Science.gov

Sample records for additional field studies

  1. Influence of Polarization on Carbohydrate Hydration: A Comparative Study Using Additive and Polarizable Force Fields.

    PubMed

    Pandey, Poonam; Mallajosyula, Sairam S

    2016-07-14

    Carbohydrates are known to closely modulate their surrounding solvent structures and influence solvation dynamics. Spectroscopic investigations studying far-IR regions (below 1000 cm(-1)) have observed spectral shifts in the libration band (around 600 cm(-1)) of water in the presence of monosaccharides and polysaccharides. In this paper, we use molecular dynamics simulations to gain atomistic insight into carbohydrate-water interactions and to specifically highlight the differences between additive (nonpolarizable) and polarizable simulations. A total of six monosaccharide systems, α and β anomers of glucose, galactose, and mannose, were studied using additive and polarizable Chemistry at HARvard Macromolecular Mechanics (CHARMM) carbohydrate force fields. Solvents were modeled using three additive water models TIP3P, TIP4P, and TIP5P in additive simulations and polarizable water model SWM4 in polarizable simulations. The presence of carbohydrate has a significant effect on the microscopic water structure, with the effects being pronounced for proximal water molecules. Notably, disruption of the tetrahedral arrangement of proximal water molecules was observed due to the formation of strong carbohydrate-water hydrogen bonds in both additive and polarizable simulations. However, the inclusion of polarization resulted in significant water-bridge occupancies, improved ordered water structures (tetrahedral order parameter), and longer carbohydrate-water H-bond correlations as compared to those for additive simulations. Additionally, polarizable simulations also allowed the calculation of power spectra from the dipole-dipole autocorrelation function, which corresponds to the IR spectra. From the power spectra, we could identify spectral signatures differentiating the proximal and bulk water structures, which could not be captured from additive simulations. PMID:27266974

  2. Additional road markings as an indication of speed limits: results of a field experiment and a driving simulator study.

    PubMed

    Daniels, Stijn; Vanrie, Jan; Dreesen, An; Brijs, Tom

    2010-05-01

    Although speed limits are indicated by road signs, road users are not always aware, while driving, of the actual speed limit on a given road segment. The Roads and Traffic Agency developed additional road markings in order to support driver decisions on speed on 70 km/h roads in Flanders-Belgium. In this paper the results are presented of two evaluation studies, both a field study and a simulator study, on the effects of the additional road markings on speed behaviour. The results of the field study showed no substantial effect of the markings on speed behaviour. Neither did the simulator study, with slightly different stimuli. Nevertheless an effect on lateral position was noticed in the simulator study, showing at least some effect of the markings. The role of conspicuity of design elements and expectations towards traffic environments is discussed. Both studies illustrate well some strengths and weaknesses of observational field studies compared to experimental simulator studies.

  3. The influence of bioaugmentation and biosurfactant addition on bioremediation efficiency of diesel-oil contaminated soil: feasibility during field studies.

    PubMed

    Szulc, Alicja; Ambrożewicz, Damian; Sydow, Mateusz; Ławniczak, Łukasz; Piotrowska-Cyplik, Agnieszka; Marecik, Roman; Chrzanowski, Łukasz

    2014-01-01

    The study focused on assessing the influence of bioaugmentation and addition of rhamnolipids on diesel oil biodegradation efficiency during field studies. Initial laboratory studies (measurement of emitted CO2 and dehydrogenase activity) were carried out in order to select the consortium for bioaugmentation as well as to evaluate the most appropriate concentration of rhamnolipids. The selected consortium consisted of following bacterial taxa: Aeromonas hydrophila, Alcaligenes xylosoxidans, Gordonia sp., Pseudomonas fluorescens, Pseudomonas putida, Rhodococcus equi, Stenotrophomonas maltophilia, Xanthomonas sp. It was established that the application of rhamnolipids at 150 mg/kg of soil was most appropriate in terms of dehydrogenase activity. Based on the obtained results, four treatment methods were designed and tested during 365 days of field studies: I) natural attenuation; II) addition of rhamnolipids; III) bioaugmentation; IV) bioaugmentation and addition of rhamnolipids. It was observed that bioaugmentation contributed to the highest diesel oil biodegradation efficiency, whereas the addition of rhamnolipids did not notably influence the treatment process.

  4. Thiopeptin, a New Feed-Additive Antibiotic: Biological Studies and Field Trials

    PubMed Central

    Mine, K.; Miyairi, N.; Takano, N.; Mori, S.; Watanabe, N.

    1972-01-01

    Thiopeptin is a new antibiotic, produced by Streptomyces tateyamensis and developed solely for animal use as a feed additive. The antibiotic content in animal tissue and feed was assayed in terms of the antimicrobial activity against Mycoplasma laidlawii A. This antibiotic was found to be relatively nontoxic in rats and mice. In chickens, this antibiotic is excreted into feces within 48 hr of administration and is not absorbed in tissue. It is well tolerated in both broilers and swine and is highly stable in animal feed. Thiopeptin-supplemented feed contributes to the improvement of weight gain, feed efficiency in chickens and swine, and the egg performance in layers. Thus, thiopeptin, when used as a feed additive, is quite suitable for supplementing animal nutrition. PMID:4680812

  5. A near-infrared spectroscopic study of young field ultracool dwarfs: additional analysis

    NASA Astrophysics Data System (ADS)

    Allers, K. N.; Liu, M. C.

    We present additional analysis of the classification system presented in \\citet{allers13}. We refer the reader to \\citet{allers13} for a detailed discussion of our near-IR spectral type and gravity classification system. Here, we address questions and comments from participants of the Brown Dwarfs Come of Age meeting. In particular, we examine the effects of binarity and metallicity on our classification system. We also present our classification of Pleiades brown dwarfs using published spectra. Lastly, we determine SpTs and calculate gravity-sensitive indices for the BT-Settl atmospheric models and compare them to observations.

  6. Addition of straw or sawdust to mitigate greenhouse gas emissions from slurry produced by housed cattle: a field incubation study.

    PubMed

    van der Weerden, Tony J; Luo, Jiafa; Dexter, Moira

    2014-07-01

    The use of housed wintering systems (e.g., barns) associated with dairy cattle farming is increasing in southern New Zealand. Typically, these wintering systems use straw or a woodmix as bedding material. Ammonia (NH) and greenhouse gas (GHG) emissions (nitrous oxide [NO] and methane [CH]) associated with storage of slurry + bedding material from wintering systems is poorly understood. A field incubation study was conducted to determine such emissions from stored slurry where bedding material (straw and sawdust) was added at two rates and stored for 7 mo. During the first 4 mo of storage, compared with untreated slurry, the addition of sawdust significantly reduced NH and CH emissions from 29 to 3% of the initial slurry nitrogen (N) content and from 0.5 to <0.01% of the initial slurry carbon (C) content. However, sawdust enhanced NO emissions to 0.7% of the initial slurry-N content, compared with <0.01% for untreated slurry. Straw generally had an intermediate effect. Extending the storage period to 7 mo increased emissions from all treatments. Ammonia emissions were inversely related to the slurry C:N ratio and total solid (TS) content, and CH emissions were inversely related to slurry TS content. Mitigation of GHG emissions from stored slurry can be achieved by reducing the storage period as much as possible after winter slurry collection, providing ground conditions allow access for land spreading and nutrient inputs match pasture requirements. Although adding bedding material can reduce GHG emissions during storage, increased manure volumes for carting and spreading need to be considered. PMID:25603082

  7. Additive empirical force field for hexopyranose monosaccharides

    PubMed Central

    Guvench, Olgun; Greene, Shannon N.; Kamath, Ganesh; Brady, John W.; Venable, Richard M.; Pastor, Richard W.; MacKerell, Alexander D.

    2010-01-01

    We present an all-atom additive empirical force field for the hexopyranose monosaccharide form of glucose and its diastereomers allose, altrose, galactose, gulose, idose, mannose, and talose. The model is developed to be consistent with the CHARMM all-atom biomolecular force fields, and the same parameters are used for all diastereomers, including both the α- and β-anomers of each monosaccharide. The force field is developed in a hierarchical manner and reproduces the gas-phase and condensed-phase properties of small-molecule model compounds corresponding to fragments of pyranose monosaccharides. The resultant parameters are transferred to the full pyranose monosaccharides and additional parameter development is done to achieve a complete hexopyranose monosaccharide force field. Parametrization target data include vibrational frequencies, crystal geometries, solute – water interaction energies, molecular volumes, heats of vaporization, and conformational energies, including those for over 1800 monosaccharide conformations at the MP2/cc-pVTZ//MP2/6-31G(d) level of theory. Though not targeted during parametrization, free energies of aqueous solvation for the model compounds compare favorably with experimental values. Also well-reproduced are monosaccharide crystal unit cell dimensions and ring pucker, densities of concentrated aqueous glucose systems, and the thermodynamic and dynamic properties of the exocyclic torsion in dilute aqueous systems. The new parameter set expands the CHARMM additive force field to allow for simulation of heterogeneous systems that include hexopyranose monosaccharides in addition to proteins, nucleic acids, and lipids. PMID:18470966

  8. Additive CHARMM force field for naturally occurring modified ribonucleotides

    PubMed Central

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D.

    2016-01-01

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all‐atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26841080

  9. Additive CHARMM force field for naturally occurring modified ribonucleotides.

    PubMed

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D; Nilsson, Lennart

    2016-04-15

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all-atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. PMID:26841080

  10. Additive CHARMM force field for naturally occurring modified ribonucleotides.

    PubMed

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D; Nilsson, Lennart

    2016-04-15

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all-atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs.

  11. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m[sup 3]) of tertiary oil have been recovered. Microbial activity has increased CO[sub 2] content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  12. Additional flow field studies of the GA(W)-1 airfoil with 30-percent chord Fowler flap including slot-gap variations and cove shape modifications

    NASA Technical Reports Server (NTRS)

    Wentz, W. H., Jr.; Ostowari, C.

    1983-01-01

    Experimental measurements were made to determine the effects of slot gap opening and flap cove shape on flap and airfoil flow fields. Test model was the GA(W)-1 airfoil with 0.30c Fowler flap deflected 35 degrees. Tests were conducted with optimum, wide and narrow gaps, and with three cove shapes. Three test angles were selected, corresponding to pre-stall and post-stall conditions. Reynolds number was 2,200,000 and Mach number was 0.13. Force, surface pressure, total pressure, and split-film turbulence measurements were made. Results were compared with theory for those parameters for which theoretical values were available.

  13. Additional electric field in real trench MOS barrier Schottky diode

    NASA Astrophysics Data System (ADS)

    Mamedov, R. K.; Aslanova, A. R.

    2016-04-01

    In real trench MOS barrier Schottky diode (TMBS diode) additional electric field (AEF) the whole is formed in the near contact region of the semiconductor and its propagation space is limited with the barrier metal and the metallic electrodes of MOS structures. Effective potential barrier height TMBS diode is formed via resulting electric field of superposition AEF and electric field of space charge region (SCR) semiconductor. The dependence of the resulting electric field intensity of the distance towards the inside the semiconductor is nonlinear and characterized by a peak at a certain distance from the interface. The thickness of the SCR in TMBS diode becomes equal to the trench depth. Force and energy parameters of the AEF, and thus resulting electric field in the SCR region, become dependent on the geometric design parameters TMBS diode. The forward I-V characteristic TMBS diode is described by the thermionic emission theory as in conventional flat Scottky diode, and in the reverse bias, current is virtually absent at initial voltage, appears abruptly at a certain critical voltage.

  14. CHARMM additive and polarizable force fields for biophysics and computer-aided drug design

    PubMed Central

    Vanommeslaeghe, K.

    2014-01-01

    Background Molecular Mechanics (MM) is the method of choice for computational studies of biomolecular systems owing to its modest computational cost, which makes it possible to routinely perform molecular dynamics (MD) simulations on chemical systems of biophysical and biomedical relevance. Scope of Review As one of the main factors limiting the accuracy of MD results is the empirical force field used, the present paper offers a review of recent developments in the CHARMM additive force field, one of the most popular bimolecular force fields. Additionally, we present a detailed discussion of the CHARMM Drude polarizable force field, anticipating a growth in the importance and utilization of polarizable force fields in the near future. Throughout the discussion emphasis is placed on the force fields’ parametrization philosophy and methodology. Major Conclusions Recent improvements in the CHARMM additive force field are mostly related to newly found weaknesses in the previous generation of additive force fields. Beyond the additive approximation is the newly available CHARMM Drude polarizable force field, which allows for MD simulations of up to 1 microsecond on proteins, DNA, lipids and carbohydrates. General Significance Addressing the limitations ensures the reliability of the new CHARMM36 additive force field for the types of calculations that are presently coming into routine computational reach while the availability of the Drude polarizable force fields offers a model that is an inherently more accurate model of the underlying physical forces driving macromolecular structures and dynamics. PMID:25149274

  15. Microbial Field Pilot Study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1990-11-01

    This report covers progress made during the first year of the Microbial Field Pilot Study project. Information on reservoir ecology and characterization, facility and treatment design, core experiments, bacterial mobility, and mathematical modeling are addressed. To facilitate an understanding of the ecology of the target reservoir analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. A preliminary design of facilities for the operation of the field pilot test was prepared. In addition, procedures for facilities installation and for injection treatments are described. The Southeast Vassar Vertz Sand Unit (SEVVSU), the site of the proposed field pilot study, is described physically, historically, and geologically. The fields current status is presented and the ongoing reservoir simulation is discussed. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. Two possible mechanisms, relative permeability effects and changes in the capillary number, are discussed and related to four Berea core experiments' results. The experiments were conducted at reservoir temperature using SEVVSU oil, brine, and bacteria. The movement and activity of bacteria in porous media were investigated by monitoring the growth of bacteria in sandpack cores under no flow conditions. The rate of bacteria advancement through the cores was determined. A mathematical model of the MEOR process has been developed. The model is a three phase, seven species, one dimensional model. Finite difference methods are used for solution. Advection terms in balance equations are represented with a third- order upwind differencing scheme to reduce numerical dispersion and oscillations. The model is applied to a batch fermentation example. 52 refs., 26 figs., 21 tabs.

  16. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year's report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  17. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year`s report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  18. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  19. Livestock poisoning from oil field drilling fluids, muds and additives.

    PubMed

    Edwards, W C; Gregory, D G

    1991-10-01

    The use and potential toxicity of various components of oil well drilling fluids, muds and additives are presented. Many components are extremely caustic resulting in rumenitis. Solvent and petroleum hydrocarbon components may cause aspiration pneumonia and rumen dysfunction. Some additives cause methemoglobinemia. The most frequently encountered heavy metals are lead, chromium, arsenic, lithium and copper. Considerations for investigating livestock poisoning cases and several typical cases are reviewed.

  20. Livestock poisoning from oil field drilling fluids, muds and additives

    SciTech Connect

    Edwards, W.C.; Gregory, D.G. )

    1991-10-01

    The use and potential toxicity of various components of oil well drilling fluids, muds and additives are presented. Many components are extremely caustic resulting in rumenitis. Solvent and petroleum hydrocarbon components may cause aspiration pneumonia and rumen dysfunction. Some additives cause methemoglobinemia. The most frequently encountered heavy metals are lead, chromium, arsenic, lithium and copper. Considerations for investigating livestock poisoning cases and several typical cases are reviewed.

  1. Additional EIPC Study Analysis. Final Report

    SciTech Connect

    Hadley, Stanton W; Gotham, Douglas J.; Luciani, Ralph L.

    2014-12-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

  2. Structure Property Studies for Additively Manufactured Parts

    SciTech Connect

    Milenski, Helen M; Schmalzer, Andrew Michael; Kelly, Daniel

    2015-08-17

    Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractive methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.

  3. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.

    1991-01-01

    The objective of this project is to perform a microbially enhanced oil recovery field pilot test in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate-reducing bacteria will be stimulated to selectively plug flow paths which have been preferentially swept by a prior waterflood. This will force future flood water to invade bypassed regions or the reservoir and increase sweep efficiency. Injection of nutrient stimulates the growth and metabolism of reservoir bacteria, which produces beneficial products to enhance oil recovery. Sometimes, chemical treatments are used to clean or condition injection water. Such a chemical treatment has been initiated by Sullivan and Company at the Southeast Vassar Vertz Sand Unit. The unit injection water was treated with a mixture of water, methanol, isopropyl alcohol, and three proprietary chemicals. To determine if the chemicals would have an impact on the pilot, it was important to determine the effects of the chemical additives on the growth and metabolism of the bacteria from wells in this field. Two types of media were used: a mineral salts medium with molasses and nitrate, and this medium with 25 ppm of the treatment chemicals added. Samples were collected anaerobically from each of two wells, 1A-9 and 7-2. A sample from each well was inoculated and cultured in the broth tubes of molasses-nitrate medium with and without the chemicals. Culturing temperature was 35{degrees}C. Absorbance, pressure and cell number were checked to determine if the chemicals affected the growth and metabolism of bacteria in the brine samples. 12 figs.

  4. Effect of Mg or Ag addition on the evaporation field of Al.

    PubMed

    Aruga, Yasuhiro; Nako, Hidenori; Tsuneishi, Hidemasa; Hasegawa, Yuki; Tao, Hiroaki; Ichihara, Chikara; Serizawa, Ai

    2013-09-01

    It is known that the distribution of the charge-states as well as the evaporation field shift to higher values as the specimen temperature is decreased at a constant rate of evaporation. This study has explored the effect of Mg or Ag addition on the evaporation field of Al in terms of the charge state distribution of the field evaporated Al ions. The fractional abundance of Al(2+) ions with respect to the total Al ions in Al-Mg alloy is lower than that in pure Al, whereas it shows higher level in the Al-Ag alloy at lower temperatures. The temperature dependence of the fractional abundance of Al(2+) ions has been also confirmed, suggesting that Al atoms in the Al-Mg alloy need lower evaporation field, while higher field is necessary to evaporate Al atoms in the Al-Ag alloy, compared with pure Al. This tendency is in agreement with that of the evaporation fields estimated theoretically by means of measurements of the work function and calculations of the binding energy of the pure Al, Al-Mg and Al-Ag alloys.

  5. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  6. Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae).

    PubMed

    Mushtaq, Muhammad; Hussain, Iftikhar; Mian, Afsar; Munir, Shahid; Ahmed, Irfan; Khan, Abdul Aziz

    2013-09-01

    This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut-maize (1:1) as basic bait. All the additives were tested under a no-choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non-significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut-maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine. PMID:24020467

  7. Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae).

    PubMed

    Mushtaq, Muhammad; Hussain, Iftikhar; Mian, Afsar; Munir, Shahid; Ahmed, Irfan; Khan, Abdul Aziz

    2013-09-01

    This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut-maize (1:1) as basic bait. All the additives were tested under a no-choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non-significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut-maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine.

  8. Multiplicative noise effects on electroconvection in controlling additive noise by a magnetic field

    NASA Astrophysics Data System (ADS)

    Huh, Jong-Hoon

    2015-12-01

    We report multiplicative noise-induced threshold shift of electroconvection (EC) in the presence of a magnetic field H . Controlling the thermal fluctuation (i.e., additive noise) of the rodlike molecules of nematic liquid crystals by H , the EC threshold is examined at various noise levels [characterized by their intensity and cutoff frequency (fc) ]. For a sufficiently strong H (i.e., ignorable additive noise), a modified noise sensitivity characterizing the shift problem is in good agreement with experimental results for colored as well as white noise (fc→∞ ) ; until now, there was a large deviation for (sufficiently) colored noises. The present study shows that H provides us with ideal conditions for studying the corresponding Carr-Helfrich theory considering pure multiplicative noise.

  9. Addition of magnetic field capability to existing extremely-low-frequency electric field exposure systems.

    PubMed

    Miller, D L; Miller, M C; Kaune, W T

    1989-01-01

    Magnetic field systems were added to existing electric field exposure apparatuses for exposing cell suspensions in vitro and small animals in vivo. Two horizontally oriented, rectangular coils, stacked one directly above the other, have opposite electric currents. This configuration minimizes leakage fields and allows sham- and field-exposure systems to be placed in the same room or incubator. For the in vitro system, copper plates formed the loop-pair, with up to 900 A supplied by a 180:1 transformer. Electric fields were supplied via electrodes at the ends of cell-culture tubes, eight of which can be accommodated by each exposure system. Two complete systems are situated in an incubator to allow simultaneous sham and field exposure up to 1 mT. For the in vivo system, four pairs of 0.8 x 2.7-m coils made of copper bus bar are employed. This arrangement is energized from the power grid via a 30:1 transformer; horizontal magnetic flux densities up to 1 mT can be generated. Pairs of electrode plates spaced 30.5 cm apart provide electric field exposure of up to 130 kV/m. Four systems with a capacity of 48 rats each are located in one room. For both the in vitro and in vivo systems, magnetic exposure fields are uniform to within +/- 2.5%, and sham levels are at least 2,500-fold lower than exposure levels. Potential confounding factors, such as heating and vibration, were examined and found to be minimal. PMID:2712843

  10. Transferability and additivity of dihedral parameters in polarizable and nonpolarizable empirical force fields.

    PubMed

    Zgarbová, Marie; Rosnik, Andreana M; Luque, F Javier; Curutchet, Carles; Jurečka, Petr

    2015-09-30

    Recent advances in polarizable force fields have revealed that major reparameterization is necessary when the polarization energy is treated explicitly. This study is focused on the torsional parameters, which are crucial for the accurate description of conformational equilibria in biomolecules. In particular, attention is paid to the influence of polarization on the (i) transferability of dihedral terms between molecules, (ii) transferability between different environments, and (iii) additivity of dihedral energies. To this end, three polarizable force fields based on the induced point dipole model designed for use in AMBER are tested, including two recent ff02 reparameterizations. Attention is paid to the contributions due to short range interactions (1-2, 1-3, and 1-4) within the four atoms defining the dihedral angle. The results show that when short range 1-2 and 1-3 polarization interactions are omitted, as for instance in ff02, the 1-4 polarization contribution is rather small and unlikely to improve the description of the torsional energy. Conversely, when screened 1-2 and 1-3 interactions are included, the polarization contribution is sizeable and shows potential to improve the transferability of parameters between different molecules and environments as well as the additivity of dihedral terms. However, to reproduce intramolecular polarization effects accurately, further fine-tuning of the short range damping of polarization is necessary.

  11. Transferability and additivity of dihedral parameters in polarizable and nonpolarizable empirical force fields.

    PubMed

    Zgarbová, Marie; Rosnik, Andreana M; Luque, F Javier; Curutchet, Carles; Jurečka, Petr

    2015-09-30

    Recent advances in polarizable force fields have revealed that major reparameterization is necessary when the polarization energy is treated explicitly. This study is focused on the torsional parameters, which are crucial for the accurate description of conformational equilibria in biomolecules. In particular, attention is paid to the influence of polarization on the (i) transferability of dihedral terms between molecules, (ii) transferability between different environments, and (iii) additivity of dihedral energies. To this end, three polarizable force fields based on the induced point dipole model designed for use in AMBER are tested, including two recent ff02 reparameterizations. Attention is paid to the contributions due to short range interactions (1-2, 1-3, and 1-4) within the four atoms defining the dihedral angle. The results show that when short range 1-2 and 1-3 polarization interactions are omitted, as for instance in ff02, the 1-4 polarization contribution is rather small and unlikely to improve the description of the torsional energy. Conversely, when screened 1-2 and 1-3 interactions are included, the polarization contribution is sizeable and shows potential to improve the transferability of parameters between different molecules and environments as well as the additivity of dihedral terms. However, to reproduce intramolecular polarization effects accurately, further fine-tuning of the short range damping of polarization is necessary. PMID:26224547

  12. Field and laboratory determination of a poly(vinyl/vinylidene chloride) additive in brick mortar.

    PubMed

    Law, S L; Newman, J H; Ptak, F L

    1990-02-01

    A polymerized vinyl/vinylidene chloride additive, used in brick mortar during the 60s and 70s, is detected at the building site by the field method, which employs a commercially available chloride test strip. The field test results can then be verified by the laboratory methods. In one method, total chlorine in the mortar is determined by an oxygen-bomb method and the additive chloride is determined by difference after water-soluble chlorides have been determined on a separate sample. In the second method, the polymerized additive is extracted directly from the mortar with tetrahydrofuran (THF). The difference in weight before and after extraction of the additive gives the weight of additive in the mortar. Evaporation of the THF from the extract leaves a thin film of the polymer, which gives an infrared "fingerprint" spectrum characteristic of the additive polymer.

  13. A Study of Additional Costs of Second Language Instruction.

    ERIC Educational Resources Information Center

    McEwen, Nelly

    A study was conducted whose primary aim was to identify and explain additional costs incurred by Alberta, Canada school jurisdictions providing second language instruction in 1980. Additional costs were defined as those which would not have been incurred had the second language program not been in existence. Three types of additional costs were…

  14. Lessons from a Dominican Republic Field Study

    ERIC Educational Resources Information Center

    Gunter, Michael M., Jr.

    2010-01-01

    Utilizing student-centered pedagogy, this case study explores an increasingly prominent and instructive addition to traditional academic coursework--the field study experience. This is particularly true in the arena of environmental education where students learn best by experiencing environmental problems first-hand and then interacting with…

  15. Study on thermal effects & sulfurized additives, in lubricating greases

    NASA Astrophysics Data System (ADS)

    Shah, Ami Atul

    Lithium Base grease constitutes about 50% of market. The greases are developed to be able to work in multiple working conditions and have longer working life. Greases with extreme pressure additives and anti-wear additives have been developed as a solution to many of the applications. These developed greases are tested under ASTM D2266 testing conditions to meet the requirements. The actual working conditions, although, differ than the real testing conditions. The loading, speed and temperature conditions can be more harsh, or fluctuating in nature. The cyclic nature of the parameters cannot be directly related to the test performance. For this purpose studies on the performance under spectrum loading, variable speed and fluctuating temperature must be performed. This study includes tests to understand the effect of thermal variation on some of the most commonly used grease additives that perform well under ASTM D2266 testing conditions. The studied additives include most widely used industrial extreme pressure additive MoS2. Performance of ZDDP which is trying to replace MoS2 in its industrial applications has also been studied. The tests cover study of extreme pressure, anti-wear and friction modifier additives to get a general idea on the effects of thermal variation in three areas. Sulphur is the most common extreme pressure additive. Sulphur based MoS 2 is extensively used grease additive. Study to understand the tribological performance of this additive through wear testing and SEM/EDX studies has been done. This performance is also studied for other metallic sulfides like WS2 and sulphur based organic compound. The aim is to study the importance of the type of bond that sulphur shares in its additive's structure on its performance. The MoS2 film formation is found to be on the basis of the FeS formation on the substrate and protection through sacrificial monolayer deposition of the MoS2 sheared structure. The free Mo then tends to oxidise. An attempt to

  16. Matching of additive and polarizable force fields for multiscale condensed phase simulations

    PubMed Central

    Baker, Christopher M.; Best, Robert B.

    2013-01-01

    Inclusion of electronic polarization effects is one of the key aspects in which the accuracy of current biomolecular force fields may be improved. The principal drawback of such approaches is the computational cost, which typically ranges from 3 – 10 times that of the equivalent additive model, and may be greater for more sophisticated treatments of polarization or other many-body effects. Here, we present a multiscale approach which may be used to enhance the sampling in simulations with polarizable models, by using the additive model as a tool to explore configuration space. We use a method based on information theory to determine the charges for an additive model that has optimal overlap with the polarizable one, and we demonstrate the feasibility of enhancing sampling via a hybrid replica exchange scheme for several model systems. An additional advantage is that, in the process, we obtain a systematic method for deriving charges for an additive model that will be the natural complement to its polarizable parent. The additive charges are found by an effective coarse-graining of the polarizable force field, rather than by ad hoc procedures. PMID:23997691

  17. Continuous field measurement of N2O isotopologues using FTIR spectroscopy following 15N addition

    NASA Astrophysics Data System (ADS)

    Phillips, R. L.; Griffith, D. W.; Dijkstra, F. A.; Lugg, G.; Lawrie, R.; Macdonald, B.

    2012-12-01

    Anthropogenic additions of fertilizer nitrogen (N) have significantly increased the mole fraction of nitrous oxide (N2O) in the troposphere. Tracking the fate of fertilizer N and its transformation to N2O is important to advance knowledge of greenhouse gas emissions from soils. Transport and transformations are frequently studied using 15N labeling experiments, but instruments capable of continuous measurements of 15N-N2O at the surface of soil have only recently come to the fore. Our primary aim was to quantify emissions of N2O and the fraction of 15N emitted as N2O from an agricultural soil following 15N addition using a mobile Fourier Transform Infrared (FTIR) spectrometer. We set up a short-term field experiment on a coastal floodplain site near Nowra, New South Wales. We deployed an automated chamber system connected to a multi-pass cell (optical pathlength 24 m) and low resolution FTIR spectrometer to measure fluxes of all N2O isotopologues collected from five 0.25 m2 chambers every three hours. We measured N2O fluxes pre and post-application of 15N-labeled substrate as potassium nitrate (KNO3) or urea [CO(NH2)2] to the soil surface. Root mean square uncertainties for all isotopologue measurements were less than 0.3 nmol mol-1 for 1 minute average concentration measurements, and minimum detectable fluxes for each isotopologue were <0.1 ng N m-2 s-1. Emissions of all N2O isotopologues were evident immediately following 15N addition. Emissions of 14N15NO, 15N14NO and 15N15NO isotopologues subsided within 10 d, but 14N14NO fluxes were evident over the entire experiment. The figure provides an overview of the emissions. Cumulative 15N-N2O fluxes (sum of the three 15N isotopologues) per chamber for the 14 days following 15N addition ranged from 1.5 to 10.3 mg 15N-N2O m-2. The chambers were destructively sampled after 2 weeks and 15N analyzed in soil and plant material using isotope ratio mass spectrometry. Approximately 1% (range 0.7 - 1.9%) of the total amount of

  18. Internal additive noise effects in stochastic resonance using organic field effect transistor

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshiharu; Matsubara, Kiyohiko; Asakawa, Naoki

    2016-08-01

    Stochastic resonance phenomenon was observed in organic field effect transistor using poly(3-hexylthiophene), which enhances performance of signal transmission with application of noise. The enhancement of correlation coefficient between the input and output signals was low, and the variation of correlation coefficient was not remarkable with respect to the intensity of external noise, which was due to the existence of internal additive noise following the nonlinear threshold response. In other words, internal additive noise plays a positive role on the capability of approximately constant signal transmission regardless of noise intensity, which can be said "homeostatic" behavior or "noise robustness" against external noise. Furthermore, internal additive noise causes emergence of the stochastic resonance effect even on the threshold unit without internal additive noise on which the correlation coefficient usually decreases monotonically.

  19. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Pilot-Scale Test Results

    SciTech Connect

    Gary M. Blythe

    2006-03-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, ''Field Testing of a Wet FGD Additive.'' The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemissions of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate that the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project will conduct pilot and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosage requirements to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB co-fired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot and full-scale jet bubbling reactor (JBR) FGD systems to be tested. A third utility, to be named later, will provide the high-sulfur Eastern bituminous coal full-scale FGD test site. Degussa Corporation is providing the TMT-15 additive and technical support to the test program. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in

  20. CHARMM General Force Field (CGenFF): A force field for drug-like molecules compatible with the CHARMM all-atom additive biological force fields

    PubMed Central

    Vanommeslaeghe, K.; Hatcher, E.; Acharya, C.; Kundu, S.; Zhong, S.; Shim, J.; Darian, E.; Guvench, O.; Lopes, P.; Vorobyov, I.; MacKerell, A. D.

    2010-01-01

    The widely used CHARMM additive all-atom force field includes parameters for proteins, nucleic acids, lipids and carbohydrates. In the present paper an extension of the CHARMM force field to drug-like molecules is presented. The resulting CHARMM General Force Field (CGenFF) covers a wide range of chemical groups present in biomolecules and drug-like molecules, including a large number of heterocyclic scaffolds. The parametrization philosophy behind the force field focuses on quality at the expense of transferability, with the implementation concentrating on an extensible force field. Statistics related to the quality of the parametrization with a focus on experimental validation are presented. Additionally, the parametrization procedure, described fully in the present paper in the context of the model systems, pyrrolidine, and 3-phenoxymethylpyrrolidine will allow users to readily extend the force field to chemical groups that are not explicitly covered in the force field as well as add functional groups to and link together molecules already available in the force field. CGenFF thus makes it possible to perform “all-CHARMM” simulations on drug-target interactions thereby extending the utility of CHARMM force fields to medicinally relevant systems. PMID:19575467

  1. Decomposition of conifer tree bark under field conditions: effects of nitrogen and phosphorus additions

    NASA Astrophysics Data System (ADS)

    Lopes de Gerenyu, Valentin; Kurganova, Irina; Kapitsa, Ekaterina; Shorokhova, Ekaterina

    2016-04-01

    In forest ecosystems, the processes of decomposition of coarse woody debris (CWD) can contribute significantly to the emission component of carbon (C) cycle and thus accelerate the greenhouse effect and global climate change. A better understanding of decomposition of CWD is required to refine estimates of the C balance in forest ecosystems and improve biogeochemical models. These estimates will in turn contribute to assessing the role of forests in maintaining their long-term productivity and other ecosystems services. We examined the decomposition rate of coniferous bark with added nitrogen (N) and phosphorus (P) fertilizers in experiment under field conditions. The experiment was carried out in 2015 during 17 weeks in Moscow region (54o50'N, 37o36'E) under continental-temperate climatic conditions. The conifer tree bark mixture (ca. 70% of Norway spruce and 30% of Scots pine) was combined with soil and placed in piles of soil-bark substrate (SBS) with height of ca. 60 cm and surface area of ca. 3 m2. The dry mass ratio of bark to soil was 10:1. The experimental design included following treatments: (1) soil (Luvisols Haplic) without bark, (S), (2) pure SBS, (3) SBS with N addition in the amount of 1% of total dry bark mass (SBS-N), and (4) SBS with N and P addition in the amount of 1% of total dry bark mass for each element (SBS-NP). The decomposition rate expressed as CO2 emission flux, g C/m2/h was measured using closed chamber method 1-3 times per week from July to early November using LiCor 6400 (Nebraska, USA). During the experiment, we also controlled soil temperature at depths of 5, 20, 40, and 60 cm below surface of SBS using thermochrons iButton (DS1921G, USA). The pattern of CO2 emission rate from SBS depended strongly on fertilizing. The highest decomposition rates (DecR) of 2.8-5.6 g C/m2/h were observed in SBS-NP treatment during the first 6 weeks of experiment. The decay process of bark was less active in the treatment with only N addition. In this

  2. Field Testing of a Wet FGD Additive for Enhanced Mercury Control

    SciTech Connect

    Gary Blythe; MariJon Owens

    2007-12-31

    This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved

  3. The force-field derivation and application of explosive/additive interfaces

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2016-10-01

    The inter-molecular force-field across RDX/(paraffin, fluoropolymer) interfaces are derived from first-principles calculated energies under the GGA+vdW functional. Based on the force-field, the polycrystal structures of mixture explosives are obtained, and a set of thermodynamic properties are calculated, including the elastic constants, thermal expansion coefficient, heat capacity, isothermal curve and the Hugoniot curve. The results are in good agreement with the available experiments, and provide a reasonable prediction about the properties of plastic bonded explosives. We find that the thermal expansion coefficient of a multi-component explosive is not only determined by the properties of the components, but is also affected by the thermal stress at the explosive/additive interfaces.

  4. Benchmark Study of Industrial Needs for Additive Manufacturing in Finland

    NASA Astrophysics Data System (ADS)

    Lindqvist, Markku; Piili, Heidi; Salminen, Antti

    Additive manufacturing (AM) is a modern way to produce parts for industrial use. Even though the technical knowledge and research of AM processes are strong in Finland, there are only few industrial applications. Aim of this study is to collect practical knowledge of companies who are interested in industrial use of AM, especially in South-Eastern Finland. Goal of this study is also to investigate demands and requirements of applications for industrial use of AM in this area of Finland. It was concluded, that two of the reasons prohibiting wider industrial use of AM in Finland, are wrong expectations against this technology as well as lack of basic knowledge of possibilities of the technology. Especially, it was noticed that strong 3D-hype is even causing misunderstandings. Nevertheless, the high-level industrial know-how in the area, built around Finnish lumber industry is a strong foundation for the additive manufacturing technology.

  5. Electrostatic Levitation for Studies of Additive Manufactured Materials

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

    2014-01-01

    The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

  6. A Study of Additive Noise Model for Robust Speech Recognition

    NASA Astrophysics Data System (ADS)

    Awatade, Manisha H.

    2011-12-01

    A model of how speech amplitude spectra are affected by additive noise is studied. Acoustic features are extracted based on the noise robust parts of speech spectra without losing discriminative information. An existing two non-linear processing methods, harmonic demodulation and spectral peak-to-valley ratio locking, are designed to minimize mismatch between clean and noisy speech features. Previously studied methods, including peak isolation [1], do not require noise estimation and are effective in dealing with both stationary and non-stationary noise.

  7. EDF field operation computerization study

    SciTech Connect

    Guillot, L.; Pirus, D.

    2006-07-01

    The main control room has been the subject of extensive research and actions into improved operations assistance. On the other hand, few studies concern the need for field operation improvements, which have few assistance resources adapted to working requirements. Why? Past studies have shown the inability of technology to assume job constraints (insufficient screen readability, excessive equipment weight, prohibitive response times). Nevertheless, today new technologies can be adapted to field operations, and they justify further study. Real needs exist: local operations are often complex and are led in difficult environments where conditions prevent the use of paper-based documents. The issue is a significant risk of error which might impact plant reliability. The cumbersome nature of paper procedures, the working environment and the operational feed-back of experience led us to concentrate on the field operation to identify how it may be improved by the use of these new technologies. Such equipment would allow a better traceability and quality of actions. Possibility of communications with other plant personnel and information sharing may be also immediately available for all. This paper presents a study which intends to collect assistance requirements through an analysis of working practices and organizations with local personnel. Our aim is to identify which of those might benefit from IT support. This collection was obtained through interviews and observations. These two methods helped us to define potential needs, constraints and consequences for work organization. This paper presents the study results and findings, identifies professions which may benefit from the use of wearable computers and describes how the reliability and efficiency of human actions would be improved. Finally we identify design requirements and criteria to be used for writing the technical specifications for a test prototype. (authors)

  8. Microwave sanitization of color additives used in cosmetics: feasibility study.

    PubMed

    Jasnow, S B; Smith, J L

    1975-08-01

    Microwave exposure has been explored as a method of microbiologically sanitizing color additives used in cosmetic products. Selected microbiologically unacceptable cosmetic color additives, D&C red no. 7 Ca lake (certified synthetic organic color), carmine (natural organic color not subject to certification), and chromium hydroxide green (inorganic color not subject to certification), were submitted to microwave exposure. Gram-negative bacteria were eliminated, as verified by enrichment procedures, and levels of gram-positive bacteria were reduced. Generally, analytical and dermal safety studies indicated no significant alterations in physical, chemical, and toxicological properties of the colors. Sanitization was also successfully performed on other colors (D&C red no. 9 Ba lake, D&C red no. 12 Ba lake, D&C green no. 5, and FD&C red no. 4); initial physical and chemical tests were satisfactory. Results indicated that this method of sanitization is feasible and warrants further investigation.

  9. BIG FROG WILDERNESS STUDY AREA AND ADDITIONS, TENNESSEE AND GEORGIA.

    USGS Publications Warehouse

    Slack, John F.; Gazdik, Gertrude C.

    1984-01-01

    A mineral-resource survey was made of the Big Frog Wilderness Study Area and additions, Tennessee-Georgia. Geochemical sampling found traces of gold, zinc, copper, and arsenic in rocks, stream sediments, and panned concentrates, but not in sufficient quantities to indicate the presence of deposits of these metals. The results of the survey indicate that there is little promise for the occurrence of metallic mineral deposits within the study area. The only apparent resources are nonmetallic commodities including rock suitable for construction materials, and small amounts of sand and gravel; however, these commodities are found in abundance outside the study area. A potential may exist for oil and natural gas at great depths, but this cannot be evaluated by the present study.

  10. Recommended Protocol for Round Robin Studies in Additive Manufacturing

    PubMed Central

    Moylan, Shawn; Brown, Christopher U.; Slotwinski, John

    2016-01-01

    One way to improve confidence and encourage proliferation of additive manufacturing (AM) technologies and parts is by generating more high quality data describing the performance of AM processes and parts. Many in the AM community see round robin studies as a way to generate large data sets while distributing the cost among the participants, thereby reducing the cost to individual users. The National Institute of Standards and Technology (NIST) has conducted and participated in several of these AM round robin studies. While the results of these studies are interesting and informative, many of the lessons learned in conducting these studies concern the logistics and methods of the study and unique issues presented by AM. Existing standards for conducting interlaboratory studies of measurement methods, along with NIST’s experience, form the basis for recommended protocols for conducting AM round robin studies. The role of round robin studies in AM qualification, some of the limitations of round robin studies, and the potential benefit of less formal collaborative experiments where multiple factors, AM machine being only one, are varied simultaneously are also discussed. PMID:27274602

  11. Making intelligent systems team players: Additional case studies

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

    1993-01-01

    Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

  12. An Approach to the Classification of Potential Reserve Additions of Giant Oil Fields of the World

    USGS Publications Warehouse

    Klett, T.R.; Tennyson, M.E.

    2008-01-01

    This report contains slides and notes for slides for a presentation given to the Committee on Sustainable Energy and the Ad Hoc Group of Experts on Harmonization of Fossil Energy and Mineral Resources Terminology on 17 October 2007 in Geneva, Switzerland. The presentation describes the U.S. Geological Survey study to characterize and quantify petroleum-reserve additions, and the application of this study to help classify the quantities.

  13. RAMSEYS DRAFT WILDERNESS STUDY AREA AND ADDITION, VIRGINIA.

    USGS Publications Warehouse

    Lesure, Frank G.; Mory, Peter C.

    1984-01-01

    Mineral-resource surveys of the Ramseys Draft Wilderness Study Area and adjoining roadless area addition in George Washington National Forest in the western valley and ridge province, Augusta and Highland Counties, Virginia, were done. The surveys outlined three small areas containing anomalous amounts of copper, lead, and zinc related to stratabound red-bed copper mineralization, but these occurrences are not large and are not considered as having mineral-resource potential. The area contains abundant sandstone suitable for construction materials and shale suitable for making brick, tile, and other low-grade ceramic products, but these commodities occur in abundance outside the wilderness study area. Structural conditions are probably favorable for the accumulation of natural gas, but exploratory drilling has not been done sufficiently near the area to evaluate the gas potential.

  14. Microbial field pilot study. Final report

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m{sup 3}) of tertiary oil have been recovered. Microbial activity has increased CO{sub 2} content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  15. Field-structured composite studies.

    SciTech Connect

    Martin, James Ellis; Williamson, Rodney L.

    2004-04-01

    Field-structured composites (FSCs) were produced by hosting micron-sized gold-coated nickel particles in a pre-polymer and allowing the mixture to cure in a magnetic field environment. The feasibility of controlling a composite's electrical conductivity using feedback control applied to the field coils was investigated. It was discovered that conductivity in FSCs is primarily determined by stresses in the polymer host matrix due to cure shrinkage. Thus, in cases where the structuring field was uniform and unidirectional so as to produce chainlike structures in the composite, no electrical conductivity was measured until well after the structuring field was turned off at the gel point. In situations where complex, rotating fields were used to generate complex, three-dimensional structures in a composite, very small, but measurable, conductivity was observed prior to the gel point. Responsive, sensitive prototype chemical sensors were developed based on this technology with initial tests showing very promising results.

  16. Experimental Study of Additives on Viscosity biodiesel at Low Temperature

    NASA Astrophysics Data System (ADS)

    Fajar, Berkah; Sukarno

    2015-09-01

    An experimental investigation was performed to find out the viscosity of additive and biodiesel fuel mixture in the temperature range from 283 K to 318 K. Solutions to reduce the viscosity of biodiesel is to add the biodiesel with some additive. The viscosity was measured using a Brookfield Rheometer DV-II. The additives were the generic additive (Diethyl Ether/DDE) and the commercial additive Viscoplex 10-330 CFI. Each biodiesel blends had a concentration of the mixture: 0.0; 0.25; 0.5; 0.75; 1.0; and 1.25% vol. Temperature of biodiesel was controlled from 40°C to 0°C. The viscosity of biodiesel and additive mixture at a constant temperature can be approximated by a polynomial equation and at a constant concentration by exponential equation. The optimum mixture is at 0.75% for diethyl ether and 0.5% for viscoplex.

  17. Size characterization by Sedimentation Field Flow Fractionation of silica particles used as food additives.

    PubMed

    Contado, Catia; Ravani, Laura; Passarella, Martina

    2013-07-25

    Four types of SiO2, available on the market as additives in food and personal care products, were size characterized using Sedimentation Field Flow Fractionation (SdFFF), SEM, TEM and Photon Correlation Spectroscopy (PCS). The synergic use of the different analytical techniques made it possible, for some samples, to confirm the presence of primary nanoparticles (10 nm) organized in clusters or aggregates of different dimension and, for others, to discover that the available information is incomplete, particularly that regarding the presence of small particles. A protocol to extract the silica particles from a simple food matrix was set up, enriching (0.25%, w w(-1)) a nearly silica-free instant barley coffee powder with a known SiO2 sample. The SdFFF technique, in conjunction with SEM observations, made it possible to identify the added SiO2 particles and verify the new particle size distribution. The SiO2 content of different powdered foodstuffs was determined by graphite furnace atomic absorption spectroscopy (GFAAS); the concentrations ranged between 0.006 and 0.35% (w w(-1)). The protocol to isolate the silica particles was so applied to the most SiO2-rich commercial products and the derived suspensions were separated by SdFFF; SEM and TEM observations supported the size analyses while GFAAS determinations on collected fractions permitted element identification.

  18. Additive Manufacturing in Production: A Study Case Applying Technical Requirements

    NASA Astrophysics Data System (ADS)

    Ituarte, Iñigo Flores; Coatanea, Eric; Salmi, Mika; Tuomi, Jukka; Partanen, Jouni

    Additive manufacturing (AM) is expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The variability of these parameters affects the manufacturing drastically and therefore standardized processes and harmonized methodologies need to be developed to characterize the technology for end use applications and enable the technology for manufacturing. This research proposes a composite methodology integrating Taguchi Design of Experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. The proposed methodology aims to characterize AM technology depending upon manufacturing process variables as well as to perform a comparative assessment of three AM technologies (Selective Laser Sintering, Laser Stereolithography and Polyjet). Results indicate that only one machine, laser-based Stereolithography, was feasible to fulfil simultaneously macro and micro level geometrical requirements but mechanical properties were not at required level. Future research will study a single AM system at the time to characterize AM machine technical capabilities and stimulate pre-normative initiatives of the technology for end use applications.

  19. Field Study Manual to Freshwater and Estuarine Habitats.

    ERIC Educational Resources Information Center

    Georgia State Dept. of Education, Atlanta.

    This field studies manual, developed by biology students in the 1971 Georgia Governor's Honors Program, was designed for collection of data pertinent to freshwater and estuarine habitats. In addition to the various methods of sampling the ecosystem and for quantification of the data, instructions for dividing the field study into three logical…

  20. Studying fringe field effect of a field emitter array

    NASA Astrophysics Data System (ADS)

    Sayfullin, M. F.; Nikiforov, K. A.

    2014-10-01

    Field emitter arrays on heavy As-doped Si wafer are studied in vacuum nanoelectronics diode configuration. Different shapes of emitters are considered: cone-shaped point-emitters and cylinder-shaped sharp-edge-emitters are compared. Micro scale field enhancement factor on the edge of cylindrical emitter was calculated via home-developed Matlab application and the results are presented. Two types of anode geometry are proposed: plane anode and spherical anode. Experimental and modelling results of surface electric field distribution are presented. The spherical shape of anode allows higher voltage (and higher field emission current) without destructive arcs risk.

  1. Planetary geomorphology field studies: Iceland and Antarctica

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1984-01-01

    Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. These studies, conducted in Iceland and in Antarctica, investigated physical and chemical weathering mechanisms and rates, eolitan processes, mudflow phenomena, drainage development, and catastrophic fluvial and volcanic phenomena. Continuing investigations in Iceland fall in three main catagories: (1) catastrophic floods of the Jokulsa a Fjollum, (2) lahars associated with explosive volcanic eruptions of Askja caldera, and (3) rates of eolian abrasion in cold, volcanic deserts. The ice-free valleys of Antarctica, in particular those in South Victoria Land, have much is common with the surface of Mars. In addition to providing independent support for the application of the Iceland findings to consideration of the martian erosional system, the Antarctic observations also provide analogies to other martian phenomena. For example, a family of sand dunes in Victoria Valley are stabilized by the incorporation of snow as beds.

  2. Health studies indicate MTBE is safe gasoline additive

    SciTech Connect

    Anderson, E.V.

    1993-09-01

    Implementation of the oxygenated fuels program by EPA in 39 metropolitan areas, including Fairbanks and Anchorage, Alaska, in the winter of 1992, encountered some unexpected difficulties. Complaints of headaches, dizziness, nausea, and irritated eyes started in Fairbanks, jumped to Anchorage, and popped up in various locations in the lower 48 states. The suspected culprit behind these complaints was the main additive for oxygenation of gasoline is methyl tert-butyl ether (MTBE). A test program, hastily organized in response to these complaints, has indicated that MTBE is a safe gasoline additive. However, official certification of the safety of MTBE is still awaited.

  3. Plasma injection and capture at electron cyclotron resonance in a mirror system with additional rf fields

    SciTech Connect

    Golovanivskii, K.S.; Dugar-Zhabon, V.D.; Karyaka, V.I.; Milant'ev, V.P.; Turikov, V.A.

    1980-03-01

    Experiments and numerical simulations have been carried out to determine how cyclotron-resonance rf fields in an open magnetic mirror system affect the capture and confinement of a plasma injected along the axis. The results show that at electron cyclotron resonance the fields greatly improve the longitudinal plasma confinement.

  4. Kinetic study of additions of dialkylmagnesium compounds to a cycloprene

    SciTech Connect

    Watkins, E.K.; Richey, H.G. Jr.

    1992-11-01

    Reaction of Et{sub 2}Mg and spiro[2.4]hept-1-ene (1) in tetahydrofuran followed by hydrolysis furnishes mainly 1-ethylspiro[2.4]heptane (3); when hydrolysis is with D{sub 2}O, {ge}98% of this (Z)-1-ethylspirol[2.4]heptane-2-d (4). Some metalation of 1 and formation of higher molecular weight products incorporating two or three molecules of 1 also take place. Formation of 3 is first order in 1 and in Et{sub 2}Mg, and at 35.47{degrees}C the rate constant is 1.2 x 10{sup -5} L M{sup -1}s{sup -1}. Under the same conditions, the rate of addition (1.5 x 10{sup -5} L M{sup -1}{sub s}{sup -1}). Under the same conditions, the rate of addition (1.5 x 10{sup -5} L mol{sup -1} {sub s}{sup -1}) of the Grignard reagent prepared from EtBr is similar. Reactions of 1 with Me{sub 2}Mg, I-Pr{sub 2}Mg, and t-Bu{sub 2}Mg. Added Fe(acac){sub 3} increases the rate of formation of 3 from reactions of 1 with either Et{sub 2}Mg or the Grignard reagent prepared from EtBr, but additional products also are formed. 55 refs., 2 tabs.

  5. Studies in Quantum Field Theory

    NASA Astrophysics Data System (ADS)

    Bastianelli, Fiorenzo

    We analyze several topics in quantum field theory, mainly motivated by their role in the formulation of string theories. The common theme in what follows is the implementation of symmetries, such as local supersymmetry or BRST symmetry, through an action principle and the analysis of anomalies, the latter describing the breakdown of these symmetries at the quantum level. In the first part of this dissertation, we analyze "chiral bosons", i.e. massless scalar fields in a two -dimensional spacetime propagating in only one of the two light-cone directions. We present a general method for constructing couplings for chiral bosons and give details for the coupling to supergravity. The notion of a two dimensional chiral boson is generalized in d = 4k + 2 spacetime dimensions to that of a self-dual antisymmetric tensor field. We derive the coupling to gravity and compute the gravitational anomalies using the Feynman rules obtained from the action. We find agreement with the important work of Alvarez-Gaume and Witten, who conjectured the relevant Feynman rules. Our result therefore completes and justifies the Alvarez-Gaume-Witten findings. For the case of d = 2 we also show how to use the method of Fujikawa for computing anomalies from the non-invariance of the path integral measure. We obtain the full effective action by integrating the anomaly equation. In the second part we focus on a method for computing the consistent anomalies in the Fujikawa scheme. In a first application, we derive the consistent regulators for the various fields of the quantum action of the spinning string in superspace. These regulators produce the anomalies which satisfy the Wess-Zumino consistency conditions. In a second application, we analyze the anomalous structure of the Green-Schwarz formulation of the heterotic string. We find anomalies which generically do not cancel on an arbitrary world-sheet manifold. This raises questions concerning the possible validity of such a formulation of

  6. Vadose Zone Transport Field Study: Summary Report

    SciTech Connect

    Ward, Andy L.; Conrad, Mark E.; Daily, William D.; Fink, James B.; Freedman, Vicky L.; Gee, Glendon W.; Hoversten, Gary M.; Keller, Jason M.; Majer, Ernest L.; Murray, Christopher J.; White, Mark D.; Yabusaki, Steven B.; Zhang, Z. F.

    2006-07-31

    migration (e.g. BC Cribs and Trenches). The improved models have been also coupled with inverse models and newly-developed parameter scaling techniques to allow estimation of field-scale and effective transport parameters for the vadose zone. The development and utility of pedotransfer functions for describing fine-scale hydrogeochemical heterogeneity and for incorporating this heterogeneity into reactive transport models was explored. An approach based on grain-size statistics appears feasible and has been used to describe heterogeneity in hydraulic properties and sorption properties, such as the cation exchange capacity and the specific surface area of Hanford sediments. This work has also led to the development of inverse modeling capabilities for time-dependent, subsurface, reactive transport with transient flow fields using an automated optimization algorithm. In addition, a number of geophysical techniques investigated for their potential to provide detailed information on the subtle changes in lithology and bedding surfaces; plume delineation, leak detection. High-resolution resistivity is now being used for detecting saline plumes at several waste sites at Hanford, including tank farms. Results from the field studies and associated analysis have appeared in more than 46 publications generated over the past 4 years. These publications include test plans and status reports, in addition to numerous technical notes and peer reviewed papers.

  7. Recent biophysical studies in high magnetic fields

    NASA Astrophysics Data System (ADS)

    Maret, Georg

    1990-06-01

    A brief overview of biophysical effects of steady magnetic fields is given. The need of high field strength is illustrated by several recent diamagnetic orientation experiments. They include rod-like viruses, purple membranes and chromosomes. Results of various studies on bees, quails, rats and pigeons exposed to fields above 7 T are also resumed.

  8. Mentoring Field Directors: A National Exploratory Study

    ERIC Educational Resources Information Center

    Ellison, Martha L.; Raskin, Miriam S.

    2014-01-01

    In social work field education, mentoring is underused and lacks research data. There is a paucity of research that examines the effect mentoring has on social work field directors who administer field programs at the undergraduate and/or graduate level. This exploratory study fills this void by examining the mentoring opportunities and…

  9. NMR relaxometry study of plaster mortar with polymer additives

    SciTech Connect

    Jumate, E.; Manea, D.; Moldovan, D.; Fechete, R.

    2013-11-13

    The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.

  10. Acceptance test report: Field test of mixer pump for 241-AN-107 caustic addition project

    SciTech Connect

    Leshikar, G.A.

    1997-05-16

    The field acceptance test of a 75 HP mixer pump (Hazleton serial number N-20801) installed in Tank 241-AN-107 was conducted from October 1995 thru February 1996. The objectives defined in the acceptance test were successfully met, with two exceptions recorded. The acceptance test encompassed field verification of mixer pump turntable rotation set-up and operation, verification that the pump instrumentation functions within established limits, facilitation of baseline data collection from the mixer pump mounted ultrasonic instrumentation, verification of mixer pump water flush system operation and validation of a procedure for its operation, and several brief test runs (bump) of the mixer pump.

  11. Government regulation and public opposition create high additional costs for field trials with GM crops in Switzerland.

    PubMed

    Bernauer, Thomas; Tribaldos, Theresa; Luginbühl, Carolin; Winzeler, Michael

    2011-12-01

    Field trials with GM crops are not only plant science experiments. They are also social experiments concerning the implications of government imposed regulatory constraints and public opposition for scientific activity. We assess these implications by estimating additional costs due to government regulation and public opposition in a recent set of field trials in Switzerland. We find that for every Euro spent on research, an additional 78 cents were spent on security, an additional 31 cents on biosafety, and an additional 17 cents on government regulatory supervision. Hence the total additional spending due to government regulation and public opposition was around 1.26 Euros for every Euro spent on the research per se. These estimates are conservative; they do not include additional costs that are hard to monetize (e.g. stakeholder information and dialogue activities, involvement of various government agencies). We conclude that further field experiments with GM crops in Switzerland are unlikely unless protected sites are set up to reduce these additional costs.

  12. Addition of the pirani condition to the Mathisson-Papapetrou equations in a Schwarzschild Field

    SciTech Connect

    Plyatsko, R.M.

    1986-01-01

    This paper obtains relations that allow one to distinguish a unique center of mass of a rotating test body as it moves in the equatorial plane of a Schwarzchild field. This center of mass can be thought of as the instantaneous analog of the classical center of mass.

  13. Additional field verification of convective scaling for the lateral dispersion parameter

    SciTech Connect

    Sakiyama, S.K.; Davis, P.A.

    1988-07-01

    The results of a series of diffusion trials over the heterogeneous surface of the Canadian Precambrian Shield provide additional support for the convective scaling of the lateral dispersion parameter. The data indicate that under convective conditions, the lateral dispersion parameter can be scaled with the convective velocity scale and the mixing depth. 10 references.

  14. Additional EIPC Study Analysis: Interim Report on High Priority Topics

    SciTech Connect

    Hadley, Stanton W

    2013-11-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 13 topics was developed for further analysis; this paper discusses the first five.

  15. Additional studies for the spectrophotometric measurement of iodine in water

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Previous work in iodine spectroscopy is briefly reviewed. Continued studies of the direct spectrophotometric determination of aqueous iodine complexed with potassium iodide show that free iodine is optimally determined at the isosbestic point for these solutions. The effects on iodine determinations of turbidity and chemical substances (in trace amounts) is discussed and illustrated. At the levels tested, iodine measurements are not significantly altered by such substances. A preliminary design for an on-line, automated iodine monitor with eventual capability of operating also as a controller was analyzed and developed in detail with respect single beam colorimeter operating at two wavelengths (using a rotating filter wheel). A flow-through sample cell allows the instrument to operate continuously, except for momentary stop flow when measurements are made. The timed automatic cycling of the system may be interrupted whenever desired, for manual operation. An analog output signal permits controlling an iodine generator.

  16. 34 CFR 350.55 - What are the additional considerations for selecting Field-Initiated Project applications for...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF EDUCATION DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM How Does the... 34 Education 2 2013-07-01 2013-07-01 false What are the additional considerations for selecting Field-Initiated Project applications for funding? 350.55 Section 350.55 Education Regulations of...

  17. 34 CFR 350.55 - What are the additional considerations for selecting Field-Initiated Project applications for...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF EDUCATION DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM How Does the... 34 Education 2 2014-07-01 2013-07-01 true What are the additional considerations for selecting Field-Initiated Project applications for funding? 350.55 Section 350.55 Education Regulations of...

  18. 34 CFR 350.55 - What are the additional considerations for selecting Field-Initiated Project applications for...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., DEPARTMENT OF EDUCATION DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM How Does the... 34 Education 2 2011-07-01 2010-07-01 true What are the additional considerations for selecting Field-Initiated Project applications for funding? 350.55 Section 350.55 Education Regulations of...

  19. 34 CFR 350.55 - What are the additional considerations for selecting Field-Initiated Project applications for...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF EDUCATION DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM How Does the... 34 Education 2 2012-07-01 2012-07-01 false What are the additional considerations for selecting Field-Initiated Project applications for funding? 350.55 Section 350.55 Education Regulations of...

  20. CHARMM additive all-atom force field for carbohydrate derivatives and its utility in polysaccharide and carbohydrate-protein modeling

    PubMed Central

    Guvench, Olgun; Mallajosyula, Sairam S.; Raman, E. Prabhu; Hatcher, Elizabeth; Vanommeslaeghe, Kenno; Foster, Theresa J.; Jamison, Francis W.; MacKerell, Alexander D.

    2011-01-01

    Monosaccharide derivatives such as xylose, fucose, N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GlaNAc), glucuronic acid, iduronic acid, and N-acetylneuraminic acid (Neu5Ac) are important components of eukaryotic glycans. The present work details development of force-field parameters for these monosaccharides and their covalent connections to proteins via O-linkages to serine or threonine sidechains and via N-linkages to asparagine sidechains. The force field development protocol was designed to explicitly yield parameters that are compatible with the existing CHARMM additive force field for proteins, nucleic acids, lipids, carbohydrates, and small molecules. Therefore, when combined with previously developed parameters for pyranose and furanose monosaccharides, for glycosidic linkages between monosaccharides, and for proteins, the present set of parameters enables the molecular simulation of a wide variety of biologically-important molecules such as complex carbohydrates and glycoproteins. Parametrization included fitting to quantum mechanical (QM) geometries and conformational energies of model compounds, as well as to QM pair interaction energies and distances of model compounds with water. Parameters were validated in the context of crystals of relevant monosaccharides, as well NMR and/or x-ray crystallographic data on larger systems including oligomeric hyaluronan, sialyl Lewis X, O- and N-linked glycopeptides, and a lectin:sucrose complex. As the validated parameters are an extension of the CHARMM all-atom additive biomolecular force field, they further broaden the types of heterogeneous systems accessible with a consistently-developed force-field model. PMID:22125473

  1. The application of additive technologies in creation a medical simulator-trainer of the human head operating field

    NASA Astrophysics Data System (ADS)

    Kashapov, L. N.; Kashapov, N. F.; Kashapov, R. N.; Pashaev, B. Y.

    2016-06-01

    The aim of the work was to determine the possible application of additive manufacturing technology during the manufacturing process as close as possible to reality of medical simulator-trainers. In work were used some additive manufacturing technologies: selective laser sintering (SLS), fused deposition modeling (FDM), binder Jetting. As a result, a prototype of simulator-trainer of the human head operating field, which based on the CT real patient, was manufactured and conducted its tests. It was found that structure, which is obtained with the use of 3D-printers ProJet 160, most appropriate and closest to the real properties of the bone.

  2. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 3 Full-scale Test Results

    SciTech Connect

    Gary Blythe

    2007-05-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB cofired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems to be tested. IPL, an AES company, provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Degussa Corporation is providing the TMT-15 additive and technical support to the test program as cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing

  3. Molecular approaches to field studies of malaria.

    PubMed

    Beck, Hans-Peter; Tetteh, Kevin

    2008-12-01

    The third 'Molecular Approaches to Malaria' conference was held in Lorne, Australia, in February 2008 and provided extensive information on the application of molecular tools in field studies on malaria. In recent years, technological advances and capacity building in malaria-endemic countries have permitted molecular tools to be applied much more frequently and successfully with exciting new findings. In this review, Hans-Peter Beck and Kevin Tetteh report on the most recent findings using molecular tools in field studies.

  4. Seismic Absorption and Modulus Measurements in Porous Rocks in Lab and Field: Physical, Chemical, and Biological Effects of Fluids (Detecting a Biosurfactant Additive in a Field Irrigation Experiment)

    SciTech Connect

    Spetzler, Hartmut

    2006-05-01

    We have been exploring a new technology that is based on using low-frequency seismic attenuation data to monitor changes in fluid saturation conditions in two-fluid phase porous materials. The seismic attenuation mechanism is related to the loss of energy due to the hysteresis of resistance to meniscus movement (changes in surface tension, wettability) when a pore containing two fluids is stressed at very low frequencies (< 10 Hz). This technology has potential applications to monitoring changes in (1) leakage at buried waste sites, (2) contaminant remediation, and (3) flooding during enhanced petroleum recovery. We have concluded a three year field study at the Maricopa Agricultural Center site of the University of Arizona. Three sets of instruments were installed along an East-West line perpendicular to the 50m by 50m inigation site. Each set of instruments consisted of one three component seismometer and one tiltmeter. Microseisms and solid Earth-tides served as strain sources. The former have a power peak at a period of about 6 seconds and the tides have about two cycles per day. Installation of instruments commenced in late summer of 2002. The instruments operated nearly continuously until April 2005. During the fall of 2003 the site was irrigated with water and one year later with water containing 150 ppm of a biosurfactant additive. This biodegradable additive served to mimic a class of contaminants that change the surface tension of the inigation fluid. Tilt data clearly show tidal tilts superimposed on local tilts due to agricultural irrigation and field work. When the observed signals were correlated with site specific theoretical tilt signals we saw no anomalies for the water irrigation in 2003, but large anomalies on two stations for the surfactant irrigation in 2004. Occasional failures of seismometers as well as data acquisition systems contributed to less than continuous coverage. These data are noisier than the tilt data, but do also show possible

  5. Field Evidence for Co-Metabolism of Trichloroethene Stimulated by Addition of Electron Donor to Groundwater

    SciTech Connect

    Conrad, Mark E.; Brodie, Eoin L.; Radtke, Corey W.; Bill, Markus; Delwiche, Mark E.; Lee, M. Hope; Swift, Dana L.; Colwell, Frederick S.

    2010-05-17

    For more than 10 years, electron donor has been injected into the Snake River aquifer beneath the Test Area North site of the Idaho National Laboratory for the purpose of stimulating microbial reductive dechlorination of trichloroethene (TCE) in groundwater. This has resulted in significant TCE removal from the source area of the contaminant plume and elevated dissolved CH4 in the groundwater extending 250 m from the injection well. The delta13C of the CH4 increases from 56o/oo in the source area to -13 o/oo with distance from the injection well, whereas the delta13C of dissolved inorganic carbon decreases from 8 o/oo to -13 o/oo, indicating a shift from methanogenesis to methane oxidation. This change in microbial activity along the plume axis is confirmed by PhyloChip microarray analyses of 16S rRNA genes obtained from groundwater microbial communities, which indicate decreasing abundances of reductive dechlorinating microorganisms (e.g., Dehalococcoides ethenogenes) and increasing CH4-oxidizing microorganisms capable of aerobic co-metabolism of TCE (e.g., Methylosinus trichosporium). Incubation experiments with 13C-labeled TCE introduced into microcosms containing basalt and groundwater from the aquifer confirm that TCE co-metabolism is possible. The results of these studies indicate that electron donor amendment designed to stimulate reductive dechlorination of TCE may also stimulate co-metabolism of TCE.

  6. Field evidence for co-metabolism of trichloroethene stimulated by addition of electron donor to groundwater.

    PubMed

    Conrad, Mark E; Brodie, Eoin L; Radtke, Corey W; Bill, Markus; Delwiche, Mark E; Lee, M Hope; Swift, Dana L; Colwell, Frederick S

    2010-06-15

    For more than 10 years, electron donor has been injected into the Snake River aquifer beneath the Test Area North site of the Idaho National Laboratory for the purpose of stimulating microbial reductive dechlorination of trichloroethene (TCE) in groundwater. This has resulted in significant TCE removal from the source area of the contaminant plume and elevated dissolved CH(4) in the groundwater extending 250 m from the injection well. The delta(13)C of the CH(4) increases from -56 per thousand in the source area to -13 per thousand with distance from the injection well, whereas the delta(13)C of dissolved inorganic carbon decreases from 8 per thousand to -13 per thousand, indicating a shift from methanogenesis to methane oxidation. This change in microbial activity along the plume axis is confirmed by PhyloChip microarray analyses of 16S rRNA genes obtained from groundwater microbial communities, which indicate decreasing abundances of reductive dechlorinating microorganisms (e.g., Dehalococcoides ethenogenes) and increasing CH(4)-oxidizing microorganisms capable of aerobic co-metabolism of TCE (e.g., Methylosinus trichosporium). Incubation experiments with (13)C-labeled TCE introduced into microcosms containing basalt and groundwater from the aquifer confirm that TCE co-metabolism is possible. The results of these studies indicate that electron donor amendment designed to stimulate reductive dechlorination of TCE may also stimulate co-metabolism of TCE. PMID:20476753

  7. Indigenous Studies as an International Field.

    ERIC Educational Resources Information Center

    Pino-Robles, Rodolfo

    This paper proposes the development of Indigenous Studies as an international field, both in the sense of advancing the discipline internationally, wherever there are Indigenous peoples, and in the sense of incorporating international perspectives into curricula. In Canada, Indigenous Studies has been and is still treated as something to be done…

  8. Interaction Between Flames and Electric Fields Studied

    NASA Technical Reports Server (NTRS)

    Yuan, Zeng-Guang; Hegde, Uday

    2003-01-01

    The interaction between flames and electric fields has long been an interesting research subject that has theoretical importance as well as practical significance. Many of the reactions in a flame follow an ionic pathway: that is, positive and negative ions are formed during the intermediate steps of the reaction. When an external electric field is applied, the ions move according to the electric force (the Coulomb force) exerted on them. The motion of the ions modifies the chemistry because the reacting species are altered, it changes the velocity field of the flame, and it alters the electric field distribution. As a result, the flame will change its shape and location to meet all thermal, chemical, and electrical constraints. In normal gravity, the strong buoyant effect often makes the flame multidimensional and, thus, hinders the detailed study of the problem.

  9. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

    SciTech Connect

    Gary Blythe; MariJon Owens

    2007-12-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management

  10. Optimization of the CHARMM additive force field for DNA: Improved treatment of the BI/BII conformational equilibrium.

    PubMed

    Hart, Katarina; Foloppe, Nicolas; Baker, Christopher M; Denning, Elizabeth J; Nilsson, Lennart; Mackerell, Alexander D

    2012-01-10

    The B-form of DNA can populate two different backbone conformations: BI and BII, defined by the difference between the torsion angles ε and ζ (BI = ε-ζ < 0 and BII = ε-ζ > 0). BI is the most populated state, but the population of the BII state, which is sequence dependent, is significant and accumulating evidence shows that BII affects the overall structure of DNA, and thus influences protein-DNA recognition. This work presents a reparametrization of the CHARMM27 additive nucleic acid force field to increase the sampling of the BII form in MD simulations of DNA. In addition, minor modifications of sugar puckering were introduced to facilitate sampling of the A form of DNA under the appropriate environmental conditions. Parameter optimization was guided by quantum mechanical data on model compounds, followed by calculations on several DNA duplexes in the condensed phase. The selected optimized parameters were then validated against a number of DNA duplexes, with the most extensive tests performed on the EcoRI dodecamer, including comparative calculations using the Amber Parm99bsc0 force field. The new CHARMM model better reproduces experimentally observed sampling of the BII conformation, including sampling as a function of sequence. In addition, the model reproduces the A form of the 1ZF1 duplex in 75 % ethanol, and yields a stable Z-DNA conformation of duplex (GTACGTAC) in its crystal environment. The resulting model, in combination with a recent reoptimization of the CHARMM27 force field for RNA, will be referred to as CHARMM36.

  11. Semi-empirical equation of limiting current for cobalt electrodeposition in the presence of magnetic field and additive electrolyte

    NASA Astrophysics Data System (ADS)

    Sudibyo, Aziz, N.

    2016-02-01

    One of the available methods to solve a roughening in cobalt electrodeposition is magneto electrodeposition (MED) in the presence of additive electrolyte. Semi-empirical equation of limiting current under a magnetic field for cobalt MED in the presence of boric acid as an additive electrolyte was successfully developed. This semi empirical equation shows the effects of the electrode area (A), the concentration of the electro active species (C), the diffusion coefficient of the electro active species (D), the kinematic viscosity of the electrolyte (v), magnetic strength (B) and the number of electrons involved in the redox process (n). The presence of boric acid led to decrease in the limiting current, but the acid was found useful as a buffer to avoid the local pH rise caused by parallel hydrogen evolution reaction (HER).

  12. Magneto-optical study of uranium additions to amorphous TbxFe1 - x

    NASA Astrophysics Data System (ADS)

    Dillon, J. F., Jr.; van Dover, R. B.; Hong, M.; Gyorgy, E. M.; Albiston, S. D.

    1987-02-01

    Recent reports of huge magneto-optical Kerr rotations in certain crystalline metallic uranium compounds prompted a study of the magnetic and magneto-optical effects of uranium additions to a rare-earth transition metal amorphous alloy. Using variable composition samples, the polar Kerr effect at a small spot (e.g., 0.5 mm diam) was measured as field, temperature, and composition were varied. Points on the Curie line and the edges of the compensation region were determined from these observations. The compositions studied included (TbxFe1-x)1-yUy with 0.125≤x≤0.550 and y=0.0, 0.04, 0.07, 0.16. The addition of uranium to TbxFe1-x depresses the TC of Tb-rich material much more strongly than that of Tb-poor material. The compensation region does not shift at all with increasing y. It appears that uranium does not contribute to the magnetization of these amorphous alloys, nor does it significantly affect the magneto-optical effects.

  13. Marine and Environmental Studies Field Manual.

    ERIC Educational Resources Information Center

    Cranston School Dept., RI.

    This laboratory manual was developed for a field-oriented high school oceanology program. The organization of the units includes a selection of supplementary activities to allow students to explore ocean studies in more depth. Included are 19 units. The units include biological oceanography, physical oceanography, and some social science topics. A…

  14. Jupiter Environmental Research & Field Studies Academy.

    ERIC Educational Resources Information Center

    Huttemeyer, Bob

    1996-01-01

    Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

  15. Outdoor Education, Junior Biology Field Studies.

    ERIC Educational Resources Information Center

    Aikman, John H.; And Others

    Field studies for grade nine and ten biology students are developed in this teacher and student guide for outdoor education. A small section is devoted to teacher pre-planning and final sections are concerned with equipment, audio-visual resources, and a large booklist. Twenty-three investigations related to earth science and biology topics are…

  16. Additional focusing of a high-intensity laser beam in a plasma with a density ramp and a magnetic field

    SciTech Connect

    Gupta, Devki Nandan; Hur, Min Sup; Suk, Hyyong

    2007-08-20

    Propagation of a high power Gaussian laser beam through a plasma with a density ramp where a magnetic field is present has been investigated. The spot size of the laser beam decreases as the beam penetrates into the plasma due to the role of a plasma density ramp. The studies show that the combined effect of a plasma density ramp and a magnetic field enhances the self-focusing property of the laser beam. Both factors not only reduce the spot size of the laser beam but also maintain it with only a mild ripple over several Rayleight lengths.

  17. Urban Dispersion Program Overview and MID05 Field Study Summary

    SciTech Connect

    Allwine, K Jerry; Flaherty, Julia E.

    2007-07-31

    The Urban Dispersion Program (UDP) was a 4-year project (2004–2007) funded by the U.S. Department of Homeland Security with additional support from the Defense Threat Reduction Agency. The U.S. Environmental Protection Agency (EPA) also contributed to UDP through funding a human-exposure component of the New York City (NYC) field studies in addition to supporting an EPA scientist in conducting modeling studies of NYC. The primary goal of UDP was to improve the scientific understanding of the flow and diffusion of airborne contaminants through and around the deep street canyons of NYC. The overall UDP project manager and lead scientist was Dr. Jerry Allwine of Pacific Northwest National Laboratory. UDP had several accomplishments that included conducting two tracer and meteorological field studies in Midtown Manhattan.

  18. Additional ECR heating of a radially inhomogeneous plasma via the absorption of satellite harmonics of the surface flute modes in a rippled magnetic field

    SciTech Connect

    Girka, V. O.; Girka, I. O.

    2006-12-15

    A theoretical study is made of the possibility of additional heating of a radially inhomogeneous plasma in confinement systems with a rippled magnetic field via the absorption of satellite harmonics of the surface flute modes with frequencies below the electron gyrofrequency in the local resonance region, {epsilon}{sub 1} (r{sub 1}) = [2{pi}c/({omega}L)]{sup 2}, where {epsilon}{sub 1} is the diagonal element of the plasma dielectric tensor in the hydrodynamic approximation, L is the period of a constant external rippled magnetic field, and the radical coordinate r{sub 1} determines the position of the local resonance. It is found that the high-frequency power absorbed near the local resonance is proportional to the square of the ripple amplitude of the external magnetic field. The mechanism proposed is shown to ensure the absorption of the energy of surface flute modes and, thereby, the heating of a radially inhomogeneous plasma.

  19. Study of wood plastic composite in the presence of nitrogen containing additives

    NASA Astrophysics Data System (ADS)

    Ali, K. M. Idriss; Khan, Mubarak A.; Husain, M. M.

    1994-10-01

    Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite.

  20. Radiative corrections to the Higgs boson couplings in the model with an additional real singlet scalar field

    NASA Astrophysics Data System (ADS)

    Kanemura, Shinya; Kikuchi, Mariko; Yagyu, Kei

    2016-06-01

    We calculate renormalized Higgs boson couplings with gauge bosons and fermions at the one-loop level in the model with an additional isospin singlet real scalar field. These coupling constants can deviate from the predictions in the standard model due to tree-level mixing effects and one-loop contributions of the extra neutral scalar boson. We investigate how they can be significant under the theoretical constraints from perturbative unitarity and vacuum stability and also the condition of avoiding the wrong vacuum. Furthermore, comparing with the predictions in the Type I two Higgs doublet model, we numerically demonstrate how the singlet extension model can be distinguished and identified by using precision measurements of the Higgs boson couplings at future collider experiments.

  1. Cellular studies and interaction mechanisms of extremely low frequency fields

    NASA Astrophysics Data System (ADS)

    Liburdy, Robert P.

    1995-01-01

    ) or the magnetic (B) field, or if combinations of static B and time-varying B fields represent an exposure metric for the cell. This question relates directly to understanding fundamental interaction mechanisms and to the development of a rationale for ELF dose threshold guidelines. The weight of experimental evidence indicates that an induced E field according to Faraday's law of induction during magnetic field exposures elicits cellular effects. An E-field-mediated interaction has interesting consequences for microdosimetry at the cellular level and is mechanistically consistent with an interaction at the cell surface, since the E field does not penetrate beyond the cell membrane. Recently, several studies have suggested that an ELF B field by itself or in combination with a static B field may elicit cellular effects. Thus in addition to E-field-mediated effects, other interaction mechanisms as yet not fully understood may operate at the cellular level; this complexity is in contrast to the case for ionizing radiation. In addition to the question of an exposure field metric, the biological state of the target cell is important in ELF interactions. Biological factors such as cell type, cell cycle, cell activation, age of donor animal, passage number of cell line, presence of specific growth/mitogenic factors, temperature, shape, and cell density/packing during exposures have been shown to play a role in mediating ELF interactions with cells. Most recently, reports of single-cell studies usher in a new direction for research that can be termed microbioelectromagnetics. Single-cell digital microscopy introduces a new approach to answer the above questions with potential for real-time microdosimetry and bioeffects limited only by the spatial resolution of state-of-the-art microscopy, which is approximately 0.1 /μm. Digital imaging microscopy should therefore permit the quantitative assessment of spatial and temporal features of ELF field interactions within living

  2. Study of mandible reconstruction using a fibula flap with application of additive manufacturing technology

    PubMed Central

    2014-01-01

    Background This study aimed to establish surgical guiding techniques for completing mandible lesion resection and reconstruction of the mandible defect area with fibula sections in one surgery by applying additive manufacturing technology, which can reduce the surgical duration and enhance the surgical accuracy and success rate. Methods A computer assisted mandible reconstruction planning (CAMRP) program was used to calculate the optimal cutting length and number of fibula pieces and design the fixtures for mandible cutting, registration, and arrangement of the fibula segments. The mandible cutting and registering fixtures were then generated using an additive manufacturing system. The CAMRP calculated the optimal fibula cutting length and number of segments based on the location and length of the defective portion of the mandible. The mandible cutting jig was generated according to the boundary surface of the lesion resection on the mandible STL model. The fibular cutting fixture was based on the length of each segment, and the registered fixture was used to quickly arrange the fibula pieces into the shape of the defect area. In this study, the mandibular lesion was reconstructed using registered fibular sections in one step, and the method is very easy to perform. Results and conclusion The application of additive manufacturing technology provided customized models and the cutting fixtures and registered fixtures, which can improve the efficiency of clinical application. This study showed that the cutting fixture helped to rapidly complete lesion resection and fibula cutting, and the registered fixture enabled arrangement of the fibula pieces and allowed completion of the mandible reconstruction in a timely manner. Our method can overcome the disadvantages of traditional surgery, which requires a long and different course of treatment and is liable to cause error. With the help of optimal cutting planning by the CAMRP and the 3D printed mandible resection jig and

  3. Benchmark field study of deep neutron penetration

    SciTech Connect

    Morgan, J.F.; Sale, K. ); Gold, R.; Roberts, J.H.; Preston, C.C. )

    1991-06-10

    A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field are described with emphasis on neutron source characteristics and room return background. The single material chosen for the first benchmark, LATAN-1, is a steel representative of Light Water Reactor (LWR) Pressure Vessels (PV). Also included is a brief description of the Little Boy replica, a critical reactor assembly designed to mimic the radiation doses from the atomic bomb dropped on Hiroshima, and its us in neutron spectrometry. 18 refs.

  4. Field studies in geophysical diffraction tomography

    SciTech Connect

    Witten, A.J.; Stevens, S.S.; King, W.C.; Ursic, J.R.

    1992-07-01

    Geophysical diffraction tomography (GDT) is a quantitative, high- resolution technique for subsurface imaging. This method has been used in a number of shallow applications to image buried waste, trenches, soil strata, tunnels, synthetic magma chambers, and the buried skeletal remains of seismosaurus, the longest dinosaur ever discovered. The theory associated with the GDT inversion and implementing software have been developed for acoustic and scalar electromagnetic waves for bistatic and monostatic measurements in cross-borehole, offset vertical seismic profiling and reflection geometries. This paper presents an overview of some signal processing algorithms, a description of the instrumentation used in field studies, and selected imaging results.

  5. Field studies in geophysical diffraction tomography

    SciTech Connect

    Witten, A.J.; Stevens, S.S. ); King, W.C. . Dept. of Geography and Environmental Engineering); Ursic, J.R. . Region V)

    1992-01-01

    Geophysical diffraction tomography (GDT) is a quantitative, high- resolution technique for subsurface imaging. This method has been used in a number of shallow applications to image buried waste, trenches, soil strata, tunnels, synthetic magma chambers, and the buried skeletal remains of seismosaurus, the longest dinosaur ever discovered. The theory associated with the GDT inversion and implementing software have been developed for acoustic and scalar electromagnetic waves for bistatic and monostatic measurements in cross-borehole, offset vertical seismic profiling and reflection geometries. This paper presents an overview of some signal processing algorithms, a description of the instrumentation used in field studies, and selected imaging results.

  6. Planetary geomorphology field studies: Washington and Alaska

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1984-01-01

    Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. Investigations discussed address principally mudflow phenomena and drainage development. At the Valley of 10,000 Smokes (Katmai, AK) and Mount St. Helens, WA, studies of the development of erosional landforms (in particular, drainage) on fresh, new surfaces permitted analysis of the result of competition between geomorphic processes. Of specific interest is the development of stream pattern as a function of the competition between perennial seepage overland flow (from glacial or groundwater sources), ephemeral overland flow (from pluvial or seasonal melt sources), and ephemeral/perennial groundwater sapping, as a function of time since initial resurfacing, material properties, and seasonal/annual environmental conditions.

  7. Additional Reserve Recovery Using New Polymer Treatment on High Water Oil Ratio Wells in Alameda Field, Kingman County, Kansas

    SciTech Connect

    James Spillane

    2005-10-01

    The Chemical Flooding process, like a polymer treatment, as a tertiary (enhanced) oil recovery process can be a very good solution based on the condition of this field and its low cost compared to the drilling of new wells. It is an improved water flooding method in which high molecular-weight (macro-size molecules) and water-soluble polymers are added to the injection water to improve the mobility ratio by enhancing the viscosity of the water and by reducing permeability in invaded zones during the process. In other words, it can improve the sweep efficiency by reducing the water mobility. This polymer treatment can be performed on the same active oil producer well rather than on an injector well in the existence of strong water drive in the formation. Some parameters must be considered before any polymer job is performed such as: formation temperature, permeability, oil gravity and viscosity, location and formation thickness of the well, amount of remaining recoverable oil, fluid levels, well productivity, water oil ratio (WOR) and existence of water drive. This improved oil recovery technique has been used widely and has significant potential to extend reservoir life by increasing the oil production and decreasing the water cut. This new technology has the greatest potential in reservoirs that are moderately heterogeneous, contain moderately viscous oils, and have adverse water-oil mobility ratios. For example, many wells in Kansas's Arbuckle formation had similar treatments and we have seen very effective results. In addition, there were previous polymer treatments conducted by Texaco in Alameda Field on a number of wells throughout the Viola-Simpson formation in the early 70's. Most of the treatments proved to be very successful.

  8. The Field Trip Book: Study Travel Experiences in Social Studies

    ERIC Educational Resources Information Center

    Morris, Ronald V.

    2010-01-01

    Looking for social studies adventures to help students find connections to democratic citizenship? Look no further! This book provides just the answer teachers need for engaging students in field trips as researching learners with emphasis on interdisciplinary social studies plus skills in collecting and reporting data gathered from field…

  9. Satellite to study earth's magnetic field

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Magnetic Field Satellite (Magsat) designed to measure the near earth magnetic field and crustal anomalies is briefly described. A scalar magnetometer to measure the magnitude of the earth's crustal magnetic field and a vector magnetometer to measure magnetic field direction as well as magnitude are included. The mission and its objectives are summarized along with the data collection and processing system.

  10. Studies of the Martian Magnetic Field

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1998-01-01

    This report covers two awards: the first NAGW-2573 was awarded to enable participation in the Mars 94 mission that slipped to become the Mars 96 mission. Upon the unfortunate failure of Mars 96 to achieve its intended trajectory, the second grant was awarded to closeout the Mars 96 activities. Our initial efforts concentrated on assisting our colleagues: W. Riedler, K. Schwingenschuh, K. Gringanz, M. Verigin and Ye. Yeroshenko with advice on the development of the magnetic field portion of the investigation and to help them with test activities. We also worked with them to properly analyze the Phobos magnetic field and plasma data in order to optimize the return from the Mars 94/96 mission. This activity resulted in 18 papers on Mars scientific topics, and two on the instrumentation. One of these latter two papers was the last of the papers written, and speaks to the value of the closeout award. These 20 papers are listed in the attached bibliography. Because we had previously studied Venus and Titan and since it was becoming evident that the magnetic field was very weak, we compared the various properties of the Martian interaction with those of the analogous interactions at Venus and Titan while other papers simply analyzed the properties of the interaction as Phobos 2 observed them. One very interesting observation was the identification of ions picked up in the solar wind, originating in Mars neutral atmosphere. These had been predicted by our earlier observation of cyclotron waves at the proton gyrofrequency in the region upstream from Mars in the solar wind. Of course, the key question we addressed was that of the intrinsic or induced nature of the Martian magnetic field. We found little evidence for the former and much for the latter point of view. We also discussed the instrumentation planned for the Mars balloon and the instrumentation on the orbiter. In all these studies were very rewarding despite the short span of the Phobos data. Although they did not

  11. Remarkable enhancement of charge carrier mobility of conjugated polymer field-effect transistors upon incorporating an ionic additive

    PubMed Central

    Luo, Hewei; Yu, Chenmin; Liu, Zitong; Zhang, Guanxin; Geng, Hua; Yi, Yuanping; Broch, Katharina; Hu, Yuanyuan; Sadhanala, Aditya; Jiang, Lang; Qi, Penglin; Cai, Zhengxu; Sirringhaus, Henning; Zhang, Deqing

    2016-01-01

    Organic semiconductors with high charge carrier mobilities are crucial for flexible electronic applications. Apart from designing new conjugated frameworks, different strategies have been explored to increase charge carrier mobilities. We report a new and simple approach to enhancing the charge carrier mobility of DPP-thieno[3,2-b]thiophene–conjugated polymer by incorporating an ionic additive, tetramethylammonium iodide, without extra treatments into the polymer. The resulting thin films exhibit a very high hole mobility, which is higher by a factor of 24 than that of thin films without the ionic additive under the same conditions. On the basis of spectroscopic grazing incidence wide-angle x-ray scattering and atomic force microscopy studies as well as theoretical calculations, the remarkable enhancement of charge mobility upon addition of tetramethylammonium iodide is attributed primarily to an inhibition of the torsion of the alkyl side chains by the presence of the ionic species, facilitating a more ordered lamellar packing of the alkyl side chains and interchain π-π interactions. PMID:27386541

  12. Remarkable enhancement of charge carrier mobility of conjugated polymer field-effect transistors upon incorporating an ionic additive.

    PubMed

    Luo, Hewei; Yu, Chenmin; Liu, Zitong; Zhang, Guanxin; Geng, Hua; Yi, Yuanping; Broch, Katharina; Hu, Yuanyuan; Sadhanala, Aditya; Jiang, Lang; Qi, Penglin; Cai, Zhengxu; Sirringhaus, Henning; Zhang, Deqing

    2016-05-01

    Organic semiconductors with high charge carrier mobilities are crucial for flexible electronic applications. Apart from designing new conjugated frameworks, different strategies have been explored to increase charge carrier mobilities. We report a new and simple approach to enhancing the charge carrier mobility of DPP-thieno[3,2-b]thiophene-conjugated polymer by incorporating an ionic additive, tetramethylammonium iodide, without extra treatments into the polymer. The resulting thin films exhibit a very high hole mobility, which is higher by a factor of 24 than that of thin films without the ionic additive under the same conditions. On the basis of spectroscopic grazing incidence wide-angle x-ray scattering and atomic force microscopy studies as well as theoretical calculations, the remarkable enhancement of charge mobility upon addition of tetramethylammonium iodide is attributed primarily to an inhibition of the torsion of the alkyl side chains by the presence of the ionic species, facilitating a more ordered lamellar packing of the alkyl side chains and interchain π-π interactions.

  13. Remarkable enhancement of charge carrier mobility of conjugated polymer field-effect transistors upon incorporating an ionic additive.

    PubMed

    Luo, Hewei; Yu, Chenmin; Liu, Zitong; Zhang, Guanxin; Geng, Hua; Yi, Yuanping; Broch, Katharina; Hu, Yuanyuan; Sadhanala, Aditya; Jiang, Lang; Qi, Penglin; Cai, Zhengxu; Sirringhaus, Henning; Zhang, Deqing

    2016-05-01

    Organic semiconductors with high charge carrier mobilities are crucial for flexible electronic applications. Apart from designing new conjugated frameworks, different strategies have been explored to increase charge carrier mobilities. We report a new and simple approach to enhancing the charge carrier mobility of DPP-thieno[3,2-b]thiophene-conjugated polymer by incorporating an ionic additive, tetramethylammonium iodide, without extra treatments into the polymer. The resulting thin films exhibit a very high hole mobility, which is higher by a factor of 24 than that of thin films without the ionic additive under the same conditions. On the basis of spectroscopic grazing incidence wide-angle x-ray scattering and atomic force microscopy studies as well as theoretical calculations, the remarkable enhancement of charge mobility upon addition of tetramethylammonium iodide is attributed primarily to an inhibition of the torsion of the alkyl side chains by the presence of the ionic species, facilitating a more ordered lamellar packing of the alkyl side chains and interchain π-π interactions. PMID:27386541

  14. Identification of Bacteria Synthesizing Ribosomal RNA in Response to Uranium Addition During Biostimulation at the Rifle, CO Integrated Field Research Site.

    PubMed

    McGuinness, Lora R; Wilkins, Michael J; Williams, Kenneth H; Long, Philip E; Kerkhof, Lee J

    2015-01-01

    Understanding which organisms are capable of reducing uranium at historically contaminated sites provides crucial information needed to evaluate treatment options and outcomes. One approach is determination of the bacteria which directly respond to uranium addition. In this study, uranium amendments were made to groundwater samples from a site of ongoing biostimulation with acetate. The active microbes in the planktonic phase were deduced by monitoring ribosomes production via RT-PCR. The results indicated several microorganisms were synthesizing ribosomes in proportion with uranium amendment up to 2 μM. Concentrations of U (VI) >2 μM were generally found to inhibit ribosome synthesis. Two active bacteria responding to uranium addition in the field were close relatives of Desulfobacter postgateii and Geobacter bemidjiensis. Since RNA content often increases with growth rate, our findings suggest it is possible to rapidly elucidate active bacteria responding to the addition of uranium in field samples and provides a more targeted approach to stimulate specific populations to enhance radionuclide reduction in contaminated sites.

  15. Identification of Bacteria Synthesizing Ribosomal RNA in Response to Uranium Addition During Biostimulation at the Rifle, CO Integrated Field Research Site

    PubMed Central

    McGuinness, Lora R.; Wilkins, Michael J.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.

    2015-01-01

    Understanding which organisms are capable of reducing uranium at historically contaminated sites provides crucial information needed to evaluate treatment options and outcomes. One approach is determination of the bacteria which directly respond to uranium addition. In this study, uranium amendments were made to groundwater samples from a site of ongoing biostimulation with acetate. The active microbes in the planktonic phase were deduced by monitoring ribosomes production via RT-PCR. The results indicated several microorganisms were synthesizing ribosomes in proportion with uranium amendment up to 2 μM. Concentrations of U (VI) >2 μM were generally found to inhibit ribosome synthesis. Two active bacteria responding to uranium addition in the field were close relatives of Desulfobacter postgateii and Geobacter bemidjiensis. Since RNA content often increases with growth rate, our findings suggest it is possible to rapidly elucidate active bacteria responding to the addition of uranium in field samples and provides a more targeted approach to stimulate specific populations to enhance radionuclide reduction in contaminated sites. PMID:26382047

  16. Identification of Bacteria Synthesizing Ribosomal RNA in Response to Uranium Addition During Biostimulation at the Rifle, CO Integrated Field Research Site.

    PubMed

    McGuinness, Lora R; Wilkins, Michael J; Williams, Kenneth H; Long, Philip E; Kerkhof, Lee J

    2015-01-01

    Understanding which organisms are capable of reducing uranium at historically contaminated sites provides crucial information needed to evaluate treatment options and outcomes. One approach is determination of the bacteria which directly respond to uranium addition. In this study, uranium amendments were made to groundwater samples from a site of ongoing biostimulation with acetate. The active microbes in the planktonic phase were deduced by monitoring ribosomes production via RT-PCR. The results indicated several microorganisms were synthesizing ribosomes in proportion with uranium amendment up to 2 μM. Concentrations of U (VI) >2 μM were generally found to inhibit ribosome synthesis. Two active bacteria responding to uranium addition in the field were close relatives of Desulfobacter postgateii and Geobacter bemidjiensis. Since RNA content often increases with growth rate, our findings suggest it is possible to rapidly elucidate active bacteria responding to the addition of uranium in field samples and provides a more targeted approach to stimulate specific populations to enhance radionuclide reduction in contaminated sites. PMID:26382047

  17. Geometrical study of nanoscale field effect diodes

    NASA Astrophysics Data System (ADS)

    Manavizadeh, Negin; Raissi, Farshid; Asl Soleimani, Ebrahim; Pourfath, Mahdi

    2012-04-01

    In this paper, the previously proposed side-contacted field effect diode (FED) is carefully studied and its characteristic is compared against that of a modified FED and a metal oxide semiconductor field effect transistor (MOSFET). The influences of the body thickness, each gate length and access resistance are investigated. The figures of merit including intrinsic gate delay time and energy-delay product, which represent the speed and switching energy of the device, respectively, are studied. Our results highlight that FEDs are good candidates for obtaining a high Ion/Ioff ratio with a relatively short delay time compared to conventional FEDs and MOSFETs. We show that by a careful scaling of the source-drain region, the access resistance can be optimized. We demonstrate that a well-tempered device with a high switching response and a lower energy consumption can be achieved with a 30 nm body thickness, 85 nm source-drain length and a drain gate length longer than the source gate length.

  18. Planning and setting objectives in field studies: Chapter 2

    USGS Publications Warehouse

    Fisher, Robert N.; Dodd, C. Kenneth

    2016-01-01

    This chapter enumerates the steps required in designing and planning field studies on the ecology and conservation of reptiles, as these involve a high level of uncertainty and risk. To this end, the chapter differentiates between goals (descriptions of what one intends to accomplish) and objectives (the measurable steps required to achieve the established goals). Thus, meeting a specific goal may require many objectives. It may not be possible to define some of them until certain experiments have been conducted; often evaluations of sampling protocols are needed to increase certainty in the biological results. And if sampling locations are fixed and sampling events are repeated over time, then both study-specific covariates and sampling-specific covariates should exist. Additionally, other critical design considerations for field study include obtaining permits, as well as researching ethics and biosecurity issues.

  19. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  20. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  1. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  2. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  3. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  4. Field testing plan for unsaturated zone monitoring and field studies

    SciTech Connect

    Young, M.H.; Wierenga, P.J.; Warrick, A.W.

    1996-10-01

    The University of Arizona, in cooperation with the Bureau of Economic Geology at The University of Texas at Austin, and Stephens and Associates in Albuquerque, New Mexico has developed a field testing plan for evaluating subsurface monitoring systems. The U.S. Nuclear Regulatory Commission has requested development of these testing plans for low-level radioactive waste disposal sites (LLW) and for monitoring at decommissioned facilities designated under the {open_quotes}Site Decommissioning Management Plan{close_quotes} (SDMP). The tests are conducted on a 50 m by 50 m plot on the University of Arizona`s Maricopa Agricultural Center. Within the 50 m by 50 m plot one finds: (1) an instrumented buried trench, (2) monitoring islands similar to those proposed for the Ward Valley, California LLW Facility, (3) deep borehole monitoring sites, (4) gaseous transport monitoring, and (5) locations for testing non-invasive geophysical measurement techniques. The various subplot areas are instrumented with commercially available instruments such as neutron probes, time domain reflectometry probes, tensiometers, psychrometers, heat dissipation sensors, thermocouples, solution samplers, and cross-hole geophysics electrodes. Measurement depths vary from ground surface to 15 m. The data from the controlled flow and transport experiments, conducted over the plot, will be used to develop an integrated approach to long-term monitoring of the vadose zone at waste disposal sites. The data will also be used to test field-scale flow and transport models. This report describes in detail the design of the experiment and the methodology proposed for evaluating the data.

  5. Dual rover human habitation field study

    NASA Astrophysics Data System (ADS)

    Litaker, Harry L.; Thompson, Shelby G.; Szabo, Richard; Twyford, Evan S.; Conlee, Carl S.; Howard, Robert L.

    2013-10-01

    For the last 3 years, the National Aeronautics and Space Administration (NASA) has been testing a pressurized rover prototype in the deserts of Arizona to obtain human-in-the-loop performance data. This year's field trial consisted of operating two rovers simultaneously while embarking on two 7-day flight-like exploration missions. During the 2010 Desert Research and Technology Studies (DRATS) at Black Point Lava Flow and SP Mountain in Arizona, NASA human factors investigators, in cooperation with other engineers and scientists, collected data on both the daily living and working within and around the Space Exploration Vehicle (SEV). Both objective and subjective data were collected using standard human factors metrics. Over 305 h of crew habitability data were recorded during the field trial with 65 elements of habitation examined. Acceptability of the vehicles over the course of the missions was considered satisfactory by the majority of the crews. As with previous testing, habitation was considered acceptable by the crews, but some issues concerning stowage, Waste Containment System (WCS) volume, and sleep curtains need to be considered for redesign for the next generation vehicle.

  6. Control of hydrogen sulfide production in oil fields by managing microbial communities through nitrate or nitrite addition

    NASA Astrophysics Data System (ADS)

    Hubert, Casey R. J.

    Nitrate or nitrite injection into oil reservoirs during water flooding has the potential to control biological souring, the production of hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). Souring control is essential because sulfide is toxic, sulfide precipitates can plug reservoir formations, souring lowers crude oil value, and SRB induce corrosion. Nitrate and nitrite can stimulate heterotrophic nitrate- or nitrite-reducing bacteria (hNRB) and nitrate- or nitrite-reducing, sulfide oxidizing bacteria (NRSOB). Nitrite also inhibits SRB activity by blocking the sulfate reduction pathway. Continuous up-flow packed-bed bioreactors were inoculated with produced water from the Coleville oil field to establish sulfide-producing biofilms similar to those found in sour reservoirs. Nitrate or nitrite addition to bioreactors indicated that the dose required for hNRB or NR-SOB to control souring depended on the concentration of oil organics. Either mechanism mediates the net removal of oil organics (lactate) with nitrate or nitrite, with lower doses of nitrate required due to its greater oxidative power. Microbial community analysis by reverse sample genome probing (RSGP) revealed that NR-SOB mediated sulfide removal at low nitrate or nitrite concentrations when lactate was still available to SRB and the redox potential was low. At high nitrate doses hNRB oxidized lactate directly, produced nitrite and maintained a high redox potential, thus excluding SRB activity. Facultatively chemolithotrophic Campylobacter sp. strains were isolated from the bioreactors and incorporated into RSGP analyses, revealing their dominance in both NR-SOB- and hNRB-containing communities. The metabolic flexibility of these strains may confer a competitive advantage over obligate chemolithotrophs like Thiomicrospira sp. strain CVO or hNRB that do not have NR-SOB activity like newly isolated Thauera sp. and Rhodobacter sp. strains. A single high dose of nitrite resulted in immediate

  7. ERICA plans for winter storms field study

    NASA Astrophysics Data System (ADS)

    Hadlock, Ron

    The Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) field study will be conducted between December 1, 1988, and February 28, 1989. The oceanic area that is approximately bounded by t he Gulf Stream and North America, from coastal Carolina to just east of Newfoundland, will be the region for special observations obtained by recently developed measurement systems, including high-resolution and safe Loran-C dropwindsondes, CLASS rawinsondes, an array of drifting data buoys, and multiple airborne Doppler radars. The special observations will be acquired within a framework of all conventional operational data available for the eastern United States and Canada, including that from the National Weather Service's land sites (plus supplemental rawinsonde observations), ocean platforms, U.S. Air Force WC-130 National Winter Storms Operations Plan reconnaissance flights, and civilian and military weather satellites. Satellite imagery and soundings willl be available in real time and archived through facilities of NOAA and the military.

  8. Coulomb Glass: a Mean Field Study

    NASA Astrophysics Data System (ADS)

    Mandra, Salvatore; Palassini, Matteo

    2012-02-01

    We study the Coulomb glass model of disordered localized electrons with long-range Coulomb interaction, which describes systems such as disordered insulators, granular metals, amorphous semiconductors, or doped crystalline semiconductors. Long ago Efros and Shklovskii showed that the long-range repulsion induces a soft Coulomb gap in the single particle density of states at low temperatures. Recent works suggested that this gap is associated to a transition to a glass phase, similar to the Almeida-Thouless transition in spin glasses. In this work, we use a mean field approach to characterize several physical properties of the Coulomb glass. In particular, following a seminal work of Bray and Moore, we show that the Edward-Anderson parameter qEA and the spin glass susceptibility χSG are directly related to spectrum distribution of the Hessian matrix around free energy minima. Using this result, we show that no glass transition is associated to the gap formation.

  9. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

    PubMed

    Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

  10. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

    PubMed

    Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.

  11. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field

    PubMed Central

    Liang, Guopeng; Houssou, Albert A.; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013–2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha-1 year-1 (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013–2014 and 2014–2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013–2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014–2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

  12. Field-scale investigation of enhanced petroleum hydrocarbon biodegradation in the vadose zone combining soil venting as an oxygen source with moisture and nutrient addition. Appendices. Doctoral thesis

    SciTech Connect

    Miller, R.N.

    1990-01-01

    This document contains appendices regarding a reprint on a field scale investigation of enhanced petroleum hydrocarbon biodegradation in the vadose zone combining soil venting as a oxygen source with moisture and nutrient addition.

  13. Studies of jet fuel additives using the quartz crystal microbalance and pressure monitoring at 140 C

    SciTech Connect

    Zabarnick, S.; Grinstead, R.R. . Aerospace Mechanics Div./KL-463)

    1994-11-01

    Recent advances in jet aircraft and engine technology have placed an ever increasing heat load on the aircraft. The bulk of this excess heat is absorbed by the aircraft fuel, as jet fuel is used as the primary coolant for the numerous heat sources. The quartz crystal microbalance (QCM) and pressure monitoring are used for the evaluation of jet fuel additives for the improvement of jet fuel thermal stability. The mechanisms of additive behavior are determined by measuring the time-dependent deposition with the QCM and oxidation by pressure measurements. Studies at various additive concentrations permits the determination of optimum additive concentrations. Additive packages made of mixtures of antioxidants, detergent/dispersants, and metal deactivators are shown to yield good improvements in thermal stability over a wide range of jet fuel types.

  14. Forestry Impacts on Mercury Mobility, Methylation, and Bioaccumulation - A Field Experiment with Enriched Stable Mercury Isotope Additions

    NASA Astrophysics Data System (ADS)

    Mitchell, Carl; Haynes, Kristine; Mazur, Maxwell; Fidler, Nathan; Eckley, Chris; Kolka, Randy; Eggert, Susan; Sebestyen, Stephen

    2013-04-01

    Forest harvesting has clear impacts on terrestrial hydrology at least over the short term. Similar biogeochemical impacts, such as augmented mercury fluxes or downstream impacts on ecosystems are not as clear, and recent studies have not demonstrated consistent or predictable impacts across systems. To gain a better process understanding of mercury cycling in upland forest-lowland peatland ecosystems, we undertook a field-scale experiment at a study site in northern Minnesota (USA) where shallow subsurface hillslope runoff flows into an adjacent peatland ecosystem. Starting in 2009, three upland forest plots (< 1 hectare each) were delineated and hydrometric infrastructure such as runoff trenches, snow lysimeters, soil moisture probes, shallow piezometers, and throughfall gauges were installed in each plot. We added 14.2 to 16.7 μg/m2 of enriched mercury-200 and mercury-204 (as dilute mercuric nitrate) in the spring of 2011 and 2012, respectively, to distinguish between contemporary and legacy mercury and to provide some insight into the duration of contemporary mercury mobility in impacted terrestrial ecosystems. During the late winter of 2012, one of the study plots was clearcut and approximately 80% of slash was removed. We clearcut a second plot without slash removal, and left the third plot as a control. Throughout the study, we have monitored (including isotopes): mercury in runoff, soil-air gaseous Hg fluxes, methylation potentials in the adjacent peatland, and bioaccumulation into invertebrates inhabiting the adjacent peatland. Early results mostly indicate that slash removal actually lessens the impacts of clearcutting on mercury mobility (although forest harvesting in general does have a significant impact) and that forestry operations at this scale have little to no impact on methylation or bioaccumulation in downstream peatlands. Thus far, the greatest impact of slash removal in forest harvested systems is an increase in mercury evasion, likely as a

  15. Electrostatic-field-enhanced photoexfoliation of bilayer benzene: A first-principles study

    NASA Astrophysics Data System (ADS)

    Uchida, Kazuki; Silaeva, Elena P.; Watanabe, Kazuyuki

    2016-06-01

    Photoexfoliation of bilayer benzene in an external electrostatic (dc) field is studied using time-dependent density functional theory combined with molecular dynamics. We find that the dc-field-induced force on the upper benzene in addition to the repulsive interaction between the positively charged benzene molecules induced by the laser field leads to fast athermal exfoliation. Thus, we conclude that the dc field enhances the photoexfoliation due to dc-field emission in addition to laser-assisted photoemission. The athermal exfoliation process is shown to depend crucially on the charge state of benzene molecules rather than on the excitation energy supplied by the laser.

  16. Evaluating Drugs and Food Additives for Public Use: A Case Studies Approach.

    ERIC Educational Resources Information Center

    Merritt, Sheridan V.

    1980-01-01

    Described is a case study used in an introductory college biology course that provides a basis for generating debate on an issue concerning the regulation of controversial food additives and prescription drugs. The case study contained within this article deals with drug screening, specifically with information related to thalidomide. (CS)

  17. Alkaline flood prediction studies, Ranger VII pilot, Wilmington Field, California

    SciTech Connect

    Mayer, E.H.; Breit, V.S.

    1982-01-01

    The paper discusses: (1) The design of a simulator to model alkaline displacement mechanisms and the current state-of-the-art understanding of in-situ caustic consumption. (2) Assimilation of laboratory core flood and rock consumption data. Use of this data in 1-D and 2-D limited area simulations, and a 3-D model of the entire pilot project. (3) Simulation studies of alkaline flood behavior in a small 2-D area of the field for various concentrations, slug sizes, long term consumption functions and two relative permeability adjustment mechanisms. (4) Scale up of 2-D simulation results, and their use in a 271 acre 1.097 x 10/sup 6/m/sup 2/), 7 layered 3-D model of the pilot. (5) Comparison of 3-D simulator results with initial field alkaline flood performance. (6) Recommended additional application of the simulator methods developed in this pilot and in other alkaline floods. 10 refs.

  18. Collaborative Technology Assessments Of Transient Field Processing And Additive Manufacturing Technologies As Applied To Gas Turbine Components

    SciTech Connect

    Ludtka, Gerard Michael; Dehoff, Ryan R.; Szabo, Attila; Ucok, Ibrahim

    2016-01-01

    ORNL partnered with GE Power & Water to investigate the effect of thermomagnetic processing on the microstructure and mechanical properties of GE Power & Water newly developed wrought Ni-Fe-Cr alloys. Exploration of the effects of high magnetic field process during heat treatment of the alloys indicated conditions where applications of magnetic fields yields significant property improvements. The alloy aged using high magnetic field processing exhibited 3 HRC higher hardness compared to the conventionally-aged alloy. The alloy annealed at 1785 F using high magnetic field processing demonstrated an average creep life 2.5 times longer than that of the conventionally heat-treated alloy. Preliminary results show that high magnetic field processing can improve the mechanical properties of Ni-Fe-Cr alloys and potentially extend the life cycle of the gas turbine components such as nozzles leading to significant energy savings.

  19. Study raises questions about measurement of 'additionality,'or maintaining domestic health spending amid foreign donations.

    PubMed

    Garg, Charu C; Evans, David B; Dmytraczenko, Tania; Izazola-Licea, José-Antonio; Tangcharoensathien, Viroj; Ejeder, Tessa Tan-Torres

    2012-02-01

    Donor nations and philanthropic organizations increasingly require that funds provided for a specific health priority such as HIV should supplement domestic spending on that priority-a concept known as "additionality." We investigated the "additionality" concept using data from Honduras, Rwanda, and Thailand, and we found that the three countries increased funding for HIV in response to increased donor funding. In contrast, the study revealed that donors, faced with increased Global Fund resources for HIV in certain countries, tended to decrease their funding for HIV or shift funds for use in non-HIV health areas. More broadly, we found many problems in the measurement and interpretation of additionality. These findings suggest that it would be preferable for donors and countries to agree on how best to use available domestic and external funds to improve population health, and to develop better means of tracking outcomes, than to try to develop more sophisticated methods to track additionality.

  20. SHEEP MOUNTAIN WILDERNESS STUDY AREA AND CUCAMONGA WILDERNESS AND ADDITIONS, CALIFORNIA.

    USGS Publications Warehouse

    Evans, James G.; Ridenour, James

    1984-01-01

    The Sheep Mountain Wilderness Study Area and Cucamonga Wilderness and additions encompass approximately 104 sq mi of the eastern San Gabriel Mountains, Los Angeles and San Bernardino Counties, California. A mineral survey indicates areas of probable and substantiated tungsten and gold resource potential for parts of the Sheep Mountain Wilderness Study Area and an area of probable tungsten and gold resource potential in the Cucamonga Wilderness and additions. The rugged topography, withdrawal of lands from mineral entry to protect watershed, and restricted entry of lands during periods of high fire danger have contributed to the continuing decline in mineral exploration. The geologic setting precludes the presence of energy resources.

  1. Examination of a Model for Field Studies in Science

    ERIC Educational Resources Information Center

    Riban, David M.

    1976-01-01

    Discusses ways to increase the effectiveness of field studies as an instructional method. Describes a study in which high school students who completed a geological field study scored higher on an earth science test than students who had not participated in the field study. (MLH)

  2. 76 FR 31823 - Technical Amendment to List of User Fee Airports: Addition of Dallas Love Field Municipal Airport...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    .... FOR FURTHER INFORMATION CONTACT: Roger Kaplan, Acting Director, Audits and Self-Inspection, Office of Field Operations, at 202-325-4543 or by e-mail at Roger.Kaplan@dhs.gov . SUPPLEMENTARY INFORMATION:...

  3. Plant Taxonomy as a Field Study

    ERIC Educational Resources Information Center

    Dalby, D. H.

    1970-01-01

    Suggests methods of teaching plant identification and taxonomic theory using keys, statistical analyses, and biometrics. Population variation, genotype- environment interaction and experimental taxonomy are used in laboratory and field. (AL)

  4. Field Ecology Studies in the Rocky Mountains.

    ERIC Educational Resources Information Center

    Robertson, Philip A.

    1978-01-01

    Describes a six-week field plant ecology course in Montana which is offered by the Botany Department at Southern Illinois University. The goals of the course, how it is taught, and student evaluation are also presented. (HM)

  5. Combustion Safety Simplified Test Protocol Field Study

    SciTech Connect

    Brand, L.; Cautley, D.; Bohac, D.; Francisco, P.; Shen, L.; Gloss, S.

    2015-11-01

    Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project team collected field data on 11 houses in 2015.

  6. Comparative study of electrolyte additives using electrochemical impedance spectroscopy on symmetric cells

    NASA Astrophysics Data System (ADS)

    Petibon, R.; Sinha, N. N.; Burns, J. C.; Aiken, C. P.; Ye, Hui; VanElzen, Collette M.; Jain, Gaurav; Trussler, S.; Dahn, J. R.

    2014-04-01

    The effect of various electrolyte additives and additive combinations added to a 1 M LiPF6 EC:EMC electrolyte on the positive and negative electrodes surface of 1 year old wound LiCoO2/graphite cells and Li[Ni0.4Mn0.4Co0.2])O2/graphite cells was studied using electrochemical impedance spectroscopy (EIS) on symmetric cells. The additives tested were: vinylene carbonate (VC), trimethoxyboroxine (TMOBX), fluoroethylene carbonate (FEC), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and H2O alone or in combination. In general, compared to control electrolyte, the additives tested reduced the impedance of the positive electrode and increased the impedance of the negative electrode with the exception of LiTFSI in Li[Ni0.4Mn0.4Co0.2]O2/graphite wound cells. Higher charge voltage led to higher positive electrode impedance, with the exception of 2%VC + 2% FEC, and 2% LiTFSI. In some cases, some additives when mixed with another controlled the formation of the SEI at one electrode, and shared the formation of the SEI at one electrode when mixed with a different additive.

  7. Monte Carlo study of MLC fields for cobalt therapy machine

    PubMed Central

    Ayyangar, Komanduri M.; Rani, Roopa A.; Kumar, Anil; Reddy, A. R.

    2014-01-01

    An automated Multi-Leaf Collimator (MLC) system has been developed as add-on for the cobalt-60 teletherapy machines available in India. The goal of the present computational study is to validate the MLC design using Monte Carlo (MC) modeling. The study was based on the Kirloskar-supplied Phoenix model machines that closely match the Atomic Energy of Canada Limited (AECL) theratron-80 machine. The MLC is a retrofit attachment to the collimator assembly, with 14 non-divergent leaf pairs of 40 mm thick, 7 mm wide, and 150 mm long tungsten alloy plates with rounded edges and 20 mm tongue and 2 mm groove in each leaf. In the present work, the source and collimator geometry has been investigated in detail to arrive at a model that best represents the measured dosimetric data. The authors have studied in detail the proto-I MLC built for cobalt-60. The MLC field sizes were MC simulated for 2 × 2 cm2 to 14 × 14 cm2 square fields as well as irregular fields, and the percent depth dose (PDD) and profile data were compared with ROPS† treatment planning system (TPS). In addition, measured profiles using the IMATRIXX system‡ were also compared with the MC simulations. The proto-I MLC can define radiation fields up to 14 × 14 cm2 within 3 mm accuracy. The maximum measured leakage through the leaf ends in closed condition was 3.4% and interleaf leakage observed was 7.3%. Good agreement between MC results, ROPS and IMATRIXX results has been observed. The investigation also supports the hypothesis that optical and radiation field coincidence exists for the square fields studied with the MLC. Plots of the percent depth dose (PDD) data and profile data for clinically significant irregular fields have also been presented. The MC model was also investigated to speed up the calculations to allow calculations of clinically relevant conformal beams. †Radiation Oncology Planning System (ROPS) is supplied by Tirumala Jyothi Computer Systems described at https

  8. Generating Scenarios of Addition and Subtraction: A Study of Japanese University Students

    ERIC Educational Resources Information Center

    Kinda, Shigehiro

    2013-01-01

    Students are presented with problems involving three scenario types of addition and subtraction in elementary mathematics: one dynamic ("Change") and two static ("Combine, Compare"). Previous studies have indicated that the dynamic type is easier for school children, whereas the static types are more difficult and comprehended only gradually…

  9. Experimental study of combustion of decane, dodecane and hexadecane with polymeric and nano-particle additives

    NASA Astrophysics Data System (ADS)

    Ghamari, Mohsen; Ratner, Albert

    2015-11-01

    Recent studies have shown that adding combustible nano-particles could have promising effects on increasing burning rate of liquid fuels. Combustible nano-particles could enhance the heat conduction and mixing within the droplet. Polymers have also higher burning rate than regular hydrocarbon fuels because of having the flame closer to the droplet surface. Therefore adding polymeric additive could have the potential to increase the burning rate. In this study, combustion of stationary fuel droplets of n-Decane, n-Dodecane and n-Hexadecane doped with different percentages of a long chain polymer and also a very fine nano carbon was examined and compared with the pure hydrocarbon behavior. In contrast with hydrocarbon droplets with no polymer addition, several zones of combustion including a slow and steady burning zone, a strong swelling zone and a final fast and fairly steady combustion zone were also detected. In addition, increasing polymer percentage resulted in a more extended swelling zone and shorter slow burning zone in addition to a shorter total burning time. Addition of nano-particles also resulted in an overall increased burning rate and shortened burning time which is due to enhanced heat conduction within the droplet.

  10. Mental addition in bilinguals: an FMRI study of task-related and performance-related activation.

    PubMed

    Lin, Jo-Fu Lotus; Imada, Toshiaki; Kuhl, Patricia K

    2012-08-01

    Behavioral studies show that bilinguals are slower and less accurate when performing mental calculation in their nondominant (second; L2) language than in their dominant (first; L1) language. However, little is known about the neural correlates associated with the performance differences observed between bilinguals' 2 languages during arithmetic processing. To address the cortical activation differences between languages, the current study examined task-related and performance-related brain activation during mental addition when problems were presented auditorily in participants' L1 and L2. Eleven Chinese-English bilinguals heard 2-digit addition problems that required exact or approximate calculations. Functional magnetic resonance imaging results showed that auditorily presented multidigit addition in bilinguals activates bilateral inferior parietal and inferior frontal regions in both L1 and L2. Language differences were observed in the form of greater activation for L2 exact addition in the left inferior frontal area. A negative correlation between brain activation and behavioral performance during mental addition in L2 was observed in the left inferior parietal area. Current results provide further evidence for the effects of language-specific experience on arithmetic processing in bilinguals at the cortical level.

  11. Preliminary Evaluation of a Field and Non-Field Based Social Studies Preservice Teacher Education Program

    ERIC Educational Resources Information Center

    Napier, John D.; Vansickle, Ronald L.

    1978-01-01

    Comparison of pre-service social studies teachers in field and non-field based methods courses indicated no significant differences with regard to teaching skills, attitudes, or behaviors teachers should exhibit in the classroom. (Author/DB)

  12. Sequential neural processes in abacus mental addition: an EEG and FMRI case study.

    PubMed

    Ku, Yixuan; Hong, Bo; Zhou, Wenjing; Bodner, Mark; Zhou, Yong-Di

    2012-01-01

    Abacus experts are able to mentally calculate multi-digit numbers rapidly. Some behavioral and neuroimaging studies have suggested a visuospatial and visuomotor strategy during abacus mental calculation. However, no study up to now has attempted to dissociate temporally the visuospatial neural process from the visuomotor neural process during abacus mental calculation. In the present study, an abacus expert performed the mental addition tasks (8-digit and 4-digit addends presented in visual or auditory modes) swiftly and accurately. The 100% correct rates in this expert's task performance were significantly higher than those of ordinary subjects performing 1-digit and 2-digit addition tasks. ERPs, EEG source localizations, and fMRI results taken together suggested visuospatial and visuomotor processes were sequentially arranged during the abacus mental addition with visual addends and could be dissociated from each other temporally. The visuospatial transformation of the numbers, in which the superior parietal lobule was most likely involved, might occur first (around 380 ms) after the onset of the stimuli. The visuomotor processing, in which the superior/middle frontal gyri were most likely involved, might occur later (around 440 ms). Meanwhile, fMRI results suggested that neural networks involved in the abacus mental addition with auditory stimuli were similar to those in the visual abacus mental addition. The most prominently activated brain areas in both conditions included the bilateral superior parietal lobules (BA 7) and bilateral middle frontal gyri (BA 6). These results suggest a supra-modal brain network in abacus mental addition, which may develop from normal mental calculation networks.

  13. Electron field emission in nanostructures: A first-principles study

    NASA Astrophysics Data System (ADS)

    Driscoll, Joseph Andrew

    The objective of this work was to study electron field emission from several nanostructures using a first-principles framework. The systems studied were carbon nanowires, graphene nanoribbons, and nanotubes of varying composition. These particular structures were chosen because they have recently been identified as showing novel physical phenomena, as well as having tremendous industrial applications. We examined the field emission under a variety of conditions, including laser illumination and the presence of adsorbates. The goal was to explore how these conditions affect the field emission performance. In addition to the calculations, this dissertation has presented computational developments by the author that allowed these demanding calculations to be performed. There are many possible choices for basis when performing an electronic structure calculation. Examples are plane waves, atomic orbitals, and real-space grids. The best choice of basis depends on the structure of the system being analyzed and the physical processes involved (e.g., laser illumination). For this reason, it was important to conduct rigorous tests of basis set performance, in terms of accuracy and computational efficiency. There are no existing benchmark calculations for field emission, but transport calculations for nanostructures are similar, and so provide a useful reference for evaluating the performance of various basis sets. Based on the results, for the purposes of studying a non-periodic nanostructure under field emission conditions, we decided to use a real-space grid basis which incorporates the Lagrange function approach. Once a basis was chosen, in this case a real-space grid, the issue of boundary conditions arose. The problem is that with a non-periodic system, field emitted electron density can experience non-physical reflections from the boundaries of the calculation volume, leading to inaccuracies. To prevent this issue, we used complex absorbing potentials (CAPs) to absorb

  14. Study finds no cancer link to electromagnetic fields

    SciTech Connect

    Sahl, J.; Kelsh, M.; Greenland, S.

    1993-05-01

    The Southern California Edison Company reports a study of their personnel which looks for an association between exposure to electromagnetic fields (EMF) and deaths due to cancer (emphasis on leukemia, brain cancer and lymphoma). A total of 36,221 employees who had been employed by the company for at least one year were included in the study. The results appear to weaken the argument that EMF is the cause of cancer in the company work environment. The study is said to be an improvement over previous studies in that all personnel from a well-defined work environment were included, complete work histories were included, actual measurements of magnetic fields were performed, and state-of-the-art methods of analysis were used. The relevance of these results to the non-Edison work environment or community exposures is uncertain and to childhood cancers is still more uncertain. The company plans to update these data and perform additional analyses as part of its policy to study and evaluate the occupational implications of EMF.

  15. Microstructural Study Of Zinc Hot Dip Galvanized Coatings with Titanium Additions In The Zinc Melt

    NASA Astrophysics Data System (ADS)

    Konidaris, S.; Pistofidis, N.; Vourlias, G.; Pavlidou, E.; Stergiou, A.; Stergioudis, G.; Polychroniadis, E. K.

    2007-04-01

    Zinc hot-dip galvanizing is a method for protecting iron and steel against corrosion. Galvanizing with pure Zn or Zn with additions like Ni, Al, Pb and Bi has been extensively studied, but there is a lack of scientific information about other additions. The present work examines the effect of a 0.5 wt% Ti addition in the Zn melt. The samples were exposed to accelerated corrosion in a salt spray chamber (SSC). The microstructure and chemical composition of the coatings were determined by Optical Microscopy, XRD and SEM associated with an EDS Analyzer. The results indicate that the coatings have a typical morphology, while Zn-Ti phases were also detected.

  16. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy.

    PubMed

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-01-01

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. The observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys. PMID:26446425

  17. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    SciTech Connect

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.

  18. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    PubMed Central

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-01-01

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. The observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys. PMID:26446425

  19. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  20. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality. PMID:26515667

  1. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.

  2. 34 CFR 350.55 - What are the additional considerations for selecting Field-Initiated Project applications for...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF EDUCATION DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM How Does the... Field-Initiated Project applications for funding? 350.55 Section 350.55 Education Regulations of the... Project applications for funding? (a) The Secretary reserves funds to support some or all of the...

  3. Toward a Field of Interfaith Studies

    ERIC Educational Resources Information Center

    Patel, Eboo

    2013-01-01

    Scholars from a range of fields have long taken an interest in how people who orient around religion differently interact with one another. Indeed, this phenomenon has been the subject of important works in political science ("The Clash of Civilizations" by Samuel Huntington), sociology ("American Grace" by Robert Putnam and…

  4. Geology Field Trip Studies to New England

    ERIC Educational Resources Information Center

    Wood, John H.

    1976-01-01

    A two week, 3,000 mile, geology field trip for secondary school earth science students through New England is discussed. Student expenses, preparation details, accommodations, meals, transportation, course credit, and fieldwork are considered. A detailed trip itinerary is included. (BT)

  5. Combustion Safety Simplified Test Protocol Field Study

    SciTech Connect

    Brand, L; Cautley, D.; Bohac, D.; Francisco, P.; Shen, L.; Gloss, S.

    2015-11-05

    "9Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project provides several key results. State weatherization agencies do not generally track combustion safety failures, the data from those that do suggest that there is little actual evidence that combustion safety failures due to spillage from non-dryer exhaust are common and that only a very small number of homes are subject to the failures. The project team collected field data on 11 houses in 2015. Of these homes, two houses that demonstrated prolonged and excessive spillage were also the only two with venting systems out of compliance with the National Fuel Gas Code. The remaining homes experienced spillage that only occasionally extended beyond the first minute of operation. Combustion zone depressurization, outdoor temperature, and operation of individual fans all provide statistically significant predictors of spillage.

  6. Study of the Cygnus Star-Forming Field

    NASA Astrophysics Data System (ADS)

    Christopherson, Christopher; Kaltcheva, Nadia

    2016-01-01

    The star-forming complexes in Cygnus extend nearly 30 deg in Galactic longitude and 20 deg in latitude, and most probably include star-formation sites located between 600 and 4000 pc. We combine the catalog by Heiles (2000) with uvbyβ photometric data from the catalog of Paunzen (2015) to collate a sample of O and B-type stars with precise homogeneous distances, color excess and available polarimetry. This allows us to identify star-forming sites at different distances along the line of sight and to investigate their spatial correlation to the interstellar matter. Further, we use this sample to study the orientation of the polarization as revealed by the polarized light of the bright early-type stars and analyze the polarization-extinction correlation for this field. Since dust grains align in the presence of a magnetic field cause the observed polarization at optical wavelengths, the data contain information about the large-scale component of the Galactic magnetic field. In addition, wide-field astrophotography equipment was used to image the Cygnus field in Hydrogen-alpha, Hydrogen-beta and the [OIII] line at 500.7 nm. This allows us to map the overall distribution of ionized material and the interstellar dust and trace large-scale regions where the physical conditions change rapidly due to supernova shock fronts and strong stellar winds. Acknowledgments: This work was supported by NSF grant AST- 1516932 and the Wisconsin Space Grant Consortium, NASA Space Grant College and Fellowship Program, NASA Training Grant #NNX14AP22H.

  7. Impact of 2'-hydroxyl sampling on the conformational properties of RNA: update of the CHARMM all-atom additive force field for RNA.

    PubMed

    Denning, Elizabeth J; Priyakumar, U Deva; Nilsson, Lennart; Mackerell, Alexander D

    2011-07-15

    Here, we present an update of the CHARMM27 all-atom additive force field for nucleic acids that improves the treatment of RNA molecules. The original CHARMM27 force field parameters exhibit enhanced Watson-Crick base pair opening which is not consistent with experiment, whereas analysis of molecular dynamics (MD) simulations show the 2'-hydroxyl moiety to almost exclusively sample the O3' orientation. Quantum mechanical (QM) studies of RNA related model compounds indicate the energy minimum associated with the O3' orientation to be too favorable, consistent with the MD results. Optimization of the dihedral parameters dictating the energy of the 2'-hydroxyl proton targeting the QM data yielded several parameter sets, which sample both the base and O3' orientations of the 2'-hydroxyl to varying degrees. Selection of the final dihedral parameters was based on reproduction of hydration behavior as related to a survey of crystallographic data and better agreement with experimental NMR J-coupling values. Application of the model, designated CHARMM36, to a collection of canonical and noncanonical RNA molecules reveals overall improved agreement with a range of experimental observables as compared to CHARMM27. The results also indicate the sensitivity of the conformational heterogeneity of RNA to the orientation of the 2'-hydroxyl moiety and support a model whereby the 2'-hydroxyl can enhance the probability of conformational transitions in RNA.

  8. Competition among Li+, Na+, K+ and Rb+ Monovalent Ions for DNA in Molecular Dynamics Simulations using the Additive CHARMM36 and Drude Polarizable Force Fields

    PubMed Central

    Savelyev, Alexey; MacKerell, Alexander D.

    2015-01-01

    In the present study we report on interactions of and competition between monovalent ions for two DNA sequences in MD simulations. Efforts included the development and validation of parameters for interactions among the first-group monovalent cations, Li+, Na+, K+ and Rb+, and DNA in the Drude polarizable and additive CHARMM36 force fields (FF). The optimization process targeted gas-phase QM interaction energies of various model compounds with ions and osmotic pressures of bulk electrolyte solutions of chemically relevant ions. The optimized ionic parameters are validated against counterion condensation theory and buffer exchange-atomic emission spectroscopy measurements providing quantitative data on the competitive association of different monovalent ions with DNA. Comparison between experimental and MD simulation results demonstrates that, compared to the additive CHARMM36 model, the Drude FF provides an improved description of the general features of the ionic atmosphere around DNA and leads to closer agreement with experiment on the ionic competition within the ion atmosphere. Results indicate the importance of extended simulation systems on the order of 25 Å beyond the DNA surface to obtain proper convergence of ion distributions. PMID:25751286

  9. Preparing for biofilm studies in the field.

    PubMed

    McLean, Robert J C; Simpson, Thomas R

    2008-08-01

    In their natural environments, microorganisms are under constant environmental selection to form biofilms. Using aquatic biofilms as an example, this unit illustrates general concepts in field biology and practical suggestions for designing, conducting, and analyzing biofilm experiments at varying distances from the laboratory. The unit also addresses an example of a special situation (space flight) where experimentation must be done by proxy through another individual or machine.

  10. A Study of Aluminum Combustion in Solids, Powders, Foams, Additively-Manufactured Lattices, and Composites

    NASA Astrophysics Data System (ADS)

    Black, James; Trammell, Norman; Batteh, Jad; Curran, Nicholas; Rogers, John; Littrell, Donald

    2015-06-01

    This study examines the fireball characteristics, blast parameters, and combustion efficiency of explosively-shocked aluminum-based materials. The materials included structural and non-structural aluminum forms - such as solid cylinders, foams, additively-manufactured lattices, and powders - and some polytetrafluoroethylene-aluminum (PTFE-Al) composites. The materials were explosively dispersed in a small blast chamber, and the blast properties and products were measured with pressure transducers, thermocouples, slow and fast ultraviolet/visible spectrometers, and high-speed video.

  11. Spectra-temporal patterns underlying mental addition: an ERP and ERD/ERS study.

    PubMed

    Ku, Yixuan; Hong, Bo; Gao, Xiaorong; Gao, Shangkai

    2010-03-12

    Functional neuroimaging data have shown that mental calculation involves fronto-parietal areas that are composed of different subsystems shared with other cognitive functions such as working memory and language. Event-related potential (ERP) analysis has also indicated sequential information changes during the calculation process. However, little is known about the dynamic properties of oscillatory networks in this process. In the present study, we applied both ERP and event-related (de-)synchronization (ERS/ERD) analyses to EEG data recorded from normal human subjects performing tasks for sequential visual/auditory mental addition. Results in the study indicate that the late positive components (LPCs) can be decomposed into two separate parts. The earlier element LPC1 (around 360ms) reflects the computing attribute and is more prominent in calculation tasks. The later element LPC2 (around 590ms) indicates an effect of number size and appears larger only in a more complex 2-digit addition task. The theta ERS and alpha ERD show modality-independent frontal and parietal differential patterns between the mental addition and control groups, and discrepancies are noted in the beta ERD between the 2-digit and 1-digit mental addition groups. The 2-digit addition (both visual and auditory) results in similar beta ERD patterns to the auditory control, which may indicate a reliance on auditory-related resources in mental arithmetic, especially with increasing task difficulty. These results coincide with the theory of simple calculation relying on the visuospatial process and complex calculation depending on the phonological process. PMID:20105450

  12. Field-assisted Densification of Superhard B6O Materials with Y2O3/Al2O3 Addition

    NASA Astrophysics Data System (ADS)

    Herrmann, M.; Raethel, J.; Sempf, K.; Thiele, M.; Bales, A.; Sigalas, I.

    B6O is a possible candidate of superhard materials with a hardness of 45 GPa measured on single crystals. Up to now, densification of these materials was only possible at high pressure. However, recently it was found that different oxides can be utilized as effective sintering additives. In this work the effect of addition of Y2O3/Al2O3 on the densification behaviour as a function of applied pressure, its microstructure evolution, and resulting mechanical properties were investigated. A strong dependence of the densification with increasing pressure was found. The material revealed characteristic triple junctions filled with amorphous residue composed of B2O3, Al2O3 and Y2O3, while no amorphous grain-boundary films were observed along internal interfaces. Mechanical testing revealed on average hardness of 33 GPa, a fracture toughness of 4 MPam1/2, and a strength value of 500 MPa.

  13. CFD Simulations of Joint Urban Atmospheric Dispersion Field Study

    SciTech Connect

    Lee, R; Humphreys III, T; Chan, S

    2004-06-17

    The application of Computational Fluid Dynamics (CFD) to the understanding of urban wind flow and dispersion processes has gained increasing attention over recent years. While many of the simpler dispersion models are based on a set of prescribed meteorology to calculate dispersion, the CFD approach has the ability of coupling the wind field to dispersion processes. This has distinct advantages when very detailed results are required, such as for the case where the releases occur around buildings and within urban areas. CFD also has great flexibility as a testbed for turbulence models, which has important implications for atmospheric dispersion problems. In the spring of 2003, a series of dispersion field experiments (Joint Urban 2003) were conducted at Oklahoma City (Allwine, et. al, 2004). These experiments were complimentary to the URBAN 2000 field studies at Salt Lake City (Shinn, et. al, 2000) in that they will provide a second set of comprehensive field data for evaluation of CFD as well as for other dispersion models. In contrast to the URBAN 2000 experiments that were conducted entirely at night, these new field studies took place during both daytime and nighttime thus including the possibility of convective as well as stable atmospheric conditions. Initially several CFD modeling studies were performed to provide guidance for the experimental team in the selection of release sites and in the deployment of wind and concentration sensors. Also, while meteorological and concentration measurements were taken over the greater Oklahoma City urban area, our CFD calculations were focused on the near field of the release point. The proximity of the source to a large commercial building and to the neighboring buildings several of which have multistories, present a significant challenge even for CFD calculations involving grid resolutions as fine as 1 meter. A total of 10 Intensive Observations Periods (IOP's) were conducted within the 2003 field experiments. SF6

  14. Geosynthetic clay liners - slope stability field study

    SciTech Connect

    Carson, D.A.; Daniel, D.E.; Koerner, R.M.; Bonaparte, R.

    1997-12-31

    A field research project was developed to examine the internal shear performance of geosynthetic clay liners (GCLs). Several combinations of cross sections were assembled using GCL materials that were available at the time of project initiation. The cross sections utilized were intended to simulate landfill cover applications. Thirteen (13) resulting test plots were constructed on two different slope angles, and each plot is instrumented for physical displacement and soil moisture characteristics. Test plots were constructed in a manner that dictated the shear plane in the clay portion of the GCL product. The project purpose is to assess field performance and to verify design parameters associated with the application of GCLs in waste containment applications. Interim research data shows that test slopes on 2H:1V show global deformation, but little internal shear evidence, and the 3H:1V slopes show little deformation at approximately 650 days. The research is ongoing, and this paper presents the most recent information available from the project.

  15. Puerto Rico - 2002 : field studies to resolve aerosol processes.

    SciTech Connect

    Gaffney, J. S.; Marley, N. A.; Ravelo, R.

    1999-10-05

    A number of questions remain concerning homogeneous aerosol formation by natural organics interacting with anthropogenic pollutants. For example, chlorine has been proposed as a potential oxidant in the troposphere because of its very high reactivity with a wide range of organics (Finlayson-Pitts, 1993). Indeed, sea salt aerosol in the presence of ozone has been shown to produce chlorine atoms in heterogeneous photochemical reactions under laboratory conditions. Whether chlorine can initiate oxidation of natural organics such as monoterpene hydrocarbons and can generate homogeneous nucleation or condensable material that contributes to aerosol loadings needs to be assessed. The nighttime reactions of ozone and nitrate radical can also result in monoterpene reactions that contribute to aerosol mass. We are currently planning field studies in Puerto Rico to assess these aerosol issues and other atmospheric chemistry questions. Puerto Rico has a number of key features that make it very attractive for a field study of this sort. The principal feature is the island's very regular meteorology and its position in the Caribbean Sea relative to the easterly trade winds. This meteorology and the island's rectangular shape (100 x 35 miles) make it highly suitable for simplification of boundary layer conditions. In addition, the long stretch between Puerto Rico and the nearest pollution sources in Africa and southern Europe make the incoming background air relatively clean and constant. Furthermore, Puerto Rico has approximately 3.5 million people with a very well defined source region and a central area of rain forest vegetation. These features make Puerto Rico an ideal locale for assessing aerosol processes. The following sections describe specific areas of atmospheric chemistry that can be explored during the proposed field study.

  16. Effect of Exogenous Phytase Addition on Soil Phosphatase Activities: a Fluorescence Spectroscopy Study.

    PubMed

    Yang, Xiao-zhu; Chen, Zhen-hua; Zhang, Yu-lan; Chen, Li-jun

    2015-05-01

    The utilization of organic phosphorus (P) has directly or indirectly improved after exogenous phytase was added to soil. However, the mechanism by which exogenous phytase affected the soil phosphatases (phosphomonoesterase and phosphodiesterase) activities was not clear. The present work was aimed to study red soil, brown soil and cinnamon soil phosphomonoesterase (acid and alkaline) (AcP and AlP) and phosphodiesterase (PD) activities responding to the addition of exogenous phytase (1 g phytase/50 g air dry soil sample) based on the measurements performed via a fluorescence detection method combined with 96 microplates using a TECAN Infinite 200 Multi-Mode Microplate Reader. The results indicated that the acid phosphomonoesterase activity was significantly enhanced in red soil (p≤0. 01), while it was significantly reduced in cinnamon soil; alkaline phosphomonoesterase activity was significantly enhanced in cinnamon soil (p≤ 0. 01), while it was significantly reduced in red soil; phosphodiesterase activity was increased in three soils but it was significantly increased in brown soil (p≤0. 01) after the addition of exogenous phytase. The activities still remained strong after eight days in different soils, which indicated that exogenous phytase addition could be enhance soil phosphatases activities effectively. This effect was not only related to soil properties, such as pH and phosphorus forms, but might also be related to the excreted enzyme amount of the stimulating microorganism. Using fluorescence spectroscopy to study exogenous phytase addition influence on soil phosphatase activities was the first time at home and abroad. Compared with the conventional spectrophotometric method, the fluorescence microplate method is an accurate, fast and simple to use method to determine the relationships among the soil phosphatases activities.

  17. Relative importance of fertiliser addition to plants and exclusion of predators for aphid growth in the field.

    PubMed

    Müller, Christine B; Fellowes, Mark D E; Godfray, H Charles J

    2005-04-01

    Herbivore dynamics and community structure are influenced both by plant quality and the actions of natural enemies. A factorial experiment manipulating both higher and lower trophic levels was designed to explore the determinants of colony growth of the aphid Aphis jacobaeae, a specialist herbivore on ragwort Senecio jacobaea. Potential plant quality was manipulated by regular addition of NPK-fertiliser and predator pressure was reduced by interception traps; the experiment was carried out at two sites. The size and persistence of aphid colonies were measured. Fertiliser addition affected plant growth in only one site, but never had a measurable effect on aphid colony growth. In both habitats the action of insect predators dominated, imposing strong and negative effects on aphid colony performance. Ants were left unmanipulated in both sites and their performance on the aphid colonies did not significantly differ between sites or between treatments. Our results suggest that, at least for aphid herbivores on S. jacobaea, the action of generalist insect predators appears to be the dominant factor affecting colony performance and can under certain conditions even improve plant productivity. PMID:15756583

  18. Comparative Study of Bacterial Growth in Magnet Fields

    NASA Astrophysics Data System (ADS)

    Smith, Derek; Masood, Samina

    It has been shown that magnetic fields affect bacterial growth. A comparative study of growth rates for gram-positive and gram-negative bacteria with different types of magnetic fields is done. Special focus is placed upon growth within liquid media, and the effect of magnetic fields relative to the chosen growth medium is considered.

  19. NASA Computational Case Study: Modeling Planetary Magnetic and Gravitational Fields

    NASA Technical Reports Server (NTRS)

    Simpson, David G.; Vinas, Adolfo F.

    2014-01-01

    In this case study, we model a planet's magnetic and gravitational fields using spherical harmonic functions. As an exercise, we analyze data on the Earth's magnetic field collected by NASA's MAGSAT spacecraft, and use it to derive a simple magnetic field model based on these spherical harmonic functions.

  20. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    DOE PAGES

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused bymore » a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.« less

  1. Couples Counseling in Alzheimer's Disease: Additional Clinical Findings from a Novel Intervention Study.

    PubMed

    Auclair, Ursula; Epstein, Cynthia; Mittelman, Mary

    2009-04-01

    This article describes the clinical findings of a study designed to assess the benefit of counseling for couples, one of whom is in the early stage of Alzheimer's disease (AD). We previously reported our findings based on the first 12 couples that enrolled in the study. Based on the treatment of 30 additional couples, we have refined our treatment strategy to include concepts of Gestalt Therapy and Transactional Analysis and identified prevalent issues of concern to this cohort. The study design has remained as described in the earlier article (Epstein et al., 2006), and has proven to be appropriate to meet the goals of this intervention as indicated by our clinical experience and feedback from the participating couples. Case vignettes demonstrate how to conduct the sessions so that the experience of each member of the dyad is validated, while acknowledging the differential impact of the disease on them. PMID:19865591

  2. Addition of fluoride to pit and fissure sealants--a feasibility study.

    PubMed

    Swartz, M L; Phillips, R W; Norman, R D; Elliason, S; Rhodes, B F; Clark, H E

    1976-01-01

    The data obtained in this in vitro study indicate that contact with pit and fissure sealants to which NaF has been added in amounts ranging from 2 to 5% substantially increases the fluoride content of the enamel and reduces its solubility in acid. The properties of the materials do not seem to be impaired by the addition of fluoride in these amounts. It thus appears that this approach to providing a backup anticariogenic mechanism may, indeed, be feasible. However, further investigation must be done to confirm the anticariogenic effect and to establish the most efficacious means of fluoride incorporation in the materials.

  3. Comparative study of glycine single crystals with additive of potassium nitrate in different concentration ratios

    NASA Astrophysics Data System (ADS)

    Gujarati, Vivek P.; Deshpande, M. P.; Patel, Kamakshi R.; Chaki, S. H.

    2016-05-01

    Semi-organic crystals of Glycine Potassium Nitrate (GPN) with potential applications in Non linear optics (NLO) were grown using slow evaporation technique. Glycine and Potassium Nitrate were taken in three different concentration ratios of 3:1, 2:1 and 1:1 respectively. We checked the solubility of the material in distilled water at different temperatures and could observe the growth of crystals in 7 weeks time. Purity of the grown crystals was confirmed by Energy Dispersive X-ray Analysis (EDAX) and CHN analysis. GSN Powder X-ray diffraction pattern was recorded to confirm the crystalline nature. To confirm the applications of grown crystals in opto-electronics field, UV-Vis-NIR study was carried out. Dielectric properties of the samples were studied in between the frequency range 1Hz to 100 KHz.

  4. An Optimization of Pulsed ElectroMagnetic Fields Study

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas J.

    2006-01-01

    To date, in our research we have focused on the use of normal human neuronal progenitor (NHNP) cells because of their importance in human nervous system regeneration, development and maintenance, but we have developed 2-D and 3-D bioreactors that can accommodate any cell line. In this Project, we will include the use of tissues important for physiological regeneration: Human osteoblasts or chondrocytes, and vascular cells. Our initial results with the NHNP cells were quite startling using extremely low-level electromagnetic fields (5 microtesla at 10Hz; 6mA). The low-amplitude, rapidly time-varying electromagnetic fields exert a very potent effect on the proliferation, morphology, and gene expression of the cells in culture, both in standard 2-dimensional culture plates as well as cells organized into 3-dimensional tissue-like assemblies (TLAs) in a 3D bioreactor. We have replicated our preliminary results many, many times, have analyzed the gene expression using gene arrays (followed by Luminex analysis for protein production), and have monitored cell proliferation, orientation, morphology, and glucose metabolism, and we are confident that we have a stable and reliable model to study the control of high-level cellular processes by application of low-amplitude, time varying electromagnetic fields (TVEMF) (1, 2). In additional studies at the University of Michigan, we have been able to generate functional in vitro engineered mammalian skeletal muscle, and have employed nerve-muscle co-culture techniques to promote axonal sprouting. We believe that nearly all tissues, in particular, neural, are susceptible to the influences of low-level TVEMF.

  5. THE FIELD STUDY NOTEBOOK FOR THE OUTDOOR SCHOOL.

    ERIC Educational Resources Information Center

    BURGESS, ROBERT A.; GILFILLAN, WARREN C.

    THE "FIELD STUDY NOTEBOOK" HAS BEEN PREPARED FOR USE BY PAROCHIAL AND PUBLIC ELEMENTARY SCHOOL STUDENTS FOR STUDYING ECOLOGY AT AN OUTDOOR SCHOOL. THE NOTEBOOK EMPHASIZES COMMUNITY DYNAMICS THROUGH STUDENT ACTIVITIES THAT ILLUSTRATE ECOLOGICAL RELATIONSHIPS. INFORMATION IS PROVIDED ON THE ORGANIZATION OF A FIELD STUDY AND ON PERFORMING VARIOUS…

  6. Global and site specific multimedia (field) studies

    SciTech Connect

    Cutshall, N.H.; Guerin, M.R.

    1987-01-01

    Experience with radioactive fallout, with organic contaminants and with heavy metals has amply demonstrated that cross-media transfers are common and that understanding the transport, cycling, and fate of these contaminants requires a multimedia approach. Nonetheless, pollutants with similar physical and chemical attributes may follow markedly different pathways. The frequency of exceptions to predictions based on simplistic models is also sufficient to show that direct investigation of environmental contamination is essential to confirm validity of models used for conceptualizing a problem or for control. Modeling based on multimedia premises and regulatory controls that encompass multimedia considerations are challenged by a dilemma, however. First, the development of multimedia models or regulatory frameworks represents simplification and generalization. This is true for several reasons: (1) inadequate understanding of physical and environmental factors which control specific cross-media transfer; (2) the absence of specific data on certain multimedia pollutant concentrations; (3) even the most powerful computers do not have sufficient speed and capacity to deal with the known complexities of natural systems. On the other hand, for contaminants such as mercury, it may be necessary to include great detail; the overall distribution in the environment may be less important than the rate of some minor process. With sufficient experience and good judgment of what can be ignored, the simplifications and generalizations can be made. For the present, and for the foreseeable future, however, they absolutely must be accompanied by thorough field validation and monitoring.

  7. A water soluble additive to suppress respirable dust from concrete-cutting chainsaws: a case study.

    PubMed

    Summers, Michael P; Parmigiani, John P

    2015-01-01

    Respirable dust is of particular concern in the construction industry because it contains crystalline silica. Respirable forms of silica are a severe health threat because they heighten the risk of numerous respirable diseases. Concrete cutting, a common work practice in the construction industry, is a major contributor to dust generation. No studies have been found that focus on the dust suppression of concrete-cutting chainsaws, presumably because, during normal operation water is supplied continuously and copiously to the dust generation points. However, there is a desire to better understand dust creation at low water flow rates. In this case study, a water-soluble surfactant additive was used in the chainsaw's water supply. Cutting was performed on a free-standing concrete wall in a covered outdoor lab with a hand-held, gas-powered, concrete-cutting chainsaw. Air was sampled at the operator's lapel, and around the concrete wall to simulate nearby personnel. Two additive concentrations were tested (2.0% and 0.2%), across a range of fluid flow rates (0.38-3.8 Lpm [0.1-1.0 gpm] at 0.38 Lpm [0.1 gpm] increments). Results indicate that when a lower concentration of additive is used exposure levels increase. However, all exposure levels, once adjusted for 3 hours of continuous cutting in an 8-hour work shift, are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 5 mg/m(3). Estimates were made using trend lines to predict the fluid flow rates that would cause respirable dust exposure to exceed both the OSHA PEL and the American Conference of Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV).

  8. Simulated Laboratory/Field Study of Evolution.

    ERIC Educational Resources Information Center

    Dubowsky, Nathan; Hartman, Elliott M., Jr.

    1986-01-01

    Immediately following a lecture discussion on early hominid characteristics and behavior, students participate in a laboratory study of bipedal locomotion based on an analysis of footprints. The development and use of this simulation are described. (JN)

  9. Characterization studies on the additives mixed L-arginine phosphate monohydrate (LAP) crystals

    NASA Astrophysics Data System (ADS)

    Haja Hameed, A. S.; Karthikeyan, C.; Ravi, G.; Rohani, S.

    2011-04-01

    L-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP (LAP:Na 2SO 3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.

  10. The guanidine and maleic acid (1:1) complex. The additional theoretical and experimental studies

    NASA Astrophysics Data System (ADS)

    Drozd, Marek; Dudzic, Damian

    2012-04-01

    On the basis of experimental literature data the theoretical studies for guanidinium and maleic acid complex with using DFT method are performed. In these studies the experimental X-ray data for two different forms of investigated crystal were used. During the geometry optimization process one equilibrium structure was found, only. According to this result the infrared spectrum for one theoretical molecule was calculated. On the basis of potential energy distribution (PED) analysis the clear-cut assignments of observed bands were performed. For the calculated molecule with energy minimum the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were obtained and graphically illustrated. The energy difference (GAP) between HOMO and LUMO was analyzed. Additionally, the nonlinear properties of this molecule were calculated. The α and β (first and second order) hyperpolarizability values are obtained. On the basis of these results the title crystal was classified as new second order NLO generator.

  11. GLOBE Aerosol Field Campaign - U.S. Pilot Study 2016

    NASA Technical Reports Server (NTRS)

    Pippin, Margaret; Marentette, Christina; Bujosa, Robert; Taylor, Jessica; Lewis, Preston

    2016-01-01

    During the spring of 2016, from April 4 - May 27, sixteen GLOBE schools participated in the GLOBE Aerosol Field Campaign - U.S. Pilot Study. Thirteen teachers from these schools had previously participated in the NASA LEARN program (Long-term Experience in Authentic Research with NASA) where they were GLOBE trained in Atmosphere protocols, and engaged in 1-3 years of research under the mentorship of NASA scientists. Each school was loaned two aerosol instruments for the Campaign duration, either 2 GLOBE sun photometers, 2 Calitoo sun photometers, or 1 of each. This allowed for students to make measurements side-by-side and in the case of the Calitoos, to compare AOT results immediately with each other for better consistency in data collection. Additionally, as part of the Field Campaign evaluation, multiple instruments allow for an assessment of the ease of use of each instrument for grade level of students, whether in middle school or high school. Before the Campaign, all GLOBE and Calitoo instruments were 'checked out' against an AERONET, then checked again upon return after the Campaign. By examining all data, before, during and after the Campaign, this gives an indication of instrument performance and proficiency obtained by the students. Support was provided to each teacher and their students at the level requested, via email, phone or video conferencing.

  12. Alkaline flood prediction studies, Ranger VII pilot, Wilmington Field, California

    SciTech Connect

    Mayer, E.H.; Breit, V.S.

    1986-01-01

    This paper discusses the design of a simulator to model alkaline displacement mechanisms, along with the current understanding of in-situ caustic consumption. Assimilation of laboratory coreflood and rock consumption data, and their use in one- and two-dimensional (1D and 2D) limited area simulations and in three-dimensional (3D) models of the entire pilot project are given. This paper also reports simulation studies of alkaline flood behavior in a small 2D area of a field for various concentrations, slug sizes, long-term consumption functions, and two relative-permeability adjustment mechanisms. The scale-up of 2D simulation results and their use in a 271-acre (1096.7-ha), seven-layered, 3D model of the pilot are also discussed and 3D simulator results are compared with initial field alkaline flood performance. Finally, recommended additional applications of the simulator methods developed in this pilot and in other alkaline floods are discussed.

  13. Prazosin addition to fluvoxamine: A preclinical study and open clinical trial in OCD.

    PubMed

    Feenstra, Matthijs G P; Klompmakers, André; Figee, Martijn; Fluitman, Sjoerd; Vulink, Nienke; Westenberg, Herman G M; Denys, Damiaan

    2016-02-01

    The efficacy of selective serotonin reuptake inhibitors (SRIs) in psychiatric disorders may be "augmented" through the addition of atypical antipsychotic drugs. A synergistic increase in dopamine (DA) release in the prefrontal cortex has been suggested to underlie this augmentation effect, though the mechanism of action is not clear yet. We used in vivo microdialysis in rats to study DA release following the administration of combinations of fluvoxamine (10 mg/kg) and quetiapine (10 mg/kg) with various monoamine-related drugs. The results confirmed that the selective 5-HT1A antagonist WAY-100635 (0.05 mg/kg) partially blocked the fluvoxamine-quetiapine synergistic effect (maximum DA increase dropped from 325% to 214%). A novel finding is that the α1-adrenergic blocker prazosin (1 mg/kg), combined with fluvoxamine, partially mimicked the effect of augmentation (maximum DA increase 205%; area-under-the-curve 163%). As this suggested that prazosin augmentation might be tested in a clinical study, we performed an open clinical trial of prazosin 20 mg addition to SRI in therapy-resistant patients with obsessive-compulsive disorder applying for neurosurgery. A small, non-significant reduction in Yale Brown Obsessive Compulsive Scale (Y-BOCS) scores was observed in 10 patients and one patient was classified as a responder with a reduction in Y-BOCS scores of more than 25%. We suggest that future clinical studies augmenting SRIs with an α1-adrenergic blocker in less treatment resistant cases should be considered. The clinical trial "Prazosin in combination with a serotonin reuptake inhibitor for patients with Obsessive Compulsive disorder: an open label study" was registered at 24/05/2011 under trial number ISRCTN61562706: http://www.controlled-trials.com/ISRCTN61562706. PMID:26712326

  14. Examining the Influence of Additional Field-Based Experiences on Pre-Service Teachers and Their Perceived Ability to Teach

    ERIC Educational Resources Information Center

    Clark, Sarah K.

    2012-01-01

    In an attempt to analyse more closely the training experiences of pre-service teachers, the author conducted an exploratory quasi-experimental study at a university located in the Rocky Mountain region of the USA. All students who were enrolled in the same reading methods course (but enrolled in different sections) were invited to participate in…

  15. Study on Antiwear and Repairing Performances about Mass of Nano-copper Lubricating Additives to 45 Steel

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Yin, Y. L.; Zhang, G. N.; Wang, W. Y.; Zhao, K. K.

    Nano-copper usually serve for lubricating additives in tribology field. The antiwear and reducing friction performances both basic lubrication oil and basic lubrication oil with nano-copper in different mass were tested by friction wear test machine. The morphologies and the main elements of worn surfaces were analyzed by SEM. The results indicated that nano-copper could improve tribology performances of basic lubrication oil. Comparing with base lubrication oil, the mass is 0.15% of nano-copper, the friction coefficient and the worn trace width can be reduced 34% and 32% respectively. Nano-copper can form self-repairing film in lubrication oil which availably separates the friction materials in friction process. Therefore, nano-copper has wonderful antiwear, reducing friction and self-repairing performances. And the function mechanism of Cu nanoparticles is studied in the paper.

  16. Framing in the Field: A Case Study

    ERIC Educational Resources Information Center

    Benjamin, Diane

    2009-01-01

    Strategic Frame Analysis can inform the daily practice of policy advocates by bringing an evidence-based communications approach to their work. This case study of FrameWorks' decade-long association with the national Kids Count Network shares stories from advocates who are transforming their communications strategies, resulting in more effective…

  17. A combined toxicity study of zinc oxide nanoparticles and vitamin C in food additives

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Yuan, Lulu; Yao, Chenjie; Ding, Lin; Li, Chenchen; Fang, Jie; Sui, Keke; Liu, Yuanfang; Wu, Minghong

    2014-11-01

    At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the cytotoxicity significantly compared with that of the ZnO only NPs. When the cells were exposed to ZnO NPs at a concentration less than 15 mg L-1, or to Vc at a concentration less than 300 mg L-1, there was no significant cytotoxicity, both in the case of gastric epithelial cell line (GES-1) and neural stem cells (NSCs). However, when 15 mg L-1 of ZnO NPs and 300 mg L-1 of Vc were introduced to cells together, the cell viability decreased sharply indicating significant cytotoxicity. Moreover, the significant increase in toxicity was also shown in the in vivo experiments. The dose of the ZnO NPs and Vc used in the in vivo study was calculated according to the state of food and nutrition enhancer standard. After repeated oral exposure to ZnO NPs plus Vc, the injury of the liver and kidneys in mice has been indicated by the change of these indices. These findings demonstrate that the synergistic toxicity presented in a complex system is essential for the toxicological evaluation and safety assessment of nanofood.At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the

  18. Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

    PubMed Central

    2014-01-01

    Background Seventeen of 172 included studies in a recent systematic review of blood tests for hepatic fibrosis or cirrhosis reported diagnostic accuracy results discordant from 2 × 2 tables, and 60 studies reported inadequate data to construct 2 × 2 tables. This study explores the yield of contacting authors of diagnostic accuracy studies and impact on the systematic review findings. Methods Sixty-six corresponding authors were sent letters requesting additional information or clarification of data from 77 studies. Data received from the authors were synthesized with data included in the previous review, and diagnostic accuracy sensitivities, specificities, and positive and likelihood ratios were recalculated. Results Of the 66 authors, 68% were successfully contacted and 42% provided additional data for 29 out of 77 studies (38%). All authors who provided data at all did so by the third emailed request (ten authors provided data after one request). Authors of more recent studies were more likely to be located and provide data compared to authors of older studies. The effects of requests for additional data on the conclusions regarding the utility of blood tests to identify patients with clinically significant fibrosis or cirrhosis were generally small for ten out of 12 tests. Additional data resulted in reclassification (using median likelihood ratio estimates) from less useful to moderately useful or vice versa for the remaining two blood tests and enabled the calculation of an estimate for a third blood test for which previously the data had been insufficient to do so. We did not identify a clear pattern for the directional impact of additional data on estimates of diagnostic accuracy. Conclusions We successfully contacted and received results from 42% of authors who provided data for 38% of included studies. Contacting authors of studies evaluating the diagnostic accuracy of serum biomarkers for hepatic fibrosis and cirrhosis in hepatitis C patients

  19. Field calibration studies for ionisation chambers in mixed high-energy radiation fields.

    PubMed

    Theis, C; Forkel-Wirth, D; Fuerstner, M; Mayer, S; Otto, Th; Roesler, S; Vincke, H

    2007-01-01

    The monitoring of ambient doses at work places around high-energy accelerators is a challenging task due the complexity of the mixed stray radiation fields encountered. At CERN, mainly Centronics IG5 high-pressure ionisation chambers are used to monitor radiation exposure in mixed fields. The monitors are calibrated in the operational quantity ambient dose equivalent H*(10) using standard, source-generated photon- and neutron fields. However, the relationship between ionisation chamber reading and ambient dose equivalent in a mixed high-energy radiation field can only be assessed if the spectral response to every component and the field composition is known. Therefore, comprehensive studies were performed at the CERN-EU high-energy reference field facility where the spectral fluence for each particle type has been assessed with Monte Carlo simulations. Moreover, studies have been performed in an accessible controlled radiation area in the vicinity of a beam loss point of CERN's proton synchrotron. The comparison of measurements and calculations has shown reasonable agreement for most exposure conditions. The results indicate that conventionally calibrated ionisation chambers can give satisfactory response in terms of ambient dose equivalent in stray radiation fields at high-energy accelerators in many cases. These studies are one step towards establishing a method of 'field calibration' of radiation protection instruments in which Monte Carlo simulations will be used to establish a correct correlation between the response of specific detectors to a given high-energy radiation field.

  20. A study of pyrazines in cigarettes and how additives might be used to enhance tobacco addiction

    PubMed Central

    Alpert, Hillel R; Agaku, Israel T; Connolly, Gregory N

    2016-01-01

    Background Nicotine is known as the drug that is responsible for the addicted behaviour of tobacco users, but it has poor reinforcing effects when administered alone. Tobacco product design features enhance abuse liability by (A) optimising the dynamic delivery of nicotine to central nervous system receptors, and affecting smokers’ withdrawal symptoms, mood and behaviour; and (B) effecting conditioned learning, through sensory cues, including aroma, touch and visual stimulation, to create perceptions of pending nicotine reward. This study examines the use of additives called ‘pyrazines’, which may enhance abuse potential, their introduction in ‘lights’ and subsequently in the highly market successful Marlboro Lights (Gold) cigarettes and eventually many major brands. Methods We conducted internal tobacco industry research using online databases in conjunction with published scientific literature research, based on an iterative feedback process. Results Tobacco manufacturers developed the use of a range of compounds, including pyrazines, in order to enhance ‘light’ cigarette products’ acceptance and sales. Pyrazines with chemosensory and pharmacological effects were incorporated in the first ‘full-flavour, low-tar’ product achieving high market success. Such additives may enhance dependence by helping to optimise nicotine delivery and dosing and through cueing and learned behaviour. Conclusions Cigarette additives and ingredients with chemosensory effects that promote addiction by acting synergistically with nicotine, increasing product appeal, easing smoking initiation, discouraging cessation or promoting relapse should be regulated by the US Food and Drug Administration. Current models of tobacco abuse liability could be revised to include more explicit roles with regard to non-nicotine constituents that enhance abuse potential. PMID:26063608

  1. A combined toxicity study of zinc oxide nanoparticles and vitamin C in food additives.

    PubMed

    Wang, Yanli; Yuan, Lulu; Yao, Chenjie; Ding, Lin; Li, Chenchen; Fang, Jie; Sui, Keke; Liu, Yuanfang; Wu, Minghong

    2014-12-21

    At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the cytotoxicity significantly compared with that of the ZnO only NPs. When the cells were exposed to ZnO NPs at a concentration less than 15 mg L(-1), or to Vc at a concentration less than 300 mg L(-1), there was no significant cytotoxicity, both in the case of gastric epithelial cell line (GES-1) and neural stem cells (NSCs). However, when 15 mg L(-1) of ZnO NPs and 300 mg L(-1) of Vc were introduced to cells together, the cell viability decreased sharply indicating significant cytotoxicity. Moreover, the significant increase in toxicity was also shown in the in vivo experiments. The dose of the ZnO NPs and Vc used in the in vivo study was calculated according to the state of food and nutrition enhancer standard. After repeated oral exposure to ZnO NPs plus Vc, the injury of the liver and kidneys in mice has been indicated by the change of these indices. These findings demonstrate that the synergistic toxicity presented in a complex system is essential for the toxicological evaluation and safety assessment of nanofood.

  2. Rate constants of hydroperoxyl radical addition to cyclic nitrones: a DFT study.

    PubMed

    Villamena, Frederick A; Merle, John K; Hadad, Christopher M; Zweier, Jay L

    2007-10-01

    Nitrones are potential synthetic antioxidants against the reduction of radical-mediated oxidative damage in cells and as analytical reagents for the identification of HO2* and other such transient species. In this work, the PCM/B3LYP/6-31+G(d,p)//B3LYP/6-31G(d) and PCM/mPW1K/6-31+G(d,p) density functional theory (DFT) methods were employed to predict the reactivity of HO2* with various functionalized nitrones as spin traps. The calculated second-order rate constants and free energies of reaction at both levels of theory were in the range of 100-103 M-1 s-1 and 1 to -12 kcal mol-1, respectively, and the rate constants for some nitrones are on the same order of magnitude as those observed experimentally. The trend in HO2* reactivity to nitrones could not be explained solely on the basis of the relationship of the theoretical positive charge densities on the nitronyl-C, with their respective ionization potentials, electron affinities, rate constants, or free energies of reaction. However, various modes of intramolecular H-bonding interaction were observed at the transition state (TS) structures of HO2* addition to nitrones. The presence of intramolecular H-bonding interactions in the transition states were predicted and may play a significant role toward a facile addition of HO2* to nitrones. In general, HO2* addition to ethoxycarbonyl- and spirolactam-substituted nitrones, as well as those nitrones without electron-withdrawing substituents, such as 5,5-dimethyl-pyrroline N-oxide (DMPO) and 5-spirocyclopentyl-pyrroline N-oxide (CPPO), are most preferred compared to the methylcarbamoyl-substituted nitrones. This study suggests that the use of specific spin traps for efficient trapping of HO2* could pave the way toward improved radical detection and antioxidant protection. PMID:17845014

  3. Microbial colonization of retorted shale in field and laboratory studies

    SciTech Connect

    Rogers, J.E.; McNair, V.M.; Li, S.W.; Garland, T.R.; Wildung, R.E.

    1982-08-01

    The microbial colonization of retorted shale was measured in field lysimeters and laboratory with retorted shale obtained from an above-ground retort operating in the direct heating mode. In field lysimeter studies, total aerobic heterotrophic bacterial colony forming units (cfu), as measured by a selective plating medium in surface horizons of retorted shale and adjacent soils, were similar (3.3 x 10/sup 6/ and 2.7 x 10/sup 6/ bacterial cfu/g dry weight) two months after disposal. However, unlike the soil that exhibited a diverse community, the retorted shale was dominated by a single Micrococcus species that composed 30% of the total bacterial community. After one and two years, the total aerobic heterotrophic bacterial cfu in the retorted shale and soil were again similar; however, no bacterium dominated either community. A core sample from the field lysimeter indicated microbial colonization to a depth of 150 cm after one year. An increased ratio of anaerobic to aerobic heterotrophic bacterial cfu in the deepest sample (120 to 150 cm) implied the development of anaerobic conditions. In the laboratory, aerobic heterotrophic bacteria were shown capable of using, as the sole source of carbon, retorted shale in liquid cultures. Of the added nutritional amendments, PO/sub 4//sup -3/, NO/sub 3//sup -/ and SO/sub 4//sup -2/, only phosphate markedly altered the colonization of retorted shale in liquid culture; shortening the lag phase of colonization from less than three to seven weeks to less than one week and leading to a greater aerobic heterotrophic population over the incubation interval. The addition of phosphate also led to a aerobic heterotrophic bacterial community composed entirely of Micrococcus species.

  4. Additional follow-up telephone counselling and initial smoking relapse: a longitudinal, controlled study

    PubMed Central

    Wu, Lei; He, Yao; Jiang, Bin; Zuo, Fang; Liu, Qinghui; Zhang, Li; Zhou, Changxi

    2016-01-01

    Objectives Smoking cessation services can help smokers to quit; however, many smoking relapse cases occur over time. Initial relapse prevention should play an important role in achieving the goal of long-term smoking cessation. Several studies have focused on the effect of extended telephone support in relapse prevention, but the conclusions remain conflicting. Design and setting From October 2008 to August 2013, a longitudinal, controlled study was performed in a large general hospital of Beijing. Participants The smokers who sought treatment at our smoking cessation clinic were non-randomised and divided into 2 groups: face-to-face individual counselling group (FC group), and face-to-face individual counselling plus telephone follow-up counselling group (FCF group). No pharmacotherapy was offered. Outcomes The timing of initial smoking relapse was compared between FC and FCF groups. Predictors of initial relapse were investigated during the first 180 days, using the Cox proportional hazards model. Results Of 547 eligible male smokers who volunteered to participate, 457 participants (117 in FC group and 340 in FCF group) achieved at least 24 h abstinence. The majority of the lapse episodes occurred during the first 2 weeks after the quit date. Smokers who did not receive the follow-up telephone counselling (FC group) tended to relapse to smoking earlier than those smokers who received the additional follow-up telephone counselling (FCF group), and the log-rank test was statistically significant (p=0.003). A Cox regression model showed that, in the FCF group, being married, and having a lower Fagerström test score, normal body mass index and doctor-diagnosed tobacco-related chronic diseases, were significantly independent protective predictors of smoking relapse. Conclusions Within the limitations of this study, it can be concluded that additional follow-up telephone counselling might be an effective strategy in preventing relapse. Further research is still

  5. Vadose Zone Transport Field Study: Status Report

    SciTech Connect

    Gee, Glendon W.; Ward, Anderson L.

    2001-11-30

    Studies were initiated at the Hanford Site to evaluate the process controlling the transport of fluids in the vadose zone and to develop a reliable database upon which vadose-zone transport models can be calibrated. These models are needed to evaluate contaminant migration through the vadose zone to underlying groundwaters at Hanford. A study site that had previously been extensively characterized using geophysical monitoring techniques was selected in the 200 E Area. Techniques used previously included neutron probe for water content, spectral gamma logging for radionuclide tracers, and gamma scattering for wet bulk density. Building on the characterization efforts of the past 20 years, the site was instrumented to facilitate the comparison of nine vadose-zone characterization methods: advanced tensiometers, neutron probe, electrical resistance tomography (ERT), high-resolution resistivity (HRR), electromagnetic induction imaging (EMI), cross-borehole radar (XBR), and cross-borehole seismic (XBS). Soil coring was used to obtain soil samples for analyzing ionic and isotopic tracers.

  6. Toxicogenomics concepts and applications to study hepatic effects of food additives and chemicals

    SciTech Connect

    Stierum, Rob . E-mail: stierum@voeding.tno.nl; Heijne, Wilbert; Kienhuis, Anne; Ommen, Ben van; Groten, John

    2005-09-01

    Transcriptomics, proteomics and metabolomics are genomics technologies with great potential in toxicological sciences. Toxicogenomics involves the integration of conventional toxicological examinations with gene, protein or metabolite expression profiles. An overview together with selected examples of the possibilities of genomics in toxicology is given. The expectations raised by toxicogenomics are earlier and more sensitive detection of toxicity. Furthermore, toxicogenomics will provide a better understanding of the mechanism of toxicity and may facilitate the prediction of toxicity of unknown compounds. Mechanism-based markers of toxicity can be discovered and improved interspecies and in vitro-in vivo extrapolations will drive model developments in toxicology. Toxicological assessment of chemical mixtures will benefit from the new molecular biological tools. In our laboratory, toxicogenomics is predominantly applied for elucidation of mechanisms of action and discovery of novel pathway-supported mechanism-based markers of liver toxicity. In addition, we aim to integrate transcriptome, proteome and metabolome data, supported by bioinformatics to develop a systems biology approach for toxicology. Transcriptomics and proteomics studies on bromobenzene-mediated hepatotoxicity in the rat are discussed. Finally, an example is shown in which gene expression profiling together with conventional biochemistry led to the discovery of novel markers for the hepatic effects of the food additives butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole.

  7. Resources allocation in healthcare for cancer: a case study using generalised additive mixed models.

    PubMed

    Musio, Monica; Sauleau, Erik A; Augustin, Nicole H

    2012-11-01

    Our aim is to develop a method for helping resources re-allocation in healthcare linked to cancer, in order to replan the allocation of providers. Ageing of the population has a considerable impact on the use of health resources because aged people require more specialised medical care due notably to cancer. We propose a method useful to monitor changes of cancer incidence in space and time taking into account two age categories, according to healthcar general organisation. We use generalised additive mixed models with a Poisson response, according to the methodology presented in Wood, Generalised additive models: an introduction with R. Chapman and Hall/CRC, 2006. Besides one-dimensional smooth functions accounting for non-linear effects of covariates, the space-time interaction can be modelled using scale invariant smoothers. Incidence data collected by a general cancer registry between 1992 and 2007 in a specific area of France is studied. Our best model exhibits a strong increase of the incidence of cancer along time and an obvious spatial pattern for people more than 70 years with a higher incidence in the central band of the region. This is a strong argument for re-allocating resources for old people cancer care in this sub-region. PMID:23242683

  8. Covalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions

    USGS Publications Warehouse

    Thorn, K.A.; Pettigrew, P.J.; Goldenberg, W.S.; Weber, E.J.

    1996-01-01

    Aromatic amines are known to undergo covalent binding with humic substances in the environment. Although previous studies have examined reaction conditions and proposed mechanisms, there has been no direct spectroscopic evidence for the covalent binding of the amines to the functional groups in humic substances. In order to further elucidate the reaction mechanisms, the Suwannee River and IHSS soil fulvic and humic acids were reacted with 15N-labeled aniline at pH 6 and analyzed using 15N NMR spectrometry. Aniline underwent nucleophilic addition reactions with the quinone and other carbonyl groups in the samples and became incorporated in the form of anilinohydroquinone, anilinoquinone, anilide, imine, and heterocyclic nitrogen, the latter comprising 50% or more of the bound amine. The anilide and anilinohydroquinone nitrogens were determined to be susceptible to chemical exchange by ammonia. In the case of Suwannee River fulvic acid, reaction under anoxic conditions and pretreatment with sodium borohydride or hydroxylamine prior to reaction under oxic conditions resulted in a decrease in the proportion of anilinohydroquinone nitrogen incorporated. The relative decrease in the incorporation of anilinohydroquinone nitrogen with respect to anilinoquinone nitrogen under anoxic conditions suggested that inter- or intramolecular redox reactions accompanied the nucleophilic addition reactions.

  9. Studies on the reuse of waste printed circuit board as an additive for cement mortar.

    PubMed

    Ban, Bong-Chan; Song, Jong-Yoon; Lim, Joong-Yeon; Wang, Soo-Kyoon; An, Kwang-Guk; Kim, Dong-Su

    2005-01-01

    The recent development in electronic industries has generated a drastic increase in production of printed circuit boards (PCB). Accordingly, the amount of waste PCB from electronic productions and waste electronics and its environmental impact such as soil and groundwater contamination have become a great concern. This study aims to propose a method for reuse of waste PCB as an additive for cement mortar. Although the expansibility of waste PCB powder finer than 0.08 mm in water was observed to be greater than 2.0%, the maximum expansion rates in water for 0.08 to approximately 0.15 and 0.15 to approximately 0.30 mm sized PCB powders were less than 2.0%, which satisfied the necessary condition as an alternative additive for cement mortar in place of sand. The difference in the compressive strength of standard mortar and waste PCB added mortar was observed to be less than 10% and their difference was expected to be smaller after prolonged aging. The durability of waste PCB added cement mortar was also examined through dry/wet conditioning cyclic tests and acidic/alkaline conditioning tests. From the tests, both weight and compressive strength of cement mortar were observed to be recovered with aging. The leaching test for heavy metals from waste PCB added mortar showed that no heavy metal ions such as copper, lead, or cadmium were detected in the leachate, which resulted from fixation effect of the cement hydrates.

  10. Assessment of Nano Cellulose from Peach Palm Residue as Potential Food Additive: Part II: Preliminary Studies.

    PubMed

    Andrade, Dayanne Regina Mendes; Mendonça, Márcia Helena; Helm, Cristiane Vieira; Magalhães, Washington L E; de Muniz, Graciela Ines Bonzon; Kestur, Satyanarayana G

    2015-09-01

    High consumption of dietary fibers in the diet is related to the reduction of the risk of non-transmitting of chronic diseases, prevention of the constipation etc. Rich diets in dietary fibers promote beneficial effects for the metabolism. Considering the above and recognizing the multifaceted advantages of nano materials, there have been many attempts in recent times to use the nano materials in the food sector including as food additive. However, whenever new product for human and animal consumption is developed, it has to be tested for their effectiveness regarding improvement in the health of consumers, safety aspects and side effects. However, before it is tried with human beings, normally such materials would be assessed through biological tests on a living organism to understand its effect on health condition of the consumer. Accordingly, based on the authors' finding reported in a previous paper, this paper presents body weight, biochemical (glucose, cholesterol and lipid profile in blood, analysis of feces) and histological tests carried out with biomass based cellulose nano fibrils prepared by the authors for its possible use as food additive. Preliminary results of the study with mice have clearly brought out potential of these fibers for the said purpose. PMID:26344977

  11. Resources allocation in healthcare for cancer: a case study using generalised additive mixed models.

    PubMed

    Musio, Monica; Sauleau, Erik A; Augustin, Nicole H

    2012-11-01

    Our aim is to develop a method for helping resources re-allocation in healthcare linked to cancer, in order to replan the allocation of providers. Ageing of the population has a considerable impact on the use of health resources because aged people require more specialised medical care due notably to cancer. We propose a method useful to monitor changes of cancer incidence in space and time taking into account two age categories, according to healthcar general organisation. We use generalised additive mixed models with a Poisson response, according to the methodology presented in Wood, Generalised additive models: an introduction with R. Chapman and Hall/CRC, 2006. Besides one-dimensional smooth functions accounting for non-linear effects of covariates, the space-time interaction can be modelled using scale invariant smoothers. Incidence data collected by a general cancer registry between 1992 and 2007 in a specific area of France is studied. Our best model exhibits a strong increase of the incidence of cancer along time and an obvious spatial pattern for people more than 70 years with a higher incidence in the central band of the region. This is a strong argument for re-allocating resources for old people cancer care in this sub-region.

  12. Mechanisms on electrical breakdown strength increment of polyethylene by aromatic carbonyl compounds addition: a theoretical study.

    PubMed

    Zhang, Hui; Shang, Yan; Wang, Xuan; Zhao, Hong; Han, Baozhong; Li, Zesheng

    2013-12-01

    A theoretical investigation is accomplished on the mechanisms of electrical breakdown strength increment of polyethylene at the atomic and molecular levels. It is found that the addition of aromatic carbonyl compounds as voltage stabilizers is one of the important factors for increasing electrical breakdown strength of polyethylene, as the additives can trap hot electrons, obtain energy of hot electrons, and transform the aliphatic cation to relatively stable aromatic cation to prevent the degradation of the polyethylene matrix. The HOMO-LUMO energy gaps (E(g)), the ionization potentials (IPs), and electron affinities (EAs) at the ground states of a series of aromatic carbonyl compounds are obtained at the B3LYP/6-311+G(d,p) level. The theoretical results are in good agreement with the available experimental findings, show that 2,4-dioctyloxybenzophenone (Bzo) and 4,4'-didodecyloxybenzil (Bd) molecules can effectively increase the electrical breakdown strength when they are doped into polyethylene because of their much smaller E g values than all the other studied aromatic carbonyl molecules and excellent compatibility with polymers matrix.

  13. Flow field studies on yawed, stranded cables

    NASA Astrophysics Data System (ADS)

    Batill, S. M.; Nelson, R. C.; Nebres, J. V.

    A study of the flowfield near yawed, stranded cables was conducted in order to investigate the mechanisms associated with the generation of both steady and unsteady fluid forces on the cables. Rigid cable models and a circular cylinder were tested in a wind tunnel at four different cable angles over a Reynolds number range from 6000 to 14,600 based on the nominal cable diameter. The smoke-wire and the kerosene smoke flow visualization techniques were used to qualitatively evaluate the flowfields associated with each cable geometry.

  14. Coastal Studies in a Comprehensive Summer Field Geology Course.

    ERIC Educational Resources Information Center

    Cameron, Barry; Jones, Richard J.

    1979-01-01

    Describes a college geology course that incorporates a coastal segment. Field studies are done on Plum Island and include examining beaches, dune fields, and an adjacent marsh and spit. Topics include sedimentation, coastal geomorphology, botanical effects, and coastal studies methodology. (MA)

  15. Study on Friction and Wear Properties of Silver Matrix Brush Material with Different Additives

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoli; Wang, Wenfang; Hong, Yu; Wu, Yucheng

    2013-07-01

    Friction and wear processes of AgCuX (G, CF and AlN) composites-CuAgV alloy friction pair and effects of different additive content in silver based composite on friction and wear behavior are studied in this paper. The microstructure of the brush wear surface is observed by SEM. The results show that when graphite content is up to 9 wt.%, Ag-Cu-CF-G composite exhibits the best wear properties; when the content of aluminum nitride is up to 0.5 wt.%, Ag-Cu-AlN-G composites has the most comprehensive performance. The wear loss of both composites arises with the increase of both pressure and speed, but when speed reaches a critical value, the increased amplitude of wear loss tends to be steady.

  16. Comparative study of dimensional accuracy of different impression techniques using addition silicone impression material.

    PubMed

    Penaflor, C F; Semacio, R C; De Las Alas, L T; Uy, H G

    1998-01-01

    This study compared dimensional accuracy of the single, double with spacer, double with cut-out and double mix impression technique using addition silicone impression material. A typhodont containing Ivorine teeth model with six (6) full-crown tooth preparations were used as the positive control. Two stone replication models for each impression technique were made as test materials. Accuracy of the techniques were assessed by measuring four dimensions on the stone dies poured from the impression of the Ivorine teeth model. Results indicated that most of the measurements for the height, width and diameter slightly decreased and a few increased compared with the Ivorine teeth model. The double with cut-out and double mix technique presents the least difference from the master model as compared to the two latter impression techniques. PMID:10202524

  17. Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method.

    PubMed

    Pérez-Marín, A B; Ballester, A; González, F; Blázquez, M L; Muñoz, J A; Sáez, J; Zapata, V Meseguer

    2008-11-01

    The biosorption of several metals (Cd2+, Zn2+ and Pb2+) by orange wastes has been investigated in binary systems. Multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by Pagnanelli et al. [Pagnanelli, F., Petrangeli, M.P., Toro, L., Trifoni, M., Veglio, F., 2001a. Biosorption of metal ions on Arthrobacter sp.: biomass characterization and biosorption modelling. Environ. Sci. Technol. 34, 2773-2778] for monoelement systems, known as subsequent addition method (SAM). Experimental sorption data were analysed using an extended multicomponent Langmuir equation. The maximum sorption uptake was approximately 0.25mmol/g for the three binary systems studied. The reliability of the proposed procedure for obtaining the equilibrium data in binary systems was verified by means of a statistical F-test. PMID:18440805

  18. Spectroscopic studies of nucleic acid additions during seed-mediated growth of gold nanoparticles

    PubMed Central

    Tapp, Maeling; Sullivan, Rick; Dennis, Patrick; Naik, Rajesh R.

    2015-01-01

    The effect of adding nucleic acids to gold seeds during the growth stage of either nanospheres or nanorods was investigated using UV-Vis spectroscopy to reveal any oligonucleotide base or structure-specific effects on nanoparticle growth kinetics or plasmonic signatures. Spectral data indicate that the presence of DNA duplexes during seed ageing drastically accelerated nanosphere growth while the addition of single-stranded polyadenine at any point during seed ageing induces nanosphere aggregation. For seeds added to a gold nanorod growth solution, single-stranded polythymine induces a modest blue-shift in the longitudinal peak wavelength. Moreover, a particular sequence comprised of 50% thymine bases was found to induce a faster, more dramatic blue-shift in the longitudinal peak wavelength compared to any of the homopolymer incubation cases. Monomeric forms of the nucleic acids, however, do not yield discernable spectral differences in any of the gold suspensions studied. PMID:25960601

  19. Rapid identification of color additives, using the C18 cartridge: collaborative study.

    PubMed

    Young, M L

    1988-01-01

    Nine laboratories collaboratively studied a method for the separation and identification of the 7 permitted FD&C color additives (Red Nos. 3 and 40; Blue Nos. 1 and 2; Yellow Nos. 5 and 6; Green No. 3) and the banned FD&C Red No. 2 in foods. The method is based on use of a commercial C18 cartridge and spectrophotometry or thin layer chromatography. Collaborators analyzed 5 commercial products (noodles, candy, carbonated soda, flavored gelatin, and powdered drink) and 2 dye mixtures (one containing FD&C Red Nos. 2, 3, and 40; the other containing FD&C Green No. 3 and Red No. 3). All of the colors were identified with little or no difficulty by 8 collaborators. The method has been adopted official first action.

  20. Genetic assessment of additional endophenotypes from the Consortium on the Genetics of Schizophrenia Family Study.

    PubMed

    Greenwood, Tiffany A; Lazzeroni, Laura C; Calkins, Monica E; Freedman, Robert; Green, Michael F; Gur, Raquel E; Gur, Ruben C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

    2016-01-01

    The Consortium on the Genetics of Schizophrenia Family Study (COGS-1) has previously reported our efforts to characterize the genetic architecture of 12 primary endophenotypes for schizophrenia. We now report the characterization of 13 additional measures derived from the same endophenotype test paradigms in the COGS-1 families. Nine of the measures were found to discriminate between schizophrenia patients and controls, were significantly heritable (31 to 62%), and were sufficiently independent of previously assessed endophenotypes, demonstrating utility as additional endophenotypes. Genotyping via a custom array of 1536 SNPs from 94 candidate genes identified associations for CTNNA2, ERBB4, GRID1, GRID2, GRIK3, GRIK4, GRIN2B, NOS1AP, NRG1, and RELN across multiple endophenotypes. An experiment-wide p value of 0.003 suggested that the associations across all SNPs and endophenotypes collectively exceeded chance. Linkage analyses performed using a genome-wide SNP array further identified significant or suggestive linkage for six of the candidate endophenotypes, with several genes of interest located beneath the linkage peaks (e.g., CSMD1, DISC1, DLGAP2, GRIK2, GRIN3A, and SLC6A3). While the partial convergence of the association and linkage likely reflects differences in density of gene coverage provided by the distinct genotyping platforms, it is also likely an indication of the differential contribution of rare and common variants for some genes and methodological differences in detection ability. Still, many of the genes implicated by COGS through endophenotypes have been identified by independent studies of common, rare, and de novo variation in schizophrenia, all converging on a functional genetic network related to glutamatergic neurotransmission that warrants further investigation. PMID:26597662

  1. Genetic assessment of additional endophenotypes from the Consortium on the Genetics of Schizophrenia Family Study.

    PubMed

    Greenwood, Tiffany A; Lazzeroni, Laura C; Calkins, Monica E; Freedman, Robert; Green, Michael F; Gur, Raquel E; Gur, Ruben C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

    2016-01-01

    The Consortium on the Genetics of Schizophrenia Family Study (COGS-1) has previously reported our efforts to characterize the genetic architecture of 12 primary endophenotypes for schizophrenia. We now report the characterization of 13 additional measures derived from the same endophenotype test paradigms in the COGS-1 families. Nine of the measures were found to discriminate between schizophrenia patients and controls, were significantly heritable (31 to 62%), and were sufficiently independent of previously assessed endophenotypes, demonstrating utility as additional endophenotypes. Genotyping via a custom array of 1536 SNPs from 94 candidate genes identified associations for CTNNA2, ERBB4, GRID1, GRID2, GRIK3, GRIK4, GRIN2B, NOS1AP, NRG1, and RELN across multiple endophenotypes. An experiment-wide p value of 0.003 suggested that the associations across all SNPs and endophenotypes collectively exceeded chance. Linkage analyses performed using a genome-wide SNP array further identified significant or suggestive linkage for six of the candidate endophenotypes, with several genes of interest located beneath the linkage peaks (e.g., CSMD1, DISC1, DLGAP2, GRIK2, GRIN3A, and SLC6A3). While the partial convergence of the association and linkage likely reflects differences in density of gene coverage provided by the distinct genotyping platforms, it is also likely an indication of the differential contribution of rare and common variants for some genes and methodological differences in detection ability. Still, many of the genes implicated by COGS through endophenotypes have been identified by independent studies of common, rare, and de novo variation in schizophrenia, all converging on a functional genetic network related to glutamatergic neurotransmission that warrants further investigation.

  2. Field evaluation of in situ remediation of Cd-contaminated soil using four additives, two foliar fertilisers and two varieties of pakchoi.

    PubMed

    Feng, Renwei; Qiu, Weiwen; Lian, Fei; Yu, Zhihong; Yang, YiXin; Song, Zhengguo

    2013-07-30

    This study was conducted to determine the optimal planting mode for pakchoi (Brassica rapa chinensis) in Cd-contaminated soil to reduce the accumulation of Cd in the edible parts while maintaining yields. Four additives (red mud (RM), silicon calcium fertiliser (SC), spodium (SP) and calcium magnesium phosphate (CMP)), two foliar fertilisers (Ca and Zn) and two varieties of pakchoi (Aijiaohuang (AJ) and Baixuegongzhu (BX)) were used in this study. The results show that the addition of SC and RM had an effect, but the other additives did not appear to increase the biomasses of AJ and BX. In some cases, the growth responses of AJ and BX to the same treatment were different. Extra additions of Ca or Zn to additive-treated pakchoi did not help the additives stimulate the growth of AJ and BX, except for SC-treated AJ and BX and SP-treated AJ. The SC and CMP additives significantly reduced the available Cd concentration in both the AJ soil and the BX soil; however, they did not significantly decrease the Cd concentration in the aboveground parts of AJ and BX. The RM treatments (for both levels) and some treatments containing SP reduced the available Cd concentration in the soils and reduced the accumulation of Cd in the two pakchoi varieties. Additions of Ca or Zn fertiliser significantly reduced the Cd concentration in the aboveground parts of AJ and BX. However, when Ca or Zn was sprayed on the additive-treated AJ and BX, they did not help the additives reduce the Cd accumulation in the aboveground parts of AJ and BX, except for the additive CMP. This study shows that RM may be an optimal amendment to reduce the accumulation of Cd in the edible part of pakchoi while simultaneously maintaining yields. The utilisation of Ca or Zn as a foliar fertiliser to additive-treated pakchoi showed positive effects only under some conditions.

  3. Field evaluation of in situ remediation of Cd-contaminated soil using four additives, two foliar fertilisers and two varieties of pakchoi.

    PubMed

    Feng, Renwei; Qiu, Weiwen; Lian, Fei; Yu, Zhihong; Yang, YiXin; Song, Zhengguo

    2013-07-30

    This study was conducted to determine the optimal planting mode for pakchoi (Brassica rapa chinensis) in Cd-contaminated soil to reduce the accumulation of Cd in the edible parts while maintaining yields. Four additives (red mud (RM), silicon calcium fertiliser (SC), spodium (SP) and calcium magnesium phosphate (CMP)), two foliar fertilisers (Ca and Zn) and two varieties of pakchoi (Aijiaohuang (AJ) and Baixuegongzhu (BX)) were used in this study. The results show that the addition of SC and RM had an effect, but the other additives did not appear to increase the biomasses of AJ and BX. In some cases, the growth responses of AJ and BX to the same treatment were different. Extra additions of Ca or Zn to additive-treated pakchoi did not help the additives stimulate the growth of AJ and BX, except for SC-treated AJ and BX and SP-treated AJ. The SC and CMP additives significantly reduced the available Cd concentration in both the AJ soil and the BX soil; however, they did not significantly decrease the Cd concentration in the aboveground parts of AJ and BX. The RM treatments (for both levels) and some treatments containing SP reduced the available Cd concentration in the soils and reduced the accumulation of Cd in the two pakchoi varieties. Additions of Ca or Zn fertiliser significantly reduced the Cd concentration in the aboveground parts of AJ and BX. However, when Ca or Zn was sprayed on the additive-treated AJ and BX, they did not help the additives reduce the Cd accumulation in the aboveground parts of AJ and BX, except for the additive CMP. This study shows that RM may be an optimal amendment to reduce the accumulation of Cd in the edible part of pakchoi while simultaneously maintaining yields. The utilisation of Ca or Zn as a foliar fertiliser to additive-treated pakchoi showed positive effects only under some conditions. PMID:23603772

  4. Study made of interaction between sound fields and structural vibrations

    NASA Technical Reports Server (NTRS)

    Lyon, R. H.; Smith, P. W., Jr.

    1967-01-01

    Study analyzes structural vibrations and the interactions between them and sound fields. It outlines a conceptual framework to analyze the vibrations of systems and their interactions, incorporating the results of earlier studies and establishing a unified basis for continuing research.

  5. Study of triallyl phosphate as an electrolyte additive for high voltage lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Xia, J.; Madec, L.; Ma, L.; Ellis, L. D.; Qiu, W.; Nelson, K. J.; Lu, Z.; Dahn, J. R.

    2015-11-01

    The role of triallyl phosphate as an electrolyte additive in Li(Ni0.42Mn0.42Co0.16)O2/graphite pouch cells was studied using ex-situ gas measurements, ultra high precision coulometry, automated storage experiments, electrochemical impedance spectroscopy, long-term cycling and X-ray photoelectron spectroscopy. Cells containing triallyl phosphate produced less gas during formation, cycling and storage than control cells. The use of triallyl phosphate led to higher coulombic efficiency and smaller charge endpoint capacity slippage during ultra high precision charger testing. Cells containing triallyl phosphate showed smaller potential drop during 500 h storage at 40 °C and 60 °C and the voltage drop decreased as the triallyl phosphate content in the electrolyte increased. However, large amounts of triallyl phosphate (>3% by weight in the electrolyte) led to large impedance after cycling and storage. Symmetric cell studies showed large amounts of triallyl phosphate (5% or more) led to significant impedance increase at both negative and positive electrodes. X-ray photoelectron spectroscopy studies suggested that the high impedance came from the polymerization of triallyl phosphate molecules which formed thick solid electrolyte interphase films at the surfaces of both negative and positive electrodes. An optimal amount of 2%-3% triallyl phosphate led to better capacity retention during long term cycling.

  6. Studies of Interstellar and Circumstellar Magnetic Field with Aligned Atoms

    NASA Astrophysics Data System (ADS)

    Lazarian, A.; Yan, H.

    2004-12-01

    Population of levels of the hyperfine and fine split ground state of an atom is affected by radiative transitions induced by anisotropic radiation flux. Such aligned atoms precess in the external magnetic field and this affects properties of polarized radiation arising from both scattering and absorption by atoms. As the result the degree of light polarization depends on the direction of the magnetic field. This provides a new tool for studies of astrophysical magnetic fields using optical and UV polarimetry. We provide calculations for several atoms and ions that can be used to study magnetic fields in interplanetary medium, interstellar medius, circumstellar regions and quasars.

  7. Study of Several Potentials as Scalar Field Dark Matter Candidates

    SciTech Connect

    Matos, Tonatiuh; Vazquez-Gonzalez, Alberto; Magan a, Juan

    2008-12-04

    In this work we study several scalar field potentials as a plausible candidate to be the dark matter in the universe. The main idea is the following; if the scalar field is an ultralight boson particle, it condensates like a Bose-Einstein system at very early times and forms the basic structure of the Universe. Real scalar fields collapse in equilibrium configurations which oscillate in space-time (oscillatons). The cosmological behavior of the field equations are solved using the dynamical system formalism. We use the current cosmological parameters as constraints for the free parameters of the scalar field potentials. We are able to reproduce very well the cosmological predictions of the standard {lambda}CDM model with some scalar field potentials. Therefore, scalar field dark matter seems to be a good alternative to be the nature of the dark matter of the universe.

  8. Field study of hydrogeologic characterization methods in a heterogeneous aquifer.

    PubMed

    Alexander, Matthew; Berg, Steven J; Illman, Walter A

    2011-01-01

    Hydraulic conductivity (K) and specific storage (S(s)) are required parameters when designing transient groundwater flow models. The purpose of this study was to evaluate the ability of commonly used hydrogeologic characterization approaches to accurately delineate the distribution of hydraulic properties in a highly heterogeneous glaciofluvial deposit. The metric used to compare the various approaches was the prediction of drawdown responses from three separate pumping tests. The study was conducted at a field site, where a 15 m × 15 m area was instrumented with four 18-m deep Continuous Multichannel Tubing (CMT) wells. Each CMT well contained seven 17 cm × 1.9 cm monitoring ports equally spaced every 2 m down each CMT system. An 18-m deep pumping well with eight separate 1-m long screens spaced every 2 m was also placed in the center of the square pattern. In each of these boreholes, cores were collected and characterized using the Unified Soil Classification System, grain size analysis, and permeameter tests. To date, 471 K estimates have been obtained through permeameter analyses and 270 K estimates from empirical relationships. Geostatistical analysis of the small-scale K data yielded strongly heterogeneous K fields in three-dimensions. Additional K estimates were obtained through slug tests in 28 ports of the four CMT wells. Several pumping tests were conducted using the multiscreen and CMT wells to obtain larger scale estimates of both K and S(s). The various K and S(s) estimates were then quantitatively evaluated by simulating transient drawdown data from three pumping tests using a 3D forward numerical model constructed using HydroGeoSphere (Therrien et al. 2005). Results showed that, while drawdown predictions generally improved as more complexity was introduced into the model, the ability to make accurate drawdown predictions at all CMT ports was inconsistent.

  9. Lattice Study of Magnetic Catalysis in Graphene Effective Field Theory

    NASA Astrophysics Data System (ADS)

    Winterowd, Christopher; Detar, Carleton; Zafeiropoulos, Savvas

    2016-03-01

    The discovery of graphene ranks as one of the most important developments in condensed matter physics in recent years. As a strongly interacting system whose low-energy excitations are described by the Dirac equation, graphene has many similarities with other strongly interacting field theories, particularly quantum chromodynamics (QCD). Graphene, along with other relativistic field theories, have been predicted to exhibit spontaneous symmetry breaking (SSB) when an external magnetic field is present. Using nonperturbative methods developed to study QCD, we study the low-energy effective field theory (EFT) of graphene subject to an external magnetic field. We find strong evidence supporting the existence of SSB at zero-temperature and characterize the dependence of the chiral condensate on the external magnetic field. We also present results for the mass of the Nambu-Goldstone boson and the dynamically generated quasiparticle mass that result from the SSB.

  10. CHARMM-GUI Input Generator for NAMD, GROMACS, AMBER, OpenMM, and CHARMM/OpenMM Simulations Using the CHARMM36 Additive Force Field

    DOE PAGES

    Lee, Jumin; Cheng, Xi; Swails, Jason M.; Yeom, Min Sun; Eastman, Peter K.; Lemkul, Justin A.; Wei, Shuai; Buckner, Joshua; Jeong, Jong Cheol; Qi, Yifei; et al

    2015-11-12

    Here we report that proper treatment of nonbonded interactions is essential for the accuracy of molecular dynamics (MD) simulations, especially in studies of lipid bilayers. The use of the CHARMM36 force field (C36 FF) in different MD simulation programs can result in disagreements with published simulations performed with CHARMM due to differences in the protocols used to treat the long-range and 1-4 nonbonded interactions. In this study, we systematically test the use of the C36 lipid FF in NAMD, GROMACS, AMBER, OpenMM, and CHARMM/OpenMM. A wide range of Lennard-Jones (LJ) cutoff schemes and integrator algorithms were tested to find themore » optimal simulation protocol to best match bilayer properties of six lipids with varying acyl chain saturation and head groups. MD simulations of a 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) bilayer were used to obtain the optimal protocol for each program. MD simulations with all programs were found to reasonably match the DPPC bilayer properties (surface area per lipid, chain order parameters, and area compressibility modulus) obtained using the standard protocol used in CHARMM as well as from experiments. The optimal simulation protocol was then applied to the other five lipid simulations and resulted in excellent agreement between results from most simulation programs as well as with experimental data. AMBER compared least favorably with the expected membrane properties, which appears to be due to its use of the hard-truncation in the LJ potential versus a force-based switching function used to smooth the LJ potential as it approaches the cutoff distance. The optimal simulation protocol for each program has been implemented in CHARMM-GUI. This protocol is expected to be applicable to the remainder of the additive C36 FF including the proteins, nucleic acids, carbohydrates, and small molecules.« less

  11. CHARMM-GUI Input Generator for NAMD, GROMACS, AMBER, OpenMM, and CHARMM/OpenMM Simulations Using the CHARMM36 Additive Force Field

    SciTech Connect

    Lee, Jumin; Cheng, Xi; Swails, Jason M.; Yeom, Min Sun; Eastman, Peter K.; Lemkul, Justin A.; Wei, Shuai; Buckner, Joshua; Jeong, Jong Cheol; Qi, Yifei; Jo, Sunhwan; Pande, Vijay S.; Case, David A.; Brooks, Charles L.; MacKerell, Alexander D.; Klauda, Jeffery B.; Im, Wonpil

    2015-11-12

    Here we report that proper treatment of nonbonded interactions is essential for the accuracy of molecular dynamics (MD) simulations, especially in studies of lipid bilayers. The use of the CHARMM36 force field (C36 FF) in different MD simulation programs can result in disagreements with published simulations performed with CHARMM due to differences in the protocols used to treat the long-range and 1-4 nonbonded interactions. In this study, we systematically test the use of the C36 lipid FF in NAMD, GROMACS, AMBER, OpenMM, and CHARMM/OpenMM. A wide range of Lennard-Jones (LJ) cutoff schemes and integrator algorithms were tested to find the optimal simulation protocol to best match bilayer properties of six lipids with varying acyl chain saturation and head groups. MD simulations of a 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) bilayer were used to obtain the optimal protocol for each program. MD simulations with all programs were found to reasonably match the DPPC bilayer properties (surface area per lipid, chain order parameters, and area compressibility modulus) obtained using the standard protocol used in CHARMM as well as from experiments. The optimal simulation protocol was then applied to the other five lipid simulations and resulted in excellent agreement between results from most simulation programs as well as with experimental data. AMBER compared least favorably with the expected membrane properties, which appears to be due to its use of the hard-truncation in the LJ potential versus a force-based switching function used to smooth the LJ potential as it approaches the cutoff distance. The optimal simulation protocol for each program has been implemented in CHARMM-GUI. This protocol is expected to be applicable to the remainder of the additive C36 FF including the proteins, nucleic acids, carbohydrates, and small molecules.

  12. The impact of bismuth addition to sequential treatment on Helicobacter pylori eradication: A pilot study.

    PubMed

    Basyigit, Sebahat; Kefeli, Ayse; Sapmaz, Ferdane; Yeniova, Abdullah Ozgür; Asilturk, Zeliha; Hokkaomeroglu, Murat; Uzman, Metin; Nazligul, Yasar

    2015-10-25

    The success of the current anti-Helicobacter pylori (H. pylori) treatment protocols is reported to decrease by years, and research is needed to strengthen the H. pylori eradication treatment. Sequential treatment (ST), one of the treatment modalities for H. pylori eradication, includes amoxicillin 1 gr b.i.d and proton pump inhibitor b.i.d for first 5 days and then includes clarithromycin 500 mg b.i.d, metronidazole 500 mg b.i.d and a proton pump inhibitor b.i.d for remaining 5 days. In this study, we investigated efficacy and tolerability of bismuth addition in to ST. We included patients that underwent upper gastrointestinal endoscopy in which H. pylori infection was diagnosed by histological examination of antral and corporal gastric mucosa biopsy. Participants were randomly administered ST or bismuth containing ST (BST) protocols for the first-line H. pylori eradication therapy. Participants have been tested by urea breath test for eradication success 6 weeks after the completion of treatment. One hundred and fifty patients (93 female, 57 male) were enrolled. There were no significant differences in eradication rates for both intention to treat population (70.2%, 95% confidence interval [CI]: 66.3-74.1% vs. 71.8%, 95% CI: 61.8-81.7%, for ST and BST, respectively, p>0.05) and per protocol population (74.6%, 95% CI: 63.2-85.8% vs. 73.7%, 95% CI: 63.9-83.5% for ST and BST, respectively, p>0.05). Despite the undeniable effect of bismuth, there may be several possible reasons of unsatisfactory eradication success. Drug administration time, coadministration of other drugs, possible H. pylori resistance to bismuth may affect the eradication success. The addition of bismuth subcitrate to ST regimen does not provide significant increase in eradication rates.

  13. Experimental Study of Disruption of Columnar Grains During Rapid Solidification in Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Manogharan, Guha; Yelamanchi, Bharat; Aman, Ronald; Mahbooba, Zaynab

    2016-03-01

    Over the years, many studies have been conducted to study and analyze the grain structures of metal alloys during additive manufacturing to improve mechanical properties. In particular, columnar grains are observed predominantly during rapid solidification of molten metal. This leads to lower mechanical properties and requires expensive secondary heat-treatment processes. This study is aimed at disrupting the formation of columnar grain growth during rapid solidification using ultrasonic vibration and analyzes the effects on grain structure and mechanical properties. A gas-metal arc welder mounted on a Rep-Rap-based low-cost metal 3 Dimension printer was used to deposit ER70S-6 mild steel layers on a plate. A contact-type ultrasonic transducer with a control system to vary the frequency and power of the vibration was used. The effects of ultrasonic vibration were determined from the statistical analysis of microstructure and micro-indentation techniques on the deposited layer and heat-affected zone. It was found that both frequency and interaction between frequency and power had significant impact on the refinement of average grain size up to 10.64% and increased the number of grains by approximately 41.78%. Analysis of micro-indentation tests showed that there was an increase of approximately 14.30% in micro-hardness due to the applied frequency during rapid solidification. A pole diagram shows that application of vibration causes randomization of grain orientation. Along with the results from this study, further efforts in modeling and experimentation of multi-directional vibrations would lead to a better understanding of disrupting columnar grains in applications that use mechanical vibrations, such as welding, directed energy deposition, brazing, etc.

  14. Evaluating the addition of positive reinforcement for learning a frightening task: a pilot study with horses.

    PubMed

    Heleski, Camie; Bauson, Laura; Bello, Nora

    2008-01-01

    Horse training often relies upon negative reinforcement (NR). This study tested the hypothesis that adding positive reinforcement (PR) to NR would enhance learning in horses (n = 34) being taught to walk over a tarp (novel/typically frightening task). Subjects were Arabians, and the same person handled all of them. This person handled half "traditionally" (NR only)--that is, halter/lead were pulled; when horse stepped forward, pressure was released; process repeated until criterion met (horse crossed the tarp with little/no obvious anxiety). The same person handled the other half traditionally--but with addition of PR < food + verbal praise > (NR + PR). Subjects "failed" the task if they refused to walk onto the tarp after 10 min. Nine horses failed; 6 of 9 failures were from NR only--no significant difference detected (p = .41). The study detected no difference in time to first crossing of the tarp (p = .30) or total time to achieve calmness criterion (p = .67). Overall, adding PR did not significantly enhance learning this task. However, there were practical implications--adding PR made the task safer/less fatiguing for the handler. PMID:18569217

  15. Evaluating the addition of positive reinforcement for learning a frightening task: a pilot study with horses.

    PubMed

    Heleski, Camie; Bauson, Laura; Bello, Nora

    2008-01-01

    Horse training often relies upon negative reinforcement (NR). This study tested the hypothesis that adding positive reinforcement (PR) to NR would enhance learning in horses (n = 34) being taught to walk over a tarp (novel/typically frightening task). Subjects were Arabians, and the same person handled all of them. This person handled half "traditionally" (NR only)--that is, halter/lead were pulled; when horse stepped forward, pressure was released; process repeated until criterion met (horse crossed the tarp with little/no obvious anxiety). The same person handled the other half traditionally--but with addition of PR < food + verbal praise > (NR + PR). Subjects "failed" the task if they refused to walk onto the tarp after 10 min. Nine horses failed; 6 of 9 failures were from NR only--no significant difference detected (p = .41). The study detected no difference in time to first crossing of the tarp (p = .30) or total time to achieve calmness criterion (p = .67). Overall, adding PR did not significantly enhance learning this task. However, there were practical implications--adding PR made the task safer/less fatiguing for the handler.

  16. Synthesis, Characterization, Molecular Modeling, and DNA Interaction Studies of Copper Complex Containing Food Additive Carmoisine Dye.

    PubMed

    Shahabadi, Nahid; Akbari, Alireza; Jamshidbeigi, Mina; Khodarahmi, Reza

    2016-06-01

    A copper complex of carmoisine dye; [Cu(carmoisine)2(H2O)2]; was synthesized and characterized by using physico-chemical and spectroscopic methods. The binding of this complex with calf thymus (ct) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, and viscosity measurements. UV-vis results confirmed that the Cu complex interacted with DNA to form a ground-state complex and the observed binding constant (2× 10(4) M(-1)) is more in keeping with the groove bindings with DNA. Furthermore, the viscosity measurement result showed that the addition of complex causes no significant change on DNA viscosity and it indicated that the intercalation mode is ruled out. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the reaction. The results of circular dichroism (CD) suggested that the complex can change the conformation of DNA from B-like form toward A-like conformation. The cytotoxicity studies of the carmoisine dye and its copper complex indicated that both of them had anticancer effects on HT-29 (colon cancer) cell line and they may be new candidates for treatment of the colon cancer.

  17. Density functional theory study of the effects of alloying additions on sulfur adsorption on nickel surfaces

    NASA Astrophysics Data System (ADS)

    Malyi, Oleksandr I.; Chen, Zhong; Kulish, Vadym V.; Bai, Kewu; Wu, Ping

    2013-01-01

    Reactions of hydrogen sulfide (H2S) with Nickel/Ytrria-doped zirconia (Ni/YDZ) anode materials might cause degradation of the performance of solid oxide fuel cells when S containing fuels are used. In this paper, we employ density functional theory to investigate S adsorption on metal (M)-doped and undoped Ni(0 0 1) and Ni(1 1 1) surfaces. Based on the performed calculations, we analyze the effects of 12 alloying additions (Ag, Au, Al, Bi, Cd, Co, Cu, Fe, Sn, Sb, V, and Zn) on the temperature of transition between clean (S atoms do not adsorb on the surfaces) and contaminated (S atoms can adsorb on the surfaces spontaneously) M-doped Ni surfaces for different concentrations of H2S in the fuel. Predicted results are consistent with many experimental studies relevant to S poisoning of both Ni/YDZ and M-doped Ni/YDZ anode materials. This study is important to understand S poisoning phenomena and to develop new S tolerant anode materials.

  18. Synthesis, Characterization, Molecular Modeling, and DNA Interaction Studies of Copper Complex Containing Food Additive Carmoisine Dye.

    PubMed

    Shahabadi, Nahid; Akbari, Alireza; Jamshidbeigi, Mina; Khodarahmi, Reza

    2016-06-01

    A copper complex of carmoisine dye; [Cu(carmoisine)2(H2O)2]; was synthesized and characterized by using physico-chemical and spectroscopic methods. The binding of this complex with calf thymus (ct) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, and viscosity measurements. UV-vis results confirmed that the Cu complex interacted with DNA to form a ground-state complex and the observed binding constant (2× 10(4) M(-1)) is more in keeping with the groove bindings with DNA. Furthermore, the viscosity measurement result showed that the addition of complex causes no significant change on DNA viscosity and it indicated that the intercalation mode is ruled out. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the reaction. The results of circular dichroism (CD) suggested that the complex can change the conformation of DNA from B-like form toward A-like conformation. The cytotoxicity studies of the carmoisine dye and its copper complex indicated that both of them had anticancer effects on HT-29 (colon cancer) cell line and they may be new candidates for treatment of the colon cancer. PMID:27152751

  19. Percutaneous Dorsal Instrumentation of Vertebral Burst Fractures: Value of Additional Percutaneous Intravertebral Reposition—Cadaver Study

    PubMed Central

    Krüger, Antonio; Schmuck, Maya; Noriega, David C.; Ruchholtz, Steffen; Baroud, Gamal; Oberkircher, Ludwig

    2015-01-01

    Purpose. The treatment of vertebral burst fractures is still controversial. The aim of the study is to evaluate the purpose of additional percutaneous intravertebral reduction when combined with dorsal instrumentation. Methods. In this biomechanical cadaver study twenty-eight spine segments (T11-L3) were used (male donors, mean age 64.9 ± 6.5 years). Burst fractures of L1 were generated using a standardised protocol. After fracture all spines were allocated to four similar groups and randomised according to surgical techniques (posterior instrumentation; posterior instrumentation + intravertebral reduction device + cement augmentation; posterior instrumentation + intravertebral reduction device without cement; and intravertebral reduction device + cement augmentation). After treatment, 100000 cycles (100–600 N, 3 Hz) were applied using a servohydraulic loading frame. Results. Overall anatomical restoration was better in all groups where the intravertebral reduction device was used (p < 0.05). In particular, it was possible to restore central endplates (p > 0.05). All techniques decreased narrowing of the spinal canal. After loading, clearance could be maintained in all groups fitted with the intravertebral reduction device. Narrowing increased in the group treated with dorsal instrumentation. Conclusions. For height and anatomical restoration, the combination of an intravertebral reduction device with dorsal instrumentation showed significantly better results than sole dorsal instrumentation. PMID:26137481

  20. Studies about space radiation promote new fields in radiation biology.

    PubMed

    Ohnishi, Takeo; Takahashi, Akihisa; Ohnishi, Ken

    2002-12-01

    Astronauts are constantly exposed to space radiation of various types of energy with a low dose-rate during long-term stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Studies about biological the effects at a low dose and a low dose-rate include various aspects of microbeams, bystander effects, radioadaptive responses and hormesis which are important fields in radiation biology. In addition, space radiations contain high linear energy transfer (LET) particles. In particular, neutrons may cause reverse effectiveness at a low dose-rate in comparison to ionizing radiation. We are also interested in p53-centered signal transduction pathways involved in the cell cycle, DNA repair and apoptosis induced by space radiations. We must also study whether the relative biological effectiveness (RBE) of space radiation is affected by microgravity which is another typical component in space. To confirm this, we must prepare centrifuge systems in an International Space Station (ISS). In addition, we must prepare many types of equipment for space experiments in an ISS, because we cannot use conventional equipment from our laboratories. Furthermore, the research for space radiation might give us valuable information about the birth and evolution of life on the Earth. We can also realize the importance of preventing the ozone layer from depletion by the use of exposure equipment to sunlight in an ISS. For these reasons, we desire to educate space researchers of the next generation based on the consideration of the preservation of the Earth from research about space radiation. PMID:12793723

  1. Studies about space radiation promote new fields in radiation biology.

    PubMed

    Ohnishi, Takeo; Takahashi, Akihisa; Ohnishi, Ken

    2002-12-01

    Astronauts are constantly exposed to space radiation of various types of energy with a low dose-rate during long-term stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Studies about biological the effects at a low dose and a low dose-rate include various aspects of microbeams, bystander effects, radioadaptive responses and hormesis which are important fields in radiation biology. In addition, space radiations contain high linear energy transfer (LET) particles. In particular, neutrons may cause reverse effectiveness at a low dose-rate in comparison to ionizing radiation. We are also interested in p53-centered signal transduction pathways involved in the cell cycle, DNA repair and apoptosis induced by space radiations. We must also study whether the relative biological effectiveness (RBE) of space radiation is affected by microgravity which is another typical component in space. To confirm this, we must prepare centrifuge systems in an International Space Station (ISS). In addition, we must prepare many types of equipment for space experiments in an ISS, because we cannot use conventional equipment from our laboratories. Furthermore, the research for space radiation might give us valuable information about the birth and evolution of life on the Earth. We can also realize the importance of preventing the ozone layer from depletion by the use of exposure equipment to sunlight in an ISS. For these reasons, we desire to educate space researchers of the next generation based on the consideration of the preservation of the Earth from research about space radiation.

  2. Experimental study of enhanced heat transfer by addition of CuO nanoparticle

    NASA Astrophysics Data System (ADS)

    Jesumathy, Stella; Udayakumar, M.; Suresh, S.

    2012-06-01

    An energy storage system has been designed to study the thermal characteristics of paraffin wax with an embedded nano size copper oxide (CuO) particle. This paper presents studies conducted on phase transition times, heat fraction as well as heat transfer characteristics of paraffin wax as phase change material (PCM) embedded with CuO nanoparticles. 40 nm mean size CuO particles of 2, 5 and 10% by weight were dispersed in PCM for this study. Experiments were performed on a heat exchanger with 1.5-10 l/min of heat transfer fluid (HTF) flow. Time-based variations of the temperature distributions are revealed from the results of observations of melting and solidification curves. The results strongly suggested that the thermal conductivity enhances 6, 6.7 and 7.8% in liquid state and in dynamic viscosity it enhances by 5, 14 and 30% with increasing mass fraction of the CNEPs. The thermal conductivity ratio of the composites can be augmented by a factor up to 1.3. The heat transfer coefficient during solidification increased about 78% for the maximum flow rate. The analysis of experimental results reveals that the addition of copper oxide nanoparticles to the paraffin wax enhances both the conduction and natural convection very effectively in composites and in paraffin wax. The paraffin wax-based composites have great potential for energy storage applications like industrial waste heat recovery, solar thermal applications and solar based dynamic space power generation with optimal fraction of copper oxide nanoparticles.

  3. Increased Risk of Additional Cancers Among Patients with Gastrointestinal Stromal Tumors: A Population-Based Study

    PubMed Central

    Murphy, James D.; Ma, Grace L.; Baumgartner, Joel M.; Madlensky, Lisa; Burgoyne, Adam M.; Tang, Chih-Min; Martinez, Maria Elena; Sicklick, Jason K.

    2015-01-01

    Purpose Most gastrointestinal stromal tumors (GIST) are considered non-hereditary or sporadic. However, single-institution studies suggest that GIST patients develop additional malignancies with increased frequencies. We hypothesized that we could gain greater insight into possible associations between GIST and other malignancies using a national cancer database inquiry. Methods Patients diagnosed with GIST (2001–2011) in the Surveillance, Epidemiology, and End Results database were included. Standardized prevalence ratios (SPRs) and standardized incidence ratios (SIRs) were used to quantify cancer risks incurred by GIST patients before and after GIST diagnoses, respectively, when compared with the general U.S. population. Results Of 6,112 GIST patients, 1,047 (17.1%) had additional cancers. There were significant increases in overall cancer rates: 44% (SPR=1.44) before diagnosis and 66% (SIR=1.66) after GIST diagnoses. Malignancies with significantly increased occurrence both before/after diagnoses included other sarcomas (SPR=5.24/SIR=4.02), neuroendocrine-carcinoid tumors (SPR=3.56/SIR=4.79), non-Hodgkin’s lymphoma (SPR=1.69/SIR=1.76), and colorectal adenocarcinoma (SPR=1.51/SIR=2.16). Esophageal adenocarcinoma (SPR=12.0), bladder adenocarcinoma (SPR=7.51), melanoma (SPR=1.46), and prostate adenocarcinoma (SPR=1.20) were significantly more common only before GIST. Ovarian carcinoma (SIR=8.72), small intestine adenocarcinoma (SIR=5.89), papillary thyroid cancer (SIR=5.16), renal cell carcinoma (SIR=4.46), hepatobiliary adenocarcinomas (SIR=3.10), gastric adenocarcinoma (SIR=2.70), pancreatic adenocarcinoma (SIR=2.03), uterine adenocarcinoma (SIR=1.96), non-small cell lung cancer (SIR=1.74), and transitional cell carcinoma of the bladder (SIR=1.65) were significantly more common only after GIST. Conclusion This is the first population-based study to characterize the associations and temporal relationships between GIST and other cancers, both by site and

  4. 78 FR 68461 - Guidance for Industry: Studies To Evaluate the Utility of Anti-Salmonella Chemical Food Additives...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-14

    ... Anti- Salmonella Chemical Food Additives in Feeds; Request for Comments AGENCY: Food and Drug... Chemical Food Additives in Feeds,'' and is seeking comments on this guidance before revisions are made... Guidance for Industry: Studies to Evaluate the Utility of Anti-Salmonella Chemical Food Additives in...

  5. Black shale weathering: An integrated field and numerical modeling study

    NASA Astrophysics Data System (ADS)

    Bolton, E. W.; Wildman, R. A., Jr.; Berner, R. A.; Eckert, J. O., Jr.; Petsch, S. T.; Mok, U.; Evans, B.

    2003-04-01

    We present an integrated study of black shale weathering in a near surface environment. Implications of this study contribute to our understanding of organic matter oxidation in uplifted sediments, along with erosion and reburial of ancient unoxidized organic matter, as major controls on atmospheric oxygen levels over geologic time. The field study used to launch the modeling effort is based on core samples from central-eastern Kentucky near Clay City (Late Devonian New Albany/Ohio Shale), where the strata are essentially horizontal. Samples from various depth intervals (up to 12 m depth) were analyzed for texture (SEM images), porosity fraction (0.02 to 0.1), and horizontal and vertical permeability (water and air permeabilities differ due to the fine-grained nature of the sediments, but are on the order of 0.01 to 1. millidarcies, respectively). Chemical analyses were also performed for per cent C, N, S, and basic mineralogy was determined (clays, quartz, pyrite, in addition to organic matter). The samples contained from 2 to 15 per cent ancient (non-modern soil) organic matter. These results were used in the creation of a numerical model for kinetically controlled oxidation of the organic matter within the shale (based on kinetics from Chang and Berner, 1999). The one-dimensional model includes erosion, oxygen diffusion in the partially saturated vadose zone as well as water percolation and solute transport. This study extends the studies of Petsch (2000) and the weathering component of Lasaga and Ohmoto (2002) to include more reactions (e.g., pyrite oxidation to sulfuric acid and weathering of silicates due to low pH) and to resolve the near-surface boundary layer. The model provides a convenient means of exploring the influence of variable rates of erosion, oxygen level, rainfall, as well as physical and chemical characteristics of the shale on organic matter oxidation.

  6. Planning for Graduate Studies in Physics and Related Fields

    ERIC Educational Resources Information Center

    Henry, Dennis C., Ed.

    2002-01-01

    This brochure is written for students considering graduate work in physics or related fields such as astronomy, biophysics, and applied physics. It also provides some information for physics undergraduates who plan on pursuing postbaccalaureate studies in the fields of engineering, medicine, law, and other professions that attract significant…

  7. Apprenticeships, Collaboration and Scientific Discovery in Academic Field Studies

    ERIC Educational Resources Information Center

    Madden, Derek Scott; Grayson, Diane J.; Madden, Erinn H.; Milewski, Antoni V.; Snyder, Cathy Ann

    2012-01-01

    Teachers may use apprenticeships and collaboration as instructional strategies that help students to make authentic scientific discoveries as they work as amateur researchers in academic field studies. This concept was examined with 643 students, ages 14-72, who became proficient at field research through cognitive apprenticeships with the…

  8. Toward a Virtual Field Trip Model for the Social Studies

    ERIC Educational Resources Information Center

    Stoddard, Jeremy

    2009-01-01

    In the current state of social studies education, field trips are being cut from many schools' curriculum. While not a true substitution, today's technologies provide some opportunities through virtual field trips (VFTs) to simulate these experiences, engage students in knowledge production and disciplined inquiry, and have interactions with the…

  9. The Field Course as an Instructional Medium in Community Studies.

    ERIC Educational Resources Information Center

    Davidson, Claud M.

    1981-01-01

    Describes a college course which uses field studies to examine communities and small urban places. The course is designed for undergraduate students with little or no field experience and is offered as an intensive two-week session between semesters. (RM)

  10. Experimental studies of sound field suppression at discrete frequencies

    NASA Astrophysics Data System (ADS)

    Fiks, I. Sh.; Korotin, P. I.; Potapov, O. A.; Fiks, G. E.

    2016-03-01

    Practical implementation of an active sound control system ensuring sound suppression in outer space is described as applied to sound insulation problems for equipment whose total noise level is mainly due to low-frequency discrete spectral components. The operational principle of the proposed system is based on inverse field generation with respect to the field of the initial source of quasi-monochromatic signals. The inverse field is formed by a set of radiators, which are controlled by the signals of pressure receivers positioned in the near field of the source. Experimental studies carried out with the proposed sound control system demonstrate its efficiency and testify to the stability of its operation.

  11. Beyond the Call of Duty: A Qualitative Study of Teachers' Additional Responsibilities Related to Sexuality Education

    ERIC Educational Resources Information Center

    Eisenberg, Marla E.; Madsen, Nikki; Oliphant, Jennifer A.; Resnick, Michael

    2011-01-01

    Seven focus groups were conducted with sexuality educators in Minnesota to explore ways that teaching sexuality education differs from teaching other health education content and to determine if additional supports or resources are needed for sexuality educators. Teachers described many specific additional responsibilities or concerns related to…

  12. Soil microbial biomass and community structure affected by repeated additions of sewage sludge in four Swedish long-term field experiments

    NASA Astrophysics Data System (ADS)

    Börjesson, G.; Kätterer, T.; Kirchmann, H.

    2012-04-01

    Soil organic matter is a key attribute of soil fertility. The pool of soil organic C can be increased, either by mineral fertilisers or by adding organic amendments such as sewage sludge. Sewage sludge has positive effects on agricultural soils through the supply of organic matter and essential plant nutrients, but sludge may also contain unwanted heavy metals, xenobiotic substances and pathogens. One obvious effect of long-term sewage sludge addition is a decrease in soil pH, caused by N mineralisation followed by nitrification, sulphate formation and presence of organic acids with the organic matter added. The objective of this study was to investigate the effect of sewage sludge on the microbial biomass and community structure. Materials and methods We analysed soil samples from four sites where sewage sludge has been repeatedly applied in long-term field experiments situated in different parts of Sweden; Ultuna (59°49'N, 17°39'E, started 1956), Lanna (58°21'N, 13°06'E, started 1997-98), Petersborg (55°32'N, 13°00'E, started 1981) and Igelösa (55°45'N, 13°18'E, started 1981). In these four experiments, at least one sewage sludge treatment is included in the experimental design. In the Ultuna experiment, all organic fertilisers, including sewage sludge, are applied every second year, corresponding to 4 ton C ha-1. The Lanna experiment has a similar design, with 8 ton dry matter ha-1 applied every second year. Lanna also has an additional treatment in which metal salts (Cd, Cu, Ni and Zn) are added together with sewage sludge. At Petersborg and Igelösa, two levels of sewage sludge (4 or 12 ton dry matter ha-1 every 4th year) are compared with three levels of NPK fertiliser (0 N, ½ normal N and normal N). Topsoil samples (0-20 cm depth) from the four sites were analysed for total C, total N, pH and PLFAs (phospholipid fatty acids). In addition, crop yields were recorded. Results At all four sites, sewage sludge has had a positive effect on crop yields

  13. Addition reaction of alkyl radical to C60 fullerene: Density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2016-02-01

    Functionalized fullerenes are known as a high-performance molecules. In this study, the alkyl-functionalized fullerenes (denoted by R-C60) have been investigated by means of the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of fullerene. Also, the reaction mechanism of alkyl radicals with C60 was investigated. The methyl, ethyl, propyl, and butyl radicals (denoted by n = 1-4, where n means the number of carbon atoms in the alkyl radical) were examined as alkyl radicals. The DFT calculation showed that the alkyl radical binds to the carbon atom of C60 at the on-top site, and a strong C-C single bond is formed. The binding energies of alkyl radicals to C60 were distributed in the range of 31.8-35.1 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists before alkyl addition, the barrier heights were calculated to be 2.1-2.8 kcal mol-1. The electronic states of R-C60 complexes were discussed on the basis of the theoretical results.

  14. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol).

    PubMed

    Jones, Matthew; Li, Calvin H; Afjeh, Abdollah; Peterson, Gp

    2011-01-01

    An experimental investigation of the combustion behavior of nano-aluminum (n-Al) and nano-aluminum oxide (n-Al2O3) particles stably suspended in biofuel (ethanol) as a secondary energy carrier was conducted. The heat of combustion (HoC) was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results. PMID:21711760

  15. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol)

    NASA Astrophysics Data System (ADS)

    Jones, Matthew; Li, Calvin H.; Afjeh, Abdollah; Peterson, Gp

    2011-12-01

    An experimental investigation of the combustion behavior of nano-aluminum (n-Al) and nano-aluminum oxide (n-Al2O3) particles stably suspended in biofuel (ethanol) as a secondary energy carrier was conducted. The heat of combustion (HoC) was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results.

  16. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol)

    PubMed Central

    2011-01-01

    An experimental investigation of the combustion behavior of nano-aluminum (n-Al) and nano-aluminum oxide (n-Al2O3) particles stably suspended in biofuel (ethanol) as a secondary energy carrier was conducted. The heat of combustion (HoC) was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results. PMID:21711760

  17. Meiofaunal and bacterial community response to diesel additions in a microcosm study.

    PubMed

    Lindgren, J Fredrik; Hassellöv, Ida-Maja; Dahllöf, Ingela

    2012-03-01

    Effects of low PAH-containing diesel were studied in a 60-day microcosm experiment at PAH concentrations 130, 1300 and 13,000μg/kg sediment. Nutrient fluxes, potential nitrification and meiofaunal community composition were analysed at three time points. Changed ∑NOx-fluxes indicated reduced sediment nitrification in Medium and High with time, in agreement with lowered potential nitrification rates in all treatments. Reduction in silicate and phosphate fluxes over time suggested severe effects on activity of meiofauna. Reduced activity increased the anoxic sediment layer, which could have contributed to the changed ∑NOx-fluxes. There were significant differences in meiofaunal community composition after 30 and 60days in Medium and High. Changes were due to increasing numbers of harpacticoids and the foraminiferan group Rotaliina, as well as decreasing numbers of Nematodes and the foraminiferan group Reophax. In spite of the low PAH-level, small additions of this diesel can still have pronounced effects on meiofaunal and bacterial communities.

  18. A theoretical study of wave dispersion and thermal conduction for HMX/additive interfaces

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2014-04-01

    The wave dispersion rule for non-uniform material is useful for ultrasonic inspection and engine life prediction, and also is key in achieving an understanding of the energy dissipation and thermal conduction properties of solid material. On the basis of linear response theory and molecular dynamics, we derive a set of formulas for calculating the wave dispersion rate of interface systems, and study four kinds of interfaces inside plastic bonded explosives: HMX/{HMX, TATB, F2312, F2313}. (HMX: octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine; TATB: 1,3,5-triamino-2,4,6-trinitrobenzene; F2312, F2313: fluoropolymers). The wave dispersion rate is obtained over a wide frequency range from kHz to PHz. We find that at low frequency, the rate is proportional to the square of the frequency, and at high frequency, the rate couples with the molecular vibration modes at the interface. By using the results, the thermal conductivities of HMX/additive interfaces are derived, and a physical model is built for describing the total thermal conductivity of mixture explosives, including HMX multi-particle systems and {TATB, F2312, F2313}-coated HMX.

  19. Study of the effects of guide field on Hall reconnection

    SciTech Connect

    Tharp, T. D.; Yamada, M.; Ji, H.; Lawrence, E.; Dorfman, S.; Myers, C.; Yoo, J.; Huang, Y.-M.; Bhattacharjee, A.

    2013-05-15

    The results from guide field studies on the Magnetic Reconnection Experiment (MRX) are compared with results from Hall magnetohydrodynamic (HMHD) reconnection simulation with guide field. The quadrupole field, a signature of two-fluid reconnection at zero guide field, is modified by the presence of a finite guide field in a manner consistent with HMHD simulation. The modified Hall current profile contains reduced electron flows in the reconnection plane, which quantitatively explains the observed reduction of the reconnection rate. The present results are consistent with the hypothesis that the local reconnection dynamics is dominated by Hall effects in the collisionless regime of the MRX plasmas. While very good agreement is seen between experiment and simulations, we note that an important global feature of the experiments, a compression of the guide field by the reconnecting plasma, is not represented in the simulations.

  20. Identification of bacteria synthesizing ribosomal RNA in response to uranium addition during biostimulation at the Rifle, CO Integrated Field Research site

    DOE PAGES

    McGuinness, Lora R.; Wilkins, Michael J.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.; Boyanov, Maxim I.

    2015-09-18

    Understanding which organisms are capable of reducing uranium at historically contaminated sites provides crucial information needed to evaluate treatment options and outcomes. One approach is determination of the bacteria which directly respond to uranium addition. In this research, uranium amendments were made to groundwater samples from a site of ongoing biostimulation with acetate. The active microbes in the planktonic phase were deduced by monitoring ribosomes production via RT-PCR. The results indicated several microorganisms were synthesizing ribosomes in proportion with uranium amendment up to 2 μM. Concentrations of U (VI) >2 μM were generally found to inhibit ribosome synthesis. Two activemore » bacteria responding to uranium addition in the field were close relatives of Desulfobacter postgateii and Geobacter bemidjiensis. Since RNA content often increases with growth rate, our findings suggest it is possible to rapidly elucidate active bacteria responding to the addition of uranium in field samples and provides a more targeted approach to stimulate specific populations to enhance radionuclide reduction in contaminated sites.« less

  1. Identification of bacteria synthesizing ribosomal RNA in response to uranium addition during biostimulation at the Rifle, CO Integrated Field Research site

    SciTech Connect

    McGuinness, Lora R.; Wilkins, Michael J.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.; Boyanov, Maxim I.

    2015-09-18

    Understanding which organisms are capable of reducing uranium at historically contaminated sites provides crucial information needed to evaluate treatment options and outcomes. One approach is determination of the bacteria which directly respond to uranium addition. In this research, uranium amendments were made to groundwater samples from a site of ongoing biostimulation with acetate. The active microbes in the planktonic phase were deduced by monitoring ribosomes production via RT-PCR. The results indicated several microorganisms were synthesizing ribosomes in proportion with uranium amendment up to 2 μM. Concentrations of U (VI) >2 μM were generally found to inhibit ribosome synthesis. Two active bacteria responding to uranium addition in the field were close relatives of Desulfobacter postgateii and Geobacter bemidjiensis. Since RNA content often increases with growth rate, our findings suggest it is possible to rapidly elucidate active bacteria responding to the addition of uranium in field samples and provides a more targeted approach to stimulate specific populations to enhance radionuclide reduction in contaminated sites.

  2. Addition of trim coils to the Tandem Mirror Experiment Upgrade (TMX-U) magnet system to improve the magnetic field mapping

    SciTech Connect

    Wong, R.L.; Pedrotti, L.R.; Baldwin, D.E.; Hibbs, S.M.; Hill, D.N.; Hornady, R.H.; Jackson, M.C.

    1985-11-14

    The mapping of the magnetic flux bundle from the center cell to the Plasma Potential Control plates (PPC) on the end fan of the Tandem Mirror Experiment Upgrade (TMX-U), was improved by the addition of trim coils (12,000 amp-turns) on each side of each end fan next to the pump beam magnetic shields. The coils' axes are oriented perpendicular to the machine centerline. These coils made the necessary corrections to the field-line mapping, while keeping the field in the nearby pump beam magnetic shield below the saturation threshold. This paper briefly describes the problem, discusses the design as it evolved, and presents the results of the field testing. The disturbance to the field mapping and the appropriate corrections were determined using the code GFUN (a three dimensional electromagnetic field analysis code that includes the presence of permeable materials). The racetrack-shaped coils have dimensions of 1.5 feet by 3 feet and are powered by a renovated 600 kW Bart-Messing power supply controlled by the machine's magnet control system. The magnets were fabricated from polyimide-coated magnet wire. They are rated to 200/sup 0/C, although in pulsed operation they rise only a few degrees centigrade. The coils are placed outside of the vacuum system, and thus are considerably simpler than the other machine magnets. The restraints are designed to withstand a force of 1000 pounds per coil and a turning moment of 1000 foot pounds. The calculated field strengths were verified on the machine by inserting a Hall probe along the axis. The perturbations to the neutral beam magnetic shields were also measured. A brief description of the improvement in the machine performance is also included.

  3. Preparation of nickel oxide powder by decomposition of basic nickel carbonate in microwave field with nickel oxide seed as a microwave absorbing additive

    SciTech Connect

    Wang, Y.; Ke, J.J.

    1996-01-01

    Nickel oxide (NiO) powder is prepared by decomposition of basic nickel carbonate (mNi(OH){sub 2}{center_dot}nNiCO{sub 3}{center_dot}xH{sub 2}O) in microwave field with NiO seed as a microwave absorbing additive. Basic nickel carbonate (BNC) can decompose completely to NiO powder in a short time. Firstly, the heat for BNC decomposition is provided by NiO seed which absorbs microwave and then by NiO product which also absorbs microwave. The decomposition process of BNC can be accelerated by increasing the amount of BNC, the amount of NiO seed or the microwave field power. The size of NiO powder product is about 180nm when the size of BNC used is about 160nm.

  4. On a two-dimensional Schrödinger equation with a magnetic field with an additional quadratic integral of motion

    NASA Astrophysics Data System (ADS)

    Marikhin, V. G.

    2011-10-01

    The problem of commuting quadratic quantum operators with a magnetic field has been considered. It has been shown that any such pair can be reduced to the canonical form, which makes it possible to construct an almost complete classification of the solutions of equations that are necessary and sufficient for a pair of operators to commute with each other. The transformation to the canonical form is performed through the change of variables to the Kovalevskaya-type variables; this change is similar to that in the theory of integrable tops. As an example, this procedure has been considered for the two-dimensional Schrödinger equation with the magnetic field; this equation has an additional quantum integral of motion.

  5. Hooking the Geographer in Children with Field-Based Studies

    ERIC Educational Resources Information Center

    Krall, Florence; And Others

    1978-01-01

    Suggests projects to help elementary students learn about man-land relationships through field experience, inquiry techniques, and a thematic, interdisciplinary approach. Children study a natural community, a human community, solid wastes, and energy conservation. (Author/AV)

  6. CANTON CAFO FIELD SITE STUDY - SITE CHARACTERIZATION AND CONTAMINANT IMPACTS

    EPA Science Inventory

    This presentation of CAFO research concerning the Canton CAFO field site study, including its characterization and contaminant impacts, was given at a NRMRL program review discussion of the CAFO Research Program.

  7. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect

    Not Available

    1990-01-01

    This paper on titan plasma engineering contains papers on the following topics: reversed-field pinch as a fusion reactor; parametric systems studies; magnetics; burning-plasma simulations; plasma transient operations; current drive; and physics issues for compact RFP reactors.

  8. Astronaut Neil Armstrong studies rock samples during geological field trip

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  9. Can additional urban development have major impacts on streamflow of a peri-urban catchment? A case study from Portugal

    NASA Astrophysics Data System (ADS)

    Ferreira, Carla; Walsh, Rory; Nunes, João; Steenhuis, Tammo; de Lima, João; Coelho, Celeste; Ferreira, António

    2016-04-01

    - and post- additional urban development periods. Response time to rainfall reduced from 60-75 minutes to 40 minutes and recession time fell from 21.3-29.5 h to 7.4-8.7 h, respectively. The relatively low runoff and storm runoff coefficients given the extent of urban land-use is due to the dispersed urban pattern and movement of at least part of the overland flow from impervious surfaces into pervious soils (within urban areas and/or downslope woodland and abandoned fields). High soil permeability, linked to the sandstone and limestone bedrock, favours the establishment of water sinks. The additional extension of observed urban development during the study period, however, also included partial routing of overland flow from additional impervious surfaces into the stream network, enhancing flow connectivity, thus, increasing storm runoff and providing quicker hydrologic response. Urban planning should consider the landscape mosaic of peri-urban areas in order to maximize water infiltration and minimize the impacts on streamflow regime and urban flooding.

  10. Comparative study of trimethyl phosphite and trimethyl phosphate as electrolyte additives in lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Yao, X. L.; Xie, S.; Chen, C. H.; Wang, Q. S.; Sun, J. H.; Li, Y. L.; Lu, S. X.

    Safety concerns of lithium ion batteries have been the key problems in their practical applications. Trimethyl phosphite (TMP(i)) and trimethyl phosphate (TMP(a)) were used as the electrolyte additives to improve the safety and electrochemical performance of lithium cells. Gallvanostatic cell cycling, flammability test and thermal stability measurements by means of accelerated rate calorimeter (ARC) and micro calorimeter were performed. It is found that both TMP(i) and TMP(a) reduce the flammability of the electrolyte. The TMP(i) additive not only enhances the thermal stability of the electrolyte, but also improves its electrochemical performance. The TMP(a) additive can improve the thermal stability of the electrolyte at the expense of some degree of degradation of its electrochemical performance. Therefore, TMP(i) is a better flame retardant additive in the electrolyte compared with TMP(a).

  11. Fortification of yogurts with different antioxidant preservatives: A comparative study between natural and synthetic additives.

    PubMed

    Caleja, Cristina; Barros, Lillian; Antonio, Amilcar L; Carocho, Márcio; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2016-11-01

    Consumers demand more and more so-called "natural" products and, therefore, the aim of this work was to compare the effects of natural versus synthetic antioxidant preservatives in yogurts. Matricaria recutita L. (chamomile) and Foeniculum vulgare Mill. (fennel) decoctions were tested as natural additives, while potassium sorbate (E202) was used as a synthetic additive. The fortification of yogurts with natural and synthetic antioxidants did not cause significant changes in the yoghurt pH and nutritional value, in comparison with control samples (yogurt without any additive). However, the fortified yogurts showed higher antioxidant activity, mainly the yogurts with natural additives (and among these, the ones with chamomile decoction). Overall, it can be concluded that plant decoctions can be used to develop novel yogurts, by replacing synthetic preservatives and improving the antioxidant properties of the final product, without changing the nutritional profile. PMID:27211646

  12. Fortification of yogurts with different antioxidant preservatives: A comparative study between natural and synthetic additives.

    PubMed

    Caleja, Cristina; Barros, Lillian; Antonio, Amilcar L; Carocho, Márcio; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2016-11-01

    Consumers demand more and more so-called "natural" products and, therefore, the aim of this work was to compare the effects of natural versus synthetic antioxidant preservatives in yogurts. Matricaria recutita L. (chamomile) and Foeniculum vulgare Mill. (fennel) decoctions were tested as natural additives, while potassium sorbate (E202) was used as a synthetic additive. The fortification of yogurts with natural and synthetic antioxidants did not cause significant changes in the yoghurt pH and nutritional value, in comparison with control samples (yogurt without any additive). However, the fortified yogurts showed higher antioxidant activity, mainly the yogurts with natural additives (and among these, the ones with chamomile decoction). Overall, it can be concluded that plant decoctions can be used to develop novel yogurts, by replacing synthetic preservatives and improving the antioxidant properties of the final product, without changing the nutritional profile.

  13. A field study of wind over a simulated block building

    NASA Technical Reports Server (NTRS)

    Frost, W.; Shahabi, A. M.

    1977-01-01

    A full-scale field study of the wind over a simulated two-dimensional building is reported. The study develops an experiment to investigate the structure and magnitude of the wind fields. A description of the experimental arrangement, the type and expected accuracy of the data, and the range of the data are given. The data are expected to provide a fundamental understanding of mean wind and turbulence structure of the wind field around the bluff body. Preliminary analysis of the data demonstrates the reliability and completeness of the data in this regard.

  14. Aristoteles - An ESA mission to study the earth's gravity field

    NASA Astrophysics Data System (ADS)

    Lambeck, K.

    In preparing for its first Solid-Earth Program, ESA has studied a satellite concept for a mission dedicated to the precise determination of the earth's geopotential (gravitational and magnetic) fields. Data from such a mission are expected to make substantial contributions to a number of research and applications fields in solid-earth geophysics, oceanography and global-change monitoring. The impact of a high-resolution gravity-field mission on studies of the various earth-science problems is assessed. The current state of our knowledge in this area is discussed and the ability of low-orbit satellite gradiometry to contribute to their solution is demonstrated.

  15. The South Carolina Coastal Erosion Study: Nearshore Hydrodynamics Field Experiment

    NASA Astrophysics Data System (ADS)

    Haas, K. A.; Voulgaris, G.; Demir, H.; Work, P. A.; Hanes, D. M.

    2004-12-01

    As part of the South Carolina Coastal Erosion Study (SCCES) a nearshore field experiment was carried out for five days in December 2003 just north of Myrtle Beach, South Carolina, providing measurements of the waves, currents and morphological evolution. This experiment occurred concurrently with an extensive field campaign several kilometers offshore which included measurements of the waves and currents on and near a significant sand shoal. The purpose of the nearshore experiment was to aid in the identification of the effect of the offshore shoal on the nearshore processes. The resulting dataset will be used for verification of numerical models being used to investigate the hydrodynamics of the region. The experiment was carried out from December 10 to December 15 and consisted of measurements of the waves and currents, extensive surveys of the bathymetry every day, grab samples of the sediments, and video imagery. The hydrodynamics were measured using two Sontek Triton downward-looking Acoustic Doppler Velocimeters and two Nortek AquaDopp profilers arranged in a cross-shore line from inside the swash to several surf zone widths past the breakers. The bathymetric surveying was accomplished using both a differential GPS system and a total station. Surveying was performed each day in order to capture the morphological changes. On the last day, seven sediment samples were taken along a single cross-section to determine the sediment characteristics across the beach. Additionally, a video camera was located on a balcony of the top floor of a nearby hotel providing an excellent field of view of the entire experimental area. Digital video was captured directly onto a computer during all daylight hours and many control points were surveyed in each day to facilitate rectification of the imagery. A variety of conditions were encountered during the experiment, including two storm fronts which passed through, generating wind speeds up to 15 m/s. The first storm generated

  16. Drastic Improvement in Wettability of 6,13-Bis(triisopropylsilylethynyl)pentacene by Addition of Silica Nanoparticles for Solution-Processable Organic Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Yamazaki, Saori; Hamada, Takashi; Nagase, Takashi; Tokai, Sakae; Yoshikawa, Masashi; Kobayashi, Takashi; Michiwaki, Yoshiki; Watase, Seiji; Watanabe, Mitsuru; Matsukawa, Kimihiro; Naito, Hiroyoshi

    2010-09-01

    It is essential to control the wettability of soluble organic semiconductors on polymer gate dielectrics to realize low-cost, flexible, and large-area electronic circuits employing organic field-effect transistors using solution processes. We find that the addition of a small amount of silica nanoparticles (SNPs) drastically improves the wettability of the soluble organic semiconductor of 6,13-bis(triisopropylsilylethynyl)pentacene onto the hydrophobic polymer gate dielectric of poly(methylsilsesquioxane) in the spin-coating process. The improvement in wettability by the addition of SNPs is also demonstrated in the ink-jet printing process, which allows the direct patterning of soluble organic semiconductors on polymer gate dielectrics.

  17. Chemostat Studies of TCE-Dehalogenating Anaerobic Consortia under Excess and Limited Electron Donor Addition

    NASA Astrophysics Data System (ADS)

    Semprini, L.; Azizian, M.; Green, J.; Mayer-Blackwell, K.; Spormann, A. M.

    2015-12-01

    Two cultures - the Victoria Strain (VS) and the Evanite Strain (EV), enriched with the organohalide respiring bacteria Dehalococcoides mccartyi - were grown in chemostats for more than 4 years at a mean cell residence time of 50 days. The slow doubling rate represents growth likely experienced in the subsurface. The chemostats were fed formate as an electron donor and trichloroethene (TCE) as the terminal electron acceptor. Under excess formate conditions, stable operation was observed with respect to TCE transformation, steady-state hydrogen (H2) concentrations (40 nM), and the structure of the dehalogenating community. Both cultures completely transformed TCE to ethene, with minor amounts of vinyl chloride (VC) observed, along with acetate formation. When formate was limited, TCE was transformed incompletely to ethene (40-60%) and VC (60- 40%), and H2 concentrations ranged from 1 to 3 nM. The acetate concentration dropped below detection. Batch kinetic studies of TCE transformation with chemostat harvested cells found transformation rates of c-DCE and VC were greatly reduced when the cells were grown with limited formate. Upon increasing formate addition to the chemostats, from limited to excess, essentially complete transformation of TCE to ethene was achieved. The increase in formate was associated with an increase in H2 concentration and the production of acetate. Results of batch kinetic tests showed increases in transformation rates for TCE and c-DCE by factors of 3.5 and 2.5, respectively, while VC rates increased by factors of 33 to 500, over a six month period. Molecular analysis of chemostat samples is being performed to quantify the changes in copy numbers of reductase genes and to determine whether shifts in the strains of Dehalococcoides mccartyi where responsible for the observed rate increases. The results demonstrate the importance of electron donor supply for successful in-situ remediation.

  18. Study of metal whiskers growth and mitigation technique using additive manufacturing

    NASA Astrophysics Data System (ADS)

    Gullapalli, Vikranth

    For years, the alloy of choice for electroplating electronic components has been tin-lead (Sn-Pb) alloy. However, the legislation established in Europe on July 1, 2006, required significant lead (Pb) content reductions from electronic hardware due to its toxic nature. A popular alternative for coating electronic components is pure tin (Sn). However, pure tin has the tendency to spontaneously grow electrically conductive Sn whisker during storage. Sn whisker is usually a pure single crystal tin with filament or hair-like structures grown directly from the electroplated surfaces. Sn whisker is highly conductive, and can cause short circuits in electronic components, which is a very significant reliability problem. The damages caused by Sn whisker growth are reported in very critical applications such as aircraft, spacecraft, satellites, and military weapons systems. They are also naturally very strong and are believed to grow from compressive stresses developed in the Sn coating during deposition or over time. The new directive, even though environmentally friendly, has placed all lead-free electronic devices at risk because of whisker growth in pure tin. Additionally, interest has occurred about studying the nature of other metal whiskers such as zinc (Zn) whiskers and comparing their behavior to that of Sn whiskers. Zn whiskers can be found in flooring of data centers which can get inside electronic systems during equipment reorganization and movement and can also cause systems failure. Even though the topic of metal whiskers as reliability failure has been around for several decades to date, there is no successful method that can eliminate their growth. This thesis will give further insights towards the nature and behavior of Sn and Zn whiskers growth, and recommend a novel manufacturing technique that has potential to mitigate metal whiskers growth and extend life of many electronic devices.

  19. A study of the electrochemistry of nickel hydroxide electrodes with various additives

    NASA Astrophysics Data System (ADS)

    Zhu, Wen-Hua; Ke, Jia-Jun; Yu, Hong-Mei; Zhang, Deng-Jun

    Nickel composite electrodes (NCE) with various additives are prepared by a chemical impregnation method from nitrate solutions on sintered porous plaques. The electrochemical properties, such as utilization of active material, swelling and the discharge potential of the nickel oxide electrode (NOE) are determined mainly through the composition of the active material and the characteristics of nickel plaques. Most additives (Mg, Ca, Sr, Ba, Zn, Cd, Co, Li and Al hydroxide) exert effects on the discharge potential and swelling of the NOE. Chemical co-precipitation with the addition of calcium, zinc, magnesium and barium hydroxide increases the discharge potential by more than 20 mV, but that with zinc hydroxide results in an obvious decrease of active-material utilization and that with calcium and magnesium hydroxide produces a larger increase of electrode thickness. The effects of anion additives are also examined. Less than 1% mol of NiS in the active material increases the discharge potential. Cadmium, cobalt and zinc hydroxide are excellent additives for preventing swelling of the NCE. Slow voltammetry (0.2 mV s -1) in 6 M KOH is applied to characterize the oxygen-evolving potential of the NCE. The difference between the oxygen-evolution potential and the potential of the oxidation peak for the NCE with additives of calcium, lithium, barium and aluminium hydroxide is at least + 60 mV.

  20. Compound Lava Flow Fields on Planetary Surfaces: Hawaiian Analogue Studies

    NASA Astrophysics Data System (ADS)

    Crown, D. A.; Byrnes, J. M.; Ramsey, M. S.

    2002-12-01

    Quantitative, process-oriented analyses of planetary volcanism have primarily been based on analogue studies of single-lobed lava flows emplaced as discrete units. Comparative analyses of compound lava flow fields on the Earth and terrestrial planets are being conducted in order to include volcanic styles characterized by complex distributary systems, stratigraphic relationships, and emplacement histories. Field observations, differential Global Positioning Systems (dGPS) measurements, and visible, thermal, and radar remote sensing are being used to characterize Hawaiian lava flow fields and develop techniques for analyses of planetary flow fields using datasets with high spatial and/or spectral resolution, such as MOC and THEMIS. These terrestrial studies allow flow field surface morphology, topography, and lava textures as well as detailed maps of distributary networks to be used to examine flow field growth and development. Information on flow field evolution is provided by delineating relationships between remote sensing signatures, surface morphology, and lava transport processes and by identifying input parameters for flowfield emplacement models. Investigations of the Mauna Ulu (1969-1974) and Puu Oo (1983-present) flow fields (Kilauea Volcano, HI) have focused on understanding the nature of distributary networks at various scales in order to determine spatial and temporal variations in lava transport. Initial work at Mauna Ulu has included analyses of 1) the distribution, network morphometry, and volumetric significance of lava channels in the medial zone of the flow field, and 2) the distribution, lava texture, and volumetric significance of breakouts from surface conduits and subsurface storage. Analyses of the temporal evolution of individual conduit systems provide the basis for interpretation of complex patterns of overlapping surface units that characterize local flow stratigraphy. Reconstruction of lava transport networks and relationships to surface

  1. Additions and corrections to the bibliography of geologic studies, Columbia Plateau (Columbia River Besalt) and adjacent Areas, in Idaho, 1980

    SciTech Connect

    Strowd, W.

    1980-01-01

    This bibliography is an update to Idaho Bureau of Mines and Geology Open-File Report 78-6, Bibliography of Geological Studies, Columbia Plateau (Columbia River Basalt Group) and adjacent areas in Idaho (also known as Rockwell Hanford Operations' contractor report RHO-BWI-C-44). To keep the original document current, this additions and corrections report was prepared for the Basalt Waste Isolation Project of Rockwell Hanford Operations. This update is supplementary; therefore, references cited in the original document have not been included here. What is included are materials that have become available since the original publication and pertinent literature that had originally been overlooked. Accompany this updated bubliography are index maps that show locations of geologic studies and geochemical petrographic, remanent paleomagnetic, and radiometric age-dated sites within the Columbia River Basalt Group field within Idaho; also identified are archeological sites, test wells, mines, quarries, and other types of excavations. References on the index maps are keyed to the bibliography and cover the Spokane, Pullman, Hamilton, Grangeville, Elk City, Baker, Boise, and Jordan Valley Army Map Service two-degree quadrangles.

  2. ELF electric and magnetic fields: Pacific Northwest Laboratory studies

    SciTech Connect

    Anderson, L.E.

    1992-06-01

    Studies have been conducted at Battelle, Pacific Northwest Laboratory, to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Three areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function, (2) experiments on cancer development in animals, and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. In behavioral experiments, rats have been shown to be responsive to ELF electric field exposure. Furthermore, experimental data indicate that short-term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies have been conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels have been shown to be significantly depressed in animals exposed to either electric or magnetic fields. A number of animal tumor models are currently under investigation to examine possible relationships between ELF exposure and carcinogenesis. Finally, theoretical and experimental measurements have been performed which form the basis for animals and human exposure comparisons.

  3. ELF electric and magnetic fields: Pacific Northwest Laboratory studies

    NASA Astrophysics Data System (ADS)

    Anderson, L. E.

    1992-06-01

    Studies were conducted at Battelle, Pacific Northwest Laboratory, to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Three areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function; (2) experiments on cancer development in animals; and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. In behavioral experiments, rats were shown to be responsive to ELF electric field exposure. Furthermore, experimental data indicate that short-term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies were conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels were shown to be significantly depressed in animals exposed to either electric or magnetic fields. A number of animal tumor models are currently under investigation to examine possible relationships between ELF exposure and carcinogenesis. Finally, theoretical and experimental measurements were performed which form the basis for animals and human exposure comparisons.

  4. Maltreated children's representations of mother and an additional caregiver: a longitudinal study.

    PubMed

    Manashko, Shany; Besser, Avi; Priel, Beatriz

    2009-04-01

    In the current longitudinal investigation, we explored the continuity of and changes in the mental representations of the mother and an additional caregiver among forty-five 9- to 11-year-old children who had been severely maltreated and subsequently placed in long-term residential care as well as the relationships between the content and structure of these representations and teacher's assessments of the child's externalizing and internalizing symptoms. At Time 1, a nonmaltreated comparison group was assessed concomitantly. Compared to nonmaltreated children, maltreated children scored higher for externalizing and internalizing symptoms, and their maternal representations were found to be significantly less benevolent and integrated and more punitive. In addition, among the maltreated children, the additional caregiver representations were found to be more benevolent and integrated, and less punitive, than the maternal representations. After 30 months, the maltreated children's levels of externalizing and internalizing symptoms diminished, their maternal representations become more benevolent and less punitive, and the additional caregiver representations became less benevolent. Moreover, the Benevolence of the additional caregiver representation was found to predict these children's changes in externalizing symptoms beyond the effects of their symptomatology and its associations with the Benevolence of these representations at Time 1. PMID:19220720

  5. High-field small animal magnetic resonance oncology studies

    NASA Astrophysics Data System (ADS)

    Bokacheva, Louisa; Ackerstaff, Ellen; LeKaye, H. Carl; Zakian, Kristen; Koutcher, Jason A.

    2014-01-01

    This review focuses on the applications of high magnetic field magnetic resonance imaging (MRI) and spectroscopy (MRS) to cancer studies in small animals. High-field MRI can provide information about tumor physiology, the microenvironment, metabolism, vascularity and cellularity. Such studies are invaluable for understanding tumor growth and proliferation, response to treatment and drug development. The MR techniques reviewed here include 1H, 31P, chemical exchange saturation transfer imaging and hyperpolarized 13C MRS as well as diffusion-weighted, blood oxygen level dependent contrast imaging and dynamic contrast-enhanced MRI. These methods have been proven effective in animal studies and are highly relevant to human clinical studies.

  6. International Field Studies in Norwegian Teacher Training Courses: Perspectives and Experiences

    ERIC Educational Resources Information Center

    Steen, Odd Inge

    2009-01-01

    Little research has been done on instructing student teachers by means of field studies in developing countries. Herein, I argue that sending geography students on such expeditions provides them with valuable perspectives, connections and improved knowledge, especially if they experience personal involvement and participation in addition to…

  7. Laboratory and field studies in rotational spectroscopy at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Drouin, Brian J.

    2004-01-01

    Rotational spectroscopy of atmospheric molecules has long been a hallmark of laboratory and field studies at the Jet Propulsion Laboratory. in addition to maintenance of the millimeter and submillimeter spectral line catalog, the laboratory has actively purued the challenging laboratory tasks of quantitative linewidth measurements and transient species identification.

  8. STUDYING THE INTERSTELLAR MAGNETIC FIELD FROM ANISOTROPIES IN VELOCITY CHANNELS

    SciTech Connect

    Esquivel, A.; Lazarian, A.; Pogosyan, D. E-mail: lazarian@astro.wisc.edu

    2015-11-20

    Turbulence in the interstellar medium is anisotropic due to the ubiquitous magnetic fields. This anisotropy depends on the strength of the magnetic field and leaves an imprint on observations of spectral line maps. We use a grid of ideal magnetohydrodynamic simulations of driven turbulence and produce synthetic position–position–velocity maps to study the turbulence anisotropy in velocity channels of various resolutions. We found that the average structure function of velocity channels is aligned with the projection of the magnetic field on the plane of the sky. We also found that the degree of such anisotropy increases with the magnitude of the magnetic field. For thick velocity channels (low velocity resolution), the anisotropy is dominated by density, and the degree of anisotropy in these maps allows one to distinguish sub-Alfvénic and super-Alfvénic turbulence regimes, but it also depends strongly on the sonic Mach number. For thin channels (high velocity resolution), we find that the anisotropy depends less on the sonic Mach number. An important limitation of this technique is that it only gives a lower limit on the magnetic field strength because the anisotropy is related only to the magnetic field component on the plane of the sky. It can, and should, be used in combination with other techniques to estimate the magnetic field, such as the Fermi-Chandrasekhar method, anisotropies in centroids, Faraday rotation measurements, or direct line-of-sight determinations of the field from Zeeman effect observations.

  9. Field studies on pesticides and birds: Unexpected and unique relations

    USGS Publications Warehouse

    Blus, L.J.; Henny, Charles J.

    1997-01-01

    We review the advantages and disadvantages of experimental and field studies for determining effects of pesticides on birds. Important problems or principles initially discovered in the field include effects of DDT (through its metabolite DDE) on eggshell thickness, reproductive success, and population stability; trophic-level bioaccumulation of the lipid-soluble organochlorine pesticides; indirect effects on productivity and survival through reductions in the food supply and cover by herbicides and insecticides; unexpected toxic effects and routes of exposure of organophosphorus compounds such as famphur and dimethoate; effects related to simultaneous application at full strength of several pesticides of different classes; and others. Also, potentially serious bird problems with dicofol, based on laboratory studies, later proved negligible in the field. In refining field tests of pesticides, the selection of a species or group of species to study is important, because exposure routes may vary greatly, and 10-fold interspecific differences in sensitivity to pesticides are relatively common. Although there are limitations with field investigations, particularly uncontrollable variables that must be addressed, the value of a well-designed field study far outweighs its shortcomings.

  10. Field studies on pesticides and birds: unexpected and unique relations

    USGS Publications Warehouse

    Blus, L.J.; Henny, C.J.

    1997-01-01

    We review the advantages and disadvantages of experimental and field studies for determining effects of pesticides on birds. Important problems or principles initially discovered in the field include effects of DDT (through its metabolite DDE) on eggshell thickness, reproductive success, and population stability; trophic-level bioaccumulation of the lipid-soluble organochlorine pesticides; indirect effects on productivity and survival through reductions in the food supply and cover by herbicides and insecticides; unexpected toxic effects and routes of exposure of organophosphorus compounds such as famphur and dimethoate; effects related to simultaneous application at full strength of several pesticides of different classes; and others. Also, potentially serious bird problems with dicofol, based on laboratory studies, later proved negligible in the field. In refining field tests of pesticides, the selection of a species or group of species to study is important, because exposure routes may vary greatly, and 10-fold interspecific differences in sensitivity to pesticides are relatively common. Although there are limitations with field investigations, particularly uncontrollable variables that must be addressed, the value of a well-designed field study far outweighs its shortcomings

  11. A study of the electric field induced by magnetic clouds

    NASA Astrophysics Data System (ADS)

    Hidalgo, M. A.

    2011-02-01

    Starting from our magnetic field model for magnetic clouds (MCs), which topologically considers them as cylinders with elliptical cross sections, we present a first attempt in the study of the electric field induced by the movements of magnetic clouds in the interplanetary medium and the expansions of their cross sections. These expansions are included in the model assuming linear time dependence in all the components of the plasma current density. In a previous paper we already determined the magnetic field and current density of our MCs model, and in its development we established that to get it physically consistent, the induced electric field has to be independent of time. In the present work we calculate the expressions for the components of this electric field and fit them to the corresponding experimental data determined from the measurements of the plasma velocity and magnetic field components through the expression $\\vec E$ = -$\\vec v$SW × $\\vec B$. To test the model, we have selected three intense and well-defined magnetic clouds observed in July 2000, November 2003, and May 2005. Until now we think it is one of the first attempts to incorporate this induced electric field in the context of analytical models for the study of MCs.

  12. Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines.

    PubMed

    Gansäuer, Andreas; Seddiqzai, Meriam; Dahmen, Tobias; Sure, Rebecca; Grimme, Stefan

    2013-01-01

    The intramolecular radical addition to aniline derivatives was investigated by DFT calculations. The computational methods were benchmarked by comparing the calculated values of the rate constant for the 5-exo cyclization of the hexenyl radical with the experimental values. The dispersion-corrected PW6B95-D3 functional provided very good results with deviations for the free activation barrier compared to the experimental values of only about 0.5 kcal mol(-1) and was therefore employed in further calculations. Corrections for intramolecular London dispersion and solvation effects in the quantum chemical treatment are essential to obtain consistent and accurate theoretical data. For the investigated radical addition reaction it turned out that the polarity of the molecules is important and that a combination of electrophilic radicals with preferably nucleophilic arenes results in the highest rate constants. This is opposite to the Minisci reaction where the radical acts as nucleophile and the arene as electrophile. The substitution at the N-atom of the aniline is crucial. Methyl substitution leads to slower addition than phenyl substitution. Carbamates as substituents are suitable only when the radical center is not too electrophilic. No correlations between free reaction barriers and energies (ΔG (‡) and ΔG R) are found. Addition reactions leading to indanes or dihydrobenzofurans are too slow to be useful synthetically.

  13. Effect of stabilizing additives on the structure and hydration of proteins: a study involving monoclinic lysozyme.

    PubMed

    Saraswathi, N T; Sankaranarayanan, R; Vijayan, M

    2002-07-01

    In pursuance of a long-range programme on the hydration, mobility and action of proteins, the structural basis of the stabilizing effect of sugars and polyols is being investigated. With two crystallographically independent molecules with slightly different packing environments in the crystal, monoclinic lysozyme constitutes an ideal system for exploring the problem. The differences in the structure and hydration of the two molecules provide a framework for examining the changes caused by stabilizing additives. Monoclinic crystals were grown under native conditions and also in the presence of 10% sucrose, 15% trehalose, 10% trehalose, 10% sorbitol and 5% glycerol. The crystal structures were refined at resolutions ranging from 1.8 to 2.1 A. The average B values, and hence the mobility of the structure, are lower in the presence of additives than in the native crystals. However, a comparison of the structures indicates that the effect of the additives on the structure and the hydration shell around the protein molecule is considerably less than that caused by differences in packing. It is also less than that caused by the replacement of NaNO(3) by NaCl as the precipitant in the crystallization experiments. This result is not in conformity with the commonly held belief that additives exert their stabilizing effect through the reorganization of the hydration shell, at least as far as the ordered water molecules are concerned.

  14. Studies on the Food Additive Propyl Gallate: Synthesis, Structural Characterization, and Evaluation of the Antioxidant Activity

    ERIC Educational Resources Information Center

    Garrido, Jorge; Garrido, E. Manuela; Borges, Fernanda

    2012-01-01

    Antioxidants are additives largely used in industry for delaying, retarding, or preventing the development of oxidative deterioration. Propyl gallate (E310) is a phenolic antioxidant extensively used in the food, cosmetics, and pharmaceutical industries. A series of lab experiments have been developed to teach students about the importance and…

  15. Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines.

    PubMed

    Gansäuer, Andreas; Seddiqzai, Meriam; Dahmen, Tobias; Sure, Rebecca; Grimme, Stefan

    2013-01-01

    The intramolecular radical addition to aniline derivatives was investigated by DFT calculations. The computational methods were benchmarked by comparing the calculated values of the rate constant for the 5-exo cyclization of the hexenyl radical with the experimental values. The dispersion-corrected PW6B95-D3 functional provided very good results with deviations for the free activation barrier compared to the experimental values of only about 0.5 kcal mol(-1) and was therefore employed in further calculations. Corrections for intramolecular London dispersion and solvation effects in the quantum chemical treatment are essential to obtain consistent and accurate theoretical data. For the investigated radical addition reaction it turned out that the polarity of the molecules is important and that a combination of electrophilic radicals with preferably nucleophilic arenes results in the highest rate constants. This is opposite to the Minisci reaction where the radical acts as nucleophile and the arene as electrophile. The substitution at the N-atom of the aniline is crucial. Methyl substitution leads to slower addition than phenyl substitution. Carbamates as substituents are suitable only when the radical center is not too electrophilic. No correlations between free reaction barriers and energies (ΔG (‡) and ΔG R) are found. Addition reactions leading to indanes or dihydrobenzofurans are too slow to be useful synthetically. PMID:24062821

  16. Vector generalized additive models for extreme rainfall data analysis (study case rainfall data in Indramayu)

    NASA Astrophysics Data System (ADS)

    Utami, Eka Putri Nur; Wigena, Aji Hamim; Djuraidah, Anik

    2016-02-01

    Rainfall pattern are good indicators for potential disasters. Global Circulation Model (GCM) contains global scale information that can be used to predict the rainfall data. Statistical downscaling (SD) utilizes the global scale information to make inferences in the local scale. Essentially, SD can be used to predict local scale variables based on global scale variables. SD requires a method to accommodate non linear effects and extreme values. Extreme value Theory (EVT) can be used to analyze the extreme value. One of methods to identify the extreme events is peak over threshold that follows Generalized Pareto Distribution (GPD). The vector generalized additive model (VGAM) is an extension of the generalized additive model. It is able to accommodate linear or nonlinear effects by involving more than one additive predictors. The advantage of VGAM is to handle multi response models. The key idea of VGAM are iteratively reweighted least square for maximum likelihood estimation, penalized smoothing, fisher scoring and additive models. This works aims to analyze extreme rainfall data in Indramayu using VGAM. The results show that the VGAM with GPD is able to predict extreme rainfall data accurately. The prediction in February is very close to the actual value at quantile 75.

  17. Teaching Young Children Decomposition Strategies to Solve Addition Problems: An Experimental Study

    ERIC Educational Resources Information Center

    Cheng, Zi-Juan

    2012-01-01

    The ability to count has traditionally been considered an important milestone in children's development of number sense. However, using counting (e.g., counting on, counting all) strategies to solve addition problems is not the best way for children to achieve their full mathematical potential and to prepare them to develop more complex and…

  18. Study on automatic optical element addition or deletion in lens optimization

    NASA Astrophysics Data System (ADS)

    Cheng, Xuemin; Wang, Yongtian; Hao, Qun

    2002-09-01

    Two lens form parameters, quantifying the symmetry of the optical system and the optical power distribution among the individual lens elements, are used as the criteria for automatic element addition or deletion in lens optimization. The scheme based on the criteria is described in this paper. Design examples are provided, which demonstrate that the scheme is practicable.

  19. Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines

    PubMed Central

    Seddiqzai, Meriam; Dahmen, Tobias; Sure, Rebecca

    2013-01-01

    Summary The intramolecular radical addition to aniline derivatives was investigated by DFT calculations. The computational methods were benchmarked by comparing the calculated values of the rate constant for the 5-exo cyclization of the hexenyl radical with the experimental values. The dispersion-corrected PW6B95-D3 functional provided very good results with deviations for the free activation barrier compared to the experimental values of only about 0.5 kcal mol−1 and was therefore employed in further calculations. Corrections for intramolecular London dispersion and solvation effects in the quantum chemical treatment are essential to obtain consistent and accurate theoretical data. For the investigated radical addition reaction it turned out that the polarity of the molecules is important and that a combination of electrophilic radicals with preferably nucleophilic arenes results in the highest rate constants. This is opposite to the Minisci reaction where the radical acts as nucleophile and the arene as electrophile. The substitution at the N-atom of the aniline is crucial. Methyl substitution leads to slower addition than phenyl substitution. Carbamates as substituents are suitable only when the radical center is not too electrophilic. No correlations between free reaction barriers and energies (ΔG ‡ and ΔG R) are found. Addition reactions leading to indanes or dihydrobenzofurans are too slow to be useful synthetically. PMID:24062821

  20. A five-year study of the impact of nitrogen addition on methane uptake in alpine grassland.

    PubMed

    Yue, Ping; Li, Kaihui; Gong, Yanming; Hu, Yukun; Mohammat, Anwar; Christie, Peter; Liu, Xuejun

    2016-01-01

    It remains unclear how nitrogen (N) deposition affects soil methane (CH4) uptake in semiarid and arid zones. An in situ field experiment was conducted from 2010 to 2014 to systematically study the effect of various N application rates (0, 10, 30, and 90 kg N ha(-1) yr(-1)) on CH4 flux in alpine grassland in the Tianshan Mountains. No significant influence of N addition on CH4 uptake was found. Initially the CH4 uptake rate increased with increasing N application rate by up to 11.5% in 2011 and then there was gradual inhibition by 2014. However, the between-year variability in CH4 uptake was very highly significant with average uptake ranging from 52.9 to 106.6 μg C m(-2) h(-1) and the rate depended largely on seasonal variability in precipitation and temperature. CH4 uptake was positively correlated with soil temperature, air temperature and to a lesser extent with precipitation, and was negatively correlated with soil moisture and NO3(-)-N content. The results indicate that between-year variability in CH4 uptake was impacted by precipitation and temperature and was not sensitive to elevated N deposition in alpine grassland. PMID:27571892

  1. A five-year study of the impact of nitrogen addition on methane uptake in alpine grassland

    PubMed Central

    Yue, Ping; Li, Kaihui; Gong, Yanming; Hu, Yukun; Mohammat, Anwar; Christie, Peter; Liu, Xuejun

    2016-01-01

    It remains unclear how nitrogen (N) deposition affects soil methane (CH4) uptake in semiarid and arid zones. An in situ field experiment was conducted from 2010 to 2014 to systematically study the effect of various N application rates (0, 10, 30, and 90 kg N ha−1 yr−1) on CH4 flux in alpine grassland in the Tianshan Mountains. No significant influence of N addition on CH4 uptake was found. Initially the CH4 uptake rate increased with increasing N application rate by up to 11.5% in 2011 and then there was gradual inhibition by 2014. However, the between-year variability in CH4 uptake was very highly significant with average uptake ranging from 52.9 to 106.6 μg C m−2 h−1 and the rate depended largely on seasonal variability in precipitation and temperature. CH4 uptake was positively correlated with soil temperature, air temperature and to a lesser extent with precipitation, and was negatively correlated with soil moisture and NO3−-N content. The results indicate that between-year variability in CH4 uptake was impacted by precipitation and temperature and was not sensitive to elevated N deposition in alpine grassland. PMID:27571892

  2. Study of high field superconducting solenoids for muon beam cooling

    SciTech Connect

    Kashikhin, V.V.; Barzi, E.; Kashikhin, V.S.; Lamm, Michael J.; Sadovskiy, Y.; Zlobin, Alexander V; /Fermilab

    2007-08-01

    The final beam cooling stages of a possible Muon Collider may require DC solenoid magnets with magnetic fields of 40-50 T in an aperture of 40-50 mm. In this paper we study possible solutions towards creating DC fields of that order using available superconductors. Several magnetic and mechanical designs, optimized for the maximum performance are presented and compared in terms of cost and size.

  3. Electroresistance and field effect studies on manganite based heterostructure

    SciTech Connect

    Solanki, P. S.; Khachar, Uma; Vagadia, Megha; Ravalia, Ashish; Katba, Savan; Kuberkar, D. G.

    2015-04-14

    Electronic properties of manganites are significantly important for various spintronic applications such as microelectronics, magnetic data storage, communication technologies, and memory devices. Influence of applied electric field on the room temperature charge transport in ZnO/La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrNb{sub 0.002}Ti{sub 0.998}O{sub 3} (SNTO) heterostructure has been investigated using field effect studies. Large negative and positive electroresistance has been observed in heterostructure under various possible circuit geometries. Field effect studies have been carried out using three different circuit geometries, namely: (i) ZnO as a control electrode (E{sub LZ}), (ii) SNTO as a control electrode (E{sub LS}), and (iii) shorted ZnO and SNTO as control electrodes (E{sub LZS}). For this, channel electric field (E{sub CH}) dependent variation in channel resistance (R{sub C}) (of manganite channel) and I-V (across manganite channel) under various control fields (E{sub C}) have been studied. Variation in barrier height (Φ{sub B}) with control field (E{sub C}) for different geometries has been discussed.

  4. Studies of cryogenic electron plasmas in magnetic mirror fields

    NASA Astrophysics Data System (ADS)

    Gopalan, Ramesh

    This thesis considers the properties of pure electron plasmas in Penning traps which have an axially varying magnetic field. Our theory of the thermal equilibrium of such plasmas in magnetic mirror fields indicates that their behavior may be characterized by the ratio of their temperature to their central density T/n. For cold, dense plasmas the density along the plasma axis scales linearly with the magnetic field, while for hot, tenuous plasmas, at the opposite limit of the parameter range, the density is constant along the axis, similar to the behavior of a neutral plasma in a magnetic mirror. We are able to conclude from this that the electrostatic potential varies along the field lines, in equilibrium. As the plasma charge and potential distribution must be consistent with the grounded potential on the trap walls, the plasma profile does not follow the geometry of the magnetic field lines; the plasma radius in the high-field region is smaller than would be obtained by mapping the field lines from the radial edge of the low-field region. Another interesting feature of these mirror equilibria is that there are trapped populations of particles both in the low-field and high-field regions. Our experiments on the Cryogenic Electron Trap have confirmed many of these theoretical results over a wide parameter range. We have been able to sample the volume charge density at various points on the axis. We have also measured the line-charge distribution of the plasma. Both these experiments are in general agreement with our theory of the global thermal equilibrium in the mirror- field. A surprising observation has been the unexpectedly long- life of the m = 1 diocotron mode in these traps where the magnetic field varies by ~100% across its length. We report these observations, along with plausible explanations for them. The trap we have constructed is intended for the eventual study of very cold electron plasmas in strong magnetic fields, where the plasma electrons are

  5. Simulation Studies of Field-Reversed Configurations with Rotating Magnetic Field Current Drive

    NASA Astrophysics Data System (ADS)

    Belova, E. V.; Davidson, R. C.

    2008-11-01

    Results of 3D kinetic simulations of rotating magnetic field (RMF) current drive in field-reversed configuration (FRC) are presented. Self-consistent hybrid simulations have been performed using the HYM code for even- and odd-parity RMF and different FRC parameters and RMF frequencies. Simulations show that the RMF pushes the plasma radially inward, resulting in a reduced plasma density outside separatrix. Lower plasma density and larger RMF amplitudes result in faster RMF field penetration, in agreement with previous two-fluid studies. Generation of axisymmetric toroidal magnetic field during the RMF current drive has been observed. Numerical study of the effects of the applied RMF field on particle confinement shows that the rate of particle losses increases for RMF frequency close to the ion cyclotron frequency. It is also shown that high-frequency even-parity RMF reduces ion losses when it is fully penetrated. It is also found that fully-penetrated, odd-parity RMF forces particles away from the midplane toward the FRC ends. The observed changes in particle confinement are related to ponderomotive forces. Partially penetrated RMF results in mostly radial ponderomotive forces which improve particle confinement in both cases.

  6. A laboratory study of the perceived benefit of additional noise attenuation by houses

    NASA Technical Reports Server (NTRS)

    Flindell, I. H.

    1983-01-01

    Two Experiments were conducted to investigate the perceived benefit of additional house attenuation against aircraft flyover noise. First, subjects made annoyance judgments in a simulated living room while an operative window with real and dummy storm windows was manipulated in full view of those subjects. Second, subjects made annoyance judgments in an anechoic audiometric test chamber of frequency shaped noise signals having spectra closely matched to those of the aircraft flyover noises reproduced in the first experiment. These stimuli represented the aircraft flyover noises in levels and spectra but without the situational and visual cues present in the simulated living room. Perceptual constancy theory implies that annoyance tends to remain constant despite reductions in noise level caused by additional attenuation of which the subjects are fully aware. This theory was supported when account was taken for a reported annoyance overestimation for certain spectra and for a simulated condition cue overreaction.

  7. A laboratory study of the perceived benefit of additional noise attenuation by houses

    NASA Astrophysics Data System (ADS)

    Flindell, I. H.

    1983-06-01

    Two Experiments were conducted to investigate the perceived benefit of additional house attenuation against aircraft flyover noise. First, subjects made annoyance judgments in a simulated living room while an operative window with real and dummy storm windows was manipulated in full view of those subjects. Second, subjects made annoyance judgments in an anechoic audiometric test chamber of frequency shaped noise signals having spectra closely matched to those of the aircraft flyover noises reproduced in the first experiment. These stimuli represented the aircraft flyover noises in levels and spectra but without the situational and visual cues present in the simulated living room. Perceptual constancy theory implies that annoyance tends to remain constant despite reductions in noise level caused by additional attenuation of which the subjects are fully aware. This theory was supported when account was taken for a reported annoyance overestimation for certain spectra and for a simulated condition cue overreaction.

  8. Structural changes in gluten protein structure after addition of emulsifier. A Raman spectroscopy study

    NASA Astrophysics Data System (ADS)

    Ferrer, Evelina G.; Gómez, Analía V.; Añón, María C.; Puppo, María C.

    2011-06-01

    Food protein product, gluten protein, was chemically modified by varying levels of sodium stearoyl lactylate (SSL); and the extent of modifications (secondary and tertiary structures) of this protein was analyzed by using Raman spectroscopy. Analysis of the Amide I band showed an increase in its intensity mainly after the addition of the 0.25% of SSL to wheat flour to produced modified gluten protein, pointing the formation of a more ordered structure. Side chain vibrations also confirmed the observed changes.

  9. Magnetic Force Microscopy Study of Zr2Co11 -Based Nanocrystalline Materials: Effect of Mo Addition

    DOE PAGES

    Yue, Lanping; Jin, Yunlong; Zhang, Wenyong; Sellmyer, David J.

    2015-01-01

    Tmore » he addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. he effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. he coercivity of the samples increases with the increase in Mo content (x≤1.5). he maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. he smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. he optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  10. Load bearing and stiffness tailored NiTi implants produced by additive manufacturing: a simulation study

    NASA Astrophysics Data System (ADS)

    Rahmanian, Rasool; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael; Elahinia, Mohammad

    2014-03-01

    Common metals for stable long-term implants (e.g. stainless steel, Titanium and Titanium alloys) are much stiffer than spongy cancellous and even stiffer than cortical bone. When bone and implant are loaded this stiffness mismatch results in stress shielding and as a consequence, degradation of surrounding bony structure can lead to disassociation of the implant. Due to its lower stiffness and high reversible deformability, which is associated with the superelastic behavior, NiTi is an attractive biomaterial for load bearing implants. However, the stiffness of austenitic Nitinol is closer to that of bone but still too high. Additive manufacturing provides, in addition to the fabrication of patient specific implants, the ability to solve the stiffness mismatch by adding engineered porosity to the implant. This in turn allows for the design of different stiffness profiles in one implant tailored to the physiological load conditions. This work covers a fundamental approach to bring this vision to reality. At first modeling of the mechanical behavior of different scaffold designs are presented as a proof of concept of stiffness tailoring. Based on these results different Nitinol scaffolds can be produced by additive manufacturing.

  11. Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study.

    PubMed

    Weiner, Myra L

    2016-01-01

    This paper provides guidance on the conduct of new in vivo and in vitro studies on high molecular weight food additives, with carrageenan, the widely used food additive, as a case study. It is important to understand the physical/chemical properties and to verify the identity/purity, molecular weight and homogeneity/stability of the additive in the vehicle for oral delivery. The strong binding of CGN to protein in rodent chow or infant formula results in no gastrointestinal tract exposure to free CGN. It is recommended that doses of high Mw non-caloric, non-nutritive additives not exceed 5% by weight of total solid diet to avoid potential nutritional effects. Addition of some high Mw additives at high concentrations to liquid nutritional supplements increases viscosity and may affect palatability, caloric intake and body weight gain. In in vitro studies, the use of well-characterized, relevant cell types and the appropriate composition of the culture media are necessary for proper conduct and interpretation. CGN is bound to media protein and not freely accessible to cells in vitro. Interpretation of new studies on food additives should consider the interaction of food additives with the vehicle components and the appropriateness of the animal or cell model and dose-response.

  12. Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study.

    PubMed

    Weiner, Myra L

    2016-01-01

    This paper provides guidance on the conduct of new in vivo and in vitro studies on high molecular weight food additives, with carrageenan, the widely used food additive, as a case study. It is important to understand the physical/chemical properties and to verify the identity/purity, molecular weight and homogeneity/stability of the additive in the vehicle for oral delivery. The strong binding of CGN to protein in rodent chow or infant formula results in no gastrointestinal tract exposure to free CGN. It is recommended that doses of high Mw non-caloric, non-nutritive additives not exceed 5% by weight of total solid diet to avoid potential nutritional effects. Addition of some high Mw additives at high concentrations to liquid nutritional supplements increases viscosity and may affect palatability, caloric intake and body weight gain. In in vitro studies, the use of well-characterized, relevant cell types and the appropriate composition of the culture media are necessary for proper conduct and interpretation. CGN is bound to media protein and not freely accessible to cells in vitro. Interpretation of new studies on food additives should consider the interaction of food additives with the vehicle components and the appropriateness of the animal or cell model and dose-response. PMID:26615870

  13. Study on advanced nanoscale near-field photolithography.

    PubMed

    Yang, Ching-Been; Chiang, Hsiu-Lu; Huang, Jen-Ching

    2010-01-01

    At present, applying a near-field optical microscope to photolithographic line segment fabrication can only obtain nanoscale line segments of equal cutting depths, and cannot result in 3D shape fabrication. This study proposes an innovative line segment fabrication model of near-field photolithography that adjusts an optical fiber probe's field distance to control the exposure energy density, and moreover constructs an exposure energy density analysis method of the innovative photolithographic line segment fabrication. During the exposure simulation process of the innovative line segment fabrication model of near-field photolithography, the near-field distance between the optical fiber probe and the photoresist surface increases gradually, whereas the exposure energy density distribution decreases gradually. As a result, the cutting depth becomes shallower and the full-width at half maximum (FWHM) increases. The results of this study can serve as a theoretical reference for developing advanced nanoscale near-field photolithography techniques, to which an important and groundbreaking contribution is made.

  14. Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study

    NASA Technical Reports Server (NTRS)

    Szabo, A.; Koval, A.; Merka, J.; Narock, T.

    2010-01-01

    The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission interplanetary magnetic field data and the solar wind key parameter search capability of the Virtual Heliospheric Observatory (VHO) affords an opportunity to study magnetic field power spectral density variations as a function of solar wind conditions. In the reprocessed Wind Magnetic Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the approx.2 Hz limit above which digitization noise becomes apparent. The power spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions . The time periods of fixed solar wind conditions are obtained from VHO searches that greatly simplify the process. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and magnetic field conditions will be discussed

  15. Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study

    NASA Technical Reports Server (NTRS)

    Szabo, A.; Koval, A.; Merka, J.; Narock, T.

    2011-01-01

    The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission interplanetary magnetic field data and the solar wind key parameter search capability of the Virtual Heliospheric Observatory (VHO) affords an opportunity to study magnetic field power spectral density variations as a function of solar wind conditions. In the reprocessed Wind Magnetic Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the 2 Hz limit above which digitization noise becomes apparent. The power spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions. The time periods of fixed solar wind conditions are obtained from VHO searches that greatly simplify the process. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and magnetic field conditions will be discussed

  16. Strategic Petroleum Reserve (SPR) additional geologic site characterization studies, Bryan Mound Salt Dome, Texas

    SciTech Connect

    Neal, J.T.; Magorian, T.R.; Ahmad, S.

    1994-11-01

    This report revises the original report that was published in 1980. Some of the topics covered in the earlier report were provisional and it is now practicable to reexamine them using new or revised geotechnical data and that obtained from SPR cavern operations, which involves 16 new caverns. Revised structure maps and sections show interpretative differences as compared with the 1980 report and more definition in the dome shape and caprock structural contours, especially a major southeast-northwest trending anomalous zone. The original interpretation was of westward tilt of the dome, this revision shows a tilt to the southeast, consistent with other gravity and seismic data. This interpretation refines the evaluation of additional cavern space, by adding more salt buffer and allowing several more caverns. Additional storage space is constrained on this nearly full dome because of low-lying peripheral wetlands, but 60 MMBBL or more of additional volume could be gained in six or more new caverns. Subsidence values at Bryan Mound are among the lowest in the SPR system, averaging about 11 mm/yr (0.4 in/yr), but measurement and interpretation issues persist, as observed values are about the same as survey measurement accuracy. Periodic flooding is a continuing threat because of the coastal proximity and because peripheral portions of the site are at elevations less than 15 ft. This threat may increase slightly as future subsidence lowers the surface, but the amount is apt to be small. Caprock integrity may be affected by structural features, especially the faulting associated with anomalous zones. Injection wells have not been used extensively at Bryan Mound, but could be a practicable solution to future brine disposal needs. Environmental issues center on the areas of low elevation that are below 15 feet above mean sea level: the coastal proximity and lowland environment combined with the potential for flooding create conditions that require continuing surveillance.

  17. Fundamental study of flow field generated by rotorcraft blades using wide-field shadowgraph

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P.; Cho, Y. I.; Back, L. H.

    1985-01-01

    The vortex trajectory and vortex wake generated by helicopter rotors are visualized using a wide-field shadowgraph technique. Use of a retro-reflective Scotchlite screen makes it possible to investigate the flow field generated by full-scale rotors. Tip vortex trajectories are visible in shadowgraphs for a range of tip Mach number of 0.38 to 0.60. The effect of the angle of attack is substantial. At an angle of attack greater than 8 degrees, the visibility of the vortex core is significant even at relatively low tip Mach numbers. The theoretical analysis of the sensitivity is carried out for a rotating blade. This analysis demonstrates that the sensitivity decreases with increasing dimensionless core radius and increases with increasing tip Mach number. The threshold value of the sensitivity is found to be 0.0015, below which the vortex core is not visible and above which it is visible. The effect of the optical path length is also discussed. Based on this investigation, it is concluded that the application of this wide-field shadowgraph technique to a large wind tunnel test should be feasible. In addition, two simultaneous shadowgraph views would allow three-dimensional reconstruction of vortex trajectories.

  18. Whole-Home Dehumidifiers: Field-Monitoring Study

    SciTech Connect

    Burke, Tom; Willem, Henry; Ni, Chun Chun; Stratton, Hannah; Whitehead, Camilla Dunham; Johnson, Russell

    2014-09-23

    Lawrence Berkeley National Laboratory (LBNL) initiated a WHD field-metering study to expand current knowledge of and obtain data on WHD operation and energy consumption in real-world applications. The field study collected real-time data on WHD energy consumption, along with information regarding housing characteristics, consumer behavior, and various outdoor conditions expected to affect WHD performance and efficiency. Although the metering study collected similar data regarding air conditioner operation, this report discusses only WHDs. The primary objectives of the LBNL field-metering study are to (1) expand knowledge of the configurations, energy consumption profiles, consumer patterns of use (e.g., relative humidity [RH] settings), and environmental parameters of whole-home dehumidification systems; and (2) develop distributions of hours of dehumidifier operation in four operating modes: off, standby, fan-only, and compressor (also called dehumidification mode). Profiling energy consumption entails documenting the power consumption, duration of power consumption in different modes, condensate generation, and properties of output air of an installed system under field conditions of varying inlet air temperature and RH, as well as system configuration. This profiling provides a more detailed and deeper understanding of WHD operation and its complexities. This report describes LBNL’s whole-home dehumidification field-metering study conducted at four homes in Wisconsin and Florida. The initial phase of the WHD field-metering study was conducted on one home in Madison, Wisconsin, from June to December of 2013. During a second phase, three Florida homes were metered from June to October of 2014. This report presents and examines data from the Wisconsin site and from the three Florida sites.

  19. Rapid rise time pulsed magnetic field circuit for pump-probe field effect studies.

    PubMed

    Salaoru, T A; Woodward, Jonathan R

    2007-03-01

    Here we describe an electronic circuit capable of producing rapidly switched dc magnetic fields of up to 20 mT with a rise time of 10 ns and a pulse length variable from 50 ns to more than 10 micros, suitable for use in the study of magnetic field effects on radical pair (RP) reactions. This corresponds to switching the field on a time scale short relative to the lifetime of typical RPs and maintaining it well beyond their lifetimes. Previous experiments have involved discharging a capacitor through a low inductance coil for a limited time using a switching circuit. These suffer from decaying field strength over the duration of the pulse given primarily by the ratio of the pulse width to the RC constant of the circuit. We describe here a simple yet elegant solution that completely eliminates this difficulty by employing a feedback loop. This allows a constant field to be maintained over the entire length of the pulse. PMID:17411229

  20. Phase diagrams of diblock copolymers in electric fields: a self-consistent field theory study.

    PubMed

    Wu, Ji; Wang, Xianghong; Ji, Yongyun; He, Linli; Li, Shiben

    2016-04-21

    We investigated the phase diagrams of diblock copolymers in external electrostatic fields by using real-space self-consistent field theory. The lamella, cylinder, sphere, and ellipsoid structures were observed and analyzed by their segment distributions, which were arranged to two types of phase diagrams to examine the phase behavior in weak and strong electric fields. One type was constructed on the basis of Flory-Huggins interaction parameter and volume fraction. We identified an ellipsoid structure with a body-centered cuboid arrangement as a stable phase and discussed the shift of phase boundaries in the electric fields. The other type of phase diagrams was established on the basis of the dielectric constants of two blocks in the electric fields. We then determined the regions of ellipsoid phase in the phase diagrams to examine the influence of dielectric constants on the phase transition between ellipsoidal and hexagonally packed cylinder phases. A general agreement was obtained by comparing our results with those described in previous experimental and theoretical studies. PMID:27020849

  1. On the two-dimensional classical motion of a charged particle in an electromagnetic field with an additional quadratic integral of motion

    NASA Astrophysics Data System (ADS)

    Marikhin, V. G.

    2013-06-01

    The problem of quadratic Hamiltonians with an electromagnetic field commuting in the sense of the standard Poisson brackets has been considered. It has been shown that, as in the quantum case, any such pair can be reduced to the canonical form, which makes it possible to construct the complete classification of the solutions in the class of meromorphic solutions for the main function of one variable. The transformation to the canonical form is performed through the change of variables to the Kovalevskaya-type variables, which is similar to that in the theory of integrable tops. This transformation has been considered for the two-dimensional Hamiltonian of a charged particle with an additional quadratic integral of motion.

  2. Complex coacervation: A field theoretic simulation study of polyelectrolyte complexation

    NASA Astrophysics Data System (ADS)

    Lee, Jonghoon; Popov, Yuri O.; Fredrickson, Glenn H.

    2008-06-01

    Using the complex Langevin sampling strategy, field theoretic simulations are performed to study the equilibrium phase behavior and structure of symmetric polycation-polyanion mixtures without salt in good solvents. Static structure factors for the segment density and charge density are calculated and used to study the role of fluctuations in the electrostatic and chemical potential fields beyond the random phase approximation. We specifically focus on the role of charge density and molecular weight on the structure and complexation behavior of polycation-polyanion solutions. A demixing phase transition to form a ``complex coacervate'' is observed in strongly charged systems, and the corresponding spinodal and binodal boundaries of the phase diagram are investigated.

  3. Apprenticeships, Collaboration and Scientific Discovery in Academic Field Studies

    NASA Astrophysics Data System (ADS)

    Madden, Derek Scott; Grayson, Diane J.; Madden, Erinn H.; Milewski, Antoni V.; Snyder, Cathy Ann

    2012-11-01

    Teachers may use apprenticeships and collaboration as instructional strategies that help students to make authentic scientific discoveries as they work as amateur researchers in academic field studies. This concept was examined with 643 students, ages 14-72, who became proficient at field research through cognitive apprenticeships with the Smithsonian Institute, School for Field Studies and Earthwatch. Control student teams worked from single research goals and sets of methods, while experimental teams varied goals, methods, and collaborative activities in Kenya, Costa Rica, Panama, and Ecuador. Results from studies indicate that students who conducted local pilot studies, collaborative symposia, and ongoing, long-term fieldwork generated significantly more data than did control groups. Research reports of the experimental groups were ranked highest by experts, and contributed the most data to international science journals. Data and anecdotal information in this report indicate that structured collaboration in local long-term studies using apprenticeships may increase the potential for students' academic field studies contribution of new information to science.

  4. Kaolinite flocculation induced by smectite addition - a transmission X-ray microscopic study.

    PubMed

    Zbik, Marek S; Song, Yen-Fang; Frost, Ray L

    2010-09-01

    The influence of smectite addition on kaolinite suspensions in water was investigated by transmission X-ray microscopy (TXM) and Scanning Electron Microscopy (SEM). Sedimentation test screening was also conducted. Micrographs were processed by the STatistic IMage Analysing (STIMAN) program and structural parameters were calculated. From the results of the sedimentation tests important influences of small smectite additions to about 3wt.% on kaolinite suspension flocculation has been found. In order to determine the reason for this smectite impact on kaolinite suspension, macroscopic behaviour micro-structural examination using Transmission X-ray Microscope (TXM) and SEM has been undertaken. TXM & SEM micrographs of freeze-dried kaolinite-smectite suspensions with up to 20% smectite showed a high degree of orientation of the fabric made of highly oriented particles and greatest density when 3wt.% of smectite was added to the 10wt.% dense kaolinite suspension. In contrast, suspensions containing pure kaolinite do not show such platelet mutual orientation but homogenous network of randomly oriented kaolinite platelets. This suggests that in kaolinite-smectite suspensions, smectite forms highly oriented basic framework into which kaolinite platelets may bond in face to face preferential contacts strengthening structure and allowing them to show plastic behaviour which is cause of platelets orientation. PMID:20621806

  5. Excitotoxic food additives--relevance of animal studies to human safety.

    PubMed

    Olney, J W

    1984-01-01

    Evidence is reviewed supporting the view that excitotoxic food additives pose a significant hazard to the developing nervous system of young children. The following points are stressed: (1) although blood-brain barriers protect most central neurons from excitotoxins, certain brain regions lack such protection (a characteristic common to all vertebrate species); (2) regardless of species, it requires only a transient increase in blood excitotoxin levels for neurons in unprotected brain regions to be "silently" destroyed; (3) humans may be at particularly high risk for this kind of brain damage, since ingestion of a given amount of excitotoxin causes much higher blood excitotoxin levels in humans than in other species; (4) in addition to the heightened risk on a species basis, risk may be further increased for certain consumer sub-populations due to youth, disease or genetic factors; (5) despite these reasons for maintaining a wide margin of safety in the use of excitotoxins in foods, no safety margin is currently being observed, i.e., a comparative evaluation of animal (extensive) and human (limited) data supports the conclusion that excitotoxins, as used in foods today, may produce blood elevations high enough to cause damage to the nervous system of young children, damage which is not detectable at the time of occurrence but which may give rise to subtle disturbances in neuroendocrine function in adolescence and/or adulthood.

  6. Magnetic field studies at Jupiter by Voyager 2 - Preliminary results

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Acuna, M. H.; Lepping, R. P.; Burlaga, L. F.; Behannon, K. W.; Neubauer, F. M.

    1979-01-01

    The Voyager 2 magnetic field experiment, for which the instrumentation is identical to that on Voyager 1, operated flawlessly throughout the second Jupiter encounter. The paper presents a brief overview of the results obtained to date on the Jovian magnetosphere, the bow shock, the magnetopause, and the extended magnetic tail. The results and the magnetic field geometry confirm the earlier conclusion from Voyager 1 that Jupiter has an enormous magnetic tail, approximately 300-400 Jupiter radii in diameter, trailing behind the planet with respect to the supersonic flow of the solar wind. Additional observations of the distortion of the inner magnetosphere by a concentrated plasma show a spatial merging of the equatorial magnetodisk current with the current sheet in the magnetic tail. Disturbances near Ganymede are discussed.

  7. Additive Manufacturing of a Microbial Fuel Cell--A detailed study.

    PubMed

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-01-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m(-3) per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments.

  8. Additive Manufacturing of a Microbial Fuel Cell—A detailed study

    PubMed Central

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-01-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m−3 per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments. PMID:26611142

  9. Additive Manufacturing of a Microbial Fuel Cell—A detailed study

    NASA Astrophysics Data System (ADS)

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-11-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m-3 per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments.

  10. Preliminary study of neutron absorption by concrete with boron carbide addition

    NASA Astrophysics Data System (ADS)

    Abdullah, Yusof; Ariffin, Fatin Nabilah Tajul; Hamid, Roszilah; Yusof, Mohd Reusmaazran; Zali, Nurazila Mat; Ahmad, Megat Harun Al Rashid Megat; Yazid, Hafizal; Ahmad, Sahrim; Mohamed, Abdul Aziz

    2014-02-01

    Concrete has become a conventional material in construction of nuclear reactor due to its properties like safety and low cost. Boron carbide was added as additives in the concrete construction as it has a good neutron absorption property. The sample preparation for concrete was produced with different weight percent of boron carbide powder content. The neutron absorption rate of these samples was determined by using a fast neutron source of Americium-241/Be (Am-Be 241) and detection with a portable backscattering neutron detector. Concrete with 20 wt % of boron carbide shows the lowest count of neutron transmitted and this indicates the most neutrons have been absorbed by the concrete. Higher boron carbide content may affect the concrete strength and other properties.

  11. Sulphur diffusion in β-NiAl and effect of Pt additive: an ab initio study

    NASA Astrophysics Data System (ADS)

    Chen, Kuiying

    2016-02-01

    Diffusivities of detrimental impurity sulfur (S) in stoichiometric and Pt doped β-NiAl were evaluated using density functional theory calculations. The apparent activation energy and the pre-exponential factor of diffusivity via the next nearest neighbour (NNN) and interstitial jumps were evaluated to identify possible preferred diffusion mechanism(s). By calculating the electron localization function (ELF), the bonding characteristics of S with its surrounding atoms were assessed for the diffusion process. By comparison with the experimental results, the S diffusion through the NNN vacancy-mediated mechanism is found to be favoured. Addition of Pt in β-NiAl was found to significantly reduce the S diffusivity, and an associated electronic effect was explored. The elucidation of the above mechanisms may shed light on the development of new Pt-modified doped β-NiAl bond coats that can extend the life of oxidation resistant and thermal barrier coatings.

  12. Preliminary study of neutron absorption by concrete with boron carbide addition

    SciTech Connect

    Abdullah, Yusof Yusof, Mohd Reusmaazran; Zali, Nurazila Mat; Ahmad, Megat Harun Al Rashid Megat; Yazid, Hafizal; Ariffin, Fatin Nabilah Tajul; Ahmad, Sahrim; Hamid, Roszilah; Mohamed, Abdul Aziz

    2014-02-12

    Concrete has become a conventional material in construction of nuclear reactor due to its properties like safety and low cost. Boron carbide was added as additives in the concrete construction as it has a good neutron absorption property. The sample preparation for concrete was produced with different weight percent of boron carbide powder content. The neutron absorption rate of these samples was determined by using a fast neutron source of Americium-241/Be (Am-Be 241) and detection with a portable backscattering neutron detector. Concrete with 20 wt % of boron carbide shows the lowest count of neutron transmitted and this indicates the most neutrons have been absorbed by the concrete. Higher boron carbide content may affect the concrete strength and other properties.

  13. THERMODYNAMIC STUDY OF THE NICKEL ADDITION IN ZINC HOT-DIP GALVANIZING BATHS

    SciTech Connect

    Pistofidis, N.; Vourlias, G.

    2010-01-21

    A usual practice during zinc hot-dip galvanizing is the addition of nickel in the liquid zinc which is used to inhibit the Sandelin effect. Its action is due to the fact that the zeta(zeta) phase of the Fe-Zn system is replaced by the TAU(tau) phase of the Fe-Zn-Ni system. In the present work an attempt is made to explain the formation of the TAU phase with thermodynamics. For this reason the Gibbs free energy changes for TAU and zeta phases were calculated. The excess free energy for the system was calculated with the Redlich-Kister polyonyme. From this calculation it was deduced that the Gibbs energy change for the tau phase is negative. As a result its formation is spontaneous.

  14. Professional Competence Development of the Social Work Specialists in the Period of Study in the System of Additional Education

    ERIC Educational Resources Information Center

    Davletkaliev, Denis Kuanyshevich; Zueva, Natalia Konstantinovna; Lebedeva, Natalya Vasilevna; Mkrtumova, Irina Vladimirovna; Timofeeva, Olga

    2015-01-01

    The goal of this work is the study of psychological-pedagogical approaches to the understanding of the idea of professional competence of social work specialists as well as the role of study in the system of additional educations in professional-personal development of the listeners. In the process of study of this problem we define main…

  15. A systematic study of well-known electrolyte additives in LiCoO2/graphite pouch cells

    NASA Astrophysics Data System (ADS)

    Wang, David Yaohui; Sinha, N. N.; Petibon, R.; Burns, J. C.; Dahn, J. R.

    2014-04-01

    The effectiveness of well-known electrolyte additives singly or in combination on LiCoO2/graphite pouch cells has been systematically investigated and compared using the ultra high precision charger (UHPC) at Dalhousie University and electrochemical impedance spectroscopy (EIS). UHPC studies are believed to identify the best electrolyte additives singly or in combination within a short time period (several weeks). Three parameters: 1) the coulombic efficiency (CE); 2) the charge endpoint capacity slippage (slippage) and 3) the charge transfer resistance (Rct), of LiCoO2/graphite pouch cells with different electrolyte additives singly or in combination were measured and the results for over 55 additive sets are compared. The experimental results suggest that a combination of electrolyte additives can be more effective than a single electrolyte additive. However, of all the additive sets tested, simply using 2 wt.% vinylene carbonate yielded cells very competitive in CE, slippage and Rct. It is hoped that this comprehensive report can be used as a guide and reference for the study of other electrolyte additives singly or in combination.

  16. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    NASA Astrophysics Data System (ADS)

    Aleksandrova, Olga

    2015-04-01

    Among different classes of veterinary pharmaceuticals, Sulfadiazine (SDZ) is widely used in animal husbandry. Its residues were detected in different environmental compartments. However, soil is a hot spot for SDZ as it receives a large portion of excreted compounds through the application of manure during soil fertilization. Ample studies on the fate of SDZ in soils showed that a large portion forms nonextractable residues (NER) along with transformation products and a low mineralization (Mueller et al., 2013). A common observation was an initially fast formation of NER up to 10% of the applied amount promptly after the application of SDZ to soil, and this portion increased up to 50% within a few days (Mueller et al., 2013; Nowak et al., 2011). A common finding for SDZ, as for other sulfonamides, was biphasic kinetics of the formation of NER, which was attributed to the occurrence of two reaction processes: a rapid, often reversible process and a slower, irreversible process (Weber et al., 1996). A single-phase reaction process was also established under anaerobic treatment (Gulkowska et al., 2014). A major focus of this work is to elucidate a reaction mechanism of covalent binding of SDZ to soil that is currently required to estimate a risk of NER formed by SDZ in soils for human health. Taking into account a key role of the amine functional groups of SDZ on its reactivity in soil, nitroxide radicals with the sewed aromatic or aliphatic amines labeled soil samples and then, were investigated by means of ESR spectroscopy. 2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-yloxy and 4-amino-2,2,6,6-Tetramethylpiperidin-1-oxyl modeled decomposition products of SDZ with the aromatic and aliphatic amines, respectively. The application of the defined combination of both spin labels (SL) to different soils well simulated a change of a paramagnetic signal of soil organic radicals interacted with SDZ. After their application to soil, SL were found in soil sites characterized

  17. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    NASA Astrophysics Data System (ADS)

    Aleksandrova, Olga

    2015-04-01

    Among different classes of veterinary pharmaceuticals, Sulfadiazine (SDZ) is widely used in animal husbandry. Its residues were detected in different environmental compartments. However, soil is a hot spot for SDZ as it receives a large portion of excreted compounds through the application of manure during soil fertilization. Ample studies on the fate of SDZ in soils showed that a large portion forms nonextractable residues (NER) along with transformation products and a low mineralization (Mueller et al., 2013). A common observation was an initially fast formation of NER up to 10% of the applied amount promptly after the application of SDZ to soil, and this portion increased up to 50% within a few days (Mueller et al., 2013; Nowak et al., 2011). A common finding for SDZ, as for other sulfonamides, was biphasic kinetics of the formation of NER, which was attributed to the occurrence of two reaction processes: a rapid, often reversible process and a slower, irreversible process (Weber et al., 1996). A single-phase reaction process was also established under anaerobic treatment (Gulkowska et al., 2014). A major focus of this work is to elucidate a reaction mechanism of covalent binding of SDZ to soil that is currently required to estimate a risk of NER formed by SDZ in soils for human health. Taking into account a key role of the amine functional groups of SDZ on its reactivity in soil, nitroxide radicals with the sewed aromatic or aliphatic amines labeled soil samples and then, were investigated by means of ESR spectroscopy. 2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-yloxy and 4-amino-2,2,6,6-Tetramethylpiperidin-1-oxyl modeled decomposition products of SDZ with the aromatic and aliphatic amines, respectively. The application of the defined combination of both spin labels (SL) to different soils well simulated a change of a paramagnetic signal of soil organic radicals interacted with SDZ. After their application to soil, SL were found in soil sites characterized

  18. Septic tank additive impacts on microbial populations.

    PubMed

    Pradhan, S; Hoover, M T; Clark, G H; Gumpertz, M; Wollum, A G; Cobb, C; Strock, J

    2008-01-01

    Environmental health specialists, other onsite wastewater professionals, scientists, and homeowners have questioned the effectiveness of septic tank additives. This paper describes an independent, third-party, field scale, research study of the effects of three liquid bacterial septic tank additives and a control (no additive) on septic tank microbial populations. Microbial populations were measured quarterly in a field study for 12 months in 48 full-size, functioning septic tanks. Bacterial populations in the 48 septic tanks were statistically analyzed with a mixed linear model. Additive effects were assessed for three septic tank maintenance levels (low, intermediate, and high). Dunnett's t-test for tank bacteria (alpha = .05) indicated that none of the treatments were significantly different, overall, from the control at the statistical level tested. In addition, the additives had no significant effects on septic tank bacterial populations at any of the septic tank maintenance levels. Additional controlled, field-based research iswarranted, however, to address additional additives and experimental conditions.

  19. Sensitization to Food Additives in Patients with Allergy: A Study Based on Skin Test and Open Oral Challenge.

    PubMed

    Moghtaderi, Mozhgan; Hejrati, Zinatosadat; Dehghani, Zahra; Dehghani, Faranak; Kolahi, Niloofar

    2016-06-01

    There has been a great increase in the consumption of various food additives in recent years. The purpose of this study was to identify the incidence of sensitization to food additives by using skin prick test in patients with allergy and to determine the concordance rate between positive skin tests and oral challenge in hypersensitivity to additives. This cross-sectional study included 125 (female 71, male 54) patients aged 2-76 years with allergy and 100 healthy individuals. Skin tests were performed in both patient and control groups with 25 fresh food additives. Among patients with allergy, 22.4% showed positive skin test at least to one of the applied materials. Skin test was negative to all tested food additives in control group. Oral food challenge was done in 28 patients with positive skin test, in whom 9 patients showed reaction to culprit (Concordance rate=32.1%). The present study suggested that about one-third of allergic patients with positive reaction to food additives showed positive oral challenge; it may be considered the potential utility of skin test to identify the role of food additives in patients with allergy.

  20. Sensitization to Food Additives in Patients with Allergy: A Study Based on Skin Test and Open Oral Challenge.

    PubMed

    Moghtaderi, Mozhgan; Hejrati, Zinatosadat; Dehghani, Zahra; Dehghani, Faranak; Kolahi, Niloofar

    2016-06-01

    There has been a great increase in the consumption of various food additives in recent years. The purpose of this study was to identify the incidence of sensitization to food additives by using skin prick test in patients with allergy and to determine the concordance rate between positive skin tests and oral challenge in hypersensitivity to additives. This cross-sectional study included 125 (female 71, male 54) patients aged 2-76 years with allergy and 100 healthy individuals. Skin tests were performed in both patient and control groups with 25 fresh food additives. Among patients with allergy, 22.4% showed positive skin test at least to one of the applied materials. Skin test was negative to all tested food additives in control group. Oral food challenge was done in 28 patients with positive skin test, in whom 9 patients showed reaction to culprit (Concordance rate=32.1%). The present study suggested that about one-third of allergic patients with positive reaction to food additives showed positive oral challenge; it may be considered the potential utility of skin test to identify the role of food additives in patients with allergy. PMID:27424134

  1. Assessing Student Learning in the Major Field of Study

    ERIC Educational Resources Information Center

    Volkwein, J. Fredericks

    2010-01-01

    Assessing student attainment in the major field of study is increasingly important to employers and accrediting bodies alike. Construction and manufacturing firms do not like engineers who design faulty bridges and airplanes. Marketing firms want to hire students who understand the difference between a niche market and a global market. School…

  2. The significance of field work in monographic studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The focus of this paper is to document the clear and obvious advantages of field work for monographic studies. These advantages include: 1) ability to understand published distributions better and greatly expand these data, 2) access to taxonomic data obscured on herbarium sheets (as colors, odors, ...

  3. Emotional Reactions of Students in Field Education: An Exploratory Study

    ERIC Educational Resources Information Center

    Litvack, Andrea; Mishna, Faye; Bogo, Marion

    2010-01-01

    An exploratory study using qualitative methodology was undertaken with recent MSW graduates (N=12) from 2 graduate social work programs to identify and describe the students' emotional reactions to experiences in field education. Significant and interrelated themes emerged including the subjective and unique definitions of emotionally charged…

  4. PACKAGE PLANTS FOR SMALL SYSTEMS: A FIELD STUDY

    EPA Science Inventory

    A joint field study was conducted by AWWA and the Drinking Water Research Division of USEPA to evaluate existing small community systems that use package plant technology. Forty-eight package plant systems representing a geographic and technological cross section were evaluated t...

  5. DIETARY EXPOSURES OF YOUNG CHILDREN, PART II: FIELD STUDY

    EPA Science Inventory

    A small, pilot field study was conducted to determine the adequacy of protocols for dietary exposure measurements. Samples were collected to estimate the amount of pesticides transferred from contaminated surfaces or hands to foods of young children and to validate a dietary mod...

  6. Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory

    ERIC Educational Resources Information Center

    MacLaren, R. David; Schulte, Dianna; Kennedy, Jen

    2012-01-01

    This work describes a new field research laboratory in an undergraduate animal behavior course involving the study of whale behavior, ecology and conservation in partnership with a non-profit research organization--the Blue Ocean Society for Marine Conservation (BOS). The project involves two weeks of training and five weekend trips on whale watch…

  7. Which Is More Consequential: Fields of Study or Institutional Selectivity?

    ERIC Educational Resources Information Center

    Ma, Yingyi; Savas, Gokhan

    2014-01-01

    The persisting gender pay gap favoring men among college graduates is a puzzle given women's remarkable success in postsecondary education. This article examines income disparities among recent college graduates by intersecting gender and social class and evaluating the relative importance of fields of study and institutional selectivity.…

  8. Four Field Studies of Appalachian Parents of Young Children.

    ERIC Educational Resources Information Center

    Shively, Joe E.; And Others

    This document contains the plans for conducting the field studies of Appalachian parents of young children which are part of the Appalachia Educational Laboratory's Home-Oriented Preschool Education Program (HOPE). HOPE is an integrated approach to education for preschool and kindergarten children being developed by AEL's Marketable Preschool…

  9. Comparison of different force fields for the study of disaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eighteen empirical force fields and the semi-empirical quantum method PM3CARB-1 were compared for studying ß-cellobiose, a-maltose, and a-galabiose [a-D-Galp-(1'4)-a-D-Galp]. For each disaccharide, the energies of 54 conformers with differing hydroxymethyl, hydroxyl and glycosidic linkage orientatio...

  10. Astronauts Armstrong and Aldrin study rock samples during field trip

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, and Astronaut Edwin Aldrin, Lunar module pilot for Apollo 11, study rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  11. Preliminary simulation studies related to the Cerro Prieto Field

    SciTech Connect

    Lippmann, M.J.; Bodvarsson, G.S.; Witherspoon, P.A.; Rivera, J.R.

    1980-01-01

    Results of preliminary numerical simulations of the behavior of the Cerro Prieto field are discussed. The purpose of these studies is to examine: (1) the effect of using conventional isothermal methods of well test data analysis for geothermal systems, and (2) the influence of recharge from over under underlying aquifers on the temperature of a producing geothermal reservoir. 8 refs.

  12. On the design of experiments to study extreme field limits

    NASA Astrophysics Data System (ADS)

    Bulanov, S. S.; Chen, M.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J. K.; Zhidkov, A. G.; Chen, P.; Mur, V. D.; Narozhny, N. B.; Popov, V. S.; Thomas, A. G. R.; Korn, G.

    2012-12-01

    We propose experiments on the collision of high intensity electromagnetic pulses with electron bunches and on the collision of multiple electromagnetic pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The effects of nonlinear QED will be revealed in these laser plasma experiments.

  13. Counselor Attractiveness, Similarity, and Session Impact: A Field Study.

    ERIC Educational Resources Information Center

    Nerison, Rebecca M.; Claiborn, Charles D.

    Past research has suggested that interpersonal influence in counseling is enhanced as clients perceive their counselors to be interpersonally attractive and similar to themselves. This study examined the relationship of specific verbal and nonverbal cues to perceived counselor attractiveness in a field setting, and explored the relation between…

  14. WATER DISTRIBUTION SYSTEM ANALYSIS: FIELD STUDIES, MODELING AND MANAGEMENT

    EPA Science Inventory

    The user‘s guide entitled “Water Distribution System Analysis: Field Studies, Modeling and Management” is a reference guide for water utilities and an extensive summarization of information designed to provide drinking water utility personnel (and related consultants and research...

  15. Te Rita Papesch: Case Study of an Exemplary Learner of Maori as an Additional Language

    ERIC Educational Resources Information Center

    Ratima, Matiu Tai; Papesch, Te Rita

    2014-01-01

    This paper presents a case study of the life experiences of one exemplar adult second language Maori learner--Te Rita Papesch. Te Rita was one of 17 participants who were interviewed as a part of the first author's PhD study which sought to answer the question: what factors lead to the development of proficiency in te reo Maori amongst adult…

  16. Study on additional carrier sensing for IEEE 802.15.4 wireless sensor networks.

    PubMed

    Lee, Bih-Hwang; Lai, Ruei-Lung; Wu, Huai-Kuei; Wong, Chi-Ming

    2010-01-01

    Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs). The slotted carrier sense multiple access with collision avoidance (CSMA/CA) is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA) detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS) algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC) delay and power consumption of CCA detection.

  17. Chromosome studies in the aquatic monocots of Myanmar: A brief review with additional records.

    PubMed

    Ito, Yu; Tanaka, Nobuyuki

    2014-01-01

    Myanmar (Burma) constitutes a significant component of the Indo-Myanmar biodiversity hotspot, with elements of the Indian, the Indochina, and the Sino-Japanese floristic regions, yet thus far only a few reliable sources of the country's flora have been available. As a part of a contribution for the floristic inventory of Myanmar, since it is important in a floristic survey to obtain as much information as possible, in addition to previous two reports, here we present three more chromosome counts in the aquatic monocots of Myanmar: Limnocharisflava with 2n = 20, Sagittariatrifolia with 2n = 22 (Alismataceae), and Potamogetondistinctus × Potamogetonnodosus with 2n = 52 (Potamogetonaceae); the third one is new to science. A brief review of cytological researches in the floristic regions' 45 non-hybrid aquatic monocots plus well investigated two inter-specific hybrids that are recorded in Myanmar is given, indicating that the further works with a focus on species in Myanmar that has infra-specific chromosome variation in the floristic regions will address the precise evolutionary history of the aquatic flora of Myanmar.

  18. Numerical study of the effect of water addition on gas explosion.

    PubMed

    Liang, Yuntao; Zeng, Wen

    2010-02-15

    Through amending the SENKIN code of CHEMKIN III chemical kinetics package, a computational model of gas explosion in a constant volume bomb was built, and the detailed reaction mechanism (GRI-Mech 3.0) was adopted. The mole fraction profiles of reactants, some selected free radicals and catastrophic gases in the process of gas explosion were analyzed by this model. Furthermore, through the sensitivity analysis of the reaction mechanism of gas explosion, the dominant reactions that affect gas explosion and the formation of catastrophic gases were found out. At the same time, the inhibition mechanisms of water on gas explosion and the formation of catastrophic gases were analyzed. The results show that the induced explosion time is prolonged, and the mole fractions of reactant species such as CH(4), O(2) and catastrophic gases such as CO, CO(2) and NO are decreased as water is added to the mixed gas. With the water fraction in the mixed gas increasing, the sensitivities of the dominant reactions contributing to CH(4), CO(2) are decreased and the sensitivity coefficients of CH(4), CO and NO mole fractions are also decreased. The inhibition of gas explosion with water addition can be ascribed to the significant decrease of H, O and OH in the process of gas explosion due to the water presence. PMID:19811873

  19. Generalized linear and generalized additive models in studies of species distributions: Setting the scene

    USGS Publications Warehouse

    Guisan, A.; Edwards, T.C.; Hastie, T.

    2002-01-01

    An important statistical development of the last 30 years has been the advance in regression analysis provided by generalized linear models (GLMs) and generalized additive models (GAMs). Here we introduce a series of papers prepared within the framework of an international workshop entitled: Advances in GLMs/GAMs modeling: from species distribution to environmental management, held in Riederalp, Switzerland, 6-11 August 2001. We first discuss some general uses of statistical models in ecology, as well as provide a short review of several key examples of the use of GLMs and GAMs in ecological modeling efforts. We next present an overview of GLMs and GAMs, and discuss some of their related statistics used for predictor selection, model diagnostics, and evaluation. Included is a discussion of several new approaches applicable to GLMs and GAMs, such as ridge regression, an alternative to stepwise selection of predictors, and methods for the identification of interactions by a combined use of regression trees and several other approaches. We close with an overview of the papers and how we feel they advance our understanding of their application to ecological modeling. ?? 2002 Elsevier Science B.V. All rights reserved.

  20. Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS).

    PubMed

    Slichter, Sherrill J; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Pellham, Esther; Bailey, S Lawrence; Bolgiano, Doug

    2014-01-01

    To evaluate the poststorage viability of apheresis platelets stored for up to 18 days in 80% platelet additive solution (PAS)/20% plasma, 117 healthy subjects donated platelets using the Haemonetics MCS+, COBE Spectra (Spectra), or Trima Accel (Trima) systems. Control platelets from the same subjects were compared with their stored test PAS platelets by radiolabeling their stored and control platelets with either (51)chromium or (111)indium. Trima platelets met Food and Drug Administration poststorage platelet viability criteria for only 7 days vs almost 13 days for Haemonetics platelets; ie, platelet recoveries after these storage times averaged 44 ± 3% vs 49 ± 3% and survivals were 5.4 ± 0.3 vs 4.6 ± 0.3 days, respectively. The differences in storage duration are likely related to both the collection system and the storage bag. The Spectra and Trima platelets were hyperconcentrated during collection, and PAS was added, whereas the Haemonetics platelets were elutriated with PAS, which may have resulted in less collection injury. When Spectra and Trima platelets were stored in Haemonetics' bags, poststorage viability was significantly improved. Platelet viability is better maintained in vitro than in vivo, allowing substantial increases in platelet storage times. However, implementation will require resolution of potential bacterial overgrowth during storage.

  1. Chromosome studies in the aquatic monocots of Myanmar: A brief review with additional records

    PubMed Central

    2014-01-01

    Abstract Myanmar (Burma) constitutes a significant component of the Indo-Myanmar biodiversity hotspot, with elements of the Indian, the Indochina, and the Sino-Japanese floristic regions, yet thus far only a few reliable sources of the country's flora have been available. As a part of a contribution for the floristic inventory of Myanmar, since it is important in a floristic survey to obtain as much information as possible, in addition to previous two reports, here we present three more chromosome counts in the aquatic monocots of Myanmar: Limnocharis flava with 2n = 20, Sagittaria trifolia with 2n = 22 (Alismataceae), and Potamogeton distinctus × Potamogeton nodosus with 2n = 52 (Potamogetonaceae); the third one is new to science. A brief review of cytological researches in the floristic regions' 45 non-hybrid aquatic monocots plus well investigated two inter-specific hybrids that are recorded in Myanmar is given, indicating that the further works with a focus on species in Myanmar that has infra-specific chromosome variation in the floristic regions will address the precise evolutionary history of the aquatic flora of Myanmar. PMID:24891826

  2. Multi-spectroscopic DNA interaction studies of sunset yellow food additive.

    PubMed

    Kashanian, Soheila; Heidary Zeidali, Sahar; Omidfar, Kobra; Shahabadi, Nahid

    2012-12-01

    The use of food dyes is at least controversial due to their essential role. Synthetic color food additives occupy an important place in the food industry. Moreover many of them have been related to health problems mainly in children that are considered the most vulnerable group. The purpose of this work is to present spectrophotometric methods to analyze the interaction of native calf thymus DNA (CT-DNA) with sunset yellow (SY) at physiological pH. Considerable hyperchromism and no red shift with an intrinsic binding constant of 7 × 10(4 )M(-1) were observed in UV absorption band of SY. Binding constants of DNA with complex were calculated at different temperatures. Slow increase in specific viscosity of DNA, induced circular dichroism spectral changes, and no significant changes in the fluorescence of neutral red-DNA solutions in the presence of SY suggest that this molecule interacts with CT-DNA via groove binding mode. Furthermore, the enthalpy and entropy of the reaction between SY and CT-DNA showed that the reaction is exothermic and enthalpy favored (∆H = -58.19 kJ mol(-1); ΔS = -274.36 kJ mol(-1) ) which are other evidences to indicate that van der Waals interactions and hydrogen bonding are the main running forces in the binding of the mentioned molecule and mode of interaction with DNA.

  3. A study of alternative metal particle structures and mixtures for dental amalgams based on mercury additions.

    PubMed

    Marquez, J A; Murr, L E; Agüero, V

    2000-08-01

    The perception that mercury in dental amalgam is toxic to the human organism has prompted worldwide efforts by the scientific community to develop alternative amalgam-like materials that utilize little or no mercury. In this investigation, an attempt is made to develop a new dental alloy system by adding liquid mercury to silver-coated Ag4Sn intermetallic particles in lesser amounts than are used in conventional amalgam alloys. An effort to precipitate the important eta-prime (Cu6Sn5) phase was made by adding pure Cu and Sn powders to the alloy formulation during trituration. Tytin a popular Ag-Sn-Cu single-composition, spray-atomized conventional dental alloy was used as the control to obtain baseline data for comparisons of microstructures and mechanical properties. Amalgamation of the coated particles with mercury, with or without the addition of Cu and Sn powders, mostly produced specimens with chemically non-coherent microstructures that were relatively weak in compression. These results were due, in part, to mercury's inability to chemically wet the Ag-coated particles and Cu and Sn powders because of naturally occurring surface oxide films. The strongest specimens tested had silver dendritic coatings, resulting in compression strength values up to 40% of the control's. Their higher strength is attributed to mechanical interlocking at the particle/matrix interfaces.

  4. High Field Small Animal Magnetic Resonance Oncology Studies

    PubMed Central

    Bokacheva, Louisa; Ackerstaff, Ellen; LeKaye, H. Carl; Zakian, Kristen; Koutcher, Jason A.

    2014-01-01

    This review focuses on the applications of high magnetic field magnetic resonance imaging (MRI) and spectroscopy (MRS) to cancer studies in small animals. High field MRI can provide information about tumor physiology, the microenvironment, metabolism, vascularity and cellularity. Such studies are invaluable for understanding tumor growth and proliferation, response to treatment and drug development. The MR techniques reviewed here include 1H, 31P, Chemical Exchange Saturation Transfer (CEST) imaging, and hyperpolarized 13C MR spectroscopy as well as diffusion-weighted, Blood Oxygen Level Dependent (BOLD) contrast imaging, and dynamic contrast-enhanced MR imaging. These methods have been proven effective in animal studies and are highly relevant to human clinical studies. PMID:24374985

  5. Magnetic field studies by Voyager 1 - Preliminary results at Saturn

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Acuna, M. H.; Lepping, R. P.; Connerney, J. E. P.; Behannon, K. W.; Burlaga, L. F.; Neubauer, F. M.

    1981-01-01

    Confirmation and refinement of Saturnian magnetosphere features established by the Pioneer 11 emission are claimed for Voyager 1 magnetic field studies of the planet. The radius of the magnetopause at the subsolar point is 23 Saturn radii, and a magnetic tail of 80 Saturn radii diameter was discovered. The tail extends away from the sun and is similar to both type II comet tails and the terrestrial and Jovian magnetic tails. Data from Voyager's very close flyby of Titan, which is located within the Saturn magnetosphere, shows an absence of any substantial, intrinsic satellite magnetic field.

  6. Voice measures of workload in the advanced flight deck: Additional studies

    NASA Technical Reports Server (NTRS)

    Schneider, Sid J.; Alpert, Murray

    1989-01-01

    These studies investigated acoustical analysis of the voice as a measure of workload in individual operators. In the first study, voice samples were recorded from a single operator during high, medium, and low workload conditions. Mean amplitude, frequency, syllable duration, and emphasis all tended to increase as workload increased. In the second study, NASA test pilots performed a laboratory task, and used a flight simulator under differing work conditions. For two of the pilots, high workload in the simulator brought about greater amplitude, peak duration, and stress. In both the laboratory and simulator tasks, high workload tended to be associated with more statistically significant drop-offs in the acoustical measures than were lower workload levels. There was a great deal of intra-subject variability in the acoustical measures. The results suggested that in individual operators, increased workload might be revealed by high initial amplitude and frequency, followed by rapid drop-offs over time.

  7. Study on Type C Coal Fly ash as an Additive to Molding Sand for Steel Casting

    NASA Astrophysics Data System (ADS)

    Palaniappan, Jayanthi

    2016-05-01

    Study of physio-chemical properties studies such as granulometric analysis, moisture, X ray fluorescence etc. were performed with Type C coal—combustion fly ash to investigate their potential as a distinct option for molding sand in foundry, thereby reducing the dependency on latter. Technological properties study such as compressive strength, tensile strength, permeability and compaction of various compositions of fly ash molding sand (10, 20 and 30 % fly ash substitute to chemically bonded sand) were performed and compared with silica molding sand. Steel casting production using this fly ash molding sand was done and the casting surface finish and typical casting parameters were assessed. It was noted that a good quality steel casting could be produced using type C fly ash molding sand, which effectively replaced 20 % of traditional molding sand and binders thereby providing greater financial profits to the foundry and an effective way of fly ash utilization (waste management).

  8. Additional Study of Water Droplet Median Volume Diameter (MVD) Effects on Ice Shapes

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching; Anderson, David N.

    2005-01-01

    This paper reports the result of an experimental study in the NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the MVD-independent effect identified previously might apply to SLD conditions in rime icing situations. Models were NACA 0012 wing sections with chords of 53.3 and 91.4 cm. Tests were conducted with a nominal airspeed of 77 m/s (150 kt) and a number of MVD's ranging from 15 to 100 m with LWC of 0.5 to 1 g/cu m. In the present study, ice shapes recorded from past studies and recent results at SLD and Appendix-C conditions are reviewed to show that droplet diameter is not important to rime ice shape for MVD of 30 microns or larger, but for less than 30 m drop sizes a rime ice shape transition from convex to wedge to spearhead type ice shape is observed.

  9. A study of grain boundary sliding in copper with and without an addition of phosphorus

    NASA Astrophysics Data System (ADS)

    Pettersson, Kjell

    2010-10-01

    Copper will be used as a corrosion barrier in the storage of high level nuclear waste. In order to improve the creep fracture properties of the material it will contain 30-50 ppm of phosphorus, OFP copper as opposed to OF copper without P. It has been suggested that the phosphorus impedes grain boundary sliding in copper and recently a quantitative theory based on this idea has shown that there is no risk for creep-brittle fracture of OFP copper under waste storage conditions. In order to verify the basis of this theory grain boundary sliding has been investigated in copper with and without a P addition. The method has been to examine intentionally scratched surfaces of tensile specimens tension tested to plastic strains of 1%, 2% and 4% at 150 and 200 °C. After testing specimen surfaces have been examined in SEM and sliding distances have been measured as in-surface displacement of scratches. The results have been plotted as distribution functions where the fraction of slides smaller than a given value is plotted versus sliding distance. The result is that in most cases the distribution functions for OF and OFP copper overlap. In a small number of cases there is a tendency that less sliding has occurred in OFP copper. The overall conclusion is however that although there may be a slight difference between the materials with regard to grain boundary sliding it is not large enough to explain the observed difference in creep brittleness. Tension tests to fracture in the temperature range 100-200 °C show that the tensile properties of the two copper qualities are more or less identical until intergranular cracking starts in the OF copper. Then the flow stress decreases in comparison with OFP. It is suggested that at least part of the observed differences in creep strength between the two coppers may be due to the effect of intergranular cracking.

  10. SCAPEGOAT WILDERNESS AND ADDITIONS, BOB MARSHALL AND GREAT BEAR WILDERNESSES, AND ADJACENT STUDY AREAS, MONTANA.

    USGS Publications Warehouse

    Earhart, Robert L.; Marks, Lawrence Y.

    1984-01-01

    Hydrocarbon and non-fuels mineral surveys indicate that parts of the Bob Marshall and Great Bear Wildernesses and several of the adjacent study areas have probable and substantiated mineral-resource potential for hydrocarbon accumulations, especially natural gas; the Scapegoat and Great Bear Wildernesses have a substantiated resource potential for copper and silver. The Bob Marshall Wilderness has a substantiated potential for barite and a probable potential for copper and silver. Lead, zinc, coal, and limestone occur locally within the study areas but such occurrences are small and low grade and no resource potential is identified.

  11. Field-Theoretic Studies of Nanostructured Triblock Polyelectrolyte Gels

    NASA Astrophysics Data System (ADS)

    Audus, Debra; Fredrickson, Glenn

    2012-02-01

    Recently, experimentalists have developed nanostructured, reversible gels formed from triblock polyelectrolytes (Hunt et al. 2011, Lemmers et al. 2010, 2011). These gels have fascinating and tunable properties that reflect a heterogeneous morphology with domains on the order of tens of nanometers. The complex coacervate domains, aggregated oppositely charged end-blocks, are embedded in a continuous aqueous matrix and are bridged by uncharged, hydrophilic polymer mid-blocks. We report on simulation studies that employ statistical field theory models of triblock polyelectrolytes, and we explore the equilibrium self-assembly of these remarkable systems. As the charge complexation responsible for the formation of coacervate domains is driven by electrostatic correlations, we have found it necessary to pursue full ``field-theoretic simulations'' of the models, as opposed to the familiar self-consistent field theory approach. Our investigations have focused on morphological trends with mid- and end-block lengths, polymer concentration, salt concentration and charge density.

  12. A Field Study on the Raindrop Fall Velocity

    NASA Astrophysics Data System (ADS)

    Rahman, Kalimur; Testik, Firat

    2016-04-01

    Raindrop fall velocity is a critical parameter in various rainfall related applications such as dual-polarization radar rainfall estimation. In such applications, it is typically assumed that raindrops fall at terminal velocity. Recent field observations, however, challenged this assumption of terminal raindrops. In this study, we investigated raindrop fall velocity in rainfall events using a new optical-type disdrometer called the High-speed Optical Disdrometer (HOD). We developed the HOD recently for precipitation microphysical observations, in particular for investigating raindrop dynamics including raindrop fall velocity. Our field observations showed clear deviations of raindrop fall velocities from predicted terminal velocities. These new field observations and our ongoing efforts to elucidate raindrop fall velocity characteristics will be discussed. This material is based upon work supported by the National Science Foundation under Grant No. AGS-1612681.

  13. Nahuatl as a Classical, Foreign, and Additional Language: A Phenomenological Study

    ERIC Educational Resources Information Center

    De Felice, Dustin

    2012-01-01

    In this study, participants learning an endangered language variety shared their experiences, thoughts, and feelings about the often complex and diverse language-learning process. I used phenomenological interviews in order to learn more about these English or Spanish language speakers' journey with the Nahuatl language. From first encounter to…

  14. CNV-based genome wide association study reveals additional variants contributing to meat quality in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pork quality is important both to the meat processing industry and consumers’ purchasing attitudes. Copy number variation (CNV) is a burgeoning kind of variant that may influence meat quality. Herein, a genome-wide association study (GWAS) was performed between CNVs and meat quality traits in swine....

  15. Genome-Wide Association Study of Intelligence: Additive Effects of Novel Brain Expressed Genes

    ERIC Educational Resources Information Center

    Loo, Sandra K.; Shtir, Corina; Doyle, Alysa E.; Mick, Eric; McGough, James J.; McCracken, James; Biederman, Joseph; Smalley, Susan L.; Cantor, Rita M.; Faraone, Stephen V.; Nelson, Stanley F.

    2012-01-01

    Objective: The purpose of the present study was to identify common genetic variants that are associated with human intelligence or general cognitive ability. Method: We performed a genome-wide association analysis with a dense set of 1 million single-nucleotide polymorphisms (SNPs) and quantitative intelligence scores within an ancestrally…

  16. A Micro-Developmental Approach to Studying Young Children's Problem Solving Behavior in Addition

    ERIC Educational Resources Information Center

    Voutsina, Chronoula

    2012-01-01

    This paper presents a study that investigated the process of change in 5-6-year-old children's successful problem-solving approaches when tackling a multiple-step task in elementary arithmetic. Micro-developmental changes in children's successful problem-solving behavior were analyzed using Karmiloff-Smith's model of representational redescription…

  17. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  18. Magnetic field studies by voyager 1: preliminary results at saturn.

    PubMed

    Ness, N F; Acuña, M H; Lepping, R P; Connerney, J E; Behannon, K W; Burlaga, L F; Neubauer, F M

    1981-04-10

    Magnetic field studies by Voyager 1 have confirmed and refined certain general features of the Saturnian magnetosphere and planetary magnetic field established by Pioneer 11 in 1979. The main field of Saturn is well represented by a dipole of moment 0.21 +/- 0.005 gauss-R(s)(3) (where 1 Saturn radius, R(s), is 60,330 kilometers), tilted 0.7 degrees +/- 0.35 degrees from the rotation axis and located within 0.02 R(s) of the center of the planet. The radius of the magnetopause at the subsolar point was observed to be 23 R(s) on the average, rather than 17 R(s). Voyager 1 discovered a magnetic tail of Saturn with a diameter of approximately 80 R(s). This tail extends away from the Sun and is similar to type II comet tails and the terrestrial and Jovian magnetic tails. Data from the very close flyby at Titan (located within the Saturnian magnetosphere) at a local time of 1330, showed an absence of any substantial intrinsic satellite magnetic field. However, the results did indicate a very well developed, induced magnetosphere with a bipolar magnetic tail. The upper limit to any possible internal satellite magnetic moment is 5 x 10(21) gauss-cubic centimeter, equivalent to a 30-nanotesla equatorial surface field.

  19. Studying quantum dot blinking through the addition of an engineered inorganic hole trap.

    PubMed

    Tenne, Ron; Teitelboim, Ayelet; Rukenstein, Pazit; Dyshel, Maria; Mokari, Taleb; Oron, Dan

    2013-06-25

    An all-inorganic compound colloidal quantum dot incorporating a highly emissive CdSe core, which is linked by a CdS tunneling barrier to an engineered charge carrier trap composed of PbS, is designed, and its optical properties are studied in detail at the single-particle level. Study of this structure enables a deeper understanding of the link between photoinduced charging and surface trapping of charge carriers and the phenomenon of quantum dot blinking. In the presence of the hole trap, a "gray" emissive state appears, associated with charging of the core. Rapid switching is observed between the "on" and the "gray" state, although the switching dynamics in and out of the dark "off" state remain unaffected. This result completes the links in the causality chain connecting charge carrier trapping, charging of QDs, and the appearance of a "gray" emission state.

  20. Brief reconnaissance study for the addition of hydropower for Carr Fork Dam, Sassafras, Kentucky

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-05-24

    The feasibility of retrofitting the Carr Fork Dam near Hazard, KY for power generation was examined. This dam has a developable head of 80 ft and was built in 1975 to provide flood protection. The study of environmental, institutional, safety, and economic factors showed that the total investment cost would be $909,600 and that hydroelectric power development at this site is not feasible unless a higher price could be obtained for the power sold. (LCL)

  1. Expanding access to primary care without additional budgets? A case study from Burkina Faso.

    PubMed

    Marschall, Paul; Flessa, Steffen

    2008-11-01

    The aim of this study is to demonstrate the impact of increased access to primary care on provider costs in the rural health district of Nouna, Burkina Faso. This study question is crucial for health care planning in this district, as other research work shows that the population has a higher need for health care services. From a public health perspective, an increase of utilisation of first-line health facilities would be necessary. However, the governmental budget that is needed to finance improved access was not known. The study is based on data of 2004 of a comprehensive provider cost information system. This database provides us with the actual costs of each primary health care facility (Centre de Santé et de Promotion Sociale, CSPS) in the health district. We determine the fixed and variable costs of each institution and calculate the average cost per service unit rendered in 2004. Based on the cost structure of each CSPS, we calculate the total costs if the demand for health care services increased. We conclude that the total provider costs of primary care (and therefore the governmental budget) would hardly rise if the coverage of the population were increased. This is mainly due to the fact that the highest variable costs are drugs, which are fully paid for by the customers (Bamako Initiative). The majority of other costs are fixed. Consequently, health care reforms that improve access to health care institutions must not fear dramatically increasing the costs of health care services. PMID:18197447

  2. Satellite Studies of Ionospheric Electric Fields and Neutral Winds

    NASA Technical Reports Server (NTRS)

    Fejer, Bela G.

    2002-01-01

    We have studied mid- and low-latitude electrodynamic and neutral thermospheric dynamic processes using measurements on board the AE-E, DE-2, and UARS (Upper Atmosphere Research Satellite) satellites, and global convection and general circulation models. These studies have determined the morphology of the equatorial zonal electric fields, the response of equatorial plasma irregularities to magnetospheric disturbances, and the time dependent response of the mid- and low latitude electric fields to magnetospheric disturbances. We have also used extensive F region zonal and meridional wind data obtained by Wind Imaging Interferometer (WINDII) instrument on board the UARS to study the latitudinal dependence of daytime disturbance winds during magnetically disturbed periods and the general characteristics of the global thermospheric disturbance wind system during geomagnetically active periods. This project has supported the PhD thesis research of John Emmert.

  3. Electron Dynamics in Intense Laser Fields: A Bohmian Mechanics Study

    NASA Astrophysics Data System (ADS)

    Jooya, Hossein Z.; Telnov, Dmitry A.; Chu, Shih-I.

    2016-05-01

    We study the electron quantum dynamics of atomic hydrogen under intense near infrared laser fields by means of the De Broglie-Bohm's framework of Bohmian mechanics. This method is used to study the mechanism of the multiple plateau generation and the cut-off extension, as the main characteristic features of high order harmonic generation spectrum. Electron multiple recollision dynamics under intense mid-infrared laser fields is also investigated. In this case, the resulting patterns in the high-order harmonic generation and the above-threshold ionization spectra are analyzed by comprehensive picture provided by Bohmian mechanics. The time evolution of individual trajectories is closely studied to address some of the major structural features of the photoelectron angular distributions. This work is partially supported by DOE.

  4. Geography Teacher Candidates' Experiences of Field Study in Western Anatolia: A Qualitative Study

    ERIC Educational Resources Information Center

    Balci, Ali

    2012-01-01

    The aim of this study is to establish expectations of 5th grade students from Marmara University's Department of Geography Teaching on geographical field study in Western Anatolia. For this reason, a field study trip was organized to Western Anatolia. A survey, which was consisted of open-ended questions, was prepared by experts and it was…

  5. Analytical and Numerical Studies of Coherent Field Configurations

    NASA Astrophysics Data System (ADS)

    Muller, Hans-Reinhard

    Motivated by the goal of investigating the dynamics of the electroweak phase transition in the early Universe, a study of dynamical aspects of nonlinear field-theoretical systems is performed. Symmetric and asymmetric double-well potentials in the φ4 theory are used as a model for these systems. In the first part, it is shown that in this model, a class of localized, time-dependent, spherically-symmetric objects dubbed oscillons exists. The most distinctive feature of these objects is that they are extremely long-lived. The properties of oscillons are studied by numerical and analytical means. In the second part of the study, the matching between (1+1)-dimensional nonlinear field theories coupled to an external stochastic environment and their lattice simulations is investigated. In particular, a method is developed to obtain numerical results which are lattice-spacing independent, and to extract the correct effective potential which emerges from the simulations. As an application, the thermal production of kinks is studied, obtaining the lattice-spacing independent number density of kinks and the effective barrier for kink production, i.e., the effective kink mass. Within its range of validity, the approach can be used to match numerical simulations to continuum studies of the emergence of coherent field structures in cosmology and condensed matter physics.

  6. Effect of Rashba and Dresselhaus interactions on the energy spectrum, chemical potential, addition energy and spin-splitting in a many-electron parabolic GaAs quantum dot in a magnetic field

    NASA Astrophysics Data System (ADS)

    Kumar, D. Sanjeev; Mukhopadhyay, Soma; Chatterjee, Ashok

    2016-11-01

    The effect of electron-electron interaction and the Rashba and Dresselhaus spin-orbit interactions on the electronic properties of a many-electron system in a parabolically confined quantum dot placed in an external magnetic field is studied. With a simple and physically reasonable model potential for electron-electron interaction term, the problem is solved exactly to second-order in the spin-orbit coupling constants to obtain the energy spectrum, the chemical potential, addition energy and the spin-splitting energy.

  7. Integrated modeling and field study of potential mechanisms forinduced seismicity at The Geysers Goethermal Field, California

    SciTech Connect

    Rutqvist, Jonny; Majer, Ernie; Oldenburg, Curt; Peterson, John; Vasco, Don

    2006-06-07

    In this paper, we present progress made in a study aimed atincreasing the understanding of the relative contributions of differentmechanisms that may be causing the seismicity occurring at The Geysersgeothermal field, California. The approach we take is to integrate: (1)coupled reservoir geomechanical numerical modeling, (2) data fromrecently upgraded and expanded NCPA/Calpine/LBNL seismic arrays, and (3)tens of years of archival InSAR data from monthly satellite passes. Wehave conducted a coupled reservoir geomechanical analysis to studypotential mechanisms induced by steam production. Our simulation resultscorroborate co-locations of hypocenter field observations of inducedseismicity and their correlation with steam production as reported in theliterature. Seismic and InSAR data are being collected and processed foruse in constraining the coupled reservoir geomechanicalmodel.

  8. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    SciTech Connect

    Tong Wang

    2002-09-18

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To

  9. ISR meets SAR outside: additive action of the endophyte Bacillus pumilus INR7 and the chemical inducer, benzothiadiazole, on induced resistance against bacterial spot in field-grown pepper

    PubMed Central

    Yi, Hwe-Su; Yang, Jung Wook; Ryu, Choong-Min

    2013-01-01

    Induced resistance has been recognized as an attractive tool for plant disease management in modern agriculture. During the last two decades, studies on chemically- and biologically elicited induced resistance have revealed previously unknown features of the plant defense response including defense priming. As a biological trigger for induced resistance, plant growth-promoting rhizobacteria (PGPR) are a group of root-associated bacteria that can reduce plant disease severity and incidence, and augment plant growth and yield under greenhouse and field conditions. We evaluated the potential of an endophytic PGPR, Bacillus pumilus INR7, to induce systemic resistance against bacterial spot caused by Xanthomonas axonopodis pv. vesicatoria in pepper. Trials in the greenhouse showed significantly less symptom development in pepper plants inoculated with strain INR7 compared to a water treatment. Furthermore, a single dipping treatment with INR7 before transplantation of pepper plants into the field elicited an induced systemic resistance response against bacterial spot caused by artificially infiltration of X. axonopodis pv. vesicatoria and even against naturally occurring bacterial spot disease. We identified an additive effect on induced resistance after administration of a combination treatment composed of strain INR7 with a chemical inducer, benzothiadiazole (BTH) in the field. The combination treatment stimulated expression of pepper defense marker genes CaPR1, CaTin1, and CaPR4 to a greater extent than did treatment with either agent alone. Similar experiments conducted with tobacco revealed no additive effects under field conditions. Interestingly, co-application of plants with INR7 lifted the growth repressing effect of BTH. Application of BTH onto pepper and tobacco did not affect rhizosphere colonization but supported a higher population density inside plant roots when compared to water-treated control plants. Our results indicate that PGPR can be used in

  10. ISR meets SAR outside: additive action of the endophyte Bacillus pumilus INR7 and the chemical inducer, benzothiadiazole, on induced resistance against bacterial spot in field-grown pepper.

    PubMed

    Yi, Hwe-Su; Yang, Jung Wook; Ryu, Choong-Min

    2013-01-01

    Induced resistance has been recognized as an attractive tool for plant disease management in modern agriculture. During the last two decades, studies on chemically- and biologically elicited induced resistance have revealed previously unknown features of the plant defense response including defense priming. As a biological trigger for induced resistance, plant growth-promoting rhizobacteria (PGPR) are a group of root-associated bacteria that can reduce plant disease severity and incidence, and augment plant growth and yield under greenhouse and field conditions. We evaluated the potential of an endophytic PGPR, Bacillus pumilus INR7, to induce systemic resistance against bacterial spot caused by Xanthomonas axonopodis pv. vesicatoria in pepper. Trials in the greenhouse showed significantly less symptom development in pepper plants inoculated with strain INR7 compared to a water treatment. Furthermore, a single dipping treatment with INR7 before transplantation of pepper plants into the field elicited an induced systemic resistance response against bacterial spot caused by artificially infiltration of X. axonopodis pv. vesicatoria and even against naturally occurring bacterial spot disease. We identified an additive effect on induced resistance after administration of a combination treatment composed of strain INR7 with a chemical inducer, benzothiadiazole (BTH) in the field. The combination treatment stimulated expression of pepper defense marker genes CaPR1, CaTin1, and CaPR4 to a greater extent than did treatment with either agent alone. Similar experiments conducted with tobacco revealed no additive effects under field conditions. Interestingly, co-application of plants with INR7 lifted the growth repressing effect of BTH. Application of BTH onto pepper and tobacco did not affect rhizosphere colonization but supported a higher population density inside plant roots when compared to water-treated control plants. Our results indicate that PGPR can be used in

  11. Magnetic field studies by Voyager 2 - Preliminary results at Saturn

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Acuna, M. H.; Behannon, K. W.; Burlaga, L. F.; Connerney, J. E. P.; Lepping, R. P.; Neubauer, F. M.

    1982-01-01

    Results of Voyager 2 studies of the magnetosphere and planetary magnetic field of Saturn are presented. Magnetometer studies have confirmed the results obtained by Voyager 1, indicating the magnetic field to be that of a centered dipole of moment 0.21 gauss Saturn radii-cubed, tilted approximately 0.8 deg from the rotation axis and a maximum measured field intensity of 1187 nT at latitude 17.3 deg N just before periapsis. Voyager 2 observed multiple bow shock and magnetopause crossings during its inbound and outbound trajectories, which were complementary to those of Voyager 1, including magnetopause crossing at 18.5 Saturn radii on the inbound trajectory, and at 48.4-50.9 Saturn radii outbound indicative of magnetospheric expansion due to changing solar wind conditions. Throughout the outbound passage, the magnetospheric field was observed to be relatively steady and smooth, with no evidence for any azimuthal asymmetry or magnetic anomaly. Results thus are incapable of accounting for the observed periodic modulation of the Saturnian kilometric radio emissions.

  12. Simulation studies of FRC with rotating magnetic field current drive

    NASA Astrophysics Data System (ADS)

    Belova, E. V.; Davidson, R. C.

    2007-11-01

    The HYM code has been modified to include the effects of rotating magnetic field (RMF) current drive. Initial 3D two-fluid and hybrid simulations have been performed for even-parity RMF and different plasma parameters. Simulations show that the RMF pushes the plasma radially inward, resulting in a reduced plasma density outside the separatrix. Lower plasma density and larger RMF amplitudes result in faster RMF field penetration, in agreement with previous studies [R. Milroy, Phys. Plasmas 8, 2804 (2001)]. Effects of the applied RMF field on particle confinement have been studied using 3D test particle simulations. Simulations of stationary RMFs show that for relatively large ion Larmor radius (S^*<20), there is very little difference between even- and odd-parity RMFs in terms of the ion losses. The rate of particle losses is larger in larger FRCs, and increases with the RMF amplitude. In contrast, high-frequency RMF can reduce ion losses provided φrmfφci, and the RMF is of even-parity. The improved particle confinement is related to ponderomotive forces due to the rapidly oscillating, inhomogeneous electromagnetic field. It is also found that high-frequency, odd-parity RMFs force particles away from the midplane toward the FRC ends.

  13. [Chewing gum as an additional agent in maintaining oral hygiene versus smoking status--preliminary study].

    PubMed

    Nakonieczna-Rudnicka, Marta; Strycharz-Dudziak, Małgorzata; Bachanek, Teresa

    2012-01-01

    Nowadays chewing gum is widely used in different age groups, so complying with proper duration and frequency of chewing is an important factor influencing the state of masticatory system. The study involved 112 dental students of the Medical University of Lublin. Everyday use of chewing gum declared 47,32% of cases. Chewing time up to 10 minutes was stated in 23,08% of respondents, 11-20 minutes in 40,38% of interviewees. Among the examined students 17,3% smoked cigarettes. In smokers group 83,33% of questioned chewed the gum every day, while among non-smokers - 43,37%. Chewing time shorter than 10 minutes declared 22,22% of smokers and 23,26% of non-smokers, while chewing time between 11-20 minutes - 27,78% i 44,35% of smokers and non-smokers respectively. Obtained results indicate the need of carrying out further studies aimed at the nicotine influence on saliva parameters with respect to development of diseases of hard tooth tissues.

  14. Study on the interaction of the toxic food additive carmoisine with serum albumins: a microcalorimetric investigation.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2014-05-30

    The interaction of the synthetic azo dye and food colorant carmoisine with human and bovine serum albumins was studied by microcalorimetric techniques. A complete thermodynamic profile of the interaction was obtained from isothermal titration calorimetry studies. The equilibrium constant of the complexation process was of the order of 10(6)M(-1) and the binding stoichiometry was found to be 1:1 with both the serum albumins. The binding was driven by negative standard molar enthalpy and positive standard molar entropy contributions. The binding affinity was lower at higher salt concentrations in both cases but the same was dominated by mostly non-electrostatic forces at all salt concentrations. The polyelectrolytic forces contributed only 5-8% of the total standard molar Gibbs energy change. The standard molar enthalpy change enhanced whereas the standard molar entropic contribution decreased with rise in temperature but they compensated each other to keep the standard molar Gibbs energy change almost invariant. The negative standard molar heat capacity values suggested the involvement of a significant hydrophobic contribution in the complexation process. Besides, enthalpy-entropy compensation phenomenon was also observed in both the systems. The thermal stability of the serum proteins was found to be remarkably enhanced on binding to carmoisine. PMID:24742664

  15. Study on the interaction of the toxic food additive carmoisine with serum albumins: a microcalorimetric investigation.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2014-05-30

    The interaction of the synthetic azo dye and food colorant carmoisine with human and bovine serum albumins was studied by microcalorimetric techniques. A complete thermodynamic profile of the interaction was obtained from isothermal titration calorimetry studies. The equilibrium constant of the complexation process was of the order of 10(6)M(-1) and the binding stoichiometry was found to be 1:1 with both the serum albumins. The binding was driven by negative standard molar enthalpy and positive standard molar entropy contributions. The binding affinity was lower at higher salt concentrations in both cases but the same was dominated by mostly non-electrostatic forces at all salt concentrations. The polyelectrolytic forces contributed only 5-8% of the total standard molar Gibbs energy change. The standard molar enthalpy change enhanced whereas the standard molar entropic contribution decreased with rise in temperature but they compensated each other to keep the standard molar Gibbs energy change almost invariant. The negative standard molar heat capacity values suggested the involvement of a significant hydrophobic contribution in the complexation process. Besides, enthalpy-entropy compensation phenomenon was also observed in both the systems. The thermal stability of the serum proteins was found to be remarkably enhanced on binding to carmoisine.

  16. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    SciTech Connect

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  17. Shelf Life and Quality Study of Minced Tilapia with Nori and Hijiki Seaweeds as Natural Additives

    PubMed Central

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage. PMID:25478593

  18. Forest health monitoring: 1991 Georgia indicator evaluation and field study

    SciTech Connect

    Alexander, S.A.; Baldwin, M.; Bechtold, W.A.; Cassell, D.L.; Cline, S.

    1994-03-01

    The pilot study was designed to test methods for quantifying vegetation structure, photosynthetically active radiation (PAR), dendrochronology, and selected root fungi. Testing the methods included comparing different data collection procedures for individual indicators, estimating sampling efficiency (both of the sampling design and the sampling unit design), and evaluating spatial variability. In addition, the accuracy and precision of tree height instruments were determined as part of the pilot study.

  19. Mechanistic study of secondary organic aerosol components formed from nucleophilic addition reactions of methacrylic acid epoxide

    NASA Astrophysics Data System (ADS)

    Birdsall, A. W.; Miner, C. R.; Mael, L. E.; Elrod, M. J.

    2014-08-01

    Recently, methacrylic acid epoxide (MAE) has been proposed as a precursor to an important class of isoprene-derived compounds found in secondary organic aerosol (SOA): 2-methylglyceric acid (2-MG) and a set of oligomers, nitric acid esters and sulfuric acid esters related to 2-MG. However, the specific chemical mechanisms by which MAE could form these compounds have not been previously studied. In order to determine the relevance of these processes to atmospheric aerosol, MAE and 2-MG have been synthesized and a series of bulk solution-phase experiments aimed at studying the reactivity of MAE using nuclear magnetic resonance (NMR) spectroscopy have been performed. The present results indicate that the acid-catalyzed MAE reaction is more than 600 times slower than a similar reaction of an important isoprene-derived epoxide, but is still expected to be kinetically feasible in the atmosphere on more acidic SOA. The specific mechanism by which MAE leads to oligomers was identified, and the reactions of MAE with a number of atmospherically relevant nucleophiles were also investigated. Because the nucleophilic strengths of water, sulfate, alcohols (including 2-MG), and acids (including MAE and 2-MG) in their reactions with MAE were found to be of a similar magnitude, it is expected that a diverse variety of MAE + nucleophile product species may be formed on ambient SOA. Thus, the results indicate that epoxide chain reaction oligomerization will be limited by the presence of high concentrations of non-epoxide nucleophiles (such as water); this finding is consistent with previous environmental chamber investigations of the relative humidity-dependence of 2-MG-derived oligomerization processes and suggests that extensive oligomerization may not be likely on ambient SOA because of other competitive MAE reaction mechanisms.

  20. Mechanistic study of secondary organic aerosol components formed from nucleophilic addition reactions of methacrylic acid epoxide

    NASA Astrophysics Data System (ADS)

    Birdsall, A. W.; Miner, C. R.; Mael, L. E.; Elrod, M. J.

    2014-12-01

    Recently, methacrylic acid epoxide (MAE) has been proposed as a precursor to an important class of isoprene-derived compounds found in secondary organic aerosol (SOA): 2-methylglyceric acid (2-MG) and a set of oligomers, nitric acid esters, and sulfuric acid esters related to 2-MG. However, the specific chemical mechanisms by which MAE could form these compounds have not been previously studied with experimental methods. In order to determine the relevance of these processes to atmospheric aerosol, MAE and 2-MG have been synthesized and a series of bulk solution-phase experiments aimed at studying the reactivity of MAE using nuclear magnetic resonance (NMR) spectroscopy have been performed. The present results indicate that the acid-catalyzed MAE reaction is more than 600 times slower than a similar reaction of an important isoprene-derived epoxide, but is still expected to be kinetically feasible in the atmosphere on more acidic SOA. The specific mechanism by which MAE leads to oligomers was identified, and the reactions of MAE with a number of atmospherically relevant nucleophiles were also investigated. Because the nucleophilic strengths of water, sulfate, alcohols (including 2-MG), and acids (including MAE and 2-MG) in their reactions with MAE were found to be of similar magnitudes, it is expected that a diverse variety of MAE + nucleophile product species may be formed on ambient SOA. Thus, the results indicate that epoxide chain reaction oligomerization will be limited by the presence of high concentrations of non-epoxide nucleophiles (such as water); this finding is consistent with previous environmental chamber investigations of the relative humidity dependence of 2-MG-derived oligomerization processes and suggests that extensive oligomerization may not be likely on ambient SOA because of other competitive MAE reaction mechanisms.

  1. l-carnitine as a Potential Additive in Blood Storage Solutions: A Study on Erythrocytes.

    PubMed

    Soumya, R; Carl, H; Vani, R

    2016-09-01

    Erythrocytes undergo various changes during storage (storage lesion) that in turn reduces their functioning and survival. Oxidative stress plays a major role in the storage lesion and antioxidants can be used to combat this stress. This study elucidates the effects of l-carnitine (LC) on erythrocytes of stored blood. Blood was obtained from male Wistar rats and stored (4 °C) for 20 days in CPDA-1 (citrate phosphate dextrose adenine) solution. Samples were divided into-(i) controls (ii) LC 10 (l-carnitine at a concentration of 10 mM) (iii) LC 30 (l-carnitine at a concentration of 30 mM) and (iv) LC 60 (l-carnitine at a concentration of 60 mM). Every fifth day, the biomarkers (haemoglobin, hemolysis, antioxidant enzymes, lipid peroxidation and protein oxidation products) were analysed in erythrocytes. Hemoglobin and protein sulfhydryls were insignificant during storage indicative of the maintenance of hemoglobin and sulfhydryls in all groups. Superoxide dismutase and malondialdehyde levels increased initially and decreased towards the end of storage. The levels of catalase and glutathione peroxidase were lower in experimentals than controls during storage. l-carnitine assisted the enzymes by scavenging the reactive oxygen species produced. Hemolysis increased in all groups with storage, elucidating that l-carnitine could not completely protect lipids and proteins from oxidative stress. Hence, this study opens up new avenues of using l-carnitine as a component of storage solutions with combinations of antioxidants in order to maintain efficacy of erythrocytes.

  2. Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study.

    PubMed

    Song, Zheng-Mei; Chen, Ni; Liu, Jia-Hui; Tang, Huan; Deng, Xiaoyong; Xi, Wen-Song; Han, Kai; Cao, Aoneng; Liu, Yuanfang; Wang, Haifang

    2015-10-01

    Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food-related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco-2 cells, differentiated Caco-2 cells and Caco-2 monolayer. TiO2 NPs with a concentration less than 200 µg ml(-1) did not induce any toxicity in differentiated cells and Caco-2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml(-1) inhibited the growth of undifferentiated Caco-2 cells. Undifferentiated Caco-2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco-2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food.

  3. A Collaborative Problem-solving Process Through Environmental Field Studies

    NASA Astrophysics Data System (ADS)

    Kim, Mijung; Teck Tan, Hoe

    2013-02-01

    This study explored and documented students' responses to opportunities for collective knowledge building and collaboration in a problem-solving process within complex environmental challenges and pressing issues with various dimensions of knowledge and skills. Middle-school students (n = 16; age 14) and high-school students (n = 16; age 17) from two Singapore public institutions participated in an environmental science field study to experience knowledge integration and a decision-making process. Students worked on six research topics to understand the characteristics of an organic farm and plan for building an ecological village. Students collected and analysed data from the field and shared their findings. Their field work and discussions were video-recorded, and their reflective notes and final reports were collected for data coding and interpretation. The results revealed that throughout the study, students experienced the needs and development of integrated knowledge, encountered the challenges of knowledge sharing and communication during their collaboration, and learned how to cope with the difficulties. Based on research findings, this study further discusses students' learning through a collaborative problem-solving process, including the interdependence of knowledge and the development of mutual relationships such as respect and care for others' knowledge and learning.

  4. MO-G-BRF-09: Investigating Magnetic Field Dose Effects in Mice: A Monte Carlo Study

    SciTech Connect

    Rubinstein, A; Guindani, M; Followill, D; Melancon, A; Hazle, J; Court, L

    2014-06-15

    Purpose: In MRI-linac treatments, radiation dose distributions are affected by magnetic fields, especially at high-density/low-density interfaces. Radiobiological consequences of magnetic field dose effects are presently unknown; therefore, preclinical studies are needed to ensure the safe clinical use of MRI-linacs. This study investigates the optimal combination of beam energy and magnetic field strength needed for preclinical murine studies. Methods: The Monte Carlo code MCNP6 was used to simulate the effects of a magnetic field when irradiating a mouse-sized lung phantom with a 1.0cmx1.0cm photon beam. Magnetic field effects were examined using various beam energies (225kVp, 662keV[Cs-137], and 1.25MeV[Co-60]) and magnetic field strengths (0.75T, 1.5T, and 3T). The resulting dose distributions were compared to Monte Carlo results for humans with various field sizes and patient geometries using a 6MV/1.5T MRI-linac. Results: In human simulations, the addition of a 1.5T magnetic field caused an average dose increase of 49% (range:36%–60%) to lung at the soft tissue-to-lung interface and an average dose decrease of 30% (range:25%–36%) at the lung-to-soft tissue interface. In mouse simulations, the magnetic fields had no effect on the 225kVp dose distribution. The dose increases for the Cs-137 beam were 12%, 33%, and 49% for 0.75T, 1.5T, and 3.0T magnetic fields, respectively while the dose decreases were 7%, 23%, and 33%. For the Co-60 beam, the dose increases were 14%, 45%, and 41%, and the dose decreases were 18%, 35%, and 35%. Conclusion: The magnetic field dose effects observed in mouse phantoms using a Co-60 beam with 1.5T or 3T fields and a Cs-137 beam with a 3T field compare well with those seen in simulated human treatments with an MRI-linac. These irradiator/magnet combinations are suitable for preclinical studies investigating potential biological effects of delivering radiation therapy in the presence of a magnetic field. Partially funded by Elekta.

  5. A digital process for additive manufacturing of occlusal splints: a clinical pilot study

    PubMed Central

    Salmi, Mika; Paloheimo, Kaija-Stiina; Tuomi, Jukka; Ingman, Tuula; Mäkitie, Antti

    2013-01-01

    The aim of this study was to develop and evaluate a digital process for manufacturing of occlusal splints. An alginate impression was taken from the upper and lower jaws of a patient with temporomandibular disorder owing to cross bite and wear of the teeth, and then digitized using a table laser scanner. The scanned model was repaired using the 3Data Expert software, and a splint was designed with the Viscam RP software. A splint was manufactured from a biocompatible liquid photopolymer by stereolithography. The system employed in the process was SLA 350. The splint was worn nightly for six months. The patient adapted to the splint well and found it comfortable to use. The splint relieved tension in the patient's bite muscles. No sign of tooth wear or significant splint wear was detected after six months of testing. Modern digital technology enables us to manufacture clinically functional occlusal splints, which might reduce costs, dental technician working time and chair-side time. Maximum-dimensional errors of approximately 1 mm were found at thin walls and sharp corners of the splint when compared with the digital model. PMID:23614943

  6. Mass analysis addition to the Differential Ion Flux Probe (DIFP) study

    NASA Technical Reports Server (NTRS)

    Wright, K. H., Jr.; Jolley, Richard

    1994-01-01

    The objective of this study is to develop a technique to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The approach, conducted in conjunction with current MSFC activities, is to extend the capabilities of the Differential Ion Flux Probe (DIFP) to include a high throughput mass measurement that does not require either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This will significantly reduce the complexity and expense of instrument fabrication, testing, and integration of flight hardware compared to classical mass analyzers. The feasibility of the enhanced DIFP has been verified by using breadboard test models in a controlled plasma environment. The ability to manipulate particles through the instrument regardless of incident angle, energy, or ionic component has been amply demonstrated. The energy analysis mode is differential and leads directly to a time-of-flight mass measurement. With the new design, the DIFP will separate multiple ion streams and analyze each stream independently for ion flux intensity, velocity (including direction of motion), mass, and temperature (or energy distribution). In particular, such an instrument will be invaluable on follow-on electrodynamic TSS missions and, possibly, for environmental monitoring on the space station.

  7. Value addition of Palmyra palm and studies on the storage life.

    PubMed

    Chaurasiya, A K; Chakraborty, I; Saha, J

    2014-04-01

    Palmyra palm (Borassus flabellifer L.) belonging to the family Palmae is referred to as tree of life with several uses including food, beverage, fibre, medicinal and timber. Unfortunately, the nutritionally enriched pulp of ripened palm has limited commercial use. Extraction of pulp has been accomplished by using water and heat to ensure maximum pulp recovery. Different recipes were tried for the preparation of two uncommon value added products like palm spread and palm toffee. On the basis of biochemical composition, organoleptic scores, microbial estimation and storage study both under ambient and refrigerated conditions; the suitable recipe was selected with the maximum acceptability. Gradual increase in total soluble solid (TSS), total sugar and reducing sugar while decrease in ascorbic acid, pH, β-carotene and protein content of processed products have been observed irrespective of storage condition. The results obtained from sensory evaluation and microbial status revealed that palm spread and toffee remained acceptable up to 9 months and 8 months, respectively at ambient temperature. The income per rupee investment for these two products was found to be remunerative. PMID:24741173

  8. Holographic fabrication of large-constant concave gratings for wide-range flat-field spectrometers with the addition of a concave lens.

    PubMed

    Zhou, Qian; Li, Xinghui; Ni, Kai; Tian, Rui; Pang, Jinchao

    2016-01-25

    We present a new design for the fabrication of concave gratings with large grating constants for flat-field miniature spectrometers with a wide spectral band. In this new design, one of the two optical paths for the holographic lithography of a curved grating structure with variable line spacing is modified by adding a concave lens in front of the point source. The addition of the concave lens allows the real point source, as well as the spatial filter for generating this point source, to be moved back. In this manner, the two spatial filters for generating two point sources are separated. Avoiding the physical conflict between these two spatial filters reduces the difficulty of fabricating large-constant concave gratings. Experimental results verify the feasibility of the proposed design in fabricating concave gratings with large grating constants. The resolution of a spectrometer using the fabricated concave grating is evaluated and found to be better than 1.1 nm across a spectral band ranging from 360 nm to 825 nm.

  9. Human melatonin in magnetic fields: Second study. Final report

    SciTech Connect

    Graham, C.; Cook, M.R.; Cohen, H.D.

    1995-11-01

    Melatonin (MLT) is a hormone secreted primarily at night by the pineal gland in the brain. A number of studies suggest it is part of the body`s natural defenses against cancer. This hormone is reported to stimulate immune function and has been implicated in the control of cell proliferation, the growth of transplanted tumors, and the promotion and/or co-promotion of mammary tumors. MLT also plays a key role in the regulation of reproductive hormones implicated in a number of carcinogenic processes. Studies with rodents, although not always consistent, suggest that nocturnal MLT levels may be suppressed by electric or magnetic field (EMF) exposure. This relationship has been proposed as a possible biological mechanism to account for epidemiological reports linking chronic EMF exposure and increased cancer risk. Research was needed to determine if a similar suppression of MLT occurs when humans are exposed to magnetic fields at night.

  10. Field Artillery Ammunition Processing System (FAAPS) concept evaluation study

    SciTech Connect

    Kring, C.T.; Babcock, S.M.; Watkin, D.C.; Oliver, R.P.

    1992-06-01

    The Field Artillery Ammunition Processing System (FAAPS) is an initiative to introduce a palletized load system (PLS) that is transportable with an automated ammunition processing and storage system for use on the battlefield. System proponents have targeted a 20% increase in the ammunition processing rate over the current operation while simultaneously reducing the total number of assigned field artillery battalion personnel by 30. The overall objective of the FAAPS Project is the development and demonstration of an improved process to accomplish these goals. The initial phase of the FAAPS Project and the subject of this study is the FAAPS concept evaluation. The concept evaluation consists of (1) identifying assumptions and requirements, (2) documenting the process flow, (3) identifying and evaluating technologies available to accomplish the necessary ammunition processing and storage operations, and (4) presenting alternative concepts with associated costs, processing rates, and manpower requirements for accomplishing the operation. This study provides insight into the achievability of the desired objectives.

  11. Canine parvovirus in vaccinated dogs: a field study.

    PubMed

    Miranda, C; Thompson, G

    2016-04-16

    The authors report a field study that investigated the canine parvovirus (CPV) strains present in dogs that developed the disease after being vaccinated. Faecal samples of 78 dogs that have been vaccinated against CPV and later presented with clinical signs suspected of parvovirus infection were used. Fifty (64.1 per cent) samples tested positive by PCR for CPV. No CPV vaccine type was detected. The disease by CPV-2b occurred in older and female dogs when compared with that by CPV-2c. The clinical signs presented by infected dogs were similar when any of both variants were involved. In most cases of disease, the resulting infection by field variants occurred shortly after CPV vaccination. Two dogs that had been subjected to a complete vaccination schedule and presented with clinical signs after 10 days of vaccination, had the CPV-2c variant associated. The phylogenetic studies showed a close relationship of the isolates in vaccinated dogs to European field strains. Despite the limited sample size in this study, the findings point to the significance of the continuous molecular typing of the virus as a tool to monitor the prevalent circulating CPV strains and access the efficacy of current vaccines. Adjustments on the vaccine types to be used may have to be evaluated again according to each epidemiological situation in order to achieve the dog's optimal immune protection against CPV. PMID:26960988

  12. Science and ecological literacy in undergraduate field studies education

    NASA Astrophysics Data System (ADS)

    Mapp, Kim J.

    There is an ever-increasing number of issues that face our world today; from climate change, water and food scarcity, to pollution and resource extraction. Science and ecology play fundamental roles in these problems, and yet the understanding of these fields is limited in our society (Miller, 2002; McBride, Brewer, Berkowitz, and Borrie, 2013). Across the nation students are finishing their undergraduate degrees and are expected to enter the workforce and society with the skills needed to succeed. The deficit of science and ecological literacy in these students has been recognized and a call for reform begun (D'Avanzo, 2003 and NRC, 2009). This mixed-methods study looked at how a field studies course could fill the gap of science and ecological literacy in undergraduates. Using grounded theory, five key themes were data-derived; definitions, systems thinking, human's role in the environment, impetus for change and transference. These themes where then triangulated for validity and reliability through qualitative and quantitative assessments. A sixth theme was also identified, the learning environment. Due to limited data to support this themes' development and reliability it is discussed in Chapter 5 to provide recommendations for further research. Key findings show that this field studies program influenced students' science and ecological literacy through educational theory and practice.

  13. Canine parvovirus in vaccinated dogs: a field study.

    PubMed

    Miranda, C; Thompson, G

    2016-04-16

    The authors report a field study that investigated the canine parvovirus (CPV) strains present in dogs that developed the disease after being vaccinated. Faecal samples of 78 dogs that have been vaccinated against CPV and later presented with clinical signs suspected of parvovirus infection were used. Fifty (64.1 per cent) samples tested positive by PCR for CPV. No CPV vaccine type was detected. The disease by CPV-2b occurred in older and female dogs when compared with that by CPV-2c. The clinical signs presented by infected dogs were similar when any of both variants were involved. In most cases of disease, the resulting infection by field variants occurred shortly after CPV vaccination. Two dogs that had been subjected to a complete vaccination schedule and presented with clinical signs after 10 days of vaccination, had the CPV-2c variant associated. The phylogenetic studies showed a close relationship of the isolates in vaccinated dogs to European field strains. Despite the limited sample size in this study, the findings point to the significance of the continuous molecular typing of the virus as a tool to monitor the prevalent circulating CPV strains and access the efficacy of current vaccines. Adjustments on the vaccine types to be used may have to be evaluated again according to each epidemiological situation in order to achieve the dog's optimal immune protection against CPV.

  14. Reversed-field pinch studies in the Madison Symmetric Torus

    SciTech Connect

    Hokin, S.; Almagri, A.; Cekic, M.; Chapman, B.; Crocker, N.; Den Hartog, D.J.; Fiksel, G.; Henry, J.; Ji, H.; Prager, S.; Sarff, J.; Scime, E.; Shen, W.; Stoneking, M.; Watts, C.

    1993-04-03

    Studies of large-size (R = 1.5 m, a = 0.5 m), moderate current (I < 750 kA) reversed-field pinch (RFP) plasmas are carried out in the Madison Symmetric Torus in order to evaluate and improve RFP confinement, study general toroidal plasma MHD issues, determine the mechanism of the RFP dynamo, and measure fluctuation-induced transport and anomalous ion heating. MST confinement has been improved by reduction of magnetic field errors with correction coils in the primary circuit and reduction of impurities using boronization; high densities have been achieved with hydrogen pellet injection. MHD tearing modes with poloidal mode number m = 1 and toroidal mode numbers n = 5--7 are prevalent and nonlinearly couple to produce sudden relaxations akin to tokamak sawteeth. Edge fluctuation-induced transport has been measured with a variety of insertable probes. Ions exhibit anomalous heating, with increases of ion temperature occuring during strong MHD relaxation. The RFP dynamo has been studied with attention to various possible mechanisms, including motion-EMF drive, the Hall effect, and superthermal electrons. Initial profile control experiments have begun using insertable biased probes and plasma guns. The toroidal field capacity of MST will be upgraded during Summer, 1993 to allow low-current tokamak operation as well as improved RFP operation.

  15. Magnetic field studies by voyager 2: preliminary results at saturn.

    PubMed

    Ness, N F; Acuna, M H; Behannon, K W; Burlaga, L F; Connerney, J E; Lepping, R P; Neubauer, F M

    1982-01-29

    Further studies of the Saturnian magnetosphere and planetary magnetic field by Voyager 2 have substantiated the earlier results derived from Voyager 1 observations in 1980. The magnetic field is primarily that of a centered dipole (moment = 0.21 gauss-RS(3); where one Saturn radius, RS, is 60,330 kilometers) tilted approximately 0.8 degrees from the rotation axis. Near closest approach to Saturn, Voyager 2 traversed a kronographic longitude and latitude range that was complementary to that of Voyager 1. Somewhat surprisingly, no evidence was found in the data or the analysis for any large-scale magnetic anomaly in the northern hemisphere which could be associated with the periodic modulation of Saturnian kilometric radiation radio emissions. Voyager 2 crossed the magnetopause of a relatively compressed Saturnian magnetosphere at 18.5 RS while inbound near the noon meridian. Outbound, near the dawn meridian, the magnetosphere had expanded considerably and the magnetopause boundary was not observed until the spacecraft reached 48.4 to 50.9 RS and possibly beyond. Throughout the outbound magnetosphere passage, a period of 46 hours (4.5 Saturn rotations), the field was relatively steady and smooth showing no evidence for any azimuthal asymmetry or magnetic anomaly in the planetary field. We are thus left with a rather enigmatic situation to understand the basic source of Saturnian kilometric radiation modulation, other than the small dipole tilt.

  16. 1992-93 Results of geomorphological and field studies Volcanic Studies Program, Yucca Mountain Project

    SciTech Connect

    Wells, S.G.

    1993-10-01

    Field mapping and stratigraphic studies were completed of the Black Tank volcanic center, which represents the southwestern most eruptive center in the Cima volcanic field of California. The results of this mapping are presented. Contacts between volcanic units and geomorphic features were field checked, incorporating data from eight field trenches as well as several exposures along Black Tank Wash. Within each of the eight trenches, logs were measured and stratigraphic sections were described. These data indicate that three, temporally separate volcanic eruptions occurred at the Black Tank center. The field evidence for significant time breaks between each stratigraphic unit is the presence of soil and pavement-bounded unconformities.

  17. A field study of the Chelyabinsk airburst impact

    NASA Astrophysics Data System (ADS)

    Jenniskens, P. M.; Popova, O. P.; Emel'yanenko, V. V.; Kartashova, A.; Biryukov, E.; Khaibrakhmanov, S.; Shuvalov, V.

    2013-12-01

    On February 15 2013 UT, a ~600 kT asteroid impact generated an airburst strong enough to cause widespread glass damage in the district of Chelyabinsk, Russia. 1,613 people requested medical assistance, while 112 people were hospitalized, two in serious condition. Starting three weeks after the event, the Russian Academy of Sciences organized a two-week field campaign, led by the Institute for Dynamics of Geospheres and the Institute of Astronomy, to investigate the extent of the damage and calibrate the entry conditions of the meteoroid by following up on the many fireball videos posted on the internet. Aim was to better understand how the airburst was generated and what damage it caused. In addition, recovered meteorites shortly after the impact were made available by Chelyabinsk State University and South Ural State University researchers to an international Chelyabinsk Airburst Consortium, to investigate their material properties. We will describe the field campaign and discuss results from the consortium research, including the meteoroid trajectory, maps of damage and injuries, and models of meteoroid fragmentation and the generation of the shock wave, and discuss the origin and dynamical history of the Chelyabinsk meteoroid.

  18. A field scale study of nZVI Mobility

    NASA Astrophysics Data System (ADS)

    O'Carroll, D. M.; Kocur, C. M.; Chowdhury, A.; Weber, K.; Boparai, H. K.; Krol, M. M.; Sakulchaicharoen, N.; Sleep, B. E.; Austrins, L.; Peace, C.

    2011-12-01

    Nanometals have received significant attention in recent years due to their ability to rapidly destroy numerous priority source zone contaminants in controlled laboratory studies. This has led to great optimism about the potential of nanometal injection for insitu remediation. However, rapid nanometal settling, reportedly due to the ferromagnetic attractive forces between particles causing agglomeration, and poor mobility have limited widespread application of this technology. In literature studies different methods have been proposed to counteract attractive forces between nanometal particles (e.g., polymers providing steric and electrostatic repulsive forces), thus limiting agglomeration and preventing rapid settling. Although laboratory characterization of these particles confirm that these methods yield nanoscale particles that are stable and readily reactive for extended periods of time under laboratory conditions, several important uncertainties remain. The laboratory procedures for synthesizing stabilized nZVI are quite involved and labour intensive, with limited scale-up of the synthesis procedure to the field described in the literature. Furthermore, it is unclear if these nanometal particles would be of high quality and mobile in the field. In this study, these questions were addressed by scaling up laboratory synthesis techniques to produce 1000 litres of nanometal suspension at 1 g/L on site. The suspension was injected into a contaminated zone containing various chlorinated solvents. Detailed characterization of the field site before, during and after the field trial suggested that the injected nanoparticles travelled in excess of 1 m at normalized concentrations in excess of 50% and would therefore be available for contaminant destruction in the target source zone. This presentation will also discuss detailed characterization (e.g., TEM, zero valent iron content) of injected nanometals and those captured at the monitoring wells.

  19. The safety of field tubal sterilization: a cohort study.

    PubMed

    Siswosudarmo, R

    1991-01-01

    A cohort study on female sterilization has been carried out to compare the safety of field-based procedures with hospital-based procedures. A total of 217 women were recruited, consisting of 103 field-based and 114 hospital-based acceptors. Married and healthy women 20-45 years of age, having at least two living children, not obese, no history of major abdominal surgery, no signs of acute pelvic inflammatory disease, and no contraindication to ketamin were included in the study. Women with severe pelvic adhesions encountered during surgery were excluded from the study. The ambulatory procedure was used for all acceptors except those who were sterilized in hospital immediately after delivery. They were asked to come to th Sarjito Hospital (hospital-based) or Puskesmas (primary health care center or field-based), after fasting the night before. Ketamin, 50-100 mg, was used intravenously for general anesthesia. Minilaparotomy followed by the Pomeroy method was used for standard female tubal sterilization. Tetracycline, 3 x 500 mg was given for five days prophylactically. Follow-up was carried out one and six weeks after the day of operation. Data were processed with an IBM-compatible PC, using version 3.0 SPSS program. Students t-test, chi-square test and relative risk (95% confidence limit (CL)) were used for statistical analysis. Both groups were comparable in terms of age, parity, body weight, and body height. The duration of operation in the field was somewhat longer than that in the hospital, i.e. 24.58 vs 21.14 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Genetic association studies in complex disease: disentangling additional predisposing loci from associated neutral loci using a constrained - permutation approach.

    PubMed

    Spijker, G T; Nolte, I M; Jansen, R C; Te Meerman, G J

    2005-01-01

    In the process of genetically mapping a complex disease, the question may arise whether a certain polymorphism is the only causal variant in a region. A number of methods can answer this question, but unfortunately these methods are optimal for bi-allelic loci only. We wanted to develop a method that is more suited for multi-allelic loci, such as microsatellite markers. We propose the Additional Disease Loci Test (ADLT): the alleles at an additional locus are permuted within the subsample of haplotypes that have identical alleles at the predisposing locus. The hypothesis being tested is, whether the predisposing locus is the sole factor predisposing to the trait that is in LD with the additional locus under study. We applied ADLT to simulated datasets and a published dataset on Type 1 Diabetes, genotyped for microsatellite markers in the HLA-region. The method showed the expected number of false-positive results in the absence of additional loci, but proved to be more powerful than existing methods in the presence of additional disease loci. ADLT was especially superior in datasets with less LD or with multiple predisposing alleles. We conclude that the ADLT can be useful in identifying additional disease loci.

  1. On the additivity of bond dipole moments. Stark effect studies of the rotationally resolved electronic spectra of aniline, benzonitrile, and aminobenzonitrile

    NASA Astrophysics Data System (ADS)

    Borst, David R.; Korter, Timothy M.; Pratt, David W.

    2001-12-01

    We study the influence of an applied electric field on the fully resolved electronic spectra of aniline (AN), benzonitrile (BN), and 4-aminobenzonitrile (ABN) in the gas phase. Using these data, we test the commonly held but rarely proven assumption that the total dipole moment of a polyatomic molecule is the vector sum of bond dipole moments, localized in different parts of the molecule. We find that μa(ABN)≈ μa(AN)+ μa(BN) in the excited S 1 state, but not in the ground S 0 state. Possible reasons for this non-additivity are discussed.

  2. Study of intermittent field hardware failure data in digital electronics

    NASA Technical Reports Server (NTRS)

    Oneill, E. J.; Halverson, J. R.

    1980-01-01

    The collection and analysis of data concerning intermittent dailures in digital devices was performed using data from a computer design for shipboard usage. The failure data consisted of actual field failures classified by failure mechanisms and their likelihood of having been intermittent, potentially intermittent, or hard. Each class was studies with respect to computer operation in the ranges of 0 to 2,000 hours, 0 to 5, hours, and 0 to 10,000 hours. The study was done at the computer level as well as the microcircuit level. Results indicate that as age increases, the quasi-intermittent failure rate increases and the mean time to failure descreases.

  3. Does the Addition of Involved Field Radiotherapy to High-Dose Chemotherapy and Stem Cell Transplantation Improve Outcomes for Patients With Relapsed/Refractory Hodgkin Lymphoma?

    SciTech Connect

    Kahn, Shannon; Flowers, Christopher; Xu Zhiheng; Esiashvili, Natia

    2011-09-01

    Purpose: To evaluate the value of adding involved field radiotherapy (IFRT) to patients with relapsed/refractory Hodgkin lymphoma (HL) undergoing high-dose chemotherapy (HDCT) and stem cell transplantation (SCT). Methods and Materials: Ninety-two patients with relapsed/refractory HL undergoing HDCT and SCT from 1995 to 2008 were analyzed in a case-control design. Forty-six HL patients treated with IFRT within 2 months of SCT were matched to 46 HL patients who did not receive IFRT based on age, stage at relapse, timing of relapse, histology, and year of SCT. All were evaluated for response, survival, and toxicity with a median followup of 63.5 months. Results: There was a trend for better disease control in patients receiving IFRT. Specifically, 10/46 IFRT patients (22%) relapsed/progressed after SCT compared with 17/46 control patients (37%). Of the failures after IFRT, 70% were inside the radiation field, all in sites of bulky disease. In patients with nonbulky disease, IFRT also resulted in significantly improved outcomes (failure rate 6% vs. 33%, respectively). When stratified by disease bulk, the use of IFRT was found to significantly improve DFS (p = 0.032), but did not affect OS. In addition, IFRT and nonbulky disease were found to be positive prognostic indicators for DFS with hazard ratios of 0.357 (p = 0.032) and 0.383 (p = 0.034), respectively. Grade IV/V toxicities were significantly higher in the IFRT vs. non-IFRT group (28% vs. 2%; p < 0.001), observed only in patients receiving a busulfan-based conditioning regimen. Conclusion: Patients with refractory or relapsed HL undergoing HDCT and SCT have a high risk of relapse in sites of prior disease involvement, especially in sites of bulky disease. The use of IFRT is associated with a lower risk of disease progression in these sites; however bulky disease sites are still difficult to control. Toxicity risk is significant, particularly when busulfan-based conditioning is combined with IFRT, and alternative

  4. Effect of Additives on Green Sand Molding Properties using Design of Experiments and Taguchi's Quality Loss Function - An Experimental Study

    NASA Astrophysics Data System (ADS)

    Desai, Bhagyashree; Mokashi, Pavani; Anand, R. L.; Burli, S. B.; Khandal, S. V.

    2016-09-01

    The experimental study aims to underseek the effect of various additives on the green sand molding properties as a particular combination of additives could yield desired sand properties. The input parameters (factors) selected were water and powder (Fly ash, Coconut shell and Tamarind) in three levels. Experiments were planned using design of experiments (DOE). On the basis of plans, experiments were conducted to understand the behavior of sand mould properties such as compression strength, shear strength, permeability number with various additives. From the experimental results it could be concluded that the factors have significant effect on the sand properties as P-value found to be less than 0.05 for all the cases studied. The optimization based on quality loss function was also performed. The study revealed that the quality loss associated with the tamarind powder was lesser compared to other additives selected for the study. The optimization based on quality loss function and the parametric analysis using ANOVA suggested that the tamarind powder of 8 gm per Kg of molding sand and moisture content of 7% yield better properties to obtain sound castings.

  5. A Pilot Study to Examine the Effect of Additional Structured Outdoor Playtime on Preschoolers' Physical Activity Levels

    ERIC Educational Resources Information Center

    Alhassan, Sofiya; Nwaokelemeh, Ogechi; Lyden, Kate; Goldsby, TaShauna; Mendoza, Albert

    2013-01-01

    The impact of additional structured outdoor playtime on preschoolers'; physical activity (PA) level is unclear. The purpose of this pilot study was to explore the effects of increasing structured outdoor playtime on preschoolers'; PA levels. Eight full-day classrooms (n = 134 children) from two preschool programmes were randomised into a treatment…

  6. STUDY OF THE EFFECT OF CHLORINE ADDITION ON MERCURY OXIDATION BY SCR CATALYST UNDER SIMULATED SUBBITUMINOUS COAL FLUE GAS

    EPA Science Inventory

    An entrained flow reactor is used to study the effect of addition of chlorine-containing species on the oxidation of elemental mercury (Hgo)by a selective catalytic reduction (SCR) catalyst in simulated subbituminous coal combustion flue gas. The combustion flue gas was doped wit...

  7. Study on Electron Heat Diffusion Across Stochastic Magnetic Field Affected by Magnitude of Perturbed Magnetic Field in Tokomak

    NASA Astrophysics Data System (ADS)

    Gao, Hong

    2013-04-01

    Electron heat diffusion across stochastic magnetic fields is studied numerically in order to find out how the magnitude of perturbed magnetic field affect the enhanced heat conductivity and its radial profile in tokomak plasma physics. For these purposes, non-local stochastic magnetic fields are chosen as research objects in our simulation work. From our numerical results, we can find that the effects of the perturbed magnetic field magnitude are dominated parameter on the enhance electron heat transport conductivity wherever the magnetic field is single island or full stochastic field. Also, a theoretical analysis is provided and compared with numerical results.

  8. Tar Creek study, Sargent oil field, Santa Clara County, California

    USGS Publications Warehouse

    Wagner, David L.; Fedasko, Bill; Carnahan, J.R.; Brunetti, Ross; Magoon, Leslie B.; Lillis, Paul G.; Lorenson, T.D.; Stanley, Richard G.

    2002-01-01

    Field work in the Tar Creek area of Sargent oil field was performed June 26 to 28, 2000. The Santa Clara County study area is located in Sections, 30, 31, and 32, Township 11 South, Range 4 East, M.D.B&M; and in Sections 25 and 36, Township 11 South, Range 3 East, M.D.B.&M., north and south of Tar Creek, west of Highway 101. The work was a cooperative effort of the California Department of Conservation's Division of Oil, Gas, and Geothermal Resources (DOGGR), California Geological Survey (CGS), and the United States Geological Survey (USGS). The purpose of the project was to map the stratigraphy and geologic structure (David Wagner, CGS); sample oil for age dating (Les Magoon, USGS); and search for undocumented wells plus conduct a GPS survey of the area (Bill Fedasko, J.P. Carnahan, and Ross Brunetti, DOGGR)

  9. Temperature field study of hot water circulation pump shaft system

    NASA Astrophysics Data System (ADS)

    Liu, Y. Y.; Kong, F. Y.; Daun, X. H.; Zhao, R. J.; Hu, Q. L.

    2016-05-01

    In the process of engineering application under the condition of hot water circulation pump, problems of stress concentration caused by the temperature rise may happen. In order to study the temperature field in bearing and electric motor chamber of the hot water circulation pump and optimize the structure, in present paper, the model of the shaft system is created through CREO. The model is analyzed by ANSYS workbench, in which the thermal boundary conditions are applied to calculate, which include the calorific values from the bearings, the thermal loss from electric motor and the temperature from the transporting medium. From the result, the finite element model can reflect the distribution of thermal field in hot water circulation pump. Further, the results show that the maximum temperature locates in the bearing chamber.The theoretical guidance for the electric motor heat dissipation design of the hot water circulation pump can be achieved.

  10. Magnetic Field Configuration Models and Reconstruction Methods: a comparative study

    NASA Astrophysics Data System (ADS)

    Al-haddad, Nada; Möstl, Christian; Roussev, Ilia; Nieves-Chinchilla, Teresa; Poedts, Stefaan; Hidalgo, Miguel Angel; Marubashi, Katsuhide; Savani, Neel

    2012-07-01

    This study aims to provide a reference to different magnetic field models and reconstruction methods. In order to understand the dissimilarities of those models and codes, we analyze 59 events from the CDAW list, using four different magnetic field models and reconstruction techniques; force- free reconstruction (Lepping et al.(1990); Lynch et al.(2003)), magnetostatic reconstruction, referred as Grad-Shafranov (Hu & Sonnerup(2001); Mostl et al.(2009)), cylinder reconstruction (Marubashi & Lepping(2007)), elliptical, non-force free (Hidalgo et al.(2002)). The resulted parameters of the reconstructions, for the 59 events are compared, statistically, as well as in more details for some cases. The differences between the reconstruction codes are discussed, and suggestions are provided as how to enhance them. Finally we look at 2 unique cases under the microscope, to provide a comprehensive idea of the different aspects of how the fitting codes work.

  11. Teaching and Learning in the Tropics: An Epistemic Exploration of "the Field" in a Development Studies Field Trip

    ERIC Educational Resources Information Center

    Patel, Kamna

    2015-01-01

    Development studies employs theories, tools and methods often found in geography, including the international field trip to a "developing" country. In 2013 and 2014, I led a two-week trip to Ethiopia. To better comprehend the effects of "the field" on students' learning, I introduced an assessed reflexive field diary to…

  12. Growth in conventional fields in high-cost areas: a case study

    USGS Publications Warehouse

    Attanasi, E.D.

    2000-01-01

    Exploration managers commonly base future drilling decisions on past experience in an area. To do this well, they should consider both discovered and undiscovered resources to characterize total future potential. Discovery-size estimates should be adjusted to account for future field growth; otherwise, the relative efficiency of recent exploration will be undervalued. This study models and projects field growth for pre-1997 discoveries in the U.S. Federal Gulf of Mexico (GOM) Outer Continental Shelf (OCS). Projected additions to reserves for these fields from field growth through 2020 are 5.2 billion bbl of oil and 46 Tcfg. Projections include growth associated with sizable new oil discoveries in deepwater areas and initial reserve additions from new subsalt plays discovered through 1996. This article focuses on the U.S. GOM because it has produced longer than other worldwide offshore areas. Its field-growth profile may be prototypical of other offshore provinces such as the North Sea, Scotian Shelf and deepwater Angola, as well as high-cost onshore areas.

  13. Mechanistic and computational studies of the atom transfer radical addition of CCl4 to styrene catalyzed by copper homoscorpionate complexes.

    PubMed

    Muñoz-Molina, José María; Sameera, W M C; Álvarez, Eleuterio; Maseras, Feliu; Belderrain, Tomás R; Pérez, Pedro J

    2011-03-21

    Experimental as well as theoretical studies have been carried out with the aim of elucidating the mechanism of the atom transfer radical addition (ATRA) of styrene and carbon tetrachloride with a Tp(x)Cu(NCMe) complex as the catalyst precursor (Tp(x) = hydrotrispyrazolyl-borate ligand). The studies shown herein demonstrate the effect of different variables in the kinetic behavior. A mechanistic proposal consistent with theoretical and experimental data is presented.

  14. Strong enhancement of high-field critical current properties and irreversibility field of MgB2 superconducting wires by coronene active carbon source addition via the new B powder carbon-coating method

    NASA Astrophysics Data System (ADS)

    Ye, Shu Jun; Matsumoto, Akiyoshi; Chao Zhang, Yun; Kumakura, Hiroaki

    2014-08-01

    We report an effective carbon-containing additive, coronene (C24H12), for MgB2 superconducting wires. We used B powder coated with C24H12 to fabricate MgB2 wires using the powder-in-tube (PIT) and internal Mg diffusion (IMD) processes. The in-field critical current properties are strongly enhanced for both PIT- and IMD-processed MgB2 wires. For PIT MgB2 wires, a critical current density (Jc) value of 1.8 × 104 A cm-2 is obtained at 4.2 K and 10 T. For IMD MgB2 wires, we obtained a Jc of 1.07 × 105 A cm-2 and an engineering Jc (Je) of 1.12 × 104 A cm-2 at 4.2 K and 10 T. These Jc and Je values are similar to the highest values reported for MgB2 wires thus far. Furthermore, the irreversibility field, Birr, determined with a current density criterion of 100 A cm-2, is strongly enhanced to 25 T at 4.2 K, which is also the highest value reported for MgB2 superconducting wires thus far. Coronene is an active carbon source for MgB2 superconducting wires because (1) coronene has a high carbon content (96 wt%) with a small amount of hydrogen (impurity), (2) the decomposition temperature for coronene is near the reaction temperature between Mg and B, and (3) uniform dispersion of coronene on the B surface can be obtained due to the melting point of coronene being lower than the decomposition temperature. Carbon substitution for B caused by the coronene active carbon source is mainly responsible for the high field critical current properties and the high Birr obtained in this work.

  15. Field studies in architectural acoustics using Tablet PCs

    NASA Astrophysics Data System (ADS)

    Boye, Daniel

    2005-04-01

    Core requirements for the sciences within the liberal arts curriculum challenge students to become directly involved in scientific study. These requirements seek to develop scientifically literate leaders and members of society. Formal laboratory periods are not usually associated with these courses. Thus, conceptual discovery and quantitative experimentation must take place outside of the classroom. Physics 115: Musical Technology at Davidson College is such a course and contains a section dealing with architectural acoustics. Field studies in the past have been an awkward and cumbersome activity, especially for non-science majors. The emerging technology of Tablet PCs overcomes many of the problems of mobile data acquisition and analysis, and allows the students to determine the locations of the rooms to be studied. The impulse method for determining reverberation time is used and compared with calculations based on room size and absorption media. The use of Tablet PCs and the publicly available freeware Audacity in field studies investigating architectural acoustics will be discussed. [Work supported in part by the Associated Colleges of the South through their Technology Fellowship program.

  16. Nursing students’ satisfaction about their field of study

    PubMed Central

    HAKIM, ASHRAFALSADAT

    2014-01-01

    Introduction: Nowadays students' opinion is considered as a necessary factor to evaluate quality in universities. This study was performed to evaluate the nursing students' satisfaction about their field of study. Methods: The research population in this study consists of all the students of nursing studying at the second to fourth year of university (72 students). The data were collected from all the studied population. Data collection instrument was a research questionnaire. In this cross-sectional research, nursing students' satisfaction (72 students) in 6 major topics (situation of educational environment, situation of clinical environment, trainers, social image, relation to colleagues and management) was studied. The data were analyzed in SPSS, version 14, using quantitative variables and descriptive statistics including frequency distribution tables and diagrams. Results: The findings indicated that 83.3% of the students had little satisfaction as to the situation of educational environment, 47.2% about situation of clinical environment, 41.7% concerning the theoretical educational method by professors, and 41.7% as to the method of clinical education by clinical trainers. Also 47.2% were not that satisfied with the method of evaluation by the school professors, 80.6% with the method of relationship with colleagues and also 62.5% with the nursing social image. Moreover, findings indicated that 33.3% of the participants in this research were dissatisfied with the method of evaluation by clinical trainers and 50% with the method of nursing management. Conclusion: In the present study, most students had little satisfaction concerning their field of study. So it is necessary to make an attempt for continuous development of quality services. PMID:25512925

  17. Unravelling the impact of hydrocarbon structure on the fumarate addition mechanism--a gas-phase ab initio study.

    PubMed

    Bharadwaj, Vivek S; Vyas, Shubham; Villano, Stephanie M; Maupin, C Mark; Dean, Anthony M

    2015-02-14

    The fumarate addition reaction mechanism is central to the anaerobic biodegradation pathway of various hydrocarbons, both aromatic (e.g., toluene, ethyl benzene) and aliphatic (e.g., n-hexane, dodecane). Succinate synthase enzymes, which belong to the glycyl radical enzyme family, are the main facilitators of these biochemical reactions. The overall catalytic mechanism that converts hydrocarbons to a succinate molecule involves three steps: (1) initial H-abstraction from the hydrocarbon by the radical enzyme, (2) addition of the resulting hydrocarbon radical to fumarate, and (3) hydrogen abstraction by the addition product to regenerate the radical enzyme. Since the biodegradation of hydrocarbon fuels via the fumarate addition mechanism is linked to bio-corrosion, an improved understanding of this reaction is imperative to our efforts of predicting the susceptibility of proposed alternative fuels to biodegradation. An improved understanding of the fuel biodegradation process also has the potential to benefit bioremediation. In this study, we consider model aromatic (toluene) and aliphatic (butane) compounds to evaluate the impact of hydrocarbon structure on the energetics and kinetics of the fumarate addition mechanism by means of high level ab initio gas-phase calculations. We predict that the rate of toluene degradation is ∼100 times faster than butane at 298 K, and that the first abstraction step is kinetically significant for both hydrocarbons, which is consistent with deuterium isotope effect studies on toluene degradation. The detailed computations also show that the predicted stereo-chemical preference of the succinate products for both toluene and butane are due to the differences in the radical addition rate constants for the various isomers. The computational and kinetic modeling work presented here demonstrates the importance of considering pre-reaction and product complexes in order to accurately treat gas phase systems that involve intra and inter

  18. Enantioselective conjugate addition of nitro compounds to α,β-unsaturated ketones: an experimental and computational study.

    PubMed

    Manzano, Rubén; Andrés, José M; Álvarez, Rosana; Muruzábal, María D; de Lera, Ángel R; Pedrosa, Rafael

    2011-05-16

    A series of chiral thioureas derived from easily available diamines, prepared from α-amino acids, have been tested as catalysts in the enantioselective Michael additions of nitroalkanes to α,β-unsaturated ketones. The best results are obtained with the bifunctional catalyst prepared from L-valine. This thiourea promotes the reaction with high enantioselectivities and chemical yields for aryl/vinyl ketones, but the enantiomeric ratio for alkyl/vinyl derivatives is very modest. The addition of substituted nitromethanes led to the corresponding adducts with excellent enantioselectivity but very poor diastereoselectivity. Evidence for the isomerization of the addition products has been obtained from the reaction of chalcone with [D(3)]nitromethane, which shows that the final addition products epimerize under the reaction conditions. The epimerization explains the low diastereoselectivity observed in the formation of adducts with two adjacent tertiary stereocenters. Density functional studies of the transition structures corresponding to two alternative activation modes of the nitroalkanes and α,β-unsaturated ketones by the bifunctional organocatalyst have been carried out at the B3LYP/3-21G* level. The computations are consistent with a reaction model involving the Michael addition of the thiourea-activated nitronate to the ketone activated by the protonated amine of the organocatalyst. The enantioselectivities predicted by the computations are consistent with the experimental values obtained for aryl- and alkyl-substituted α,β-unsaturated ketones.

  19. The Application of Pulsed Field Gel Electrophoresis in Clinical Studies

    PubMed Central

    Parizad, Eskandar Gholami; Valizadeh, Azar

    2016-01-01

    Pulsed-field gel electrophoresis is a method applied in separating large segments of deoxyribonucleotide using an alternating and cross field. In a uniform magnetic field, components larger than 50kb pass a route through the gel and since the movement of DNA (Deoxyribonucleic acid) molecules are in a Zigzag form, separation of DNAs as bands carried out better via gel. PFGE in microbiology is a standard method which is used for typing of bacteria. It is also a very useful tool in epidemiological studies and gene mapping in microbes and mammalian cell, also motivated development of large-insert cloning system such as bacterial and yeast artifical chromosomes. In this method, close and similar species in terms of genetic patterns show alike profiles regarding DNA separation, and those ones which don’t have similarity or are less similar, reveal different separation profiles. So this feature can be used to determine the common species as the prevalence agent of a disease. PFGE can be utilized for monitoring and evaluating different micro-organisms in clinical samples and existing ones in soil and water. This method can also be a reliable and standard method in vaccine preparation. In recent decades, PFGE is highly regarded as a powerful tool in control, prevention and monitoring diseases in different populations. PMID:26894068

  20. Cryogenic apparatus for study of near-field heat transfer.

    PubMed

    Kralik, T; Hanzelka, P; Musilova, V; Srnka, A; Zobac, M

    2011-05-01

    For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 10(0) to 10(3) μm. The heat transferred from the hot (10 - 100 K) to the cold sample (∼5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within ∼2 nW∕cm(2) and ∼30 μW∕cm(2) is derived from the temperature drop along the thermal resistor. For tungsten samples, the distance of the near-field effect onset was inversely proportional to temperature and the heat power increase was observed up to three orders of magnitude greater than the power of far-field radiative heat transfer.

  1. Cryogenic apparatus for study of near-field heat transfer

    SciTech Connect

    Kralik, T.; Hanzelka, P.; Musilova, V.; Srnka, A.; Zobac, M.

    2011-05-15

    For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 10{sup 0} to 10{sup 3} {mu}m. The heat transferred from the hot (10 - 100 K) to the cold sample ({approx}5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within {approx}2 nW/cm{sup 2} and {approx}30 {mu}W/cm{sup 2} is derived from the temperature drop along the thermal resistor. For tungsten samples, the distance of the near-field effect onset was inversely proportional to temperature and the heat power increase was observed up to three orders of magnitude greater than the power of far-field radiative heat transfer.

  2. Cryogenic apparatus for study of near-field heat transfer.

    PubMed

    Kralik, T; Hanzelka, P; Musilova, V; Srnka, A; Zobac, M

    2011-05-01

    For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 10(0) to 10(3) μm. The heat transferred from the hot (10 - 100 K) to the cold sample (∼5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within ∼2 nW∕cm(2) and ∼30 μW∕cm(2) is derived from the temperature drop along the thermal resistor. For tungsten samples, the distance of the near-field effect onset was inversely proportional to temperature and the heat power increase was observed up to three orders of magnitude greater than the power of far-field radiative heat transfer. PMID:21639537

  3. Cryogenic apparatus for study of near-field heat transfer

    NASA Astrophysics Data System (ADS)

    Kralik, T.; Hanzelka, P.; Musilova, V.; Srnka, A.; Zobac, M.

    2011-05-01

    For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 100 to 103 μm. The heat transferred from the hot (10 - 100 K) to the cold sample (˜5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within ˜2 nW/cm2 and ˜30 μW/cm2 is derived from the temperature drop along the thermal resistor. For tungsten samples, the distance of the near-field effect onset was inversely proportional to temperature and the heat power increase was observed up to three orders of magnitude greater than the power of far-field radiative heat transfer.

  4. Biosorption of metal contaminants using immobilized biomass--Field studies

    SciTech Connect

    Jeffers, T.H.; Bennett, P.G.; Corwin, R.R.

    1993-01-01

    The US Bureau of Mines has developed porous beads containing immobilized biological materials such as sphagnum peat moss for extracting metal contaminants from waste waters. The beads, designated as BIO-FIX beads, have removed toxic metals from over 100 waters in laboratory tests. These waters include acid mine drainage (AMD) water from mining sites, metallurgical and chemical industry waste water, and contaminated ground water. Following the laboratory studies, cooperative field tests were conducted to evaluate the metal adsorption properties of the beads in column and low-maintenance circuits, determine bead stability in varied climatic situations, and demonstrate the beads' potential as a viable waste water treatment technique. Field results indicated that BIO-FIX beads readily adsorbed cadmium, lead, and other toxic metals from dilute waters; effluents frequently met drinking water standards and other discharge criteria. The beads exhibited excellent handling characteristics in both column and low-maintenance circuits, and continued to extract metal ions after repeated loading-elution cycles. Based on laboratory and field data, cost evaluations for using BIO-FIX technology to treat two AMD waters were prepared. Operating costs for BIO-FIX treatment, which ranged from $1.40 to $2.30 per 1,000 gal of water treated, were comparable with chemical precipitation costs.

  5. Experimental study on the effect of applying a crossed magnetic field on the insulator flashover behavior in high vacuum

    NASA Astrophysics Data System (ADS)

    Abu-Elabass, K.

    2015-09-01

    In this study, a possible method of reducing the flashover stress is achieved by the effect of an additional magnetic field in the transverse direction on the main applied electric field. The degree of vacuum used in this study was 5×10-5 Pa. The magnetic flux density B employed in this study extends from 4×10-3 to 24×10-3 T. From the results obtained throughout this work, the transverse magnetic field increases the flashover voltage and decreases the leakage current. The effect of the transverse magnetic field on the surface flashover of the dielectric solid in vacuum shows a marked dependence on the material and the thickness of the test specimen, the vacuum degree, the type of electric field (AC or DC) as well as the type of magnetic field (AC or DC).

  6. Classroom HVAC: Improving ventilation and saving energy -- field study plan

    SciTech Connect

    Apte, Michael G.; Faulkner, David; Hodgson, Alfred T.; Sullivan, Douglas P.

    2004-10-14

    The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms (CRs) with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many CRs are under-ventilated, and public concerns about indoor environmental quality in CRs. This document provides a summary of the detailed plans developed for the field study that will take place in 2005 to evaluate the energy and IAQ performance of a new classroom HVAC technology. The field study will include measurements of HVAC energy use, ventilation rates, and IEQ conditions in 10 classrooms with the new HVAC technology and in six control classrooms with a standard HVAC system. Energy use and many IEQ parameters will be monitored continuously, while other IEQ measurements will be will be performed seasonally. Continuously monitored data will be remotely accessed via a LonWorks network. Instrument calibration plans that vary with the type of instrumentation used are established. Statistical tests will be employed to compare energy use and IEQ conditions with the new and standard HVAC systems. Strengths of this study plan include the collection of real time data for a full school year, the use of high quality instrumentation, the incorporation of many quality control measures, and the extensive collaborations with industry that limit costs to the sponsors.

  7. Study of pattern fabrication model using near-field photolithography.

    PubMed

    Yang, Ching-Been

    2011-01-01

    This study established a pattern fabrication model for near-field photolithography (NFP) and conducted pattern fabrication and analysis to understand the process of NFP. This study proposed that exposure energy density can accumulate when two exposure beams overlap. We also presented a method to analyze the exposure energy density of patterns and an error function derived from the results of the exposure energy simulation and the maximum exposure energy density. Using the Levenberg-Marquardt method and a reasonable convergence criterion, the exposure interval of two line segments for optimum pattern flatness was obtained. A simulation of the pattern fabrication model showed that when the exposure interval S = 1.66ρ(0) , optimum flatness could be obtained. The results of this study have potential for industrial application in fabrication of micro- and nano-scale channels.

  8. A study of internal structure in components made by additive manufacturing process using 3 D X-ray tomography

    SciTech Connect

    Raguvarun, K. Balasubramaniam, Krishnan Rajagopal, Prabhu; Palanisamy, Suresh; Nagarajah, Romesh; Kapoor, Ajay; Hoye, Nicholas; Curiri, Dominic

    2015-03-31

    Additive manufacturing methods are gaining increasing popularity for rapidly and efficiently manufacturing parts and components in the industrial context, as well as for domestic applications. However, except when used for prototyping or rapid visualization of components, industries are concerned with the load carrying capacity and strength achievable by additive manufactured parts. In this paper, the wire-arc additive manufacturing (AM) process based on gas tungsten arc welding (GTAW) has been examined for the internal structure and constitution of components generated by the process. High-resolution 3D X-ray tomography is used to gain cut-views through wedge-shaped parts created using this GTAW additive manufacturing process with titanium alloy materials. In this work, two different control conditions for the GTAW process are considered. The studies reveal clusters of porosities, located in periodic spatial intervals along the sample cross-section. Such internal defects can have a detrimental effect on the strength of the resulting AM components, as shown in destructive testing studies. Closer examination of this phenomenon shows that defect clusters are preferentially located at GTAW traversal path intervals. These results highlight the strong need for enhanced control of process parameters in ensuring components with minimal defects and higher strength.

  9. Simulation studies of wide and medium field of view earth radiation data analysis

    NASA Technical Reports Server (NTRS)

    Green, R. N.

    1978-01-01

    A parameter estimation technique is presented to estimate the radiative flux distribution over the earth from radiometer measurements at satellite altitude. The technique analyzes measurements from a wide field of view (WFOV), horizon to horizon, nadir pointing sensor with a mathematical technique to derive the radiative flux estimates at the top of the atmosphere for resolution elements smaller than the sensor field of view. A computer simulation of the data analysis technique is presented for both earth-emitted and reflected radiation. Zonal resolutions are considered as well as the global integration of plane flux. An estimate of the equator-to-pole gradient is obtained from the zonal estimates. Sensitivity studies of the derived flux distribution to directional model errors are also presented. In addition to the WFOV results, medium field of view results are presented.

  10. Comparative studies of color fields, visual acuity fields, and movement perception limits among varsity athletes and non-varsity groups.

    PubMed

    Mizusawa, K; Sweeting, R L; Knouse, S B

    1983-06-01

    This paper examined effects of sports practice on patterns of color fields, limits of peripheral movement perception, and visual acuity field by comparing varsity ball players and non-varsity control groups. The first study measured extent of color fields and limits of horizontal and vertical meridians for peripheral movement perception of 139 college students. The second study tested visual acuity fields of female and male basketball players and female and male controls. The first study indicated that athletes had wider limits for horizontal movement perception, while the non-athletes had better vertical movement perception limits. Basketball players demonstrated color fields and limits for peripheral movement perception superior to those of soccer players. In the second study, athletes did not have any wider visual acuity fields than non-athletes, but their movement-perception limits were significantly wider than those of non-athletes.

  11. Ex-situ experimental studies on serpentine flow field design for redox flow battery systems

    NASA Astrophysics Data System (ADS)

    Jyothi Latha, T.; Jayanti, S.

    2014-02-01

    Electrolyte distribution using parallel flow field for redox flow battery (RFB) applications shows severe non-uniformity, while the conventional design of using the carbon felt itself as the flow distributor gives too high pressure drop. An optimized flow field design for uniform flow distribution at a minimal parasitic power loss is therefore needed for RFB systems. Since the materials and geometrical dimensions in RFBs are very different from those used in fuel cells, the hydrodynamics of the flow fields in RFBs is likely to be very different. In the present paper, we report on a fundamental study of the hydrodynamics of a serpentine flow field relevant to RFB applications. The permeability of the porous medium has been measured under different compression ratios and this is found to be in the range of 5-8 × 10-11 m2. The pressure drop in two serpentine flow fields of different geometric characteristics has been measured over a range of Reynolds numbers. Further analysis using computational fluid dynamics simulations brings out the importance of the compression of the porous medium as an additional parameter in determining the flow distribution and pressure drop in these flow fields.

  12. Human aquaporin 4 gating dynamics in dc and ac electric fields: A molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Garate, J.-A.; English, Niall J.; MacElroy, J. M. D.

    2011-02-01

    Water self-diffusion within human aquaporin 4 has been studied using molecular dynamics (MD) simulations in the absence and presence of external ac and dc electric fields. The computed diffusive (pd) and osmotic (pf) permeabilities under zero-field conditions are (0.718 ± 0.24) × 10-14 cm3 s-1 and (2.94 ± 0.47) × 10-14 cm3 s-1, respectively; our pf agrees with the experimental value of (1.50 ± 0.6) × 10-14 cm3 s-1. A gating mechanism has been proposed in which side-chain dynamics of residue H201, located in the selectivity filter, play an essential role. In addition, for nonequilibrium MD in external fields, it was found that water dipole orientation within the constriction region of the channel is affected by electric fields (e-fields) and that this governs the permeability. It was also found that the rate of side-chain flipping motion of residue H201 is increased in the presence of e-fields, which influences water conductivity further.

  13. Field study of disposed solid wastes from advanced coal processes

    SciTech Connect

    Not Available

    1992-01-01

    Radian Corporation and the North Dakota Energy and Environmental Research Center (EERC) are funded to develop information to be used by private industry and government agencies for managing solid wastes produced by advanced coal combustion processes. This information will be developed by conducting several field studies on disposed wastes from these processes. Data will be collected to characterize these wastes and their interactions with the environments in which they are disposed. Three sites were selected for the field studies: Colorado Ute's fluidized bed combustion (FBC) unit in Nucla, Colorado; Ohio Edison's limestone injection multistage burner (LIMB) retrofit in Lorain, Ohio; and Freeman United's mine site in central Illinois with wastes supplied by the nearby Midwest Grain FBC unit. During the past year, field monitoring and sampling of the four landfill test cases constructed in 1989 and 1991 has continued. Option 1 of the contract was approved last year to add financing for the fifth test case at the Freeman United site. The construction of the Test Case 5 cells is scheduled to begin in November, 1992. Work during this past year has focused on obtaining data on the physical and chemical properties of the landfilled wastes, and on developing a conceptual framework for interpreting this information. Results to date indicate that hydration reactions within the landfilled wastes have had a major impact on the physical and chemical properties of the materials but these reactions largely ceased after the first year, and physical properties have changed little since then. Conditions in Colorado remained dry and no porewater samples were collected. In Ohio, hydration reactions and increases in the moisture content of the waste tied up much of the water initially infiltrating the test cells.

  14. Delineation of Hydrocarbon Contamination of Soils and Sediments With Environmental Magnetic Methods: Laboratory and Field Studies

    NASA Astrophysics Data System (ADS)

    Rijal, M. L.; Appel, E.; Porsch, K.; Kappler, A.; Blaha, U.; Petrovsky, E.

    2008-12-01

    Hydrocarbon contamination of soils and sediments is a worldwide environmental problem. The present research focuses on the study of magnetic properties of hydrocarbon contaminated soils and sediments using environmental magnetic methods both on field sites as well as in laboratory batch experiments. The main objectives of this research are i) to determine a possible application of magnetic proxies for the delineation of organic contamination in soils and sediments and ii) to examine the role of bacteria in changing soil magnetic properties after hydrocarbon contamination. A former oil field and a former military site which are heavily contaminated with hydrocarbons were studied. Additionally, three different types of natural clean soils were investigated in laboratory experiments by simulating hydrocarbon contamination in sterile and microbial active setups. Magnetic properties, soil properties, iron bioavailability, iron redox state and hydrocarbon content of samples were measured. Additionally, magnetic susceptibility (MS) was monitored weekly in laboratory batch set-ups during several months. Results from the field sites showed that there is an increase of MS and a good correlation between MS and hydrocarbon content. A weekly monitored MS result from the laboratory study clearly indicated~~10% change (increase as well as decrease) of initial MS of respective soils only in microbial active set-ups with saturation after a few weeks of experimental period. This depicts that there is a change of MS caused by microbial iron mineral transformation in presence of hydrocarbon contamination in soils. The results from the field study demonstrate that magnetic proxies can be used to localize hydrocarbon contamination. However, more field sites with hydrocarbon contaminated soils and sediments need to be investigated by using environmental magnetic methods for better understanding the factors driving such changes in magnetic properties.

  15. Field-induced magnetostructural transition in Gd5ge4 studied by pulsed magnetic fields

    SciTech Connect

    Ouyang, Z.W.; Nojiri, H.; Yoshii, S.; Rao, G.H.; Wang, Y.C.; Pecharsky, V.K.; Gschneidner Jr., K.A.

    2008-05-22

    The field-induced magnetostructural transformation in Gd{sub 5}Ge{sub 4} was examined by magnetization measurements in pulsed magnetic fields. The low-temperature irreversibility of the transition can be destroyed by the magnetocaloric effect, and depending on the heat exchange between the sample and its surroundings, the irreversibility (or kinetic arrest) can also be retained. Measurements by using various magnetic-field sweep rates were conducted to examine the dynamic response of the system in the transition region. The critical fields for the magnetostructural transition below 20 K are field sweep rate dependent--the larger the field sweep rate, the higher the critical field. However, this rate dependence is readily suppressed with increasing temperature.

  16. Numerical study of the magnetic field diffusion in the toroidal field coils of the TFTR

    SciTech Connect

    Preis, H.

    1983-01-01

    The diffusion of the vertical magnetic field through the toroidal field coils is numerically analyzed in TFTR. Two different excitations of the vertical field are assumed whose behavior can be described by either a step function or a ramp function. Using the computer code FEDIFF, the distribution of the eddy currents in the windings and casing of the toroidal field coils, as well as their time behavior, is calculated for these functions. From integration of the eddy current functions over their pulse length, the energy dissipated by them is obtained. Finally, the magnetic field of the eddy currents within the torous is calculated. Based upon this field, which is represented as a function of time and space coordinates, the influence of this diffusion upon the field curvature index is described.

  17. Impact of additional Pt and NiSi crystal orientation on channel stress induced by Ni silicide film in metal-oxide-semiconductor field-effect transistors

    NASA Astrophysics Data System (ADS)

    Mizuo, Mariko; Yamaguchi, Tadashi; Kudo, Shuichi; Hirose, Yukinori; Kimura, Hiroshi; Tsuchimoto, Jun-ichi; Hattori, Nobuyoshi

    2014-01-01

    The impact of additional Pt and Ni monosilicide (NiSi) crystal orientation on channel stress from Ni silicide in metal-oxide-semiconductor field-effect transistors (MOSFETs) has been demonstrated. The channel stress generation mechanism can be explained by the NiSi crystal orientation. In pure Ni silicide films, the channel stress in the p-type substrate is much larger than that in the n-type one, since the NiSi a-axis parallel to the channel direction is strongly aligned on the p-type substrate compared with on the n-type one. On the other hand, in NiPt silicide films, the difference in the channel stress between the p- and n-type substrates is small, because the NiSi crystal orientation on the p-type substrate is similar to that on the n-type one. These results can be explained by the Pt segregation at the interface between the NiSi film and the Si surface. Segregated Pt atoms cause the NiSi b-axis to align normal to the Si(001) surface in the nucleation step owing to the expansion of the NiSi lattice spacing at the NiSi/Si interface. Furthermore, the Pt segregation mechanism is considered to be caused by the grain boundary diffusion in the Ni2Si film during NiSi formation. We confirmed that the grains of Ni2Si on the p-type substrate are smaller than those on the n-type one. The Ni2Si film on the p-type substrate has more grain boundary diffusion paths than that on the n-type one. Therefore, the amount of Pt segregation at the NiSi/Si interface on the p-type substrate is larger than that on the n-type one. Consequently, the number of NiSi grains with the b-axis aligned normal to the Si(001) in the p-type substrate is larger than that in the n-type one. As a result, the channel stress induced by NiPt silicide in PMOS is larger than that in NMOS. According to this mechanism, controlling the Pt concentration at the NiSi/Si interface is one of the key factors for channel stress engineering.

  18. Studies on animal schistosomes in Peninsular Malaysia: record of naturally infected animals and additional hosts of Schistosoma spindale.

    PubMed

    Inder Singh, K; Krishnasamy, M; Ambu, S; Rasul, R; Chong, N L

    1997-06-01

    Surveillance studies on cercarial dermatitis were carried out in paddy growing areas in Peninsular Malaysia. It was observed that dermatitis in paddy planters occurred in paddy fields which were cultivated using animals such as bafflos or fields where domestic animals were allowed to graze during the off planting season as these animals harbored the parasite. The causative agent of cercarial dermatitis was Schistosoma spindale. A total of 215 small mammals trapped from Alor Setar and 126 trapped from Labu were examined for the schistosome. In Alor Setar Bandicota indica, Rattus argentiventer and Rattus rattus diardii were the only wild mammals found to be infected with the parasite, while in the Labu areas only Rattus tiomanicus jalorensis was positive for the schistosome. The occurrence of S. spindale in R. argentiventer and R.r. diardii in Alor Setar and in R.t. jalorensis in Labu constitute new host and geographic distribution records of the schistosome.

  19. Bioaerosol sampling: sampling mechanisms, bioefficiency and field studies.

    PubMed

    Haig, C W; Mackay, W G; Walker, J T; Williams, C

    2016-07-01

    Investigations into the suspected airborne transmission of pathogens in healthcare environments have posed a challenge to researchers for more than a century. With each pathogen demonstrating a unique response to environmental conditions and the mechanical stresses it experiences, the choice of sampling device is not obvious. Our aim was to review bioaerosol sampling, sampling equipment, and methodology. A comprehensive literature search was performed, using electronic databases to retrieve English language papers on bioaerosol sampling. The review describes the mechanisms of popular bioaerosol sampling devices such as impingers, cyclones, impactors, and filters, explaining both their strengths and weaknesses, and the consequences for microbial bioefficiency. Numerous successful studies are described that point to best practice in bioaerosol sampling, from the use of small personal samplers to monitor workers' pathogen exposure through to large static samplers collecting airborne microbes in various healthcare settings. Of primary importance is the requirement that studies should commence by determining the bioefficiency of the chosen sampler and the pathogen under investigation within laboratory conditions. From such foundations, sampling for bioaerosol material in the complexity of the field holds greater certainty of successful capture of low-concentration airborne pathogens. From the laboratory to use in the field, this review enables the investigator to make informed decisions about the choice of bioaerosol sampler and its application.

  20. Practical use of video imagery in nearshore oceanographic field studies

    USGS Publications Warehouse

    Holland, K.T.; Holman, R.A.; Lippmann, T.C.; Stanley, J.; Plant, N.

    1997-01-01

    An approach was developed for using video imagery to quantify, in terms of both spatial and temporal dimensions, a number of naturally occurring (nearshore) physical processes. The complete method is presented, including the derivation of the geometrical relationships relating image and ground coordinates, principles to be considered when working with video imagery and the two-step strategy for calibration of the camera model. The techniques are founded on the principles of photogrammetry, account for difficulties inherent in the use of video signals, and have been adapted to allow for flexibility of use in field studies. Examples from field experiments indicate that this approach is both accurate and applicable under the conditions typically experienced when sampling in coastal regions. Several applications of the camera model are discussed, including the measurement of nearshore fluid processes, sand bar length scales, foreshore topography, and drifter motions. Although we have applied this method to the measurement of nearshore processes and morphologic features, these same techniques are transferable to studies in other geophysical settings.

  1. Bioaerosol sampling: sampling mechanisms, bioefficiency and field studies.

    PubMed

    Haig, C W; Mackay, W G; Walker, J T; Williams, C

    2016-07-01

    Investigations into the suspected airborne transmission of pathogens in healthcare environments have posed a challenge to researchers for more than a century. With each pathogen demonstrating a unique response to environmental conditions and the mechanical stresses it experiences, the choice of sampling device is not obvious. Our aim was to review bioaerosol sampling, sampling equipment, and methodology. A comprehensive literature search was performed, using electronic databases to retrieve English language papers on bioaerosol sampling. The review describes the mechanisms of popular bioaerosol sampling devices such as impingers, cyclones, impactors, and filters, explaining both their strengths and weaknesses, and the consequences for microbial bioefficiency. Numerous successful studies are described that point to best practice in bioaerosol sampling, from the use of small personal samplers to monitor workers' pathogen exposure through to large static samplers collecting airborne microbes in various healthcare settings. Of primary importance is the requirement that studies should commence by determining the bioefficiency of the chosen sampler and the pathogen under investigation within laboratory conditions. From such foundations, sampling for bioaerosol material in the complexity of the field holds greater certainty of successful capture of low-concentration airborne pathogens. From the laboratory to use in the field, this review enables the investigator to make informed decisions about the choice of bioaerosol sampler and its application. PMID:27112048

  2. Doppler lidar studies of atmospheric wind field dynamics

    NASA Technical Reports Server (NTRS)

    Hardesty, R. M.; Post, M. J.; Lawrence, T. R.; Hall, F. F., Jr.

    1986-01-01

    For the past 5 years the Wave Propagation Lab. has operated a pulsed CO2 Doppler lidar system to evaluate coherent laser radar technology and to investigate applications of the technique in atmospheric research. The capability of the system to provide measurements of atmospheric winds, backscatter, and water vapor has been extensively studied over this period. Because Doppler lidar can measure atmospheric wind structure in the clear air without degradation by terrain features, it offers a unique capability as a research tool for studies of many transient or local scale atmospheric events. This capability was demonstrated in recent field experiments near Boulder, Colo. and Midland, Tex., in which the lidar clearly depicted the wind field structure associated with several types of phenomena, including thunderstorm microbursts, valley drainage flow, and passage of a dryline front. To improve sensitivity during the periods of low aerosol backscatter, the system has recently been upgraded with new transmitter/receiver hardware. The upgraded system, which transmit 2 J per pulse of output energy at a rate of 50 Hz and incorporates computer control for automated operation, underwent calibration testing during the spring of 1986.

  3. A model study of the role of workfunction variations in cold field emission from microstructures with inclusion of field enhancements

    NASA Astrophysics Data System (ADS)

    Qiu, H.; Joshi, R. P.; Neuber, A.; Dickens, J.

    2015-10-01

    An analytical study of field emission from microstructures is presented that includes position-dependent electric field enhancements, quantum corrections due to electron confinement and fluctuations of the workfunction. Our calculations, applied to a ridge microstructure, predict strong field enhancements. Though quantization lowers current densities as compared to the traditional Fowler-Nordheim process, strong field emission currents can nonetheless be expected for large emitter aspect ratios. Workfunction variations arising from changes in electric field penetration at the surface, or due to interface defects or localized screening, are shown to be important in enhancing the emission currents.

  4. Wide Field X-Ray Telescope Mission Concept Study Results

    NASA Technical Reports Server (NTRS)

    Hopkins, R. C.; Thomas, H. D.; Fabisinski, L. L.; Baysinger, M.; Hornsby, L. S.; Maples, C. D.; Purlee, T. E.; Capizzo, P. D.; Percy, T. K.

    2014-01-01

    The Wide Field X-Ray Telescope (WFXT) is an astrophysics mission concept for detecting and studying extra-galactic x-ray sources, including active galactic nuclei and clusters of galaxies, in an effort to further understand cosmic evolution and structure. This Technical Memorandum details the results of a mission concept study completed by the Advanced Concepts Office at NASA Marshall Space Flight Center in 2012. The design team analyzed the mission and instrument requirements, and designed a spacecraft that enables the WFXT mission while using high heritage components. Design work included selecting components and sizing subsystems for power, avionics, guidance, navigation and control, propulsion, structures, command and data handling, communications, and thermal control.

  5. A field study of pollutant deposition in radiation fog

    SciTech Connect

    Waldman, J.M.; Jacob, D.J.; Munger, J.W.; Hoffman, M.R.

    1986-04-01

    Deposition during fog episodes can make a significant contribution to the overall flux of pollutants in certain ecosystems. Furthermore, when atmospheric stagnation prevents normal ventilation in a region, fog deposition may become the main route of pollutant removal. Fogs can consequently exert dominant control over pollutant levels in certain atmospheres. The southern San Joaquin Valley (SJV) of California is a region prone to wintertime episodes of atmospheric stagnation. These lead to elevated pollutant concentrations and/or dense, widespread fogs. Major oil-recovery operations plus widespread agricultural and livestock feeding activities are important sources of SO/sub 2/, NO/sub X/ and NH/sub 3/ in the valley. A multifaceted program of field monitoring was conducted in the SJV during the winter 1984-1985, focusing on aspects of pollutant scavenging and removal in the fog-laden atmosphere. Concentrations of major species were measured in gas, dry aerosol and fogwater phases. In addition, depositional fluxes were monitored by surrogate-surface methods. These measurements were employed to directly assess the magnitude of removal enhancement by fog.

  6. Colloid Mobilization in Two Atlantic Coastal Plain Aquifers: Field Studies

    NASA Astrophysics Data System (ADS)

    Ryan, Joseph N.; Gschwend, Philip M.

    1990-02-01

    The geochemical mechanisms leading to the mobilization of colloids in groundwater were investigated in the Pine Barrens of New Jersey and in rural central Delaware by sampling pairs of wells screened in oxic and anoxic groundwaters in the same geologic formations. Samples were carefully taken at very low flow rates (˜100 mL min-1) to avoid suspending immobilized particles. The colloidal matter was characterized by light-scattering photometry, scanning electron microscopy, energy-dispersive X ray analysis, microelectrophoresis, and Fe, Al, Si, and organic carbon analyses. The colloids, composed primarily of clays, were observed at high concentrations (up to 60 mg colloids/L) in the anoxic groundwaters, while the oxic groundwaters exhibited ≤1 mg colloids/L. Colloidal organic carbon was present in all groundwaters; but under anoxic conditions, one-third to one-half of the total organic carbon was associated with the inorganic colloids. The field evidence indicates that anoxic conditions cause the mobilization of soil colloids by dissolving the ferric oxyhydroxide coatings cementing the clay particles to the aquifer solids. The depletion of oxidized iron on the surfaces of immobile particles and the addition of organic carbon coatings on the soil particles and colloids apparently stabilizes the colloidal suspension in the anoxic groundwaters.

  7. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  8. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  9. Microstructural Development and Technical Challenges in Laser Additive Manufacturing: Case Study with a 316L Industrial Part

    NASA Astrophysics Data System (ADS)

    Marya, Manuel; Singh, Virendra; Marya, Surendar; Hascoet, Jean Yves

    2015-08-01

    Additive manufacturing (AM) brings disruptive changes to the ways parts, and products are designed, fabricated, tested, qualified, inspected, marketed, and sold. These changes introduce novel technical challenges and concerns arising from the maturity and diversity of today's AM processes, feedstock materials, and process parameter interactions. AM bears a resemblance with laser and electron beam welding in the so-called conduction mode, which involves a multitude of dynamic physical events between the projected feedstock and a moving heat source that eventually influence AM part properties. For this paper, an air vent was selected for its thin-walled, hollow, and variable cross section, and limited size. The studied air vents, randomly selected from a qualification batch, were fabricated out of 316L stainless steel using a 4 kW fiber laser powder-fed AM system, referred to as construction laser additive direct (CLAD). These were systematically characterized by microhardness indentation, visual examination, optical and scanning electron microscopy, and electron-back-scattering diffraction in order to determine AM part suitability for service and also broadly discuss metallurgical phenomena. The paper then briefly expands the discussion to include additional engineering alloys and further analyze relationships between AM process parameters and AM part properties, consistently utilizing past experience with the same powder-fed CLAD 3D printer, the well-established science and technology of welding and joining, and recent publications on additive manufacturing.

  10. Cathodoluminescence studies of nanocrystalline silicon films for field emission displays

    NASA Astrophysics Data System (ADS)

    Biaggi Labiosa, Azlin M.

    The cathodoluminescence (CL) emission from p-type porous silicon (PSi) films excited with low energy electron beams compatible with field emission display (FED) technologies was investigated. First, a study was carried out to find the optimal PSi configuration that would yield the strongest CL emission. It was found that the highest, stable CL intensities were obtained from samples prepared from p-type wafers with resistivity between 1-2 Ocm. Afterwards, the effects on the morphological details and the chemical composition due to the electron irradiation of the PSi films were studied. During a continuous irradiation of 10 hours the CL intensity of the films reduced in less than 10%. In situ SIMS analyses before and after prolonged e-beam excitation showed minor compositional changes of the film and reduced sputtering of the silicon nanoparticles due to the electron irradiation. It was also found that the electron bombardment causes microscale morphological modifications of the films, but the nanoscale features appear to be unchanged. The structural changes are manifested by the increase in the density of the nanoparticles which explains the significant enhancement of the photoluminescence (PL) that follows the electron irradiation. Second, after a thorough characterization of the PSi films under electron irradiation, tuning of the CL emission of PSi films was investigated. The PSi films used for this experiment were non-oxidized films unlike the ones used for the CL characterization that were oxidized films. The tuning was achieved by controlling the average size of the nanostructure thus showing that the origin of this CL emission is associated with the quantum confinement and the surface chemistry effects that are known to exist in the porous silicon system. However, the CL emission obtained from these samples was unstable which is attributed to the breaking of Si--H bonds due to the electron irradiation. Dangling bonds are then formed on the surface and this in

  11. Effect of One Percent Chlorhexidine Addition on the Antibacterial Activity and Mechanical Properties of Sealants: An in vitro Study

    PubMed Central

    Asokan, Sharath; John, J Baby; Priya, PR Geetha; Devi, Jagadeesan Gnana

    2015-01-01

    ABSTRACT Aim: The aim of the study was to evaluate the effect of addition of 1% chlorhexidine digluconate solution on the antibacterial activity and mechanical properties of glass ionomer and resin based sealant. Materials and methods: Conventional glass ionomer sealant (GIS) (Fuji VII, Japan) and resin sealant (Clinpro 3M ESPE, USA) were used in this study. Chlorhexidine digluconate (CHX) (20%) liquid was added to both the sealants, and the concentration of chlorhexidine in sealants was adjusted to 1%. The sealants were divided into four groups as: group A (GIS), group B (GIS + 1% CHX), group C (resin sealant), group D (resin sealant + 1% CHX). Five cylindrical specimens were prepared in each group. Their antibacterial activity against Streptococcus mutans and Lactobacillus acidophilus, and their mechanical properties (compressive strength and diametrical tensile strength) were assessed. Mann-Whitney and Wilcoxon signed rank test were used appropriately for statistical analysis (SPSS version 19). Result: Addition of one percent chlorhexidine significantly increased the antibacterial activity of both the sealants. There was a significant difference between groups A and B (p < 0.009), and groups C and D (p < 0.008). There was no significant difference in the mechanical properties of the sealants. Conclusion: Addition of one percent chlorhexidine to the glass ionomer and resin based sealants provided sufficient antibacterial activity, without significantly affecting the mechanical property of the sealants. How to cite this article: Shanmugaavel AK, Asokan S, John JB, Geetha Priya PR, Gnana Devi J. Effect of one percent Chlorhexidine Addition on the Antibacterial Activity and Mechanical Properties of Sealants: An in vitro Study. Int J Clin Pediatr Dent 2015;8(3):196-201. PMID:26628854

  12. A study on the effect of halloysite nanoparticle addition on the strength of glass fiber reinforced plastic

    NASA Astrophysics Data System (ADS)

    Kim, Yun-Hae; Park, Soo-Jeong; Lee, Jin-Woo; Moon, Kyung-Man

    2015-03-01

    Halloysite nanotube, which has been used in the polymer, has been spotlighted as a useful functional materials in the improvement of mechanical properties. In the current study, we established the optimal nanoparticle dispersion and analyzed the mechanical characteristics and the behavior of composites reinforced by HNTs have been synthesized by dispersing HNTs to the unsaturated polyester resin (UPR) and their mechanical characteristics, especially the tensile strength, interlaminar shear strength have been analyzed. Additionally, the reinforcement effect and its variation according to the amount of HNTs was also studied.

  13. Investigation of exposure to Extremely Low Frequency (ELF) magnetic and electric fields: Ongoing animal studies

    SciTech Connect

    Anderson, L.E.

    1994-03-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Three major challenges exist for ongoing research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) researchers do not as yet understand what physical aspects of exposure produce biological responses, and (3) health consequences resulting from ELF exposure are unknown. Although no animal studies clearly demonstrate deleterious effects of ELF fields, several are suggestive of potential health impacts. From the perspective of laboratory animal studies, this paper will discuss biological responses to ELF magnetic and/or electric field exposures.

  14. Leaching of coal combustion products: Field and laboratory studies

    NASA Astrophysics Data System (ADS)

    Cheng, Chin-Min

    This study combines field monitoring and laboratory experiments to investigate the environmental impacts associated with the re-use of coal combustion by-products (CCPs). The monitoring data obtained from two full-scale CCP applications (i.e., re-use of fixated flue gas desulfurization (FGD) material as a low permeability liner for a swine manure pond and portland cement concrete pavements containing CCPs) allowed environmental impacts to be evaluated under real or simulated in-service conditions. A complimentary laboratory leaching study elucidated fundamental physical and chemical mechanisms that determine the leaching kinetics of inorganic contaminants from CCPs. In the first field study, water quality impacts associated with the re-use of FGD material as a low permeability liner for a swine manure pond were examined by monitoring the water quality of water samples collected from the pond surface water and a sump collection system beneath the liner over a period of 5 years. Water samples collected from the sump and pond surface water met all Ohio non-toxic criteria, and in fact, generally met all national primary and secondary drinking water standards. Furthermore it was found that hazardous (i.e., As, B, Cr, Cu, and Zn) and agricultural pollutants (i.e., phosphate and ammonia) were effectively retained by the FGD liner system. The retention might be due to both sorption and precipitation. In the second field study, the release of metals and metalloids from full-scale portland cement concrete pavements containing CCPs was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections under controlled loading and environmental conditions. Three types of portland-cement-concrete driving surfaces were tested, including a control section (i.e., ordinary portland cement (OPC) concrete) containing no fly ash and two sections in which fly ash was substituted for a fraction of the cement; i.e., 30% fly ash (FA30) and 50% fly ash (FA50

  15. Pore and grain boundary migration under a temperature gradient: A phase-field model study

    DOE PAGES

    Biner, S. B.

    2016-03-16

    In this study, the collective migration behavior of pores and grain boundaries under a temperature gradient is studied for simple single crystal, bi-crystal and polycrystal configurations with a phase-field model formulism. For simulation of the microstructure of solids, composed of pores and grain boundaries, the results indicate that not only the volume fraction of pores, but also its spatial partitioning between the grain boundary junctions and the grain boundary segments appears to be important. In addition to various physical properties, the evolution kinetics, under given temperature gradients, will be strongly influenced with the initial morphology of a poly-crystalline microstructure.

  16. A quantum chemical study of the mechanisms of olefin addition to group 9 transition metal dioxo compounds.

    PubMed

    Ahmed, Issahaku; Tia, Richard; Adei, Evans

    2016-01-01

    triplet PES than on the singlet PES for the formation of similar analogues. There are fewer competitive reaction pathways on the triplet surface than on the singlet PES. Also, cycloadditions that seem impossible on the singlet PES seem possible on the doublet and or triplet PESs, this is the case typically for the Rh and Co complexes, illustrating the importance of multiple spin states in organometallic reactions.Graphical AbstractTable of Contents Synopsis: A study of the mechanism of ethylene addition to MO2(CH2)(CH3)(M=Co,Rh,Ir) shows the reactions of the Co complex have lower activation barriers for the preferred [3+2] and [2+2] addition pathways and fewer side reactions than those of Rh and Ir. Reactions are more feasible and selective on the triplet PES than on the singlet PES. These illustrate the importance of multiple spin states in organometallic reactions and shows catalyst activity and selectivity decreases down the group.

  17. A fundamental study of the oxidation behavior of SI primary reference fuels with propionaldehyde and DTBP as an additive

    NASA Astrophysics Data System (ADS)

    Johnson, Rodney

    In an effort to combine the benefits of SI and CI engines, Homogeneous Charge Compression Ignition (HCCI) engines are being developed. HCCI combustion is achieved by controlling the temperature, pressure, and composition of the fuel and air mixture so that autoignition occurs in proper phasing with the piston motion. This control system is fundamentally more challenging than using a spark plug or fuel injector to determine ignition timing as in SI and CI engines, respectively. As a result, this is a technical barrier that must be overcome to make HCCI engines applicable to a wide range of vehicles and viable for high volume production. One way to tailor the autoignition timing is to use small amounts of ignition enhancing additives. In this study, the effect of the addition of DTBP and propionaldehyde on the autoignition behavior of SI primary reference fuels was investigated. The present work was conducted in a new research facility built around a single cylinder Cooperative Fuels Research (CFR) octane rating engine but modified to run in HCCI mode. It focused on the effect of select oxygenated hydrocarbons on hydrocarbon fuel oxidation, specifically, the primary reference fuels n-heptane and iso-octane. This work was conducted under HCCI operating conditions. Previously, the operating parameters for this engine were validated for stable combustion under a wide range of operating parameters such as engine speeds, equivalence ratios, compression ratios and inlet manifold temperature. The stable operating range under these conditions was recorded and used for the present study. The major focus of this study was to examine the effect of the addition of DTBP or propionaldehyde on the oxidation behavior of SI primary reference fuels. Under every test condition the addition of the additives DTBP and propionaldehyde caused a change in fuel oxidation. DTBP always promoted fuel oxidation while propionaldehyde promoted oxidation for lower octane number fuels and delayed

  18. Complexities in using sentinel pigs to study Taenia solium transmission dynamics under field conditions.

    PubMed

    Devleesschauwer, Brecht; Aryal, Arjun; Tharmalingam, Jayaraman; Joshi, Durga Datt; Rijal, Suman; Speybroeck, Niko; Gabriël, Sarah; Victor, Bjorn; Dorny, Pierre

    2013-03-31

    The transmission dynamics of the pork tapeworm, Taenia solium, remain a matter of research and debate. In a longitudinal field study performed in southeastern Nepal, 18 sentinel pigs were serologically monitored to study the field kinetics of Taenia antigens and anti-T. solium antibodies. At the end of the twelve months' study period, necropsy was performed and suspected lesions were subjected to molecular identification of the Taenia species. The study generated new hypotheses on the transmission dynamics of Taenia spp. and exposed crucial complexities in the use of sentinel pigs in longitudinal field studies. Sentinel pigs can be useful epidemiological tools, but their use should be thoroughly planned before initiating a study and carefully monitored throughout the course of the study. Important aspects to be considered are those affecting the pig's susceptibility to infection, such as passive immunity, age, hormonal levels, and infection with competing Taenia species. In addition, serological test results should be interpreted considering possible cross-reactions and with proper understanding of the significance of a positive test result.

  19. A study of field independence versus field dependence of school teachers and university students in mathematics.

    PubMed

    Chao, Li; Huang, Jianyi; Li, Angie

    2003-12-01

    The Group Embedded Figures Test was administered to 72 secondary school teachers and 54 university students in mathematics to measure their cognitive styles of field independence-dependence. A mean difference was found between the teachers and students as teachers scored more field-independent than the students. There was also a group-by-sex interaction, which indicated that the female teachers scored more field-independent than the male teachers, whereas the male students scored as more field-independent than the female students. Implications of the findings are reflected in the discussion.

  20. Applicability of the DPPH assay for evaluating the antioxidant capacity of food additives - inter-laboratory evaluation study -.

    PubMed

    Shimamura, Tomoko; Sumikura, Yoshihiro; Yamazaki, Takeshi; Tada, Atsuko; Kashiwagi, Takehiro; Ishikawa, Hiroya; Matsui, Toshiro; Sugimoto, Naoki; Akiyama, Hiroshi; Ukeda, Hiroyuki

    2014-01-01

    An inter-laboratory evaluation study was conducted in order to evaluate the antioxidant capacity of food additives by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Four antioxidants used as existing food additives (i.e., tea extract, grape seed extract, enju extract, and d-α-tocopherol) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were used as analytical samples, and 14 laboratories participated in this study. The repeatability relative standard deviation (RSD(r)) of the IC50 of Trolox, four antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) were 1.8-2.2%, 2.2-2.9%, and 2.1-2.5%, respectively. Thus, the proposed DPPH assay showed good performance within the same laboratory. The reproducibility relative standard deviation (RSD(R)) of IC50 of Trolox, four antioxidants, and TEAC were 4.0-7.9%, 6.0-11%, and 3.7-9.3%, respectively. The RSD(R)/RSD(r) values of TEAC were lower than, or nearly equal to, those of IC50 of the four antioxidants, suggesting that the use of TEAC was effective for reducing the variance among the laboratories. These results showed that the proposed DPPH assay could be used as a standard method to evaluate the antioxidant capacity of food additives.

  1. Confinement and heating studies of field-reversed configurations

    NASA Astrophysics Data System (ADS)

    Chrien, Robert E.

    1990-10-01

    Confinement studies of field-reversed configurations (FRCs) have been actively pursued during the past ten years with the larger and longer-lived FRCs produced in the FRX-C and FRX-C/LSM devices. Confinement measurements have included the global FRC quantities and, in some cases, profiles of electron temperature and density. The inferred confinement times and transport coefficients are used for comparison with transport models as well as to find the best operating conditions in the experiment. Global power flow modelling shows that energy confinement during the equilibrium phase is usually dominated by particle losses, with a substantial secondary contribution from electron thermal conduction. Particle losses in present kinetic FRCs are strongly influenced by open field line confinement, which complicates the study of transport mechanisms. The electron thermal conduction is observed to be anomalous, as in other plasma devices. The bulk electrical resistivity is also anomalous and shows no evidence of classical Spitzer scaling. Recently, the resistive anomaly has been shown to correlate with tilt-like magnetic perturbations observed with Mirnov coils. FRC confinement studies have also been extended to a higher temperature regime during magnetic compression heating. In these experiments, translated FRCs are compressed by increasing the external magnetic flux up to a factor of seven on a time scale between the radial Alfven time and the FRC lifetime. Electron and ion temperatures up to 0.4 keV and 1.6 keV, respectively have been obtained. Confinement times scale roughly as r(exp 2) during compression.

  2. Field and data analysis studies related to the atmospheric environment

    NASA Technical Reports Server (NTRS)

    Kidder, Stanley; Mach, Douglas; Bailey, Jeff; Stewart, Michael; Slaton, Dave; Buechler, Dennis; Botts, Michael; Collins, Laurie

    1994-01-01

    This report summarizes work on a broad array of projects including: (1) applications of meteorological and/or oceanographic satellites; (2) improvement of the current set of NASA/USAF lightning related launch commit criteria rules; (3) the design, building, testing and deployment of a set of cylindrical field mills for aircraft use; (4) the study of marginal electrification storm conditions in relationship to the current launch commit rules for the space shuttle and various other launch vehicles using an instrumented aircraft; (5) support of the DC-8 and ER-2 lightning instrument package as part of both the Tropical Ocean - Global Atmospheric/Coupled Ocean-Atmospheric Response Experiment and the Convection and Moisture Experiment; (6) design of electronic circuitry and microprocessor firmware for the NASA Advanced Ground Based Field Mill; (7) design and testing of electronic and computer instrumentation for atmospheric electricity measurements; (8) simulating observations from a lightning imaging sensor on the Tropical Rainfall Measuring satellite; and (9) supporting scientific visualization and the development of computer software tools.

  3. The influence of deposit control additives on nitrogen oxides emissions from spark ignition engines (case study: Tehran).

    PubMed

    Bidhendi, Gholamreza Nabi; Zand, Ali Daryabeigi; Tabrizi, Alireza Mikaeili; Pezeshk, Hamid; Baghvand, Akbar

    2007-04-15

    In the present research, the influence of a deposit control additive on NOx emissions from two types of gasoline engine vehicles i.e., Peykan (base on Hillman) and Pride (South Korea Kia motors) was studied. Exhaust NOx emissions were measured in to stages, before decarbonization process and after that. Statistical analysis was conducted on the measurement results. Results showed that NOx emissions from Peykans increased 0.28% and NOx emissions from Pride automobiles decreased 6.18% on average, due to the elimination of engine deposits. The observed variations were not statistically and practically significant. The results indicated that making use of detergent additives is not an effective way to reduce the exhaust NOx emissions from gasoline engine vehicles. PMID:19069943

  4. A mechanistic study of the addition of alcohol to a five-membered ring silene via a photochemical reaction.

    PubMed

    Su, Ming-Der

    2016-03-21

    The mechanism for the photochemical rearrangement of a cyclic divinyldisilane (1-Si) in its first excited state ((1)π → (1)π*) is determined using the CAS/6-311G(d) and MP2-CAS/6-311++G(3df,3pd) levels of theory. The photoproduct, a cyclic silene, reacts with various alcohols to yield a mixture of cis- and trans- adducts. The two reaction pathways are denoted as the cis- addition path (path A) and the trans-addition path (path B). These model studies demonstrate that conical intersections play a crucial role in the photo-rearrangements of cyclic divinyldisilanes. The theoretical evidence also demonstrates that the addition of alcohol to a cyclic divinyldisilane follows the reaction path: cyclic divinyldisilane → Franck-Condon region → conical intersection → photoproduct (cyclic silene) → local intermediate (with alcohol) → transition state → cis- or trans-adduct. The theoretical studies demonstrate that the steric effects as well as the concentrations of CH3OH must have a dominant role in determining the yields of the final adducts by stereochemistry. The same mechanism for the carbon derivative (1-C) is also considered in this work. However, the theoretical results indicate that 1-C does not undergo a methanol addition reaction via the photochemical reaction pathway, since its energy of conical intersection (S1/S0-CI-C) is more than that of its FC (FC-C). The reason for these phenomena could be that the atomic radius of carbon is much smaller than that of silicon (77 and 117 pm, respectively). As a result, the conformation for 1-C is more sterically congested than that for 1-Si, along the 1,3-silyl-migration pathway. PMID:26928893

  5. A study of spin chemistry in weak magnetic fields.

    PubMed

    Timmel, Christiane R; Henbest, Kevin B

    2004-12-15

    This paper reviews the latest developments in the field of spin chemistry with a particular focus on the effects of weak static and/or oscillating magnetic fields (typically smaller than the average hyperfine coupling) on radical recombination reactions. Anisotropic magnetic field effects and their significance in the debate about potential mechanisms controlling magnetoreception in birds are discussed.

  6. Biological and Agricultural Studies on Application of Discharge Plasma and Electromagnetic Fields 5. Effects of High Electric Fields on Animals

    NASA Astrophysics Data System (ADS)

    Isaka, Katsuo

    The biological effects of extremely low frequency electric fields on animals are reviewed with emphasis on studies of the nervous system, behavior, endocrinology, and blood chemistry. First, this paper provides a histrical overview of studies on the electric field effects initiated in Russia and the United States mainly regarding electric utility workers in high voltage substations and transmission lines. Then, the possible mechanisms of electric field effects are explained using the functions of surface electric fields and induced currents in biological objects. The real mechanisms have not yet been identified. The thresholds of electric field perception levels for rats, baboons, and humans are introduced and compared. The experimental results concerning the depression of melatonin secretion in rats exposed to electric fields are described.

  7. Studying Geology of Central Texas through Web-Based Virtual Field Trips

    NASA Astrophysics Data System (ADS)

    Chan, C.; Khan, S. D.; Wellner, J. S.

    2007-12-01

    Each year over 2500 students, mainly non-science majors, take introductory geology classes at the University of Houston. Optional field trips to Central Texas for these classes provide a unique learning opportunity for students to experience geologic concepts in a real world context. The field trips visit Enchanted Rock, Inks Lake, Bee Cave Road, Lion Mountain, and Slaughter Gap. Unfortunately, only around 10% of our students participate in these field trips. We are developing a web-based virtual field trip for Central Texas to provide an additional effective learning experience for students in these classes. The module for Enchanted Rock is complete and consists of linked geological maps, satellite imagery, digital elevation models, 3-D photography, digital video, and 3-D virtual reality visualizations. The ten virtual stops focus on different geologic process and are accompanied by questions and answers. To test the efficacy of the virtual field trip, we developed a quiz to measure student learning and a survey to evaluate the website. The quiz consists of 10 questions paralleling each stop and information on student attendance on the Central Texas field trip and/or the virtual field trip. From the survey, the average time spent on the website was 26 minutes, and overall the ratings of the virtual field trip were positive. Most noticeably students responded that the information on the website was relevant to their class and that the pictures, figures, and animations were essential to the website. Although high correlation coefficients between responses were expected for some questions (i.e., 0.89 for "The content or text of the website was clear" and "The information on the website was easy to read"), some correlations were less expected: 0.77 for "The number of test questions was appropriate" and "The information on the website was easy to read," and 0.70 for "The test questions reinforced the material presented on the website" and "The information on the

  8. A Scoping-Level Field Monitoring Study of Synthetic Turf Fields and Playgrounds

    EPA Science Inventory

    Recycled tire material, or "tire crumb," is used as a component in many recreational fields, including synthetic turf fields and playgrounds. The use of tire crumbs in these applications provides several benefits, including reduced sports injury. The public recently has raised co...

  9. Meta-analysis of high-latitude nitrogen-addition and warming studies implies ecological mechanisms overlooked by land models

    DOE PAGES

    Bouskill, N. J.; Riley, W. J.; Tang, J. Y.

    2014-12-11

    Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the climate. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the aboveground and belowground responses to warming and nitrogen addition in high-latitude ecosystems, and identified absent or poorly parameterized mechanisms in CLM4.5. While the two model versions predicted similar soil carbon stock trajectories following both warming and nitrogen addition, other predicted variables (e.g., belowgroundmore » respiration) differed from observations in both magnitude and direction, indicating that CLM4.5 has inadequate underlying mechanisms for representing high-latitude ecosystems. On the basis of observational synthesis, we attribute the model–observation differences to missing representations of microbial dynamics, aboveground and belowground coupling, and nutrient cycling, and we use the observational meta-analysis to discuss potential approaches to improving the current models. However, we also urge caution concerning the selection of data sets and experiments for meta-analysis. For example, the concentrations of nitrogen applied in the synthesized field experiments (average = 72 kg ha-1 yr-1) are many times higher than projected soil nitrogen concentrations (from nitrogen deposition and release during mineralization), which precludes a rigorous evaluation of the model responses to likely nitrogen perturbations. Overall, we demonstrate that elucidating ecological mechanisms via meta-analysis can identify deficiencies in ecosystem models and empirical experiments.« less

  10. Olfactory communication among Costa Rican squirrel monkeys: a field study.

    PubMed

    Boinski, S

    1992-01-01

    Behaviors with a possible role in olfactory communication among troop members were investigated as part of a field study on the reproductive and foraging ecology of squirrel monkeys (Saimiri oerstedi) in Costa Rica. All age classes engaged in the olfaction-related behaviors. Apart from olfactory investigation of female genitals by males during the mating season, no other potential olfaction-related behavior (urine wash, branch investigation, rump, chest, back rub and sneeze) exceeded 1% of mean behavioral samples. Assessment of reproduction condition appears to be the primary function of such olfactory investigation of the female genital region. The primary function of urine washing is suggested to be the general communication of reproductive status, possibly facilitating reproductive synchrony. Sneezing, rump, back and chest rubbing do not appear to deposit substances active in olfactory communication. PMID:1306175

  11. Communication Problems in Requirements Engineering: A Field Study

    NASA Technical Reports Server (NTRS)

    Al-Rawas, Amer; Easterbrook, Steve

    1996-01-01

    The requirements engineering phase of software development projects is characterized by the intensity and importance of communication activities. During this phase, the various stakeholders must be able to communicate their requirements to the analysts, and the analysts need to be able to communicate the specifications they generate back to the stakeholders for validation. This paper describes a field investigation into the problems of communication between disparate communities involved in the requirements specification activities. The results of this study are discussed in terms of their relation to three major communication barriers: (1) ineffectiveness of the current communication channels; (2) restrictions on expressiveness imposed by notations; and (3) social and organizational barriers. The results confirm that organizational and social issues have great influence on the effectiveness of communication. They also show that in general, end-users find the notations used by software practitioners to model their requirements difficult to understand and validate.

  12. Studies of the interplanetary magnetic field: IMP's to Voyager

    NASA Technical Reports Server (NTRS)

    Ness, Norman F.

    1987-01-01

    During the last two decades, spacecraft projects and individual experiments for which Frank McDonald was a leader have contributed very significantly to the current understanding of the structure of interplanetary space and the correlation between solar and interplanetary disturbances. Studies on the IMP, HELIOS, and Pioneer spin-stabilized spacecraft and the larger attitude-stabilized Voyager spacecraft have provided data sets from which the modern view of the heliosphere has evolved. That concept in which the inner solar system is shown to be dominated by individual streams associated with specific source regions on the Sun is illustrated. As these high-speed streams overtake the preexisting solar plasma, they coalesce and modify the characteristics so that at larger heliocentric distances, these disturbances appear as radially propagating concentric shells of compressed magnetic fields and enhanced fluctuations

  13. Optimization studies of the ITER low field side reflectometer

    SciTech Connect

    Hanson, Gregory R; Wilgen, John B; Bigelow, Tim S; Diem, Stephanie J

    2010-01-01

    Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, ELM density transients, and as a L-H transition monitor. The ITER low field side (LFS) reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

  14. Optimization studies of the ITER low field side reflectometer

    SciTech Connect

    Diem, S. J.; Wilgen, J. B.; Bigelow, T. S.; Hanson, G. R.; Harvey, R. W.; Smirnov, A. P.

    2010-10-15

    Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, edge localized mode (ELM) density transients, and as an L-H transition monitor. The ITER low field side reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

  15. A field study of tritium migration in groundwater.

    PubMed

    Zhang, L X; Zhang, M S; Tu, G R

    1995-12-01

    A field study of tritium migration from an underground nuclear explosion was carried out for more than 7 years. A series of satellite wells was drilled around the explosion cavity, which is within a nuclear test site water-supply aquifer. Samples from various wells were analysed. In this way, variations in the tritium concentration of water from different wells were determined, and the extent of tritium migration during the 7 years after the detonation was examined. The maximum tritium concentration reached in water from various wells is just 52-times higher than the maximum permissible concentration for drinking water and decreased afterwards. According to the results obtained, the flow rate of groundwater was inferred to be about 91 m per year and the maximum contamination distance of water supplies by the tritium were < or = 2 km from the explosion cavity.

  16. Optimization studies of the ITER low field side reflectometer.

    PubMed

    Diem, S J; Wilgen, J B; Bigelow, T S; Hanson, G R; Harvey, R W; Smirnov, A P

    2010-10-01

    Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, edge localized mode (ELM) density transients, and as an L-H transition monitor. The ITER low field side reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

  17. Multidisciplinary study of Hewett Field, Zechstein Kalk Formation

    SciTech Connect

    West, K.L. )

    1994-04-01

    New technology and a multidisciplinary team approach were effectively used by Phillips Petroleum for optimum reservoir development in the Hewett field, North Sea. Near-horizontal drilling technology and depositional environment and fracture studies were used by engineering and geology. Geophysics contributed structure and porosity trend maps and used new technology developed by Phillips called Incremental Pay Thickness modeling. IPT modeling enhances the integration of well-log data and seismic wiggle traces so porosity and pay thickness can be estimated directly from seismic data. Seismic amplitude values were mapped and processed into estimated porosity thickness using the IPT mathematical relationship. This interpretation aided in locating three successful development wells in areas of predicted high porosity, which increased production by 67 MMCF/D and optimized recovery.

  18. Phreatomagmatic explosive eruption processes informed by field and experimental studies

    NASA Astrophysics Data System (ADS)

    Valentine, Greg; Graettinger, Alison; Sonder, Ingo

    2015-04-01

    Phreatomagmatic explosive eruptions occur during the lifetime of nearly every volcano. Maar-diatremes form excellent case studies to understand such eruptions because most of these volcanoes are monogenetic so that the effects of the dominant phreatomagmatic activity are not overprinted by other processes as might occur at a polygenetic volcano. Diatremes preserve evidence of magma injection and explosions at various levels, in the form of irregularly shaped intrusions and vertical domains of country rock breccia and pyroclasts, and usually have subsidence features around the outer parts. Field data on intrusions in diatremes give analog information on the sizes of magma batches that might fuel phreatomagmatic explosions, and therefore the energies of individual explosions. Tephra rings often are dominated by country rock clasts, with progressively deeper-seated clasts appearing at progressively higher stratigraphic levels in the tephra. Scaled experiments with buried explosives show that only shallow explosions (<200 m) can deposit material onto tephra rings, and coarse ballistics are emplaced onto tephra rings mainly by explosions less than 100 m deep; therefore the presence of deep-seated lithics is related to mixing by multiple (non-erupting) explosions at various depths within the diatremes, not necessarily to progressive deepening of explosions. Excavation of experimental craters shows that mixing occurs through a combination of upward displacement and progressive disaggregation of host material domains, and marginal subsidence. Experimental explosion jets show a range of behaviors that depend on the scaled depth of explosions (physical depth scaled against explosion energy) and on the effects of pre-explosion crater morphology. Many scaled depth and pre-explosion crater combinations result in jets that collapse back into the crater and expel fine-grained density currents that travel radially outward. Field observations of fine-grained ash beds in tephra

  19. Large-scale compensation of errors in pairwise-additive empirical force fields: comparison of AMBER intermolecular terms with rigorous DFT-SAPT calculations.

    PubMed

    Zgarbová, Marie; Otyepka, Michal; Sponer, Jirí; Hobza, Pavel; Jurecka, Petr

    2010-09-21

    The intermolecular interaction energy components for several molecular complexes were calculated using force fields available in the AMBER suite of programs and compared with Density Functional Theory-Symmetry Adapted Perturbation Theory (DFT-SAPT) values. The extent to which such comparison is meaningful is discussed. The comparability is shown to depend strongly on the intermolecular distance, which means that comparisons made at one distance only are of limited value. At large distances the coulombic and van der Waals 1/r(6) empirical terms correspond fairly well with the DFT-SAPT electrostatics and dispersion terms, respectively. At the onset of electronic overlap the empirical values deviate from the reference values considerably. However, the errors in the force fields tend to cancel out in a systematic manner at equilibrium distances. Thus, the overall performance of the force fields displays errors an order of magnitude smaller than those of the individual interaction energy components. The repulsive 1/r(12) component of the van der Waals expression seems to be responsible for a significant part of the deviation of the force field results from the reference values. We suggest that further improvement of the force fields for intermolecular interactions would require replacement of the nonphysical 1/r(12) term by an exponential function. Dispersion anisotropy and its effects are discussed. Our analysis is intended to show that although comparing the empirical and non-empirical interaction energy components is in general problematic, it might bring insights useful for the construction of new force fields. Our results are relevant to often performed force-field-based interaction energy decompositions.

  20. Cognitive, cardiac, and physiological safety studies in ultra high field magnetic resonance imaging.

    PubMed

    Kangarlu, A; Burgess, R E; Zhu, H; Nakayama, T; Hamlin, R L; Abduljalil, A M; Robitaille, P M

    1999-12-01

    A systematic analysis of the effect of an 8.0 tesla static magnetic field on physiological and/or cognitive function is presented in the normal volunteer and in the swine. A study of ten human subjects revealed no evidence of detectable changes in body temperature, heart rate, respiratory rate, systolic pressure, and diastolic blood pressure after 1 hour of exposure. In addition, no cognitive changes were detected. Important ECG changes were noted which were related both to the position of the subject in the magnet and to the absolute strength of the magnetic field. As such, the ECG tracing at 8 tesla was not diagnostically useful. Nonetheless, all subjects exhibited normal ECG readings both before and following exposure to the 8 tesla field. Cardiac function was also examined in detail in the swine. No significant changes in body temperature, heart rate, left ventricular pressure, left ventricular end diastollic pressure, time rate of change of left ventricular pressure, myocardial stiffness index, cardiac output, systolic volume, troponin, and potassium levels could be detected following 3 h of exposure to a field strength of 8.0 tesla. It is concluded that no short term cardiac or cognitive effects are observed following significant exposure to a magnetic field of up to 8.0 tesla.