was observed in the loam or loess. Soils irrigated with fresh water or treated GW exhibited no increase in hydrophobicity. Fecal coliform bacteria were absent or <10 CFU g(-1) in soils irrigated with fresh water or treated GW, but at least 1 order of magnitude higher in raw artificial GW irrigated soils. Only in the last sampling event and only for the loess soil was plant growth significantly higher for fresh water irrigated vs. raw or treated GW irrigated soils. This study demonstrates that treated GW can be effectively irrigated without detrimental effects on soil or plant growth; however, raw GW may significantly change soil properties that can impact the movement of water in soil and the transport of contaminants in the vadose zone.

  5. Sustainability of irrigated crops under future climate: the interplay of irrigation strategies and cultivar responses

    Science.gov (United States)

    De Lorenzi, F.; Bonfante, A.; Alfieri, S.; Patanè, C.; Basile, A.; Di Tommasi, P.; Monaco, E.; Menenti, M.

    2012-04-01

    Climate evolution will cause significant changes in the quality and availability of water resources, affecting many sectors including food production, where available water resources for irrigation play a crucial role. Strategies focused on managing and conserving water are one way to deal with the impact; moreover concurring adaptation measurements will be needed to cope with the foreseen decline of water resource. This work deals with i) the impacts of climate change on water requirements of an horticultural crop, determined in an irrigated district in Southern Italy, ii) the possible irrigation scheduling options and their sustainability in the future, iii) the adaptation measurements that can be undertaken to protect production, relying on intra-specific biodiversity of agricultural crops. Two climate scenarios were considered: present climate (1961-90) and future climate (2021-2050), the former from climatic statistics, and the latter from statistical downscaling of general circulation models (AOGCM). Climatic data set consists of daily time series of maximum and minimum temperature, and rainfall on a grid with spatial resolution of 35 km. The analysis of climate scenarios showed that significant increases in summer maximum daily temperature could be expected in 2021-2050 period. Soil water regime was determined by means of a mechanistic model (SWAP) of water flow in the soil-plant-atmosphere system. Twenty? soil units were identified in the district (in Sele Plain, Campania Region) and simulations were performed accounting for hydro-pedological properties of different soil units. Parameters of a generic tomato crop, in a rotation typical of the area, were used in simulations. Soil water balance was simulated in the present and future climate, both with optimal water availability and under constrains that irrigation schemes will pose. Indicators of soil water availability were calculated, in terms of soil water or evapotranspiration deficit. For several tomato

  6. On the Controllability and Observability of Actively Lubricated Journal Bearings with Pads Featuring Different Nozzle-Pivot Configurations

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2017-01-01

    and/or actively high pressurized oil into the rotor-pad gap through, commonly, a single radial nozzle. For the work goal, a four degrees-of-freedom (DOFs) ALB system linking the mechanical with the hydraulic dynamics is presented and studied, comprising: (i) the vertical journal movement, (ii) the pad...... tilt angle, (iii) the vertical pad movement-due to the pivot flexibility, and (iv) the controllable force as the hydraulic DOF. The test rig consists of a rigid rotor supported by a single rocker-pivoted rigid pad. A thorough parametric study is carried out by investigating the effects of: (a) nozzle...

  7. A new method for real-time quantification of irrigant extrusion during root canal irrigation ex vivo

    NARCIS (Netherlands)

    Psimma, Z.; Boutsioukis, C.; Vasiliadis, L.; Kastrinakis, E.

    2013-01-01

    Aim (i) To introduce a new method of quantifying extruded irrigant during root canal irrigation ex vivo. (ii) to evaluate the effect of periapical tissue simulation and pressure equalization and (iii) to determine the effect of needle type, apical preparation size and apical constriction diameter

  8. Agro-Ecology and Irrigation Technology : Comparative Research on Farmer-Management Irrigation Systems in the Mid- Hills of Nepal

    NARCIS (Netherlands)

    Parajuli, U.N.

    1999-01-01

    Design and management of irrigation infrastructure in farmer managed irrigation systems (FMISs) are strongly influenced by social and agro-ecological conditions of an area. This thesis analyzes the elements of social and agro-ecological conditions in FMISs in the mid-hills of Nepal and examines thei

  9. Comparative effects of partial root-zone irrigation and deficit irrigation on phosphorus uptake in tomato plants

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Jensen, Christian Richardt

    2012-01-01

    The comparative effects of partial root-zone irrigation (PRI) and deficit irrigation (DI) on phosphorus (P) uptake in tomato (Lycopersicon esculentum Mill.) plants were investigated in a split-root pot experiment. The results showed that PRI treatment improved water-use efficiency (WUE) compared...

  10. Can subsurface drip irrigation (SDI) be a competitive irrigation system in the Great Plains region for commodity crops

    Science.gov (United States)

    Subsurface drip irrigation (SDI) as with all microirrigation systems is typically only used on crops with greater value. In the U.S. Great Plains region, the typical irrigated crops are the cereal and oil seed crops and cotton. These crops have less economic revenue than typical microirrigated cro...

  11. Experimental Investigation of Soil Evaporation and Evapotranspiration of Winter Wheat Under Sprinkler Irrigation

    Institute of Scientific and Technical Information of China (English)

    YU Li-peng; HUANG Guan-hua; LIU Hai-jun; WANG Xiang-ping; WANG Ming-qiang

    2009-01-01

    Sprinkler irrigation is one of the typical irrigation technologies used for the winter wheat-summer maize double cropping system in the North China Plain. To evaluate the evapotranspiration (ET) of winter wheat under sprinkler irrigation in Beijing area, field experiments were conducted in growing seasons through 2005-2008, in the experimental station located in Tongzhou County, Beijing, China, with different irrigation depths. Results indicated that a relatively large variation of soil water content occurred within 0-40 cm soil layer. The seasonal ET of winter wheat generally increased with increasing irrigation amount, while the seasonal usage of soil water had a negative relationship with irrigation amount. Soil evaporation (Es) was about 25% of winter wheat ET during the period from reviving to maturity. Es increased while Es/ET decreased with increasing irrigation amount. Sprinkler irrigation scheduling with relatively large irrigation quota and low irrigation frequency can reduce E, and promote the irrigation water use efficiency.

  12. Estimating irrigation water use in the humid eastern United States

    Science.gov (United States)

    Levin, Sara B.; Zarriello, Phillip J.

    2013-01-01

    Accurate accounting of irrigation water use is an important part of the U.S. Geological Survey National Water-Use Information Program and the WaterSMART initiative to help maintain sustainable water resources in the Nation. Irrigation water use in the humid eastern United States is not well characterized because of inadequate reporting and wide variability associated with climate, soils, crops, and farming practices. To better understand irrigation water use in the eastern United States, two types of predictive models were developed and compared by using metered irrigation water-use data for corn, cotton, peanut, and soybean crops in Georgia and turf farms in Rhode Island. Reliable metered irrigation data were limited to these areas. The first predictive model that was developed uses logistic regression to predict the occurrence of irrigation on the basis of antecedent climate conditions. Logistic regression equations were developed for corn, cotton, peanut, and soybean crops by using weekly irrigation water-use data from 36 metered sites in Georgia in 2009 and 2010 and turf farms in Rhode Island from 2000 to 2004. For the weeks when irrigation was predicted to take place, the irrigation water-use volume was estimated by multiplying the average metered irrigation application rate by the irrigated acreage for a given crop. The second predictive model that was developed is a crop-water-demand model that uses a daily soil water balance to estimate the water needs of a crop on a given day based on climate, soil, and plant properties. Crop-water-demand models were developed independently of reported irrigation water-use practices and relied on knowledge of plant properties that are available in the literature. Both modeling approaches require accurate accounting of irrigated area and crop type to estimate total irrigation water use. Water-use estimates from both modeling methods were compared to the metered irrigation data from Rhode Island and Georgia that were used to

  13. Yield and Irrigation Water Use Efficiency Response of Chufa (Cyperus esculentus L. var. sativus Boeck.) to Drip Irrigation Management

    Science.gov (United States)

    Pascual-Seva, Nuria; San Bautista, Alberto; López-Galarza, Salvador; Maroto, José Vicente; Pascual, Bernardo

    2016-04-01

    Chufa, also known as tigernut, is a typical crop in Valencia, Spain, where it is cultivated in ridges with furrow irrigation. Its cultivation uses large amounts of water, in the order of 10,000 m3 ha-1 year-1, so different studies have been undertaken in order to maximize the irrigation water use efficiency (IWUE). One of these studies faced the application of drip irrigation in the chufa cultivation, comparing three different irrigation strategies. These strategies differed on the volumetric soil water content (VSWC) when each irrigation event started. Starting each irrigation when the VSWC dropped to 90% of field capacity (FC) leaded to the highest yield, while the highest IWUE was obtained when irrigation started at 80% FC. It can be stated that starting each irrigation event when the VSWC is between 80 and 90% FC leads to the best results in terms of yield and IWUE. However, these results may still be improved by defining the best strategy in the irrigation stop, which is the aim of the herein presented research. This investigation comprises the productive response of the chufa crop with drip irrigation, determining yield and IWUE. The VSWC was monitored using multi-depth capacitance probes, with sensors at 0.10, 0.20 and 0.30 m below the top of the ridge. Each irrigation event started when the volumetric soil water content at 0.10 m dropped to 85% FC. Three irrigation strategies were considered, T1: each event being stopped when the average of the VSWC values at 0.10, 0.20 and 0.30 m depth reached the corresponding FC value; T2: each event being stopped when the VSWC values at 0.20 m reached the corresponding FC value; T3 each irrigation event lasted 30 min (corresponding to 7.33 mm). The largest yield (P ≤0.05) was obtained in T2 (2.31 kg m-2), with no statistical differences (P ≤0.05) between T1 (1.94 kg m-2) and T3 (1.92 kg m-2). The highest yield in T2 was obtained with the largest volume of irrigation water applied (722 mm), resulting in the lowest (P

  14. Pivot method for global optimization: A study of structures and phase changes in water clusters

    Science.gov (United States)

    Nigra, Pablo Fernando

    In this thesis, we have carried out a study of water clusters. The research work has been developed in two stages. In the first stage, we have investigated the properties of water clusters at zero temperature by means of global optimization. The clusters were modeled by using two well known pairwise potentials having distinct characteristics. One is the Matsuoka-Clementi-Yoshimine potential (MCY) that is an ab initio fitted function based on a rigid-molecule model, the other is the Sillinger-Rahman potential (SR) which is an empirical function based on a flexible-molecule model. The algorithm used for the global optimization of the clusters was the pivot method, which was developed in our group. The results have shown that, under certain conditions, the pivot method may yield optimized structures which are related to one another in such a way that they seem to form structural families. The structures in a family can be thought of as formed from the aggregation of single units. The particular types of structures we have found are quasi-one dimensional tubes built from stacking cyclic units such as tetramers, pentamers, and hexamers. The binding energies of these tubes form sequences that span smooth curves with clear asymptotic behavior; therefore, we have also studied the sequences applying the Bulirsch-Stoer (BST) algorithm to accelerate convergence. In the second stage of the research work, we have studied the thermodynamic properties of a typical water cluster at finite temperatures. The selected cluster was the water octamer which exhibits a definite solid-liquid phase change. The water octamer also has several low lying energy cubic structures with large energetic barriers that cause ergodicity breaking in regular Monte Carlo simulations. For that reason we have simulated the octamer using paralell tempering Monte Carlo combined with the multihistogram method. This has permited us to calculate the heat capacity from very low temperatures up to T = 230 K. We

  15. Pivotal results for the Medtronic Valiant Thoracic Stent Graft System in the VALOR II trial.

    Science.gov (United States)

    Fairman, Ronald M; Tuchek, J Michael; Lee, W Anthony; Kasirajan, Karthikeshwar; White, Rodney; Mehta, Manish; Lyden, Sean; Mukherjee, Dipankar; Bavaria, Joseph

    2012-11-01

    We report 30-day and 12-month results of endovascular treatment with the Valiant Thoracic Stent Graft System (Medtronic Vascular, Santa Rosa, Calif) in patients with descending thoracic aortic aneurysms of degenerative etiology. The Valiant stent graft is an evolution of the Talent thoracic stent graft (Medtronic Vascular). The VALOR II (Evaluation of the Clinical Performance of the Valiant Thoracic Stent Graft System in the Treatment of Descending Thoracic Aneurysms of Degenerative Etiology in Subjects Who Are Candidates for Endovascular Repair) was a prospective, nonrandomized, pivotal trial conducted at 24 U.S. sites with enrollment between December 2006 and September 2009. Standard follow-up examinations, including physical examination, computed tomography, and chest radiography, were at 1, 6, and 12 months, and annually through 5 years. VALOR II outcomes were compared with those from the pivotal VALOR (Evaluation of the Medtronic Vascular Talent Thoracic Stent Graft System for the Treatment of Thoracic Aortic Aneurysms) trial of the Talent stent graft, which enrolled 195 patients with similar enrollment criteria. VALOR II enrolled 160 patients. Compared with VALOR patients, VALOR II patients had similar age and sex distribution but higher rates of cardiovascular risk factors and significantly more severe modified Society for Vascular Surgery/American Association for Vascular Surgery risk scores. Stent graft delivery and deployment were successful in 154 patients (96.3%). Outcomes at 30 days in VALOR II were perioperative mortality, 3.1%; major adverse events, 38.1%; paraplegia, 0.6%; paraparesis, 1.9%; and stroke, 2.5%. At 12 months, after the minimum sample size was reached, 151 patients were evaluated: aneurysm-related mortality was 4.0%, stent graft migration was 2.9%, and endoleak was 13.0%. Through 12 months, there were no ruptures, conversions to open surgery, secondary procedures due to endoleak >30 days, or loss of stent graft patency. The Valiant

  16. On-irrigator pasture soil moisture sensor

    Science.gov (United States)

    Eng-Choon Tan, Adrian; Richards, Sean; Platt, Ian; Woodhead, Ian

    2017-02-01

    In this paper, we presented the development of a proximal soil moisture sensor that measured the soil moisture content of dairy pasture directly from the boom of an irrigator. The proposed sensor was capable of soil moisture measurements at an accuracy of  ±5% volumetric moisture content, and at meter scale ground area resolutions. The sensor adopted techniques from the ultra-wideband radar to enable measurements of ground reflection at resolutions that are smaller than the antenna beamwidth of the sensor. An experimental prototype was developed for field measurements. Extensive field measurements using the developed prototype were conducted on grass pasture at different ground conditions to validate the accuracy of the sensor in performing soil moisture measurements.

  17. Saline Nasal Irrigation for Upper Respiratory Conditions

    Science.gov (United States)

    2009-01-01

    Acute and chronic upper respiratory conditions are common and expensive disorders with enormous impact on patient quality of life and society at large. Saline nasal irrigation (SNI), a therapy with roots in Ayurvedic medicine that bathes the nasal mucosa with in spray or liquid saline, has been used as adjunctive care for upper respiratory conditions. In liquid form, SNI has been found to be effective adjunctive care by the Cochrane Collaboration for symptoms associated with chronic rhinosinusitis. Less conclusive clinical trial evidence supports its use in spray and liquid forms as adjunctive treatment for mild-to-moderate allergic rhinitis and acute upper respiratory infections. Consensus or expert opinion recommendations exist for SNI as a treatment for a variety of other conditions including rhinitis of pregnancy. SNI appears safe; side effects are minimal and transient. It can be recommended by clinicians to interested patients with a range of upper respiratory conditions in the context of patient education and printed instructional handouts. PMID:19904896

  18. Subsurface drip irrigation in different planting spacing of sugarcane

    Science.gov (United States)

    Pires, R. C. M.; Barbosa, E. A. A.; Arruda, F. B.; Silva, T. J. A.; Sakai, E.; Landell, M. G. A.

    2012-04-01

    The use of subsurface drip irrigation (SDI) in sugarcane cultivation is an interesting cultural practice to improve production and allow cultivation in marginal lands due to water deficits conditions. The SDI provides better water use efficiency, due to the water and nutrients application in root zone plants. However, it is important to investigate the long-term effect of irrigation in the yield and technological quality in different ecological condition cultivation. Thus, the aim of this work was to evaluate the effect of SDI in sugarcane cultivated in different planting spacings on technological quality, yield and theoretical recoverable sugar during four cycles of sugarcane cultivation. The experiment was carried out at Colorado Mill, Guaíra, São Paulo State in Brazil, in a clay soil. The experiment was installed in randomized blocks, with six replications. The treatments were three different planting spacings (S1 - 1.5 m between rows; S2 - 1.8 m between rows and S3 - planting in double line of 0.5 m x 1.3 m between planting rows) which were subdivided in irrigated and non-irrigated plots. In S1 and S2 treatments were installed one drip line in each plant row and in treatment S3 one drip line was installed between the rows with smaller spacing (0.5 m). The RB855536 genotype was used and the planting date occurred in May, 25th 2005. The analyzed parameters were: percentage of soluble solids (brix), percent apparent sucrose juice (Pol), total recoverable sugar (ATR), yield and theoretically recoverable sugar (RTR). Four years of yield (plant cane and first, second and third ratoon) were analyzed. Data were submitted to variance analysis and the averages compared by Duncan test at 5% probability. Two months before the first harvest a yield estimate was realized. According to the observed results the irrigated plants provided increase of about 20 % compared to non irrigated plants. However there was a great tipping of plants specially in irrigated plots. The

  19. EFFICACY OF DIFFERENT ENDODONTIC IRRIGATION PROTOCOLS IN CALCIUM HYDROXIDE REMOVAL

    Directory of Open Access Journals (Sweden)

    Elka N. Radeva

    2016-10-01

    Full Text Available Introduction: Calcium hydroxide is widely used in the field of endodontics as a temporary root canal filling. This medicament significantly increases pH and optimizes the treatment outcome. Its total removal before final obturation is very important. Otherwise it could affect the hermetic filling and respectively the endodontic success. Aim: To evaluate the most effective irrigation protocol of calcium hydroxide removal from root canals. Materials and methods: In this study 36 single root canal teeth were observed. They were randomly divided into three groups (n=10 each group according to the technique applied for calcium hydroxide removal - manual irrigation, irrigation and Revo-S rotary instrumentation; and passive ultrasonic irrigation, and a control group (n=6 – irrigation with distilled water only. After calcium hydroxide removals following the procedures above, teeth were separated longitudinally in a buccal-lingual direction and remnants of medicaments were observed in the apical, middle and coronal part of each tooth. Then all of the specimens were observed using scanning electron microscopy and evaluated by a specified scale. The results have undergone statistical analysis. Results: In the case of calcium hydroxide in the apex and in the middle with highest average is Revo-S, followed by Ultrasonic and irrigation. In the coronal part the highest average belongs to Revo-S, irrigation and Ultrasonic. In all groups the highest average is represented by control group. Conclusion: There is not a universal technique for removal of intracanal medicaments and applying more than one protocol is required.

  20. Impacts of Irrigation and Drought on Salem Ground Water

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available This investigation is the first of three phases of a ground-water management study. In this report, effects of irrigation and drought on the ground-water resources of Salem are examined. Irrigation water use for five soil types is estimated from a monthly water budget model on the basis of precipitation and temperature data from the last 30 years at selected weather stations across Salem. Moisture deficits are computed for each soil type on the basis of the water requirements of a corn crop. It is assumed that irrigation is used to make up the moisture deficit in those places where irrigation systems already exist. Irrigation water use from each township with irrigated acreage is added to municipal and industrial ground-water use data and then compared to aquifer potential yields. The spatial analysis is accomplished with a statewide geographic information system. An important distinction is made between the seasonal effects of irrigation water use and the annual or long-term effects.

  1. Wastewater Irrigation: Persistent Organic Pollutans in Soil and Product

    Directory of Open Access Journals (Sweden)

    Mehmet Emin AYDIN

    2015-06-01

    Full Text Available Treated or untreated wastewaters, used for irrigation purpose, contain various persistent organic pollutants. The long use of these waters for irrigation purpose results in deposition of the pollutants in soil, contaminates products and has adverse health affect on the human through food chain, and biologic activity of flora and fauna. The wastewaters of Konya were conveyed to the Salt Lake through the main drainage channel without any treatment until 2010.  During the arid period, the wastewater in the main drainage channel was used for irrigation and the products were cultivated. In this work, persistent organic pollutants i.e., polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, 180 and polycyclic aromatic hydrocarbons (naphthalene, acenaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene are determined in wastewater irrigated agricultural soil samples and the wheat samples cultivated in the region. High alkaline properties and clay structure of Konya soil were determined. These properties of soil result in the accumulation of contaminants in top soil layer used for agricultural production. On the other hand, PCB and PAH compounds were determined in comparable concentrations in well water irrigated reference soils with wastewater irrigated soils. PCB and PAH sources other than wastewater irrigation was evidenced for the study field.

  2. [Optimal allocation of irrigation water resources based on systematical strategy].

    Science.gov (United States)

    Cheng, Shuai; Zhang, Shu-qing

    2015-01-01

    With the development of the society and economy, as well as the rapid increase of population, more and more water is needed by human, which intensified the shortage of water resources. The scarcity of water resources and growing competition of water in different water use sectors reduce water availability for irrigation, so it is significant to plan and manage irrigation water resources scientifically and reasonably for improving water use efficiency (WUE) and ensuring food security. Many investigations indicate that WUE can be increased by optimization of water use. However, present studies focused primarily on a particular aspect or scale, which lack systematic analysis on the problem of irrigation water allocation. By summarizing previous related studies, especially those based on intelligent algorithms, this article proposed a multi-level, multi-scale framework for allocating irrigation water, and illustrated the basic theory of each component of the framework. Systematical strategy of optimal irrigation water allocation can not only control the total volume of irrigation water on the time scale, but also reduce water loss on the spatial scale. It could provide scientific basis and technical support for improving the irrigation water management level and ensuring the food security.

  3. Study on Intermittent Irrigation for Paddy Rice: II. Crop Responses

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effect of intermittent irrigation on the production of paddy rice was studied in a well-puddled paddy field with four treatments and 2 replicates: continuous flooding irrigation (CFI), and intermittent irrigation II-0, II-1 and II-2, in which plants were re-irrigated when the soil water potential fell below 0, -10, and -20 kPa, respectively, at soil depth of about 5 cm. Results showed that the reduction in soil water potential to about -10 or -20 kPa did not significantly affect the number of grains and the percentage of ripened grains. While, a lower crop growth rate (CGR) resulted from a decrease in the net assimilation rate (NAR) during intermittent irrigation II-1 and II-2, and there was also a reduction in the leaf area index (LAI) during intermittent irrigation II-2. Senescence of lower leaves on stems was promoted in treatments II-1 and II-2 at the ripening stage. Early senescence at ripening stage and water stress around midday decreased the rate of photosynthesis in leaves, causing the lower NAR. These physiological responses of the plants were responsible for the reduction in the dry matter production and grain yield in the intermittent irrigation treatments.

  4. Ocean-atmosphere interactions modulate irrigation's climate impacts

    Science.gov (United States)

    Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa

    2016-11-01

    Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean-atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that ocean-atmosphere interaction does impact the magnitude of global-mean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the oceans, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and midlatitudes in our simulations, approximately doubling the global-mean amplitude of surface temperature changes due to irrigation. The fractions of global area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with ocean-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern Ocean, and that attribution studies should include interactive oceans and need to consider LCLUC, including irrigation, as a truly global forcing that affects climate and the water cycle over ocean as well as land areas.

  5. Comparison of final irrigation techniques in removal of calcium hydroxide.

    Science.gov (United States)

    Yücel, Ali Çağın; Gürel, Melek; Güler, Eda; Karabucak, Bekir

    2013-12-01

    The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter-appointment calcium hydroxide [Ca(OH)2 ]. Forty-seven extracted human single-rooted teeth were instrumented, and Ca(OH)2 paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30-gauge slot-tipped needle, EndoVac system and ProUltra® PiezoFlow™ ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5-grade scale. The influence of the irrigation system was evaluated using a two-way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores (P ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls. © 2011 The Authors. Australian Endodontic Journal © 2011 Australian Society of Endodontology.

  6. Small ruminant macrophage polarization may play a pivotal role on lentiviral infection.

    Science.gov (United States)

    Crespo, Helena; Bertolotti, Luigi; Juganaru, Magda; Glaria, Idoia; de Andrés, Damián; Amorena, Beatriz; Rosati, Sergio; Reina, Ramsés

    2013-09-26

    Small ruminant lentiviruses (SRLV) infect the monocyte/macrophage lineage inducing a long-lasting infection affecting body condition, production and welfare of sheep and goats all over the world. Macrophages play a pivotal role on the host's innate and adaptative immune responses against parasites by becoming differentially activated. Macrophage heterogeneity can tentatively be classified into classically differentiated macrophages (M1) through stimulation with IFN-γ displaying an inflammatory profile, or can be alternatively differentiated by stimulation with IL-4/IL-13 into M2 macrophages with homeostatic functions. Since infection by SRLV can modulate macrophage functions we explored here whether ovine and caprine macrophages can be segregated into M1 and M2 populations and whether this differential polarization represents differential susceptibility to SRLV infection. We found that like in human and mouse systems, ovine and caprine macrophages can be differentiated with particular stimuli into M1/M2 subpopulations displaying specific markers. In addition, small ruminant macrophages are plastic since M1 differentiated macrophages can express M2 markers when the stimulus changes from IFN-γ to IL-4. SRLV replication was restricted in M1 macrophages and increased in M2 differentiated macrophages respectively according to viral production. Identification of the infection pathways in macrophage populations may provide new targets for eliciting appropriate immune responses against SRLV infection.

  7. Dichromatic state sum models for four-manifolds from pivotal functors

    CERN Document Server

    Bärenz, Manuel

    2016-01-01

    A family of invariants of smooth, oriented four-dimensional manifolds is defined via handle decompositions and Kirby calculus. It is shown that some of them are stronger than the signature and Euler invariant. The invariants are parameterised by a pivotal functor from a spherical fusion category into a ribbon fusion category. A state sum formula for the invariant is constructed via a chain mail procedure, so a large class of topological state sum models can be phrased in terms of it. Most prominently, the Crane-Yetter state sum over an arbitrary ribbon fusion category is recovered, including the nonmodular case. Another example is the four-dimensional Dijkgraaf-Witten model. Derivations of state space dimensions of some TQFTs as special cases agree with recent calculations of ground state degeneracies in Walker-Wang models. It is also shown that the Crane-Yetter invariant for nonmodular categories is stronger than signature and Euler invariant. Relations to different approaches to quantum gravity such as Cart...

  8. Pivotal role of median eminence tanycytes for hypothalamic function and neurogenesis.

    Science.gov (United States)

    Rizzoti, Karine; Lovell-Badge, Robin

    2017-04-15

    Along with the sub-ventricular zone of the forebrain lateral ventricles and the sub-granular zone of the dentate gyrus in the hippocampus, the hypothalamus has recently emerged as a third gliogenic and neurogenic niche in the central nervous system. The hypothalamus is the main regulator of body homeostasis because it centralizes peripheral information to regulate crucial physiological functions through the pituitary gland and the autonomic nervous system. Its ability to sense signals originating outside the brain relies on its exposure to blood-born molecules through the median eminence, which is localized outside the blood brain barrier. Within the hypothalamus, a population of specialized radial glial cells, the tanycytes, control exposure to blood-born signals by acting both as sensors and regulators of the hypothalamic input and output. In addition, lineage-tracing experiments have recently revealed that tanycytes represent a population of hypothalamic stem cells, defining them as a pivotal cell type within the hypothalamus. Hypothalamic neurogenesis has moreover been shown to have an important role in feeding control and energy metabolism, which challenges previous knowledge and offers new therapeutic options.

  9. Tlx3 Function in the Dorsal Root Ganglion is Pivotal to Itch and Pain Sensations

    Directory of Open Access Journals (Sweden)

    Chengcheng Huang

    2017-06-01

    Full Text Available Itch, a sensation eliciting a desire to scratch, is distinct from but not completely independent of pain. Inspiring achievements have been made in the characterization of itch-related receptors and neurotransmitters, but the molecular mechanisms controlling the development of pruriceptors remain poorly understood. Here, our RNAseq and in situ hybridization data show that the transcription factor Tlx3 is required for the expression of a majority of itch-related molecules in the dorsal root ganglion (DRG. As a result, Tlx3F/F;Nav1.8-cre mice exhibit significantly attenuated acute and dry skin-induced chronic itch. Furthermore, our study indicates that TRPV1 plays a pivotal role in the chronic itch evoked by dry skin and allergic contact dermatitis (ACD. The mutants also display impaired response to cold and inflammatory pain and elevated response to capsaicin, whereas the responses to acute mechanical, thermal stimuli and neuropathic pain remain normal. In Tlx3F/F;Nav1.8-cre mice, TRPV1 is derepressed and expands predominantly into IB4+ non-peptidergic (NP neurons. Collectively, our data reveal a molecular mechanism in regulating the development of pruriceptors and controlling itch and pain sensations.

  10. Pivotal role of innate and adaptive immunity in anthracycline chemotherapy of established tumors.

    Science.gov (United States)

    Mattarollo, Stephen R; Loi, Sherene; Duret, Helene; Ma, Yuting; Zitvogel, Laurence; Smyth, Mark J

    2011-07-15

    We show, in a series of established experimental breast adenocarcinomas and fibrosarcomas induced by carcinogen de novo in mice, that the therapeutic efficacy of doxorubicin treatment is dependent on CD8 T cells and IFN-γ production. Doxorubicin treatment enhances tumor antigen-specific proliferation of CD8 T cells in tumor-draining lymph nodes and promotes tumor infiltration of activated, IFN-γ-producing CD8 T cells. Optimal doxorubicin treatment outcome also requires both interleukin (IL)-1β and IL-17 cytokines, as blockade of IL-1β/IL-1R or IL-17A/IL-17Rα signaling abrogated the therapeutic effect. IL-23p19 had no observed role. The presence of γδ T cells, but not Jα18(+) natural killer T cells, at the time of doxorubicin treatment was also important. In tumor samples taken from breast cancer patients prior to treatment with anthracycline chemotherapy, a correlation between CD8α, CD8β, and IFN-γ gene expression levels and clinical response was observed, supporting their role in the therapeutic efficacy of anthracyclines in humans. Overall, these data strongly support the pivotal contribution of both innate and adaptive immunity in treatment outcomes of anthracycline chemotherapy. ©2011 AACR.

  11. Effect of pivot location and passive heave on propulsion from a pitching airfoil

    Science.gov (United States)

    Mackowski, A. W.; Williamson, C. H. K.

    2017-01-01

    We experimentally investigate the propulsive characteristics of a pitching NACA 0012 airfoil section, with emphasis on thrust and propulsive efficiency, at a Reynolds number of 1.7 ×104 . For the sake of mechanical simplicity, we consider an airfoil restricted to a single actuator in the pitching direction. We examine the effect of changing the airfoil's axis of rotation, finding that contrary to Garrick's linear theory, there exists a pitching axis near the airfoil that maximizes propulsive efficiency. Next, we examine the effect of placing passive springs on the airfoil in the heave (transverse) direction using our Cyber-Physical Fluid Dynamics technique. This elastic heaving motion allows the airfoil to combine pitching and heaving modes while being actuated only in the pitching direction. Two sets of dynamics are considered: one case where the airfoil is weighted unevenly and pitched about its center of mass (so that the resulting heaving motion is independent of inertial forces), and another case where the airfoil's center of mass is fixed at its centroid. For pitching at an amplitude of 8∘ and a reduced frequency k of two, we find that elastic heave produces a maximum propulsive efficiency of 35%, compared to 25% without any heave motion. Further, while operating at the same efficiency as the static-pivot case, we find that passive heaving greatly increases the magnitude of the airfoil's thrust. The airfoil configurations with highest propulsive efficiency generally involve pitching near or ahead of the airfoil's leading edge.

  12. Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex.

    Science.gov (United States)

    Alaimo, Alessandro; Alberdi, Araitz; Gomis-Perez, Carolina; Fernández-Orth, Juncal; Bernardo-Seisdedos, Ganeko; Malo, Covadonga; Millet, Oscar; Areso, Pilar; Villarroel, Alvaro

    2014-01-01

    Kv7.2 (KCNQ2) is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM) binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. However, the molecular mechanisms by which CaM controls channel trafficking are currently unknown. Here we used two complementary approaches to explore the molecular events underlying the association between CaM and Kv7.2 and their regulation by Ca(2+). First, we performed a fluorometric assay using dansylated calmodulin (D-CaM) to characterize the interaction of its individual lobes to the Kv7.2 CaM binding site (Q2AB). Second, we explored the association of Q2AB with CaM by NMR spectroscopy, using (15)N-labeled CaM as a reporter. The combined data highlight the interdependency of the N- and C-lobes of CaM in the interaction with Q2AB, suggesting that when CaM binds Ca(2+) the binding interface pivots between the N-lobe whose interactions are dominated by helix B and the C-lobe where the predominant interaction is with helix A. In addition, Ca(2+) makes CaM binding to Q2AB more difficult and, reciprocally, the channel weakens the association of CaM with Ca(2+).

  13. Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex.

    Directory of Open Access Journals (Sweden)

    Alessandro Alaimo

    Full Text Available Kv7.2 (KCNQ2 is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. However, the molecular mechanisms by which CaM controls channel trafficking are currently unknown. Here we used two complementary approaches to explore the molecular events underlying the association between CaM and Kv7.2 and their regulation by Ca(2+. First, we performed a fluorometric assay using dansylated calmodulin (D-CaM to characterize the interaction of its individual lobes to the Kv7.2 CaM binding site (Q2AB. Second, we explored the association of Q2AB with CaM by NMR spectroscopy, using (15N-labeled CaM as a reporter. The combined data highlight the interdependency of the N- and C-lobes of CaM in the interaction with Q2AB, suggesting that when CaM binds Ca(2+ the binding interface pivots between the N-lobe whose interactions are dominated by helix B and the C-lobe where the predominant interaction is with helix A. In addition, Ca(2+ makes CaM binding to Q2AB more difficult and, reciprocally, the channel weakens the association of CaM with Ca(2+.

  14. Minimal clinically important difference in Parkinson's disease as assessed in pivotal trials of pramipexole extended release.

    Science.gov (United States)

    Hauser, Robert A; Gordon, Mark Forrest; Mizuno, Yoshikuni; Poewe, Werner; Barone, Paolo; Schapira, Anthony H; Rascol, Olivier; Debieuvre, Catherine; Fräßdorf, Mandy

    2014-01-01

    Background. The minimal clinically important difference (MCID) is the smallest change in an outcome measure that is meaningful for patients. Objectives. To calculate the MCID for Unified Parkinson's Disease Rating Scale (UPDRS) scores in early Parkinson's disease (EPD) and for UPDRS scores and "OFF" time in advanced Parkinson's disease (APD). Methods. We analyzed data from two pivotal, double-blind, parallel-group trials of pramipexole ER that included pramipexole immediate release (IR) as an active comparator. We calculated MCID as the mean change in subjects who received active treatment and rated themselves "a little better" on patient global impression of improvement (PGI-I) minus the mean change in subjects who received placebo and rated themselves unchanged. Results. MCIDs in EPD (pramipexole ER, pramipexole IR) for UPDRS II were -1.8 and -2.0, for UPDRS III -6.2 and -6.1, and for UPDRS II + III -8.0 and -8.1. MCIDs in APD for UPDRS II were -1.8 and -2.3, for UPDRS III -5.2 and -6.5, and for UPDRS II + III -7.1 and -8.8. MCID for "OFF" time (pramipexole ER, pramipexole IR) was -1.0 and -1.3 hours. Conclusions. A range of MCIDs is emerging in the PD literature that provides the basis for power calculations and interpretation of clinical trials.

  15. Square-Root Lasso: Pivotal Recovery of Sparse Signals via Conic Programming

    CERN Document Server

    Belloni, Alexandre; Wang, Lie

    2010-01-01

    We propose a pivotal method for estimating high-dimensional sparse linear regression models, where the overall number of regressors $p$ is large, possibly much larger than $n$, but only $s$ regressors are significant. The method is a modification of LASSO, called square-root LASSO. The method neither relies on the knowledge of the standard deviation $\\sigma$ of the regression errors nor does it need to pre-estimate $\\sigma$. Despite not knowing $\\sigma$, square-root LASSO achieves near-oracle performance, attaining the convergence rate $\\sigma \\sqrt{(s/n)\\log p}$, and thus matching the performance of the standard LASSO that knows $\\sigma$. Moreover, we show that these results are valid for both Gaussian and non-Gaussian errors, under some mild moment restrictions, using moderate deviation theory. Finally, we formulate the square-root LASSO as a solution to a convex conic programming problem, which allows us to use efficient computational methods, such as interior point methods, to implement the estimator.

  16. A long term clinical outcome of the Medial Pivot Knee Arthroplasty System.

    Science.gov (United States)

    Macheras, George A; Galanakos, Spyridon P; Lepetsos, Panagiotis; Anastasopoulos, Panagiotis P; Papadakis, Stamatios A

    2017-03-01

    The ideal total knee arthroplasty (TKA) should provide maximum range of motion and functional stability for all desired daily activities and, if possible, to replicate normal knee kinematics and function. The ADVANCE® Medial Pivot (AMP) Knee System was designed with a highly congruent medial compartment and a less conforming lateral compartment to more closely mimic the kinematics of the normal knee and to offer more stability through out of range of motion (ROM). The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of this TKA system. Three hundred and twenty-five (325) patients (347 knees) with knee osteoarthritis underwent a TKA using the AMP prosthesis in our Department. For evaluation, objective and subjective clinical rating systems along with radiograph series were used. The average follow-up was 15.2years. All patients showed a statistically significant improvement (p<0.0005) in the Knee Society clinical rating system, Western Ontario and McMaster Universities Osteoarthritis Index questionnaire, SF-12® questionnaire, and Oxford knee score. The majority of patients (94%) were able to perform age-appropriate activities with a mean knee flexion of 120° (range, 105°-135°) at final follow-up. Survival analysis showed a cumulative success rate of 98.8% at 17years. The obtained results demonstrate excellent long-term clinical outcome for this knee design. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Decision support system for economic value of irrigation water

    Science.gov (United States)

    El-Gafy, Inas; El-Ganzori, Akram

    2012-06-01

    The mismatch between the supply and demand, inequitable distribution and the over irrigation of water consuming crops are the main constraints that are faced in the implementation of the integrated water resources management in Egypt. With water scarcity, the problem under consideration is that the current cropping pattern is not economically efficient in the utilization of the available water resource. Moreover, in consequence of the importance of the agricultural sector to the national economies, it is necessary to be aware of the economic performance of water use in the crops production. The scope of this study is to develop economic value of irrigation water maps of Egypt. The objective of the study is carried out by acquiring a Decision Support System for economic value of irrigation water of Egypt. This Decision Support System is applied for developing economic value maps for the irrigation water that is used for cultivating 45 crops under cereal, fiber, legumes, and vegetables, herbalist, and forages categories at each governorate of Egypt in year 2008 and 2009. The crops that achieve the highest and lowest economic value of irrigation water at each governorate of Egypt were identified. The reasons of the variations in the economic value of irrigation water at the governorates of Egypt were determined. The developed Decision Support System could be used yearly as a tool for demonstrating a picture about the economic value of irrigation water for the decision makers in the areas of water resources and agriculture. The developed economic value of irrigation water maps can be used in proposing a cropping pattern that maximizes the economic value of irrigation water in each governorate of Egypt.

  18. Estimating soil wetting patterns for drip irrigation using genetic programming

    Energy Technology Data Exchange (ETDEWEB)

    Samadianfard, S.; Sadraddini, A. A.; Nazemi, A. H.; Provenzano, G.; Kisi, O.

    2012-07-01

    Drip irrigation is considered as one of the most efficient irrigation systems. Knowledge of the soil wetted perimeter arising from infiltration of water from drippers is important in the design and management of efficient irrigation systems. To this aim, numerical models can represent a powerful tool to analyze the evolution of the wetting pattern during irrigation, in order to explore drip irrigation management strategies, to set up the duration of irrigation, and finally to optimize water use efficiency. This paper examines the potential of genetic programming (GP) in simulating wetting patterns of drip irrigation. First by considering 12 different soil textures of USDA-SCS soil texture triangle, different emitter discharge and duration of irrigation, soil wetting patterns have been simulated by using HYDRUS 2D software. Then using the calculated values of depth and radius of wetting pattern as target outputs, two different GP models have been considered. Finally, the capability of GP for simulating wetting patterns was analyzed using some values of data set that were not used in training. Results showed that the GP method had good agreement with results of HYDRUS 2D software in the case of considering full set of operators with R{sup 2} of 0.99 and 0.99 and root mean squared error of 2.88 and 4.94 in estimation of radius and depth of wetting patterns, respectively. Also, field experimental results in a sandy loam soil with emitter discharge of 4 L h{sup -}1 showed reasonable agreement with GP results. As a conclusion, the results of the study demonstrate the usefulness of the GP method for estimating wetting patterns of drip irrigation. (Author) 40 refs.

  19. Irrigation water quality as indicator of sustainable rural development

    Directory of Open Access Journals (Sweden)

    Trajković Slaviša

    2004-01-01

    Full Text Available The sustainable rural development more and more depends on the efficient usage of water resources. Most often, at least in one part of the year, the rain is not sufficient for plant growth and rain plant production significantly depends on the yearly precipitation variation. The increase and stability of the agricultural production is possible in the irrigation conditions. The most part (around 70% of the global water resources is used for food production. Irrigation water quality indicator is used to show if the available water resources have the required quality for application in agriculture. Irrigation is characterised by the complex water-plant-soil relationship, and in that eco-system the man as the end user of the irrigated fields occupies a very important place. That explains the difficulties in producing one universal classification of irrigation water quality. The paper analyses numerous water quality classifications from the aspect of the applicability on the quantifying of this indicator. The adopted classification should possess understandable, qualified and internationally comparable indicator. Thus, local classifications (Neigebauer, Miljkovic cannot be used for this indicator. United Nation Food and Agricultural Organization (FAO and US Salinity Laboratory (USSL classifications are used for the evaluation of the irrigation water quality throughout the world. FAO classification gives the complex picture of the usability of the irrigation water from the point of its influence on the soil and the plants. However, the scope of the analyses is not often suited to the needs of that classification, which makes it difficult to apply. The conclusion is that the USSL (US Salinity Laboratory classification is best suited to this range of chemical water analyses. The evaluation of the irrigation water quality indicator in the Juzna Morava river basin, upstream from the Toplica river estuary is given in this paper. Based on the obtained

  20. Uncertainties in modelling the climate impact of irrigation

    Science.gov (United States)

    de Vrese, Philipp; Hagemann, Stefan

    2017-04-01

    Many issues related to the climate impact of irrigation are addressed in studies that apply a wide range of models. These involve uncertainties related to differences in the model's general structure and parametrizations on the one hand and the need for simplifying assumptions with respect to the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In several simulations, we varied certain irrigation characteristics to estimate the resulting variations in irrigation's climate impact and found a large sensitivity with respect to the irrigation effectiveness. Here, the assumed effectiveness of the scheme is a combination of the target soil moisture and the degree to which water losses are accounted for. In general, the simulated impact of irrigation on the state of the land surface and the atmosphere is more than three times larger when assuming a low irrigation effectiveness compared to a high effectiveness. In an additional set of simulations, we varied certain aspects of the model's general structure, namely the land-surface-atmosphere coupling, to estimate the related uncertainties. Here we compared the impact of irrigation between simulations using a parameter aggregation, a simple flux aggregation scheme and a coupling scheme that also accounts for spatial heterogeneity within the lowest layers of the atmosphere. It was found that changes in the land-surface-atmosphere coupling do not only affect the magnitude of climate impacts but they can even affect the direction of the impacts.

  1. The importance of timing of precipitation for irrigation scheduling

    Science.gov (United States)

    Franz, T.; Hunt, E. D.; Wardlow, B.

    2016-12-01

    Irrigated agriculture, like rainfed agriculture, continues to serve an important role in the production of cereal crops, with increasing importance in the developing world. Many areas however, including the U.S. High Plains region, are faced with the daunting task of increasing crop production with less water, as groundwater reserves become further depleted. Climate change could further exacerbate limited supplies of groundwater in these regions. Thus, monitoring soil moisture under cereal crops is critical for determining the best irrigation strategies. The results obtained during an eight-year period from an irrigated field in eastern Nebraska demonstrated the importance of the timing of precipitation and soil moisture response for irrigation scheduling. The years with the fewest irrigation applications for both maize and soybeans were not the wettest years during the study period. Paradoxically, the year with the fewest irrigation treatments when soybeans were the common crop at the irrigated field and a nearby rainfed field was in 2006, which had below average growing season precipitation. The year with the most irrigation treatments (2008) when soybeans were also the common crop occurred during one of the wettest growing seasons over the past 30 years at Mead. The primary difference between the below average 2006 growing season and the wet 2008 growing season was that precipitation fell at regular intervals during critical reproductive stages for soybeans in 2006 keeping the soil profile moist. Conversely, the only dry spell of the 2008 growing season occurred during that same critical period, thus necessitating irrigation applications that prevented depletion of soil profile.

  2. Water Management For Drip Irrigated Corn In The Arid Southeastern Anatolia Project Area In Turkey

    Science.gov (United States)

    Yazar, A.; Gencel, B.

    Microirrigation has the potential to minimize application losses to evaporation, runoff and deep percolation; improve irrigation control with smaller, frequent applications; supply nutrients to the crop as needed; and improve crop yields. The Southeastern Anatolia Project (GAP), when completed, 1.7 million ha of land will be irrigated. Wa- ter supplies are limited, and traditional irrigation practices result in high losses and low irrigation efficiences. This study was conducted to evaluate surface drip irrigation on crop performance. The effect of irrigation frequency and amount on crop yield, yield components, water use, and water use efficiency of corn (Zea mays L., PIO- 3267) were investigated in the Harran Plain in the arid Southeastern Turkey on a clay textured Harran Soil Series. Irrigation frequencies were once in three-day, and once in six-day; irrigation levels varied from full (I-100), medium (I-67; 2/3rd of full), and low (I-33; 1/3rd of full). The full irrigation treatment received 100% of the cumula- tive evaporation within the irrigation interval. Liquid nitrogen was injected into the irrigation water throughout the growing season. Treatments received the same amount of fertilizers. Highest average corn grain yield (11920 kg/ha) was obtained from the full irrigation treatment (I-100) with six-day irrigation interval. Irrigation intervals did not affect corn yields; however, deficit irrigation affected crop yields by reducing seed mass, and the seed number. Maximum water use efficiency (WUE) was found as 2.27 kg/m3 in the I-33 treatment plots with three-day irrigation interval. On the clay soil at Harran, irrigation frequencies are less critical than proper irrigation management for drip irrigation systems to avoid water deficits that have a greater effect on corn yields. The results revealed that about 40% water saving is possible with drip irrigation as compared to traditional surface irrigation methods in the region.

  3. Changes of soil organic matter and microbial activity in irrigated and non irrigated olive groves

    Science.gov (United States)

    Kavvadias, Victor; Papadopoulou, Maria; Theocharopoulos, Sideris; Vavoulidou, Evagelia; Doula, Maria; Reppas, Spiros

    2014-05-01

    The implementation of olive cultivation techniques in Greece has not been systematically tested under the prevailing Mediterranean conditions. A LIFE+ project was initiated (oLIVE-CLIMA; LIFE 11/ENV/000942) aiming to introduce new management practices in olive tree crops that lead to increased carbon dioxide uptake by plants as well as carbon sequestration from the atmosphere and reverse the trend of soil organic matter decline, erosion and desertification. This paper presents data on soil organic matter and microbial activity from a soil campaign in a pilot region in Greece, and particularly in the area of Chora, prefecture of Messinia, South west Peloponnese. The soil campaign took place during the period December 2012-February 2013. Twelve soil parcels of olive groves were selected (6 irrigated and 6 rainfed) and in each soil parcel six composite soil samples were taken from 0-10 cm depth at equal intervals along a straight line of the trunk of the tree to the middle of the distance from the nearest tree of the next tree series. The first three samples were under olive tree canopy. An additional composite sample was taken at depth of 10-40 cm. Soil samples were analyzed for soil physicochemical and biological properties. In this study results for total organic carbon (TOC), soil basal microbial respiration (BR), microbial biomass C (MB-C) from the region of Messinia, are presented. Organic matter was determined by dichromate oxidation. The microbial activity was measured by the amount of CO2 evolution, while microbial biomass C was determined by substrate-induced respiration, after the addition of glucose. The results showed considerable differences in TOC, BR and MB-C associated with the sampling position and soil depth. The higher TOC, BR and MB-C values, in most cases, were determined in samples taken from points under the canopy, but not close to the tree trunk compared to the sampling points outside the canopy. This indicates the positive effect of

  4. Climate change and irrigation demand: Uncertainty and adaptation

    Directory of Open Access Journals (Sweden)

    Sean A. Woznicki

    2015-03-01

    New hydrological insights for the region: Uncertainty in irrigation demand was found to increase moving from 2020–2039 to 2060–2079, with demand generally decreasing moving further into the future for corn and soybean. A shift in timing of peak irrigation demand and increases in temperature lead to corn yield reductions. However, soybean yield increased under these conditions. Finally, the adaptation strategy of planting earlier increased irrigation demand and water available for transpiration, while delaying planting resulted in demand decreases for both crops.

  5. Irrigation management using an expert system, soil water potentials, and vegetative indices for spatial applications

    Science.gov (United States)

    Variable rate irrigation (VRI) systems are irrigation systems that are capable of applying different water depths both in the direction of travel and along the length of the irrigation system. However, when compared to traditional irrigation systems, VRI systems require a higher level of management...

  6. Alternate partial root-zone drying irrigation improves fruit quality in tomatoes

    DEFF Research Database (Denmark)

    Sun, Y.; Holm, Peter Engelund; Liu, Fulai

    2014-01-01

    Alternate partial root-zone drying (PRD) irrigation and deficit irrigation (DI) are water-saving irrigation strategies. Here, comparative effects of PRD and DI on fruit quality of tomato (Solanum lycopersicum L.) were investigated. The results showed that the irrigation treatments had no effect...

  7. Irrigation Scheduling for Green Bell Peppers Using Capacitance Soil Moisture Sensors

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Femminella, K.; Munoz-Carpena, R.

    2011-01-01

    Vegetable production areas are intensively managed with high inputs of fertilizer and irrigation. The objectives of this study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling using soil moisture sensor irrigation controllers (SMS) on yield, irrigation water use

  8. The phenology of malaria mosquitos in irrigated rice fields in Mali

    NARCIS (Netherlands)

    Klinkenberg, E.; Takken, W.; Huibers, F.P.; Touré, Y.T.

    2003-01-01

    A field study was carried out in the large-scale rice irrigation scheme of the Office du Niger in Mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency.

  9. Estimation of furrow irrigation sediment loss using an artificial neural network

    Science.gov (United States)

    The area irrigated by furrow irrigation in the U.S. has been steadily decreasing but still represents about 20% of the total irrigated area in the U.S. Furrow irrigation sediment loss is a major water quality issue and a method for estimating sediment loss is needed to quantify the environmental imp...

  10. 25 CFR 171.410 - Can I install a fence on a BIA irrigation project?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I install a fence on a BIA irrigation project? 171... IRRIGATION OPERATION AND MAINTENANCE Irrigation Facilities § 171.410 Can I install a fence on a BIA irrigation project? Yes. Fences are considered structures and may be installed in compliance with § 171.405....

  11. Alternate partial root-zone drying irrigation improves fruit quality in tomatoes

    DEFF Research Database (Denmark)

    Sun, Y.; Holm, Peter Engelund; Liu, Fulai

    2014-01-01

    Alternate partial root-zone drying (PRD) irrigation and deficit irrigation (DI) are water-saving irrigation strategies. Here, comparative effects of PRD and DI on fruit quality of tomato (Solanum lycopersicum L.) were investigated. The results showed that the irrigation treatments had no effect...

  12. 25 CFR 171.210 - Where will BIA provide my irrigation service?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Where will BIA provide my irrigation service? 171.210 Section 171.210 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.210 Where will BIA provide my irrigation service? (a)...

  13. Irrigation Scheduling for Green Bell Peppers Using Capacitance Soil Moisture Sensors

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Femminella, K.; Munoz-Carpena, R.

    2011-01-01

    Vegetable production areas are intensively managed with high inputs of fertilizer and irrigation. The objectives of this study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling using soil moisture sensor irrigation controllers (SMS) on yield, irrigation water use

  14. "Anatomic" single-bundle anterior cruciate ligament reconstruction reduces both anterior translation and internal rotation during the pivot shift.

    Science.gov (United States)

    Porter, Mark D; Shadbolt, Bruce

    2014-12-01

    The ability of single-bundle anterior cruciate ligament (ACL) reconstruction to restore rotational control has been questioned by proponents of the double-bundle technique. The term anatomic positioning has become popularized in recognition of the incorrect positioning sometimes used in the past, which may have contributed to the lack of rotation control. The pivot-shift test remains the most clinically useful measure of ACL deficiency, and it is now possible to measure it both accurately and objectively using computer navigation. Single-bundle ACL reconstruction will reduce anterior translation and internal rotation of the tibia during the pivot-shift test when compared with the contralateral uninjured knee. Descriptive laboratory study. A total of 20 patients with an acute isolated ACL rupture underwent reconstruction with a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the pivot shift before and after reconstruction. The opposite uninjured knee was used as a control. Statistical analysis was used to compare the pivot shifts before and after surgery. Single-bundle ACL reconstruction produced a significant reduction in anterior translation, from a mean ± SD of 17.4 ± 3.80 mm to 6.4 ± 1.95 mm (P operated knee both before and after surgery. It is possible to reduce both anterior translation and internal rotation, which occur during the pivot-shift test in the ACL-deficient knee, using single-bundle ACL reconstruction, when measured at the time of surgery. However, normal motion is not fully restored. © 2014 The Author(s).

  15. Optimization of irrigation water in stone fruit and table grapes

    Science.gov (United States)

    de la Rosa, Jose Mª; Castillo, Cristina; Temnani, Abdel; Pérez-Pastor, Alejandro

    2017-04-01

    In water scarcity areas, it must be highlighted that the maximum productions of the crops do not necessarily imply maximum profitability. Therefore, during the last years a special interest in the development of deficit irrigation strategies based on significant reductions of the seasonal ET without affecting production or quality has been observed. The strategies of regulated deficit irrigation (RDI) are based on the reduction of water supply during non critical periods, the covering of water needs during critical periods and maximizing, at the same time, the production by unit of applied water. The main objective of this experiment was to implement, demonstrate and disseminate a sustainable irrigation strategy based on deficit irrigation to promote its large scale acceptance and use in woody crops in Mediterranean agroecosystems, characterized by water scarcity, without affecting the quality standards demanded by exportation markets. Five demonstration plots were established in representative crops of the irrigating community of Campotejar (Murcia, Spain): i) Peach trees, cv. catherina in the "Periquitos" farm; ii) Apricot trees, cv. "Red Carlet" in "La Hoya del Fenazar" farm; iii) Nectarine trees, cv. Viowhite in "Agrícola Don Fernando" farm; iv) Table grape, cv "Crimson Seedless" in "La Hornera" farm; and v) Paraguayan cv. carioca in "The Hornera" farm. In each demonstration plot, at least two irrigation treatments were established: i) Control (CTL), irrigated to ensure non-limiting water conditions (120% of crop evapotranspiration) and ii) Regulated deficit irrigation (RDI) irrigated as CTL during critical periods and decreasing irrigation in non-critical periods. The plant water status indicators evaluated were midday stem water potential and Trunk Diameter Fluctuation derived indices: maximum daily shrinkage (MDS) and trunk daily growth rate (TGR); vegetative growth of the different crops from trunk diameter and pruning dry weight, fruit growth and fruit

  16. Corelation between Machines Assisted Endodontic Irrigant Agitation and Apical Extrusion of Debris and Irrigant: A Laboratory Study

    Directory of Open Access Journals (Sweden)

    Jatin Gupta

    2014-01-01

    Full Text Available Aims. To compare amount of root canal debris and irrigant extruded apically after irrigants agitation using closed and open chambers. Methods and Material. Sixty maxillary central incisors were selected, decoronated, and mounted in preweighed glass vials filled with distilled water. Biomechanical preparation was completed using ProTaper rotary files until number F4 and 1 mL of 3% NaOCl solution after each file use. Samples were randomly divided into closed or open chamber sets which were further subdivided into 6 groups, based on the agitation techniques: no agitation (control, canalBrush, lentulospiral, passive ultrasonic agitation (PUA, EndoActivator, and EndoVac. Canals were irrigated with 1 mL of 17% EDTA and agitated for 30 s and then flushed with 2 mL of distilled water. Apically extruded irrigant was measured and vials were kept in incubator for 5 days at 68°C for drying for weight calculation. Statistical Analysis. Analysis was done using Student’s t-test, one-way ANOVA, and post-hoc. Results. All agitation techniques showed apical extrusion of the debris and irrigant. The closed chamber apparatus showed significantly less extrusion of debris and irrigant than open chamber (P<0.05. Conclusions. EndoVac was found to be the safest agitation system among all test groups with regard to apical extrusion of debris and irrigant.

  17. Effects of drip irrigation under plastic film with saline water on cotton growth and yields

    Science.gov (United States)

    Wang, B.; Jin, M.; He, Y.; Zhou, J.; Brusseau, M. L.

    2012-12-01

    To study the influence of different irrigation system for drip irrigation under plastic film with saline water on cotton growth and yields, field experiments at key irrigation experiment station of water resources management division in Bayingolin Mongol Autonomous Prefecture, Xinjiang, China were set up consist of different irrigation ratio (5250, 4500, 3750, 3000m3/hm2), different irrigation times (24, 12 and 8 times) and different rotation irrigation modes. The results show that: with the larger irrigation ratio, the cotton growth and yields was also better, and the significant influence on cotton growth and yields for irrigation ratio is between 3750-4500 m3/hm2. When the irrigation ratio is smaller (3000m3/hm2), cotton growth and yields for irrigation times of 8 times are higher, When the irrigation ratio is bigger (4500m3/hm2), cotton growth for irrigation times of 12 times are better and its cotton yields are higher correspondingly. According to the growth of cotton, yields and water productivity, the suitable irrigation system of cotton is the irrigation ratio of 4500-3750 m3/ hm2 and the irrigation times of 18 times for drip irrigation under plastic film with saline water. For different rotation drip irrigation experiments with saline water and fresh water, the cotton yields and irrigation water productivity is higher under the disposal of SF (rotation irrigation in first 6 times with saline water irrigation and then 6 times with fresh water irrigation) compared to FS (rotation irrigation in first 6 times with fresh water and then 6 times with saline water) and SSFA (rotation irrigation with twice saline water and once fresh water) compared to SFA (alternative irrigation with saline water and fresh water). Compared to the different alternate irrigation experiments, the cotton yields and water productivity for pure saline water irrigation is higher. In addition, the trend is the larger the irrigation ratio and the higher the yields. It maybe dues to the low

  18. Microeconomics of Deficit Irrigation and Subjective Water Response Function for Intensive Olive Groves

    Directory of Open Access Journals (Sweden)

    Alfonso Expósito

    2016-06-01

    Full Text Available This research paper analyzes the economics of deficit irrigation based on the use of subjective estimates of the crop yield–water relationship to determine water supply in irrigated olive groves. Interviewed farmers were asked to give three estimates for the yield-water relationship as a function of water supply (full irrigation, usual deficit irrigation and extreme deficit irrigation. Those responses are contrasted with the actual irrigation dose and the results appear to support the hypothesis that a majority of farmers use deficit irrigation as a strategy that maximizes the value of limited water input rather than the conventional microeconomic behavior of maximizing the return to land.

  19. An assessment of global net irrigation water requirements from various water supply sources to sustain irrigation: rivers and reservoirs (1960–2000 and 2050

    Directory of Open Access Journals (Sweden)

    A. Khajuria

    2013-01-01

    Full Text Available Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependency of the supply of irrigation water from rivers, large reservoirs with a greater than 1.0 km3 storage capacity, medium-size reservoirs with storage capacities ranging from 1.0 km3 to 3.0 Mm3, and non-local non-renewable blue water (NNBW, particularly taking into account variations in irrigation area during the period 1960–2000. We also estimated the future irrigation water requirements from water supply sources in addition to these four sources, using an irrigation area scenario. The net irrigation water requirements from various supply sources were assessed using the global H08 water resources model. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0°. We obtained net irrigation water from rivers and medium-size reservoirs, and determined that the NNBW increased continuously from 1960 to 1985, but the net irrigation water from large reservoirs increased only marginally. After 1985, the net irrigation water from rivers approached a critical limit with the continued expansion of the irrigation area. The irrigation water requirements from medium-size reservoirs and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of medium-size reservoirs. Under the irrigation area scenario without climate change, global net irrigation water requirements from additional water supply sources will account for 26% of the total requirements in the year 2050. We found that expansion of irrigation areas due to population growth will generate an enormous demand for irrigation water from additional resources.

  20. An assessment of global net irrigation water requirements from various water supply sources to sustain irrigation: rivers and reservoirs (1960-2000 and 2050)

    Science.gov (United States)

    Yoshikawa, S.; Cho, J.; Yamada, H. G.; Hanasaki, N.; Khajuria, A.; Kanae, S.

    2013-01-01

    Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependency of the supply of irrigation water from rivers, large reservoirs with a greater than 1.0 km3 storage capacity, medium-size reservoirs with storage capacities ranging from 1.0 km3 to 3.0 Mm3, and non-local non-renewable blue water (NNBW), particularly taking into account variations in irrigation area during the period 1960-2000. We also estimated the future irrigation water requirements from water supply sources in addition to these four sources, using an irrigation area scenario. The net irrigation water requirements from various supply sources were assessed using the global H08 water resources model. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0°. We obtained net irrigation water from rivers and medium-size reservoirs, and determined that the NNBW increased continuously from 1960 to 1985, but the net irrigation water from large reservoirs increased only marginally. After 1985, the net irrigation water from rivers approached a critical limit with the continued expansion of the irrigation area. The irrigation water requirements from medium-size reservoirs and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of medium-size reservoirs. Under the irrigation area scenario without climate change, global net irrigation water requirements from additional water supply sources will account for 26% of the total requirements in the year 2050. We found that expansion of irrigation areas due to population growth will generate an enormous demand for irrigation water from additional resources.