Open Access. Powered by Scholars. Published by Universities.®
Social and Behavioral Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 27 of 27
Full-Text Articles in Social and Behavioral Sciences
Velocity Contour Weighting Method. Ii: Evaluation In Trapezoidal Channels And Roughness Sensitivity, Daniel Howes, Brett F. Sanders
Velocity Contour Weighting Method. Ii: Evaluation In Trapezoidal Channels And Roughness Sensitivity, Daniel Howes, Brett F. Sanders
BioResource and Agricultural Engineering
The Velocity Contour Weighting Method (VCWM) was developed in Part I to accurately estimate the cross-sectional average velocity of a prismatic channel flow using acoustic Doppler velocity meter (ADVM) measurements of centerline velocity. Here, the VCWM is validated by its successful application to 25 different concrete-lined trapezoidal channels used for irrigation water delivery. At each site, the cross-sectional distribution of velocity is measured by an acoustic Doppler velocimeter (ADV), which is moved horizontally and vertically through a sampling grid. Multiple tests at some sites led to a total of 51 sets of cross-sectional measurements. ADVM measurements are simulated by interpolating …
Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders
Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders
BioResource and Agricultural Engineering
An algorithm is developed for real-time estimation of the cross-sectional average velocity of a channel flow by using an upward-looking pulsed wave acoustic Doppler velocity meters (ADVM). The Velocity Contour Weighting Method (VCWM) is applicable to gradually varied flows in prismatic channels and requires little to no calibration. VCWM estimates the average velocity as a weighted average of ADVM bin velocities. Weights are based on the velocity distribution sampled by the ADVM. Collectively, the VCWM is able to adapt to a wide range of channel geometry and roughness features. Expressions for the velocity weights are developed by first applying a …
Subcritical Contraction For Improved Open-Channel Flow Measurement Accuracy With An Upward-Looking Advm, Daniel Howes, Charles M. Burt, Brett F. Sanders
Subcritical Contraction For Improved Open-Channel Flow Measurement Accuracy With An Upward-Looking Advm, Daniel Howes, Charles M. Burt, Brett F. Sanders
BioResource and Agricultural Engineering
Acoustic Doppler velocity meters (ADVMs) provide an alternative to more traditional flow measurement devices and procedures such as flumes, weirs, and stage rating for irrigation and drainage canals. However, the requirements for correct calibration are extensive and complex. A three-dimensional computational fluid dynamics (CFD) model was used to design a subcritical rapidly varied flow contraction that provides a consistent linear relationship between the upward-looking ADVM sample velocity and the cross-sectional average velocity in order to improve ADVM accuracy without the need for in situ calibration. CFD simulations validated the subcritical contraction in a rectangular and trapezoidal cross section by showing …
Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure - Qip, Stuart W. Styles, Bryan Busch, Daniel J. Howes, Marcus Cardenas
Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure - Qip, Stuart W. Styles, Bryan Busch, Daniel J. Howes, Marcus Cardenas
BioResource and Agricultural Engineering
This report details the proper installation and calibration techniques for hydroacoustic meters. The calibration procedure developed as part of this study is called the Flow Rate Indexing Procedure (QIP). The QIP can be competed by a professional technician with a boat-mounted Acoustic Doppler Profiler (ADP) or a standard current meter. Once the QIP has been used to properly calibrate a hydroacoustic flow meter, the device can then measure and record the flow rate and volume in a channel to within +/- 6% of actual values.
California Agricultural Water Electrical Energy Requirements, Charles M. Burt, Daniel J. Howes, Gary Wilson
California Agricultural Water Electrical Energy Requirements, Charles M. Burt, Daniel J. Howes, Gary Wilson
BioResource and Agricultural Engineering
The Irrigation Training and Research Center, working under agreement with the California Energy Commission as part of its Public Interest Energy Research Program, conducted an analysis of the energy used to supply water to California's agriculture and examined potential future trends in the agriculture water community to predict future energy requirements.
Benchmarking Of Flexibility And Needs 2002: Survey Of Non-Federal Irrigation Districts (California Department Of Water Resources), Stuart W. Styles, Daniel Howes
Benchmarking Of Flexibility And Needs 2002: Survey Of Non-Federal Irrigation Districts (California Department Of Water Resources), Stuart W. Styles, Daniel Howes
BioResource and Agricultural Engineering
ITRC interviewed irrigation district personnel from 17 agricultural districts throughout California. Data were analyzed to determine the degree of water delivery flexibility provided to farmers and the extent of existing and planned district modernization. This report did not include irrigation districts with long-term federal contracts.
Evaporation From Irrigated Agricultural Land In California, Charles M. Burt, Andrew Mutziger, Daniel Howes, Kenneth H. Solomon
Evaporation From Irrigated Agricultural Land In California, Charles M. Burt, Andrew Mutziger, Daniel Howes, Kenneth H. Solomon
BioResource and Agricultural Engineering
No abstract provided.
Evaporation Estimates For Irrigated Agriculture In California, Charles M. Burt, Daniel J. Howes, Andrew Mutziger
Evaporation Estimates For Irrigated Agriculture In California, Charles M. Burt, Daniel J. Howes, Andrew Mutziger
BioResource and Agricultural Engineering
All California irrigation districts that receive either federal or state water are now required to prepare Water Conservation Plans. For the first time in the history of most districts, they are developing an elementary water balance. The term "elementary" should be emphasized, because there are significant weaknesses in our knowledge of subsurface flows and some components of Evapotranspiration (ET). Irrigation districts generally use published "typical" values of ET for their water balance computations.
Water Balance-Related Performance Indicators For International Projects, Charles M. Burt, Stuart W. Styles
Water Balance-Related Performance Indicators For International Projects, Charles M. Burt, Stuart W. Styles
BioResource and Agricultural Engineering
A unique study to examine the impacts of irrigation project modernization was funded by the Research Committee of the World Bank and managed by the International Program for Technology Research in Irrigation and Drainage (IPTRID). The project examined 16 irrigation projects in 10 developing countries, 15 of which have been partially modernized in some aspects of hardware and/or management. Besides developing specific recommendations for donor agencies interested in irrigation project modernization, this project also accomplished the following: 1. A Rapid Appraisal Process (RAP) was developed to quickly (within a week) evaluate an irrigation project to assess what type of modernization …
Evaluation Of Subsurface Drip Irrigation On Peppers, Stuart W. Styles, Charles M. Burt
Evaluation Of Subsurface Drip Irrigation On Peppers, Stuart W. Styles, Charles M. Burt
BioResource and Agricultural Engineering
This paper is a summary of two farms that utilized the California Energy Commission's low-interest loan program to facilitate their entry into drip irrigation. One farm is located near Oxnard, California, USA and the other is located near Gilroy, California, USA. Both of these growers farm about 162 hectares (400 acres) in their overall operations and used the loans to purchase subsurface drip irrigation systems for Peppers. Over $4 million in low-interest loans have been made available to California growers from the California Energy Commission (CEC) since 1986. The CEC initiated the loan program for growers to help implement energy …
Improving Water Properties To Increase Infiltration Characteristics, Richard W. O. Soppe, Stuart W. Styles
Improving Water Properties To Increase Infiltration Characteristics, Richard W. O. Soppe, Stuart W. Styles
BioResource and Agricultural Engineering
Water properties, such as the viscosity and surface tension, can be affected by temperature and surfactants to Increase infiltration rates into soils. Specifically, they will change the hydraulic conductivity of the soil. A simple soap solution and the new material PAM (inexpensive polymer chemical) were evaluated as surfactants. Laboratory experiments and field tests on a site in Davis, California were done to quantify the effects of changing the water properties. Additional effects, like the improved soil structure during infiltration and less soil particles in tailwater (reduced erosion due to runoff) were observed and are described in this paper. The conclusions …
Drip Irrigation Technology: A Resource Management Tool For Farmers, John C. Roberts, Stuart W. Styles
Drip Irrigation Technology: A Resource Management Tool For Farmers, John C. Roberts, Stuart W. Styles
BioResource and Agricultural Engineering
No abstract provided.
Sizing Of Header And Flushing Manifolds For Row Crop Drip, Charles M. Burt, Stuart W. Styles
Sizing Of Header And Flushing Manifolds For Row Crop Drip, Charles M. Burt, Stuart W. Styles
BioResource and Agricultural Engineering
No abstract provided.
Incorporation Of Reservoirs Into Irrigation Supply Systems To Simplify Flexible Operations, John L. Merriam, Stuart W. Styles
Incorporation Of Reservoirs Into Irrigation Supply Systems To Simplify Flexible Operations, John L. Merriam, Stuart W. Styles
BioResource and Agricultural Engineering
No abstract provided.
Grassland Basin Irrigation And Drainage Study, Stuart W. Styles, Dennis Westcot, Dr. Charles M. Burt, Ross Steensen
Grassland Basin Irrigation And Drainage Study, Stuart W. Styles, Dennis Westcot, Dr. Charles M. Burt, Ross Steensen
BioResource and Agricultural Engineering
This paper summarizes a project that analyzed the district irrigation efficiency for six subareas of the Grassland Basin roughly representing 80,000 acres on the west side of the San Joaquin Valley near Firebaugh, California. The objectives of this project were to: • Determine the district irrigation efficiency for the six subareas. • Update district drainage policies and water reuse. • Update the geographical information system (GIS). • Perform a pre-plant irrigation efficiency analysis. • Establish a relationship between the drainage volumes and the district irrigation efficiency. • Determine the maximum district irrigation efficiency attainable. • Determine the impact of optimizing …
Evaluating Strength & Energy Requirements For Workers Picking Vegetables, R. A. Cavaletto, J. Miles, J. Meyers, J. Mehlschau
Evaluating Strength & Energy Requirements For Workers Picking Vegetables, R. A. Cavaletto, J. Miles, J. Meyers, J. Mehlschau
BioResource and Agricultural Engineering
The paper discusses the need to obtain field data to evaluate the strength and energy requirements for workers picking a variety of vegetables. This information is central to the evaluation of hazards related to repetitive motion, excessive stress, and fatigue. Results can be used to select activities which should be targeted for future engineering design projects. Preliminary data from a commercial broccoli harvesting operation is included.
Irrigation Methods For Drainage Reduction Subsurface Drip Vs. Furrow Irrigation, J.. D. Oster, R. B. Smith, C. Phene, A. Fulton, S. W. Styles, T. Fernandes
Irrigation Methods For Drainage Reduction Subsurface Drip Vs. Furrow Irrigation, J.. D. Oster, R. B. Smith, C. Phene, A. Fulton, S. W. Styles, T. Fernandes
BioResource and Agricultural Engineering
No abstract provided.
Broad-Crested Weir Application On 15,000-Acre Farm, Stuart W. Styles
Broad-Crested Weir Application On 15,000-Acre Farm, Stuart W. Styles
BioResource and Agricultural Engineering
Growers in California have been subjected to increasing pressure to account for water used on the farm due to limited water supplies and increasing energy costs. Water measurement capability provides for equitable distribution of assigned costs and enables effective water management to be accomplished. Broad-crested weirs are proven water measurement devices, especially when applied to on-farm applications. The broad-crested weirs and published data were developed by the USDA Agricultural Research Service in Phoenix, Arizona. This paper is a discussion of an application of these weirs.
Tailwater Recovery Demonstration Program Study, Doug Welch, Tim O'Halloran, Stuart Styles
Tailwater Recovery Demonstration Program Study, Doug Welch, Tim O'Halloran, Stuart Styles
BioResource and Agricultural Engineering
No abstract provided.
Spray Drift Reduction With Shrouded Boom Sprayers, Ronald J. Fehringer, Richard Cavaletto
Spray Drift Reduction With Shrouded Boom Sprayers, Ronald J. Fehringer, Richard Cavaletto
BioResource and Agricultural Engineering
Downwind drift was measured from a standard boom sprayer and a shrouded boom sprayer. Using 8002 flat fan nozzles, the hooded sprayer provided a 180 to 275% reduction in drift. The effectiveness of the shroud is dependent upon the spray droplet spectrum.
Water Seepage From Unlined Ditches And Reservoirs, Nigel W.T. Quinn, Richard B. Smith, Charles M. Burt, Tracy S. Slavin, Stuart W. Styles, Amir Mansoubi
Water Seepage From Unlined Ditches And Reservoirs, Nigel W.T. Quinn, Richard B. Smith, Charles M. Burt, Tracy S. Slavin, Stuart W. Styles, Amir Mansoubi
BioResource and Agricultural Engineering
Seepage losses in the San Joaquin Valley's Westlands Water Districts were estimated at 27,000 acre-feet a year, or about 2% of the district's water supply. Ditch configuration and construction techniques appear to influence seepage rates.
Guarding Against Machine Hazards, R. A. Cavaletto
Guarding Against Machine Hazards, R. A. Cavaletto
BioResource and Agricultural Engineering
Successful guarding strategies requires knowledge of machine functions, the physical and psychological characteristics of man, and the their interactions. Machine hazards are identified along with recognized guarding methods. Material is included that could be used to teach this subject (case study, prob!em set, glossary}.
Evaluation Of Two Models For Light Transmission In Biological Materials, R. A. Cavaletto, S. Upadhyaya, M. O'Brien, T. Cahill
Evaluation Of Two Models For Light Transmission In Biological Materials, R. A. Cavaletto, S. Upadhyaya, M. O'Brien, T. Cahill
BioResource and Agricultural Engineering
Two light transmission models for biological materials are developed and evaluated. The energy balance model showed promise. It's developed as a 3 coefficient model permitting varied sample absorption and scattering properties. The second model performed unsatisfactorily.
Evaluation Of Micro Irrigation Systems, Charles M. Burt, Robert E. Walker, Stuart W. Styles
Evaluation Of Micro Irrigation Systems, Charles M. Burt, Robert E. Walker, Stuart W. Styles
BioResource and Agricultural Engineering
No abstract provided.
A Light Transmission Model For Biological Materials, R. A. Cavaletto, Shrinivasa Upadhyaya, Michael O'Brien
A Light Transmission Model For Biological Materials, R. A. Cavaletto, Shrinivasa Upadhyaya, Michael O'Brien
BioResource and Agricultural Engineering
This paper describes a model to predict light transmission in biological materials. The model can be used for any shaped sample. Scattering and absorption coefficients are used in the model and may be varied throughout the sample, thus allowing both uniformly distributed and concentrated defects to be modelled.
Guarding Of Table Saws With Light Beams: The Light Guard Concept, R. A. Cavaletto, M. S. Kaminaka, C. M. Zahner
Guarding Of Table Saws With Light Beams: The Light Guard Concept, R. A. Cavaletto, M. S. Kaminaka, C. M. Zahner
BioResource and Agricultural Engineering
This paper describes a unique type of psychological safety guard for hazardous tools such as table saws, presses. and other tools with areas and components which are dangerous to human fingers, hands, and limbs. It is not a piece of hardware but rather a shalt of light which defines a danger zone around the saw blade or cutting area.
Method For Stemming Tomatoes, Henry F. Studer, R. A. Cavaletto, Gene Giacomelli
Method For Stemming Tomatoes, Henry F. Studer, R. A. Cavaletto, Gene Giacomelli
BioResource and Agricultural Engineering
Method and apparatus for de-stemming picked tomatoes. Each tomato is introduced into the upper end of a generally vertically disposed, open-ended, resilient, open-mesh fabric tube, a substantial portion of which approximates but is larger than the diameter of the tomato. The stem penetrates into and through the open mesh at some point, the open areas being somewhat larger than the stem, while the tomato continues to fall, thereby exerting a bending moment on the stem that snaps the stem from the fruit. The tomato, free from its stem, is discharged from a lower end of the tube.