Master of Science / Department of Grain Science and Industry / Leland McKinney / Carryover of medicated feed additives between batches of feed can potentially result in harmful drug residues in the edible tissues of food-animals. Flushing the equipment with an ingredient, such as ground grain, is one method used to remove any residual medicated feed from the system. It is generally recommended that the quantity of flush used be between 5 and 10% of the mixer's capacity. However, there is little data that supports this recommendation. Therefore, two experiments were conducted to 1.)determine which manufacturing equipment is the major source of carryover, 2.)evaluate which flush size adequately prevents drug carryover, and 3.) quantify the interrelationship between flush size and drug concentration. In Experiment 1, feed medicated with nicarbazin (Nicarb 25%®; 0.0125%) was manufactured and conveyed from the mixer, through a drag conveyor and bucket elevator, and then into a finished product bin. The system was then flushed using ground corn in the amount of 2.5, 5, 10, 15, or 20% of the mixer's capacity (454.5 kg). Subsequently, a non-medicated diet was conveyed through the system and samples were collected and analyzed for nicarbazin. No significant (P > 0.05) differences were detected among the flush treatments, and all treatments were effective in preventing nicarbazin carryover to the non-medicated diet. In Experiment 2, feed medicated with three levels of monensin (Rumensin® 80; 100, 600, and 1,200 g/ton) was manufactured and handled in the same manner as in Experiment 1. The flushing treatments examined were: 1, 2.5, and 5% of the mixer's capacity. Samples of the non-medicated diet for each treatment were collected and analyzed for monensin. There was significant interaction (P < 0.05)between drug level and sampling location between treatments. As the drug level in the medicated diet increased, higher concentrations of monensin were detected in the non-medicated diet. Collectively, these studies demonstrate that a 2.5%, even a 1% flush size, is effective in preventing carryover of medicated feed additives. It was also demonstrated that the bucket elevator and finished product bin were the major sources of drug carryover in this particular feed manufacturing system.

From the agent-based, correlated random walk model presented, we observe the effects of varying the parameter values of maximum insect turning area, 𝛿max, density of trees, ω, maximum pollen carryover, 𝜅max, and probability of fertilization, P𝜅, on the distribution of pollen within a population of Cornus florida (flowering dogwood). We see that varying 𝛿max and 𝜅max changes the dispersal distance of pollen, which greatly affects many measures of connectivity. The clustering coefficient of fathers is maximized when 𝛿max is between 60° and 90°. Varying ω does not have a major effect on the clustering coefficient of fathers, but it does have a greater effect on other measures of genetic diversity. Lastly, we compare our simulations with randomly-placed trees with that of actual tree placement of C. florida at the VCU Rice Center, concluding that in order to truly understand how pollen is distributed within a specific ecosystem, specificity in describing tree locations is necessary.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-13T17:48:46Z No. of bitstreams: 1 2017 - Camila da Costa Barros de Souza.pdf: 3294573 bytes, checksum: 19a6a94e300565df61e362d626a65cf1 (MD5) / Made available in DSpace on 2018-09-13T17:48:46Z (GMT). No. of bitstreams: 1 2017 - Camila da Costa Barros de Souza.pdf: 3294573 bytes, checksum: 19a6a94e300565df61e362d626a65cf1 (MD5) Previous issue date: 2017-02-17 / FAPERJ / Residual herbicides, in some cases, can affect subsequente crops. In these situations, The use of phytoremediation species may be an alternative in the degradation of these molecules, minimizing the carryover risks. The first step in establishing if some species can be used as a phytoremediation, is check that it has tolerance to the product, for later verify its remedial effect. Against the foregoing, The present master's thesis aimed to identify plant species capable of phytoremediation the diclosulam herbicide, elucidating the biological mechanism of phytoremediation used by plants. For this, 3 different experiments were performed. In the first experiment, conducted at the Dow Agrosciences Experiment Station, it was selected, among the species Arachis pintoi, Brachiaria brizantha, Brachiaria decumbens, Canavalia ensiformis, Cajanus cajan e Crotalaria juncea, those that shows tolerance to the diclosulam herbicide. In the second experiment, conducted in the Universidade Federal Rural do Rio de Janeiro, it was evaluated the efficiency of the previously selected plant species to remediate soil contaminated with the diclosulam herbicide, using cucumber as a bioindicator plant. In the third experiment, conducted at Centro de Energia Nuclear na Agricultura (CENA/USP), it was verified if the tolerance mechanism of the two species that presented the greatest phytoremediation potential occurs due to the phenomena of absorption and / or translocation of the herbicide by the plant. The doses of diclosulam herbicide tested in the first and second experiments were 21, 42, 63, e 84 g ha-1 + control (without presence of the herbicide); And in the third experiment, the doses that were tested was 42 g ha-1 + control (without presence of the herbicide). The species Arachis pintoi, Canavalia ensiformis, Cajanus cajan e Crotalaria juncea showed a tolerance to the diclosulam herbicide at the doses tested, and the species Canavalia ensiformis, Cajanus cajan e Crotalaria juncea were efficient in the dissipation/degradation of these molecules in the soil, it is pointed out that the last two species were those that presented the greatest remedial effect. Using the 14C radiolabeled herbicide in its moleculares structure, could be inferred through the mass balance and observation of the radioimagens of the species Crotalaria juncea e Cajanus cajan that the phytoremediative action performed by these species is, probably, through phytostimulation. In addition, there is an anatomic / metabolic barrier of diclosulam translocation in the collar of these species, which gives them tolerance to this herbicidal molecule. / Herbicidas residuais, em alguns casos, podem afetar culturas subsequentes. Nestas situa??es, o uso de esp?cies fitorremediadoras pode ser uma alternativa na degrada??o destas mol?culas, minimizando o risco de carryover. O primeiro passo para estabelecer se uma esp?cie pode ser utilizada como fitorremediadora, ? verificar se a mesma apresenta toler?ncia ao produto, para posteriormente verificar o seu efeito remediador. Diante do exposto, a presente disserta??o de mestrado teve por objetivo identificar esp?cies vegetais capazes de fitorremediar o herbicida diclosulam, elucidando o mecanismo biol?gico de fitorremedia??o empregado pelas plantas. Para isso foram realizados 3 experimentos distintos. No primeiro experimento, realizado na Esta??o Experimental da Empresa Dow Agrosciences, foi selecionado, dentre as esp?cies Arachis pintoi, Brachiaria brizantha, Brachiaria decumbens, Canavalia ensiformis, Cajanus cajan e Crotalaria juncea, aquelas que apresentem toler?ncia ao herbicida diclosulam. No segundo experimento, realizado na Universidade Federal Rural do Rio de Janeiro, avaliou-se a efici?ncia das esp?cies vegetais, previamente selecionadas, em remediar solo contaminado com o herbicida diclosulam, utilizando o pepino como planta bioindicadora. No terceiro experimento, realizado no Centro de Energia Nuclear na Agricultura (CENA/USP), foi verificado se o mecanismo de toler?ncia das duas esp?cies que apresentaram maior potencial fitorremediador ocorre devido aos fen?menos de absor??o e/ou transloca??o do herbicida pela planta. As doses do herbicida diclosulam testadas no primeiro e segundo experimento foram 21, 42, 63, e 84 g ha-1 + controle (sem presen?a do herbicida); E no terceiro experimento foram testadas as doses 42 g ha-1 + controle (sem presen?a do herbicida). As esp?cies Arachis pintoi, Canavalia ensiformis, Cajanus cajan e Crotalaria juncea apresentaram toler?ncia ao herbicida diclosulam nas doses testadas, sendo as esp?cies Canavalia ensiformis, Cajanus cajan e Crotalaria juncea eficientes na dissipa??o/degrada??o dessas mol?culas no solo, posto que as duas ?ltimas esp?cies foram as que apresentaram maior efeito remediador. Utilizando o herbicida radiomarcado com 14C em sua estrutura molecular, p?de-se inferir atrav?s do balan?o de massa e observa??o das radioimagens das esp?cies Crotalaria juncea e Cajanus cajan que a a??o fitorremediadora exercida por essas esp?cies ?, provavelmente, atrav?s da fitoestimula??o. Ademais, existe uma barreira anat?mica/metab?lica de transloca??o do diclosulam no coleto dessas esp?cies, o que lhes confere toler?ncia ? essa mol?cula herbicida.

This dissertation focuses on the economic and environmental benefits of planting switchgrass as a bioenergy feedstock. The first chapter presents a dynamic optimization model of fertilizer and land allocation between switchgrass and corn to estimate economic benefits. Subsequent chapters utilize Geographic Information System (GIS)-based Soil and Water Assessment Tool (SWAT) to be calibrated to evaluate the environmental (nutrient and sediment loading) effects of land use conversion to switchgrass production on water quality and analyze the Water Quality Trading (WQT) program with cost-effectiveness ratios ordered for abatements of nutrient loadings in an East Tennessee watershed.

abstract: In this thesis, a single-level, multi-item capacitated lot sizing problem with setup carryover, setup splitting and backlogging is investigated. This problem is typically used in the tactical and operational planning stage, determining the optimal production quantities and sequencing for all the products in the planning horizon. Although the capacitated lot sizing problems have been investigated with many different features from researchers, the simultaneous consideration of setup carryover and setup splitting is relatively new. This consideration is beneficial to reduce costs and produce feasible production schedule. Setup carryover allows the production setup to be continued between two adjacent periods without incurring extra setup costs and setup times. Setup splitting permits the setup to be partially finished in one period and continued in the next period, utilizing the capacity more efficiently and remove infeasibility of production schedule. The main approaches are that first the simple plant location formulation is adopted to reformulate the original model. Furthermore, an extended formulation by redefining the idle period constraints is developed to make the formulation tighter. Then for the purpose of evaluating the solution quality from heuristic, three types of valid inequalities are added to the model. A fix-and-optimize heuristic with two-stage product decomposition and period decomposition strategies is proposed to solve the formulation. This generic heuristic solves a small portion of binary variables and all the continuous variables rapidly in each subproblem. In addition, the case with demand backlogging is also incorporated to demonstrate that making additional assumptions to the basic formulation does not require to completely altering the heuristic. The contribution of this thesis includes several aspects: the computational results show the capability, flexibility and effectiveness of the approaches. The average optimality gap is 6% for data without backlogging and 8% for data with backlogging, respectively. In addition, when backlogging is not allowed, the performance of fix-and-optimize heuristic is stable regardless of period length. This gives advantage of using such approach to plan longer production schedule. Furthermore, the performance of the proposed solution approaches is analyzed so that later research on similar topics could compare the result with different solution strategies. / Dissertation/Thesis / Masters Thesis Industrial Engineering 2015

Submitted by JACKELINE DEL CARMEN HUACCHA NEYRA null (jacky_157_93@hotmail.com) on 2017-03-24T15:38:11Z No. of bitstreams: 1 dissertação jackeline.pdf: 1416143 bytes, checksum: 3865afc18803fe4e45d315a9ee3afaf9 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-24T18:02:08Z (GMT) No. of bitstreams: 1 huacchaneyra_jc_me_sjrp.pdf: 1416143 bytes, checksum: 3865afc18803fe4e45d315a9ee3afaf9 (MD5) / Made available in DSpace on 2017-03-24T18:02:08Z (GMT). No. of bitstreams: 1 huacchaneyra_jc_me_sjrp.pdf: 1416143 bytes, checksum: 3865afc18803fe4e45d315a9ee3afaf9 (MD5) Previous issue date: 2017-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os problemas de dimensionamento de lotes consistem em determinar a quantidade de itens que devem ser produzidos em todos os períodos de um horizonte de planejamento. Em geral, são considerados custos de produção, preparação de máquina e de manutenção de estoque. Neste trabalho estuda-se uma extensão do problema de dimensionamento de lotes com restrição de capacidade que considera tempos de preparação, preparação carryover e crossover, em que se tem uma única máquina, único estágio, multi-itens e big-bucket (CLSP-SCC). Novas formulações para o CLSP-SCC são apresentadas e evitam a necessidade de definir novas variáveis binárias para modelar a preparação crossover. Também são propostas restrições de quebra de simetria para formulações propostas na literatura. São provadas as relações teóricas que existem entre cada uma destas formulações estudadas. Além disso, é proposta uma heurística híbrida que combina as heurísticas Relax-and-Fix e Fix-and-Optimize (RF-FO), em que a heurística Relax-and-Fix é usada para obter uma solução inicial e a heurística Fix-and-Optimize melhora essa solução. Por fim, apresentam-se os resultados computacionais e conclui-se que os resultados obtidos melhoram significativamente quando comparam-se a formulação clássica com as formulações sem preparação carryover. Compara-se também os resultados da heurística com os do pacote computacional CPLEX e, quando ambos são limitados ao mesmo tempo computacional, a heurística RF-FO obtém melhores resultados. / Lot-Sizing Problems consist of determining the quantity of items to be produced in each period of a planning horizon. In general, production, setup and inventory costs are considered. In this work an extension of the Capacitated Lot-Sizing Problem is studied, which considers setup times, Setup Carryover and Setup Crossover, single machine, single level, multi items, multi periods and big-bucket (CLSP-SCC). New formulations to the CLSP-SCC are presented and avoid the necessity of defining new extra binary variables to model the setup crossover. Furthermore, symmetry breaking constraints are proposed for formulations from the literature. The theoretical relations between the studied formulations are proved. A Relax-and-Fix and Fixand-Optimize (RF-FO) hybrid heuristic is proposed, in which the Relax-and-Fix helps to find an initial solution and the Fix-and-Optimize improves it. Computational results are presented and the obtained results improve significantly when comparing the classical formulation with the formulation without setup carryover. Finally, the results obtained by the RF-FO heuristic and the computational package CPLEX are compared and, when they both are limited to the same computational time, the RF-FO heuristic obtains better results.

Today, there is a high demand on clean steel for high performance materialproperties. Thus, steel producers try to deliver a steel product with the highestquality and cleanliness to the market. The number of parameters that affect thesteel cleanliness may vary depending on the required material properties of thefinal product. However, the non-metallic inclusion characteristics represent one ofthe most important parameters. More specifically, the composition, size, numberand morphology affect steel cleanliness. In this work, selected parameters affectingthe inclusion characteristics were studied using the following methods: i)thermodynamic calculations (including computational thermodynamiccalculations), ii) inclusion determinations using a cross sectional (CS) method (2Dinvestigations) and iii) inclusion determinations using an electrolytic extraction(EE) method (3D investigations). The computational thermodynamic calculations of the slag-steel and inclusion-steelequilibriums were carried out using the Thermo-Calc software. With the help ofthese calculations, the influence of the slag carryover on the top slag, aluminumcontent in steel and sulfur distribution ratio as well as predictions of stable phasesof inclusions were studied. In addition, inclusion determinations of tool steel gradesamples collected during various stages of the ladle treatment in a scrap-based steelplant were carried out using both 2D and 3D methods. Furthermore, inclusiondeterminations of bearing steel grade samples from a runner system after ingotcasting were performed using a 2D metallographic method (CS-method). Also, theINCAFeature software was used, when using cross sectional method, in order tocollect more statistics of the inclusion characteristics. It was found that slag carryover has a large influence on the composition of theactual top slag as well as the aluminum content in the steel as well as the sulfurdistribution ratio. In addition, steel and slag were found to be in “near”-equilibriumconditions, after the completion of the vacuum degassing operation. Furthermore,the composition of small-size inclusions in samples taken from tool steel was foundto be very scattered. Moreover, the composition of the large-size inclusions wasfound to be less scattered. Furthermore, closer to the top slag composition insamples collected after vacuum degassing. Finally, the accuracy of the inclusioncomposition determinations of tool steel samples using the electrolytic extractionmethod was found to be better than for the cross sectional method. The worseaccuracy of the CS-method is due to a considerable effect of matrix elements oninclusion composition. / QC 20100709

Labyrinth seals are often utilized in locations where contact seals cannot be utilized due to the large displacements of the rotating shaft. The performance evaluation of a labyrinth seal is very important to make sure that optimum performance of turbomachinery is attained. Performance parameters such as carryover coefficient, discharge coefficient were evaluated for a see through triangular tooth on stator labyrinth seal. This computational study investigates how flow conditions and seal parameter variations for see through tooth on stator triangular cavity labyrinth seals affect the value of the carryover coefficient and discharge coefficient. A Finite volume CFD commercial code was used to accomplish the above study. The influence of Reynolds number, rotational speed, seal radial clearance, pitch, tooth angle, tooth width are considered using the finite volume method of computational fluid dynamics. It was found that Reynolds number, high shaft speed and clearance have a significant effect on the carryover coefficient and the discharge coefficient. Clearance is the major influential parameter to be considered among all seal geometric parameters to optimize an ideal seal.

Variable mortality of Pyrenophora semeniperda–infected Bromus tectorum seeds has been referred to as a “race for survival.” Dormant seeds are highly susceptible to P. semeniperda infection. While much is known about primary dormancy little is known about secondary dormancy in B. tectorum seeds. Dormancy status is not the only variable determining outcomes within the Bromus - Pyrenophora pathosystem. Varying temperature and intermittent hydration may strongly influence germination outcomes of B. tectorum in the presence of P. semeniperda. While it has long been assumed that B. tectorum seeds are infected by P. semeniperda in the fall it was recently suggested that seeds may be infected in the summer; however, there is little evidence to support this. To further characterize the Pyrenophora semeniperda - Bromus tectorum pathosystem two studies were conducted to address the following: (1) characterization of secondary dormancy in B. tectorum seeds and (2) summer interactions between host and pathogen after summer inoculation. Studies were conducted using dormant and/or non-dormant B. tectorum (along with B. rubens in one study) seeds and two strains of P. semeniperda. Study one used laboratory and field experiments to characterize secondary dormancy in B. tectorum seeds in terms of temperature (0.5-20°C), and water potential (-2.0-0 MPa). Data was used in repeated probit regression analysis to determine hydrothermal parameters (ψb(50), σψb, θHT) for secondary dormancy induction and loss. In the second study seeds were inoculated with one of two strains of P. semeniperda then exposed to intermittent hydration or dry storage at warm temperatures (30-60°C). After treatment seeds were rehydrated and outcomes observed. Optimum conditions for secondary dormancy induction were incubation at -1.0 MPa at 5°C. Seeds were likely to enter secondary dormancy through the cold winter months indicated by an increase or more positive ψb(50), while a decrease or more negative ψb(50) is associated with dormancy loss which is generally observed in the hot, dry summer months. When seeds were inoculated in the summer they only escaped death when summer conditions were ideal for after-ripening which allowed them to germinate rapidly under favorable autumn conditions. However, the pathogen caused high seed mortality no matter the treatment when disease progression advanced enough to inhibit seed germination. Thus this research shows that in areas with frequent summer rain storms, it would be highly advantageous to apply P. semeniperda as a biocontrol on seeds at maturity.

No description available.