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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.
31

Planting date as an adaptive strategy to improve yield of Chickpea (Cicer arietinum) under under climate change condition in Southern Africa

Mubvuma, Michael Ticharwa 21 September 2018 (has links)
PhD (Plant Production) / Department of Plant Production / Planting chickpea genotypes at different dates within the same season may expose the crop to different environmental factors (temperature and moisture) during their vegetative and reproduction stages. Thus, knowledge of optimum planting date that minimises extreme temperature and water stress conditions during crital stages of chickpea plant development may increase biomass and grain yield. The objective of the study was to determine the effect of planting date and genotype on aboveground biomass and grain yield of chickpea under climate change scenario in North Eastern Region of South Africa. The hypothesis tested was that planting date and genotype have an effect on biomass and grain yield of chickpea under climate change scenario. Thus, a study design incorporating a combination of field and modelling experiments was set to run in 2014 and 2015 winter planting seasons at the University of Venda, South Africa. Field experiments determined the effect of planting date and genotype on chickpea flower retention and pod abortion, aboveground biomass and grain yield, water use and radiation use efficiency, whilst modelling experiments calibrated and validated the FAO AquaCrop model to simulate chickpea aboveground biomass and grain yield using climate datasets (1950 - 2100), simulated from 15 global circulation models (GCMs) under the representative carbon dioxide concentration pathways (RCP) 4.5 and 8.5. Field experiments results showed significant effect of planting date and genotype on biomass and grain yield of chickpea. Planting early, particularly under well-watered conditions appeared to be the most suitable sowing period for chickpea in this region. In contrast, late planting had lowest biomass and grain yield. The high grain yield in early planting (1.99 t ha-1) was supported by greater yield components (seed weight (13.8 gm-2) and pod weight 23 gm-2), number of pods per plant (75 pods plant-1) and harvest index (43 %)). Moreover, plant phenological factors such as plant height (46 cm) and number of branches per plant (16 branches) were also greater in early planting, with late planting recording lowest values in all the measured parameters. In addition, the greater biomass and grain yield in early planting compared with the normal and late sowings was caused by greater intercepted radiation (91%), improved flower retention (45.2%) and minimised water use (174 mm) and pod abortion (13.6%). Late maturing genotypes (Range 4 & 5) showed greater water use efficiency of grain yield (7.3 & 7.1 kg ha-1 mm-1) and had the highest radiation use efficiency of grain yield, which was on average 7.2% (0.07 g MJ-1) greater than ICCV9901, and 15.6% (0.13 g MJ-1) greater than Range 1 & 3, but this depended on soil moisture availability. vi The simulation results, indicated a significant increase in temperature (by 4.2 to 5.5 oC) over a period from 1950 to 2100. This increase lead to a concomitant increase in chickpea evapotranspiration and accumulated growing degree days. Moreover, optimal planting date for chickpea shifted from mid-month of April during 1950 to end of May in 2100 and reduced growing season length from 140 days in 1950 to 85 days in 2100. Aboveground biomass increased from 2.0 & 2.05 t ha-1 in 1950 to 4.3 & 4.57 t ha-1 in 2100, respectively in RCP 4.5 and 8.5, whilst grain yield increased from 1.07 & 1.08 t ha-1 in 1950 to 1.68 & 2.21 t ha-1 in 2100, respectively under RCP 4.5 and 8.5. Planting dates that were recommended by AquaCrop model recorded the highest increase in aboveground biomass and grain yield compared with early, normal and late planting dates. Late maturing genotypes (Range 4 & 5) showed greater grain yield and biomass, whilst early and medium maturing genotypes had low biomass and grain yield. The study recommend early planting date together with late maturing chickpea genotypes (Range 4 and 5) in the region so as to improve water use efficiency, radiation use efficiency, heat use efficiency and aboveground biomass and grain yield of the crop under the present time and under climate change scenario. The early maturing genotype (Range 1) and medium maturing genotypes (Range 3 and ICCV9901) may only be recommended under normal planting date, although there will not be any significant yield advantages compared with late maturing genotypes. The study also recommend the use of planting dates generated by AquaCrop model so as to improve biomass and grain yield when chickpea is sown under climate change scenario in Southern Africa. The yield improvement using AquaCrop recommended planting dates was partly caused by greater water use efficiency, heat use efficiency and corbon dioxide productivity. Given the potential importance of planting dates in improving current and future productivity of chickpea shown in the study, there is need to work on development of a sowing (planting date) criteria for chickpea in the / NRF
32

Improving the Quality of Scheduling Decisions for the Engineering Function

Grabenstetter, Douglas H 15 December 2012 (has links)
The Engineer to Order (ETO) model is used by a significant number of manufacturers across multiple sectors. Indeed, ETO firms comprise approximately one fourth of all North American manufacturing and are growing at a rate of twenty percent (Cutler [10]). In the ETO environment, the engineering process is the largest controllable consumer of lead-time in ETO firms. Since one half of the total lead-time is typically consumed by the engineering process, it is a critical task to accurately set the due date and later sequence the jobs in queue. However, unlike other manufacturing models such as Make to Stock or Make to Order, the product for each order is unique. Hence the resulting design is not realized until after the engineering process has been completed an the only information available is limited to information which has been gathered during the quoting stage of the order fulfillment process. These facts drive uncertainty into the front-end process. Therefore, the question becomes how does one predict the job difficulty let alone the due date in a complex transactional process when the job has not even been designed yet? In regard to the state of the art for the topic of design complexity, due date setting and sequencing, there is an abundance of research. Unfortunately little of it is aimed at the ETO environment. Additionally, there is not an agreed upon way in the literature to define complexity nor is there one overarching methodology for assessing complexity. Therefore, this research investigates the topics of job complexity, due date setting and job sequencing in the context of the Engineer to Order model. Analytical research is conducted with in conjunction with multiple ETO firms and several common factors are identified which drive complexity in the ETO engineering environment. These complexity factors are can be used is as an input to the accurate prediction of flow times for the ETO engineering process as well as sequencing. The research results in new innovative approaches for complexity assessment, due date setting and sequencing which outperform existing approaches.
33

A computer simulation analysis of a flow shop

Walters, Robert H. January 1984 (has links)
No description available.
34

Consórcio de milho com forrageiras: atributos físicos do solo e produtividade / Corn consortium with forage: attributes physical soil and productivity

Santos, Paulo Ricardo Alves dos January 2016 (has links)
SANTOS, Paulo Ricardo Alves dos. Consórcio de milho com forrageiras: atributos físicos do solo e produtividade. 2016. 84 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza, CE, 2016. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-08-01T13:27:48Z No. of bitstreams: 1 2016_dis_prasantos.pdf: 1948037 bytes, checksum: e1770d22fe7e64bae84ffa607d041a49 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-08-01T13:28:25Z (GMT) No. of bitstreams: 1 2016_dis_prasantos.pdf: 1948037 bytes, checksum: e1770d22fe7e64bae84ffa607d041a49 (MD5) / Made available in DSpace on 2016-08-01T13:28:25Z (GMT). No. of bitstreams: 1 2016_dis_prasantos.pdf: 1948037 bytes, checksum: e1770d22fe7e64bae84ffa607d041a49 (MD5) Previous issue date: 2016 / The intensification of agricultural production systems is increasing in the current agriculture. In this sense, the simultaneous planting forage to grain crops, constitutes an alternative in the intensification of the production system, which can increase or not the productivity of the main crop, and produce straw for mulching. In order to check the occurrence of changes in the physical properties of the soil and in corn yield and dry matter production due to the corn consortium / forage in two sowing dates, this study was conducted in the experimental area of the Department of Agricultural Engineering of the Federal University of Ceará. The design was used in a randomized block design in a factorial scheme (3x2) + 1 with four replications, totaling 28 experimental units. The treatments consisted of three forages: Brachiaria, Panicum maximum cv. Mombaça and Crotalaria spectabilis intercropped with maize in two of fodder sowing dates, between the lines of simultaneous sowing maize (season 1 - E1) and corn leading the V4 stage of corn (season 2 - E2), and the control. The results showed that intercropping maize / forage did not interfere in phytotechnical characteristics of corn, nor in productivity, however produced changes in soil physical properties when the day of sowing in season 1. Despite the changes that have occurred in the soil, they were not sufficient to enhance the productivity of maize, which could possibly be related assessments on only one crop cycle. But when the goal was the production of dry straw, it is concluded that fodder Brachiaria brizantha and Mombasa at the time 1 (E1) are recommended / A intensificação dos sistemas de produção agrícola é cada vez maior na atual agricultura. Nesse sentido, o plantio simultâneo de forrageiras com culturas produtoras de grãos, constitui em uma alternativa na intensificação do sistema de produção, que poderá incrementar ou não a produtividade da cultura principal, além de produzir palha para cobertura do solo. Com o objetivo de verificar a ocorrência de mudanças nas propriedades físicas do solo, bem como na produtividade do milho e produção de matéria seca em função do consórcio milho/forrageiras em duas épocas de semeadura, o presente trabalho foi conduzido na área experimental do Departamento de Engenharia Agrícola da Universidade Federal do Ceará. Foi utilizado o delineamento em blocos ao acaso, no esquema fatorial (3x2) + 1 com quatro repetições, totalizando 28 unidades experimentais. Os tratamentos foram constituídos por três forrageiras: Brachiaria brizantha, Panicum maximum cv. Mombaça e Crotalária spectabilis consorciadas com o milho em duas épocas de semeadura das forrageiras, na entrelinha do milho simultâneo a semeadura (época 1 – E1) e na entrelinha do milho no estádio V4 do milho (época 2 – E2), além da testemunha. Os resultados permitiram concluir que a consorciação milho/forrageiras não interferiram nas características fitotécnicas do milho, nem tampouco, na produtividade, porém proporcionaram modificações nas propriedades físicas do solo quando da realização da semeadura na época 1. Apesar das modificações ocorridas no solo, as mesmas não foram suficientes em incrementar a produtividade do milho, o que possivelmente pode estar relacionado as avaliações em apenas um ciclo da cultura. Já quando o objetivo foi a produção de matéria seca de palha, conclui-se que as forrageiras Brachiaria Brizantha e Mombaça na época 1 (E1) são recomendadas
35

Perishable Inventory Management Solutions and Challenges of Kosovo FFRs : Avoiding Product Expiration at Retails Shelves

Rexhaj, Betim January 2019 (has links)
Title: Perishable Inventory Management Solutions and Challenges of Kosovo FFRs. Avoiding Product Expiration at Retails ShelvesPurpose: In this thesis perishable inventory management solutions and challenges at Kosovo FFRs have been studied and identified. Hence, after identifying PIM solutions and challenges the research suggests ideas that will contribute to avoid the expiration of perishable products if selling them takes more time than their actual shelf life. This contributes to minimizing food waste in food supply chains and fresh food retailers. Methodology: Thesis consist of qualitative methods where multiple case studies in cooperation with Kosovo FFRs have been performed. Data collection methods included semi structured interviews, site visits and some financial data accessed from annual and government reports. Theory: Theoretical chapter has been developed from preexisting theory on perishable inventory management. Five phases of fresh food retailing inventory management have been developed and used as the basis for practical research. Moreover, part two of the theoretical chapter talks about the perishable inventory management challenges and is the basis for the second research question. Findings: The findings have shown that Kosovo FFRs use a mixture of PIM solutions with a focus on shelf life and replenishment solutions. The study also revealed that Kosovo FFRs are outdated regarding to product identification and software solutions, however, manage to perform somehow satisfactorily. Consequently, because of the lack of contemporary identification technologies Kosovo FFRs PIM challenges where found to be related to data accuracy and real time data access.
36

El Teatro Dominicano: Instrumento Político y Voz de una Identidad

Curiel, Sandra Y. 05 1900 (has links)
Throughout the history of the Dominican Republic, theater has played an instrumental role in the cultural life its people, one which transcends purely artistic and cultural dimensions extending its influence into the political and social fabric of the nation. In spite of Spanish colonization and later Haitian occupation, a nascent national identity began forming early on. The staging of certain plays exposed latent conflicts and revealed sectorial, class interests. Theater provided a means of expression for popular sentiments, thus revealing an urge by the people to manifest their concerns, usually under the heavy weight of censorship. This thesis focuses on key moments of the first 140 years of Dominican Republic theater. It is organized into three chapters: "Historical Antecedents", "Theater of the Dictatorship" and "Theater of the Post-Dictatorship." The first chapter deals with the struggle for independence through 1844; the next focuses on the theatrical plays and political climate of bloody Rafael Leonidas Trujillo dictatorship which spanned from 1930 to his assassination in 1961, and the third presents the theater that appeared in the subsequent years of the equally repressive Joaquin Balaguer presidency (1966-1978). The analysis of these key historical moments, in conjunction with the dramaturgy of playwrights such as Franklin Domínguez, Marcio Veloz Maggiolo and Héctor Incháustegui Cabral, maps the function of theater as a tool of raising awareness, transmitting ideologies, and unifying a nation, in spite of despotism and oppression often disguised as democracy. As such, it documents the role that theatre played during a nation-building process that stages the history of political repression, lack of freedom of expression as well as social and political injustice.
37

Ensemble Singing in the Bel Canto Salon Repertory: A Pedagogical Reconsideration

Brown, Shaun (Shaun Joseph) 12 1900 (has links)
Vocal duets have had a long history in the Western classical music tradition. Their use as a teaching resource can be traced back to the Renaissance, where duets were used for the development of singing, performance, and musicianship. In the late 19th and all of the 20th centuries, this pathway of vocal pedagogy has markedly declined. This study proposes a reintroduction of this methodology of teaching, asserting that it provides the collegiate vocal student with maximum opportunity for growth and development in terms of technique, musicianship, ensemble skills, and performance development. Four vocal duets ("La pesca," "Il brindisi," "Il gallop," and "La caccia") of Saverio Mercadante (1795-1870) serve as the point of discussion. These songs from Les soirées italiennes (C.1836), which are representative of the salon culture of the 19th century, are given detailed attention through a discussion of their pedagogical value. Since they are long out of print, a new performance edition is presented.
38

Lint Yield of Several Cotton Varieties Planted on 5 Dates at 3 Locations in Arizona in 1986

Kittock, D. L., Hofmann, W. C. 03 1900 (has links)
There were some wide variations in cotton variety performance at five planting dates among locations and years. However, on an average, DP 90 and DP 77 performed best when planted between 28 March and 24 April. Stoneville 506 and DP 50 averaged best for May plantings and DP 20, Stoneville 112, and DP 50 averaged best for early June plantings.
39

High Yielding Short Season Cotton Production in Arizona

Tollefson, Scott 03 1900 (has links)
No description available.
40

New single machine scheduling problems with deadline for the characterization of optimal solutions / Nouveaux problèmes d'ordonnancement à une machine avec deadlines pour la caractérisation de solutions optimales

Ta, Thanh Thuy Tien 06 July 2018 (has links)
Nous considérons un problème d'ordonnancement à une machine avec dates de fin impératives et nous cherchons caractériser l'ensemble des solutions optimales, sans les énumérer. Nous supposons que les travaux sont numérotés selon la règle EDD et que cette séquence est réalisable. La méthode consiste à utiliser le treillis des permutations et d'associer à la permutation maximale du treillis la séquence EDD. Afin de caractériser beaucoup de solutions, nous cherchons une séquence réalisable aussi loin que possible de cette séquence. La distance utilisée est le niveau de la séquence dans le treillis, qui doit être minimum (le plus bas possible). Cette nouvelle fonction objectif est étudiée. Quelques cas particuliers polynomiaux sont identifiés, mais la complexité du problème général reste ouverte. Quelques méthodes de résolution, polynomiales et exponentielles, sont proposées et évaluées. Le niveau de la séquence étant en rapport avec la position des travaux dans la séquence, de nouvelles fonctions objectifs en rapport avec les positions des travaux sont identifiées et étudiées. Le problème de la minimisation de la somme pondérée des positions des travaux est prouvé fortement NP-difficile. Quelques cas particuliers sont étudiés et des méthodes de résolution proposées et évaluées. / We consider a single machine scheduling problem with deadlines and we want to characterise the set of optimal solutions, without enumerating them. We assume that jobs are numbered in EDD order and that this sequence is feasible. The key idea is to use the lattice of permutations and to associate to the supremum permutation the EDD sequence. In order to characterize a lot of solutions, we search for a feasible sequence, as far as possible to the supremum. The distance is the level of the sequence in the lattice, which has to be minimum. This new objective function is investigated. Some polynomially particular cases are identified, but the complexity of the general case problem remains open. Some resolution methods, polynomial and exponential, are proposed and evaluated. The level of the sequence being related to the positions of jobs in the sequence, new objective functions related to the jobs positions are identified and studied. The problem of minimizing the total weighted positions of jobs is proved to be strongly NP-hard. Some particular cases are investigated, resolution methods are also proposed and evaluated.

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