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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Commercial Production of Wheat Grain Irrigated with Municipal Wastewater

Day, A. D., McFadyen, J. A., Tucker, T. C., Cluff, C. B. Unknown Date (has links)
Authors' manuscript; no date on item. / Experiments were conducted in southern Arizona to study the effects of irrigating wheat (Triticum aestivum L.) with a mixture of pump water and wastewater and pump water alone on wheat growth, grain yield, grain quality, soil properties, and irrigation water quality. In small plot research, wheat irrigated with a mixture of pump water and wastewater produced taller plants, more heads per unit area, heavier seeds, higher grain yields, and higher straw yields than did wheat grown with only pump water. When large fields were compared, wheat grown with a mixture of pump water and wastewater had taller plants, more lodging, lower grain volume-weights, and higher grain yields than did wheat produced with pump water. The pH and exchangeable sodium of soil irrigated with pump water alone or a mixture of pump water and wastewater were similar. Electricalconductivity and nitrate-nitrogen were higher in soils irrigated with pump water than they were in soils irrigated with a mixture of pump water and wastewater. Extractable phosphorus was higher in soils irrigated with a mixture of pump water and wastewater than in soils irrigated with pump water. Total soluble salts and nitrate-nitrogen were higher in pump water than they were in the pump water and wastewater mixture; however, the pump water and wastewater mixture had a higher level of phosphorus than did pump water.
92

Potential of Wastewater for Commercial Barley Production

Day, A. D., McFadyen, J. A., Tucker, T. C., Cluff, C. B. 21 March 2014 (has links)
No date on item; authors' manuscript. / Experiments were conducted in southern Arizona to investigate the effects of irrigation with pump water and a pump water-wastewater mixture on barley (Hordium vulgare L.) growth, grain yield, and grain quality; soil properties; and irrigation water quality. In 1974 and 1975, on small plot research, barley irrigated with a 50:50 mixture of pump water and wastewater significantly exceeded barley irrigated with pump water alone in plant height, number of heads per unit area, number of seeds per head, seed weight, grain yield, and straw yield. In large field studies conducted from 1970 through 1977, barley irrigated with the mixture had taller plants, more lodging, lower grain volume-weights and higher grain yields than barley irrigated with pump water alone. Soils irrigated with both types of irrigation water had similar pH. Soluble salts (ECx103), exchangeable sodium percentage, nitrate-nitrogen, and extractable phosphorus were significantly higher in soils irrigated with the pump water-wastewater mixture than in soils irrigated with pump water. Water quality analyses showed that the pump water-wastewater mixture had lower total soluble salts, lower nitrate-nitrogen, and higher phosphorus levels than pump water alone.
93

Absorption and accumulation of cadmium from cereal grains

Moberg Wing, Anncatherine January 1993 (has links)
Cadmium (Cd) is a potentially toxic trace element. Cereal grains contribute one-third to one-half of the Cd exposure via the diet. Among cereal grains, wheat generally contains the highest Cd concentration and the bran and germ fractions contain more Cd than the endosperm. An increase in the consumption of unrefined grains may cause an increase in the body burden of Cd if an increase in the exposure to Cd via the diet leads directly to increased Cd absorption and accumulation. However, there is evidence that certain factors may reduce the availability of Cd for absorption from the diet. The purposes of these studies were to refine an atomic absorption spectrometric method for measuring the accumulation of Cd from diets with low, naturally occuring concentrations of Cd, to evaluate the extent to which Cd is accumulated from different milling fractions of wheat and from different cereal grains, and to determine to what extent the presence of certain minerals and mineral-binding factors in the diet and the iron (Fe) status of the individual affect Cd accumulation from cereal grain diets. The results of the method studies showed that the amount of Cd in the liver and kidneys of rats after six weeks on different diets and the retention of 109Cd in these organs three weeks after the ingestion of 109Cd-labelled test meals of the diets were in agreement on the fractional and total accumulation of Cd from the diets. To a first approximation, the accumulation of Cd in the liver and kidneys in rats appears to be the product of the separate effects of the concentration of Cd in the diet which is available for absorption and the Fe status of the rats. The Cd concentration in grains varied by a factor of five between whole wheat and rye and the amounts of Cd accumulated in rats from diets with whole grains were nearly proportional to the Cd concentrations in the grains. The fractional accumulation of Cd was lower in rats given diets with whole grains or wheat fractions high in fiber and phytic acid than in rats fed endosperm wheat diets. This lower fractional Cd accumulation did not compensate for the high Cd concentrations in whole wheat and wheat bran. The fractional accumulation of Cd in the liver of rats is inversely related to their Fe status. The fractional Cd accumulation in the liver of rats with low Fe status was as much as ten times that in rats with high Fe status. The Cd accumulation in the kidneys appears to be even more sensitive to Fe status. The accumulation of Cd in human placenta supports these conclusions. Women who eat diets with less cereal grain fiber and who also maintain their Fe stores during pregnancy generally accumulate less Cd in the placenta than those who eat more grain fiber and/or have lower Fe status. On the basis of these results, it is recommended that as much as possible of the dietary fiber from cereal grains should derive from grains with low Cd concentrations. It is also imperative that the diet provide sufficient Fe and other nutrients to promote Fe status and thereby limit Cd accumulation. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 5 uppsatser.</p> / digitalisering@umu
94

The cause of bitter flavour development in toasted rolled oats (Avena sativa L.)

Yan, Rong (Mary) January 2007 (has links)
Hubbard Foods Limited of Auckland makes a variety of oats-based value-added products. In the preparation of a range of products at Hubbard Foods, technical staff has become aware of a bitterness problem that sporadically appears in toasted oats. Toasting involves dry heating to about 150°C resulting in the golden colour and flavour development necessary for range of products. Bitterness development has been described in the literature, but Hubbard staff is necessarily focussed on production issues, rather than on a sporadic problem seemingly outside the scope of production variables. The author of this thesis set out to identify the cause and suggest a remedy. Prior research with oats has shown that bitterness and associated off-flavours are linked to the accumulation of free fatty acids, their volatile oxidation products, and possibly amino acids and certain phenols. Oats are distinguished from related grains by their high relative fat content, about seven percent, and an associated very active lipase. The free fatty acids stem from the lipase activity that should be, but may not be, inactivated at source in Australia. This is achieved in the milling process by physical disruption and moist heating to a temperature at which the enzyme is denatured. However, residual lipase activity may adversely affect oats quality during time in storage and transit. A number of analytical methods for cereals were adapted to match the constraints of time and resources. These methods were for colour, moisture, peroxidase activity, p-anisidine, and fat and free fatty acids content, composition of fatty acids, total phenols, volatiles, and bitterness as perceived by an analytical sensory panel of four people. Determination of lipase activity is very expensive, so peroxidase activity is commercially used as an indicator. If the latter is inactive, the former will necessarily be also inactive. The designed methods were first applied to 17 oats lots passing through the Hubbard environment, where 14 were paired raw and toasted. The values of moisture, fat content, free fatty acids content and total phenols were within the normal limits expected for commercial lots of oats compared with the previous studies. Not much variation was observed among the 17 oats lots, with the exception of lot DWHE25. Lot DWHE25 was a faulty product, which had high moisture content, high free fatty acids content, and tasted very bitter. The results suggested that moisture content, free fatty acids and bitterness were usually correlated. In spite of the differences encountered and the clues provided by extremes, the data generated from Hubbard oats lots did not provide enough variation in quality to lead to a definitive chemical model of bitter flavour development. But perhaps crucially, it was found that most samples as received from Hubbard Foods were peroxidase-active which conflicted with the results reported on specification sheets prepared by the oats supplier. These specifications accompanied each lot delivered to Hubbard Foods. Therefore, the supplier’s method was examined and was found to be deficient in one critically important respect. Their method omitted the key reactant hydrogen peroxide. Therefore, it is possible that the lipase was active in many of the samples. Therefore, some experiments were conducted where raw oats, from Hubbard Foods and a supermarket, were treated with water additions and stored for a period to examine the effect of moisture content on the quality and flavour deterioration on subsequent storage. Water-treated oats were toasted to simulate a typical Hubbard process, yielding a total of 58 samples with carrying moisture contents. The data set was statistically analysed to identify the cause of bitterness and the means of its control. The free fatty acids content, volatile compounds particularly hexanal, and total phenols increased with moisture content and storage time. The correlations between chemical analysis and sensory test indicated that free fatty acids positively correlated with bitterness (r = 0.71), and hexanal was also positively correlated. Total phenols did not appear to correlate with bitterness. Oats lots with high peroxidase activity tended to have the poorest quality, strongly implicating residual lipase activity as the critical factor. There were no important interactions between water addition and toasting for most of the experiments. Therefore, it seems likely that the toasting procedures at Hubbard Foods are not responsible for bitterness formation. The cause(s) of bitterness is certainly at source, with a faulty peroxidase test strongly implicated.
95

The cause of bitter flavour development in toasted rolled oats (Avena sativa L.)

Yan, Rong (Mary) January 2007 (has links)
Hubbard Foods Limited of Auckland makes a variety of oats-based value-added products. In the preparation of a range of products at Hubbard Foods, technical staff has become aware of a bitterness problem that sporadically appears in toasted oats. Toasting involves dry heating to about 150°C resulting in the golden colour and flavour development necessary for range of products. Bitterness development has been described in the literature, but Hubbard staff is necessarily focussed on production issues, rather than on a sporadic problem seemingly outside the scope of production variables. The author of this thesis set out to identify the cause and suggest a remedy. Prior research with oats has shown that bitterness and associated off-flavours are linked to the accumulation of free fatty acids, their volatile oxidation products, and possibly amino acids and certain phenols. Oats are distinguished from related grains by their high relative fat content, about seven percent, and an associated very active lipase. The free fatty acids stem from the lipase activity that should be, but may not be, inactivated at source in Australia. This is achieved in the milling process by physical disruption and moist heating to a temperature at which the enzyme is denatured. However, residual lipase activity may adversely affect oats quality during time in storage and transit. A number of analytical methods for cereals were adapted to match the constraints of time and resources. These methods were for colour, moisture, peroxidase activity, p-anisidine, and fat and free fatty acids content, composition of fatty acids, total phenols, volatiles, and bitterness as perceived by an analytical sensory panel of four people. Determination of lipase activity is very expensive, so peroxidase activity is commercially used as an indicator. If the latter is inactive, the former will necessarily be also inactive. The designed methods were first applied to 17 oats lots passing through the Hubbard environment, where 14 were paired raw and toasted. The values of moisture, fat content, free fatty acids content and total phenols were within the normal limits expected for commercial lots of oats compared with the previous studies. Not much variation was observed among the 17 oats lots, with the exception of lot DWHE25. Lot DWHE25 was a faulty product, which had high moisture content, high free fatty acids content, and tasted very bitter. The results suggested that moisture content, free fatty acids and bitterness were usually correlated. In spite of the differences encountered and the clues provided by extremes, the data generated from Hubbard oats lots did not provide enough variation in quality to lead to a definitive chemical model of bitter flavour development. But perhaps crucially, it was found that most samples as received from Hubbard Foods were peroxidase-active which conflicted with the results reported on specification sheets prepared by the oats supplier. These specifications accompanied each lot delivered to Hubbard Foods. Therefore, the supplier’s method was examined and was found to be deficient in one critically important respect. Their method omitted the key reactant hydrogen peroxide. Therefore, it is possible that the lipase was active in many of the samples. Therefore, some experiments were conducted where raw oats, from Hubbard Foods and a supermarket, were treated with water additions and stored for a period to examine the effect of moisture content on the quality and flavour deterioration on subsequent storage. Water-treated oats were toasted to simulate a typical Hubbard process, yielding a total of 58 samples with carrying moisture contents. The data set was statistically analysed to identify the cause of bitterness and the means of its control. The free fatty acids content, volatile compounds particularly hexanal, and total phenols increased with moisture content and storage time. The correlations between chemical analysis and sensory test indicated that free fatty acids positively correlated with bitterness (r = 0.71), and hexanal was also positively correlated. Total phenols did not appear to correlate with bitterness. Oats lots with high peroxidase activity tended to have the poorest quality, strongly implicating residual lipase activity as the critical factor. There were no important interactions between water addition and toasting for most of the experiments. Therefore, it seems likely that the toasting procedures at Hubbard Foods are not responsible for bitterness formation. The cause(s) of bitterness is certainly at source, with a faulty peroxidase test strongly implicated.
96

Alkylresorcinols in cereal grains : occurrence, absorption, and possible use as biomarkers of whole grain wheat and rye intake /

Ross, Alastair Benjamin, January 2003 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 8 uppsatser.
97

Prospects of grain production, consumption and trade in North Korea /

Nam, Sung Wook, January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 226-231). Also available on the Internet.
98

Prospects of grain production, consumption and trade in North Korea

Nam, Sung Wook, January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 226-231). Also available on the Internet.
99

EFFECT OF COVER CROPS ON NUTRIENT DYNAMICS AND SOIL PROPERTIES IN CORN-SOYBEAN ROTATION IN SOUTHERN ILLINOIS

Singh, Gurbir 01 May 2018 (has links)
Corn (Zea mays L.) and soybean (Glycine max L.) production in the Midwest US can result in significant nutrient leaching to groundwater and surface waters, which contributes to eutrophication and hypoxia in the Gulf of Mexico. A promising strategy to control nutrient leaching and sediment runoff loss during winter fallow period is the use of cover crops (CCs). In southern Illinois, CCs are not widely adopted by farmers due to economic constraints and the lack of scientific data that supports benefits of incorporating CCs into the corn-soybean rotation. Therefore, this doctoral dissertation addresses the critical question of the feasibility of the use of CCs in southern Illinois and is divided into three overarching research studies with different objectives divided into six research chapters. Research study 1 was a field experiment conducted from 2013 to 2017 to examine the effect of CCs (CC vs noCC) under two tillage systems [(no-tillage (NT) and conventional tillage (CT)] on aboveground plant attributes [dry matter yield, C:N ratio and nitrogen uptake (N uptake)], crop yields, available soil N content and N leaching in the vadose zone. The experimental layout was a randomized design with three rotations including corn-noCC-soybean-noCC [CncSnc], corn-cereal rye (Secale cereale L.) –soybean-hairy vetch (Vicia villosa R.) [CcrShv], and corn-cereal rye-soybean-oats+radish (Avena sativa L. + Raphanus sativus L.) [CcrSor] and two tillage systems. Soil samples collected after corn or soybean harvest and CC termination were analyzed for standard soil fertility parameters. Pan lysimeters installed below the ‘A’ horizon with depth varying from 22 to 30 cm were used for measuring soil solution nutrient concentration on weekly or biweekly basis depending on the precipitation. In NT system, the corn yield was 14% greater with CcrShv compared to CncSnc, whereas no significant difference existed in corn yield due to CC treatments within CT. Both CC treatments under NT reduced soybean yield by 24 to 27% compared to noCC. The rotations CcrShv and CcrSor with hairy vetch and oats+radish as preceding CCs resulted in 89% (37.73 vs 19.96 kg ha-1) and 68% (33.46 vs 19.96 kg ha-1) more nitrate-N (NO3-N) leaching than the CncSnc during cash crop season 2015. During the CC season in spring 2016, cereal rye CC in CcrShv and CcrSor reduced the NO3-N leaching by 84% (0.68 kg ha-1) and 78% (0.63 kg ha-1) compared to the CncSnc, respectively, under the CT system. Overall, our results indicated that the CT system had greater N leaching losses compared to NT system due to higher N availability in the tilled soil profile. The goal of the second research study was to understand the mechanisms of N cycling by CCs. Therefore, we applied 15N labeled urea fertilizer (9.2% atom) to corn that followed hairy vetch and noCC in May 2017 to evaluate the contribution of fertilizer and soil organic matter to N leaching and quantify the 15N content of surface runoff after storm events. During the 2017 corn season, repeated soil samples were collected and analyzed for 15N fertilizer recovery in soil at three depths. 15N recovery was higher in the corn that had hairy vetch as the preceding CC than the corn that had noCC by 13.13 and 3.68 kg ha-1 on soil sampling events of 7 and 21 days after planting of corn, respectively, at the depth 15-30 cm. Overall, the cumulative loss of 15NO3-N during corn season 2017 was <2% of the applied fertilizer. The contribution of NO3-N from soil organic matter to leaching was 61% higher for the corn rotation with hairy vetch CC compared to corn rotation with noCC (1.12 vs 0.69 kg ha-1). Research study 3 evaluated the effects of CCs (cereal rye and hairy vetch) and topography (shoulder, backslope, footslope) on corn-soybean production, soil and water quality, nutrient and sediment export in agricultural headwater streams in a paired-watershed experimental design. The crop rotation followed in the CC-watershed was corn-cereal rye-soybean-hairy vetch whereas the rotation in the noCC watershed was corn-noCC-soybean-noCC. Use of hairy vetch CC increased N uptake at shoulder, backslope and footslope positions by 110.90, 85.02, and 44.89 kg ha-1, respectively, when compared to noCC treatment. The corn yield at the shoulder position was increased by 69% in CC-watershed compared to noCC watershed in 2017 likely by providing large N additions following decomposition. Cereal rye increased soybean yield by 17% and 8% at the shoulder and backslope position, respectively in 2016. Additionally, the effects of topography and CCs on soil N levels and N leaching in the watersheds were also evaluated. The NO3-N concentrations measured using suction cup lysimeters in CC-watershed were reduced by 2.54 mg L-1 (67%) when compared to noCC watershed. During the hairy vetch CC season, the reduction in NO3-N concentrations in soil solution was only seen at the footslope position. The excessive N at footslope positions may have been immobilized or denitrified due to soil waterlogging from higher water availability at the footslope. Forty-two and 18 storm events were collected during a 4-yr calibration period and CC-treatment period, respectively. Predictive regression equations developed from the calibration period were used for calculating TSS, NO3-N, NH4-N, and DRP losses of surface runoff for the CC-treatment watershed. The CCs reduced TSS and discharge by 33% and 34%, respectively in the CC-watershed during the treatment period. However, EMCs for NO3-N, NH4-N, and DRP did not decrease. Overall, CCs are a recommended conservation practice for farmers who want to enhance the long term profitability of their production systems, while building soil health and protecting downstream water quality. The CCs have the potential to reduce nutrient leaching, peak/total discharge, improve soil quality and crop yields. However, reduction in leaching will depend on the type of CC (legume vs non-legume crops) used in rotation, the time of termination of CCs, cover crop establishment and number of years under CCs. Synchronizing N availability from CCs to N uptake by cash crop is important for reducing nitrate leaching and increasing crop yields.
100

Využití obilovin k přikrmování kapra na rybnících. Rybářství Lomnice nad Lužnicí / Utilization of cereals on suplementary carp feeding on Ponds Fishery Lomnice nad Lužnicí

EISERT, Zdeněk January 2008 (has links)
Theme of my Diploma work refers about possibility of feeding up the common carp with the cereal food in the ponds. Research was monitor on 4 ponds in Naděje ponds system. The ponds have 2,4 ha together. Three of them were used for research and fourth pond was for control. This control pound had only a natural food. During the research was every year plant into the ponds 363 carps type (K 3) for 1 ha and after fish out was this sort K 4. For the research were very pilot fish outs. Fish out carp were for weight, length of the body and perimeter of the body monitoring. This data was use for a statistics evaluation. Feeding run 3 days in a week (Monday, Wednesday, Friday) in a day ration 2 % of the fish weight in a pound.

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