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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.
41

Evaluation of sealed storage silos for grain fumigation

Cook, Samuel A.L. January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Dirk E. Maier / Fumigation of stored grain is a common way to kill stored-grain insect pests. However, fumigating in unsealed structures is the leading cause of control failures and subsequent development of insect resistance. Sealing the storage structure is the only practical way to ensure a complete kill of all insects at all life stages. The cost, effort, and feasibility of sealing a U.S. corrugated steel silo during construction was evaluated and compared against an Australian sealed silo designed for fumigation. Gas monitoring and thermosiphon recirculation equipment was installed on both silos. Fumigation efficacy was evaluated using pressure half-life decay times, fumigant concentrations, insect bioassays, and grain quality data. Three fumigations with phosphine (PH₃) pellets or tablets and two with VAPORPH₃OS® cylinderized PH₃ and ProFume® cylinderized sulfuryl fluoride (SF) were performed in each silo for a total of ten experimental treatments. The Australian silo required 266 man-hours to construct and cost $180 for additional sealing, compared to 359 man-hours and $3,284 for constructing and sealing the U.S. silo. The Australian silo had a maximum pressure half-life decay time of 163 s versus 50 s for the U.S. silo. At application rates of 1.5 g/mᶟ of PH₃ both silos maintained an average concentration of approximately 0.28 g/mᶟ for 14 days. With thermosiphon recirculation the average minimum-to-maximum PH₃ concentration ratio in the U.S. silo was 0.52, compared to a ratio of 0.17 when fumigating without thermosiphon recirculation. Greater than 99% adult mortality was observed in all insect bioassays which included PH₃ resistant strains of R. dominica and T. castaneum. The average emergence from fumigated bioassays was 7 adult insects, compared to an average of 383 adults for the non-fumigated controls. Grain stored for 10 months in the sealed silos increased from approximately 11.5% to 17% m.c. in the top 0.3 m of grain, and decreased in test weight from approximately 77 to 65 kg/hL. Although the Australian silo retained higher fumigant concentrations than the U.S. silo, fumigations were successful in both. Long-term storage in sealed silos is a concern because grain quality can deteriorate due to condensation and mold in the top grain layer.
42

The population genetics of the invasive Psocoptera (Liposcelididae) species Liposcelis bostrychophila Badonnel and Liposcelis decolor (Pearman) in Australian grain storage systems

Mikac, Katarina Maryann, n/a January 2006 (has links)
This thesis is a comprehensive treatment of the invasion genetics of two major Liposcelis pest species, Liposcelis bostrychophila Badonnel and L. decolor (Pearman), in Australian grain storage systems. Randomly amplified polymorphic DNA (RAPDs) and microsatellite DNA markers were used to investigate Liposcelis invasions in grain storage systems. The RAPD and microsatellite markers used provided insights into the genetic diversity of L. bostrychophila and L. decolor populations both in Australia and internationally, providing information integral to gaining an understanding of Liposcelis invasions in Australian grain storage systems. The thesis is divided into discrete chapters, and for each chapter an abstract is provided. Chapter 1 provides background on Liposcelis invasions in Australia in relation to the biology of Liposcelis species, the infrastructure of the Australian grain industry and the history of invasions in comparison to other invasive invertebrate species. The use of DNA and PCR technologies to investigate Liposcelis invasions are discussed and the aims and objectives of this thesis are introduced. Chapter 2 uses RAPDs to trace the geographic origin of L. bostrychophila populations in Australia from unknown geographic sources internationally. High levels of clonal genetic diversity among populations of L. bostrychophila in Australia and internationally were found. In addition, multiple introductions, from a wide range of international source populations were detected and this obscured our ability to accurately determine the geographic origin of L. bostrychophila in Australia. Given the high clonal genetic diversity found in populations of parthenogenetic L. bostrychophila in Australia, diagnostic Wolbachia PCR primers were used in Chapter 3 to investigate whether L. bostrychophila individuals from these populations were infected by Wolbachia and if infected, to investigate the strain of Wolbachia characteristic of Australian L. bostrychophila populations. Results from Chapter 3 provide the first evidence of multiple Wolbachia infection from strains A and B in Australian L. bostrychophila populations. Chapter 4 details the extensive molecular procedures undertaken to isolate microsatellite loci from Liposcelis decolor using both enrichment and nonenrichment methods. Microsatellite loci were optimised for use in PCR in single individuals following extensive troubleshooting. Troubleshooting efforts focused on elucidating the factors controlling the specificity, efficiency and sensitivity of the PCR to amplify small Liposcelis individuals known to be rich in lipids and proteins, all inhibitory to PCR. In Chapter 5 lipids and proteins were investigated from L. decolor and L. entomophila to determine total concentrations and characterize the lipids from these species. This chapter discusses whether the lipid and protein concentrations found were of a level that could be inhibitory to PCR in relation to the microsatellite techniques used in this study. From the work conducted in both Chapters 4 and 5 a troubleshooting protocol adapted for use in L. decolor was developed and implemented to determine the endogenous and exogenous parameters responsible for the function and reproducibility of PCR of microsatellite loci in L. decolor. In Chapter 6, the novel microsatellites isolated from L. decolor in Chapter 4 were used to investigate genetic structure and gene flow from Australian and international L. decolor populations. In Chapter 6 the first evidence of population differentiation, gene flow and dispersal in invasive populations of L. decolor was found. In addition, the eleven microsatellites isolated from L. decolor were cross-amplified in five other important Liposcelis pests, L. bostrychophila, L. entomophila, L. paeta, L. rufa, and L. corrodens, from which informative population genetic studies are now possible. Finally, Chapter 7 comprises the thesis synopsis, implications and future research.
43

Skirtingų veislių žieminių kviečių (Triticum aestivum L.) laikomų grūdų kokybės rodiklių palyginimas / The comparison of different varieties winter wheat (Triticum aestivum L.) storage grain quality indexes

Aperavičiūtė, Vaida 13 June 2014 (has links)
Tyrimo objektas žieminių kviečių veislių 'Julius', 'Leifer', 'Operetka' ir 'Skagen' technologinių savybių kitimas laikymo metu. Tyrimo tikslas ištirti skirtingų veislių žieminių kviečių technologinių savybių kitimo dėsningumus priklausomai nuo laikymo trukmės. Uždaviniai 1. Ištirti skirtingų veislių žieminių kviečių grūdų kokybę tik nuėmus derlių. 2. Įvertinti laikomų grūdų kokybę. 3. Apibendrinti grūdų technologinių savybių kitimo dėsningumus. Tyrimo metodai 2012–2013 m. Pakruojo rajone buvo auginti kviečiai. Žieminių kviečių derlius nuimtas 2013 m. rugpjūčio 20 d. Atlikti kviečių kokybės rodiklių tyrimai. Standartiniais metodais ištirta: grūdų drėgnis, baltymų, šlapiojo glitimo, krakmolo kiekis, sedimentacijos rodiklis, kritimo skaičius, piltinis tankis, pesticidų likučiai. Vėliau kviečių mėginiai laikomi Diliauskų elevatoriuje, sandėlyje dėžutėse po 4 kg, trimis pakartojimais. Kas mėnesį atliekami kviečių rodiklių kokybės tyrimai. Tyrimo rezultatai. Žieminių kviečių auginimo agrotechnikoje naudojant pesticidus pagal rekomendacijas ir prisilaikant leidžiamų normų, pesticidų likučiai grūduose nesikaupia. Laikant sausus grūdus sandėlyje jų drėgmė padidėja, baltymų kiekis ir saiko svoris nesikeičia. Glitimo kiekis laikomuose žieminiuose kviečiuose padidėjo nežymiai. Krakmolo kiekis laikomuose žieminiuose kviečiuose didėjo vidutiniškai 1,3 %. Laikymo laikotarpiu sedimentacijos vertės žieminiuose kviečiuose mažėjo, vidutiniškai 6,45 ml. Kritimo skaičius turėjo tendensiją... [toliau žr. visą tekstą] / Research object winter wheat varieties 'Julius', 'Leifer', 'Operetka' and 'Skagen' technological characteristics change during storage. Research aim explore the different varieties of winter wheat technological properties change dependent on the storage time. Objectives 1. First investigate the different varieties of winter wheat grain quality after the harvest. 2. Evaluate the quality of stored grain. 3. Summarize the technological properties of grain variation patterns. Research methods 2012-2013 year Pakruojo area were grown winter wheat. Winter wheat harvested in 2013 August 20 d. Perform quality in wheat research. Analyzed by standard methods of grain moisture content, protein, wet gluten, starch content, sedimentation value, falling number, bulk density, pesticide residues. Winter wheat samples kept in Diliauskų elevators, stock boxes of 4 kg, with three replications. Monthly indicators made of wheat quality tests. Research results. Winter wheat agricultural equipment, the use of pesticides in accordance with guidelines and in compliance with the allowable limits of pesticide residues in grain accumulation. Keeping dry grain stock of humidity increases the protein content moderation and weight does not change. Gluten content stored in winter wheat increased slightly . The starch content is stored in winter wheat increased an average of 1, 3 % . The storage period of sedimentation values in winter wheat decreased an average of 6, 45 ml . Falling number was... [to full text]
44

Mathematical models for a population of insects infesting stored cereal products : with reference to weevils in wheat / by Livingstone Serwadda Luboobi

Luboobi, Livingstone Serwadda January 1980 (has links)
Bibliography: leaves A19-A23 / ix, 183, 23 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1982
45

The behaviour of grain-infesting beetles with reference to the effects of gamma-irradiation upon development of populations and intraspecific communication

Khan, Muhammad Zainul Abedin January 1977 (has links)
v, 78 leaves : photo., graphs, tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Entomology, Waite Agricultural Research Institute, 1978
46

Mathematical models for a population of insects infesting stored cereal products : with reference to weevils in wheat

Luboobi, Livingstone Serwadda. January 1980 (has links) (PDF)
Bibliography: leaves A19-A23.
47

Análise da capacidade estática de armazenagem de grãos no Brasil no período de 1980 a 2015 / Analysis of static capacity grain storage in Brazil in the period 1980 to 2015

Fernandes, Queli Silvério 26 September 2016 (has links)
Submitted by Jaqueline Silva (jtas29@gmail.com) on 2016-10-18T17:04:13Z No. of bitstreams: 2 Dissertação - Queli Silvério Fernandes - 2016.pdf: 1375648 bytes, checksum: 2802e9c975aac50366bae452d23a7cc8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-10-18T17:05:07Z (GMT) No. of bitstreams: 2 Dissertação - Queli Silvério Fernandes - 2016.pdf: 1375648 bytes, checksum: 2802e9c975aac50366bae452d23a7cc8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-10-18T17:05:07Z (GMT). No. of bitstreams: 2 Dissertação - Queli Silvério Fernandes - 2016.pdf: 1375648 bytes, checksum: 2802e9c975aac50366bae452d23a7cc8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-09-26 / This study has as objective analyze the evolution of the static capacity of grain storage in Brazil by region, compared to the production, from 1980 to 2015. This is a research exploratory in descriptive character, and the technical procedure used was documentary analysis of public reports National Supply Company - CONAB. Data were analyzed in statistical program Statistical Package for Social Sciences - SPSS, version 22.0. Firstly for to analyze the evolution of static storage capacity and of grain yield per region in Brazil, from 1980 to 2015, were performed polynomial regressions. In the second analysis we observed the correlation between the static capacity and the grain production by region, from 1980 to 2015, using the Spearman correlation test, and, to analyze the occurrence of deficit or surplus storage by region was accomplished calculating percentage. Lastly was it described the present situation of the location of warehouses and the predominant type of storage unit in each region. Is Significant the increased static storage capacity of concentrate grains in the last 15 years, however, in disproportion with the rhythm to the rate of growth presented in grain production, presenting static capacity below the production in four regions, being them the Midwest, South, Northeast and North. Already the Southeast region has a higher static capacity than the capacity productive current. In Brazil it was observed since 2002 the increase in the deficit of static capacity of storage which in 2015 presented a value of 26%. In Brazil only 14% of the static capacity of storage is located on farms and most of the static capacity concentrates on units collecting and intermediate. / Este estudo tem como objetivo analisar a evolução da capacidade estática de armazenagem de grãos no Brasil por região, comparando com a produção, no período de 1980 a 2015. Esta é uma pesquisa exploratória de caráter descritivo, e o procedimento técnico utilizado foi a análise documental dos relatórios públicos da Companhia Nacional de Abastecimento - CONAB. Os dados foram analisados no programa estatístico Statistical Package for Social Sciences - SPSS, versão 22.0. Primeiramente para análise da evolução da capacidade estática de armazenagem e da produção de grãos por região do Brasil, no período de 1980 a 2015, foram realizadas regressões polinomiais. Em segunda análise observou-se a correlação entre a capacidade estática e a produção de grãos por região, no período de 1980 a 2015, com a utilização do teste de correlação de Spearman, e, para analisar a ocorrência de déficit ou superávit de armazenagem por região foi realizado cálculo em porcentagem. Por último foi descrita a atual situação da localização dos armazéns e do tipo de unidade armazenadora predominante em cada região. É significativo o aumento da capacidade estática de armazenagem de grãos concentrado nos últimos 15 anos, porém, em desproporção com o ritmo da taxa de crescimento apresentado na produção de grãos, estando com a capacidade estática de armazenagem inferior a produção em quatro regiões sendo Centro-Oeste, Sul, Nordeste e Norte. Já a região Sudeste apresenta maior capacidade estática que a atual capacidade produtiva. No Brasil observou-se desde 2002 o aumento do déficit da capacidade estática de armazenagem que em 2015 apresentou o valor de 26%. No Brasil somente 14% da capacidade estática de armazenagem está localizada nas fazendas e a maior parte da capacidade estática se concentra nas unidades coletoras e intermediárias.
48

Improved Hermetic Grain Storage System for Smallholder Farmers in Tanzania

Milindi, Paschal 29 December 2016 (has links)
No description available.
49

A Descriptive Study of Grain Production, Consumption, and Storage in Virginia

Caffarelli, Peter Anthony 20 January 2016 (has links)
Agriculture is an important industry in Virginia, with an array of crops grown and animals produced. Virginia's crop, livestock, and poultry sectors sold agricultural products worth $1.4 billion and $2.4 billion, respectively, in 2012. One of the products, grain, serves as an important input for raising livestock and poultry. Virginia needs to import grain from other states (Eastern Corn Belt states) to meet current livestock feed requirements, an expense that raises the cost of production over locally sourced grains . Further, such movements of grain from producing-areas to demand-areas rely on the efficient and timely interaction of grain storage and transportation. Describing the details of the grain supply chain provides insights into the interplay and relationships among production, storage, transportation, and end users of grains and oilseeds in Virginia. Results of a state-wide survey of Virginia grain producers shed light on the following topics: current cropping practices; current grain storage practices; available farm-level storage and its use, age, and expected life; and future storage plans and constraints. Overall findings include, grain production in Virginia has generally increased over the last decade, yet storage capacity remains constant and continues to age; livestock and poultry populations are declining leading to less demand for feed grains and oilseeds; grain farmers report satisfaction with their current storage situation and higher returns to stored grain may encourage "non-storers" to build storage; and the majority the grain leaving the farm is hauled by truck over short distances (25 miles or less). Overall, the results provide a foundation for understanding the grain supply chain in Virginia and offer useful information to Virginia's agricultural stakeholders. / Master of Science
50

Determinants of the supply-side fragmentation of maize storage in the North Western Free State production area / Mathys Johannes Nicolaas van der Merwe.

Van der Merwe, Mathys Johannes Nicolaas January 2012 (has links)
For decades commercial silos in South Africa was the only option in which maize could be delivered and sold. After deregulation in the late 1990s commercial silo owners came to face the challenge of alternative storage solutions and loss of market share. The reasons are determined for a shift from commercial storage to on-farm storage. The extent to which on-farm storage will change the current maize storage industry is discussed. The study commences by describing the birth and rapid growth of maize production in South Africa. Soon after maize became a major role-player in the export industry, it was characterised by regulation. The rationale why the market was regulated and how it influenced grain storage is explained. The deregulation process and the objectives of the new Marketing of Agricultural Products Act, No. 47 of 1996, are paraphrased. In the deregulated market, current and future, maize prices are determined by supply and demand. Incentives for storage emerged and cheaper substitutes with various other advantages began to propose alternative storage solutions to farmers. These concurrences of circumstances then lead to fragmentation of grain storage in South Africa. As a relatively young free market, the maize value chain is described to illustrate the position of each role-player in relation to the silo owner. The new price determination factors, price movement rationale and the use of market instruments are subsequently explained. Naturally, a critical assessment of the main different storage solutions available for farmers, are investigated next. Fragmentation is defined and discussed in terms of market equilibrium. A comparison is drawn between the South African and the Australian as well as the US maize storage industry. The empirical research was conducted on two sample groups of farmers in the Free State. The first group is farmers that already make use of an on-farm storage facility. The second group is farmers that annually produce more than 5000 tons of maize and currently do not make use of an on-farm storage facility. Seven important reasons for an on-farm storage facility are determined in the literature study as well as a qualitative study that preceded the quantitative study. Respondents are asked to rank the reasons in order of, in their opinion, importance. A generalized profile of a respondent in each sample group was compiled. Hereafter the outcome of the reasons ranked by both sample groups is discussed. It appeared that Flexible Marketing Option was the most important reason for farmers that already make use of on-farm storage. Farmers did not indicate that Handling and Storage costs are the most important reason why they would invest in an on-farm storage facility. Correlations are drawn between groups and the significance of differences is determined. It is concluded that on-farm storage is sustainable and there will be an increase of the phenomenon over the next three years. Recommendations are given for commercial silo owners to regain market share. Costs analyses and effective cost management along with the promotion that marketing options are just as flexible within commercial silos, as it is outside, are some of the recommendations made. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.

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