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Sample records for yield yield components

  1. 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.

  2. The effect of water deficit on yield and yield components of safflower (Carthamus tinctorius L.).

    PubMed

    Nabipour, M; Meskarbashee, M; Yousefpour, H

    2007-02-01

    The aim of this study carried out in Shahid Chamran Ahwaz, University, in 2001-2002 to determine the effect of different forms of irrigation on the safflower (Carthamus tinctorius L.) yield and yield components. Information was needed on application time of irrigation water on cultivars of safflower (Carthamus tinctorius L.). Increasing competition for water supplies and rising costs of applying water make efficient irrigation important. Yield and water use of safflower were evaluated on silt loam soil. Deficit irrigation treatments; I1: normal irrigation, I2: cutoff irrigation in budding period, I3: cutoff irrigation in flowering period (blooming), I4: cutoff irrigation in maturity period, were examined in Randomized Complete Block Design (RCB) with three replications. In this field experiment irrigation regimes were the main plots and cvs (ARAK 28, ESFAHAN LOCALITY and FO2 cvs) were as sub plots. The plant height, the plant head number, the 1000 seed weight, and the seed yield were measured in this experiment. The different irrigation regimes had a significant effects (p < 0.05) on the seed, the crude oil yields (kg ha(-1)), seed number per boll, harvest index, total dry weight. The highest seed yield (2679 kg seed ha(-1) in cv. ESFAHAN Lo.) and the crude oil yield (855 kg oil ha(-1) in cv. ARAK) were obtained from the I1 irrigation regime. I3 gave the lowest seed yield (1499 kg seed ha(-1) in cv. FO2) and the crude oil yield (449 kg oil ha(-1) in cv. FO2). I1 gave the highest oil percentage (35% in ARAK cv.) and the lowest (27.4% in FO2 cv.) obtained in I4. The different between cvs were significant in number of boll per plant, number of seed per boll, the 1000 seed, high, number of branch per plant, seed yield (kg ha(-1)), crude oil yield and total dry weight.

  3. QTL mapping of forage yield and forage yield component traits in Sorghum bicolor x S. sudanense.

    PubMed

    Liu, Y L; Wang, L H; Li, J Q; Zhan, Q W; Zhang, Q; Li, J F; Fan, F F

    2015-04-22

    The sorghum-sudangrass hybrid (Sorghum bicolor x S. sudanense) is an important forage crop. However, little is known about the genetic mechanisms related to forage yield and the 4 forage yield component traits in this forage crop. In this study, a linkage map was constructed with 124 assigned SSR markers using an F2 mapping population derived from the crossing of sorghum Tx623A and sudangrass Sa. Nine quantitative trait loci (QTLs) were detected for forage yield and the 4 forage yield component traits using inclusive composite interval mapping. Five fresh weight QTLs were identified and contributed >50% of the total phenotypic variance. Of these QTLs, all showed additive and dominant effects, but most exhibited mainly dominant effects. These results will provide useful information for improvements in sorghum-sudangrass hybrid breeding.

  4. Effects of nitrogen application method and weed control on corn yield and yield components.

    PubMed

    Sepahvand, Pariya; Sajedi, Nurali; Mousavi, Seyed Karim; Ghiasvand, Mohsen

    2014-04-01

    The effects of nitrogen fertilizer application and different methods for weed control on yield and yield components of corn was evaluated in Khorramabad in 2011. The experiment was conducted as a split plot based on randomized complete block design in 3 replications. Nitrogen application was as main plot in 4 levels (no nitrogen, broadcasting nitrogen, banding nitrogen and sprayed nitrogen) and methods of weed control were in 4 levels (non-control weeds, application Equip herbicide, once hand control of weeds and application Equip herbicide+once time weeding) was as subplots. Result illustrated that effects of nitrogen fertilizer application were significant on grain and forage yield, 100 seeds weight, harvest index, grain number per row and cob weight per plant. Grain yield increased by 91.4 and 3.9% in application banding and broadcasting for nitrogen fertilizer, respectively, compared to the no fertilizer treatment. The results show improved efficiency of nitrogen utilization by banding application. Grain yield, harvest index, seed rows per cob, seeds per row and cob weight were increased by weed control. In the application of Equip herbicide+ hand weeding treatment corn grain yield was increased 126% in comparison to weedy control. It represents of the intense affects of weed competition with corn. The highest corn grain yield (6758 kg h(-1)) was related to the application banding of nitrogen fertilizer and Equip herbicide+once hand weeding.

  5. Combining Ability, Maternal Effects, and Heritability of Drought Tolerance, Yield and Yield Components in Sweetpotato

    PubMed Central

    Rukundo, Placide; Shimelis, Hussein; Laing, Mark; Gahakwa, Daphrose

    2017-01-01

    Knowledge on gene action and trait expression are important for effective breeding. The objective of this study was to determine the general combining ability (GCA), specific combining ability (SCA), maternal effects and heritability of drought tolerance, yield and yield components of candidate sweetpotato clones. Twelve genotypes selected for their high yield, dry matter content or drought tolerance were crossed using a full diallel mating design. Families were field evaluated at Masoro, Karama, and Rubona Research Stations of Rwanda Agriculture Board. Success rate of crosses varied from 1.8 to 62.5% with a mean of 18.8%. Family by site interaction had significant effect (P < 0.01) on storage root and vine yields, total biomass and dry matter content of storage roots. The family effects were significant (P < 0.01) for all parameters measured. Broad sense heritability estimates were 0.95, 0.84, 0.68, 0.47, 0.74, 0.75, 0.50, and 0.58 for canopy temperature (CT), canopy wilting (CW), root yield, skin color, flesh color, dry matter content, vine yield and total biomass, respectively. The GCA effects of parents and SCA effects of crosses were significant (P < 0.01) for CT, CW, storage root, vine and biomass yields, and dry matter content of storage root. The ratio of GCA/SCA effects for CT, CW, yield of storage roots and dry matter content of storage roots were higher than 50%, suggesting the preponderance of additive over non-additive gene action in the expression of these traits. Maternal effects were significant (P < 0.05) among families for CT, CW, flesh color and dry matter content, vine yield and total biomass. Across sites, the best five selected families with significant SCA effects for storage root yield were, Nsasagatebo × Otada 24, Otada 24 × Ukerewe, 4-160 × Nsasagatebo, K513261 × 2005-034 and Ukerewe × K513261 with 11.0, 9.7, 9.3, 9.2, 8.6 t/ha, respectively. The selected families are valuable genetic resources for sweetpotato breeding for drought

  6. Phosphorus, zinc, and boron influence yield components in Earliglow strawberry

    SciTech Connect

    May, G.M.; Pritts, M.P. . Dept. of Fruit and Vegetable Science)

    1993-01-01

    The main effects and interactions of soil-applied P, B, and Zn on yield and its components were examined in the field at two pH levels with Earliglow' strawberries (Fragaria ananassa Duch.). Applied nutrients had significant effects on several yield components, but responses depended on the levels of other nutrients or the soil pH. At a soil pH of 5.5, yield responded linearly to B and quadratically to P. At pH 6.5, P interacted with B and Zn. Fruit count per inflorescence was the yield component most strongly associated with yield, followed by individual fruit weight. However, these two yield components responded differently to soil-applied nutrients. Foliar nutrient levels generally did not increase with the amount of applied nutrient, but often an applied nutrient had a strong effect on the level of another nutrient. Leaf nutrient levels were often correlated with fruit levels, but foliar and fruit levels at harvest were not related to reproductive performance. The study identifies some of the problems inherent in using foliar nutrient levels to predict a yield response and demonstrates how plant responses to single nutrients depend on soil chemistry and the presence of other nutrients.

  7. Acidogenic fermentation of lignocellulose - acid yield and conversion of components

    SciTech Connect

    Datta, R.

    1981-01-01

    Corn stover was fermented with a mixed culture of anaerobic microorganisms to form simple (C2-C6), volatile organic acids. Alkaline pretreatment allowed a greater fermentation of the pectin and hemicellulose than of the cellulose and lignin, but all components were utilized. The percent fermentation of the soluble fraction, hemicellulose, cellulose, and lignin was 79.6, 74.1, 36.9, and 20.9%, respively. The yield of acid (as acetate) with respect to material fermented was 84%.

  8. Exploitation of heterosis loci for yield and yield components in rice using chromosome segment substitution lines

    PubMed Central

    Tao, Yajun; Zhu, Jinyan; Xu, Jianjun; Wang, Liujun; Gu, Houwen; Zhou, Ronghua; Yang, Zefeng; Zhou, Yong; Liang, Guohua

    2016-01-01

    We constructed 128 chromosome segment substitution lines (CSSLs), derived from a cross between indica rice (Oryza sativa L.) 9311 and japonica rice Nipponbare, to investigate the genetic mechanism of heterosis. Three photo-thermo-sensitive-genic male sterile lines (Guangzhan63-4s, 036s, and Lian99s) were selected to cross with each CSSL to produce testcross populations (TCs). Field experiments were carried out in 2009, 2011, and 2015 to evaluate yield and yield-related traits in the CSSLs and TCs. Four traits (plant height, spikelet per panicle, thousand-grain weight, and grain yield per plant) were significantly related between CSSLs and TCs. In the TCs, plant height, panicle length, seed setting rate, thousand-grain weight, and grain yield per plant showed partial dominance, indicating that dominance largely contributes to heterosis of these five traits. While overdominance may be more important for heterosis of panicles per plant and spikelet per panicle. Based on the bin-maps of CSSLs and TCs, we detected 62 quantitative trait loci (QTLs) and 97 heterotic loci (HLs) using multiple linear regression analyses. Some of these loci were clustered together. The identification of QTLs and HLs for yield and yield-related traits provide useful information for hybrid rice breeding, and help to uncover the genetic basis of rice heterosis. PMID:27833097

  9. Exploitation of heterosis loci for yield and yield components in rice using chromosome segment substitution lines.

    PubMed

    Tao, Yajun; Zhu, Jinyan; Xu, Jianjun; Wang, Liujun; Gu, Houwen; Zhou, Ronghua; Yang, Zefeng; Zhou, Yong; Liang, Guohua

    2016-11-11

    We constructed 128 chromosome segment substitution lines (CSSLs), derived from a cross between indica rice (Oryza sativa L.) 9311 and japonica rice Nipponbare, to investigate the genetic mechanism of heterosis. Three photo-thermo-sensitive-genic male sterile lines (Guangzhan63-4s, 036s, and Lian99s) were selected to cross with each CSSL to produce testcross populations (TCs). Field experiments were carried out in 2009, 2011, and 2015 to evaluate yield and yield-related traits in the CSSLs and TCs. Four traits (plant height, spikelet per panicle, thousand-grain weight, and grain yield per plant) were significantly related between CSSLs and TCs. In the TCs, plant height, panicle length, seed setting rate, thousand-grain weight, and grain yield per plant showed partial dominance, indicating that dominance largely contributes to heterosis of these five traits. While overdominance may be more important for heterosis of panicles per plant and spikelet per panicle. Based on the bin-maps of CSSLs and TCs, we detected 62 quantitative trait loci (QTLs) and 97 heterotic loci (HLs) using multiple linear regression analyses. Some of these loci were clustered together. The identification of QTLs and HLs for yield and yield-related traits provide useful information for hybrid rice breeding, and help to uncover the genetic basis of rice heterosis.

  10. Analyzing the components of hybrid cotton yield and its relationship with environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton hybrids show a commercially useful level of heterosis for lint yield. In poor yielding environments percent heterosis for lint yield is higher than in high yielding environments. Lint yield is a product of several yield components of which boll number has been reported to contribute the most ...

  11. Ascribing soil erosion of hillslope components to river sediment yield.

    PubMed

    Nosrati, Kazem

    2017-06-01

    In recent decades, soil erosion has increased in catchments of Iran. It is, therefore, necessary to understand soil erosion processes and sources in order to mitigate this problem. Geomorphic landforms play an important role in influencing water erosion. Therefore, ascribing hillslope components soil erosion to river sediment yield could be useful for soil and sediment management in order to decrease the off-site effects related to downstream sedimentation areas. The main objectives of this study were to apply radionuclide tracers and soil organic carbon to determine relative contributions of hillslope component sediment sources in two land use types (forest and crop field) by using a Bayesian-mixing model, as well as to estimate the uncertainty in sediment fingerprinting in a mountainous catchment of western Iran. In this analysis, (137)Cs, (40)K, (238)U, (226)Ra, (232)Th and soil organic carbon tracers were measured in 32 different sampling sites from four hillslope component sediment sources (summit, shoulder, backslope, and toeslope) in forested and crop fields along with six bed sediment samples at the downstream reach of the catchment. To quantify the sediment source proportions, the Bayesian mixing model was based on (1) primary sediment sources and (2) combined primary and secondary sediment sources. The results of both approaches indicated that erosion from crop field shoulder dominated the sources of river sediments. The estimated contribution of crop field shoulder for all river samples was 63.7% (32.4-79.8%) for primary sediment sources approach, and 67% (15.3%-81.7%) for the combined primary and secondary sources approach. The Bayesian mixing model, based on an optimum set of tracers, estimated that the highest contribution of soil erosion in crop field land use and shoulder-component landforms constituted the most important land-use factor. This technique could, therefore, be a useful tool for soil and sediment control management strategies.

  12. Effect of sowing dates on yield and yield components of spring safflower (Carthamus tinctorius L.) in Isfahan region.

    PubMed

    Nikabadi, S; Soleimani, A; Dehdashti, S M; Yazdanibakhsh, M

    2008-08-01

    In order to study the effect of sowing dates on the yield and yield components of two safflower varieties, an experiment was conducted at Agriculture Research Station of Isfahan Kabotar Abad in 2004. A split plot layout within randomized complete block design with three replications was used in the experimentation. Eight sowing dates were in the main plots, consist March 6, March 21, April 6, April 21, May 6, May 21, June 6 and June 21 and two varieties (Isfahan 14 and I.L111) were in the sub plots. The results showed that the number of seed per capitulum and seed yield were decreased significantly as the sowings dates were delayed. The Isfahan 14 variety in comparison with I.L111 produced more fertile capitulum in square meter and also, respectively seed per capitulum. The second sowing date (March 21) produced the highest seed yield (2306.2 kg ha(-1)), whereas the 7th sowing date (June 6) produced the lowest seed yield (622 kg ha(-1)). The effect of variety for seed yield was not significant. Farmers in the Kabotar Abad of Isfahan and in other areas with similar conditions are recommended to plant the Isfahan 14 variety on March 21.

  13. Estimates of broad-sense heritability for seed yield and yield components of safflower (Carthamus tinctorius L.).

    PubMed

    Camaş, Necdet; Esendal, Enver

    2006-12-01

    This study was carried out to estimate the broad-sense heritability for seed yield and some yield components of safflower (Carthamus tinctorius L.) cultivars. The experimental design was a randomized complete block design with three replications in the 2004 growing season in the Middle Black Sea Region conditions of Turkey. Three safflower cultivars (5-154, Dinçer and Yenice) were grown at five locations (Bafra, Ladik, Suluova, Gümüşhaciköy and Osmancik). The heritability for seed yield, plant height, first branch height, number of branch, head diameter, number of seed per head, 1000-seed weight and oil content were estimates as 35%, 93%, 99%, 45%, 21%, 69%, 81% and 59%, respectively. It was found that first branch height was the least affected trait over environments and followed plant height, thousand seed weight and number of seed per head. On the other hand, head diameter, seed yield, number of branch and oil content were the most affected traits versus environmental conditions. The first branch height, plant height and 1000-seed weight could be used to succeed in selection in early generation.

  14. Mapping quantitative trait loci associated with yield and yield components under reproductive stage salinity stress in rice (Oryza sativa L.).

    PubMed

    Mohammadi, Reza; Mendioro, Merlyn S; Diaz, Genaleen Q; Gregorio, Glenn B; Singh, Rakesh K

    2013-12-01

    Salinity tolerance in rice is critical at reproductive stage because it ultimately determines grain yield. An F2 mapping population derived from a Sadri/FL478 cross was exposed to saline field conditions (6-8 dS m(-1)) after the active tillering stage to identify reproductive stage specific QTLs for salinity tolerance. Genetic linkage map was constructed using 123 microsatellite markers on 232 F2 progenies. Totally 35 QTLs for 11 traits under salinity stress were detected with LOD > 3, out of which 28 QTLs that explained from 5.9 to 30.0% phenotypic variation were found to be significant based on permutation test. Three major QTL clusters were found on chromosomes 2 (RM423-RM174), 4 (RM551-RM518) and 6 (RM20224-RM528) for multiple traits under salinity stress. Both parental lines contributed additively for QTLs identified for the yield components. A majority of the QTLs detected in our study are reported for the first time for reproductive stage salinity stress. Fine-mapping of selected putative QTLs will be the next step to facilitate marker-assisted backcrossing and to detect useful genes for salinity tolerance at the reproductive stage in rice.

  15. An analysis of association of components of yield and oil in safflower (Carthamus tinctorius L.).

    PubMed

    Ranga Rao, V; Ramachandram, M; Arunachalam, V

    1977-07-01

    Inter-relationships of various component characters with yield and oil content were analysed using 215 entries of safflower from India and U.S.A. Correlation of capsule number per plant and capsule weight with yield per plant was pronounced and they showed large direct effects on yield. All other components influenced seed yield mainly through these two components. Seed size had little effect on yield while seed number exerted a positive influence. The proportion of hull expressed as per cent of the whole seed revealed a highly significant and inverse relationship with oil content and was mainly responsible for the observed variability in oil content in the material. Although negative association was indicated between seed size and oil content, it was observed to be due to the indirect effect of hull content and not due to direct effect of seed size. Interestingly, yield per plant and its major components, number of capsules and capsule weight, revealed a negligible relationship with oil content. Both direct as well as indirect effects of hull percent and yield per plant were responsible for the favourable effect of seed number on oil content. The correlation of plant height, days to first flowering and total crop growth period with yield and oil content was either negligible or low, offering scope for developing early maturing and dwarf varieties with high yield and oil content. Spine index showed a non-significant association with yield and oil content. Capsule number, capsule weight and hull per cent were observed to be the most important components in breeding for higher yield and oil content.

  16. Effect of laser priming on canola yield and its components under salt stress

    NASA Astrophysics Data System (ADS)

    Mohammadi, S. K.; Shekari, F.; Fotovat, R.; Darudi, A.

    2012-02-01

    The effect of laser priming at different irradiation times on canola yield and its components under saline conditions were investigated. The results showed that laser priming had a positive effect on yield and its components and caused yield increase under saline conditions. Increase in salt levels had a negative and significant effect on seed yield, number of seeds per pod, number of pod per plant, pod length and plant height. The results showed that 45-min laser priming had the strongest effect on yield and yield components and reduced significantly the adverse effects of salinity. By contrast, laser radiation applied for 60 and 75 min, resulted in a dramatic decrease in yield and its components. Correlation coefficients between the attributes showed that canola yield had a positive and significant correlation with plant height, number of seeds, pod per main branch and lateral branches, length of pod and number of lateral branches. Effects of laser and salinity were significant on lateral branch pod length but not on main branch pods.

  17. Relationships between Sugarcane Canopy Reflectance and Yield Components across a Large Number of Genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane (Saccharum spp.) growth and yield components are important traits in breeding and cultivar selection programs. Canopy reflectance of sugarcane during the growing season may be used to evaluate genotypes in growth and yield potential in the early stages of a sugarcane breeding program. The ...

  18. Yield Components and Nutritive Value of Black Locust and Mimosa in Arkansas.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ranchers need to provide alternative livestock feeds when herbaceous forages become limiting in summer. We determined foliar yield components and nutritive value (in vitro digestibility [IVDMD], total nonstructural carbohydrate [TNC], N, robinin, and mimosine) of transplanted Robinia pseudoacacia (b...

  19. Yield components and nutritive value of Robinia pseudoacacia and Albizia julibrissin in Arkansas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ranchers need to provide alternative livestock feeds when herbaceous forages become limiting in summer. We determined foliar yield components and nutritive value (in vitro digestibility [IVDMD], total nonstructural carbohydrate [TNC], N, robinin, and mimosine) of transplanted Robinia pseudoacacia (...

  20. Genotypic diversity in the responses of yield and yield components to elevated ozone of diverse inbred and hybrid maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current tropospheric ozone concentrations ([O3]), an important air pollutant, are phytotoxic and detrimental to crop yield causing significant losses of ~14-26 billion in 4 of the world’s major crops. Until recent years, it was believed that agricultural and economically important C4 plants, such as...

  1. Genetic analysis of seed yield, oil content and their components in safflower (Carthamus tinctorius L.).

    PubMed

    Ramachandram, M; Goud, J V

    1981-05-01

    The genetic architecture of seed yield, oil content and their components was studied in a diallel cross of F1 and F2: eleven parents, representing an adequate diversity for all considered characters in safflower were used. Combining ability analysis revealed the predominance of gca variance for plant height, total capitula, seed weight, seed number and seed yield in F1 and F2 generations and for days to flowering and oil content in F1. The analysis of components of variance indicated that the non-additive factor was the major influence on total capitula and seed yield in F1s, and F2s, and on plant height, seed weight and seed number in the F2 alone. The heterogeneity of the dominance component over generations has been attributed to coupling phase linkage. All four Indian parents, namely S 144, A1, MS 49 and 6 spl, together with G 1157 and US 104 in the exotic group, were the best combiners for seed yield and/or for one of its components while the remainder of the exotic parents were characterized by high gca effects for oil content. VFstp 1 and Frio were the only parents approximating both properties of oil content and seed yield. Breeding methods, such as biparental mating followed by reciprocal recurrent selection, were suggested for the simultaneous improvement of seed yield and oil content.

  2. Path and Ridge Regression Analysis of Seed Yield and Seed Yield Components of Russian Wildrye (Psathyrostachys juncea Nevski) under Field Conditions

    PubMed Central

    Wang, Quanzhen; Zhang, Tiejun; Cui, Jian; Wang, Xianguo; Zhou, He; Han, Jianguo; Gislum, René

    2011-01-01

    The correlations among seed yield components, and their direct and indirect effects on the seed yield (Z) of Russina wildrye (Psathyrostachys juncea Nevski) were investigated. The seed yield components: fertile tillers m-2 (Y1), spikelets per fertile tillers (Y2), florets per spikelet- (Y3), seed numbers per spikelet (Y4) and seed weight (Y5) were counted and the Z were determined in field experiments from 2003 to 2006 via big sample size. Y1 was the most important seed yield component describing the Z and Y2 was the least. The total direct effects of the Y1, Y3 and Y5 to the Z were positive while Y4 and Y2 were weakly negative. The total effects (directs plus indirects) of the components were positively contributed to the Z by path analyses. The seed yield components Y1, Y2, Y4 and Y5 were significantly (P<0.001) correlated with the Z for 4 years totally, while in the individual years, Y2 were not significant correlated with Y3, Y4 and Y5 by Peason correlation analyses in the five components in the plant seed production. Therefore, selection for high seed yield through direct selection for large Y1, Y2 and Y3 would be effective for breeding programs in grasses. Furthermore, it is the most important that, via ridge regression, a steady algorithm model between Z and the five yield components was founded, which can be closely estimated the seed yield via the components. PMID:21533153

  3. Interrelationship and path coefficient analysis of yield components in F4 progenies of tef (Eragrostis tef).

    PubMed

    Debebe, Abel; Singh, Harijat; Tefera, Hailu

    2014-01-01

    This experiment was conducted at Debre Zeit and Akaki during 2004-2005 cropping season on F2-derived F4 bulk families of three crosses, viz, DZ-01-974 x DZ-01-2786, DZ-01-974 x DZ-Cr-37 and Alba x Kaye Murri. To estimate the correlations and path coefficients between yield and yield components, 63 F4 families were taken randomly from each of the three crosses. The 189 F4 families, five parents and two checks were space planted following in 14 x 14 simple lattice design. Study of associations among traits indicated that yield was positively associated with shoot biomass, harvest index, lodging index and panicle kernel weight at phenotypic level at Debre Zeit. At Akaki, yield had significant positive correlation with shoot biomass, harvest index, plant height, panicle length and panicle weight. At genotypic level, grain yield per plot exhibited positive association with harvest index, shoot biomass, lodging index and panicle kernel weight at Debre Zeit. By contrast, days to heading, days to maturity, plant height and panicle length showed negative association with yield. At Akaki, kernel yield per plot was positively correlated at genotypic level with all the traits considered where lodging index had the highest correlation followed by shoot biomass, panicle kernel weight and harvest index. Path coefficient analysis at both phenotypic and genotypic levels for both the locations suggested those shoot biomass and harvest indexes are the two important yield determining traits. These two traits might be useful in indirect selection for yield improvement in the material generated from the three crosses under consideration.

  4. QTL analysis for fruit yield components in table grapes (Vitis vinifera).

    PubMed

    Fanizza, G; Lamaj, F; Costantini, L; Chaabane, R; Grando, M S

    2005-08-01

    A segregation population of 184 genotypes derived from a pseudo-testcross of table grapes (Vitis vinifera), together with 203 AFLP and 110 SSR markers was used to detect quantitative trait loci (QTLs) for fruit yield components. Diffferent QTLs, a low percentage of phenotypic variance explained by the QTLs detected and QTL instability over years were detected for each fruit yield component. These results confirm the complex genetic architecture of the yield components in grapevine due to the perennial nature of this species, which has to adapt to yearly variations in climate. Phenotypic correlation analyses between fruit yield components were also performed. The negative correlation between berry weight and the number of berries per cluster seems to have an indirect negative effect on cluster weight, as revealed by the path coefficient analysis; however, this negative correlation was not supported at the molecular level because no coincident QTLs were observed between these traits. Nonetheless, the possibility to select seedless genotypes with large berries without affecting cluster weight needs to be substantiated in future experiments because factors such as sample size and heritability might influence QTL identification in table grapes.

  5. Dissecting the components of hybrid vigor associated lint yield in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of heterosis to increase yield of cotton has long been a breeding objective. A previous study suggests that mid-parent heterosis is negatively correlated with environment mean yield thus suggesting lint yield is higher in hybrids compared to parents in low yielding environments. We present here ...

  6. Impact of low concentration factor microfiltration on milk component recovery and Cheddar cheese yield.

    PubMed

    Neocleous, M; Barbano, D M; Rudan, M A

    2002-10-01

    The effect of microfiltration (MF) on the composition of Cheddar cheese, fat, crude protein (CP), calcium, total solids recovery, and Cheddar cheese yield efficiency (i.e., composition adjusted yield divided by theoretical yield) was determined. Raw skim milk was microfiltered twofold using a 0.1-microm ceramic membrane at 50 degrees C. Four vats of cheese were made in one day using milk at lx, 1.26x, 1.51x, and 1.82x concentration factor (CF). An appropriate amount of cream was added to achieve a constant casein (CN)-to-fat ratio across treatments. Cheese manufacture was repeated on four different days using a randomized complete block design. The composition of the cheese was affected by MF. Moisture content of the cheese decreased with increasing MF CF. Standardization of milk to a constant CN-to-fat ratio did not eliminate the effect of MF on cheese moisture content. Fat recovery in cheese was not changed by MF. Separation of cream prior to MF, followed by the recombination of skim or MF retentate with cream resulted in lower fat recovery in cheese for control and all treatments and higher fat loss in whey when compared to previous yield experiments, when control Cheddar cheese was made from unseparated milk. Crude protein, calcium, and total solids recovery in cheese increased with increasing MF CF, due to partial removal of these components prior to cheese making. Calcium and calcium as a percentage of protein increased in the cheese, suggesting an increase in calcium retention in the cheese with increasing CF. While the actual and composition adjusted cheese yields increased with increasing MF CF, as expected, there was no effect of MF CF on cheese yield efficiency.

  7. Soil Texture and Cultivar Effects on Rice (Oryza sativa, L.) Grain Yield, Yield Components and Water Productivity in Three Water Regimes

    PubMed Central

    Dou, Fugen; Soriano, Junel; Tabien, Rodante E.; Chen, Kun

    2016-01-01

    The objective of this study was to determine the effects of water regime/soil condition (continuous flooding, saturated, and aerobic), cultivar (‘Cocodrie’ and ‘Rondo’), and soil texture (clay and sandy loam) on rice grain yield, yield components and water productivity using a greenhouse trial. Rice grain yield was significantly affected by soil texture and the interaction between water regime and cultivar. Significantly higher yield was obtained in continuous flooding than in aerobic and saturated soil conditions but the latter treatments were comparable to each other. For Rondo, its grain yield has decreased with soil water regimes in the order of continuous flooding, saturated and aerobic treatments. The rice grain yield in clay soil was 46% higher than in sandy loam soil averaged across cultivar and water regime. Compared to aerobic condition, saturated and continuous flooding treatments had greater panicle numbers. In addition, panicle number in clay soil was 25% higher than in sandy loam soil. The spikelet number of Cocodrie was 29% greater than that of Rondo, indicating that rice cultivar had greater effect on spikelet number than soil type and water management. Water productivity was significantly affected by the interaction of water regime and cultivar. Compared to sandy loam soil, clay soil was 25% higher in water productivity. Our results indicated that cultivar selection and soil texture are important factors in deciding what water management option to practice. PMID:26978525

  8. Seed yield and its components of indeterminate and determinate lines in recombinant inbred lines of soybean

    PubMed Central

    Kato, Shin; Fujii, Kenichiro; Yumoto, Setsuzo; Ishimoto, Masao; Shiraiwa, Tatsuhiko; Sayama, Takashi; Kikuchi, Akio; Nishio, Takeshi

    2015-01-01

    The present study was conducted to evaluate the benefits of indeterminate growth habit in breeding to improve yield potential of Japanese soybean varieties, which exclusively have determinate growth habit. Two populations of recombinant inbred lines (RILs) derived from crosses between determinate Japanese cultivars and indeterminate US cultivars were grown in Akita and Kyoto, and seed weight per plant (SW) and its components were compared between indeterminate and determinate RILs. The difference of SW between the two growth habits in RILs varied depending on maturation time. The SW of early indeterminate lines was significantly higher than that of early determinate ones in Akita, but not in Kyoto. Among yield components, the number of seeds per pod was constantly larger in indeterminate lines than that in determinate ones irrespective of maturation time. The number of seeds per plant and the number of pods per plant of the indeterminate lines were greater than those of the determinate lines in early maturation in Akita. These results suggest that the indeterminate growth habit is an advantageous characteristic in breeding for high yield of early maturing soybean varieties in the Tohoku region. PMID:26069445

  9. The effects of nitrogen starter fertilizer and plant density on yield, yield components and oil and protein content of soybean (Glycine max L. Merr).

    PubMed

    Boroomandan, P; Khoramivafa, M; Haghi, Y; Ebrahimi, A

    2009-02-15

    Effects of nitrogen starter fertilizer and plant density on yield and oil and protein content of soybean (Glycine max L. Merr) are not well understood, because nitrogen starter fertilizer and plant density has been tested separately. Two years field experiment was conducted to evaluate effects of these factors on yield, yield components, oil and protein content in 2006 and 2007 in Kermanshah, Iran. The experiment was conducted on soybean (var. Williams) as a split-plot based on randomized complete blocks design with three replications. Nitrogen starter fertilizer treatments were arranged in three rates (0, 40, 80 kg ha(-1)) as main plots and plant density as sub plots arranged with three levels (15, 30, 45 plant m(-2)). Based on similarity treatments and experimental designs, the results of analysis of combined variance and mean comparisons showed significant (528.4 kg ha(-1) yield increase as density increased from 30 to 45 plant m(-2) and nitrogen starter fertilizer increased from 0 to 40 kg ha(-1) in two years. Analysis of correlation showed a positive significant correlation between yield and number of seed per plant (r = 0.724), number of pods and yield (r = 0.463), thousand seed weight and yield (r = 0.437). A linear regression was found between yield and number of seed per plant, number of pods and thousand seed weight (yield = 37.58 + 0.73x1-0.14x2 + 0.7x3; r2 = 0.56); p < 0.01). Seed protein was unaffected by plant densities, but nitrogen application changed it. Dissimilarly, oil content has a diverse respond to treatments. This experiment showed density of 45 plant m(-2) and application of nitrogen starter fertilizer 40 kg ha(-1) are optimum and increase grain yield under condition of our experiment. We suggest to conduct some experiments for understanding of linear relationship for number of pod for understanding of linear relationship for number of pod for levels of nitrogen starter and quadratic relationship for number of seed for levels of density.

  10. Responses of Nigella sativa L. to Zinc Excess: Focus on Germination, Growth, Yield and Yield Components, Lipid and Terpene Metabolism, and Total Phenolics and Antioxidant Activities.

    PubMed

    Marichali, Ahmed; Dallali, Sana; Ouerghemmi, Saloua; Sebei, Houcine; Casabianca, Hervé; Hosni, Karim

    2016-03-02

    A comprehensive analysis of the responses of Nigella sativa L. to elevated zinc concentrations was assessed in pot experiments. Zn excess supply did not affect the germination but drastically reduced radicle elongation. A concentration-dependent reduction in all growth parameters, yield, and yield components was observed. With the increasing Zn concentrations, total lipid contents decreased and changes in fatty composition toward the production of saturated ones were underscored. Despite the reduction in the seeds essential oil yield, a redirection of the terpene metabolism toward the synthesis of oxygenated compounds has been evidenced. A significant increase in the total phenols and flavonoids contents concomitant with improved antioxidant activities has also been found. Collectively, these results highlight the possible use of N. sativa L. in phytoremediation applications, on the one hand, and that Zn excess could represent an excellent alternative to improve the nutritional attributes of this important species, on the other hand.

  11. Investigation the growth, yield and yield components of rice varieties in rotation with garlic, Faba bean, lettuce, pea and fallow in north of Iran.

    PubMed

    Nasiri, Morteza; Pirdashti, Hemmatollah; Tari, Davood Barari

    2007-08-15

    In order to investigating the effects of second crop cultivation on growth, yield and yield components of rice, a field experiment was conducted at the Rice Research Institute of Iran-Deputy of Mazandaran (Amol) during 2004 and 2005. Tarom as a traditional variety and Fajr as a improved variety were used in this research. Faba, pea, Lettuce and garlic were used as a second crop in rotation with rice. Second crop cultivation, variety and interaction between them had a significant effect on tiller number at 0.01 probability level. Results showed that rice yield after lettuce and garlic rotation was lower than with Faba bean, pea and fallow rotation. These results indicated that rice varieties had different reaction to second crop cultivation. For example, Tarom variety in rotation with lettuce and garlic had higher yield deficiency than Fajr variety. These results suggested that Lettuce and garlic can not be a permanent second crop in paddy field. According to results, pea and faba bean in rotation with rice for the best performance of yield attributes of rice varieties were recommended.

  12. Effects of stage of pregnancy on variance components, daily milk yields and 305-day milk yield in Holstein cows, as estimated by using a test-day model.

    PubMed

    Yamazaki, T; Hagiya, K; Takeda, H; Osawa, T; Yamaguchi, S; Nagamine, Y

    2016-08-01

    Pregnancy and calving are elements indispensable for dairy production, but the daily milk yield of cows decline as pregnancy progresses, especially during the late stages. Therefore, the effect of stage of pregnancy on daily milk yield must be clarified to accurately estimate the breeding values and lifetime productivity of cows. To improve the genetic evaluation model for daily milk yield and determine the effect of the timing of pregnancy on productivity, we used a test-day model to assess the effects of stage of pregnancy on variance component estimates, daily milk yields and 305-day milk yield during the first three lactations of Holstein cows. Data were 10 646 333 test-day records for the first lactation; 8 222 661 records for the second; and 5 513 039 records for the third. The data were analyzed within each lactation by using three single-trait random regression animal models: one model that did not account for the stage of pregnancy effect and two models that did. The effect of stage of pregnancy on test-day milk yield was included in the model by applying a regression on days pregnant or fitting a separate lactation curve for each days open (days from calving to pregnancy) class (eight levels). Stage of pregnancy did not affect the heritability estimates of daily milk yield, although the additive genetic and permanent environmental variances in late lactation were decreased by accounting for the stage of pregnancy effect. The effects of days pregnant on daily milk yield during late lactation were larger in the second and third lactations than in the first lactation. The rates of reduction of the 305-day milk yield of cows that conceived fewer than 90 days after the second or third calving were significantly (P<0.05) greater than that after the first calving. Therefore, we conclude that differences between the negative effects of early pregnancy in the first, compared with later, lactations should be included when determining the optimal number of days open

  13. Relationship between physiological traits and yield components of peanut genotypes with different levels of terminal drought resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationships between physiological traits related to drought tolerance and yield components of peanut genotypes are not well understood. The objective of this study was to investigate the relationships between physiological traits related to drought tolerance and yield components of peanut gen...

  14. Response of Yield and Yield Components of Tef [Eragrostis tef (Zucc.) Trotter] to Tillage, Nutrient, and Weed Management Practices in Dura Area, Northern Ethiopia.

    PubMed

    Tesfahunegn, Gebreyesus Brhane

    2014-01-01

    The low average grain yield (0.7 ton ha(-1)) of tef in Ethiopia is mainly attributed to low soil fertility, and inappropriate tillage and weeds control practices. Despite this, limited scientific information has been documented so far on their interaction effects on tef crop productivity in northern Ethiopia. The objective of this study was to assess the separate and interaction effects of tillage, fertilizer, and weed control practices on tef yield and yield components in the conditions of northern Ethiopia. A two-year study (2008-2009) was conducted using split-split-plot design with three replications. In the main plot, three tillage treatments: conventional tillage (6 times tillage passes) (T1), four times tillage passes (T2), and reduced tillage (single tillage pass at sowing) (T3) were applied. The fertilizer treatments in the subplots were: no fertilizer (F1); 23 kg N ha(-1) (F2); 23 kg N ha(-1) and 10 kg P ha(-1) (F3); 23 kg N ha(-1) and 2.5 ton manure ha(-1) (F4); and 2.5 ton manure ha(-1) (F5). The sub-subplot weed control treatments included farmer weed control practice or hand weeding (W1); 2,4 D at 0.75 kg ha(-1) at five-leaf stage; 2,4 D at 0.75 kg ha(-1) at six-leaf stage; 2,4 D at 1.5 kg ha(-1) at five-leaf stage; and 2,4 D at 1.5 kg ha(-1) at six-leaf stage. This study showed that the separate and interaction effects of tillage, fertilizer, and weed control practices significantly affected tef crop yield and yield components in both crop seasons. T2 increased tef yield by >42% over the other tillage and F3 increased yield by >21% over the other fertilizer treatments. Grain yield increased by >23% due to W1. This study thus suggested that promising treatments such as T2, F3, and W1 should be demonstrated at on-farm fields in order to evaluate their performance at farmers' conditions.

  15. Response of Yield and Yield Components of Tef [Eragrostis tef (Zucc.) Trotter] to Tillage, Nutrient, and Weed Management Practices in Dura Area, Northern Ethiopia

    PubMed Central

    Tesfahunegn, Gebreyesus Brhane

    2014-01-01

    The low average grain yield (0.7 ton ha−1) of tef in Ethiopia is mainly attributed to low soil fertility, and inappropriate tillage and weeds control practices. Despite this, limited scientific information has been documented so far on their interaction effects on tef crop productivity in northern Ethiopia. The objective of this study was to assess the separate and interaction effects of tillage, fertilizer, and weed control practices on tef yield and yield components in the conditions of northern Ethiopia. A two-year study (2008-2009) was conducted using split-split-plot design with three replications. In the main plot, three tillage treatments: conventional tillage (6 times tillage passes) (T1), four times tillage passes (T2), and reduced tillage (single tillage pass at sowing) (T3) were applied. The fertilizer treatments in the subplots were: no fertilizer (F1); 23 kg N ha−1 (F2); 23 kg N ha−1 and 10 kg P ha−1 (F3); 23 kg N ha−1 and 2.5 ton manure ha−1 (F4); and 2.5 ton manure ha−1 (F5). The sub-subplot weed control treatments included farmer weed control practice or hand weeding (W1); 2,4 D at 0.75 kg ha−1 at five-leaf stage; 2,4 D at 0.75 kg ha−1 at six-leaf stage; 2,4 D at 1.5 kg ha−1 at five-leaf stage; and 2,4 D at 1.5 kg ha−1 at six-leaf stage. This study showed that the separate and interaction effects of tillage, fertilizer, and weed control practices significantly affected tef crop yield and yield components in both crop seasons. T2 increased tef yield by >42% over the other tillage and F3 increased yield by >21% over the other fertilizer treatments. Grain yield increased by >23% due to W1. This study thus suggested that promising treatments such as T2, F3, and W1 should be demonstrated at on-farm fields in order to evaluate their performance at farmers' conditions. PMID:27379271

  16. Can principal components yield a dimension reduced description of protein dynamics on long time scales?

    PubMed

    Lange, Oliver F; Grubmüller, Helmut

    2006-11-16

    The suitability of principal component analysis (PCA) to yield slow collective coordinates for use within a dimension reduced description of conformational motions in proteins is evaluated. Two proteins are considered, T4 lysozyme and crambin. We present a quantitative evaluation of the convergence of conformational coordinates obtained with principal component analysis. Detailed analyses of (>200 ns) molecular dynamics trajectories and crystallographic data suggests that simulations of a few nanoseconds should generally provide a stable and statistically reliable definition of the essential and near constraints subspaces. Moreover, a systematic assessment of the density of states of the dynamics of all principal components showed that for an optimal separation of time scales it is crucial to include also side chain atoms in the PCA.

  17. To study of different level of nitrogen manure and density on yield and yield component of variety of K.S.C 704 in dry region of sistan

    SciTech Connect

    Dahmardeh, M.; Forghani, F.; Khammari, E.

    2008-01-30

    Out of three grain of the world, Corn is one of the best, About 7 to 10 thousand years ago in south of Mexico corn become domesticated. In the year 1995 culfivation of corn in the world was 130 mil/ha, and to Total production of the world of corn is 507 M/Tons. Average yield of corn in the year 1995 Among Producer countries was 7.78 To 7.60 t/ha in fance and united state was state was 2.36 To 2.20 t/ha, but in Brazil and Mexico Production of corn was different. With this regards, special manner has been arranged for the suitable cultivation or suitable density plants in one heactar on cultivation variety of K.S.C 704 corn. Also suitable level of Nitrogen manure, this Protect in climatic condition of Sistan region done, sith complete block design with 3 replication. Experiment has been selected as split plot, the main plot with 4 different concentration level such as (200-250-3500 and 350 Kg/ha) and sub plot density with 3 different level such as 111000,83000 and 66000 plan/ha respectively. From stage growth up to harvesting of corn in this reache having Data for each treat. ment, After harvesting Analysis of variance and companion of Average of each treatment has been done by DunKan method. Results has been shown, Measurment of characteristics (yield component) seed yield effected different density level of manure, with increasing of manure weight of one thousand seed yield and also in high density showed high significant differente amoung each other. These are with suitable climatic condition of sistan region if enough water will be available ed using Amount of 350 ks/ha Nitrogen manure and with density 111000 plants/ha we can product suitable seed yield Biological yield.

  18. To study of different level of nitrogen manure and density on yield and yield component of variety of K.S.C 704 in dry region of sistan

    NASA Astrophysics Data System (ADS)

    Dahmardeh, M.; Forghani, F.; Khammari, E.

    2008-01-01

    Out of three grain of the world, Corn is one of the best, About 7 to 10 thousand years ago in south of Mexico corn become domesticated. In the year 1995 culfivation of corn in the world was 130 mil/ha, and to Total production of the world of corn is 507 M/Tons. Average yield of corn in the year 1995 Among Producer countries was 7.78 To 7.60 t/ha in fance and united state was state was 2.36 To 2.20 t/ha, but in Brazil and Mexico Production of corn was different. With this regards, special manner has been arranged for the suitable cultivation or suitable density plants in one heactar on cultivation variety of K.S.C 704 corn. Also suitable level of Nitrogen manure, this Protect in climatic condition of Sistan region done, sith complete block design with 3 replication. Experiment has been selected as split plot, the main plot with 4 different concentration level such as (200-250-3500 and 350 Kg/ha) and sub plot density with 3 different level such as 111000,83000 and 66000 plan/ha respectively. From stage growth up to harvesting of corn in this reache having Data for each treat. ment, After harvesting Analysis of variance and companion of Average of each treatment has been done by DunKan method. Results has been shown, Measurment of characteristics (yield component) seed yield effected different density level of manure, with increasing of manure weight of one thousand seed yield and also in high density showed high significant differente amoung each other. These are with suitable climatic condition of sistan region if enough water will be available ed using Amount of 350 ks/ha Nitrogen manure and with density 111000 plants/ha we can product suitable seed yield Biological yield.

  19. Yield Advances in Peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Average yields of peanut in the U.S. set an all time record of 4,695 kg ha-1 in 2012. This far exceeded the previous record yield of 3,837 kg ha-1 in 2008. Favorable weather conditions undoubtedly contributed to the record yields in 2012; however, these record yields would not have been achievable...

  20. Pistil Smut Infection Increases Ovary Production, Seed Yield Components, and Pseudosexual Reproductive Allocation in Buffalograss

    PubMed Central

    Chandra, Ambika; Huff, David R.

    2014-01-01

    Sex expression of dioecious buffalograss [Bouteloua dactyloides Columbus (syn. Buchloë dactyloides (Nutt.) Engelm.)] is known to be environmentally stable with approximate 1:1, male to female, sex ratios. Here we show that infection by the pistil smut fungus [Salmacisia buchloëana Huff & Chandra (syn. Tilletia buchloëana Kellerman and Swingle)] shifts sex ratios of buffalograss to be nearly 100% phenotypically hermaphroditic. In addition, pistil smut infection decreased vegetative reproductive allocation, increased most seed yield components, and increased pseudosexual reproductive allocation in both sex forms compared to uninfected clones. In female sex forms, pistil smut infection resulted in a 26 fold increase in ovary production and a 35 fold increase in potential harvest index. In male sex forms, pistil smut infection resulted in 2.37 fold increase in floret number and over 95% of these florets contained a well-developed pistil. Although all ovaries of infected plants are filled with fungal teliospores and hence reproductively sterile, an average male-female pair of infected plants exhibited an 87 fold increase in potential harvest index compared to their uninfected clones. Acquiring an ability to mimic the effects of pistil smut infection would enhance our understanding of the flowering process in grasses and our efforts to increase seed yield of buffalograss and perhaps other grasses. PMID:27135522

  1. Response to Phenotypic and Marker-Assisted Selection for Yield and Quality Component Traits in Cucumber (Cucumis Sativus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Even though the potential benefits of marker-assisted selection (MAS) for line and population development to improve yield in cucumber have been demonstrated, its application during tandem selection for yield and quality components has not been investigated. Therefore, two cucumber recombinant inbr...

  2. Transgressive variation for yield components measured throughout the growth cycle of Jefferson rice (Oryza sativa) x O. rufipogon introgression lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies demonstrated alleles introduced into elite rice (Oryza sativa) cultivars from the wild ancestral species, O. rufipogon, enhanced yield and yield components as a result of transgressive variation. A study was conducted to unveil phenological and agronomic mechanisms that underlie in...

  3. Conditional QTL mapping of protein content in wheat with respect to grain yield and its components.

    PubMed

    Wang, Lin; Cui, Fa; Wang, Jinping; Jun, Li; Ding, Anming; Zhao, Chunhua; Li, Xingfeng; Feng, Deshun; Gao, Jurong; Wang, Honggang

    2012-01-01

    Grain protein content in wheat (Triticum aestivum L.) is generally considered a highly heritable character that is negatively correlated with grain yield and yield-related traits. Quantitative trait loci (QTL) for protein content was mapped using data on protein content and protein content conditioned on the putatively interrelated traits to evaluate possible genetic interrelationships between protein content and yield, as well as yield-related traits. Phenotypic data were evaluated in a recombinant inbred line population with 302 lines derived from a cross between the Chinese cultivar Weimai 8 and Luohan 2. Inclusive composite interval mapping using IciMapping 3.0 was employed for mapping unconditional and conditional QTL with additives. A strong genetic relationship was found between protein content and grain yield, and yield-related traits. Unconditional QTL mapping analysis detected seven additive QTL for protein content, with additive effects ranging in absolute size from 0.1898% to 0.3407% protein content, jointly accounting for 43.45% of the trait variance. Conditional QTL mapping analysis indicated two QTL independent from yield, which can be used in marker-assisted selection for increasing yield without affecting grain protein content. Three additional QTL with minor effects were identified in the conditional mapping. Of the three QTLs, two were identified when protein content was conditioned on yield, which had pleiotropic effects on those two traits. Conditional QTL mapping can be used to dissect the genetic interrelationship between two traits at the individual QTL level for closely correlated traits. Further, conditional QTL mapping can reveal additional QTL with minor effects that are undetectable in unconditional mapping.

  4. Yield and yield components of hybrid corn (Zea mays L.) as affected by mycorrhizal symbiosis and zinc sulfate under drought stress.

    PubMed

    Sajedi, N A; Ardakani, M R; Rejali, F; Mohabbati, F; Miransari, Mohammad

    2010-12-01

    With respect to the significance of improving hybrid corn performance under stress, this experiment was conducted at the Islamic Azad University, Arak Branch, Iran. A complete randomized block design with three levels of irrigations (at 100%, 75% and 50% crop water requirement), two levels of arbuscular mycorrhizal (AM) fungi (Glumus intraradisis) (including control), and three levels of zinc (Zn) sulfate (0, 25 and 45 kg ha(-1)), was performed. Results of the 2-year experiments indicated that irrigation treatment significantly affected corn yield and its components at P = 1%. AM fungi and increasing Zn levels also resulted in similar effects on corn growth and production. Although AM fungi did not significantly affect corn growth at the non-stressed irrigation treatment, at moderate drought stress AM fungi significantly enhanced corn quality and yield relative to the control treatment. The combined effects of AM fungi and Zn sulfate at 45 kg ha(-1) application significantly affected corn growth and production. In addition, the tripartite treatments significantly enhanced corn yield at P = 1%. Effects of Zn and AM fungi on plant growth under drought stress is affected by the stress level.

  5. Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice

    PubMed Central

    Tanger, Paul; Klassen, Stephen; Mojica, Julius P.; Lovell, John T.; Moyers, Brook T.; Baraoidan, Marietta; Naredo, Maria Elizabeth B.; McNally, Kenneth L.; Poland, Jesse; Bush, Daniel R.; Leung, Hei; Leach, Jan E.; McKay, John K.

    2017-01-01

    To ensure food security in the face of population growth, decreasing water and land for agriculture, and increasing climate variability, crop yields must increase faster than the current rates. Increased yields will require implementing novel approaches in genetic discovery and breeding. Here we demonstrate the potential of field-based high throughput phenotyping (HTP) on a large recombinant population of rice to identify genetic variation underlying important traits. We find that detecting quantitative trait loci (QTL) with HTP phenotyping is as accurate and effective as traditional labor-intensive measures of flowering time, height, biomass, grain yield, and harvest index. Genetic mapping in this population, derived from a cross of an modern cultivar (IR64) with a landrace (Aswina), identified four alleles with negative effect on grain yield that are fixed in IR64, demonstrating the potential for HTP of large populations as a strategy for the second green revolution. PMID:28220807

  6. Phylogeny of endocytic components yields insight into the process of nonendosymbiotic organelle evolution

    PubMed Central

    Dacks, Joel B.; Poon, Pak P.; Field, Mark C.

    2008-01-01

    The process by which some eukaryotic organelles, for example the endomembrane system, evolved without endosymbiotic input remains poorly understood. This problem largely arises because many major cellular systems predate the last common eukaryotic ancestor (LCEA) and thus do not provide examples of organellogenesis in progress. A model is emerging whereby gene duplication and divergence of multiple “specificity-” or “identity-” encoding proteins for the various endomembranous organelles produced the diversity of nonendosymbiotically derived cellular compartments present in modern eukaryotes. To address this possibility, we analyzed three molecular components of the endocytic membrane-trafficking machinery. Phylogenetic analyses of the endocytic syntaxins, Rab 5, and the β-adaptins each reveal a pattern of ancestral, undifferentiated endocytic homologues in the LCEA. Subsequently, these undifferentiated progenitors independently duplicated in widely divergent lineages, convergently producing components with similar endocytic roles, e.g., β1 and β2-adaptin. In contrast, β3, β4, and all other adaptin complex subunits, as well as paralogues of the syntaxins and Rabs specific for the other membrane-trafficking organelles, all evolved before the LCEA. Thus, the process giving rise to the differentiated organelles of the endocytic system appears to have been interrupted by the major speciation event that produced the extant eukaryotic lineages. These results suggest that although many endocytic components evolved before the LCEA, other major features evolved independently and convergently after diversification into the primary eukaryotic supergroups. This finding provides an example of a basic cellular system that was simpler in the LCEA than in many extant eukaryotes and yields insight into nonendosymbiotic organelle evolution. PMID:18182495

  7. Analysis of hadron yield data within hadron resonance gas model with multi-component eigenvolume corrections

    NASA Astrophysics Data System (ADS)

    Vovchenko, Volodymyr; Stoecker, Horst

    2017-01-01

    We analyze the sensitivity of thermal fits to heavy-ion hadron yield data of ALICE and NA49 collaborations to the systematic uncertainties in the hadron resonance gas (HRG) model related to the modeling of the eigenvolume interactions. We find a surprisingly large sensitivity in extraction of chemical freeze-out parameters to the assumptions regarding eigenvolumes of different hadrons. We additionally study the effect of including yields of light nuclei into the thermal fits to LHC data and find even larger sensitivity to the modeling of their eigenvolumes. The inclusion of light nuclei yields, thus, may lead to further destabilization of thermal fits. Our results show that modeling of eigenvolume interactions plays a crucial role in thermodynamics of HRG and that conclusions based on a non-interacting HRG are inconclusive.

  8. Mutations in Durum Wheat SBEII Genes affect Grain Yield Components, Quality, and Fermentation Responses in Rats.

    PubMed

    Hazard, Brittany; Zhang, Xiaoqin; Naemeh, Mahmoudreza; Hamilton, M Kristina; Rust, Bret; Raybould, Helen E; Newman, John W; Martin, Roy; Dubcovsky, Jorge

    2015-01-01

    Increased amylose in wheat (Triticum ssp.) starch is associated with increased resistant starch, a fermentable dietary fiber. Fermentation of resistant starch in the large intestine produces short-chain fatty acids that are associated with human health benefits. Since wheat foods are an important component of the human diet, increases in amylose and resistant starch in wheat grains have the potential to deliver health benefits to a large number of people. In three replicated field trials we found that mutations in starch branching enzyme II genes (SBEIIa and SBEIIb) in both A and B genomes (SBEIIa/b-AB) of durum wheat [T. turgidum L. subsp. durum (Desf.) Husn.] resulted in large increases of amylose and resistant starch content. The presence of these four mutations was also associated with an average 5% reduction in kernel weight (P = 0.0007) and 15% reduction in grain yield (P = 0.06) compared to the wild type. Complete milling and pasta quality analysis showed that the mutant lines have an acceptable quality with positive effects on pasta firmness and negative effects on semolina extraction and pasta color. Positive fermentation responses were detected in rats (Rattus spp.) fed with diets incorporating mutant wheat flour. This study quantifies benefits and limitations associated with the deployment of the SBEIIa/b-AB mutations in durum wheat and provides the information required to develop realistic strategies to deploy durum wheat varieties with increased levels of amylose and resistant starch.

  9. Mutations in Durum Wheat SBEII Genes affect Grain Yield Components, Quality, and Fermentation Responses in Rats

    PubMed Central

    Hazard, Brittany; Zhang, Xiaoqin; Naemeh, Mahmoudreza; Hamilton, M. Kristina; Rust, Bret; Raybould, Helen E.; Newman, John W.; Martin, Roy; Dubcovsky, Jorge

    2016-01-01

    Increased amylose in wheat (Triticum ssp.) starch is associated with increased resistant starch, a fermentable dietary fiber. Fermentation of resistant starch in the large intestine produces short-chain fatty acids that are associated with human health benefits. Since wheat foods are an important component of the human diet, increases in amylose and resistant starch in wheat grains have the potential to deliver health benefits to a large number of people. In three replicated field trials we found that mutations in starch branching enzyme II genes (SBEIIa and SBEIIb) in both A and B genomes (SBEIIa/b-AB) of durum wheat [T. turgidum L. subsp. durum (Desf.) Husn.] resulted in large increases of amylose and resistant starch content. The presence of these four mutations was also associated with an average 5% reduction in kernel weight (P = 0.0007) and 15% reduction in grain yield (P = 0.06) compared to the wild type. Complete milling and pasta quality analysis showed that the mutant lines have an acceptable quality with positive effects on pasta firmness and negative effects on semolina extraction and pasta color. Positive fermentation responses were detected in rats (Rattus spp.) fed with diets incorporating mutant wheat flour. This study quantifies benefits and limitations associated with the deployment of the SBEIIa/b-AB mutations in durum wheat and provides the information required to develop realistic strategies to deploy durum wheat varieties with increased levels of amylose and resistant starch. PMID:27134286

  10. 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

  11. Genome-wide association of rice blast disease resistance and yield-related components of rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Robust disease resistance may require an expenditure of energy that may limit crop yield potential. In the present study, a subset of a USDA rice core collection consisting of 151 accessions was selected using a major blast resistance (R) gene Pi-ta marker, and was genotyped with 156 simple sequence...

  12. Mendelizing all Components of a Pyramid of Three Yield QTL in Tomato

    PubMed Central

    Gur, Amit; Zamir, Dani

    2015-01-01

    Molecular markers allowed breeders to mendelize quantitative trait loci (QTL) providing another demonstration that quantitative traits are governed by the same principles as single qualitative genes. This research extends the QTL analysis to two and three QTL and tests our ability to mendelize an oligogenic trait. In tomato, agricultural yield is determined by the weight of the fruits harvested per unit area and the total soluble solids (% Brix)–sugars and acids. The current study explores the segregation of multiple independent yield-related QTL that were identified and mapped using introgression lines (IL) of Solanum pennellii in cultivated processing tomato (S. lycopersicum). We screened 45 different double and triple IL-QTL combinations for agricultural yield, to identify QTL pyramids that behaved in an additive manner and were suitable substrate for mendelizing an oligogenic trait. A pyramid of three independent QTL that significantly improved Brix∗Yield (BXY - the soluble solids output per unit area) compared to M82 was selected. In the progenies of the tri-hybrid we bred using markers a nearly isogenic ‘immortalized F2.’ While the common mode of QTL–QTL interactions across the 45 IL-QTLs combinations was less than additive, the three QTLs in the selected triple-stack performed in an additive manner which made it an exceptional material for breeding. This study demonstrates that using the phenotypic effect of all 27 possible QTL-alleles combinations it is possible to make reliable predictions about the genotypes that will maximize the yield. PMID:26697048

  13. 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.

  14. Energy use efficiency is characterized by an epigenetic component that can be directed through artificial selection to increase yield.

    PubMed

    Hauben, Miriam; Haesendonckx, Boris; Standaert, Evi; Van Der Kelen, Katrien; Azmi, Abdelkrim; Akpo, Hervé; Van Breusegem, Frank; Guisez, Yves; Bots, Marc; Lambert, Bart; Laga, Benjamin; De Block, Marc

    2009-11-24

    Quantitative traits, such as size and weight in animals and seed yield in plants, are distributed normally, even within a population of genetically identical individuals. For example, in plants, various factors, such as local soil quality, microclimate, and sowing depth, affect growth differences among individual plants of isogenic populations. Besides these physical factors, also epigenetic components contribute to differences in growth and yield. The network that regulates crop yield is still not well understood. Although this network is expected to have epigenetic elements, it is completely unclear whether it would be possible to shape the epigenome to increase crop yield. Here we show that energy use efficiency is an important factor in determining seed yield in canola (Brassica napus) and that it can be selected artificially through an epigenetic feature. From an isogenic canola population of which the individual plants and their self-fertilized progenies were recursively selected for respiration intensity, populations with distinct physiological and agronomical characteristics could be generated. These populations were found to be genetically identical, but epigenetically different. Furthermore, both the DNA methylation patterns as well as the agronomical and physiological characteristics of the selected lines were heritable. Hybrids derived from parent lines selected for high energy use efficiencies had a 5% yield increase on top of heterosis. Our results demonstrate that artificial selection allows the increase of the yield potential by selecting populations with particular epigenomic states.

  15. Effect of GA-sensitivity on wheat early vigor and yield components under deep sowing

    PubMed Central

    Amram, Avishay; Fadida-Myers, Aviya; Golan, Guy; Nashef, Kamal; Ben-David, Roi; Peleg, Zvi

    2015-01-01

    Establishment of seedlings is a key factor in achievement of uniform field stands and, consequently, stable yields. Under Mediterranean conditions, soil moisture in the upper layer is limited and seedlings may be exposed to frequent dehydration events. The presence of the Reduced height (Rht)-B1b and Rht-D1b semi-dominant dwarfing alleles results in insensitivity to gibberellin (GAI) and, hence, poor emergence from deep sowing. Introduction of alternative dwarfing genes and, thereby, preservation of the gibberellin response (GAR) and coleoptile length, contributes to better emergence from deep sowing. Initially 47 wheat cultivars carrying different Rht alleles were screened for their ability to emerge from deep sowing, and then 17 of them were selected for detailed physiological characterization in the field. The modern wheat lines containing GAI alleles showed significantly lower percentages of emergence from deep sowing than the GAR lines, i.e., 52 and 74%, respectively. Differences in early developmental stages were associated with grain yield, as indicated by a reduction of 37.3% in the modern GAI cultivars. Our results demonstrate the potential of alternative dwarfing genes for improving seedling establishment and grain yields in Mediterranean-like environments. PMID:26217347

  16. Relative ion yields in mammalian cell components using C60 SIMS.

    PubMed

    Keskin, Selda; Piwowar, Alan; Hue, Jonathan; Shen, Kan; Winograd, Nicholas

    2014-01-01

    Time of flight secondary ion mass spectrometry has been used to better understand the influence of molecular environment on the relative ion yields of membrane lipid molecules found in high abundance in a model mammalian cell line, RAW264.7. Control lipid mixtures were prepared to simulate lipid-lipid interactions in the inner and outer leaflet of cell membranes. Compared with its pure film, the molecular ion yields of 1,2-dioleoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine are suppressed when mixed with 2-dipalmitoyl-sn-glycero-3-phosphocholine. In the mixture, proton competition between 1,2-dioleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 2-dipalmitoyl-sn-glycero-3-phosphocholine led to lower ionization efficiency. The possible mechanism for ion suppression was also investigated with (1)H and (13)C nuclear magnetic resonance spectroscopy. The formation of a hydroxyl bond in lipid mixtures confirms the mechanism involving proton exchange with the surrounding environment. Similar effects were observed for lipid mixtures mimicking the composition of the inner leaflet of cell membranes. The secondary molecular ion yield of 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine was observed to be enhanced in the presence of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine.

  17. Overdominant epistatic loci are the primary genetic basis of inbreeding depression and heterosis in rice. II. Grain yield components.

    PubMed

    Luo, L J; Li, Z K; Mei, H W; Shu, Q Y; Tabien, R; Zhong, D B; Ying, C S; Stansel, J W; Khush, G S; Paterson, A H

    2001-08-01

    The genetic basis underlying inbreeding depression and heterosis for three grain yield components of rice was investigated in five interrelated mapping populations using a complete RFLP linkage map, replicated phenotyping, and the mixed model approach. The populations included 254 F(10) recombinant inbred lines (RILs) derived from a cross between Lemont (japonica) and Teqing (indica), two backcross (BC) and two testcross populations derived from crosses between the RILs and the parents plus two testers (Zhong413 and IR64). For the yield components, the RILs showed significant inbreeding depression and hybrid breakdown, and the BC and testcross populations showed high levels of heterosis. The average performance of the BC or testcross hybrids was largely determined by heterosis. The inbreeding depression values of individual RILs were negatively associated with the heterosis measurements of the BC or testcross hybrids. We identified many epistatic QTL pairs and a few main-effect QTL responsible for >65% of the phenotypic variation of the yield components in each of the populations. Most epistasis occurred between complementary loci, suggesting that grain yield components were associated more with multilocus genotypes than with specific alleles at individual loci. Overdominance was also an important property of most loci associated with heterosis, particularly for panicles per plant and grains per panicle. Two independent groups of genes appeared to affect grain weight: one showing primarily nonadditive gene action explained 62.1% of the heterotic variation of the trait, and the other exhibiting only additive gene action accounted for 28.1% of the total trait variation of the F(1) mean values. We found no evidence suggesting that pseudo-overdominance from the repulsive linkage of completely or partially dominant QTL for yield components resulted in the overdominant QTL for grain yield. Pronounced overdominance resulting from epistasis expressed by multilocus

  18. Components of yield in pecan depend on tree height due to the distribution of scab in the canopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scab (caused by Fusicladium effusum) severity (SS) and sample height in a pecan canopy has been previously characterized. In 3 field experiment in GA, SS at different sample heights and consequent effect on components of yield were characterized in fungicide treated (FT) and control (C) trees. FT tr...

  19. Ideotype population exploration: growth, photosynthesis, and yield components at different planting densities in winter oilseed rape (Brassica napus L.).

    PubMed

    Ma, Ni; Yuan, Jinzhan; Li, Ming; Li, Jun; Zhang, Liyan; Liu, Lixin; Naeem, Muhammad Shahbaz; Zhang, Chunlei

    2014-01-01

    Rapeseed is one of the most important edible oil crops in the world and the seed yield has lagged behind the increasing demand driven by population growth. Winter oilseed rape (Brassica napus L.) is widely cultivated with relatively low yield in China, so it is necessary to find the strategies to improve the expression of yield potential. Planting density has great effects on seed yield of crops. Hence, field experiments were conducted in Wuhan in the Yangtze River basin with one conventional variety (Zhongshuang 11, ZS11) and one hybrid variety (Huayouza 9, HYZ9) at five planting densities (27.0×10(4), 37.5×10(4), 48.0×10(4), 58.5×10(4), 69.0×10(4) plants ha(-1)) during 2010-2012 to investigate the yield components. The physiological traits for high-yield and normal-yield populations were measured during 2011-2013. Our results indicated that planting densities of 58.5×10(4) plants ha(-1) in ZS11 and 48.0×10(4) plants ha(-1) in HYZ9 have significantly higher yield compared with the density of 27.0×10(4) plants ha(-1) for both varieties. The ideal silique numbers for ZS11 and HYZ9 were ∼0.9×10(4) (n m(-2)) and ∼1×10(4) (n m(-2)), respectively, and ideal primary branches for ZS11 and HYZ9 were ∼250 (n m(-2)) and ∼300 (n m(-2)), respectively. The highest leaf area index (LAI) and silique wall area index (SAI) was ∼5.0 and 7.0, respectively. Moreover, higher leaf net photosynthetic rate (Pn) and water use efficiency (WUE) were observed in the high-yield populations. A significantly higher level of silique wall photosynthesis and rapid dry matter accumulation were supposed to result in the maximum seed yield. Our results suggest that increasing the planting density within certain range is a feasible approach for higher seed yield in winter rapeseed in China.

  20. 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.

  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. A complete genetic linkage map and QTL analyses for bast fibre quality traits, yield and yield components in jute (Corchorus olitorius L.).

    PubMed

    Topdar, N; Kundu, A; Sinha, M K; Sarkar, D; Das, M; Banerjee, S; Kar, C S; Satya, P; Balyan, H S; Mahapatra, B S; Gupta, P K

    2013-01-01

    We report the first complete microsatellite genetic map of jute (Corchorus olitorius L.; 2n = 2x = 14) using an F6 recombinant inbred population. Of the 403 microsatellite markers screened, 82 were mapped on the seven linkage groups (LGs) that covered a total genetic distance of 799.9 cM, with an average marker interval of 10.7 cM. LG5 had the longest and LG7 the shortest genetic lengths, whereas LG1 had the maximum and LG7 the minimum number of markers. Segregation distortion of microsatellite loci was high (61%), with the majority of them (76%) skewed towards the female parent. Genomewide non-parametric single-marker analysis in combination with multiple quantitative trait loci (QTL)-models (MQM) mapping detected 26 definitive QTLs for bast fibre quality, yield and yield-related traits. These were unevenly distributed on six LGs, as colocalized clusters, at genomic sectors marked by 15 microsatellite loci. LG1 was the QTL-richest map sector, with the densest colocalized clusters of QTLs governing fibre yield, yield-related traits and tensile strength. Expectedly, favorable QTLs were derived from the desirable parents, except for nearly all of those of fibre fineness, which might be due to the creation of new gene combinations. Our results will be a good starting point for further genome analyses in jute.

  4. Identification of heterotic loci associated with grain yield and its components using two CSSL test populations in maize

    PubMed Central

    Wang, Hongqiu; Zhang, Xiangge; Yang, Huili; Liu, Xiaoyang; Li, Huimin; Yuan, Liang; Li, Weihua; Fu, Zhiyuan; Tang, Jihua; Kang, Dingming

    2016-01-01

    Heterosis has widely been used to increase grain yield and quality. In this study, the genetic basis of heterosis on grain yield and its main components in maize were examined over 2 years in two locations in two test populations constructed from a set of 184 chromosome segment substitution lines (CSSLs) and two inbred lines (Zheng58 and Xun9058). Of the 169 heterotic loci (HL) associated with grain yield and its five components identified in CSSL × Zheng58 and CSSL × Xun9058 test populations, only 25 HL were detected in both populations. The comparison of quantitative trait loci (QTLs) detected in the CSSL population with HL detected in the two test populations revealed that only 15.46% and 17.35% of the HL in the given populations respectively, shared the same chromosomal regions as that of the corresponding QTLs and showed dominant effects as well as pleiotropism with additive and dominant effects. In addition, most of the HL (74.23% and 74.49%) had overdominant effects. These results suggest that overdominance is the main contributor to the effects of heterosis on grain yield and its components in maize, and different HL are associated with heterosis for different traits in different hybrids. PMID:27917917

  5. The influence of purge times on the yields of essential oil components extracted from plants by pressurized liquid extraction.

    PubMed

    Wianowska, Dorota

    2014-01-01

    The influence of different purge times on the yield of the main essential oil constituents of rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and chamomile (Chamomilla recutita L.) was investigated. The pressurized liquid extraction process was performed by applying different extraction temperatures and solvents. The results presented in the paper show that the estimated yield of essential oil components extracted from the plants in the pressurized liquid extraction process is purge time-dependent. The differences in the estimated yields are mainly connected with the evaporation of individual essential oil components and the applied solvent during the purge; the more volatile an essential oil constituent is, the greater is its loss during purge time, and the faster the evaporation of the solvent during the purge process is, the higher the concentration of less volatile essential oil components in the pressurized liquid extraction receptacle. The effect of purge time on the estimated yield of individual essential oil constituents is additionally differentiated by the extraction temperature and the extraction ability of the applied solvent.

  6. Effect of the hope FT-B1 allele on wheat heading time and yield components.

    PubMed

    Nitcher, Rebecca; Pearce, Stephen; Tranquilli, Gabriela; Zhang, Xiaoqin; Dubcovsky, Jorge

    2014-01-01

    Precise regulation of flowering time is critical for plant reproductive success and, in cereals, to maximize grain yields. Seasonal cues including temperature and day length are integrated to regulate the timing of flowering. In temperate cereals, extended periods of cold (vernalization) release the repression of FLOWERING LOCUS T1 (FT1), which is upregulated in the leaves in response to inductive long-day photoperiods. FT1 is a homolog of rice HD3a, which encodes a protein transported from leaves to the shoot apical meristem to induce flowering. A rare FT-B1 allele from the wheat variety "Hope" has been previously shown to be associated with an early flowering phenotype under long-day photoperiods. Here, we demonstrate that the Hope FT-B1 allele accelerates flowering even under short days, and that it is epistatic to the VERNALIZATION 1 (VRN1) gene. On average, the introgression of Hope FT-B1 into 6 genetic backgrounds resulted in 2.6 days acceleration of flowering (P<0.0001) and 4.1% increase in spike weight (P=0.0093), although in one variety, it was associated with a decrease in spike weight. These results suggest that the Hope FT-B1 allele could be useful in wheat breeding programs to subtly accelerate floral development and increase adaptation to changing environments.

  7. Combining Ability of Different Agronomic Traits and Yield Components in Hybrid Barley

    PubMed Central

    Lv, Chao; Guo, Baojian; Xu, Rugen

    2015-01-01

    Selection of parents based on their combining ability is an effective approach in hybrid breeding. In this study, eight maintainer lines and nine restorer lines were used to obtain 72 crosses for analyzing the general combining ability (GCA) and special combining ability (SCA) for seven agronomic and yield characters including plant height (PH), spike length excluding awns (SL), inter-node length (IL), spikes per plant (SP), thousand kernel weight (TKW), kernel weight per plant (KWP) and dry matter weight per plant (DWP). The results showed that GCA was significantly different among parents and SCA was also significantly different among crosses. The performance of hybrid was significantly correlated with the sum of female and male GCA (TGCA), SCA and heterosis. Hu1154 A, Mian684 A, 86F098 A, 8036 R and 8041 R were excellent parents with greater general combining ability. Five crosses, Hu1154 A×8032 R, Humai10 A×8040 R, Mian684 A×8037 R, Mian684 A×8041 R and 86F098 A×8037 R, showed superior heterosis for most characters. PMID:26061000

  8. 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

  9. Salt sensitivity in chickpea: Growth, photosynthesis, seed yield components and tissue ion regulation in contrasting genotypes.

    PubMed

    Khan, Hammad Aziz; Siddique, Kadambot H M; Munir, Rushna; Colmer, Timothy David

    2015-06-15

    Chickpea is a relatively salt sensitive species but shows genotypic variation for salt tolerance, measured as grain yield per plant in mild-to-moderately saline soil. This experiment was designed to evaluate some physiological responses to salinity in three contrasting genotypes. One tolerant (Genesis836), one moderately tolerant (JG11) and one sensitive (Rupali) genotype were grown for 108d in non-saline nutrient solution (controls) and two levels of salinity treatment (30 and 60mM NaCl). No plants survived to maturity in the 60mM NaCl treatment; however, Genesis836 survived longer (87d) than JG11 (67d) while Rupali died after 27d; only Genesis836 flowered, but no pods were filled. At 30mM NaCl, Genesis836 produced a few filled pods, whereas JG11 and Rupali did not. Genotypic differences in plant dry mass at the vegetative stage were evident only at 60mM NaCl, while at maturity differences were evident at 30mM NaCl. Photosynthesis was maintained to different degrees by the three genotypes (e.g. at 30mM NaCl, 35-81% of controls; highest in Genesis836); photosynthesis was restricted predominately due to non-stomatal limitations as the intercellular CO2 concentration was only modestly affected (94-99% of controls). Photosystem II damage was evident in the less tolerant genotypes (e.g. at 30mM NaCl, actual quantum efficiency of photosystem II values were 63-96% of controls). Across treatments, shoot dry mass was negatively correlated with both Na(+) and Cl(-) shoot concentrations. However, the sensitive genotype (Rupali) had equal or lower concentrations of these ions in green leaves, stems or roots compared to tolerant genotypes (JG11 and Genesis836); ion 'exclusion' does not explain variation for salt tolerance among these three chickpea genotypes. The large difference between Rupali (sensitive) and Genesis836 (tolerant) in the salt-induced reduction in net photosynthesis via non-stomatal limitations and the assessed damage to photosystem II, but with similar leaf

  10. 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.

  11. Enhancement of growth, photosynthetic performance and yield by exclusion of ambient UV components in C3 and C4 plants.

    PubMed

    Kataria, Sunita; Guruprasad, K N; Ahuja, Sumedha; Singh, Bupinder

    2013-10-05

    A field experiment was conducted under tropical climate for assessing the effect of ambient UV-B and UV-A by exclusion of UV components on the growth, photosynthetic performance and yield of C3 (cotton, wheat) and C4 (amaranthus, sorghum) plants. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (<315nm), UV-A+B (<400nm), transmitted all the UV (280-400nm) or without filters. All the four plant species responded to UV exclusion by a significant increase in plant height, leaf area, leaf biomass, total biomass accumulation and yield. Measurements of the chlorophyll, chlorophyll fluorescence parameters, gas exchange parameters and the activity of Ribulose-1,5-bisphosphate carboxylase (Rubisco) by fixation of (14)CO2 indicated a direct relationship between enhanced rate of photosynthesis and yield of the plants. Quantum yield of electron transport was enhanced by the exclusion of UV indicating better utilization of PAR assimilation and enhancement in reducing power in all the four plant species. Exclusion of UV-B in particular significantly enhanced the net photosynthetic rate, stomatal conductance and activity of Rubisco. Additional fixation of carbon due to exclusion of ambient UV-B was channeled towards yield as there was a decrease in the level of UV-B absorbing substances and an increase in soluble proteins in all the four plant species. The magnitude of the promotion in all the parameters studied was higher in dicots (cotton, amaranthus) compared to monocots (wheat, sorghum) after UV exclusion. The results indicated a suppressive action of ambient UV-B on growth and photosynthesis; dicots were more sensitive than monocots in this suppression while no great difference in sensitivity was found between C3 and C4 plants. Experiments indicated the suppressive action of ambient UV on carbon fixation and yield of C3 and C4 plants. Exclusion of solar UV-B will have agricultural benefits in both C3 and C4 plants

  12. Genetic dissection of yield and its component traits using high-density composite map of wheat chromosome 3A: bridging gaps between QTLs and underlying genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield compon...

  13. Effect of source/sink ratios on yield components, growth dynamics and structural characteristics of oil palm (Elaeis guineensis) bunches.

    PubMed

    Pallas, Benoît; Mialet-Serra, Isabelle; Rouan, Lauriane; Clément-Vidal, Anne; Caliman, Jean-Pierre; Dingkuhn, Michael

    2013-04-01

    Source/sink ratios are known to be one of the main determinants of oil palm growth and development. A long-term experiment (9 years) was conducted in Indonesia on mature oil palms subjected to continuous bunch ablation and partial defoliation treatments to artificially modify source/sink ratios. During the experiment, all harvested bunches were dissected and phenological measurements were carried out to analyse the effect of source/sink ratios on yield components explaining variations in bunch number, the number of fruits per bunch and oil dry weight per fruit. An integrative variable (supply/demand ratio) describing the ratio between the assimilate supply from sources and the growing organ demand for carbohydrate was computed for each plant on a daily basis from observations of the number of developing organs and their sink strength, and of climate variables. Defoliation and bunch ablation affected the bunch number and the fruit number per bunch. Variations in bunch number per month were mainly due to variations in the fraction of aborted inflorescence and in the ratio between female and male inflorescences. Under fluctuating trophic conditions, variations in fruit number per bunch resulted both from changes in fruit-set and in the number of branches (rachillae) per inflorescence. For defoliated plants, the decrease in the number of developing reproductive sinks appeared to be sufficient to maintain fruit weight and oil concentration at the control level, without any major decrease in the concentration of non-structural carbohydrate reserves. Computation of the supply/demand ratio revealed that each yield component had a specific phase of sensitivity to supply/demand ratios during inflorescence development. Establishing quantitative relationships between supply/demand ratios, competition and yield components is the first step towards a functional model for oil palm.

  14. The effects of planting methods and head pruning on seed yield and yield components of medicinal pumpkin (Cucurbita pepo subsp. Pepo convar. Pepo var. styriaca) at low temperature areas.

    PubMed

    Bahrami, R Nikkhah; Khodadadi, M; Pirivatlo, S Piry; Hassanpanah, D

    2009-03-15

    This experiment carried out to evaluate the effects of planting methods (seed sowing and transplanting) and head pruning (no pruning, pruning after 12th node and pruning after 16th node) on yield and yield components such as number of branches (sub-branches) per plant, fruits per plant, growth, fruit size, weight of fresh fruit, weight of seeds per fruit, number of seeds per fruit and seed yield of medicinal pumpkin. The experiment was carried out based of factorial experiment with Randomized Completely Blocks Design (RCBD) by three replications in Ardabil Agricultural and Natural Resources Researches Station at 2007. Seedlings were grown in heated greenhouse. When the climatic condition became suitable and seedlings were at the four leaves stage, both seeds and seedlings were planted at the same time in the farm. Maintenance operations were done during the growth season. Head pruning treatments were done the forecast time. The results showed that the planting methods had significant effect on the number of ripen fruits per plant, fruits diameter, weight of seeds per fruit, weight of 1000 seeds and seed yield and had no significant effect on the other traits. Also the results indicated that head pruning treatments had significant effects on the number of branches per plant, growth and seed yield and no significant on the other traits. In this experiment the most seed yield (997.8 kg ha(-1)) obtained from transplanting method with head pruning after 12th node and the least seed yield obtained from control.

  15. Yield components and nutritive value of Robinia pseudoacacia and Albizia julibrissin in Arkansas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ranchers need alternative livestock feeds when herbaceous forages become limiting in summer. Our objectives were to determine: 1) leaf and stem biomass components, 2) nutritive value (in vitro dry matter digestibility [IVDMD], total nonstructural carbohydrate [TNC], N and N digestibility) of leaves ...

  16. Improving Target Repeatability Yields Broader Results in Component Fabrication and Overall Build

    NASA Astrophysics Data System (ADS)

    Klein, Sallee; Gamboa, Eliseo; Gillespie, Robb; Huntington, Channing; Krauland, Christine; Kuranz, Carolyn; di Stefano, Carlos; Susalla, Peter; Lairson, Bruce; Elsner, Fred; Keiter, Paul; Drake, R. Paul

    2012-10-01

    The University of Michigan has been fabricating targets for high energy density experiments since 2003. Our experiments study physics relevant to laboratory astrophysics. Machined acrylic structures serve as a backbone supporting all the components on our targets, as well as providing us with a method that eases our build. A most vital component to nearly every target we build, is shielding. Employing techniques to bend gold foils, enables complex geometries and eliminates seams that possibly allow unwanted emission in our diagnostics. Many of our experiments explore the dynamics of a radiative shock launched into xenon or argon gas. Polyimide (PI) tubing confines the gas and is transmissive to the diagnostic x-rays used to probe the experiment. Recent interest in the shock dynamics of non-axisymmetric shocks has lead to the development of PI tubes with non-circular cross sections. We present the techniques we use to produce repeatable targets as well as recent improvements in our techniques.

  17. Unattended exposure to components of speech sounds yields same benefits as explicit auditory training.

    PubMed

    Seitz, Aaron R; Protopapas, Athanassios; Tsushima, Yoshiaki; Vlahou, Eleni L; Gori, Simone; Grossberg, Stephen; Watanabe, Takeo

    2010-06-01

    Learning a second language as an adult is particularly effortful when new phonetic representations must be formed. Therefore the processes that allow learning of speech sounds are of great theoretical and practical interest. Here we examined whether perception of single formant transitions, that is, sound components critical in speech perception, can be enhanced through an implicit task-irrelevant learning procedure that has been shown to produce visual perceptual learning. The single-formant sounds were paired at subthreshold levels with the attended targets in an auditory identification task. Results showed that task-irrelevant learning occurred for the unattended stimuli. Surprisingly, the magnitude of this learning effect was similar to that following explicit training on auditory formant transition detection using discriminable stimuli in an adaptive procedure, whereas explicit training on the subthreshold stimuli produced no learning. These results suggest that in adults learning of speech parts can occur at least partially through implicit mechanisms.

  18. Unattended exposure to components of speech sounds yields same benefits as explicit auditory training

    PubMed Central

    Seitz, Aaron R.; Protopapas, Athanassios; Tsushima, Yoshiaki; Vlahou, Eleni L.; Gori, Simone; Grossberg, Stephen; Watanabe, Takeo

    2010-01-01

    Learning a second language as an adult is particularly effortful when new phonetic representations must be formed. Therefore the processes that allow learning of speech sounds are of great theoretical and practical interest. Here we examined whether perception of single formant transitions, that is, sound components critical in speech perception, can be enhanced through an implicit task-irrelevant learning procedure that has been shown to produce visual perceptual learning. The single-formant sounds were paired at sub-threshold levels with the attended targets in an auditory identification task. Results showed that task-irrelevant learning occurred for the unattended stimuli. Surprisingly, the magnitude of this learning effect was similar to that following explicit training on auditory formant transition detection using discriminable stimuli in an adaptive procedure, whereas explicit training on the subthreshold stimuli produced no learning. These results suggest that in adults learning of speech parts can occur at least partially through implicit mechanisms. PMID:20346448

  19. Drilling ban yields verdict

    SciTech Connect

    Nation, L.M.

    1992-01-01

    This paper briefly reviews a lawsuit which is under appeal by the State of Michigan regarding a takings claim filed over a petroleum exploration site. The dispute arose as a result of a 1987 decision by the Michigan Department of Natural Resources forbidding the property owners from developing the mineral rights leased to Miller Brothers in the Huron/Manistee National Forest. This area is bisected by a trend of Silurian Niagaran reef complexes which has a known production history throughout the State. The dunes area of the national forest has been deemed a wilderness area. As a result of the State's decision, the courts have awarded a sum of 71 million dollars to the developer to cover damages and lost resources. The reserve estimates were taken from adjacent areas which showed that the Niagaran reefs are relatively consistent in their yield.

  20. Transgressive variation for yield components and dynamic traits in Jefferson (Oryza sativa) x O. rufipogon introgression lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alleles from wild progenitors of crops can be a source of transgressive variation in modern cultivars. Introgressions from the Oryza rufipogon donor (IRGC104591) in an O. sativa tropical japonica cultivar (Jefferson) were shown to confer a yield advantage in multi-location field trials. Yield loci...

  1. Enhanced expression of OsSPL14 gene and its association with yield components in rice (Oryza sativa) under low nitrogen conditions.

    PubMed

    Srikanth, B; Subhakara Rao, I; Surekha, K; Subrahmanyam, D; Voleti, S R; Neeraja, C N

    2016-01-15

    Nitrogen use efficiency (NUE) in rice crop is the need of the hour for reduction of nitrous oxide emission resulting from excess nitrogen (N) fertilizer application and also in reduction of cost of cultivation. Ten rice genotypes were grown under low and recommended dose of N application and characterized in terms of parameters related to yield, yield related components and NUE indicators. Wide genetic variability under low N conditions was observed with significant variation for 15 yield related parameters in interactions of genotypes and treatment. Limitation of N has led to the decrease of all yield and yield related parameters, but for grain filling % and 1000 grain weight. Two genotypes, Rasi and Varadhan have shown minimum differences between low and recommended N conditions. Correlation analysis of various yield components showed the importance of the secondary branches for the total grains under low N. Expression analysis of OsSPL14 (LOC_Os08g39890) gene reported to be associated with increased panicle branching and higher grain yield through real time PCR in leaf and three stages of panicle has shown differential temporal expression and its association with yield and yield related components across the genotypes. The expression of OsSPL14 at panicle stage 3, has shown correlation (P<0.05) with N% in grain. Since OsSPL14 is a functional transcription activator, its association of expression in leaf and three panicle stages with yield components as observed in the present study suggests the role of nitrogen metabolism related genes in plant growth and development and its conversion into yield components in rice.

  2. A Novel Role of the Potyviral Helper Component Proteinase Contributes To Enhance the Yield of Viral Particles

    PubMed Central

    Gallo, Araíz; Calvo, María; Pérez, José de Jesús

    2014-01-01

    ABSTRACT The helper component proteinase (HCPro) is an indispensable, multifunctional protein of members of the genus Potyvirus and other viruses of the family Potyviridae. This viral factor is directly involved in diverse steps of viral infection, such as aphid transmission, polyprotein processing, and suppression of host antiviral RNA silencing. In this paper, we show that although a chimeric virus based on the potyvirus Plum pox virus lacking HCPro, which was replaced by a heterologous silencing suppressor, caused an efficient infection in Nicotiana benthamiana plants, its viral progeny had very reduced infectivity. Making use of different approaches, here, we provide direct evidence of a previously unknown function of HCPro in which the viral factor enhances the stability of its cognate capsid protein (CP), positively affecting the yield of virions and consequently improving the infectivity of the viral progeny. Site-directed mutagenesis revealed that the ability of HCPro to stabilize CP and enhance the yield of infectious viral particles is not linked to any of its previously known activities and helped us to delimit the region of HCPro involved in this function in the central region of the protein. Moreover, the function is highly specific and cannot be fulfilled by the HCPro of a heterologous potyvirus. The importance of this novel requirement in regulating the sorting of the viral genome to be subjected to replication, translation, and encapsidation, thus contributing to the synchronization of these viral processes, is discussed. IMPORTANCE Potyviruses form one of the most numerous groups of plant viruses and are a major cause of crop loss worldwide. It is well known that these pathogens make use of virus-derived multitasking proteins, as well as dedicated host factors, to successfully infect their hosts. Here, we describe a novel requirement for the proper yield and infectivity of potyviral progeny. In this case, such a function is performed by the

  3. 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.

  4. Shortcomings in wheat yield predictions

    NASA Astrophysics Data System (ADS)

    Semenov, Mikhail A.; Mitchell, Rowan A. C.; Whitmore, Andrew P.; Hawkesford, Malcolm J.; Parry, Martin A. J.; Shewry, Peter R.

    2012-06-01

    Predictions of a 40-140% increase in wheat yield by 2050, reported in the UK Climate Change Risk Assessment, are based on a simplistic approach that ignores key factors affecting yields and hence are seriously misleading.

  5. Crop yield gaps in Cameroon.

    PubMed

    Yengoh, Genesis T; Ardö, Jonas

    2014-03-01

    Although food crop yields per hectare have generally been increasing in Cameroon since 1961, the food price crisis of 2008 and the ensuing social unrest and fatalities raised concerns about the country's ability to meet the food needs of its population. This study examines the country's potential for increasing crop yields and food production to meet this food security challenge. Fuzzy set theory is used to develop a biophysical spatial suitability model for different crops, which in turn is employed to ascertain whether crop production is carried out in biophysically suited areas. We use linear regression to examine the trend of yield development over the last half century. On the basis of yield data from experimental stations and farmers' fields we assess the yield gap for major food crops. We find that yields have generally been increasing over the last half century and that agricultural policies can have significant effects on them. To a large extent, food crops are cultivated in areas that are biophysically suited for their cultivation, meaning that the yield gap is not a problem of biophysical suitability. Notwithstanding, there are significantly large yield gaps between actual yields on farmers' farms and maximum attainable yields from research stations. We conclude that agronomy and policies are likely to be the reasons for these large yield gaps. A key challenge to be addressed in closing the yield gaps is that of replenishing and properly managing soil nutrients.

  6. Evaluation of the effects of irrigation and fertilization on tomato fruit yield and quality: a principal component analysis.

    PubMed

    Wang, Xiukang; Xing, Yingying

    2017-03-23

    Irrigation and fertilization are key practices for improving the fruit quality and yield of vegetables grown in greenhouses. We carried out an experiment in a solar greenhouse spanning three consecutive growing seasons to evaluate the effects of irrigation and fertilization on the fruit yield and quality, water use efficiency (WUE) and fertilizer partial factor productivity (PFP) of tomatoes. Interactions between irrigation and fertilization treatments and individual factors of irrigation and fertilization significantly (p < 0.01) affected fruit yield, WUE and PFP. WUE and fruit yield and quality were more sensitive to changes in irrigation than to changes in fertilizer, but PFP showed the opposite trend. Interestingly, the treatment with moderate irrigation (W2: 75% ET 0 ) and high fertilizer level (F1: 240N-120P2O5-150K2O kg ha(-1)) was twice ranked first after a combinational evaluation. In conclusion, the proper application of drip fertigation (W2F1) may be a good compromise for solar greenhouse-grown tomatoes with regard to fruit yield and quality, WUE, and PFP. The present study sheds light on the contributions of these practices, clarifies their impacts, and provides a basis for evaluating and selecting better management practices for growing greenhouse vegetables.

  7. Random regression test day models to estimate genetic parameters for milk yield and milk components in Philippine dairy buffaloes.

    PubMed

    Flores, E B; van der Werf, J

    2015-08-01

    Heritabilities and genetic correlations for milk production traits were estimated from first-parity test day records on 1022 Philippine dairy buffalo cows. Traits analysed included milk (MY), fat (FY) and protein (PY) yields, and fat (Fat%) and protein (Prot%) concentrations. Varying orders of Legendre polynomials (Leg(m)) as well as the Wilmink function (Wil) were used in random regression models. These various models were compared based on log likelihood, Akaike's information criterion, Bayesian information criterion and genetic variance estimates. Six residual variance classes were sufficient for MY, FY, PY and Fat%, while seven residual classes for Prot%. Multivariate analysis gave higher estimates of genetic variance and heritability compared with univariate analysis for all traits. Heritability estimates ranged from 0.25 to 0.44, 0.13 to 0.31 and 0.21 to 0.36 for MY, FY and PY, respectively. Wilmink's function was the better fitting function for additive genetic effects for all traits. It was also the preferred function for permanent environment effects for Fat% and Prot%, but for MY, FY and PY, the Legm was the appropriate function. Genetic correlations of MY with FY and PY were high and they were moderately negative with Fat% and Prot%. To prevent deterioration in Fat% and Prot% and improve milk quality, more weight should be applied to milk component traits.

  8. Greenhouse validation of yield component transgressive variation effects of wild Oryza species introgressions in an elite US rice cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of global studies have been conducted which have shown that the wild ancestral species, Oryza rufipogon, possesses beneficial alleles that can be used to improve cultivated rice, O. sativa, for biotic and abiotic stress tolerance as well as yield. Introgression lines (IL) were developed thr...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Yield surfaces for anisotropic plates

    NASA Astrophysics Data System (ADS)

    Walker, J. D.; Thacker, B. H.

    2000-04-01

    Aerospace systems are incorporating composite materials into their structures. The composite materials are often anisotropic in mechanical response due to their geometric layout. For many years, the failure surfaces of anisotropic materials were thought to be characterizable by a quadratic function in the stress, referred to as a Tsai-Wu yield surface, or, in a more restrictive form, a Tsai-Hill yield surface. Such a representation does not work for materials that are strong in two directions and weak in one direction, which is the case of most interest since it represents fiber/epoxy composite plates. This paper demonstrates the impossibility of modeling the failure surface with either the Tsai-Wu or Tsai-Hill failure surfaces. A yield surface is presented based on the lemniscate, which is quartic in the stress. This new yield surface addresses the case of strong in two directions and weak in one.

  14. Yield Surfaces for Anisotropic Plates

    NASA Astrophysics Data System (ADS)

    Walker, J. D.; Thacker, B. H.

    1999-06-01

    Modern aerospace systems are incorporating composite materials into their structures. Often, the composite materials are anisotropic in their mechanical response due to the geometric layout of fibers. For many years, the failure surfaces of anisotropic materials were thought to be characterizable by a quadratic function in the stress, often referred to as a Tsai-Wu yield surface, or, in a more restrictive form, a Tsai-Hill yield surface. Such a representation does not work for materials that are strong in two directions and weak in one direction, which, unfortunately, is the case of most interest since it represents most composite plates. This paper demonstrates the impossibility of modeling the failure surface with both the Tsai-Wu and Tsai-Hill failure surfaces. We then present a yield surface based on the lemniscate, which is quartic in the stress. This new yield surface addresses the case of strong in two directions and weak in one. Calculations with a fragment impacting a composite plate modeled with the new yield surface are presented. Modifications of the yield surface are presented to allow, in a limited way, materials that are both anisotropic and have differing strengths in tension and compression.

  15. 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.

  16. Genome-Wide Linkage Mapping of QTL for Yield Components, Plant Height and Yield-Related Physiological Traits in the Chinese Wheat Cross Zhou 8425B/Chinese Spring

    PubMed Central

    Gao, Fengmei; Wen, Weie; Liu, Jindong; Rasheed, Awais; Yin, Guihong; Xia, Xianchun; Wu, Xiaoxia; He, Zhonghu

    2015-01-01

    Identification of genes for yield components, plant height (PH), and yield-related physiological traits and tightly linked molecular markers is of great importance in marker-assisted selection (MAS) in wheat breeding. In the present study, 246 F8 RILs derived from the cross of Zhou 8425B/Chinese Spring were genotyped using the high-density Illumina iSelect 90K single nucleotide polymorphism (SNP) assay. Field trials were conducted at Zhengzhou and Zhoukou of Henan Province, during the 2012–2013 and 2013–2014 cropping season under irrigated conditions, providing data for four environments. Analysis of variance (ANOVA) of agronomic and physiological traits revealed significant differences (P < 0.01) among RILs, environments, and RILs × environments interactions. Broad-sense heritabilities of all traits including thousand kernel weight (TKW), PH, spike length (SL), kernel number per spike (KNS), spike number/m2 (SN), normalized difference in vegetation index at anthesis (NDVI-A) and at 10 days post-anthesis (NDVI-10), SPAD value of chlorophyll content at anthesis (Chl-A) and at 10 days post-anthesis (Chl-10) ranged between 0.65 and 0.94. A linkage map spanning 3609.4 cM was constructed using 5636 polymorphic SNP markers, with an average chromosome length of 171.9 cM and marker density of 0.64 cM/marker. A total of 866 SNP markers were newly mapped to the hexaploid wheat linkage map. Eighty-six QTL for yield components, PH, and yield-related physiological traits were detected on 18 chromosomes except 1D, 5D, and 6D, explaining 2.3–33.2% of the phenotypic variance. Ten stable QTL were identified across four environments, viz. QTKW.caas-6A.1, QTKW.caas-7AL, QKNS.caas-4AL, QSN.caas-1AL.1, QPH.caas-4BS.2, QPH.caas-4DS.1, QSL.caas-4AS, QSL.caas-4AL.1, QChl-A.caas-5AL, and QChl-10.caas-5BL. Meanwhile, 10 QTL-rich regions were found on chromosome 1BS, 2AL (2), 3AL, 4AL (2), 4BS, 4DS, 5BL, and 7AL exhibiting pleiotropic effects. These QTL or QTL clusters are tightly

  17. Increasing crude tall oil yield

    SciTech Connect

    Gupta, J.

    1983-10-01

    In the kraft pulping process for softwoods and hardwood, tall oil recovery is an important part of making profit. During the past 10 years, crude tall oil (CTO) production in the U.S. and Canada has dropped. Estimated CTO yield from fresh Canadian pine is 36-40 lb/a.d. ton and from Southern U.S. 70-80 lb/a.d. ton, while the average yield of CTO is approximately 40% of available tall oil in pine wood. Besides low yield, many pulp mills fail to achieve a CTO quality that lives up to market expectations. The moisture content of CTO is reported to vary widely (1.5-3.5%), whereas it should not exceed 1.5% for marketable quality. The acid number of CTO varies in the range of 135 to 150, whereas industry standards are 145-150. At present the average sale price of CTO is approximately $150/ton. By upgrading existing plants, the yield can be increased, resulting in additional revenues. Thus, if a batch acidulation plant is replaced by a continuous acidulation plant, the yield will increase by approximately 15-50%. The capital required for installing a continuous system is approximately $1.1-1.5 million for a 500-a.d. ton/day pulp mill, requiring a payback period of approximatley 5-7 years. 7 references.

  18. Two transgenic mouse models for β-subunit components of succinate-CoA ligase yielding pleiotropic metabolic alterations

    PubMed Central

    Kacso, Gergely; Ravasz, Dora; Doczi, Judit; Németh, Beáta; Madgar, Ory; Saada, Ann; Ilin, Polina; Miller, Chaya; Ostergaard, Elsebet; Iordanov, Iordan; Adams, Daniel; Vargedo, Zsuzsanna; Araki, Masatake; Araki, Kimi; Nakahara, Mai; Ito, Haruka; Gál, Aniko; Molnár, Mária J.; Nagy, Zsolt; Patocs, Attila; Adam-Vizi, Vera; Chinopoulos, Christos

    2016-01-01

    Succinate-CoA ligase (SUCL) is a heterodimer enzyme composed of Suclg1 α-subunit and a substrate-specific Sucla2 or Suclg2 β-subunit yielding ATP or GTP, respectively. In humans, the deficiency of this enzyme leads to encephalomyopathy with or without methylmalonyl aciduria, in addition to resulting in mitochondrial DNA depletion. We generated mice lacking either one Sucla2 or Suclg2 allele. Sucla2 heterozygote mice exhibited tissue- and age-dependent decreases in Sucla2 expression associated with decreases in ATP-forming activity, but rebound increases in cardiac Suclg2 expression and GTP-forming activity. Bioenergetic parameters including substrate-level phosphorylation (SLP) were not different between wild-type and Sucla2 heterozygote mice unless a submaximal pharmacological inhibition of SUCL was concomitantly present. mtDNA contents were moderately decreased, but blood carnitine esters were significantly elevated. Suclg2 heterozygote mice exhibited decreases in Suclg2 expression but no rebound increases in Sucla2 expression or changes in bioenergetic parameters. Surprisingly, deletion of one Suclg2 allele in Sucla2 heterozygote mice still led to a rebound but protracted increase in Suclg2 expression, yielding double heterozygote mice with no alterations in GTP-forming activity or SLP, but more pronounced changes in mtDNA content and blood carnitine esters, and an increase in succinate dehydrogenase activity. We conclude that a partial reduction in Sucla2 elicits rebound increases in Suclg2 expression, which is sufficiently dominant to overcome even a concomitant deletion of one Suclg2 allele, pleiotropically affecting metabolic pathways associated with SUCL. These results as well as the availability of the transgenic mouse colonies will be of value in understanding SUCL deficiency. PMID:27496549

  19. Status of fission yield data

    SciTech Connect

    England, T.R.; Blachot, J.

    1988-01-01

    In this paper we summarize the current status of the recent US evaluation for 34 fissioning nuclides at one or more neutron incident energies and for spontaneous fission. Currently there are 50 yields sets, and for each we have independent and cumulative yields and uncertainties for approximately 1100 fission products. When finalized the recommended data will become part of Version VI of the US ENDF/B. Other major evaluations in progress that are included in a recently formed IAEA Coordinated Research Program are also summarized. In a second part we review two empirical models in use to estimate independent yields. Comparison of model estimates with measured data is presented, including a comparison with some recent data obtained from Lohengrin (Cf-249 T). 18 refs., 13 figs., 3 tabs.

  20. Yield statistics of interpolated superoscillations

    NASA Astrophysics Data System (ADS)

    Katzav, Eytan; Perlsman, Ehud; Schwartz, Moshe

    2017-01-01

    Yield optimized interpolated superoscillations have been recently introduced as a means for possibly making the use of the phenomenon of superoscillation practical. In this paper we study how good is a superoscillation that is not optimal. Namely, by how much is the yield decreased when the signal departs from the optimal one. We consider two situations. One is the case where the signal strictly obeys the interpolation requirement and the other is when that requirement is relaxed. In the latter case the yield can be increased at the expense of deterioration of signal quality. An important conclusion is that optimizing superoscillations may be challenging in terms of the precision needed, however, storing and using them is not at all that sensitive. This is of great importance in any physical system where noise and error are inevitable.

  1. Amplitude Models for Discrimination and Yield Estimation

    SciTech Connect

    Phillips, William Scott

    2016-09-01

    This seminar presentation describes amplitude models and yield estimations that look at the data in order to inform legislation. The following points were brought forth in the summary: global models that will predict three-component amplitudes (R-T-Z) were produced; Q models match regional geology; corrected source spectra can be used for discrimination and yield estimation; three-component data increase coverage and reduce scatter in source spectral estimates; three-component efforts must include distance-dependent effects; a community effort on instrument calibration is needed.

  2. Fission Reaction Event Yield Algorithm

    SciTech Connect

    Hagmann, Christian; Verbeke, Jerome; Vogt, Ramona; Roundrup, Jorgen

    2016-05-31

    FREYA (Fission Reaction Event Yield Algorithm) is a code that simulated the decay of a fissionable nucleus at specified excitation energy. In its present form, FREYA models spontaneous fission and neutron-induced fission up to 20 MeV. It includes the possibility of neutron emission from the nuclear prior to its fussion (nth chance fission).

  3. Salt sensitivity in chickpea (Cicer arietinum L.): ions in reproductive tissues and yield components in contrasting genotypes.

    PubMed

    Kotula, Lukasz; Khan, Hammad A; Quealy, John; Turner, Neil C; Vadez, Vincent; Siddique, Kadambot H M; Clode, Peta L; Colmer, Timothy D

    2015-08-01

    The reproductive phase in chickpea (Cicer arietinum L.) is affected by salinity, but little is known about the underlying cause. We investigated whether high concentrations of Na(+) and Cl(-) in the reproductive structures influence reproductive processes. Chickpea genotypes contrasting in tolerance were subjected to 0, 35 or 50 mm NaCl applied to soil in pots. Flower production and abortion, pod number, percentage of empty pods, seed number and size were evaluated. The concentrations of Na(+) , K(+) and Cl(-) were measured in various plant tissues and, using X-ray microanalysis, in specific cells of developing reproductive structures. Genotypic variation in reproductive success measured as seed yield in saline conditions was associated with better maintenance of flower production and higher numbers of filled pods (and thus seed number), whereas seed size decreased in all genotypes. Despite the variation in reproductive success, the accumulation of Na(+) and Cl(-) in the early reproductive tissues of developing pods did not differ between a tolerant (Genesis836) and a sensitive (Rupali) genotype. Similarly, salinity tolerance was not associated with the accumulation of salt ions in leaves at the time of reproduction or in seeds at maturity.

  4. 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...

  5. Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron.

    PubMed

    Hiscock, Michael R; Lance, Veronica P; Apprill, Amy M; Bidigare, Robert R; Johnson, Zackary I; Mitchell, B Greg; Smith, Walker O; Barber, Richard T

    2008-03-25

    It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (phi(m)) rapidly doubled, from 0.011 to 0.025 mol C.mol quanta(-1). Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (P(max)(b)). P(max)(b), maximum Chl normalized productivity, was 1.34 mg C.mg Chl(-1).h(-1) outside and 1.49 mg C.mg Chl(-1).h(-1) inside the iron-enriched patch. The importance of phi(m) as compared with P(max)(b) in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in phi(m) is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of phi(m) over P(max)(b) in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of P(max)(b) but largely ignore variability in phi(m) and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved.

  6. Effects of varying forage particle size and fermentable carbohydrates on feed sorting, ruminal fermentation, and milk and component yields of dairy cows.

    PubMed

    Maulfair, D D; Heinrichs, A J

    2013-05-01

    Ration sorting is thought to affect ruminal fermentation in such a manner that milk yield milk and components are often decreased. However, the influence of ruminally degradable starch on ration sorting has not been studied. Therefore, the objective of this experiment was to evaluate the interactions between forage particle size (FPS) and ruminally fermentable carbohydrates (RFC) for dry matter intake (DMI), ration sorting, ruminal fermentation, chewing activity, and milk yield and components. In this study, 12 (8 ruminally cannulated) multiparous, lactating Holstein cows were fed a total mixed ration that varied in FPS and RFC. Two lengths of corn silage were used to alter FPS and 2 grind sizes of corn grain were used to alter RFC. It was determined that increasing RFC increased ruminating time and did not affect eating time, whereas increasing FPS increased eating time and did not affect ruminating time. Ruminal fermentation did not differ by altering either FPS or RFC. However, increasing FPS tended to increase mean and maximum ruminal pH and increasing RFC tended to decrease minimum ruminal pH. Particle size distribution became more diverse and neutral detergent fiber content of refusals increased over time, whereas starch content decreased, indicating that cows were sorting against physically effective neutral detergent fiber and for RFC. Selection indices determined that virtually no interactions occurred between FPS and RFC and that despite significant sorting throughout the day, by 24h after feeding cows had consumed a ration very similar to what was offered. This theory was reinforced by particle fraction intakes that very closely resembled the proportions of particle fractions in the offered total mixed ration. An interaction between FPS and RFC was observed for DMI, as DMI decreased with increasing FPS when the diet included low RFC and did not change when the diet included high RFC. Dry matter intake increased with RFC for long diets and did not change

  7. Yield components, leaf pigment contents, patterns of seed filling, dry matter, LAI and LAID of some safflower (Carthamus tinctorius L.) genotypes in Iran.

    PubMed

    Mokhtassi-Bidgoli, A; Akbari, Gh Al; Mirhadi, M J; Pazoki, A R; Soufizadeh, S

    2007-05-01

    In order to assess the genotypic variation among yield components and different physiological parameters and their relationships with safflower seed yield, six safflower genotypes were grown in Pakdasht, Iran in a randomized complete block design with four replications, during 2003-2004 growing season. Among the genotypes, chlorophyll a, chlorophyll b, chlorophyll a+b, total carotenoids contents, chlorophyll a/chlorophyll b ratio and Chlorophyll a+b/total cartenoids ratio ranged from 0.78 to 1.10, from 0.54 to 0.71, from 1.37 to 1.71, from 0.09 to 0.13 mg g(-1), from 1.33 to 1.68 and from 13.52 to 14.82, respectively. Negative relationships existed between seed yield and pigment contents. There were significant yield differences among genotypes and varied from 2452.60 to 3897.20 kg ha(-1). A diverse range of capitulum diameter (24.08-28.91 mm), seed weight/capitulum (1.18-2.04 g), number of seeds/m2 (8704.5-13165.4), number of capitula/plant (16.38-23.27), number of seeds/capitulum (35.65-41.90) and 1000-seed weight (29.94-50.60 g) was recorded. Genotypes differed in HI and the HI values ranged from 21.83% (LRK-262) to 29.62% (IL.111). In the studied set of 6 safflower genotypes, total biomass and LAI peaked around after full flowering and at the beginning of flowering, respectively. Zarghan-279 (with the greatest LAID) had 25% longer LAID than LRV.51.51 (with the lowest LAID). Differences among genotypes for rate of seed filling and effective seed filling duration were significant and differences in seed yield could be attributed to differences in the rate of seed filling. The results of this experiment indicate that physiological parameters including rate of seed filling, rapid leaf formation and expansion and delayed plant senescence are the characteristics of high-yielding safflower. Also, higher dry matter accumulation, HI, seed weight/capitulum, 1000-seed weight and capitulum diameter were found to be closely related to high-yield genotypes.

  8. 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

  9. Electron yields from spacecraft materials

    NASA Technical Reports Server (NTRS)

    Yang, K.; Gordon, W. L.; Hoffman, R. W.

    1985-01-01

    Photoyields and secondary electron emission (SEE) characteristics were determined under UHV conditions for a group of insulating materials used in spacecraft applications. The SEE studies were carried out with a pulsed primary beam while photoyields were obtained with a chopped photon beam from a Kr resonance source with major emission at 123.6 nm. This provides a photon flux close to that of the Lyman alpha in the space environment. Yields per incident photon are obtained relative to those from a freshly evaporated and air oxidized Al surface. Results are presented for Kapton, FEP Teflon, the borosilicate glass covering of a shuttle tile, and spacesuit outer fabric.

  10. Alternative to peat for Agaricus brasiliensis yield.

    PubMed

    Colauto, Nelson Barros; da Silveira, Adriano Reis; da Eira, Augusto Ferreira; Linde, Giani Andrea

    2010-01-01

    Casing layer is one of the most important components of Agaricus spp. production and it directly affects mushroom productivity, size and mass. The aim of this study was to evaluate potential raw materials as a casing layer and their effect on Agaricus brasiliensis productivity. Raw materials from Brazil with potential use were selected and characterized, and the most promising ones were tested as casing layers for mushroom yield. Evaluated raw materials included lime schist, vermiculite, eucalyptus sawdust, sand, São Paulo peat, Santa Catarina peat, subsoil and charcoal. Particle size, porosity and water absorption in relation to mushroom yield for casing layers were determined. Lime schist, an alternate casing layer to peat, is presented and the effects of the casing layer on the mushroom yield are discussed.

  11. 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

  12. 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

  13. Animal component-free Agrobacterium tumefaciens cultivation media for better GMP-compliance increases biomass yield and pharmaceutical protein expression in Nicotiana benthamiana.

    PubMed

    Houdelet, Marcel; Galinski, Anna; Holland, Tanja; Wenzel, Kathrin; Schillberg, Stefan; Buyel, Johannes Felix

    2017-02-21

    Transient expression systems allow the rapid production of recombinant proteins in plants. Such systems can be scaled up to several hundred kilograms of biomass, making them suitable for the production of pharmaceutical proteins required at short notice, such as emergency vaccines. However, large-scale transient expression requires the production of recombinant Agrobacterium tumefaciens strains with the capacity for efficient gene transfer to plant cells. The complex media often used for the cultivation of this species typically include animal-derived ingredients that can contain human pathogens, thus conflicting with the requirements of good manufacturing practice (GMP). We replaced all the animal-derived components in yeast extract broth (YEB) cultivation medium with soybean peptone, and then used a design-of-experiments approach to optimize the medium composition, increasing the biomass yield while maintaining high levels of transient expression in subsequent infiltration experiments. The resulting plant peptone Agrobacterium medium (PAM) achieved a two-fold increase in OD600 compared to YEB medium during a 4-L batch fermentation lasting 18 h. Furthermore, the yields of the monoclonal antibody 2G12 and the fluorescent protein DsRed were maintained when the cells were cultivated in PAM rather than YEB. We have thus demonstrated a simple, efficient and scalable method for medium optimization that reduces process time and costs. The final optimized medium for the cultivation of A. tumefaciens completely lacks animal-derived components, thus facilitating the GMP-compliant large-scale transient expression of recombinant proteins in plants.

  14. 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...

  15. Mapping of quantitative trait loci for root hair length in wheat identifies loci that co-locate with loci for yield components

    PubMed Central

    Horn, R.; Wingen, L. U.; Snape, J. W.; Dolan, L.

    2016-01-01

    Root hairs are fast growing, ephemeral tubular extensions of the root epidermis. They arise in the unsuberized maturation zone of the root, effectively increasing the root surface area in the region over which nutrient and water uptake occur. Variation in root hair length (RHL) between varieties has been shown to be genetically determined, and could, therefore, have consequences for nutrient capture and yield potential in crops. We describe the development of a medium-to-high throughput screening method for assessing RHL in wheat at the seedling stage. This method was used to screen a number of wheat mapping population parental lines for variation in RHL. Parents of two populations derived from inter-varietal crosses differed for RHL: Spark vs Rialto and Charger vs Badger. We identified quantitative trait loci (QTLs) for RHL in the populations derived from these crosses. In Spark × Rialto, QTLs on chromosomes 1A, 2A and 6A were associated with variation in RHL, whilst in Charger × Badger, a QTL for RHL was identified on 2BL. The QTLs on 2A and 6A co-localized with previously described QTLs for yield components. Longer root hairs may confer an advantage by exploiting limiting mineral and water resources. This first QTL analysis of root hair length in wheat identifies loci that could usefully be further investigated for their role in tolerance to limiting conditions. PMID:27315832

  16. Dynamics of yield components and essential oil production in a commercial hybrid sage (Salvia officinalis x Salvia fruticosa cv. Newe Ya'ar no. 4).

    PubMed

    Dudai, N; Lewinsohn, E; Larkov, O; Katzir, I; Ravid, U; Chaimovitsh, D; Sa'adi, D; Putievsky, E

    1999-10-01

    The fresh yields, the essential oil content, and the quality of a sage hybrid (Salvia officinalis x Salvia fruticosa, cv. Newe Ya'ar No. 4, Lamiaceae) as affected by development and harvest time were determined. Marked increases in plant height and in the number of nodes developed per plant together with a modest increase in leaf size were accompanied by dramatic increases (more than 20-fold) in the fresh yields throughout a 50-day growth period. No major changes in the essential oil content per fresh weight and its composition were detected throughout the growth period. In contrast, the compositions of the essential oils obtained from stems, as compared to leaves and leaf-primordia, had marked differences. Developmentally controlled changes in the extractives from individual leaf pairs from the same plant were also noted. In upper young leaves, the oxygenated diterpene manool and the sesquiterpene hydrocarbons alpha-humulene and beta-caryophyllene constituted up to 20%, 8%, and 4% of the total extractives, respectively. In older leaves, the abundance of these components steadily dropped to roughly half their levels in young leaves. Conversely, the proportions of the monoterpenes, particularly the ketones camphor and alpha-thujone, steadily increased with leaf position. Minor changes in the levels of other extractives were also recorded. These studies imply independent regulatory patterns for di-, sesqui-, and monoterpenes in this sage hybrid, and suggest possible agrotechnical means to obtain preferred chemical compositions of its essential oil.

  17. Relationship between Yield Components and Partial Resistance to Lecanicillium fungicola in the Button Mushroom, Agaricus bisporus, Assessed by Quantitative Trait Locus Mapping

    PubMed Central

    Rodier, Anne; Savoie, Jean-Michel

    2012-01-01

    Dry bubble, caused by Lecanicillium fungicola, is one of the most detrimental diseases affecting button mushroom cultivation. In a previous study, we demonstrated that breeding for resistance to this pathogen is quite challenging due to its quantitative inheritance. A second-generation hybrid progeny derived from an intervarietal cross between a wild strain and a commercial cultivar was characterized for L. fungicola resistance under artificial inoculation in three independent experiments. Analysis of quantitative trait loci (QTL) was used to determine the locations, numbers, and effects of genomic regions associated with dry-bubble resistance. Four traits related to resistance were analyzed. Two to four QTL were detected per trait, depending on the experiment. Two genomic regions, on linkage group X (LGX) and LGVIII, were consistently detected in the three experiments. The genomic region on LGX was detected for three of the four variables studied. The total phenotypic variance accounted for by all QTL ranged from 19.3% to 42.1% over all traits in all experiments. For most of the QTL, the favorable allele for resistance came from the wild parent, but for some QTL, the allele that contributed to a higher level of resistance was carried by the cultivar. Comparative mapping with QTL for yield-related traits revealed five colocations between resistance and yield component loci, suggesting that the resistance results from both genetic factors and fitness expression. The consequences for mushroom breeding programs are discussed. PMID:22247161

  18. Relationship between yield components and partial resistance to Lecanicillium fungicola in the button mushroom, Agaricus bisporus, assessed by quantitative trait locus mapping.

    PubMed

    Foulongne-Oriol, Marie; Rodier, Anne; Savoie, Jean-Michel

    2012-04-01

    Dry bubble, caused by Lecanicillium fungicola, is one of the most detrimental diseases affecting button mushroom cultivation. In a previous study, we demonstrated that breeding for resistance to this pathogen is quite challenging due to its quantitative inheritance. A second-generation hybrid progeny derived from an intervarietal cross between a wild strain and a commercial cultivar was characterized for L. fungicola resistance under artificial inoculation in three independent experiments. Analysis of quantitative trait loci (QTL) was used to determine the locations, numbers, and effects of genomic regions associated with dry-bubble resistance. Four traits related to resistance were analyzed. Two to four QTL were detected per trait, depending on the experiment. Two genomic regions, on linkage group X (LGX) and LGVIII, were consistently detected in the three experiments. The genomic region on LGX was detected for three of the four variables studied. The total phenotypic variance accounted for by all QTL ranged from 19.3% to 42.1% over all traits in all experiments. For most of the QTL, the favorable allele for resistance came from the wild parent, but for some QTL, the allele that contributed to a higher level of resistance was carried by the cultivar. Comparative mapping with QTL for yield-related traits revealed five colocations between resistance and yield component loci, suggesting that the resistance results from both genetic factors and fitness expression. The consequences for mushroom breeding programs are discussed.

  19. 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.

  20. Short communication: Effects of prill size of a palmitic acid-enriched fat supplement on the yield of milk and milk components, and nutrient digestibility of dairy cows.

    PubMed

    de Souza, J; Garver, J L; Preseault, C L; Lock, A L

    2017-01-01

    The objective of our experiment was to evaluate the effects of prill size of a palmitic acid-enriched fatty acid supplement (PA; 85% C16:0) on feed intake, nutrient digestibility, and production responses of dairy cows. Twenty-four primiparous and multiparous Holstein cows were assigned based on parity and production level to replicated 4×4 Latin squares balanced for carryover effects with 21-d periods. Treatments were a control diet (no added PA), or 2.0% PA added as a small prill size (PA-SM; 284±12.4µm), a medium prill size (PA-MD; 325±14.7µm), or a large prill size (PA-LG; 600±17.4µm) supplement. Overall, PA treatments increased milk fat content (4.25 vs. 3.99%), milk fat yield (1.48 vs. 1.39kg/d), 3.5% fat-corrected milk (39.2 vs. 37.7kg/d), and improved feed efficiency (fat-corrected milk:dry matter intake; 1.51 vs. 1.42) compared with control. Compared with control, PA treatments did not affect dry matter intake, body weight, body condition score, or yields of milk, protein, and lactose. The PA treatments increased neutral detergent fiber digestibility (44.8 vs. 42.4%) and reduced the digestibility of 16-carbon fatty acids (72.3 vs. 79.1%) and total fatty acids (76.6 vs. 80.3%). Compared with control, PA treatments reduced the contents of de novo synthesized milk fatty acids (23.0 vs. 25.8g/100g of fatty acids) and preformed milk fatty acids (36.3 vs. 39.1g/100g of fatty acids), but did not affect their yields. In contrast, PA treatments increased the content (40.8 vs. 35.1g/100g of fatty acids) and yield (570 vs. 436g/d) of 16-carbon milk fatty acids compared with control. The PA prill size had no effect on dry matter intake, yield of milk and milk components, or feed efficiency. However, PA-LG tended to increase milk fat content compared with PA-SM (4.28 vs. 4.22%), and it increased 16-carbon fatty acid digestibility compared with PA-MD (74.2 vs. 71.0%) and PA-SM (74.2 vs. 71.7%). Additionally, PA-LG increased total fatty acid digestibility compared

  1. Method for improving reformer yield selectivity

    SciTech Connect

    Ramella, A.; Wang, H. Y.

    1985-11-05

    Yield selectivity of a multibed catalytic reformer operating below design capacity is enhanced by adjusting inlet temperature of at least one catalyst bed to nearquenching conditions while adjusting the inlet temperature of at least one catalyst bed to favor yield selective reforming reactions. Significant increases in C/sub 5/+ yields are obtained without any modification of the reforming unit.

  2. 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...

  3. Heterois in Switchgrass: Biomass Yield in Swards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving the biomass yield of switchgrass (Panicum virgatum L.) will improve its utility as a dedicated energy crop by increasing energy yield per acre. In a previous space-transplanted study, mid-parent heterosis for biomass yield was reported for population and specific F1 hybrids of the lowland-...

  4. Quantitative Trait Locus Mapping of Yield-Related Components and Oligogenic Control of the Cap Color of the Button Mushroom, Agaricus bisporus

    PubMed Central

    Rodier, Anne; Rousseau, Thierry; Savoie, Jean-Michel

    2012-01-01

    As in other crops, yield is an important trait to be selected for in edible mushrooms, but its inheritance is poorly understood. Therefore, we have investigated the complex genetic architecture of yield-related traits in Agaricus bisporus through the mapping of quantitative trait loci (QTL), using second-generation hybrid progeny derived from a cross between a wild strain and a commercial cultivar. Yield, average weight per mushroom, number of fruiting bodies per m2, earliness, and cap color were evaluated in two independent experiments. A total of 23 QTL were detected for 7 yield-related traits. These QTL together explained between 21% (two-flushes yield) and 59% (earliness) of the phenotypic variation. Fifteen QTL (65%) were consistent between the two experiments. Four regions underlying significant QTL controlling yield, average weight, and number were detected on linkage groups II, III, IV, and X, suggesting a pleiotropic effect or tight linkage. Up to six QTL were identified for earliness. The PPC1 locus, together with two additional genomic regions, explained up to 90% of the phenotypic variation of the cap color. Alleles from the wild parent showed beneficial effects for some yield traits, suggesting that the wild germ plasm is a valuable source of variation for several agronomic traits. Our results constitute a key step toward marker-assisted selection and provide a solid foundation to go further into the biological mechanisms controlling productive traits in the button mushroom. PMID:22267676

  5. Invited review: A commentary on predictive cheese yield formulas.

    PubMed

    Emmons, D B; Modler, H W

    2010-12-01

    Predictive cheese yield formulas have evolved from one based only on casein and fat in 1895. Refinements have included moisture and salt in cheese and whey solids as separate factors, paracasein instead of casein, and exclusion of whey solids from moisture associated with cheese protein. The General, Barbano, and Van Slyke formulas were tested critically using yield and composition of milk, whey, and cheese from 22 vats of Cheddar cheese. The General formula is based on the sum of cheese components: fat, protein, moisture, salt, whey solids free of fat and protein, as well as milk salts associated with paracasein. The testing yielded unexpected revelations. It was startling that the sum of components in cheese was <100%; the mean was 99.51% (N × 6.31). The mean predicted yield was only 99.17% as a percentage of actual yields (PY%AY); PY%AY is a useful term for comparisons of yields among vats. The PY%AY correlated positively with the sum of components (SofC) in cheese. The apparent low estimation of SofC led to the idea of adjusting upwards, for each vat, the 5 measured components in the formula by the observed SofC, as a fraction. The mean of the adjusted predicted yields as percentages of actual yields was 99.99%. The adjusted forms of the General, Barbano, and Van Slyke formulas gave predicted yields equal to the actual yields. It was apparent that unadjusted yield formulas did not accurately predict yield; however, unadjusted PY%AY can be useful as a control tool for analyses of cheese and milk. It was unexpected that total milk protein in the adjusted General formula gave the same predicted yields as casein and paracasein, indicating that casein or paracasein may not always be necessary for successful yield prediction. The use of constants for recovery of fat and protein in the adjusted General formula gave adjusted predicted yields equal to actual yields, indicating that analyses of cheese for protein and fat may not always be necessary for yield prediction

  6. 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.

  7. Yields of bedrock wells in Massachusetts

    USGS Publications Warehouse

    Hansen, B.P.; Simcox, A.C.

    1994-01-01

    Six to seven percent of the population of Massachusetts obtains its water from domestic bedrock wells. Additional public, commercial, industrial, and domestic supplies from bedrock will be needed in the future. Information about the factors that are related to large well yields is needed. The factors associated with well yields were identified by use of statistical analysis of reported data from 4,218 bedrock wells. The median reported yield of all bedrock wells was 7 gallons per minute, and the median depth was 170 feet. Wells in valleys and lowlands had the largest median yield--I0 gallons per minute. The median well yield on hilltops and slopes was 6 gallons per minute. In valleys and lowlands, significant increases in well yields corresponded to increasing thickness of overburden. On hilltops and slopes, only small increases in well yield corresponded to increases in overburden thickness. Increases in well diameter corresponded to significant increases in well yields for all well locations, depths, and use categories. The common assumptions that fractured crystalline rocks generally yield only small quantities of water to wells and that the fractures that yield water to wells pinch out or are closed because of lithostatic pressure at depths greater than 300 to 400 feet may be in error. Analysis of well data indicates that the median yield of all bedrock wells decreased as well depth increased to 400 feet and increased slightly with well depths greater than 600 feet. The median yield of bedrock wells located in valleys and lowlands reached 50 gallons per minute at depths of 600 to 700 feet. The median yield of wells located on hilltops and slopes reached 15 gallons per minute at depths of 600 to 700 feet. Carbonate bedrock, with a median well yield of 25 gallons per minute, seemed to be the most productive bedrock type. A reported yield of 1,700 gallons per minute from an industrial well completed in carbonate bedrock is the largest reported yield from a bedrock

  8. Uncertainty analysis for water supply reservoir yields

    NASA Astrophysics Data System (ADS)

    Kuria, Faith; Vogel, Richard

    2015-10-01

    Understanding the variability of water supply reservoir yields is central for planning purposes. The basis of this study is an empirical global relationship between reservoir storage capacity, water supply yield and reliability based on a global database of 729 rivers. Monte Carlo simulations reveal that the coefficient of variation of estimates of water supply reservoir yields depend only on the length of streamflows record and the coefficient of variation of the streamflows used to estimate the yield. We compare the results of those Monte Carlo experiments with an analytical uncertainty method First Order Variance Approximation (FOVA). FOVA is shown to produce a general, accurate and useful expression for estimating the coefficient of variation of water supply reservoir yield estimates. We also document how the FOVA analytical model can be used to determine the minimum length of streamflow record required during the design of water supply reservoirs so as to ensure that the yield delivered from reservoir falls within a prespecified margin of error.

  9. Seismological Discrimination and Yield Determination Research

    DTIC Science & Technology

    1980-02-01

    yield for NTS granodiorite . . . 31 iii 9 . . LIST OF ILLUSTRATIONS (continued) Figure Page 18. mb versus yield for NTS granodiorite . . . 32 19...depth of burial on surface wave and body wave magnitudes. The rock environ- ment was NTS fractured granodiorite . Near field data from the PILEDRIVER...Figure 17. M s versus yield for NTS granodiorite . 𔃺 31 SYSTEMS. SCIENCE AND SOFTWARE 0 c 3: C Cc -M4 co Z=_ CU .,., 32 SvSTEM S SCIE’NCE AND

  10. Effects of Beak Trimming, Stocking Density and Sex on Carcass Yield, Carcass Components, Plasma Glucose and Triglyceride Levels in Large White Turkeys.

    PubMed

    Sengul, Turgay; Inci, Hakan; Sengul, Ahmet Y; Sogut, Bunyamin; Kiraz, Selahattin

    2015-01-01

    This study was conducted to determine the effects of beak trimming, stocking density (D) and sex (S) on live weight (LW), carcass yield and its component, and plasma glucose (PG) and triglyceride levels in Large White turkeys. To accomplish this aims, totally 288 d old large white turkey chicks (144 in each sex) were used. Beaks of 77 male and female poults were trimmed when 8 d old with an electrical beak trimmer. The birds were fed by commercial turkey rasion. Experiment was designed as 2 × 2 × 2 factorial arrangement with 3 replications in each group. Beak trimming and stocking density did not affect live weight, carcass composition and its components. The higher LW and carcass weight observed in trimmed groups. As expected, male birds are heavier than female, and carcass percentage (CP) would be adverse. However, in this study, CP of male was higher in trimmed, in 0.25 m(2)/bird. (D) × sex (S) interaction had an effect on both CP and thigh weights (p<0.05). Significantly D × S was observed in LW, CP and PG. The weight of carcass and its some components were higher in male. S × D interaction had an effect on plasma glucose level (p<0.05). Triglyceride level was affected (p<0.05) by sex. Significant relationships were found between percentage of thighs (r=0.447, p<0.01) and percentage of breast (r=0.400, p<0.01). According to this study, it can be said that trimming is useful with density of 0.25 m(2)/bird in turkey fattening.

  11. 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.

  12. 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.

  13. 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.

  14. Linear unmixing of multidate hyperspectral imagery for crop yield estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we have evaluated an unsupervised unmixing approach, vertex component analysis (VCA), for the application of crop yield estimation. The results show that abundance maps of the vegetation extracted by the approach are strongly correlated to the yield data (the correlation coefficients ...

  15. Nitrogen fertilization reduces yield declines following no-till adoption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation agriculture (CA) has been promoted as a method of sustainable intensification and climate change mitigation and is being widely practiced and implemented globally. However, notill (NT) practices, a fundamental component of CA, have been shown to reduce yields. In order to maintain yield...

  16. Crop Yield Response to Increasing Biochar Rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The benefit or detriment to crop yield from biochar application varies with biochar type/rate, soil, crop, or climate. The objective of this research was to identify yield response of cotton (Gossypium hirsutum L.), corn (Zea mayes L.), and peanut (Arachis hypogaea L.) to hardwood biochar applied at...

  17. 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...

  18. Yielding behavior of dense microgel glasses

    NASA Astrophysics Data System (ADS)

    Joshi, R. G.; Tata, B. V. R.; Karthickeyan, D.

    2013-02-01

    We report here the yielding behavior of dense suspensions of stimuli-responsive poly-N-isopropyl acrylamide (PNIPAM) microgel particles studied by performing oscillatory shear measurements. At a volume fraction of φ = 0.6 (labeled as sample S1) the suspension is characterized to be repulsive glass by dynamic light scattering technique and showed one step yielding. Quite interestingly higher volume fraction sample (S2) prepared by osmotically compressing sample S1, showed yielding occurring in two steps. Such one step yielding behavior turning into two step yielding was reported by Pham et al [Europhys. Lett., 75, 624 (2006)] in hard-sphere repulsive colloidal glass when transformed into an attractive glass by inducing depletion attraction. We confirm the repulsive interparticle interaction between PNIPAM microgel particles turning into attractive upon osmotic compression by static light scattering measurements.

  19. Wheat yield dynamics: a structural econometric analysis.

    PubMed

    Sahin, Afsin; Akdi, Yilmaz; Arslan, Fahrettin

    2007-10-15

    In this study we initially have tried to explore the wheat situation in Turkey, which has a small-open economy and in the member countries of European Union (EU). We have observed that increasing the wheat yield is fundamental to obtain comparative advantage among countries by depressing domestic prices. Also the changing structure of supporting schemes in Turkey makes it necessary to increase its wheat yield level. For this purpose, we have used available data to determine the dynamics of wheat yield by Ordinary Least Square Regression methods. In order to find out whether there is a linear relationship among these series we have checked each series whether they are integrated at the same order or not. Consequently, we have pointed out that fertilizer usage and precipitation level are substantial inputs for producing high wheat yield. Furthermore, in respect for our model, fertilizer usage affects wheat yield more than precipitation level.

  20. Partitioning potential fish yields from the Great Lakes

    USGS Publications Warehouse

    Loftus, D.H.; Olver, C.H.; Brown, Edward H.; Colby, P.J.; Hartman, Wilbur L.; Schupp, D.H.

    1987-01-01

    We proposed and implemented procedures for partitioning future fish yields from the Great Lakes into taxonomic components. These projections are intended as guidelines for Great Lakes resource managers and scientists. Attainment of projected yields depends on restoration of stable fish communities containing some large piscivores that will use prey efficiently, continuation of control of the sea lamprey (Petromyzon marinus), and restoration of high-quality fish habitat. Because Great Lakes fish communities were harmonic before their collapse, we used their historic yield properties as part of the basis for projecting potential yields of rehabilitated communities. This use is qualified, however, because of possible inaccuracies in the wholly commercial yield data, the presence now of greatly expanded sport fisheries that affect yield composition and magnitude, and some possibly irreversible changes since the 1950s in the various fish communities themselves. We predict that total yields from Lakes Superior, Huron, and Ontario will be increased through rehabilitation, while those from Lakes Michigan and Erie will decline. Salmonines and coregonines will dominate future yields from the upper lakes. The Lake Erie fishery will continue to yield mostly rainbow smelt (Osmerus mordax), but the relative importance of percids, especially of walleye (Stizostedion vitreum vitreum) will increase. In Lake Ontario, yields of salmonines will be increased. Managers will have to apply the most rigorous management strictures to major predator species.

  1. 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.

  2. 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.

  3. 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

  4. Pollinator shortage and global crop yield

    PubMed Central

    Aizen, Marcelo A; Cunningham, Saul A; Klein, Alexandra M

    2009-01-01

    A pollinator decline caused by environmental degradation might be compromising the production of pollinator-dependent crops. In a recent article, we compared 45 year series (1961–2006) in yield, production and cultivated area of pollinator-dependent and nondependent crop around the world. If pollinator shortage is occurring globally, we expected a lower annual growth rate in yield for pollinator-dependent than nondependent crops, but a higher growth in cultivated area to compensate the lower yield. We have found little evidence for the first “yield” prediction but strong evidence for the second “area” prediction. Here, we present an additional analysis to show that the first and second predictions are both supported for crops that vary in dependency levels from nondependent to moderate dependence (i.e., up to 65% average yield reduction without pollinators). However, those crops for which animal pollination is essential (i.e., 95% average yield reduction without pollinators) showed higher growth in yield and lower expansion in area than expected in a pollination shortage scenario. We propose that pollination management for highly pollinator-dependent crops, such us renting hives or hand pollination, might have compensated for pollinator limitation of yield. PMID:19704865

  5. 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.

  6. Mapping genomic loci for cotton plant architecture, yield components, and fiber properties in an interspecific (Gossypium hirsutum L. × G. barbadense L.) RIL population.

    PubMed

    Yu, John Z; Ulloa, Mauricio; Hoffman, Steven M; Kohel, Russell J; Pepper, Alan E; Fang, David D; Percy, Richard G; Burke, John J

    2014-12-01

    A quantitative trait locus (QTL) mapping was conducted to better understand the genetic control of plant architecture (PA), yield components (YC), and fiber properties (FP) in the two cultivated tetraploid species of cotton (Gossypium hirsutum L. and G. barbadense L.). One hundred and fifty-nine genomic regions were identified on a saturated genetic map of more than 2,500 SSR and SNP markers, constructed with an interspecific recombinant inbred line (RIL) population derived from the genetic standards of the respective cotton species (G. hirsutum acc. TM-1 × G. barbadense acc. 3-79). Using the single nonparametric and MQM QTL model mapping procedures, we detected 428 putative loci in the 159 genomic regions that confer 24 cotton traits in three diverse production environments [College Station F&B Road (FB), TX; Brazos Bottom (BB), TX; and Shafter (SH), CA]. These putative QTL loci included 25 loci for PA, 60 for YC, and 343 for FP, of which 3, 12, and 60, respectively, were strongly associated with the traits (LOD score ≥ 3.0). Approximately 17.7 % of the PA putative QTL, 32.9 % of the YC QTL, and 48.3 % of the FP QTL had trait associations under multiple environments. The At subgenome (chromosomes 1-13) contributed 72.7 % of loci for PA, 46.2 % for YC, and 50.4 % for FP while the Dt subgenome (chromosomes 14-26) contributed 27.3 % of loci for PA, 53.8 % for YC, and 49.6 % for FP. The data obtained from this study augment prior evidence of QTL clusters or gene islands for specific traits or biological functions existing in several non-homoeologous cotton chromosomes. DNA markers identified in the 159 genomic regions will facilitate further dissection of genetic factors underlying these important traits and marker-assisted selection in cotton.

  7. The optical depth of the 158 micrometer (C-12 II) line: Detection of the F=1 yields 0 (C-13 III) hyperfine-structure component

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Townes, C. H.; Poglitsch, A.; Madden, S. C.; Jackson, J. M.; Herrmann, F.; Genzel, R.; Geis, N.

    1991-01-01

    The first detection of the F = 1 yields 0 hyperfine component of the 158 micrometer (C-13 II) fine structure line in the interstellar medium is reported. A twelve point intensity map was obtained of the (C-13 II) distribution over the inner 190 inch (right ascension) by 190 inch (declination) regions of the Orion nebula using an imaging Fabry-Perot interferometer. The (C-12 II)/(C-13 II) line intensity ratio varied significantly over the region mapped. It is highest (86 plus or minus 9) in the core of the Orion H II region and significantly lower (62 plus or minus 7) in the outer regions of the map, reflecting higher optical depth in the (C-12 II) line here. It is suggested that this enhanced optical depth is the result of limb brightening of the optically thin (C-13 II) line at the edges of the bowl-shaped H II region blister. If the C-12/C-13 abundance ratio is 43, the (C-12 II) line in the inner regions of the Orion nebula, has a low optical depth: tau sub 12 approximately = 0.75 plus or minus 0.25. The optical depth together with the large brightness temperature of the (C-12 II) line (approximately 160 K) requires that the excitation temperature of the P-2 sub 3/2 level be approximately 310 K, in very good agreement with the previous analysis of the physical conditions of the Orion interface region based on fine structure line intensity ratios and photodissociation region models. If the C-12/C-13 abundance ratio is 67, the line optical depth is somewhat larger (tau sub 12 approximately = 1.85), and the transition excitation temperature is somewhat smaller (approximately 190 K) than that predicted by these models. The present results therefore support values approximately = 43 for the C-12/C-13 abundance ratio in the Orion nebula.

  8. 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.

  9. Neutron yield for chemical compounds of actinides

    SciTech Connect

    Vukolov, V.A.; Chukreev, F.E.

    1987-10-01

    The authors assess the neutron yield for a variety of nuclear fuels--uranium hexafluoride, plutonium dioxide, plutonium carbide, plutonium fluoride, americium dioxide, americium fluoride, curium dioxide, and alloys of beryllium with plutonium and americium--by analyzing and configuring experimental data on the cross sections of alpha reactions with lithium 6, lithium 7, beryllium 9, boron 10, boron 11, carbon 13, and fluorine 19 targets. They present a mathematical formulation which, when compared to experimentally derived values, shows comparable accuracy in forecasting neutron yield. They find that the inclusion of stopping power data increases the agreement between experimental and theoretical yields.

  10. Yield-centric layout optimization with precise quantification of lithographic yield loss

    NASA Astrophysics Data System (ADS)

    Kobayashi, Sachiko; Kyoh, Suigen; Kinoshita, Koichi; Urakawa, Yukihiro; Morifuji, Eiji; Kuramoto, Satoshi; Inoue, Soichi

    2008-05-01

    Continuous shrinkage of the design rule in LSI devices brings about greater difficulty in the manufacturing process. Since not only process engineers' efforts but also yield-centric layout optimization is becoming increasingly important, such optimization has recently become a focus of interest. One of the approached is lithographic hotspot modification in design data. Using lithography compliance check and a hotspot fixing system in the early stage of design, design with wider process margin can be obtained. In order to achieve higher process yield after hotspot fixing, layout should be carefully optimized to decrease pattern-dependent yield loss. Since yield value for the design will fluctuate sensitively as designed pattern are modified, pattern should be optimized based on a comprehensive consideration of yield loss covering parametric, systematic and random effects. In this work, using lithography simulation, a lithographic yield loss model is defined and applied for precise quantification of process yield loss in 45 nm logic design. Yield loss values of each cell for lithographic, parametric and random effects are estimated, and then layouts through multiple layers are optimized to decrease total yield loss. As a result, litho-yield loss is greatly improved without deteriorating total yield value. Thus, layout is obtained that reflects an awareness of overall process yield.

  11. The yield stress of foamy sands

    SciTech Connect

    Kam, S. I.; Gauglitz, Phillip A.; Rossen, W R.

    2002-03-26

    The yield stress of a mixture of foam and solids, or foamy sand, was investigated theoretically using 2D periodic model. The range of solid fractions considered was from about 40 to 68%. The yield stress of a foamy sand increases with gas fraction at a given solid fraction and increases with solid fraction at a given gas fraction. At a fixed fraction of solid plus gas, yield stress is relatively insensitive to gas or solid fraction alone. There exists a maximum liquid fraction above which the yield stress disappears. These trends agree with those reported for foamy sands encountered in tunneling through soft sediments and proppant-laden fracturing fluids used in the petroleum industry.

  12. Predicting yields for autotrophic and cometabolic processes

    SciTech Connect

    Andrews, G.

    1995-12-31

    The goal of bioprocess engineering is to state how the optimum design and control strategy for a bioprocess follow from the metabolism of the particular microorganism. A necessary step toward this goal is to show how the parameters used in quantitative descriptions of a process (e.g., yield and maintenance coefficients) are related to those describing the metabolism [e.g., Y{sub ATP}, (P/O)]. The {open_quotes}yield equation{close_quotes} approach to this problem involves dividing metabolism into the separate pathways for catabolism, anabolism, respiration, and product formation and balancing the production and consumption of reducing equivalents and ATP. The general approach, demonstrated previously for heterotrophic cell growth and products of fermentation, is illustrated by three new examples: the cell yield for chemoautotrophic iron-oxidizing bacteria, the cometabolic degradation of chloroform by methanotrophic bacteria, and the theoretical yield of succinic acid from glucose.

  13. Suspended sediment yield mapping of Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Maltsev, K. A.; Yermolaev, O. P.; Mozzherin, V. V.

    2015-03-01

    The mapping of river sediment yields at continental or global scale involves a number of technical difficulties that have largely been ignored. The maps need to show the large zonal peculiarities of river sediment yields, as well as the level (smoothed) local anomalies. This study was carried out to create a map of river sediment yields for Northern Eurasia (within the boundaries of the former Soviet Union, 22 × 106 km2) at a scale of 1:1 500 000. The data for preparing the map were taken from the long-term observations recorded at more than 1000 hydrological stations. The data have mostly been collected during the 20th century by applying a single method. The creation of this map from the study of river sediment yield is a major step towards enhancing international research on understanding the mechanical denudation of land due mainly to erosion.

  14. 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.

  15. 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.

  16. Absolute quantum yield measurement of powder samples.

    PubMed

    Moreno, Luis A

    2012-05-12

    Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and research of illumination, AV equipment, organic EL material, films, filters and fluorescent probes for bio-industry. Quantum yield is calculated as the ratio of the number of photons absorbed, to the number of photons emitted by a material. The higher the quantum yield, the better the efficiency of the fluorescent material. For the measurements featured in this video, we will use the Hitachi F-7000 fluorescence spectrophotometer equipped with the Quantum Yield measuring accessory and Report Generator program. All the information provided applies to this system. Measurement of quantum yield in powder samples is performed following these steps: 1. Generation of instrument correction factors for the excitation and emission monochromators. This is an important requirement for the correct measurement of quantum yield. It has been performed in advance for the full measurement range of the instrument and will not be shown in this video due to time limitations. 2. Measurement of integrating sphere correction factors. The purpose of this step is to take into consideration reflectivity characteristics of the integrating sphere used for the measurements. 3. Reference and Sample measurement using direct excitation and indirect excitation. 4. Quantum Yield calculation using Direct and Indirect excitation. Direct excitation is when the sample is facing directly the excitation beam, which would be the normal measurement setup. However, because we use an integrating sphere, a portion of the emitted photons resulting from the sample fluorescence are reflected by the integrating sphere and will re-excite the sample, so we need to take into consideration indirect excitation. This is accomplished by measuring the sample placed in the port facing the emission monochromator, calculating indirect quantum yield and correcting the direct

  17. 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.

  18. 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.

  19. 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.

  20. Modulus and yield stress of drawn LDPE

    NASA Astrophysics Data System (ADS)

    Thavarungkul, Nandh

    Modulus and yield stress were investigated in drawn low density polyethylene (LDPE) film. Uniaxially drawn polymeric films usually show high values of modulus and yield stress, however, studies have normally only been conducted to identify the structural features that determine modulus. In this study small-angle x-ray scattering (SAXS), thermal shrinkage, birefringence, differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA) were used to examine, directly and indirectly, the structural features that determine both modulus and yield stress, which are often closely related in undrawn materials. Shish-kebab structures are proposed to account for the mechanical properties in drawn LDPE. The validity of this molecular/morphological model was tested using relationships between static mechanical data and structural and physical parameters. In addition, dynamic mechanical results are also in line with static data in supporting the model. In the machine direction (MD), "shish" and taut tie molecules (TTM) anchored in the crystalline phase account for E; whereas crystal lamellae with contributions from "shish" and TTM determine yield stress. In the transverse direction (TD), the crystalline phase plays an important roll in both modulus and yield stress. Modulus is determined by crystal lamellae functioning as platelet reinforcing elements in the amorphous matrix with an additional contributions from TTM and yield stress is determined by the crystal lamellae's resistance to deformation.

  1. Water limits to closing yield gaps

    NASA Astrophysics Data System (ADS)

    Davis, Kyle Frankel; Rulli, Maria Cristina; Garrassino, Francesco; Chiarelli, Davide; Seveso, Antonio; D'Odorico, Paolo

    2017-01-01

    Agricultural intensification is often seen as a suitable approach to meet the growing demand for agricultural products and improve food security. It typically entails the use of fertilizers, new cultivars, irrigation, and other modern technology. In regions of the world affected by seasonal or chronic water scarcity, yield gap closure is strongly dependent on irrigation (blue water). Global yield gap assessments have often ignored whether the water required to close the yield gap is locally available. Here we perform a gridded global analysis (10 km resolution) of the blue water consumption that is needed annually to close the yield gap worldwide and evaluate the associated pressure on renewable freshwater resources. We find that, to close the yield gap, human appropriation of freshwater resources for irrigation would have to increase at least by 146%. Most study countries would experience at least a doubling in blue water requirement, with 71% of the additional blue water being required by only four crops - maize, rice, soybeans, and wheat. Further, in some countries (e.g., Algeria, Morocco, Syria, Tunisia, and Yemen) the total volume of blue water required for yield gap closure would exceed sustainable levels of freshwater consumption (i.e., 40% of total renewable surface and groundwater resources).

  2. Mutations in single FT- and TFL1-paralogs of rapeseed (Brassica napus L.) and their impact on flowering time and yield components

    PubMed Central

    Guo, Yuan; Hans, Harloff; Christian, Jung; Molina, Carlos

    2014-01-01

    Rapeseed (Brassica napus L.) is grown in different geographical regions of the world. It is adapted to different environments by modification of flowering time and requirement for cold. A broad variation exists from very early-flowering spring-type to late-flowering winter cultivars which only flower after exposure to an extended cold period. B. napus is an allopolyploid species which resulted from the hybridization between B. rapa and B. oleracea. In Arabidopsis thaliana, the PEBP-domain genes FLOWERING LOCUS-T (FT) and TERMINAL FLOWER-1 (TFL1) are important integrators of different flowering pathways. Six FT and four TFL1 paralogs have been identified in B. napus. However, their role in flowering time control is unknown. We identified EMS mutants of the B. napus winter-type inbreed line Express 617. In total, 103 mutant alleles have been determined for BnC6FTb, BnC6FTa, and BnTFL1-2 paralogs. We chose three non-sense and 15 missense mutant lines (M3) which were grown in the greenhouse. Although only two out of 6 FT paralogs were mutated, 6 out of 8 BnC6FTb mutant lines flowered later as the control, whereas all five BnC6FTa mutant lines started flowering as the non-mutated parent. Mutations within the BnTFL1-2 paralog had no large effects on flowering time but on yield components. F1 hybrids between BnTFL1-2 mutants and non-mutated parents had increased seed number per pod and total seeds per plant suggesting that heterozygous mutations in a TFL1 paralog may impact heterosis in rapeseed. We demonstrate that single point-mutations in BnFT and BnTFL1 paralogs have effects on flowering time despite the redundancy of the rapeseed genome. Moreover, our results suggest pleiotropic effects of BnTFL1 paralogs beyond the regulation of flowering time. PMID:24987398

  3. Lactation persistency as a component trait of the selection index and increase in reliability by using single nucleotide polymorphism in net merit defined as the first five lactation milk yields and herd life.

    PubMed

    Togashi, K; Hagiya, K; Osawa, T; Nakanishi, T; Yamazaki, T; Nagamine, Y; Lin, C Y; Matsumoto, S; Aihara, M; Hayasaka, K

    2012-08-01

    We first sought to clarify the effects of discounted rate, survival rate, and lactation persistency as a component trait of the selection index on net merit, defined as the first five lactation milks and herd life (HL) weighted by 1 and 0.389 (currently used in Japan), respectively, in units of genetic standard deviation. Survival rate increased the relative economic importance of later lactation traits and the first five lactation milk yields during the first 120 months from the start of the breeding scheme. In contrast, reliabilities of the estimated breeding value (EBV) in later lactation traits are lower than those of earlier lactation traits. We then sought to clarify the effects of applying single nucleotide polymorphism (SNP) on net merit to improve the reliability of EBV of later lactation traits to maximize their increased economic importance due to increase in survival rate. Net merit, selection accuracy, and HL increased by adding lactation persistency to the selection index whose component traits were only milk yields. Lactation persistency of the second and (especially) third parities contributed to increasing HL while maintaining the first five lactation milk yields compared with the selection index whose only component traits were milk yields. A selection index comprising the first three lactation milk yields and persistency accounted for 99.4% of net merit derived from a selection index whose components were identical to those for net merit. We consider that the selection index comprising the first three lactation milk yields and persistency is a practical method for increasing lifetime milk yield in the absence of data regarding HL. Applying SNP to the second- and third-lactation traits and HL increased net merit and HL by maximizing the increased economic importance of later lactation traits, reducing the effect of first-lactation milk yield on HL (genetic correlation (rG) = -0.006), and by augmenting the effects of the second- and third

  4. Association of puroindoline b-2 variants with grain traits, yield components and flag leaf size in bread wheat (Triticum aestivum L.) varieties of Yellow and Huai Valley of China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 169 wheat (Triticum aestivum L.) varieties (landraces and cultivars) were used to asses the relationship between Puroindoline D1 alleles and Puroindoline b-B2 variants and grain hardness, other grain traits, grain yield components, and flag leaf size. Results indicated that the average SK...

  5. Defect reduction methodologies: pellicle yield improvement

    NASA Astrophysics Data System (ADS)

    Daugherty, Susan V.

    1993-03-01

    The pelliclization process at Intel during the first half of 1991 was not in control. Weekly process yield was trending downward, and the range of the weekly yield during that time frame was greater than 40%. A focused effort in process yield improvement, that started in the second half of 1991 and continued through 1992, brought process yield up an average of 20%, and reduced the range of the process yield to 20 - 25%. This paper discusses the continuous process improvement guidelines that are being followed to reduce variations/defects in the pelliclization process. Teamwork tools, such as Pareto charts, fishbone diagrams, and simple experiments, prioritize efforts and help find the root cause of the defects. Best known methods (BKM), monitors, PMs, and excursion control aid in the elimination and prevention of defects. Monitoring progress and repeating the whole procedure are the final two guidelines. The benefits from the use of the continuous process improvement guidelines and tools can be seen in examples of the actions, impacts, and results for the last half of 1991 and the first half of 1992.

  6. Regional crop yield forecasting: a probabilistic approach

    NASA Astrophysics Data System (ADS)

    de Wit, A.; van Diepen, K.; Boogaard, H.

    2009-04-01

    Information on the outlook on yield and production of crops over large regions is essential for government services dealing with import and export of food crops, for agencies with a role in food relief, for international organizations with a mandate in monitoring the world food production and trade, and for commodity traders. Process-based mechanistic crop models are an important tool for providing such information, because they can integrate the effect of crop management, weather and soil on crop growth. When properly integrated in a yield forecasting system, the aggregated model output can be used to predict crop yield and production at regional, national and continental scales. Nevertheless, given the scales at which these models operate, the results are subject to large uncertainties due to poorly known weather conditions and crop management. Current yield forecasting systems are generally deterministic in nature and provide no information about the uncertainty bounds on their output. To improve on this situation we present an ensemble-based approach where uncertainty bounds can be derived from the dispersion of results in the ensemble. The probabilistic information provided by this ensemble-based system can be used to quantify uncertainties (risk) on regional crop yield forecasts and can therefore be an important support to quantitative risk analysis in a decision making process.

  7. Identification of Quantitative Trait Loci Conditioning the Main Biomass Yield Components and Resistance to Melampsora spp. in Salix viminalis × Salix schwerinii Hybrids

    PubMed Central

    Sulima, Paweł; Przyborowski, Jerzy A.; Kuszewska, Anna; Załuski, Dariusz; Jędryczka, Małgorzata; Irzykowski, Witold

    2017-01-01

    The biomass of Salix viminalis is the most highly valued source of green energy, followed by S. schwerinii, S. dasyclados and other species. Significant variability in productivity and leaf rust resistance are noted both within and among willow species, which creates new opportunities for improving willow yield parameters through selection of desirable recombinants supported with molecular markers. The aim of this study was to identify quantitative trait loci (QTLs) linked with biomass yield-related traits and the resistance/susceptibility of Salix mapping population to leaf rust. The experimental material comprised a mapping population developed based on S. viminalis × S. schwerinii hybrids. Phenotyping was performed on plants grown in a field experiment that had a balanced incomplete block design with 10 replications. Based on a genetic map, 11 QTLs were identified for plant height, 9 for shoot diameter, 3 for number of shoots and 11 for resistance/susceptibility to leaf rust. The QTLs identified in our study explained 3%–16% of variability in the analyzed traits. Our findings make significant contributions to the development of willow breeding programs and research into shrubby willow crops grown for energy. PMID:28327519

  8. The ozone component of global change: potential effects on agricultural and horticultural plant yield, product quality and interactions with invasive species.

    PubMed

    Booker, Fitzgerald; Muntifering, Russell; McGrath, Margaret; Burkey, Kent; Decoteau, Dennis; Fiscus, Edwin; Manning, William; Krupa, Sagar; Chappelka, Arthur; Grantz, David

    2009-04-01

    The productivity, product quality and competitive ability of important agricultural and horticultural plants in many regions of the world may be adversely affected by current and anticipated concentrations of ground-level ozone (O3). Exposure to elevated O3 typically results in suppressed photosynthesis, accelerated senescence, decreased growth and lower yields. Various approaches used to evaluate O3 effects generally concur that current yield losses range from 5% to 15% among sensitive plants. There is, however, considerable genetic variability in plant responses to O3. To illustrate this, we show that ambient O3 concentrations in the eastern United States cause substantially different levels of damage to otherwise similar snap bean cultivars. Largely undesirable effects of O3 can also occur in seed and fruit chemistry as well as in forage nutritive value, with consequences for animal production. Ozone may alter herbicide efficacy and foster establishment of some invasive species. We conclude that current and projected levels of O3 in many regions worldwide are toxic to sensitive plants of agricultural and horticultural significance. Plant breeding that incorporates O3 sensitivity into selection strategies will be increasingly necessary to achieve sustainable production with changing atmospheric composition, while reductions in O3 precursor emissions will likely benefit world food production and reduce atmospheric concentrations of an important greenhouse gas.

  9. Plasmonic light yield enhancement of a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Bignell, Lindsey J.; Mume, Eskender; Jackson, Timothy W.; Lee, George P.

    2013-05-01

    We demonstrate modifications to the light yield properties of an organic liquid scintillator due to the localization of the tertiary fluorophore component to the surface of Ag-core silica-shell nanoparticles. We attribute this enhancement to the near-field interaction of Ag nanoparticle plasmons with these fluor molecules. The scintillation light yield enhancement is shown to be equal to the fluorescence enhancement within measurement uncertainties. With a suitable choice of plasmon energy and scintillation fluor, this effect may be used to engineer scintillators with enhanced light yields for radiation detection applications.

  10. Positronium yields in amorphous, cross-linked and conductive polystyrene

    NASA Astrophysics Data System (ADS)

    Procházka, Ivan; Čížek, Jakub; Motyčka, Václav

    2007-02-01

    Variations in positronium yields due to positron irradiation of specimens during experiment were investigated on the three commercially available modifications of polystyrene (Goodfellow): amorphous, cross-linked and conductive. Positron lifetime technique was employed. The variations of the positronium yields were expressed as changes of the ortho-positronium intensity as functions of the irradiation time. It was found that the positronium yield curves obtained for the amorphous and cross-linked polystyrene cannot be represented as a simple single-exponential relaxation towards a steady state and at least one additional component or a modified shape of the relaxation curve should be considered.

  11. Plasmonic light yield enhancement of a liquid scintillator

    SciTech Connect

    Bignell, Lindsey J.; Jackson, Timothy W.; Mume, Eskender; Lee, George P.

    2013-05-27

    We demonstrate modifications to the light yield properties of an organic liquid scintillator due to the localization of the tertiary fluorophore component to the surface of Ag-core silica-shell nanoparticles. We attribute this enhancement to the near-field interaction of Ag nanoparticle plasmons with these fluor molecules. The scintillation light yield enhancement is shown to be equal to the fluorescence enhancement within measurement uncertainties. With a suitable choice of plasmon energy and scintillation fluor, this effect may be used to engineer scintillators with enhanced light yields for radiation detection applications.

  12. Correlation between biogas yield and chemical composition of energy crops.

    PubMed

    Dandikas, V; Heuwinkel, H; Lichti, F; Drewes, J E; Koch, K

    2014-12-01

    The scope of this study was to investigate the influence of the chemical composition of energy crops on biogas and methane yield. In total, 41 different plants were analyzed in batch test and their chemical composition was determined. For acid detergent lignin (ADL) content below 10% of total solids, a significant negative correlation for biogas and methane yields (r≈-0.90) was observed. Based on a simple regression analysis, more than 80% of the sample variation can be explained through ADL. Based on a principal component analysis and multiple regression analysis, ADL and hemicellulose are suggested as suitable model variables for biogas yield potential predictions across plant species.

  13. 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.

  14. Fission yield studies at the IGISOL facility

    NASA Astrophysics Data System (ADS)

    Penttilä, H.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Kankainen, A.; Moore, I. D.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Rubchenya, V.; Saastamoinen, A.; Weber, C.; Äystö, J.

    2012-04-01

    Low-energy-particle-induced fission is a cost-effective way to produce neutron-rich nuclei for spectroscopic studies. Fission has been utilized at the IGISOL to produce isotopes for decay and nuclear structure studies, collinear laser spectroscopy and precision mass measurements. The ion guide technique is also very suitable for the fission yield measurements, which can be performed very efficiently by using the Penning trap for fission fragment identification and counting. The proton- and neutron-induced fission yield measurements at the IGISOL are reviewed, and the independent isotopic yields of Zn, Ga, Rb, Sr, Cd and In in 25MeV deuterium-induced fission are presented for the first time. Moving to a new location next to the high intensity MCC30/15 light-ion cyclotron will allow also the use of the neutron-induced fission to produce the neutron rich nuclei at the IGISOL in the future.

  15. 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.

  16. Yielding and flow of colloidal glasses.

    PubMed

    Petekidis, Georgios; Vlassopoulos, Dimitris; Pusey, Peter N

    2003-01-01

    We investigate the yielding and flow of hard-sphere colloidal glasses by combining rheological measurements with the technique of light scattering echo. The polymethylmethacrylate particles used are sufficiently polydisperse that crystallization is suppressed. Creep and recovery measurements show that the glasses can tolerate surprisingly large strains, up to at least 15%, before yielding irreversibly. We attribute this behaviour to 'cage elasticity', the ability of a particle and its cage of neighbours to retain their identity under quite large distortion. Results from light scattering echo, which measures the extent of irreversible particle rearrangement under oscillatory shear, support the notion of cage elasticity. In the lower concentration glasses we find that particle trajectories are partly reversible under strains which significantly exceed the yield strain.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. High yield fabrication of fluorescent nanodiamonds.

    PubMed

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

    2009-06-10

    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.

  2. Yielding and post-yield behaviour of closed-cell cellular materials under multiaxial dynamic loading

    NASA Astrophysics Data System (ADS)

    Vesenjak, Matej; Ren, Zoran

    2016-05-01

    The paper focuses on characterisation of yielding and post-yield behaviour of metals with closed-cell cellular structure when subjected to multiaxial dynamic loading, considering the influence of the relative density, base material, strain rate and pore gas pressure. Research was conducted by extensive parametric fully-coupled computational simulations using the finite element code LS-DYNA. Results have shown that the macroscopic yield stress of cellular material rises with increase of the relative density, while its dependence on the hydrostatic stress decreases. The yield limit also rises with increase of the strain rate, while the hydrostatic stress influence remains more or less the same at different strain-rates. The macroscopic yield limit of the cellular material is also strongly influenced by the choice of base material since the base materials with higher yield limit contribute also to higher macroscopic yield limit of the cellular material. By increasing the pore gas filler pressure the dependence on hydrostatic stress increases while at the same time the yield surface shifts along the hydrostatic axis in the negative direction. This means that yielding at compression is delayed due to influence of the initial pore pressure and occurs at higher compressive loading, while the opposite is true for tensile loading.

  3. Yield and yield components of winter-type safflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safflower (Carthamus tinctorius L.) is a minor yet widely grown oil seed crop adapted to semi-arid regions. The nascent development of winter adapted safflower, allowing fall planting,could substantially increase seed production over spring planting. In this study four winter type safflower accessi...

  4. Nutrient database improvement project: the influence of USDA quality and yield grade on the separable components and proximate composition of raw and cooked retail cuts from the beef chuck.

    PubMed

    West, S E; Harris, K B; Haneklaus, A N; Savell, J W; Thompson, L D; Brooks, J C; Pool, J K; Luna, A M; Engle, T E; Schutz, J S; Woerner, D R; Arcibeque, S L; Belk, K E; Douglass, L; Leheska, J M; McNeill, S; Howe, J C; Holden, J M; Duvall, M; Patterson, K

    2014-08-01

    This study was designed to provide updated information on the separable components, cooking yields, and proximate composition of retail cuts from the beef chuck. Additionally, the impact the United States Department of Agriculture (USDA) Quality and Yield Grade may have on such factors was investigated. Ultimately, these data will be used in the USDA - Nutrient Data Laboratory's (NDL) National Nutrient Database for Standard Reference (SR). To represent the current United States beef supply, seventy-two carcasses were selected from six regions of the country based on USDA Yield Grade, USDA Quality Grade, gender, and genetic type. Whole beef chuck primals from selected carcasses were shipped to three university laboratories for subsequent retail cut fabrication, raw and cooked cut dissection, and proximate analyses. The incorporation of these data into the SR will improve dietary education, product labeling, and other applications both domestically and abroad, thus emphasizing the importance of accurate and relevant beef nutrient data.

  5. 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)

  6. High-yield pulping effluent treatment technologies

    SciTech Connect

    Su, W.X.; Hsieh, J.S. . School of Chemical Engineering)

    1993-03-01

    The objective of this report is to examine the high-yield (mechanical) pulp processes with respect to environmental issues affected by the discharge of their waste streams. Various statistics are given that support the view that high-yield pulping processes will have major growth in the US regions where pulp mills are located, and sites for projects in the development phase are indicated. Conventional and innovative effluent-treatment technologies applicable to these processes are reviewed. The different types of mechanical pulping or high-yield processes are explained, and the chemical additives are discussed. The important relationship between pulp yield and measure of BOD in the effluent is graphically presented. Effluent contaminants are identified, along with other important characteristics of the streams. Current and proposed environmental limitations specifically related to mechanical pulp production are reviewed. Conventional and innovative effluent-treatment technologies are discussed, along with their principle applications, uses, advantages, and disadvantages. Sludge management and disposal techniques become an intimate part of the treatment of waste streams. The conclusion is made that conventional technologies can successfully treat effluent streams under current waste-water discharge limitations, but these systems may not be adequate when stricter standards are imposed. At present, the most important issue in the treatment of pulp-mill waste is the management and disposal of the resultant sludge.

  7. High Energy Explosive Yield Enhancer Using Microencapsulation.

    DTIC Science & Technology

    The invention consists of a class of high energy explosive yield enhancers created through the use of microencapsulation techniques. The... microcapsules consist of combinations of highly reactive oxidizers that are encapsulated in either passivated inorganic fuels or inert materials and inorganic...fuels. Depending on the application, the availability of the various oxidizers and fuels within the microcapsules can be customized to increase the

  8. Crop yields in a geoengineered climate

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    Crop models predict that recent and future climate change may have adverse effects on crop yields. Intentional deflection of sunlight away from the Earth could diminish the amount of climate change in a high-CO2 world. However, it has been suggested that this diminution would come at the cost of threatening the food and water supply for billions of people. Here, we carry out high-CO2, geoengineering and control simulations using two climate models to predict the effects on global crop yields. We find that in our models solar-radiation geoengineering in a high-CO2 climate generally causes crop yields to increase, largely because temperature stresses are diminished while the benefits of CO2 fertilization are retained. Nevertheless, possible yield losses on the local scale as well as known and unknown side effects and risks associated with geoengineering indicate that the most certain way to reduce climate risks to global food security is to reduce emissions of greenhouse gases.

  9. 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

  10. 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...

  11. 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...

  12. 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.

  13. 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…

  14. 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...

  15. Venetoclax Yields Strong Responses in CLL.

    PubMed

    2016-02-01

    Results from an international phase II study show that the investigational BCL2 inhibitor venetoclax is effective in patients with chronic lymphocytic leukemia and the chromosome 17p deletion, whose prognosis is particularly poor. Venetoclax yielded high and durable responses in this population, including several complete remissions.

  16. Enormous yield of photoelectrons from small particles

    NASA Astrophysics Data System (ADS)

    Schmidt-Ott, A.; Schurtenberger, P.; Siegmann, H. C.

    1980-10-01

    The paper reports a large enhancement of the yield of photoelectrons per incident photon if ultrafine particles with radii not greater than 50 A are chosen as photoemitters. The results are obtained with Ag and WO3 by the use of an ac bridge technique making it possible to study very small particles suspended in gases.

  17. 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.

  18. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... crop was out of rotation, not planted, or prevented from being planted. (3) Shall be calculated... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE PROGRAM... yield is the total amount of harvested and appraised production from unit acreage for the crop year on...

  19. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... crop was out of rotation, not planted, or prevented from being planted. (3) Shall be calculated... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE PROGRAM... yield is the total amount of harvested and appraised production from unit acreage for the crop year on...

  20. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... crop was out of rotation, not planted, or prevented from being planted. (3) Shall be calculated... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE PROGRAM... yield is the total amount of harvested and appraised production from unit acreage for the crop year on...

  1. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... crop was out of rotation, not planted, or prevented from being planted. (3) Shall be calculated... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE PROGRAM... yield is the total amount of harvested and appraised production from unit acreage for the crop year on...

  2. 7 CFR 1437.102 - Yield determinations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... crop was out of rotation, not planted, or prevented from being planted. (3) Shall be calculated... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE PROGRAM... yield is the total amount of harvested and appraised production from unit acreage for the crop year on...

  3. 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

  4. 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

  5. Estimation of liquid fuel yields from biomass.

    PubMed

    Singh, Navneet R; Delgass, W Nicholas; Ribeiro, Fabio H; Agrawal, Rakesh

    2010-07-01

    We have estimated sun-to-fuel yields for the cases when dedicated fuel crops are grown and harvested to produce liquid fuel. The stand-alone biomass to liquid fuel processes, that use biomass as the main source of energy, are estimated to produce one-and-one-half to three times less sun-to-fuel yield than the augmented processes. In an augmented process, solar energy from a fraction of the available land area is used to produce other forms of energy such as H(2), heat etc., which are then used to increase biomass carbon recovery in the conversion process. However, even at the highest biomass growth rate of 6.25 kg/m(2).y considered in this study, the much improved augmented processes are estimated to have sun-to-fuel yield of about 2%. We also propose a novel stand-alone H(2)Bioil-B process, where a portion of the biomass is gasified to provide H(2) for the fast-hydropyrolysis/hydrodeoxygenation of the remaining biomass. This process is estimated to be able to produce 125-146 ethanol gallon equivalents (ege)/ton of biomass of high energy density oil but needs experimental development. The augmented version of fast-hydropyrolysis/hydrodeoxygenation, where H(2) is generated from a nonbiomass energy source, is estimated to provide liquid fuel yields as high as 215 ege/ton of biomass. These estimated yields provide reasonable targets for the development of efficient biomass conversion processes to provide liquid fuel for a sustainable transport sector.

  6. 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.

  7. The plastic yield and flow behavior in metallic glasses

    NASA Astrophysics Data System (ADS)

    Thamburaja, Prakash; Klusemann, Benjamin; Adibi, Sara; Bargmann, Swantje

    2015-02-01

    Metallic glasses have vast potential applications as components in microelectronics- and nanoelectronics-type devices. The design of such components through computer simulations requires the input of a faithful set of continuum-based constitutive equations. However, one long-standing controversial issue in modeling the plastic behavior of metallic glasses at the continuum level is the use of the most appropriate plastic yield criterion and flow rule. Guided by a series of molecular dynamics simulations conducted at low-homologous temperatures under homogeneous deformations, we quantitatively prove that the continuum plastic behavior in metallic glasses is most accurately described by a von Mises-type plastic yield criterion and flow rule.

  8. Establishment, persistence and effectiveness of arbuscular mycorrhizal fungal inoculants in the field revealed using molecular genetic tracing and measurement of yield components.

    PubMed

    Pellegrino, Elisa; Turrini, Alessandra; Gamper, Hannes A; Cafà, Giovanni; Bonari, Enrico; Young, J Peter W; Giovannetti, Manuela

    2012-05-01

    • Inoculation of crop plants by non-native strains of arbuscular mycorrhizal (AM) fungi as bio-enhancers is promoted without clear evidence for symbiotic effectiveness and fungal persistence. To address such gaps, the forage legume Medicago sativa was inoculated in an agronomic field trial with two isolates of Funneliformis mosseae differing in their nuclear rDNA sequences from native strains. • The inoculants were traced by PCR with a novel combination of the universal fungal NS31 and Glomeromycota-specific LSUGlom1 primers which target the nuclear rDNA cistron. The amplicons were classified by restriction fragment length polymorphism and sequencing. • The two applied fungal inoculants were successfully traced and discriminated from native strains in roots sampled from the field up to 2 yr post inoculation. Moreover, field inoculation with inocula of non-native isolates of F. mosseae appeared to have stimulated root colonization and yield of M. sativa. • Proof of inoculation success and sustained positive effects on biomass production and quality of M. sativa crop plants hold promise for the role that AM fungal inoculants could play in agriculture.

  9. Methods for high yield production of terpenes

    DOEpatents

    Kutchan, Toni; Higashi, Yasuhiro; Feng, Xiaohong

    2017-01-03

    Provided are enhanced high yield production systems for producing terpenes in plants via the expression of fusion proteins comprising various combinations of geranyl diphosphate synthase large and small subunits and limonene synthases. Also provided are engineered oilseed plants that accumulate monoterpene and sesquiterpene hydrocarbons in their seeds, as well as methods for producing such plants, providing a system for rapidly engineering oilseed crop production platforms for terpene-based biofuels.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Xenon Sputter Yield Measurements for Ion Thruster Materials

    NASA Technical Reports Server (NTRS)

    Williams, John D.; Gardner, Michael M.; Johnson, Mark L.; Wilbur, Paul J.

    2003-01-01

    In this paper, we describe a technique that was used to measure total and differential sputter yields of materials important to high specific impulse ion thrusters. The heart of the technique is a quartz crystal monitor that is swept at constant radial distance from a small target region where a high current density xenon ion beam is aimed. Differential sputtering yields were generally measured over a full 180 deg arc in a plane that included the beam centerline and the normal vector to the target surface. Sputter yield results are presented for a xenon ion energy range from 0.5 to 10 keV and an angle of incidence range from 0 deg to 70 deg from the target surface normal direction for targets consisting of molybdenum, titanium, solid (Poco) graphite, and flexible graphite (grafoil). Total sputter yields are calculated using a simple integration procedure and comparisons are made to sputter yields obtained from the literature. In general, the agreement between the available data is good. As expected for heavy xenon ions, the differential and total sputter yields are found to be strong functions of angle of incidence. Significant under- and over-cosine behavior is observed at low- and high-ion energies, respectively. In addition, strong differences in differential yield behavior are observed between low-Z targets (C and Ti) and high-Z targets (Mo). Curve fits to the differential sputter yield data are provided. They should prove useful to analysts interested in predicting the erosion profiles of ion thruster components and determining where the erosion products re-deposit.

  16. 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.

  17. 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.

  18. Genetic composition of yield heterosis in an elite rice hybrid.

    PubMed

    Zhou, Gang; Chen, Ying; Yao, Wen; Zhang, Chengjun; Xie, Weibo; Hua, Jinping; Xing, Yongzhong; Xiao, Jinghua; Zhang, Qifa

    2012-09-25

    Heterosis refers to the superior performance of hybrids relative to the parents. Utilization of heterosis has contributed tremendously to the increased productivity in many crops for decades. Although there have been a range of studies on various aspects of heterosis, the key to understanding the biological mechanisms of heterotic performance in crop hybrids is the genetic basis, much of which is still uncharacterized. In this study, we dissected the genetic composition of yield and yield component traits using data of replicated field trials of an "immortalized F(2)" population derived from an elite rice hybrid. On the basis of an ultrahigh-density SNP bin map constructed with population sequencing, we calculated single-locus and epistatic genetic effects in the whole genome and identified components pertaining to heterosis of the hybrid. The results showed that the relative contributions of the genetic components varied with traits. Overdominance/pseudo-overdominance is the most important contributor to heterosis of yield, number of grains per panicle, and grain weight. Dominance × dominance interaction is important for heterosis of tillers per plant and grain weight and has roles in yield and grain number. Single-locus dominance has relatively small contributions in all of the traits. The results suggest that cumulative effects of these components may adequately explain the genetic basis of heterosis in the hybrid.

  19. Do more seeds per panicle improve grain sorghum yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed number rather than seed mass is largely considered to be the most important yield component of grain sorghum [Sorghum bicolor (L.) Moench]. An experimental sorghum hybrid with enhanced seed number (tri-seed) was grown at the Soil-Plant-Environment Research (SPER) facility, USDA-ARS, Bushland, ...

  20. Identification of genomic regions for grain yield and yield stability and their epistatic interactions

    PubMed Central

    Sehgal, Deepmala; Autrique, Enrique; Singh, Ravi; Ellis, Marc; Singh, Sukhwinder; Dreisigacker, Susanne

    2017-01-01

    The task of identifying genomic regions conferring yield stability is challenging in any crop and requires large experimental data sets in conjunction with complex analytical approaches. We report findings of a first attempt to identify genomic regions with stable expression and their individual epistatic interactions for grain yield and yield stability in a large elite panel of wheat under multiple environments via a genome wide association mapping (GWAM) approach. Seven hundred and twenty lines were genotyped using genotyping-by-sequencing technology and phenotyped for grain yield and phenological traits. High gene diversity (0.250) and a moderate genetic structure (five groups) in the panel provided an excellent base for GWAM. The mixed linear model and multi-locus mixed model analyses identified key genomic regions on chromosomes 2B, 3A, 4A, 5B, 7A and 7B. Further, significant epistatic interactions were observed among loci with and without main effects that contributed to additional variation of up to 10%. Simple stepwise regression provided the most significant main effect and epistatic markers resulting in up to 20% variation for yield stability and up to 17% gain in yield with the best allelic combination. PMID:28145508

  1. Predicting the Potential Planet Yield from Kepler

    NASA Astrophysics Data System (ADS)

    Caldwell, Douglas A.; Dunham, E. W.; Argabright, V. S.; Borucki, W. J.; Burke, C. J.; Christiansen, J. L.; Gilliland, R. L.; Jenkins, J. M.; Rowe, J. F.; Seader, S.; Tenenbaum, P.; Van Cleve, J.

    2012-05-01

    The pre-eminent scientific goal of the Kepler Mission is to determine the frequency of Earth-size and larger planets in or near the habitable zone of their stars. Two related key requirements needed to support this fundamental goal are the combined photometric precision for target stars and the mission lifetime. Kepler was designed to achieve a combined photometric precision -including intrinsic stellar variability- of 20 parts per million in 6.5 hours for 12th magnitude stars and to have a mission lifetime of 3.5 years. Based on the first 2 ½ years of data collection, we find that Kepler's precision for these stars is nearer to 30 ppm. We used the measured precision for each target to predict the detectability of habitable zone terrestrial planets based on the pipeline detection threshold of 7.1σ, the mission duration, and the measured data completeness. Combining this with the transit alignment probability and summing over all targets gives the potential planet yield for such planets. We find that the absolute value of the planet yield depends strongly on how biases in the Kepler Input Catalog values of surface gravity and effective temperature are handled, but that the relative improvement in planet yield is a factor of 2.5 to 3 in going from a 3.5 to a 7.5 year mission, largely independent of the KIC biases. Increasing the mission duration to 7.5 years makes up for the factor of 1.5 increase in noise, restoring Kepler’s ability to meet its primary mission goal.

  2. Avalanche behavior in yield stress fluids.

    PubMed

    Coussot, Philippe; Nguyen, Q D; Huynh, H T; Bonn, Daniel

    2002-04-29

    We show that, above a critical stress, typical yield stress fluids (gels and clay suspensions) and soft glassy materials (colloidal glasses) start flowing abruptly and subsequently accelerate, leading to avalanches that are remarkably similar to those of granular materials. Rheometrical tests reveal that this is associated with a bifurcation in rheological behavior: for small stresses, the viscosity increases in time; the material eventually stops flowing. For slightly larger stresses the viscosity decreases continuously in time; the flow accelerates. Thus the viscosity jumps discontinuously to infinity at the critical stress. We propose a simple physical model capable of reproducing these effects.

  3. Yield behavior of metal powder assemblages

    NASA Astrophysics Data System (ADS)

    Brown, Stuart; Abou-Chedid, Georges

    1994-03-01

    W E PRESENT EXPERIMENTAL data on the compaction of powder metals using two powder systems with different powder particle morphologies. The data have been collected using biaxial and triaxial compaction systems that load powders radially in deformation space. Our results indicate that several current models proposed for powder metal compaction do not represent actual constitutive behavior. Additionally, the powders tested demonstrate a strong dependence on powder morphology and a possible associated dependence on interparticle cohesion. This dependence on cohesion may necessitate the use of an additional state variable beyond those of relative density and particle hardening ordinarily used to represent powder yield behavior.

  4. Neutron yield of medical electron accelerators

    SciTech Connect

    McCall, R.C.

    1987-11-01

    Shielding calculations for medical electron accelerators above about 10 MeV require some knowledge of the neutron emission from the machine. This knowledge might come from the manufacturer's specifications or from published measurements of the neutron leakage of that particular model and energy of accelerator. In principle, the yield can be calculated if details of the accelerator design are known. These details are often not available because the manufacturer considers them proprietary. A broader knowledge of neutron emission would be useful and it is the purpose of this paper to present such information. 5 refs., 1 tab.

  5. 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.

  6. Light propagation and fluorescence quantum yields in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Buck, C.; Gramlich, B.; Wagner, S.

    2015-09-01

    For the simulation of the scintillation and Cherenkov light propagation in large liquid scintillator detectors a detailed knowledge about the absorption and emission spectra of the scintillator molecules is mandatory. Furthermore reemission probabilities and quantum yields of the scintillator components influence the light propagation inside the liquid. Absorption and emission properties are presented for liquid scintillators using 2,5-Diphenyloxazole (PPO) and 4-bis-(2-Methylstyryl)benzene (bis-MSB) as primary and secondary wavelength shifter. New measurements of the quantum yields for various aromatic molecules are shown.

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. Comparisons of Yield Calculations with Data

    SciTech Connect

    Dugan, G.

    1986-02-01

    Given what is claimed to a reasonably accurate technique for calculating the pbar yield, it is useful to ask for comparisons with the data available from the recent commissioning run. The simplest comparison to make is that of the yield. The number of pbars circulating in the Debuncher was measured many times; the total number of secondaries at IC728 in AP-2 was also measured many times. The ratio of pbars to total flux at IC728 was measured once (Bk. I, p 166); this number was {bar P}/total = 0.032. Typically, the ratio of secondaries at IC728 to protons on target was about 0.0012 (this was about the same number, independent of whether the lens was operated at 600 or 1000 T/m.). Thus, at IC728 we have N{sub P}/N{sub {bar P}} {approx} 1.2 x 10{sup -3} x 3.2 x 10{sup -2} = 3.8 x 10{sup -5} = 38 ppm.

  13. Yield of Polymethylmethacrylate (PMMA) - a Simulation Study

    NASA Astrophysics Data System (ADS)

    Soddemann, Thomas; Robbins, Mark O.

    2002-03-01

    The mechanical properties of thermotropic materials are important in many industrial applications, however their complex structure and nonlinear response make theoretical studies difficult. Recent computer simulations [1] show that a simple bead-spring model captures generic features of their mechanical response. In this work we calculate the response of a specific polymer, PMMA, that has been extensively studied in experiments and has a simple chemical structure. Two different force fields are used, the all-atom Polymer Consistent Force Field by MSI [2], and a force-field [3] that combines carbons and hydrogens into united atoms. Glass transitions, pressures, elastic constants, yield points and yield stresses are obtained from both models and compared to each other and experimental data. Qualitatively similar behavior is seen, but quantitative results are sensitive to specific details in the potentials. 1. J. Rottler and M. O. Robbins, Phys. Rev. E 64 051801 (2001). 2. J.R. Maple et al., J. Comp. Chem. 15 162 (1994) 3. O. Okada et al., Comp. Theo. Pol. Sci. 10 371 (2000)

  14. Statistical circuit design for yield improvement in CMOS circuits

    NASA Technical Reports Server (NTRS)

    Kamath, H. J.; Purviance, J. E.; Whitaker, S. R.

    1990-01-01

    This paper addresses the statistical design of CMOS integrated circuits for improved parametric yield. The work uses the Monte Carlo technique of circuit simulation to obtain an unbiased estimation of the yield. A simple graphical analysis tool, the yield factor histogram, is presented. The yield factor histograms are generated by a new computer program called SPICENTER. Using the yield factor histograms, the most sensitive circuit parameters are noted, and their nominal values are changed to improve the yield. Two basic CMOS example circuits, one analog and one digital, are chosen and their designs are 'centered' to illustrate the use of the yield factor histograms for statistical circuit design.

  15. 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.

  16. Examining the roles that changing harvested areas, closing yield-gaps, and increasing yield ceilings have had on crop production

    NASA Astrophysics Data System (ADS)

    Johnston, M.; Ray, D. K.; Mueller, N. D.; Foley, J. A.

    2011-12-01

    With an increasing and increasingly affluent population, there has been tremendous effort to examine strategies for sustainably increasing agricultural production to meet this surging global demand. Before developing new solutions from scratch, though, we believe it is important to consult our recent agricultural history to see where and how agricultural production changes have already taken place. By utilizing the newly created temporal M3 cropland datasets, we can for the first time examine gridded agricultural yields and area, both spatially and temporally. This research explores the historical drivers of agricultural production changes, from 1965-2005. The results will be presented spatially at the global-level (5-min resolution), as well as at the individual country-level. The primary research components of this study are presented below, including the general methodology utilized in each phase and preliminary results for soybean where available. The complete assessment will cover maize, wheat, rice, soybean, and sugarcane, and will include country-specific analysis for over 200 countries, states, territories and protectorates. Phase 1: The first component of our research isolates changes in agricultural production due to variation in planting decisions (harvested area) from changes in production due to intensification efforts (yield). We examine area/yield changes at the pixel-level over 5-year time-steps to determine how much each component has contributed to overall changes in production. Our results include both spatial patterns of changes in production, as well as spatial maps illustrating to what degree the production change is attributed to area and/or yield. Together, these maps illustrate where, why, and by how much agricultural production has changed over time. Phase 2: In the second phase of our research we attempt to determine the impact that area and yield changes have had on agricultural production at the country-level. We calculate a production

  17. 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...

  18. OPTIMIZING SYNTHESIS GAS YIELD FROM THE CROSS ...

    EPA Pesticide Factsheets

    Symposium Paper Biomass can be gasified to yield synthesis gas, tars, and ash. The process is governed by a number of parameters such as the temperature of the gasifying medium (in this case), and the moisture content of the feedstock. Synthesis gas from gasifying wood pellets was collected and analyzed as a function of inlet air temperature and feedstock moisture content. The air was introduced at temperatures ranging from 630 to 730 °C and the moisture content of the feedstock ranged from 8 to 20%. The data collected was used to establish the relationship between the outcome of gasification and these two parameters, and then to determine optimal operating parameters for maximizing the fuel value (maximizing the concentrations of flammable gases in the synthesis gas) while minimizing the production of gasification tars.

  19. 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.

  20. Diode laser welding of high yield steel

    NASA Astrophysics Data System (ADS)

    Lisiecki, Aleksander

    2013-01-01

    The following article describes results of investigations on influence of laser welding parameters on the weld shape, quality and mechanical properties of 2.5 mm thick butt joints of thermo-mechanically rolled, high yield strength steel for cold forming S420MC (according to EN 10149 - 3 and 060XLK according to ASTM) welded with high power diode laser HPDL ROFIN SINAR DL 020 with rectangular laser beam spot and 2.2 kW output power, and 808 nm wavelength. The investigations at the initial stage were focused on detailed analysis of influence of the basic laser welding parameters such as laser power and welding speed on the shape and quality of single bead produced during bead-on-plate welding. Then the optimal parameters were chosen for laser welding of 2.5 mm thick butt joints of the thermo-mechanically rolled, high yield strength steel sheets for cold forming S420MC. The test joints were prepared as single square groove and one-side laser welded without an additional material, at a flat position. Edges of steel sheets were melted in argon atmosphere by the laser beam focused on the top joint surface. The test welded joints were investigated by visual inspection, metallographic examinations, mechanical tests such as tensile tests and bending tests. It was found that the high power diode laser may be applied successfully for one-side welding of the S420MC steel butt joints. Additionally it was found that in the optimal range of laser welding parameters the high quality joint were produced.

  1. 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.

  2. Large Area Crop Inventory Experiment (LACIE). Feasibility of assessing crop condition and yield from LANDSAT data

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The author has identified the following significant results. Yield modelling for crop production estimation derived a means of predicting the within-a-year yield and the year-to-year variability of yield over some fixed or randomly located unit of area. Preliminary studies indicated that the requirements for interpreting LANDSAT data for yield may be sufficiently similar to those of signature extension that it is feasible to investigate the automated estimation of production. The concept of an advanced yield model consisting of both spectral and meteorological components was endorsed. Rationale for using meteorological parameters originated from known between season and near harvest dynamics in crop environmental-condition-yield relationships.

  3. New methods for automatic delay time compensation in grain yield maps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield data is a key component of precision agriculture, critical for both development and evaluation of precision management strategies. Ideally, software that generates grain yield maps from raw yield monitor data should automatically correct common errors associated with machine and operating...

  4. Sugarcane genotype variation in leaf photosynthesis properties and yield as affected by mill mud application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variability in yield among sugarcane (a complex hybrid of Saccharum spp.) genotypes grown with and without mill mud application on sand soils in Florida has been documented, but little is known about what causes yield differences and if there are any relationships between yield components and physio...

  5. Identification of expressed genes in the mapped QTLs for yield related traits in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvement of grain yield is a perpetual goal in rice breeding. Yield and its component traits are quantitatively inherited and controlled by many genes. To identify the Quantitative Trait Loci (QTL) involved in yield, a recombinant inbred line (RIL) population consisting of 259 progeny was devel...

  6. Principal component structuring of the non-REM Sleep EEG spectrum in older adults yields age-related changes in the sleep and wake drives.

    PubMed

    Putilov, Arcady A; Münch, Mirjam Y; Cajochen, Christian

    2013-12-01

    Age-related disturbances of the sleep-wake cycle can reflect ontogenetic changes in regulatory mechanisms underlying normal and pathological aging, but the exact nature of these changes remains unclear. The present report is the first attempt to apply principal component analysis to the electroencephalographic (EEG) spectrum to examine of whether the observed age-related changes in the objective sleep measures can be linked to the opponent sleep-promoting and wake-promoting processes. The EEG indicators of these processes--scores on the 1st and 2nd principal components of the EEG spectrum, respectively--were compared in 15 older (57-74 years) and 16 younger (20-31 years) healthy volunteers. The scores were calculated for non-REM sleep episodes which occurred during ten 75-min naps scheduled every 150 min throughout a 40-h constant routine protocol. Both, a decrease of the 1st principal component score and an increase of the 2nd principal component score were found to contribute to such most obvious age-related modification of the sleep EEG spectrum as attenuation of EEG slow-wave activity in older people. Therefore, we concluded that the normal aging process can reflect both a weakening of the sleep-promoting process and a strengthening of the wake-promoting process, respectively. Such bidirectional changes in chronoregulatory processes may explain why sleep of older people is characterized by the few profitable and a number of detrimental features (i.e., a better ability to cope with daytime sleepiness and sleep loss vs. difficulty of falling asleep, decreased total nighttime sleep, "lightened" and fragmentized sleep, unwanted early morning awakenings, etc.).

  7. A decade of precision agriculture impacts on grain yield and yield variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Targeting management practices and inputs with precision agriculture has high potential to meet some of the grand challenges of sustainability in the coming century, including simultaneously improving crop yields and reducing environmental impacts. Although the potential is high, few studies have do...

  8. 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.

  9. 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.

  10. 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.

  11. When does this cortical area drop off? Principal component structuring of the EEG spectrum yields yes-or-no criteria of local sleep onset.

    PubMed

    Putilov, Arcady A

    2014-06-22

    The traditional sleep scoring approach has been invented long before the recognition of strictly local nature of the sleep process. It considers sleep as a whole-organism behavior state, and, thus, it cannot be used for identification of sleep onset in a separate brain region. Therefore, this paper was aimed on testing whether the practically useful, simple and reliable yes-or-no criterion of sleep onset in a particular cortical region might be developed through applying principal component analysis to the electroencephalographic (EEG) spectra. The resting EEG was recorded with 2-hour intervals throughout 43-61-hour prolongation of wakefulness, and during 12 20-minute attempts to nap in the course of 24-hour wakefulness (15 and 18 adults, respectively). The EEG power spectra were averaged on 1-min intervals of each resting EEG record and on 1-min intervals of each napping attempt, respectively. Since we earlier demonstrated that scores on the first and second principal components of the EEG spectrum exhibit dramatic changes during the sleep onset period, a zero-crossing buildup of the first score and a zero-crossing decline of the second score were examined as possible yes-or-no markers of regional sleep onsets. The results suggest that, irrespective of electrode location, sleep onset criterion and duration of preceding wakefulness, a highly significant zero-crossing decline of the second principal component score always occurred within 1-minute interval of transition from wakefulness to sleep. Therefore, it was concluded that such zero-crossing decline can serve as a reliable, simple, and practically useful yes-or-no marker of drop off event in a given cortical area.

  12. 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

  13. Quantitative trait loci mapping in Brassica rapa revealed the structural and functional conservation of genetic loci governing morphological and yield component traits in the A, B, and C subgenomes of Brassica species.

    PubMed

    Li, Xiaonan; Ramchiary, Nirala; Dhandapani, Vignesh; Choi, Su Ryun; Hur, Yoonkang; Nou, Ill-Sup; Yoon, Moo Kyoung; Lim, Yong Pyo

    2013-02-01

    Brassica rapa is an important crop species that produces vegetables, oilseed, and fodder. Although many studies reported quantitative trait loci (QTL) mapping, the genes governing most of its economically important traits are still unknown. In this study, we report QTL mapping for morphological and yield component traits in B. rapa and comparative map alignment between B. rapa, B. napus, B. juncea, and Arabidopsis thaliana to identify candidate genes and conserved QTL blocks between them. A total of 95 QTL were identified in different crucifer blocks of the B. rapa genome. Through synteny analysis with A. thaliana, B. rapa candidate genes and intronic and exonic single nucleotide polymorphisms in the parental lines were detected from whole genome resequenced data, a few of which were validated by mapping them to the QTL regions. Semi-quantitative reverse transcriptase PCR analysis showed differences in the expression levels of a few genes in parental lines. Comparative mapping identified five key major evolutionarily conserved crucifer blocks (R, J, F, E, and W) harbouring QTL for morphological and yield components traits between the A, B, and C subgenomes of B. rapa, B. juncea, and B. napus. The information of the identified candidate genes could be used for breeding B. rapa and other related Brassica species.

  14. Improving Seed Germination and Peanut Yields by Cold Plasma Treatment

    NASA Astrophysics Data System (ADS)

    Li, Ling; Li, Jiangang; Shen, Minchong; Hou, Jinfeng; Shao, Hanliang; Dong, Yuanhua; Jiang, Jiafeng

    2016-10-01

    This study explored the effects of cold plasma treatment on seed germination, plant growth, and peanut yield. Cold plasma treatment improved germination and seedling growth, and the 120 W treatment produced the best effect. Germination potential and germination rate were markedly raised by 150% and 21%, respectively. Germination was accelerated and the uniformity of emergence improved. The apparent contact angle was decreased by 53%. Seedling shoot and root dry weights increased by 11% and 9%. Leaf area, leaf thickness, leaf nitrogen concentration, chlorophyll contents, and dry weight at the fruiting stage, together with plant height, stem diameter, and root dry weight at the mature stage were all markedly raised by the cold plasma treatment. The cold plasma treatment enhanced yield components, such as branch numbers per plant, pod numbers per plant, and 100 pod weights by 8%, 13%, and 9%, respectively, compared to the control. Furthermore, the yield improved by 10%. These results suggested that cold plasma treatment improved germination, plant growth, and yield, which might be due to the cold plasma increasing the leaf area, nitrogen concentrations, and chlorophyll contents. supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China (No. 2012BAD05B04), National Natural Science Foundation of China (No. 41201241), “Strategic Priority Research Program” of the Chinese Academy of Sciences (No. XDB15030301) and Jiangsu Province Science and Technology Support Program (No. BE2013452)

  15. Ice sheets on plastically-yielding beds

    NASA Astrophysics Data System (ADS)

    Hewitt, Ian

    2016-11-01

    Many fast flowing regions of ice sheets are underlain by a layer of water-saturated sediments, or till. The rheology of the till has been the subject of some controversy, with laboratory tests suggesting almost perfectly plastic behaviour (stress independent of strain rate), but many models adopting a pseudo-viscous description. In this work, we consider the behaviour of glaciers underlain by a plastic bed. The ice is treated as a viscous gravity current, on a bed that allows unconstrained slip above a critical yield stress. This simplified description allows rapid sliding, and aims to investigate 'worst-case' scenarios of possible ice-sheet disintegration. The plastic bed results in an approximate ice-sheet geometry that is primarily controlled by force balance, whilst ice velocity is determined from mass conservation (rather than the other way around, as standard models would hold). The stability of various states is considered, and particular attention is given to the pace at which transitions between unstable states can occur. Finally, we observe that the strength of basal tills depends strongly on pore pressure, and combine the model with a description of subglacial hydrology. Implications for the present-day ice sheets in Greenland and Antarctica will be discussed. Funding: ERC Marie Curie FP7 Career Integration Grant.

  16. 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.

  17. Yield and Economic Responses of Peanut to Crop Rotation Sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Peanut Research Laboratory, Dawson, GA 39842. Proper crop rotation is essential to maintaining high peanut yield and quality. However, the economic considerations of maintaining or altering crop rotation sequences must incorporate the commodity prices, production costs, and yield responses...

  18. Primary and Secondary Yield Losses Caused by Pests and Diseases: Assessment and Modeling in Coffee

    PubMed Central

    Gary, Christian; Tixier, Philippe; Lechevallier, Esther

    2017-01-01

    The assessment of crop yield losses is needed for the improvement of production systems that contribute to the incomes of rural families and food security worldwide. However, efforts to quantify yield losses and identify their causes are still limited, especially for perennial crops. Our objectives were to quantify primary yield losses (incurred in the current year of production) and secondary yield losses (resulting from negative impacts of the previous year) of coffee due to pests and diseases, and to identify the most important predictors of coffee yields and yield losses. We established an experimental coffee parcel with full-sun exposure that consisted of six treatments, which were defined as different sequences of pesticide applications. The trial lasted three years (2013–2015) and yield components, dead productive branches, and foliar pests and diseases were assessed as predictors of yield. First, we calculated yield losses by comparing actual yields of specific treatments with the estimated attainable yield obtained in plots which always had chemical protection. Second, we used structural equation modeling to identify the most important predictors. Results showed that pests and diseases led to high primary yield losses (26%) and even higher secondary yield losses (38%). We identified the fruiting nodes and the dead productive branches as the most important and useful predictors of yields and yield losses. These predictors could be added in existing mechanistic models of coffee, or can be used to develop new linear mixed models to estimate yield losses. Estimated yield losses can then be related to production factors to identify corrective actions that farmers can implement to reduce losses. The experimental and modeling approaches of this study could also be applied in other perennial crops to assess yield losses. PMID:28046054

  19. 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...

  20. Sediment yield as a desertification risk indicator.

    PubMed

    Vanmaercke, M; Poesen, J; Maetens, W; de Vente, J; Verstraeten, G

    2011-04-01

    Soil erosion is often regarded as one of the main processes of desertification. This has led to the use of various desertification indicators that are related to soil erosion. Most of these indicators focus, however, on small spatial units, while little attention has been given to the amount of sediment exported at the catchment scale. Such a small spatial unit approach neglects the transfer of sediment through catchments as well as the scale-dependency of erosion processes. Furthermore, this approach does not consider important off-site impacts of soil erosion, such as sediment deposition in reservoirs, flooding as well as ecological impacts. This study aims to illustrate the importance of also considering catchment sediment yield (SY, t km(-2) y(-1)) in desertification assessment studies. Based on recently established databases of SY and soil loss rates in Europe and examples from previous studies, we illustrate that soil erosion rates at the plot scale are not representative for catchment SY, as they are often several orders of magnitude smaller. Also, the erosion response of catchments to changes in land use or climate often differs strongly from responses to those changes at the plot scale. We further discuss several of the impacts of SY and their link with desertification: i.e. the sedimentation of reservoirs, problems related to flooding, catchment hydrology, export of nutrients and ecological implications. Using earlier established criteria we evaluate the potential for using catchment SY as a desertification indicator and conclude that this could give an important added value to desertification studies. SY, used in combination with other indicators, allows the identification of other sediment sources than those considered at the plot scale and can reflect the results of desertification processes over longer time periods than periods over which assessments at the plot scale have been made. We argue therefore, that SY is a strong complementary indicator of

  1. 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.

  2. Anomalous DD and TT yields relative to the DT yield in inertial-confinement-fusion implosions

    NASA Astrophysics Data System (ADS)

    Casey, Daniel T.

    2011-10-01

    Measurements of the D(d,p)T (DD), T(t,2n)4He (TT) and D(t,n)4He (DT) reactions have been conducted using deuterium-tritium gas-filled inertial confinement fusion (ICF) implosions. In these experiments, which were carried out at the OMEGA laser facility, absolute spectral measurements of the DD protons and TT neutrons were conducted and compared to neutron-time-of-flight measured DT-neutron yields. From these measurements, it is concluded that the DD yield is anomalously low and the TT yield is anomalously high relative to the DT yield, an effect that is enhanced with increasing ion temperature. These results can be explained by an enrichment of tritium in the core of an ICF implosion, which may be present in ignition experiments planned on the National Ignition Facility. In addition, the spectral measurements of the TT-neutron spectrum were conducted for the first time at reactant central-mass energies in the range of 15-30 keV. The results from these measurements indicate that the TT reaction proceeds primarily through the direct three-body reaction channel, producing a continuous TT-neutron spectrum in the range 0 - 9.5 MeV. This work was conducted in collaboration with J. A. Frenje, M. Gatu Johnson, M. J.-E. Manuel, H. G. Rinderknecht, N. Sinenian, F. H. Seguin, C. K. Li, R. D. Petrasso, P. B. Radha, J. A. Delettrez, V. Yu Glebov, D. D. Meyerhofer, T. C. Sangster, D. P. McNabb, P. A. Amendt, R. N. Boyd, J. R. Rygg, H. W. Herrmann, Y. H. Kim, G. P. Grim and A. D. Bacher. This work was supported in part by the U.S. Department of Energy (Grant No. DE-FG03-03SF22691), LLE (subcontract Grant No. 412160-001G), LLNL (subcontract Grant No. B504974).

  3. Ethiopian wheat yield and yield gap estimation: A spatially explicit small area integrated data approach.

    PubMed

    Mann, Michael L; Warner, James M

    2017-02-01

    Despite the routine collection of annual agricultural surveys and significant advances in GIS and remote sensing products, little econometric research has integrated these data sources in estimating developing nations' agricultural yields. In this paper, we explore the determinants of wheat output per hectare in Ethiopia during the 2011-2013 principal Meher crop seasons at the kebele 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. Reflecting on the high interannual variability in output per hectare, we explore whether these changes can be explained by weather, shocks to, and management of rain-fed agricultural systems. The model identifies specific contributors to wheat yields that include farm management techniques (e.g. area planted, improved seed, fertilizer, and irrigation), weather (e.g. rainfall), water availability (e.g. vegetation and moisture deficit indexes) and policy intervention. Our findings suggest that woredas produce between 9.8 and 86.5% of their locally attainable wheat yields given their altitude, weather conditions, terrain, and plant health. In conclusion, we believe the combination of field surveys with spatial data can be used to identify management priorities for improving production at a variety of administrative levels.

  4. Search for D{sup 0}{yields}pe{sup +} and D{sup 0}{yields}pe{sup -}

    SciTech Connect

    Rubin, P.; Lowrey, N.; Mehrabyan, S.; Selen, M.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Poling, R.; Scott, A. W.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.

    2009-05-01

    We search for simultaneous baryon and lepton number violating decays of the D{sup 0} meson. Specifically, we use 281 pb{sup -1} of data taken on the {psi}(3770) resonance with the CLEO-c detector at the CESR collider to look for decays D{sup 0}{yields}pe{sup +}, D{sup 0}{yields}pe{sup +}, D{sup 0}{yields}pe{sup -}, and D{sup 0}{yields}pe{sup -}. We find no significant signals and set the following branching fraction upper limits: D{sup 0}{yields}pe{sup +}(D{sup 0}{yields}pe{sup +})<1.1x10{sup -5} and D{sup 0}{yields}pe{sup -}(D{sup 0}{yields}pe{sup -})<1.0x10{sup -5}, both at the 90% confidence level.

  5. 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.

  6. 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.

  7. The two-component regulators GacS and GacA positively regulate a nonfluorescent siderophore through the Gac/Rsm signaling cascade in high-siderophore-yielding Pseudomonas sp. strain HYS.

    PubMed

    Yu, Xinyan; Chen, Min; Jiang, Zhen; Hu, Yi; Xie, Zhixiong

    2014-09-01

    Siderophores, which are produced to overcome iron deficiency, are believed to be closely related to the adaptability of bacteria. The high-siderophore-yielding Pseudomonas sp. strain HYS simultaneously secretes the fluorescent siderophore pyoverdine and another nonfluorescent siderophore that is a major contributor to the high siderophore yield. Transposon mutagenesis revealed siderophore-related genes, including the two-component regulators GacS/GacA and a special cluster containing four open reading frames (the nfs cluster). Deletion mutations of these genes abolished nonfluorescent-siderophore production, and expression of the nfs cluster depended on gacA, indicating that gacS-gacA may control the nonfluorescent siderophore through regulation of the nfs cluster. Furthermore, regulation of the nonfluorescent siderophore by GacS/GacA involved the Gac/Rsm pathway. In contrast, inactivation of GacS/GacA led to upregulation of the fluorescent pyoverdine. The two siderophores were secreted under different iron conditions, probably because of differential effects of GacS/GacA. The global GacS/GacA regulatory system may control iron uptake by modulating siderophore production and may enable bacteria to adapt to changing iron environments.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Model-independent Higgs coupling measurements at the LHC using the H{yields}ZZ{yields}4l lineshape

    SciTech Connect

    Logan, Heather E.; Salvail, Jeff Z.

    2011-10-01

    We show that combining a direct measurement of the Higgs total width from the H{yields}ZZ{yields}4l lineshape with Higgs signal rate measurements allows Higgs couplings to be extracted in a model-independent way from CERN LHC data. Using existing experimental studies with 30 fb{sup -1} at one detector of the 14 TeV LHC, we show that the couplings squared of a 190 GeV Higgs to WW, ZZ, and gg can be extracted with statistical precisions of about 10%, and a 95% confidence level upper limit on an unobserved component of the Higgs decay width of about 22% of the standard model Higgs width can be set. The method can also be applied for heavier Higgs masses.

  13. Kok Effect and the Quantum Yield of Photosynthesis 1

    PubMed Central

    Sharp, Robert E.; Matthews, Mark A.; Boyer, John S.

    1984-01-01

    The linear response of photosynthesis to light at low photon flux densities is known to change abruptly in the vicinity of the light compensation point so that the quantum yield seems to decrease as radiation increases. We studied this `Kok effect' in attached sunflower (Helianthus annuus L. cv IS894) leaves using gas exchange techniques. The effect was present even though respiration was constant in the dark. It was observed at a similar photon flux density (7 to 11 micromole photons per square meter per second absorbed photosynthetically active radiation) despite a wide range of light compensation points as well as rates of photosynthesis. The effect was not apparent when photorespiration was inhibited at low pO2 (1 kilopascal), but this result was complicated because dark respiration was quite O2-sensitive and was partially suppressed under these conditions. The Kok effect was observed at saturating pCO2 and, therefore, could not be explained by a change in photorespiration. Instead, the magnitude of the effect varied as dark respiration varied in a single leaf, and was minimized when dark respiration was minimized, indicating that a partial suppression of dark respiration by light is responsible. Quantum yields measured at photon flux densities between 0 and 7 to 11 micromole photons per square meter per second, therefore, represent the combined yields of photosynthesis and of the suppression of a component of dark respiration by light. This leads to an overestimate of the quantum yield of photosynthesis. In view of these results, quantum yields of photosynthesis must be measured (a) when respiration is constant in the dark, and (b) when dark respiration has been inhibited either at low pO2 to eliminate most of the light-induced suppression of dark respiration or at photon flux densities above that required to saturate the light-induced suppression of dark respiration. Significant errors in quantum yields of photosynthesis can result in leaves exhibiting this

  14. Yield Stress Modeling of Electrorheological Fluids Using Neural Network

    NASA Astrophysics Data System (ADS)

    Wei, Kexiang; Meng, Guang

    Electrorheological (ER) fluids are a kind of smart materials whose rheological properties can be rapidly changed by applied electric fields. Many potential industrial applications of ER technology have been proposed. In order to formulate better ER fluids and design ER devices, it is important to predict the yield stress of ER fluids based on the ER fluids components and the operating conditions. This paper proposes a new method for predicting the yield stress of ER fluids with neural network (NN). A multilayer perceptron with a single hidden layer of neurons is used to model the ER effect. The data for training and test were produced from the simulation of previous proposed mathematical models. The Levernberg-Marquardt back propagation algorithm was selected for fast learning. The results show the neural network model can well approximate the previous theoretical model, and the predicted outputs of NN agree nearly with the theoretical model values under the same input, all of which demonstrate that it is possible to generate a robust NN model for rapidly predicting the yield stress of ER fluids under different input parameters.

  15. Projecting crop yield in northern high latitude area.

    PubMed

    Matsumura, Kanichiro

    2014-01-01

    Changing climatic conditions on seasonal and longer time scales influence agricultural production. Improvement of soil and fertilizer is a strong factor in agricultural production, but agricultural production is influenced by climate conditions even in highly developed countries. It is valuable if fewer predictors make it possible to conduct future projections. Monthly temperature and precipitation, wintertime 500hPa geopotential height, and the previous year's yield are used as predictors to forecast spring wheat yield in advance. Canadian small agricultural divisions (SAD) are used for analysis. Each SAD is composed of a collection of Canadian Agricultural Regions (CAR) of similar weather and growing conditions. Spring wheat yields in each CAR are forecast from the following variables: (a) the previous year's yield, (b) earlier stages of the growing season's climate conditions and, (c) the previous year's wintertime northern hemisphere 500hPa geopotential height field. Arctic outflow events in the Okanagan Valley in Canada are associated with episodes of extremely low temperatures during wintertime. Principal component analysis (PCA) is applied for wintertime northern hemisphere 500hPa geopotential height anomalies. The spatial PCA mode1 is defined as Arctic Oscillation and it influences prevailing westerlies. The prevailing westerlies meanders and influences climatic conditions. The spatial similarity between wintertime top 5 Arctic outflow event year's composites of 500hPa geopotential height anomalies and mode 3's spatial pattern is found. Mode 3's spatial pattern looks like the Pacific/North American (PNA) pattern which describes the variation of atmospheric circulation pattern over the Pacific Ocean and North America. Climate conditions from April to June, May to July, mode 3's time coefficients, and previous year's yield are used for forecasting spring wheat yield in each SAD. Cross-validation procedure which generates eight sets of models for the eight

  16. 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

  17. Closing yield gaps: perils and possibilities for biodiversity conservation.

    PubMed

    Phalan, Ben; Green, Rhys; Balmford, Andrew

    2014-04-05

    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.

  18. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

    PubMed

    Zhang, Jie; Yin, Binjie; Xie, Yuhuai; Li, Jing; Yang, Zaibin; Zhang, Guiguo

    2015-01-01

    Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn-rye exhibited a greater

  19. Boosting Crop Yields with Plant Steroids[W

    PubMed Central

    Vriet, Cécile; Russinova, Eugenia; Reuzeau, Christophe

    2012-01-01

    Plant sterols and steroid hormones, the brassinosteroids (BRs), are compounds that exert a wide range of biological activities. They are essential for plant growth, reproduction, and responses to various abiotic and biotic stresses. Given the importance of sterols and BRs in these processes, engineering their biosynthetic and signaling pathways offers exciting potentials for enhancing crop yield. In this review, we focus on how alterations in components of sterol and BR metabolism and signaling or application of exogenous steroids and steroid inhibitors affect traits of agronomic importance. We also discuss areas for future research and identify the fine-tuning modulation of endogenous BR content as a promising strategy for crop improvement. PMID:22438020

  20. Climate variation explains a third of global crop yield variability

    NASA Astrophysics Data System (ADS)

    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.

  1. Shear Yielding and Shear Jamming of Dense Hard Sphere Glasses

    NASA Astrophysics Data System (ADS)

    Urbani, Pierfrancesco; Zamponi, Francesco

    2017-01-01

    We investigate the response of dense hard sphere glasses to a shear strain in a wide range of pressures ranging from the glass transition to the infinite-pressure jamming point. The phase diagram in the density-shear strain plane is calculated analytically using the mean-field infinite-dimensional solution. We find that just above the glass transition, the glass generically yields at a finite shear strain. The yielding transition in the mean-field picture is a spinodal point in presence of disorder. At higher densities, instead, we find that the glass generically jams at a finite shear strain: the jamming transition prevents yielding. The shear yielding and shear jamming lines merge in a critical point, close to which the system yields at extremely large shear stress. Around this point, highly nontrivial yielding dynamics, characterized by system-spanning disordered fractures, is expected.

  2. Climate variation explains a third of global crop yield variability.

    PubMed

    Ray, Deepak K; Gerber, James S; MacDonald, Graham K; West, Paul C

    2015-01-22

    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.

  3. Assessment of factors influencing the biomethane yield of maize silages.

    PubMed

    Mayer, Frédéric; Gerin, Patrick A; Noo, Anaïs; Foucart, Guy; Flammang, Jos; Lemaigre, Sébastien; Sinnaeve, Georges; Dardenne, Pierre; Delfosse, Philippe

    2014-02-01

    A large set of maize silage samples was produced to assess the major traits influencing the biomethane production of this crop. The biomass yield, the volatile solids contents and the biochemical methane potential (BMP) were measured to calculate the biomethane yield per hectare (average=7266m(3)ha(-1)). The most influential factor controlling the biomethane yield was the cropping environment. The biomass yield had more impact than the anaerobic digestibility. Nevertheless, the anaerobic digestibility of maize silages was negatively affected by high VS content in mature maize. Late maturing maize varieties produced high biomass yield with high digestibility resulting in high biomethane yield per hectare. The BMP was predicted with good accuracy using solely the VS content.

  4. Impacts of variability in cellulosic biomass yields on energy security.

    PubMed

    Mullins, Kimberley A; Matthews, H Scott; Griffin, W Michael; Anex, Robert

    2014-07-01

    The practice of modeling biomass yields on the basis of deterministic point values aggregated over space and time obscures important risks associated with large-scale biofuel use, particularly risks related to drought-induced yield reductions that may become increasingly frequent under a changing climate. Using switchgrass as a case study, this work quantifies the variability in expected yields over time and space through switchgrass growth modeling under historical and simulated future weather. The predicted switchgrass yields across the United States range from about 12 to 19 Mg/ha, and the 80% confidence intervals range from 20 to 60% of the mean. Average yields are predicted to decrease with increased temperatures and weather variability induced by climate change. Feedstock yield variability needs to be a central part of modeling to ensure that policy makers acknowledge risks to energy supplies and develop strategies or contingency plans that mitigate those risks.

  5. 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

  6. Yield QTLome distribution correlates with gene density in maize.

    PubMed

    Martinez, Ana Karine; Soriano, Jose Miguel; Tuberosa, Roberto; Koumproglou, Rachil; Jahrmann, Torben; Salvi, Silvio

    2016-01-01

    The genetic control of yield and related traits in maize has been addressed by many quantitative trait locus (QTL) studies, which have produced a wealth of QTL information, also known as QTLome. In this study, we assembled a yield QTLome database and carried out QTL meta-analysis based on 44 published studies, representing 32 independent mapping populations and 49 parental lines. A total of 808 unique QTLs were condensed to 84 meta-QTLs and were projected on the 10 maize chromosomes. Seventy-four percent of QTLs showed a proportion of phenotypic variance explained (PVE) smaller than 10% confirming the high genetic complexity of grain yield. Yield QTLome projection on the genetic map suggested pericentromeric enrichment of QTLs. Conversely, pericentromeric depletion of QTLs was observed when the physical map was considered, suggesting gene density as the main driver of yield QTL distribution on chromosomes. Dominant and overdominant yield QTLs did not distribute differently from additive effect QTLs.

  7. 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.

  8. Roll-your-own smoke yields: theoretical and practical aspects

    PubMed Central

    Darrall, K.; Figgins, J.

    1998-01-01

    OBJECTIVE—To identify the key parameters that influence smoke yields from roll-your-own (RYO) cigarettes and to compare smoke yields of cigarettes made under laboratory conditions with those made by habitual RYO consumers.
DESIGN AND SETTING—One-way parametric variations in the laboratory-based production of RYO cigarettes complemented by a consumer survey conducted in a busy street at Romford, Essex, United Kingdom.
SUBJECTS—26 habitual RYO consumers.
MAIN OUTCOME MEASURES—Cigarette weights, puff numbers, and yields (carbon monoxide, nicotine, and tar).
RESULTS—Smoke yields vary for specimen changes in weight of tobacco used, paper porosity, and the incorporation of a filter in the cigarette. Yields of cigarettes produced by 26 RYO smokers ranged from 9.9 to 21.0 mg tar per cigarette and from 0.9 to 1.8 mg nicotine per cigarette, and were generally lower than yields of laboratory-produced RYO cigarettes.
CONCLUSIONS—Laboratory studies can provide useful information concerning the parameters that affect smoke yields of RYO cigarettes such as the incorporation of a filter to reduce yields. However, such studies must be complemented by surveys of cigarettes made by actual current RYO smokers. In one such investigation, it was found that the mean tar yields from cigarettes produced by 57% of the smokers were above the current maximum of 15 mg per cigarette for manufactured cigarettes. Currently 8% of manufactured cigarettes in the UK have a declared nicotine yield of greater than 1.1 mg per cigarette whereas 77% of RYO smokers produced cigarettes with a nicotine yield greater than this value.


Keywords: roll-your-own cigarettes; smoke yield; carbon monoxide; tar; nicotine PMID:9789936

  9. 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.

  10. 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

  11. 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.

  12. Single-molecule mountains yield nanoscale cell images

    PubMed Central

    Moerner, W E

    2009-01-01

    Methods to simultaneously localize the positions of multiple single fluorophores by precisely determining their individual positions are now yielding impressive gains in fluorescence microscopy resolution. PMID:16990808

  13. In-situ determination of energy species yields of intense particle beams

    DOEpatents

    Kugel, Henry W.; Kaita, Robert

    1987-03-03

    An arrangement is provided for the in-situ determination of energy species yields of intense particle beams. The beam is directed onto a target surface of known composition, such that Rutherford backscattering of the beam occurs. The yield-energy characteristic response of the beam to backscattering from the target is analyzed using Rutherford backscattering techniques to determine the yields of energy species components of the beam.

  14. In-situ determination of energy species yields of intense particle beams

    DOEpatents

    Kugel, Henry W.; Kaita, Robert

    1987-01-01

    An arrangement is provided for the in-situ determination of energy species yields of intense particle beams. The beam is directed onto a target surface of known composition, such that Rutherford backscattering of the beam occurs. The yield-energy characteristic response of the beam to backscattering from the target is analyzed using Rutherford backscattering techniques to determine the yields of energy species components of the beam.

  15. Silybum marianum pericarp yields enhanced silymarin products.

    PubMed

    AbouZid, Sameh F; Chen, Shao-Nong; McAlpine, James B; Friesen, J Brent; Pauli, Guido F

    2016-07-01

    An improved method for the purification of silymarin, the flavonolignan complex from the fruits of milk thistle, Silybum marianum, is reported. The method enables a more efficient extraction of silymarin from the pericarp after it has been separated mechanically from the rest of the fruits. Accelerated solvent extraction (ASE) was employed for each extraction procedure. Quantitation of the eight major silymarin components in the pericarp extract was compared to that of the whole fruit extract using two orthogonal analytical methods. The pericarp extract showed higher silymarin content (2.24-fold by HPLC and 2.12-fold by qHNMR) than whole fruit extract using acetone as an extraction solvent following defatting with hexane. Furthermore, the mg/g recovery of silymarin major components was not diminished by eliminating the hexane defatting step from the pericarp extraction procedure. The efficiencies of acetone, ethanol, and methanol as extraction solvents were compared. Methanol pericarp extract showed the highest content of the silymarin major components, 2.72-fold higher than an extract prepared from the whole fruits using acetone. Finally, all of the major silymarin components showed a higher w/w content in the pericarp extract than in a commercial extract.

  16. Uncertainty in Simulating Wheat Yields Under Climate Change

    SciTech Connect

    Asseng, S.; Ewert, F.; Rosenzweig, C.; Jones, J.W.; Hatfield, Jerry; Ruane, Alex; Boote, K. J.; Thorburn, Peter; Rotter, R.P.; Cammarano, D.; Brisson, N.; Basso, B.; Martre, P.; Aggarwal, P.K.; Angulo, C.; Bertuzzi, P.; Biernath, C.; Challinor, AJ; Doltra, J.; Gayler, S.; Goldberg, R.; Grant, Robert; Heng, L.; Hooker, J.; Hunt, L.A.; Ingwersen, J.; Izaurralde, Roberto C.; Kersebaum, K.C.; Mueller, C.; Naresh Kumar, S.; Nendel, C.; O'Leary, G.O.; Olesen, JE; Osborne, T.; Palosuo, T.; Priesack, E.; Ripoche, D.; Semenov, M.A.; Shcherbak, I.; Steduto, P.; Stockle, Claudio O.; Stratonovitch, P.; Streck, T.; Supit, I.; Tao, F.; Travasso, M.; Waha, K.; Wallach, D.; White, J.W.; Williams, J.R.; Wolf, J.

    2013-09-01

    Anticipating the impacts of climate change on crop yields is critical for assessing future food security. Process-based crop simulation models are the most commonly used tools in such assessments1,2. Analysis of uncertainties in future greenhouse gas emissions and their impacts on future climate change has been increasingly described in the literature3,4 while assessments of the uncertainty in crop responses to climate change are very rare. Systematic and objective comparisons across impact studies is difficult, and thus has not been fully realized5. Here we present the largest coordinated and standardized crop model intercomparison for climate change impacts on wheat production to date. We found that several individual crop models are able to reproduce measured grain yields under current diverse environments, particularly if sufficient details are provided to execute them. However, simulated climate change impacts can vary across models due to differences in model structures and algorithms. The crop-model component of uncertainty in climate change impact assessments was considerably larger than the climate-model component from Global Climate Models (GCMs). Model responses to high temperatures and temperature-by-CO2 interactions are identified as major sources of simulated impact uncertainties. Significant reductions in impact uncertainties through model improvements in these areas and improved quantification of uncertainty through multi-model ensembles are urgently needed for a more reliable translation of climate change scenarios into agricultural impacts in order to develop adaptation strategies and aid policymaking.

  17. Decays Z{yields}gg{gamma} and Z{sup '}{yields}gg{gamma} in the minimal 331 model

    SciTech Connect

    Flores-Tlalpa, A.; Montano, J.; Ramirez-Zavaleta, F.; Toscano, J. J.

    2009-10-01

    The one-loop induced Z{yields}gg{gamma} and Z{sup '}{yields}gg{gamma} decays are studied within the context of the minimal 331 model, which predicts the existence of new gauge bosons and three exotic quarks. It is found that the Z{yields}gg{gamma} decay is insensitive to the presence of the exotic quarks, as it is essentially governed by the first two families of known quarks. As to the Z{sup '}{yields}gg{gamma} decay, it is found that the exotic quark contribution dominates and that for a heavy Z{sup '} boson it leads to a {gamma}(Z{sup '}{yields}gg{gamma}) that is more than 1 order of magnitude larger than that associated with {gamma}(Z{sup '}{yields}ggg). This result may be used to distinguish a new neutral Z{sup '} boson from those models that do not introduce exotic quarks.

  18. Process Yields Strong, Void-Free Laminates

    NASA Technical Reports Server (NTRS)

    Bryant, L. E.; Covington, E. W., III; Dale, W. J.; Hall, E. T., Jr; Justice, J. E.; Taylor, E. C.; Wilson, M. L.

    1983-01-01

    Need for lightweight materials as structural components for future space transportation systems stimulated development of systematic method for manufacturing a polyimide/graphite composite. Laminates manufactured by process are void-free, exhibit excellent thermo-oxidative stability up to 315 degrees C (600 degrees F) and are 40 percent lighter than aluminum. Process is precise, repeatable, and ideally suited for researchers and small-lot producers of composite materials.

  19. Prediction of Potato Crop Yield Using Precision Agriculture Techniques

    PubMed Central

    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

  20. Comparison of statistical models for analyzing wheat yield time series.

    PubMed

    Michel, Lucie; Makowski, David

    2013-01-01

    The world's population is predicted to exceed nine billion by 2050 and there is increasing concern about the capability of agriculture to feed such a large population. Foresight studies on food security are frequently based on crop yield trends estimated from yield time series provided by national and regional statistical agencies. Various types of statistical models have been proposed for the analysis of yield time series, but the predictive performances of these models have not yet been evaluated in detail. In this study, we present eight statistical models for analyzing yield time series and compare their ability to predict wheat yield at the national and regional scales, using data provided by the Food and Agriculture Organization of the United Nations and by the French Ministry of Agriculture. The Holt-Winters and dynamic linear models performed equally well, giving the most accurate predictions of wheat yield. However, dynamic linear models have two advantages over Holt-Winters models: they can be used to reconstruct past yield trends retrospectively and to analyze uncertainty. The results obtained with dynamic linear models indicated a stagnation of wheat yields in many countries, but the estimated rate of increase of wheat yield remained above 0.06 t ha⁻¹ year⁻¹ in several countries in Europe, Asia, Africa and America, and the estimated values were highly uncertain for several major wheat producing countries. The rate of yield increase differed considerably between French regions, suggesting that efforts to identify the main causes of yield stagnation should focus on a subnational scale.

  1. 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

  2. Comparison of Statistical Models for Analyzing Wheat Yield Time Series

    PubMed Central

    Michel, Lucie; Makowski, David

    2013-01-01

    The world's population is predicted to exceed nine billion by 2050 and there is increasing concern about the capability of agriculture to feed such a large population. Foresight studies on food security are frequently based on crop yield trends estimated from yield time series provided by national and regional statistical agencies. Various types of statistical models have been proposed for the analysis of yield time series, but the predictive performances of these models have not yet been evaluated in detail. In this study, we present eight statistical models for analyzing yield time series and compare their ability to predict wheat yield at the national and regional scales, using data provided by the Food and Agriculture Organization of the United Nations and by the French Ministry of Agriculture. The Holt-Winters and dynamic linear models performed equally well, giving the most accurate predictions of wheat yield. However, dynamic linear models have two advantages over Holt-Winters models: they can be used to reconstruct past yield trends retrospectively and to analyze uncertainty. The results obtained with dynamic linear models indicated a stagnation of wheat yields in many countries, but the estimated rate of increase of wheat yield remained above 0.06 t ha−1 year−1 in several countries in Europe, Asia, Africa and America, and the estimated values were highly uncertain for several major wheat producing countries. The rate of yield increase differed considerably between French regions, suggesting that efforts to identify the main causes of yield stagnation should focus on a subnational scale. PMID:24205280

  3. Increasing crop diversity mitigates weather variations and improves yield stability.

    PubMed

    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

  4. 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.

  5. 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.

  6. A Study of Specialty Clones’ Yield Performance in Early and Late Harvests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: A study was conducted on specialty potato breeding lines to examine yield components in an early and late harvest. Upon first examination it was apparent that the early water cutoff had a large effect on total yield. In the early trial only one clone achieved 600 cwt/A of total...

  7. MARKERS ASSOCIATED WITH A QTL FOR GRAIN YIELD IN WHEAT UNDER DROUGHT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought is a major abiotic stress that adversely affects wheat production in many regions of the world. The objective of this study was to identify quantitative trait loci (QTL) controlling grain yield and yield components under reduced moisture. A cross between common wheat cultivars ‘Dharwar Dry’ ...

  8. Improving precision of forage yield trials: A case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field-based agronomic and genetic research relies heavily on the data generated from field evaluations. Therefore, it is imperative to optimize the precision of yield estimates in cultivar evaluation trials to make reliable selections. Experimental error in yield trials is sensitive to several facto...

  9. Factors influencing yield of plateletpheresis using intermittent flow cell separator.

    PubMed

    DAS, S S; Chaudhary, R K; Shukla, J S

    2005-10-01

    Platelet recovery in the recipient is influenced by the transfused dose of platelets, which in turn is dependent on the quality of single donor platelets (SDPs) in terms of platelet yield. Various donor factors such as predonation platelet count and Hemoglobin (Hb) concentration affect the platelet yield. A total of 61 plateletpheresis procedures performed on intermittent flow cell separator (MCS3p, Hemonetics) were evaluated for platelet yield. A relationship between predonation platelet count and Hb concentration with yield of platelets was studied using Pearson Correlation. The mean platelet yield was 2.9 +/- 0.64 x 10(11). While a direct relationship was observed between predonation platelet count and yield (r = 0.51, P < 0.001), no such correlation was noticed with donor Hb concentration (r = -0.05, P > 0.005). The yield was > or =3 x 10(11) in >80% of procedures when the predonation platelet count was > or =250 x 10(3)/mm. Optimization of platelet yield, which is influenced by predonation platelet count, is an emerging issue in blood transfusion services. However, further studies in this regard are needed using more advanced cell separators.

  10. Primary radical yields in pulse irradiated alkaline aqueous solution

    NASA Technical Reports Server (NTRS)

    Fielden, E. M.; Hart, E. J.

    1969-01-01

    Primary radical yields of hydrated electrons, H atoms, and OH radicals are determined by measuring hydrated electron formation following a 4 microsecond pulse of X rays. The pH dependence of free radical yields beyond pH 12 is determined by observation of the hydrated electrons.

  11. Effects of capillarity and microtopography on wetland specific yield

    USGS Publications Warehouse

    Sumner, D.M.

    2007-01-01

    Hydrologic models aid in describing water flows and levels in wetlands. Frequently, these models use a specific yield conceptualization to relate water flows to water level changes. Traditionally, a simple conceptualization of specific yield is used, composed of two constant values for above- and below-surface water levels and neglecting the effects of soil capillarity and land surface microtopography. The effects of capiltarity and microtopography on specific yield were evaluated at three wetland sites in the Florida Everglades. The effect of capillarity on specific yield was incorporated based on the fillable pore space within a soil moisture profile at hydrostatic equilibrium with the water table. The effect of microtopography was based on areal averaging of topographically varying values of specific yield. The results indicate that a more physically-based conceptualization of specific yield incorporating capillary and microtopographic considerations can be substantially different from the traditional two-part conceptualization, and from simpler conceptualizations incorporating only capillarity or only microtopography. For the sites considered, traditional estimates of specific yield could under- or overestimate the more physically based estimates by a factor of two or more. The results suggest that consideration of both capillarity and microtopography is important to the formulation of specific yield in physically based hydrologic models of wetlands. ?? 2007, The Society of Wetland Scientists.

  12. Response of switchgrass yield to future climate change

    NASA Astrophysics Data System (ADS)

    Tulbure, Mirela G.; Wimberly, Michael C.; Owens, Vance N.

    2012-12-01

    A climate envelope approach was used to model the response of switchgrass, a model bioenergy species in the United States, to future climate change. The model was built using general additive models (GAMs), and switchgrass yields collected at 45 field trial locations as the response variable. The model incorporated variables previously shown to be the main determinants of switchgrass yield, and utilized current and predicted 1 km climate data from WorldClim. The models were run with current WorldClim data and compared with results of predicted yield obtained using two climate change scenarios across three global change models for three time steps. Results did not predict an increase in maximum switchgrass yield but showed an overall shift in areas of high switchgrass productivity for both cytotypes. For upland cytotypes, the shift in high yields was concentrated in northern and north-eastern areas where there were increases in average growing season temperature, whereas for lowland cultivars the areas where yields were projected to increase were associated with increases in average early growing season precipitation. These results highlight the fact that the influences of climate change on switchgrass yield are spatially heterogeneous and vary depending on cytotype. Knowledge of spatial distribution of suitable areas for switchgrass production under climate change should be incorporated into planning of current and future biofuel production. Understanding how switchgrass yields will be affected by future changes in climate is important for achieving a sustainable biofuels economy.

  13. 50 CFR 600.310 - National Standard 1-Optimum Yield.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 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....

  14. 50 CFR 600.310 - National Standard 1-Optimum Yield.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 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....

  15. 50 CFR 600.310 - National Standard 1-Optimum Yield.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 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....

  16. 50 CFR 600.310 - National Standard 1-Optimum Yield.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 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....

  17. 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....

  18. Yield estimation of sugarcane based on agrometeorological-spectral models

    NASA Technical Reports Server (NTRS)

    Rudorff, Bernardo Friedrich Theodor; Batista, Getulio Teixeira

    1990-01-01

    This work has the objective to assess the performance of a yield estimation model for sugarcane (Succharum officinarum). The model uses orbital gathered spectral data along with yield estimated from an agrometeorological model. The test site includes the sugarcane plantations of the Barra Grande Plant located in Lencois Paulista municipality in Sao Paulo State. Production data of four crop years were analyzed. Yield data observed in the first crop year (1983/84) were regressed against spectral and agrometeorological data of that same year. This provided the model to predict the yield for the following crop year i.e., 1984/85. The model to predict the yield of subsequent years (up to 1987/88) were developed similarly, incorporating all previous years data. The yield estimations obtained from these models explained 69, 54, and 50 percent of the yield variation in the 1984/85, 1985/86, and 1986/87 crop years, respectively. The accuracy of yield estimations based on spectral data only (vegetation index model) and on agrometeorological data only (agrometeorological model) were also investigated.

  19. Fiber optic yield monitor for a sugarcane chopper harvester

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A fiber optic yield monitoring system was developed for a sugarcane chopper harvester that utilizes a duty-cycle type approach with three fiber optic sensors mounted in the elevator floor to estimate cane yield. Field testing of the monitor demonstrated that there was a linear relationship between t...

  20. What's holding us back? Raising the alfalfa yield bar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measuring yield of commodity crops is easy – weight and moisture content are determined on delivery. Consequently, reports of production or yield for grain crops can be made reliably to the agencies that track crop production, such as the USDA-National Agricultural Statistics Service (NASS). The s...

  1. Genetic Diversity and Soybean Yield: Finding the Balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on national production statistics since 1924, average soybean yield in the U.S. has increased at a nearly steady rate of 22 kg ha-1 year-1. It is possible to show some changes in this rate depending on how these past 85 years are divided, but two conclusions seem evident. Soybean yield has not...

  2. The alfalfa yield gap: A review of the evidence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of feasibly attainable crop yields is needed for many purposes, from field-scale management to national policy decisions. For alfalfa (Medicago sativa L.), the most widely used estimates of yield in the US are whole-farm reports from the National Agriculture Statistics Service, which are b...

  3. 7 CFR 1437.105 - Determining payments for low yield.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Determining payments for low yield. 1437.105 Section 1437.105 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT... for low yield. (a) Except to the extent that the loss calculation provisions of other subparts...

  4. Microchannels affect runoff and sediment yield from a shortgrass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Runoff and sediment yield from rangelands are extremely important variables that affect productivity, but are difficult to quantify. Studies have been conducted to assess erosion on rangelands, but very little has been done to determine if microchannels (rills) affect runoff and sediment yield. Rain...

  5. Understanding grain yield: It is a journey, not a destination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 20 years ago, we began our efforts to understand grain yield in winter wheat using chromosome substitution lines between Cheyenne and Wichita. We found that two chromosome substitutions, 3A and 6A, greatly affected grain yield. Cheyenne(Wichita 3A) and Cheyenne(Wichita 6A) had 15 to 20...

  6. Surprising yields with no-till cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers using no-till systems have found that crop yields often exceed their expectation based on nutrient and water supply. For example, corn yields 7% higher in a no-till system in central South Dakota than in a tilled system in eastern South Dakota. This is surprising because rainfall is 5 in...

  7. Surprising yields with no-till cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers using no-till practices have observed that crop yields can greatly exceed expectations based on nutrient and water supply. For example, Ralph Holzwarth, who farms near Gettysburg, SD, has averaged 150 bu/ac of corn on his farm for the past 6 years. We were surprised with this yield, as c...

  8. Impact of switchgrass harvest time on biomass yield and conversion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.) is a perennial grass native to much of North America being developed as a dedicated energy crop for conversion to biofuels. Breeding efforts are focused on producing high-yielding cultivars that can maintain high yield across multiple environments, including poor so...

  9. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are limited by the release of phytotoxic compounds as the previous year’s maize residue decomposes. We tested the hypothesis that soil biochar applications could help mitigate maize autotoxicity and the associated yield depression. Eighteen small field plots (23.7 m2) were es...

  10. Yield and Economic Responses of Peanut to Crop Rotation Sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper crop rotation is essential to maintaining high peanut yield and quality. However, the economic considerations of maintaining or altering crop rotation sequences must incorporate the commodity prices, production costs, and yield responses of all crops in, or potentially in, the crop rotation ...

  11. EDIBLE FRUIT YIELDING PLANTS OF SHEVAROY HILLS IN TAMIL NADU

    PubMed Central

    Alagesaboopathi, C.; Balu, S.; Dwarakan, P.

    1996-01-01

    The paper deals with the common edible fruit yielding plants, During the course of medicinal plant survey of shevaroy hills of Eastern ghats. Salem district, Tamil Nadu. Thirty species belonging to 23 genera and 21 families yield edible fruits. They are listed in alphabetical order followed by family, common name and Tamil names. PMID:22556784

  12. Computing wheat nitrogen requirements from grain yield and protein maps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful post-harvest information for evaluating water or nitrogen (...

  13. Computing wheat nitrogen requirements from grain yield and protein maps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful postharvest information for evaluating water or nitrogen (N)...

  14. Topsoil Depth Effects on Crop Yields as Affected by Weather

    NASA Astrophysics Data System (ADS)

    Lee, Scott; Cruse, Richard

    2015-04-01

    Topsoil (A-horizon) depth is positively correlated with crop productivity; crop roots and available nutrients are concentrated in this layer; topsoil is critical for nutrient retention and water holding capacity. Its loss or reduction can be considered an irreversible impact of soil erosion. Climatic factors such as precipitation and temperature extremes that impose production stress further complicate the relationship between soil erosion and crop productivity. The primary research objective was to determine the effects of soil erosion on corn and soybean yields of loess and till-derived soils in the rain-fed farming region of Iowa. Data collection took place from 2007 to 2012 at seven farm sites located in different major soil regions. Collection consisted of 40 to 50 randomly selected georeferenced soil probe locations across varying erosion classes in well drained landscape positions. Soil probes were done to a minimum depth of 100 cm and soil organic carbon samples were obtained in the top 10 cm. Crop yields were determined utilizing georeferenced harvest maps from yield monitoring devices and cross referenced with georeferenced field data points. Data analysis targeted relationships between crop yields versus soil organic carbon contents (SOC) and crop yields versus topsoil depths (TSD). The variation of yield and growing season rainfall across multiple years were also evaluated to provide an indication of soil resiliency associated with topsoil depth and soil organic carbon levels across varying climatic conditions. Results varied between sites but generally indicated a greater yield potential at thicker TSD's and higher SOC concentrations; an annual variation in yield response as a function of precipitation amount during the growing season; largest yield responses to both TSD and SOC occurred in the driest study year (2012); and little to no significant yield responses to TSD occurred during the wettest study year (2010). These results were not

  15. Climate change impacts on crop yield: evidence from China.

    PubMed

    Wei, Taoyuan; Cherry, Todd L; Glomrød, Solveig; Zhang, Tianyi

    2014-11-15

    When estimating climate change impact on crop yield, a typical assumption is constant elasticity of yield with respect to a climate variable even though the elasticity may be inconstant. After estimating both constant and inconstant elasticities with respect to temperature and precipitation based on provincial panel data in China 1980-2008, our results show that during that period, the temperature change contributes positively to total yield growth by 1.3% and 0.4% for wheat and rice, respectively, but negatively by 12% for maize. The impacts of precipitation change are marginal. We also compare our estimates with other studies and highlight the implications of the inconstant elasticities for crop yield, harvest and food security. We conclude that climate change impact on crop yield would not be an issue in China if positive impacts of other socio-economic factors continue in the future.

  16. The yielding transition in amorphous solids under oscillatory shear deformation

    NASA Astrophysics Data System (ADS)

    Leishangthem, Premkumar; Parmar, Anshul D. S.; Sastry, Srikanth

    2017-03-01

    Amorphous solids are ubiquitous among natural and man-made materials. Often used as structural materials for their attractive mechanical properties, their utility depends critically on their response to applied stresses. Processes underlying such mechanical response, and in particular the yielding behaviour of amorphous solids, are not satisfactorily understood. Although studied extensively, observed yielding behaviour can be gradual and depend significantly on conditions of study, making it difficult to convincingly validate existing theoretical descriptions of a sharp yielding transition. Here we employ oscillatory deformation as a reliable probe of the yielding transition. Through extensive computer simulations for a wide range of system sizes, we demonstrate that cyclically deformed model glasses exhibit a sharply defined yielding transition with characteristics that are independent of preparation history. In contrast to prevailing expectations, the statistics of avalanches reveals no signature of the impending transition, but exhibit dramatic, qualitative, changes in character across the transition.

  17. Resolution to the B{yields}{pi}K puzzle

    SciTech Connect

    Li Hsiangnan; Mishima, Satoshi; Sanda, A.I.

    2005-12-01

    We calculate the important next-to-leading-order contributions to the B{yields}{pi}K, {pi}{pi} decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B{yields}{pi}K branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}} and B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}} modes. The puzzle from the large B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} branching ratio still remains.

  18. The yielding transition in amorphous solids under oscillatory shear deformation

    PubMed Central

    Leishangthem, Premkumar; Parmar, Anshul D. S.; Sastry, Srikanth

    2017-01-01

    Amorphous solids are ubiquitous among natural and man-made materials. Often used as structural materials for their attractive mechanical properties, their utility depends critically on their response to applied stresses. Processes underlying such mechanical response, and in particular the yielding behaviour of amorphous solids, are not satisfactorily understood. Although studied extensively, observed yielding behaviour can be gradual and depend significantly on conditions of study, making it difficult to convincingly validate existing theoretical descriptions of a sharp yielding transition. Here we employ oscillatory deformation as a reliable probe of the yielding transition. Through extensive computer simulations for a wide range of system sizes, we demonstrate that cyclically deformed model glasses exhibit a sharply defined yielding transition with characteristics that are independent of preparation history. In contrast to prevailing expectations, the statistics of avalanches reveals no signature of the impending transition, but exhibit dramatic, qualitative, changes in character across the transition. PMID:28248289

  19. Covariance Matrix Evaluations for Independent Mass Fission Yields

    SciTech Connect

    Terranova, N.; Serot, O.; Archier, P.; De Saint Jean, C.

    2015-01-15

    Recent needs for more accurate fission product yields include covariance information to allow improved uncertainty estimations of the parameters used by design codes. The aim of this work is to investigate the possibility to generate more reliable and complete uncertainty information on independent mass fission yields. Mass yields covariances are estimated through a convolution between the multi-Gaussian empirical model based on Brosa's fission modes, which describe the pre-neutron mass yields, and the average prompt neutron multiplicity curve. The covariance generation task has been approached using the Bayesian generalized least squared method through the CONRAD code. Preliminary results on mass yields variance-covariance matrix will be presented and discussed from physical grounds in the case of {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f) reactions.

  20. Recent patterns of crop yield growth and stagnation.

    PubMed

    Ray, Deepak K; Ramankutty, Navin; Mueller, Nathaniel D; West, Paul C; Foley, Jonathan A

    2012-01-01

    In the coming decades, continued population growth, rising meat and dairy consumption and expanding biofuel use will dramatically increase the pressure on global agriculture. Even as we face these future burdens, there have been scattered reports of yield stagnation in the world's major cereal crops, including maize, rice and wheat. Here we study data from ∼2.5 million census observations across the globe extending over the period 1961-2008. We examined the trends in crop yields for four key global crops: maize, rice, wheat and soybeans. Although yields continue to increase in many areas, we find that across 24-39% of maize-, rice-, wheat- and soybean-growing areas, yields either never improve, stagnate or collapse. This result underscores the challenge of meeting increasing global agricultural demands. New investments in underperforming regions, as well as strategies to continue increasing yields in the high-performing areas, are required.

  1. Predicting paddlefish roe yields using an extension of the Beverton–Holt equilibrium yield-per-recruit model

    USGS Publications Warehouse

    Colvin, M.E.; Bettoli, Phillip William; Scholten, G.D.

    2013-01-01

    Equilibrium yield models predict the total biomass removed from an exploited stock; however, traditional yield models must be modified to simulate roe yields because a linear relationship between age (or length) and mature ovary weight does not typically exist. We extended the traditional Beverton-Holt equilibrium yield model to predict roe yields of Paddlefish Polyodon spathula in Kentucky Lake, Tennessee-Kentucky, as a function of varying conditional fishing mortality rates (10-70%), conditional natural mortality rates (cm; 9% and 18%), and four minimum size limits ranging from 864 to 1,016mm eye-to-fork length. These results were then compared to a biomass-based yield assessment. Analysis of roe yields indicated the potential for growth overfishing at lower exploitation rates and smaller minimum length limits than were suggested by the biomass-based assessment. Patterns of biomass and roe yields in relation to exploitation rates were similar regardless of the simulated value of cm, thus indicating that the results were insensitive to changes in cm. Our results also suggested that higher minimum length limits would increase roe yield and reduce the potential for growth overfishing and recruitment overfishing at the simulated cm values. Biomass-based equilibrium yield assessments are commonly used to assess the effects of harvest on other caviar-based fisheries; however, our analysis demonstrates that such assessments likely underestimate the probability and severity of growth overfishing when roe is targeted. Therefore, equilibrium roe yield-per-recruit models should also be considered to guide the management process for caviar-producing fish species.

  2. Calculation of the total electron excitation cross section in the Born approximation using Slater wave functions for the Li (2s yields 2p), Li (2s yields 3p), Na (3s yields 4p), Mg (3p yields 4s), Ca (4s yields 4p) and K (4s yields 4p) excitations. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Simsic, P. L.

    1974-01-01

    Excitation of neutral atoms by inelastic scattering of incident electrons in gaseous nebulae were investigated using Slater Wave functions to describe the initial and final states of the atom. Total cross sections using the Born Approximation are calculated for: Li(2s yields 2p), Na(3s yields 4p), k(4s yields 4p). The intensity of emitted radiation from gaseous nebulae is also calculated, and Maxwell distribution is employed to average the kinetic energy of electrons.

  3. Atomistic simulations of the yielding of gold nanowires.

    SciTech Connect

    Zimmerman, Jonathan A.; Dunn, Martin L.; Diao, Jiankuai; Gall, Ken

    2004-07-01

    We performed atomistic simulations to study the effect of free surfaces on the yielding of gold nanowires. Tensile surface stresses on the surfaces of the nanowires cause them to contract along the length with respect to the bulk face-centered cubic lattice and induce compressive stress in the interior. When the cross-sectional area of a (100) nanowire is less than 2.45 nm x 2.45 nm, the wire yields under its surface stresses. Under external forces and surface stresses, nanowires yield via the nucleation and propagation of the {l_brace}111{r_brace}<112> partial dislocations. The magnitudes of the tensile and compressive yield stress of (100) nanowires increase and decrease, respectively, with a decrease of the wire width. The magnitude of the tensile yield stress is much larger than that of the compressive yield stress for small (100) nanowires, while for small <111> nanowires, tensile and compressive yield stresses have similar magnitudes. The critical resolved shear stress (RSS) by external forces depends on wire width, orientation and loading condition (tension vs. compression). However, the critical RSS in the interior of the nanowires, which is exerted by both the external force and the surface-stress-induced compressive stress, does not change significantly with wire width for same orientation and same loading condition, and can thus serve as a 'local' criterion. This local criterion is invoked to explain the observed size dependence of yield behavior and tensile/compressive yield stress asymmetry, considering surface stress effects and different slip systems active in tensile and compressive yielding.

  4. Comparing the yields of organic and conventional agriculture.

    PubMed

    Seufert, Verena; Ramankutty, Navin; Foley, Jonathan A

    2012-05-10

    Numerous reports have emphasized the need for major changes in the global food system: agriculture must meet the twin challenge of feeding a growing population, with rising demand for meat and high-calorie diets, while simultaneously minimizing its global environmental impacts. Organic farming—a system aimed at producing food with minimal harm to ecosystems, animals or humans—is often proposed as a solution. However, critics argue that organic agriculture may have lower yields and would therefore need more land to produce the same amount of food as conventional farms, resulting in more widespread deforestation and biodiversity loss, and thus undermining the environmental benefits of organic practices. Here we use a comprehensive meta-analysis to examine the relative yield performance of organic and conventional farming systems globally. Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak-acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable). Under certain conditions—that is, with good management practices, particular crop types and growing conditions—organic systems can thus nearly match conventional yields, whereas under others it at present cannot. To establish organic agriculture as an important tool in sustainable food production, the factors limiting organic yields need to be more fully understood, alongside assessments of the many social, environmental and economic benefits of organic farming systems.

  5. Large-area rice yield forecasting using satellite imageries

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Ping; Chang, Kuo-Wei; Chen, Rong-Kuen; Lo, Jeng-Chung; Shen, Yuan

    2010-02-01

    Ability to make large-area yield prediction before harvest is important in many aspects of agricultural decision-making. In this study, canopy reflectance band ratios (NIR/RED, NIR/GRN) of paddy rice ( Oryza sativa L.) at booting stage, from field measurements conducted from 1999 to 2005, were correlated with the corresponding yield data to derive regression-type yield prediction models for the first and second season crop, respectively. These yield models were then validated with ground truth measurements conducted in 2007 and 2008 at eight sites, of different soil properties, climatic conditions, and various treatments in cultivars planted and N application rates, using surface reflectance retrieved from atmospherically corrected SPOT imageries. These validation tests indicated that root mean square error of predicting grain yields per unit area by the proposed models were less than 0.7 T ha -1 for both cropping seasons. Since village is the basic unit for national rice yield census statistics in Taiwan, the yield models were further used to forecast average regional yields for 14 selected villages and compared with officially reported data. Results indicate that the average yield per unit area at village scale can be forecasted with a root mean square error of 1.1 T ha -1 provided no damaging weather occurred during the final month before actual harvest. The methodology can be applied to other optical sensors with similar spectral bands in the visible/near-infrared and to different geographical regions provided that the relation between yield and spectral index is established.

  6. The SPIDER fission fragment spectrometer for fission product yield measurements

    DOE PAGES

    Meierbachtol, K.; Tovesson, F.; Shields, D.; ...

    2015-04-01

    We developed the SPectrometer for Ion DEtermination in fission Research (SPIDER) for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products has been utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). Moreover, the SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, has been assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission productsmore » from spontaneous fission of 252Cf. Individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). Finally, these mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.« less

  7. The SPIDER fission fragment spectrometer for fission product yield measurements

    SciTech Connect

    Meierbachtol, K.; Tovesson, F.; Shields, D.; Arnold, C.; Blakeley, R.; Bredeweg, T.; Devlin, M.; Hecht, A. A.; Heffern, L. E.; Jorgenson, J.; Laptev, A.; Mader, D.; O׳Donnell, J. M.; Sierk, A.; White, M.

    2015-04-01

    We developed the SPectrometer for Ion DEtermination in fission Research (SPIDER) for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products has been utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). Moreover, the SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, has been assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission products from spontaneous fission of 252Cf. Individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). Finally, these mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.

  8. Changes in diurnal temperature range and national cereal yields

    SciTech Connect

    Lobell, D

    2007-04-26

    Models of yield responses to temperature change have often considered only changes in average temperature (Tavg), with the implicit assumption that changes in the diurnal temperature range (DTR) can safely be ignored. The goal of this study was to evaluate this assumption using a combination of historical datasets and climate model projections. Data on national crop yields for 1961-2002 in the 10 leading producers of wheat, rice, and maize were combined with datasets on climate and crop locations to evaluate the empirical relationships between Tavg, DTR, and crop yields. In several rice and maize growing regions, including the two major nations for each crop, there was a clear negative response of yields to increased DTR. This finding reflects a nonlinear response of yields to temperature, which likely results from greater water and heat stress during hot days. In many other cases, the effects of DTR were not statistically significant, in part because correlations of DTR with other climate variables and the relatively short length of the time series resulted in wide confidence intervals for the estimates. To evaluate whether future changes in DTR are relevant to crop impact assessments, yield responses to projected changes in Tavg and DTR by 2046-2065 from 11 climate models were estimated. The mean climate model projections indicated an increase in DTR in most seasons and locations where wheat is grown, mixed projections for maize, and a general decrease in DTR for rice. These mean projections were associated with wide ranges that included zero in nearly all cases. The estimated impacts of DTR changes on yields were generally small (<5% change in yields) relative to the consistently negative impact of projected warming of Tavg. However, DTR changes did significantly affect yield responses in several cases, such as in reducing US maize yields and increasing India rice yields. Because DTR projections tend to be positively correlated with Tavg, estimates of yields

  9. Cotton Yield Assessment Using Remotely Sensed Drought Indices

    NASA Astrophysics Data System (ADS)

    Tsiros, Emmanouel; Dalezios, Nicolas R.

    2010-05-01

    Agricultural drought is a natural hazard having direct impacts to crop yield. One major application of remote sensing to agriculture is crop monitoring and assessment of vegetative stress, whereas satellite derived indices have been extensively used for identifying stress periods in crops. In this paper, two remotely sensed indices are used in order to quantify agricultural drought impact to cotton growth and estimate the final yield. In specific, Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) are used to monitor agricultural drought and estimate cotton yield. VCI and TCI characterises the moisture and thermal conditions of vegetation, respectively. VCI has excellent ability to detect drought, whereas TCI can identify thermal stresses that have direct impact in vegetation's health. The two indices are computed for 20 hydrological years, from October 1981 to September 2001, from NOAA/AVHRR ten -day composite images with 8x8 Km spatial resolution. VCI and TCI are correlated with yield data in order to identify the critical ten-day showing the highest correlation coefficient with the final yield. Two approaches are tested for deriving the empirical model for estimating cotton yield. The first uses VCI values and yield for developing the empirical relationship. The second incorporates VCI and TCI values along with yield data in a multiple regression analysis. In order to test the derived models on independent dataset, the period 1981-1996 is used for developing the empirical models, whereas the years 1997-2000 are used for validation. The study area is the Prefecture of Thessaly, the largest lowland formation of Greece and the country's largest agricultural centre, located in Central Greece. The critical ten-days for cotton yield regarding the values of the two indices are the 2nd and 3rd of July for VCI and TCI, respectively, corresponding to blooming to bolls open phenological stage. The two approaches gave similar results denoting the

  10. Explicit CP violation in the MSSM through gg{yields}H{sub 1{yields}{gamma}{gamma}}

    SciTech Connect

    Hesselbach, S.; Moretti, S.; Munir, S.; Poulose, P.

    2010-10-01

    We prove the strong sensitivity of the gg{yields}H{sub 1{yields}{gamma}{gamma}} cross section at the Large Hadron Collider on the explicitly CP-violating phases of the minimal supersymmetric standard model, where H{sub 1} is the lightest supersymmetric Higgs boson.

  11. Analysis of the trade-off between high crop yield and low yield instability at the global scale

    NASA Astrophysics Data System (ADS)

    Ben-Ari, Tamara; Makowski, David

    2016-10-01

    Yield dynamics of major crops species vary remarkably among continents. Worldwide distribution of cropland influences both the expected levels and the interannual variability of global yields. An expansion of cultivated land in the most productive areas could theoretically increase global production, but also increase global yield instability if the most productive regions are characterized by high interannual yield variability. In this letter, we use portfolio analysis to quantify the tradeoff between the expected values and the interannual variance of global yield. We compute optimal frontiers for four crop species i.e., maize, rice, soybean and wheat and show how the distribution of cropland among large world regions can be optimized to either increase expected global crop production or decrease its interannual variability. We also show that a preferential allocation of cropland in the most productive regions can increase global expected yield at the expense of yield stability. Theoretically, optimizing the distribution of a small fraction of total cultivated areas can help find a good compromise between low instability and high crop yields at the global scale.

  12. Water and Sediment Yields for Wala Dam Catchment Area

    NASA Astrophysics Data System (ADS)

    Tarawneh, E.

    2009-04-01

    Wala Watershed occupies the upper part of Al-Mujib Basin, Jordan, with Mediterranean climate, sparse inhabitants and moderate agriculture. The area, in spite of its limited water resources, is considered as an important water supply as it encompasses Al-Heidan springs and pumping wells, which supply Amman city with a considerable amount of water, it also includes Wala Dam that has been constructed for groundwater recharge purposes. Recognizing the threats of water and soil loss with the consequent sedimentation problems, and the benefits of watershed modeling techniques in studying such topics, this study comprised an application of the Soil and Water Assessment Tool (SWAT), associated with the Geographic Information System (GIS) to simulate the hydrology, soil erosion and sedimentation of Wala Dam Catchment Area. A set of hydrological techniques was utilized to simulate various components such as the Curve Number Method, the Rational Method and the Universal Soil Loss Equation (USLE) and modified USLE models. The use of such techniques in a GIS environment required certain types of data, which were collected and prepared either as database files such as the daily rainfall records, or as analytical GIS layers of soil, landuse/cover, drainage pattern and Digital Elevation Model (DEM). A weather generator was incorporated to generate any missed weather data. The area was discretized into 43 subbasins and 82 hydrologic response units. Two simulation series were performed using annual and monthly printout frequency. Several results were obtained including water and sediment yields at Wala Dam location with the respective delivery ratios, and spatial representation of precipitation, surface runoff, soil erosion, sediment and water yield on subbasin level. Model calibration and verification were carried out using flow rate and sediment yield data observed at Wala flow station and the results were satisfactory, indicating that this model can represent well the climatic

  13. Ensemble approach to wheat yield forecasting in Ukraine

    NASA Astrophysics Data System (ADS)

    Kussul, Nataliia; Kolotii, Andrii; Skakun, Sergii; Shelestov, Andrii; Kussul, Olga; Kravchenko, Oleksii

    2014-05-01

    Crop yield forecasting is an extremely important component of the agriculture monitoring domain. In our previous study [1], we assessed relative efficiency and feasibility of using an NDVI-based empirical model for winter wheat yield forecasting at oblast level in Ukraine. Though the NDVI-based model provides minimum data requirements, it has some limitations since NDVI is indirectly related just to biomass but not meteorological conditions. Therefore, it is necessary to assess satellite-derived parameters that incorporate meteorology while maintaining the requirement of minimum data inputs. The objective of the proposed paper is several-fold: (i) to assess efficiency of using biophysical satellite-derived parameters for crop yield forecasting for Ukraine and select the optimal ones based on rigorous feature selection procedure; (ii) to assimilate predictions made by models built on various satellite-derived parameters. Two new parameters are considered in the paper: (i) vegetation health index (VHI) at 4 km spatial resolution derived from a series of NOAA satellites; (ii) Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) derived from SPOT-VEGETATION at 1 km spatial resolution. VHI data are provided as weekly composites and FAPAR data are provided as decadal composites. The particular advantage of using VHI is that it incorporates moisture and thermal conditions of vegetation canopy, while FAPAR is directly related to the primary productivity of photosynthesis It is required to find a day of the year for which a parameter is taken and used in the empirical model. For this purpose, a Random Forest feature selection procedure is applied. It is found that VHI and FAPAR values taken in April-May provided the minimum error value when comparing to the official statistics, thus enabling forecasts 2-3 months prior to harvest, and this corresponds to results derived from LOOCV procedure. The best timing for making reliable yield forecasts is nearly the same

  14. Rice yields decline with higher night temperature from global warming

    PubMed Central

    Peng, Shaobing; Huang, Jianliang; Sheehy, John E.; Laza, Rebecca C.; Visperas, Romeo M.; Zhong, Xuhua; Centeno, Grace S.; Khush, Gurdev S.; Cassman, Kenneth G.

    2004-01-01

    The impact of projected global warming on crop yields has been evaluated by indirect methods using simulation models. Direct studies on the effects of observed climate change on crop growth and yield could provide more accurate information for assessing the impact of climate change on crop production. We analyzed weather data at the International Rice Research Institute Farm from 1979 to 2003 to examine temperature trends and the relationship between rice yield and temperature by using data from irrigated field experiments conducted at the International Rice Research Institute Farm from 1992 to 2003. Here we report that annual mean maximum and minimum temperatures have increased by 0.35°C and 1.13°C, respectively, for the period 1979–2003 and a close linkage between rice grain yield and mean minimum temperature during the dry cropping season (January to April). Grain yield declined by 10% for each 1°C increase in growing-season minimum temperature in the dry season, whereas the effect of maximum temperature on crop yield was insignificant. This report provides a direct evidence of decreased rice yields from increased nighttime temperature associated with global warming. PMID:15226500

  15. Hydrostatic Stress Effect on the Yield Behavior of Inconel 100

    NASA Technical Reports Server (NTRS)

    Allen, Phillip A.; Wilson, Christopher D.

    2003-01-01

    Classical metal plasticity theory assumes that hydrostatic stress has negligible effect on the yield and postyield behavior of metals. Recent reexaminations of classical theory have revealed a significant effect of hydrostatic stress on the yield behavior of various geometries. Fatigue tests and nonlinear finite element analyses (FEA) of Inconel 100 (IN100) equal-arm bend specimens and new monotonic tests and nonlinear finite element analyses of IN100 smooth tension, smooth compression, and double-edge notch tension (DENT) test specimens have revealed the effect of internal hydrostatic tensile stresses on yielding. Nonlinear FEA using the von Mises (yielding is independent of hydrostatic stress) and the Drucker-Prager (yielding is linearly dependent on hydrostatic stress) yield functions were performed. A new FEA constitutive model was developed that incorporates a pressure-dependent yield function with combined multilinear kinematic and multilinear isotropic hardening using the ABAQUS user subroutine (UMAT) utility. In all monotonic tensile test cases, the von Mises constitutive model, overestimated the load for a given displacement or strain. Considering the failure displacements or strains for the DENT specimen, the Drucker-Prager FEM s predicted loads that were approximately 3% lower than the von Mises values. For the failure loads, the Drucker Prager FEM s predicted strains that were up to 35% greater than the von Mises values. Both the Drucker-Prager model and the von Mises model performed equally-well in simulating the equal-arm bend fatigue test.

  16. Statistical estimates to emulate yields from global gridded crop models

    NASA Astrophysics Data System (ADS)

    Blanc, Elodie

    2016-04-01

    This study provides a statistical emulator of crop yields based on global gridded crop model simulations from the Inter-Sectoral Impact Model Intercomparison Project Fast Track project. The ensemble of simulations is used to build a panel of annual crop yields from five crop models and corresponding monthly weather variables for over a century at the grid cell level. This dataset is then used to estimate, for each crop and gridded crop model, the statistical relationship between yields and temperature, precipitation and carbon dioxide. This study considers a new functional form to better capture the non-linear response of yields to weather, especially for extreme temperature and precipitation events. In- and out-of-sample validations show that the statistical models are able to closely replicate crop yields projected by the crop models and perform well out-of-sample. This study therefore provides a reliable and accessible alternative to global gridded crop yield models. By emulating crop yields for several models using parsimonious equations, the tools will be useful for climate change impact assessments and to account for uncertainty in crop modeling.

  17. Design and chemical evaluation of reduced machine-yield cigarettes.

    PubMed

    McAdam, K G; Gregg, E O; Bevan, M; Dittrich, D J; Hemsley, S; Liu, C; Proctor, C J

    2012-02-01

    Experimental cigarettes (ECs) were made by combining technological applications that individually reduce the machine measured yields of specific toxicants or groups of toxicants in mainstream smoke (MS). Two tobacco blends, featuring a tobacco substitute sheet or a tobacco blend treatment, were combined with filters containing an amine functionalised resin (CR20L) and/or a polymer-derived, high activity carbon adsorbent to generate three ECs with the potential for generating lower smoke toxicant yields than conventional cigarettes. MS yields of smoke constituents were determined under 4 different smoking machine conditions. Health Canada Intense (HCI) machine smoking conditions gave the highest MS yields for nicotine-free dry particulate matter and for most smoke constituents measured. Toxicant yields from the ECs were compared with those from two commercial comparator cigarettes, three scientific control cigarettes measured contemporaneously and with published data on 120 commercial cigarettes. The ECs were found to generate some of the lowest machine yields of toxicants from cigarettes for which published HCI smoke chemistry data are available; these comparisons therefore confirm that ECs with reduced MS machine toxicant yields compared to commercial cigarettes can be produced. The results encourage further work examining human exposure to toxicants from these cigarettes, including human biomarker studies.

  18. Effect of warming temperatures on US wheat yields.

    PubMed

    Tack, Jesse; Barkley, Andrew; Nalley, Lawton Lanier

    2015-06-02

    Climate change is expected to increase future temperatures, potentially resulting in reduced crop production in many key production regions. Research quantifying the complex relationship between weather variables and wheat yields is rapidly growing, and recent advances have used a variety of model specifications that differ in how temperature data are included in the statistical yield equation. A unique data set that combines Kansas wheat variety field trial outcomes for 1985-2013 with location-specific weather data is used to analyze the effect of weather on wheat yield using regression analysis. Our results indicate that the effect of temperature exposure varies across the September-May growing season. The largest drivers of yield loss are freezing temperatures in the Fall and extreme heat events in the Spring. We also find that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure to freezing temperatures. Our analysis indicates that there exists a tradeoff between average (mean) yield and ability to resist extreme heat across varieties. More-recently released varieties are less able to resist heat than older lines. Our results also indicate that warming effects would be partially offset by increased rainfall in the Spring. Finally, we find that the method used to construct measures of temperature exposure matters for both the predictive performance of the regression model and the forecasted warming impacts on yields.

  19. Closing yield gaps in China by empowering smallholder farmers

    NASA Astrophysics Data System (ADS)

    Zhang, Weifeng; Cao, Guoxin; Li, Xiaolin; Zhang, Hongyan; Wang, Chong; Liu, Quanqing; Chen, Xinping; Cui, Zhenling; Shen, Jianbo; Jiang, Rongfeng; Mi, Guohua; Miao, Yuxin; Zhang, Fusuo; Dou, Zhengxia

    2016-09-01

    Sustainably feeding the world’s growing population is a challenge, and closing yield gaps (that is, differences between farmers’ yields and what are attainable for a given region) is a vital strategy to address this challenge. The magnitude of yield gaps is particularly large in developing countries where smallholder farming dominates the agricultural landscape. Many factors and constraints interact to limit yields, and progress in problem-solving to bring about changes at the ground level is rare. Here we present an innovative approach for enabling smallholders to achieve yield and economic gains sustainably via the Science and Technology Backyard (STB) platform. STB involves agricultural scientists living in villages among farmers, advancing participatory innovation and technology transfer, and garnering public and private support. We identified multifaceted yield-limiting factors involving agronomic, infrastructural, and socioeconomic conditions. When these limitations and farmers’ concerns were addressed, the farmers adopted recommended management practices, thereby improving production outcomes. In one region in China, the five-year average yield increased from 67.9% of the attainable level to 97.0% among 71 leading farmers, and from 62.8% to 79.6% countywide (93,074 households); this was accompanied by resource and economic benefits.

  20. General lower bounds for b{yields}d penguin processes

    SciTech Connect

    Fleischer, Robert; Recksiegel, Stefan

    2005-03-01

    For the exploration of flavor physics, b{yields}d penguin processes are an important aspect, with the prominent example of B{sub d}{sup 0}{yields}K{sup 0}K{sup 0}. We recently derived lower bounds for the CP-averaged branching ratio of this channel in the standard model; they were found to be very close to the corresponding experimental upper limits, thereby suggesting that B{sub d}{sup 0}{yields}K{sup 0}K{sup 0} should soon be observed. In fact, the BABAR Collaboration subsequently announced the first signals of this transition. Here we point out that it is also possible to derive lower bounds for B{yields}{rho}{gamma} decays, which are again surprisingly close to the current experimental upper limits. We show that these bounds are realizations of a general bound that holds within the standard model for b{yields}d penguin processes, allowing further applications to decays of the kind B{sup {+-}}{yields}K{sup (}*{sup ){+-}}K{sup (}*{sup )} and B{sup {+-}}{yields}{pi}{sup {+-}}l{sup +}l{sup -}, {rho}{sup {+-}}l{sup +}l{sup -}.

  1. Closing yield gaps in China by empowering smallholder farmers.

    PubMed

    Zhang, Weifeng; Cao, Guoxin; Li, Xiaolin; Zhang, Hongyan; Wang, Chong; Liu, Quanqing; Chen, Xinping; Cui, Zhenling; Shen, Jianbo; Jiang, Rongfeng; Mi, Guohua; Miao, Yuxin; Zhang, Fusuo; Dou, Zhengxia

    2016-09-29

    Sustainably feeding the world's growing population is a challenge, and closing yield gaps (that is, differences between farmers' yields and what are attainable for a given region) is a vital strategy to address this challenge. The magnitude of yield gaps is particularly large in developing countries where smallholder farming dominates the agricultural landscape. Many factors and constraints interact to limit yields, and progress in problem-solving to bring about changes at the ground level is rare. Here we present an innovative approach for enabling smallholders to achieve yield and economic gains sustainably via the Science and Technology Backyard (STB) platform. STB involves agricultural scientists living in villages among farmers, advancing participatory innovation and technology transfer, and garnering public and private support. We identified multifaceted yield-limiting factors involving agronomic, infrastructural, and socioeconomic conditions. When these limitations and farmers' concerns were addressed, the farmers adopted recommended management practices, thereby improving production outcomes. In one region in China, the five-year average yield increased from 67.9% of the attainable level to 97.0% among 71 leading farmers, and from 62.8% to 79.6% countywide (93,074 households); this was accompanied by resource and economic benefits.

  2. The Safe Yield and Climatic Variability: Implications for Groundwater Management.

    PubMed

    Loáiciga, Hugo A

    2016-10-25

    Methods for calculating the safe yield are evaluated in this paper using a high-quality and long historical data set of groundwater recharge, discharge, extraction, and precipitation in a karst aquifer. Consideration is given to the role that climatic variability has on the determination of a climatically representative period with which to evaluate the safe yield. The methods employed to estimate the safe yield are consistent with its definition as a long-term average extraction rate that avoids adverse impacts on groundwater. The safe yield is a useful baseline for groundwater planning; yet, it is herein shown that it is not an operational rule that works well under all climatic conditions. This paper shows that due to the nature of dynamic groundwater processes it may be most appropriate to use an adaptive groundwater management strategy that links groundwater extraction rates to groundwater discharge rates, thus achieving a safe yield that represents an estimated long-term sustainable yield. An example of the calculation of the safe yield of the Edwards Aquifer (Texas) demonstrates that it is about one-half of the average annual recharge.

  3. Crop yield forecast for France based on the CNDVI technique

    NASA Astrophysics Data System (ADS)

    Vignolles, Cecile; Genovese, Giampiero; Negre, Thierry

    2002-01-01

    The objective of the research presented here is to obtain crop yield forecasts basing on the information of NOAA- AVHRR/NDVI and CORINE land cover data. The methodology described in Genovese et al. (2001) consists of extracting yield indicators from CNDVI (CORINE-NDVI) time series at a regional scale. In Genovese et al. (2001), a preliminary study on Spain for a four year span (1995-1998) has shown that indicators extracted from the CNDVI profiles can be more closely related to crop yield performances than indicators based on simple NDVI profiles. To prove the validity of this approach, a more complete experiment was realised on France for the same period. Linear regressions were calculated using regional CNDVI-based indicators versus regional wheat yield data (EUROSTAT NEW CRONOS database). A French national wheat yield forecast was then derived by aggregation of regional results. The goodness of the results confirms the advantages of such approach. The combination of a CNDVI-based indicator with the linear trend observed on yields between 1975 and 1997 led to very good regression criteria (coefficient of determination higher than 86%) and allowed a satisfying prediction of wheat yields.

  4. Soybean yield in relation to distance from the Itaipu reservoir

    NASA Astrophysics Data System (ADS)

    de Faria, Rogério Teixeira; Junior, Ruy Casão; Werner, Simone Silmara; Junior, Luiz Antônio Zanão; Hoogenboom, Gerrit

    2016-07-01

    Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

  5. Soybean yield in relation to distance from the Itaipu reservoir.

    PubMed

    de Faria, Rogério Teixeira; Junior, Ruy Casão; Werner, Simone Silmara; Junior, Luiz Antônio Zanão; Hoogenboom, Gerrit

    2016-07-01

    Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

  6. Hydrostatic Stress Effect On the Yield Behavior of Inconel 100

    NASA Technical Reports Server (NTRS)

    Allen, Phillip A.; Wilson, Christopher D.

    2002-01-01

    Classical metal plasticity theory assumes that hydrostatic stress has no effect on the yield and postyield behavior of metals. Recent reexaminations of classical theory have revealed a significant effect of hydrostatic stress on the yield behavior of notched geometries. New experiments and nonlinear finite element analyses (FEA) of Inconel 100 (IN 100) equal-arm bend and double-edge notch tension (DENT) test specimens have revealed the effect of internal hydrostatic tensile stresses on yielding. Nonlinear FEA using the von Mises (yielding is independent of hydrostatic stress) and the Drucker-Prager (yielding is linearly dependent on hydrostatic stress) yield functions was performed. In all test cases, the von Mises constitutive model, which is independent of hydrostatic pressure, overestimated the load for a given displacement or strain. Considering the failure displacements or strains, the Drucker-Prager FEMs predicted loads that were 3% to 5% lower than the von Mises values. For the failure loads, the Drucker Prager FEMs predicted strains that were 20% to 35% greater than the von Mises values. The Drucker-Prager yield function seems to more accurately predict the overall specimen response of geometries with significant internal hydrostatic stress influence.

  7. Nicotine yield and measures of cigarette smoke exposure in a large population: are lower-yield cigarettes safer?

    PubMed Central

    Maron, D J; Fortmann, S P

    1987-01-01

    We examined the relationship of machine-estimated nicotine yield by cigarette brand with the level of cigarette consumption and two biochemical measures of smoke exposure (expired-air carbon monoxide and plasma thiocyanate) in a large, population-based sample of smokers (N = 713). The lower the nicotine yield of the cigarette, the greater the number of cigarettes smoked per day. Prior to adjusting for number of cigarettes smoked per day, nicotine yield was not related to the actual measures of smoke exposure. Smokers of ultralow-yield cigarettes had laboratory tests of smoke exposure which were not significantly different from those of smokers of higher-yield brands. Only after adjustment for number of cigarettes smoked per day did nicotine yield become significantly related to expired-air carbon monoxide and to plasma thiocyanate. In multivariate analysis, the number of cigarettes smoked per day accounted for 28 per cent and 22 per cent of the variance in observed expired-air carbon monoxide and plasma thiocyanate levels, respectively, whereas nicotine yield accounted for only 1 per cent and 2 per cent of the variance, respectively. The relative lack of an effect of nicotine yield on the biochemical measure appears to be due to the fact that smokers of lower nicotine brands smoked more cigarettes per day, thereby compensating for reduced delivery of smoke products. Our data do not support the concept that ultralow-yield cigarettes are less hazardous than others. Machine estimates suggesting low nicotine yield underrepresent actual human consumption of harmful cigarette constituents. PMID:3565645

  8. Combining information from B{yields}{pi}{pi} and B{yields}{pi}{rho},{pi}{omega} decays

    SciTech Connect

    Sowa, M.; Zenczykowski, P.

    2005-06-01

    We consider the B{yields}{pi}{pi} and B{yields}{pi}{rho},{pi}{omega} decays alongside each other, taking into account the contributions from all individual penguin amplitudes generated by the internal t, c, and u quarks. We argue that three ratios of penguin amplitudes, each for a different internal quark, formed by dividing the individual penguin amplitude in B{yields}{pi}{pi} by the corresponding amplitude in B{yields}{pi}{rho},{pi}{omega}, should be equal. We study the implications of the assumed existence of this connection between B{yields}{pi}{pi} and B{yields}{pi}{rho},{pi}{omega}. First, accepting that in the B{yields}{pi}{pi} decays the ratio C/T of the color-suppressed factorization amplitude C to the tree factorization amplitude T is negligible, we determine the ratio of individual penguin amplitudes. Then, from the B{yields}{pi}{rho},{pi}{omega} data, we extract the effective (i.e. possibly containing some penguin terms) tree and the effective color-suppressed amplitudes relevant for these processes, and the corresponding solutions for the factorization amplitudes. Finally, we argue that the C/T ratio in B{yields}{pi}{pi} should be identical to its counterpart in B{yields}{pi}{rho},{pi}{omega} (relevant for pion emission from the decaying b quark). This constraint permits the determination of C/T and of other amplitude ratios directly from the data. Although the |C/T| ratio extracted from the available data still carries a substantial error, it is consistent with the expected value of 0.25-0.5.

  9. Numerical Modeling for Yield Pillar Design: A Case Study

    NASA Astrophysics Data System (ADS)

    Li, Wenfeng; Bai, Jianbiao; Peng, Syd; Wang, Xiangyu; Xu, Ying

    2015-01-01

    Two single-entry gateroad systems employing a yield pillar for bump control in a Chinese coal mine were introduced. The overburden depth of the longwall panels was approximately 390 m. When the width/height (W/H) ratio of the yield pillar was 2.67, coal bumps in the tailgate occurred in front of the longwall retreating face. However, in another panel, the coal bump was eliminated because the W/H ratio was reduced to 1.67. Under this condition, instrumentation results indicated that the roof-to-floor and rib-to-rib convergences reached 1,050 and 790 mm, respectively, during longwall retreat. The numerical model was used to back-analyze the two cases of yield pillar application in the hope to find the principle for yield pillar design. In order to improve the reliability of the numerical model, the strain-hardening gob and strain-softening pillar materials were meticulously calibrated, and the coal/rock interface strength was determined by laboratory direct shear tests. The results of the validated model indicate that if the W/H ratio of the yield pillar equals 1.67, the peak vertical stress in the panel rib (37.7 MPa) is much larger than that in the yield pillar (21.1 MPa); however, the peak vertical stress in the panel rib (30.87 MPa) is smaller than that in the yield pillar (36 MPa) when the W/H ratio of yield pillar is 2.67. These findings may be helpful to the design of yield pillars for bump control.

  10. Empirical Geographic Modeling of Switchgrass Yields in the United States

    SciTech Connect

    Jager, Yetta; Baskaran, Latha Malar; Brandt, Craig C; Davis, Ethan; Gunderson, Carla A; Wullschleger, Stan D

    2010-01-01

    Switchgrass (Panicum virgatum L.) is a perennial grass native to the US that has been studied as a sustainable source of biomass fuel. Although many field-scale studies have examined the potential of this grass as a bioenergy crop, these studies have not been integrated. In this study, we present an empirical model for switchgrass yield and use this model to predict yield for the conterminous US. We added environmental covariates to assembled yield data from field trials based on geographic location. We developed empirical models based on these data. The resulting empirical models, which account for spatial autocorrelation in the field data, provide the ability to estimate yield from factors associated with climate, soils, and management for both lowland and upland varieties of switchgrass. Yields of both ecotypes showed quadratic responses to temperature, increased with precipitation and minimum winter temperature, and decreased with stand age. Only the upland ecotype showed a positive response to our index of soil wetness and only the lowland ecotype showed a positive response to fertilizer. We view this empirical modeling effort, not as an alternative to mechanistic plant-growth modeling, but rather as a first step in the process of functional validation that will compare patterns produced by the models with those found in data. For the upland variety, the correlation between measured yields and yields predicted by empirical models was 0.62 for the training subset and 0.58 for the test subset. For the lowland variety, the correlation was 0.46 for the training subset and 0.19 for the test subset. Because considerable variation in yield remains unexplained, it will be important in future to characterize spatial and local sources of uncertainty associated with empirical yield estimates.

  11. Closing yield gaps through nutrient and water management.

    PubMed

    Mueller, Nathaniel D; Gerber, James S; Johnston, Matt; Ray, Deepak K; Ramankutty, Navin; Foley, Jonathan A

    2012-10-11

    In the coming decades, a crucial challenge for humanity will be meeting future food demands without undermining further the integrity of the Earth's environmental systems. Agricultural systems are already major forces of global environmental degradation, but population growth and increasing consumption of calorie- and meat-intensive diets are expected to roughly double human food demand by 2050 (ref. 3). Responding to these pressures, there is increasing focus on 'sustainable intensification' as a means to increase yields on underperforming landscapes while simultaneously decreasing the environmental impacts of agricultural systems. However, it is unclear what such efforts might entail for the future of global agricultural landscapes. Here we present a global-scale assessment of intensification prospects from closing 'yield gaps' (differences between observed yields and those attainable in a given region), the spatial patterns of agricultural management practices and yield limitation, and the management changes that may be necessary to achieve increased yields. We find that global yield variability is heavily controlled by fertilizer use, irrigation and climate. Large production increases (45% to 70% for most crops) are possible from closing yield gaps to 100% of attainable yields, and the changes to management practices that are needed to close yield gaps vary considerably by region and current intensity. Furthermore, we find that there are large opportunities to reduce the environmental impact of agriculture by eliminating nutrient overuse, while still allowing an approximately 30% increase in production of major cereals (maize, wheat and rice). Meeting the food security and sustainability challenges of the coming decades is possible, but will require considerable changes in nutrient and water management.

  12. High-Yield D-T Neutron Generator

    SciTech Connect

    Ludewigt, B.A.; Wells, R.P.; Reijonen, J.

    2006-11-15

    A high-yield D-T neutron generator has been developed for neutron interrogation in homeland security applications such as cargo screening. The generator has been designed as a sealed tube with a performance goal of producing 5 {center_dot} 10{sup 11} n/s over a long lifetime. The key generator components developed are a radio-frequency (RF) driven ion source and a beam-loaded neutron production target that can handle a beam power of 10 kW. The ion source can provide a 100 mA D{sup +}/T{sup +} beam current with a high fraction of atomic species and can be pulsed up to frequencies of several kHz for pulsed neutron generator operation. Testing in D-D operation has been started.

  13. Methods to assess factors that influence grass seed yield

    NASA Astrophysics Data System (ADS)

    Louhaichi, Mounir

    A greater than 10-fold increase in Canada goose (Branta canadensis ) populations over the past several years has resulted in concerns over grazing impacts on grass seed production in the mid-Willamette Valley, Oregon. This study was designed to develop methods to quantify and statistically analyze goose-grazing impacts on seed yields of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.). Yield-mapping-system equipped combines, incorporating global positioning system (GPS) technology, were used to measure and map yields. Image processing of ground-level photography to estimate crop cover and other relevant observations were spatially located via GPS to establish spatial-temporal goose grazing patterns. We sampled each field semi-monthly from mid-winter through spring. Spatially located yield data, soils information, exclosure locations, and grazing patterns were integrated via geographical information system (GIS) technology. To avoid concerns about autocorrelation, a bootstrapping procedure for subsampling spatially contiguous seed yield data was used to organize the data for appropriate use of analysis of variance. The procedure was used to evaluate grazing impacts on seed yield for areas of fields with different soils and with differential timing and intensity of goose grazing activity. We also used a standard paired-plot procedure, involving exclosures and associated plots available for grazing. The combination of spatially explicit photography and yield mapping, integrated with GIS, proved effective in establishing cause-and-effect relationships between goose grazing and seed yield differences. Exclosures were essential for providing nongrazed controls. Both statistical approaches were effective in documenting goose-grazing impacts. Paired-plots were restricted by small size and few numbers and did not capture grazing impacts as effectively as comparison of larger areas to exclosures. Bootstrapping to subsample larger areas of

  14. Spatial and Temporal Uncertainty of Crop Yield Aggregations

    NASA Technical Reports Server (NTRS)

    Porwollik, Vera; Mueller, Christoph; Elliott, Joshua; Chryssanthacopoulos, James; Iizumi, Toshichika; Ray, Deepak K.; Ruane, Alex C.; Arneth, Almut; Balkovic, Juraj; Ciais, Philippe; Deryng, Delphine; Folberth, Christian; Izaurralde, Robert C.; Jones, Curtis D.; Khabarov, Nikolay; Lawrence, Peter J.; Liu, Wenfeng; Pugh, Thomas A. M.; Reddy, Ashwan; Sakurai, Gen; Schmid, Erwin; Wang, Xuhui; Wu, Xiuchen; de Wit, Allard

    2016-01-01

    The aggregation of simulated gridded crop yields to national or regional scale requires information on temporal and spatial patterns of crop-specific harvested areas. This analysis estimates the uncertainty of simulated gridded yield time series related to the aggregation with four different harvested area data sets. We compare aggregated yield time series from the Global Gridded Crop Model Inter-comparison project for four crop types from 14 models at global, national, and regional scale to determine aggregation-driven differences in mean yields and temporal patterns as measures of uncertainty. The quantity and spatial patterns of harvested areas differ for individual crops among the four datasets applied for the aggregation. Also simulated spatial yield patterns differ among the 14 models. These differences in harvested areas and simulated yield patterns lead to differences in aggregated productivity estimates, both in mean yield and in the temporal dynamics. Among the four investigated crops, wheat yield (17% relative difference) is most affected by the uncertainty introduced by the aggregation at the global scale. The correlation of temporal patterns of global aggregated yield time series can be as low as for soybean (r = 0.28).For the majority of countries, mean relative differences of nationally aggregated yields account for10% or less. The spatial and temporal difference can be substantial higher for individual countries. Of the top-10 crop producers, aggregated national multi-annual mean relative difference of yields can be up to 67% (maize, South Africa), 43% (wheat, Pakistan), 51% (rice, Japan), and 427% (soybean, Bolivia).Correlations of differently aggregated yield time series can be as low as r = 0.56 (maize, India), r = 0.05*Corresponding (wheat, Russia), r = 0.13 (rice, Vietnam), and r = -0.01 (soybean, Uruguay). The aggregation to sub-national scale in comparison to country scale shows that spatial uncertainties can cancel out in countries with

  15. Yield enhancement methodologies for 90-nm technology and beyond

    NASA Astrophysics Data System (ADS)

    Allgair, John; Carey, Todd; Dougan, James; Etnyre, Tony; Langdon, Nate; Murray, Brooke

    2006-03-01

    In order to stay competitive in the rapidly advancing international semiconductor industry, a manufacturing company needs to continually focus on several areas including rapid yield learning, manufacturing cost, statistical process control limits, process yield, equipment availability, cycle time, turns per direct labor hour, customer on time delivery and zero customer defects. To hold a competitive position in the semiconductor market, performance to these measurable factors mut be maintained regardless of the technology generation. In this presentation, the methodology applied by Freescale Semiconductor to achieve the fastest yield learning curve in the industry, as cited by Dr. Robert Leachman of UC Berkley in 2003, will be discussed.

  16. Influence of soil properties on crop yield: a multivariate statistical approach

    NASA Astrophysics Data System (ADS)

    Juhos, Katalin; Szabó, Szilárd; Ladányi, Márta

    2015-10-01

    The aim of the study was to reveal the relationship between soil properties and grain yields in an East Hungarian region in regard to weather conditions. Soil pH, EC, carbonate content, soluble and exchangeable Na+, texture, organic carbon, and nutrient contents were analyzed. Yield data (maize, winter wheat, sunflower) from 10 years were standardized using calculated relative yield and yield variability. Weather conditions were characterized by the Pálfai Drought Index. Hydrological and topographical conditions were characterized by the mean altitude of plots. The ranged pedological variables were analyzed using principal component analysis with Varimax rotation. The principal component analysis showed that three principal components with eigenvalues greater than one explained more than 84% of the variability of soil properties. The multiple stepwise principal regression analysis showed that the mean relative yield was linearly correlated with all the three principal component factors (R2 = 0.49, p < 0.01). In droughty years, the sodification, salinization, soil texture, and nutrient contents determined the yields (R2 = 0.30, p < 0.05). In humid years, the lower topographical position, soil organic matter, and nutrient contents were the main limiting factors (R2 = 0.40, p < 0.01). Consequently, the variables can effectively explain the yield variability together with other variables as linear combinations.

  17. B{yields}X{sub s}{gamma} constraints on the top quark anomalous t{yields}c{gamma} coupling

    SciTech Connect

    Yuan Xingbo; Hao Yang; Yang Yadng

    2011-01-01

    Observation of the top quark flavor changing neutral process t{yields}c+{gamma} at the LHC would be the signal of physics beyond the standard model. If anomalous t{yields}c{gamma} coupling exists, it will affect the precisely measured B(B{yields}X{sub s}{gamma}). In this paper, we study the effects of a dimension 5 anomalous tc{gamma} operator in B{yields}X{sub s}{gamma} decay to derive constraints on its possible strength. It is found that, for real anomalous t{yields}c{gamma} coupling {kappa}{sub tcR}{sup {gamma}}, the constraints correspond to the upper bounds B(t{yields}c+{gamma})<6.54x10{sup -5} (for {kappa}{sub tcR}{sup {gamma}}>0) and B(t{yields}c+{gamma})<8.52x10{sup -5} (for {kappa}{sub tcR}{sup {gamma}}<0), respectively, which are about the same order as the 5{sigma} discovery potential of ATLAS (9.4x10{sup -5}) and slightly lower than that of CMS (4.1x10{sup -4}) with 10 fb{sup -1} integrated luminosity operating at {radical}(s)=14 TeV.

  18. Lepton flavor violating l{yields}l{sup '}{gamma} and Z{yields}ll{sup '} decays induced by scalar leptoquarks

    SciTech Connect

    Benbrik, Rachid; Chua, C.-K.

    2008-10-01

    Motivated by the recent muon g-2 data, we study the lepton flavor violating (LFV) l{yields}l{sup '}{gamma} and Z{yields}ll{sup '} (l, l{sup '}=e, {mu}, {tau} decays with l{ne}l{sup '}) in a scalar leptoquark model. Leptoquarks can produce sizable LFV l{yields}l{sup '}{gamma} decay rates that can be easily reached by present or near future experiments. Leptoquark masses and couplings are constrained by the muon g-2 data and the current l{yields}l{sup '}{gamma} bounds. We predict Br(Z{yields}{tau}{sup {+-}}e{sup {+-}}) reaching the present limit (10{sup -5}) and Br(Z{yields}{mu}{sup {+-}}{tau}{sup {+-}}) reaching 2x10{sup -8}, which will be accessible by future linear colliders, whereas, the current bounds on LFV impose very strong constraints on the Br(Z{yields}{mu}{sup {+-}}e{sup {+-}}) and the ratio is too low to be observed in the near future.

  19. Biaxial Yield Surface Investigation of Polymer-Matrix Composites

    PubMed Central

    Ye, Junjie; Qiu, Yuanying; Zhai, Zhi; He, Zhengjia

    2013-01-01

    This article presents a numerical technique for computing the biaxial yield surface of polymer-matrix composites with a given microstructure. Generalized Method of Cells in combination with an Improved Bodner-Partom Viscoplastic model is used to compute the inelastic deformation. The validation of presented model is proved by a fiber Bragg gratings (FBGs) strain test system through uniaxial testing under two different strain rate conditions. On this basis, the manufacturing process thermal residual stress and strain rate effect on the biaxial yield surface of composites are considered. The results show that the effect of thermal residual stress on the biaxial yield response is closely dependent on loading conditions. Moreover, biaxial yield strength tends to increase with the increasing strain rate. PMID:23529150

  20. Estimating ethanol yield from switchgrass strains using NIRS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying actual and theoretical ethanol yields from biomass conversion processes requires expensive, complex fermentation tests and extensive laboratory analyses of the biomass sample with costs exceeding $300 per sample. Near infrared reflectance spectroscopy (NIRS) is a non-destructive technolo...

  1. High pressure intensification of cassava resistant starch (RS3) yields.

    PubMed

    Lertwanawatana, Proyphon; Frazier, Richard A; Niranjan, Keshavan

    2015-08-15

    Cassava starch, typically, has resistant starch type 3 (RS3) content of 2.4%. This paper shows that the RS3 yields can be substantially enhanced by debranching cassava starch using pullulanase followed by high pressure or cyclic high-pressure annealing. RS3 yield of 41.3% was obtained when annealing was carried out at 400MPa/60°C for 15 min, whereas it took nearly 8h to obtain the same yield under conventional atmospheric annealing at 60°C. The yield of RS3 could be further significantly increased by annealing under 400 MPa/60°C pressure for 15 min followed by resting at atmospheric pressure for 3h 45 min, and repeating this cycle for up to six times. Microstructural surface analysis of the product under a scanning electron microscope showed an increasingly rigid density of the crystalline structure formed, confirming higher RS3 content.

  2. Optimizing the yield and selectivity of high purity nanoparticle clusters

    NASA Astrophysics Data System (ADS)

    Pease, Leonard F.

    2011-05-01

    Here we investigate the parameters that govern the yield and selectivity of small clusters composed of nanoparticles using a Monte Carlo simulation that accounts for spatial and dimensional distributions in droplet and nanoparticle density and size. Clustering nanoparticles presents a powerful paradigm with which to access properties not otherwise available using individual molecules, individual nanoparticles or bulk materials. However, the governing parameters that precisely tune the yield and selectivity of clusters fabricated via an electrospray droplet evaporation method followed by purification with differential mobility analysis (DMA) remain poorly understood. We find that the product of the electrospray droplet mean diameter to the third power and nanoparticle concentration governs the yield of individual clusters, while the ratio of the nanoparticle standard deviation to the mean diameter governs the selectivity. The resulting, easily accessible correlations may be used to minimize undesirable clustering, such as protein aggregation in the biopharmaceutical industry, and maximize the yield of a particular type of cluster for nanotechnology and energy applications.

  3. Yield-stress fluid drop impact on heated surfaces

    NASA Astrophysics Data System (ADS)

    Blackwell, Brendan; Wu, Alex; Ewoldt, Randy

    2015-11-01

    Yield-stress fluids, including gels and pastes, are effectively fluid at high stress and solid at low stress. In liquid-solid impacts, these fluids can stick and accumulate where they impact, motivating several applications of these rheologically-complex materials. Here we use high-speed imaging to experimentally study liquid-solid impact of yield-stress fluids on heated surfaces. At low temperatures yield-stress fluids tend to stick to surfaces and leave a coating layer. At sufficiently high temperatures the Leidenfrost effect can be observed, wherein a layer of vapor is created between the material and the surface due to rapid boiling, which can prevent a droplet of yield-stress fluid from sticking to the surface. In this study rheological material properties, drop size, drop velocity, and surface temperature are varied to characterize behavioral regimes. Material sticking to and releasing from the surface is observed as a function of the input parameters.

  4. Unused natural variation can lift yield barriers in plant breeding.

    PubMed

    Gur, Amit; Zamir, Dani

    2004-10-01

    Natural biodiversity is an underexploited sustainable resource that can enrich the genetic basis of cultivated plants with novel alleles that improve productivity and adaptation. We evaluated the progress in breeding for increased tomato (Solanum lycopersicum) yield using genotypes carrying a pyramid of three independent yield-promoting genomic regions introduced from the drought-tolerant green-fruited wild species Solanum pennellii. Yield of hybrids parented by the pyramided genotypes was more than 50% higher than that of a control market leader variety under both wet and dry field conditions that received 10% of the irrigation water. This demonstration of the breaking of agricultural yield barriers provides the rationale for implementing similar strategies for other agricultural organisms that are important for global food security.

  5. Optimizing Dense Plasma Focus Neutron Yields with Fast Gas Jets

    NASA Astrophysics Data System (ADS)

    McMahon, Matthew; Kueny, Christopher; Stein, Elizabeth; Link, Anthony; Schmidt, Andrea

    2016-10-01

    We report a study using the particle-in-cell code LSP to perform fully kinetic simulations modeling dense plasma focus (DPF) devices with high density gas jets on axis. The high density jet models fast gas puffs which allow for more mass on axis while maintaining the optimal pressure for the DPF. As the density of the jet compared to the background fill increases we find the neutron yield increases, as does the variability in the neutron yield. Introducing perturbations in the jet density allow for consistent seeding of the m =0 instability leading to more consistent ion acceleration and higher neutron yields with less variability. Jets with higher on axis density are found to have the greatest yield. The optimal jet configuration is explored. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. Relative yield of two transferrin phenotypes in coho salmon

    USGS Publications Warehouse

    McIntyre, John D.; Johnson, A. Kenneth

    1977-01-01

    Experimental groups of coho salmon (Oncorhynchus kisutch) of transferring types AA and AC were compared to determine relative growth and survival before release, yields from the fishery, and returns of fish to the hatchery as 2- and 3-yr-olds. In the hatchery, growth was faster and survival higher in the AA than in the AC types. However, yields of AA and AC types were equal, although the yield of AC types as 3-yr-olds was greater than that of AA types because more of the AA males matured in 2 years. We concluded that it would be futile to attempt to increase the yield of coho salmon by maximizing the frequency of biochemical phenotypes that display only a temporary advantage over other types.

  7. An approximate yield criterion for anisotropic porous media

    NASA Astrophysics Data System (ADS)

    Keralavarma, Shyam M.; Benzerga, A. Amine

    2008-09-01

    We derive a new yield function for materials containing spheroidal voids embedded in a perfectly-plastic anisotropic Hill-type matrix. Using approximate limit-analysis and a restricted set of trial velocity fields, analytical yield loci are derived for a hollow, spheroidal volume element containing a confocal spheroidal void. Alternatively, the yield loci are determined through numerical limit-analysis, i.e., employing a larger set of velocity fields. The numerical results are quasi-exact for transversely isotropic materials under axisymmetric loading. We show that an enhanced description of admissible microscopic deformation fields results in a close agreement between analytical and numerical macroscopic yield loci. To cite this article: S.M. Keralavarma, A.A. Benzerga, C. R. Mecanique 336 (2008).

  8. Yield of illicit indoor cannabis cultivation in the Netherlands.

    PubMed

    Toonen, Marcel; Ribot, Simon; Thissen, Jac

    2006-09-01

    To obtain a reliable estimation on the yield of illicit indoor cannabis cultivation in The Netherlands, cannabis plants confiscated by the police were used to determine the yield of dried female flower buds. The developmental stage of flower buds of the seized plants was described on a scale from 1 to 10 where the value of 10 indicates a fully developed flower bud ready for harvesting. Using eight additional characteristics describing the grow room and cultivation parameters, regression analysis with subset selection was carried out to develop two models for the yield of indoor cannabis cultivation. The median Dutch illicit grow room consists of 259 cannabis plants, has a plant density of 15 plants/m(2), and 510 W of growth lamps per m(2). For the median Dutch grow room, the predicted yield of female flower buds at the harvestable developmental stage (stage 10) was 33.7 g/plant or 505 g/m(2).

  9. Measurement of the fluorescence quantum yield of bis-MSB

    NASA Astrophysics Data System (ADS)

    Ding, Xue-Feng; Wen, Liang-Jian; Zhou, Xiang; Ding, Ya-Yun; Ye, Xing-Chen; Zhou, Li; Liu, Meng-Chao; Cai, Hao; Cao, Jun

    2015-12-01

    The fluorescence quantum yield of bis-MSB, a widely used liquid scintillator wavelength shifter, was measured to study the photon absorption and re-emission processes in a liquid scintillator. The re-emission process affects the photoelectron yield and distribution, especially in a large liquid scintillator detector, thus must be understood to optimize the liquid scintillator for good energy resolution and to precisely simulate the detector with Monte Carlo. In this study, solutions of different bis-MSB concentration were prepared for absorption and fluorescence emission measurements to cover a broad range of wavelengths. Harmane was used as a standard reference to obtain the absolution fluorescence quantum yield. For the first time we measured the fluorescence quantum yield of bis-MSB up to 430 nm as inputs required by Monte Carlo simulation, which is 0.926±0.053 at λex=350 nm. Supported by National Natural Science Foundation of China (11205183, 11225525, 11390381)

  10. Calculated secondary yields for proton broadband using DECAY TURTLE

    SciTech Connect

    Sondgeroth, A.

    1995-02-01

    The calculations for the yields were done by Al Sondgeroth and Anthony Malensek. The authors used the DECAY deck called PBSEC{_}E.DAT from the CMS DECKS library. After obtaining the run modes and calibration modes from the liaison physicist, they made individual decay runs, using DECAY TURTLE from the CMS libraries and a production spectrum subroutine which was modified by Anthony, for each particle and decay mode for all particle types coming out of the target box. Results were weighted according to branching ratios for particles with more than one decay mode. The production spectra were produced assuming beryllium as the target. The optional deuterium target available to broadband will produce slightly higher yields. It should be noted that they did not include pion yields from klong decays because they could not simulate three body decays. Pions from klongs would add a very small fraction to the total yield.

  11. Agriculture and Bioactives: Achieving Both Crop Yield and Phytochemicals

    PubMed Central

    García-Mier, Lina; Guevara-González, Ramón G.; Mondragón-Olguín, Víctor M.; Verduzco-Cuellar, Beatriz del Rocío; Torres-Pacheco, Irineo

    2013-01-01

    Plants are fundamental elements of the human diet, either as direct sources of nutrients or indirectly as feed for animals. During the past few years, the main goal of agriculture has been to increase yield in order to provide the food that is needed by a growing world population. As important as yield, but commonly forgotten in conventional agriculture, is to keep and, if it is possible, to increase the phytochemical content due to their health implications. Nowadays, it is necessary to go beyond this, reconciling yield and phytochemicals that, at first glance, might seem in conflict. This can be accomplished through reviewing food requirements, plant consumption with health implications, and farming methods. The aim of this work is to show how both yield and phytochemicals converge into a new vision of agricultural management in a framework of integrated agricultural practices. PMID:23429238

  12. 50 CFR 648.20 - Maximum optimum yield (OYs).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.20 Maximum optimum yield (OYs...) Mackerel—that quantity of mackerel that is less than or equal to the allowable biological catch (ABC) in...

  13. Developing scaling relations for the yield strength of nanoporous gold

    NASA Astrophysics Data System (ADS)

    Briot, Nicolas J.; Balk, T. John

    2015-09-01

    In this work, the applicability of Gibson and Ashby's porous scaling relations to nanoporous metals is discussed, and an updated equation is proposed for relating the yield strength of nanoporous gold to the yield strength of individual gold ligaments that form the porous structure. This new relation is derived from experimental measurements obtained by small-scale tensile testing and by nanoindentation, and incorporates the average ligament diameter. Nanoindentation data, obtained experimentally by the authors as well as reported by others in the literature, are reconciled with tensile test measurements previously reported by the present authors. The values of ligament yield strength calculated with the new scaling relation are found to agree with data reported from mechanical testing of nanowires, and the scaling relation thus represents a bridge between nanowire and nanoporous metal behaviour. In addition, calculations of yield strength for nanoporous gold samples with various ligament size and relative density are consistent with the experimentally determined values.

  14. Hierarchy of scales in B{yields}PS decays

    SciTech Connect

    Delepine, D.; Lucio M, J. L.; Mendoza S, J. A.; Ramirez, Carlos A.

    2008-08-31

    We show that the naive factorization approach can accommodate the existence of the observed hierarchy of branching ratios for the B{yields}PS decays (P stands for pseudoscalar and S for scalar mesons respectively.

  15. Parameterization of ion channeling half-angles and minimum yields

    NASA Astrophysics Data System (ADS)

    Doyle, Barney L.

    2016-03-01

    A MS Excel program has been written that calculates ion channeling half-angles and minimum yields in cubic bcc, fcc and diamond lattice crystals. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different power functions of the arguments. The program then offers an extremely convenient way to calculate axial and planar half-angles, minimum yields, effects on half-angles and minimum yields of amorphous overlayers. The program can calculate these half-angles and minimum yields for axes and [h k l] planes up to (5 5 5). The program is open source and available at

  16. Comparison of broiler performance when fed diets containing grain from YieldGard (MON810), YieldGard x Roundup Ready (GA21), nontransgenic control, or commercial corn.

    PubMed

    Taylor, M L; Hartnell, G F; Riordan, S G; Nemeth, M A; Karunanandaa, K; George, B; Astwood, J D

    2003-05-01

    This 42-day experiment was undertaken to compare the nutritional value of insect-protected corn event MON810 (YieldGard) and YieldGard x herbicide-tolerant corn event GA21 (Roundup Ready) to their nontransgenic controls as well as four different commercial reference corns, when fed to growing Cobb x Cobb broilers. A randomized complete block design was used, and each treatment was replicated with five pens of males and five pens of females with 10 broilers per pen. Broilers were fed approximately 55% wt/wt corn during the first 20 d and approximately 60% wt/wt corn thereafter. The corn component of diets fed to broilers was supplied entirely with grain from the eight hybrids included in the experiment. Final live weights averaged 2.09 kg/bird fed YieldGard corn and 2.15 kg/bird fed YieldGard x Roundup Ready corn and were not different (P > 0.05) from final weights for birds fed control or commercial corn. Feed conversion was not affected (P > 0.05) by YieldGard (1.72) or YieldGard x Roundup Ready (1.77) corn feeding when compared with the feeding of other corn diets. Chill weights, fat pad, thigh weights, and wing weights were not affected by diets (P > 0.05). Differences (P < 0.05) were noted for breast and drum weights across treatments. Broilers overall performed consistently and had similar carcass yield and meat composition when fed diets containing YieldGard (event MON810) or YieldGard (event MON810) x Roundup Ready (event GA21) as compared with their nontransgenic controls and commercial diets.

  17. Heritability and expected selection response for yield traits in blanched asparagus.

    PubMed

    Gatti, Ileana; López Anido, Fernando; Cravero, Vanina; Asprelli, Pablo; Cointry, Enrique

    2005-03-31

    Despite the continuous breeding that has been conducted with asparagus (Asparagus officinalis L.) since the beginning of the last century, there is little information on parameters for predicting direct and indirect selection response. Yield traits for blanched asparagus production were studied along a two-year period in a half-sib family population planted in Zavalla, Argentina. Half-sib family mean heritability values were low for total yield and marketable spear number (0.31 and 0.35), intermediate for marketable yield and total spear number (0.55 and 0.64), and relatively high for spear diameter and spear weight (0.75 and 0.74). An average increase in marketable yield of 15.9% is expected after each cycle of selection of the top 5% of the families. Total yield failed to express significant genetic correlations with any of the yield components; meanwhile marketable yield showed highly significant relations with market spear number (0.96) and spear weight (0.89). Indirect selection response over yield components (CRx) failed to be advantageous over direct selection (Rx), since the ratio CRx/Rx was always equal or below unity.

  18. Integrated electrical and SEM-based defect characterization for rapid yield ramp

    NASA Astrophysics Data System (ADS)

    Orbon, Jacob; Levin, Lior; Bokobza, Ofer; Shimshi, Rinat; Dutta, Manjari; Zhang, Brian; Ciplickas, Dennis; Pham, Teri; Jensen, Jim

    2004-04-01

    Challenges of the new nanometer processes have complicated the yield enhancement process. The systematic yield loss component is increasing, due to the complexity and density of the new processes and the designs that are developed for them. High product yields can now only be achieved when process failure rates are on the order of a few parts per billion structures. Traditional yield ramping techniques cannot ramp yields to these levels and new methods are required. This paper presents a new systematic approach to yield loss pareto generation. The approach uses a sophisticated Design-of-Experiments (DOE) approach to characterize systematic and random yield loss mechanisms in the Back End Of the Line (BEOL). Sophisticated Characterization Vehicle (CV)TM test chips, fast electrical test and Automatic Defect Localization (ADL) are critical components of the method. Advanced statistical analysis and visualization of the detected and localized electrical defects provides a comprehensive view of the yield loss mechanisms. In situations where the defects are not visible in a SEM of the structure surface, automated FIB and imaging is used to characterize the defect. The combined approach provides the required resolution to appropriately characterize parts per billion failure rates.

  19. Detection of two major grain yield QTL in bread wheat (Triticum aestivum L.) under heat, drought and high yield potential environments.

    PubMed

    Bennett, Dion; Reynolds, Matthew; Mullan, Daniel; Izanloo, Ali; Kuchel, Haydn; Langridge, Peter; Schnurbusch, Thorsten

    2012-11-01

    A large proportion of the worlds' wheat growing regions suffers water and/or heat stress at some stage during the crop growth cycle. With few exceptions, there has been no utilisation of managed environments to screen mapping populations under repeatable abiotic stress conditions, such as the facilities developed by the International Wheat and Maize Improvement Centre (CIMMYT). Through careful management of irrigation and sowing date over three consecutive seasons, repeatable heat, drought and high yield potential conditions were imposed on the RAC875/Kukri doubled haploid population to identify genetic loci for grain yield, yield components and key morpho-physiological traits under these conditions. Two of the detected quantitative trait loci (QTL) were located on chromosome 3B and had a large effect on canopy temperature and grain yield, accounting for up to 22 % of the variance for these traits. The locus on chromosome arm 3BL was detected under all three treatments but had its largest effect under the heat stress conditions, with the RAC875 allele increasing grain yield by 131 kg ha(-1) (or phenotypically, 7 % of treatment average). Only two of the eight yield QTL detected in the current study (including linkage groups 3A, 3D, 4D 5B and 7A) were previously detected in the RAC875/Kukri doubled haploid population; and there were also different yield components driving grain yield. A number of discussion points are raised to understand differences between the Mexican and southern Australian production environments and explain the lack of correlation between the datasets. The two key QTL detected on chromosome 3B in the present study are candidates for further genetic dissection and development of molecular markers.

  20. The yield behavior of polyethylene tubes subjected to biaxial loadings

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    High-density polyethylene is subjected to biaxial states of stress to examine the yield behavior of the semicrystalline thermoplastic under constant octahedral shear-stress rates. Combinations of internal pressures and axial loads are applied to thin-walled tubes of polyethylene, and the strain response in the axial and hoop directions are measured. The polyethylene specimens are found to be anisotropic, and the experimental measurements are compared to yield criteria that are applicable to isotropic and anisotropic materials.

  1. Diversification practices reduce organic to conventional yield gap.

    PubMed

    Ponisio, Lauren C; M'Gonigle, Leithen K; Mace, Kevi C; Palomino, Jenny; de Valpine, Perry; Kremen, Claire

    2015-01-22

    Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. How organic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (±3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9 ± 4% and 8 ± 5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions.

  2. Influence of excitonic effects on luminescence quantum yield in silicon

    NASA Astrophysics Data System (ADS)

    Sachenko, A. V.; Kostylyov, V. P.; Vlasiuk, V. M.; Sokolovskyi, I. O.; Evstigneev, M.

    2017-03-01

    Nonradiative exciton lifetime in silicon is determined by comparison of the experimental and theoretical curves of bulk minority charge carriers lifetime on doping and excitation levels. This value is used to analyze the influence of excitonic effects on internal luminescence quantum yield at room temperature, taking into account both nonradiative and radiative exciton lifetimes. A range of Shockley-Hall-Reed lifetimes is found, where excitonic effects lead to an increase of internal luminescence quantum yield.

  3. Effect of particle size on the alcohol yield from corn

    SciTech Connect

    Gantt, R.E.; Hegg, R.O.

    1981-01-01

    A laboratory study was conducted to determine the effect of particle size on the conversion of corn to ethanol. Standard analytical procedures were used to measure carbohydrates, sugar, and alcohol. The highest yield obtained was 2.4 gal/bu with the average being 1.8 gal/bu. The results showed that particle size has little effect on alcohol yield. 7 refs.

  4. Maximum photosynthetic yield of green microalgae in photobioreactors.

    PubMed

    Zijffers, Jan-Willem F; Schippers, Klaske J; Zheng, Ke; Janssen, Marcel; Tramper, Johannes; Wijffels, René H

    2010-11-01

    The biomass yield on light energy of Dunaliella tertiolecta and Chlorella sorokiniana was investigated in a 1.25- and 2.15-cm light path panel photobioreactor at constant ingoing photon flux density (930 µmol photons m⁻² s⁻¹). At the optimal combination of biomass density and dilution rate, equal biomass yields on light energy were observed for both light paths for both microalgae. The observed biomass yield on light energy appeared to be based on a constant intrinsic biomass yield and a constant maintenance energy requirement per gram biomass. Using the model of Pirt (New Phytol 102:3-37, 1986), a biomass yield on light energy of 0.78 and 0.75 g mol photons⁻¹ and a maintenance requirement of 0.0133 and 0.0068 mol photons g⁻¹ h⁻¹ were found for D. tertiolecta and C. sorokiniana, respectively. The observed yield decreases steeply at low light supply rates, and according to this model, this is related to the increase of the amount of useable light energy diverted to biomass maintenance. With this study, we demonstrated that the observed biomass yield on light in short light path bioreactors at high biomass densities decreases because maintenance requirements are relatively high at these conditions. All our experimental data for the two strains tested could be described by the physiological models of Pirt (New Phytol 102:3-37, 1986). Consequently, for the design of a photobioreactor, we should maintain a relatively high specific light supply rate. A process with high biomass densities and high yields at high light intensities can only be obtained in short light path photobioreactors.

  5. Diversification practices reduce organic to conventional yield gap

    PubMed Central

    Ponisio, Lauren C.; M'Gonigle, Leithen K.; Mace, Kevi C.; Palomino, Jenny; de Valpine, Perry; Kremen, Claire

    2015-01-01

    Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. How organic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (±3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9 ± 4% and 8 ± 5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions. PMID:25621333

  6. A global water supply reservoir yield model with uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Kuria, Faith W.; Vogel, Richard M.

    2014-09-01

    Understanding the reliability and uncertainty associated with water supply yields derived from surface water reservoirs is central for planning purposes. Using a global dataset of monthly river discharge, we introduce a generalized model for estimating the mean and variance of water supply yield, Y, expected from a reservoir for a prespecified reliability, R, and storage capacity, S assuming a flow record of length n. The generalized storage-reliability-yield (SRY) relationships reported here have numerous water resource applications ranging from preliminary water supply investigations, to economic and climate change impact assessments. An example indicates how our generalized SRY relationship can be combined with a hydroclimatic model to determine the impact of climate change on surface reservoir water supply yields. We also document that the variability of estimates of water supply yield are invariant to characteristics of the reservoir system, including its storage capacity and reliability. Standardized metrics of the variability of water supply yields are shown to depend only on the sample size of the inflows and the statistical characteristics of the inflow series.

  7. Mapping Crop Yield and Sow Date Using High Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Royal, K.

    2015-12-01

    Keitasha Royal, Meha Jain, Ph.D., David Lobell, Ph.D Mapping Crop Yield and Sow Date Using High Resolution ImageryThe use of satellite imagery in agriculture is becoming increasingly more significant and valuable. Due to the emergence of new satellites, such as Skybox, these satellites provide higher resolution imagery (e.g 1m) therefore improving the ability to map smallholder agriculture. For the smallholder farm dominated area of northern India, Skybox high-resolution satellite imagery can aid in understanding how to improve farm yields. In particular, we are interested in mapping winter wheat in India, as this region produces approximately 80% of the country's wheat crop, which is important given that wheat is a staple crop that provides approximately 20% of household calories. In northeast India, the combination of increased heat stress, limited irrigation access, and the difficulty for farmers to access advanced farming technologies results in farmers only producing about 50% of their potential crop yield. The use of satellite imagery can aid in understanding wheat yields through time and help identify ways to increase crop yields in the wheat belt of India. To translate Skybox satellite data into meaningful information about wheat fields, we examine vegetation indices, such as the normalized difference vegetation index (NDVI), to measure the "greenness" of plants to help determine the health of the crops. We test our ability to predict crop characteristics, like sow date and yield, using vegetation indices of 59 fields for which we have field data in Bihar, India.

  8. Calculation of Delayed Neutron Yields for Various Libraries

    NASA Astrophysics Data System (ADS)

    Huynh, T. D.; Jouanne, C.

    2014-04-01

    This paper presents the comparison between the total delayed neutron yields (νdbar) calculated and the recommended values proposed by Tuttle, the experimental data of Waldo and those of Benedetti. These data are given for thermal, fast, and high energy fission ranges. The calculation of total delayed neutron yields is performed either by the NJOY nuclear data processing system or by the summation method. The decay data found in the various evaluations as the delayed neutron branching ratios (Pn) and the cumulative fission yields (CY) can also be validated by delayed neutron yield calculation using the summation method. In the first method, where the treatment is performed by the NJOY system, the general purpose evaluation files (JEFF-3, JEF-2, ENDF/B-VII.0 and ENDF/B-VI.4 were considered. In the summation calculation, the data used are the delayed neutron branching ratios (also called delayed neutron emission probabilities) and the cumulative fission yields that are given for thermal, fast, high energy fission and spontaneous fission. These data are found in the Radioactive Decay Data and Fission Yield Data files (File 8) of nuclear data evaluations. In this study, we also perform a benchmark calculation with various libraries: JEF-2.2, JEFF3.1.1, ENDF/B-VII.0, ENDF/B-VII.1 and JENDL/FP-2011.

  9. Forecasting Moroccan Wheat Yields using Two Statistical Models

    NASA Astrophysics Data System (ADS)

    Wechsung, F.; Childers, K.; Frieler, K.; Hoffmann, P.

    2015-12-01

    The economy of Morocco is highly dependent on fluctuations in wheat yield. Since very little of the Moroccan wheat harvest is irrigated, this leaves the annual wheat yield dependent on precipitation fluctuations and large scale weather patterns over the north Atlantic. Here we suggest two predictors of the annual change in Moroccan wheat yield based on these relationships. The first, pre-planting indicator relies on the sea surface temperature (SST) anomalies of the north Atlantic in September through November and are reinforced by a mid-season predictor based on the weighted precipitation from October through February. Partial least squares regression is used to determine the three most relevant patterns of Atlantic SST which offer an early indication of the upcoming wheat yield. The prediction is greatly enhanced by the inclusion of the cumulative monthly precipitation weighted by the wheat cultivation areas, from October through the wheat harvest. It is not surprising that the total precipitation in Morocco influences the annual wheat yield, however it is remarkable the degree to which early season precipitation sums are able to forecast the national wheat yield. Higher resolution precipitation reanalysis products from AgMERRA and NOAA have coefficients of determination greater than 0.5 by February (r2=0.78 and 0.57, respectively). The more frequently updated NOAA 0.5° resolution precipitation product has a slightly lower but still significant correlation (r2=0.48).

  10. Maximized exoEarth candidate yields for starshades

    NASA Astrophysics Data System (ADS)

    Stark, Christopher C.; Shaklan, Stuart; Lisman, Doug; Cady, Eric; Savransky, Dmitry; Roberge, Aki; Mandell, Avi M.

    2016-10-01

    The design and scale of a future mission to directly image and characterize potentially Earth-like planets will be impacted, to some degree, by the expected yield of such planets. Recent efforts to increase the estimated yields, by creating observation plans optimized for the detection and characterization of Earth-twins, have focused solely on coronagraphic instruments; starshade-based missions could benefit from a similar analysis. Here we explore how to prioritize observations for a starshade given the limiting resources of both fuel and time, present analytic expressions to estimate fuel use, and provide efficient numerical techniques for maximizing the yield of starshades. We implemented these techniques to create an approximate design reference mission code for starshades and used this code to investigate how exoEarth candidate yield responds to changes in mission, instrument, and astrophysical parameters for missions with a single starshade. We find that a starshade mission operates most efficiently somewhere between the fuel- and exposuretime-limited regimes and, as a result, is less sensitive to photometric noise sources as well as parameters controlling the photon collection rate in comparison to a coronagraph. We produced optimistic yield curves for starshades, assuming our optimized observation plans are schedulable and future starshades are not thrust-limited. Given these yield curves, detecting and characterizing several dozen exoEarth candidates requires either multiple starshades or an η≳0.3.

  11. Efficient SRAM yield optimization with mixture surrogate modeling

    NASA Astrophysics Data System (ADS)

    Zhongjian, Jiang; Zuochang, Ye; Yan, Wang

    2016-12-01

    Largely repeated cells such as SRAM cells usually require extremely low failure-rate to ensure a moderate chi yield. Though fast Monte Carlo methods such as importance sampling and its variants can be used for yield estimation, they are still very expensive if one needs to perform optimization based on such estimations. Typically the process of yield calculation requires a lot of SPICE simulation. The circuit SPICE simulation analysis accounted for the largest proportion of time in the process yield calculation. In the paper, a new method is proposed to address this issue. The key idea is to establish an efficient mixture surrogate model. The surrogate model is based on the design variables and process variables. This model construction method is based on the SPICE simulation to get a certain amount of sample points, these points are trained for mixture surrogate model by the lasso algorithm. Experimental results show that the proposed model is able to calculate accurate yield successfully and it brings significant speed ups to the calculation of failure rate. Based on the model, we made a further accelerated algorithm to further enhance the speed of the yield calculation. It is suitable for high-dimensional process variables and multi-performance applications.

  12. Predicting the yield and composition of mature cow carcasses.

    PubMed

    Johnson, D D; Rogers, A L

    1997-07-01

    Cow carcasses (n = 60) were selected based on conformation and external fat to develop more current and useful prediction equations for estimating yield and composition. Adjusted preliminary yield grade was highly correlated to percentage of the carcass as fat (.91), percentage fat in the total lean (.89), and percentage fat in the lean trimmings (.88) of carcasses from non-grain-fed mature cows. Equations for predicting percentage of the carcass as chemical fat had higher -R2 values than equations predicting other compositional end points. The "best" regression equation for predicting total yield (i.e., whole muscle cuts plus lean trimmings adjusted to 10% chemical fat) included hot carcass weight (HCWT), adjusted preliminary yield grade (APYG), longissimus area (LMA), and marbling (MARB), with R2 = .75 and residual standard deviation (RSD) = 2.47. A similar equation predicting total yield from unribbed carcass data included HCWT, APYG, and conformation (CONF) with R2 = .69 and RSD = 3.11. These two equations were applied to a test group of cow carcasses (n = 20), and the average difference between the actual and predicted total yield values from ribbed data and unribbed data was .45 and .83% of HCWT; simple correlations between the actual and predicted values were .74 and .69, respectively. These equations contain relatively simple independent variables to identify and more nearly represent current industry processing practices than equations previously available.

  13. Ecoinformatics reveals effects of crop rotational histories on cotton yield.

    PubMed

    Meisner, Matthew H; Rosenheim, Jay A

    2014-01-01

    Crop rotation has been practiced for centuries in an effort to improve agricultural yield. However, the directions, magnitudes, and mechanisms of the yield effects of various crop rotations remain poorly understood in many systems. In order to better understand how crop rotation influences cotton yield, we used hierarchical Bayesian models to analyze a large ecoinformatics database consisting of records of commercial cotton crops grown in California's San Joaquin Valley. We identified several crops that, when grown in a field the year before a cotton crop, were associated with increased or decreased cotton yield. Furthermore, there was a negative association between the effect of the prior year's crop on June densities of the pest Lygus hesperus and the effect of the prior year's crop on cotton yield. This suggested that some crops may enhance L. hesperus densities in the surrounding agricultural landscape, because residual L. hesperus populations from the previous year cannot continuously inhabit a focal field and attack a subsequent cotton crop. In addition, we found that cotton yield declined approximately 2.4% for each additional year in which cotton was grown consecutively in a field prior to the focal cotton crop. Because L. hesperus is quite mobile, the effects of crop rotation on L. hesperus would likely not be revealed by small plot experimentation. These results provide an example of how ecoinformatics datasets, which capture the true spatial scale of commercial agriculture, can be used to enhance agricultural productivity.

  14. SAS: a yield/failure analysis software tool

    NASA Astrophysics Data System (ADS)

    de Jong Perez, Susana

    1996-09-01

    As the device sizes decrease and the number of interconnect levels and wafer size increase, the device yield and failure analysis becomes more complex. Currently, software tools are being used to perform visual inspection techniques after many operations during which defects are detected on a sample of wafers. However, it has been observed that the correlation between the yield predicted on the basis of the defects found during such observations and the yield determined electrically at wafer final test is low. Of a greater interest to yield/failure analysis software tools is statistical analysis software. SASTM can perform extensive data analysis on kerf test structures' electrical parameters. In addition, the software can merge parametric and yield/fail bins data which reduces the data collection and data reduction activities involved in the correlation of device parameters to circuit functional operation. The data is saved in large databases which allow storage and later retrieval of historical data in order to evaluate process shifts and changes and their effect on yield. The merge of process parameters and on-line measurements with final electrical data, is also possible with the aid of process parameter extraction software. All of this data analysis provides excellent feedback about integrated circuit wafer processing.

  15. Managment oriented analysis of sediment yield time compression

    NASA Astrophysics Data System (ADS)

    Smetanova, Anna; Le Bissonnais, Yves; Raclot, Damien; Nunes, João P.; Licciardello, Feliciana; Le Bouteiller, Caroline; Latron, Jérôme; Rodríguez Caballero, Emilio; Mathys, Nicolle; Klotz, Sébastien; Mekki, Insaf; Gallart, Francesc; Solé Benet, Albert; Pérez Gallego, Nuria; Andrieux, Patrick; Moussa, Roger; Planchon, Olivier; Marisa Santos, Juliana; Alshihabi, Omran; Chikhaoui, Mohamed

    2016-04-01

    The understanding of inter- and intra-annual variability of sediment yield is important for the land use planning and management decisions for sustainable landscapes. It is of particular importance in the regions where the annual sediment yield is often highly dependent on the occurrence of few large events which produce the majority of sediments, such as in the Mediterranean. This phenomenon is referred as time compression, and relevance of its consideration growths with the increase in magnitude and frequency of extreme events due to climate change in many other regions. So far, time compression has ben studied mainly on events datasets, providing high resolution, but (in terms of data amount, required data precision and methods), demanding analysis. In order to provide an alternative simplified approach, the monthly and yearly time compressions were evaluated in eight Mediterranean catchments (of the R-OSMed network), representing a wide range of Mediterranean landscapes. The annual sediment yield varied between 0 to ~27100 Mg•km-2•a-1, and the monthly sediment yield between 0 to ~11600 Mg•km-2•month-1. The catchment's sediment yield was un-equally distributed at inter- and intra-annual scale, and large differences were observed between the catchments. Two types of time compression were distinguished - (i) the inter-annual (based on annual values) and intra- annual (based on monthly values). Four different rainfall-runoff-sediment yield time compression patterns were observed: (i) no time-compression of rainfall, runoff, nor sediment yield, (ii) low time compression of rainfall and runoff, but high compression of sediment yield, (iii) low compression of rainfall and high of runoff and sediment yield, and (iv) low, medium and high compression of rainfall, runoff and sediment yield. All four patterns were present at inter-annual scale, while at intra-annual scale only the two latter were present. This implies that high sediment yields occurred in

  16. The limits of crop productivity: validating theoretical estimates and determining the factors that limit crop yields in optimal environments

    NASA Technical Reports Server (NTRS)

    Bugbee, B.; Monje, O.

    1992-01-01

    Plant scientists have sought to maximize the yield of food crops since the beginning of agriculture. There are numerous reports of record food and biomass yields (per unit area) in all major crop plants, but many of the record yield reports are in error because they exceed the maximal theoretical rates of the component processes. In this article, we review the component processes that govern yield limits and describe how each process can be individually measured. This procedure has helped us validate theoretical estimates and determine what factors limit yields in optimal environments.

  17. Resilience of catchment sediment yield to climate perturbations

    NASA Astrophysics Data System (ADS)

    Van De Wiel, Marco; Lipkowski, Emily

    2015-04-01

    It is commonly thought that catchment sediment yield is largely governed by allogenic controls acting on the catchment. Under this paradigm, variations in climatic, tectonic or anthropogenic forcing are directly transmitted to the catchment sediment yield. The sediment yield thus represents a temporal signature of the governing external forces. This paradigm, however, has been challenged by recent research, which has shown that autogenic controls from within the catchment can significantly affect and, in some cases, overwrite the allogenic signal in the sediment yield signal. In these cases the catchment sediment yield can be considered to be resilient to external perturbation. On the other hand, it also has been shown that, in some other cases, the allogenic signal can indeed be transmitted efficiently through the catchment, without too much distortion by the autogenic controls. In these latter cases, the sediment yield signal, and hence the downstream sediment deposits, can be a reliable archive of past environmental forcing. This study uses computer simulation to investigate the autogenic resilience of catchment sediment yields. Specifically, it investigates allogenic signal preservation in catchment sediment yield in the context of climate signals. It is hypothesized that 1) the resilience of the catchment sediment yield signal is largely determined by the catchment's spatial heterogeneity (of topography, vegetation, soil properties, ...) and the external signal's temporal heterogeneity and amplitude; and 2) catchment resilience is inversely correlated with spatial heterogeneity and positively correlated with the temporal heterogeneity and amplitude of the allogenic signal. This hypothesis is tested using a set of similar catchments, but with different relief ranges, different levels of topographic smoothness, different sediment distributions, and different artificial vegetation covers. These catchments are subjected to a range of rainfall scenarios over a 300

  18. Essential oil yield and composition reflect browsing damage of junipers.

    PubMed

    Markó, Gábor; Gyuricza, Veronika; Bernáth, Jeno; Altbacker, Vilmos

    2008-12-01

    The impact of browsing on vegetation depends on the relative density and species composition of browsers. Herbivore density and plant damage can be either site-specific or change seasonally and spatially. For juniper (Juniperus communis) forests of a sand dune region in Hungary, it has been assumed that plant damage investigated at different temporal and spatial scales would reflect selective herbivory. The level of juniper damage was tested for a possible correlation with the concentration of plant secondary metabolites (PSMs) in plants and seasonal changes in browsing pressure. Heavily browsed and nonbrowsed junipers were also assumed to differ in their chemical composition, and the spatial distribution of browsing damage within each forest was analyzed to reveal the main browser. Long-term differences in local browsing pressure were also expected and would be reflected in site-specific age distributions of distant juniper populations. The concentrations of PSMs (essential oils) varied significantly among junipers and seasons. Heavily browsed shrubs contained the lowest oil yield; essential oils were highest in shrubs bearing no damage, indicating that PSMs might contribute to reduce browsing in undamaged shrubs. There was a seasonal fluctuation in the yield of essential oil that was lower in the summer period than in other seasons. Gas chromatography (GC) revealed differences in some essential oil components, suggesting that certain chemicals could have contributed to reduced consumption. The consequential long-term changes were reflected in differences in age distribution between distant juniper forests. These results confirm that both the concentration of PSMs and specific compounds of the essential oil may play a role in selective browsing damage by local herbivores.

  19. High yield neutron generators using the DD reaction

    SciTech Connect

    Vainionpaa, J. H.; Harris, J. L.; Piestrup, M. A.; Gary, C. K.; Williams, D. L.; Apodaca, M. D.; Cremer, J. T.; Ji, Qing; Ludewigt, B. A.; Jones, G.

    2013-04-19

    A product line of high yield neutron generators has been developed at Adelphi technology inc. The generators use the D-D fusion reaction and are driven by an ion beam supplied by a microwave ion source. Yields of up to 5 Multiplication-Sign 10{sup 9} n/s have been achieved, which are comparable to those obtained using the more efficient D-T reaction. The microwave-driven plasma uses the electron cyclotron resonance (ECR) to produce a high plasma density for high current and high atomic ion species. These generators have an actively pumped vacuum system that allows operation at reduced pressure in the target chamber, increasing the overall system reliability. Since no radioactive tritium is used, the generators can be easily serviced, and components can be easily replaced, providing essentially an unlimited lifetime. Fast neutron source size can be adjusted by selecting the aperture and target geometries according to customer specifications. Pulsed and continuous operation has been demonstrated. Minimum pulse lengths of 50 {mu}s have been achieved. Since the generators are easily serviceable, they offer a long lifetime neutron generator for laboratories and commercial systems requiring continuous operation. Several of the generators have been enclosed in radiation shielding/moderator structures designed for customer specifications. These generators have been proven to be useful for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA) and fast neutron radiography. Thus these generators make excellent fast, epithermal and thermal neutron sources for laboratories and industrial applications that require neutrons with safe operation, small footprint, low cost and small regulatory burden.

  20. High yield neutron generators using the DD reaction

    NASA Astrophysics Data System (ADS)

    Vainionpaa, J. H.; Harris, J. L.; Piestrup, M. A.; Gary, C. K.; Williams, D. L.; Apodaca, M. D.; Cremer, J. T.; Ji, Qing; Ludewigt, B. A.; Jones, G.

    2013-04-01

    A product line of high yield neutron generators has been developed at Adelphi technology inc. The generators use the D-D fusion reaction and are driven by an ion beam supplied by a microwave ion source. Yields of up to 5 × 109 n/s have been achieved, which are comparable to those obtained using the more efficient D-T reaction. The microwave-driven plasma uses the electron cyclotron resonance (ECR) to produce a high plasma density for high current and high atomic ion species. These generators have an actively pumped vacuum system that allows operation at reduced pressure in the target chamber, increasing the overall system reliability. Since no radioactive tritium is used, the generators can be easily serviced, and components can be easily replaced, providing essentially an unlimited lifetime. Fast neutron source size can be adjusted by selecting the aperture and target geometries according to customer specifications. Pulsed and continuous operation has been demonstrated. Minimum pulse lengths of 50 μs have been achieved. Since the generators are easily serviceable, they offer a long lifetime neutron generator for laboratories and commercial systems requiring continuous operation. Several of the generators have been enclosed in radiation shielding/moderator structures designed for customer specifications. These generators have been proven to be useful for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA) and fast neutron radiography. Thus these generators make excellent fast, epithermal and thermal neutron sources for laboratories and industrial applications that require neutrons with safe operation, small footprint, low cost and small regulatory burden.

  1. {mu}{yields}e{gamma} and {tau}{yields}l{gamma} decays in the fermion triplet seesaw model

    SciTech Connect

    Abada, A.; Bonnet, F.; Biggio, C.; Gavela, M. B.

    2008-08-01

    In the framework of the seesaw models with triplets of fermions, we evaluate the decay rates of {mu}{yields}e{gamma} and {tau}{yields}l{gamma} transitions. We show that although, due to neutrino mass constraints, those rates are in general expected to be well under the present experimental limits, this is not necessarily always the case. Interestingly enough, the observation of one of those decays in planned experiments would nevertheless contradict bounds stemming from present experimental limits on the {mu}{yields}eee and {tau}{yields}3l decay rates, as well as from {mu} to e conversion in atomic nuclei. Such detection of radiative decays would therefore imply that there exist sources of lepton flavor violation not associated to triplet fermions.

  2. Potential yields and properties of oil from the hydrothermal liquefaction of microalgae with different biochemical content.

    PubMed

    Biller, P; Ross, A B

    2011-01-01

    A range of model biochemical components, microalgae and cyanobacteria with different biochemical contents have been liquefied under hydrothermal conditions at 350 °C, ∼200 bar in water, 1M Na(2)CO(3) and 1M formic acid. The model compounds include albumin and a soya protein, starch and glucose, the triglyceride from sunflower oil and two amino acids. Microalgae include Chlorella vulgaris,Nannochloropsis occulata and Porphyridium cruentum and the cyanobacteria Spirulina. The yields and product distribution obtained for each model compound have been used to predict the behaviour of microalgae with different biochemical composition and have been validated using microalgae and cyanobacteria. Broad agreement is reached between predictive yields and actual yields for the microalgae based on their biochemical composition. The yields of bio-crude are 5-25 wt.% higher than the lipid content of the algae depending upon biochemical composition. The yields of bio-crude follow the trend lipids>proteins>carbohydrates.

  3. Coordinated regulation of photosynthesis in rice increases yield and tolerance to environmental stress.

    PubMed

    Ambavaram, Madana M R; Basu, Supratim; Krishnan, Arjun; Ramegowda, Venkategowda; Batlang, Utlwang; Rahman, Lutfor; Baisakh, Niranjan; Pereira, Andy

    2014-10-31

    Plants capture solar energy and atmospheric carbon dioxide (CO2) through photosynthesis, which is the primary component of crop yield, and needs to be increased considerably to meet the growing global demand for food. Environmental stresses, which are increasing with climate change, adversely affect photosynthetic carbon metabolism (PCM) and limit yield of cereals such as rice (Oryza sativa) that feeds half the world. To study the regulation of photosynthesis, we developed a rice gene regulatory network and identified a transcription factor HYR (HIGHER YIELD RICE) associated with PCM, which on expression in rice enhances photosynthesis under multiple environmental conditions, determining a morpho-physiological programme leading to higher grain yield under normal, drought and high-temperature stress conditions. We show HYR is a master regulator, directly activating photosynthesis genes, cascades of transcription factors and other downstream genes involved in PCM and yield stability under drought and high-temperature environmental stress conditions.

  4. Process gg{yields}h{sub 0}{yields}{gamma}{gamma} in the Lee-Wick standard model

    SciTech Connect

    Krauss, F.; Underwood, T. E. J.; Zwicky, R.

    2008-01-01

    The process gg{yields}h{sub 0}{yields}{gamma}{gamma} is studied in the Lee-Wick extension of the standard model (LWSM) proposed by Grinstein, O'Connell, and Wise. In this model, negative norm partners for each SM field are introduced with the aim to cancel quadratic divergences in the Higgs mass. All sectors of the model relevant to gg{yields}h{sub 0}{yields}{gamma}{gamma} are diagonalized and results are commented on from the perspective of both the Lee-Wick and higher-derivative formalisms. Deviations from the SM rate for gg{yields}h{sub 0} are found to be of the order of 15%-5% for Lee-Wick masses in the range 500-1000 GeV. Effects on the rate for h{sub 0}{yields}{gamma}{gamma} are smaller, of the order of 5%-1% for Lee-Wick masses in the same range. These comparatively small changes may well provide a means of distinguishing the LWSM from other models such as universal extra dimensions where same-spin partners to standard model fields also appear. Corrections to determinations of Cabibbo-Kobayashi-Maskawa (CKM) elements |V{sub t(b,s,d)}| are also considered and are shown to be positive, allowing the possibility of measuring a CKM element larger than unity, a characteristic signature of the ghostlike nature of the Lee-Wick fields.

  5. Estimation of corn and soybeans yield using remote sensing and crop yield data in the United States

    NASA Astrophysics Data System (ADS)

    Kim, Nari; Lee, Yang-Won

    2014-10-01

    The crop yield estimation is essential for the food security and the economic development of any nation. Particularly, the United States is the world largest grain exporter, and the total amount of corn exported from the U.S. accounted for 49.2% of the world corn trade in 2010 and 2011. Thus, accurate estimation of crop yield in U.S. is very significant for not only the U.S. crop producers but also decision makers of food importing countries. Estimating the crop yield using remote sensing data plays an important role in the Agricultural Sector, and it is actively discussed and studied in many countries. This is because remote sensing can observe the large areas repetitively. Consequently, the use of various techniques based on remote sensing data is steadily increasing to accurately estimate for crop yield. Therefore, the objective of this study is to estimate the accurate yield of corn and soybeans using climate dataset of PRISM climate group and Terra/MODIS products in the United States. We construct the crop yield estimation model for the decade (2001-2010) and perform predictions and validation for 2011 and 2012.

  6. 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

  7. Quantitative analysis of factors controlling sediment yield in mountainous watersheds

    NASA Astrophysics Data System (ADS)

    Shi, Z. H.; Huang, X. D.; Ai, L.; Fang, N. F.; Wu, G. L.

    2014-12-01

    Sediment and turbidity are primary causes of impaired river ecosystems; remedial action for these impairments requires the identification of their sources and controlling factors. This paper examines the combined effects of watershed complexity in terms of land use and physiography on the specific sediment yield of the upper Du River watershed (8973 km2) in China. The land use composition, land use pattern, morphometric variables, and soil properties of the watershed were calculated at the subwatershed scale and considered to be potentially influential factors. Because these watershed characteristics are highly codependent, a partial least-squares regression (PLSR) was used to elucidate the linkages between the specific sediment yield and metrics composed of 19 selected watershed characteristics. The first-order factors were identified by calculating the variable importance for the projection (VIP). The results revealed that the land use composition and land use pattern exerted the largest effects on the specific sediment yield and explained 65.2% of the variation in the specific sediment yield. A set of physiographic indices was also found to have a large effect on the specific sediment yield and explained 17.7% of the observed variation in the specific sediment yield. The following are the dominant first-order factors of the specific sediment yield at the subwatershed scale: the areal percentages of agriculture and forest, patch density, value of the Shannon's diversity index, contagion, value of the hypsometric integral, and saturated soil hydraulic conductivity. The watershed size exerted a substantial effect on the sediment delivery ratio (SDR). The VIP values also suggested that the Shannon's diversity index, contagion, and hypsometric integral are important factors in the SDR. With a readily available digital spatial database and rapid developments in geographic information system (GIS) technology, this practical and simple PLSR approach could be applied to

  8. Closing Yield Gaps: How Sustainable Can We Be?

    PubMed Central

    Pradhan, Prajal; Fischer, Günther; van Velthuizen, Harrij; Reusser, Dominik E.; Kropp, Juergen P.

    2015-01-01

    Global food production needs to be increased by 60–110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45–73%, P2O5-fertilizer by 22–46%, and K2O-fertilizer by 2–3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way

  9. Plausible rice yield losses under future climate warming.

    PubMed

    Zhao, Chuang; Piao, Shilong; Wang, Xuhui; Huang, Yao; Ciais, Philippe; Elliott, Joshua; Huang, Mengtian; Janssens, Ivan A; Li, Tao; Lian, Xu; Liu, Yongwen; Müller, Christoph; Peng, Shushi; Wang, Tao; Zeng, Zhenzhong; Peñuelas, Josep

    2016-12-19

    Rice is the staple food for more than 50% of the world's population(1-3). Reliable prediction of changes in rice yield is thus central for maintaining global food security. This is an extraordinary challenge. Here, we compare the sensitivity of rice yield to temperature increase derived from field warming experiments and three modelling approaches: statistical models, local crop models and global gridded crop models. Field warming experiments produce a substantial rice yield loss under warming, with an average temperature sensitivity of -5.2 ± 1.4% K(-1). Local crop models give a similar sensitivity (-6.3 ± 0.4% K(-1)), but statistical and global gridded crop models both suggest less negative impacts of warming on yields (-0.8 ± 0.3% and -2.4 ± 3.7% K(-1), respectively). Using data from field warming experiments, we further propose a conditional probability approach to constrain the large range of global gridded crop model results for the future yield changes in response to warming by the end of the century (from -1.3% to -9.3% K(-1)). The constraint implies a more negative response to warming (-8.3 ± 1.4% K(-1)) and reduces the spread of the model ensemble by 33%. This yield reduction exceeds that estimated by the International Food Policy Research Institute assessment (-4.2 to -6.4% K(-1)) (ref. 4). Our study suggests that without CO2 fertilization, effective adaptation and genetic improvement, severe rice yield losses are plausible under intensive climate warming scenarios.

  10. 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.

  11. Is yield increase sufficient to achieve food security in China?

    PubMed

    Wei, Xing; Zhang, Zhao; Shi, Peijun; Wang, Pin; Chen, Yi; Song, Xiao; Tao, Fulu

    2015-01-01

    Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4%) and wheat (41.9%). As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area) has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security.

  12. Closing Yield Gaps: How Sustainable Can We Be?

    PubMed

    Pradhan, Prajal; Fischer, Günther; van Velthuizen, Harrij; Reusser, Dominik E; Kropp, Juergen P

    2015-01-01

    Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73%, P2O5-fertilizer by 22-46%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way

  13. Is Yield Increase Sufficient to Achieve Food Security in China?

    PubMed Central

    Wei, Xing; Zhang, Zhao; Shi, Peijun; Wang, Pin; Chen, Yi; Song, Xiao; Tao, Fulu

    2015-01-01

    Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4%) and wheat (41.9%). As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area) has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security. PMID:25680193

  14. Increasing yield gap of Brazilian pasturelands and implications for intensification

    NASA Astrophysics Data System (ADS)

    Costa, M. H.; Santos, A. B.; Dias, L. C. P.; Pimenta, F. M.

    2015-12-01

    Brazil has 213 M cattle heads (AUs) and 152 M ha of pasturelands, most with very low yields (average stocking rate in 2013 was 1.39 AU/ha). We merged Landsat imagery with municipal level agricultural census data for the period 1974-2013, to produce 30 arc-second resolution (1 km x 1 km) yearly datasets of pasturelands and cattle stocking rate (see Dias et al poster in this same session). Our analysis of this dataset indicates that, in the period 1993-2013, the total pastureland area in the country has decreased at a rate of 1.4 M ha/yr, while average stocking rate is increasing at the rate of 0.025 AU/(ha.yr). Moreover, we calculated the stocking rate of the top 5% and top 10% hectares, and the yield gap, or the difference between these top rates and the average. The yield gap is the productivity difference between what is largely possible with current technology and climate (top 5% or top 10%) and the typical cattle raiser, represented by the average. Closing the yield gap is often considered as a standard form of increasing agricultural output in general. Our results indicate that, in the same period, the top 10% are increasing at the rate of 0.040 AU/(ha.yr), while the top 5% are increasing at the rate of 0.048 AU/(ha.yr), twice as high as the average. The yield gap is widening and the rate of separation is increasing in recent years. These data suggest that top yield cattle raisers in Brazil are investing in technology significantly more than the average. Regional analysis indicates that this is happening mainly in southern and northern Brazil, while in Central, Southeast and Northeast Brazil, high productivities are not increasing as fast. Since top yields are far from stabilizing, there is a very large potential for intensification, increasing cattle size and total cattle output in Brazil.

  15. Particle structuring and yield stress in magnetofluidized beds

    NASA Astrophysics Data System (ADS)

    Valverde, J. M.; Espin, M. J.; Quintanilla, M. A. S.; Castellanos, A.

    2010-05-01

    A novel experimental technique to measure the tensile yield stress of fluidized beds of magnetic powders stabilized by an externally applied cross-flow magnetic field is shown. Basically, the tensile yield stress of the magnetically stabilized bed (MSB) is measured by means of the pressure drop of a gas flow that puts the bed under tension. A first relevant result is that the yield stress depends strongly on the field operation mode. In the H off/on operation mode, the bed was driven to bubbling by imposing a high gas velocity in the absence of magnetic field. Once the gas velocity was decreased below the bubbling onset and the bed was stabilized by the natural cohesive forces alone, the field was applied. The yield stress of the naturally stabilized bed is not essentially changed by application of the field a posteriori (H off/on), which can be attributed to the inability of the field to alter the arrangement of the particles once they were jammed in the stable fluidization state. In the H on/on mode, the field was kept during the whole process of bubbling and stabilization at reduced gas velocities. In this operation mode, the field was the main stabilizing source. In contrast with the H off/on mode results, the yield stress in the H on/on mode was observed to be appreciably increased, which is a consequence of the formation of particle chains as the gas velocity is decreased in the presence of the magnetic field. The influence of other parameters such as particle size distribution reveals also a correlation between the microstructure of the MSB and its yield stress. In analogy with structured magneto-and electro-rheological fluids, it is found that the yield stress increases as the average particle size is increased. Moreover, the microstructure of the MSB is relevantly affected by the natural cohesiveness of the powder due to van der Waals forces, which leads to the formation of large-scale branched chains when the field is applied, thus enhancing the yield

  16. Measurement of the Helicity Difference in {gamma}{sup {yields}p{yields}{yields}p{pi}+{pi}-} with the CLAS Spectrometer at Jefferson Laboratory

    SciTech Connect

    Park, Sungkyun

    2010-08-05

    The study of the properties of baryon resonances can provide us with hints to help us understand the structure of non-perturbative QCD and the effect of a particular resonance on polarization observables. The investigation of double-pion photoproduction data is needed to discover higher-lying states and their properties at and above W {approx_equal} 1.8 GeV. Therefore, the analysis of the helicity difference in gp {gamma}p{yields}p{pi}{sup +{pi}-} will help us in our understanding of QCD.The CLAS g9a (FROST) experiment, as part of the N* spectroscopy program at Jefferson Laboratory, has accumulated photoproduction data using linearly and circularly polarized photons incident on a longitudinally-polarized butanol target in the photon energy range 0.3 to 2.4 GeV. The FROST experiment provides an important step toward a ''complete'' experiment for the reaction {gamma}N{yields}KY.In this contribution, the method to calculate the helicity difference for the reaction {gamma}p{yields}p{pi}{sup +{pi}-} will be described and preliminary results will be discussed.

  17. A Comprehensive Theory of Yielding and Failure for Isotropic Materials

    SciTech Connect

    Christensen, R M

    2006-08-10

    A theory of yielding and failure for homogeneous and isotropic materials is given. The theory is calibrated by two independent, measurable properties and from those it predicts possible failure for any given state of stress. It also differentiates between ductile yielding and brittle failure. The explicit ductile-brittle criterion depends not only upon the material specification through the two properties, but also and equally importantly depends upon the type of imposed stress state. The Mises criterion is a special (limiting) case of the present theory. A close examination of this case shows that the Mises material idealization does not necessarily imply ductile behavior under all conditions, only under most conditions. When the first invariant of the yield/failure stress state is sufficiently large relative to the distortional part, brittle failure will be expected to occur. For general material types, it is shown that it is possible to have a state of spreading plastic flow, but as the elastic-plastic boundary advances, the conditions for yielding on it can change over to conditions for brittle failure because of the evolving stress state. The general theory is of a three dimensional form and it applies to full density materials for which the yield/failure strength in uniaxial tension is less than or at most equal to the magnitude of that in uniaxial compression.

  18. From macroscopic yield criteria to atomic stresses in polymer glasses

    SciTech Connect

    MacNeill, David; Rottler, Joerg

    2010-01-15

    The relationship between macroscopic shear yield criteria and local stress distributions in deformed polymer glasses is investigated via molecular dynamics simulations on different scales of coarse-graining. Macroscopic shear stresses at the yield point obey a pressure-modified von Mises (pmvM) criterion for many different loading conditions and strain rates. Average local stresses in small volume elements obey the same yield criterion for volumes containing approx. 100 atoms or more. Qualitatively different behavior is observed on smaller scales: the average octahedral atomic shear stress has a simple linear relationship to hydrostatic pressure regardless of macroscopic stress state and failure mode. Local plastic events are identified through a threshold in the mean-squared nonaffine displacement and compared to the local stress state. We find that the pmvM criterion only predicts local yield events when stress and displacements are averaged over at least 100 atoms. By contrast, macroscopic shear yield criteria appear to lose their ability to predict plastic activity on the atomic scale.

  19. Improving peppermint essential oil yield and composition by metabolic engineering.

    PubMed

    Lange, Bernd Markus; Mahmoud, Soheil Seyed; Wildung, Mark R; Turner, Glenn W; Davis, Edward M; Lange, Iris; Baker, Raymond C; Boydston, Rick A; Croteau, Rodney B

    2011-10-11

    Peppermint (Mentha × piperita L.) was transformed with various gene constructs to evaluate the utility of metabolic engineering for improving essential oil yield and composition. Oil yield increases were achieved by overexpressing genes involved in the supply of precursors through the 2C-methyl-D-erythritol 4-phosphate (MEP) pathway. Two-gene combinations to enhance both oil yield and composition in a single transgenic line were assessed as well. The most promising results were obtained by transforming plants expressing an antisense version of (+)-menthofuran synthase, which is critical for adjusting the levels of specific undesirable oil constituents, with a construct for the overexpression of the MEP pathway gene 1-deoxy-D-xylulose 5-phosphate reductoisomerase (up to 61% oil yield increase over wild-type controls with low levels of the undesirable side-product (+)-menthofuran and its intermediate (+)-pulegone). Elite transgenic lines were advanced to multiyear field trials, which demonstrated consistent oil yield increases of up to 78% over wild-type controls and desirable effects on oil composition under commercial growth conditions. The transgenic expression of a gene encoding (+)-limonene synthase was used to accumulate elevated levels of (+)-limonene, which allows oil derived from transgenic plants to be recognized during the processing of commercial formulations containing peppermint oil. Our study illustrates the utility of metabolic engineering for the sustainable agricultural production of high quality essential oils at a competitive cost.

  20. The Fingerprint of Climate Trends on European Crop Yields

    NASA Astrophysics Data System (ADS)

    Moore, F.; Lobell, D. B.

    2014-12-01

    Europe has experienced a stagnation of some crop yields since the early-1990s as well as statistically-significant warming during the growing-season. While it has been argued that these two are causally connected, no previous studies have formally attributed long-term European yield trends to a changing climate. Here we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these test to European agriculture, we find evidence that long-term temperature and precipitation trends have reduced continent-wide wheat, maize, and barley yields by 2.7%, 1.1%, and 3.9% respectively, and have increased sugarbeet yields by 1.0%. This can account for approximately 10% of the yield stagnation in Europe, with changes in agricultural and environmental policies likely explaining the remainder.

  1. The buffer value of groundwater when well yield is limited

    NASA Astrophysics Data System (ADS)

    Foster, T.; Brozović, N.; Speir, C.

    2017-04-01

    A large proportion of the total value of groundwater in conjunctive use systems is associated with the ability to smooth out shortfalls in surface water supply during droughts. Previous research has argued that aquifer depletion in these regions will impact farmers negatively by reducing the available stock of groundwater to buffer production in future periods, and also by increasing the costs of groundwater extraction. However, existing studies have not considered how depletion may impact the productivity of groundwater stocks in conjunctive use systems through reductions in well yields. In this work, we develop a hydro-economic modeling framework to quantify the effects of changes in well yields on the buffer value of groundwater, and apply this model to an illustrative case study of tomato production in California's Central Valley. Our findings demonstrate that farmers with low well yields are forced to forgo significant production and profits because instantaneous groundwater supply is insufficient to buffer surface water shortfalls in drought years. Negative economic impacts of low well yields are an increasing function of surface water variability, and are also greatest for farmers operating less efficient irrigation systems. These results indicate that impacts of well yield reductions on the productivity of groundwater are an important economic impact of aquifer depletion, and that failure to consider this feedback may lead to significant errors in estimates of the value of groundwater management in conjunctive use systems.

  2. Respiration hastens maturation and lowers yield in rice.

    PubMed

    Sitaramam, V; Bhate, R; Kamalraj, P; Pachapurkar, S

    2008-07-01

    Role of respiration in plant growth remains an enigma. Growth of meristematic cells, which are not photosynthetic, is entirely driven by endogenous respiration. Does respiration determine growth and size or does it merely burn off the carbon depleting the biomass? We show here that respiration of the germinating rice seed, which is contributed largely by the meristematic cells of the embryo, quantitatively correlates with the dynamics of much of plant growth, starting with the time for germination to the time for flowering and yield. Seed respiration appears to define the quantitative phenotype that contributes to yield via growth dynamics that could be discerned even in commercial varieties, which are biased towards higher yield, despite considerable susceptibility of the dynamics to environmental perturbations. Intrinsic variation, irreducible despite stringent growth conditions, required independent validation of relevant physiological variables both by critical sampling design and by constructing dendrograms for the interrelationships between variables that yield high consensus. More importantly, seed respiration, by mediating the generation clock time via variable time for maturation as seen in rice, directly offers the plausible basis for the phenotypic variation, a major ecological stratagem in a variable environment with uncertain water availability. Faster respiring rice plants appear to complete growth dynamics sooner, mature faster, resulting in a smaller plant with lower yield. Counter to the common allometric views, respiration appears to determine size in the rice plant, and offers a valid physiological means, within the limits of intrinsic variation, to help parental selection in breeding.

  3. Genomic architecture of heterosis for yield traits in rice.

    PubMed

    Huang, Xuehui; Yang, Shihua; Gong, Junyi; Zhao, Qiang; Feng, Qi; Zhan, Qilin; Zhao, Yan; Li, Wenjun; Cheng, Benyi; Xia, Junhui; Chen, Neng; Huang, Tao; Zhang, Lei; Fan, Danlin; Chen, Jiaying; Zhou, Congcong; Lu, Yiqi; Weng, Qijun; Han, Bin

    2016-09-29

    Increasing grain yield is a long-term goal in crop breeding to meet the demand for global food security. Heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. To examine the genetic basis of heterosis for yield in rice, here we generate, sequence and record the phenotypes of 10,074 F2 lines from 17 representative hybrid rice crosses. We classify modern hybrid rice varieties into three groups, representing different hybrid breeding systems. Although we do not find any heterosis-associated loci shared across all lines, within each group, a small number of genomic loci from female parents explain a large proportion of the yield advantage of hybrids over their male parents. For some of these loci, we find support for partial dominance of heterozygous locus for yield-related traits and better-parent heterosis for overall performance when all of the grain-yield traits are considered together. These results inform on the genomic architecture of heterosis and rice hybrid breeding.

  4. Improvement of Rice Biomass Yield through QTL-Based Selection

    PubMed Central

    Matsubara, Kazuki; Yamamoto, Eiji; Kobayashi, Nobuya; Ishii, Takuro; Tanaka, Junichi; Tsunematsu, Hiroshi; Yoshinaga, Satoshi; Matsumura, Osamu; Yonemaru, Jun-ichi; Mizobuchi, Ritsuko; Yamamoto, Toshio; Kato, Hiroshi; Yano, Masahiro

    2016-01-01

    Biomass yield of rice (Oryza sativa L.) is an important breeding target, yet it is not easy to improve because the trait is complex and phenotyping is laborious. Using progeny derived from a cross between two high-yielding Japanese cultivars, we evaluated whether quantitative trait locus (QTL)-based selection can improve biomass yield. As a measure of biomass yield, we used plant weight (aboveground parts only), which included grain weight and stem and leaf weight. We measured these and related traits in recombinant inbred lines. Phenotypic values for these traits showed a continuous distribution with transgressive segregation, suggesting that selection can affect plant weight in the progeny. Four significant QTLs were mapped for plant weight, three for grain weight, and five for stem and leaf weight (at α = 0.05); some of them overlapped. Multiple regression analysis showed that about 43% of the phenotypic variance of plant weight was significantly explained (P < 0.0001) by six of the QTLs. From F2 plants derived from the same parental cross as the recombinant inbred lines, we divergently selected lines that carried alleles with positive or negative additive effects at these QTLs, and performed successive selfing. In the resulting F6 lines and parents, plant weight significantly differed among the genotypes (at α = 0.05). These results demonstrate that QTL-based selection is effective in improving rice biomass yield. PMID:26986071

  5. Yield stress anomaly in B2 FeAl

    SciTech Connect

    Yoshimi, K.; Hanada, S.; Yoo, M.H.

    1996-12-31

    The studies on yield stress anomaly of B2 FeAl single crystals are reviewed in this paper. A positive temperature dependence of yield stress, so-called yield stress anomaly, is observed in B2 FeAl in which excess vacancies are fully annealed out. Associated with the anomaly, characteristic asymmetry is found between tension and compression. While the strain-rate sensitivity is almost zero in the temperature range of the yield stress anomaly, the stress relaxation becomes significant with increasing temperature, indicating that a recovery process is thermally activated. It is ascertained by the two-surface trace analysis that slip transition from <111> direction at intermediate temperature to <100> at high temperature occurs around the peak temperature. Even at the peak temperature, in addition, operative slip vector for yielding is confirmed to be predominantly <111> by TEM. Also, it is observed that <111>-type superdislocations are frequently climb-dissociated in the temperature range of the anomaly. APB formation on {l_brace}111{r_brace} plane is energetically favorable, which is in agreement with the Flinn`s calculation for the B2 superlattice that APB energy on {l_brace}111{r_brace} plane is lower than that on {l_brace}110{r_brace} plane. Such an anisotropy of APB energy would offer specific driving force for the climb dissociation on <111> superdislocations. On the basis of the observed results, the anomalous strengthening behavior of B2 FeAl single crystals is discussed.

  6. Metabolism and growth yields in Bacteroides ruminicola strain b14.

    PubMed Central

    Howlett, M R; Mountfort, D O; Turner, K W; Roberton, A M

    1976-01-01

    Metabolism of D-glucose by Bacteroides ruminicola subsp. brevis, strain B14, has been examined. Growth yield studies gave molar growth yields, corrected for storage polysaccharide, of approximately 66 g (dry weight)/mol of glucose fermented. The storage polysaccharide amounted to about 14% of the total dry weight, or 55% of the total cellular carbohydrate, at full growth. After correcting glucose utilization for incorporation into cellular carbohydrate, measurement of product formation showed that 1.1 succinate, 0.8 acetate, and 0.35 formate are produced and 0.5 CO2 net is taken up during the fermentation of 1 glucose under the conditions used. The implication of these results with respect to adenosine 5'-triphosphate (ATP) molar growth yield calculations is discussed. If substrate-level phosphorylation reactions alone are responsible for ATP generation, then the ATP molar growth yield must be about 23 g (dry weight)/mol of ATP. Alternatively, if anaerobic electron transfer-linked phosphorylation also occurs, the ATP molar growth yield will be lower. Images PMID:970946

  7. The fingerprint of climate trends on European crop yields

    PubMed Central

    Moore, Frances C.; Lobell, David B.

    2015-01-01

    Europe has experienced a stagnation of some crop yields since the early 1990s as well as statistically significant warming during the growing season. Although it has been argued that these two are causally connected, no previous studies have formally attributed long-term yield trends to a changing climate. Here, we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these tests to European agriculture, we find evidence that long-term temperature and precipitation trends since 1989 have reduced continent-wide wheat and barley yields by 2.5% and 3.8%, respectively, and have slightly increased maize and sugar beet yields. These averages disguise large heterogeneity across the continent, with regions around the Mediterranean experiencing significant adverse impacts on most crops. This result means that climate trends can account for ∼10% of the stagnation in European wheat and barley yields, with likely explanations for the remainder including changes in agriculture and environmental policies. PMID:25691735

  8. The fingerprint of climate trends on European crop yields.

    PubMed

    Moore, Frances C; Lobell, David B

    2015-03-03

    Europe has experienced a stagnation of some crop yields since the early 1990s as well as statistically significant warming during the growing season. Although it has been argued that these two are causally connected, no previous studies have formally attributed long-term yield trends to a changing climate. Here, we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these tests to European agriculture, we find evidence that long-term temperature and precipitation trends since 1989 have reduced continent-wide wheat and barley yields by 2.5% and 3.8%, respectively, and have slightly increased maize and sugar beet yields. These averages disguise large heterogeneity across the continent, with regions around the Mediterranean experiencing significant adverse impacts on most crops. This result means that climate trends can account for ∼ 10% of the stagnation in European wheat and barley yields, with likely explanations for the remainder including changes in agriculture and environmental policies.

  9. Atomic Oxygen Erosion Yield Dependence Upon Texture Development in Polymers

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Loftus, Ryan J.; Miller, Sharon K.

    2016-01-01

    The atomic oxygen erosion yield (volume of a polymer that is lost due to oxidation per incident atom) of polymers is typically assumed to be reasonably constant with increasing fluence. However polymers containing ash or inorganic pigments, tend to have erosion yields that decrease with fluence due to an increasing presence of protective particles on the polymer surface. This paper investigates two additional possible causes for erosion yields of polymers that are dependent upon atomic oxygen. These are the development of surface texture which can cause the erosion yield to change with fluence due to changes in the aspect ratio of the surface texture that develops and polymer specific atomic oxygen interaction parameters. The surface texture development under directed hyperthermal attack produces higher aspect ratio surface texture than isotropic thermal energy atomic oxygen attack. The fluence dependence of erosion yields is documented for low Kapton H (DuPont, Wilmington, DE) effective fluences for a variety of polymers under directed hyperthermal and isotropic thermal energy attack.

  10. ICF Gamma-Ray Yield Measurements on the NIF

    NASA Astrophysics Data System (ADS)

    Herrmann, H. W.; Kim, Y. H.; Hoffman, N. M.; Stoeffl, W. S.; Watts, P. W.; Carpenter, A. C.; Church, J. A.; Liebman, J.; Grafil, E.

    2011-10-01

    The primary objective of the NIF Gamma Reaction History (GRH) diagnostic is to provide bang time and burn width information in order to constrain implosion simulation parameters such as shell velocity and confinement time. This is accomplished by measuring DT fusion γ-rays with energy-thresholded Gas Cherenkov detectors that convert MeV γ-rays into UV/visible photons for high-bandwidth optical detection. For yield determination, absolute uncertainties associated with the d(t,n) α/d(t,γ)5He branching ratio and detector response are removed by cross-calibrating the GRH signal against independent neutron yield measurements of directly-driven DT exploding pushers with negligible neutron downscatter. The GRH signal can then be used to make Total DTn Yield inferences on indirectly-driven, cryogenically-layered DT implosions which achieve high areal density and hence scatter a significant fraction of DTn out of the 14 MeV primary peak. By comparing the Total DTn Yield from γ-ray measurements with the Primary DTn Yield (13-15 MeV) from neutron measurements, the Total Downscatter Fraction (TDSF) can be inferred. Results of recent measurements will be presented. This work supported by US DOE under contract DE-AC52-06NA25396.

  11. Strontium and barium iodide high light yield scintillators

    NASA Astrophysics Data System (ADS)

    Cherepy, Nerine J.; Hull, Giulia; Drobshoff, Alexander D.; Payne, Stephen A.; van Loef, Edgar; Wilson, Cody M.; Shah, Kanai S.; Roy, Utpal N.; Burger, Arnold; Boatner, Lynn A.; Choong, Woon-Seng; Moses, William W.

    2008-02-01

    Europium-doped strontium and barium iodide are found to be readily growable by the Bridgman method and to produce high scintillation light yields. SrI2(Eu ) emits into the Eu2+ band, centered at 435nm, with a decay time of 1.2μs and a light yield of ˜90000photons/MeV. It offers energy resolution better than 4% full width at half maximum at 662keV, and exhibits excellent light yield proportionality. BaI2(Eu ) produces >30000photons/MeV into the Eu2+ band at 420nm (<1μs decay). An additional broad impurity-mediated recombination band is present at 550nm (>3μs decay), unless high-purity feedstock is used.

  12. Secondary-neutron-yield measurements by current-mode detectors

    SciTech Connect

    Glebov, V. Yu.; Meyerhofer, D. D.; Stoeckl, C.; Zuegel, J. D.

    2001-01-01

    Secondary deuterium--tritium (DT) neutrons from pure-deuterium inertial confinement fusion targets can be used to diagnose the fuel areal density. Single-hit detectors like LaNSA at Lawrence Livermore National Laboratory or MEDUSA at the Laboratory for Laser Energetics (LLE) saturate for fairly low secondary DT- and primary DD-neutron yields. These detectors are not suitable for the high-yield, direct-drive implosion experiments currently carried out on the 30 kJ, 60 beam OMEGA laser system or for future cryogenic-capsule experiments on OMEGA. The status of several current-mode detectors (e.g., a single scintillator and a photomultiplier tube) now being developed at LLE for secondary-neutron-yield measurements is described.

  13. Dependence of Simulated Supernova Yields on the Explosion Morphology

    NASA Astrophysics Data System (ADS)

    Vance, Gregory; Young, Patrick A.

    2016-06-01

    Supernovae are the principal source of heavy elements in the universe, and their yields can vary significantly depending on the morphology of the explosion. The structure of the circumstellar medium, the rotation or magnetic fields of the progenitor, the presence of a companion, and other factors can all affect the proportions of different isotopes that are synthesized, as well as where those products are deposited. To examine in detail the effects of these different factors, we employ supercomputer simulations of supernova explosions in three dimensions using the SNSPH code, with postprocessing to predict total and spatially mapped yields for 522 isotopes. We present visualizations and comparative analysis of the yields from simulations with spherically symmetric, unipolar, and bipolar geometries for 15- and 20-solar-mass progenitors. These allow us to begin identifying the effects of the explosion morphology and improving our understanding of how these events influence the composition of matter in the universe.

  14. Simulation of DSB yield for high LET radiation.

    PubMed

    Friedrich, T; Durante, M; Scholz, M

    2015-09-01

    A simulation approach for the calculation of the LET-dependent yield of double-strand breaks (DSB) is presented. The model considers DSB formed as two close-lying single-strand breaks (SSB), whose formation is mediated by both intra-track processes (single electrons) or at local doses larger than about 1000 Gy in particle tracks also by electron inter-track processes (two independent electron tracks). A Monte Carlo algorithm and an analytical formula for the DSB yield are presented. The approach predicts that the DSB yield is enhanced after charged particle irradiation of high LET compared with X-ray or gamma radiation. It is used as an inherent part of the local effect model, which is applied to estimate the relative biological effectiveness of high LET radiation.

  15. Pyrolysis of wood to biochar: increasing yield while maintaining microporosity.

    PubMed

    Veksha, Andrei; McLaughlin, Hugh; Layzell, David B; Hill, Josephine M

    2014-02-01

    The objective of this study was to determine if biochar yield could be increased by the deposition of volatile pyrolysis species within the bed during production, without negatively influencing the microporosity and adsorption properties. Aspen (Populus tremuloides) wood chips were loaded into three vertically stacked zones within a reactor and heated in nitrogen to temperatures between 420 and 650°C (i.e., pyrolyzed). The yield did increase from the zone at the reactor inlet to the subsequent zones as volatile species deposited and carbonized, and importantly, the carbonized deposits had a similar microporous structure and organic vapor uptake (1,1,1,2-tetrafluoroethane) to that of the primary biochar. Based on these results, bio-oil from previous runs at 600°C was recycled to the bed, which further increased the yield while maintaining the desirable adsorption properties of the biochar.

  16. Combining high biodiversity with high yields in tropical agroforests.

    PubMed

    Clough, Yann; Barkmann, Jan; Juhrbandt, Jana; Kessler, Michael; Wanger, Thomas Cherico; Anshary, Alam; Buchori, Damayanti; Cicuzza, Daniele; Darras, Kevin; Putra, Dadang Dwi; Erasmi, Stefan; Pitopang, Ramadhanil; Schmidt, Carsten; Schulze, Christian H; Seidel, Dominik; Steffan-Dewenter, Ingolf; Stenchly, Kathrin; Vidal, Stefan; Weist, Maria; Wielgoss, Arno Christian; Tscharntke, Teja

    2011-05-17

    Local and landscape-scale agricultural intensification is a major driver of global biodiversity loss. Controversially discussed solutions include wildlife-friendly farming or combining high-intensity farming with land-sparing for nature. Here, we integrate biodiversity and crop productivity data for smallholder cacao in Indonesia to exemplify for tropical agroforests that there is little relationship between yield and biodiversity under current management, opening substantial opportunities for wildlife-friendly management. Species richness of trees, fungi, invertebrates, and vertebrates did not decrease with yield. Moderate shade, adequate labor, and input level can be combined with a complex habitat structure to provide high biodiversity as well as high yields. Although livelihood impacts are held up as a major obstacle for wildlife-friendly farming in the tropics, our results suggest that in some situations, agroforests can be designed to optimize both biodiversity and crop production benefits without adding pressure to convert natural habitat to farmland.

  17. Ants and termites increase crop yield in a dry climate

    PubMed Central

    Evans, Theodore A.; Dawes, Tracy Z.; Ward, Philip R.; Lo, Nathan

    2011-01-01

    Agricultural intensification has increased crop yields, but at high economic and environmental cost. Harnessing ecosystem services of naturally occurring organisms is a cheaper but under-appreciated approach, because the functional roles of organisms are not linked to crop yields, especially outside the northern temperate zone. Ecosystem services in soil come from earthworms in these cooler and wetter latitudes; what may fulfill their functional role in agriculture in warmer and drier habitats, where they are absent, is unproven. Here we show in a field experiment that ants and termites increase wheat yield by 36% from increased soil water infiltration due to their tunnels and improved soil nitrogen. Our results suggest that ants and termites have similar functional roles to earthworms, and that they may provide valuable ecosystem services in dryland agriculture, which may become increasingly important for agricultural sustainability in arid climates. PMID:21448161

  18. Critical study of the B{yields}K{pi} puzzle

    SciTech Connect

    Kim, C.S.; Oh, Sechul; Yu, Chaehyun

    2005-10-01

    In the light of new experimental results on B{yields}K{pi} decays, we critically study the decay processes B{yields}K{pi} in a phenomenological way. Using the quark diagram approach and the currently available data, we determine the allowed values of the relevant theoretical parameters, corresponding to the electroweak (EW) penguin, the color-suppressed tree contribution, etc. In order to find the most likely values of the parameters in a statistically reliable way, we use the {chi}{sup 2} minimization technique. Our result shows that the current data for B{yields}K{pi} decays strongly indicate (large) enhancements of both the EW penguin and the color-suppressed tree contributions. In particular, the color-suppressed tree effect needs to be enhanced by about an order of magnitude to fit the present data.

  19. High-yield positron systems for linear colliders

    SciTech Connect

    Clendenin, J.E.

    1989-04-01

    Linear colliders, such as the SLC, are among those accelerators for which a high-yield positron source operating at the repetition rate of the accelerator is desired. The SLC, having electron energies up to 50 GeV, presents the possibility of generating positron bunches with useful charge even exceeding that of the initial electron bunch. The exact positron yield to be obtained depends on the particular capture, transport and damping system employed. Using 31 GeV electrons impinging on a W-type converter phase-space at the target to the acceptance of the capture rf section, the SLC source is capable of producing, for every electron, up to two positrons within the acceptance of the positron damping ring. The design of this source and the performance of the positron system as built are described. Also, future prospects and limitations for high-yield positron systems are discussed. 11 refs., 5 figs., 3 tabs.

  20. Viscoplasticity with dynamic yield surface coupled to damage

    NASA Astrophysics Data System (ADS)

    Johansson, M.; Runesson, K.

    1997-07-01

    A formulation of viscoplasticity theory, with kinetic coupling to damage, is presented. The main purpose is to describe rate-dependent material behavior and failure processes, including creep-rupture (for constant load) and creep-fatigue (for cyclic load). The Duvaut-Lions' formulation of viscoplasticity is adopted with quite general hardening of the quasistatic yield surface. The formulation is thermodynamically consistent, i.e. the dissipation inequality is satisfied. Like in the classical viscoplasticity formulations, the rate-independent response is activated at a very small loading rate. In addition, an (unconventional) dynamic yield surface is introduced, and this is approached asymptotically at infinite loading rate. Explicit constitutive relations are established for a quasistatic yield surface of von Mises type with nonlinear hardening. The resulting model is assessed for a variety of loading situations.

  1. Specific Yield--Column drainage and centrifuge moisture content

    USGS Publications Warehouse

    Johnson, A.I.; Prill, R.C.; Morris, D.A.

    1963-01-01

    The specific yield of a rock or soil, with respect to water, is the ratio of (1) the volume of water which, after being saturated, it will yield by gravity to (2) its own volume. Specific retention represents the water retained against gravity drainage. The specific yield and retention when added together are equal to the total interconnected porosity of the rock or soil. Because specific retention is more easily determined than specific yield, most methods for obtaining yield first require the determination of specific retention. Recognizing the great need for developing improved methods of determining the specific yield of water-bearing materials, the U.S. Geological Survey and the California Department of Water Resources initiated a cooperative investigation of this subject. The major objectives of this research are (1) to review pertinent literature on specific yield and related subjects, (2) to increase basic knowledge of specific yield and rate of drainage and to determine the most practical methods of obtaining them, (3) to compare and to attempt to correlate the principal laboratory and field methods now commonly used to obtain specific yield, and (4) to obtain improved estimates of specific yield of water-bearing deposits in California. An open-file report, 'Specific yield of porous media, an annotated bibliography,' by A. I. Johnson, D. A. Morris, and R. C. Prill, was released in 1960 in partial fulfillment of the first objective. This report describes the second phase of the specific-yield study by the U.S. Geological Survey Hydrologic Laboratory at Denver, Colo. Laboratory research on column drainage and centrifuge moisture equivalent, two methods for estimating specific retention of porous media, is summarized. In the column-drainage study, a wide variety of materials was packed into plastic columns of 1- to 8-inch diameter, wetted with Denver tap water, and drained under controlled conditions of temperature and humidity. The effects of cleaning the

  2. Sputtering yield of Pu bombarded by fission Fragments from Cf

    SciTech Connect

    Danagoulian, Areg; Klein, Andreas; Mcneil, Wendy V; Yuan, Vincent W

    2008-01-01

    We present results on the yield of sputtering of Pu atoms from a Pu foil, bombarded by fission fragments from a {sup 252}Cf source in transmission geometry. We have found the number of Pu atoms/incoming fission fragments ejected to be 63 {+-} 1. In addition, we show measurements of the sputtering yield as a function of distance from the central axis, which can be understood as an angular distribution of the yield. The results are quite surprising in light of the fact that the Pu foil is several times the thickness of the range of fission fragment particles in Pu. This indicates that models like the binary collision model are not sufficient to explain this behavior.

  3. Yielding transitions and grain-size effects in dislocation theory

    NASA Astrophysics Data System (ADS)

    Langer, J. S.

    2017-03-01

    The statistical-thermodynamic dislocation theory developed in previous papers is used here in an analysis of yielding transitions and grain-size effects in polycrystalline solids. Calculations are based on the 1995 experimental results of Meyers, Andrade, and Chokshi [Metall. Mater. Trans. A 26, 2881 (1995), 10.1007/BF02669646] for polycrystalline copper under strain-hardening conditions. The main assertion is that the well-known Hall-Petch effects are caused by enhanced strengths of dislocation sources at the edges of grains instead of the commonly assumed resistance to dislocation flow across grain boundaries. The theory describes rapid transitions between elastic and plastic deformation at yield points; thus it can be used to predict grain-size dependence of both yield stresses and flow stresses.

  4. Products and yields from O3 photodissociation at 1576 A

    NASA Technical Reports Server (NTRS)

    Taherian, M. R.; Slanger, T. G.

    1985-01-01

    An analysis has been made of the primary atomic and molecular products arising from O3 photodissociation at 1576 A. The yield of oxygen atoms is 1.90 + or - 0.30, of which 71 percent are O(3P) and 29 percent are O(1D). Since a primary yield greater than unity can only be a consequence of three-fragment dissociation, these results suggest that fragmentation into three O(3P) atoms, and production of O(1D) plus a singlet oxygen molecule, have comparable yields. Observation of prompt emission in the 7300-8100 A spectral region indicates that the singlet O2 is O2(b 1Sigma + g). Vibrational levels in the range v = 0-6 have been detected, the distribution corresponding to a vibrational temperature of 1000 K.

  5. On the photoelectric quantum yield of small dust particles

    NASA Astrophysics Data System (ADS)

    Kimura, Hiroshi

    2016-07-01

    Photoelectron emission is crucial to electric charging of dust particles around main-sequence stars and gas heating in various dusty environments. An estimate of the photoelectric processes contains an ill-defined parameter called the photoelectric quantum yield, which is the total number of electrons ejected from a dust particle per absorbed photon. Here we revisit the so-called small particle effect of photoelectron emission and provide an analytical model to estimate photoelectric quantum yields of small dust particles in sizes down to nanometers. We show that the small particle effect elevates the photoelectric quantum yields of nanoparticles up to by a factor of 103 for carbon, water ice, and organics, and a factor of 102 for silicate, silicon carbide, and iron. We conclude the surface curvature of the particles is a quantity of great importance to the small particle effect, unless the particles are submicrometers in radius or larger.

  6. Bats and birds increase crop yield in tropical agroforestry landscapes.

    PubMed

    Maas, Bea; Clough, Yann; Tscharntke, Teja

    2013-12-01

    Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management.

  7. Neutron emission and fragment yield in high-energy fission

    SciTech Connect

    Grudzevich, O. T. Klinov, D. A.

    2013-07-15

    The KRIS special library of spectra and emission probabilities in the decays of 1500 nuclei excited up to energies between 150 and 250 MeV was developed for correctly taking into account the decay of highly excited nuclei appearing as fission fragments. The emission of neutrons, protons, and photons was taken into account. Neutron emission fromprimary fragments was found to have a substantial effect on the formation of yields of postneutron nuclei. The library was tested by comparing the calculated and measured yields of products originating from the fission of nuclei that was induced by high-energy protons. The method for calculating these yields was tested on the basis of experimental data on the thermal-neutroninduced fission of {sup 235}U nuclei.

  8. Universality in fragment inclusive yields from Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Insolia, A.; Tuvè, C.; Albergo, S.; Bieser, F.; Brady, F. P.; Caccia, Z.; Cebra, D.; Chacon, A. D.; Chance, J. L.; Choi, Y.; Costa, S.; Elliott, J. B.; Gilkes, M.; Hauger, J. A.; Hirsch, A. S.; Hjort, E. L.; Justice, M.; Keane, D.; Kintner, J.; Lisa, M.; Matis, H. S.; McMahan, M.; McParland, C.; Olson, D. L.; Partlan, M. D.; Porile, N. T.; Potenza, R.; Rai, G.; Rasmussen, J.; Ritter, H. G.; Romero, J. L.; Russo, G. V.; Scharenberg, R.; Scott, A.; Shao, Y.; Srivastava, B. K.; Symons, T. J. M.; Tincknell, M. L.; Wang, S.; Warren, P. G.; Wieman, H. H.; Wolf, K. L.

    2001-11-01

    The inclusive light fragment (Z⩽7) yield data in Au+Au reactions, measured by the EOS Collaboration at the LBNL Bevalac, are presented and discussed. For peripheral collisions the measured charge distributions develop progressively according to a power law which can be fitted by a single τ exponent independently of the bombarding energy in the range 250-1200 A MeV. In addition to this universal feature, we observe that the location of the maximum in the individual yields of different charged fragments shift towards lower multiplicity as the fragment charge increases from Z=3 to Z=7. This trend is common to all six measured beam energies. Moments of charge distributions and correlations among different moments are reported. Finally, the THe,DT thermometer has been constructed for central and peripheral collisions using the double yield ratios of He and D, T projectile fragments. The measured nuclear temperatures are in agreement with experimental findings in other fragmentation reactions.

  9. Step edge sputtering yield at grazing incidence ion bombardment.

    PubMed

    Hansen, Henri; Polop, Celia; Michely, Thomas; Friedrich, Andreas; Urbassek, Herbert M

    2004-06-18

    The surface morphology of Pt(111) was investigated by scanning tunneling microscopy after 5 keV Ar+ ion bombardment at grazing incidence in dependence of the ion fluence and in the temperature range between 625 and 720 K. The average erosion rate was found to be strongly dependent on the ion fluence and the substrate temperature during bombardment. This dependence is traced back to the variation of step concentration with temperature and fluence. We develop a simple model allowing us to determine separately the constant sputtering yields for terraces and for impact area stripes in front of ascending steps. The experimentally determined yield of these stripes--the step-edge sputtering yield--is in excellent agreement with our molecular dynamics simulations performed for the experimental situation.

  10. Breeding Value of Primary Synthetic Wheat Genotypes for Grain Yield

    PubMed Central

    Jafarzadeh, Jafar; Bonnett, David; Jannink, Jean-Luc; Akdemir, Deniz; Dreisigacker, Susanne; Sorrells, Mark E.

    2016-01-01

    To introduce new genetic diversity into the bread wheat gene pool from its progenitor, Aegilops tauschii (Coss.) Schmalh, 33 primary synthetic hexaploid wheat genotypes (SYN) were crossed to 20 spring bread wheat (BW) cultivars at the International Wheat and Maize Improvement Center. Modified single seed descent was used to develop 97 populations with 50 individuals per population using first back-cross, biparental, and three-way crosses. Individuals from each cross were selected for short stature, early heading, flowering and maturity, minimal lodging, and free threshing. Yield trials were conducted under irrigated, drought, and heat-stress conditions from 2011 to 2014 in Ciudad Obregon, Mexico. Genomic estimated breeding values (GEBVs) of parents and synthetic derived lines (SDLs) were estimated using a genomic best linear unbiased prediction (GBLUP) model with markers in each trial. In each environment, there were SDLs that had higher GEBVs than their recurrent BW parent for yield. The GEBVs of BW parents for yield ranged from -0.32 in heat to 1.40 in irrigated trials. The range of the SYN parent GEBVs for yield was from -2.69 in the irrigated to 0.26 in the heat trials and were mostly negative across environments. The contribution of the SYN parents to improved grain yield of the SDLs was highest under heat stress, with an average GEBV for the top 10% of the SDLs of 0.55 while the weighted average GEBV of their corresponding recurrent BW parents was 0.26. Using the pedigree-based model, the accuracy of genomic prediction for yield was 0.42, 0.43, and 0.49 in the drought, heat and irrigated trials, respectively, while for the marker-based model these values were 0.43, 0.44, and 0.55. The SYN parents introduced novel diversity into the wheat gene pool. Higher GEBVs of progenies were due to introgression and retention of some positive alleles from SYN parents. PMID:27656893

  11. Climate change: implications for the yield of edible rice.

    PubMed

    Zhao, Xiangqian; Fitzgerald, Melissa

    2013-01-01

    Global warming affects not only rice yield but also grain quality. A better understanding of the effects of climate factors on rice quality provides information for new breeding strategies to develop varieties of rice adapted to a changing world. Chalkiness is a key trait of physical quality, and along with head rice yield, is used to determine the price of rice in all markets. In the present study, we show that for every ∼1% decrease in chalkiness, an increase of ∼1% in head rice yield follows, illustrating the dual impact of chalk on amount of marketable rice and its value. Previous studies in controlled growing conditions report that chalkiness is associated with high temperature. From 1980-2009 at IRRI, Los Baños, the Philippines, annual minimum and mean temperatures, and diurnal variation changed significantly. The objective of this study was to determine how climate impacts chalkiness in field conditions over four wet and dry seasons. We show that low relative humidity and a high vapour pressure deficit in the dry season associate with low chalk and high head rice yield in spite of higher maximum temperature, but in the opposite conditions of the wet season, chalk is high and head rice yield is low. The data therefore suggest that transpirational cooling is a key factor affecting chalkiness and head rice yield, and global warming per se might not be the major factor that decreases the amount and quality of rice, but other climate factors in combination, that enable the crop to maintain a cool canopy.

  12. Evaluation and compilation of fission product yields 1993

    SciTech Connect

    England, T.R.; Rider, B.F.

    1995-12-31

    This document is the latest in a series of compilations of fission yield data. Fission yield measurements reported in the open literature and calculated charge distributions have been used to produce a recommended set of yields for the fission products. The original data with reference sources, and the recommended yields axe presented in tabular form. These include many nuclides which fission by neutrons at several energies. These energies include thermal energies (T), fission spectrum energies (F), 14 meV High Energy (H or HE), and spontaneous fission (S), in six sets of ten each. Set A includes U235T, U235F, U235HE, U238F, U238HE, Pu239T, Pu239F, Pu241T, U233T, Th232F. Set B includes U233F, U233HE, U236F, Pu239H, Pu240F, Pu241F, Pu242F, Th232H, Np237F, Cf252S. Set C includes U234F, U237F, Pu240H, U234HE, U236HE, Pu238F, Am241F, Am243F, Np238F, Cm242F. Set D includes Th227T, Th229T, Pa231F, Am241T, Am241H, Am242MT, Cm245T, Cf249T, Cf251T, Es254T. Set E includes Cf250S, Cm244S, Cm248S, Es253S, Fm254S, Fm255T, Fm256S, Np237H, U232T, U238S. Set F includes Cm243T, Cm246S, Cm243F, Cm244F, Cm246F, Cm248F, Pu242H, Np237T, Pu240T, and Pu242T to complete fission product yield evaluations for 60 fissioning systems in all. This report also serves as the primary documentation for the second evaluation of yields in ENDF/B-VI released in 1993.

  13. Anomalous softening of yield strength in tantalum at high pressures

    SciTech Connect

    Jing, Qiumin Wu, Qiang; Xu, Ji-an; Bi, Yan; Liu, Lei; Liu, Shenggang; Zhang, Yi; Geng, Huayun

    2015-02-07

    The pressure dependence of the yield strength of tantalum was investigated experimentally up to 101 GPa at room temperature using a diamond anvil cell. A yield strength softening is observed between 52 and 84 GPa, whereas a normal trend is observed below 52 GPa and above 84 GPa. The onset pressure of the softening is in agreement with previous results obtained by the pressure gradient method and shock wave experiments. This unusual strength softening in tantalum is not related with structural transformation, preferred orientation, or material damage. Our measurements indicate that microscopic deviatoric strain is the major reason for the observed strength softening in tantalum.

  14. Using Landsat TM data to model corn and soybean yields

    NASA Astrophysics Data System (ADS)

    Candanedo Guevara, Martin Edmundo

    2001-07-01

    Early research in agriculture used remotely sensed data mostly for the identification of spectral signatures, where crop type/area classification would depend on data acquired from hand-held or truck-mounted instruments. Through time different approaches were taken for crop type/area classification, such as a systematic sampling of inventory ground data that were used later for training and testing using image processing techniques. Later, technology such as the global positioning system (GPS) and geographic information systems (GIS) were used for application to precision agriculture. These new tools provided a better meaning to understand and analyze the complex variability of the crop-soil-atmosphere system to estimate crop yields. The present research used data collected in the Management System Evaluation Area (MSEA) in 1998 and two Landsat thematic Mapper images (July and August) to analyze the crop variability. Ground truth parameters, such as chlorophyll, leaf area index (LAI), and electricity conductivity, were collected throughout the growing season. In addition, vegetation indexes (VI) such as the Normalized difference vegetation index (NDVI), simple vegetation index (SVI), soil adjusted ratio vegetation index (SARVI), were computed for the two images. Both ground truth data and VI's were statistically analyzed with yield measurements taken with an on-the-go yield monitor to estimate a best fit yield model for use with soybeans and corn. The correlation analysis within a Landsat pixel reported SVI52 (r = 0.62), SVI53 (r = 0.56), and SVI54 (r = 0.53) as the most significant relationships. The results from the ground truth data vs. on-the-go yields reported total clay (%) (r = 0.90), leaf area (r = 0.76), and tissue plant analysis (r = 0.73) A stepwise regression analysis was performed using the Landsat TM images and the VI's selected. A series of linear models were evaluated taking into account the Landsat TM and yield while varying the scale (1 pixel to

  15. pi {sup 0} {yields} gamma gamma to NLO in CHPT

    SciTech Connect

    Jose Goity

    2003-05-01

    The pi 0 {yields} gamma gamma width is determined to next to leading order in the combined chiral and 1/Nc expansions. It is shown that corrections driven by chiral symmetry breaking produce an enhancement of about 4.5% with respect to the width calculated in terms of the chiral-limit amplitude leading to Gamma{sub {pi}}{sup 0} {yields} {gamma}{gamma} = 8.1 +/- 0.08 MeV. This theoretical prediction will be tested via pi 0 Primakoff production by the PRIMEX experiment at Jefferson Lab.

  16. Enhanced Electroweak Penguin Amplitude in B{yields}VV Decays

    SciTech Connect

    Beneke, M.; Rohrer, J.; Yang, D.

    2006-04-14

    We discuss a novel electromagnetic penguin contribution to the transverse helicity amplitudes in B decays to two vector mesons, which is enhanced by two powers of m{sub B}/{lambda} relative to the standard penguin amplitudes. This leads to unique polarization signatures in penguin-dominated decay modes such as B{yields}{rho}K* similar to polarization effects in the radiative decay B{yields}K*{gamma} and offers new opportunities to probe the magnitude and chirality of flavor-changing neutral current couplings to photons.

  17. A new yield criterion for the concrete materials

    NASA Astrophysics Data System (ADS)

    François, Marc

    2008-05-01

    The yield criterion proposed depends upon two material constants and is proven to be smooth and convex under a simple condition. These properties induce a mathematical robustness that allows a further use in a damage mechanics model. The analytical gradient and Hessian are given. The obtained yield surface is relevant to Kupfer's biaxial testings on concrete. The identification procedure, with respect to the classical uniaxial tension and compression testings, is detailed. To cite this article: M. François, C. R. Mecanique 336 (2008).

  18. The kinetic origin of delayed yielding in metallic glasses

    NASA Astrophysics Data System (ADS)

    Ye, Y. F.; Liu, X. D.; Wang, S.; Fan, J.; Liu, C. T.; Yang, Y.

    2016-06-01

    Recent experiments showed that irreversible structural change or plasticity could occur in metallic glasses (MGs) even within the apparent elastic limit after a sufficiently long waiting time. To explain this phenomenon, a stochastic shear transformation model is developed based on a unified rate theory to predict delayed yielding in MGs, which is validated afterwards through extensive atomistic simulations carried out on different MGs. On a fundamental level, an analytic framework is established in this work that links time, stress, and temperature altogether into a general yielding criterion for MGs.

  19. Material and methods to increase plant growth and yield

    DOEpatents

    Kirst, Matias

    2015-09-15

    The present invention relates to materials and methods for modulating growth rates, yield, and/or resistance to drought conditions in plants. In one embodiment, a method of the invention comprises increasing expression of an hc1 gene (or a homolog thereof that provides for substantially the same activity), or increasing expression or activity of the protein encoded by an hc1 gene thereof, in a plant, wherein expression of the hc1 gene or expression or activity of the protein encoded by an hc1 gene results in increased growth rate, yield, and/or drought resistance in the plant.

  20. Executive Summary High-Yield Scenario Workshop Series Report

    SciTech Connect

    Leslie Park Ovard; Thomas H. Ulrich; David J. Muth Jr.; J. Richard Hess; Steven Thomas; Bryce Stokes

    2009-12-01

    To get a collective sense of the impact of research and development (R&D) on biomass resource availability, and to determine the feasibility that yields higher than baseline assumptions used for past assessments could be achieved to support U.S. energy independence, an alternate “High-Yield Scenario” (HYS) concept was presented to industry experts at a series of workshops held in December 2009. The workshops explored future production of corn/agricultural crop residues, herbaceous energy crops (HECs), and woody energy crops (WECs). This executive summary reports the findings of that workshop.

  1. Peptide tessellation yields micron-scale collagen triple helices

    PubMed Central

    Tanrikulu, I. Caglar; Forticaux, Audrey; Jin, Song; Raines, Ronald T.

    2016-01-01

    Sticky-ended DNA duplexes can associate spontaneously into long double helices; however, such self-assembly is much less developed with proteins. Collagen is the most prevalent component of the extracellular matrix and a common clinical biomaterial. Like natural DNA, the ∼103-residue triple-helices (∼300 nm) of natural collagen are recalcitrant to chemical synthesis. Here we show how the self-assembly of short collagen-mimetic peptides (CMPs) can enable the fabrication of synthetic collagen triple-helices that are nearly a micron in length. Inspired by the mathematics of tessellations, we derive rules for the design of single CMPs that self-assemble into long triple helices with perfect symmetry. Sticky-ends thus created are uniform across the assembly and drive its growth. Enacting this design yields individual triple-helices that match or exceed those in natural collagen in length and are remarkably thermostable, despite the absence of higher-order association. Symmetric assembly of CMPs provides an enabling platform for the development of advanced materials for medicine and nanotechnology. PMID:27768103

  2. Peptide tessellation yields micrometre-scale collagen triple helices

    NASA Astrophysics Data System (ADS)

    Tanrikulu, I. Caglar; Forticaux, Audrey; Jin, Song; Raines, Ronald T.

    2016-11-01

    Sticky-ended DNA duplexes can associate spontaneously into long double helices; however, such self-assembly is much less developed with proteins. Collagen is the most prevalent component of the extracellular matrix and a common clinical biomaterial. As for natural DNA, the ~103-residue triple helices (~300 nm) of natural collagen are recalcitrant to chemical synthesis. Here we show how the self-assembly of short collagen-mimetic peptides (CMPs) can enable the fabrication of synthetic collagen triple helices that are nearly a micrometre in length. Inspired by the mathematics of tessellations, we derive rules for the design of single CMPs that self-assemble into long triple helices with perfect symmetry. Sticky ends thus created are uniform across the assembly and drive its growth. Enacting this design yields individual triple helices that, in length, match or exceed those in natural collagen and are remarkably thermostable, despite the absence of higher-order association. The symmetric assembly of CMPs provides an enabling platform for the development of advanced materials for medicine and nanotechnology.

  3. Trading forests for yields in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Gibbs, Holly

    2012-03-01

    Our knowledge of how agriculture expands, and the types of land it replaces, is remarkably limited across the tropics. Most remote-sensing studies focus on the net gains and losses in forests and agricultural land rather than the land-use transition pathways (Gibbs et al 2010). Only a handful of studies identify land sources for new croplands or plantations, and then only for farming systems aggregated together (e.g., Koh and Wilcove 2008, Morton et al 2006, Gibbs et al 2010). Gutiérrez-Vélez et al (2011), however, have taken a leap forward by tracking the different expansion pathways for smallholder and industrial oil palm plantations. Using a combination of Landsat, MODIS and field surveys, they investigate whether higher yields in new agricultural lands spare forests in the Peruvian Amazon and in a smaller focus area in the Ucayali region. Across the Peruvian Amazon, they show that between 2000 and 2010, new high-yield oil palm plantations replaced forests 72% of the time and accounted for 1.3% of total deforestation, with most expansion occurring after 2006. Gutiérrez-Vélez et al went further in the Ucayali region and compared land sources for new high-yield and low-yield plantations. Expansion of higher-yield agricultural lands should logically reduce the total area needed for production, thus potentially sparing forests. In the Ucayali focus area, expansion of high-yield oil palm did convert less total land area but more forest was cleared than with low-yield expansion. Smaller-scale plantations tended to expand into already cleared areas while industrial-scale plantations traded their greater yields for forests, leading to higher land-clearing carbon emissions per production unit (Gibbs et al 2008). Gutiérrez-Vélez et al show that higher yields may require less land for production but more forest may be lost in the process, and they emphasize the need for stronger incentives for land sparing. The potential land-saving nature of these high-yield

  4. Foliar application of Zn at flowering stage improves plant's performance, yield and yield attributes of black gram.

    PubMed

    Pandey, Nalini; Gupta, Bhavana; Pathak, Girish Chandra

    2013-07-01

    Black gram plants subjected to varying levels of Zn supply (0.01 to 10 microM Zn) showed optimum growth and dry matter yield in plants receiving 1 microM Zn. The dry matter yield of plants decreased in plants receiving 0.01 and 0.1 microM Zn (deficient) and excess levels of Zn (2 and 10 microM Zn). The plants grown with Zn deficient supply showed delayed flowering, premature bud abscission, reduced size of anthers, pollen producing capacity, pollen viability and stigma receptivity resulting in poor pod formation and seed yield. Providing Zn as a foliar spray at pre-flowering stage minimized the severity of Zn deficiency on reproductive structure development and enhanced the seed nutritional status by enhancing seed Zn density, seed carbohydrate (sugar and starch content) and storage proteins (albumins, globulins, glutenins, and prolamines).

  5. {mu} {yields} e{gamma} decay versus the {mu} {yields} eee bound and lepton flavor violating processes in supernova

    SciTech Connect

    Lychkovskiy, O. V. Vysotsky, M. I.

    2012-03-15

    Even tiny lepton flavor violation (LFV) due to some New Physics is able to alter the conditions inside a collapsing supernova core and probably to facilitate the explosion. LFV emerges naturally in a see-saw type-II model of neutrino mass generation. Experimentally, the LFV beyond the Standard Model is constrained by rare lepton decay searches. In particular, strong bounds are imposed on the {mu} {yields} eee branching ratio and on the {mu}-e conversion in muonic gold. Currently, the {mu}{yields}e{gamma} is under investigation in the MEG experiment that aims at a dramatic increase in sensitivity in the next three years. We seek a see-saw type-II LFV pattern that fits all the experimental constraints, leads to Br({mu} {yields}e{gamma}) Greater-Than-Or-Equivalent-To Br({mu}{mu} {yields}eee), and ensures a rate of LFV processes in supernova high enough to modify the supernova physics. These requirements are sufficient to eliminate almost all freedom in the model. In particular, they lead to the prediction 0.4 Multiplication-Sign 10{sup -12} Less-Than-Or-Equivalent-To Br({mu} {yields} e{gamma}) Less-Than-Or-Equivalent-To 6 Multiplication-Sign 10{sup -12}, which will be testable by MEG in the nearest future. The considered scenario also constrains the neutrino mass-mixing pattern and provides lower and upper bounds on {tau}-lepton LFV decays. We also briefly discuss a model with a single bilepton in which the {mu} {yields} eee decay is absent at the tree level.

  6. 24 CFR 320.8 - Excess Yield Securities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Excess Yield Securities. 320.8 Section 320.8 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) GOVERNMENT NATIONAL MORTGAGE ASSOCIATION, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GUARANTY...

  7. 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 and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Production and Process...

  8. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are often 1 to 2 Mg/ha lower than those achieved when maize is grown in rotation with soybean in the U.S. Midwest. One factor contributing to this difference is the release of phytotoxic compounds as the previous year’s maize residue decomposes. Based on laboratory results sh...

  9. Integrated process for high conversion and high yield protein PEGylation.

    PubMed

    Pfister, David; Morbidelli, Massimo

    2016-08-01

    Over the past decades, PEGylation has become a powerful technique to increase the in vivo circulation half-life of therapeutic proteins while maintaining their activity. The development of new therapeutic proteins is likely to require further improvement of the PEGylation methods to reach even better selectivity and yield for reduced costs. The intensification of the PEGylation process was investigated through the integration of a chromatographic step in order to increase yield and conversion for the production of mono-PEGylated protein. Lysozyme was used as a model protein to demonstrate the feasibility of such approach. In the integrated reaction/separation process, chromatography was used as fractionation technique in order to isolate and recycle the unreacted protein from the PEGylated products. This allows operating the reactor with short reaction times so as to minimize the production of multi-PEGylated proteins (i.e., conjugated to more than one polymer). That is, the reaction is stopped before the desired product (i.e., the mono-PEGylated protein) can further react, thus leading to limited conversion but high yield. The recycling of the unreacted protein was then considered to drive the protein overall conversion to completion. This approach has great potential to improve processes whose yield is limited by the further reaction of the product leading to undesirable by-products. Biotechnol. Bioeng. 2016;113: 1711-1718. © 2016 Wiley Periodicals, Inc.

  10. UOP R-72 staged loading for maximum reformer yields

    SciTech Connect

    Haizmann, R.S.; Moser, M.D.; Wei, D.Y.

    1995-09-01

    The steady improvement over the last 25 years in the activity and stability of UOP`s platinum-rhenium (Pt-Re) semiregenerative Platforming catalysts is a direct result of UOP`s continuing commitment to meeting customer`s requirements. Many semiregenerative reforming operations took advantage of these improved catalytic offerings by raising octane and throughput. Others benefited by lowering reactor pressure to increase yields of gasoline, aromatics, and hydrogen. In 1994, UOP commercialized the R-72 semiregenerative catalyst. This catalyst offers 1 to 2 LV-% higher C{sub 5}{sup +} yield and 10 to 15% higher hydrogen yield than Pt-Re catalysts. More recently, UOP introduced a new, patented flow scheme called R-72 staged loading. The R-72 staged loading produces a synergistic effect from the use of R-72 in the lead reactors and R-56 Pt-Re catalyst in the latter reactors. The results are R-72 yields as well as the excellent activity and stability of the R-56 Pt-Re catalyst. No modifications or revamps are required to take advantage of this technology. This paper describes how R-72 staged loading works and the economic benefits that customers can derive from its use.

  11. Potato growth and yield using nutrient film technique (NFT)

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Hinkle, C. R.

    1990-01-01

    Potato plants, cvs Denali and Norland, were grown in polyvinyl chloride (PVC) trays using a continuous flowing nutrient film technique (NFT) to study tuber yield for NASA's Controlled Ecological Life Support Systems (CELSS) program. Nutrient solution pH was controlled automatically using 0.39M (2.5% (v/v) nitric acid (HNO3), while water and nutrients were replenished manually each day and twice each week, respectively. Plants were spaced either one or two per tray, allotting 0.2 or 0.4 m2 per plant. All plants were harvested after 112 days. Denali plants yielded 2850 and 2800 g tuber fresh weight from the one- and two-plant trays, respectively, while Norland plants yielded 1800 and 2400 g tuber fresh weight from the one- and two-plant trays. Many tubers of both cultivars showed injury to the periderm tissue, possibly caused by salt accumulation from the nutrient solution on the surface. Total system water usage throughout the study for all the plants equaled 709 liters (L), or approximately 2 L m-2 d-1. Total system acid usage throughout the study (for nutrient solution pH control) equaled 6.60 L, or 18.4 ml m-2 d-1 (7.2 mmol m-2 d-1). The results demonstrate that continuous flowing nutrient film technique can be used for tuber production with acceptable yields for the CELSS program.

  12. Setting the Record Straight on "High-Yield" Strategies

    ERIC Educational Resources Information Center

    Marzano, Robert J.

    2009-01-01

    Widely credited with proposing nine "high-yield" instructional strategies, author Robert J. Marzano sets the record straight about the broader number of strategies identified by the research. He provides a list of 41 strategies and suggests more nuanced ways of using, observing, and evaluating them. (Contains 1 figure.)

  13. Improving yield and protein content of forages under flooded condition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flooding can have catastrophic impacts on the productivity of arable farmland, grassland pastures, as most crops including forages are intolerant to excess water. The objectives of this study were to determine the effect of flooding duration and nitrogen (N) fertilization on dry matter yield (DMY) a...

  14. Does Conspecific Fighting Yield Conditioned Taste Aversion in Rats?

    ERIC Educational Resources Information Center

    Nakajima, Sadahiko; Kumazawa, Gaku; Ieki, Hayato; Hashimoto, Aya

    2012-01-01

    Running in an activity wheel yields conditioned aversion to a taste solution consumed before the running, but its underlying physiological mechanism is unknown. According to the claim that energy expenditure or general stress caused by physical exercise is a critical factor for this taste-aversion learning, not only running but also other…

  15. Simulating effects of microtopography on wetland specific yield and hydroperiod

    USGS Publications Warehouse

    Summer, David M.; Wang, Xixi

    2011-01-01

    Specific yield and hydroperiod have proven to be useful parameters in hydrologic analysis of wetlands. Specific yield is a critical parameter to quantitatively relate hydrologic fluxes (e.g., rainfall, evapotranspiration, and runoff) and water level changes. Hydroperiod measures the temporal variability and frequency of land-surface inundation. Conventionally, hydrologic analyses used these concepts without considering the effects of land surface microtopography and assumed a smoothly-varying land surface. However, these microtopographic effects could result in small-scale variations in land surface inundation and water depth above or below the land surface, which in turn affect ecologic and hydrologic processes of wetlands. The objective of this chapter is to develop a physically-based approach for estimating specific yield and hydroperiod that enables the consideration of microtopographic features of wetlands, and to illustrate the approach at sites in the Florida Everglades. The results indicate that the physically-based approach can better capture the variations of specific yield with water level, in particular when the water level falls between the minimum and maximum land surface elevations. The suggested approach for hydroperiod computation predicted that the wetlands might be completely dry or completely wet much less frequently than suggested by the conventional approach neglecting microtopography. One reasonable generalization may be that the hydroperiod approaches presented in this chapter can be a more accurate prediction tool for water resources management to meet the specific hydroperiod threshold as required by a species of plant or animal of interest.

  16. Photoperiod shift effects on yield characteristics of rice

    NASA Technical Reports Server (NTRS)

    Volk, G. M.; Mitchell, C. A.

    1995-01-01

    Edible yield must be maximized for each crop species selected for inclusion in the Controlled Ecological Life-Support System (CELSS) proposed by NASA to support long-term manned space missions. In a greenhouse study aimed at increasing biomass partitioning to rice (Oryza sativa L.) grain, plants of the high yielding semi-dwarf rice cultivar Ai-Nan-Tsao were started in pots under 8-h photoperiods at a density of 212 plants m-2. After different periods of time under 8-h photoperiods, pots were switched to continuous light for the remainder of the cropping cycle. Continuous light did not delay time to first panicle emergence (60 d) or time to harvest (83 d). There was a positive correlation between the length of continuous light treatments and nongrain biomass. Grain yield (1.6 +/- 0.2 g plant-1) did not increase in continuous light. Yield-efficiency rate (grain weight per length of cropping cycle, canopy volume, and weight of nongrain shoot biomass) was used to compare treatments. Small Ai-Nan-Tsao rice canopies grown under 8-h photoperiods were more efficient producers of grain than canopies grown under continuous light for a portion of the rice cropping cycle.

  17. 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.

  18. Breaking wheat yield barriers requires integrated efforts in developing countries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most yield progress obtained through the so called “green revolution”, particularly in the irrigated areas of Asia, has reached a limit, and major resistance genes are quickly overcome by the appearance of new strains of disease causing organisms. New plant stresses due to a changing environment are...

  19. Confirmation of a seed yield QTL in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic germplasm can be an important source of genetic diversity for soybean [Glycine max (L.) Merr.] improvement. Previously, four yield quantitative trait loci (QTL) had been identified in a cross between the exotic soybean plant introduction (PI) 68658 and the U.S. cultivar Lawrence. The confirma...

  20. Computing Realized Compound Yield with a Financial Calculator: A Note

    ERIC Educational Resources Information Center

    Moy, Ronald L.; Terregrossa, Ralph

    2011-01-01

    This note points out that realized compound yield (RCY) has a similar concept from capital budgeting; namely, modified internal rate of return. Recognizing this relationship makes it easier to teach the concept and allows students to easily compute RCY using a financial calculator.