Bioresource and Agricultural Engineering Commons^™

Hierarchical Assemblies Of Block-Copolymer-Based Supramolecules In Thin Films, Shih-Huang Tung, Nisha C. Kalarickal, Jimmy W. Mays, Ting Xu

United States Department of Energy: Publications

The hierarchical assemblies of supramolecules, which consisted of polystyrene-b-poly(4- vinylpyridine) (PS-b-P4VP) with 3-pentadecylphenol (PDP) hydrogen-bonded to the 4VP, were investigated in thin films after solvent annealing in a chloroform atmosphere. The synergistic coassembly of PS-b-P4VP and PDP was utilized to generate oriented hierarchical structures in thin films. Hierarchical assemblies, including lamellae-within-lamellae and cylinders-within-lamellae, were simultaneously ordered and oriented from a few to several tens of nanometers over macroscopic length scales. The macroscopic orientation of supramolecular assembly depends on the P4VP(PDP) fraction and can be tailored by varying the PDP to P4VP ratio without interfering …

Association And Structure Of Thermosensitive Comblike Block Copolymers In Aqueous Solutions, Gang Cheng, Fengjun Hua, Yuri B. Melnichenko, Kunlun Hong, Jimmy W. Mays, Boualem Hammouda, George D. Wignall

United States Department of Energy: Publications

The structures and association properties of thermosensitive block copolymers of poly(methoxyoligo( ethylene glycol) norbornenyl esters) in D₂O were investigated by small angle neutron scattering (SANS). Each block is a comblike polymer with a polynorbornene (PNB) backbone and oligo ethylene glycol (OEG) side chains (one side chain per NB repeat unit). The chemical formula of the block copolymer is (OEG₃NB) ₇₉- (OEG_6.6NB) ₆₇, where subscripts represent the degree of polymerization (DP) of OEG and NB in each block. The polymer concentration was fixed at 2.0 wt % and the structural changes were investigated …

Biogeochemical Processes In Ethanol Stimulated Uranium-Contaminated Subsurface Sediments, Santosh R. Mohanty, Bharati Kollah, David B. Hedrick, Aaron D. Peacock, Ravi K. Kukkadapu, E. E. Roden

United States Department of Energy: Publications

A laboratory incubation experiment was conducted with uranium contaminated subsurface sediment to assess the geochemical and microbial community response to ethanol amendment. A classical sequence of terminal electron-accepting processes (TEAPs) was observed in ethanol-amended slurries, with NO₃^- reduction, Fe(III) reduction, SO₄^2- reduction, and CH4 production proceeding in sequence until all of the added ¹³Cethanol (9 mM) was consumed. Approximately 60% of the U(VI) content of the sediment was reduced during the period of Fe(III) reduction. No additional U(VI) reduction took place during the sulfate-reducing and methanogenic phases of the experiment. Only gradual reduction of NO …

Reduction Of Tc(Vii) By Fe(Ii) Sorbed On Al (Hydr)Oxides, T. Peretyazhko, J.M. Zachara, S.M. Heald, Ravi K. Kukkadapu, C. Liu, A.E. Plymale, C.T. Resch

United States Department of Energy: Publications

Under oxic conditions, Tc exists as the soluble, weakly sorbing pertechnetate [TcO₄^-] anion. The reduced form of technetium, Tc(IV), is stable in anoxic environments and is sparingly soluble as TcO₂ ·nH₂O_(s). Here we investigate the heterogeneous reduction of Tc(VII) by Fe(II) adsorbed on Al (hydr)oxides [diaspore (α-AlOOH) and corundum (α-Al₂O₃)]. Experiments were performed to study the kinetics of Tc(VII) reduction, examine changes in Fe surface speciation during Tc(VII) reduction (Mössbauer spectroscopy), and identify the nature of Tc(IV)-containing reaction products (X-ray absorption spectroscopy). We found that Tc(VII) was completely …

Long-Term Dynamics Of Uranium Reduction/Reoxidation Under Low Sulfate Conditions, John Komlos, Aaron Peacock, Ravi K. Kukkadapu, Peter R. Jaffe

United States Department of Energy: Publications

The biological reduction and precipitation of uranium in groundwater has the potential to prevent uranium migration from contaminated sites. Although previous research has shown that uranium bioremediation is maximized during iron reduction, little is known on how long-term iron/uranium reducing conditions can be maintained. Questions also remain about the stability of uranium and other reduced species after a long-term biostimulation scheme is discontinued and oxidants (i.e., oxygen) re-enter the bioreduced zone. To gain further insights into these processes, four columns, packed with sediment containing iron as Fe-oxides (mainly Al-goethite) and silicate Fe (Fe-containing clays), were operated in the laboratory under …

Kinetics Of Reduction Of Fe(Iii) Complexes By Outer Membrane Cytochromes Mtrc And Omca Of Shewanella Oneidensis Mr-1, Zheming Wang, Chongxuan Liu, Xuelin Wang, Matthew J. Marshall, John M. Zachara, Kevin M. Rosso, Michel Dupuis, James K. Fredrickson, Steve Heald, Liang Shi

United States Department of Energy: Publications

Because of their cell surface locations, the outer membrane c-type cytochromes MtrC and OmcA of Shewanella oneidensis MR-1 have been suggested to be the terminal reductases for a range of redox-reactive metals that form poorly soluble solids or that do not readily cross the outer membrane. In this work, we determined the kinetics of reduction of a series of Fe(III) complexes with citrate, nitrilotriacetic acid (NTA), and EDTA by MtrC and OmcA using a stopped-flow technique in combination with theoretical computation methods. Stopped-flow kinetic data showed that the reaction proceeded in two stages, a fast stage that was completed …

Hydrogenase- And Outer Membrane C-Type Cytochrome-Facilitated Reduction Of Technetium(Vii) By Shewanella Oneidensis Mr-1, Matthew J. Marshall, Andrew Plymale, David W. Kennedy, Liang Shi, Zheming Wang, Samantha B. Reed, Alice Dohnalkova, Cody Simonson, Chongxuan Liu, Daad A. Saffarini, Margaret F. Romine, John M. Zachara, Alexander S. Beliaev, James K. Fredrickson

United States Department of Energy: Publications

Pertechnetate, ⁹⁹Tc(VII)O₄^–, is a highly mobile radionuclide contaminant at US Department of Energy sites that can be enzymatically reduced by a range of anaerobic and facultatively anaerobic microorganisms, including Shewanella oneidensis MR-1, to poorly soluble Tc(IV)O_2(s). In other microorganisms, Tc(VII)O₄^– reduction is generally considered to be catalysed by hydrogenase. Here, we provide evidence that although the NiFe hydrogenase of MR-1 was involved in the H2-driven reduction of Tc(VII)O₄^– [presumably through a direct coupling of H₂ oxidation and Tc(VII) reduction], the deletion of both hydrogenase genes did not completely eliminate …

Electron Transfer At The Microbe–Mineral Interface: A Grand Challenge In Biogeochemistry, James K. Fredrickson, John M. Zachara

United States Department of Energy: Publications

The interplay between microorganisms and minerals is a complex and dynamic process that has sculpted the geosphere for nearly the entire history of the Earth. The work of Dr. Terry Beveridge and colleagues provided some of the first insights into metal–microbe and mineral–microbe interactions and established a foundation for subsequent detailed investigations of interactions between microorganisms and minerals. Beveridge also envisioned that interdisciplinary approaches and teams would be required to explain how individual microbial cells interact with their immediate environment at nano- or microscopic scales and that through such approaches and using emerging technologies that the details of such interactions …

The Minimum Information About A Genome Sequence (Migs) Specification, Dawn Field, George Garrity, Tanya Gray, Norman Morrison, Jeremy Selengut, Peter Sterk, Tatiana Tatusova, Nicholas Thomson, Michael J. Allen, Samuel V. Angiuoli, Michael Ashburner, Nelson Axelrod, Sandra Baldauf, Stuart Ballard, Jeffrey Boore, Guy Cochrane, James Cole, Peter Dawyndt, Paul De Vos, Claude Depamphilis, Robert Edwards, Nadeem Faruque, Robert Feldman, Jack Gilbert, Paul Gilna, Frank Oliver Glöckner, Philip Goldstein, Robert Guralnick, Dan Haft, David Hancock, Henning Hermjakob, Christiane Hertz-Fowler, Phil Hugenholtz, Ian Joint, Leonid Kagan, Matthew Kane, Jessie Kennedy, George Kowalchuk, Renzo Kottmann, Eugene Kolker, Saul Kravitz, Nikos Kyrpides, Jim Leebens-Mack, Suzanna E. Lewis, Kelvin Li, Allyson L. Lister, Phillip Lord, Natalia Maltsev, Victor Markowitz, Jennifer Martiny, Barbara Methe, Ilene Mizrachi, Richard Moxon, Karen Nelson, Julian Parkhill, Lita Proctor, Owen White, Susanna-Assunta Sansone, Andrew Spiers, Robert Stevens, Paul Swift, Chris Taylor, Yoshio Tateno, Adrian Tett, Sarah Turner, David Ussery, Bob Vaughan, Naomi Ward, Trish Whetzel, Ingio San Gil, Gareth Wilson, Anil Wipat

United States Department of Energy: Publications

With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange. As part of its …

Genomics: Gtl 2008 Strategic Plan, Sharlene Weatherwax

United States 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 …

Pursuing Energy Efficiency As A Hedge Against Carbon Regulatory Risks: Current Resource Planning Practices In The West, Ryan Wiser, Amol Phadke, Charles Goldman

United States Department of Energy: Publications

Uncertainty surrounding the nature and timing of future carbon regulations poses a fundamental and far-reaching financial risk for electric utilities and their ratepayers. Long-term resource planning provides a potential framework within which utilities can assess carbon regulatory risk and evaluate options for mitigating exposure to this risk through investments in energy efficiency and other low-carbon resources. In this paper, we examine current resource planning practices related to managing carbon regulatory risk, based on a comparative analysis of the most-recent long-term resource plans filed by fifteen major utilities in the Western U.S. First, we compare the assumptions and methods used by …

Tribal Renewable Energy – Final Report, A. David Lester

United States Department of Energy: Publications

DOE/CERT Cooperative Agreement has demonstrated that Indian Tribes are ready to undertake the positive steps in developing their internal governmental capacities in program planning and project development as well as the enterprise management capability to undertake the development of their substantial natural base of renewable energy resources and to learn the basic technologies in wind, solar, bio-mass and alternative energy production. The project also demonstrated that virtually every Indian Tribe and community in the United States would benefit socially, economically and in public health values thru a sustained federally coordinated Tribal energy efficiency initiative; and, that a small amount of …

Effects Of Gamma-Sterilization On The Physico-Chemical Properties Of Natural Sediments, T.L. Bank, Ravi K. Kukkadapu, A.S. Madden, M.A. Ginder-Vogel, M.E. Baldwin, P.M. Jardine

United States Department of Energy: Publications

Batch U(VI) sorption/reduction experiments were completed on sterilized and non-sterilized sediment samples to elucidate biological and geochemical reduction mechanisms. Results from X-ray absorption nearedge structure (XANES) spectroscopy revealed that γ-sterilized sediments were actually better sorbents of U(VI), despite the absence of any measurable biological activity. These results indicate that γ-irradiation induced significant physico-chemical changes in the sediment which is contrary to numerous other studies identifying γ-sterilization as an effective and minimally invasive technique. To identify the extent and method of alteration of the soil as a result of γ-sterilization, untreated soil samples, physically separated size fractions, …

Packing Factors Of Feed Products In Storage Structures, Samuel G. Mcneill, Michael D. Montross, Sidney A. Thompson, I. Joseph Ross, Thomas C. Bridges

Biosystems and Agricultural Engineering Faculty Publications

Experiments were conducted to measure the changes in bulk density of cracked corn, corn meal, soybean meal, cotton seed meal, and distillers dried grain (without solubles) when subjected to simulated overburden pressures. All materials were tested at two moisture content levels (approximately 8% and 12% w.b.) and seven pressures between 0 and 69 kPa (0 and 10 psi). A mathematical model was fitted to the data to predict the bulk density of each feed ingredient as a function of pressure and moisture content. These relationships were inserted into a previously developed computer model to predict ingredient packing within conventional storage …

Airflow Resistance Of Wheat Bedding As Influenced By The Filling Method, J. Łukaszuk, M. Molenda, J. Horabik, B. Szot, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

A study was conducted to estimate the degree of variability of the airflow resistance in wheat caused by the filling method, compaction of the sample, and airflow direction. Two types of grain chambers were used: a cylindrical column 0.95 m high and 0.196 m in diameter, and a cubical box of 0.35 m side. All factors examined were found to influence considerably the airflow resistance. Gravitational axial filling of the grain column from three heights (0.0, 0.95 and 1.8 m) resulted in the pressure drops of 1.0, 1.3, and 1.5 kPa at the airflow velocity of 0.3 m/s. Consolidation of …

Scale-Dependent Desorption Of Uranium From Contaminated Subsurface Sediments, Chongxuan Liu, John M. Zachara, Nikolla P. Qafoku, Zheming Wang

United States Department of Energy: Publications

Column experiments were performed to investigate the scale-dependent desorption of uranyl [U(VI)] from a contaminated sediment collected from the Hanford 300 Area at the U.S. Department of Energy (DOE) Hanford Site, Washington. The sediment was a coarse-textured alluvial flood deposit containing significant mass percentage of river cobble. U(VI) was, however, only associated with its minor fine-grained (<2 mm) mass fraction. U(VI) desorption was investigated both from the field-textured sediment using a large column (80 cm length by 15 cm inner diameter) and from its <2 mm U(VI)- associated mass fraction using a small column (10 cm length by 3.4 cm inner diameter). Dynamic advection conditions with intermittent flow and stop-flow events of variable durations were employed to investigate U(VI) desorption kinetics and its scale dependence. A multicomponent kinetic model that integrated a distributed rate of mass transfer with surface complexation reactions successfully described U(VI) release from the fine-grained U(VI)-associated materials. The field-textured sediment in the large column displayed dual-domain tracer-dependent mass transfer properties that affected the breakthrough curves of bromide, pentafluorobenzoic acid (PFBA), and tritium. The tritium breakthrough curve showed stronger nonequilibrium behavior than did PFBA and bromide and required a larger immobile porosity to describe. The dual-domain mass transfer properties were then used to scale the kinetic model of U(VI) desorption developed for the fine-grained materials to describe U(VI) release and reactive transport in the field-textured sediment. Numerical simulations indicated that the kinetic model that was integrated with the dual-domain properties determined from tracer PFBA and Br best described the experimental results. The kinetic model without consideration of the dual-domain properties overpredicted effluent U(VI) concentrations, while the model based on tritium mass transfer underpredicted the rate of U(VI) release. Overall, our results indicated that the kinetics of U(VI) release from the field-textured sediment were different from that of its fine-grained U(VI)-associated mass fraction. However, the desorption kinetics measured on the U(VI)-containing mass fraction could be scaled to describe U(VI) reactive transport in the contaminated field-textured sediment after proper consideration of the physical transport properties of the sediment. The research also demonstrated a modeling approach to integrate geochemical processes into field-scale reactive transport models.

Enhanced Polymer Grafting From Multiwalled Carbon Nanotubes Through Living Anionic Surface-Initiated Polymerization, Georgios Sakellariou, Haining Ji, Jimmy W. Mays, Durairaj Baskaran

United States Department of Energy: Publications

Anionic surface-initiated polymerization of ethylene oxide and styrene has been performed using multiwalled carbon nanotubes (MWNTs) functionalized with anionic initiators. The surface of MWNTs was modified via covalent attachment of precursor anions such as 4-hydroxyethyl benzocyclobutene (BCBEO) and 1-benzocyclobutene-1′-phenylethylene (BCB-PE) through Diels-Alder cycloaddition at 235 °C. Surface-functionalized MWNTs-_g-(BCB-EO) _n and MWNTs-_g-(BCB-PE) _{n with 23 and 54 wt % precursor initiators, respectively, were used for the polymerizations. Alkoxide anion on the surface of MWNTs-g-(BCB-EO) n was generated through reaction with potassium triphenylmethane for the polymerization of ethylene oxide in tetrahydrofuran and phenyl substituted alkyllithium was …}

Generic Simulation Models For Facilitating Stakeholder Involvement In Water Resources Planning And Management: A Comparison, Evaluation, And Identification Of Future Needs, H. Assata, E. Van Beek, C. Borden, P. Gijsbers, A. Jolma, S. Kaden, M. Kaltofen, J.W. Labadie, D.P. Loucks, N.W.T. Quinn, J. Sieber, A. Sulis, W.J. Werick, D.M. Wood

United States Department of Energy: Publications

Water resources planning and management tools have been moving away from a top down (command and control) approach to a bottom up (grass-roots) approach - which emphasizes the involvement of stakeholders, not only specialists, in all stages of planning - from the identification of problems and issues, the selection of potential solutions to project implementation and operation. Ideally, a participatory grassroots planning process should provide a transparent and flexible platform for all stakeholders to collectively: examine the main elements of their shared water system; understand the main issues and problems to be addressed; participate in identifying alternative policies; and select …

Advective Removal Of Intraparticle Uranium From Contaminated Vadose Zone Sediments, Hanford, U.S., Eugene Ilton, Nikolla P. Qafoku, Chongxuan Liu, Dean Moore, John M. Zachara

United States Department of Energy: Publications

A column study on U(VI)-contaminated vadose zone sediments from the Hanford Site, WA, was performed to investigate U(VI) release kinetics with water advection and variable geochemical conditions. The sediments were collected from an area adjacent to and below tank BX-102 that was contaminated as a result of a radioactive tank waste overfill event. The primary reservoir for U(VI) in the sediments are micro-meter size precipitates composed of nanocrystallite aggregates of a Na- U-Silicate phase, most likely Na-boltwoodite, that nucleated and grew within microfractures of the plagioclase component of sand-sized granitic clasts. Two sediment samples, with different U(VI) concentrations and intra-particle …

Direct Involvement Of Type Ii Secretion System In Extracellular Translocation Of Shewanella Oneidensis Outer Membrane Cytochromes Mtrc And Omca, Liang Shi, Shuang Deng, Matthew Marshall, Zheming Wang, David Kennedy, Alice Dohnalkova, Heather Mottaz, Eric Hill, Yuri Gorby, Alexander Beliaev, David Richardson, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

MtrC and OmcA are cell surface-exposed lipoproteins important for reducing solid metal oxides. Deletions of type II secretion system (T2SS) genes reduced their extracellular release and their accessibility to the proteinase K treatment, demonstrating the direct involvement of T2SS in translocation of MtrC and OmcA to the bacterial cell surface.

Economic Benefits, Carbon Dioxide (Co2) Emissions Reductions, And Water Conservation Benefits From 1,000 Megawatts (Mw) Of New Wind Power In Nebraska, Eric Lantz, Suzanne Tegen

United States Department of Energy: Publications

Wind power is one of the fastest-growing forms of new power generation in the United States. Industry growth in 2007 was an astounding 45%. New wind power installations constituted 35% of all new electric power installations. This growth is the result of many drivers, includ¬ing increased economic competitiveness and favorable state policies such as Renewable Portfolio Standards. However, new wind power installations provide more than cost-competitive electricity. Wind power brings economic development to rural regions, reduces water consumption in the electric power sector, and reduces greenhouse gas production by displacing fossil fuels.
The U.S. Department of Energy’s Wind Powering America …

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …

Estimating The Savings From Improving Pumping Plant Performance., Derrel L. Martin

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This brochure describes a method to estimate the cost of pumping water and to compare the amount of energy used to that for a well maintained and designed pumping plant. The results can help determine the feasibility of repairing the pumping plant.

Review Of Career Development In Bioengineering And Biotechnology By Guruprasad Madhavan, Barbara Oakley, And Luis Kun (Editors), Springer Science+Business Media, Llc, 2008, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

As an educator in biological engineering, I am often asked by students about career opportunities in this growing field. The field of biological engineering merges approaches and methodologies from a variety of traditional disciplines, and so practitioners of biological engineering can find professional opportunities in numerous areas.

The recently published book Career Development in Bioengineering and Biotechnology, (485 pages) edited by Madhavan, Oakley, and Kun, represents an ambitious undertaking with the goal of not only presenting career options and career development techniques but also addressing how the work of an individual can impact society. The book contains 71 chapters divided …

System And Method For Analyzing Material Properties Using Hyperspectral Imaging, Jeyamkondan Subbiah, Chris Richard Calkins, Ashok Samal

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Systems and methods are provided for analyzing material properties of an object using hyperspectral imaging. An exemplary method includes obtaining a hyperspectral image of an object; analyzing the hyperspectral image according to an algorithm; and correlating data obtained from the analysis with material properties of the object.

Pyrene Fate Affected By Humic Acid Amendment In Soil Slurry Systems, Y. Liang, D. Sorensen, Ronald C. Sims, Joan Mclean

Biological Engineering Faculty Publications

Background

Humic acid (HA) has been found to affect the solubility, mineralization, and bound residue formation of polycyclic aromatic hydrocarbons (PAHs). However, most of the studies on the interaction between HA and PAH concentrated on one or two of the three phases. Few studies have provided a simple protocol to demonstrate the overall effects of HA on PAH distribution in soil systems for all three phases.

Methods

In this study, three doses of standard Elliott soil HA (ESHA), 15, 187.5, and 1,875 μg ESHA/g soil slurry, were amended to soil slurry systems. ¹⁴C-pyrene was added to the systems along …

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 …

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 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 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 …