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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.
1

Vyhodnocování účinnosti strojů pro zabezpečení výrobního úkolu / Evaluation of machine efficiency for production task assurance

Harnová, Veronika January 2020 (has links)
The diploma thesis concerns evaluation of machinery efficiency in selected production department. The theoretical part briefly describes production management and theoretical methods of OEE evaluation. The thesis also discusses selected IT systems utilised in engineering. The main body of the thesis analyses data acquired from those IT systems. The conclusion outlines proposals for improvement.
2

Freqüência e severidade de desfolhação e eficiência de utilização de forragem em pastos de capim-marandu manejados sob lotação contínua e ritmos de crescimento induzidos por fertilização nitrogenada / Frequency and severity of defoliation and utilisation efficiency on marandu palisadegrass subjected to continuous stocking and nitrogen-induced rhythms of growth

Guarda, Vitor Del'Alamo 24 June 2010 (has links)
Modificações no ritmo de crescimento de plantas forrageiras podem ter implicações nos processos de acúmulo de forragem e colheita da forragem produzida. Desse modo, a adequação de estratégias de manejo que proporcionem melhor eficiência, tanto no processo de crescimento como de utilização são objetivos de um sistema de produção ideal. Nesse contexto, o objetivo deste trabalho foi avaliar a freqüência e severidade de desfolhação de perfilhos e folhas e quantificar a eficiência de utilização da forragem produzida em pastos de capim-marandu manejados a 30 cm sob lotação contínua e submetidos a ritmos de crescimento gerados pela aplicação das doses de nitrogênio 150, 300 e 450 kg/ha.ano, mais o controle (sem adubação). Os tratamentos foram alocados às unidades experimentais (piquetes de 1200 m2) segundo um delineamento de blocos completos casualizados, com quatro repetições. Foram coletados dados de 30 perfilhos por piquete em ciclos de 28 dias. Após 28 dias, novos perfilhos eram selecionados e um novo ciclo de avaliações realizado. Foram avaliadas as seguintes variáveis-resposta de janeiro de 2007 a abril de 2008: densidade de lotação animal, freqüência de desfolhação de perfilhos, freqüência de desfolhação de folhas, freqüência de desfolhação para cada categoria de folha (senescente, expandida e em expansão), severidade de desfolhação do perfilho estendido, severidade de desfolhação de folhas, severidade de desfolhação para cada categoria de folha (senescente, expandida e em expansão), intervalo de desfolhação de folhas, duração de vida de folhas, probabilidade de desfolhação de folhas durante o período de vida das folhas e eficiência de utilização. Pastos mantidos sob ritmos de crescimento mais acelerados mantiveram maior densidade de lotação animal relativamente àqueles mantidos sob ritmos de crescimento mais lentos, o que resultou em maiores freqüências de desfolhação (menores intervalos de desfolhação) tanto de perfilhos como de folhas nos pastos adubados (150, 300 e 450 kg/ha de N) em relação aos não adubados. Por outro lado, pastos mantidos sob ritmos de crescimento mais acelerados apresentaram menor duração de vida das folhas, reduzindo, assim, o período possível de colheita antes de início do processo de senescência. Dessa forma, apesar do aumento em freqüência de desfolhação causado, pelas maiores densidades de lotação nos pastos adubados, houve diminuição correspondente em tempo de vida da folha, o que resultou em pequena variação em eficiência de utilização da forragem produzida. O uso de N altera os padrões de desfolhação de folhas e perfilhos individuais durante as épocas de maior crescimento das plantas, porém para o capim-marandu manejado a 30 cm sob lotação contínua, a utilização de nitrogênio não resultou em aumento de eficiência de utilização, uma vez que o aumento em freqüência de desfolhação foi compensado pela redução em duração de vida das folhas. / Variations in growth rhythm of plants may have implications to the herbage accumulation and utilisation processes, indicating that adjustments in management strategies aiming at improving growth and utilisation efficiencies may contribute to augment productivity of pastoral systems of animal production. The objective of this study was to evaluate frequency and severity of defoliation of individual tillers and leaves on continuously stocked marandu palisadegrass swards managed at 30 cm and subjected to nitrogen-induced growth rhythms created by the application of 150, 300 and 450 kg/ha.year of N, plus the control (non-fertilisation). Treatments were allocated to experimental units (1200 m2 paddocks) according to a randomised complete block design, with four replications. Data were collected from a set of 30 tillers per paddock during 28-day evaluation cycles. After 28 days, a new set of tillers was selected and a new evaluation cycle performed. From January 2007 until April 2008 the following response variables were evaluated: stocking density, defoliation frequency of tillers and leaves (senescent, expanded and expanding leaves), defoliation severity of extended tillers and leaves (senescent, expanded and expanding leaves), leaf defoliation interval, leaf lifespan, probability of leaf defoliation during its lifespan and utilisation efficiency. Swards fertilised with 300 and 450 kg/ha of N supported larger stocking density than those non-fertilised or fertilised with 150 kg/ha of N, resulting in higher defoliation frequency of tillers and leaves on fertilised than on non-fertilised swards. On the other hand, swards fertilised with high rates of nitrogen application (300 and 450 kg/ha) showed shorter leaf lifespan than those with low rates (non-fertilised and fertilised with 150 kg/ha), reducing the period available for harvest before commencement of senescence. As a result, in spite of the increase in defoliation frequency caused by the higher stocking densities used on fertilised swards, there was a corresponding decrease in leaf lifespan that caused small variation in utilisation efficiency. Use of nitrogen fertiliser during seasons of fast plant growth alters patterns of individual leaves and tillers defoliation. However, on marandu palisadegrass managed at 30 cm under continuous stocking, the use of nitrogen fertiliser did not result in increased utilisation efficiency of the produced herbage, since the increase in leaf defoliation frequency was compensated for by reduction in leaf lifespan.
3

A study of the interactions between Holstein-Friesian genotypes and feeding systems, with emphasis on system performance and cow grazing ability : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, New Zealand

Rossi, José Luis January 2006 (has links)
Imported genetic material of the Holstein-Friesian breed from overseas (OS), mainly from North America, has been used in New Zealand (NZ) since the late 1960's. This has diluted the genetic base of the former NZ Friesian genotype selected under intensive seasonal pasture-based systems. As a result, increased concerns have been raised about the negative influence of these overseas genes on the modern NZ Holstein- Friesian, as it is apparent that the OS Holstein-Friesian has a lower capacity to perform on grazed pasture. The objective of the present thesis was to investigate differences in production performance between three Holstein-Friesian genotypes farmed at different feed allowances (FA) on pasture-based systems; in addition, to investigate differences in the grazing process between strains under contrasting managements and sward conditions, and so to identify animal and pasture factors that affect the herbage intake (DMIH) and performance of the grazing cow. An accurate procedure was also established to estimate DMIH for cows fed forage and maize supplements, grazing in groups. Two modern high breeding worth (BW) Holstein-Friesian strains from NZ (NZ90) or overseas (OS90) origin and a low BW 1970's NZ Friesian genotype (NZ70) were farmed in two field experiments: (1) a long-term 'system' study that compared the yield performance of these genotypes in a range of systems with different feed allowance (FA) per cow, and a (2) a short-term 'component' study that compared the grazing capacity of the strains under contrasting sward conditions but at a common daily herbage allowance. The differences in productive performance between genotypes increased as the study progressed in the system study, with the largest observed in the last season. The mean milksolids (MS) yield per cow and per hectare were higher in NZ90 (395 kg cow-1 and 1,236 k ha-1) than in the NZ70 (336 kg cow-1 and 1,093 kg ha-1) and the OS90 (377 kg cow-1 and 1,154 kg ha-1). The higher production of NZ90 cows was supported by their higher mean daily MS yield than the NZ70 (1.45 vs. 1.21 kg MS cow-1 day-1) and more days in milk than OS90 cows (271 vs. 257 DIM). The lower lactation length of the OS90 strain occurred due to its lower body condition score (BCS) in late lactation, which determined an early dry-off for these cows. The lowest BCS of OS90 at the nadir (irrespective of FA), during lactation and at dry-off indicate these cows mobilised greater amount of body reserves and partitioned most of the energy ingested to yield. Genotype by FA interactions for milk and lactose yields, protein content in the milk and BCS were observed in the second and third seasons of the 'system' study. Milk yield increased as FA increased to a greater extent in OS90 than in the two NZ strains, whereas the content of solids in milk, particularly protein, increased to a greater extent for NZ90 than in both OS90 and NZ70. During lactation DMIH was higher for NZ90, intermediate in OS90 and lower in NZ70 (14.5, 13.9 and 12.6 kg DM cow-1 day-1 respectively for NZ90, OS90 and NZ70, as measured with nalkanes), and declined as lactation progressed, with a smaller difference for the total intake achieved (15.5, 15.2 and 13.1 kg DM cow-1 day-1 respectively) due to the increased supplement consumption. These results indicate that the OS90 needs more feed with a higher proportion of supplement in the diet to improve productive performance on pasture-based systems; the NZ90 would perform better when cow nutrition is mainly supported by grazing pasture, although further increments in performance could be expected from strategic supplementation, but requiring more feed than NZ70. The DMIH per unit of live weight (DMIH/LW) was highest in NZ90 strain in both the 'system' and in the short sward of the 'component' study (31.5 and 31.1 g DM kg-1 DM in NZ90 vs. 28.9 and 28.6 g DM kg-1 DM for OS90 in 'system' and 'component' studies respectively). The higher intake of NZ90 on pasture was sustained by a higher capacity to graze short swards than NZ70 and OS90, and to deal with the herbage of higher bulk density and lower quality present at the base of taller swards. The NZ90 can maintain DMIH in swards with different structures, indicating higher flexibility to perform under different managements and sward conditions. The size of the jaw is smaller in NZ90 than OS90 (88.4 vs. 92.4 mm) with effects on bite area and bite size, and this flexibility to adapt the size of the bite to swards of different structure may improve bite penetration under constraining sward conditions. The reduced ability of the OS90 to adjust ingestive behaviour to different swards would limit the capacity of this strain to perform on pasture. The fact that OS90 cows increased DMIH and DMIH/LW substantially in a leafy and taller sward (up to 21.6 kg cow-1 and 40.8 g DM kg-1Lw vs. 19.2 kg cow-1 and 41.0 g DM kg-1Lw in NZ90 during early lactation) suggests that yield performance can be improved in these cows even on pasture, by fine-tuning pasture management.
4

Freqüência e severidade de desfolhação e eficiência de utilização de forragem em pastos de capim-marandu manejados sob lotação contínua e ritmos de crescimento induzidos por fertilização nitrogenada / Frequency and severity of defoliation and utilisation efficiency on marandu palisadegrass subjected to continuous stocking and nitrogen-induced rhythms of growth

Vitor Del'Alamo Guarda 24 June 2010 (has links)
Modificações no ritmo de crescimento de plantas forrageiras podem ter implicações nos processos de acúmulo de forragem e colheita da forragem produzida. Desse modo, a adequação de estratégias de manejo que proporcionem melhor eficiência, tanto no processo de crescimento como de utilização são objetivos de um sistema de produção ideal. Nesse contexto, o objetivo deste trabalho foi avaliar a freqüência e severidade de desfolhação de perfilhos e folhas e quantificar a eficiência de utilização da forragem produzida em pastos de capim-marandu manejados a 30 cm sob lotação contínua e submetidos a ritmos de crescimento gerados pela aplicação das doses de nitrogênio 150, 300 e 450 kg/ha.ano, mais o controle (sem adubação). Os tratamentos foram alocados às unidades experimentais (piquetes de 1200 m2) segundo um delineamento de blocos completos casualizados, com quatro repetições. Foram coletados dados de 30 perfilhos por piquete em ciclos de 28 dias. Após 28 dias, novos perfilhos eram selecionados e um novo ciclo de avaliações realizado. Foram avaliadas as seguintes variáveis-resposta de janeiro de 2007 a abril de 2008: densidade de lotação animal, freqüência de desfolhação de perfilhos, freqüência de desfolhação de folhas, freqüência de desfolhação para cada categoria de folha (senescente, expandida e em expansão), severidade de desfolhação do perfilho estendido, severidade de desfolhação de folhas, severidade de desfolhação para cada categoria de folha (senescente, expandida e em expansão), intervalo de desfolhação de folhas, duração de vida de folhas, probabilidade de desfolhação de folhas durante o período de vida das folhas e eficiência de utilização. Pastos mantidos sob ritmos de crescimento mais acelerados mantiveram maior densidade de lotação animal relativamente àqueles mantidos sob ritmos de crescimento mais lentos, o que resultou em maiores freqüências de desfolhação (menores intervalos de desfolhação) tanto de perfilhos como de folhas nos pastos adubados (150, 300 e 450 kg/ha de N) em relação aos não adubados. Por outro lado, pastos mantidos sob ritmos de crescimento mais acelerados apresentaram menor duração de vida das folhas, reduzindo, assim, o período possível de colheita antes de início do processo de senescência. Dessa forma, apesar do aumento em freqüência de desfolhação causado, pelas maiores densidades de lotação nos pastos adubados, houve diminuição correspondente em tempo de vida da folha, o que resultou em pequena variação em eficiência de utilização da forragem produzida. O uso de N altera os padrões de desfolhação de folhas e perfilhos individuais durante as épocas de maior crescimento das plantas, porém para o capim-marandu manejado a 30 cm sob lotação contínua, a utilização de nitrogênio não resultou em aumento de eficiência de utilização, uma vez que o aumento em freqüência de desfolhação foi compensado pela redução em duração de vida das folhas. / Variations in growth rhythm of plants may have implications to the herbage accumulation and utilisation processes, indicating that adjustments in management strategies aiming at improving growth and utilisation efficiencies may contribute to augment productivity of pastoral systems of animal production. The objective of this study was to evaluate frequency and severity of defoliation of individual tillers and leaves on continuously stocked marandu palisadegrass swards managed at 30 cm and subjected to nitrogen-induced growth rhythms created by the application of 150, 300 and 450 kg/ha.year of N, plus the control (non-fertilisation). Treatments were allocated to experimental units (1200 m2 paddocks) according to a randomised complete block design, with four replications. Data were collected from a set of 30 tillers per paddock during 28-day evaluation cycles. After 28 days, a new set of tillers was selected and a new evaluation cycle performed. From January 2007 until April 2008 the following response variables were evaluated: stocking density, defoliation frequency of tillers and leaves (senescent, expanded and expanding leaves), defoliation severity of extended tillers and leaves (senescent, expanded and expanding leaves), leaf defoliation interval, leaf lifespan, probability of leaf defoliation during its lifespan and utilisation efficiency. Swards fertilised with 300 and 450 kg/ha of N supported larger stocking density than those non-fertilised or fertilised with 150 kg/ha of N, resulting in higher defoliation frequency of tillers and leaves on fertilised than on non-fertilised swards. On the other hand, swards fertilised with high rates of nitrogen application (300 and 450 kg/ha) showed shorter leaf lifespan than those with low rates (non-fertilised and fertilised with 150 kg/ha), reducing the period available for harvest before commencement of senescence. As a result, in spite of the increase in defoliation frequency caused by the higher stocking densities used on fertilised swards, there was a corresponding decrease in leaf lifespan that caused small variation in utilisation efficiency. Use of nitrogen fertiliser during seasons of fast plant growth alters patterns of individual leaves and tillers defoliation. However, on marandu palisadegrass managed at 30 cm under continuous stocking, the use of nitrogen fertiliser did not result in increased utilisation efficiency of the produced herbage, since the increase in leaf defoliation frequency was compensated for by reduction in leaf lifespan.
5

Critical Transmission Sectors of Energy-Water-GHG Nexus / Critical Transmission Sectors of Energy-Water-GHG Nexus

Wang, Xuechao January 2020 (has links)
Využití vody, spotřeba energie a emise skleníkových plynů (GHG) jsou rozhodujícími ukazateli a do značné míry souvisí s udržováním nebo dosahováním environmentální a sociální udržitelnosti. Tato práce prezentuje vyvinuté metodiky. Představuje také provedené případové studie, které prozkoumaly a identifikovaly Water-Energy-GHG Nexus (WEGN) z pohledu dodavatelského řetězce. Pro analýzu a návrh sítě WEGN jsou navrženy tři metodiky, které jsou založeny na nové aplikaci a integraci modelu vstup-výstup (IO), geografického informačního systému (GIS) a sítě dodavatelského řetězce (SCN), a zároveň řeší výzvy, které dříve neumožňovali praktické implementace. Použitelnost těchto metod je prokázána třemi komplexními případovými studiemi zaměřenými na odvětvovou environmentální účinnost, regionální environmentální účinnost a kritické přenosy WEGN. Mezi mé příspěvky v této oblasti patří: i. Nový nástroj pro hodnocení založený na IO pro identifikaci regionální environmentální účinnosti z hlediska WEGN, zejména pro regiony, které jsou úzce propojenyobchodem. ii. Pokročilá integrace metodik GIS a IO (GIS-IO) za účelem odhalení a mapování sítě WEGN, sledování kritických meziregionálních a sektorových toků WEGN, vyjasnění regionálních, odvětvových a celosvětových vzorců sítě WEGN a určení souvisejících výhod pro různé regiony. iii. Efektivní metoda hodnocení založená na IO a SCN pro kvantifikaci sektorových koeficientů WEGN. Navrhované metodiky, s podporou sady komplexních základních rovnic, transformují komplikované výzvy identifikace a analýzy sítě WEGN do snadno srozumitelného formátu, z čehož vznikají robustní řešení pro zlepšení posuzování environmentální udržitelnosti a zmírnění environmentálních tlaků. Například v jedné z případových studií ukazují výsledky nového přístupu GIS-IO zjevné rozdíly mezi různými zeměmi v rámci EU27, mezi různými sektory a také pokud srovnáme EU27 jako blok zemí, s ostatními státy světa. Analýza ukázala, že země EU27 přispěly o 1.4 Gt nižšími emisemi CO2, o 64.5 Gm3 menší spotřebou vody a 4.9 × 104 PJ nižší spotřebou energie ve srovnání se zbytkem světa, přičemž generovaly ekvivalentní ekonomickou produkci. To má dramatický dopad na globální prostředí. Největší úspěch v CWE mezi zeměmi EU27 měly Německo, Francie a Itálie. Práce doporučuje, aby EU27 poskytovala více technické podpory zemím, které těchto výsledků nedosahují, aby se zvýšila účinnost využívání zdrojů.

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