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Full-Text Articles in Engineering

Hypro: A Financial Tool For Simulating Hydrogen Infrastructure Development, Brian D. James, Peter O. Schmidt, Julie Perez Dec 2008

Hypro: A Financial Tool For Simulating Hydrogen Infrastructure Development, Brian D. James, Peter O. Schmidt, Julie Perez

US Department of Energy Publications

This report summarizes an analysis of the options and trade-offs for the establishment of the hydrogen production infrastructure necessary for a complete transition to hydrogen fuel cell vehicles by the year 2050. The primary tool used for the analysis is a custom created MatLab simulation tool entitled HyPro (short for Hydrogen Production). This report describes both the calculation methodology of HyPro and the assumptions and results of the baseline analysis and its many corollary cases. This study was made possible with funding from the U.S. Department of Energy (DOE).
The report and supporting primary analyses were overseen by Fred Joseck …


Geothermal (Ground-Source) Heat Pumps: Market Status, Barriers To Adoption, And Actions To Overcome Barriers, Patrick J. Hughes Dec 2008

Geothermal (Ground-Source) Heat Pumps: Market Status, Barriers To Adoption, And Actions To Overcome Barriers, Patrick J. Hughes

US Department of Energy Publications

More effective stewardship of our resources contributes to the security, environmental sustainability, and economic well-being of the nation. Buildings present one of the best opportunities to economically reduce energy consumption and limit greenhouse gas emissions. Geothermal heat pumps (GHPs), sometimes called ground-source heat pumps, have been proven capable of producing large reductions in energy use and peak demand in buildings. However, GHPs have received little attention at the policy level as an important component of a national strategy. Have policymakers mistakenly overlooked GHPs, or are GHPs simply unable to make a major contribution to the national goals for various reasons? …


Canal Seepage Reduction By Soil Compaction, Charles M. Burt, Marcus Gardenas, Mohamed Grissa Nov 2008

Canal Seepage Reduction By Soil Compaction, Charles M. Burt, Marcus Gardenas, Mohamed Grissa

BioResource and Agricultural Engineering

Large-scale tests were conducted of in-place compaction of irrigation district earthen canal bottoms and sides. Five canal pools with sandy loam soils were compacted. Seepage reduction of about 86% was obtained when the sides and bottoms were compacted; reductions of 12 – 31% were obtained when only sides were compacted.


Improving Pump Performance, Charles M. Burt, Frankline Gaudi, Daniel J. Howes Nov 2008

Improving Pump Performance, Charles M. Burt, Frankline Gaudi, Daniel J. Howes

BioResource and Agricultural Engineering

Options can be specified to minimize power consumption by vertical pumps – both when new and over the life of the pump. Options discussed include bowl coatings, proper well development, improved suction screens, using closed impeller designs, increasing column size, using new bearings, providing proper bearing lubrication, impeller balancing, and polishing impellers. The proper TDH and flow rate must be specified, and the advantages of VFD controls are covered.


Economic Development Benefits From Wind Power In Nebraska: A Report For The Nebraska Energy Office, E. Lantz Nov 2008

Economic Development Benefits From Wind Power In Nebraska: A Report For The Nebraska Energy Office, E. Lantz

US Department of Energy Publications

Wind power constituted more than 35% of new U.S. electric generating capacity in 2007. Common drivers of wind power include Renewable Portfolio Standards (RPS), the federal production tax credit (PTC), and rural economic development benefits. Continued expansion of the wind industry into Nebraska would bring new employment and economic development to Nebraska and the country. This report by the National Renewable Energy Laboratory (NREL) focuses on the economic development impacts that would result in Nebraska from development and operation of wind power in the state as envisioned in the U.S. Department of Energy’s (DOE’s) report 20% Wind Energy by 2030 …


An Analysis Of The Technical And Economic Potential For Mid-Scale Distributed Wind, K. Granfield, A. Kagel, A. Appleton Oct 2008

An Analysis Of The Technical And Economic Potential For Mid-Scale Distributed Wind, K. Granfield, A. Kagel, A. Appleton

US Department of Energy Publications

This report examines the status, restrainers, drivers, and estimated development potential of mid-scale (10 kW to 5000 kW) distributed wind projects. This segment of the wind market has not enjoyed the same growth that central-station wind has experienced. The purpose of this report is to analyze why, and to assess the market potential for this technology under current market and policy conditions.

As discussed in section 2, one of the most significant barriers to the development of distributed wind is a general scarcity of turbine choices and turbine inventory available for purchase. Most turbine manufacturers have scaled back their involvement …


Agricultural Water Conservation And Efficiency In California - A Commentary, Charles M. Burt, Peter Canessa, Lawrence J. Schwankl, David F. Zoldoske Oct 2008

Agricultural Water Conservation And Efficiency In California - A Commentary, Charles M. Burt, Peter Canessa, Lawrence J. Schwankl, David F. Zoldoske

BioResource and Agricultural Engineering

This is a Commentary on some of the key points that are presented in “More with Less: Agricultural Water Conservation and Efficiency in California” by Cooley, ChristianSmith, and Gleick of the Pacific Institute, September 2008 (referred to as the “PacInst Paper” in the remainder of this discussion).

The authors of this Commentary have over 120 years combined of experience in agricultural and landscape irrigation. They have worked world-wide in design and installation of all types of irrigation systems (including automated drip systems from 1975 on), design and implementation of irrigation scheduling programs since 1977; design and implementation of water conservation …


Avoiding Common Problems With Drip Tape, Charles M. Burt Sep 2008

Avoiding Common Problems With Drip Tape, Charles M. Burt

BioResource and Agricultural Engineering

This publication is meant to help farmers, dealers, and manufacturers recognize and understand some of the problems that have been experienced with drip tape – problems that are quite different from manufacturing defects. Problems that are quickly detected and properly identified can often be remedied, or be avoided in the future. The report addresses drip tape damage caused by pests, installation, emitter pressure, plugging, and other categories.


Exploring Potential U.S. Switchgrass Production For Lignocellulosic Ethanol, Ethan B. Davis, Henriette I. Jager, Tristram O. West, Robert D. Perlack, Craig C. Brandt, Stan D. Wullschleger, Latha M. Baskaran, Erin G. Wilkerson, Mark E. Downing, Carla A. Gunderson Aug 2008

Exploring Potential U.S. Switchgrass Production For Lignocellulosic Ethanol, Ethan B. Davis, Henriette I. Jager, Tristram O. West, Robert D. Perlack, Craig C. Brandt, Stan D. Wullschleger, Latha M. Baskaran, Erin G. Wilkerson, Mark E. Downing, Carla A. Gunderson

US Department of Energy Publications

In response to concerns about oil dependency and the contributions of fossil fuel use to climatic change, the U.S. Department of Energy has begun a research initiative to make 20% of motor fuels biofuel based in 10 years, and make 30% of fuels bio-based by 2030. Fundamental to this objective is developing an understanding of feedstock dynamics of crops suitable for cellulosic ethanol production. This report focuses on switchgrass, reviewing the existing literature from field trials across the United States, and compiling it for the first time into a single database. Data available from the literature included cultivar and crop …


Technical Concepts Related To Conservation Of Irrigation And Rain Water In Agricultural Systems, A. J. Clemmens, R. G. Allen, Charles M. Burt Jul 2008

Technical Concepts Related To Conservation Of Irrigation And Rain Water In Agricultural Systems, A. J. Clemmens, R. G. Allen, Charles M. Burt

BioResource and Agricultural Engineering

Forty percent of freshwater withdrawals in the United States are for irrigated agriculture, which contribute more than $50 billion to the economy. Increasing diversions of water for urban, environmental, and other uses will likely decrease water available to agriculture. Water conservation in agriculture is touted as a good method for minimizing the impact of reduced agricultural diversions on production. Because “wasted” water is often reused until it reaches the ocean, there are limitations to the true water savings that result from programs that aim to increase irrigation efficiency. True water savings can come from four areas: reduction of unnecessary evaporation …


Facilitating Use Of The Odor Footprint Tool By Nebraska Pork Producers, Rick R. Stowell Jul 2008

Facilitating Use Of The Odor Footprint Tool By Nebraska Pork Producers, Rick R. Stowell

Biological Systems Engineering: Papers and Publications

The goal of this project was to make Odor Footprint Tool (OFT) resources readily usable by pork producers and their technical advisors as a planning and screening tool when siting swine facilities. Detailed odor footprints for five specified sizes of swine facilities were developed for twenty-four locations throughout Nebraska: six regional sites and three “localized” sites within each region. Each odor footprint shows the predicted odor annoyance-free frequency as a function of the distance from the facility. Footprints developed using localized weather data differed only slightly from footprints produced using weather data from a regional site when the general topography …


Climate Models: An Assessment Of Strengths And Limitations, David Bader, Curt Covey, William Gutowski, Isaac Held, Kenneth Kunkel, Ronald Miller, Robin Tokmakian, Minghua Zhang Jul 2008

Climate Models: An Assessment Of Strengths And Limitations, David Bader, Curt Covey, William Gutowski, Isaac Held, Kenneth Kunkel, Ronald Miller, Robin Tokmakian, Minghua Zhang

US Department of Energy Publications

Scientists extensively use mathematical models of Earth’s climate, executed on the most powerful computers available, to examine hypotheses about past and present-day climates. Development of climate models is fully consistent with approaches being taken in many other fields of science dealing with very complex systems. These climate simulations provide a framework within which enhanced understanding of climate-relevant processes, along with improved observations, are merged into coherent projections of future climate change. This report describes the models and their ability to simulate current climate.
The science of climate modeling has matured through finer spatial resolution, the inclusion of a greater number …


Conversion To Groundwater Pumping With Drip/Micro Irrigation Systems, Charles M. Burt, Monte Soto Jun 2008

Conversion To Groundwater Pumping With Drip/Micro Irrigation Systems, Charles M. Burt, Monte Soto

BioResource and Agricultural Engineering

Twenty one irrigation districts in the Central Valley reported “conversion acres”. Conversion acres are those on which farmers used only groundwater for drip/micro irrigation although surface irrigation water was available.

The twenty one districts include about 2 million acres of irrigated area. Approximately 3.6% of that acreage (73,000 acres) has been “converted” to groundwater when farmers switched to drip/micro. Fourteen of these districts anticipate more conversion in the future. ITRC thinks that the conversion will be more rapid and greater than district personnel suspect.

The dominant factor that influences the conversion was the lack of flexible water delivery service to …


Accuracy Of Global Microirrigation Distribution Uniformity Estimates, Stuart W. Styles, Charles M. Burt, Franklin Gaudi, Sierra Layous Jun 2008

Accuracy Of Global Microirrigation Distribution Uniformity Estimates, Stuart W. Styles, Charles M. Burt, Franklin Gaudi, Sierra Layous

BioResource and Agricultural Engineering

Emitter pressures and flow rates were systematically and extensively sampled in one drip and one microspray field. The data distributions are presented. The accuracy of rapid (limited samples) evaluation pressure sampling procedures was found to be quite good if the pressure distribution was systematic, but erroneous if the pressure distribution throughout a field was random. A simple mathematical combination of two nonuniformity components (due to pressure differences, and other causes of flow variation) provided a better estimate of overall system distribution uniformity than more complex mathematics.


Automatic Guidance System Development Using Low Cost Ranging Devices, Santosh Pitla, Joe D. Luck, Scott A. Shearer Jun 2008

Automatic Guidance System Development Using Low Cost Ranging Devices, Santosh Pitla, Joe D. Luck, Scott A. Shearer

Department of Biological Systems Engineering: Conference Presentations and White Papers

Autonomous guidance of agricultural vehicles for various field operations serves to increase productivity. Low cost infra-red ranging devices were used in this study to estimate the guidance directrix (offset distance (d) and heading error angle (Ø)). Two kinds of tracks were used for evaluating the performance of the infra-red sensors, one track was made of a cardboard in the laboratory and the other track was made of wheat crop in the field. The cardboard track consisted of straight parallel and non parallel edges whereas the wheat crop track had a series of different edges including few curves. From the results …


Sensor Ranging Technique For Determining Corn Plant Population, Joe D. Luck, Santosh Pitla, Scott A. Shearer Jun 2008

Sensor Ranging Technique For Determining Corn Plant Population, Joe D. Luck, Santosh Pitla, Scott A. Shearer

Department of Biological Systems Engineering: Conference Presentations and White Papers

Mapping of corn plant population can provide useful information for making field management decisions. This research focused on using low cost infra-red sensors to count plants. The voltage output data from the sensors were processed using an algorithm developed to extract plant populations. Preliminary investigations were conducted using sensors mounted on a stationary track for laboratory testing and on a row crop tractor for field testing. Repeated measurements were taken on a manually counted corn row. Visual inspection of the data from the field test indicated the potential to identify corn stalks based on approximate physical widths of the stalks. …


Genome Sequencing And Analysis Of The Biomass-Degrading Fungus Trichoderma Reesei (Syn. Hypocrea Jecorina), Diego Martinez, Randy M. Berka, Bernard Henrissat, Markku Saloheimo, Mikko Arvas, Scott E. Baker, Jarod Chapman, Olga Chertkov, Pedro M. Coutinho, Dan Cullen, Etienne G. J. Danchin, Igor V. Grigoriev, Paul Harris, Melissa Jackson, Christian P. Kubicek, Cliff S. Han, Isaac Ho, Luis F. Larrondo, Alfredo Lopez De Leon, Jon K. Magnuson, Sandy Merino, Monica Misra, Beth Nelson, Nicholas Putnam, Barbara Robbertse, Asaf A. Salamov, Monika Schmoll, Astrid Terry, Nina Thayer, Ann Westerholm-Parvinen, Conrad L. Schoch, Jian Yao, Ravi Barabote, Mary Anne Nelson, Chris Detter, David Bruce, Cheryl R. Kuske, Gary Xie, Paul Richardson, Daniel S. Rokhsar, Susan M. Lucas, Edward M. Rubin, Nigel Dunn-Coleman, Michael Ward, Thomas Brettin May 2008

Genome Sequencing And Analysis Of The Biomass-Degrading Fungus Trichoderma Reesei (Syn. Hypocrea Jecorina), Diego Martinez, Randy M. Berka, Bernard Henrissat, Markku Saloheimo, Mikko Arvas, Scott E. Baker, Jarod Chapman, Olga Chertkov, Pedro M. Coutinho, Dan Cullen, Etienne G. J. Danchin, Igor V. Grigoriev, Paul Harris, Melissa Jackson, Christian P. Kubicek, Cliff S. Han, Isaac Ho, Luis F. Larrondo, Alfredo Lopez De Leon, Jon K. Magnuson, Sandy Merino, Monica Misra, Beth Nelson, Nicholas Putnam, Barbara Robbertse, Asaf A. Salamov, Monika Schmoll, Astrid Terry, Nina Thayer, Ann Westerholm-Parvinen, Conrad L. Schoch, Jian Yao, Ravi Barabote, Mary Anne Nelson, Chris Detter, David Bruce, Cheryl R. Kuske, Gary Xie, Paul Richardson, Daniel S. Rokhsar, Susan M. Lucas, Edward M. Rubin, Nigel Dunn-Coleman, Michael Ward, Thomas Brettin

US Department of Energy Publications

Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to depolymerize biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. We assembled 89 scaffolds (sets of ordered and oriented contigs) to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models. Unexpectedly, considering the industrial utility and effectiveness of the carbohydrate-active enzymes of T. reesei, its genome encodes fewer cellulases and hemicellulases than any other sequenced fungus able to hydrolyze plant cell wall polysaccharides. Many T. reesei genes encoding carbohydrate-active enzymes are distributed nonrandomly in …


Implementing Mass Nutrient Balance Procedures On Swine Production Facilities, Richard Koelsch, Alan Sutton Apr 2008

Implementing Mass Nutrient Balance Procedures On Swine Production Facilities, Richard Koelsch, Alan Sutton

Biological Systems Engineering: Papers and Publications

Whole Farm Nutrient Balance (WFNB) approaches have been used to provide a measure of environmental performance (Aarts et al., 1992; Lanyon and Beegle, 1993; Klausner, 1995). Whole farm balance concepts are used as part of the Netherlands Mineral Accounting System public policy that includes compulsory mineral input and output reports from livestock farms and levies for excess imbalances (Jongbloed and Lenis, 1998). Procedures for measuring WFNB will be followed in measurements made on commercial swine facilities for 2006 and 2007. The conclusions developed based upon data from 13 for 2006 include:

  • On average, the participating swine producers import 1.5 units …


Electric Motor Efficiency Under Variable Frequencies And Loads, Charles M. Burt, Xianshu Piao, Franklin Gaudi, Bryan Busch, N. F. N. Taufik Mar 2008

Electric Motor Efficiency Under Variable Frequencies And Loads, Charles M. Burt, Xianshu Piao, Franklin Gaudi, Bryan Busch, N. F. N. Taufik

BioResource and Agricultural Engineering

This paper details a study performed by the Irrigation Training and Research Center to determine motor performances under varying speeds [induced by a variable frequency drives (VFD) controller] and loads. A further goal of the study was to provide sufficient information to designers so that they could estimate total pumping plant power usage with a VFD-controlled installation. Motors were tested with a VFD as well as across-the-line. On average, the relative efficiency of the electrical system with a VFD may be approximately 8% lower than the relative efficiency of a properly designed, full-load across-the-line system. If one considers actual field …


The Genome Of Laccaria Bicolor Provides Insights Into Mycorrhizal Symbiosis, F. Martin, A. Aerts, D. Ahren, A. Brun, E. G. J. Danchin, F. Duchaussoy, J. Gibon, A. Kohler, E. Lindquist, V. Pereda, A. Salamov, H. J. Shapiro, J. Wuyts, D. Blaudez, M. Buee, P. Brokstein, B. Canback, D. Cohen, P. E. Courty, P. M. Coutinho, C. Delaruelle, J. C. Detter, A. Deveau, S. Difazio, S. Duplessis, L. Fraissinet-Tachet, E. Lucic, P. Frey-Klett, C. Fourrey, I. Feussner, G. Gay, J. Grimwood, P. J. Hoegger, P. Jain, S. Kilaru, J. Labbe, Y. C. Lin, V. Legue, F. Le Tacon, R. Marmeisse, D. Melayah, B. Montanini, M. Muratet, U. Nehls, H. Niculita-Hirzel, M. P. Oudot-Le Secq, M. Peter, H. Quesneville, B. Rajashekar, M. Reich, N. Rouhier, J. Schmutz, T. Yin, M. Chalot, B. Henrissat, U. Kues, S. Lucas, Y. Van De Peer, G. K. Podila, A. Polle, P. J. Pukkila, P. M. Richardson, P. Rouze, I. R. Sanders, J. E. Stajich, A. Tunlid, G. Tuskan, I. V. Grigoriev Mar 2008

The Genome Of Laccaria Bicolor Provides Insights Into Mycorrhizal Symbiosis, F. Martin, A. Aerts, D. Ahren, A. Brun, E. G. J. Danchin, F. Duchaussoy, J. Gibon, A. Kohler, E. Lindquist, V. Pereda, A. Salamov, H. J. Shapiro, J. Wuyts, D. Blaudez, M. Buee, P. Brokstein, B. Canback, D. Cohen, P. E. Courty, P. M. Coutinho, C. Delaruelle, J. C. Detter, A. Deveau, S. Difazio, S. Duplessis, L. Fraissinet-Tachet, E. Lucic, P. Frey-Klett, C. Fourrey, I. Feussner, G. Gay, J. Grimwood, P. J. Hoegger, P. Jain, S. Kilaru, J. Labbe, Y. C. Lin, V. Legue, F. Le Tacon, R. Marmeisse, D. Melayah, B. Montanini, M. Muratet, U. Nehls, H. Niculita-Hirzel, M. P. Oudot-Le Secq, M. Peter, H. Quesneville, B. Rajashekar, M. Reich, N. Rouhier, J. Schmutz, T. Yin, M. Chalot, B. Henrissat, U. Kues, S. Lucas, Y. Van De Peer, G. K. Podila, A. Polle, P. J. Pukkila, P. M. Richardson, P. Rouze, I. R. Sanders, J. E. Stajich, A. Tunlid, G. Tuskan, I. V. Grigoriev

US Department of Energy Publications

Mycorrhizal symbioses—the union of roots and soil fungi—are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants. Boreal, temperate and montane forests all depend on ectomycorrhizae. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains ~20,000 …


Biofuel Feedstock Assessment For Selected Countries, Keith L. Kline, Gbadebo A. Oladosu, Amy K. Wolfe, Robert D. Perlack, Virginia H. Dale, Matthew J. Mcmahon Feb 2008

Biofuel Feedstock Assessment For Selected Countries, Keith L. Kline, Gbadebo A. Oladosu, Amy K. Wolfe, Robert D. Perlack, Virginia H. Dale, Matthew J. Mcmahon

Economics & Finance Faculty Publications

Findings from biofuel feedstock production assessments and projections of future supply are presented and discussed. The report aims to improve capabilities to assess the degree to which imported biofuel could contribute to meeting future U.S. targets to reduce dependence on imported oil. The study scope was focused to meet time and resource requirements. A screening process identified Argentina, Brazil, Canada, China, Colombia, India, Mexico, and the Caribbean Basin Initiative (CBI) region for initial analysis, given their likely role in future feedstock supply relevant to U.S. markets. Supply curves for selected feedstocks in these countries are projected for 2012, 2017 and …


Effects Of Climate Change On Energy Production And Use In The United States, Thomas Wilbanks, Vatsal Bhatt, Daniel Bilello, Stanley Bull, James Ekmann, William Horak, Y. Joe Huang, Mark D. Levine, Michael J. Sale, David Schmalzer, Michael J. Scott Feb 2008

Effects Of Climate Change On Energy Production And Use In The United States, Thomas Wilbanks, Vatsal Bhatt, Daniel Bilello, Stanley Bull, James Ekmann, William Horak, Y. Joe Huang, Mark D. Levine, Michael J. Sale, David Schmalzer, Michael J. Scott

US Department of Energy Publications

Climate change is expected to have noticeable effects in the United States: a rise in average temperatures in most regions, changes in precipitation amounts and seasonal patterns in many regions, changes in the intensity and pattern of extreme weather events, and sea level rise. Some of these effects have clear implications for energy production and use. For instance, average warming can be expected to increase energy requirements for cooling and reduce energy requirements for warming. Changes in precipitation could affect prospects for hydropower, positively or negatively. Increases in storm intensity could threaten further disruptions of the sorts experienced in 2005 …


Genomics: Gtl 2008 Strategic Plan, Sharlene Weatherwax Jan 2008

Genomics: Gtl 2008 Strategic Plan, Sharlene Weatherwax

US Department of Energy Publications

Table of Contents:
Mission-Inspired Science
GTL Concept and History
National Academy of Sciences Evaluation of GTL Program
GTL’s Fundamental Research Approach to Its Mission
Hallmarks of the GTL Research Approach
Multiscale Explorations
Office of Biological and Environmental Research User Facilities
Metamethods: Metagenomics and Metaproteomics
Robust Computational Framework for GTL Research
GTL Information and Data Sharing Policy
Elaboration of GTL Science for DOE Missions
Systems Biology for Energy Solutions
Systems Biology for Understanding the Carbon Cycle
Planet-Transforming Microbes
Systems Biology for Understanding Contaminant Transport in the Environment
Microbe-Mineral Interface in Contaminated Environments
DOE Office of Science
DOE Office of Biological and …


Small Angle Neutron Scattering Study Of Conformation Of Oligo(Ethylene Glycol)-Grafted Polystyrene In Dilute Solutions: Effect Of The Backbone Length, Gang Cheng, Yuri B. Melnichenko, George D. Wignall, Fengjun Hua, Kunlun Hong, Jimmy W. Mays Jan 2008

Small Angle Neutron Scattering Study Of Conformation Of Oligo(Ethylene Glycol)-Grafted Polystyrene In Dilute Solutions: Effect Of The Backbone Length, Gang Cheng, Yuri B. Melnichenko, George D. Wignall, Fengjun Hua, Kunlun Hong, Jimmy W. Mays

US Department of Energy Publications

The conformation and clusterization of comblike polymers of polystyrene densely grafted with oligo(ethylene glycol) (OEG) side chains in 1.0 wt % solutions of D2O, toluene-d8, and methanol-d4 was investigated as a function of the degree of polymerization (DP) of the backbone by small angle neutron scattering (SANS). Each side chain had four EG repeat units, and the DP of the polystyrene backbone varied from 8 to 85. The global conformation of the polymers in toluene and methanol was shown to assume ellipsoidal, rigid cylindrical, or wormlike morphologies with increasing DP of the polystyrene …


Simulated Effects Of Dynamic Row Spacing On Energy And Water Conservation In Semi-Arid Central California Greenhouses, A. Moya, T. Mehlitz, Ilhami Yildiz, S. F. Kelly, C. Hardin Jan 2008

Simulated Effects Of Dynamic Row Spacing On Energy And Water Conservation In Semi-Arid Central California Greenhouses, A. Moya, T. Mehlitz, Ilhami Yildiz, S. F. Kelly, C. Hardin

BioResource and Agricultural Engineering

Considerable effort is expended to conserve energy and water in current greenhouse systems, and look for alternative energy sources, especially passive heating and cooling strategies. Proper environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. In this study, specifically, influences of dynamic row spacing on energy and water conservation were investigated. A dynamic computer simulation model was used to compare different row spacings, plant heights, and leaf dimensions to draw a conclusion about energy and water conservation. The results showed that using smaller spacings between cucumber crop rows (for instance, 0.5 m instead of …


Simulated Performance Of A Renewable Energy Technology – Heat Pump Systems In Semi-Arid California Greenhouses, C. Hardin, T. Mehlitz, Ilhami Yildiz, S. F. Kelly Jan 2008

Simulated Performance Of A Renewable Energy Technology – Heat Pump Systems In Semi-Arid California Greenhouses, C. Hardin, T. Mehlitz, Ilhami Yildiz, S. F. Kelly

BioResource and Agricultural Engineering

In addition to the labor, energy and water consumption are the two main cost drivers in current greenhouse systems. Consequently, considerable effort is expended to conserve energy and water, and look for alternative energy sources, especially environmentally friendly renewable energy sources and technologies. Greenhouses in hot and arid regions also require large quantities of water for irrigation. Using proper technologies and environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. This study aims to focus on reducing natural gas, electricity, and water consumption in semi-arid California greenhouses introducing renewable energy heat pump technologies to …


Simulated Effects Of Reflective Mulch On Energy And Water Conservation In Semi-Arid Central California Greenhouses, T. Mehlitz, Ilhami Yildiz, S. Rahman, C. Hardin Jan 2008

Simulated Effects Of Reflective Mulch On Energy And Water Conservation In Semi-Arid Central California Greenhouses, T. Mehlitz, Ilhami Yildiz, S. Rahman, C. Hardin

BioResource and Agricultural Engineering

In addition to the labor, energy and water consumption are the two main cost drivers in current greenhouse systems. Consequently, considerable effort is expended to conserve energy and water, and look for alternative energy sources. Greenhouses in hot and arid regions also require large quantities of water for irrigation. Proper environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. This study aims to focus on reducing energy and water consumption in semi-arid California greenhouses. Influences of mulch (having different reflectivities) on energy and water conservation were investigated. The reflectivity of mulch used as a …


Design And Evaluation Of A Greenhouse Interface For Climate Control Programming And Networking, G. Diaz, S. F. Kelly, Ilhami Yildiz Jan 2008

Design And Evaluation Of A Greenhouse Interface For Climate Control Programming And Networking, G. Diaz, S. F. Kelly, Ilhami Yildiz

BioResource and Agricultural Engineering

At Cal Poly the motto is “Learn by Doing”. In the College of Agriculture, this is especially true and many of the labs provide an opportunity for students to implement this philosophy. Updated climate controls were installed in a series of greenhouses on the top floor of the Agricultural Science building that are used for student and faculty research projects. A Programmable Logic Controller (PLC) was installed to actuate the various vents, shading, heating, cooling and irrigation. A control program was developed to control and log temperatures and other operating parameters to monitor the greenhouse. An easy to use computer …


Simulated Effects Of Various Environmental Management Practices On Energy Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh Jan 2008

Simulated Effects Of Various Environmental Management Practices On Energy Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The objective of this study was to evaluate the effects of relative humidity, light management levels, minimum ventilation rates, CO2 enrichment and canopy size on energy consumption in three different greenhouse systems (conventional, open-loop heat pump, and confined heat pump) in winter, spring, and summer months. No difference was observed in energy consumption with relative humidity set point levels in winter due to the already low relative humidity levels. Some differences were observed in spring and summer due to extra dehumidification required to maintain the inside relative humidity at lower levels. Energy consumption in summer was reduced up to …


Simulated Effects Of Various Environmental Management Practices On Water Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh Jan 2008

Simulated Effects Of Various Environmental Management Practices On Water Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The objective of this study was to evaluate the effects of relative humidity, light management, minimum ventilation rates, CO2 enrichment and canopy size on water consumption in three different greenhouse systems (conventional, open heat pump, and confined heat pump) in winter, spring, and summer months. Using different relative humidity set points resulted in almost the same relative humidity regimes within the confined greenhouse system, resulting in similar transpiration rates. No difference was observed in transpiration rates in the open system in winter either, because the inside relative humidity levels never reached the 70% and 80% set points. Some differences …