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Sample records for fxg chemical yield

  1. Application of radiochromic gel detector (FXG) for UVA dose measurements

    NASA Astrophysics Data System (ADS)

    Abukassem, Issam; Bero, Mamdouh A.

    2010-12-01

    Tissue equivalent radiochromic gel material containing ferrous ions, xylenol-orange ion indicator and gelatin as gelling agent (FXG) is known to be sensitive to γ- and X-rays; hence it has been used for ionizing radiation dosimetry. Changes in optical absorbance properties of FXG material over a wide region in the visible spectrum were found to be proportional to the radiation absorbed dose. An earlier study demonstrated the sensitivity of FXG gel detector to ultraviolet radiation and therefore that could give quantitative measure for UV exposure. This study focuses on the detection of UVA radiation (315-400 nm), which forms an important part (˜97%) of the natural solar UV radiation reaching the earth surface. A solar UV simulator device was used to deliver UVA radiation to FXG samples. The beam was optically modified to irradiate gel samples at an exposure level about 58 W/m 2, which is comparable to the summer natural UVA radiation measured outside the laboratory building at midday (˜60 W/m 2). Experimental results were used to generate mathematical second order formulas that give the relationship between UVA dose and optical absorbance changes observed at two wavelengths in the visible region of the spectrum—430 and 560 nm.

  2. FXG mass attenuation coefficient evaluation for radiotherapy routine

    NASA Astrophysics Data System (ADS)

    Moreira, M. V.; de Almeida, A.; Costa, R. T.; Perles, L. A.

    2004-01-01

    The knowledge of a radioactive beam energy or quality is important in radiotherapy once it is correlated with the type, size, and localization of the tumor. One indicative of the radiation quality is the half-value-layer (HVL), the material thickness which reduces the beam intensity to half. The analysis of a treatment beam spectrum can be inferred through its homogeneity coefficient (HC, ratio between the first and the second HVL) that for values >= 0.7 has the indication to be adequate for treatments. Another important indicator of radiation quality is the mass absorption coefficient (cm2/g), related to the photons energies absorbed in a particular exposed material. Once that several materials can be used as radiation detectors for X and γ dosimetry, this work has the purpose to verify the ferrous Xylenol gelatin (FXG) material performance, through its μ/ρ behavior and compare it with the μ/ρ behavior for soft tissue. The X and γ energies where selected, in the energies normally used in radiotherapy and their spectra were evaluated using the HC coefficient. The μ/ρ, for the FXG material, were obtained experimentally and from simulation with X-COM and a developed routine using the GEANT4 Library. From the results from all μ/ρ values obtained for the FXG material, when compared to those from water, one can see similar behaviors, when one considers measurements for energies greater than 78.0 keV. These results indicate that, once the human body is composed with +/-80 % of water, the FXG for the energies used, could also be used as soft tissue simulator.

  3. Threshold dose effect in FXG gels: real or apparent?

    NASA Astrophysics Data System (ADS)

    Babic, S.; Battista, J.; Jordan, K.

    2006-12-01

    The purpose of this present study was to identify the chemical and or physical mechanism responsible for the threshold dose effect in ferrous xylenol orange gelatin gels and to control it in order to achieve better reproducibility and reliable calibration across the entire linear dose range.

  4. SU-E-T-606: Performance of MR-Based 3D FXG Dosimetry for Preclinical Irradiation

    SciTech Connect

    Welch, M; Jaffray, D

    2015-06-15

    Purpose: Technological advances have revolutionized preclinical radiation research to enable precise radiation delivery in preclinical models. Kilovoltage x-rays and complex geometries in preclinical radiation studies challenge conventional dosimetry methods. Previously developed gel-based dosimetry provides a viable means of accommodating complex geometries and accurately reporting dose at kV energies. This paper will describe the development and evaluation of gel-based ferrous xylenol-orange (FXG) dosimetry using a 7T preclinical imaging system. Methods: To confirm water equivalence, Zeff values were calculated for the FXG material, water and ICRU defined soft tissue. Proton T1 relaxivity response in FXG was measured using a preclinical 7T MR and a small animal irradiator for a dose range of 1–22 Gy. FXG was contained in 50 ml centrifuge tubes and irradiated with a 225 kVp x-ray beam at a nominal dose rate of 2.3 Gy/min. Pre and post irradiation maps of the T1 relaxivity were collected using variable TR spin-echo imaging (TE 6.65 ms; TR 500, 750, 1000, 1500, 2000, 3000 and 5000 ms) with 2 mm thick slices, 0.325 mm/pixel, 3 averages and an acquisition time of 26 minutes. A linear fit to the change in relaxation rate (1/T1) for the delivered doses reported the gel sensitivity in units of ms{sup -1}Gy{sup -1}. Irradiation and imaging studies were repeated using three batches of gel over 72 hrs. Results: FXG has a Zeff of 3.8 for the 225 kVp spectrum used; differing from water and ICRU defined soft tissue by 0.5% and 2.5%, respectively. The average sensitivity for the FXG dosimeter was 31.5 ± 0.7 ms{sup -1}Gy{sup -1} (R{sup 2} = 0.9957) with a y-intercept of −29.4 ± 9.0 ms{sup -1}. Conclusion: Preliminary results for the FXG dosimeter properties, sensitivity, and dose linearity at preclinical energies is promising. Future work will explore anatomically relevant tissue inclusions to test MR performance. Student funding provided by The Terry Fox Foundation

  5. Reduced product yield in chemical processes by second law effects

    NASA Technical Reports Server (NTRS)

    England, C.; Funk, J. E.

    1980-01-01

    An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value of a product. As a result, it is particularly convenient in analyzing fuel conversion plants and their potential for improvement. Relationships are also given for the effects of irreversibilities on requirements for process heat and for feedstocks.

  6. AGB yields and Galactic Chemical Evolution: last updated

    NASA Astrophysics Data System (ADS)

    Bisterzo, S.; Travaglio, C.; Wiescher, M.; Gallino, R.; Köppeler, F.; Straniero, O.; Cristallo, S.; Imbriani, G.; Görres, J.; deBoer, R. J.

    2016-01-01

    We study the s-process abundances at the epoch of the Solar-system formation as the outcome of nucleosynthesis occurring in AGB stars of various masses and metallicities. The calculations have been performed with the Galactic chemical evolution (GCE) model presented by [1, 2]. With respect to previous works, we used updated solar meteoritic abundances, a neutron capture cross section network that includes the most recent measurements, and we implemented the s-process yields with an extended range of AGB initial masses. The new set of AGB yields includes a new evaluation of the 22Ne(α, n)25Mg rate, which takes into account the most recent experimental information.

  7. Timing considerations for preclinical MRgRT: effects of ion diffusion, SNR and imaging times on FXG gel calibration

    NASA Astrophysics Data System (ADS)

    Welch, M.; Foltz, W. D.; Jaffray, D. A.

    2015-01-01

    Sub-millimeter resolution images are required for gel dosimeters to be used in preclinical research, which is challenging for MR probed ferrous xylenol-orange (FXG) dosimeters due to ion diffusion and inadequate SNR. A preclinical 7 T MR, small animal irradiator and FXG dosimeters were used in all experiments. Ion diffusion was analyzed using high resolution (0.2 mm/pixel) T1 MR images collected every 5 minutes, post-irradiation, for an hour. Using Fick's second law, ion diffusion was approximated for the first hour post-irradiation. SNR, T1 map precision and calibration fit were determined for two MR protocols: (1) 10 minute acquisition, 0.35mm/pixel and 3mm slices, (2) 45 minute acquisition, 0. 25 mm/pixel and 2 mm slices. SNR and T1 map precision were calculated using a Monte Carlo simulation. Calibration curves were determined by plotting R1 relaxation rates versus depth dose data, and fitting a linear trend line. Ion diffusion was estimated as 0.003mm2 in the first hour post-irradiation. For protocols (1) and (2) respectively, Monte Carlo simulation predicted T1 precisions of 3% and 5% within individual voxels using experimental SNRs; the corresponding measured T1 precisions were 8% and 12%. The linear trend lines reported slopes of 27 ± 3 Gy*s (R2: 0.80 ± 0.04) and 27 ± 4 Gy*s (R2: 0.90 ± 0.04). Ion diffusion is negligible within the first hour post-irradiation, and an accurate and reproducible calibration can be achieved in a preclinical setting with sub-millimeter resolution.

  8. Chemical Mass Production of Graphene Nanoplatelets in ∼100% Yield.

    PubMed

    Dimiev, Ayrat M; Ceriotti, Gabriel; Metzger, Andrew; Kim, Nam Dong; Tour, James M

    2016-01-26

    Successful application of graphene is hampered by the lack of cost-effective methods for its production. Here, we demonstrate a method of mass production of graphene nanoplatelets (GNPs) by exfoliation of flake graphite in the tricomponent system made by a combination of ammonium persulfate ((NH4)2S2O8), concentrated sulfuric acid, and fuming sulfuric acid. The resulting GNPs are tens of microns in diameter and 10-35 nm in thickness. When in the liquid phase of the tricomponent media, graphite completely loses its interlayer registry. This provides a ∼100% yield of GNPs from graphite in 3-4 h at room temperature or in 10 min at 120 °C. PMID:26580092

  9. [Coupling effects of water and chemical fertilizers on Hevea brasiliensis latex yield].

    PubMed

    Hua, Yuan-Gang; Chen, Qiu-Bo; Lin, Zhao-Mu; Luo, Wei

    2008-06-01

    Water and nutrient are the two main factors limiting Hevea brasiliensis growth and its latex yield. With 17 year-old Clone SCATC 7-33-97 H. brasiliensis as test material, the coupling effects of water and chemical N, P and K fertilizers on latex yield were studied by general orthogonal rotation design of quadratic regression with four factors and five levels under field condition, and a regressive mathematical model was set up based on the latex yield by quadratic regression analysis. The results showed that all test coupling levels of water and chemical fertilizers had significant effects on the latex yield. The yield-increasing effect of test factors was in the order of N application rate > irrigation amount > P application rate > K application rate, while the coupling effect of water and chemical fertilizers was in the sequence of water and N > N and P > water and P > water and K. There was a negative coupling effect of K application rate and soil moisture content. For latex yield, the optimum application rates of chemical fertilizers were 476.39 kg x hm(-2) of urea, 187.70 kg x hm(-2) of superphosphate and 225.77 kg x hm(-2) of potassium chloride, and the optimum irrigation amount was to have 82.78% soil relative water content. PMID:18808010

  10. Enhanced c2 yields from methane oxidative coupling by means of a separative chemical reactor.

    PubMed

    Tonkovich, A L; Carr, R W; Aris, R

    1993-10-01

    Of the processes for converting natural gas into a more useful chemical feedstock, the oxidative coupling of methane to form ethane and ethylene (C(2)) has perhaps been the most intensively investigated in recent years, but it has proved extremely difficult to obtain C(2) yields in excess of 20 to 25%. Methane oxidative coupling was carried out in a separative chemical reactor that simulated a countercurrent chromatographic moving-bed. This reaction gives 65% methane conversion, 80% C(2) selectivity, and a C(2) yield slightly better than 50% with Sm(2)O(3) catalyst at approximately 1000 K. PMID:17841868

  11. Essential oil yield and chemical composition changes during leaf ontogeny of palmarosa (Cymbopogon martinii var. motia).

    PubMed

    Rao, Bhaskaruni R Rajeswara; Rajput, Dharmendra K; Patel, Rajendra P; Purnanand, Somasi

    2010-12-01

    Changes in leaf biomass yield, essential oil yield, and chemical composition were investigated during leaf ontogeny of palmarosa {Cymbopogon martinii (Roxb.) Wats. var. motia Burk., family Poaceae}. Eleven leaves representing different developmental stages, serially numbered from the apex to the base of the plant were utilized for the study. Leaf biomass yield increased up to the eighth leaf. Essential oil recovery increased up to the third leaf; thereafter it decreased. Minimum essential oil recovery was observed in the eleventh leaf. Essential oil yield/leaf increased up to the sixth leaf. Essential oil yield and concentrations of linalool, alpha-terpineol, geranyl isobutyrate and geraniol were relatively higher in the essential oils of mature, older leaves. Essential oil recovery, and percentages of myrcene, beta-caryophyllene, geranyl acetate, (E,Z) farnesol and geranyl hexanoate were higher in the essential oils of young, expanding leaves. PMID:21299128

  12. Novel Approach for Evaluating Secondary Organic Aerosol from Aromatic Hydrocarbons: SOA Yield and Chemical Composition

    NASA Astrophysics Data System (ADS)

    Li, Lijie; Tang, Ping; Nakao, Shunsuke; Qi, Li; Kacarab, Mary; Cocker, David

    2016-04-01

    Aromatic hydrocarbons account for 20%-30% of urban atmospheric VOCs and are major contributors to anthropogenic secondary organic aerosol (SOA). However, prediction of SOA from aromatic hydrocarbons as a function of structure, NOx concentration, and OH radical levels remains elusive. Innovative SOA yield and chemical composition evaluation approaches are developed here to investigate SOA formation from aromatic hydrocarbons. SOA yield is redefined in this work by adjusting the molecular weight of all aromatic precursors to the molecular weight of benzene (Yield'= Yieldi×(MWi/MWBenzene); i: aromatic hydrocarbon precursor). Further, SOA elemental ratio is calculated on an aromatic ring basis rather than the classic mole basis. Unified and unique characteristics in SOA formed from aromatic hydrocarbons with different alkyl groups (varying in carbon number and location on aromatic ring) are explored by revisiting fifteen years of UC Riverside/CE-CERT environmental chamber data on 129 experiments from 17 aromatic precursors at urban region relevant low NOx conditions (HC:NO 11.1-171 ppbC:ppb). Traditionally, SOA mass yield of benzene is much greater than that of other aromatic species. However, when adjusting for molecular weight, a similar yield is found across the 17 different aromatic precursors. More importantly, four oxygens per aromatic ring are observed in the resulting SOA regardless of the alkyl substitutes attached to the ring, which majorly affect H/C ratio in SOA. Therefore, resulting SOA bulk composition from aromatic hydrocarbons can be predicted as C6+nH6+2nO4 (n: alkyl substitute carbon number). Further, the dominating role of the aromatic ring carbons is confirmed by studying the chemical composition of SOA formed from the photooxidation of an aromatic hydrocarbon with a 13C isotopically labeled alkyl carbon. Overall, this study unveils the similarity in SOA formation from aromatic hydrocarbons enhancing the understanding of SOA formation from

  13. Comparison of Seven Chemical Pretreatments of Corn Straw for Improving Methane Yield by Anaerobic Digestion

    PubMed Central

    Song, Zilin; GaiheYang; Liu, Xiaofeng; Yan, Zhiying; Yuan, Yuexiang; Liao, Yinzhang

    2014-01-01

    Agriculture straw is considered a renewable resource that has the potential to contribute greatly to bioenergy supplies. Chemical pretreatment prior to anaerobic digestion can increase the anaerobic digestibility of agriculture straw. The present study investigated the effects of seven chemical pretreatments on the composition and methane yield of corn straw to assess their effectiveness of digestibility. Four acid reagents (H2SO4, HCl, H2O2, and CH3COOH) at concentrations of 1%, 2%, 3%, and 4% (w/w) and three alkaline reagents (NaOH, Ca(OH)2, and NH3·H2O) at concentrations of 4%, 6%, 8%, and 10% (w/w) were used for the pretreatments. All pretreatments were effective in the biodegradation of the lignocellulosic straw structure. The straw, pretreated with 3% H2O2 and 8% Ca(OH)2, acquired the highest methane yield of 216.7 and 206.6 mL CH4 g VS −1 in the acid and alkaline pretreatments, which are 115.4% and 105.3% greater than the untreated straw. H2O2 and Ca(OH)2 can be considered as the most favorable pretreatment methods for improving the methane yield of straw because of their effectiveness and low cost. PMID:24695485

  14. Determination of pure neutron radiolysis yields for use in chemical modeling of supercritical water

    NASA Astrophysics Data System (ADS)

    Edwards, Eric J.

    This work has determined pure neutron radical yields at elevated temperature and pressure up to supercritical conditions using a reactor core radiation. The data will be necessary to provides realistic conditions for material corrosion experiments for the supercritical water reactor (SCWR) through water chemistry modeling. The work has been performed at the University of Wisconsin Nuclear Reactor using an apparatus designed to transport supercritical water near the reactor core. Low LET yield data used in the experiment was provided by a similar project at the Notre Dame Radiation Lab. Radicals formed by radiolysis were measured through chemical scavenging reactions. The aqueous electron was measured by two methods, a reaction with N2O to produce molecular nitrogen and a reaction with SF6 to produce fluoride ions. The hydrogen radical was measured through a reaction with ethanol-D6 (CD3CD2OD) to form HD. Molecular hydrogen was measured directly. Gaseous products were measured with a mass spectrometer and ions were measured with an ion selective electrode. Radiation energy deposition was calibrated for neutron and gamma radiation separately with a neutron activation analysis and a radiolysis experiment. Pure neutron yields were calculated by subtracting gamma contribution using the calibrated gamma energy deposition and yield results from work at the Notre Dame Radiation Laboratory. Pure neutron yields have been experimentally determined for aqueous electrons from 25°C to 400°C at 248 bar and for the hydrogen radical from 25°C to 350°C at 248 bar, Isothermal data has been acquired for the aqueous electron at 380°C and 400°C as a function of density. Molecular hydrogen yields were measured as a function of temperature and pressure, although there was evidence that chemical reactions with the walls of the water tubing were creating molecular hydrogen in addition to that formed through radiolysis. Critical hydrogen concentration behavior was investigated but a

  15. Targeting Hormone-Related Pathways to Improve Grain Yield in Rice: A Chemical Approach

    PubMed Central

    Tamaki, Hiroaki; Reguera, Maria; Abdel-Tawab, Yasser M.; Takebayashi, Yumiko; Kasahara, Hiroyuki; Blumwald, Eduardo

    2015-01-01

    Sink/source relationships, regulating the mobilization of stored carbohydrates from the vegetative tissues to the grains, are of key importance for grain filling and grain yield. We used different inhibitors of plant hormone action to assess their effects on grain yield and on the expression of hormone-associated genes. Among the tested chemicals, 2-indol-3-yl-4-oxo-4-phenylbutanoic acid (PEO-IAA; antagonist of auxin receptor), nordihydroguaiaretic acid (NDGA; abscisic acid (ABA) biosynthesis inhibitor), and 2-aminoisobutyric acid (AIB; ethylene biosynthesis inhibitor) improved grain yield in a concentration dependent manner. These effects were also dependent on the plant developmental stage. NDGA and AIB treatments induced an increase in photosynthesis in flag leaves concomitant to the increments of starch content in flag leaves and grains. NDGA inhibited the expression of ABA-responsive gene, but did not significantly decrease ABA content. Instead, NDGA significantly decreased jasmonic acid and jasmonic acid-isoleucine. Our results support the notion that the specific inhibition of jasmonic acid and ethylene biosynthesis resulted in grain yield increase in rice. PMID:26098557

  16. Targeting Hormone-Related Pathways to Improve Grain Yield in Rice: A Chemical Approach.

    PubMed

    Tamaki, Hiroaki; Reguera, Maria; Abdel-Tawab, Yasser M; Takebayashi, Yumiko; Kasahara, Hiroyuki; Blumwald, Eduardo

    2015-01-01

    Sink/source relationships, regulating the mobilization of stored carbohydrates from the vegetative tissues to the grains, are of key importance for grain filling and grain yield. We used different inhibitors of plant hormone action to assess their effects on grain yield and on the expression of hormone-associated genes. Among the tested chemicals, 2-indol-3-yl-4-oxo-4-phenylbutanoic acid (PEO-IAA; antagonist of auxin receptor), nordihydroguaiaretic acid (NDGA; abscisic acid (ABA) biosynthesis inhibitor), and 2-aminoisobutyric acid (AIB; ethylene biosynthesis inhibitor) improved grain yield in a concentration dependent manner. These effects were also dependent on the plant developmental stage. NDGA and AIB treatments induced an increase in photosynthesis in flag leaves concomitant to the increments of starch content in flag leaves and grains. NDGA inhibited the expression of ABA-responsive gene, but did not significantly decrease ABA content. Instead, NDGA significantly decreased jasmonic acid and jasmonic acid-isoleucine. Our results support the notion that the specific inhibition of jasmonic acid and ethylene biosynthesis resulted in grain yield increase in rice. PMID:26098557

  17. Red cabbage yield, heavy metal content, water use and soil chemical characteristics under wastewater irrigation.

    PubMed

    Tunc, Talip; Sahin, Ustun

    2016-04-01

    The objective of this 2-year field study was to evaluate the effects of drip irrigation with urban wastewaters reclaimed using primary (filtration) and secondary (filtration and aeration) processes on red cabbage growth and fresh yield, heavy metal content, water use and efficiency and soil chemical properties. Filtered wastewater (WW1), filtered and aerated wastewater (WW2), freshwater and filtered wastewater mix (1:1 by volume) (WW3) and freshwater (FW) were investigated as irrigation water treatments. Crop evapotranspiration decreased significantly, while water use efficiency increased under wastewater treatments compared to FW. WW1 treatment had the lowest value (474.2 mm), while FW treatments had the highest value (556.7 mm). The highest water use efficiency was found in the WW1 treatment as 8.41 kg m(-3), and there was a twofold increase with regard to the FW. Wastewater irrigation increased soil fertility and therefore red cabbage yield. WW2 treatment produced the highest total fresh yield (40.02 Mg ha(-1)). However, wastewater irrigation increased the heavy metal content in crops and soil. Cd content in red cabbage heads was above the safe limit, and WW1 treatment had the highest value (0.168 mg kg(-1)). WW3 treatment among wastewater treatments is less risky in terms of soil and crop heavy metal pollution and faecal coliform contamination. Therefore, WW3 wastewater irrigation for red cabbage could be recommended for higher yield and water efficiency with regard to freshwater irrigation. PMID:26611631

  18. Chemical process yielding stimulating emission of visible radiation via fast near resonant energy transfer

    SciTech Connect

    Gole, J.L.; Woodward, J.R.; Cobb, S.H.

    1991-05-28

    This patent describes a chemical process yielding stimulated emission of visible radiation via fast rear resonant intermolecular energy transfer. It comprises: providing a first source of vapor selected from the group consisting of metal or semimetal vapor; providing a second source of atomic vapor selected from the group consisting of metal or semimetal vapor to serve as receptor atoms to receive the energy; providing a source of reactant to react with the first source of vapor in a highly exothermic reaction which liberates energy exceeding 2.5 eV; chemically reacting the reactant and the first source of vapor to form metastable states of a final reaction product; transferring energy stored in the metastable states of the the reaction product to the second source of atomic vapor serving as receptor atoms by means of near resonant energy transfer; and providing a mirror configuration having first and second mirrors and windows associated with the mirrors.

  19. Upper Limits for Power Yield in Thermal, Chemical, and Electrochemical Systems

    NASA Astrophysics Data System (ADS)

    Sieniutycz, Stanislaw

    2010-03-01

    We consider modeling and power optimization of energy converters, such as thermal, solar and chemical engines and fuel cells. Thermodynamic principles lead to expressions for converter's efficiency and generated power. Efficiency equations serve to solve the problems of upgrading or downgrading a resource. Power yield is a cumulative effect in a system consisting of a resource, engines, and an infinite bath. While optimization of steady state systems requires using the differential calculus and Lagrange multipliers, dynamic optimization involves variational calculus and dynamic programming. The primary result of static optimization is the upper limit of power, whereas that of dynamic optimization is a finite-rate counterpart of classical reversible work (exergy). The latter quantity depends on the end state coordinates and a dissipation index, h, which is the Hamiltonian of the problem of minimum entropy production. In reacting systems, an active part of chemical affinity constitutes a major component of the overall efficiency. The theory is also applied to fuel cells regarded as electrochemical flow engines. Enhanced bounds on power yield follow, which are stronger than those predicted by the reversible work potential.

  20. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence.

    PubMed

    Sainju, Upendra M; Allen, Brett L; Caesar-TonThat, Thecan; Lenssen, Andrew W

    2015-01-01

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-year effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and cation exchange capacity (CEC) at the 0-120 cm depth and annualized crop yield in the northern Great Plains, USA. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (FSTCW), fall and spring till spring wheat-barley (Hordeum vulgare L., 1984-1999) followed by spring wheat-pea (Pisum sativum L., 2000-2013) (FSTW-B/P), and spring till spring wheat-fallow (STW-F, traditional system). At 0-7.5 cm, P, K, Zn, Na, and CEC were 23-60% were greater, but pH, buffer pH, and Ca were 6-31% lower in NTCW, STCW, and FSTW-B/P than STW-F. At 7.5-15 cm, K was 23-52% greater, but pH, buffer pH, and Mg were 3-21% lower in NTCW, STCW, FSTCW, FSTW-B/P than STW-F. At 60-120 cm, soil chemical properties varied with treatments. Annualized crop yield was 23-30% lower in STW-F than the other treatments. Continuous N fertilization probably reduced soil pH, Ca, and Mg, but greater crop residue returned to the soil increased P, K, Na, Zn, and CEC in NTCW and STCW compared to STW-F. Reduced tillage with continuous cropping may be adopted for maintaining long-term soil fertility and crop yields compared with the traditional system. PMID:26171303

  1. Comparison of different methods for extraction from Tetraclinis articulata: yield, chemical composition and antioxidant activity.

    PubMed

    Herzi, Nejia; Bouajila, Jalloul; Camy, Séverine; Romdhane, Mehrez; Condoret, Jean-Stéphane

    2013-12-15

    In the present study, three techniques of extraction: hydrodistillation (HD), solvent extraction (conventional 'Soxhlet' technique) and an innovative technique, i.e., the supercritical fluid extraction (SFE), were applied to ground Tetraclinis articulata leaves and compared for extraction duration, extraction yield, and chemical composition of the extracts as well as their antioxidant activities. The extracts were analyzed by GC-FID and GC-MS. The antioxidant activity was measured using two methods: ABTS(•+) and DPPH(•). The yield obtained using HD, SFE, hexane and ethanol Soxhlet extractions were found to be 0.6, 1.6, 40.4 and 21.2-27.4 g/kg respectively. An original result of this study is that the best antioxidant activity was obtained with an SFE extract (41 mg/L). The SFE method offers some noteworthy advantages over traditional alternatives, such as shorter extraction times, low environmental impact, and a clean, non-thermally-degraded final product. Also, a good correlation between the phenolic contents and the antioxidant activity was observed with extracts obtained by SFE at 9 MPa. PMID:23993518

  2. Quantitative determination of oxygen yield in a chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Kendrick, Kip R.; Helms, Charles A.; Quillen, Brian; Copland, R. J.

    1998-05-01

    With the advent of the Airborne Laser program, the emphasis of chemical oxygen-iodine laser (COIL) research has shifted toward improving the overall efficiency. A key component of COIL is the singlet-oxygen generator (SOG). To asses the efficiency of the SOG an accurate method of determining the yield of O2((alpha) 1(Delta) g),[O2((alpha) 1(Delta) g)]/[O2(total)] where [O2(total)]equals[O2((alpha) 1(Delta) g)]+[O2(X3(Sigma) g-)], has been developed. Absorption measurements of ground-state oxygen utilizing the magnetic-dipole transition, O2(X3(Sigma) g-) at 763 nm, have been obtained using a diode laser in conjunction with a multiple-pass Herriot-cell on a 10 kW class supersonic SOIL (RADICL). When RADICL is configured with a 0.35' throat, 15' diskpack, and a medium volume transition duct, with a diluent ratio (He:O2) of 3:1, the yield of O2((alpha) 1(Delta) g) in the diagnostic duct is 0.41 +/- 0.02.

  3. Wild Thymbra capitata from Western Rif (Morocco): essential oil composition, chemical homogeneity and yield variability.

    PubMed

    Bakhy, Khadija; Benlhabib, Ouafae; Al Faiz, Chaouki; Bighelli, Ange; Casanova, Joseph; Tomi, Felix

    2013-08-01

    Essential oils (EO, 15 collective samples and 47 individual samples) of Thymbra capitata collected from Moroccan Western Rif were analyzed using gas chromatography (GC) in combination with retention indices (RI), gas chromatography-mass spectrometry (GC-SM) and 13C NMR spectroscopy. Twenty components were identified. Carvacrol (68.2%-85.9%) was by far the major component of all the samples, while the content of thymol (0.1-0.3%) was very low. Other components present in appreciable amounts were gamma-terpinene (up to 8.9%), p-cymene (up to 7.1%), linalool (up to 4.4%) and (E)-beta-caryophyllene (up to 4.1%). In contrast, the yield of EO varied drastically from sample to sample (0.5-3.7%). No correlation could be established between yield of EO and altitude, pH, chemical composition and granularity of the soil. Cultivation under controlled conditions is suggested to improve the quantitative characteristics of carvacrol-rich Moroccan T. capitata. PMID:24079192

  4. Stellar yields with rotation and their effect on chemical evolution models

    NASA Astrophysics Data System (ADS)

    Chiappini, C.; Matteucci, F.; Meynet, G.

    2003-10-01

    We compute the evolution of different abundance ratios in the Milky Way (MW) for two different sets of stellar yields. In one of them stellar rotation is taken into account and we investigate its effects on the chemical evolution model predictions. Moreover, we show that some abundance ratios offer an important tool to investigate the halo-disk discontinuity. For the first time it is shown that the effect of a halt in the star formation between the halo/thick disk and thin disk phases, already suggested from studies based both on Fe/O vs. O/H and Fe/Mg vs. Mg/H, should also be seen in a C/O versus O/H plot if C is produced mainly by low- and intermediate-mass stars (LIMS). The idea that C originates mainly from LIMS is suggested by the flat behavior of the [C/Fe] ratio as a function of metallicity, from [Fe/H] ~ -2.2 to solar, and by the fact that very recent C/O measurements for stars in the MW halo and disk seem to show a discontinuity around log (O/H) + 12 ~ 8.4. Finally, a more gentle increase of N abundance with metallicity (or time), relative to models adopting the yields of van den Hoek & Groenewegen (\\cite{Hoe97}), is predicted by using the stellar yields of Meynet & Maeder (\\cite{Mey02} - which include stellar rotation but not hot-bottom burning) for intermediate mass stars. This fact has some implications for the timescales of N enrichment and thus for the interpretation of the nature of Damped Lyman Alpha Systems. The figures are available in color in electronic form.

  5. Effect of bio-regulator and foliar fertilizers on chemical composition and yield of soybean.

    PubMed

    Piccinin, Gleberson Guillen; Braccini, Alessandro Lucca; da Silva, Luiz Henrique; Mariucci, Giovanna Emanuêlle Gonçalves; Suzukawa, Andréia Kazumi; Dan, Lilian Gomes de Morais; Tonin, Telmo António

    2013-11-15

    Current study evaluates the effects of bio-regulator associated with foliar fertilizers on the yield components, productivity and chemical composition of soybean. The experimental design was entirely randomized blocks, with four replications. The treatments consisted of: T1-absolute control, T2-application of 0.25 L h(-1) Stimulate in R1 stage of development, T3-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1, T4-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1; T5-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 2 L h(-1) Mover in R5.1, T6-application of 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1 and T7-application of 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R1. Application of Sett and Mover is a potentially efficient handling as it favors the soybean agronomic performance in R1 stage. Chemical composition of processed grains has influence with applying bio-regulator and foliar fertilizers. PMID:24511692

  6. Probing a chemical compass: novel variants of low-frequency reaction yield detected magnetic resonance.

    PubMed

    Maeda, Kiminori; Storey, Jonathan G; Liddell, Paul A; Gust, Devens; Hore, P J; Wedge, C J; Timmel, Christiane R

    2015-02-01

    We present a study of a carotenoid-porphyrin-fullerene triad previously shown to function as a chemical compass: the photogenerated carotenoid-fullerene radical pair recombines at a rate sensitive to the orientation of an applied magnetic field. To characterize the system we develop a time-resolved Low-Frequency Reaction Yield Detected Magnetic Resonance (tr-LF-RYDMR) technique; the effect of varying the relative orientation of applied static and 36 MHz oscillating magnetic fields is shown to be strongly dependent on the strength of the oscillating magnetic field. RYDMR is a diagnostic test for involvement of the radical pair mechanism in the magnetic field sensitivity of reaction rates or yields, and has previously been applied in animal behavioural experiments to verify the involvement of radical-pair-based intermediates in the magnetic compass sense of migratory birds. The spectroscopic selection rules governing RYDMR are well understood at microwave frequencies for which the so-called 'high-field approximation' is valid, but at lower frequencies different models are required. For example, the breakdown of the rotating frame approximation has recently been investigated, but less attention has so far been given to orientation effects. Here we gain physical insights into the interplay of the different magnetic interactions affecting low-frequency RYDMR experiments performed in the challenging regime in which static and oscillating applied magnetic fields as well as internal electron-nuclear hyperfine interactions are of comparable magnitude. Our observations aid the interpretation of existing RYDMR-based animal behavioural studies and will inform future applications of the technique to verify and characterize further the biological receptors involved in avian magnetoreception. PMID:25537133

  7. Enhancing the Yield of Active Recombinant Chitobiase by Physico-Chemical and In Vitro Refolding Studies.

    PubMed

    Dangi, Arun Kumar; Rishi, Praveen; Tewari, Rupinder

    2016-02-01

    Chitobiase (CHB) is an important enzyme for the production of N-acetyl-D-glucosamine from the chitin biopolymer in the series of chitinolytic enzymes. Majority of over-expressed CHB (58%) in E. coli expression system led to formation of inclusion bodies. The production and soluble yield of active CHB was enhanced by co-expression with GroEL/ES chaperonin, optimizing culture conditions and solubilization followed by refolding of remaining inactive chitobiase present in the form of inclusion bodies. The growth of recombinant E. coli produced 42% CHB in soluble form and the rest (~58%) as inclusion bodies. The percentage of active CHB was enhanced to 71% by co-expression with GroEL/ES chaperonin system and optimizing culture conditions (37 °C, 200 rpm, IPTG--0.5 mM, L-arabinose--13.2 mM). Of the remaining inactive CHB present in inclusion bodies, 37% could be recovered in active form using pulsatile dilution method involving denaturants (2 M urea, pH 12.5) and protein refolding studies (1.0 M L-arginine, 5% glycerol). Using combinatorial approach, 80% of the total CHB expressed, could be recovered from cells grown in one litre of LB medium is a step forward in replacing hazardous chemical technology by biotechnological process for the production of NAG from chitinous waste. PMID:26831864

  8. Chemical and physical properties of high-yield alkaline sulfite green liquor

    SciTech Connect

    Sell, N.J.; Norman, J.C. . Natural and Applied Sciences)

    1993-11-01

    The majority of sodium sulfite pulping liquor recovery systems are based on the reductive burning of the spent liquor, followed by acidification of the resulting smelt solution by CO[sub 2]. This study investigated a number of the physical and chemical properties of the resulting green liquor which might be relevant to the optimum design of this type of sulfite and carbonate recovery system for an alkaline sulfite high-yield process. CO[sub 2] gas does generate H[sub 2]S when bubbled through green liquor; however, a large amount of solid soon is formed. Continuing the flow leads to increased amounts of H[sub 2]S, but the ratio of H[sub 2]S to CO[sub 2] remains less than 1.0. Solutions more highly concentrated in Na[sub 2]S absorb relatively more CO[sub 2], regardless of the ratios of H[sub 2]S to CO[sub 2] in the initial gas stream. The percentage of H[sub 2]S released increases with increasing Na[sub 2]S concentration. Stripping the green liquor with inert gas, steam, or vacuum does not improve the H[sub 2]S removal efficiency. The maximum CO[sub 2] pressure can be generated by decomposing pure 6 M NaHCO[sub 3]. If the starting material is a bicarbonate/carbonate mixture, conversion is incomplete and a portion of the NaHCO[sub 3] forms a dead load.

  9. Growth kinetics and yield study on Chlorella pyrenoidosa in chemically defined media

    SciTech Connect

    Joung, J.J.; Akin, C.

    1983-01-01

    A Chlorella culture free from heterotrophic bacteria was obtained by eliminating the bacteria with successive use of antibiotics and agar plants. The purified Chlorella was cultured in chemically defined media. Under a photon flux (16.7 mw/cmS) similar to insolation, both heterotrophic and mixotrophic cultures were luxurious but the growth rates of autotrophic cultures were reduced substantially. The Chlorella culture grew most rapidly at 30 C in the absence of heterotrophic bacteria, and the highest specific growth rates were 1.43 x 10 h and 0.46 x 10 h for mixotrophic and autotrophic cultures, respectively. The highest photosynthetic efficiency over its growth period was 2.9% for autotrophic cultures. Elimination of heterotrophic bacteria from Chlorella cultures improved the algal growth rate as well as biomass yield significantly. A parasite of 0.1- m size was identified. The motile microorganism played an important role in the growth of the Chlorella and appeared to be common to green algae. 16 references, 2 tables.

  10. The radiation-chemical yields of H 3O + and OH - as determined by nanosecond conductimetric measurements

    NASA Astrophysics Data System (ADS)

    Anderson, Robert F.; Vojnovic, Borivoj; Michael, Barry D.

    The radiation-chemical yields of ionic species formed upon irradiation of water by 3.5 MeV electrons have been determined directly using dc conductivity and optical measurements. Yields (expressed in μmol J -1) at 10 and 110 ns after the end of a 10 ns pulse are: for H 3O + = 0.371, 0.320; for OH - = 0.082, 0.045, and for e -aq = 0.299 and 0.275, respectively.

  11. Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

    NASA Astrophysics Data System (ADS)

    Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

    2016-04-01

    Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

  12. Yields, photosynthetic efficiencies, and proximate chemical composition of dense cultures of marine microalgae. A subcontract report

    SciTech Connect

    Thomas, W.H.; Seibert, D.L.R.; Alden, M.; Eldridge, P.; Neori, A.

    1983-07-01

    The yields, photosynthetic efficiencies, and proximate composition of several microalgae were compared in dense cultures grown at light intensities up to 70% sunlight. Yields ranged from 3.4 to 21.7 g dry weight/m/sup 2/ day. The highest yield was obtained with Phaeodactylum; the lowest in Botryococcus cultures. The same species had the highest and lowest efficiencies of utilization of photosynthetically active radiation. In nitrogen-sufficient cells of all but one species, most of the dry weight consisted of protein. Lipid content of all species was 20 to 29%, and carbohydrate content 11 to 23%. Lipid content increased somewhat in N-deficient Phaeodactylum and Isochrysis cells, but decreased in deficient Monallanthus cells. Because the overall dry weight yield was reduced by deficiency, lipid yields did not increase. However, since the carbohydrate content increased to about 65% in N-deficient Dunaliella and Tetraselmis cells, the carbohydrate yield increased. In Phaeodactylum the optimum light intensity was about 40% of full sunlight. Most experimets with this alga included a CUSO/sub 4/ filter to decrease infrared irradiance. When this filter was removed, the yield increased because more red light in the photosynthetically active spectral range was included. These results should prove useful to workers attempting to maximize yields and efficiencies, but additional studies are needed. 69 references, 27 figures, 18 tables.

  13. Bioinoculants: A sustainable approach to maximize the yield of Ethiopian mustard (Brassica carinata L.) under low input of chemical fertilizers.

    PubMed

    Nosheen, Asia; Bano, Asghari; Ullah, Faizan

    2016-02-01

    This study aimed to find out the effect of plant growth-promoting rhizobacteria (PGPR; Azospirillum brasilense and Azotobacter vinelandii) either alone or in combination with different doses of nitrogen and phosphate fertilizers on growth, seed yield, and oil quality of Brassica carinata (L.) cv. Peela Raya. PGPR were applied as seed inoculation at 10(6) cells/mL(-1) so that the number of bacterial cells per seed was 2.6 × 10(5) cells/seed. The chemical fertilizers, namely, urea and diammonium phosphate (DAP) were applied in different doses (full dose (urea 160 kg ha(-1) + DAP 180 kg ha(-1)), half dose (urea 80 kg ha(-1) + DAP 90 kg ha(-1)), and quarter dose (urea 40 kg ha(-1) + DAP 45 kg ha(-1)). The chemical fertilizers at full and half dose significantly increased the chlorophyll, carotenoids, and protein content of leaves and the seed yield (in kilogram per hectare) but had no effect on the oil content of seed. The erucic acid (C22:1) content present in the seed was increased. Azospirillum performed better than Azotobacter and its effect was at par with full dose of chemical fertilizers (CFF) for pigments and protein content of leaves when inoculated in the presence of half dose of chemical fertilizers (SPH). The seed yield and seed size were greater. Supplementing Azospirillum with SPH assisted Azospirillum to augment the growth and yield, reduced the erucic acid (C22:1) and glucosinolates contents, and increased the unsaturation in seed oil. It is inferred that A. brasilense could be applied as an efficient bioinoculant for enhancing the growth, seed yield, and oil quality of Ethiopian mustard at low fertilizer costs and sustainable ways. PMID:24097367

  14. Rate and yield relationships in the production of xanthan gum by batch fermentations using complex and chemically defined growth media

    SciTech Connect

    Pinches, A.; Pallent, L.J.

    1986-10-01

    Rate and yield information relating to biomass and product formation and to nitrogen, glucose and oxygen consumption are described for xanthan gum batch fermentations in which both chemically defined (glutamate nitrogen) and complex (peptone nitrogen) media are employed. Simple growth and product models are used for data interpretation. For both nitrogen sources, rate and yield parameter estimates are shown to be independent of initial nitrogen concentrations. For stationary phases, specific rates of gum production are shown to be independent of nitrogen source but dependent on initial nitrogen concentration. The latter is modeled empirically and suggests caution in applying simple product models to xanthan gum fermentations. 13 references.

  15. Ion Yields in the Coupled Chemical and Physical Dynamics Model of Matrix-Assisted Laser Desorption/Ionization

    NASA Astrophysics Data System (ADS)

    Knochenmuss, Richard

    2015-08-01

    The Coupled Chemical and Physical Dynamics (CPCD) model of matrix assisted laser desorption ionization has been restricted to relative rather than absolute yield comparisons because the rate constant for one step in the model was not accurately known. Recent measurements are used to constrain this constant, leading to good agreement with experimental yield versus fluence data for 2,5-dihydroxybenzoic acid. Parameters for alpha-cyano-4-hydroxycinnamic acid are also estimated, including contributions from a possible triplet state. The results are compared with the polar fluid model, the CPCD is found to give better agreement with the data.

  16. Effect of N on yield and chemical profile of winter canola in Mississippi.

    PubMed

    Zheljazkov, Valtcho D; Vick, Brady; Ebelhar, Wayne; Buehring, Normie; Astatkie, Tess

    2013-01-01

    There is increased interest in winter canola as an oilseeds crop for production of oil or biodiesel in the southeastern United States, but research has been limited. The objective of this study was to evaluate the effect of N (0, 60, 120, 180 kg N ha⁻¹) on productivity, oil content and oil composition of winter canola grown for two cropping seasons at three locations in Mississippi (Stoneville, and two locations at Verona: Verona upland silt loam, Verona-SL and Verona upland clay, Verona-C). Overall, increasing N application rates resulted in corresponding stepwise increase in seed yields in the two locations at Verona, whereas yields in the 60 and 120 kg N ha⁻¹ at Stoneville were not different from each other. Seed yields reached 3,383 and 3,166 kg ha⁻¹ in the 180 kg N treatment at Verona and at Stoneville, respectively. Oil yields were also increased with increasing N rates, however, oil yields at 60 and 120 kg N ha⁻¹ at Verona-C were not different from each other. Oil yields in the 180 kg N ha⁻¹ treatment reached 1,363 and 1,151 kg ha⁻¹ at Verona-SL and Stoneville, respectively. At Verona-SL location, higher N rates resulted in increased stearic acid compared to the lower N rates. However, the reverse effect was observed on the concentration of linolenic acid, which was lower at higher N rates. Also at that location, N application reduced the concentration of linoleic acid. At the Verona-C location, N application at 180 kg N ha⁻¹ reduced concentration of linolenic acid relative to the other fertility treatments. Overall, the increase in N application rates resulted in greater yield (kg FA ha⁻¹) of palmitic, palmitoleic, stearic, oleic, linoleic, linolenic, arachidic, eicosanoic, behenic, lignoceric and nervonic acids in all three locations, with N at 0 kg ha⁻¹ providing the lowest yields and N at 180 kg ha⁻¹ providing the highest yields. Winter canola production in the hot humid environment of southeastern United States can be

  17. Biochemical methane potential, biodegradability, alkali treatment and influence of chemical composition on methane yield of yard wastes.

    PubMed

    Gunaseelan, Victor Nallathambi

    2016-03-01

    In this study, the biochemical CH4 potential, rate, biodegradability, NaOH treatment and the influence of chemical composition on CH4 yield of yard wastes generated from seven trees were examined. All the plant parts were sampled for their chemical composition and subjected to the biochemical CH4 potential assay. The component parts exhibited significant variation in biochemical CH4 potential, which was reflected in their ultimate CH4 yields that ranged from 109 to 382 ml g(-1) volatile solids added and their rate constants that ranged from 0.042 to 0.173 d(-1). The biodegradability of the yard wastes ranged from 0.26 to 0.86. Variation in the biochemical CH4 potential of the yard wastes could be attributed to variation in the chemical composition of the different fractions. In the Thespesia yellow withered leaf, Tamarindus fruit pericarp and Albizia pod husk, NaOH treatment enhanced the ultimate CH4 yields by 17%, 77% and 63%, respectively, and biodegradability by 15%, 77% and 61%, respectively, compared with the untreated samples. The effectiveness of NaOH treatment varied for different yard wastes, depending on the amounts of acid detergent fibre content. Gliricidia petals, Prosopis leaf, inflorescence and immature pod, Tamarindus seeds, Albizia seeds, Cassia seeds and Delonix seeds exhibited CH4 yields higher than 300 ml g(-1) volatile solids added. Multiple linear regression models for predicting the ultimate CH4 yield and biodegradability of yard wastes were designed from the results of this work. PMID:26790450

  18. Sugarcane yields and soil chemical properties due to mill mud application to a sandy soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mill mud is a potentially beneficial by-product from the sugar milling process. An experiment was conducted to assess sugarcane yield and nutrient movement into subs after mill mud application in sandy soil. Treatments consisted of fertilizer (low fertilizer (LF) and adequate fertilizer (AF)), and m...

  19. Effect of extraction conditions on the yield and chemical properties of pectin from cocoa husks.

    PubMed

    Chan, Siew-Yin; Choo, Wee-Sim

    2013-12-15

    Different extraction conditions were applied to investigate the effect of temperature, extraction time and substrate-extractant ratio on pectin extraction from cocoa husks. Pectin was extracted from cocoa husks using water, citric acid at pH 2.5 or 4.0, or hydrochloric acid at pH 2.5 or 4.0. Temperature, extraction time and substrate-extractant ratio affected the yields, uronic acid contents, degrees of methylation (DM) and degrees of acetylation (DA) of the extracted pectins using the five extractants differently. The yields and uronic acid contents of the extracted pectins ranged from 3.38-7.62% to 31.19-65.20%, respectively. The DM and DA of the extracted pectins ranged from 7.17-57.86% to 1.01-3.48%, respectively. The highest yield of pectin (7.62%) was obtained using citric acid at pH 2.5 [1:25 (w/v)] at 95 °C for 3.0 h. The highest uronic acid content (65.20%) in the pectin was obtained using water [1:25 (w/v)] at 95 °C for 3.0 h. PMID:23993545

  20. Stellar yields from rotating stellar models: Their effect on chemical evolution model predictions

    NASA Astrophysics Data System (ADS)

    Chiappini, C.; Matteucci, F.

    In this work we evaluate the impact of the new stellar yields recently computed by \\citet{mm02}, where stellar rotation is taken into account, on important open questions related to the C, N and He enrichment in galaxies. Moreover, we show that some abundance ratios offer an important tool to investigate the halo-disk discontinuity. It is shown that the effect of a halt in the star formation between the halo/thick disk and thin disk phases, already suggested from studies based both on Fe/O and Fe/Mg, should also be seen in a C/O versus O/H plot if C is produced mainly by low- and intermediate-mass stars (LIMS). Recent C/O measurements for stars in the MW halo and disk seem to confirm the above prediction. Finally, a more gentle increase of N abundance with metallicity (or time) is predicted when adopting the stellar yields with rotation of \\citet{mm02}, which do not include hot-bottom burning, than when adopting the yields of \\citet{vdhg97}, for intermediate mass stars. This fact has some implications for the timescales for the N enrichment and thus for the interpretation of the nature of damped lyman alpha systems (DLAs).

  1. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-yr effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and catio...

  2. Impact of deficit irrigation on sorghum physical and chemical properties and ethanol yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the effect of irrigation levels (five levels from 304.8 to 76.2 mm water) on the physical and chemical properties and ethanol fermentation performance of sorghum. Ten sorghum samples grown under semi-arid climatic conditions were harvested in 2011 from the...

  3. Impact of deficit irrigation on maize physical and chemical properties and ethanol yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the effect of irrigation levels (five levels from 102 to 457 mm of water) on the physical and chemical properties and ethanol fermentation performance of maize. Twenty maize samples with two crop rotation systems, grain sorghum–maize and maize–maize, were ...

  4. Effect of fat reduction on chemical composition, proteolysis, functionality, and yield of Mozzarella cheese.

    PubMed

    Rudan, M A; Barbano, D M; Yun, J J; Kindstedt, P S

    1999-04-01

    Mozzarella cheese was made from skim milk standardized with cream (unhomogenized, 40% milk fat) to achieve four different target fat percentages in the cheese (ca. 5, 10, 15, and 25%). No statistically significant differences were detected for cheese manufacturing time, stretching time, concentration of salt in the moisture phase, pH, or calcium as a percentage of the protein in the cheese between treatments. As the fat percentage was reduced, there was an increase in the moisture and protein content of the cheese. However, because the moisture did not replace the fat on an equal basis, there was a significant decrease in the moisture in the nonfat substance in the cheese as the fat percentage was reduced. This decrease in total filler volume (fat plus moisture) was associated with an increase in the hardness of the unmelted cheese. Whiteness and opacity of the unmelted cheese decreased as the fat content decreased. Pizza baking performance, meltability, and free oil release significantly decreased as the fat percentage decreased. The minimum amount of free oil release necessary to obtain proper functionality during pizza baking was between 0.22 and 2.52 g of fat/100 g of cheese. Actual cheese yield was about 30% lower for cheese containing 5% fat than for cheese with 25% fat. Maximizing fat recovery in the cheese becomes less important to maintain high cheese yield, and moisture control and the retention of solids in the water phase become more important as the fat content of the cheese is reduced. PMID:10212453

  5. Sputtering yields and surface chemical modification of tin-doped indium oxide in hydrocarbon-based plasma etching

    SciTech Connect

    Li, Hu; Karahashi, Kazuhiro; Hamaguchi, Satoshi; Fukasawa, Masanaga; Nagahata, Kazunori; Tatsumi, Tetsuya

    2015-11-15

    Sputtering yields and surface chemical compositions of tin-doped indium oxide (or indium tin oxide, ITO) by CH{sup +}, CH{sub 3}{sup +}, and inert-gas ion (He{sup +}, Ne{sup +}, and Ar{sup +}) incidence have been obtained experimentally with the use of a mass-selected ion beam system and in-situ x-ray photoelectron spectroscopy. It has been found that etching of ITO is chemically enhanced by energetic incidence of hydrocarbon (CH{sub x}{sup +}) ions. At high incident energy incidence, it appears that carbon of incident ions predominantly reduce indium (In) of ITO and the ITO sputtering yields by CH{sup +} and CH{sub 3}{sup +} ions are found to be essentially equal. At lower incident energy (less than 500 eV or so), however, a hydrogen effect on ITO reduction is more pronounced and the ITO surface is more reduced by CH{sub 3}{sup +} ions than CH{sup +} ions. Although the surface is covered more with metallic In by low-energy incident CH{sub 3}{sup +} ions than CH{sup +} ions and metallic In is in general less resistant against physical sputtering than its oxide, the ITO sputtering yield by incident CH{sub 3}{sup +} ions is found to be lower than that by incident CH{sup +} ions in this energy range. A postulation to account for the relation between the observed sputtering yield and reduction of the ITO surface is also presented. The results presented here offer a better understanding of elementary surface reactions observed in reactive ion etching processes of ITO by hydrocarbon plasmas.

  6. Quantitative genetic parameters for yield, plant growth and cone chemical traits in hop (Humulus lupulus L.)

    PubMed Central

    2014-01-01

    Background Most traits targeted in the genetic improvement of hop are quantitative in nature. Improvement based on selection of these traits requires a comprehensive understanding of their inheritance. This study estimated quantitative genetic parameters for 20 traits related to three key objectives for the genetic improvement of hop: cone chemistry, cone yield and agronomic characteristics. Results Significant heritable genetic variation was identified for α-acid and β-acid, as well as their components and relative proportions. Estimates of narrow-sense heritability for these traits (h 2  = 0.15 to 0.29) were lower than those reported in previous hop studies, but were based on a broader suite of families (108 from European, North American and hybrid origins). Narrow-sense heritabilities are reported for hop growth traits for the first time (h 2  = 0.04 to 0.20), relating to important agronomic characteristics such as emergence, height and lateral morphology. Cone chemistry and growth traits were significantly genetically correlated, such that families with more vigorous vegetative growth were associated with lower α-acid and β-acid levels. This trend may reflect the underlying population structure of founder genotypes (European and North American origins) as well as past selection in the Australian environment. Although male and female hop plants are thought to be indistinguishable until flowering, sex was found to influence variation in many growth traits, with male and female plants displaying differences in vegetative morphology from emergence to cone maturity. Conclusions This study reveals important insights into the genetic control of quantitative hop traits. The information gained will provide hop breeders with a greater understanding of the additive genetic factors which affect selection of cone chemistry, yield and agronomic characteristics in hop, aiding in the future development of improved cultivars. PMID:24524684

  7. Aging of secondary organic aerosol from small aromatic VOCs. Changes in chemical composition, mass yield, volatility and hygroscopicity

    DOE PAGESBeta

    Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K.; Nenes, A.; Donahue, N. M.; Pandis, S. N.

    2014-12-12

    Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form and transform SOA from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NOx. The effects of chemical aging on organic aerosol (OA) composition, mass yield, volatility and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state OSC) and mass yield. The OA oxidation state generally increased during photo-oxidation, and the final OA OSmore » C ranged from -0.29 to 0.45 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have significantly different saturation concentration. There was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

  8. High Yield Chemical Vapor Deposition Growth of High Quality Large-Area AB Stacked Bilayer Graphene

    PubMed Central

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-01-01

    Bernal stacked (AB stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electrical field. Mechanical exfoliation can be used to produce AB stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB and randomly stacked structures. Herein we report a rational approach to produce large-area high quality AB stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H2/CH4 ratio in a low pressure CVD process to enable the continued growth of bilayer graphene. A high temperature and low pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90 %) and high coverage (up to 99 %). The electrical transport studies demonstrated that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB stacked bilayer graphene with the highest carrier mobility exceeding 4,000 cm2/V·s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

  9. Changes in Metabolic Chemical Reporter Structure Yield a Selective Probe of O-GlcNAc Modification

    PubMed Central

    2015-01-01

    Metabolic chemical reporters (MCRs) of glycosylation are analogues of monosaccharides that contain bioorthogonal functionalities and enable the direct visualization and identification of glycoproteins from living cells. Each MCR was initially thought to report on specific types of glycosylation. We and others have demonstrated that several MCRs are metabolically transformed and enter multiple glycosylation pathways. Therefore, the development of selective MCRs remains a key unmet goal. We demonstrate here that 6-azido-6-deoxy-N-acetyl-glucosamine (6AzGlcNAc) is a specific MCR for O-GlcNAcylated proteins. Biochemical analysis and comparative proteomics with 6AzGlcNAc, N-azidoacetyl-glucosamine (GlcNAz), and N-azidoacetyl-galactosamine (GalNAz) revealed that 6AzGlcNAc exclusively labels intracellular proteins, while GlcNAz and GalNAz are incorporated into a combination of intracellular and extracellular/lumenal glycoproteins. Notably, 6AzGlcNAc cannot be biosynthetically transformed into the corresponding UDP sugar-donor by the canonical salvage-pathway that requires phosphorylation at the 6-hydroxyl. In vitro experiments showed that 6AzGlcNAc can bypass this roadblock through direct phosphorylation of its 1-hydroxyl by the enzyme phosphoacetylglucosamine mutase (AGM1). Taken together, 6AzGlcNAc enables the specific analysis of O-GlcNAcylated proteins, and these results suggest that specific MCRs for other types of glycosylation can be developed. Additionally, our data demonstrate that cells are equipped with a somewhat unappreciated metabolic flexibility with important implications for the biosynthesis of natural and unnatural carbohydrates. PMID:25153642

  10. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    DOE PAGESBeta

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; et al

    2015-03-18

    We performed a systematic intercomparison study of the chemistry and yields of secondary organic aerosol (SOA) generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0 × 108 to 2.2 × 1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2 × 106 to 2 × 107 molec cm-3 over exposure times of several hours. The OH concentration in themore » chamber experiments is close to that found in the atmosphere, but the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. In most cases, for a specific SOA type the most-oxidized chamber SOA and the least-oxidized flow reactor SOA have similar mass spectra, oxygen-to-carbon and hydrogen-to-carbon ratios, and carbon oxidation states at integrated OH exposures between approximately 1 × 1011 and 2 × 1011 molec cm-3 s, or about 1–2 days of equivalent atmospheric oxidation. This observation suggests that in the range of available OH exposure overlap for the flow reactor and chambers, SOA elemental composition as measured by an aerosol mass spectrometer is similar whether the precursor is exposed to low OH concentrations over long exposure times or high OH concentrations over short exposure times. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of

  11. Evaluation of climatic factors on the yield and chemical composition of the essential oil of Myrocarpus frondosus.

    PubMed

    Cabrera, D C; Gomes, G L S; Flach, A; da Costa, L A M A; Rosa, G R; de Moura, N F

    2015-01-01

    The species Myrocarpus frondosus is native to southern Brazil, and it is known as cabreúva. It is a large tree, and its wood is used as a reservoir for distilled spirits, especially Cachaça. In this pioneering work, the essential oil was extracted monthly from the leaves of M. frondosus, for a period of 1 year. The essential oil was extracted by using hydrodistillation and the determination of the chemical composition of essential oil was performed by using the chromatographic techniques GC-FID and GC-MS. Thirty-three compounds were identified in the essential oil and bicyclogermacrene was the major compound. Through multivariate analysis, it was determined that β-caryophyllene, limonene and terpinen-4-ol were directly proportional to climatic factors. The yield of the oil was directly proportional to temperature and radiation. PMID:25421822

  12. Effects of extraction methods on the yield, chemical structure and anti-tumor activity of polysaccharides from Cordyceps gunnii mycelia.

    PubMed

    Zhu, Zhen-Yuan; Dong, Fengying; Liu, Xiaocui; Lv, Qian; YingYang; Liu, Fei; Chen, Ling; Wang, Tiantian; Wang, Zheng; Zhang, Yongmin

    2016-04-20

    This study was to investigate the effects of different extraction methods on the yield, chemical structure and antitumor activity of polysaccharides from Cordyceps gunnii (C. gunnii) mycelia. Five extraction methods were used to extract crude polysaccharides (CPS), which include room-temperature water extraction (RWE), hot-water extraction (HWE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and cellulase-assisted extraction (CAE). Then Sephadex G-100 was used for purification of CPS. As a result, the antitumor activities of CPS and PPS on S180 cells were evaluated. Five CPS and purified polysaccharides (PPS) were obtained. The yield of CPS by microwave-assisted extraction (CPSMAE) was the highest and its anti-tumor activity was the best and its macromolecular polysaccharide (3000-1000kDa) ratio was the largest. The PPS had the same monosaccharide composition, but their obvious difference was in the antitumor activity and the physicochemical characteristics, such as intrinsic viscosity, specific rotation, scanning electron microscopy and circular dichroism spectra. PMID:26876874

  13. High-yield chemical synthesis of hexagonal ZnO nanoparticles and nanorods with excellent optical properties.

    PubMed

    Giri, P K; Bhattacharyya, S; Chetia, B; Kumari, Satchi; Singh, Dilip K; Iyer, P K

    2012-01-01

    Large yield and low temperature growth of nanostructures are key requirements for fulfilling the demand of large scale applications of nanomaterials. Here, we report a highly efficient chemical method to synthesize high quality hexagonal ZnO nanoparticle and nanorods utilizing the low temperature oxidation of metallic zinc powder in the presence of an appropriate catalyst. This one-step method has advantages such as low temperature (90 degrees C) and atmospheric pressure synthesis and a high yield (> 90%). Microstructure and optical properties of the as-synthesized ZnO nanoparticles are found to be identical or better than those of the commercial ZnO nanopower (Sigma-Aldrich). In particular, in comparison to the commercial nanopowder the as-grown ZnO nanorods and nanoparticles exhibit stronger UV absorption at 376 nm and intense UV photoluminescence emission at -382 nm, with negligible defect emission band. This method is suitable for large-scale production of nanosized ZnO and could be extended for the synthesis of other metal oxides. PMID:22523966

  14. [Yield and chemical composition of the vegetal parts of the amaranth (Amaranthus hypochondriacus, L.) at different physiological stages].

    PubMed

    Alfaro, M A; Martínez, A; Ramírez, R; Bressani, R

    1987-03-01

    The genus Amaranthus comprises species which, consumed as vegetables, provide essential nutrients to man; they also have a high acceptability among the population. These two factors justify the need to increase their cultivation. Therefore, the purpose of this research was to establish the most adequate physiological state of maturity, to harvest the leaves for human consumption. The field experiment utilized a randomized block design with three treatments and eight replications. These treatments consisted in harvesting the plants at 25, 40 and 60 days after emergence of the seedlings, samples which served to evaluate: plant height, number of leaves, leaf surface area, gross weight (leaves and stems), net weight (leaves), green matter and dry matter yield, as well as protein. The chemical composition of the harvested material was evaluated also in terms of moisture, protein, crude fiber, ether extract, ash, carbohydrate, calcium, phosphorus, iron, beta-carotene and oxalates. The results obtained in the agronomic study were subjected to analysis of variance for the respective design, with significant differences found between treatments for all the variables studied. In its turn, the results of the chemical analysis were analyzed by a completely randomized design, with significant differences obtained for most of the variables studied, except for ether extract, calcium, iron and oxalates. From the nutritional point of view, the first harvest was the most acceptable due to the chemical composition of the plant, in particular protein (29.5%), beta-carotene (33.7 mg%), calcium (2,356.1 mg%), phosphorus (759.1 mg%) and due to its low crude fiber content, only 11.1 g%. It did not occur so from the agronomic point of view, since during this stage, very low yields of green matter (575.9 kg/ha), dry matter (66.6 kg/ha) and protein (19.7 kg/ha) were obtained. At the second harvest, besides obtaining adequate yields of green matter (6,530.4 kg/ha), dry matter (681.8 kg

  15. Impact of vetch cover crop on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Demelash, Nigus; Klik, Andreas; Holzmann, Hubert; Ziadat, Feras; Strohmeier, Stefan; Bayu, Wondimu; Zucca, Claudio; Abera, Atikilt

    2016-04-01

    Cover crops improve the sustainability and quality of both natural system and agro ecosystem. In Gumara-Maksegnit watershed which is located in Lake Tana basin, farmers usually use fallow during the rainy season for the preceding chickpea production system. The fallowing period can lead to soil erosion and nutrient losses. A field experiment was conducted during growing seasons 2014 and 2015 to evaluate the effect of cover crops on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia. The plot experiment contained four treatments arranged in Randomized Complete Block Design with three replications: 1) Control plot (Farmers' practice: fallowing- without cover crop), 2) Chickpea planted with Di-ammonium phosphate (DAP) fertilizer with 46 k ha-1 P2O5 and 23 k ha-1 nitrogen after harvesting vetch cover crop, 3) Chick pea planted with vetch cover crop incorporated with the soil as green manure without fertilizer, 4) Chick pea planted with vetch cover crop and incorporated with the soil as green manure and with 23 k ha-1 P2O5 and 12.5 k ha-1 nitrogen. Each plot with an area of 36 m² was equipped with a runoff monitoring system. Vetch (Vicia sativa L.) was planted as cover crop at the onset of the rain in June and used as green manure. The results of the experiment showed statistically significant (P < 0.05) differences on the number of pods per plant, above ground biomass and grain yield of chick pea. However, there was no statistically significant difference (P > 0.05) on average plant height, average number of branches and hundred seed weight. Similarly, the results indicated that cover crop has a clear impact on runoff volume and sediment loss. Plots with vetch cover crop reduce the average runoff by 65% and the average soil loss decreased from 15.7 in the bare land plot to 8.6 t ha-1 with plots covered by vetch. In general, this result reveales that the cover crops, especially vetch, can be used to improve chickpea grain yield

  16. Application of diamond films to electric propulsion: Low energy sputter yield measurement and MPD plasma assisted chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Blandino, John Joseph

    One application of chemically vapor deposited (CVD) diamond films under evaluation at the Jet Propulsion Laboratory is the coating of ion thruster electrodes subject to sputter erosion from xenon ions. Sputter yields were measured for polycrystalline diamond, single crystal diamond, a carbon-carbon composite, and molybdenum subject to xenon ion bombardment. The tests were performed using a 3 cm Kaufman ion source to produce incident ions with energy in the range of 150--750 eV and a profilometry-based technique to measure the amount of sputtered material. The yields increased monotonically with energy with values ranging from 0.16 atoms/ion at 150 eV to 0.80 at 750 eV for the molybdenum and 0.06 to 0.14 for the carbon-carbon. At 150 eV the yield for both diamond samples was 0.07 and at 7 50 eV, 0.19 and 0.17 for the CVD and single crystal diamond respectively. In terms of erosion rate, this translates into a factor of 7--12 lower erosion rate for diamond compared to molybdenum and at least a factor of 1.5 compared to carbon-carbon. In addition, an experimental investigation of an electromagnetic (magnetoplasmadynamic or MPD) plasma source for diamond CVD was undertaken using gas mixtures of methane, hydrogen and argon. Numerous trials were conducted using methane to hydrogen mixture ratios of 1.5--3.5 percent by volume, four different methane injector configurations, and substrate biasing at potentials of 25--75 V positive with respect to facility ground. These tests were performed at discharge currents of 700--950 A at approximately 18 V (12--17 kW). Crystalline films were produced with growth rates of 0.8 to 6.3 microns/hr. X-ray diffraction spectroscopy was used to identify at least one unambiguous diamond peak in each sample. The films all exhibited poor Raman spectra with no well defined peak at 1332 cm-1 and a broad background possibly due to high background levels of nitrogen, defects, and metal vapor contamination. Finally, the potential benefits of the MPD

  17. Chemical Composition and Yield of Six Genotypes of Common Purslane (Portulaca oleracea L.): An Alternative Source of Omega-3 Fatty Acids.

    PubMed

    Petropoulos, Spyridon Α; Karkanis, Anestis; Fernandes, Ângela; Barros, Lillian; Ferreira, Isabel C F R; Ntatsi, Georgia; Petrotos, Konstantinos; Lykas, Christos; Khah, Ebrahim

    2015-12-01

    Common purslane (Portulaca oleracea L.) is an annual weed rich in omega-3 fatty acids which is consumed for its edible leaves and stems. In the present study six different genotypes of common purslane (A-F) were evaluated for their nutritional value and chemical composition. Nutritional value and chemical composition depended on genotype. Oxalic acid content was the lowest for genotype D, whereas genotypes E and F are more promising for commercial cultivation, since they have low oxalic acid content. Genotype E had a very good antioxidant profile and a balanced composition of omega-3 and omega-6 fatty acids. Regarding yield, genotype A had the highest yield comparing to the other genotypes, whereas commercial varieties (E and F) did not differ from genotypes B and C. This study provides new information regarding common purslane bioactive compounds as affected by genotype and could be further implemented in food industry for products of high quality and increased added value. PMID:26510561

  18. Influence of ultrasonic pretreatment on the yield of bio-oil prepared by thermo-chemical conversion of rice husk in hot-compressed water.

    PubMed

    Shi, Wen; Jia, Jingfu; Gao, Yahui; Zhao, Yaping

    2013-10-01

    The aim of the current study is to investigate the feasibility of thermo-chemical conversion of rice husk in hot-compressed water via ultrasonic pretreatment to increase the bio-oil yield. The results show that ultrasonic pretreatment remarkably changes the structures of the rice husk, such as enhancing swelling and surface area, eroding lignin structure, and resulting in more exposure of the cellulose and hemicellulose. The highest bio-oil yield of 42.8% was obtained from the thermo-chemical conversion at 300 °C and 0 min of the residence time for the 1 h pretreated rice husk. GC-MS analysis indicates that the relative contents of phenols, 5-Hydroxymethylfurfural, and lactic acid are higher in bio-oils obtained from the pretreated rice husks than that from the raw rice husk. PMID:23948273

  19. Effect of jasmonic acid elicitation on the yield, chemical composition, and antioxidant and anti-inflammatory properties of essential oil of lettuce leaf basil (Ocimum basilicum L.).

    PubMed

    Złotek, Urszula; Michalak-Majewska, Monika; Szymanowska, Urszula

    2016-12-15

    The effect of elicitation with jasmonic acid (JA) on the plant yield, the production and composition of essential oils of lettuce leaf basil was evaluated. JA-elicitation slightly affected the yield of plants and significantly increased the amount of essential oils produced by basil - the highest oil yield (0.78±0.005mL/100gdw) was achieved in plants elicited with 100μM JA. The application of the tested elicitor also influenced the chemical composition of basil essential oils - 100μM JA increased the linalool, eugenol, and limonene levels, while 1μM JA caused the highest increase in the methyl eugenol content. Essential oils from JA-elicited basil (especially 1μM and 100μM) exhibited more effective antioxidant and anti-inflammatory potential; therefore, this inducer may be a very useful biochemical tool for improving production and composition of herbal essential oils. PMID:27451148

  20. Hydrothermal carbonisation of poultry litter: Effects of treatment temperature and residence time on yields and chemical properties of hydrochars.

    PubMed

    Ghanim, Bashir M; Pandey, Daya Shankar; Kwapinski, Witold; Leahy, James J

    2016-09-01

    In this study, hydrochars were prepared by hydrothermal carbonisation (HTC) of poultry litter (PL) at temperatures between 150-300°C with residence times of 30, 120 and 480min. The effects of treatment temperature and residence time on the yield and composition of hydrochar were investigated. Both treatment temperature and residence time effects were observed however, the effect of residence time was lower. The results indicated that the HHV was improved by up to 25.17% and the overall ash in hydrochar was significantly lower compared to PL, however this coincided with a lower hydrochar yield. PMID:27262091

  1. Effects of growth parameters on the yield and morphology of Si{sub 3}N{sub 4} microcoils prepared by chemical vapor deposition

    SciTech Connect

    Du, Hongli; Zhang, Wei; Li, Yan

    2014-02-01

    Highlights: • CVD method was successfully applied to obtain Si{sub 3}N{sub 4} microcoils in high yield without the presence of catalyst. • The process was systematically investigated through a series of control experiments. • The effects of synthesis parameters on the yield and morphology of Si{sub 3}N{sub 4} microcoils were found. • The growth mechanism of the Si{sub 3}N{sub 4} microcoils could be explained by the different growth rates between the amorphous layer and the crystalline layer. - Abstract: In this study, we provided a reliable chemical vapor deposition (CVD) method to synthesize high-purity Si{sub 3}N{sub 4} microcoils in high yield without the presence of catalyst. The achieved products were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscope. The results indicated that the yield and morphology of Si{sub 3}N{sub 4} products were influenced by the synthesis parameters such as reaction temperature, reaction time and gas flow rate. The particular conditions favorable to high yield synthesis of Si{sub 3}N{sub 4} microcoils were obtained through a series of control experiments. Furthermore, the growth of Si{sub 3}N{sub 4} microcoils was supposed to be in accord with vapor-solid (VS) growth process and the different growth rates between the amorphous layer and the crystalline layer were used to explain the formation of the coil geometry.

  2. Growth and yield responses of crops and macronutrient balance influenced by commercial organic manure used as a partial substitute for chemical fertilizers in an intensive vegetable cropping system

    NASA Astrophysics Data System (ADS)

    Lu, H. J.; Ye, Z. Q.; Zhang, X. L.; Lin, X. Y.; Ni, W. Z.

    A long-term field experiment was conducted with an annual rotation of tomato-radish-pakchoi to assess the effects of a commercial organic manure (COM) used as a partial substitute for chemical fertilizers on crop yield and nutrient balance in an intensive vegetable cropping system. Four treatments as chemical fertilizers (T1), chemical fertilizers + lower rate of COM (T2), chemical fertilizers + medium rate of COM (T3), and chemical fertilizers + high rate of COM (T4) were designed in the present experiment. The supplied doses of N, P, and K were equal for all treatments. Results showed that there were no significant differences in shoot biomass and market yields of tomato, radish and pakchoi among treatments ( P > 0.05). It was found that positive P and K balance existed in the tomato-radish-pakchoi cropping system of all treatments. Compared with no manure treatment (T1), application of medium rate of COM (T3) decreased N, P runoff losses, increased N, P, K contents in crop tissues except N, P in pakchoi shoot, and lessened P, K accumulation in soils, accordingly, improved the efficiency of macronutrient. It was concluded that appropriate COM used as a partial substitute for chemical fertilizers could not only meet the crops’ nutrient requirement, but also improved the efficiency of macronutrient and remained positive balance of P and K in the intensive tomato-radish-pakchoi cropping system, which can be regarded as an effective measure for a contribution towards sustainable agriculture and a control pathway for reducing the potential risk of castoff to water environment.

  3. Genetic parameters for body weight, carcass chemical composition and yield in a broiler-layer cross developed for QTL mapping

    PubMed Central

    Nunes, Beatriz do Nascimento; Ramos, Salvador Boccaletti; Savegnago, Rodrigo Pelicioni; Ledur, Mônica Corrêa; Nones, Kátia; Klein, Claudete Hara; Munari, Danísio Prado

    2011-01-01

    The objective of this study was to estimate genetic and phenotypic correlations of body weight at 6 weeks of age (BW6), as well as final carcass yield, and moisture, protein, fat and ash contents, using data from 3,422 F2 chickens originated from reciprocal cross between a broiler and a layer line. Variance components were estimated by the REML method, using animal models for evaluating random additive genetic and fixed contemporary group (sex, hatch and genetic group) effects. The heritability estimates (h2) for BW6, carcass yield and percentage of carcass moisture were 0.31 ± 0.07, 0.20 ± 0.05 and 0.33 ± 0.07, respectively. The h2 for the percentages of protein, fat and ash on a dry matter basis were 0.48 ± 0.09, 0.55 ± 0.10 and 0.36 ± 0.08, respectively. BW6 had a positive genetic correlation with fat percentage in the carcass, but a negative one with protein and ash contents. Carcass yield, thus, appears to have only low genetic association with carcass composition traits. The genetic correlations observed between traits, measured on a dry matter basis, indicated that selection for carcass protein content may favor higher ash content and a lower percentage of carcass fat. PMID:21931515

  4. Effect of intercropping Panicum maximum var. Ntchisi and Lablab purpureus on the growth, herbage yield and chemical composition of Panicum maximum var. Ntchisi at different harvesting times.

    PubMed

    Ojo, V O A; Dele, P A; Amole, T A; Anele, U Y; Adeoye, S A; Hassan, O A; Olanite, J A; Idowu, O J

    2013-11-15

    The study was conducted to evaluate the effect of intercropping Panicum maximum var. Ntchisi and Lablab purpureus on the growth, herbage yield and chemical composition of P. maximum var. Ntchisi at different harvesting times at the Teaching and Research farm, Federal University of Agriculture, Abeokuta in a randomized complete block design. Samples were collected at different harvesting times (8, 10, 12, 14 weeks after planting). The growth parameters which were plant height, leaf length, leaf number and tiller number measured showed that the intercropping of grass with legume were higher than in the sole plot of P. maximum var. Ntchisi. The plant yield was consistently higher (p < 0.05) in intercropped forages than in sole throughout the harvesting times. The crude protein contents of the forages were also higher for the intercropped across the treatments. The values of the fibre components were significantly different (p < 0.05) at different harvesting times and it was increasing as the harvesting time was increasing. From this study, considering the herbage yield and chemical composition of intecropping Panicum maximum var. Ntchisi and Lablab purpureus, they can be grazed by ruminant animals or harvested at 12 weeks after planting when the quality and quantity will support livestock productivity and can be conserved to be fed to ruminant animals during dry season when feed availability and quality are extremely low. PMID:24511710

  5. Monash Chemical Yields Project (Monχey) - Element production in low- and intermediate-mass stars of metallicities Z = 0 to 0.04

    NASA Astrophysics Data System (ADS)

    Doherty, Carolyn Louise; Lattanzio, John; Angelou, George; Wattana Campbell, Simon; Church, Ross; Constantino, Thomas; Cristallo, Sergio; Gil-Pons, Pilar; Karakas, Amanda; Lugaro, Maria; Stancliffe, Richard James

    2015-08-01

    The Monχey project provides a large and homogeneous set of stellar yields for the low- and intermediate- mass stars and has applications particularly to galactic chemical evolution modelling.We present a detailed grid of stellar evolutionary models and corresponding nucleosynthetic yields for stars of initial mass 0.8 M⊙ up to the limit for core collapse supernova ≈ 10 M⊙. Our study covers a broad range of metallicities, ranging from the first, primordial stars (Z=0) to those of super-solar metallicity (Z=0.04). The models are evolved from the zero-age main-sequence until the end of the asymptotic giant branch (AGB) and the nucleosynthesis calculations include all elements from H to Bi.A major innovation of our work is the first complete grid of heavy element nucleosynthetic predictions for primordial AGB stars as well as the inclusion of extra-mixing processes (in this case thermohaline) during the red giant branch. We provide a broad overview of our results with implications for galactic chemical evolution as well as highlight interesting results such as heavy element production in dredge-out events of super-AGB stars.We briefly introduce our easy to use web-based database which provides the evolutionary tracks, structural properties, internal/surface nucleosynthetic compositions and stellar yields. Our web interface includes user- driven plotting capabilities with output available in a range of formats. Our nucleosynthetic results are available for further use in post processing calculations for dust production yields.

  6. Heat-affected zone fracture toughness of 420-500 MPa yield strength steels: Effects of chemical composition and welding conditions

    SciTech Connect

    Tronskar, J.P. )

    1993-02-01

    During the last five years, high-strength steels with yield strengths in the range 420 to 500 MPa have attracted considerable interest within the offshore industry, primarily due to the potential for weight saving and reduction in volume of weld metal through the use of reduced section thicknesses. With respect to chemical composition these steels are developed following much the same philosophy as for the modern normalized structural steels. Due to the increased stress level in these higher strength steels, it is anticipated that brittle fracture initiation occurring in the coarse-gained HAZ will be more critical for these steels than for the lower strength normalized grades. The objective of this paper is to present the results from several experimental investigations carried out at VERITEC during the last five years to study the factors affecting the crack tip opening displacement (CTOD) fracture toughness of the heat-affected zone (HAZ) in structural steels in the yield strength range 420-500 MPa. Typical CTOD fracture toughnesses of the HAZ in normalized 350-MPa yield strength steels used in offshore structures are also presented for comparison. The results of the investigations confirm that the same chemical compositional factors which are known to influence the HAZ fracture toughness of normalized steels are also important for the 420-500-MPa yield strength steels. It is demonstrated that the width of the HAZ is important for the initiation of brittle fracture of pop-in and that this width must exceed a certain minimum value for such events to occur.

  7. Effects of synthetic and natural extraction chemicals on yield, composition and protein quality of soy protein isolates extracted from full-fat and defatted flours.

    PubMed

    Chamba, Moses Vernonxious Madalitso; Hua, Yufei; Murekatete, Nicole; Chen, Yeming

    2015-02-01

    With increasing preference for all-natural foods to those involving synthetic chemicals, native isoelectrically precipitated soy protein isolate (SPI) was prepared using amaranth (Amaranthus tricolor L.) lye (pH > 12.5) and lemon extract, (pH < 2.5) as natural, food-plant-based chemicals. Protein content (91.21 %), yield (43.62 %) and digestibility correlation amino acid score (0.77) were obtained and were comparable to those of SPI prepared using synthetic chemicals (NaOH and HCl). Methionine and cystein-s were significantly higher in the natural SPI while glutamine and serine were higher in synthetic SPI (p < 0.01). Most of the determined minerals were higher in the natural SPI with potassium being the highest. Sodium was very high in the synthetic SPI. The rest of the minerals including phosphorus, iron and nickel, showed no significant difference. Anti-nutritional factors (trypsin inhibitors and phytic acid) were considerably lower in the natural SPI. Thus, a quality all-natural SPI can be produced using amaranth lye and lemon extract to address concerns regarding use of synthetic chemicals. PMID:25694713

  8. Accurate fast method with high chemical yield for determination of uranium isotopes (234U, 235U, 238U) in granitic samples using alpha spectroscopy

    NASA Astrophysics Data System (ADS)

    Guirguis, Laila A.; Farag, Nagdy M.; Salim, Adham K.

    2015-03-01

    The present study aims to use the α-spectroscopy at Nuclear Materials Authority (NMA) of Egypt. A radiochemical technique for analysis uranium isotopes was carried out for ten mineralized granitic samples together with the International standards RGU-1 (IAEA) and St4 (NMA). Several steps of sample preparation, radiochemical separation and source preparation were performed before analysis. Uranium was separated from sample matrix with 0.2 M TOPO in cyclohexane as an extracting agent with a chemical yield 98.95% then uranium was purified from lanthanides and actinides present with 0.2 M TOA in xylene as an extracting agent. The pure fraction was electrodeposited on a mirror-polished copper disc from buffer solution (NaHSO4+H2SO4+NH4OH). Rectangle pt-electrode with an anode-cathode distance of 2 cm was used. Current was 900 mA and the electrodeposition time reach up to 120 min. The achieved results show that the chemical yield ranged between 87.9±6.8 and 98±8.6.

  9. High-yield chemical vapor deposition growth of high-quality large-area AB-stacked bilayer graphene.

    PubMed

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-09-25

    Bernal-stacked (AB-stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electric field. Mechanical exfoliation can be used to produce AB-stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB- and randomly stacked structures. Herein we report a rational approach to produce large-area high-quality AB-stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H(2)/CH(4) ratio in a low-pressure CVD process to enable the continued growth of bilayer graphene. A high-temperature and low-pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90%) and high coverage (up to 99%). The electrical transport studies demonstrate that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB-stacked bilayer graphene with the highest carrier mobility exceeding 4000 cm(2)/V · s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

  10. Improved production of recombinant human Fas ligand extracellular domain in Pichia pastoris: yield enhancement using disposable culture-bag and its application to site-specific chemical modifications

    PubMed Central

    2014-01-01

    Background A useful heterologous production system is required to obtain sufficient amounts of recombinant therapeutic proteins, which are often necessary for chemical characterization and engineering studies on the development of molecules with improved properties. Human Fas ligand extracellular domain (hFasLECD) is an agonistic death ligand protein that has potential applications for medical purposes. Site-specific chemical modifications can provide a powerful means for the development of engineered proteins with beneficial functions. This study aimed to enhance the yield of hFasLECD using a Pichia pastoris secretory expression system suitable for efficient production on a small laboratory scale, and further to provide procedures for its site-specific chemical modification without impairing the biological functions based on the developed production system. Results A convenient cultivation system using a disposable plastic bag provided a three-fold increase in purification yield of tag-free hFasLECD as compared with the conventional system using a baffled glass flask. The system was further applied to the production of a mutant, which contains an additional reactive cysteine residue in the N-terminal tag-sequence region. Site-specific conjugations and cross-linking without impairing biological functions were achieved by reaction of the mutant hFasLECD with single maleimide group containing compounds and a linear polyethylene glycol derivative containing two maleimide groups at either end, respectively. All purified tag-free and chemically modified hFasLECDs showed an evident receptor binding activity in co-immunoprecipitation experiments mediated by wild-type and N-glycosylation site deficient mutant human Fas receptor extracellular domain derivatives. An N-Ethylmaleimide conjugated hFasLECD derivative demonstrated a significant cytotoxic activity against human HT-29 colorectal cancer cells. Conclusions A new, efficient cultivation system for enhanced secretory

  11. A composite of complex and chemical hydrides yields the first Al-based amidoborane with improved hydrogen storage properties.

    PubMed

    Dovgaliuk, Iurii; Jepsen, Lars H; Safin, Damir A; Łodziana, Zbigniew; Dyadkin, Vadim; Jensen, Torben R; Devillers, Michel; Filinchuk, Yaroslav

    2015-10-01

    The first Al-based amidoborane Na[Al(NH2 BH3 )4 ] was obtained through a mechanochemical treatment of the NaAlH4 -4 AB (AB=NH3 BH3 ) composite releasing 4.5 wt % of pure hydrogen. The same amidoborane was also produced upon heating the composite at 70 °C. The crystal structure of Na[Al(NH2 BH3 )4 ], elucidated from synchrotron X-ray powder diffraction and confirmed by DFT calculations, contains the previously unknown tetrahedral ion [Al(NH2 BH3 )4 ](-) , with every NH2 BH3 (-) ligand coordinated to aluminum through nitrogen atoms. Combination of complex and chemical hydrides in the same compound was possible due to both the lower stability of the AlH bonds compared to the BH ones in borohydride, and due to the strong Lewis acidity of Al(3+) . According to the thermogravimetric analysis-differential scanning calorimetry-mass spectrometry (TGA-DSC-MS) studies, Na[Al(NH2 BH3 )4 ] releases in two steps 9 wt % of pure hydrogen. As a result of this decomposition, which was also supported by volumetric studies, the formation of NaBH4 and amorphous product(s) of the surmised composition AlN4 B3 H(0-3.6) were observed. Furthermore, volumetric experiments have also shown that the final residue can reversibly absorb about 27 % of the released hydrogen at 250 °C and p(H2 )=150 bar. Hydrogen re-absorption does not regenerate neither Na[Al(NH2 BH3 )4 ] nor starting materials, NaAlH4 and AB, but rather occurs within amorphous product(s). Detailed studies of the latter one(s) can open an avenue for a new family of reversible hydrogen storage materials. Finally, the NaAlH4 -4 AB composite might become a starting point towards a new series of aluminum-based tetraamidoboranes with improved hydrogen storage properties such as hydrogen storage density, hydrogen purity, and reversibility. PMID:26306666

  12. Growth Performance, Carcass Yield, and Quality and Chemical Traits of Meat from Commercial Korean Native Ducks with 2-Way Crossbreeding

    PubMed Central

    Heo, K. N.; Hong, E. C.; Kim, C. D.; Kim, H. K.; Lee, M. J.; Choo, H. J.; Choi, H. C.; Mushtaq, M. M. H.; Parvin, R.; Kim, J. H.

    2015-01-01

    This work was conducted to investigate the performance and meat characteristics of commercial Korean native duck (KND). A total of 180 1-d-old ducklings of 2-way crossbreds from A and B lines (from National Institute of Animal Science) were used in this work and divided into 4 groups (3 replicates/group, 15 birds/replicate). The four groups were 4 crossbreds as AA (A line [♀]×A line [♂]), AB (A line [♀]×B line [♂]), BB (Pure line B strains) and BA (B strains [♀]×A strain [♂]). Ducks were fed diets based on corn-soybean meal for 0 to 3 wk (22.4% crude protein [CP], 2,945 kcal/kg metabolizable energy [ME]) and 3 to 8 wk (18.4% CP, 3,047 kcal/kg ME). As a result of this study, average body weight of 4 crossbreds were 625, 1,617, 2,466, and 2,836 g at 2, 4, 6, and 8 weeks, respectively, and significantly increased over the period of time (p<0.05). Body weight of BB group was greater than other crossbreds at the age of 6 weeks (p<0.05). There was a significant difference in weekly body weight gains (p<0.05), which were 573, 991, 850, and 371 g at 2, 4, 6, and 8 weeks old, respectively. Uniformity of 4 crossbreds was 84.9%, 80.5%, and 72.5% at 6, 7, and 8 weeks, respectively, and there was no difference among crossbreds. Body weight gain of BB crossbred was highest among crossbreds (p<0.05). Weekly feed intake significantly increased with weeks as 669, 1,839, 2,812, and 3,381 g at 2, 4, 6, and 8 weeks respectively (p<0.05). Feed intakes of AA and BB crossbreds were higher at 2 to 4 weeks old than others and that of BB crossbred was highest at 4 to 6 weeks old (p<0.05). Weekly feed conversion ratios were 1.17, 1.86, 3.32, and 9.37 at 0 to 2, 2 to 4, 4 to 6, and 6 to 8 weeks old, respectively, and it increased with age (p<0.05). There was no significant difference in feed conversion ratio among crossbreds. Carcass yields of 4 crossbreds were 73.6%, 71.6%, 73.5%, and 71.7%, respectively, so there was no significant difference among crossbreds. There was no

  13. Effect of fly ash, organic wastes and chemical fertilizers on yield, nutrient uptake, heavy metal content and residual fertility in a rice-mustard cropping sequence under acid lateritic soils.

    PubMed

    Rautaray, S K; Ghosh, B C; Mittra, B N

    2003-12-01

    A field experiment was conducted for two years in sandy loam acid lateritic soil to study the direct effect of fly ash, organic wastes and chemical fertilizers on rice (Oryza sativa) and their residual effect on mustard (Brassica napus var glauca) grown in sequence. Rice yields were higher when fly ash, organic wastes and chemical fertilizers were used in an integrated manner as compared to sole application of chemical fertilizers. Yields of mustard were also higher under the residual effect of the former rather than the latter. However, this beneficial residual effect under integrated nutrient sources was inadequate for the mustard crop in the low fertility test soil. Hence, direct application of fertilizers was needed, in addition to residual fertility. The effect of fly ash on mean rice equivalent yield of the rice-mustard cropping sequence was highest (up to 14%) when it was used in combination with organic wastes and chemical fertilizers. While the yield increase was 10% when it was used in combination with only chemical fertilizers. The minimum yield advantage, 3%, occurred when fly ash was applied alone. The equivalent yield of the rice-mustard cropping sequence was equally influenced by either of the organic wastes. Cadmium and Ni content in rice grain and straw were less under the direct effect of fly ash. The residual effect on mustard was similar for Ni content in seed and stover; however, Cd content was increased. Beneficial residual soil chemical properties in terms of pH, organic carbon and available N, P and K were noted for integrated nutrient treatments involved fly ash, organic wastes and chemical fertilizers as compared to continuous use of only chemical fertilizers. Application of fly ash alone was effective in raising soil available P. Thus, integrated use of fly ash, organic wastes and chemical fertilizers was beneficial in improving crop yield, soil pH, organic carbon and available N, P and K in sandy loam acid lateritic soil. PMID:14575950

  14. Yield and depth Estimation of Selected NTS Nuclear and SPE Chemical Explosions Using Source Equalization by modeling Local and Regional Seismograms (Invited)

    NASA Astrophysics Data System (ADS)

    Saikia, C. K.; Roman-nieves, J. I.; Woods, M. T.

    2013-12-01

    Source parameters of nuclear and chemical explosions are often estimated by matching either the corner frequency and spectral level of a single event or the spectral ratio when spectra from two events are available with known source parameters for one. In this study, we propose an alternative method in which waveforms from two or more events can be simultaneously equalized by setting the differential of the processed seismograms at one station from any two individual events to zero. The method involves convolving the equivalent Mueller-Murphy displacement source time function (MMDSTF) of one event with the seismogram of the second event and vice-versa, and then computing their difference seismogram. MMDSTF is computed at the elastic radius including both near and far-field terms. For this method to yield accurate source parameters, an inherent assumption is that green's functions for the any paired events from the source to a receiver are same. In the frequency limit of the seismic data, this is a reasonable assumption and is concluded based on the comparison of green's functions computed for flat-earth models at various source depths ranging from 100m to 1Km. Frequency domain analysis of the initial P wave is, however, sensitive to the depth phase interaction, and if tracked meticulously can help estimating the event depth. We applied this method to the local waveforms recorded from the three SPE shots and precisely determined their yields. These high-frequency seismograms exhibit significant lateral path effects in spectrogram analysis and 3D numerical computations, but the source equalization technique is independent of any variation as long as their instrument characteristics are well preserved. We are currently estimating the uncertainty in the derived source parameters assuming the yields of the SPE shots as unknown. We also collected regional waveforms from 95 NTS explosions at regional stations ALQ, ANMO, CMB, COR, JAS LON, PAS, PFO and RSSD. We are

  15. Chemical properties of colliding sources in 124, 136Xe and 112, 124Sn induced collisions in isobaric yield ratio difference and isoscaling methods

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Wang; Wang, Shan-Shan; Zhang, Yan-Li; Wei, Hui-Ling

    2013-12-01

    Isoscaling and isobaric yield ratio difference (IBD) methods are used to study Δμ/T (Δμ being the difference between the chemical potentials of the neutron and proton, and T being the temperature) in the measured 1 A GeV 124Sn + 124Sn, 112Sn + 112Sn, 136Xe + Pb and 124Xe + Pb reactions. The isoscaling phenomena in the 124Sn/112Sn and 136Xe/124Xe reaction pairs are investigated, and the isoscaling parameters α and β are obtained. The Δμ/T determined by the isoscaling method (IS-Δμ/T) and the IBD method (IB-Δμ/T) in the measured Sn and Xe reactions are compared. It is shown that in most fragments, the IS- and IB-Δμ/T are consistent in the Xe reactions, while the IS- and IB-Δμ/T ones are only similar in the less neutron-rich fragments in the Sn reactions. The shell effects in IB-Δμ/T are also discussed.

  16. Synthesis of high yield single helical carbon microsprings by catalytic chemical vapor deposition and an experimental investigation of their growth mechanism

    SciTech Connect

    Xie Jining; Varadan, V. K.

    2007-06-01

    A type of single helical carbon microsprings (SHCMSs) was synthesized by catalytic chemical vapor deposition. The as-prepared SHCMSs were characterized by a number of techniques such as scanning and transmission electron microscopy, x-ray powder diffraction, and x-ray photoelectron spectroscopy. Experimental results indicate that during the synthesis both morphology change and crystalline phase transformation occur for cobalt catalytic particles and certain chemical bonding form between cobalt and sulfur atoms. Based on the data from this study, a possible growth mechanism of SHCMSs was discussed.

  17. Use of Peroxyacetic Acid as Green Chemical on Yield and Sensorial Quality in Watercress (Nasturtium officinale R. Br.) Under Soilless Culture

    PubMed Central

    Carrasco, Gilda; Moggia, Claudia; Osses, Ingrid Jennifer; Álvaro, Juan Eugenio; Urrestarazu, Miguel

    2011-01-01

    The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L−1 of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L−1 of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L−1 dose were 1.3 g plant−1 in the control group and 3.4 g plant−1 in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality. PMID:22272143

  18. Use of peroxyacetic acid as green chemical on yield and sensorial quality in Watercress (Nasturtium officinale R. Br.) under soilless culture.

    PubMed

    Carrasco, Gilda; Moggia, Claudia; Osses, Ingrid Jennifer; Alvaro, Juan Eugenio; Urrestarazu, Miguel

    2011-01-01

    The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L(-1) of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L(-1) of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L(-1) dose were 1.3 g plant(-1) in the control group and 3.4 g plant(-1) in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality. PMID:22272143

  19. Chemical characterisation and in vitro assessment of the nutritive value of co-products yield from the corn wet-milling process.

    PubMed

    Malumba, Paul; Boudry, Christelle; Roiseux, Olivier; Bindelle, Jérôme; Beckers, Yves; Béra, François

    2015-01-01

    The chemical characteristics of co-products recovered during a laboratory-scale wet milling procedure as well as that of whole corn flour were characterised and their digestibility and fermentability value determined using a 2 steps in vitro digestibility and fermentation model of the pig digestive tract. Five co-products differing in their chemical composition were collected and analysed. These co-products differed in their in vitro dry matter Digestibility and in their kinetic of fermentation. High coefficients of digestibility were observed for starchy samples, while low coefficients of digestibility were observed for samples rich in lignocellulosic components. Fermentation patterns of samples analysed were different as well as the profile of volatile fatty acids produced during the fermentation. The production of straight-chain fatty acids produced was significantly correlated with the proportion of starch in the sample, while branched-chain fatty acids were correlated to proteins concentration of samples. PMID:25053039

  20. Alternative bio-based solvents for extraction of fat and oils: solubility prediction, global yield, extraction kinetics, chemical composition and cost of manufacturing.

    PubMed

    Sicaire, Anne-Gaëlle; Vian, Maryline; Fine, Frédéric; Joffre, Florent; Carré, Patrick; Tostain, Sylvain; Chemat, Farid

    2015-01-01

    The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop's byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil) and non-food (bio fuel) applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS) simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols). Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF) as alternative solvent compared to hexane as petroleum solvent. PMID:25884332

  1. Quantum-chemical calculations of the metallofullerene yields in the X@C{sub 74}, L@C{sub 74}, and Z@C{sub 82} series

    SciTech Connect

    Uhlík, Filip; Slanina, Zdeněk; Nagase, Shigeru

    2015-01-22

    The contribution reports computations for Al@C{sub 82}, Sc@C{sub 82}, Y@C{sub 82} and La@C{sub 82} based on encapsulation into the IPR (isolated pentagon rule) C{sub 2ν} C{sub 82} cage and also on Mg@C{sub 74}, Ca@C{sub 74}, Sr@C{sub 74} and Ba@C{sub 74} based on encapsulation into the only C{sub 74} IPR cage as well as for three selected lanthanoids La@C{sub 74}, Yb@C{sub 74}, and Lu@C{sub 74}. Their structural and energetic characteristics are used for evaluations of the relative production yields, using the encapsulation Gibbs-energy and saturated metal pressures. It is shown that the results can be well related to the ionization potentials of the free metal atoms.

  2. Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction, Global Yield, Extraction Kinetics, Chemical Composition and Cost of Manufacturing

    PubMed Central

    Sicaire, Anne-Gaëlle; Vian, Maryline; Fine, Frédéric; Joffre, Florent; Carré, Patrick; Tostain, Sylvain; Chemat, Farid

    2015-01-01

    The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil) and non-food (bio fuel) applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS) simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols). Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF) as alternative solvent compared to hexane as petroleum solvent. PMID:25884332

  3. Quantum-chemical calculations of the metallofullerene yields in the X @ C74, L @ C74, and Z @ C82 series

    NASA Astrophysics Data System (ADS)

    Uhlík, Filip; Slanina, Zdeněk; Nagase, Shigeru

    2015-01-01

    The contribution reports computations for Al @ C82, Sc @ C82, Y @ C82 and La @ C82 based on encapsulation into the IPR (isolated pentagon rule) C2ν C82 cage and also on Mg @ C74, Ca @ C74, Sr @ C74 and Ba @ C74 based on encapsulation into the only C74 IPR cage as well as for three selected lanthanoids La @ C74, Yb @ C74, and Lu @ C74. Their structural and energetic characteristics are used for evaluations of the relative production yields, using the encapsulation Gibbs-energy and saturated metal pressures. It is shown that the results can be well related to the ionization potentials of the free metal atoms.

  4. Joining Chemical Pressure and Epitaxial Strain to Yield Y-doped BiFeO3 Thin Films with High Dielectric Response.

    PubMed

    Scarisoreanu, N D; Craciun, F; Birjega, R; Ion, V; Teodorescu, V S; Ghica, C; Negrea, R; Dinescu, M

    2016-01-01

    BiFeO3 is one of the most promising multiferroic materials but undergoes two major drawbacks: low dielectric susceptibility and high dielectric loss. Here we report high in-plane dielectric permittivity (ε' ∼2500) and low dielectric loss (tan δ < 0.01) obtained on Bi0.95Y0.05FeO3 films epitaxially grown on SrTiO3 (001) by pulsed laser deposition. High resolution transmission electron microscopy and geometric phase analysis evidenced nanostripe domains with alternating compressive/tensile strain and slight lattice rotations. Nanoscale mixed phase/domain ensembles are commonly found in different complex materials with giant dielectric/electromechanical (ferroelectric/ relaxors) or magnetoresistance (manganites) response. Our work brings insight into the joined role of chemical pressure and epitaxial strain on the appearance of nanoscale stripe structure which creates conditions for easy reorientation and high dielectric response, and could be of more general relevance for the field of materials science where engineered materials with huge response to external stimuli are a highly priced target. PMID:27157090

  5. Joining Chemical Pressure and Epitaxial Strain to Yield Y-doped BiFeO3 Thin Films with High Dielectric Response

    PubMed Central

    Scarisoreanu, N. D.; Craciun, F.; Birjega, R.; Ion, V.; Teodorescu, V. S.; Ghica, C.; Negrea, R.; Dinescu, M.

    2016-01-01

    BiFeO3 is one of the most promising multiferroic materials but undergoes two major drawbacks: low dielectric susceptibility and high dielectric loss. Here we report high in-plane dielectric permittivity (ε’ ∼2500) and low dielectric loss (tan δ < 0.01) obtained on Bi0.95Y0.05FeO3 films epitaxially grown on SrTiO3 (001) by pulsed laser deposition. High resolution transmission electron microscopy and geometric phase analysis evidenced nanostripe domains with alternating compressive/tensile strain and slight lattice rotations. Nanoscale mixed phase/domain ensembles are commonly found in different complex materials with giant dielectric/electromechanical (ferroelectric/ relaxors) or magnetoresistance (manganites) response. Our work brings insight into the joined role of chemical pressure and epitaxial strain on the appearance of nanoscale stripe structure which creates conditions for easy reorientation and high dielectric response, and could be of more general relevance for the field of materials science where engineered materials with huge response to external stimuli are a highly priced target. PMID:27157090

  6. Joining Chemical Pressure and Epitaxial Strain to Yield Y-doped BiFeO3 Thin Films with High Dielectric Response

    NASA Astrophysics Data System (ADS)

    Scarisoreanu, N. D.; Craciun, F.; Birjega, R.; Ion, V.; Teodorescu, V. S.; Ghica, C.; Negrea, R.; Dinescu, M.

    2016-05-01

    BiFeO3 is one of the most promising multiferroic materials but undergoes two major drawbacks: low dielectric susceptibility and high dielectric loss. Here we report high in-plane dielectric permittivity (ε’ ∼2500) and low dielectric loss (tan δ < 0.01) obtained on Bi0.95Y0.05FeO3 films epitaxially grown on SrTiO3 (001) by pulsed laser deposition. High resolution transmission electron microscopy and geometric phase analysis evidenced nanostripe domains with alternating compressive/tensile strain and slight lattice rotations. Nanoscale mixed phase/domain ensembles are commonly found in different complex materials with giant dielectric/electromechanical (ferroelectric/ relaxors) or magnetoresistance (manganites) response. Our work brings insight into the joined role of chemical pressure and epitaxial strain on the appearance of nanoscale stripe structure which creates conditions for easy reorientation and high dielectric response, and could be of more general relevance for the field of materials science where engineered materials with huge response to external stimuli are a highly priced target.

  7. Evaluation of the potential for using old-field vegetation as an energy feedstock: Biomass yield, chemical composition, environmental concerns, and economics

    SciTech Connect

    Johnston, J.W. Jr.

    1990-07-01

    The major focus of current research on production of biomass for use as energy feedstock involves selection of species and genotypes best suited for specific regions of the United States and development of crop management techniques that maximize biomass productivity while minimizing environmental impacts and economic costs. The two experimental sites, and abandoned soybean field (AS) and an abandoned pasture (AP) were studied. At the AS site, the effects of two harvest frequencies (1 or 2 harvests annually), two nitrogen fertilizer treatments (1 or 2 harvests annually), two nitrogen fertilizer treatments (0 or 87 kg{center dot}ha{sup {minus}1}{center dot}yr{sup {minus}1}), and two phosphorous fertilizer treatments (0 or 111 kg{center dot}ha{sup {minus}1}{center dot}yr{sup {minus}1}) were determined. At the AP site, the effects of two harvest treatments (1 or 2 harvests annually), two fertilizer treatments (56:56:135 kg of N:P:K{center dot}ha{sup {minus}1}{center dot}yr{sup {minus}1}), and two lime treatments (0 or 4600 kg{center dot}ha{sup {minus}1}{center dot}yr{sup {minus}1}) were determined. At both sites, treatments were arranged in a randomized complete block 2 {times} 2 {times} 2 factorial experiment. The results of this research indicated that old-field vegetation is: (1) sufficiently productive to provide significant quantities of energy feedstock; (2) chemically suitable as an energy feedstock; (3) environmentally benign with respect to impacts related to soil erosion and nutrient depletion; (4) relatively unresponsive to fertilizer and lime inputs; and (5) economically competitive with other biomass energy feedstock candidates. 38 refs., 8 figs., 68 tabs.

  8. Two-silane chemical vapor deposition treatment of polymer (nylon) and oxide surfaces that yields hydrophobic (and superhydrophobic), abrasion-resistant thin films

    SciTech Connect

    Saini, Gaurav; Sautter, Ken; Hild, Frank E.; Pauley, Jerry; Linford, Matthew R.

    2008-09-15

    This article describes a two-silane, chemical vapor deposition (CVD) approach to creating hydrophobic (or even superhydrophobic), abrasion-resistant coatings on silicon oxide and polymer (nylon) substrates. This multistep approach employs only reagents delivered in the gas phase, as follows: (i) plasma cleaning/oxidation of the substrate, (ii) CVD of 3-isocyanatopropyltriethoxysilane, which is used as an adhesion promoter for the substrate, (iii) hydrolysis with water vapor, and (iv) CVD of (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane (the 'R{sub f}-Cl silane'). Surfaces are characterized by wetting, spectroscopic ellipsometry, x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). This work has the following unique features. First, the authors explore an all gas phase deposition of a new silane coating that is scientifically interesting and technologically useful. Second, the authors show that the presence of an adhesion promoter in the process leads to thinner films that are more robust in abrasion testing. Third, results obtained using plasma/deposition equipment that is relatively inexpensive and/or available in most laboratories are compared to those obtained with a much more sophisticated, commercially available plasma/CVD system (the YES-1224P). The entire deposition process can be completed in only {approx}1 h using the industrial equipment (the 1224P). It is of significance that the polymer surfaces modified using the 1224P are superhydrophobic. Fourth, the thickness of the R{sub f}-Cl silane layer deposited by CVD correlates well with the thickness of the underlying spin coated nylon surface, suggesting that the nylon film acts as a reservoir of water for the hydrolysis and condensation of the R{sub f}-Cl silane.

  9. Comparison of secondary organic aerosol formed with an aerosol flow reactor and environmental reaction chambers: effect of oxidant concentration, exposure time and seed particles on chemical composition and yield

    DOE PAGESBeta

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; et al

    2014-12-02

    We performed a systematic intercomparison study of the chemistry and yields of SOA generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0×108 to 2.2×1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2×106 to 2×107 molec cm-3 over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, butmore » the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. A linear correlation analysis of the mass spectra (m=0.91–0.92, r2=0.93–0.94) and carbon oxidation state (m=1.1, r2=0.58) of SOA produced in the flow reactor and environmental chambers for OH exposures of approximately 1011 molec cm-3 s suggests that the composition of SOA produced in the flow reactor and chambers is the same within experimental accuracy as measured with an aerosol mass spectrometer. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors, rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are

  10. Chemical and toxicological characterization of residential oil burner emissions: I. Yields and chemical characterization of extractables from combustion of No. 2 fuel oil at different Bacharach Smoke Numbers and firing cycles.

    PubMed Central

    Leary, J A; Biemann, K; Lafleur, A L; Kruzel, E L; Prado, G P; Longwell, J P; Peters, W A

    1987-01-01

    Particulates and complex organic mixtures were sampled from the exhaust of a flame retention head residential oil burner combusting No. 2 fuel oil at three firing conditions: continuous at Bacharach Smoke No. 1, and cyclic (5 min on, 10 min off) at Smoke Nos. 1 and 5. The complex mixtures were recovered by successive Soxhlet extraction of filtered particulates and XAD-2 sorbent resin with methylene chloride (DCM) and then methanol (MeOH). Bacterial mutagenicity [see Paper II (8)] was found in the DCM extractables. Samples of DCM extracts from the two cyclic firing conditions and of the raw fuel were separated by gravity column chromatography on alumina. The resulting fractions were further characterized by a range of instrumental methods. Average yields of both unextracted particulates and of DCM extractables, normalized to a basis of per unit weight of fuel fired, were lower for continuous firing than for cyclic firing. For cyclic firing, decreasing the smoke number lowered the particulates emissions but only slightly reduced the average yield of DCM extractables. These and similar observations, here reported for two other oil burners, show that adjusting the burner to a lower smoke number has little effect on, or may actually increase, emissions of organic extractables of potential public health interest. Modifications of the burner firing cycle aimed at approaching continuous operation offer promise for reducing the amount of complex organic emissions. Unburned fuel accounted for roughly half of the DCM extractables from cyclic firing of the flame retention head burner at high and low smoke number. Large (i.e., greater than 3 ring) polycyclic aromatic hydrocarbons (PAH) were not observed in the DCM extractables from cyclic firing. However, nitroaromatics, typified by alkylated nitronaphthalenes, alkyl-nitrobiphenyls, and alkyl-nitrophenanthrenes were found in a minor subfraction containing a significant portion of the total mutagenic activity of the cyclic low

  11. Formation and Yield of Multi-Walled Carbon Nanotubes Synthesized via Chemical Vapour Deposition Routes Using Different Metal-Based Catalysts of FeCoNiAl, CoNiAl and FeNiAl-LDH

    PubMed Central

    Hussein, Mohd Zobir; Mohamad Jaafar, Adila; Hj. Yahaya, Asmah; Masarudin, Mas Jaffri; Zainal, Zulkarnain

    2014-01-01

    Multi-walled carbon nanotubes (MWCNTs) were prepared via chemical vapor deposition (CVD) using a series of different catalysts, derived from FeCoNiAl, CoNiAl and FeNiAl layered double hydroxides (LDHs). Catalyst-active particles were obtained by calcination of LDHs at 800 °C for 5 h. Nitrogen and hexane were used as the carrier gas and carbon source respectively, for preparation of MWCNTs using CVD methods at 800 °C. MWCNTs were allowed to grow for 30 min on the catalyst spread on an alumina boat in a quartz tube. The materials were subsequently characterized through X-ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, field emission scanning electron microscopy and transmission electron microscopy. It was determined that size and yield of MWCNTs varied depending on the type of LDH catalyst precursor that is used during synthesis. MWCNTs obtained using CoNiAl-LDH as the catalyst precursor showed smaller diameter and higher yield compared to FeCoNiAl and FeNiAl LDHs. PMID:25380526

  12. Formation and yield of multi-walled carbon nanotubes synthesized via chemical vapour deposition routes using different metal-based catalysts of FeCoNiAl, CoNiAl and FeNiAl-LDH.

    PubMed

    Hussein, Mohd Zobir; Jaafar, Adila Mohamad; Yahaya, Asmah Hj; Masarudin, Mas Jaffri; Zainal, Zulkarnain

    2014-01-01

    Multi-walled carbon nanotubes (MWCNTs) were prepared via chemical vapor deposition (CVD) using a series of different catalysts, derived from FeCoNiAl, CoNiAl and FeNiAl layered double hydroxides (LDHs). Catalyst-active particles were obtained by calcination of LDHs at 800 °C for 5 h. Nitrogen and hexane were used as the carrier gas and carbon source respectively, for preparation of MWCNTs using CVD methods at 800 °C. MWCNTs were allowed to grow for 30 min on the catalyst spread on an alumina boat in a quartz tube. The materials were subsequently characterized through X-ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, field emission scanning electron microscopy and transmission electron microscopy. It was determined that size and yield of MWCNTs varied depending on the type of LDH catalyst precursor that is used during synthesis. MWCNTs obtained using CoNiAl-LDH as the catalyst precursor showed smaller diameter and higher yield compared to FeCoNiAl and FeNiAl LDHs. PMID:25380526

  13. Yield Improvement in Steel Casting (Yield II)

    SciTech Connect

    Richard A. Hardin; Christoph Beckermann; Tim Hays

    2002-02-18

    This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to four time s the

  14. Reckoning wheat yield trends

    NASA Astrophysics Data System (ADS)

    Lin, M.; Huybers, P.

    2012-06-01

    Wheat yields have increased approximately linearly since the mid-twentieth century across the globe, but stagnation of these trends has now been suggested for several nations. We present a new statistical test for whether a yield time series has leveled off and apply it to wheat yield data from 47 different regions to show that nearly half of the production within our sample has transitioned to level trajectories. With the major exception of India, the majority of leveling in wheat yields occurs within developed nations—including the United Kingdom, France and Germany—whose policies appear to have disincentivized yield increases relative to other objectives. The effects of climate change and of yields nearing their maximum potential may also be important.

  15. Atmospheric Nitrogen Fluorescence Yield

    NASA Technical Reports Server (NTRS)

    Adams, J. H., Jr.; Christl, M. J.; Fountain, W. F.; Gregory, J. C.; Martens, K. U.; Sokolsky, Pierre; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Several existing and planned experiments estimate the energies of ultra-high energy cosmic rays from air showers using the atmospheric nitrogen fluorescence. The nitrogen fluorescence yield from air shower electrons depends on the atmospheric composition. We will discuss the uncertainties in the fluorescence yield form electrons in the real atmosphere and describe a concept for a small balloon payload to measure the atmospheric fluorescence yield as a function of attitude.

  16. Yield and Temporal Yield Variability Under Conventional and Alternative Management Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Year to year variation in yield is an inherit risk associated with crop production and many growers rely on intensive mechanical or chemical inputs to secure crop yields in the face of fluctuating environmental conditions. However, as interest in alternative approaches to crop management which are ...

  17. Reed canarygrass yield improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reed canarygrass is well adapted to the northern USA. Eight cultivars and 72 accessions collected in rural landscapes from Iowa to New Hampshire were evaluated for yield. Accessions produced on average 7% higher biomass yield compared to existing cultivars. Naturalized populations of reed canarygras...

  18. Management of ISOLDE yields

    NASA Astrophysics Data System (ADS)

    Turrión, M.; Eller, M.; Catherall, R.; Fraile, L. M.; Herman-Izycka, U.; Köster, U.; Lettry, J.; Riisager, K.; Stora, Th.

    2008-10-01

    Isotope yields at ISOLDE are regularly measured online (with dedicated gamma and beta detectors) and off line by implantation and subsequent alpha-, beta- or gamma spectroscopy. The Java based measurement software, dedicated to tape station measurements, has been updated in order to automate yield measurements and provide possibilities to repeat existing measurements. A procedure supported by dedicated programs was established to analyze data. The results are centrally stored and provide an interface to the existing ISOLDE yield database. The present ISOLDE yield database has been recently created and updated with a large number of yields compiled from published data. The database developed on ORACLE guarantees reliability and security and provides a simple way of compiling new information. A user oriented interface has been programmed allowing accessing the information via a web browser. Several levels in the database structure provide selective access to different layers of technical information for advanced users and for technical R&D. The improvements in the yield measurement procedure, the data storage and accessibility, as well as the new database structure, the web application and the access interfaces, enhance the communication between technical information like yields and the users of the ISOLDE facility.

  19. Conversion of cornstalk to bio-oil in hot-compressed water: effects of ultrasonic pretreatment on the yield and chemical composition of bio-oil, carbon balance, and energy recovery.

    PubMed

    Shi, Wen; Gao, Yahui; Yang, Guohui; Zhao, Yaping

    2013-08-01

    An ultrasonic pretreatment method was developed to enhance the yield of bio-oil obtained from the liquefaction of cornstalks in hot-compressed water at different reaction temperatures (260-340 °C) and residence times (0-40 min). Influences of ultrasonic pretreatment on the physicochemical properties of cornstalks and bio-oil yields were investigated. The results show that ultrasonic pretreatment obviously increases surface areas of cornstalks, decreases crystallinities, and erodes the structures of lignin, leading to more exposure of cellulose and hemicellulose. The yield of bio-oil was increased remarkably by 10.1% for 40 min sonicated cornstalks under the optimum liquefied conditions (300 °C for 0 min of residence time). Carbon balance indicates that ultrasonic pretreatment increases the carbon conversion of cornstalks to heavy oil and water-soluble oil. Energy balance indicates that the sonicated cornstalks have positive energy efficiencies. GC-MS analyses demonstrate ultrasonic pretreatment increases the contents of the phenols in heavy oil and water-soluble oil. PMID:23859803

  20. Low-Yield Cigarettes

    MedlinePlus

    ... Secondhand Smoke Smokeless Products Youth Tobacco Prevention Tobacco Industry and Products Federal Tax Increase Tobacco Ingredient Reporting ... be used. 3 In the past, the tobacco industry categorized low-yield cigarettes using measurements of tar ...

  1. Argentina wheat yield model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    Five models based on multiple regression were developed to estimate wheat yields for the five wheat growing provinces of Argentina. Meteorological data sets were obtained for each province by averaging data for stations within each province. Predictor variables for the models were derived from monthly total precipitation, average monthly mean temperature, and average monthly maximum temperature. Buenos Aires was the only province for which a trend variable was included because of increasing trend in yield due to technology from 1950 to 1963.

  2. Argentina soybean yield model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    A model based on multiple regression was developed to estimate soybean yields for the country of Argentina. A meteorological data set was obtained for the country by averaging data for stations within the soybean growing area. Predictor variables for the model were derived from monthly total precipitation and monthly average temperature. A trend variable was included for the years 1969 to 1978 since an increasing trend in yields due to technology was observed between these years.

  3. Argentina corn yield model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    A model based on multiple regression was developed to estimate corn yields for the country of Argentina. A meteorological data set was obtained for the country by averaging data for stations within the corn-growing area. Predictor variables for the model were derived from monthly total precipitation, average monthly mean temperature, and average monthly maximum temperature. A trend variable was included for the years 1965 to 1980 since an increasing trend in yields due to technology was observed between these years.

  4. Physical and chemical water-quality data and nitrogen and phosphorus yields for 29 sites sampled in two synoptic surveys of streams within the Lewisville Lake watershed are presented in this report. The two synoptic surveys were conducted in March 1984 and March 1985, as a reconnaissance and assessment of water quality and nitrogen and phosphorus yields throughout the watershed. This work was cooperatively funded by the city of Dallas and the U.S. Geological Survey (USGS) as part of a hydrologic study to quantify nonpoint nutrient loads to Lewisville Lake.

    USGS Publications Warehouse

    Gain, W. Scott

    1989-01-01

    Physical and chemical water-quality data and nitrogen and phosphorus yields for 29 sites sampled in two synoptic surveys of streams within the Lewisville Lake watershed are presented in this report. The two synoptic surveys were conducted in March 1984 and March 1985, as a reconnaissance and assessment of water quality and nitrogen and phosphorus yields throughout the watershed. This work was cooperatively funded by the city of Dallas and the U.S. Geological Survey (USGS) as part of a hydrologic study to quantify nonpoint nutrient loads to Lewisville Lake.

  5. Yield threshold decision framework

    SciTech Connect

    Judd, B.R.; Younker, L.W.; Hannon, W.J.

    1989-08-17

    The USA is developing a decision analysis framework for evaluating the relative value of lower yield thresholds and related verification policies. The framework facilitates systematic analysis of the major issues in the yield threshold decision. The framework can be used to evaluate options proposed either in the inter-agency process or in the negotiations. In addition, the framework can measure the importance of uncertainties and alternative judgments, and thereby determine the advantages of additional research. Since the model is explicit and quantitative, it provides a rational, defensible approach for reaching important treaty and verification decisions. 9 figs.

  6. Plasma-Enhanced Chemical Vapor Deposition (PE-CVD) yields better Hydrolytical Stability of Biocompatible SiOx Thin Films on Implant Alumina Ceramics compared to Rapid Thermal Evaporation Physical Vapor Deposition (PVD).

    PubMed

    Böke, Frederik; Giner, Ignacio; Keller, Adrian; Grundmeier, Guido; Fischer, Horst

    2016-07-20

    Densely sintered aluminum oxide (α-Al2O3) is chemically and biologically inert. To improve the interaction with biomolecules and cells, its surface has to be modified prior to use in biomedical applications. In this study, we compared two deposition techniques for adhesion promoting SiOx films to facilitate the coupling of stable organosilane monolayers on monolithic α-alumina; physical vapor deposition (PVD) by thermal evaporation and plasma enhanced chemical vapor deposition (PE-CVD). We also investigated the influence of etching on the formation of silanol surface groups using hydrogen peroxide and sulfuric acid solutions. The film characteristics, that is, surface morphology and surface chemistry, as well as the film stability and its adhesion properties under accelerated aging conditions were characterized by means of X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and tensile strength tests. Differences in surface functionalization were investigated via two model organosilanes as well as the cell-cytotoxicity and viability on murine fibroblasts and human mesenchymal stromal cells (hMSC). We found that both SiOx interfaces did not affect the cell viability of both cell types. No significant differences between both films with regard to their interfacial tensile strength were detected, although failure mode analyses revealed a higher interfacial stability of the PE-CVD films compared to the PVD films. Twenty-eight day exposure to simulated body fluid (SBF) at 37 °C revealed a partial delamination of the thermally deposited PVD films whereas the PE-CVD films stayed largely intact. SiOx layers deposited by both PVD and PE-CVD may thus serve as viable adhesion-promoters for subsequent organosilane coupling agent binding to α-alumina. However, PE-CVD appears to be favorable for long-term direct film exposure to aqueous

  7. Atmospheric Fluorescence Yield

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Christl, M. J.; Fountain, W. F.; Gregory, J. C.; Martens, K.; Sokolsky, P.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Several existing and planned experiments estimate the energies of ultra-high energy cosmic rays from air showers using the atmospheric fluorescence from these showers. Accurate knowledge of the conversion from atmospheric fluorescence to energy loss by ionizing particles in the atmosphere is key to this technique. In this paper we discuss a small balloon-borne instrument to make the first in situ measurements versus altitude of the atmospheric fluorescence yield. The instrument can also be used in the lab to investigate the dependence of the fluorescence yield in air on temperature, pressure and the concentrations of other gases that present in the atmosphere. The results can be used to explore environmental effects on and improve the accuracy of cosmic ray energy measurements for existing ground-based experiments and future space-based experiments.

  8. International peanut yield gains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut is grown in more than 100 countries, with China, India, the U.S., Nigeria, and Indonesia being the largest producers. Peanut production systems range from very primitive with only hand labor and few inputs of fertilizer or chemical controls for weeds or diseases to other systems that are h...

  9. Stellar yields of rotating first stars

    SciTech Connect

    Takahashi, Koh; Umeda, Hideyuki; Yoshida, Takashi

    2014-05-02

    First stars, also called population III stars, are born in the earliest universe without any heavy elements. These stars are the first nuclear reactor in the universe and affect their circumstances emitting synthesized materials. Not only the stellar evolution, but also their chemical yields have many distinctive characteristics. We have modeled evolution of population III stars including effect of stellar rotation. Internal mixing induced by rotation naturally results in primary nitrogen production. Evolution of rotating massive stars is followed until the core collapse phase. The new Pop III yield model will consistently explain the observed abundances of metal-poor systems.

  10. H{sub 2}(v = 0,1) + C{sup +}({sup 2} P) {yields} H+CH{sup +} STATE-TO-STATE RATE CONSTANTS FOR CHEMICAL PUMPING MODELS IN ASTROPHYSICAL MEDIA

    SciTech Connect

    Zanchet, Alexandre; Bulut, Niyazi; Roncero, Octavio; Godard, B.; Cernicharo, Jose; Halvick, Philippe

    2013-04-01

    State-to-state rate constants for the title reaction are calculated using the electronic ground state potential energy surface and an accurate quantum wave-packet method. The calculations are performed for H{sub 2} in different rovibrational states, v = 0, 1 and J = 0 and 1. The simulated reaction cross section for v = 0 shows a rather good agreement with the experimental results of Gerlich et al., both with a threshold of 0.36 eV and within the experimental error of 20%. The total reaction rate coefficients simulated for v = 1 are two times smaller than those estimated by Hierl et al. from cross sections measured at different temperatures and neglecting the contribution from v > 1 with an uncertainty factor of two. Thus, part of the disagreement is attributed to the contributions of v > 1. The computed state-to-state rate coefficients are used in our radiative transfer model code applied to the conditions of the Orion Bar photodissociation region, and leads to an increase of the line fluxes of high-J lines of CH{sup +}. This result partially explains the discrepancies previously found with measurements and demonstrates that CH{sup +} excitation is mostly driven by chemical pumping.

  11. YIELD EDITOR: SOFTWARE FOR REMOVING ERRORS FROM CROP YIELD MAPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield maps are a key component of precision agriculture, due to their usefulness in both development and evaluation of precision management strategies. The value of these yield maps can be compromised by the fact that raw yield maps contain a variety of inherent errors. Researchers have reported t...

  12. Yield enhancement with DFM

    NASA Astrophysics Data System (ADS)

    Paek, Seung Weon; Kang, Jae Hyun; Ha, Naya; Kim, Byung-Moo; Jang, Dae-Hyun; Jeon, Junsu; Kim, DaeWook; Chung, Kun Young; Yu, Sung-eun; Park, Joo Hyun; Bae, SangMin; Song, DongSup; Noh, WooYoung; Kim, YoungDuck; Song, HyunSeok; Choi, HungBok; Kim, Kee Sup; Choi, Kyu-Myung; Choi, Woonhyuk; Jeon, JoongWon; Lee, JinWoo; Kim, Ki-Su; Park, SeongHo; Chung, No-Young; Lee, KangDuck; Hong, YoungKi; Kim, BongSeok

    2012-03-01

    A set of design for manufacturing (DFM) techniques have been developed and applied to 45nm, 32nm and 28nm logic process technologies. A noble technology combined a number of potential confliction of DFM techniques into a comprehensive solution. These techniques work in three phases for design optimization and one phase for silicon diagnostics. In the DFM prevention phase, foundation IP such as standard cells, IO, and memory and P&R tech file are optimized. In the DFM solution phase, which happens during ECO step, auto fixing of process weak patterns and advanced RC extraction are performed. In the DFM polishing phase, post-layout tuning is done to improve manufacturability. DFM analysis enables prioritization of random and systematic failures. The DFM technique presented in this paper has been silicon-proven with three successful tape-outs in Samsung 32nm processes; about 5% improvement in yield was achieved without any notable side effects. Visual inspection of silicon also confirmed the positive effect of the DFM techniques.

  13. Secondary Electron Emission Yields

    NASA Technical Reports Server (NTRS)

    Krainsky, I.; Lundin, W.; Gordon, W. L.; Hoffman, R. W.

    1981-01-01

    The secondary electron emission (SEE) characteristics for a variety of spacecraft materials were determined under UHV conditions using a commercial double pass CMA which permits sequential Auger electron electron spectroscopic analysis of the surface. The transparent conductive coating indium tin oxide (ITO) was examined on Kapton and borosilicate glass and indium oxide on FED Teflon. The total SEE coefficient ranges from 2.5 to 2.6 on as-received surfaces and from 1.5 to 1.6 on Ar(+) sputtered surfaces with 5 nm removed. A cylindrical sample carousel provides normal incidence of the primary beam as well as a multiple Faraday cup measurement of the approximately nA beam currents. Total and true secondary yields are obtained from target current measurements with biasing of the carousel. A primary beam pulsed mode to reduce electron beam dosage and minimize charging of insulating coatings was applied to Mg/F2 coated solar cell covers. Electron beam effects on ITO were found quite important at the current densities necessary to do Auger studies.

  14. Technique for increasing yield of trifluoroni-trosomethane-tetrafluoro- ethylene copolymer

    NASA Technical Reports Server (NTRS)

    Glickman, S. A.

    1972-01-01

    Polymerization technique using equimolar amounts of trifluoronitrosomethane and tetrafluoroethylene to increase yield of copolymer is described. Yields were increased by ninety percent and final product displayed better physical properties. Test equipment and chemical reactions for process are described.

  15. Yield gains in leafy vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield of all crops have increased during the past century through improved cultural practices and plant breeding. We reviewed gains in yield of lettuce and spinach in the U.S., principally California and Arizona. We proposed several genetic models for yield of lettuce based on the market type: whole...

  16. Total radical yields from tropospheric ethene ozonolysis.

    PubMed

    Alam, Mohammed S; Camredon, Marie; Rickard, Andrew R; Carr, Timo; Wyche, Kevin P; Hornsby, Karen E; Monks, Paul S; Bloss, William J

    2011-06-21

    The gas-phase reactions of ozone with alkenes can be significant sources of free radicals (OH, HO(2) and RO(2)) in the Earth's atmosphere. In this study the total radical production and degradation products from ethene ozonolysis have been measured, under conditions relevant to the troposphere, during a series of detailed simulation chamber experiments. Experiments were carried out in the European photoreactor EUPHORE (Valencia, Spain), utilising various instrumentation including a chemical-ionisation-reaction time-of-flight mass-spectrometer (CIR-TOF-MS) measuring volatile organic compounds/oxygenated volatile organic compounds (VOCs/OVOCs), a laser induced fluorescence (LIF) system for measuring HO(2) radical products and a peroxy radical chemical amplification (PERCA) instrument measuring HO(2) + ΣRO(2). The ethene + ozone reaction system was investigated with and without an OH radical scavenger, in order to suppress side reactions. Radical concentrations were measured under dry and humid conditions and interpreted through detailed chemical chamber box modelling, incorporating the Master Chemical Mechanism (MCMv3.1) degradation scheme for ethene, which was updated to include a more explicit representation of the ethene-ozone reaction mechanism.The rate coefficient for the ethene + ozone reaction was measured to be (1.45 ± 0.25) × 10(-18) cm(3) molecules(-1) s(-1) at 298 K, and a stabilised Criegee intermediate yield of 0.54 ± 0.12 was determined from excess CO scavenger experiments. An OH radical yield of 0.17 ± 0.09 was determined using a cyclohexane scavenger approach, by monitoring the formation of the OH-initiated cyclohexane oxidation products and HO(2). The results highlight the importance of knowing the [HO(2)] (particularly under alkene limited conditions and high [O(3)]) and scavenger chemistry when deriving radical yields. An averaged HO(2) yield of 0.27 ± 0.07 was determined by LIF/model fitting. The observed yields are interpreted in terms of

  17. Chemical Emergencies

    MedlinePlus

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  18. OSSY (On Site Seismic Yield) source characterization

    SciTech Connect

    Johnson, L.R.; McEvilly, T.V.

    1990-09-01

    The On Site Seismic Yield (OSSY) experiment was performed during September 1989. It was a collaborative effort between scientists at the Lawrence Livermore National Laboratory, Lawrence Berkeley Laboratory, and the Seismographic Stations at UC Berkeley. It was performed in Yucca Valley at the Nevada Test Site (NTS). The general objective of the OSSY experiment was to investigate techniques for using seismic measurements to estimate the yield of nuclear explosions. The basic idea is to use chemical explosions of known size to calibrate source coupling and wave propagation effects near the site of a nuclear explosion. Once calibrated in this way, seismic measurements, obtained at locations sufficiently far from the source to be in the region of linear elastic response but sufficiently close to provide accurate registration, can be used to estimate the yield of the nuclear explosion. If such a technique can be shown to be sufficiently accurate, it has the advantages of being relatively inexpensive, flexible in experimental design, and applicable to either large or small yields. This investigation has proceeded in a two-stage process. The first stage is to develop and test the calibration procedure. The second stage is to apply the method to actual nuclear explosions. Partly because it was considered desirable to preform a complete analysis of the calibration procedure before applying it to a nuclear explosion and partly because no convenient nuclear explosion tests were available at the time, the OSSY experiment was concentrated on the calibration stage of the process. 9 refs., 18 figs., 2 tabs.

  19. An empirical method for prediction of cheese yield.

    PubMed

    Melilli, C; Lynch, J M; Carpino, S; Barbano, D M; Licitra, G; Cappa, A

    2002-10-01

    Theoretical cheese yield can be estimated from the milk fat and casein or protein content of milk using classical formulae, such as the VanSlyke formula. These equations are reliable predictors of theoretical or actual yield based on accurately measured milk fat and casein content. Many cheese makers desire to base payment for milk to dairy farmers on the yield of cheese. In small factories, however, accurate measurement of fat and casein content of milk by either chemical methods or infrared milk analysis is too time consuming and expensive. Therefore, an empirical test to predict cheese yield was developed which uses simple equipment (i.e., clinical centrifuge, analytical balance, and forced air oven) to carry out a miniature cheese making, followed by a gravimetric measurement of dry weight yield. A linear regression of calculated theoretical versus dry weight yields for milks of known fat and casein content was calculated. A regression equation of y = 1.275x + 1.528, where y is theoretical yield and x is measured dry solids yield (r2 = 0.981), for Cheddar cheese was developed using milks with a range of theoretical yield from 7 to 11.8%. The standard deviation of the difference (SDD) between theoretical cheese yield and dry solids yield was 0.194 and the coefficient of variation (SDD/mean x 100) was 1.95% upon cross validation. For cheeses without a well-established theoretical cheese yield equation, the measured dry weight yields could be directly correlated to the observed yields in the factory; this would more accurately reflect the expected yield performance. Payments for milk based on these measurements would more accurately reflect quality and composition of the milk and the actual average recovery of fat and casein achieved under practical cheese making conditions. PMID:12416825

  20. Chemical properties of transactinides

    NASA Astrophysics Data System (ADS)

    Gäggeler, H. W.

    2005-09-01

    First investigations of chemical properties of bohrium (Z = 107) and hassium (Z = 108) showed an expected behaviour as ordinary members of groups 7 and 8 of the periodic table. Two attempts to study element 112 yielded some indication for a behaviour like a very volatile noble metal. However, a very recent experiment to confirm this preliminary observation failed. Two examples are described how chemical studies may help to support element discovery claims from purely physics experiments. The two examples are the discovery claims of the elements 112 and 115, respectively, where the progenies hassium and dubnium were chemically identified.

  1. Incorporating phenology into yield models

    NASA Astrophysics Data System (ADS)

    Gray, J. M.; Friedl, M. A.

    2015-12-01

    Because the yields of many crops are sensitive to meteorological forcing during specific growth stages, phenological information has potential utility in yield mapping and forecasting exercises. However, most attempts to explain the spatiotemporal variability in crop yields with weather data have relied on growth stage definitions that do not change from year-to-year, even though planting, maturity, and harvesting dates show significant interannual variability. We tested the hypothesis that quantifying temperature exposures over dynamically determined growth stages would better explain observed spatiotemporal variability in crop yields than statically defined time periods. Specifically, we used National Agricultural and Statistics Service (NASS) crop progress data to identify the timing of the start of the maize reproductive growth stage ("silking"), and examined the correlation between county-scale yield anomalies and temperature exposures during either the annual or long-term average silking period. Consistent with our hypothesis and physical understanding, yield anomalies were more correlated with temperature exposures during the actual, rather than the long-term average, silking period. Nevertheless, temperature exposures alone explained a relatively low proportion of the yield variability, indicating that other factors and/or time periods are also important. We next investigated the potential of using remotely sensed land surface phenology instead of NASS progress data to retrieve crop growth stages, but encountered challenges related to crop type mapping and subpixel crop heterogeneity. Here, we discuss the potential of overcoming these challenges and the general utility of remotely sensed land surface phenology in crop yield mapping.

  2. Rx for low cash yields.

    PubMed

    Tobe, Chris

    2003-10-01

    Certain strategies can offer not-for-profit hospitals potentially greater investment yields while maintaining stability and principal safety. Treasury inflation-indexed securities can offer good returns, low volatility, and inflation protection. "Enhanced cash" strategies offer liquidity and help to preserve capital. Stable value "wrappers" allow hospitals to pursue higher-yielding fixed-income securities without an increase in volatility. PMID:14560584

  3. Brazil soybean yield covariance model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    A model based on multiple regression was developed to estimate soybean yields for the seven soybean-growing states of Brazil. The meteorological data of these seven states were pooled and the years 1975 to 1980 were used to model since there was no technological trend in the yields during these years. Predictor variables were derived from monthly total precipitation and monthly average temperature.

  4. Decomposing global crop yield variability

    NASA Astrophysics Data System (ADS)

    Ben-Ari, Tamara; Makowski, David

    2014-11-01

    Recent food crises have highlighted the need to better understand the between-year variability of agricultural production. Although increasing future production seems necessary, the globalization of commodity markets suggests that the food system would also benefit from enhanced supplies stability through a reduction in the year-to-year variability. Here, we develop an analytical expression decomposing global crop yield interannual variability into three informative components that quantify how evenly are croplands distributed in the world, the proportion of cultivated areas allocated to regions of above or below average variability and the covariation between yields in distinct world regions. This decomposition is used to identify drivers of interannual yield variations for four major crops (i.e., maize, rice, soybean and wheat) over the period 1961-2012. We show that maize production is fairly spread but marked by one prominent region with high levels of crop yield interannual variability (which encompasses the North American corn belt in the USA, and Canada). In contrast, global rice yields have a small variability because, although spatially concentrated, much of the production is located in regions of below-average variability (i.e., South, Eastern and South Eastern Asia). Because of these contrasted land use allocations, an even cultivated land distribution across regions would reduce global maize yield variance, but increase the variance of global yield rice. Intermediate results are obtained for soybean and wheat for which croplands are mainly located in regions with close-to-average variability. At the scale of large world regions, we find that covariances of regional yields have a negligible contribution to global yield variance. The proposed decomposition could be applied at any spatial and time scales, including the yearly time step. By addressing global crop production stability (or lack thereof) our results contribute to the understanding of a key

  5. Grapevine canopy reflectance and yield

    NASA Technical Reports Server (NTRS)

    Minden, K. A.; Philipson, W. R.

    1982-01-01

    Field spectroradiometric and airborne multispectral scanner data were applied in a study of Concord grapevines. Spectroradiometric measurements of 18 experimental vines were collected on three dates during one growing season. Spectral reflectance, determined at 30 intervals from 0.4 to 1.1 microns, was correlated with vine yield, pruning weight, clusters/vine, and nitrogen input. One date of airborne multispectral scanner data (11 channels) was collected over commercial vineyards, and the average radiance values for eight vineyard sections were correlated with the corresponding average yields. Although some correlations were significant, they were inadequate for developing a reliable yield prediction model.

  6. Brazil wheat yield covariance model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    A model based on multiple regression was developed to estimate wheat yields for the wheat growing states of Rio Grande do Sul, Parana, and Santa Catarina in Brazil. The meteorological data of these three states were pooled and the years 1972 to 1979 were used to develop the model since there was no technological trend in the yields during these years. Predictor variables were derived from monthly total precipitation, average monthly mean temperature, and average monthly maximum temperature.

  7. Fission yield measurements at IGISOL

    NASA Astrophysics Data System (ADS)

    Lantz, M.; Al-Adili, A.; Gorelov, D.; Jokinen, A.; Kolhinen, V. S.; Mattera, A.; Moore, I.; Penttilä, H.; Pomp, S.; Prokofiev, A. V.; Rakopoulos, V.; Rinta-Antila, S.; Simutkin, V.; Solders, A.

    2016-06-01

    The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

  8. Acid soil infertility effects on peanut yields and yield components

    SciTech Connect

    Blamey, F.P.C.

    1983-01-01

    The interpretation of soil amelioration experiments with peanuts is made difficult by the unpredictibility of the crop and by the many factors altered when ameliorating acid soils. The present study was conducted to investigate the effects of lime and gypsum applications on peanut kernel yield via the three first order yield components, pods per ha, kernels per pod, and kernel mass. On an acid medium sandy loam soil (typic Plinthustult), liming resulted in a highly significant kernel yield increase of 117% whereas gypsum applications were of no significant benefit. As indicated by path coefficient analysis, an increase in the number of pods per ha was markedly more important in increasing yield than an increase in either the number of kernels per pod or kernel mass. Furthermore, exch. Al was found to be particularly detrimental to pod number. It was postulated that poor peanut yields resulting from acid soil infertility were mainly due to the depressive effect of exch. Al on pod number. Exch. Ca appeared to play a secondary role by ameliorating the adverse effects of exch. Al.

  9. Riparian vegetation and water yield: A synthesis

    NASA Astrophysics Data System (ADS)

    Salemi, Luiz Felippe; Groppo, Juliano Daniel; Trevisan, Rodrigo; Marcos de Moraes, Jorge; de Paula Lima, Walter; Martinelli, Luiz Antonio

    2012-08-01

    SummaryForested riparian zones perform numerous ecosystem functions, including the following: storing and fixing carbon; serving as wildlife habitats and ecological corridors; stabilizing streambanks; providing shade, organic matter, and food for streams and their biota; retaining sediments and filtering chemicals applied on cultivated/agricultural sites on upslope regions of the catchments. In this paper, we report a synthesis of a different feature of this type of vegetation, which is its effect on water yield. By synthesizing results from studies that used (i) the nested catchment and (ii) the paired catchment approaches, we show that riparian forests decrease water yield on a daily to annual basis. In terms of the treated area increases on average were 1.32 ± 0.85 mm day-1 and 483 ± 309 mm yr-1, respectively; n = 9. Similarly, riparian forest plantation or regeneration promoted reduced water yield (on average 1.25 ± 0.34 mm day-1 and 456 ± 125 mm yr-1 on daily and annual basis, respectively, when prorated to the catchment area subjected to treatment; n = 5). Although there are substantially fewer paired catchment studies assessing the effect of this vegetation type compared to classical paired catchment studies that manipulate the entire vegetation of small catchments, our results indicate the same trend. Despite the occurrence of many current restoration programs, measurements of the effect on water yield under natural forest restoration conditions are still lacking. We hope that presenting these gaps will encourage the scientific community to enhance the number of observations in these situations as well as produce more data from tropical regions.

  10. Corn yield prediction using climatology

    SciTech Connect

    Duchon, C.E.

    1986-05-01

    A method is developed to predict corn yield during the growing season using a plant process model (CERES-Maize), current weather data and climatological data. The procedure is to place the current year's daily weather (temperature and precipitation) into the model up to the time the yield prediction is to be made and sequences of historical data (one sequence per year) after that time until the end of the growing season to produce yield estimates. The mean of the distribution of yield estimates is taken as the prediction. The variance associated with a prediction is relatively constant until the time of tassel initiation and then decreases toward zero as the season progresses. As a consequence, perfect weather forecasts reach their peak value between the beginning of ear growth and the beginning of grain fill. The change in the predicted yield in response to weather as the growing season progresses is discussed for 1983 and 1976 at Peoria, Illinois. Results are given of an attempt to incorporate 30-day Climate Analytic Center outlooks into the predictive scheme. 21 references, 14 figures, 1 table.

  11. Yields of Fission Products from Various Uranium and Thorium Targets

    SciTech Connect

    Kronenberg, Andreas; Spejewski, Eugene H.; Mervin, Brenden T.; Jost, Cara; Carter, H Kennon; Stracener, Daniel W; Greene, John P.; Nolen, Jerry A.; Talbert, Willard L.

    2008-01-01

    Yield measurements from proton-induced fission have been performed on a number of actinide targets, both Th and U, at the on-line test facility at Oak Ridge National Laboratory. The results are discussed with a focus on the production process and physical and chemical properties of the targets.

  12. Yields of fission products from various uranium and thorium targets.

    SciTech Connect

    Kronenberg, A.; Spejewski, E. H.; Mervin, B.; Jost, C.; Carter, H. K.; Stracener, D. W.; Greene, J. P.; Nolen, J. A.; Talbert, W. L.; Physics; Oak Ridge Associated Univ.; ORNL; TechSource, Inc.

    2008-10-31

    Yield measurements from proton-induced fission have been performed on a number of actinide targets, both Th and U, at the on-line test facility at Oak Ridge National Laboratory. The results are discussed with a focus on the production process and physical and chemical properties of the targets.

  13. Plant species composition and biofuel yields of conservation grasslands.

    PubMed

    Adler, Paul R; Sanderson, Matt A; Weimer, Paul J; Vogel, Kenneth P

    2009-12-01

    Marginal croplands, such as those in the Conservation Reserve Program (CRP), have been suggested as a source of biomass for biofuel production. However, little is known about the composition of plant species on these conservation grasslands or their potential for ethanol production. Our objective was to assess the potential of CRP and other conservation grasslands for biofuel production, describing the relationships of plant species richness and tall native C4 prairie grass abundance with plant chemical composition and the resulting potential ethanol yield. We determined plant species composition and diversity at multiple scales with the modified Whittaker plot technique, aboveground biomass, plant chemical composition, and potential ethanol yield at 34 sites across the major ecological regions of the northeastern USA. Conservation grasslands with higher numbers of plant species had lower biomass yields and a lower ethanol yield per unit biomass compared with sites with fewer species. Thus, biofuel yield per unit land area decreased by 77% as plant species richness increased from 3 to 12.8 species per m2. We found that, as tall native C4 prairie grass abundance increased from 1.7% to 81.6%, the number of plant species decreased and aboveground biomass per unit land area and ethanol yield per unit biomass increased resulting in a 500% increased biofuel yield per unit land area. Plant species richness and composition are key determinants of biomass and ethanol yields from conservation grasslands and have implications for low-input high-diversity systems. Designing systems to include a large proportion of species with undesirable fermentation characteristics could reduce ethanol yields. PMID:20014588

  14. Defining and managing sustainable yield.

    PubMed

    Maimone, Mark

    2004-01-01

    Ground water resource management programs are paying increasing attention to the integration of ground water and surface water in the planning process. Many plans, however, show a sophistication in approach and presentation that masks a fundamental weakness in the overall analysis. The plans usually discuss issues of demand and yield, yet never directly address a fundamental issue behind the plan--how to define sustainable yield of an aquifer system. This paper points out a number of considerations that must be addressed in defining sustainable yield in order to make the definition more useful in practical water resource planning studies. These include consideration for the spatial and temporal aspects of the problem, the development of a conceptual water balance, the influence of boundaries and changes in technology on the definition, the need to examine water demand as well as available supply, the need for stakeholder involvement, and the issue of uncertainty in our understanding of the components of the hydrologic system. PMID:15584295

  15. Evaluation of a cotton stripper yield monitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this work was to evaluate the accuracy of a microwave sensor based yield monitor for measuring yield on a cotton stripper harvester and determine if the yield monitor can discriminate differences in yield to the same level as a reference scale system. A new yield monitor was instal...

  16. Biomass - chemicals

    SciTech Connect

    Kovaly, K.A.

    1982-08-01

    A host of industrial chemicals, specialty items, solvents, plastics, elastomers, fibers and films can be produced from agricultural crops, wood, paper mill wastes, food processing wastes, municipal waste and sewage. Existing chemical processes based on readily renewable plant materials are reviewed. These include ethanol and acetone-butanol fermentations, oilseed chemicals, furfural and cellulosics. (Refs. 16).

  17. Chemical sensor

    NASA Technical Reports Server (NTRS)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  18. Advanced Chemical Propulsion

    NASA Technical Reports Server (NTRS)

    Alexander, Leslie, Jr.

    2006-01-01

    Advanced Chemical Propulsion (ACP) provides near-term incremental improvements in propulsion system performance and/or cost. It is an evolutionary approach to technology development that produces useful products along the way to meet increasingly more demanding mission requirements while focusing on improving payload mass fraction to yield greater science capability. Current activities are focused on two areas: chemical propulsion component, subsystem, and manufacturing technologies that offer measurable system level benefits; and the evaluation of high-energy storable propellants with enhanced performance for in-space application. To prioritize candidate propulsion technology alternatives, a variety of propulsion/mission analyses and trades have been conducted for SMD missions to yield sufficient data for investment planning. They include: the Advanced Chemical Propulsion Assessment; an Advanced Chemical Propulsion System Model; a LOx-LH2 small pumps conceptual design; a space storables propellant study; a spacecraft cryogenic propulsion study; an advanced pressurization and mixture ratio control study; and a pump-fed vs. pressure-fed study.

  19. Chemical Leukoderma.

    PubMed

    Bonamonte, Domenico; Vestita, Michelangelo; Romita, Paolo; Filoni, Angela; Foti, Caterina; Angelini, Gianni

    2016-01-01

    Chemical leukoderma, often clinically mimicking idiopathic vitiligo and other congenital and acquired hypopigmentation, is an acquired form of cutaneous pigment loss caused by exposure to a variety of chemicals that act through selective melanocytotoxicity. Most of these chemicals are phenols and aromatic or aliphatic catechols derivatives. These chemicals, however, are harmful for melanocytes in individuals with an individual susceptibility. Nowadays, chemical leukoderma is fairly common, caused by common domestic products. The presence of numerous acquired confetti- or pea-sized macules is clinically characteristic of chemical leukoderma, albeit not diagnostic. Other relevant diagnostic elements are a history of repeated exposure to a known or suspected depigmenting agent at the sites of onset and a macules distribution corresponding to sites of chemical exposure. Spontaneous repigmentation has been reported when the causative agent is avoided; the repigmentation process is perifollicular and gradual, taking place for a variable period of weeks to months. PMID:27172302

  20. Preventing pesticide contamination of groundwater while maximizing irrigated crop yield

    NASA Astrophysics Data System (ADS)

    Peralta, R. C.; Hegazy, M. A.; Musharrafieh, G. R.

    1994-11-01

    A simulation/optimization model is developed for maximizing irrigated crop yield while avoiding unacceptable pesticide leaching. The optimization model is designed to help managers prevent non-point source contamination of shallow groundwater aquifers. It computes optimal irrigation amounts for given soil, crop, chemical, and weather data and irrigation frequencies. It directly computes the minimum irrigated crop yield reduction needed to prevent groundwater contamination. Constraint equations used in the model maintain a layered soil moisture volume balance; describe percolation, downward unsaturated zone solute transport and pesticide degradation; and limit the amount of pesticide reaching groundwater. Constraints are linear, piecewise linear, nonlinear, and exponential. The problem is solved using nonlinear programming optimization. The model is tested for different scenarios of irrigating corn. The modeling approach is promising as a tool to aid in the development of environmentally sound agricultural production practices. It allows direct estimation of trade-offs between crop production and groundwater protection for different management approaches. More frequent irrigation tends to give better crop yield and reduce solute movement. Trade-offs decrease with increasing irrigation frequency. More frequent irrigation reduces yield loss due to moisture stress and requires less water to fill the root zone to field capacity. This prevents the solute from moving to deeper soil layers. Yield-environmental quality trade-offs are smaller for deeper groundwater tables because deeper groundwater allows more time for chemical degradation.

  1. [Chemical weapons and chemical terrorism].

    PubMed

    Nakamura, Katsumi

    2005-10-01

    Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary. PMID:16296384

  2. Switchgrass yield on reclaimed surface mines for bioenergy production.

    PubMed

    Marra, Michael; Keene, Travis; Skousen, Jeff; Griggs, Thomas

    2013-01-01

    The high cost of transportation fuels and the environmental risks associated with acquiring and using nonrenewable energy sources have created a demand for developing renewable bioenergy crops. Switchgrass ( L.), a warm-season perennial grass, is a promising feedstock due to its high biomass production under a wide range of growing conditions and its satisfactory forage quality and chemical composition. West Virginia contains vast expanses of reclaimed surface mine lands that could be used to produce switchgrass as a bioenergy feedstock. This study determined dry matter yields of three switchgrass varieties (Cave-In-Rock, Shawnee, and Carthage) during the second to fourth years of production. Two research sites were established on reclaimed surface mines in southern West Virginia: Hobet and Hampshire. The Hobet site was prepared using crushed, unweathered sandstone as the soil material, and yields were significantly lower at 803 kg ha averaged across varieties and years than annual yields at Hampshire. The highest yield at Hobet, with Shawnee in the third year, was 1964 kg ha. The Hamphire site, which was reclaimed in the late 1990s using topsoil and treated municipal sludge, averaged 5760 kg ha of switchgrass across varieties and years. The highest yield, obtained with Cave-in-Rock during the third year, was 9222 kg ha. Switchgrass yields on agricultural lands in this region averaged 12,000 kg ha. Although average switchgrass yields at Hampshire were about 50% lower than agricultural lands, they were greater than a target yield of 5000 kg ha, a threshold for economically feasible production. Yields during the fourth year from a two-harvest per year system were not significantly different from a single, end-of-year harvest at both sites. Reclaimed lands show promise for growing bioenergy crops such as switchgrass on areas where topsoil materials are replaced and amended like that at the Hampshire site. PMID:23673936

  3. Chemical microsensors

    DOEpatents

    Li, DeQuan; Swanson, Basil I.

    1995-01-01

    An article of manufacture is provided including a substrate having an oxide surface layer and a selective thin film of a cyclodextrin derivative chemically bound upon said substrate, said film is adapted for the inclusion of a selected organic compound therewith. Such an article can be either a chemical sensor capable of detecting a resultant mass change from inclusion of the selected organic compound or a chemical separator capable of reversibly selectively separating a selected organic compound.

  4. Science Yield Modeling with EXOSIMS

    NASA Astrophysics Data System (ADS)

    Garrett, Daniel; Savransky, Dmitry

    2016-01-01

    Accurately modeling science yield of an exoplanet direct imaging mission to build confidence in the achievement of science goals can be almost as complicated as designing the mission itself. It is challenging to compare science simulation results and systematically test the effects of changing instrument or mission designs. EXOSIMS (Exoplanet Open-Source Imaging Mission Simulator) addresses this by generating ensembles of mission simulations for exoplanet direct imaging missions to estimate distributions of science yield. EXOSIMS consists of stand-alone modules written in Python which may be individually modified without requiring modifications to the code elsewhere. This structure allows for user driven systemic exploration of the effects of changing designs on the estimated science yield.The modules of EXOSIMS are classified as either input or simulation modules. Input modules contain specific mission design parameters and functions. These include Planet Population, Star Catalog, Optical System, Zodiacal Light, Planet Physical Model, Observatory, Time Keeping, and Post-Processing. Simulation modules perform tasks requiring input from one or more input modules as well as calling functions from other simulation modules. These include Completeness, Target List, Simulated Universe, Survey Simulation, and Survey Ensemble. The required parameters and functionality of each of these modules is defined in the documentation for EXOSIMS.EXOSIMS is available to the public at https://github.com/dsavransky/EXOSIMS. Included in the documentation is an interface control document which defines the required inputs and outputs to each input and simulation module. Future development of EXOSIMS is intended to be community-driven. Mission planners and instrument designers may quickly write their own modules, following the guidelines in the interface control document, and drop them directly into the code without making additional modifications elsewhere. It is expected that EXOSIMS

  5. Achieving yield gains in wheat.

    PubMed

    Reynolds, Matthew; Foulkes, John; Furbank, Robert; Griffiths, Simon; King, Julie; Murchie, Erik; Parry, Martin; Slafer, Gustavo

    2012-10-01

    Wheat provides 20% of calories and protein consumed by humans. Recent genetic gains are <1% per annum (p.a.), insufficient to meet future demand. The Wheat Yield Consortium brings expertise in photosynthesis, crop adaptation and genetics to a common breeding platform. Theory suggest radiation use efficiency (RUE) of wheat could be increased ~50%; strategies include modifying specificity, catalytic rate and regulation of Rubisco, up-regulating Calvin cycle enzymes, introducing chloroplast CO(2) concentrating mechanisms, optimizing light and N distribution of canopies while minimizing photoinhibition, and increasing spike photosynthesis. Maximum yield expression will also require dynamic optimization of source: sink so that dry matter partitioning to reproductive structures is not at the cost of the roots, stems and leaves needed to maintain physiological and structural integrity. Crop development should favour spike fertility to maximize harvest index so phenology must be tailored to different photoperiods, and sensitivity to unpredictable weather must be modulated to reduce conservative responses that reduce harvest index. Strategic crossing of complementary physiological traits will be augmented with wide crossing, while genome-wide selection and high throughput phenotyping and genotyping will increase efficiency of progeny screening. To ensure investment in breeding achieves agronomic impact, sustainable crop management must also be promoted through crop improvement networks. PMID:22860982

  6. Chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.

    2001-01-01

    A chemical preconcentrator is disclosed with applications to chemical sensing and analysis. The preconcentrator can be formed by depositing a resistive heating element (e.g. platinum) over a membrane (e.g. silicon nitride) suspended above a substrate. A coating of a sorptive material (e.g. a microporous hydrophobic sol-gel coating or a polymer coating) is formed on the suspended membrane proximate to the heating element to selective sorb one or more chemical species of interest over a time period, thereby concentrating the chemical species in the sorptive material. Upon heating the sorptive material with the resistive heating element, the sorbed chemical species are released for detection and analysis in a relatively high concentration and over a relatively short time period. The sorptive material can be made to selectively sorb particular chemical species of interest while not substantially sorbing other chemical species not of interest. The present invention has applications for use in forming high-sensitivity, rapid-response miniaturized chemical analysis systems (e.g. a "chem lab on a chip").

  7. Chemical sensors

    DOEpatents

    Lowell, Jr., James R.; Edlund, David J.; Friesen, Dwayne T.; Rayfield, George W.

    1991-01-01

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising (a) a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, operatively coupled to (b) a transducer capable of directly converting said expansion or contraction to a measurable electrical response.

  8. Chemical sensors

    DOEpatents

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1991-07-02

    Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

  9. Chemical Peels

    MedlinePlus

    ... the complications or potential side effects of a chemical peel? Temporary or permanent change in skin color, particularly for women on birth control pills, who subsequently become pregnant or have a history of brownish facial ... after having a chemical peel? All peels require some follow-up care: ...

  10. Chemical Emergencies

    MedlinePlus

    ... agents such as sarin and VX. Many hazardous chemicals are used in industry - for example, chlorine, ammonia, and benzene. Some can be made from everyday items such as household cleaners. Although there are no guarantees of safety during a chemical emergency, you can take actions to protect yourself. ...

  11. Long-Term No-Till and Conventional-Till Soybean Yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual crop yields of long-term no-till soybean (Glycine max) and conventional-till soybean at Holly Springs, Mississippi were summarized for a 16-year period, 1984 through 1999. This research report provides a complete data set of crop yields, cultural practices, and chemical applications used for...

  12. More on Chemical Reaction Balancing.

    ERIC Educational Resources Information Center

    Swinehart, D. F.

    1985-01-01

    A previous article stated that only the matrix method was powerful enough to balance a particular chemical equation. Shows how this equation can be balanced without using the matrix method. The approach taken involves writing partial mathematical reactions and redox half-reactions, and combining them to yield the final balanced reaction. (JN)

  13. High Yielding Microbubble Production Method

    PubMed Central

    Fiabane, Joe; Prentice, Paul; Pancholi, Ketan

    2016-01-01

    Microfluidic approaches to microbubble production are generally disadvantaged by low yield and high susceptibility to (micro)channel blockages. This paper presents an alternative method of producing microbubbles of 2.6 μm mean diameter at concentrations in excess of 30 × 106 mL−1. In this method, the nitrogen gas flowing inside the liquid jet is disintegrated into spray of microbubble when air surrounding this coflowing nitrogen gas-liquid jet passes through a 100 μm orifice at high velocity. Resulting microbubble foam has the polydispersity index of 16%. Moreover, a ratio of mean microbubble diameter to channel width ratio was found to be less than 0.025, which substantially alleviates the occurrence of blockages during production. PMID:27034935

  14. Chemical vapor deposition of mullite coatings

    DOEpatents

    Sarin, Vinod; Mulpuri, Rao

    1998-01-01

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  15. Unnecessary Chemicals

    ERIC Educational Resources Information Center

    Johnson, Anita

    1978-01-01

    Discusses the health hazards resulting from chemical additions of many common products such as cough syrups, food dyes, and cosmetics. Steps being taken to protect consumers from these health hazards are included. (MDR)

  16. Chemical geodynamics

    NASA Astrophysics Data System (ADS)

    Zindler, A.; Hart, S.

    Consideration is given to the following three principal boundary conditions relating to the nature and development of chemical structure in the earth's mantle: (1) inferred scale lengths for mantle chemical heterogeneities, (2) interrelationships of the various isotopic tracers, and (3) the bulk composition of the earth. These boundary conditions are integrated with geophysical constraints in order to evaluate models for the development of the physical and chemical structure of the mantle. Data indicate that: (1) km-size heterogeneities can survive diffusive equilibrium for billions of years; (2) the mantle is chemically heterogeneous on both very small and very large scales; (3) isotopic heterogeneities in the mantle require the existence of four 'end-member' components (DMM, HIMU, EM I, and EM II) and are consistent with the existence of at least two additional components (BSE, PREMA); and (4) primitive undepleted mantle can made up no more than about 55 percent of the total mantle.

  17. Chemical sensors

    DOEpatents

    Lowell, Jr., James R.; Edlund, David J.; Friesen, Dwayne T.; Rayfield, George W.

    1992-01-01

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material.

  18. Chemical sensors

    DOEpatents

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1992-06-09

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material. 12 figs.

  19. Galactic chemical evolution

    NASA Astrophysics Data System (ADS)

    Chiappini, C.; Matteucci, F.

    2001-11-01

    In this paper we review the current ideas about the formation of our Galaxy. In particular, the main ingredients necessary to build chemical evolution models (star formation, initial mass function and stellar yields) are described and discussed. A critical discussion about the main observational constraints available is also presented. Finally, our model predictions concerning the evolution of the abundances of several chemical elements (H, D, He, C, N, O, Ne, Mg, Si, Ca and Fe) are compared with observations relative to the solar neighborhood and the whole disk. We show that from this comparison we can constrain the history of the formation and evolution of the Milky Way as well as the nucleosynthesis theories concerning the Big Bang and the stars. .

  20. RADIATION CHEMISTRY OF HIGH ENERGY CARBON, NEON AND ARGON IONS: INTEGRAL YIELDS FROM FERROUS SULFATE SOLUTIONS

    SciTech Connect

    Christman, E.A.; Appleby, A.; Jayko, M.

    1980-07-01

    Chemical yields of Fe{sup 3+} have been measured from FeSO{sub 4} solutions irradiated in the presence and absence of oxygen with carbon, neon, and argon ions from the Berkeley Bevalac facility. G(Fe{sup 3+}) decreases with increasing beam penetration and with increasing atomic number of the incident ion. The results are compared with current theoretical expectations of the behavior of these particles in an aqueous absorber. The chemical yields are consistently higher than theoretically predicted, by amounts varying from <6.2% (carbon ions) to <13.2% (argon ions). The additional yields are possibly attributable to fragmentation of the primary particle beams.

  1. Yield and yield gaps in central U.S. corn production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The magnitude of yield gaps (YG) (potential yield – farmer yield) provides some indication of the prospects for increasing crop yield. Quantile regression analysis was applied to county maize (Zea mays L.) yields (1972 – 2011) from Kentucky, Iowa and Nebraska (irrigated) (total of 115 counties) to e...

  2. Possible changes to arable crop yields by 2050.

    PubMed

    Jaggard, Keith W; Qi, Aiming; Ober, Eric S

    2010-09-27

    By 2050, the world population is likely to be 9.1 billion, the CO(2) concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2 degrees C. In these conditions, what contribution can increased crop yield make to feeding the world? CO(2) enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO(2)-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations. PMID:20713388

  3. Possible changes to arable crop yields by 2050

    PubMed Central

    Jaggard, Keith W.; Qi, Aiming; Ober, Eric S.

    2010-01-01

    By 2050, the world population is likely to be 9.1 billion, the CO2 concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2°C. In these conditions, what contribution can increased crop yield make to feeding the world? CO2 enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO2-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations. PMID:20713388

  4. Yield model development project implementation plan

    NASA Technical Reports Server (NTRS)

    Ambroziak, R. A.

    1982-01-01

    Tasks remaining to be completed are summarized for the following major project elements: (1) evaluation of crop yield models; (2) crop yield model research and development; (3) data acquisition processing, and storage; (4) related yield research: defining spectral and/or remote sensing data requirements; developing input for driving and testing crop growth/yield models; real time testing of wheat plant process models) and (5) project management and support.

  5. Possible future directions in crop yield forecasting

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.

    1979-01-01

    This paper examines present and future possible applications of remote sensing to crop yield forecasting. It is concluded that there are ways in which Landsat data could be used to assist in crop yield forecasting using present technology. A framework for global crop yield forecasting which uses remote sensing, meteorological, field and ancillary data, as available, is proposed for the future.

  6. SOME QUESTIONS OF EVALUATION OF YIELD MAPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ultimate goal for the application of yield maps is to provide profitable crop output in farming systems. Recently, several methods and tools have been developed for the evaluation of yield maps. It is based on crisp and fuzzy modeling. However, the process of evaluation of yield maps is full o...

  7. Chemical sensors

    SciTech Connect

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section.

  8. FMC Chemicals: Burner Management System Upgrade Improves Performance and Saves Energy at a Chemical Plant

    SciTech Connect

    Not Available

    2004-07-01

    FMC Chemicals Corporation increased the efficiency of two large coal-fired boilers at its soda ash mine in Green River, Wyoming, by upgrading the burner management system. The project yields annual energy savings of 250,000 MMBtu.

  9. Chemical networks

    NASA Astrophysics Data System (ADS)

    Thi, Wing-Fai

    2015-09-01

    This chapter discusses the fundamental ideas of how chemical networks are build, their strengths and limitations. The chemical reactions that occur in disks combine the cold phase reactions used to model cold molecular clouds with the hot chemistry applied to planetary atmosphere models. With a general understanding of the different types of reactions that can occur, one can proceed in building a network of chemical reactions and use it to explain the abundance of species seen in disks. One on-going research subject is finding new paths to synthesize species either in the gas-phase or on grain surfaces. Specific formation routes for water or carbon monoxide are discussed in more details. 13th Lecture of the Summer School "Protoplanetary Disks: Theory and Modelling Meet Observations"

  10. Linking Drought Information to Crop Yield

    NASA Astrophysics Data System (ADS)

    Madadgar, S.; Farahmand, A.; Li, L.; Aghakouchak, A.

    2015-12-01

    Droughts have detrimental impacts on agricultural yields all over the world every year. This study analyzes the relationship between three drought indicators including Standardized Precipitation Index (SPI); Standardized Soil Moisture Index (SSI), Multivariate Standardized Drought Index (MSDI) and the yields of five largest rain-fed crops in Australia (wheat, broad beans, canola, lupins and barley). Variation of the five chosen crop yields is overall in agreement with the three drought indicators SPI, SSI, and MSDI during the analysis period of 1980-2012. This study develops a bivariate copula model to investigate the statistical dependence of drought and crop yield. Copula functions are used to establish the existing connections between climate variables and crop yields during the Millennium drought in Australia. The proposed model estimates the likelihood of crop yields given the observed or predicted drought indicators SPI, SSI or MSDI. The results are also useful to estimate crop yields associated with different thresholds of precipitation or soil moisture.

  11. Delicious Chemicals.

    ERIC Educational Resources Information Center

    Barry, Dana M.

    This paper presents an approach to chemistry and nutrition that focuses on food items that people consider delicious. Information is organized according to three categories of food chemicals that provide energy to the human body: (1) fats and oils; (2) carbohydrates; and (3) proteins. Minerals, vitamins, and additives are also discussed along with…

  12. Chemical sensors

    SciTech Connect

    Janata, J.; Josowicz, M.; DeVaney, D.M. )

    1994-06-15

    This review of chemical sensors contains the following topics of interest: books and reviews; reviews of sensors by their type; fabrication and selectivity; data processing; thermal sensors; mass sensors (fabrication, gas sensors, and liquid sensors); electrochemical sensors (potentiometric sensors, amperometric sensors, and conductometric sensors); and optical sensors (fabrication, liquid sensors, biosensors, and gas sensors). 795 refs., 1 tab.

  13. Chemical Mahjong

    ERIC Educational Resources Information Center

    Cossairt, Travis J.; Grubbs, W. Tandy

    2011-01-01

    An open-access, Web-based mnemonic game is described whereby introductory chemistry knowledge is tested using mahjong solitaire game play. Several tile sets and board layouts are included that are themed upon different chemical topics. Introductory tile sets can be selected that prompt the player to match element names to symbols and metric…

  14. Yield Stress Enhancement in Glassy-Polyethylene Block Copolymers

    NASA Astrophysics Data System (ADS)

    Mulhearn, William; Register, Richard

    Polyethylene (PE) has the highest annual production volume of all synthetic polymers worldwide, and is valuable across many applications due to its low cost, toughness, processability, and chemical resistance. However, PE is not well suited to certain applications due to its modest yield stress and Young's modulus (approximately 30 MPa and 1 GPa, respectively for linear, high-density PE). Irreversible deformation of PE results from dislocation of crystal stems and eventual crystal fragmentation under applied stress. The liquid-like amorphous fraction provides no useful mechanical support to the crystal fold surface in a PE homopolymer, so the only method to enhance the force required for crystal slip, and hence the yield stress, is crystal thickening via thermal treatment. An alternative route towards modifying the mechanical properties of PE involves copolymerization of a minority high-glass transition temperature block into a majority-PE block copolymer. In this work, we investigate a system of glassy/linear-PE block copolymers prepared via ring-opening metathesis polymerization of cyclopentene and substituted norbornene monomers followed by hydrogenation. We demonstrate that a large change in mechanical properties can be achieved with the addition of a short glassy block (e.g. a doubling of the yield stress and Young's modulus versus PE homopolymer with the addition of 25 percent glassy block). Furthermore, owing to the low interaction energy between PE and the substituted polynorbornene blocks employed, these high-yield PE block copolymers can exhibit single-phase melts for ease of processability.

  15. Systematics of Fission-Product Yields

    SciTech Connect

    A.C. Wahl

    2002-05-01

    Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z{sub F} = 90 thru 98, mass number A{sub F} = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru {approx}200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from {approx} 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron ({approx} fission spectrum) induced fission reactions.

  16. Chemical warfare

    PubMed Central

    Samuels, Richard Ian; Mattoso, Thalles Cardoso; Moreira, Denise D.O.

    2013-01-01

    Leaf-cutting ants are well known for their highly complex social organization, which provides them with a strong defense against parasites invading their colonies. Besides this attribute, these insects have morphological, physiological and structural characteristics further reinforcing the defense of their colonies. With the discovery of symbiotic bacteria present on the integument of leaf-cutting ants, a new line of defense was proposed and considered to be specific for the control of a specialized fungal parasite of the ants’ fungus gardens (Escovopsis). However, recent studies have questioned the specificity of the integumental bacteria, as they were also found to inhibit a range of fungi, including entomopathogens. The microbiota associated with the leaf-cutting ant gardens has also been proposed as another level of chemical defense, protecting the garden from parasite invasion. Here we review the chemical defense weaponry deployed by leaf-cutting ants against parasites of their fungus gardens and of the ants themselves. PMID:23795235

  17. Efficient prediction of (p,n) yields

    SciTech Connect

    Swift, D C; McNaney, J M; Higginson, D P; Beg, F

    2009-09-09

    In the continuous deceleration approximation, charged particles decelerate without any spread in energy as they traverse matter. This approximation simplifies the calculation of the yield of nuclear reactions, for which the cross-section depends on the particle energy. We calculated (p,n) yields for a LiF target, using the Bethe-Bloch relation for proton deceleration, and predicted that the maximum yield would be around 0.25% neutrons per incident proton, for an initial proton energy of 70 MeV or higher. Yield-energy relations calculated in this way can readily be used to optimize source and (p,n) converter characteristics.

  18. Comparative yield estimation via shock hydrodynamic methods

    SciTech Connect

    Attia, A.V.; Moran, B.; Glenn, L.A.

    1991-06-01

    Shock TOA (CORRTEX) from recent underground nuclear explosions in saturated tuff were used to estimate yield via the simulated explosion-scaling method. The sensitivity of the derived yield to uncertainties in the measured shock Hugoniot, release adiabats, and gas porosity is the main focus of this paper. In this method for determining yield, we assume a point-source explosion in an infinite homogeneous material. The rock is formulated using laboratory experiments on core samples, taken prior to the explosion. Results show that increasing gas porosity from 0% to 2% causes a 15% increase in yield per ms/kt{sup 1/3}. 6 refs., 4 figs.

  19. Wheat yield forecasts using LANDSAT data

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.; Rice, D. P.; Nalepka, R. F.

    1977-01-01

    Several considerations of winter wheat yield prediction using LANDSAT data were discussed. In addition, a simple technique which permits direct early season forecasts of wheat production was described.

  20. Crop status evaluations and yield predictions

    NASA Technical Reports Server (NTRS)

    Haun, J. R.

    1976-01-01

    One phase of the large area crop inventory project is presented. Wheat yield models based on the input of environmental variables potentially obtainable through the use of space remote sensing were developed and demonstrated. By the use of a unique method for visually qualifying daily plant development and subsequent multifactor computer analyses, it was possible to develop practical models for predicting crop development and yield. Development of wheat yield prediction models was based on the discovery that morphological changes in plants are detected and quantified on a daily basis, and that this change during a portion of the season was proportional to yield.

  1. Ab initio yield curve dynamics [rapid communication

    NASA Astrophysics Data System (ADS)

    Hawkins, Raymond J.; Roy Frieden, B.; D'Anna, Joseph L.

    2005-09-01

    We derive an equation of motion for interest-rate yield curves by applying a minimum Fisher information variational approach to the implied probability density. By construction, solutions to the equation of motion recover observed bond prices. More significantly, the form of the resulting equation explains the success of the Nelson Siegel approach to fitting static yield curves and the empirically observed modal structure of yield curves. A practical numerical implementation of this equation of motion is found by using the Karhunen Lòeve expansion and Galerkin's method to formulate a reduced-order model of yield curve dynamics.

  2. Isotope Dependence of Chemical Erosion of Carbon

    SciTech Connect

    Reinhold, Carlos O; Krstic, Predrag S; Stuart, S. J.; Zhang, Hengda; Harris, Peter R; Meyer, Fred W

    2010-01-01

    We study the chemical erosion of hydrogen-supersaturated carbon due to bombardment by hydrogen isotopes H, D, and T at energies of 1 30 eV using classical molecular dynamics simulations. The chemical structure at the hydrogen-saturated interface (the distribution of terminal hydrocarbon moieties, in particular) shows a weak dependence on the mass of the impinging atoms. However the sputtering yields increase considerably with increasing projectile mass. We analyze the threshold energies of chemical sputtering reaction channels and show that they are nearly mass independent, as expected from elementary bond-breaking chemical reactions involving hydrocarbons. Chemical sputtering yields for D impact are compared with new experimental data. Good agreement is found for small hydrocarbons but the simulations overestimate the production of large hydrocarbons for energies larger than 15 eV. We present a thorough analysis of the dependence of our simulations on the parameters of the bombardment schemes and discuss open questions and possible avenues for development.

  3. Germplasm for genetic improvement of lint yield in Upland cotton genetic analysis of lint yield with yield components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of genetic effects for lint yield and yield components in cotton (Gossypium hirsutum L.) germplasm is critical for its utilization in breeding programs. This study was designed to apply the conditional approach and an additive and dominant (AD) model to analyze genetic effects and gen...

  4. [Effects of interaction between vermicompost and probiotics on soil nronerty, yield and quality of tomato].

    PubMed

    Shen, Fei; Zhu, Tong-bin; Teng, Ming-jiao; Chen, Yue; Liu, Man-qiang; Hu, Feng; Li, Hui-xin

    2016-02-01

    In this study, we investigated the effects of two strains of probiotic bacteria (Bacillus megaterium BM and Bacillus amyloliquefaciens BA) combined with chemical fertilizers and vermicompost on the soil property, the yield and quality of tomato. The results showed that under the same nutrient level, vermicompost significantly increased the yield, soluble sugar and protein contents of fruit, the soil pH and available phosphorus when compared with chemical fertilizers. Vermicompost combined with probiotics not only increased the tomato yield, soluble sugar, protein and vitamin C contents, sugar/acid ratio of fruit, and reduced the organic acid and nitrate nitrogen contents of fruit, also increased the soil pH and nitrate nitrogen content, and reduced soil electric conductivity when compared with vermicompost treatment. This improved efficiency was better than that by chemical fertilizers combined with probiotics. For BA and BM applied with chemical fertilizers or vermicompost, both stains had no significant effect on tomato quality. When co-applied with vermicompost, BA and BM showed significant difference in tomato yield. High soil available phosphorus content was determined when BM was combined with chemical fertilizers, while high soil available potassium content was obtained when BA was combined with vermicompost. Our results suggested that probiotics and vermicompost could be used as alternatives of chemical fertilizers in tomato production and soil fertility improvement. PMID:27396121

  5. [Effects of fertilizer application on greenhouse vegetable yield: a case study of Shouguang].

    PubMed

    Liu, Ping; Li, Yan; Jiang, Li-Hua; Liu, Zhao-Hui; Gao, Xin-Hao; Lin, Hai-Tao; Zheng, Fu-Li; Shi, Jing

    2014-06-01

    Data collected from 51 representative greenhouses of Shouguang through questionnaire survey were analyzed to investigate the effect of chemical fertilizers on vegetable yield, relationship between application of organic manure and yield, and influence factors and evolution rule of fertilizer application rate. The results showed that averages of 3338 kg N x hm(-2), 1710 kg P2O5 x hm(-2) 3446 kg K2O x hm(-2) were applied to greenhouse vegetables annually in Shouguang, 6-14 times as that in the local wheat-maize rotation system. The application rates of chemical N, P, and K fertilizers accounted for about 35%, 49% and 42% of the total input. Increasing application of chemical fertilizers had no significant effect on vegetable yields, while organic manure input significantly increased the vegetable yields. With the increase of greenhouse cultivating time, no significant changes in the input of chemical N, P, and K fertilizers were observed in greenhouse vegetable production while organic manure input decreased significantly. Differences in vegetable species, planting pattern and cultivating time of greenhouses was one of the reasons for large variations in nutrient application rate. In recent more than ten years, organic manure nutrient input increased significantly, chemical N and P fertilizer input presented a downward trend, chemical K fertilizer input increased significantly, and the N/P/K ratio became more and more reasonable in greenhouse vegetable production in Shouguang. PMID:25223034

  6. Theory of pulsed Reaction Yield Detected Magnetic Resonance.

    PubMed

    Nasibulov, Egor A; Kulik, Leonid V; Kaptein, Robert; Ivanov, Konstantin L

    2012-10-14

    We propose pulse sequences for Reaction Yield Detected Magnetic Resonance (RYDMR), which are based on refocusing the zero-quantum coherences in radical pairs by non-selective microwave pulses and using the population of a radical pair singlet spin state as an observable. The new experiments are analogues of existing EPR experiments such as the primary echo, Carr-Purcell, ESEEM, stimulated echo and Mims ENDOR. All pulse sequences are supported by analytical results and numerical calculations. The pulse sequences can be used for more efficient and highly detailed characterization of intermediates of chemical reactions and charge carriers in organic semiconductors. PMID:22930135

  7. Isobaric yield ratio difference and Shannon information entropy

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Wang; Wei, Hui-Ling; Wang, Shan-Shan; Ma, Yu-Gang; Wada, Ryoichi; Zhang, Yan-Li

    2015-03-01

    The Shannon information entropy theory is used to explain the recently proposed isobaric yield ratio difference (IBD) probe which aims to determine the nuclear symmetry energy. Theoretically, the difference between the Shannon uncertainties carried by isobars in two different reactions (ΔIn21), is found to be equivalent to the difference between the chemical potentials of protons and neutrons of the reactions [the IBD probe, IB- Δ(βμ)21, with β the reverse temperature]. From the viewpoints of Shannon information entropy, the physical meaning of the above chemical potential difference is interpreted by ΔIn21 as denoting the nuclear symmetry energy or density difference between neutrons and protons in reactions more concisely than from the statistical ablation-abrasion model.

  8. Improving Photosynthetic Efficiency for Greater Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the yield potential of the major food grain crops has contributed very significantly to a rising global supply of grain over the past 50 years, which has until recently more than kept pace with rising global demand. Yield potential is the product of the solar radiation available at a giv...

  9. THE ZONES PROJECTS: UNDERSTANDING SOYBEAN YIELD VARIABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two regional projects funded by the North Central Soybean Research Program and the United Soybean Board are entitled Mapping of Soil and Field Characteristics to Understand Soybean Yield and Using Remotely Sensed Data to Diagnose Soybean Yield Limiting Factors. These projects were developed in resp...

  10. Effects of cultivation frequency on sugarcane yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the number of cultivations during one or more years of a four year crop cycle reduces production expenses and could increase profitability if yields are not adversely affected. This study was initiated to determine the effects of cultivation on yields of sugarcane grown on a clay soil both ...

  11. The Tradeoff Between Alfalfa Yield and Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive cutting management research has documented the effects of date and frequency of harvest on alfalfa (Medicago sativa L.) forage yield and quality. Information is lacking, however, on the change in quality relative to yield that occurs as alfalfa matures within individual harvest periods. ...

  12. Calibrating your forage harvester's yield monitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With some attention to the details, you will have a harvester that should be able to produce yield maps that will allow the same precision management that is expected in cereal crops. Forage yield maps, coupled with site-specific technologies in application of soil amendments, fertilizers, and pesti...

  13. Winter wheat yield response to available water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dryland winter wheat yields in eastern Colorado can vary greatly from year to year and are primarily limited by available water supplies. Yields increase linearly with water use at an average rate of 4.7 bu/a per inch of water used after the first 5 inches of water use. An Excel-based spreadsheet ca...

  14. Sugarcane yield loss due to ratoon stunt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yield response of recently released CP-cultivars to ratoon stunt has not been determined. Cane and sugar yields of Liefsonia xyli subsp. xyli (Lxx)-infected and healthy sugarcane plants of cultivars that are currently major commercial cultivars that have not been in prior tests as well as former...

  15. High yielding Indica germplasm from China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1996, 213 rice accessions were introduced from China for enriching USDA rice germplasm collection. Evaluation for the Chinese germplasm on yield potential, disease resistances and grain quality was conducted in 2000 and 2001. Fifteen accessions yielded in excess of 10,130 kg/ha rough rice that ...

  16. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Determining Yield Coverage Using Actual Production History § 1437.102 Yield determinations. (a) An actual... used in the actual production history base period when less than four consecutive crop years of actual... calculated, in the actual production history base period when the producer reports acreage for the crop...

  17. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Determining Yield Coverage Using Actual Production History § 1437.102 Yield determinations. (a) An actual... used in the actual production history base period when less than four consecutive crop years of actual... calculated, in the actual production history base period when the producer reports acreage for the crop...

  18. Improved Yield Estimation by Trellis Tension Monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most yield estimation practices for commercial vineyards rely on hand-sampling fruit on one or a small number of dates during the growing season. Limitations associated with the static yield estimates may be overcome with Trellis Tension Monitors (TTMs), systems that measure dynamically changes in t...

  19. Yield potential of pigeon pea cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield potential of twelve vegetable pigeon pea (Cajanus cajun) cultivars was evaluated at two locations in eastern Kenya during 2012 and 2013 cropping years. Pigeon pea pod numbers, seeds per pod, seed mass, grain yield and shelling percentage were quantified in three replicated plots, arranged in a...

  20. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... adjusted on an administrative county-wide basis for: (i) Yield variations due to different farming practices in the administrative county such as irrigated, non-irrigated, and organic practices; and (ii... missing crop years actual yield. (h) If producers add land in the farming operation and do not...

  1. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... adjusted on an administrative county-wide basis for: (i) Yield variations due to different farming practices in the administrative county such as irrigated, non-irrigated, and organic practices; and (ii... missing crop years actual yield. (h) If producers add land in the farming operation and do not...

  2. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... adjusted on an administrative county-wide basis for: (i) Yield variations due to different farming practices in the administrative county such as irrigated, non-irrigated, and organic practices; and (ii... missing crop years actual yield. (h) If producers add land in the farming operation and do not...

  3. Weed competition and dry bean yield components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed competition can significantly reduce dry bean (Phaseolus vulgaris L.) yields and therefore the profitability for the producer. Depending on the dry bean variety produced, the yield components may be affected differently by the stress produced by weed competition. This research was conducted to ...

  4. Chemical lasers

    NASA Astrophysics Data System (ADS)

    Khariton, Y.

    1984-08-01

    The application and the advances of quantum electronics, specifically, of optical quantum generators lasers is reviewed. Materials are cut, their surfaces are machined, chemical transformations of substances are carried out, surgical operations are performed, data are transmitted, three dimensional images are produced and the content of microimpurities, in the atmosphere, are analyzed by use of a beam. Laser technology is used in conducting investigations in the most diverse fields of the natural and technical sciences from controlled thermonuclear fusion to genetics. Many demands are placed on lasers as sources of light energy. The importance of low weight, compactness of the optical generator and the efficiency of energy conversion processes is emphasized.

  5. High-Yield Synthesis of Stoichiometric Boron Nitride Nanostructures

    DOE PAGESBeta

    Nocua, José E.; Piazza, Fabrice; Weiner, Brad R.; Morell, Gerardo

    2009-01-01

    Boron nimore » tride (BN) nanostructures are structural analogues of carbon nanostructures but have completely different bonding character and structural defects. They are chemically inert, electrically insulating, and potentially important in mechanical applications that include the strengthening of light structural materials. These applications require the reliable production of bulk amounts of pure BN nanostructures in order to be able to reinforce large quantities of structural materials, hence the need for the development of high-yield synthesis methods of pure BN nanostructures. Using borazine ( B 3 N 3 H 6 ) as chemical precursor and the hot-filament chemical vapor deposition (HFCVD) technique, pure BN nanostructures with cross-sectional sizes ranging between 20 and 50 nm were obtained, including nanoparticles and nanofibers. Their crystalline structure was characterized by (XRD), their morphology and nanostructure was examined by (SEM) and (TEM), while their chemical composition was studied by (EDS), (FTIR), (EELS), and (XPS). Taken altogether, the results indicate that all the material obtained is stoichiometric nanostructured BN with hexagonal and rhombohedral crystalline structure.« less

  6. Fermentable sugars by chemical hydrolysis of biomass

    PubMed Central

    Binder, Joseph B.; Raines, Ronald T.

    2010-01-01

    Abundant plant biomass has the potential to become a sustainable source of fuels and chemicals. Realizing this potential requires the economical conversion of recalcitrant lignocellulose into useful intermediates, such as sugars. We report a high-yielding chemical process for the hydrolysis of biomass into monosaccharides. Adding water gradually to a chloride ionic liquid-containing catalytic acid leads to a nearly 90% yield of glucose from cellulose and 70–80% yield of sugars from untreated corn stover. Ion-exclusion chromatography allows recovery of the ionic liquid and delivers sugar feedstocks that support the vigorous growth of ethanologenic microbes. This simple chemical process, which requires neither an edible plant nor a cellulase, could enable crude biomass to be the sole source of carbon for a scalable biorefinery. PMID:20194793

  7. Climate change and maize yield in Iowa

    DOE PAGESBeta

    Xu, Hong; Twine, Tracy E.; Girvetz, Evan

    2016-05-24

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output frommore » six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Lastly, our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century.« less

  8. Climate Change and Maize Yield in Iowa.

    PubMed

    Xu, Hong; Twine, Tracy E; Girvetz, Evan

    2016-01-01

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century. PMID:27219116

  9. Regression Models For Saffron Yields in Iran

    NASA Astrophysics Data System (ADS)

    S. H, Sanaeinejad; S. N, Hosseini

    Saffron is an important crop in social and economical aspects in Khorassan Province (Northeast of Iran). In this research wetried to evaluate trends of saffron yield in recent years and to study the relationship between saffron yield and the climate change. A regression analysis was used to predict saffron yield based on 20 years of yield data in Birjand, Ghaen and Ferdows cities.Climatologically data for the same periods was provided by database of Khorassan Climatology Center. Climatologically data includedtemperature, rainfall, relative humidity and sunshine hours for ModelI, and temperature and rainfall for Model II. The results showed the coefficients of determination for Birjand, Ferdows and Ghaen for Model I were 0.69, 0.50 and 0.81 respectively. Also coefficients of determination for the same cities for model II were 0.53, 0.50 and 0.72 respectively. Multiple regression analysisindicated that among weather variables, temperature was the key parameter for variation ofsaffron yield. It was concluded that increasing temperature at spring was the main cause of declined saffron yield during recent years across the province. Finally, yield trend was predicted for the last 5 years using time series analysis.

  10. Climate Change and Maize Yield in Iowa

    PubMed Central

    Xu, Hong; Twine, Tracy E.; Girvetz, Evan

    2016-01-01

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10–20% by the end of the 21st century. PMID:27219116

  11. Optimizing rice yields while minimizing yield-scaled global warming potential.

    PubMed

    Pittelkow, Cameron M; Adviento-Borbe, Maria A; van Kessel, Chris; Hill, James E; Linquist, Bruce A

    2014-05-01

    To meet growing global food demand with limited land and reduced environmental impact, agricultural greenhouse gas (GHG) emissions are increasingly evaluated with respect to crop productivity, i.e., on a yield-scaled as opposed to area basis. Here, we compiled available field data on CH4 and N2 O emissions from rice production systems to test the hypothesis that in response to fertilizer nitrogen (N) addition, yield-scaled global warming potential (GWP) will be minimized at N rates that maximize yields. Within each study, yield N surplus was calculated to estimate deficit or excess N application rates with respect to the optimal N rate (defined as the N rate at which maximum yield was achieved). Relationships between yield N surplus and GHG emissions were assessed using linear and nonlinear mixed-effects models. Results indicate that yields increased in response to increasing N surplus when moving from deficit to optimal N rates. At N rates contributing to a yield N surplus, N2 O and yield-scaled N2 O emissions increased exponentially. In contrast, CH4 emissions were not impacted by N inputs. Accordingly, yield-scaled CH4 emissions decreased with N addition. Overall, yield-scaled GWP was minimized at optimal N rates, decreasing by 21% compared to treatments without N addition. These results are unique compared to aerobic cropping systems in which N2 O emissions are the primary contributor to GWP, meaning yield-scaled GWP may not necessarily decrease for aerobic crops when yields are optimized by N fertilizer addition. Balancing gains in agricultural productivity with climate change concerns, this work supports the concept that high rice yields can be achieved with minimal yield-scaled GWP through optimal N application rates. Moreover, additional improvements in N use efficiency may further reduce yield-scaled GWP, thereby strengthening the economic and environmental sustainability of rice systems. PMID:24115565

  12. A universal model for estimating wheat yields

    NASA Technical Reports Server (NTRS)

    Feyerherm, A. M.; Paulsen, G. M. (Principal Investigator)

    1979-01-01

    A universal wheat yield model applicable to both fall- and spring-planted wheat was developed to show separate and joint effects of weather and culture on yields. Data from state experiment stations in a wide range of climates in the U.S. Great Plains were used to build basic relationships among yields, weather, and culture. The application of the model on a macroclimatic scale in the U.S., the U.S.S.R., and India is discussed along with potential improvements.

  13. Yield Editor 2.0: software for automated removal of yield map errors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield maps provide important information for developing and evaluating precision management strategies. The high-quality yield maps needed for decision-making require screening raw yield monitor datasets for errors and removing them before maps are made. To facilitate this process, we developed the ...

  14. Yield drag associated with resistance to root-knot nematodes in high-yielding cotton germplasm.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In plant breeding, accidental incorporation of deleterious DNA near a desirable gene is called linkage drag; if it reduces yield, it is called yield drag. Yield drag is best documented by comparing near isogenic lines with and without the DNA containing the desired gene to minimize other genetic di...

  15. Influence of Organic Pesticides on Nematode and Corn Earworm Damage and on Yield of Sweet Corn

    PubMed Central

    Johnson, A. W.; Chalfant, R. B.

    1973-01-01

    Soil fumigants and nonvolatile pesticides increased growth and yield of sweet corn 'Seneca Chief' over that of control plants in a 3-year study. Nematicide treatments increased average yields by 31% over controls, but did not significantly affect the mean weight per ear. Increase in yield was related to control of Belonolaimus longicaudatus, Trichodorus christiei and Pratylenchus zeae. Nonvolatile chemicals more effectively reduced populations of B. longicaudatus and T. christiei than did soil fumigants. Aldicarb did not control Criconemoides ornatus. All pesticides controlled P. zeae. Pesticides did not control Heliothis zea effectively. PMID:19319328

  16. Yielding to Stress: Recent Developments in Viscoplastic Fluid Mechanics

    NASA Astrophysics Data System (ADS)

    Balmforth, Neil J.; Frigaard, Ian A.; Ovarlez, Guillaume

    2014-01-01

    The archetypal feature of a viscoplastic fluid is its yield stress: If the material is not sufficiently stressed, it behaves like a solid, but once the yield stress is exceeded, the material flows like a fluid. Such behavior characterizes materials common in industries such as petroleum and chemical processing, cosmetics, and food processing and in geophysical fluid dynamics. The most common idealization of a viscoplastic fluid is the Bingham model, which has been widely used to rationalize experimental data, even though it is a crude oversimplification of true rheological behavior. The popularity of the model is in its apparent simplicity. Despite this, the sudden transition between solid-like behavior and flow introduces significant complications into the dynamics, which, as a result, has resisted much analysis. Over recent decades, theoretical developments, both analytical and computational, have provided a better understanding of the effect of the yield stress. Simultaneously, greater insight into the material behavior of real fluids has been afforded by advances in rheometry. These developments have primed us for a better understanding of the various applications in the natural and engineering sciences.

  17. Oxidation of heterocyclic nitrogen yields to nitroheterocycles. [Nitrofurazans

    SciTech Connect

    Coburn, M.D.

    1985-01-01

    In the process of finding new routes to synthesize nitrofurazans the investigators compared the oxidation of a sulfilimide and a phosphine imine derived from 3-amino-4-(chlorophenyl)furazan (1). The sulfilimine, 3-(4-chlorophenyl)-4-dimethyl-sulfiliminofurazan (2), was prepared by treating 1 with dimethyl sulfide ditriflate. Oxidation of 1 with peroxytrifluoroacetic acid (ptfa) in dichloromethane gave a mixture that was chromatographed to give 3-(4-chlorophenyl)-4- nitro-furazan (5) in 11% yield and azoxy(4-chlorophenylfurazan) (6) in 32% yield. Under the same conditions, 2 gave a 96% yield of 5 with no trace of 6. Oxidation of diaminofurazan (7) with ptfa gives 3-amino-4-nitrofurazan (8), which was converted to the sulfilimine. Treatment of the sulfilimine with anhydrous ptfa in dichloromethane gave a solution that contained dimethyl sulfone according to /sup 13/C-NMR analysis, but no nitrocarbon could be detected. However, the /sup 14/N-NMR spectrum contained a very sharp singlet with a width at half-height of 19 Hz and a chemical shift almost identical to that of 5. Thus, it appears that we may have formed dinitrofurazan in solution, but we have not been able to isolate it in pure form as yet. 10 refs., 4 figs.

  18. Alculation of the SSP chemical evolution

    NASA Astrophysics Data System (ADS)

    Berczik, P. P.; Petrov, N. I.

    2003-02-01

    We present a new public access ANSI C software for calculating the chemical evolution of a Single Stellar Population (SSP). We calculate the yields from 9 "heavy" elements: 12C, 14N, 16O, 20Ne, 24Mg, 28Si, 32S, 40Ca, 56Fe, as well as the yields for 1H and 4He. The characteristic feature of the present code is a high modularity, which allows one to use it together with other programs in a user's code. As a test of our code in the distributive we present calculating the chemical evolution of a closed system in the Simple Model approximation.

  19. Boosting production yield of biomedical peptides

    NASA Technical Reports Server (NTRS)

    Manatt, S. L.

    1978-01-01

    Nuclear magnetic resonance (NMR) technique is employed to monitor synthesis of biomedical peptides. Application of NMR technique may improve production yields of insulin, ACTH, and growth hormones, as well as other synthesized biomedical peptides.

  20. User's appraisal of yield model evaluation criteria

    NASA Technical Reports Server (NTRS)

    Warren, F. B. (Principal Investigator)

    1982-01-01

    The five major potential USDA users of AgRISTAR crop yield forecast models rated the Yield Model Development (YMD) project Test and Evaluation Criteria by the importance placed on them. These users were agreed that the "TIMELINES" and "RELIABILITY" of the forecast yields would be of major importance in determining if a proposed yield model was worthy of adoption. Although there was considerable difference of opinion as to the relative importance of the other criteria, "COST", "OBJECTIVITY", "ADEQUACY", AND "MEASURES OF ACCURACY" generally were felt to be more important that "SIMPLICITY" and "CONSISTENCY WITH SCIENTIFIC KNOWLEDGE". However, some of the comments which accompanied the ratings did indicate that several of the definitions and descriptions of the criteria were confusing.

  1. Spectral behavior of wheat yield variety trials

    NASA Technical Reports Server (NTRS)

    Hatfield, J. L.

    1981-01-01

    Little variation between varieties is seen at jointing, but the variability is found to increase during grain filling and decline again at maturity. No relationship is found between spectral response and yield, and when yields are segregated into various classes the spectral response is the same. Spring and winter nurseries are found to separate during the reproductive stage because of differences in dates of heading and maturity, but they exhibit similar spectral responses. The transformed normalized difference is at a minimum after the maximum grain weight occurs and the leaves begin to brown and fall off. These data of 100% ground cover demonstrate that it is not possible to predict grain yield from only spectral data. This, however, may not apply when reduced yields are caused by less-than-full ground cover

  2. Acid hydrolysis of cellulose to yield glucose

    DOEpatents

    Tsao, George T.; Ladisch, Michael R.; Bose, Arindam

    1979-01-01

    A process to yield glucose from cellulose through acid hydrolysis. Cellulose is recovered from cellulosic materials, preferably by pretreating the cellulosic materials by dissolving the cellulosic materials in Cadoxen or a chelating metal caustic swelling solvent and then precipitating the cellulose therefrom. Hydrolysis is accomplished using an acid, preferably dilute sulfuric acid, and the glucose is yielded substantially without side products. Lignin may be removed either before or after hydrolysis.

  3. LACIE: Wheat yield models for the USSR

    NASA Technical Reports Server (NTRS)

    Sakamoto, C. M.; Leduc, S. K.

    1977-01-01

    A quantitative model determining the relationship between weather conditions and wheat yield in the U.S.S.R. was studied to provide early reliable forecasts on the size of the U.S.S.R. wheat harvest. Separate models are developed for spring wheat and for winter. Differences in yield potential and responses to stress conditions and cultural improvements necessitate models for each class.

  4. Interactive effects of pests increase seed yield.

    PubMed

    Gagic, Vesna; Riggi, Laura Ga; Ekbom, Barbara; Malsher, Gerard; Rusch, Adrien; Bommarco, Riccardo

    2016-04-01

    Loss in seed yield and therefore decrease in plant fitness due to simultaneous attacks by multiple herbivores is not necessarily additive, as demonstrated in evolutionary studies on wild plants. However, it is not clear how this transfers to crop plants that grow in very different conditions compared to wild plants. Nevertheless, loss in crop seed yield caused by any single pest is most often studied in isolation although crop plants are attacked by many pests that can cause substantial yield losses. This is especially important for crops able to compensate and even overcompensate for the damage. We investigated the interactive impacts on crop yield of four insect pests attacking different plant parts at different times during the cropping season. In 15 oilseed rape fields in Sweden, we estimated the damage caused by seed and stem weevils, pollen beetles, and pod midges. Pest pressure varied drastically among fields with very low correlation among pests, allowing us to explore interactive impacts on yield from attacks by multiple species. The plant damage caused by each pest species individually had, as expected, either no, or a negative impact on seed yield and the strongest negative effect was caused by pollen beetles. However, seed yield increased when plant damage caused by both seed and stem weevils was high, presumably due to the joint plant compensatory reaction to insect attack leading to overcompensation. Hence, attacks by several pests can change the impact on yield of individual pest species. Economic thresholds based on single species, on which pest management decisions currently rely, may therefore result in economically suboptimal choices being made and unnecessary excessive use of insecticides. PMID:27099712

  5. Fricke xylenol gel characterization using a photoacustic technique

    NASA Astrophysics Data System (ADS)

    Caldeira, A. M. F.; de Almeida, A.; Neto, A. M.; Baesso, M. L.; Bento, A. C.; Silva, M. A.

    2007-11-01

    Fricke chemical dosimetry measurements of the absorbed dose of ionizing radiation depend on the quality and characteristics of the system that reads each dosimeter. The final accuracy is significantly dependent on the technique used for measuring the chemical concentration changes in the dosimeters. We have used a photoacoustic technique to detect the Fricke xylenol gel (FXG) optical absorbance. The FXG, a derivation of the aqueous Fricke dosimeter, is made more sensitive and stable with addition of gelatin (300 Bloom) and xylenol orange. The light intensity transmitted through an FXG sample before and after irradiation was measured with an acoustic detector. The incremental optical absorbance is directly proportional to the ionizing radiation absorbed dose. We present the optical absorbance measurements as a function of absorbed dose and of post-irradiation time. We apply our photoacoustic technique to determine absorbed dose profiles. The results show that the photoacoustic technique applied to FXG provides a new dosimetric system, as good as those already established using spectrophotometric techniques.

  6. Renewable chemicals: dehydroxylation of glycerol and polyols.

    PubMed

    ten Dam, Jeroen; Hanefeld, Ulf

    2011-08-22

    The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de-functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil-based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect. PMID:21887771

  7. Renewable Chemicals: Dehydroxylation of Glycerol and Polyols

    PubMed Central

    ten Dam, Jeroen; Hanefeld, Ulf

    2011-01-01

    The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de-functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil-based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect. PMID:21887771

  8. Earthflow yield strength constrained by lateral levee morphology

    NASA Astrophysics Data System (ADS)

    Nereson, A. L.; Finnegan, N. J.

    2015-12-01

    Slow-moving landslides, or earthflows, are characterized by persistent, flow-like motion that is commonly modeled using various viscous and viscoplastic rheologies. One of the manifestations of viscoplastic flow down a slope is the emergence of stationary bodies of fluid at the margins of the flow (i.e. lateral levees). These levees are common signatures of earthflow morphology and, while they are frequently used to outline boundaries for mapping purposes, they have received little attention for what they may indicate about the history and properties of the flow itself. In contrast, lateral levees along lava flows have long been used by physical volcanologists as tools to learn about their non-Newtonian rheologies and chemical compositions. Hulme (1974) was the first to note that, for a given slope, levee width may be characteristic of a fluids's yield strength and his methodology has been subsequently used to infer properties of lavas on the Earth, the Moon, and Mars. Using these lavas as analogies, we apply Hulme's approach to earthflows in a variety of settings globally. We find that calculated yield strengths for individual earthflows fall within a relatively narrow range between 101-102 kPa. In addition, individual earthflow complexes often preserve multiple generations of levees, which in some cases may record apparent reductions in yield strength over time for a given flow, possibly from weakening of previously failed material. Knowledge of earthflow yield strength permits the calculation of a critical earthflow thickness below which there will be no downslope motion for a given slope angle. Thicknesses calculated in this manner could thus be used to estimate the flux of landslide material for earthflows without direct depth constraints, provided that surface velocity measurements are obtained by other methods (e.g. InSAR, GPS, manual feature tracking).

  9. Chemical Engineering in Space

    NASA Technical Reports Server (NTRS)

    Lobmeyer, Dennis A.; Meneghelli, Barry; Steinrock, Todd (Technical Monitor)

    2001-01-01

    sources is paramount to success. We are currently working on several processes to produce the propellants that would allow us to visit and explore the surface of Mars. The capabilities currently at our disposal for launching and delivering equipment to another planet or satellite dictate that the size and scale of any hardware must be extremely small. The miniaturization of the processes needed to prepare the in situ propellants and life support commodities is a real challenge. Chemical engineers are faced with the prospect of reproducing an entire production facility in miniature so the complex can be lifted into space and delivered to our destination. Another area that does not normally concern chemical engineers is the extreme physical aspects payloads are subjected to with the launch of a spacecraft. Extreme accelerations followed by the sudden loss of nearly all gravitational forces are well outside normal equipment design conditions. If the equipment cannot survive the overall trip, then it obviously will not be able to yield the needed products upon arrival. These launch constraints must be taken into account. Finally, we must consider both the effectiveness and efficiencies of the processes. A facility located on the Moon or Mars will not have an unlimited supply of power or other ancillary utilities. For a Mars expedition, the available electric power is severely limited. The design of both the processes and the equipment must be considered. With these constraints in mind, only the most efficient designs will be viable. Cryogenics, in situ resource utilization, miniaturization, launchability, and power/process efficiencies are only a few of the areas that chemical engineers provide support and expertise for the exploration of space.

  10. Yield stress measurements using novel squeezing flows

    NASA Astrophysics Data System (ADS)

    Ward, Daniel

    Techniques for measuring the yield stress of materials are numerous, but often plagued with difficulties and uncertainties in measurement. The primary methods include shear rheometry and, more recently, squeezing flow. Shear rheometry requires care on the part of the experimentalist to generate uniform flow fields and avoid shear banding or wall slip which may interfere with measurements. Squeezing flow tests are often performed with poorly controlled boundary conditions creating complicated flow fields. Further, the effects of the experimental modifications made to produce these boundary conditions in measurements are often not investigated and simply ignored. The main objective of this study was to develop a novel measuring technique to study the yield stress behavior of a model material, Carbopol. First attempts were made towards a novel lubricant injection squeezing (LIS) flow technique based on the continuous lubricated squeezing flow (CLSF) setup, as well as a novel lubricant film squeezing (LFS) technique which will allow measurement of the yield stress without the complicated treatment of either the sample or experimental setup required by currently favored methods. The novel techniques were developed and validated by direct comparison with shear measurements, the current gold standard for determining yield stress. Common squeezing techniques for characterizing yield stress fluids were also compared and found to be inadequate and inconsistent when compared to the shear measurements. The results from this study showed that the LIS and LFS methods are able to qualitatively determine a yield stress, but further investigation is required before they can be achieve their full potential as viable methods for determine yield stress.

  11. Yield strength of molybdenum at high pressures.

    PubMed

    Jing, Qiumin; Bi, Yan; Wu, Qiang; Jing, Fuqian; Wang, Zhigang; Xu, Jian; Jiang, Sheng

    2007-07-01

    In the diamond anvil cell technology, the pressure gradient approach is one of the three major methods in determining the yield strength for various materials at high pressures. In the present work, by in situ measuring the thickness of the sample foil, we have improved the traditional technique in this method. Based on this modification, the yield strength of molybdenum at pressures has been measured. Our main experimental conclusions are as follows: (1) The measured yield strength data for three samples with different initial thickness (100, 250, and 500 microm) are in good agreement above a peak pressure of 10 GPa. (2) The measured yield strength can be fitted into a linear formula Y=0.48(+/-0.19)+0.14(+/-0.01)P (Y and P denote the yield strength and local pressure, respectively, both of them are in gigapascals) in the local pressure range of 8-21 GPa. This result is in good agreement with both Y=0.46+0.13P determined in the pressure range of 5-24 GPa measured by the radial x-ray diffraction technique and the previous shock wave data below 10 GPa. (3) The zero-pressure yield strength of Mo is 0.5 GPa when we extrapolate our experimental data into the ambient pressure. It is close to the tensile strength of 0.7 GPa determined by Bridgman [Phys. Rev. 48, 825 (1934)] previously. The modified method described in this article therefore provides the confidence in determination of the yield strength at high pressures. PMID:17672772

  12. Best prediction of yields for long lactations.

    PubMed

    Cole, J B; Null, D J; Vanraden, P M

    2009-04-01

    Lactation records of any reasonable length now can be processed with the selection index method known as best prediction (BP). Previous prediction programs were limited to the 305-d standard used since 1935. Best prediction was implemented in 1998 to calculate lactation records in USDA genetic evaluations, replacing the test interval method used since 1969 to calculate lactation records. Best prediction is more complex but also more accurate, particularly when testing is less frequent. Programs were reorganized to output better graphics, give users simpler access to options, and provide additional output, such as BP of daily yields. Test-day data for 6 breeds were extracted from the national dairy database, and lactation lengths were required to be > or =500 d (Ayrshire, Milking Shorthorn) or > or =800 d (all others). Average yield and SD at any day in milk (DIM) were estimated by fitting 3-parameter Wood's curves (milk, fat, protein) and 4-parameter exponential functions (somatic cell score) to means and SD of 15- (< or =300 DIM) and 30-d (>300 DIM) intervals. Correlations among TD yields were estimated using an autoregressive matrix to account for biological changes and an identity matrix to model daily measurement error. Autoregressive parameters (r) were estimated separately for first (r = 0.998) and later parities (r = 0.995). These r values were slightly larger than previous estimates due to the inclusion of the identity matrix. Correlations between traits were modified so that correlations between somatic cell score and other traits may be nonzero. The new lactation curves and correlation functions were validated by extracting TD data from the national database, estimating 305-d yields using the original and new programs, and correlating those results. Daily BP of yield were validated using daily milk weights from on-farm meters in university research herds. Correlations ranged from 0.900 to 0.988 for 305-d milk yield. High correlations ranged from 0.844 to

  13. Role of Yield Stress in Magma Rheology

    NASA Astrophysics Data System (ADS)

    Kurokawa, A.; Di Giuseppe, E.; Davaille, A.; Kurita, K.

    2012-04-01

    Magmas are essentially multiphase material composed of solid crystals, gaseous bubbles and silicate liquids. They exhibit various types of drastic change in rheology with variation of mutual volumetric fractions of the components. The nature of this variable rheology is a key factor in controlling dynamics of flowing magma through a conduit. Particularly the existence of yield stress in flowing magma is expected to control the wall friction and formation of density waves. As the volumetric fraction of solid phase increases yield stress emerges above the critical fraction. Several previous studies have been conducted to clarify this critical value of magmatic fluid both in numerical simulations and laboratory experiments ([Lejeune and Pascal, 1995], [Saar and Manga 2001], [Ishibashi and Sato 2010]). The obtained values range from 13.3 to 40 vol%, which display wide variation and associated change in rheology has not been clarified well. In this presentation we report physical mechanism of emergence of yield stress in suspension as well as the associated change in the rheology based on laboratory experiments using analog material. We utilized thermogel aqueous suspension as an analog material of multiphase magma. Thermogel, which is a commercial name for poly(N-isopropyl acrylamide) (PNIPAM) undergoes volumetric phase change at the temperature around 35C:below this temperature the gel phase absorbs water and swells while below this it expels water and its volume shrinks. Because of this the volumetric fraction of gel phase systematically changes with temperature and the concentration of gel powder. The viscosity measured at lower stress drastically decreases across this phase change with increasing temperature while the viscosity at higher stress does not exhibit large change across the transition. We have performed a series of rheological measurements focusing on the emergence of yield stress on this aqueous suspension. Since the definition of yield stress is not

  14. Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Bank, Bruce A.; de Groh, Kim K.; Backus, Jane A.

    2008-01-01

    A predictive tool was developed to estimate the low Earth orbit (LEO) atomic oxygen erosion yield of polymers based on the results of the Polymer Erosion and Contamination Experiment (PEACE) Polymers experiment flown as part of the Materials International Space Station Experiment 2 (MISSE 2). The MISSE 2 PEACE experiment accurately measured the erosion yield of a wide variety of polymers and pyrolytic graphite. The 40 different materials tested were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The resulting erosion yield data was used to develop a predictive tool which utilizes chemical structure and physical properties of polymers that can be measured in ground laboratory testing to predict the in-space atomic oxygen erosion yield of a polymer. The properties include chemical structure, bonding information, density and ash content. The resulting predictive tool has a correlation coefficient of 0.914 when compared with actual MISSE 2 space data for 38 polymers and pyrolytic graphite. The intent of the predictive tool is to be able to make estimates of atomic oxygen erosion yields for new polymers without requiring expensive and time consumptive in-space testing.

  15. Multiaxial yield behaviour of Al replicated foam

    NASA Astrophysics Data System (ADS)

    Combaz, E.; Bacciarini, C.; Charvet, R.; Dufour, W.; Mortensen, A.

    2011-09-01

    Multiaxial experiments are performed on replicated aluminium foam using a custom-built apparatus. The foam structure is isotropic, and features open monomodal pores 75 μm in average diameter. Plane stress ( σ1, σ2, σ3=0) and axisymmetric ( σ1, σ2=σ3) yield envelopes are measured using cubical specimens, supplemented by tests on hollow cylindrical and uniaxial samples. In addition to the three stress components at 0.2% offset strain, the computer-controlled testing apparatus also measures the three instantaneous displacement vectors. Results show that the shape of the yield surface is independent of the relative density of the foam in the explored range (13-28%). Strain increment vectors lie, within error, roughly normal to the line traced through data points in stress space. Replicated foams feature asymmetric yield behaviour between tension and compression. The data additionally show an influence on the yield surface of the third stress tensor invariant (i.e., of the Lode angle). Simple general expressions for the yield surface are fitted to the data, leading to conclude that their behaviour is slightly better captured by parabolic rather than elliptic expressions dependent on all three stress invariants.

  16. Genes that influence yield in tomato

    PubMed Central

    Ariizumi, Tohru; Shinozaki, Yoshihito; Ezura, Hiroshi

    2013-01-01

    Yield is the most important breeding trait of crops. For fruit-bearing plants such as Solanum lycopersicum (tomato), fruit formation directly affects yield. The final fruit size depends on the number and volume of cell layers in the pericarp of the fruit, which is determined by the degree of cell division and expansion in the fertilized ovaries. Thus, fruit yield in tomato is predominantly determined by the efficiency of fruit set and the final cell number and size of the fruits. Through domestication, tomato fruit yield has been markedly increased as a result of mutations associated with fruit size and genetic studies have identified the genes that influence the cell cycle, carpel number and fruit set. Additionally, several lines of evidence have demonstrated that plant hormones control fruit set and size through the delicate regulation of genes that trigger physiological responses associated with fruit expansion. In this review, we introduce the key genes involved in tomato breeding and describe how they affect the physiological processes that contribute to tomato yield. PMID:23641176

  17. The yield surface of textured polycrystals†

    NASA Astrophysics Data System (ADS)

    Canova, G. R.; Kocks, U. F.; Tomé, C. N.; Jonas, J. J.

    T HE PLASTIC anisotropy of a material is characterized in part by its yield surface. It is shown that conventional descriptions, based on extensions of the von Mises hypothesis for isotropic materials, are experimentally and theoretically inadequate in many instances. Symmetry arguments are used to derive the dimensionality and extent of the space necessary for representing the yield surface under various conditions of anisotropy. A useful concept is introduced: "closed" subspaces, in which sections and projections of the yield surface are identical and in which, therefore, normality is complete. Yield surfaces of heavily rolled or sheared sheets are derived from a computer simulation of polycrystal plasticity. It is found that even mild textures give rise to significant departures from "oval" yield surfaces: they develop sharp ridges and extensive flats. The anisotropy coefficients for in-plane tension of rolled sheets have been calculated. For torsion testing under fixed and free end conditions, respectively, the axial force and the length change have been calculated, as well as the change in the ratio of wall thickness to diameter.

  18. Rice yield estimation using Landsat ETM+ Data

    NASA Astrophysics Data System (ADS)

    Siyal, Altaf Ali; Dempewolf, Jan; Becker-Reshef, Inbal

    2015-01-01

    Paddy rice areas in Larkana district in Sindh province, Pakistan, were mapped over eight years. Landsat 7 ETM+ satellite imagery was classified for rice areas using training data collected through visual interpretation and using a bagged decision tree approach. Within the rice areas, we estimated yield for the 2013 season using regression models based on Landsat-derived normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) values against historic, reported yield values. The annual cropped rice area estimated from satellite imagery was between 19% and 24% lower than the area reported by the Crop Reporting Service, Sindh. A positive and strong relationship with coefficient of determination (R2) of 0.94 was observed between the reported rice crop yield and NDVI at the peak of the growing season for the years 2006 to 2013. A fair relation (R2=0.875) between rice crop yield and RVI was observed for the same years. A strong relationship between observed and predicted rice production with model efficiency=0.925, mean bias error=-85,016 t, and RMSE=80,726 t was obtained. Thus, Landsat ETM+ has a high potential for estimating rice yield and production at the district level in Pakistan and elsewhere.

  19. Soil attributes, soybean mineral nutrition and yield in diverse crop rotations under no-till conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of sustainable agricultural systems depends on understanding complex relationships between soil attributes, crop rotations, and crop yield. Objectives were to measure how soil chemical and physical attributes as well as soybean (Glycine max Merr.) stover dry weight and mineral concentra...

  20. Crop yield estimation based on unsupervised linear unmixing of multidate hyperspectral imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imagery, which contains hundreds of spectral bands, has the potential to better describe the biological and chemical attributes on the plants than multispectral imagery and has been evaluated in this paper for the purpose of crop yield estimation. The spectrum of each pixel in a hypers...

  1. Corn grain yield and nutrient uptake from application of enhanced-efficiency nitrogen fertilizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing demand for food and agricultural products directly impact the use of chemical fertilizers particularly nitrogen (N). This study examined corn grain yield and nutrient uptake resulting from applications of different N fertilizer sources, urea (U), urea-ammonium nitrate (UAN), ammonium nitr...

  2. Develop a field grid system for yield mapping and machine control. Final report, Invention 544

    SciTech Connect

    1995-12-15

    The objective of this project was to build and test the Field Grid Sense system for yield mapping and machine control during harvesting. Secondly, to use Field Grid Sense system with chemical application equipment to demonstrate a workable in-field system. This document contains summarized quarterly reports.

  3. Effective lactation yield: A measure to compare milk yield between cows with different dry period lengths.

    PubMed

    Kok, A; van Middelaar, C E; Engel, B; van Knegsel, A T M; Hogeveen, H; Kemp, B; de Boer, I J M

    2016-04-01

    To compare milk yields between cows or management strategies, lactations are traditionally standardized to 305-d yields. The 305-d yield, however, gives no insight into the combined effect of additional milk yield before calving, decreased milk yield after calving, and a possible shorter calving interval in the case of a shortened dry period. We aimed to develop a measure that would enable the comparison of milk yield between cows with different dry period (DP) lengths. We assessed the importance of accounting for additional milk yield before calving and for differences in calving interval. The 305-d yield was compared with a 365-d yield, which included additional milk yield in the 60 d before calving. Next, an effective lactation yield was computed, defined as the daily yield from 60d before calving to 60 d before the next calving, to account for additional milk yield before calving and for differences in calving interval. Test-day records and drying-off dates of 15 commercial farms were used to compute the 305-d, 365-d, and effective lactation yields for individual cows. We analyzed 817 second-parity lactations preceded by no DP, a short DP (20 to 40 d), or a conventional DP (49 to 90 d). Compared with cows with a conventional DP, the 305-d yield of cows with no DP was 7.0 kg of fat- and protein-corrected milk (FPCM) per day lower, and the 305-d yield of cows with a short DP was 2.3 kg of FPCM per day lower. Including additional milk yield before calving in the 365-d yield reduced this difference to 3.4 kg of FPCM per cow per day for cows with no DP and to 0.9 kg of FPCM per cow per day for cows with a short DP. Compared with cows with a conventional DP, median days open were reduced by 25d for cows with no DP and by 18d for cows with a short DP. Accounting for these differences in calving interval in the effective lactation yield further decreased yield reductions for cows with no DP or a short DP by 0.3 kg of FPCM per cow per day. At the herd level, estimated

  4. Climate risks on potato yield in Europe

    NASA Astrophysics Data System (ADS)

    Sun, Xun; Lall, Upmanu

    2016-04-01

    The yield of potatoes is affected by water and temperature during the growing season. We study the impact of a suite of climate variables on potato yield at country level. More than ten climate variables related to the growth of potato are considered, including the seasonal rainfall and temperature, but also extreme conditions at different averaging periods from daily to monthly. A Bayesian hierarchical model is developed to jointly consider the risk of heat stress, cold stress, wet and drought. Future climate risks are investigated through the projection of future climate data. This study contributes to assess the risks of present and future climate risks on potatoes yield, especially the risks of extreme events, which could be used to guide better sourcing strategy and ensure food security in the future.

  5. Evaluation of trends in wheat yield models

    NASA Technical Reports Server (NTRS)

    Ferguson, M. C.

    1982-01-01

    Trend terms in models for wheat yield in the U.S. Great Plains for the years 1932 to 1976 are evaluated. The subset of meteorological variables yielding the largest adjusted R(2) is selected using the method of leaps and bounds. Latent root regression is used to eliminate multicollinearities, and generalized ridge regression is used to introduce bias to provide stability in the data matrix. The regression model used provides for two trends in each of two models: a dependent model in which the trend line is piece-wise continuous, and an independent model in which the trend line is discontinuous at the year of the slope change. It was found that the trend lines best describing the wheat yields consisted of combinations of increasing, decreasing, and constant trend: four combinations for the dependent model and seven for the independent model.

  6. Analyzing Landscape Effects on Corn and Soybean Yield and Yield Risk from a Large Yield Monitor Dataset

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield variability is due to a variety of factors including many manageable variables such as genetics, weeds and pests, drainage, irrigation, and nutrient supply, but many factors cannot be managed and/or they have un-manageable interactions with climate. Therefore climate and it’s interaction...

  7. Satellite-based assessment of grassland yields

    NASA Astrophysics Data System (ADS)

    Grant, K.; Siegmund, R.; Wagner, M.; Hartmann, S.

    2015-04-01

    Cutting date and frequency are important parameters determining grassland yields in addition to the effects of weather, soil conditions, plant composition and fertilisation. Because accurate and area-wide data of grassland yields are currently not available, cutting frequency can be used to estimate yields. In this project, a method to detect cutting dates via surface changes in radar images is developed. The combination of this method with a grassland yield model will result in more reliable and regional-wide numbers of grassland yields. For the test-phase of the monitoring project, a study area situated southeast of Munich, Germany, was chosen due to its high density of managed grassland. For determining grassland cutting robust amplitude change detection techniques are used evaluating radar amplitude or backscatter statistics before and after the cutting event. CosmoSkyMed and Sentinel-1A data were analysed. All detected cuts were verified according to in-situ measurements recorded in a GIS database. Although the SAR systems had various acquisition geometries, the amount of detected grassland cut was quite similar. Of 154 tested grassland plots, covering in total 436 ha, 116 and 111 cuts were detected using CosmoSkyMed and Sentinel-1A radar data, respectively. Further improvement of radar data processes as well as additional analyses with higher sample number and wider land surface coverage will follow for optimisation of the method and for validation and generalisation of the results of this feasibility study. The automation of this method will than allow for an area-wide and cost efficient cutting date detection service improving grassland yield models.

  8. Evaluation of environmental factors affecting yields of major dissolved ions of streams in the United States

    USGS Publications Warehouse

    Peters, Norman E.

    1984-01-01

    The seven major dissolved ions in streams-sodium, potassium, magnesium, calcium, chloride, sulfate, and bicarbonate and their sum dissolved solids from 56 basins in the conterminous United States and Hawaii were correlated with bedrock type, annual precipitation, population density, and average stream temperature of their respective basins through multiple linear-regression equations to predict annual yields. The study was restricted to basins underlain by limestone, sandstone, or crystalline rock. Depending on the constituent, yields ranged from about 10 to 100,000 kilograms per square kilometer. Predicted yields were within 1 order of magnitude of measured yields. The most important factor in yield prediction was annual precipitation, which accounted for 58 to 71 percent of all yields. Rock type was second in importance. Yields of magnesium, calcium, bicarbonate, and dissolved solids from limestone basins were 4 to 10 times larger than those from sandstone or crystalline basins as a result of carbonate weathering. Population density was an ineffective indicator of all constituents except sodium and chloride; it accounted for 13 percent of the annual sodium yield and 20 percent of the annual chloride yield. Average stream temperature was significant only for calcium and bicarbonate in limestone basins. Its relationship with yields was consistently negative. Either carbonate dissolution increases at low temperatures, or weathering in northern basins, which contain glacial deposits and have the lowest stream temperatures, is greater than in southern basins. Average ion contributions from atmospheric deposition accounted for 30 percent of the sodium and chloride and 60 percent of the sulfate in annual yields. The amount of sulfate derived from atmospheric contributions was higher in sandstone and crystalline basins (65 and 80 percent, respectively) than limestone basins (38 percent). This disparity is attributed to the lack of available sulfate in crystalline rock

  9. Exchange coupled ferrite nanocomposites through chemical synthesis.

    PubMed

    Dai, Qilin; Patel, Ketan; Ren, Shenqiang

    2016-08-16

    Exchange coupling between magnetically hard and soft phases has the potential to yield a large gain in the energy product. In this work, we present a scalable chemical synthetic route to produce magnetic iron oxide based nanocomposites, consisting of cobalt ferrite (CoFe2O4) and strontium ferrite (SrFe12O19) components. PMID:27476744

  10. Precise Measurement of the Absolute Fluorescence Yield

    NASA Astrophysics Data System (ADS)

    Ave, M.; Bohacova, M.; Daumiller, K.; Di Carlo, P.; di Giulio, C.; San Luis, P. Facal; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; D'Orfeuil, B. Rouille; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.

    2011-09-01

    We present preliminary results of the absolute yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. Absolute calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources--the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.

  11. Managing declining yields from ageing tea plantations.

    PubMed

    Kibblewhite, Mark G; Prakash, Sudhir; Hazarika, Mridul; Burgess, Paul J; Sakrabani, Ruben

    2014-06-01

    Strong growth in the demand for tea requires further increases in the productivity of plantations. Declining or stagnant yields are commonly observed in older plantations. Possible controlling factors for yield decline are reviewed including ageing of plants, chronic disease and sub-optimal soil conditions such as excess soil acidity and low soil organic matter. Management options for addressing these factors are evaluated, including replanting. A systematic approach to decision-making about replanting is presented. Practice for replanting is reviewed and it is concluded that evidence to support a general case for replanting is limited, unless based on the introduction of more productive clones and/or better plant spacing. PMID:24464583

  12. Groundwater subsidies and penalties to corn yield

    NASA Astrophysics Data System (ADS)

    Zipper, S. C.; Booth, E.; Loheide, S. P.

    2013-12-01

    Proper water management is critical to closing yield gaps (observed yield below potential yield) as global populations continue to expand. However, the impacts of shallow groundwater on crop production and surface processes are poorly understood. The presence of groundwater within or just below the root zone has the potential to cause (via oxygen stress in poorly drained soils) or eliminate (via water supply in dry regions) yield gaps. The additional water use by a plant in the presence of shallow groundwater, compared to free drainage conditions, is called the groundwater subsidy; the depth at which the groundwater subsidy is greatest is the optimal depth to groundwater (DTGW). In wet years or under very shallow water table conditions, the groundwater subsidy is likely to be negative due to increased oxygen stress, and can be thought of as a groundwater penalty. Understanding the spatial dynamics of groundwater subsidies/penalties and how they interact with weather is critical to making sustainable agricultural and land-use decisions under a range of potential climates. Here, we examine patterns of groundwater subsidies and penalties in two commercial cornfields in the Yahara River Watershed, an urbanizing agricultural watershed in south-central Wisconsin. Water table levels are generally rising in the region due to a long-term trend of increasing precipitation over the last several decades. Biophysical indicators tracked throughout both the 2012 and 2013 growing seasons show a strong response to variable groundwater levels on a field scale. Sections of the field with optimal DTGW exhibit consistently higher stomatal conductance rates, taller canopies and higher leaf area index, higher ET rates, and higher pollination success rates. Patterns in these biophysical lines of evidence allow us to pinpoint specific periods within the growing season that plants were experiencing either oxygen or water stress. Most importantly, groundwater subsidies and penalties are

  13. DMSO Increases Radioiodination Yield of Radiopharmaceuticals

    PubMed Central

    Wang, Ketai; Adelstein, S. James; Kassis, Amin I.

    2007-01-01

    A high-yield radioiodination method for various types of molecules is described. The approach employs DMSO as precursor solvent, a reaction ratio of 2–5 precursor molecules per iodine atom, 5–10 μg oxidant, and a 10–25-μl reaction volume. The solution is vortexed at room temperature for 1–5 min and progress of the reaction is assessed by HPLC. Radioiodinated products are obtained in ≥95% yield and meet the requirements for radiotracer imaging, biodistribution studies, and molecular and cellular biology research. PMID:17931872

  14. Operation of the yield estimation subsystem

    NASA Technical Reports Server (NTRS)

    Mccrary, D. G.; Rogers, J. L.; Hill, J. D. (Principal Investigator)

    1979-01-01

    The organization and products of the yield estimation subsystem (YES) are described with particular emphasis on meteorological data acquisition, yield estimation, crop calendars, weekly weather summaries, and project reports. During the three phases of LACIE, YES demonstrated that it is possible to use the flow of global meteorological data and provide valuable information regarding global wheat production. It was able to establish a capability to collect, in a timely manner, detailed weather data from all regions of the world, and to evaluate and convert that data into information appropriate to the project's needs.

  15. High yield fabrication of fluorescent nanodiamonds

    PubMed Central

    Boudou, Jean-Paul; Curmi, Patrick; Jelezko, Fedor; Wrachtrup, Joerg; Aubert, Pascal; Sennour, Mohamed; Balasubramanian, Gopalakrischnan; Reuter, Rolf; Thorel, Alain; Gaffet, Eric

    2009-01-01

    A new fabrication method to produce homogeneously fluorescent nanodiamonds with high yields is described. The powder obtained by high energy ball milling of fluorescent high pressure, high temperature diamond microcrystals was converted in a pure concentrated aqueous colloidal dispersion of highly crystalline ultrasmall nanoparticles with a mean size less than or equal to 10 nm. The whole fabrication yield of colloidal quasi-spherical nanodiamonds was several orders of magnitude higher than those previously reported starting from microdiamonds. The results open up avenues for the industrial cost-effective production of fluorescent nanodiamonds with well-controlled properties. PMID:19451687

  16. Direct calibration of the yield of nuclear explosion

    SciTech Connect

    Nakanishi, K.; Nikolayev, A.

    1994-06-01

    The determination of the power of underground nuclear explosions (UNE) is of great significance. The seismic method of UNE yield determination allows monitoring at large distances, but is less precise than local monitoring methods. A way is proposed to calibrate UNE based on the idea of the vibroseis method in which powerful vibrators are used to produce seismic waves in the UNE epicenter; UNE calibration is carried out by comparison of the vibroseis record with a UNE seismogram. Results of preliminary work on the problem are presented. It is based on experience with vibrosounding of the Earth as well as earthquakes and chemical and nuclear explosions wave field structure studies. It is concluded that UNE calibration with the aid of seismic vibrators is both possible and expedient.

  17. DETECTING TEMPORAL CHANGE IN WATERSHED NUTRIENT YIELDS

    EPA Science Inventory

    Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increase...

  18. Squeeze Flow of Yield Stress Fluids

    NASA Astrophysics Data System (ADS)

    Pelot, David; Yarin, Alexander

    2014-03-01

    The squeeze flow of yield stress materials are investigated using a non-invasive optical technique. In the experiments, cylindrically-shaped samples of Carbopol solutions and Bentonite dispersions are rapidly compressed between two transparent plates using a constant force and the instantaneous cross-sectional area is recorded as a function of time using a high speed CCD camera. Furthermore, visualization of the boundary reveals that the no-slip condition holds. In addition, shear experiments are conducted using parallel-plate and vane viscometers. The material exhibits first a fast stage of squeezing in which the normal stresses dominate and viscosity plays the main role. Then, the second (slow) stage sets in where the material exhibits a slow deformation dominated by yield stress. At the end, the deformation process is arrested by yield stress. The material response is attributed to the Bingham-like or Herschel-Bulkley-like rheological behavior. Squeeze flow is developed into a convenient and simple tool for studying yield stress materials. This work is supported by the United States Gypsum Corp.

  19. Predicting collector well yields with MODFLOW.

    PubMed

    Kelson, Vic

    2012-01-01

    Groundwater flow models are commonly used to design new wells and wellfields. As the spatial scale of the problem is large and much local-scale detail is not needed, modelers often utilize two-dimensional (2D) or quasi three-dimensional models based on the Dupuit-Forchheimer assumption. Dupuit models offer a robust set of tools for simulating regional groundwater flow including interactions with surface waters, the potential for well interference, and varying aquifer properties and recharge rates. However, given an assumed operating water level or drawdown at a well screen, Dupuit models systematically overpredict well yields. For design purposes, this discrepancy is unacceptable, and a method for predicting accurate well yields is needed. While published methods exist for vertical wells, little guidance is available for predicting yields in horizontal screens or collector wells. In plan view, a horizontal screen has a linear geometry, and will likely extend over several neighboring cells that may not align with rows or columns in a numerical model. Furthermore, the model must account for the effects of converging three-dimensional (3D) flow to the well screens and hydraulic interference among the well screens; these all depend on the design of a specific well. This paper presents a new method for simulating the yield of angled or horizontal well screens in numerical groundwater flow models, specifically using the USGS code MODFLOW. The new method is compared to a detailed, 3D analytic element model of a collector well in a field of uniform flow. PMID:22339406

  20. Yielding Elastic Tethers Stabilize Robust Cell Adhesion

    PubMed Central

    Whitfield, Matt J.; Luo, Jonathon P.; Thomas, Wendy E.

    2014-01-01

    Many bacteria and eukaryotic cells express adhesive proteins at the end of tethers that elongate reversibly at constant or near constant force, which we refer to as yielding elasticity. Here we address the function of yielding elastic adhesive tethers with Escherichia coli bacteria as a model for cell adhesion, using a combination of experiments and simulations. The adhesive bond kinetics and tether elasticity was modeled in the simulations with realistic biophysical models that were fit to new and previously published single molecule force spectroscopy data. The simulations were validated by comparison to experiments measuring the adhesive behavior of E. coli in flowing fluid. Analysis of the simulations demonstrated that yielding elasticity is required for the bacteria to remain bound in high and variable flow conditions, because it allows the force to be distributed evenly between multiple bonds. In contrast, strain-hardening and linear elastic tethers concentrate force on the most vulnerable bonds, which leads to failure of the entire adhesive contact. Load distribution is especially important to noncovalent receptor-ligand bonds, because they become exponentially shorter lived at higher force above a critical force, even if they form catch bonds. The advantage of yielding is likely to extend to any blood cells or pathogens adhering in flow, or to any situation where bonds are stretched unequally due to surface roughness, unequal native bond lengths, or conditions that act to unzip the bonds. PMID:25473833

  1. Effects of cultivation frequency on sugarcane yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the number of cultivations during one or more years of a four year crop cycle may potentially reduce production expenses for Louisiana sugarcane growers. This study was initiated to determine the effects of cultivation on yields of sugarcane grown on a clay soil both on an annual basis and ...

  2. Yield advances in peanut - weed control effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvements in weed management are a contributing factor to advancements in peanut yield. Widespread use of vacuum planters and increased acceptance of narrow row patterns enhance weed control by lessening bareground caused by skips and promoting quick canopy closure. Cultivation was traditionall...

  3. 6-Benzyladenine enhancements of cotton yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton (Gossypium hirsutum L. and Gossypium barbadense L.) has been studied for over half a century. A recent study suggested that cytokinin treatment of young cotton seedlings may enhance overall performanc...

  4. Encapsulation Processing and Manufacturing Yield Analysis

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1984-01-01

    The development of encapsulation processing and a manufacturing productivity analysis for photovoltaic cells are discussed. The goals were: (1) to understand the relationships between both formulation variables and process variables; (2) to define conditions required for optimum performance; (3) to predict manufacturing yield; and (4) to provide documentation to industry.

  5. What Your Yield Says about You

    ERIC Educational Resources Information Center

    Hoover, Eric

    2009-01-01

    The recession has turned Americans into numbers addicts. Seemingly endless supplies of statistics--stock prices, retail sales, and the gross domestic product--offer various views about the health of the nation's economy. Higher education has its own economic indicators. Among the most important is "yield," the percentage of admitted students who…

  6. EXPERIMENTAL STATUS OF K YIELDS PVV-.

    SciTech Connect

    KETTELL,S.H.

    2002-05-27

    The experimental program for the study of the rare kaon decays, K + {pi}{nu}{bar {nu}} is summarized. A review of recent results is provided along with a discussion of prospects for the future of this program. The primary focus of the world-wide kaon program is the two golden modes: K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and K{sub L}{sup o} {yields} {pi}{sup o} {nu}{bar {nu}}. The first step in an ambitious program to precisely measure both branching ratios has been successfully completed with the observation of two K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} events by E787. The E949 experiment is poised to reach an order of magnitude further in sensitivity and to observe {approx}10 Standard Model events, and the CKM experiment should observe {approx}100 SM events by the end of this decade. Limits on the neutral analog K{sub L}{sup o} {yields} {pi}{sup o} {nu}{bar {nu}} have been set by KTeV and within the next couple of years will be pushed by E391a. Measurements of the branching ratio should be made within the next 10 years by KOPIO, with a goal of {approx}50 events, and at the JHF, with a goal of up to 1000 events.

  7. Evaluation of Yield Maps Using Fuzzy Indicators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents a new methodology for the evaluation of yield maps using fuzzy indicators, which takes into account atypical phenomena and expert opinions regarding the maps. This methodology could allow for improved methods for deciding boundary locations for precision application of production...

  8. Comparison of oilseed yields: a preliminary review

    SciTech Connect

    Duke, J.A.; Bagby, M.O.

    1982-01-01

    It was assumed that for most oilseed crops, 90% of the oil yield might be considered as profit. To compare oil seeds, pertinent portions of the yield and energy paragraphs from a summary published by Dr. Duke for DOE Grant No. 59-2246-1-6-054-0 with Dr. Bagby as ADODR were reproduced. The seed yields ranged from 200 to 14,000 kg/ha, the low one too low to consider and the high one suspiciously high. The yield of 14,000 kg oil per hectare is equivalent to more than 30 barrels of oil per hectare. The energy species included ambrette, tung-oil tree, cashew, wood-oil tree, mu-oil tree, peanut, mustard greens; rape, colza; black mustard, turnip, safflower, colocynth, coconut, crambe, African oil palm, soybean, cotton, sunflower, Eastern black walnut, Engligh walnut, meadow foam, flax, macadamia nuts, opium poppy, perilla, almond, castorbean, Chinese tallow tree, sesame, jojoba, yellow mustard, stokes' aster, and Zanzibar oilvine. 1 table. (DP)

  9. Effects of geoengineering on crop yields

    NASA Astrophysics Data System (ADS)

    Pongratz, J.; Lobell, D. B.; Cao, L.; Caldeira, K.

    2011-12-01

    The potential of "solar radiation management" (SRM) to reduce future climate change and associated risks has been receiving significant attention in scientific and policy circles. SRM schemes aim to reduce global warming despite increasing atmospheric CO2 concentrations by diminishing the amount of solar insolation absorbed by the Earth, for example, by injecting scattering aerosols into the atmosphere. Climate models predict that SRM could fully compensate warming at the global mean in a high-CO2 world. While reduction of global warming may offset a part of the predicted negative effects of future climate change on crop yields, SRM schemes are expected to alter regional climate and to have substantial effects on climate variables other than temperature, such as precipitation. It has therefore been warned that, overall, SRM may pose a risk to food security. Assessments of benefits and risks of geoengineering are imperative, yet such assessments are only beginning to emerge; in particular, effects on global food security have not previously been assessed. Here, for the first time, we combine climate model simulations with models of crop yield responses to climate to assess large-scale changes in yields and food production under SRM. In most crop-growing regions, we find that yield losses caused by climate changes are substantially reduced under SRM as compared with a non-geoengineered doubling of atmospheric CO2. Substantial yield losses with SRM are only found for rice in high latitudes, where the limits of low temperatures are no longer alleviated. At the same time, the beneficial effect of CO2-fertilization on plant productivity remains active. Overall therefore, SRM in our models causes global crop yields to increase. We estimate the direct effects of climate and CO2 changes on crop production, and do not quantify effects of market dynamics and management changes. We note, however, that an SRM deployment would be unlikely to maintain the economic status quo, as

  10. Global crop yield losses from recent warming

    SciTech Connect

    Lobell, D; Field, C

    2006-06-02

    Global yields of the world-s six most widely grown crops--wheat, rice, maize, soybeans, barley, sorghum--have increased since 1961. Year-to-year variations in growing season minimum temperature, maximum temperature, and precipitation explain 30% or more of the variations in yield. Since 1991, climate trends have significantly decreased yield trends in all crops but rice, leading to foregone production since 1981 of about 12 million tons per year of wheat or maize, representing an annual economic loss of $1.2 to $1.7 billion. At the global scale, negative impacts of climate trends on crop yields are already apparent. Annual global temperatures have increased by {approx}0.4 C since 1980, with even larger changes observed in several regions (1). While many studies have considered the impacts of future climate changes on food production (2-5), the effects of these past changes on agriculture remain unclear. It is likely that warming has improved yields in some areas, reduced them in others, and had negligible impacts in still others; the relative balance of these effects at the global scale is unknown. An understanding of this balance would help to anticipate impacts of future climate changes, as well as to more accurately assess recent (and thereby project future) technologically driven yield progress. Separating the contribution of climate from concurrent changes in other factors--such as crop cultivars, management practices, soil quality, and atmospheric carbon dioxide (CO{sub 2}) levels--requires models that describe the response of yields to climate. Studies of future global impacts of climate change have typically relied on a bottom-up approach, whereby field scale, process-based models are applied to hundreds of representative sites and then averaged (e.g., ref 2). Such approaches require input data on soil and management conditions, which are often difficult to obtain. Limitations on data quality or quantity can thus limit the utility of this approach

  11. Calculation of K-shell fluorescence yields for low-Z elements

    NASA Astrophysics Data System (ADS)

    Nekkab, M.; Kahoul, A.; Deghfel, B.; Aylikci, N. Küp; Aylikçi, V.

    2015-03-01

    The analytical methods based on X-ray fluorescence are advantageous for practical applications in a variety of fields including atomic physics, X-ray fluorescence surface chemical analysis and medical research and so the accurate fluorescence yields (ωK) are required for these applications. In this contribution we report a new parameters for calculation of K-shell fluorescence yields (ωK) of elements in the range of 11≤Z≤30. The experimental data are interpolated by using the famous analytical function (ωk/(1 -ωk)) 1 /q (were q=3, 3.5 and 4) vs Z to deduce the empirical K-shell fluorescence yields. A comparison is made between the results of the procedures followed here and those theoretical and other semi-empirical fluorescence yield values. Reasonable agreement was typically obtained between our result and other works.

  12. Calculation of K-shell fluorescence yields for low-Z elements

    SciTech Connect

    Nekkab, M.; Kahoul, A.; Deghfel, B.; Aylikci, N. Küp; Aylikçi, V.

    2015-03-30

    The analytical methods based on X-ray fluorescence are advantageous for practical applications in a variety of fields including atomic physics, X-ray fluorescence surface chemical analysis and medical research and so the accurate fluorescence yields (ω{sub K}) are required for these applications. In this contribution we report a new parameters for calculation of K-shell fluorescence yields (ω{sub K}) of elements in the range of 11≤Z≤30. The experimental data are interpolated by using the famous analytical function (ω{sub k}/(1−ω{sub k})){sup 1/q} (were q=3, 3.5 and 4) vs Z to deduce the empirical K-shell fluorescence yields. A comparison is made between the results of the procedures followed here and those theoretical and other semi-empirical fluorescence yield values. Reasonable agreement was typically obtained between our result and other works.

  13. Neutron monitor yield function: New improved computations

    NASA Astrophysics Data System (ADS)

    Mishev, A. L.; Usoskin, I. G.; Kovaltsov, G. A.

    2013-06-01

    A ground-based neutron monitor (NM) is a standard tool to measure cosmic ray (CR) variability near Earth, and it is crucially important to know its yield function for primary CRs. Although there are several earlier theoretically calculated yield functions, none of them agrees with experimental data of latitude surveys of sea-level NMs, thus suggesting for an inconsistency. A newly computed yield function of the standard sea-level 6NM64 NM is presented here separately for primary CR protons and α-particles, the latter representing also heavier species of CRs. The computations have been done using the GEANT-4 PLANETOCOSMICS Monte-Carlo tool and a realistic curved atmospheric model. For the first time, an effect of the geometrical correction of the NM effective area, related to the finite lateral expansion of the CR induced atmospheric cascade, is considered, which was neglected in the previous studies. This correction slightly enhances the relative impact of higher-energy CRs (energy above 5-10 GeV/nucleon) in NM count rate. The new computation finally resolves the long-standing problem of disagreement between the theoretically calculated spatial variability of CRs over the globe and experimental latitude surveys. The newly calculated yield function, corrected for this geometrical factor, appears fully consistent with the experimental latitude surveys of NMs performed during three consecutive solar minima in 1976-1977, 1986-1987, and 1996-1997. Thus, we provide a new yield function of the standard sea-level NM 6NM64 that is validated against experimental data.

  14. Dip-coating of yield stress fluids

    NASA Astrophysics Data System (ADS)

    Maillard, M.; Bleyer, J.; Andrieux, A. L.; Boujlel, J.; Coussot, P.

    2016-05-01

    We review and discuss the characteristics of dip-coating of yield stress fluids on the basis of theoretical considerations, numerical simulations of the flow in the bath, and experimental data with different materials. We show that in general, due to the yield stress, viscous dissipations are sufficiently large for capillary effects to be negligible in the process. Dip-coating with yield stress fluids is thus essentially governed by an equilibrium between viscous and gravity effects. In contrast with simple liquids, the coated thickness is uniform and remains fixed to the plate. At low velocities, it appears to tend to a value significantly smaller than the Derjaguin and Levi prediction [B. V. Derjaguin and S. M. Levi, Film Coating Theory (The Focal Press, London, 1964)], i.e., critical thickness of stoppage of a free surface flow along a vertical plate. We show that this comes from the fact that in the bath only a relatively small layer of fluid is in its liquid regime along the moving plate, while the rest of the material is in a solid regime. From numerical simulations, we describe the general trends of this liquid layer, and in particular, its thickness as a function of the rheological characteristics and plate velocity. We finally propose a model for the dip-coating of yield stress fluid, assuming that the solid volume of fluid finally fixed to the plate results from the mass flux of the liquid layer in the bath minus a mass flux due to some downward flow under gravity in the transition zone. A good agreement between this model and experimental data is found for a fluid with a yield stress larger than 20 Pa.

  15. Chemical Ecology: Chemical Communication in Nature.

    ERIC Educational Resources Information Center

    Wood, William F.

    1983-01-01

    Substances that deliver chemical messages between same/different species are called semiochemicals. Surveyed are three types of semiochemicals (pheromones, allomones, and kairomones), types of organisms involved, and specific chemicals used to carry the various kinds of messages. (JN)

  16. Dynamics of mean-variance-skewness of cumulative crop yield impact temporal yield variance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production risk associated with cropping systems influences farmers’ decisions to adopt a new management practice or a production system. Cumulative yield (CY), temporal yield variance (TYV) and coefficient of variation (CV) were used to assess the risk associated with adopting combinations of new m...

  17. Terapascal static pressure generation with ultrahigh yield strength nanodiamond

    PubMed Central

    Dubrovinskaia, Natalia; Dubrovinsky, Leonid; Solopova, Natalia A.; Abakumov, Artem; Turner, Stuart; Hanfland, Michael; Bykova, Elena; Bykov, Maxim; Prescher, Clemens; Prakapenka, Vitali B.; Petitgirard, Sylvain; Chuvashova, Irina; Gasharova, Biliana; Mathis, Yves-Laurent; Ershov, Petr; Snigireva, Irina; Snigirev, Anatoly

    2016-01-01

    Studies of materials’ properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (~460 GPa at a confining pressure of ~70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications. PMID:27453944

  18. Terapascal static pressure generation with ultrahigh yield strength nanodiamond.

    PubMed

    Dubrovinskaia, Natalia; Dubrovinsky, Leonid; Solopova, Natalia A; Abakumov, Artem; Turner, Stuart; Hanfland, Michael; Bykova, Elena; Bykov, Maxim; Prescher, Clemens; Prakapenka, Vitali B; Petitgirard, Sylvain; Chuvashova, Irina; Gasharova, Biliana; Mathis, Yves-Laurent; Ershov, Petr; Snigireva, Irina; Snigirev, Anatoly

    2016-07-01

    Studies of materials' properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (~460 GPa at a confining pressure of ~70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications. PMID:27453944

  19. Impacts of biofuel cultivation on mortality and crop yields

    NASA Astrophysics Data System (ADS)

    Ashworth, K.; Wild, O.; Hewitt, C. N.

    2013-05-01

    Ground-level ozone is a priority air pollutant, causing ~ 22,000 excess deaths per year in Europe, significant reductions in crop yields and loss of biodiversity. It is produced in the troposphere through photochemical reactions involving oxides of nitrogen (NOx) and volatile organic compounds (VOCs). The biosphere is the main source of VOCs, with an estimated 1,150TgCyr-1 (~ 90% of total VOC emissions) released from vegetation globally. Isoprene (2-methyl-1,3-butadiene) is the most significant biogenic VOC in terms of mass (around 500TgCyr-1) and chemical reactivity and plays an important role in the mediation of ground-level ozone concentrations. Concerns about climate change and energy security are driving an aggressive expansion of bioenergy crop production and many of these plant species emit more isoprene than the traditional crops they are replacing. Here we quantify the increases in isoprene emission rates caused by cultivation of 72Mha of biofuel crops in Europe. We then estimate the resultant changes in ground-level ozone concentrations and the impacts on human mortality and crop yields that these could cause. Our study highlights the need to consider more than simple carbon budgets when considering the cultivation of biofuel feedstock crops for greenhouse-gas mitigation.

  20. Flood-tolerant rice reduces yield variability and raises expected yield, differentially benefitting socially disadvantaged groups

    PubMed Central

    Dar, Manzoor H.; de Janvry, Alain; Emerick, Kyle; Raitzer, David; Sadoulet, Elisabeth

    2013-01-01

    Approximately 30% of the cultivated rice area in India is prone to crop damage from prolonged flooding. We use a randomized field experiment in 128 villages of Orissa India to show that Swarna-Sub1, a recently released submergence-tolerant rice variety, has significant positive impacts on rice yield when fields are submerged for 7 to 14 days with no yield penalty without flooding. We estimate that Swarna-Sub1 offers an approximate 45% increase in yields over the current popular variety when fields are submerged for 10 days. We show additionally that low-lying areas prone to flooding tend to be more heavily occupied by people belonging to lower caste social groups. Thus, a policy relevant implication of our findings is that flood-tolerant rice can deliver both efficiency gains, through reduced yield variability and higher expected yield, and equity gains in disproportionately benefiting the most marginal group of farmers. PMID:24263095

  1. DETECTION AND ADJUSTMENT OF ABNORMAL TEST-DAY YIELDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method to detect and to adjust abnormally low or high milk, fat, and protein yields on test-day (TD) was developed. TD yields are compared to previous and subsequent yields and are restricted to be between a floor and ceiling based on predicted yield. Lactation yields are then calculated from the ...

  2. The Chemical Engineer in the Chemical Industry.

    ERIC Educational Resources Information Center

    Zabicky, Jacob

    1986-01-01

    Describes a course for third- or fourth-year chemical engineering students designed to acquaint them with the chemical industry. The course deals with productivity, characteristics of the chemical industry, sources of information, industrial intelligence, research and development, patent law, technology transfer, and quality control. (TW)

  3. Atomic Oxygen Erosion Yield Prediction for Spacecraft Polymers in Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Backus, Jane A.; Manno, Michael V.; Waters, Deborah L.; Cameron, Kevin C.; deGroh, Kim K.

    2009-01-01

    The ability to predict the atomic oxygen erosion yield of polymers based on their chemistry and physical properties has been only partially successful because of a lack of reliable low Earth orbit (LEO) erosion yield data. Unfortunately, many of the early experiments did not utilize dehydrated mass loss measurements for erosion yield determination, and the resulting mass loss due to atomic oxygen exposure may have been compromised because samples were often not in consistent states of dehydration during the pre-flight and post-flight mass measurements. This is a particular problem for short duration mission exposures or low erosion yield materials. However, as a result of the retrieval of the Polymer Erosion and Contamination Experiment (PEACE) flown as part of the Materials International Space Station Experiment 2 (MISSE 2), the erosion yields of 38 polymers and pyrolytic graphite were accurately measured. The experiment was exposed to the LEO environment for 3.95 years from August 16, 2001 to July 30, 2005 and was successfully retrieved during a space walk on July 30, 2005 during Discovery s STS-114 Return to Flight mission. The 40 different materials tested (including Kapton H fluence witness samples) were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The MISSE 2 PEACE Polymers experiment used carefully dehydrated mass measurements, as well as accurate density measurements to obtain accurate erosion yield data for high-fluence (8.43 1021 atoms/sq cm). The resulting data was used to develop an erosion yield predictive tool with a correlation coefficient of 0.895 and uncertainty of +/-6.3 10(exp -25)cu cm/atom. The predictive tool utilizes the chemical structures and physical properties of polymers to predict in-space atomic oxygen erosion yields. A predictive tool concept (September 2009 version) is presented which represents an improvement over an earlier (December 2008) version.

  4. b{yields}s penguin amplitude in charmless B{yields}PP decays

    SciTech Connect

    Gronau, Michael; Rosner, Jonathan L.

    2005-04-01

    The b{yields}s penguin amplitude affects a number of B meson decays to two pseudoscalar (P) mesons in which potential anomalies are being watched carefully, though none has yet reached a statistically compelling level. These include (a) a sum of rates for B{sup 0}{yields}K{sup 0}{pi}{sup 0} and B{sup +}{yields}K{sup +}{pi}{sup 0} enhanced relative to half the sum for B{sup 0}{yields}K{sup +}{pi}{sup -} and B{sup +}{yields}K{sup 0}{pi}{sup +} (b) a time-dependent CP asymmetry parameter S for B{sup 0}{yields}K{sup 0}{pi}{sup 0} which is low in comparison with the expected value of sin2{beta}{approx_equal}0.73, and (c) a similar deviation in the parameter S for B{sup 0}{yields}{eta}{sup '}K{sub S}. These and related phenomena involving vector mesons in the final state are discussed in a unified way in and beyond the standard model. Future experiments which would conclusively indicate the presence of new physics are identified. Several of these involve decays of the strange B meson B{sub s}. In the standard model we prove an approximate sum rule for CP rate differences in B{sup 0}{yields}K{sup +}{pi}{sup -}, B{sup +}{yields}K{sup +}{pi}{sup 0} and B{sup 0}{yields}K{sup 0}{pi}{sup 0}, predicting a negative sign for the latter asymmetry.

  5. Chemical Conversions of Biomass-Derived Platform Chemicals over Copper-Silica Nanocomposite Catalysts.

    PubMed

    Upare, Pravin P; Hwang, Young Kyu; Lee, Jong-Min; Hwang, Dong Won; Chang, Jong-San

    2015-07-20

    Biomass and biomass-derived carbohydrates have a high extent of functionality, unlike petroleum, which has limited functionality. In biorefinery applications, the development of methods to control the extent of functionality in final products intended for use as fuels and chemicals is a challenge. In the chemical industry, heterogeneous catalysis is an important tool for the defunctionalization of functionalized feedstocks and biomass-derived platform chemicals to produce value-added chemicals. Herein, we review the recent progress in this field, mainly of vapor phase chemical conversion of biomass-derived C4 -C6 carboxylic acids and esters using copper-silica nanocomposite catalysts. We also demonstrate that these nanocomposite catalysts very efficiently convert biomass-derived platform chemicals into cyclic compounds, such as lactones and hydrofurans, with high selectivities and yields. PMID:26192888

  6. Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical Reactions

    ERIC Educational Resources Information Center

    Schultz, Emeric

    2008-01-01

    A highly flexible learning tool, referred to as a dynamic reaction figure, is described. Application of these figures can (i) yield the correct chemical equation by simply following a set of menu driven directions; (ii) present the underlying "mechanism" in chemical reactions; and (iii) help to solve quantitative problems in a number of different…

  7. Introduction to Galactic Chemical Evolution

    NASA Astrophysics Data System (ADS)

    Matteucci, Francesca

    2016-04-01

    In this lecture I will introduce the concept of galactic chemical evolution, namely the study of how and where the chemical elements formed and how they were distributed in the stars and gas in galaxies. The main ingredients to build models of galactic chemical evolution will be described. They include: initial conditions, star formation history, stellar nucleosynthesis and gas flows in and out of galaxies. Then some simple analytical models and their solutions will be discussed together with the main criticisms associated to them. The yield per stellar generation will be defined and the hypothesis of instantaneous recycling approximation will be critically discussed. Detailed numerical models of chemical evolution of galaxies of different morphological type, able to follow the time evolution of the abundances of single elements, will be discussed and their predictions will be compared to observational data. The comparisons will include stellar abundances as well as interstellar medium ones, measured in galaxies. I will show how, from these comparisons, one can derive important constraints on stellar nucleosynthesis and galaxy formation mechanisms. Most of the concepts described in this lecture can be found in the monograph by Matteucci (2012).

  8. Chemical kin label in seabirds.

    PubMed

    Célérier, Aurélie; Bon, Cécile; Malapert, Aurore; Palmas, Pauline; Bonadonna, Francesco

    2011-12-23

    Chemical signals yield critical socio-ecological information in many animals, such as species, identity, social status or sex, but have been poorly investigated in birds. Recent results showed that chemical signals are used to recognize their nest and partner by some petrel seabirds whose olfactory anatomy is well developed and which possess a life-history propitious to olfactory-mediated behaviours. Here, we investigate whether blue petrels (Halobaena caerulea) produce some chemical labels potentially involved in kin recognition and inbreeding avoidance. To overcome methodological constraints of chemical analysis and field behavioural experiments, we used an indirect behavioural approach, based on mice olfactory abilities in discriminating odours. We showed that mice (i) can detect odour differences between individual petrels, (ii) perceive a high odour similarity between a chick and its parents, and (iii) perceive this similarity only before fledging but not during the nestling developmental stage. Our results confirm the existence of an individual olfactory signature in blue petrels and show for the first time, to our knowledge, that birds may exhibit an olfactory kin label, which may have strong implications for inbreeding avoidance. PMID:21525047

  9. Microfluidic chemical reaction circuits

    DOEpatents

    Lee, Chung-cheng; Sui, Guodong; Elizarov, Arkadij; Kolb, Hartmuth C.; Huang, Jiang; Heath, James R.; Phelps, Michael E.; Quake, Stephen R.; Tseng, Hsian-rong; Wyatt, Paul; Daridon, Antoine

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  10. CHEMICAL SAFETY ALERTS-

    EPA Science Inventory

    Chemical Safety Alerts are short publications which explain specific hazards that have become evident through chemical accident investigation efforts. EPA has produced over a dozen Alerts to date. This year's Alert: Managing Chemical Reactivity Hazards

  11. CHEMICALS IN PROGRESS BULLETIN

    EPA Science Inventory

    Chemicals in Progress Bulletin is a quarterly newsletter which highlights regulatory and program activities of the Office of Pollution Prevention and Toxics. Regular features and news items include the existing chemicals program, new chemicals program, pollution prevention activi...

  12. Hardening and yielding in colloidal gels

    NASA Astrophysics Data System (ADS)

    Del Gado, Emanuela; Colombo, Jader; Bouzid, Mehdi

    Attractive colloidal gel networks are disordered elastic solids that can form even in extremely dilute particle suspensions. With interaction strengths comparable to the thermal energy, their stress-bearing network can locally restructure via breaking and reforming inter-particle bonds. We use molecular dynamics simulations of a model system to investigate the strain hardening and the yielding process. During shear start up protocol, the system exhibits strong localization of tensile stresses that may be released through the breaking and formation of new bonds. In this regime, the small amplitude oscillatory shear analysis shows that the storage and the loss modulus follow a power law behavior that are closely reminiscent of experimental observations. At large accumulated strains, the strain-induced reorganization of the gel may trigger flow heterogeneities and eventually lead to the yielding of the gel via a quasi brittle damage of its structure.

  13. Primary quantum yields of NO2 photodissociation

    NASA Technical Reports Server (NTRS)

    Gardner, Edward P.; Sperry, Paul D.; Calvert, Jack G.

    1987-01-01

    The quantum yields of formation of NO, O2, and NO2 loss are measured for NO2 vapor at low pressures (0.13-0.30 torr) irradiated at 334-405 nm wavelengths and temperature in the range 273-370 K in order to study the primary quantum efficiencies of NO2 photodecomposition. The temperature and wavelength dependences of the primary quantum efficiencies are examined. It is observed that the primary quantum efficiencies increase rapidly from near zero at 424 nm to near unity for excitation at wavelengths less than 394 nm. The theory of Pitts et al. (1964) that the energy deficiency for photodissociation of NO2 excited at wavelengths greater than 397.9 nm is due to the rotational and vibrational energy of the NO2 molecules is confirmed by the data. Values for the primary quantum yields of NO2 photodecomposition as a function of wavelength are presented.

  14. Quantum Yield of Gold-Cathode Photomultipliers

    NASA Technical Reports Server (NTRS)

    Childs, Charles B.

    1961-01-01

    Two gold-cathode EMI 6255G tubes have been investigated for their quantum yield between 3100 and 1900 A. The tubes had cathodes of different appearances. One of these, numbered 3012, had a slight bluish tinge and was very transparent to visible light; the other, numbered 3021, had a definite gold coloration. The relative quantum yield of each tube was determined with the aid of a Cary model 14 recording spectrophotometer used as a monochromator. The monochromator relative-energy output was determined from the current output of a sodium-salicylate-coated RCA 1P21 photomultiplier. Each gold-cathode tube was then operated at 3000 v, and the central 1.8 cm cube of the cathode was exposed to the monochromator output.

  15. Low Odor, High Yield Kraft Pulping

    SciTech Connect

    W.T. McKean

    2000-12-15

    In laboratory cooks pure oxygen was profiled into the circulation line of a batch digester during two periods of the cooking cycle: The first injection occurred during the heating steps for the purpose of in-situ generation of polysulfide. This chip treatment was studied to explore stabilization against alkaline induced carbohydrate peeling and to increase pulp yield. Under optimum conditions small amounts of polysulfide were produced with yield increase of about 0.5% These increases fell below earlier reports suggesting that unknown differences in liquor composition may influence the relative amounts of polysulfide and thiosulfate generated during the oxidation. Consequently, further studies are required to understand the factors that influence the ratios of those two sulfur species.

  16. Chemical Management System

    Energy Science and Technology Software Center (ESTSC)

    1998-10-30

    CMS provides an inventory of all chemicals on order or being held in the laboratory, to provide a specific location for all chemical containers, to ensure that health and safety regulatory codes are being upheld, and to provide PNNL staff with hazardous chemical information to better manage their inventories. CMS is comprised of five major modules: 1) chemical purchasing, 2) chemical inventory, 3) chemical names, properties, and hazard groups, 4) reporting, and 5) system administration.

  17. Nature's chemicals and synthetic chemicals: Comparative toxicology

    SciTech Connect

    Ames, B.N.; Profet, M.; Gold, L.S. )

    1990-10-01

    The toxicology of synthetic chemicals is compared to that of natural chemicals, which represent the vast bulk of the chemicals to which humans are exposed. It is argued that animals have a broad array of inducible general defenses to combat the changing array of toxic chemicals in plant food (nature's pesticides) and that these defenses are effective against both natural and synthetic toxins. Synthetic toxins such as dioxin are compared to natural chemicals, such as indole carbinol (in broccoli) and ethanol. Trade-offs between synthetic and natural pesticides are discussed. The finding that in high-dose tests, a high proportion of both natural and synthetic chemicals are carcinogens, mutagens, teratogens, and clastogens (30-50{percent} for each group) undermines current regulatory efforts to protect public health from synthetic chemicals based on these tests.

  18. Dynamic yielding in lithium fluoride and aluminum

    NASA Astrophysics Data System (ADS)

    Sano, Yukio; Sano, Tomokazu

    2010-02-01

    At a time immediately after shock loading, a kink (a weak discontinuity or a discontinuity in slope) occurs at a position in an unsteady portion in a smooth plane wave front in a lithium fluoride single crystal (material IIIb) or in 1060-0 aluminum due to the instability of the wave front. After the occurrence of the kink, a zone is produced and broadened with time between a near steady precursor ahead of the kink and a plastic wave behind it in a weak-discontinuity plane wave by the difference in the propagation velocity between them. Stress relaxes in the zone, which is called a follower, and the precursor decay takes place due to the stress relaxation. During the decay process, the large increase in plastic flow occurs in the vicinity of the leading edge of the follower, causes yielding at the leading edge, and stabilizes the weak-discontinuity wave. The stress-strain (σ-ε) history caused by the follower rotates clockwise with time around the yield point. The rotation yields different σ-ε histories behind the point and therefore different types of the dynamic σ-ε relation. Dynamic yield phenomena are illustrated by showing the schematic diagrams of three different types of the dynamic σ-ε relation, which are caused by weak-discontinuity plane waves composed of a precursor C, a follower (i) C, (ii) I or II, or (iii) R' or Rb, and a plastic wave C behind the follower. Here C is the contraction (compression) wave, I and II are the degenerate contraction waves I and II, R' is the subrarefaction wave, and Rb is the rarefaction wave.

  19. Method for improving xanthan yield. [Xanthomonas sp

    SciTech Connect

    Weisrock, W.P.

    1981-11-17

    A process is provided for producing heteropolysaccharides by culturing a microorganism of genus Xanthomonas in a nutrient medium and recovering the heteropolysaccharide containing product. The method covers culturing the microorganism in the presence of a sufficient amount of an additive compound selected from a group consisting of deoxycholic acid, cholic acid, salts thereof, and mixtures thereof, whereby the yield of the heteropolysaccharide produced is increased. 11 claims.

  20. Method for improving Xanthan yield. [Xanthomonas sp

    SciTech Connect

    Weisrock, W.P.

    1981-11-17

    A process is provided for producing heteropolysaccharides by culturing a microorganism of genus Xanthomonas in a nutrient medium and recovering the heteropolysaccharide containing product. The method covers culturing the microorganism in the presence of a sufficient amount of an additive compound selected from a group consisting of deoxycholic acid, cholic acid, salts thereof, and mixtures thereof, whereby the yield of the heteropolysaccharide produced is increased. 11 claims.

  1. Deep enteroscopy - indications, diagnostic yield and complications.

    PubMed

    Moeschler, Oliver; Mueller, Michael Karl

    2015-02-01

    Since its introduction in 2001 capsule endoscopy opened up the small bowel for diagnostic approaches followed by double balloon enteroscopy which enabled the endoscopic community to perform therapeutic interventions in the whole small intestine. In this review the scientific developments related to indications, diagnostic yield and complications of the last years between the competing devices double ballon enteroscopy, single balloon enteroscopy and spiral enteroscopy are illustrated. PMID:25663758

  2. Fractional Yields Inferred from Halo and Thick Disk Stars

    NASA Astrophysics Data System (ADS)

    Caimmi, R.

    2013-12-01

    Linear [Q/H]-[O/H] relations, Q = Na, Mg, Si, Ca, Ti, Cr, Fe, Ni, are inferred from a sample (N=67) of recently studied FGK-type dwarf stars in the solar neighbourhood including different populations (Nissen and Schuster 2010, Ramirez et al. 2012), namely LH (N=24, low-α halo), HH (N=25, high-α halo), KD (N=16, thick disk), and OL (N=2, globular cluster outliers). Regression line slope and intercept estimators and related variance estimators are determined. With regard to the straight line, [Q/H]=a_{Q}[O/H]+b_{Q}, sample stars are displayed along a "main sequence", [Q,O] = [a_{Q},b_{Q},Δ b_{Q}], leaving aside the two OL stars, which, in most cases (e.g. Na), lie outside. The unit slope, a_{Q}=1, implies Q is a primary element synthesised via SNII progenitors in the presence of a universal stellar initial mass function (defined as simple primary element). In this respect, Mg, Si, Ti, show hat a_{Q}=1 within ∓2hatσ_ {hat a_{Q}}; Cr, Fe, Ni, within ∓3hatσ_{hat a_{Q}}; Na, Ca, within ∓ rhatσ_{hat a_{Q}}, r>3. The empirical, differential element abundance distributions are inferred from LH, HH, KD, HA = HH + KD subsamples, where related regression lines represent their theoretical counterparts within the framework of simple MCBR (multistage closed box + reservoir) chemical evolution models. Hence, the fractional yields, hat{p}_{Q}/hat{p}_{O}, are determined and (as an example) a comparison is shown with their theoretical counterparts inferred from SNII progenitor nucleosynthesis under the assumption of a power-law stellar initial mass function. The generalized fractional yields, C_{Q}=Z_{Q}/Z_{O}^{a_{Q}}, are determined regardless of the chemical evolution model. The ratio of outflow to star formation rate is compared for different populations in the framework of simple MCBR models. The opposite situation of element abundance variation entirely due to cosmic scatter is also considered under reasonable assumptions. The related differential element abundance

  3. Rice Research to Break Yield Barriers

    NASA Astrophysics Data System (ADS)

    Verma, Vivek; Ramamoorthy, Rengasamy; Kohli, Ajay; Kumar, Prakash P.

    2015-10-01

    The world’s population continues to expand and it is expected to cross 9 billion by 2050. This would significantly amplify the demand for food, which will pose serious threats to global food security. Additional challenges are being imposed due to a gradual decrease in the total arable land and global environmental changes. Hence, it is of utmost importance to review and revise the existing food production strategies by incorporating novel biotechnological approaches that can help to break the crop yield barriers in the near future. In this review, we highlight some of the concerns hampering crop yield enhancements. The review also focuses on modern breeding techniques based on genomics as well as proven biotechnological approaches that enable identification and utilization of candidate genes. Another aspect of discussion is the important area of research, namely hormonal regulation of plant development, which is likely to yield valuable regulatory genes for such crop improvement efforts in the future. These strategies can serve as potential tools for developing elite crop varieties for feeding the growing billions.

  4. Whey cheese: membrane technology to increase yields.

    PubMed

    Riera, Francisco; González, Pablo; Muro, Claudia

    2016-02-01

    Sweet cheese whey has been used to obtain whey cheese without the addition of milk. Pre-treated whey was concentrated by nanofiltration (NF) at different concentration ratios (2, 2.5 and 2.8) or by reverse osmosis (RO) (2-3 times). After the concentration, whey was acidified with lactic acid until a final pH of 4.6-4.8, and heated to temperatures between 85 and 90 °C. The coagulated fraction (supernatant) was collected and freely drained over 4 h. The cheese-whey yield and protein, fat, lactose and ash recoveries in the final product were calculated. The membrane pre-concentration step caused an increase in the whey-cheese yield. The final composition of products was compared with traditional cheese-whey manufacture products (without membrane concentration). Final cheese yields found were to be between 5 and 19.6%, which are higher than those achieved using the traditional 'Requesón' process. PMID:26869115

  5. EVIDENCE FOR K+ YIELDS P+ VV-.

    SciTech Connect

    KETTELL,S.

    1998-12-18

    The first observation of the decay K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}} has been reported. The E787 experiment presented evidence for the K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}} decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}}) = 4.2{sub -3.5}{sup +9.7} x 10{sup -10}, is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E7878 data sample, from the 1995-98 runs, should reach a sensitivity of about five times that of the 1995 run alone. A new experiment, E949, has been given scientific approval and should start data collected in 2001. It is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model.

  6. Second Generation Crop Yield Models Review

    NASA Technical Reports Server (NTRS)

    Hodges, T. (Principal Investigator)

    1982-01-01

    Second generation yield models, including crop growth simulation models and plant process models, may be suitable for large area crop yield forecasting in the yield model development project. Subjective and objective criteria for model selection are defined and models which might be selected are reviewed. Models may be selected to provide submodels as input to other models; for further development and testing; or for immediate testing as forecasting tools. A plant process model may range in complexity from several dozen submodels simulating (1) energy, carbohydrates, and minerals; (2) change in biomass of various organs; and (3) initiation and development of plant organs, to a few submodels simulating key physiological processes. The most complex models cannot be used directly in large area forecasting but may provide submodels which can be simplified for inclusion into simpler plant process models. Both published and unpublished models which may be used for development or testing are reviewed. Several other models, currently under development, may become available at a later date.

  7. Chemical Industry Corrosion Management

    SciTech Connect

    2003-02-01

    Improved Corrosion Management Could Provide Significant Cost and Energy Savings for the Chemical Industry. In the chemical industry, corrosion is often responsible for significant shutdown and maintenance costs.

  8. Spontaneous high-yield hydrogen production from cellulosic materials and water catalyzed by enzyme cocktail

    SciTech Connect

    Ye, Xinhao; Wang, Yiran; Hopkins, Robert C.; Adams, Michael W. W.; Evans, Barbara R; Mielenz, Jonathan R; Zhang, Y.-H. Percival

    2009-01-01

    Carbon-neutral hydrogen gas is a compelling energy carrier, especially for the transportation section. Low-cost hydrogen can be produced from abundant renewable lignocellulosic biomass through a number of methods employing chemical catalysis, biocatalysis or a combination of both, but these technologies suffer from low hydrogen yields (well below the theoretical yield of 12 H2 per glucose), undesired side-products and/or required severe reaction conditions. Here we present a novel in vitro synthetic biology approach for producing near theoretical hydrogen yields from cellulosic materials (cellodextrins) and water at 32oC and 1 atm. These non-natural catabolic pathways containing up to 14 enzymes and one coenzyme degrade cellodextrins initially to glucose-1-phosphate and eventually to CO2, split water and finally release the chemical energy in the form of hydrogen gas. Up to 11.2 H2 per anhydroglucose was produced in a batch reaction. This spontaneous endothermic reaction is driven by entropy gain, suggesting that the thermal energy is adsorbed for generating more chemical energy (hydrogen gas) than that in cellodextrins, i.e., output/input of chemical energy > 1, with an input of ambient-temperature thermal energy.

  9. Winter Cereal Termination and Conservation Agriculture Cotton Yield Following Mechanical and Chemical Management Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An integral component of conservation-tillage systems in cotton is the use of a high-residue winter cover crop; however, managing such cover crops is a challenge. Black oat (Avena strigosa Schreb.), rye (Secale cereale L.), and wheat (Triticum aestivum L.) winter cover crops were established in ear...

  10. Process for chemical reaction of amino acids and amides yielding selective conversion products

    DOEpatents

    Holladay, Jonathan E.

    2006-05-23

    The invention relates to processes for converting amino acids and amides to desirable conversion products including pyrrolidines, pyrrolidinones, and other N-substituted products. L-glutamic acid and L-pyroglutamic acid provide general reaction pathways to numerous and valuable selective conversion products with varied potential industrial uses.

  11. Yield Improvement and Energy Savings Uing Phosphonates as Additives in Kraft pulping

    SciTech Connect

    Ulrike W. Tschirner; Timothy Smith

    2007-03-31

    Project Objective: Develop a commercially viable modification to the Kraft process resulting in energy savings, increased yield and improved bleachability. Evaluate the feasibility of this technology across a spectrum of wood species used in North America. Develop detailed fundamental understanding of the mechanism by which phosphonates improve KAPPA number and yield. Evaluate the North American market potential for the use of phosphonates in the Kraft pulping process. Examine determinants of customer perceived value and explore organizational and operational factors influencing attitudes and behaviors. Provide an economic feasibility assessment for the supply chain, both suppliers (chemical supply companies) and buyers (Kraft mills). Provide background to most effectively transfer this new technology to commercial mills.

  12. Evidence for Ni-56 yields Co-56 yields Fe-56 decay in type Ia supernovae

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc J.; Kirshner, Robert P.; Pinto, Philip A.; Leibundgut, Bruno

    1994-01-01

    In the prevailing picture of Type Ia supernovae (SN Ia), their explosive burning produces Ni-56, and the radioactive decay chain Ni-56 yields Co-56 yields Fe-56 powers the subsequent emission. We test a central feature of this theory by measuring the relative strengths of a (Co III) emission feature near 5900 A and a (Fe III) emission feature near 4700 A. We measure 38 spectra from 13 SN Ia ranging from 48 to 310 days after maximum light. When we compare the observations with a simple multilevel calculation, we find that the observed Fe/Co flux ratio evolves as expected when the Fe-56/Co-56 abundance ratio follows from Ni-56 yields Co-56 yields Fe-56 decay. From this agreement, we conclude that the cobalt and iron atoms we observe through SN Ia emission lines are produced by the radioactive decay of Ni-56, just as predicted by a wide range of models for SN Ia explosions.

  13. The yield and post-yield behavior of high-density polyethylene

    NASA Technical Reports Server (NTRS)

    Semeliss, M. A.; Wong, R.; Tuttle, M. E.

    1990-01-01

    An experimental and analytical evaluation was made of the yield and post-yield behavior of high-density polyethylene, a semi-crystalline thermoplastic. Polyethylene was selected for study because it is very inexpensive and readily available in the form of thin-walled tubes. Thin-walled tubular specimens were subjected to axial loads and internal pressures, such that the specimens were subjected to a known biaxial loading. A constant octahederal shear stress rate was imposed during all tests. The measured yield and post-yield behavior was compared with predictions based on both isotropic and anisotropic models. Of particular interest was whether inelastic behavior was sensitive to the hydrostatic stress level. The major achievements and conclusions reached are discussed.

  14. Spatio-temporal evolution of the L {yields} I {yields} H transition

    SciTech Connect

    Miki, K.; Diamond, P. H.; Guercan, Oe. D.; Tynan, G. R.; Estrada, T.; Schmitz, L.; Xu, G. S.

    2012-09-15

    We investigate the dynamics of the low(L) {yields} high(H) transition using a time-dependent, one dimensional (in radius) model which self-consistently describes the time evolution of zonal flows (ZFs), mean flows (MFs), poloidal spin-up, and density and pressure profiles. The model represents the physics of ZF and MF competition, turbulence suppression via E Multiplication-Sign B shearing, and poloidal flows driven by turbulence. Numerical solutions of this model show that the L{yields}H transition can occur via an intermediate phase (I-phase) which involves oscillations of profiles due to ZF and MF competition. The I-phase appears as a nonlinear transition wave originating at the edge boundary and propagates inward. Locally, I-phase exhibits the characteristics of a limit-cycle oscillation. All these observations are consistent with recent experimental results. We examine the trigger of the L{yields}H transition, by defining a ratio of the rate of energy transfer from the turbulence to the zonal flow to the rate of energy input into the turbulence. When the ratio exceeds order unity, ZF shear gains energy, and a net decay of the turbulence is possible, thus triggering the L{yields}H transition. Numerical calculations indicate that the L{yields}H transition is triggered by this peak of the normalized ZF shearing. Zonal flows act as 'reservoir,' in which to store increasing fluctuation energy without increasing transport, thus allowing the mean flow shear to increase and lock in the transition. A counterpart of the L {yields} I{yields}H transition, i.e., an L{yields}H transition without I-phase, is obtained in a fast power ramp, for which I-phase is compressed into a single burst of ZF, which triggers the transition. Effects of neutral charge exchange on the L{yields}H transition are studied by varying ZF damping and neoclassical viscosity. Results show that the predicted L{yields}H transition power increases when either ZF damping or viscosity increase, suggesting

  15. Effect of subsoiling on the yield of sugar beet under conditions of rhizomania infection.

    PubMed

    Németh, L; Kuroli, G

    2002-01-01

    The rhizomania is known in Hungary since 1982. The causal agent, Beet necrotic yellow vein benyvirus (BNYVV) is transmitted by a soil-borne fungus Polymyxa betae Keskin. A field experiment was done under rhizomania infested and non-infested conditions to compare the yield parameters of five tolerant and four sensitive sugar beet hybrids. Tolerant varieties produced higher root yield under rhizomania infected conditions. The root yields of the sensitive varieties were similar to the tolerant ones on the uninfested field, but the root mass of some tolerant varieties exceeded the production of the former group. Subsoiling was carried out in two strips of a heavily infested field, while conventional soil cultivation was done on the other parts. There was not any other difference in the cultivation of the treated and control areas. Sugar beet root samples were collected at the time of harvesting from the subsoiled and control plots. Beet necrotic yellow vein virus (BNYVV) infection was tested by means of ELISA. Virus content, yield and yield parameters of samples were compared. There were no significant differences in virus infection between sugar beet roots derived from subsoiled and untreated plots. Ratio of BNYVV infected plants was about 90% in both areas. However, yield and yield parameters showed remarkable difference. Root yield of treated plots, calculated from average individual root weight and 80,000 plant/ha plant density exceeded by 140% the yield of control. Sugar content was 2.6% higher and the harmful non-sugar content was lower on the subsoiled plots. Owing to the favourable chemical and technological value of beet the white sugar content was approximately three-times higher on the treated area. PMID:12701439

  16. Safe handling of potential peroxide forming compounds and their corresponding peroxide yielded derivatives.

    SciTech Connect

    Sears, Jeremiah Matthew; Boyle, Timothy J.; Dean, Christopher J.

    2013-06-01

    This report addresses recent developments concerning the identification and handling of potential peroxide forming (PPF) and peroxide yielded derivative (PYD) chemicals. PPF chemicals are described in terms of labeling, shelf lives, and safe handling requirements as required at SNL. The general peroxide chemistry concerning formation, prevention, and identification is cursorily presented to give some perspective to the generation of peroxides. The procedure for determining peroxide concentrations and the proper disposal methods established by the Hazardous Waste Handling Facility are also provided. Techniques such as neutralization and dilution are provided for the safe handling of any PYD chemicals to allow for safe handling. The appendices are a collection of all available SNL documentation pertaining to PPF/PYD chemicals to serve as a single reference.

  17. Multimedia regulated chemicals

    SciTech Connect

    Lee, C.C.; Huffman, G.L.; Mao, Y.L.

    1999-10-01

    This article examines those chemicals that are listed in either environmental laws or regulations. Its objective is to help readers determine which laws regulate what types of chemicals and which types of chemicals are regulated by what laws. It is multimedia in scope, describing the various chemicals that are regulated in the different media (i.e., air, water, or land).

  18. Yield impacting systematic defects search and management

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Xu, Qingxiu; Zhang, Xin; Zhao, Xing; Ning, Jay; Cheng, Guojie; Chen, Shijie; Zhang, Gary; Vikram, Abhishek; Su, Bo

    2012-03-01

    Despite great effort before design tapeout, there are still some pattern related systematic defects showing up in production, which impact product yield. Through various check points in the production life cycle endeavor is made to detect these defective patterns. It is seen that apart from the known defective patterns, slight variations of polygon sizes and shapes in the known defective patterns also cause yield loss. This complexity is further compounded when interactions among multiple process layers causes the defect. Normally the exact pattern matching techniques cannot detect these variations of the defective patterns. With the currently existing tools in the fab it is a challenge to define the 'sensitive patterns', which are arbitrary variations in the known 'defective patterns'. A design based approach has been successfully experimented on product wafers to detect yield impacting defects that greatly reduces the TAT for hotspot analysis and also provides optimized care area definition to enable high sensitivity wafer inspection. A novel Rule based pattern search technique developed by Anchor Semiconductor has been used to find sensitive patterns in the full chip design. This technique allows GUI based pattern search rule generation like, edge move or edge-to-edge distance range, so that any variations of a particular sensitive pattern can be captured and flagged. Especially the pattern rules involving multiple process layers, like M1-V1-M2, can be defined easily using this technique. Apart from using this novel pattern search technique, design signatures are also extracted around the defect locations in the wafer and used in defect classification. This enhanced defect classification greatly helps in determining most critical defects among the total defect population. The effectiveness of this technique has been established through design to defect correlation and SEM verification. In this paper we will report details of the design based experiments that

  19. Gas breakdown and secondary electron yields

    NASA Astrophysics Data System (ADS)

    Marić, Dragana; Savić, Marija; Sivoš, Jelena; Škoro, Nikola; Radmilović-Radjenović, Marija; Malović, Gordana; Petrović, Zoran Lj.

    2014-06-01

    In this paper we present a systematic study of the gas breakdown potentials. An analysis of the key elementary processes in low-current low-pressure discharges is given, with an aim to illustrate how such discharges are used to determine swarm parameters and how such data may be applied to modeling discharges. Breakdown data obtained in simple parallel-plate geometry are presented for a number of atomic and molecular gases. Ionization coefficients, secondary electron yields and their influence on breakdown are analyzed, with special attention devoted to non-hydrodynamic conditions near cathode.

  20. {mu}{yields}e{gamma}-MEG

    SciTech Connect

    Sawada, Ryu

    2009-12-17

    The MEG experiment started a search for a lepton violating (LFV) muon decay, {mu}{sup +}{yields}e{sup +}{gamma}, at Paul Scherrer Institut(PSI) in Switzerland. The LFV muon decay does not occur in the standard model, while new theories, such as super symmetric grand unified theory and seesaw model of neutrinos, predict observable branching ratio just below the current upper limit (1.2x10{sup -12}). MEG is designed to improve the sensitivity by two orders of magnitude. In this article, the system of the MEG experiment and its data taking in 2008 are described.

  1. The Journey from Safe Yield to Sustainability

    USGS Publications Warehouse

    Alley, W.M.; Leake, S.A.

    2004-01-01

    Safe-yield concepts historically focused attention on the economic and legal aspects of ground water development. Sustainability concerns have brought environmental aspects more to the forefront and have resulted in a more integrated outlook. Water resources sustainability is not a purely scientific concept, but rather a perspective that can frame scientific analysis. The evolving concept of sustainability presents a challenge to hydrologists to translate complex, and sometimes vague, socioeconomic and political questions into technical questions that can be quantified systematically. Hydrologists can contribute to sustainable water resources management by presenting the longer-term implications of ground water development as an integral part of their analyses.

  2. Varactor-diode modulator yields conversion gain

    NASA Astrophysics Data System (ADS)

    Breitkopf, K.

    1980-05-01

    It is shown that varactor diodes used as modulator elements can make a balanced diode mixer yield conversion gain when employed in an upconverter. Replacing the normal mixer diodes with varactor diodes and inserting the IF and LO voltages at a level that drives the diodes into their nonlinear voltage-capacitance region produces a parametric amplifying effect. This modification results in conversion gain rather than loss, and brings the desired output power up to the 0.1-1.0 W level. The use of this technique in a lower-sideband UHF TV upconverter is considered.

  3. The chemical life(1).

    PubMed

    Hodges, Nathan

    2015-01-01

    You write this narrative autoethnography to open up a conversation about our chemical lives. You go through your day with chemical mindfulness, questioning taken-for-granted ideas about natural and artificial, healthy and unhealthy, dependency and addiction, trying to understand the chemical messages we consume through the experiences of everyday life. You reflect on how messages about chemicals influence and structure our lives and why some chemicals are celebrated and some are condemned. Using a second-person narrative voice, you show how the personal is relational and the chemical is cultural. You write because you seek a connection, a chemical bond. PMID:24905820

  4. PINS chemical identification software

    DOEpatents

    Caffrey, Augustine J.; Krebs, Kennth M.

    2004-09-14

    An apparatus and method for identifying a chemical compound. A neutron source delivers neutrons into the chemical compound. The nuclei of chemical elements constituting the chemical compound emit gamma rays upon interaction with the neutrons. The gamma rays are characteristic of the chemical elements constituting the chemical compound. A spectrum of the gamma rays is generated having a detection count and an energy scale. The energy scale is calibrated by comparing peaks in the spectrum to energies of pre-selected chemical elements in the spectrum. A least-squares fit completes the calibration. The chemical elements constituting the chemical compound can be readily determined, which then allows for identification of the chemical compound.

  5. Yield and quality attributes of faba bean inbred lines grown under marginal environmental conditions of Sudan.

    PubMed

    Gasim, Seif; Hamad, Solafa A A; Abdelmula, Awadalla; Mohamed Ahmed, Isam A

    2015-11-01

    Faba beans (Vicia faba L.) represent an essential source of food protein for many people in Sudan, especially those who cannot afford to buy animal meat. The demand for faba bean seeds is greatly increased in recent years, and consequently its production area was extended southward where the climate is marginally suitable. Therefore, this study was aimed to evaluate seed yield and nutritional quality of five faba bean inbred lines grown under marginal environmental conditions of Sudan. The inbred lines have considerable (P ≤ 0.05) variability in yield and yield components, and seed chemical composition. The mean carbohydrate content was very high (501.1 g kg(-1)) and negatively correlated with seed yield, whereas the average protein content was relatively high (253.1 g kg(-1)) and positively correlated with seed yield. Globulin was the significant fraction (613.5 g kg(-1)protein) followed by albumin (200.2 g kg(-1)protein). Biplot analysis indicates that inbred lines Hudeiba/93-S5 and Ed-damar-S5 outscore other lines in terms of seed yield and nutritional quality. This study demonstrates that Hudeiba/93-S5 and Ed-damar-S5 are useful candidates in faba bean breeding program to terminate the protein deficiency malnutrition and provide healthy and nutritious meal for people living in subtropical areas. PMID:26788295

  6. 7 CFR 868.206 - Milling yield determination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Milling yield determination. 868.206 Section 868.206... Application of Standards § 868.206 Milling yield determination. Milling yield shall be determined by the use... that is approved by the Administrator as giving equivalent results. Note: Milling yield shall not...

  7. 7 CFR 868.206 - Milling yield determination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Milling yield determination. 868.206 Section 868.206... Application of Standards § 868.206 Milling yield determination. Milling yield shall be determined by the use... that is approved by the Administrator as giving equivalent results. Note: Milling yield shall not...

  8. Potential use of MODIS imagery for operational crop yield assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring crop condition and yields at regional scales remains a challenge. Ground-based sampling for assessment of crop yields at regional and national scales require enormous resources. Crop yield simulation models have shown great success in predicting crop yields at field and small scales; how...

  9. 21 CFR 211.103 - Calculation of yield.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Calculation of yield. 211.103 Section 211.103 Food... § 211.103 Calculation of yield. Actual yields and percentages of theoretical yield shall be determined... the drug product. Such calculations shall either be performed by one person and independently...

  10. 7 CFR 868.206 - Milling yield determination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Milling yield determination. 868.206 Section 868.206... Application of Standards § 868.206 Milling yield determination. Milling yield shall be determined by the use... that is approved by the Administrator as giving equivalent results. Note: Milling yield shall not...

  11. 7 CFR 868.206 - Milling yield determination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Milling yield determination. 868.206 Section 868.206... Application of Standards § 868.206 Milling yield determination. Milling yield shall be determined by the use... that is approved by the Administrator as giving equivalent results. Note: Milling yield shall not...

  12. 7 CFR 868.206 - Milling yield determination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Milling yield determination. 868.206 Section 868.206... Application of Standards § 868.206 Milling yield determination. Milling yield shall be determined by the use... that is approved by the Administrator as giving equivalent results. Note: Milling yield shall not...

  13. Hydrogeologic framework and borehole yields in Ghana

    NASA Astrophysics Data System (ADS)

    Dapaah-Siakwan, S.; Gyau-Boakye, P.

    2000-08-01

    In Ghana, 68% of the population live in rural communities, which are scattered and remote. Groundwater is the most feasible source of potable water supply for most of these dispersed and remote settlements. To meet the present and future challenges of population expansion vis-à-vis the observed declining rainfall in most parts of Africa including Ghana, it is necessary to assess, efficiently manage, and utilize the groundwater resources. The objective of this paper is therefore to describe the hydrogeologic framework and analyze borehole yields as part of the groundwater-resources assessment of Ghana. The hydrogeologic units are broadly categorized as: (1) the Basement Complex (crystalline rocks), which underlies about 54% of the country; (2) the Voltaian System, which underlies about 45%; and (3) the Cenozoic, Mesozoic, and Paleozoic sedimentary strata (Coastal Provinces), which underlie the remaining 1% of the country. The Basement Complex and the Coastal Provinces have higher groundwater potential than the Voltaian System. This is particularly significant, because the Basement Complex and the Coastal Provinces underlie the most densely populated areas of the country and can hence be tapped for human use. The average borehole yields of the Basement Complex, the Coastal Provinces and the Voltaian System range from 2.7-12.7, 3.9-15.6, and 6.2-8.5 m3/h, respectively.

  14. Impact of ozone on winter wheat yield

    SciTech Connect

    Kress, L.W.; Miller, J.E.; Smith, H.J.

    1985-01-01

    Wheat is one of the more-important agricultural crops in the USA, and the major production areas may be subjected to potentially damaging concentrations of ozone (O/sub 3/). Since no information was available regarding the O/sub 3/ sensitivity of winter-wheat cultivars grown in the Midwest, plants of three cultivars were field-grown in open-top chambers and exposed to O/sub 3/ daily throughout the spring growing season to determine impact on grain yield. Also included was a non-chambered ambient air plot. Tests were conducted over a two-year period and compared. The study was initiated to provide further biological response data suitable for evaluating ambient air-quality standards and for use in the NCLAN economic assessment of the consequences of O/sub 3/ exposure to crops. The specific objective was to establish the exposure-response relationships between yield of three important cultivars of soft red winter wheat grown in the Midwest and chronic exposures to a range of O/sub 3/ concentrations.

  15. Information on tar and nicotine yields on cigarette packages.

    PubMed Central

    Davis, R M; Healy, P; Hawk, S A

    1990-01-01

    We examined information on tar and nicotine yields on the packages of 160 cigarette brands, 58 percent of the 275 brands for which tar and nicotine yields were listed in a recent Federal Trade Commission report. The tar yield was indicated on 14 percent, the nicotine yield was indicated on 11 percent. As tar yield increased among brands, the yield was progressively less likely to be shown on the package and was not disclosed on the package of any cigarette yielding 11 mg or more of tar. PMID:2327530

  16. ON-LINE PREDICTION OF YIELD GRADE, LONGISSIMUS MUSCLE AREA, PRELIMINARY YIELD GRADE, ADJUSTED PRELIMINARY YIELD GRADE, AND MARBLING SCORE USING THE MARC BEEF CARCASS IMAGE ANALYSIS SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present experiment was conducted to evaluate the ability of the MARC Beef Carcass Image Analysis System to predict calculated yield grade, longissimus area, preliminary yield grade, adjusted preliminary yield grade, and marbling score under commercial beef processing conditions. In two commerci...

  17. Coupling chemical and biological catalysis: a flexible paradigm for producing biobased chemicals.

    PubMed

    Schwartz, Thomas J; Shanks, Brent H; Dumesic, James A

    2016-04-01

    Advances in metabolic engineering have allowed for the development of new biological catalysts capable of selectively de-functionalizing biomass to yield platform molecules that can be upgraded to biobased chemicals using high efficiency continuous processing allowed by heterogeneous chemical catalysis. Coupling these disciplines overcomes the difficulties of selectively activating COH bonds by heterogeneous chemical catalysis and producing petroleum analogues by biological catalysis. We show that carboxylic acids, pyrones, and alcohols are highly flexible platforms that can be used to produce biobased chemicals by this approach. More generally, we suggest that molecules with three distinct functionalities may represent a practical upper limit on the extent of functionality present in the platform molecules that serve as the bridge between biological and chemical catalysis. PMID:26785391

  18. THE CHEMICAL EVOLUTION OF PHOSPHORUS

    SciTech Connect

    Jacobson, Heather R.; Thanathibodee, Thanawuth; Frebel, Anna; Roederer, Ian U.; Cescutti, Gabriele; Matteucci, Francesca

    2014-12-01

    Phosphorus is one of the few remaining light elements for which little is known about its nucleosynthetic origin and chemical evolution, given the lack of optical absorption lines in the spectra of long-lived FGK-type stars. We have identified a P I doublet in the near-ultraviolet (2135/2136 Å) that is measurable in stars of low metallicity. Using archival Hubble Space Telescope-Space Telescope Imaging Spectrograph spectra, we have measured P abundances in 13 stars spanning –3.3 ≤ [Fe/H] ≤ -0.2, and obtained an upper limit for a star with [Fe/H] ∼ -3.8. Combined with the only other sample of P abundances in solar-type stars in the literature, which spans a range of –1 ≤ [Fe/H] ≤ +0.2, we compare the stellar data to chemical evolution models. Our results support previous indications that massive-star P yields may need to be increased by a factor of a few to match stellar data at all metallicities. Our results also show that hypernovae were important contributors to the P production in the early universe. As P is one of the key building blocks of life, we also discuss the chemical evolution of the important elements to life, C-N-O-P-S, together.

  19. Chemical recycling of scrap composites

    NASA Technical Reports Server (NTRS)

    Allred, Ronald E.; Salas, Richard M.

    1994-01-01

    There are no well-developed technologies for recycling composite materials other than grinding to produce fillers. New approaches are needed to reclaim these valuable resources. Chemical or tertiary recycling, conversion of polymers into low molecular weight hydrocarbons for reuse as chemicals or fuels, is emerging as the most practical means for obtaining value from waste plastics and composites. Adherent Technologies is exploring a low-temperature catalytic process for recycling plastics and composites. Laboratory results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products. This novel catalytic process runs at 200 C, conversion times are rapid, the process is closed and, thus, nonpolluting, and no highly toxic gas or liquid products have been observed so no negative environmental impact will result from its implementation. Tests on reclamation of composite materials show that epoxy, imide, and engineering thermoplastic matrices can be converted to low molecular weight hydrocarbons leaving behind the reinforcing fibers for reuse as composite reinforcements in secondary, lower-performance applications. Chemical recycling is also a means to dispose of sensitive or classified organic materials without incineration and provides a means to eliminate or reduce mixed hazardous wastes containing organic materials.

  20. Ethiopian Wheat Yield and Yield Gap Estimation: A Spatial Small Area Integrated Data Approach

    NASA Astrophysics Data System (ADS)

    Mann, M.; Warner, J.

    2015-12-01

    Despite the collection of routine annual agricultural surveys and significant advances in GIS and remote sensing products, little econometric research has been undertaken in predicting developing nation's agricultural yields. In this paper, we explore the determinants of wheat output per hectare in Ethiopia during the 2011-2013 Meher crop seasons aggregated to the woreda administrative area. Using a panel data approach, combining national agricultural field surveys with relevant GIS and remote sensing products, the model explains nearly 40% of the total variation in wheat output per hectare across the country. The model also identifies specific contributors to wheat yields that include farm management techniques (eg. area planted, improved seed, fertilizer, irrigation), weather (eg. rainfall), water availability (vegetation and moisture deficit indexes) and policy intervention. Our findings suggest that woredas produce between 9.8 and 86.5% of their potential wheat output per hectare given their altitude, weather conditions, terrain, and plant health. At the median, Amhara, Oromiya, SNNP, and Tigray produce 48.6, 51.5, 49.7, and 61.3% of their local attainable yields, respectively. This research has a broad range of applications, especially from a public policy perspective: identifying causes of yield fluctuations, remotely evaluating larger agricultural intervention packages, and analyzing relative yield potential. Overall, the combination of field surveys with spatial data can be used to identify management priorities for improving production at a variety of administrative levels.

  1. The Chemical Heritage Foundation

    NASA Astrophysics Data System (ADS)

    Orna, Mary Virginia

    1998-04-01

    This first in a series of articles on the Chemical Heritage Foundation will outline a brief history of the foundation and give an overview of its present programs, with emphasis on the Othmer Library of Chemical History. The Chemical Heritage Foundation (CHF) is a unique asset and unique partnership of the chemical community. It had its origins in a simple written agreement some 15 years ago, in January 1982. CHF's mission of recording, preserving, and making known the heritage of chemical achievement does not reflect the concerns of the chemical corporations or of anyone directly concerned with the "image" or economic and political future of the chemical sciences. Rather, it was an idea of academics and professional scientists. Thus it was appropriate that the three founding organizations were the American Chemical Society, the American Institute of Chemical Engineers and the University of Pennsylvania.

  2. Effect of nitrogen and water deficit type on the yield gap between the potential and attainable wheat yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water deficit and N fertilizer are the two primary limiting factors for wheat yield in the North China plain, the most important winter wheat (Triticum aestivum L.) production area in China. Analyzing the yield gap between the potential yield and the attainable yield can quantify the potential for i...

  3. Infrasound Propagation Modeling for Explosive Yield Estimation

    NASA Astrophysics Data System (ADS)

    Howard, J. E.; Golden, P.; Negraru, P.

    2013-12-01

    This study focuses on developing methods of estimating the size or yield of HE surface explosions from local and regional infrasound measurements in the southwestern United States. A munitions disposal facility near Mina, Nevada provides a repeating ground-truth source for this study, with charge weights ranging from 870 - 3800 lbs. Detonation logs and GPS synchronized videos were obtained for a sample of shots representing the full range of weights. These are used to calibrate a relationship between charge weight and spectral level from seismic waveforms recorded at the Nevada Seismic Array (NVAR) at a distance of 36 km. Origin times and yields for the remaining shots are inferred from the seismic recordings at NVAR. Infrasound arrivals from the detonations have been continuously recorded on three four-element, small aperture infrasound arrays since late 2009. NVIAR is collocated with NVAR at a range of approximately 36 km to the northeast. FALN and DNIAR are located at ranges of 154 km to the north, and 293 km to the southeast respectively. Travel times and amplitudes for stratospheric arrivals at DNIAR show strong seasonal variability with the largest amplitudes and celerities occurring during the winter months when the stratospheric winds are favorable. Stratospheric celerities for FNIAR to the north are more consistent as they are not strongly affected by the predominantly meridional stratospheric winds. Tropospheric arrivals at all three arrays show considerable variability that does not appear to be a seasonal effect. Naval Research Laboratory Ground to Space (NRL-G2S) Mesoscale models are used to specify the atmosphere along the propagation path for each detonation. Ray-tracing is performed for each source/receiver pair to identify events for which the models closely match the travel-time observations. This subset of events is used to establish preliminary wind correction formulas using wind values from the G2S profile for the entire propagation path. These

  4. Effect of Modified Mechanical Treatment Facilities on SRF Yield in Korea

    NASA Astrophysics Data System (ADS)

    Jo, Mi-Hyun; Lee, Byung-Jin; Lee, Jai-Young

    2013-12-01

    An SRF plant which can produce 100 ton/month of SRF, one of the largest manufacturing plants in Korea, was investigated in this study. The actual operated SRF yield at 21.7 % that showed a lower yield than expected; originally designed value was 25.0%. The cause of these results was the difference between characteristics of MSW applied to this plant originally and that which was actual incoming. The MSW led to decrease the separation efficiency of the mechanical treatment process. Thus, each element of the facility was modified. After modification, the SRF yield increased to 30.9%, whereas the physico-chemical properties of SRF were satisfied with domestic standard of SRF regardless of modifying MT facilities.

  5. Seismic Methods of Identifying Explosions and Estimating Their Yield

    NASA Astrophysics Data System (ADS)

    Walter, W. R.; Ford, S. R.; Pasyanos, M.; Pyle, M. L.; Myers, S. C.; Mellors, R. J.; Pitarka, A.; Rodgers, A. J.; Hauk, T. F.

    2014-12-01

    Seismology plays a key national security role in detecting, locating, identifying and determining the yield of explosions from a variety of causes, including accidents, terrorist attacks and nuclear testing treaty violations (e.g. Koper et al., 2003, 1999; Walter et al. 1995). A collection of mainly empirical forensic techniques has been successfully developed over many years to obtain source information on explosions from their seismic signatures (e.g. Bowers and Selby, 2009). However a lesson from the three DPRK declared nuclear explosions since 2006, is that our historic collection of data may not be representative of future nuclear test signatures (e.g. Selby et al., 2012). To have confidence in identifying future explosions amongst the background of other seismic signals, and accurately estimate their yield, we need to put our empirical methods on a firmer physical footing. Goals of current research are to improve our physical understanding of the mechanisms of explosion generation of S- and surface-waves, and to advance our ability to numerically model and predict them. As part of that process we are re-examining regional seismic data from a variety of nuclear test sites including the DPRK and the former Nevada Test Site (now the Nevada National Security Site (NNSS)). Newer relative location and amplitude techniques can be employed to better quantify differences between explosions and used to understand those differences in term of depth, media and other properties. We are also making use of the Source Physics Experiments (SPE) at NNSS. The SPE chemical explosions are explicitly designed to improve our understanding of emplacement and source material effects on the generation of shear and surface waves (e.g. Snelson et al., 2013). Finally we are also exploring the value of combining seismic information with other technologies including acoustic and InSAR techniques to better understand the source characteristics. Our goal is to improve our explosion models

  6. Crop status evaluations and yield predictions

    NASA Technical Reports Server (NTRS)

    Haun, J. R.

    1975-01-01

    A model was developed for predicting the day 50 percent of the wheat crop is planted in North Dakota. This model incorporates location as an independent variable. The Julian date when 50 percent of the crop was planted for the nine divisions of North Dakota for seven years was regressed on the 49 variables through the step-down multiple regression procedure. This procedure begins with all of the independent variables and sequentially removes variables that are below a predetermined level of significance after each step. The prediction equation was tested on daily data. The accuracy of the model is considered satisfactory for finding the historic dates on which to initiate yield prediction model. Growth prediction models were also developed for spring wheat.

  7. Semiconductor yield improvements through automatic defect classification

    SciTech Connect

    Gleason, S.; Kulkarni, A.

    1995-09-30

    Automatic detection of defects during the fabrication of semiconductor wafers is largely automated, but the classification of those defects is still performed manually by technicians. Projections by semiconductor manufacturers predict that with larger wafer sizes and smaller line width technology the number of defects to be manually classified will increase exponentially. This cooperative research and development agreement (CRADA) between Martin Marietta Energy Systems (MMES) and KLA Instruments developed concepts, algorithms and systems to automate the classification of wafer defects to decrease inspection time, improve the reliability of defect classification, and hence increase process throughput and yield. Image analysis, feature extraction, pattern recognition and classification schemes were developed that are now being used as research tools for future products and are being integrated into the KLA line of wafer inspection hardware. An automatic defect classification software research tool was developed and delivered to the CRADA partner to facilitate continuation of this research beyond the end of the partnership.

  8. Effects of season on the yield and quality of agar from Gracilaria species (Gracilariaceae, Rhodophyta).

    PubMed

    Marinho-Soriano, E; Bourret, E

    2003-12-01

    The effect of season on yield and physical properties of agars extracted from Gracia gracilis and G. bursa-pastoris were determined. The agar yield from G. gracilis was maximum during spring (30%) and minimum during autumn (19%). In G. bursa-pastoris, the agar yield was greatest in summer (36%) and lowest in winter (23%). Agar yield from G. bursa-pastoris was positively correlated with temperature (r=0.94; P<0.01) and salinity (r=0.97; P<0.01) and negatively with nitrogen content (r=-0.93; P<0.01). Agar gel strengths fluctuated from 229 to 828 gcm(-2) and 23 to 168 gcm(-2) for G. gracilis and G. bursa-pastoris, respectively. The gelling temperature showed significant seasonal variation for both species. Chemical analysis of agar from the two seaweeds indicated variation in 3,6-anhydrogalactose and sulfate content (P<0.01). Furthermore, there was an inverse correlation between the two chemical variables. In general, agar extracted from G. gracilis possessed better qualities than agar extracted from G. bursa-pastoris and can be considered a candidate for industrial use. PMID:14575957

  9. Computed barrier heights for H + CH2O yields CH3O yields CH2OH

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.

    1993-01-01

    The barrier heights (including zero-point effects) for H + CH2O yields CH3O and CH3O yields CH2OH have been computed using complete active space self consistent field (CASSCF)/gradient calculations to define the stationary point geometries and harmonic frequencies and internally contracted configuration-interaction (CCI) to refine the energetics. The computed barrier heights are 5.6 kcal/mol and 30.1 kcal/mol, respectively. The former barrier height compares favorably to an experimental activation energy of 5.2 kcal/mol.

  10. Biosurfactants: a sustainable replacement for chemical surfactants?

    PubMed

    Marchant, Roger; Banat, Ibrahim M

    2012-09-01

    Glycolipid biosurfactants produced by bacteria and yeasts provide significant opportunities to replace chemical surfactants with sustainable biologically produced alternatives in bulk commercial products such as laundry detergents and surface cleaners. Sophorolipids are already available in sufficient yield to make their use feasible while rhamnolipids and mannosylerythritol lipids require further development. The ability to tailor the biosurfactant produced to the specific needs of the product formulation will be an important future step. PMID:22618240

  11. Silicon refinement by chemical vapor transport

    NASA Technical Reports Server (NTRS)

    Olson, J.

    1984-01-01

    Silicon refinement by chemical vapor transport is discussed. The operating characteristics of the purification process, including factors affecting the rate, purification efficiency and photovoltaic quality of the refined silicon were studied. The casting of large alloy plates was accomplished. A larger research scale reactor is characterized, and it is shown that a refined silicon product yields solar cells with near state of the art conversion efficiencies.

  12. Chemical Synthesis of a Hyaluronic Acid Decasaccharide

    PubMed Central

    Lu, Xiaowei; Kamat, Medha N.; Huang, Lijun; Huang, Xuefei

    2009-01-01

    The chemical synthesis of a hyaluronic acid decasaccharide using the pre-activation based chemoselective glycosylation strategy is described. Assembly of large oligosaccharides is generally challenging due to the increased difficulties in both glycosylation and deprotection. Indeed, the same building blocks previously employed for hyaluronic acid hexasaccharide syntheses failed to yield the desired decasaccharide. After extensive experimentation, the decasaccharide backbone was successfully constructed with an overall yield of 37% from disaccharide building blocks. The trichloroacetyl group was used as the nitrogen protective group for the glucosamine units and the addition of TMSOTf was found to be crucial to suppress the formation of trichloromethyl oxazoline side-product and enable high glycosylation yield. For deprotections, the combination of a mild basic condition and the monitoring methodology using 1H-NMR allowed the removal of all base-labile protective groups, which facilitated the generation of the fully deprotected HA decasaccharide. PMID:19764799

  13. [Yield loss model and yield loss mechanism of high-yielding summer maize infected by Physoderma maydis].

    PubMed

    Wu, Shu-hua; Jiang, Xing-yin; Nie, Le-xing; Li, Jun-hu; Zhang, Ji-wang; Liu, Peng

    2011-03-01

    A total of 21 different disease-grading summer maize groups were formed by fixed-point natural infection of maize brown spot in the field, and mass loss estimation models of single ear mass and 100-grain mass were constructed by stepwise regression with DPS software. The mass loss estimation models of single ear and 100-grain were Y = -4.012 + 0.377X1 - 0.228X2 + 0.694X3 - 0.144X4 and Y = -4.536 + 0.173X1 + 0.188X2 + 0.248X3 - 0.034X4, respectively, where Y was yield loss rate, X1 was the disease index at flowering stage, X2 was the disease index at pollination stage, X3 was the disease index at filling stage, and X4 was the disease index at dough stage. The measured relationships between the disease indices at different growth stages and the mass loss for single ear and 100-grain coincided well with the modeling results. Maize brown spot directly affected the net photosynthetic rate of ear height leaf and the activities of RuBP carboxylase and PEP carboxylase. The higher the disease-grade, the lower the net photosynthetic rate and the activities of the two enzymes were. PMID:21657030

  14. Chemical evaluation of electronic cigarettes

    PubMed Central

    Cheng, Tianrong

    2014-01-01

    Objective To review the available evidence evaluating the chemicals in refill solutions, cartridges, aerosols and environmental emissions of electronic cigarettes (e-cigarettes). Methods Systematic literature searches were conducted to identify research related to e-cigarettes and chemistry using 5 reference databases and 11 search terms. The search date range was January 2007 to September 2013. The search yielded 36 articles, of which 29 were deemed relevant for analysis. Results The levels of nicotine, tobacco-specific nitrosamines (TSNAs), aldehydes, metals, volatile organic compounds (VOCs), flavours, solvent carriers and tobacco alkaloids in e-cigarette refill solutions, cartridges, aerosols and environmental emissions vary considerably. The delivery of nicotine and the release of TSNAs, aldehydes and metals are not consistent across products. Furthermore, the nicotine level listed on the labels of e-cigarette cartridges and refill solutions is often significantly different from measured values. Phenolic compounds, polycyclic aromatic hydrocarbons and drugs have also been reported in e-cigarette refill solutions, cartridges and aerosols. Varying results in particle size distributions of particular matter emissions from e-cigarettes across studies have been observed. Methods applied for the generation and chemical analyses of aerosols differ across studies. Performance characteristics of e-cigarette devices also vary across and within brands. Conclusions Additional studies based on knowledge of e-cigarette user behaviours and scientifically validated aerosol generation and chemical analysis methods would be helpful in generating reliable measures of chemical quantities. This would allow comparisons of e-cigarette aerosol and traditional smoke constituent levels and would inform an evaluation of the toxicity potential of e-cigarettes. PMID:24732157

  15. Radiation and chemical pretreatment of cellulosic waste

    NASA Astrophysics Data System (ADS)

    Chosdu, Rahayu; Hilmy, Nazly; Erizal; Erlinda, T. B.; Abbas, B.

    1993-10-01

    RADIATION AND CHEMICAL PRETREATMENT OF CELLULOSIC WASTE. Combination pretreatment of cellulosic wastes such as corn stalk, cassava bark and peanut husk were studied using chemical and irradiation of electron beam. The effect of 2 % NaOH and irradiation at the doses of 100, 300 and 500 kGy on the cellulosic wastes were evaluated by measurement of the glucose yield in enzymatic hydrolysis. Irradiation was carried out with an electron beam machine EPS-300 (Energy 300 kev, current 50 mA). The result shows that the glucose yield were higher by increasing of dose irradiation and treated with 2 % of NaOH especially in corn stalk. The glucose yield of corn stalk were 20 % in untreated samples and increases to 43 % after treated with electron beam irradiation at the dose of 500 kGy and 2 % NaOH. Cassava bark and peanut husk show the glucose yield are only 3.5, and 2.5% respectively. The effect of E-beam current in enzymatic hydrolysis of corn stalk, and preliminary studied E-beam radiation pretreatment of cassava bark are also reported.

  16. Thermal and chemical convection in planetary mantles

    NASA Technical Reports Server (NTRS)

    Dupeyrat, L.; Sotin, C.; Parmentier, E. M.

    1995-01-01

    Melting of the upper mantle and extraction of melt result in the formation of a less dense depleted mantle. This paper describes series of two-dimensional models that investigate the effects of chemical buoyancy induced by these density variations. A tracer particles method has been set up to follow as closely as possible the chemical state of the mantle and to model the chemical buoyant force at each grid point. Each series of models provides the evolution with time of magma production, crustal thickness, surface heat flux, and thermal and chemical state of the mantle. First, models that do not take into account the displacement of plates at the surface of Earth demonstrate that chemical buoyancy has an important effect on the geometry of convection. Then models include horizontal motion of plates 5000 km wide. Recycling of crust is taken into account. For a sufficiently high plate velocity which depends on the thermal Rayleigh number, the cell's size is strongly coupled with the plate's size. Plate motion forces chemically buoyant material to sink into the mantle. Then the positive chemical buoyancy yields upwelling as depleted mantle reaches the interface between the upper and the lower mantle. This process is very efficient in mixing the depleted and undepleted mantle at the scale of the grid spacing since these zones of upwelling disrupt the large convective flow. At low spreading rates, zones of upwelling develop quickly, melting occurs, and the model predicts intraplate volcanism by melting of subducted crust. At fast spreading rates, depleted mantle also favors the formation of these zones of upwelling, but they are not strong enough to yield partial melting. Their rapid displacement toward the ridge contributes to faster large-scale homogenization.

  17. Chemical burn or reaction

    MedlinePlus

    ... different products that contain toxic chemicals such as ammonia and bleach. The mixture can give off hazardous ... chemicals immediately after use. Use paints, petroleum products, ammonia, bleach, and other products that give off fumes ...

  18. Chemical Engineering Division Activities

    ERIC Educational Resources Information Center

    Chemical Engineering Education, 1978

    1978-01-01

    The 1978 ASEE Chemical Engineering Division Lecturer was Theodore Vermeulen of the University of California at Berkeley. Other chemical engineers who received awards or special recognition at a recent ASEE annual conference are mentioned. (BB)

  19. Tobacco and chemicals (image)

    MedlinePlus

    Some of the chemicals associated with tobacco smoke include ammonia, carbon dioxide, carbon monoxide, propane, methane, acetone, hydrogen cyanide and various carcinogens. Other chemicals that are associated with chewing ...

  20. Chemical Industry Bandwidth Study

    SciTech Connect

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  1. Capacitive chemical sensor

    DOEpatents

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  2. Chemicals Industry Vision

    SciTech Connect

    none,

    1996-12-01

    Chemical industry leaders articulated a long-term vision for the industry, its markets, and its technology in the groundbreaking 1996 document Technology Vision 2020 - The U.S. Chemical Industry. (PDF 310 KB).

  3. Alternatives in Chemical Education

    ERIC Educational Resources Information Center

    Pecsok, Robert L.

    1971-01-01

    Summarizes the educational objectives and strategies of the Chemical Technician Curriculum Project (Chem TeC), which has the primary objective of preparing a set of texts specifically for training chemical technicians. (PR)

  4. Chemical Transformation Simulator

    EPA Science Inventory

    The Chemical Transformation Simulator (CTS) is a web-based, high-throughput screening tool that automates the calculation and collection of physicochemical properties for an organic chemical of interest and its predicted products resulting from transformations in environmental sy...

  5. Personal Chemical Exposure informatics

    EPA Science Inventory

    Chemical Exposure science is the study of human contact with chemicals (from manufacturing facilities, everyday products, waste) occurring in their environments and advances knowledge of the mechanisms and dynamics of events that cause or prevent adverse health outcomes. (adapted...

  6. Relations for Direct CP asymmetries in B {yields} PP and B {yields} PV decays

    SciTech Connect

    Pham, T. N.

    2006-01-12

    The presence of additional strong phase from power corrections and other chirally enhanced terms makes it more difficult to predict direct CP asymmetries in two-body charmless B decays. In this talk, I would like to report on a recent work on QCD Factorisation and Power Corrections in Charmless B Decays. Using the measured branching ratios for B {yields} PV, it is shown that power corrections in charmless B decays are probably large, at least for penguin dominated PV channels. Since the tree-penguin interference responsible for direct CP asymmetries in two-body charmless B decays are related by CKM factors and SU(3) symmetry, we find that, if power corrections other than the chirally enhanced power corrections and annihilation topology were negligible, QCD Factorisation would predict the direct CP asymmetry of B {yields} {pi}+{pi}- to be about 3 times larger than that of B {yields} {pi}{+-}K{+-}, with opposite sign, in agreement with the latest measurement from Belle. Similar relations are also given for direct CP asymmetries in B {yields} PV.

  7. Yield and yield formation of winter wheat in response to enhanced solar ultraviolet-B radiation

    NASA Astrophysics Data System (ADS)

    Zheng, Youfei; Gao, Wei; Slusser, James R.; Grant, Richard H.; Wang, Chuanhai

    2002-01-01

    The stratospheric ozone decrease has heightened concern over the ecological implications of increasing solar UVB radiation on agricultural production and natural plant ecosystems. UVB is absorbed and can damage many important plant species through a variety of interacting mechanisms. The effects of enhanced UVB exposure on yield and yield formation of winter wheat associated with photosynthetic activity and total biomass development were investigated in this study. The overall experimental design was three UVB treatments (two supplemental UVB treatments and an ambient level) and three replicates of each treatment. The results suggested that the supplemental UVB can cause the decrease of yield of winter wheat up to 24% with 11.4% increased UVB. The key growing stage which cause the yield decrease is during the jointing-spike formation. This study also investigated the effects of supplemental UVB on production of dry matter, allocation, LAI, total biomass, and photosynthetic activity of winter wheat. The combined UVB effect with other environmental stress factors on wheat was discussed in this study.

  8. The effects of climate change on United States rice yields and California wheat yields

    SciTech Connect

    Barry, T.A.; Geng, S.

    1995-12-31

    The USA produces 7.9 million tons of rice (Oryza sativa L.), 28% of which is exported to developing countries. Rice is one of the most important grain crops both in the USA and the world. Therefore it is important to understand the impact of weather and climate change on rice yields and production. In the USA rice is produced in California and the Gulf Coast states. It is anticipated that global climate change will have a major influence on agricultural practices and crop selection in these states. This study uses simulation techniques to quantify the potential magnitude of this influence. In addition, the impact of climate change on fall planted dryland spring wheat (Triticum aestivum L.) in California is evaluated. Results indicate that rice yields decrease by between 14 and 24% in the Gulf Coast states and between 11 and 21% in California. In both regions the decrease in rice yields were due primarily to the large increase in summer temperatures. On the other hand, dryland fall planted spring wheat yields in California increase by 62 and 125%. This is because of the increased rainfall and temperatures during the winter months in California.

  9. Validation of yield enhancing QTLs from a low-yielding wild ancestor of rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A set of introgression lines (ILs) containing chromosomal segments from O. rufipogon (IRGC 105491), a wild relative of O. sativa, in the genetic background of an elite U.S. variety, cv. Jefferson, was developed to confirm the performance of six yield-enhancing quantitative trait loci (QTLs). Fifty B...

  10. An evolutionary yield function based on Barlat 2000 yield function for the superconducting niobium sheet

    SciTech Connect

    Darbandi, Payam; Pourboghrat, Farhang

    2011-08-22

    Superconducting radio frequency (SRF) niobium cavities are widely used in high-energy physics to accelerate particle beams in particle accelerators. The performance of SRF cavities is affected by the microstructure and purity of the niobium sheet, surface quality, geometry, etc. Following optimum strain paths in the forming of these cavities can significantly control these parameters. To select these strain paths, however, information about the mechanical behavior, microstructure, and formability of the niobium sheet is required. In this study the Barlat 2000 yield function has been used as a yield function for high purity niobium. Results from this study showed that, due to intrinsic behavior, it is necessary to evolve the anisotropic coefficients of Barlat's yield function in order to properly model the plastic behavior of the niobium sheet. The accuracy of the newly developed evolutionary yield function was verified by applying it to the modeling of the hydrostatic bulging of the niobium sheet. Also, in a separate attempt crystal plasticity finite element method was use to model the behavior of the polycrystalline niobium sheet with a particular initial texture.

  11. Biomass yields and geography of large marine ecosystems

    SciTech Connect

    Sherman, K.; Alexander, L.M.

    1989-01-01

    Large Marine Ecosystems (LMEs) regions with unique hydrographic regimes, submarine topography, productivity, and trophically dependent populations. Over the past several decades, some populations of organisms within LMEs have increased and others declined amidst a background of natural environmental perturbation, disposal of urban wastes, aerosol contamination, spills of petrogenic hydrocarbons, overexploitation of fisheries resources, and growing evidence of global changes in atmospheric levels of carbon dioxide, methane, and ozone. The paper presented at the symposium, with appropriate revision based on peer- review, are given in this volume. Participants were encouraged to synthesize scattered information on biological, physical, and chemical processes affecting decadal fluctuations in biomass yields for LMEs including the Huanghai (Yellow) Sea, Kuroshio Current, Oyashio Current, Gulf of Thailand, and the Great Barrier Reef ecosystem around the Pacific basin, and for the Barents Sea, Gulf of Mexico, the Iberian coastal and Benguela Current ecosystems around the margins of the Atlantic. Participants also provided the results of studies of the geographic extent and boundaries of LMEs and the legal basis for the management of marine resources within LMEs.

  12. High yield, single crystal ice via the Bridgman method

    NASA Astrophysics Data System (ADS)

    Bisson, Patrick; Groenzin, Henning; Barnett, Irene Li; Shultz, Mary Jane

    2016-03-01

    The surface chemistry of ice and of water is an important topic of study, especially given the role of ice and water in shaping the environment. Although snow, granular, and polycrystalline ice are often used in research, there are applications where large surface areas of a known crystallographic plane are required. For example, fundamental spectroscopy or scattering studies rely on large area samples of known crystalline orientation. In addition, due to its slower dynamics and decreased number of molecular configurations, ice can be viewed as a reduced complexity model for the complex hydrogen bonding environment found at the surface and within the bulk of liquid water. In our studies using Sum Frequency Generation (SFG) vibrational spectroscopy, we have shown that each crystalline face has a unique spectral signature and therefore a unique chemistry and chemical activity. A reliable, reproducible, high performance method of producing large single crystal samples is needed to support this surface chemistry research. The design, construction, and use of a computer-controlled, ice-growth machine based on the Stockbarger modified Bridgeman technique is described. The instrument reliably produces relatively large single crystals that are optically flawless (that is, no visible flaws when viewed in a crossed polarizer), and in very high yield. Success rates of 95% are typical. Such performance has not been observed in the literature.

  13. High yield, single crystal ice via the Bridgman method.

    PubMed

    Bisson, Patrick; Groenzin, Henning; Barnett, Irene Li; Shultz, Mary Jane

    2016-03-01

    The surface chemistry of ice and of water is an important topic of study, especially given the role of ice and water in shaping the environment. Although snow, granular, and polycrystalline ice are often used in research, there are applications where large surface areas of a known crystallographic plane are required. For example, fundamental spectroscopy or scattering studies rely on large area samples of known crystalline orientation. In addition, due to its slower dynamics and decreased number of molecular configurations, ice can be viewed as a reduced complexity model for the complex hydrogen bonding environment found at the surface and within the bulk of liquid water. In our studies using Sum Frequency Generation (SFG) vibrational spectroscopy, we have shown that each crystalline face has a unique spectral signature and therefore a unique chemistry and chemical activity. A reliable, reproducible, high performance method of producing large single crystal samples is needed to support this surface chemistry research. The design, construction, and use of a computer-controlled, ice-growth machine based on the Stockbarger modified Bridgeman technique is described. The instrument reliably produces relatively large single crystals that are optically flawless (that is, no visible flaws when viewed in a crossed polarizer), and in very high yield. Success rates of 95% are typical. Such performance has not been observed in the literature. PMID:27036790

  14. Iron sensitizer converts light to electrons with 92% yield

    NASA Astrophysics Data System (ADS)

    Harlang, Tobias C. B.; Liu, Yizhu; Gordivska, Olga; Fredin, Lisa A.; Ponseca, Carlito S.; Huang, Ping; Chábera, Pavel; Kjaer, Kasper S.; Mateos, Helena; Uhlig, Jens; Lomoth, Reiner; Wallenberg, Reine; Styring, Stenbjörn; Persson, Petter; Sundström, Villy; Wärnmark, Kenneth

    2015-11-01

    Solar energy conversion in photovoltaics or photocatalysis involves light harvesting, or sensitization, of a semiconductor or catalyst as a first step. Rare elements are frequently used for this purpose, but they are obviously not ideal for large-scale implementation. Great efforts have been made to replace the widely used ruthenium with more abundant analogues like iron, but without much success due to the very short-lived excited states of the resulting iron complexes. Here, we describe the development of an iron-nitrogen-heterocyclic-carbene sensitizer with an excited-state lifetime that is nearly a thousand-fold longer than that of traditional iron polypyridyl complexes. By the use of electron paramagnetic resonance, transient absorption spectroscopy, transient terahertz spectroscopy and quantum chemical calculations, we show that the iron complex generates photoelectrons in the conduction band of titanium dioxide with a quantum yield of 92% from the 3MLCT (metal-to-ligand charge transfer) state. These results open up possibilities to develop solar energy-converting materials based on abundant elements.

  15. Iron sensitizer converts light to electrons with 92% yield.

    PubMed

    Harlang, Tobias C B; Liu, Yizhu; Gordivska, Olga; Fredin, Lisa A; Ponseca, Carlito S; Huang, Ping; Chábera, Pavel; Kjaer, Kasper S; Mateos, Helena; Uhlig, Jens; Lomoth, Reiner; Wallenberg, Reine; Styring, Stenbjörn; Persson, Petter; Sundström, Villy; Wärnmark, Kenneth

    2015-11-01

    Solar energy conversion in photovoltaics or photocatalysis involves light harvesting, or sensitization, of a semiconductor or catalyst as a first step. Rare elements are frequently used for this purpose, but they are obviously not ideal for large-scale implementation. Great efforts have been made to replace the widely used ruthenium with more abundant analogues like iron, but without much success due to the very short-lived excited states of the resulting iron complexes. Here, we describe the development of an iron-nitrogen-heterocyclic-carbene sensitizer with an excited-state lifetime that is nearly a thousand-fold longer than that of traditional iron polypyridyl complexes. By the use of electron paramagnetic resonance, transient absorption spectroscopy, transient terahertz spectroscopy and quantum chemical calculations, we show that the iron complex generates photoelectrons in the conduction band of titanium dioxide with a quantum yield of 92% from the (3)MLCT (metal-to-ligand charge transfer) state. These results open up possibilities to develop solar energy-converting materials based on abundant elements. PMID:26492008

  16. Emerging engineering principles for yield improvement in microbial cell design

    PubMed Central

    Comba, Santiago; Arabolaza, Ana; Gramajo, Hugo

    2012-01-01

    Metabolic Engineering has undertaken a rapid transformation in the last ten years making real progress towards the production of a wide range of molecules and fine chemicals using a designed cellular host. However, the maximization of product yields through pathway optimization is a constant and central challenge of this field. Traditional methods used to improve the production of target compounds from engineered biosynthetic pathways in non-native hosts include: codon usage optimization, elimination of the accumulation of toxic intermediates or byproducts, enhanced production of rate-limiting enzymes, selection of appropriate promoter and ribosome binding sites, application of directed evolution of enzymes, and chassis re-circuit. Overall, these approaches tend to be specific for each engineering project rather than a systematic practice based on a more generalizable strategy. In this mini-review, we highlight some novel and extensive approaches and tools intended to address the improvement of a target product formation, founded in sophisticated principles such as dynamic control, pathway genes modularization, and flux modeling. PMID:24688676

  17. Near-unity photoluminescence quantum yield in MoS₂.

    PubMed

    Amani, Matin; Lien, Der-Hsien; Kiriya, Daisuke; Xiao, Jun; Azcatl, Angelica; Noh, Jiyoung; Madhvapathy, Surabhi R; Addou, Rafik; KC, Santosh; Dubey, Madan; Cho, Kyeongjae; Wallace, Robert M; Lee, Si-Chen; He, Jr-Hau; Ager, Joel W; Zhang, Xiang; Yablonovitch, Eli; Javey, Ali

    2015-11-27

    Two-dimensional (2D) transition metal dichalcogenides have emerged as a promising material system for optoelectronic applications, but their primary figure of merit, the room-temperature photoluminescence quantum yield (QY), is extremely low. The prototypical 2D material molybdenum disulfide (MoS2) is reported to have a maximum QY of 0.6%, which indicates a considerable defect density. Here we report on an air-stable, solution-based chemical treatment by an organic superacid, which uniformly enhances the photoluminescence and minority carrier lifetime of MoS2 monolayers by more than two orders of magnitude. The treatment eliminates defect-mediated nonradiative recombination, thus resulting in a final QY of more than 95%, with a longest-observed lifetime of 10.8 ± 0.6 nanoseconds. Our ability to obtain optoelectronic monolayers with near-perfect properties opens the door for the development of highly efficient light-emitting diodes, lasers, and solar cells based on 2D materials. PMID:26612948

  18. The Start Of Ebullition In Quiescent, Yield-Stress Fluids

    SciTech Connect

    Reed, G. R.; Sherwood, David J.; Saez, A. Eduardo

    2012-08-30

    Non-Newtonian rheology is typical for the high-level radioactive waste (HLW) slurries processed in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Hydrogen and other flammable gases are generated in the aqueous phase by radiolytic and chemical reactions. HLW slurries have a capacity for retaining gas characterized by the shear strength holding the bubbles still. The sizes and degassing characteristics of flammable gas bubbles in the HLW slurries expected to be processed by the WTP are important considerations for designing equipment and operating procedures. Slurries become increasingly susceptible to degassing as the bubble concentration increases. This susceptibility and the process of ebullitive bubble enlargement are described here. When disturbed, the fluid undergoes localized flow around neighboring bubbles which are dragged together and coalesce, producing an enlarged bubble. For the conditions considered in this work, bubble size increase is enough to displace the weight required to overcome the fluid shear strength and yield the surroundings. The buoyant bubble ascends and accumulates others within a zone of influence, enlarging by a few orders of magnitude. This process describes how the first bubbles appear on the surface of a 7 Pa shear strength fluid a few seconds after being jarred.

  19. Computing Equilibrium Chemical Compositions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  20. Drought impacts on cereal yields in Iberia

    NASA Astrophysics Data System (ADS)

    Gouveia, Célia; Liberato, Margarida L. R.; Russo, Ana; Montero, Irene

    2014-05-01

    In the present context of climate change, land degradation and desertification it becomes crucial to assess the impact of droughts to determine the environmental consequences of a potential change of climate. Large drought episodes in Iberian Peninsula have widespread ecological and environmental impacts, namely in vegetation dynamics, resulting in significant crop yield losses. During the hydrological years of 2004/2005 and 2011/2012 Iberia was affected by two extreme drought episodes (Garcia-Herrera et al., 2007; Trigo et al., 2013). This work aims to analyze the spatial and temporal behavior of climatic droughts at different time scales using spatially distributed time series of drought indicators, such as the Standardized Precipitation Evapotranspiration Index (SPEI) (Vicente-Serrano et al., 2010). This climatic drought index is based on the simultaneous use of precipitation and temperature. We have used CRU TS3 dataset to compute SPEI and the Standardized Precipitation Index (SPI). Results will be analyzed in terms of the mechanisms that are responsible by these drought events and will also be used to assess the impact of droughts in crops. Accordingly an analysis is performed to evaluate the large-scale conditions required for a particular extreme anomaly of long-range transport of water vapor from the subtropics. We have used the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA Interim reanalyses, namely, the geopotential height fields, temperature, wind, divergence data and the specific humidity at all pressure levels and mean sea level pressure (MSLP) and total column water vapor (TCWV) for the Euro-Atlantic sector (100°W to 50°E, 0°N-70°N) at full temporal (six hourly) and spatial (T255; interpolated to 0.75° regular horizontal grid) resolutions available to analyse the large-scale conditions associated with the drought onset. Our analysis revealed severe impacts on cereals crop productions and yield (namely wheat) for Portugal and

  1. Chemical and Environmental Technology.

    ERIC Educational Resources Information Center

    Sheather, Harry

    The two-year curriculum in chemical technology presented in the document is designed to prepare high school graduates for technical positions in the chemical industry. Course outlines are given for general chemistry, chemical calculations, quantitative analysis, environmental chemistry, organic chemistry 1 and 2, instrumental analysis, and…

  2. Establishing Chemical Technology Programs.

    ERIC Educational Resources Information Center

    Hajian, Harry G.

    In light of the increasing demand for well-prepared chemical technicians, this paper provides suggestions for two-year colleges interested in initiating or upgrading a chemical technology program. Introductory comments indicate that, from the industry standpoint, chemical technicians are invaluable, but inadequate in numbers and often unprepared.…

  3. Microreactors for chemical synthesis.

    PubMed

    DeWitt, S H

    1999-06-01

    The advances of the past few years in microreactors have demonstrated that the miniaturization of chemistry has significant advantages with respect to cost, safety, throughput, kinetics and scale-up. The use of chemical microreactors for catalytic oxidations, heterocyclic syntheses and photochemical reactions has illustrated the utility and benefits for both chemical discovery and chemical development applications. PMID:10359719

  4. Chemical Physics Courses.

    ERIC Educational Resources Information Center

    Lee, J.; Munn, R. W.

    1978-01-01

    This is a guide to the chemical physics major. The scope of chemical physics is presented, along with the general features of course contents and possible course structures. This information was derived from a survey of British universities and colleges offering undergraduate degree courses in chemical physics. (BB)

  5. Naturally occurring chemical carcinogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural products are chemicals found in nature which have unique pharmacological effects. Humans are exposed to many of these bioactive naturally occurring chemicals via the air breathed, the water drunk and the food eaten. Exposure also occurs in clinical settings. Naturally occurring chemicals ...

  6. What Is Chemical Stoichiometry?

    ERIC Educational Resources Information Center

    Smith, William R.; Missen, Ronald W.

    1979-01-01

    Chemical stoichiometry is discussed free from kinetic or thermodynamic considerations. The means for determining the following are presented: the number of stoichiometric degrees of freedom, the number of components, a permissible set of chemical equations, and a permissible set of components, for a closed system undergoing chemical reaction.…

  7. AGRICULTURAL CHEMICAL USAGE DATA

    EPA Science Inventory

    This report, which summarizes the use of agricultural chemicals is issued by the National Agricultural Statistics Service (NASS) as part of its series on Agricultural Chemical Usage. Other publications in the series present statistics for on-farm agricultural chemical usage for f...

  8. Chemicals for worldwide aquaculture

    USGS Publications Warehouse

    Schnick, R.A.

    1991-01-01

    Regulations and therapeutants or other safe chemicals that are approved or acceptable for use in the aquaculture industry in the US, Canada, Europe and Japan are presented, discussing also compounds that are unacceptable for aquaculture. Chemical use practices that could affect public health are considered and details given regarding efforts to increase the number of registered and acceptable chemicals.

  9. Toxicology and Chemical Safety.

    ERIC Educational Resources Information Center

    Hall, Stephen K.

    1983-01-01

    Topics addressed in this discussion of toxicology and chemical safety include routes of exposure, dose/response relationships, action of toxic substances, and effects of exposure to chemicals. Specific examples are used to illustrate the principles discussed. Suggests prudence in handling any chemicals, whether or not toxicity is known. (JN)

  10. The Chemical Literature

    ERIC Educational Resources Information Center

    Crombie, D. A.

    1975-01-01

    Describes a course designed to acquaint students with making a search of chemical literature. The course presents various classes of chemical publication and the methods of using Beilstein and Chemical Abstracts. A follow-up project involves each student in a search for references for one or two organic compounds. (GS)

  11. Genesis Capsule Yields Solar Wind Samples

    NASA Astrophysics Data System (ADS)

    Wiens, Roger C.; Burnett, Donald S.; Stansbery, Eileen K.; McNamara, Karen M.

    2004-11-01

    NASA's Genesis capsule, carrying the first samples ever returned from beyond the Moon, took a hard landing in the western Utah desert on 8 September after its parachutes failed to deploy. Despite the impact, estimated at 310 km per hour, some valuable solar wind collector materials have been recovered. With these samples, the Genesis team members are hopeful that nearly all of the primary science goals may be met. The Genesis spacecraft was launched in August 2001 to collect and return samples of solar wind for precise isotopic and elemental analysis. The spacecraft orbited the Earth-Sun Lagrangian point (L1), ~1.5 million km sunward of the Earth, for 2.3 years. It exposed ultrapure materials-including wafers of silicon, silicon carbide, germanium, chemically deposited diamond, gold, aluminum, and metallic glass-to solar wind ions, which become embedded within the substrates' top 100 nm of these materials.

  12. Improvement in the yield and quality of kalmegh (Andrographis paniculata Nees) under the sustainable production system.

    PubMed

    Verma, Rajesh Kumar; Verma, Sanjeet K; Pankaj, Umesh; Gupta, Anand K; Khan, Khushboo; Shankar, Karuna

    2015-02-01

    Andrographis paniculata Nees is an annual erect herb with wide medicinal and pharmacological applications due to the presence of andrographolide and other active chemical constituents. The large-scale cultivation of the kalmegh is not in practice. The aim of this study was to establish sustainable production systems of A. paniculata cv CIM-Megha with the application of different bioinoculants and chemical fertilisers. A. paniculata herb and andrographolide yield in the dried leaves was found to be highest (218% and 61.3%, respectively) in treatment T3 (NPK+Bacillus sp.) compared with T1 (control). The soil organic carbon, soil microbial respiration, soil enzymes activity and available nutrients improved significantly with combined application of bioinoculants and chemical fertilisers. PMID:25348874

  13. Climate change influence on catchment sediment yield

    NASA Astrophysics Data System (ADS)

    Rulli, Maria Cristina; Grossi, Giovanna

    2010-05-01

    The effects of a change in climate are expected to be recognizable in many environmental aspects even at small spatial scales: atmospheric carbon dioxide concentration, air temperature, precipitation pattern (days of snowfall translate in days of rainfall), rainfall intensity and erosivity. As a consequence, strong modifications may affect the rate of evapo-transpiration, infiltration and plant biomass production, but also of the soil erosion. To which extent climate change may affect runoff production, soil erosion and sediment transport in upland catchments is investigated here by combining data of long term precipitation, sediment yield and future climate change provided by Global Circulation Models (GCMs) with a spatially distributed modeling approach to flow generation and surface erosion. The model accounts for changes in the structure and properties of soil and vegetation cover by combining the tube-flux approach to the topographic watershed partitioning through a parsimonious parametrization of the main hydrological processes. This model is used to predict hydrological and sediment fluxes for three small catchments in Saint Gabriel mountains of Southern California under control and climate change conditions. Simulation runs using a 45 years long record of hourly precipitation, both observed and referred to a future scenario, show that climate change may induce a significant modification in the catchment response to storms, with major effects on erosion and flood flows.

  14. On Strength at Yield in Condensed Matter

    NASA Astrophysics Data System (ADS)

    Bourne, Neil K.

    2015-10-01

    This paper concerns the lower of a range of thresholds that control the response of condensed matter under loading in compression, from the ambient laboratory state to the point at which the bond strength is overcome and warm dense matter is formed. One oft-used term is yield stress and its variation with the rise time of the loading pulse are considered in this first paper. This threshold shows a correlation between the length scale swept by the rise of the pulse and the defect distribution within the target for a range of materials. Strain rate is also a useful term that reflects the evolution of the stress state within a target but must be defined for a particular volume element containing a particular defect distribution to reflect continuum conditions acting within and thus applies to a defined length scale within a target. This overview of behavior suggests concepts borrowed from rate-independent plasticity have served the community well but that to advance it may be necessary to use viscoplastic concepts in constitutive descriptions for the future.

  15. Diploid yeast cells yield homozygous spontaneous mutations

    NASA Technical Reports Server (NTRS)

    Esposito, M. S.; Bruschi, C. V.; Brushi, C. V. (Principal Investigator)

    1993-01-01

    A leucine-requiring hybrid of Saccharomyces cerevisiae, homoallelic at the LEU1 locus (leu1-12/leu1-12) and heterozygous for three chromosome-VII genetic markers distal to the LEU1 locus, was employed to inquire: (1) whether spontaneous gene mutation and mitotic segregation of heterozygous markers occur in positive nonrandom association and (2) whether homozygous LEU1/LEU1 mutant diploids are generated. The results demonstrate that gene mutation of leu1-12 to LEU1 and mitotic segregation of heterozygous chromosome-VII markers occur in strong positive nonrandom association, suggesting that the stimulatory DNA lesion is both mutagenic and recombinogenic. In addition, genetic analysis of diploid Leu+ revertants revealed that approximately 3% of mutations of leu1-12 to LEU1 result in LEU1/LEU1 homozygotes. Red-white sectored Leu+ colonies exhibit genotypes that implicate post-replicational chromatid breakage and exchange near the site of leu1-12 reversion, chromosome loss, and subsequent restitution of diploidy, in the sequence of events leading to mutational homozygosis. By analogy, diploid cell populations can yield variants homozygous for novel recessive gene mutations at biologically significant rates. Mutational homozygosis may be relevant to both carcinogenesis and the evolution of asexual diploid organisms.

  16. Feature Selection for Wheat Yield Prediction

    NASA Astrophysics Data System (ADS)

    Ruß, Georg; Kruse, Rudolf

    Carrying out effective and sustainable agriculture has become an important issue in recent years. Agricultural production has to keep up with an everincreasing population by taking advantage of a field’s heterogeneity. Nowadays, modern technology such as the global positioning system (GPS) and a multitude of developed sensors enable farmers to better measure their fields’ heterogeneities. For this small-scale, precise treatment the term precision agriculture has been coined. However, the large amounts of data that are (literally) harvested during the growing season have to be analysed. In particular, the farmer is interested in knowing whether a newly developed heterogeneity sensor is potentially advantageous or not. Since the sensor data are readily available, this issue should be seen from an artificial intelligence perspective. There it can be treated as a feature selection problem. The additional task of yield prediction can be treated as a multi-dimensional regression problem. This article aims to present an approach towards solving these two practically important problems using artificial intelligence and data mining ideas and methodologies.

  17. Boosting investor yields through bond insurance

    SciTech Connect

    Mosbacher, M.L.; Burkhardt, D.A.

    1993-02-01

    The market for utility securities generally tends to be fairly static. Innovative financing techniques are rarely used because of the marketability of utility securities stemming from the companies' generally strong financial credit and the monopoly markets most utilities serve. To many people, utility securities are considered the pillars of the financial world, and innovation is not needed. Further, plain vanilla utility issues are easily understood by investors, as well as by regulators and customers. Over the past several years, however, a new utility bond product has crept into the world of utility securities - insured secondary utility bonds. These insured bonds may possibly be used as an alternative financing technique for newly issued debt. Individual investors often tend to rely on insurance as a tool for reducing credit risk and are willing to take the lower yields as a tradeoff. Insured utility bonds are created by brokerage firms through the acqusition of a portion of an outstanding utility bond issue and subsequent solicitation of the insurance companies for bids. The insurance company then agrees to insure that portion of the issue until maturity for a fee, and the brokerage firm sells those bonds to their customers as a AAA-insured bond. Issuers are encouraged to explore the retail market as a financing alternative. They may find a most cost-effective means of raising capital.

  18. Dynamic Yielding Behind Near-Steady Precursors

    NASA Astrophysics Data System (ADS)

    Sano, Yukio; Sano, Tomokazu

    2007-12-01

    In the precursor decay process in a lithium fluoride single crystal, plastic flow is revealed to occur in an evolving follower through an evaluated time variation in the dislocation density at its leading edge that is considerable higher than the initial density in the bulk. The occurrence of plastic flow in the follower suggests that the compressibility changes in an unsteady portion behind a near-steady precursor in a single plane wave, and its change causes the plane wave to be unstable and to separate into a near-steady precursor and a follower. The follower changes from wave C to waves I, II, R', and Rb in sequence. Here C is the contraction (compression) wave; I and II the degenerate contraction waves I and II; R' the subrarefaction wave; and Rb the rarefaction wave. Dynamic yield phenomena are illustrated by the schematics of three different types of dynamic relations between stress and strain, which are induced by a precursor C, a follower (i) C, (ii) I or II, or (iii) R' or Rb, and a plastic wave C behind the follower.

  19. Fusion yield: Guderley model and Tsallis statistics

    NASA Astrophysics Data System (ADS)

    Haubold, H. J.; Kumar, D.

    2011-02-01

    The reaction rate probability integral is extended from Maxwell-Boltzmann approach to a more general approach by using the pathway model introduced by Mathai in 2005 (A pathway to matrix-variate gamma and normal densities. Linear Algebr. Appl. 396, 317-328). The extended thermonuclear reaction rate is obtained in the closed form via a Meijer's G-function and the so-obtained G-function is represented as a solution of a homogeneous linear differential equation. A physical model for the hydrodynamical process in a fusion plasma-compressed and laser-driven spherical shock wave is used for evaluating the fusion energy integral by integrating the extended thermonuclear reaction rate integral over the temperature. The result obtained is compared with the standard fusion yield obtained by Haubold and John in 1981 (Analytical representation of the thermonuclear reaction rate and fusion energy production in a spherical plasma shock wave. Plasma Phys. 23, 399-411). An interpretation for the pathway parameter is also given.

  20. 7 CFR 760.811 - Rates and yields; calculating payments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield...

  1. Fly ash application in nutrient poor agriculture soils: impact on methanotrophs population dynamics and paddy yields.

    PubMed

    Singh, Jay Shankar; Pandey, Vimal Chandra

    2013-03-01

    There are reports that the application of fly ash, compost and press mud or a combination thereof, improves plant growth, soil microbial communities etc. Also, fly ash in combination with farmyard manure or other organic amendments improves soil physico-chemical characteristics, rice yield and microbial processes in paddy fields. However, the knowledge about the impact of fly ash inputs alone or in combination with other organic amendments on soil methanotrophs number in paddy soils is almost lacking. We hypothesized that fly ash application at lower doses in paddy agriculture soil could be a potential amendment to elevate the paddy yields and methanotrophs number. Here we demonstrate the impact of fly ash and press mud inputs on number of methanotrophs, antioxidants, antioxidative enzymatic activities and paddy yields at agriculture farm. The impact of amendments was significant for methanotrophs number, heavy metal concentration, antioxidant contents, antioxidant enzymatic activities and paddy yields. A negative correlation was existed between higher doses of fly ash-treatments and methanotrophs number (R(2)=0.833). The content of antioxidants and enzymatic activities in leaves of higher doses fly ash-treated rice plants increased in response to stresses due to heavy metal toxicity, which was negatively correlated with rice grain yield (R(2)=0.944) and paddy straw yield (R(2)=0.934). A positive correlation was noted between heavy metals concentrations and different antioxidant and enzymatic activities across different fly ash treated plots.The data of this study indicate that heavy metal toxicity of fly ash may cause oxidative stress in the paddy crop and the antioxidants and related enzymes could play a defensive role against phytotoxic damages. We concluded that fly ash at lower doses with press mud seems to offer the potential amendments to improving soil methanotrophs population and paddy crop yields for the nutrient poor agriculture soils. PMID:23260239

  2. Chemical Abundances of Metal-poor stars in Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Venn, Kim A.; Jablonka, Pascale; Hill, Vanessa; Starkenburg, Else; Lemasle, Bertrand; Shetrone, Matthew; Irwin, Mike; Norris, John; Yong, David; Gilmore, Gerry; Salvadori, Stephania; Skuladottir, Asa; Tolstoy, Eline

    2016-08-01

    Stars in low-mass dwarf galaxies show a larger range in their chemical properties than those in the Milky Way halo. The slower star formation efficiency make dwarf galaxies ideal systems for testing nucleosynthetic yields. Not only are alpha-poor stars found at lower metallicities, and a higher fraction of carbon-enhanced stars, but we are also finding stars in dwarf galaxies that appear to be iron-rich. These are compared with yields from a variety of supernova predictions.

  3. Inhomogeneous chemical enrichment in the Galactic Halo

    NASA Astrophysics Data System (ADS)

    Kobayashi, Chiaki

    2016-08-01

    In a galaxy, chemical enrichment takes place in an inhomogeneous fashion, and the Galactic Halo is one of the places where the inhomogeneous effects are imprinted and can be constrained from observations. I show this using my chemodynamical simulations of Milky Way type galaxies. The scatter in the elemental abundances originate from radial migration, merging/accretion of satellite galaxies, local variation of star formation and chemical enrichment, and intrinsic variation of nucleosynthesis yields. In the simulated galaxies, there is no strong age-metallicity relation. This means that the most metal-poor stars are not always the oldest stars, and can be formed in chemically unevolved clouds at later times. The long-lifetime sources of chemical enrichment such as asymptotic giant branch stars or neutron star mergers can contribute at low metallicities. The intrinsic variation of yields are important in the early Universe or metal-poor systems such as in the Galactic halo. The carbon enhancement of extremely metal-poor (EMP) stars can be best explained by faint supernovae, the low [α/Fe] ratios in some EMP stars naturally arise from low-mass (~ 13 - 15M ⊙) supernovae, and finally, the [α/Fe] knee in dwarf spheroidal galaxies can be produced by subclasses of Type Ia supernovae such as SN 2002cx-like objects and sub-Chandrasekhar mass explosions.

  4. Gluphosate Glufosinate-Ammonium, and Atrazine Applications Do Not Affect Grain Yields or Quality of Resistant Corn Hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advent of glyphosate and glufosinate-ammonium resistant corn hybrids has expanded the number of weed species in corn that can be chemically controlled. Research at Stoneville, MS examined the possible influence these herbicides and atrazine might have on growth, yield, and mycotoxin incidence o...

  5. Revision of the JENDL FP Fission Yield Data

    NASA Astrophysics Data System (ADS)

    Katakura, Jun-ichi; Minato, Futoshi; Ohgama, Kazuya

    2016-03-01

    Some fission yields data of JENDL FP Fission Yields Data File 2011 (JENDL/FPY-2011) revealed inadequacies when applied to delayed neutron related subjects. The sensitivity analyses of decay heat summation calculations also showed some problems. From these results the fission yields of JENDL/FPY-2011 have been revised. The present report describes the revision of the yield data by emphasizing the sensitivity analyses.

  6. Modeling the impact of bubbling bed hydrodynamics on tar yield and its fluctuations during biomass fast pyrolysis

    SciTech Connect

    Xiong, Qingang; Ramirez, Emilio; Pannala, Sreekanth; Daw, C. Stuart; Xu, Fei

    2015-10-09

    The impact of bubbling bed hydrodynamics on temporal variations in the exit tar yield for biomass fast pyrolysis was investigated using computational simulations of an experimental laboratory-scale reactor. A multi-fluid computational fluid dynamics model was employed to simulate the differential conservation equations in the reactor, and this was combined with a multi-component, multi-step pyrolysis kinetics scheme for biomass to account for chemical reactions. The predicted mean tar yields at the reactor exit appear to match corresponding experimental observations. Parametric studies predicted that increasing the fluidization velocity should improve the mean tar yield but increase its temporal variations. Increases in the mean tar yield coincide with reducing the diameter of sand particles or increasing the initial sand bed height. However, trends in tar yield variability are more complex than the trends in mean yield. The standard deviation in tar yield reaches a maximum with changes in sand particle size. As a result, the standard deviation in tar yield increases with the increases in initial bed height in freely bubbling state, while reaches a maximum in slugging state.

  7. Modeling the impact of bubbling bed hydrodynamics on tar yield and its fluctuations during biomass fast pyrolysis

    DOE PAGESBeta

    Xiong, Qingang; Ramirez, Emilio; Pannala, Sreekanth; Daw, C. Stuart; Xu, Fei

    2015-10-09

    The impact of bubbling bed hydrodynamics on temporal variations in the exit tar yield for biomass fast pyrolysis was investigated using computational simulations of an experimental laboratory-scale reactor. A multi-fluid computational fluid dynamics model was employed to simulate the differential conservation equations in the reactor, and this was combined with a multi-component, multi-step pyrolysis kinetics scheme for biomass to account for chemical reactions. The predicted mean tar yields at the reactor exit appear to match corresponding experimental observations. Parametric studies predicted that increasing the fluidization velocity should improve the mean tar yield but increase its temporal variations. Increases in themore » mean tar yield coincide with reducing the diameter of sand particles or increasing the initial sand bed height. However, trends in tar yield variability are more complex than the trends in mean yield. The standard deviation in tar yield reaches a maximum with changes in sand particle size. As a result, the standard deviation in tar yield increases with the increases in initial bed height in freely bubbling state, while reaches a maximum in slugging state.« less

  8. Total chemical management in photographic processing

    USGS Publications Warehouse

    Luden, Charles; Schultz, Ronald

    1985-01-01

    The mission of the U. S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center is to produce high-quality photographs of the earth taken from aircraft and Landsat satellite. In order to meet the criteria of producing research-quality photographs, while at the same time meeting strict environmental restrictions, a total photographic chemical management system was installed. This involved a three-part operation consisting of the design of a modern chemical analysis laboratory, the implementation of a chemical regeneration system, and the installation of a waste treatment system, including in-plant pretreatment and outside secondary waste treatment. Over the last ten years the result of this program has yielded high-quality photographs while saving approximately 30,000 per year and meeting all Environmental Protection Agency (EPA) restrictions.

  9. 7 CFR 760.638 - Determination of SURE yield.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Determination of SURE yield. 760.638 Section 760.638....638 Determination of SURE yield. (a) Except for value loss crops as specified in § 760.634, a SURE yield will be determined for each crop, type, and intended use on a farm, using the higher of...

  10. 7 CFR 1437.105 - Determining payments for low yield.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Determining payments for low yield. 1437.105 Section... ASSISTANCE PROGRAM Determining Yield Coverage Using Actual Production History § 1437.105 Determining payments for low yield. (a) Except to the extent that the loss calculation provisions of other subparts...

  11. 24 CFR 320.8 - Excess Yield Securities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Excess Yield Securities. 320.8... MORTGAGE-BACKED SECURITIES Pass-Through Type Securities § 320.8 Excess Yield Securities. (a) Definition. Excess Yield Securities are securities backed by the excess servicing income relating to...

  12. 24 CFR 320.8 - Excess Yield Securities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Excess Yield Securities. 320.8... MORTGAGE-BACKED SECURITIES Pass-Through Type Securities § 320.8 Excess Yield Securities. (a) Definition. Excess Yield Securities are securities backed by the excess servicing income relating to...

  13. Raising yield potential in wheat: increasing photosynthesis capacity and efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing wheat yields to help to ensure food security is a major challenge. Meeting this challenge requires a quantum improvement in the yield potential of wheat. Past increases in yield potential have largely resulted from improvements in harvest index not through increased biomass. Further large...

  14. Solid Surface Combustion Experiment Yields Significant Observations

    NASA Technical Reports Server (NTRS)

    Sacksteder, Kurt R.; Koudelka, John M.; Vergilii, Franklin

    1999-01-01

    The spread of a flame over solid fuel is not only a fundamental textbook combustion phenomenon, but also the central element of destructive fires that cause tragic loss of life and property each year. Throughout history, practical measures to prevent and fight fires have been developed, but these have often been based on lessons learned in a costly fire. Since the 1960 s, scientists and engineers have employed powerful tools of scientific research to understand the details of flame spread and how a material can be rendered nonflammable. High-speed computers have enabled complex flame simulations, whereasand lasers have provided measurements of the chemical composition, temperature, and air velocities inside flames. The microgravity environment has emerged as the third great tool for these studies. Spreading flames are complex combinations of chemical reactions and several physical processes including the transport of oxygen and fuel vapor to the flame and the transfer of heat from the flame to fresh fuel and to the surroundings. Depending on its speed, air motion in the vicinity of the flame can affect the flame in substantially different ways. For example, consider the difference between blowing on a campfire and blowing out a match. On Earth, gravity induces air motion because of buoyancy (the familiar rising hot gases); this process cannot be controlled experimentally. For theoreticians, buoyant air motion complicates the problem modeling of flame spread beyond the capacity of modern computers to simulate. The microgravity environment provides experimental control of air motion near spreading flames, with results that can be compared with detailed theory. The Solid Surface Combustion Experiment (SSCE) was designed to obtain benchmark flame spreading data in quiescent test atmospheres--the limiting case of flames spreading. Professor Robert Altenkirch, Vice President for Research at Mississippi State University, proposed the experiment concept, and the NASA Lewis

  15. Methane Yield Database: Online infrastructure and bioresource for methane yield data and related metadata.

    PubMed

    Murovec, Boštjan; Kolbl, Sabina; Stres, Blaž

    2015-01-01

    The aim of this study was to develop and validate a community supported online infrastructure and bioresource for methane yield data and accompanying metadata collected from published literature. In total, 1164 entries described by 15,749 data points were assembled. Analysis of data collection showed little congruence in reporting of methodological approaches. The largest identifiable source of variation in reported methane yields was represented by authorship (i.e. substrate batches within particular substrate class) within which experimental scales (volumes (0.02-5l), incubation temperature (34-40 °C) and % VS of substrate played an important role (p < 0.05, npermutations = 999) as well. The largest fraction of variability, however, remained unaccounted for and thus unexplained (> 63%). This calls for reconsideration of accepted approaches to reporting data in currently published literature to increase capacity to service industrial decision making to a greater extent. PMID:25898082

  16. Dynamical and chemical evolution of NGC 1569

    NASA Astrophysics Data System (ADS)

    Recchi, S.; Hensler, G.; Angeretti, L.; Matteucci, F.

    2006-01-01

    Blue Compact Dwarf and Dwarf Irregular galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Many of these objects show an ongoing intense burst of star formation or have experienced it in the recent past. By means of 2-D hydrodynamical simulations, coupled with detailed chemical yields originating from SNeII, SNeIa, and intermediate-mass stars, we study the dynamical and chemical evolution of model galaxies with structural parameters similar to NGC 1569, a prototypical starburst galaxy. A burst of star formation with short duration is not able to account for the chemical and morphological properties of this galaxy. The best way to reproduce the chemical composition of this object is by assuming long-lasting episodes of star formation and a more recent burst, separated from the previous episodes by a short quiescent period. The last burst of star formation, in most of the explored cases, does not affect the chemical composition of the galaxy, since the enriched gas produced by young stars is in a too hot phase to be detectable with the optical spectroscopy. Models assuming the infall of a big cloud towards the center of the galaxy reproduce the chemical composition of the NGC 1569, but the pressure exercised by the cloud hampers the expansion of the galactic wind, at variance with what observed in NGC 1569.

  17. Chemical Microsensor Development for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Xu, Jennifer C.; Hunter, Gary W.; Lukco, Dorothy; Chen, Liangyu; Biaggi-Labiosa, Azlin M.

    2013-01-01

    Numerous aerospace applications, including low-false-alarm fire detection, environmental monitoring, fuel leak detection, and engine emission monitoring, would benefit greatly from robust and low weight, cost, and power consumption chemical microsensors. NASA Glenn Research Center has been working to develop a variety of chemical microsensors with these attributes to address the aforementioned applications. Chemical microsensors using different material platforms and sensing mechanisms have been produced. Approaches using electrochemical cells, resistors, and Schottky diode platforms, combined with nano-based materials, high temperature solid electrolytes, and room temperature polymer electrolytes have been realized to enable different types of microsensors. By understanding the application needs and chemical gas species to be detected, sensing materials and unique microfabrication processes were selected and applied. The chemical microsensors were designed utilizing simple structures and the least number of microfabrication processes possible, while maintaining high yield and low cost. In this presentation, an overview of carbon dioxide (CO2), oxygen (O2), and hydrogen/hydrocarbons (H2/CxHy) microsensors and their fabrication, testing results, and applications will be described. Particular challenges associated with improving the H2/CxHy microsensor contact wire-bonding pad will be discussed. These microsensors represent our research approach and serve as major tools as we expand our sensor development toolbox. Our ultimate goal is to develop robust chemical microsensor systems for aerospace and commercial applications.

  18. Radiation chemical effects of X-rays on liquids

    SciTech Connect

    Holroyd, R.A.; Preses, J.M.

    1998-11-01

    This review describes some of the chemical changes induced by photoelectrons which are released in liquids when X-rays are absorbed. Both experimental studies and theory are discussed. In part 1, the basic processes occurring upon absorption of X-rays are described. Parts 2 and 3 deal with hydrocarbon liquids; in part 2 the ion yields, including effects at K-edges, and in part 3, the yields of excited states. Part 4 discusses chemical effects of X-rays in aqueous solutions. The authors end with a summary of future needs and directions.

  19. High-yield maize with large net energy yield and small global warming intensity.

    PubMed

    Grassini, Patricio; Cassman, Kenneth G

    2012-01-24

    Addressing concerns about future food supply and climate change requires management practices that maximize productivity per unit of arable land while reducing negative environmental impact. On-farm data were evaluated to assess energy balance and greenhouse gas (GHG) emissions of irrigated maize in Nebraska that received large nitrogen (N) fertilizer (183 kg of N · ha(-1)) and irrigation water inputs (272 mm or 2,720 m(3) ha(-1)). Although energy inputs (30 GJ · ha(-1)) were larger than those reported for US maize systems in previous studies, irrigated maize in central Nebraska achieved higher grain and net energy yields (13.2 Mg · ha(-1) and 159 GJ · ha(-1), respectively) and lower GHG-emission intensity (231 kg of CO(2)e · Mg(-1) of grain). Greater input-use efficiencies, especially for N fertilizer, were responsible for better performance of these irrigated systems, compared with much lower-yielding, mostly rainfed maize systems in previous studies. Large variation in energy inputs and GHG emissions across irrigated fields in the present study resulted from differences in applied irrigation water amount and imbalances between applied N inputs and crop N demand, indicating potential to further improve environmental performance through better management of these inputs. Observed variation in N-use efficiency, at any level of applied N inputs, suggests that an N-balance approach may be more appropriate for estimating soil N(2)O emissions than the Intergovernmental Panel on Climate Change approach based on a fixed proportion of applied N. Negative correlation between GHG-emission intensity and net energy yield supports the proposition that achieving high yields, large positive energy balance, and low GHG emissions in intensive cropping systems are not conflicting goals. PMID:22232684

  20. High-yield maize with large net energy yield and small global warming intensity

    PubMed Central

    Grassini, Patricio; Cassman, Kenneth G.

    2012-01-01

    Addressing concerns about future food supply and climate change requires management practices that maximize productivity per unit of arable land while reducing negative environmental impact. On-farm data were evaluated to assess energy balance and greenhouse gas (GHG) emissions of irrigated maize in Nebraska that received large nitrogen (N) fertilizer (183 kg of N⋅ha−1) and irrigation water inputs (272 mm or 2,720 m3 ha−1). Although energy inputs (30 GJ⋅ha−1) were larger than those reported for US maize systems in previous studies, irrigated maize in central Nebraska achieved higher grain and net energy yields (13.2 Mg⋅ha−1 and 159 GJ⋅ha−1, respectively) and lower GHG-emission intensity (231 kg of CO2e⋅Mg−1 of grain). Greater input-use efficiencies, especially for N fertilizer, were responsible for better performance of these irrigated systems, compared with much lower-yielding, mostly rainfed maize systems in previous studies. Large variation in energy inputs and GHG emissions across irrigated fields in the present study resulted from differences in applied irrigation water amount and imbalances between applied N inputs and crop N demand, indicating potential to further improve environmental performance through better management of these inputs. Observed variation in N-use efficiency, at any level of applied N inputs, suggests that an N-balance approach may be more appropriate for estimating soil N2O emissions than the Intergovernmental Panel on Climate Change approach based on a fixed proportion of applied N. Negative correlation between GHG-emission intensity and net energy yield supports the proposition that achieving high yields, large positive energy balance, and low GHG emissions in intensive cropping systems are not conflicting goals. PMID:22232684

  1. Has the use of talc an effect on yield and extra virgin olive oil quality?

    PubMed

    Caponio, Francesco; Squeo, Giacomo; Difonzo, Graziana; Pasqualone, Antonella; Summo, Carmine; Paradiso, Vito Michele

    2016-08-01

    The maximization of both extraction yield and extra virgin olive oil quality during olive processing are the main objectives of the olive oil industry. As regards extraction yield, it can be improved by both acting on time/temperature of malaxation and using physical coadjuvants. It is well known that, generally, increasing temperature of malaxation gives an increase in oil extraction yield due to a reduction in oily phase viscosity; however, high malaxation temperature can compromise the nutritional and health values of extra virgin olive oil, leading to undesirable effects such as accelerated oxidative process and loss of volatile compounds responsible for oil flavor and fragrance. The addition of physical coadjuvants in olive oil processing during the malaxation phase, not excluded by EC regulations owing to its exclusively physical action, is well known to promote the breakdown of oil/water emulsions and consequently make oil extraction easier, thus increasing the yield. Among physical coadjuvants, micronized natural talc is used for olive oil processing above all for Spanish and Italian olive cultivars. The quality of extra virgin olive oil depends on numerous variables such as olive cultivar, ripeness degree and quality, machines utilized for processing, oil storage conditions, etc. However, the coadjuvants utilized in olive processing can also influence virgin olive oil characteristics. The literature highlights an increase in oil yield by micronized natural talc addition during olive processing, whereas no clear trend was observed as regards the chemical, nutritional and sensory characteristics of extra virgin olive oil. Although an increase in oil stability was reported, no effect of talc was found on the evolution of virgin olive oil quality indices during storage. © 2016 Society of Chemical Industry. PMID:26847164

  2. The effects of presalting methods from injection to pickling, on the yields of heavily salted cod (Gadus morhua).

    PubMed

    Thorarinsdottir, Kristin Anna; Arason, Sigurjon; Thorkelsson, Gudjon; Sigurgisladottir, Sjofn; Tornberg, Eva

    2010-10-01

    The production of heavy-salted cod (Bacalao) has changed from being a single-step process (kench) salting to a multistep procedure varying between producers and countries. Presalting by injection, brining, or pickling is increasingly applied prior to pile (dry) salting. This article describes the effects of different presalting methods (injection and brining, brining only, and pickling) on yield and chemical composition of salted cod fillets, in comparison to a single-kench salting step. The procedures used influenced the weight yields and chemical composition of the products. Injection was significantly different from other methods in increasing weight yields throughout brining, dry salting, and rehydration. The yield of nitrogenous compounds tended to be lower for injected and brine-salted fillets, mainly due to higher losses of nonprotein nitrogen. Practical Application: Salting procedures for cod have changed rapidly in recent years. Injection is increasingly used as a presalting method. It has been suggested to have strong effects on weight yields of salted cod products. This article describes the effects of injection on weight yields on products in salted, rehydrated, and cooked stage. PMID:21535494

  3. Global Agriculture Yields and Conflict under Future Climate

    NASA Astrophysics Data System (ADS)

    Rising, J.; Cane, M. A.

    2013-12-01

    Aspects of climate have been shown to correlate significantly with conflict. We investigate a possible pathway for these effects through changes in agriculture yields, as predicted by field crop models (FAO's AquaCrop and DSSAT). Using satellite and station weather data, and surveyed data for soil and management, we simulate major crop yields across all countries between 1961 and 2008, and compare these to FAO and USDA reported yields. Correlations vary by country and by crop, from approximately .8 to -.5. Some of this range in crop model performance is explained by crop varieties, data quality, and other natural, economic, and political features. We also quantify the ability of AquaCrop and DSSAT to simulate yields under past cycles of ENSO as a proxy for their performance under changes in climate. We then describe two statistical models which relate crop yields to conflict events from the UCDP/PRIO Armed Conflict dataset. The first relates several preceding years of predicted yields of the major grain in each country to any conflict involving that country. The second uses the GREG ethnic group maps to identify differences in predicted yields between neighboring regions. By using variation in predicted yields to explain conflict, rather than actual yields, we can identify the exogenous effects of weather on conflict. Finally, we apply precipitation and temperature time-series under IPCC's A1B scenario to the statistical models. This allows us to estimate the scale of the impact of future yields on future conflict. Centroids of the major growing regions for each country's primary crop, based on USDA FAS consumption. Correlations between simulated yields and reported yields, for AquaCrop and DSSAT, under the assumption that no irrigation, fertilization, or pest control is used. Reported yields are the average of FAO yields and USDA FAS yields, where both are available.

  4. Quantifying yield gaps in wheat production in Russia

    NASA Astrophysics Data System (ADS)

    Schierhorn, Florian; Faramarzi, Monireh; Prishchepov, Alexander V.; Koch, Friedrich J.; Müller, Daniel

    2014-08-01

    Crop yields must increase substantially to meet the increasing demands for agricultural products. Crop yield increases are particularly important for Russia because low crop yields prevail across Russia’s widespread and fertile land resources. However, reliable data are lacking regarding the spatial distribution of potential yields in Russia, which can be used to determine yield gaps. We used a crop growth model to determine the yield potentials and yield gaps of winter and spring wheat at the provincial level across European Russia. We modeled the annual yield potentials from 1995 to 2006 with optimal nitrogen supplies for both rainfed and irrigated conditions. Overall, the results suggest yield gaps of 1.51-2.10 t ha-1, or 44-52% of the yield potential under rainfed conditions. Under irrigated conditions, yield gaps of 3.14-3.30 t ha-1, or 62-63% of the yield potential, were observed. However, recurring droughts cause large fluctuations in yield potentials under rainfed conditions, even when the nitrogen supply is optimal, particularly in the highly fertile black soil areas of southern European Russia. The highest yield gaps (up to 4 t ha-1) under irrigated conditions were detected in the steppe areas in southeastern European Russia along the border of Kazakhstan. Improving the nutrient and water supply and using crop breeds that are adapted to the frequent drought conditions are important for reducing yield gaps in European Russia. Our regional assessment helps inform policy and agricultural investors and prioritize research that aims to increase crop production in this important region for global agricultural markets.

  5. A versatile detector for total fluorescence and electron yield experiments

    SciTech Connect

    Thielemann, N.; Hoffmann, P.; Foehlisch, A.

    2012-09-15

    The combination of a non-coated silicon photodiode with electron repelling meshes makes a versatile detector for total fluorescence yield and electron yield techniques highly suitable for x-ray absorption spectroscopy. In particular, a copper mesh with a bias voltage allows to suppress or transmit the electron yield signal. The performance of this detection scheme has been characterized by near edge x-ray absorption fine structure studies of thermal oxidized silicon and sapphire. The results show that the new detector probes both electron yield and for a bias voltage exceeding the maximum photon energy the total fluorescence yield.

  6. Simple chemical transformation of lignocellulosic biomass into furans for fuels and chemicals.

    PubMed

    Binder, Joseph B; Raines, Ronald T

    2009-02-11

    Lignocellulosic biomass is a plentiful and renewable resource for fuels and chemicals. Despite this potential, nearly all renewable fuels and chemicals are now produced from edible resources, such as starch, sugars, and oils; the challenges imposed by notoriously recalcitrant and heterogeneous lignocellulosic feedstocks have made their production from nonfood biomass inefficient and uneconomical. Here, we report that N,N-dimethylacetamide (DMA) containing lithium chloride (LiCl) is a privileged solvent that enables the synthesis of the renewable platform chemical 5-hydroxymethylfurfural (HMF) in a single step and unprecedented yield from untreated lignocellulosic biomass, as well as from purified cellulose, glucose, and fructose. The conversion of cellulose into HMF is unabated by the presence of other biomass components, such as lignin and protein. Mechanistic analyses reveal that loosely ion-paired halide ions in DMA-LiCl are critical for the remarkable rapidity (1-5 h) and yield (up to 92%) of this low-temperature (chemical transformation of lignocellulose contrasts markedly with the complexity of extant bioprocesses and provides a new paradigm for the use of biomass as a raw material for a renewable energy and chemical industries. PMID:19159236

  7. Groundwater management under sustainable yield uncertainty

    NASA Astrophysics Data System (ADS)

    Delottier, Hugo; Pryet, Alexandre; Dupuy, Alain

    2015-04-01

    The definition of the sustainable yield (SY) of a groundwater system consists in adjusting pumping rates so as to avoid groundwater depletion and preserve environmental flows. Once stakeholders have defined which impacts can be considered as "acceptable" for both environmental and societal aspects, hydrogeologists use groundwater models to estimate the SY. Yet, these models are based on a simplification of actual groundwater systems, whose hydraulic properties are largely unknown. As a result, the estimated SY is subject to "predictive" uncertainty. We illustrate the issue with a synthetic homogeneous aquifer system in interaction with a stream for steady state and transient conditions. Simulations are conducted with the USGS MODFLOW finite difference model with the river-package. A synthetic dataset is first generated with the numerical model that will further be considered as the "observed" state. In a second step, we conduct the calibration operation as hydrogeologists dealing with real word, unknown groundwater systems. The RMSE between simulated hydraulic heads and the synthetic "observed" values is used as objective function. But instead of simply "calibrating" model parameters, we explore the value of the objective function in the parameter space (hydraulic conductivity, storage coefficient and total recharge). We highlight the occurrence of an ellipsoidal "null space", where distinct parameter sets lead to equally low values for the objective function. The optimum of the objective function is not unique, which leads to a range of possible values for the SY. With a large confidence interval for the SY, the use of modeling results for decision-making is challenging. We argue that prior to modeling operations, efforts must be invested so as to narrow the intervals of likely parameter values. Parameter space exploration is effective to estimate SY uncertainty, but not efficient because of its computational burden and is therefore inapplicable for real world

  8. Suspended sediment yield in Texas watersheds

    NASA Astrophysics Data System (ADS)

    Coonrod, Julia Ellen Allred

    The Texas Water Development Board collected suspended sediment samples across the state of Texas for approximately 60 years. Until this research, no comprehensive analysis of the data had been conducted. This study compiles the suspended sediment data along with corresponding streamflow and rainfall. GIS programs are developed which characterize watersheds corresponding to the sediment gauging stations. The watersheds are characterized according to topography, climate, soils, and land use. All of the data is combined to form several SAS data sets which can subsequently be analyzed using regression. Annual data for all of the stations across the state are classified temporally and spatially to determine trends in the sediment yield. In general, the suspended sediment load increases with increasing runoff but no correlation exists with rainfall. However, the annual average rainfall can be used to classify the watersheds according to climate, which improves the correlation between sediment load and runoff. The watersheds with no dams have higher sediment loads than watersheds with dams. Dams in the drier parts of Texas reduce the sediment load more than dams in the wetter part of the state. Sediment rating curves are developed separately for each basin in Texas. All but one of the curves fall into a band which varies by about two orders of magnitude. The study analyzes daily time series data for the Lavaca River near Edna station. USGS data are used to improve the sediment rating curve by the addition of physically related variables and interaction terms. The model can explain an additional 41% of the variability in sediment concentration compared to a simple bivariate regression of sediment load and flow. The TWDB daily data for the Lavaca River near Edna station are used to quantify temporal trends. There is a high correlation between sediment load and flowrate for the Lavaca River. The correlation can be improved by considering a flow-squared term and by

  9. Weather-based forecasts of California crop yields

    SciTech Connect

    Lobell, D B; Cahill, K N; Field, C B

    2005-09-26

    Crop yield forecasts provide useful information to a range of users. Yields for several crops in California are currently forecast based on field surveys and farmer interviews, while for many crops official forecasts do not exist. As broad-scale crop yields are largely dependent on weather, measurements from existing meteorological stations have the potential to provide a reliable, timely, and cost-effective means to anticipate crop yields. We developed weather-based models of state-wide yields for 12 major California crops (wine grapes, lettuce, almonds, strawberries, table grapes, hay, oranges, cotton, tomatoes, walnuts, avocados, and pistachios), and tested their accuracy using cross-validation over the 1980-2003 period. Many crops were forecast with high accuracy, as judged by the percent of yield variation explained by the forecast, the number of yields with correctly predicted direction of yield change, or the number of yields with correctly predicted extreme yields. The most successfully modeled crop was almonds, with 81% of yield variance captured by the forecast. Predictions for most crops relied on weather measurements well before harvest time, allowing for lead times that were longer than existing procedures in many cases.

  10. Miniature chemical measurement systems

    SciTech Connect

    Ramsey, J.M.

    1996-12-31

    Prospect of microfabricated monolithic devices that accomplish complete chemical assays is enticing. Early work with microfabricated chemical analysis devices focused on separations methods. More recently reagent manipulation has been integrated with separation devices to create more powerful capabilities. Examples of procedures, other than separations, that have been demonstrated on micromachined structures include reagent mixing, dilution, and reaction, preconcentration through sample stacking and biopolymer tagging for detection. Developments in liquid phase microfabricated chemical analysis devices are reviewed.

  11. Excimer laser chemical problems

    SciTech Connect

    Tennant, R.; Peterson, N.

    1982-01-01

    Techniques need to be developed to maintain XeF and XeCl laser performance over long periods of time without degradation resulting from chemical processes occurring within the laser. The dominant chemical issues include optical damage, corrosions of laser materials, gas contamination, and control of halogen concentration. Each of these issues are discussed and summarized. The methods of minimizing or controlling the chemical processes involved are presented.

  12. Field emission chemical sensor

    DOEpatents

    Panitz, J.A.

    1983-11-22

    A field emission chemical sensor for specific detection of a chemical entity in a sample includes a closed chamber enclosing two field emission electrode sets, each field emission electrode set comprising (a) an electron emitter electrode from which field emission electrons can be emitted when an effective voltage is connected to the electrode set; and (b) a collector electrode which will capture said electrons emitted from said emitter electrode. One of the electrode sets is passive to the chemical entity and the other is active thereto and has an active emitter electrode which will bind the chemical entity when contacted therewith.

  13. Chemically Layered Porous Solids

    NASA Technical Reports Server (NTRS)

    Koontz, Steve

    1991-01-01

    Aerogels and other porous solids in which surfaces of pores have chemical properties varying with depth below macroscopic surfaces prepared by sequences of chemical treatments. Porous glass or silica bead treated to make two depth zones having different chemical properties. Beads dropped along tube filled with flowing gas containing atomic oxygen, generated in microwave discharge. General class of materials treatable include oxides of aluminum, silicon, zirconium, tin, titanium, and nickel, and mixtures of these oxides. Potential uses of treated materials include chromatographic separations, membrane separations, controlled releases of chemicals, and catalysis.

  14. Chemical Processing Manual

    NASA Technical Reports Server (NTRS)

    Beyerle, F. J.

    1972-01-01

    Chemical processes presented in this document include cleaning, pickling, surface finishes, chemical milling, plating, dry film lubricants, and polishing. All types of chemical processes applicable to aluminum, for example, are to be found in the aluminum alloy section. There is a separate section for each category of metallic alloy plus a section for non-metals, such as plastics. The refractories, super-alloys and titanium, are prime candidates for the space shuttle, therefore, the chemical processes applicable to these alloys are contained in individual sections of this manual.

  15. Apparatus for chemical synthesis

    DOEpatents

    Kong, Peter C.; Herring, J. Stephen; Grandy, Jon D.

    2011-05-10

    A method and apparatus for forming a chemical hydride is described and which includes a pseudo-plasma-electrolysis reactor which is operable to receive a solution capable of forming a chemical hydride and which further includes a cathode and a movable anode, and wherein the anode is moved into and out of fluidic, ohmic electrical contact with the solution capable of forming a chemical hydride and which further, when energized produces an oxygen plasma which facilitates the formation of a chemical hydride in the solution.

  16. 310 Facility chemical specifications

    SciTech Connect

    Hagerty, K.J.

    1997-05-21

    The 300 area Treated Effluent Disposal Facility (TEDF) was designed and built to treat the waste water from the 300 area process sewer system. Several treatment technologies are employed to remove the trace quantities of contaminants in the stream, including iron coprecipitation, clarification, filtration, ion exchange, and ultra violet light/hydrogen peroxide oxidation of organics. The chemicals that will be utilized in the treatment process are hydrogen peroxide, sulfuric acid, sodium hydroxide, and ferric chloride. This document annotates the required chemical characteristics of TEDF bulk chemicals as well as the criteria that were used to establish these criteria. The chemical specifications in appendix B are generated from this information.

  17. CHEMICAL CATEGORIES IN EPA'S NEW CHEMICALS PROGRAM

    EPA Science Inventory

    Under section 5 of the Toxic Substances Control Act (TSCA),any person who intends to manufacture or import a new chemical substance, or mixture containing such a substance, in the United States for commercial purposes must submit a premanufacture notice (PMN) to the Environmental...

  18. The yield and decay coefficients of exoelectrogenic bacteria in bioelectrochemical systems.

    PubMed

    Wilson, Erica L; Kim, Younggy

    2016-05-01

    In conventional wastewater treatment, waste sludge management and disposal contribute the major cost for wastewater treatment. Bioelectrochemical systems, as a potential alternative for future wastewater treatment and resources recovery, are expected to produce small amounts of waste sludge because exoelectrogenic bacteria grow on anaerobic respiration and form highly populated biofilms on bioanode surfaces. While waste sludge production is governed by the yield and decay coefficient, none of previous studies have quantified these kinetic constants for exoelectrogenic bacteria. For yield coefficient estimation, we modified McCarty's free energy-based model by using the bioanode potential for the free energy of the electron acceptor reaction. The estimated true yield coefficient ranged 0.1 to 0.3 g-VSS (volatile suspended solids) g-COD(-1) (chemical oxygen demand), which is similar to that of most anaerobic microorganisms. The yield coefficient was sensitively affected by the bioanode potential and pH while the substrate and bicarbonate concentrations had relatively minor effects on the yield coefficient. In lab-scale experiments using microbial electrolysis cells, the observed yield coefficient (including the effect of cell decay) was found to be 0.020 ± 0.008 g-VSS g-COD(-1), which is an order of magnitude smaller than the theoretical estimation. Based on the difference between the theoretical and experimental results, the decay coefficient was approximated to be 0.013 ± 0.002 d(-1). These findings indicate that bioelectrochemical systems have potential for future wastewater treatment with reduced waste sludge as well as for resources recovery. Also, the found kinetic information will allow accurate estimation of wastewater treatment performance in bioelectrochemical systems. PMID:26963605

  19. Biochar effect on maize yield and soil characteristics in five conservation farming sites in Zambia

    USGS Publications Warehouse

    Cornelissen, Gerard; Martinsen, Vegard; Shitumbanuma, Victor; Alling, Vanja; Breedveld, Gijs D.; Rutherford, David W.; Sparrevik, Magnus; Hale, Sarah E.; Obia, Alfred; Mulder, Jan

    2013-01-01

    Biochar addition to agricultural soils can improve soil fertility, with the added bonus of climate change mitigation through carbon sequestration. Conservation farming (CF) is precision farming, often combining minimum tillage, crop rotation and residue retention. In the present farmer-led field trials carried out in Zambia, the use of a low dosage biochar combined with CF minimum tillage was tested as a way to increase crop yields. Using CF minimum tillage allows the biochar to be applied to the area where most of the plant roots are present and mirrors the fertilizer application in CF practices. The CF practice used comprised manually hoe-dug planting 10-L sized basins, where 10%–12% of the land was tilled. Pilot trials were performed with maize cob biochar and wood biochar on five soils with variable physical/chemical characteristics. At a dosage as low as 4 tons/ha, both biochars had a strong positive effect on maize yields in the coarse white aeolian sand of Kaoma, West-Zambia, with yields of 444% ± 114% (p = 0.06) and 352% ± 139% (p = 0.1) of the fertilized reference plots for maize and wood biochar, respectively. Thus for sandy acidic soils, CF and biochar amendment can be a promising combination for increasing harvest yield. Moderate but non-significant effects on yields were observed for maize and wood biochar in a red sandy clay loam ultisol east of Lusaka, central Zambia (University of Zambia, UNZA, site) with growth of 142% ± 42% (p > 0.2) and 131% ± 62% (p > 0.2) of fertilized reference plots, respectively. For three other soils (acidic and neutral clay loams and silty clay with variable cation exchange capacity, CEC), no significant effects on maize yields were observed (p > 0.2). In laboratory trials, 5% of the two biochars were added to the soil samples in order to study the effect of the biochar on physical and chemical soil characteristics. The large increase in crop yield in Kaoma soil was tentatively explained by a combination of an

  20. Closing yield gaps: perils and possibilities for biodiversity conservation

    PubMed Central

    Phalan, Ben; Green, Rhys; Balmford, Andrew

    2014-01-01

    Increasing agricultural productivity to ‘close yield gaps’ creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms. PMID:24535392

  1. Maximizing DNA yield for epidemiologic studies: no more buffy coats?

    PubMed

    Gail, Mitchell H; Sheehy, Tim; Cosentino, Mark; Pee, David; Diaz-Mayoral, Norma A; Garcia-Closas, Montserrat; Caporaso, Neil E; Pitt, Karen; Ziegler, Regina G

    2013-10-01

    Some molecular analyses require microgram quantities of DNA, yet many epidemiologic studies preserve only the buffy coat. In Frederick, Maryland, in 2010, we estimated DNA yields from 5 mL of whole blood and from equivalent amounts of all-cell-pellet (ACP) fraction, buffy coat, and residual blood cells from fresh blood (n = 10 volunteers) and from both fresh and frozen blood (n = 10). We extracted DNA with the QIAamp DNA Blood Midi Kit (Qiagen Sciences, Germantown, Maryland) for silica spin column capture and measured double-stranded DNA. Yields from frozen blood fractions were not statistically significantly different from those obtained from fresh fractions. ACP fractions yielded 80.6% (95% confidence interval: 66, 97) of the yield of frozen whole blood and 99.3% (95% confidence interval: 86, 100) of the yield of fresh blood. Frozen buffy coat and residual blood cells each yielded only half as much DNA as frozen ACP, and the yields were more variable. Assuming that DNA yield and quality from frozen ACP are stable, we recommend freezing plasma and ACP. Not only does ACP yield twice as much DNA as buffy coat but it is easier to process, and its yield is less variable from person to person. Long-term stability studies are needed. If one wishes to separate buffy coat before freezing, one should also save the residual blood cell fraction, which contains just as much DNA. PMID:23857774

  2. A yield line evaluation methodology for reinforced concrete structures

    SciTech Connect

    Mertz, G.E.

    1997-03-01

    Yield line theory is an analytical technique that can be used to determine the ultimate bending capacity of flat reinforced concrete plates. Alternately, yield line theory, combined with rotation limits, can be used to determine the energy absorption capacity of plates subjected to impulsive and impact loadings. Typical components analyzed by yield line theory are basements, floor and roof slabs subjected to vertical loads, and walls subjected to out of plane loadings. Yield line theory equates plastic strain energy to external work for postulated collapse mechanisms. Multiple collapse mechanisms are evaluated and the mechanism with the minimum strain energy corresponds to the collapse load. Numerous investigators have verified yield line theory by experiment. Analysis by yield line theory is currently accepted by the ACI-318 Building Code Requirements for Reinforced Concrete and ACI-349 Code Requirements for Nuclear Safety Related Concrete Structures. One limitation of yield line theory is that it is computational difficult to evaluate some collapse mechanism. This problem is aggravated by the complex geometry nd reinforcing layouts commonly found in practice. The Yield Line Evaluator (YLE) is a computer program which was developed to solve computationally tedious yield line mechanisms. The program has the capability to either evaluate a single user-defined mechanism or to iterate over a range of mechanisms to determine the minimum ultimate capacity. The program is verified by comparison to a series of yield line mechanisms with known solutions.

  3. Students Enjoy Chemical Sensation

    ERIC Educational Resources Information Center

    Barry, Dana M.; Kanematsu, Hideyuki

    2003-01-01

    This exciting new way of teaching high school/college chemistry combines music, visual aids, and chemical experiments in multi-sensory lessons that motivate students and provide them with meaningful learning experiences in science. The method, known as the Chemical Sensation Project, acknowledges that some individuals learn by seeing or hearing,…

  4. Chemical Reaction Problem Solving.

    ERIC Educational Resources Information Center

    Veal, William

    1999-01-01

    Discusses the role of chemical-equation problem solving in helping students predict reaction products. Methods for helping students learn this process must be taught to students and future teachers by using pedagogical skills within the content of chemistry. Emphasizes that solving chemical reactions should involve creative cognition where…

  5. Chemical Equation Balancing.

    ERIC Educational Resources Information Center

    Blakley, G. R.

    1982-01-01

    Reviews mathematical techniques for solving systems of homogeneous linear equations and demonstrates that the algebraic method of balancing chemical equations is a matter of solving a system of homogeneous linear equations. FORTRAN programs using this matrix method to chemical equation balancing are available from the author. (JN)

  6. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  7. Chemical Compositions of Stars

    NASA Astrophysics Data System (ADS)

    Leckrone, D.; Murdin, P.

    2000-11-01

    In 1835, in a famously inaccurate forecast, the French philosopher Auguste Comte wrote of stars that, `We understand the possibility of determining their shapes, their distances, their sizes and their movements; whereas we would never know how to study by any means their chemical composition…'. At the close of the 20th century the accurate measurement of the abundances of the chemical elements in...

  8. Chemicals in Everyday Life.

    ERIC Educational Resources Information Center

    Seymour, Raymond B.

    1987-01-01

    Discusses the dependencies of people on chemicals in various aspects of life. Describes some of the natural and synthetic chemicals currently used in food production, clothing, shelter, travel and exploration, sports and recreation, ventilation, heating and cooling, communications, decoration, sanitation, and education. (TW)

  9. Chemicals and Allied Products.

    ERIC Educational Resources Information Center

    Nelson, R. F.; Hovious, J. C.

    1978-01-01

    Presents a literature review of wastes from chemical industry, covering publications of 1976-77. This review covers: (1) wastewater treatment by-product type; (2) biological, and physical/chemical treatments; and (3) source treatment. A list of 80 references is also presented. (HM)

  10. Difficult Decisions: Chemical Warfare.

    ERIC Educational Resources Information Center

    Slesnick, Irwin L.; Miller, John A.

    1988-01-01

    Gives the background history and chemistry of modern day chemical warfare from World War I to the present. Provides discussion questions to stimulate deeper thinking on the issue. Contains a discussion activity called "Can New Chemical Weapons Lead to Humane Warfare?" (CW)

  11. Systems Chemical Biology

    PubMed Central

    Oprea, Tudor I.; Tropsha, Alexander; Faulon, Jean-Loup; Rintoul, Mark D.

    2009-01-01

    The increasing availability of data related to genes, proteins and their modulation by small molecules, paralleled by the emergence of simulation tools in systems biology, has provided a vast amount of biological information. However, there is a critical need to develop cheminformatics tools that can integrate chemical knowledge with these biological databases, with the goal of creating systems chemical biology. PMID:17637771

  12. Microorganisms and Chemical Pollution

    ERIC Educational Resources Information Center

    Alexander, M.

    1973-01-01

    Discusses the importance of microorganisms in chemical pollution and pollution abatement. Selected chemical pollutants are chosen to illustrate that microorganisms synthesize hazardous substances from reasonably innocuous precursors, while others act as excellent environmental decontaminating agents by removing undesirable natural and synthetic…

  13. Elemental Chemical Puzzlers

    ERIC Educational Resources Information Center

    Thomas, Nicholas C.

    2009-01-01

    This paper provides nine short chemically based puzzles or problems extensible for use with students from middle school to college. Some of these will strengthen students' recognition of individual elements and element names. Others require students to focus on the salient properties of given chemical elements.

  14. Chemical burn or reaction

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000059.htm Chemical burn or reaction To use the sharing features on this page, please enable JavaScript. Chemicals that touch skin can lead to a reaction on the skin, throughout the body, or both. ...

  15. Chemical reactions confined within carbon nanotubes.

    PubMed

    Miners, Scott A; Rance, Graham A; Khlobystov, Andrei N

    2016-08-22

    In this critical review, we survey the wide range of chemical reactions that have been confined within carbon nanotubes, particularly emphasising how the pairwise interactions between the catalysts, reactants, transition states and products of a particular molecular transformation with the host nanotube can be used to control the yields and distributions of products of chemical reactions. We demonstrate that nanoscale confinement within carbon nanotubes enables the control of catalyst activity, morphology and stability, influences the local concentration of reactants and products thus affecting equilibria, rates and selectivity, pre-arranges the reactants for desired reactions and alters the relative stability of isomeric products. We critically evaluate the relative advantages and disadvantages of the confinement of chemical reactions inside carbon nanotubes from a chemical perspective and describe how further developments in the controlled synthesis of carbon nanotubes and the incorporation of multifunctionality are essential for the development of this ever-expanding field, ultimately leading to the effective control of the pathways of chemical reactions through the rational design of multi-functional carbon nanoreactors. PMID:27301444

  16. Chemical recognition software

    SciTech Connect

    Wagner, J.S.; Trahan, M.W.; Nelson, W.E.; Hargis, P.J. Jr.; Tisone, G.C.

    1994-12-01

    We have developed a capability to make real time concentration measurements of individual chemicals in a complex mixture using a multispectral laser remote sensing system. Our chemical recognition and analysis software consists of three parts: (1) a rigorous multivariate analysis package for quantitative concentration and uncertainty estimates, (2) a genetic optimizer which customizes and tailors the multivariate algorithm for a particular application, and (3) an intelligent neural net chemical filter which pre-selects from the chemical database to find the appropriate candidate chemicals for quantitative analyses by the multivariate algorithms, as well as providing a quick-look concentration estimate and consistency check. Detailed simulations using both laboratory fluorescence data and computer synthesized spectra indicate that our software can make accurate concentration estimates from complex multicomponent mixtures. even when the mixture is noisy and contaminated with unknowns.

  17. Chemical recognition software

    SciTech Connect

    Wagner, J.S.; Trahan, M.W.; Nelson, W.E.; Hargis, P.H. Jr.; Tisone, G.C.

    1994-06-01

    We have developed a capability to make real time concentration measurements of individual chemicals in a complex mixture using a multispectral laser remote sensing system. Our chemical recognition and analysis software consists of three parts: (1) a rigorous multivariate analysis package for quantitative concentration and uncertainty estimates, (2) a genetic optimizer which customizes and tailors the multivariate algorithm for a particular application, and (3) an intelligent neural net chemical filter which pre-selects from the chemical database to find the appropriate candidate chemicals for quantitative analyses by the multivariate algorithms, as well as providing a quick-look concentration estimate and consistency check. Detailed simulations using both laboratory fluorescence data and computer synthesized spectra indicate that our software can make accurate concentration estimates from complex multicomponent mixtures, even when the mixture is noisy and contaminated with unknowns.

  18. Tortuous path chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Lewis, Patrick R.; Adkins, Douglas R.; Wheeler, David R.; Simonson, Robert J.

    2010-09-21

    A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

  19. Chemical and process thermodynamics

    SciTech Connect

    Kyle, B.G.

    1984-01-01

    The book is intended mainly to be used as a text for undergraduate chemical engineering studies. Presented is a unified and up-to-date treatment of the major chemical and engineering applications of thermodynamics. Special features include a four chapter sequence on phase equilibrium which begins with simple concepts discussions. More difficult concepts are introduced gradually. Partial molar properties and infinite dilution activity coefficients appear toward the end of the sequence. Solution behavior, including activity coefficients via UNIVAC, is covered. Chapter 14 discusses heat exchange, separation processes, and second law analysis of chemical processes. Chapter 12 provides a firm foundation for chemical equilibrium, and Chapter 13 includes complex chemical equilibrium and free energy minimization. A selection of end-of-chapter problems is included to help the student apply principles and concepts in practical situations.

  20. Chemical Polysialylation of Recombinant Human Proteins.

    PubMed

    Smirnov, Ivan V; Vorobiev, Ivan I; Belogurov, Alexey A; Genkin, Dmitry D; Deyev, Sergey M; Gabibov, Alexander G

    2015-01-01

    Design of drug with prolonged therapeutic action is one of the rapid developing fields of modern medical science and required implementation of different methods of protein chemistry and molecular biology. There are several therapeutic proteins needing increasing of their stability, pharmacokinetic, and pharmacodynamics parameters. To make long-live DNA-encoded drug PEGylation was proposed. Alternatively polysialic (colominic) acid, extracted from the cell wall of E. coli, fractionated to the desired size by anion-exchange chromatography and chemically activated to the amine-reactive aldehyde form, may be chemically attached to the polypeptide chain. Conjugates of proteins and polysialic acid generally resemble properties of protein-PEG conjugates, but possess significant negative net charge and are thought to be fully degradable after endocytosis due to the presence of intracellular enzymes, hydrolyzing the polysialic acid. Complete biodegradation of the polysialic acid moiety makes this kind of conjugates preferable for creation of drugs, intended for chronic use. Here, we describe two different protocols of chemical polysialylation. First protocol was employed for the CHO-derived human butyrylcholinesterase with optimized for recovery of specific enzyme activity. Polysialic acid moieties are attached at various lysine residues. Another protocol was developed for high-yield conjugation of human insulin; major conjugation point is the N-terminal residue of the insulin's light chain. These methods may allow to produce polysialylated conjugates of various proteins or polypeptides with reasonable yield and without significant loss of functional activity. PMID:26082236

  1. Waste yield, proximate and mineral composition of three different types of land snails found in Nigeria.

    PubMed

    Adeyeye, E I

    1996-03-01

    Some aspects of the chemical and anatomical weight composition of land snails in Nigeria were analysed with a view to assessing the waste yield, carcass yield and their nutritional evaluation on wet weight basis. Proximate analysis of Archachatina, Archatina and Limicolaria species was carried out on the carcass. Moisture and protein contents were high in all samples, fat and ash contents were generally low while crude fibre was not detected. The concentrations of iron, copper, zinc, manganese, sodium, calcium, magnesium, potassium and cobalt were determined in the carcass. Values of iron, calcium, magnesium, sodium and potassium were consistently high while both chromium and cobalt were not detected. Anatomical fractionation showed the shell to vary between 17.12 - 31.99%, carcass varied between 36.97 - 45.14% and the intestine varied between 18.80 - 22.74%. Snails interact with man in a variety of ways, the beneficial interactions are enumerated. PMID:8833175

  2. Evolution of Yield Stress during Structural Relaxation for the Epoxy 828DEA

    NASA Astrophysics Data System (ADS)

    Arechederra, Gabriel; McCoy, John; Kropka, Jamie

    The evolution of yield stress from structural relaxation of diethanolamine cured diglycidyl ether of bisphenol-A, 828DEA, was tracked using uniaxial compression experiments. Samples were aged isothermally for up to 3 months at 5 temperatures ranging from deep in the glass to above Tg. Since 828DEA has remaining reactive potential, it is anticipated that the Tg will continue to evolve throughout the course of the study as new chemical crosslinks are formed. Consequently, it is important to track the evolution of Tg as well as the progression of the fictive temperature in order to interpret the evolution of yield stress. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE.

  3. Will current trends close major crop yield gaps by 2025?

    NASA Astrophysics Data System (ADS)

    Ray, D. K.; Mueller, N. D.; Gerber, J. S.; Johnston, M.; Foley, J. A.

    2012-12-01

    Several studies have projected a need to double global agricultural production by 2050 to meet the demands posed by population growth, increased dairy and meat consumption, and biofuel use. However, recent work shows many regions where there are shortfalls in production compared to the regions with the highest yield. While these "yield gaps" could be closed through more intensive and advanced management, already between 24% and 39% of the global crop growing regions are witnessing yield stagnation. In this presentation we will identify the areas across the globe where yield gaps (as quantified circa the year 2000) are projected to either close or persist given observed rates of yield increases. Major investments in better management are needed in areas where yield gaps are projected to persist.

  4. Predicting Great Lakes fish yields: tools and constraints

    USGS Publications Warehouse

    Lewis, C.A.; Schupp, D.H.; Taylor, W.W.; Collins, J.J.; Hatch, Richard W.

    1987-01-01

    Prediction of yield is a critical component of fisheries management. The development of sound yield prediction methodology and the application of the results of yield prediction are central to the evolution of strategies to achieve stated goals for Great Lakes fisheries and to the measurement of progress toward those goals. Despite general availability of species yield models, yield prediction for many Great Lakes fisheries has been poor due to the instability of the fish communities and the inadequacy of available data. A host of biological, institutional, and societal factors constrain both the development of sound predictions and their application to management. Improved predictive capability requires increased stability of Great Lakes fisheries through rehabilitation of well-integrated communities, improvement of data collection, data standardization and information-sharing mechanisms, and further development of the methodology for yield prediction. Most important is the creation of a better-informed public that will in turn establish the political will to do what is required.

  5. Relationship of spectral data to grain yield variation

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Holben, B. N.; Elgin, J. H., Jr.; Mcmurtrey, J. E., III

    1980-01-01

    Two-band hand-held radiometer data from a winter wheat field, collected on 21 dates during the spring growing season, were correlated with within-field final grain yield. Significant linear relationships were found between various combinations of the red and photographic infrared radiance data collected and the grain yield. The spectral data explained about 64 percent of the within-field grain yield variation. This variation in grain yield could not be explained using meteorological data as these were similar for all areas of the wheat field. Most importantly, data collected early in the spring were highly correlated with grain yield, a five-week time window existed from stem elongation through anthesis in which the spectral data were most highly correlated with grain yield, and manifestations of wheat canopy water stress were readily apparent in the spectral data.

  6. Climate variation explains a third of global crop yield variability

    PubMed Central

    Ray, Deepak K.; Gerber, James S.; MacDonald, Graham K.; West, Paul C.

    2015-01-01

    Many studies have examined the role of mean climate change in agriculture, but an understanding of the influence of inter-annual climate variations on crop yields in different regions remains elusive. We use detailed crop statistics time series for ~13,500 political units to examine how recent climate variability led to variations in maize, rice, wheat and soybean crop yields worldwide. While some areas show no significant influence of climate variability, in substantial areas of the global breadbaskets, >60% of the yield variability can be explained by climate variability. Globally, climate variability accounts for roughly a third (~32–39%) of the observed yield variability. Our study uniquely illustrates spatial patterns in the relationship between climate variability and crop yield variability, highlighting where variations in temperature, precipitation or their interaction explain yield variability. We discuss key drivers for the observed variations to target further research and policy interventions geared towards buffering future crop production from climate variability. PMID:25609225

  7. Yield prediction by analysis of multispectral scanner data

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.; Suits, G. H.

    1975-01-01

    A preliminary model describing the growth and grain yield of wheat was developed. The modeled growth characteristics of the wheat crop were used to compute wheat canopy reflectance using a model of vegetation canopy reflectance. The modeled reflectance characteristics were compared with the corresponding growth characteristics and grain yield in order to infer their relationships. It appears that periodic wheat canopy reflectance characteristics potentially derivable from earth satellites will be useful in forecasting wheat grain yield.

  8. Rice yield estimation with multi-temporal Radarsat-2 data

    NASA Astrophysics Data System (ADS)

    Chen, Chi-Farn; Son, Nguyen-Thanh; Chen, Cheng-Ru

    2015-04-01

    Rice is the most important food crop in Taiwan. Monitoring rice crop yield is thus crucial for agronomic planners to formulate successful strategies to address national food security and rice grain export issues. However, there is a real challenge for this monitoring purpose because the size of rice fields in Taiwan was generally small and fragmented, and the cropping calendar was also different from region to region. Thus, satellite-based estimation of rice crop yield requires the data that have sufficient spatial and temporal resolutions. This study aimed to develop models to estimate rice crop yield from multi-temporal Radarsat-2 data (5 m resolution). Data processing were carried out for the first rice cropping season from February to July in 2014 in the western part of Taiwan, consisting of four main steps: (1) constructing time-series backscattering coefficient data, (2) spatiotemporal noise filtering of the time-series data, (3) establishment of crop yield models using the time-series backscattering coefficients and in-situ measured yield data, and (4) model validation using field data and government's yield statistics. The results indicated that backscattering behavior varied from region to region due to changes in cultural practices and cropping calendars. The highest correlation coefficient (R2 > 0.8) was obtained at the ripening period. The robustness of the established models was evaluated by comparisons between the estimated yields and in-situ measured yield data showed satisfactory results, with the root mean squared error (RMSE) smaller than 10%. Such results were reaffirmed by the correlation analysis between the estimated yields and government's rice yield statistics (R2 > 0.8). This study demonstrates advantages of using multi-temporal Radarsat-2 backscattering data for estimating rice crop yields in Taiwan prior to the harvesting period, and thus the methods were proposed for rice yield monitoring in other regions.

  9. Climatic and technological ceilings for Chinese rice stagnation based on yield gaps and yield trend pattern analysis.

    PubMed

    Zhang, Tianyi; Yang, Xiaoguang; Wang, Hesong; Li, Yong; Ye, Qing

    2014-04-01

    Climatic or technological ceilings could cause yield stagnation. Thus, identifying the principal reasons for yield stagnation within the context of the local climate and socio-economic conditions are essential for informing regional agricultural policies. In this study, we identified the climatic and technological ceilings for seven rice-production regions in China based on yield gaps and on a yield trend pattern analysis for the period 1980-2010. The results indicate that 54.9% of the counties sampled experienced yield stagnation since the 1980. The potential yield ceilings in northern and eastern China decreased to a greater extent than in other regions due to the accompanying climate effects of increases in temperature and decreases in radiation. This may be associated with yield stagnation and halt occurring in approximately 49.8-57.0% of the sampled counties in these areas. South-western China exhibited a promising scope for yield improvement, showing the greatest yield gap (30.6%), whereas the yields were stagnant in 58.4% of the sampled counties. This finding suggests that efforts to overcome the technological ceiling must be given priority so that the available exploitable yield gap can be achieved. North-eastern China, however, represents a noteworthy exception. In the north-central area of this region, climate change has increased the yield potential ceiling, and this increase has been accompanied by the most rapid increase in actual yield: 1.02 ton ha(-1) per decade. Therefore, north-eastern China shows a great potential for rice production, which is favoured by the current climate conditions and available technology level. Additional environmentally friendly economic incentives might be considered in this region. PMID:24130084

  10. SLUDGE BATCH SUPPLEMENTAL SRAT RUNS EFFECTS OF YIELD STRESS AND CYCLE TIME INCREASE

    SciTech Connect

    Fernandez, A.

    2010-08-10

    The Defense Waste Processing Facility (DWPF) has transitioned from Sludge Batch 5 (SB5) processing to Sludge Batch 6 (SB6) processing. Phase III-Tank 40 Chemical Process Cell (CPC) flowsheet simulations have been completed to determine the initial processing conditions for the DWPF transition. The impact of higher yield stress (SB-25) and cycle time extension (SB6-26) on the physical and chemical effects of SB6 processing during the SRAT (Sludge Receipt and Adjustment Tank) cycle were evaluated. No significant impacts on the SRAT chemistry were noted during the higher yield stress run. In particular, no impact on mercury stripping was noted, indicating that settling of elemental mercury was not the primary factor in the low mercury recovery noted in the flowsheet testing. The SRAT product from this run retained the higher yield stress of the starting sludge. The run indicated that ultrasonication is an effective tool to increase the yield stress of simulants to targeted values and the chemistry of downstream processing is not impacted. Significant differences were noted in the cycle time extension test compared to the Phase III flowsheet baseline runs. Large decreases in the ammonia and hydrogen generation rates were noted along with reduced mercury stripping efficiency. The latter effect is similar to that of operating under a high acid stoichiometry. It is conceivable that, under the distinctly different conditions of high formic acid concentration (high acid run) or slow formic acid addition (extended run), that mercury could form amalgams with noble metals, possibly rendering both inert. Thus, the removal of free mercury and noble metals could decrease the rate of catalytic formic acid reactions which would decrease generation of ammonium and hydrogen. The potential underlying reasons for the behavior noted during this run would require additional testing.

  11. Chemical syntheses of inulin and levan structures.

    PubMed

    Oscarson, Stefan; Sehgelmeble, Fernando W

    2002-11-29

    A fructofuranosyl thiglycoside donor, ethyl 6-O-acetyl-3-O-benzyl-1,4-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)-2-thio-beta-D-fructofuranoside (11), designed to yield stereospecifically beta-linkages and also to allow subsequent elongation in the 6- and/or 1-positions, was prepared and used in syntheses of levan and inulin structures. DMTST-promoted glycosylation between 11 (1.3 mol equiv) and methyl beta-D-fructofuranoside 6-OH and 1-OH acceptors (3 and 6) gave stereospecifically the protected methyl levanobioside 12 and inulinobioside 17 in excellent yields (80 and 86%), respectively. Protecting group manipulations on these afforded new disaccharide 6'-OH and 1'-OH acceptors (13 and 19), which were coupled again with donor 11 (1.0 mol equiv) to yield methyl levanotrioside 14 and inulinotrioside 20 in high yields, 65 and 67%, respectively. These were transformed into new acceptors and also fully deprotected to afford the methyl glycosides of levanotriose and inulinotriose, all structures that have earlier not been accessible by chemical synthesis. PMID:12444625

  12. Random Forests for Global and Regional Crop Yield Predictions

    PubMed Central

    Jeong, Jig Han; Resop, Jonathan P.; Mueller, Nathaniel D.; Fleisher, David H.; Yun, Kyungdahm; Butler, Ethan E.; Timlin, Dennis J.; Shim, Kyo-Moon; Gerber, James S.; Reddy, Vangimalla R.

    2016-01-01

    Accurate predictions of crop yield are critical for developing effective agricultural and food policies at the regional and global scales. We evaluated a machine-learning method, Random Forests (RF), for its ability to predict crop yield responses to climate and biophysical variables at global and regional scales in wheat, maize, and potato in comparison with multiple linear regressions (MLR) serving as a benchmark. We used crop yield data from various sources and regions for model training and testing: 1) gridded global wheat grain yield, 2) maize grain yield from US counties over thirty years, and 3) potato tuber and maize silage yield from the northeastern seaboard region. RF was found highly capable of predicting crop yields and outperformed MLR benchmarks in all performance statistics that were compared. For example, the root mean square errors (RMSE) ranged between 6 and 14% of the average observed yield with RF models in all test cases whereas these values ranged from 14% to 49% for MLR models. Our results show that RF is an effective and versatile machine-learning method for crop yield predictions at regional and global scales for its high accuracy and precision, ease of use, and utility in data analysis. RF may result in a loss of accuracy when predicting the extreme ends or responses beyond the boundaries of the training data. PMID:27257967

  13. Direct laboratory tensile testing of select yielding rock bolt systems

    SciTech Connect

    VandeKraats, J.D.; Watson, S.O.

    1996-08-01

    Yielding rock bolt support systems have been developed to accommodate ground movement in shifting ground such as in coal operations; in creeping ground such as salt, trona, and potash; and in swelling ground associated with some clays. These systems, designed to remain intact despite ground movement, should enhance mine safety and help contain costs in areas where rebolting of rigid non-yielding systems is typically required. Four such systems were tested in straight tensile pulls in the laboratory. They include the Slip Nut System from Dywidag Systems International USA, Inc., Ischebeck`s bolt mounted Titan Load Indicator, Rocky Mountain Bolt Company`s Yielding Cable Bolt, and a rock bolt installed variation of the yielding steel post developed by RE/SPEC Inc. The first two systems are currently marketed products and the latter two are prototype systems. Each system responds to load and displacement by yielding in an unique manner. All are designed to yield at predetermined loads. A description of each system and its yield function is provided. Each system was tested over its prescribed yield range in a test machine. At least five tests were performed on each system. Each system yielded and continued to provide support according to its design. Each shows promise for ground control use in shifting or creeping rock. This work helps to illustrate the comparative differences in performance between these specialized systems and the applications where they may be most useful.

  14. {lambda}(1520) {yields} {lambda}{gamma} Radiative-Decay Width

    SciTech Connect

    Vavilov, D.V.; Antipov, Yu.M.; Artamonov, A.V.; Batarin, V.A.; Victorov, V.A.; Golovkin, S.V.; Gorin, Yu.P.; Eroshin, O.V.; Kozhevnikov, A.P.; Konstantinov, A.S.; Kubarovsky, V.P.; Kurshetsov, V.F.; Landsberg, L.G.; Leontiev, V.M.; Molchanov, V.V.; Mukhin, V.A.; Patalakha, D.I.; Petrenko, S.V.; Petrukhin, A.I.; Kolganov, V.Z.

    2005-03-01

    The radiative decay {lambda}(1520) {yields} {lambda}{gamma} was recorded in the exclusive reaction p + N {yields} {lambda}(1520)K{sup +} + N at the SPHINX facility. The branching ratio for this decay and the corresponding partial width were found to be, respectively, Br[{lambda}(1520) {yields} {lambda}{gamma}] = (1.02 {+-} 0.21) x 10{sup -2} and {gamma}[{lambda}(1520) {yields} {lambda}{gamma}] = 159 {+-} 35 keV (the quoted errors are purely statistical, the systematic errors being within 15%)

  15. The measurements of total electron yield from silver

    NASA Astrophysics Data System (ADS)

    Xie, A.-G.; Li, C.-Q.; Wang, L.; Pei, Y.-J.

    2009-12-01

    A device for measuring total electron yields in the energy range 4-65 keV from conductor was set up successfully, which was made up of electron gun system, vacuum system and electrical system. By the pulse electron gun method, the total electron yields in the energy range 4-65 keV from silver were measured, based on the relation between the secondary electron yield and total electron yield at high incident electron energy from metals, the secondary electron yields in the energy range 10-65 keV from silver were deduced. Total electron yields measured with the device were compared with theoretical values, and the deduced secondary electron yield were compared with several authors' values, the results were discussed and a conclusion was drawn that the deduced secondary electron yields and the total electron yields from silver measured with the device are credible. This project was supported by the Science Foundation of Nanjing University of Information and Technology (Grant No. QD65).

  16. Tensile Yielding of Multi-Wall Carbon Nanotube

    NASA Technical Reports Server (NTRS)

    Wei, Chenyu; Cho, Kyeongjae; Srivastava, Deepak; Parks, John W. (Technical Monitor)

    2002-01-01

    The tensile yielding of multiwall carbon nanotubes (MWCNTs) has been studied using Molecular Dynamics simulations and a Transition State Theory based model. We find a strong dependence of the yielding on the strain rate. A critical strain rate has been predicted above/below which yielding strain of a MWCNT is larger/smaller than that of the corresponding single-wall carbon nanotubes. At experimentally feasible strain rate of 1% /hour and T = 300K, the yield strain of a MWCNT is estimated to be about 3-4 % higher than that of an equivalent SWCNT (Single Wall Carbon Nanotube), in good agreement with recent experimental observations.

  17. Quantitative detection of pesticide concentration by Raman chemical method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticides are used in agricultural production to control pests, diseases, weeds and other plant pathogens to minimize yield losses and maintain high product quality. Since residues from those chemical compounds can be present on the surfaces of vegetables and fruits which may cause major health pro...

  18. Simulation for thick-target yields of transmutation reactions on radioactive targets, based on inverse kinematics

    NASA Astrophysics Data System (ADS)

    Ebata, Shuichiro; Aikawa, Masayuki; Imai, Shotaro

    2016-06-01

    To dispose of long-lived fission products (LLFP) ejected from nuclear reactor plants is one of the most important tasks on nuclear physics and engineering. The experiments with the radiative target are limited, due to the high radioactivity and chemical property of the target. In consequence, the nuclear reaction data for LLFP are insufficient. In this work, we propose a feasible method to obtain the data for radiative targets using inverse kinematics and simulate specific systems to evaluate the thick-target yields of the nuclear transmutation reactions for LLFP.

  19. Stochastic distribution of the fibrils that yielded the Shroud of Turin body image

    NASA Astrophysics Data System (ADS)

    Fazio, G.; Mandaglio, G.

    2011-07-01

    The fibrils that yielded the Shroud body image show a stochastic distribution on the Linen of Turin. In fact, the probability of a fibril yellowing is a function of the energy, while this is not the case for the optical density value. This means that the above image is a latent image. We suggest thermal radiation or low-temperature chemical processes as possible natural energy sources to explain, by stochastic effects, the Shroud body image formation. Unfortunately, due to the nature of the phenomenon, we are not able to extract the energy source.

  20. Chemical process hazards analysis

    SciTech Connect

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  1. Development of techniques for tagging precursor and essential chemicals

    SciTech Connect

    Swansiger, W.A.; Shepodd, T.J.; Phillips, M.L.F.

    1994-01-01

    The ability to identify the manufacturers and distributors of chemicals seized in raids of illicit drug labs would be of great value in controlling the diversion of these chemicals. We developed a tagging scheme based on the addition of sub-ppM concentrations of various combinations of rare-earth elements to the target chemicals and evaluated a number of techniques for detecting the tags. We developed soluble tags for tagging liquids and selected Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) as the preferred detection technique. We developed insoluble tags for tagging solids and developed methods to analyze them and mix them into solid precursors. We have successfully demonstrated the tagging of several solvents and two of the precursor chemicals used in one of the most popular clandestine methamphetamine syntheses (ephedrine reacting with hydriodic acid/red phosphorus). The tagging scheme is capable of yielding tens of thousands of signatures (using holmium as an internal standard and up to 9 rare-earths at up to 3 concentrations yields 3{sup 9} {minus} 1 = 19,682 signatures) and is applicable to most of the chemicals on the precursor and essential chemicals list. In the concentrations employed, the tags are safe enough to be added to pharmaceuticals and cheap enough to tag tanker loads of chemicals.

  2. Maintaining yields and reducing nitrogen loss in rice-wheat rotation system in Taihu Lake region with proper fertilizer management

    NASA Astrophysics Data System (ADS)

    Xue, Lihong; Yu, Yingliang; Yang, Linzhang

    2014-11-01

    In the Tailake region of China, heavy nitrogen (N) loss of rice-wheat rotation systems, due to high fertilizer-N input with low N use efficiency (NUE), was widely reported. To alleviate the detrimental impacts caused by N loss, it is necessary to improve the fertilizer management practices. Therefore, a 3 yr field experiments with different N managements including organic combined chemical N treatment (OCN, 390 kg N ha-1 yr-1, 20% organic fertilizer), control-released urea treatment (CRU, 390 kg N ha-1 yr-1, 70% resin-coated urea), reduced chemical N treatment (RCN, 390 kg N ha-1 yr-1, all common chemical fertilizer), and site-specific N management (SSNM, 333 kg N ha-1 yr-1, all common chemical fertilizer) were conducted in the Taihu Lake region with the ‘farmer’s N’ treatment (FN, 510 kg N ha-1 yr-1, all common chemical fertilizer) as a control. Grain yield, plant N uptake (PNU), NUE, and N losses via runoff, leaching, and ammonia volatilization were assessed. In the rice season, the FN treatment had the highest N loss and lowest NUE, which can be attributed to an excessive rate of N application. Treatments of OCN and RCN with a 22% reduced N rate from FN had no significant effect on PNU nor the yield of rice in the 3 yr; however, the NUE was improved and N loss was reduced 20-32%. OCN treatment achieved the highest yield, while SSNM has the lowest N loss and highest NUE due to the lowest N rate. In wheat season, N loss decreased about 28-48% with the continuous reduction of N input, but the yield also declined, with the exception of OCN treatment. N loss through runoff, leaching and ammonia volatilization was positively correlated with the N input rate. When compared with the pure chemical fertilizer treatment of RCN under the same N input, OCN treatment has better NUE, better yield, and lower N loss. 70% of the urea replaced with resin-coated urea had no significant effect on yield and NUE improvement, but decreased the ammonia volatilization loss. Soil

  3. Chemical warfare agents.

    PubMed

    Ganesan, K; Raza, S K; Vijayaraghavan, R

    2010-07-01

    Among the Weapons of Mass Destruction, chemical warfare (CW) is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided. PMID:21829312

  4. Chemical ecology of fungi.

    PubMed

    Spiteller, Peter

    2015-07-01

    Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology. PMID:26038303

  5. Chemical warfare detectors worldwide

    SciTech Connect

    Corriveau, J.

    1995-06-01

    The purpose of this presentation is to provide information on the principal technologies used to detect and identify chemical warfare (CW) agents. Detectors of harmful CW agents may be grouped into three major categories based on their operating principles. The three technologies involved are biochemical, ion mobility spectrometry (IMS), and flame photometry (FP). Once a chemical agent has been detected by one of these means, the presence must often be {open_quotes}confirmed{close_quotes} by a second test that is based on a different technology. Two major means of confirming the presence of a chemical agent are mass spectrometry (MS) and {open_quotes}classical{close_quotes} wet chemistry.

  6. Chemical warfare agents

    PubMed Central

    Ganesan, K.; Raza, S. K.; Vijayaraghavan, R.

    2010-01-01

    Among the Weapons of Mass Destruction, chemical warfare (CW) is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided. PMID:21829312

  7. Chemical Hygiene Program

    NASA Technical Reports Server (NTRS)

    Mayor, Antoinette C.

    1999-01-01

    The Chemical Management Team is responsible for ensuring compliance with the OSHA Laboratory Standard. The program at Lewis Research Center (LeRC) evolved over many years to include training, developing Standard Operating Procedures (SOPS) for each laboratory process, coordinating with other safety and health organizations and teams at the Center, and issuing an SOP binder. The Chemical Hygiene Policy was first established for the Center. The Chemical Hygiene Plan was established and reviewed by technical, laboratory and management for viability and applicability to the Center. A risk assessment was conducted for each laboratory. The laboratories were prioritized by order of risk, higher risk taking priority. A Chemical Management Team staff member interviewed the lead researcher for each laboratory process to gather the information needed to develop the SOP for the process. A binder containing the Chemical Hygiene Plan, the SOP, a map of the laboratory identifying the personal protective equipment and best egress, and glove guides, as well as other guides for safety and health. Each laboratory process has been captured in the form of an SOP. The chemicals used in the procedure have been identified and the information is used to reduce the number of chemicals in the lab. The Chemical Hygiene Plan binder is used as a training tool for new employees. LeRC is in compliance with the OSHA Standard. The program was designed to comply with the OSHA standard. In the process, we have been able to assess the usage of chemicals in the laboratories, as well as reduce or relocate the chemicals being stored in the laboratory. Our researchers are trained on the hazards of the materials they work with and have a better understanding of the hazards of the process and what is needed to prevent any incident. From the SOP process, we have been able to reduce our chemical inventory, determine and implement better hygiene procedures and equipment in the laboratories, and provide

  8. Reduced yield stress for zirconium exposed to iodine: Reactive force field simulation

    DOE PAGESBeta

    Rossi, Matthew L.; Taylor, Christopher D.; van Duin, Adri C. T.

    2014-11-04

    Iodine-induced stress-corrosion cracking (ISCC), a known failure mode for nuclear fuel cladding, occurs when iodine generated during the irradiation of a nuclear fuel pellet escapes the pellet through diffusion or thermal cracking and chemically interacts with the inner surface of the clad material, inducing a subsequent effect on the cladding’s resistance to mechanical stress. To complement experimental investigations of ISCC, a reactive force field (ReaxFF) compatible with the Zr-I chemical and materials systems has been developed and applied to simulate the impact of iodine exposure on the mechanical strength of the material. The study shows that the material’s resistance tomore » stress (as captured by the yield stress of a high-energy grain boundary) is related to the surface coverage of iodine, with the implication that ISCC is the result of adsorption-enhanced decohesion.« less

  9. Yield, Purity and Mobility of a Silver-DNA Fluorophore in Solution

    NASA Astrophysics Data System (ADS)

    O'Neill, Patrick; Velazquez, Lourdes; Goodwin, Peter; Driehorst, Til; Pennathur, Sumita; Fygenson, Deborah

    2010-03-01

    Chemical reduction of DNA oligonucleotide:Ag+ mixtures leads to the formation of fluorescent few-atom Ag clusters stabilized by the DNA. This reaction typically produces many species, some of which are fluorescent, with emission wavelengths and stabilities that vary widely with DNA sequence. While most DNA sequences studied produce many different Ag:DNA products, we identify a specific DNA sequence that strongly favors the formation of a green 11Ag cluster, stable for months under ambient conditions. We generate pure solutions of this emitter by synthesizing in the presence of excess silver and then removing free silver from solution. We report on results enabled by the purity of these samples, including determination of the extinction coefficient (using FCS), diffusion coefficient (using microfluidics) and bulk chemical yield of this fluorophore, and comment on the challenges that remain on the path to production of sufficient quantity and purity for high-resolution structure determination.

  10. Reduced yield stress for zirconium exposed to iodine: Reactive force field simulation

    SciTech Connect

    Rossi, Matthew L.; Taylor, Christopher D.; van Duin, Adri C. T.

    2014-11-04

    Iodine-induced stress-corrosion cracking (ISCC), a known failure mode for nuclear fuel cladding, occurs when iodine generated during the irradiation of a nuclear fuel pellet escapes the pellet through diffusion or thermal cracking and chemically interacts with the inner surface of the clad material, inducing a subsequent effect on the cladding’s resistance to mechanical stress. To complement experimental investigations of ISCC, a reactive force field (ReaxFF) compatible with the Zr-I chemical and materials systems has been developed and applied to simulate the impact of iodine exposure on the mechanical strength of the material. The study shows that the material’s resistance to stress (as captured by the yield stress of a high-energy grain boundary) is related to the surface coverage of iodine, with the implication that ISCC is the result of adsorption-enhanced decohesion.

  11. Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability

    PubMed Central

    Gaudin, Amélie C. M.; Tolhurst, Tor N.; Ker, Alan P.; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C.; Deen, William

    2015-01-01

    Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental

  12. Prediction of Potato Crop Yield Using Precision Agriculture Techniques.

    PubMed

    Al-Gaadi, Khalid A; Hassaballa, Abdalhaleem A; Tola, ElKamil; Kayad, Ahmed G; Madugundu, Rangaswamy; Alblewi, Bander; Assiri, Fahad

    2016-01-01

    Crop growth and yield monitoring over agricultural fields is an essential procedure for food security and agricultural economic return prediction. The advances in remote sensing have enhanced the process of monitoring the development of agricultural crops and estimating their yields. Therefore, remote sensing and GIS techniques were employed, in this study, to predict potato tuber crop yield on three 30 ha center pivot irrigated fields in an agricultural scheme located in the Eastern Region of Saudi Arabia. Landsat-8 and Sentinel-2 satellite images were acquired during the potato growth stages and two vegetation indices (the normalized difference vegetation index (NDVI) and the soil adjusted vegetation index (SAVI)) were generated from the images. Vegetation index maps were developed and classified into zones based on vegetation health statements, where the stratified random sampling points were accordingly initiated. Potato yield samples were collected 2-3 days prior to the harvest time and were correlated to the adjacent NDVI and SAVI, where yield prediction algorithms were developed and used to generate prediction yield maps. Results of the study revealed that the difference between predicted yield values and actual ones (prediction error) ranged between 7.9 and 13.5% for Landsat-8 images and between 3.8 and 10.2% for Sentinel-2 images. The relationship between actual and predicted yield values produced R2 values ranging between 0.39 and 0.65 for Landsat-8 images and between 0.47 and 0.65 for Sentinel-2 images. Results of this study revealed a considerable variation in field productivity across the three fields, where high-yield areas produced an average yield of above 40 t ha-1; while, the low-yield areas produced, on the average, less than 21 t ha-1. Identifying such great variation in field productivity will assist farmers and decision makers in managing their practices. PMID:27611577

  13. Biotechnology for producing fuels and chemicals from biomass. Volume 2: Fermentation chemicals from biomass

    NASA Astrophysics Data System (ADS)

    Villet, R.

    1981-02-01

    The technological and economic feasibility of producing chemicals by fermentation is discussed: acetone; butanol; acetic acid; citric acid; 2,3-butanediol, and propionic acid. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5 percent to 7 percent/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. The feedstock cost is 15 to 20 percent of the overall cost of production. The anticipated 5 percent growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. The commercial fermentative production of propionic acid has not yet been developed.

  14. Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds.

    PubMed

    Pope, Katherine S; Dose, Volker; Da Silva, David; Brown, Patrick H; DeJong, Theodore M

    2015-06-01

    Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond (Prunus dulcis), pistachio (Pistacia vera), and walnut (Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change. PMID:25119825

  15. Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds

    NASA Astrophysics Data System (ADS)

    Pope, Katherine S.; Dose, Volker; Da Silva, David; Brown, Patrick H.; DeJong, Theodore M.

    2015-06-01

    Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond ( Prunus dulcis), pistachio ( Pistacia vera), and walnut ( Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change.

  16. Process for preparing a chemical compound enriched in isotope content

    DOEpatents

    Michaels, Edward D.

    1982-01-01

    A process to prepare a chemical enriched in isotope content which includes: (a) A chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; (b) the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; (c) the conversion of the remainder of the first compound to the second compound for reflux at the product end of the chemical exchange reaction region; (d) the conversion of the remainder of the second compound to the first compound for reflux at the spent material end of the chemical exchange region; and the cycling of the additional chemicals produced by one conversion reaction to the other conversion reaction, for consumption therein. One of the conversion reactions is an oxidation reaction, and the energy that it yields is used to drive the other conversion reaction, a reduction. The reduction reaction is carried out in a solid polymer electrolyte electrolytic reactor. The overall process is energy efficient and yields no waste by-products.

  17. Mixing enhancement in chemical lasers. II. Theory

    SciTech Connect

    Driscoll, R.J.

    1987-07-01

    A phenomenological model for reactant mixing in trip nozzle chemical lasers by means of a surface-stretching mechanism is used in conjunction with a two-level laser model to derive scaling laws for numerous features noted in the trip nozzle data. This mixing model is then employed with an aerokinetics code in order to obtain quantitative laser gain predictions. The results yielded by the code are in good agreement with small-signal data. It is determined that trip jet mixing will not increase laser efficiency at low cavity pressures, but will at high cavity pressures result in a doubling of laser power output. 12 references.

  18. Cofactor engineering for advancing chemical biotechnology.

    PubMed

    Wang, Yipeng; San, Ka-Yiu; Bennett, George N

    2013-12-01

    Cofactors provide redox carriers for biosynthetic reactions, catabolic reactions and act as important agents in transfer of energy for the cell. Recent advances in manipulating cofactors include culture conditions or additive alterations, genetic modification of host pathways for increased availability of desired cofactor, changes in enzyme cofactor specificity, and introduction of novel redox partners to form effective circuits for biochemical processes and biocatalysts. Genetic strategies to employ ferredoxin, NADH and NADPH most effectively in natural or novel pathways have improved yield and efficiency of large-scale processes for fuels and chemicals and have been demonstrated with a variety of microbial organisms. PMID:23611567

  19. Chemical Expertise: Chemistry in the Royal Prussian Porcelain Manufactory.

    PubMed

    Klein, Ursula

    2014-01-01

    Eighteenth-century chemists defined chemistry as both a "science and an art." By "chemical art" they meant not merely experimentation but also parts of certain arts and crafts. This raises the question of how to identify the "chemical parts" of the arts and crafts in eighteenth-century Europe. In this essay I tackle this question with respect to porcelain manufacture. My essay begins with a brief discussion of historiographical problems related to this question. It then analyzes practices involved in porcelain manufacture that can be reasonably identified as chemical practices or a chemical art. My analysis yields evidence for the argument that chemical experts and expertise fulfilled distinct technical functions in porcelain manufacture and, by extension, in eighteenth-century "big industry," along with its system of division of labor. PMID:26103759

  20. 50 CFR 600.310 - National Standard 1-Optimum Yield.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false National Standard 1-Optimum Yield. 600.310 Section 600.310 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS National Standards § 600.310 National Standard 1—Optimum Yield....