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2008

Bioresource and Agricultural Engineering

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Articles 91 - 100 of 100

Full-Text Articles in Engineering

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 Jan 2008

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

US 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 …


Understanding The Grafting Of Telechelic Polymers On A Solid Substrate To Form Loops, Zhenyu Huang, Haining Ji, Jimmy W. Mays, Mark D. Dadmun Jan 2008

Understanding The Grafting Of Telechelic Polymers On A Solid Substrate To Form Loops, Zhenyu Huang, Haining Ji, Jimmy W. Mays, Mark D. Dadmun

US Department of Energy Publications

Recent experimental and theoretical studies have demonstrated that relative to singly tethered chains, the presence of polymer loops at interfaces significantly improves interfacial properties such as adhesion, friction, and wettability. In the present study, a simple system was studied to examine the formation of polymeric loops on a solid surface, where the grafting of carboxylic acid terminated telechelic polystyrene from the melt to an epoxy functionalized silicon is chosen. The impact of telechelic molecular weight, grafting temperature, and surface functionality on the telechelic attachment process is studied. It was found that grafting of the telechelic to the surface at both …


A New Fluorinated Polymer Having Two Connected Rings In The Main Chain: Synthesis And Characterization Of Fluorinated Poly(1,3-Cyclohexadiene), Tianzi Huang, Jamie M. Messman, Jimmy W. Mays Jan 2008

A New Fluorinated Polymer Having Two Connected Rings In The Main Chain: Synthesis And Characterization Of Fluorinated Poly(1,3-Cyclohexadiene), Tianzi Huang, Jamie M. Messman, Jimmy W. Mays

US Department of Energy Publications

The high electronegativity and small size of the fluorine atom and the high stability of C-F bonds impart interesting properties and applications to fluorine containing polymers. The unique properties of fluoropolymers include high thermal stability, improved chemical resistance, low surface energies, low coefficients of friction, and low dielectric constants. Applications of fluorinated polymers include use as noncorrosive materials, polymer processing aids, chemically resistant and antifouling coatings, as well as interlayer dielectrics. Fluorine-containing polymers can be directly synthesized via polymerization of fluorine-containing monomers or by post-polymerization modification. The latter method can be used to attach fluorinated species, such as perfluoroalkyl groups, …


Synthesis And Characterization Of An Abc Miktoarm Star Terpolymer Of Cyclohexadiene, Styrene, And 2-Vinylpyridine, David Uhrig, Kunlun Hong, Jimmy W. Mays, S. Michael Kilbey Ii, Phillip F. Britt Jan 2008

Synthesis And Characterization Of An Abc Miktoarm Star Terpolymer Of Cyclohexadiene, Styrene, And 2-Vinylpyridine, David Uhrig, Kunlun Hong, Jimmy W. Mays, S. Michael Kilbey Ii, Phillip F. Britt

US Department of Energy Publications

Several research groups have expended great effort toward the preparation of miktoarm (mixed-arm) star copolymers and terpolymers. We describe herein a novel synthesis, using anionicpolymerization,ofapoly(cyclohexadiene)[PCHD]-polystyrene [PS]-poly(2-vinylpyridine) [P2VP] miktoarm star terpolymer.

Previously, miktoarm A2B and A3B star polydiene copolymers comprised partially of poly(cyclohexadiene) have been synthesized by Tsoukatos and Hadjichristidis by employing chlorosilane linking techniques. More recently, an ABC star terpolymer of PS, polyisoprene, and PCHD was prepared by Yang and co-workers by using meta-double-diphenylethylene-based linking chemistry.


Hierarchical Assemblies Of Block-Copolymer-Based Supramolecules In Thin Films, Shih-Huang Tung, Nisha C. Kalarickal, Jimmy W. Mays, Ting Xu Jan 2008

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

US 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 …


Impact Of Solvent Quality On The Density Profiles Of Looped Triblock Copolymer Brushes By Neutron Reflectivity Measurements, Zhenyu Huang, Jose Alonzo, Ming Liu, Haining Ji, Fang Yin, Grant D. Smith, Jimmy W. Mays, S. Michael Kilbey Ii, Mark D. Dadmun Jan 2008

Impact Of Solvent Quality On The Density Profiles Of Looped Triblock Copolymer Brushes By Neutron Reflectivity Measurements, Zhenyu Huang, Jose Alonzo, Ming Liu, Haining Ji, Fang Yin, Grant D. Smith, Jimmy W. Mays, S. Michael Kilbey Ii, Mark D. Dadmun

US Department of Energy Publications

Preferential adsorption of poly(2-vinylpyridine)-deuterated polystyrene-poly(2-vinylpyridine) (PVP-dPS-PVP) triblock copolymers from toluene onto silicon leads to the formation of dPS loops tethered by the PVP end blocks. Using neutron reflectometry, we have determined the segment density profiles of these looped polymer brushes in toluene, a good solvent for the dPS block, and in cyclohexane at 20 °C (poor solvent), 32 °C, (near-Θ solvent), and 50 °C (marginal solvent). While the swelling behavior qualitatively agrees with that observed for singly grafted brushes, there are interesting differences in the local structural details: In a good solvent, the segment density profiles are composed of an …


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 Jan 2008

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

US 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- (OEG6.6NB) 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 …


System And Method For Analyzing Material Properties Using Hyperspectral Imaging, Jeyamkondan Subbiah, Chris Richard Calkins, Ashok Samal Jan 2008

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

Biological Systems Engineering: Papers and 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.


Estimating The Savings From Improving Pumping Plant Performance., Derrel L. Martin Jan 2008

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

Department of Biological Systems Engineering: Conference 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.


Detection Of Soil Properties With Airborne Hyperspectral Measurements Of Bare Fields, William R. Detar, J. H. Chesson, J. V. Penner, J. C. Ojala Dec 2007

Detection Of Soil Properties With Airborne Hyperspectral Measurements Of Bare Fields, William R. Detar, J. H. Chesson, J. V. Penner, J. C. Ojala

William R DeTar

ABSTRACT. Remote sensing with aircraft‐based sensors can provide the fine resolution required for site‐specific farming. The within‐field spatial distribution of some soil properties was found by using multiple linear regression to select the best combinations of wave bands, taken from among a full set of 60 narrow bands in the wavelength range of 429 to 1010 nm. The resulting regression equations made it possible to calculate the value of the soil property at every pixel, with a spatial resolution of 1.2 m. Both surface and subsurface samples of soil were taken from the center of each of 321 equal‐sized grids …