The Experts below are selected from a list of 1790280 Experts worldwide ranked by ideXlab platform
Giuseppe Passarella - One of the best experts on this subject based on the ideXlab platform.
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Simulation of peak-demand hydrographs in pressurized irrigation delivery systems using a deterministic–stochastic combined model. Part I: model development
Irrigation Science, 2013Co-Authors: Daniele Zaccaria, Nicola Lamaddalena, Christopher M. U. Neale, Gary P. Merkley, Nicola Palmisano, Giuseppe PassarellaAbstract:This study describes a model named HydroGEN that was conceived for simulating hydrographs of daily volumes and hourly flow rates during peak-demand periods in pressurized irrigation delivery networks with On-Demand Operation. The model is based on a methodology consisting of deterministic and stochastic components and is composed of a set of input parameters to reproduce the crop irrigation management practices followed by farmers and of computational procedures enabling to simulate the soil water balance and the irrigation events for all cropped fields supplied by each delivery hydrant in a distribution network. The input data include values of weather, crop, and soil parameters, as well as information on irrigation practices followed by local farmers. The resulting model outputs are generated flow hydrographs during the peak-demand period, which allow the subsequent analysis of performance achievable under different delivery scenarios. The model can be applied either for system design or re-design, as well as for analysis of Operation and evaluation of performance achievements of On-Demand pressurized irrigation delivery networks. Results from application of HydroGEN to a real pressurized irrigation system at different scales are presented in a companion paper (Part II: model applications).
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simulation of peak demand hydrographs in pressurized irrigation delivery systems using a deterministic stochastic combined model part i model development
Irrigation Science, 2013Co-Authors: Daniele Zaccaria, Nicola Lamaddalena, Christopher M. U. Neale, Gary P. Merkley, Nicola Palmisano, Giuseppe PassarellaAbstract:This study describes a model named HydroGEN that was conceived for simulating hydrographs of daily volumes and hourly flow rates during peak-demand periods in pressurized irrigation delivery networks with On-Demand Operation. The model is based on a methodology consisting of deterministic and stochastic components and is composed of a set of input parameters to reproduce the crop irrigation management practices followed by farmers and of computational procedures enabling to simulate the soil water balance and the irrigation events for all cropped fields supplied by each delivery hydrant in a distribution network. The input data include values of weather, crop, and soil parameters, as well as information on irrigation practices followed by local farmers. The resulting model outputs are generated flow hydrographs during the peak-demand period, which allow the subsequent analysis of performance achievable under different delivery scenarios. The model can be applied either for system design or re-design, as well as for analysis of Operation and evaluation of performance achievements of On-Demand pressurized irrigation delivery networks. Results from application of HydroGEN to a real pressurized irrigation system at different scales are presented in a companion paper (Part II: model applications).
Doyoung Byun - One of the best experts on this subject based on the ideXlab platform.
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fabrication of terahertz metamaterial with high refractive index using high resolution electrohydrodynamic jet printing
Applied Physics Letters, 2013Co-Authors: Hadi Teguh Yudistira, Vu Dat Nguyen, Ayodya Pradhipta Tenggara, Fariza Dian Prasetyo, Choongi Choi, Muhan Choi, Doyoung ByunAbstract:Metamaterial is an engineered material whose electromagnetic properties can be determined by the unit structure. Lithography is one of main methods to fabricate metamaterials for fine patterning which has limitations in large-area fabrication. We present a direct fabrication method for metamaterial using the electrohydrodynamic jet printing. An electrical pulse was controlled to make drop-On-Demand Operation, through which flexible high refractive-index metamaterial could be fabricated in the form of I-shaped silver electrodes with 10-μm widths and 5-μm gaps on polyimide substrate. The peak value of the refractive index was 18.4 at a frequency of around 0.48 THz.
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Liquid meniscus oscillation and drop ejection by ac voltage, pulsed dc voltage, and superimposing dc to ac voltages.
Physical review. E Statistical nonlinear and soft matter physics, 2009Co-Authors: Si Bui Quang Tran, Vu Dat Nguyen, Doyoung Byun, Tae Sam KangAbstract:The electrohydrodynamic (EHD) spraying technique has been utilized in applications such as inkjet printing and mass spectrometry technologies. In this paper, the role of electrical potential signals in jetting and on the oscillation of the meniscus is evaluated. The jetting and the meniscus oscillation behavior are experimentally investigated under ac voltage, ac voltage superimposed on dc voltage, and pulsed dc voltage. Based on this in-depth study of the meniscus behavior under various signals, the optimal signal is implemented to an EHD inkjet head for drop-On-Demand Operation. For applied ac voltage and ac voltage superimposed on dc voltage, the jetting phenomenon is a dynamic process due to sequential opposite sign signals. The jetting occurs at the end of the oscillation cycle, where the meniscus oscillates upward and arrives at its highest position.
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Fabrication of nanoscale nozzle for electrohydrodynamic (EHD) inkjet head and high precision patterning by drop-On-Demand Operation.
Journal of nanoscience and nanotechnology, 2009Co-Authors: Vu Dat Nguyen, Michael G. Schrlau, Haim H. Bau, Si Bui Quang Tran, Doyoung ByunAbstract:Electrohydrodynamic (EHD) spraying has been utilized in applications varying from micro-colloid thrusters to technology for film deposition and inkjet printing. Recently, EHD inkjet heads were developed to facilitate the fabrication of printed electronics such as digital displays, printed circuit boards (PCBs), and solar cells. Here, we report the fabrication and application of nanoscale nozzles for EHD inkjet printing. The nozzles were fabricated by depositing an electrically conductive layer on either the inside or outside of quartz micropipettes with sub-micron diameter tips. With the drop-On-Demand control needed for inkjet heads, our nanoscale nozzles dispensed silver droplets in fine patterns on glass substrates.
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Drop-On-Demand printing of conductive ink by electrostatic field induced inkjet head
Applied Physics Letters, 2008Co-Authors: Jaeyong Choi, Vu Dat Nguyen, Sukhan Lee, Yong-jae Kim, Sang Uk Son, Doyoung ByunAbstract:Recently, inkjet printing technology has become crucial in many industrial fabrication fields mainly due to its advantages of noncontact and fast pattern generation. In this paper, we investigate an electrostatic field induced inkjet printing system, which is based on an electrohydrodynamic process, for drop-On-Demand jetting. In order to locate the optimal jetting conditions, we tested jetting performance for various bias voltages and pulse signals. To investigate the characteristics of drop-On-Demand Operation and micropatterning, we used conductive silver ink and examined the drops and lines patterned on a substrate.
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Fabrication of nanoscale nozzle for electrostatic field induced inkjet head and test of drop-On-Demand Operation
2008Co-Authors: Vu Dat Nguyen, Doyoung Byun, Si Bui, Quang Tran, Michael G. Schrlau, Haim H. Bau, Jaeyong Choi, Sukhan LeeAbstract:This paper presents the fabrication of microscale to nanoscale nozzle and patterning by means of electrostatic field induced drop-On-Demand inkjet printing system. Typically using the nanoscale nozzle we could eject nanoscale droplets and show feasibility to form patterns ranging from micro scale to nano scale on large area substrates at high speed.
Daniele Zaccaria - One of the best experts on this subject based on the ideXlab platform.
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Simulation of peak-demand hydrographs in pressurized irrigation delivery systems using a deterministic–stochastic combined model. Part I: model development
Irrigation Science, 2013Co-Authors: Daniele Zaccaria, Nicola Lamaddalena, Christopher M. U. Neale, Gary P. Merkley, Nicola Palmisano, Giuseppe PassarellaAbstract:This study describes a model named HydroGEN that was conceived for simulating hydrographs of daily volumes and hourly flow rates during peak-demand periods in pressurized irrigation delivery networks with On-Demand Operation. The model is based on a methodology consisting of deterministic and stochastic components and is composed of a set of input parameters to reproduce the crop irrigation management practices followed by farmers and of computational procedures enabling to simulate the soil water balance and the irrigation events for all cropped fields supplied by each delivery hydrant in a distribution network. The input data include values of weather, crop, and soil parameters, as well as information on irrigation practices followed by local farmers. The resulting model outputs are generated flow hydrographs during the peak-demand period, which allow the subsequent analysis of performance achievable under different delivery scenarios. The model can be applied either for system design or re-design, as well as for analysis of Operation and evaluation of performance achievements of On-Demand pressurized irrigation delivery networks. Results from application of HydroGEN to a real pressurized irrigation system at different scales are presented in a companion paper (Part II: model applications).
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simulation of peak demand hydrographs in pressurized irrigation delivery systems using a deterministic stochastic combined model part i model development
Irrigation Science, 2013Co-Authors: Daniele Zaccaria, Nicola Lamaddalena, Christopher M. U. Neale, Gary P. Merkley, Nicola Palmisano, Giuseppe PassarellaAbstract:This study describes a model named HydroGEN that was conceived for simulating hydrographs of daily volumes and hourly flow rates during peak-demand periods in pressurized irrigation delivery networks with On-Demand Operation. The model is based on a methodology consisting of deterministic and stochastic components and is composed of a set of input parameters to reproduce the crop irrigation management practices followed by farmers and of computational procedures enabling to simulate the soil water balance and the irrigation events for all cropped fields supplied by each delivery hydrant in a distribution network. The input data include values of weather, crop, and soil parameters, as well as information on irrigation practices followed by local farmers. The resulting model outputs are generated flow hydrographs during the peak-demand period, which allow the subsequent analysis of performance achievable under different delivery scenarios. The model can be applied either for system design or re-design, as well as for analysis of Operation and evaluation of performance achievements of On-Demand pressurized irrigation delivery networks. Results from application of HydroGEN to a real pressurized irrigation system at different scales are presented in a companion paper (Part II: model applications).
S Marco - One of the best experts on this subject based on the ideXlab platform.
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low power Operation of temperature modulated metal oxide semiconductor gas sensors
Sensors, 2018Co-Authors: Javier Burgues, S MarcoAbstract:Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX) gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device Operation. This work benchmarks two low-power, duty-cycling, and On-Demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-Demand Operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA) sensors were exposed to low concentrations of carbon monoxide (0–9 ppm) with environmental conditions, such as ambient humidity (15–75% relative humidity) and temperature (21–27 °C), varying within the indicated ranges. Partial Least Squares (PLS) models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that On-Demand Operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous Operation (2.2 versus 0.45 ppm). Applying a 10% duty-cycling Operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm). The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate slightly higher prediction errors.
J. A. Rodríguez Díaz - One of the best experts on this subject based on the ideXlab platform.
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Optimal Design of Pressurized Irrigation Networks to Minimize the Operational Cost under Different Management Scenarios
Water Resources Management, 2017Co-Authors: I. Fernández García, P. Montesinos, E. Camacho Poyato, J. A. Rodríguez DíazAbstract:The adoption of measures leading to higher efficiencies in the use of both water and energy in water distribution networks is strongly demanded. The methodology proposed combines a multi-objective approach and a financial analysis to determine de optimal design of pressurized irrigation networks which entails the minimization of both the investment cost and Operational cost under three operating scenarios that incorporate energy saving strategies: 1- all hydrants operate simultaneously; 2- hydrants are grouped into sectors and irrigation turns are established; 3- the On-Demand Operation of the network is assumed. This methodology has been applied in a real irrigation network located in Southern Spain showing that the lowest overall design cost (investment and Operational costs) is achieved in scenario 2. The comparison of the selected solutions in the three proposed scenarios with the current network design considering the total fulfillment of irrigation requirements showed that Operational cost savings between 65% and 76% could be achieved.
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Rehabilitating pressurized irrigation networks for an increased energy efficiency
Agricultural Water Management, 2016Co-Authors: I. Fernández García, Enrico Creaco, J. A. Rodríguez Díaz, P. Montesinos, E. Camacho Poyato, Dragan SavicAbstract:This paper presents a methodology aimed at assisting irrigation district managers in the optimal rehabilitation of pressurized irrigation networks. The methodology uses a multi-objective approach and finds optimal trade-off between investments and long term Operational costs. The approach is based on two steps: 1—application of two alternative optimization algorithms to determine optimal trade-offs between installation costs and pump power absorption; 2—post-processing of the optimal solutions in terms of long term costs under various possible scenarios generated featuring various values of the useful construction life and of the capital recovery factor. Applications were carried out on a real case study, considering a pre-fixed electricity tariff and the On-Demand Operation of the network.
