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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.
11

Under construction : En kvalitativ studie om färdigt och ofärdigt i slöjdämnet. / Under construcioin : En kvalitativ studie om färdigt och ofärdigt i slöjdämnet.

Ahlin, Mikaela January 2020 (has links)
Kan resan någonsin vara målet eller är det alltid slutdestinationen som är målet?Studien Under construction undersöker hur slöjdämnet förhåller sig till färdigt och ofärdigt. Med bakgrund i vad jag uppfattar som kursplanens otydlighet gällande möjlighet att bedöma ofärdiga arbeten tycks det finnas stor oenighet bland lärare kring hur slöjdämnet ska ta sig an ofärdiga slöjdföremål. Syftet med denna studie är därmed att ge större klarhet i hur man som lärare kan förhålla sig till detta. Ämnet har undersökts utifrån två frågeställningar, vilka är:• Hur förhåller sig slöjdämnets styrdokument till temat färdigt och ofärdigt?• Hur förhåller sig slöjdlärare till temat färdigt och ofärdigt?Studien tar avstamp i det läroplansteoretiska forskningsfältet som baseras på att jämföra läroplanens tre arenor, dvs. den formulerade läroplanen jämfört med lärarnas tolkning av den samt den läroplan som tar sig uttryck i den faktiska undervisningen. Metoder som använts för att undersöka detta är observation av slöjdlektioner samt intervjuer med verksamma slöjdlärare. För att analysera empirin har en tematisk analysmetod använts.Studien har gestaltats genom en workshop där deltagarna under begränsad tid själva fick tillverka ett slöjdföremål utifrån slumpvis valda ledord som talade om på vilket sätt deltagaren skulle ta sig an uppgiften. När tiden var slut skulle deltagaren rangordna samtliga slöjdobjekt och samtidigt sortera in sitt eget, dels efter funktion men också efter uttryck.
12

Effects of Beef Finishing Diets and Muscle Type on Meat Quality, Fatty Acids and Volatile Compounds

Chail, Arkopriya 01 May 2015 (has links)
Consumer evaluation, proximate data, Warner-Bratzler shear force (WBSF), fatty acid (FA) composition and volatile compounds were analyzed from the Longissimus thoracis (LT), Tricep brachii (TB) and Gluteus medius (GM) muscles finished on conventional feedlot (FL) and forages, including a perennial legume, birdsfoot trefoil (BFT; Lotus corniculatus), and a grass, meadow brome (Bromus riparius Rehmann, Grass). Representative retail forage (USDA Certified Organic Grass-fed, COGF) and conventional beef (USDA Top Choice, TC) were investigated (n = 6) for LT. Additionally, the effects of diet on Gluteus medius (GM) and Tricep brachii (TB) muscles were explored. Forage-finished beef scored lower (P < 0.05) in most of the affected sensory attributes except BFT which was similar to grain-finished beef. In forage-finished beef GM was more liked and in FL, TB was similar to GM except juiciness where it scored greater. The fat percent was found to be greatest (P < 0.05) in TC followed by BFT and FL. Nutritionally beneficial ratios of FAs were observed in forage-finished diet. Fatty acid concentrations were majorly affected (P ≤ 0.046) by diet. Few long-chain PUFAs were affected (P ≤ 0.015) by muscle type. No FA was a effected (P > 0.05) by the interaction of muscle and diet. 3-hydroxy-2-butanone, known to evoke a buttery sensation was affected (P = 0.011) by diet with greater (P < 0.05) concentration in GM across all diets. Strecker degradation products were affected (P ≤ 0.014) by muscle type being prominent in GM. Meanwhile, 2-ethyl-3,5-dimethyl-pyrazine was greatest (P < 0.05) in BFT. All pyrazine compounds were (P < 0.05) greater in GM. These results indicate that when consumer evaluated beef of finishing diets, FL beef was rated highly. Additionally, not all forages produce similar beef. There were similar ratings for BFT for all attributes except flavor having lower values compared with FL. The chemical composition of BFT beef was found to be intermediary and similar to both FL and Grass beef in many cases. Diet was found to interact with muscle for sensory and chemical measures. The GM and TB of FL did not differ (P < 0.05), while within forage treatments sensory response and chemical composition varied. These results indicate the meat quality of secondary beef muscles is more greatly impacted by forage diets.
13

Evaluation of Weaning Stress in Beef Calves

Landa, Chelsea E. 19 July 2011 (has links)
Conventional techniques within the beef cattle industry involve weaning the calf from the dam when the calf is about 205 days of age. Weaning induces a stress-response that is implicated in reducing the health and productivity of newly weaned calves. Our goal was to evaluate the impact of weaning on the stress immune responses of beef calves. To that end, we 1) evaluated novel methods to quantify physiological markers of stress, 2) compared immune function and growth of calves grazing legume versus grass forages, and 3) compared the effects of abrupt versus two-stage weaning on calves. In study 1, calf, yearling, and adult beef cattle were used to assess the accuracy and precision of handheld glucometers in quantifying bovine blood glucose concentration. Precision Xtra® and ReliOn® glucometers were used chute side to quantify blood glucose concentrations in cattle and were compared to an accepted plasma glucose analysis on the same samples for validation. The Precision Xtra® glucometer was more accurate and precise than the ReliOn® glucometer. In study 2, weaned heifers were used to compare the immunomodulatory effects of grazing alfalfa versus fescue over a 30 day grazing period. No differences were detected in the interferon gamma (IFNγ) production and weight gain between the heifers on alfalfa and fescue. In study 3, effects of two-stage (fenceline) and abrupt weaning were compared. Calf weights, immune cell function, antibody production, blood glucose concentrations, fecal cortisol concentrations, and gene expression (FAS, IL-4,IL-10, and IFNγ) were measured pre- and post-weaning. On the day after weaning, the abruptly weaned calves had higher blood glucose concentrations than fenceline weaned calves. Fecal cortisol concentration and gene expression of FAS and IL-4 increased in both groups after weaning, but no differences were detected between the weaning treatments. Gene expression of IL-10 and IFNγ did not change over time. No date, treatment or treatment*date effect was detected for total weight gain or IFNγ production within the non-stimulated and the mitogen-stimulated whole blood samples. / Master of Science
14

Produção e avaliação de painéis de partículas de eucalipto e couro com adesivo poliuretano derivado de óleo de mamona /

Oliveira, Renato Cardoso de January 2019 (has links)
Orientador: Sérgio Augusto Mello da Silva / Resumo: Um dos grandes desafios da última década é o aproveitamento de subprodutos objetivando-se proteger o meio ambiente e agregar valor ao produto final. A fabricação de painéis com madeira reconstituída vem registrando constante crescimento, sendo o Eucalipto a espécie de madeira exótica de reflorestamento mais utilizada no Brasil para a produção de painéis aglomerados. Considerando-se que na Cidade de Franca, no interior do Estado de São Paulo, a indústria calçadista gera grande quantidade de resíduos durante o processo de corte de couro para a montagem de calçados com um significativo volume de resíduos descartados em aterros sanitários. Na maioria dos casos, não ocorre seu reaproveitamento; sendo assim, considerou-se, nesse trabalho, o aproveitamento desses resíduos na produção de painéis aglomerados. Para produção dos painéis e avaliação das propriedades físicas e mecânicas, propuseram-se três tratamentos com proporções diferentes entre partículas de eucalipto e partículas provenientes de resíduos de couro aglutinadas com resina poliuretana bicomponente à base de óleo de mamona em prensa hidráulica, com controle de temperatura e pressão. Após avaliação das propriedades físicas e mecânicas dos painéis, com base no documento normativo brasileiro ABNT NBR 14810/2013, realizou-se a Análise de Variância (ANOVA) e Teste de Tukey. De modo geral, os valores obtidos para as propriedades dos painéis atenderam aos valores mínimos propostos pela NBR; entretanto, com base nos resultados o... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: One of the biggest challenges of the last decade is the use of by-products aiming to protect the environment and add value to the final product. The manufacture of panels with reconstituted wood has been steadily growing, with Eucalyptus being the most commonly used exotic reforestation wood in Brazil for the production of particle board. Considering that in the city of Franca, in the interior of the state of São Paulo, the footwear industry generates a large amount of waste during the leather cutting process to assemble footwear with a significant volume of waste disposed of in landfills. In most cases, reuse does not occur; Thus, this research considered the use of these residues in the production of particle board. For the production of panels and evaluation of physical and mechanical properties, It was proposed three components with different proportions between eucalyptus and waste residues bonded with bicomponent castor oil-based polyurethane resin in hydraulic press, with temperature and pressure control. After evaluating the physical and mechanical properties of the panels, based on the Brazilian normative document ABNT NBR 14810/2013, it was performed the analysis of variance (ANOVA) and Tukey test. In general, the values obtained for the properties of the panels met the minimum values proposed by the NBR; However, based on the results obtained by the statistical analysis, it was found that there was a need for adjustments in the parameters for making the panels. / Mestre
15

Návrh na zefektivnění výroby polotovarů pro hlavně / Efficiency Improvement Proposal of Production of Semi-Finished Products for Gun-Barrels

Zemánek, Patrik January 2018 (has links)
This thesis is focused for manufacturing of a gun barrels and his issues. In thesis is involved introducing of the company Česká zbrojovka a.s. and definition of hand fired guns. Written analysis present the state of a technological process and describe an individual phase of manufacturing of the semi-finished product of gun barrel and the following conclusion of a complex manufacturing of a gun barrel from the semi-finished product to the stand, when the gun barrel installed into the gun is. Subsequently are suggested possibly solutions of manufacturing rationalization and possibly purchasing of a new modern CNC machines. In the end is accomplished a technical-economic evaluation, which compares existing and suggesting of the technology.
16

Effektivisering av lagerstruktu

Salih, Azad January 2021 (has links)
I dagsläget tas enbart hänsyn till variation i geometri. Detta leder till att moduler som levereras inom kort befinner sig längst ner i högen. Projektet handlar om att göra en nulägesbeskrivning och analys för att hitta slöserier samt en studie över hur en lageryta ska formas för att utnyttjas maximalt.  Teori i form av kurslitteraturen i och vetenskapliga artiklar har tillämpats i rapporten. Teorin omfattar lagerstyrning och lagerutformning för ena frågeställningen och lean för den andra frågeställningen. Datainsamlingen har gjort med hjälp av en kvalitativ metod, då personalen har intervjuats. Med hjälp av teorin har förbättringsförslag för företaget tagits fram. Svar på de två olika frågeställningarna har framställts. Företaget har många faktorer som resulterar i en ineffektiv modulhantering och det som påverkar mest är informationsflödet. Företaget uppmuntras till att utnyttja lagerpersonalens kompetens och förbättra informationsflödet. / The report is an analysis of the current situation at the warehouse at the company Vossloh nordic switch systems in Örebro. Vossloh Nordic Switch Systems manufactures prefabricated switches for the railway industry. The switches consist of two to three modules weighing between 6 to 25 tons depending on the type of module. In accordance with the customer contract, Vossloh produces and stores the switches until the customer wants them to be delivered, this leads to the switches spending a long time in the warehouse. Since switches cannot be installed during the colder period out in the field, the company has high and low seasons regarding deliveries of switches. The company has an internal goal to even out the finished goods inventory and believes that free stacking of the switches leads to safety risks. The free stacked modules are in a random order and this leads to many unnecessary lifts, from which the staff collects from the module piles. Due to inadequate information flow, the various factors for the modules are not taken into account. The company has four factors that result in the modules lying here wildly.
17

Dimensionering av färdigvarulager / Dimensioning of finished goods inventory

Ané, Gustav, Karlsson, Martin January 2019 (has links)
Denna skriftiga avhandling omfattar en redogörelse kring examensarbetet dimensionering av färdigvarulager. Arbetet har genomförts på Scania DT i Södertälje inom avdelningen för transmission och axlar. Den centrala delen i arbetet har varit att studera hur dagens färdigvarulager för transmission skall kunna möta framtidens produktionsrelaterade utmaningar. I samband med att högre produktionsvolymer var prognostiserade inom den ärmaste åren samt att ett helt nytt artikelprogram parallellt skulle införas i sortimentet så talade sammantaget för att dagens kapacitet skulle överskridas. För att säkra färdigvarulagrets kapacitet inför de framtida omställningarna skulle området granskas för att sedan presentera lösningsförslag på en rad punkter i syfte att ge lagret ökad kapacitet. Primärt inriktades fokus på att se över lagrets dimensionering, och genom byggnation av simuleringsmodeller kunna presentera förslag på nödvändiga dimensionersom skulle kunna hantera de ökade produktionsvolymerna. Scania efterfrågade även att simuleringsmodellerna skulle kunna appliceras på deras övriga system för färdigvarulager och då kunna presentera liknande dimensionsförslag inför framtida scenarion. Arbetet avgränsades till att se över tre tidshorisonter som hade avgörande betydelse för lagrets kapacitet. Horisonterna omfattade att överskåda dagens volymer samt två framtida steg av produktionsökning och reducering av systemets takttider vilket skulle generera större volymflöden av produkter. Genom lösningsmetoderna semistrukturerade intervjuer, byggnation av simuleringsmodeller, observationer och datakällor samlades fakta in för modellbyggnaden.  Modellens första steg var att motsvara dagens färdigvarulager, i syfte att validera resultaten från modellen emot bekräftad data. Sedan skulle framtida produktionsdata genereras utifrån dagens in- och utflöden för att motsvara framtidens produktionsökningar. Framtidens produktionsdata genererades genom att reducera dagens ut- och in leveransdata med differenserna mellan de nya och gamla takttiderna. Dataverktyget Excel tillämpades för hantering av de stora datamängderna, medan simuleringsprogrammet Extendsim9 användes för modellbyggnaden. Programmen kopplades sedan samman och genererade framtidens volymflöden som lagret sedan skulle dimensioneras efter. Dessa resultat skulle även ligga till grund för vidare formulering av lösningsförslag kring hur aspekterna arbetsmetodik och lagerlayout kunnat omarbetas för att öka lagrets hanteringsförmåga. Dessa två aspekter granskades utöver dimensioneringsförslagen eftersom det ända lösningsförslaget som var tillämpningsbara utifrån aspekten dimensionering var utbyggnation i höjd eller bredd för att ge rum för fler ställage. Detta lösningsförslag var mycket kostsamt och inte ett förstahandsval för Scania, vilket efterfrågade andra lösningsmetoder på problemet. Efter att simuleringarna hade genomförts så granskades resultaten från modellens olika komponenter. Resultaten indikerade att nästa produktionsomställning skulle medföra ett produktflöde som överskrider dagens lagringskapacitet. Dessutom skulle truckarnas kapacitet i färdigvarulagret överbeläggas i samband med reducerad takttid, vilket skulle innebära regelbundna produktionstopp då transportbanorna överbeläggs med artiklar. Lösningsförslag presenterades i syfte att säkerställa färdigvarulagrets framtida kapacitet, där förslagen riktades emot de flaskhalsar som hade identifierats parallellt med omställningarna. Förslagen omfattade implementering av höglager, tillförd truck- och transport kapacitet, reducerad liggtid för lagrets artiklar och omarbetad slottid för att möjliggöra ett tillräckligt brett utflöde inför de nya volymerna. Sammantaget resulterar i en kapacitetsökning för dagens färdigvarulager, så att det kan möta framtidens kapacitetskrav. / This written summary includes an account of the thesis project “dimensioning of finished goods inventory”. The work has been carried out at Scania DT in Södertälje within the department for transmission and axles. The central part of the work has been to study how today's finished goods inventory for transmission should be able to face the future production-related challenges. In conjunction with the fact that higher production volumes were forecasted for the next few years and that a completely new article program would be introduced in parallel with today’s assortment concludes that the overall current capacity would be exceeded. In order to secure the capacity of the finished goods inventory before the future changes, the area would be reviewed so that solutions could be proposed on a number of points in order to increase the capacity of the finished goods inventory. Primarily the focus was on reviewing the dimensions of the inventory and building simulation models to be able to present proposals for necessary dimensions that could handle the increased production volumes. Scania also requested that the simulation models could be applied to their other finished goods inventories so the model could be used to present similar dimensional proposals for future scenarios in other inventories. The work was limited to look at three time horizons that were of crucial importance for the inventories capacity. The horizons included the current volumes of today as well as two future stages of increase in production with a reduction of the system's cycle times, which would generate larger volume flows of products. Data for the simulation models were collected with the solution methods, semistructured interviews, construction of simulation models, observations and data sources. The model's first step was to mirror to today's finished goods inventory, in order to validate the model against confirmed data. Then future production data would be generated based on the current input and output flows to correspond to future production increases. The production data of the future was generated by reducing today's output and input data with the differences between the new and old cycle times. The Excel data tool was used to manage the large amounts of data, while the simulation program Extendsim9 was used for the construction of the model. The data in the programs were then linked together and generated the future volume flows that the inventory would be dimensioned for. These results would be the basis for the solutions that would be proposed on how the aspects of working methodology and inventory layout could be reworked to increase the storage capacity of the inventory. These two aspects were examined in addition to the proposals for dimensioning, since the only solution proposal that was applicable on the aspect of dimensioning was expansion in height or width to give room for more stalls. This solution was very costly and not a first choice for Scania, which requested other solution methods to the problem. After the simulations were completed, the results of the various components of the model were examined. The results indicated that the next production increase would result in a product flow that exceeds today's storage capacity. In addition the capacity of the trucks in the finished goods inventory would be overloaded in conjunction with reduced cycle time, which would mean regular production stoppages when the conveyor belts were overloaded with articles. Solution proposals were presented in order to ensure the future capacity of the finished goods inventory, where the solutions were aimed against the bottlenecks that had been identified in parallel with the changes. The proposals included the implementation of high bay warehouse, added truck and transport capacity, reduced lay time for the inventory´sarticles and revised time slots to enable a sufficiently wide outflow for the new volumes. This results in an overall increase in capacity for todays finished goods inventory, so that it can meet the future capacity requirements.
18

The impact of COVID-19 and the importance of supply chain resilience building : Case study of Swedish firms using offshoring for finished goods

Prytz-Sund, Isak January 2023 (has links)
Purpose: This study aims to look deeper at how Swedish firms using offshoring have dealt with the COVID-19 pandemic regarding their supply chains and make them more resilient. Design/methodology/approach: This study is a case study that examines two Swedish companies that have outsourced their production processes to other countries. The study's main focus is on the impact of COVID-19 on global supply chains and how it has affected the operations of these companies. The objective of the study is to investigate the challenges faced by these firms and the strategies they have employed to mitigate the disruptions caused by the pandemic. Additionally, the study aims to emphasize the importance of strengthening supply chain resilience. To achieve this, a literature review of previous research on the topic of supply chain risk management and supply chain resilience is presented. Findings: The study used thematic analysis to categorize findings for answering two research questions. RQ1 identified four categories showing how external and internal factors affected operations, including a lack of internal decision support for supply chain resilience. RQ2 explored the supply chain resilience aspect and found the supply chains to be especially agile and flexible in capabilities, with supply chains reacting more than proactively due to a lack of resilience-focused decision support. Technology's positive impact on the supply chain was noted in the literature. Additionally, nearshoring gained attention for improving SCR in response to logistical challenges. Research limitations/implications: The thesis studies supply chain resilience and proposes ways to enhance it using different enablers. It examines businesses' management of COVID-19 disruption within their supply chains and supplements existing literature on the topic. The research has limitations due to time constraints and lack of accessibility to interesting cases, affecting the generalizability and validity of the findings. Practical implications: In supply chain management, supply chain resilience plays a vital role in improving performance. The thesis stresses the importance of factors that boost supply chain resilience, which in turn enhances overall efficiency. This knowledge equips practitioners with the tools to better equip their supply chains against disturbances and thus improve their resilience.
19

Novel heuristic for low-batch manufacturing process scheduling optimisation with reference to process engineering

Maqsood, Shahid, Khan, M. Khurshid, Wood, Alastair S. 05 August 2011 (has links)
Yes / Scheduling is an important element that has a major impact on the efficiency of all manufacturing processes. It plays an important role in optimising the manufacturing times and costs resulting in energy efficient processes. It has been estimated that more than 75% of manufacturing processes occur in small batches. In such environments, processes must be able to perform a variety of operations on a mix of different batches. Batch-job scheduling optimisation is the response to such low batch manufacturing problems. The optimisation of batch-job process scheduling problem is still a challenge to researchers and is far from being completely solved due to its combinatorial nature. In this paper, a novel hybrid heuristic (HybH) solution approach for batch-job scheduling problem is presented with the objective of optimising the overall Makespan (Cmax). The proposed HybH is the combination of Index Based Heuristic (IBH) and the Finished Batch-Job (FBJ) process schedule. The heuristic assigns the first operation to a batch-job using IBH and the remaining operations on the basis FBJ process schedule. The FBJ process schedule gives priority to the batch-job with early finished operations, without violating the constraints of process order. The proposed HybH is explained with the help of a detailed example. Several benchmark problems are solved from the literature to check the validity and effectiveness of the proposed heuristic. The presented HybH has achieved batch-job process schedules which have outperformed the traditional heuristics. The results are encouraging and show that the proposed heuristic is a valid methodology for batch process scheduling optimisation.
20

Optimising supply chain performance via information sharing and coordinated management

Xu, Wei January 2013 (has links)
Supply chain management has attracted much attention in the last decade. There has been a noticeable shift from a traditional individual organisation-based management to an integrated management across the supply chain network since the end of the last century. The shift contributes to better decision making in the supply chain context, as it is necessary for a company to cooperate with other supply chain members by utilising relevant information such as inventory, demand and resource capacity. In other words, information sharing and coordinated management are essential mechanisms to improve supply chain performance. Supply chains may differ significantly in terms of industry sectors, geographic locations, and firm sizes. This study was based on case studies from small and medium sized manufacturing supply chains in People Republic of China. The study was motivated by the following facts. Firstly, small and medium enterprises have made a big contribution to China’s economic growth. Several studies revealed that most of the Chinese manufacturing enterprises became aware of the importance of supply chain management, but compared to western firms, the supply chain management level of Chinese firms had been lagging behind. Research on supply chain management and performance optimisation in Chinese small and medium sized enterprises (SMEs) was very scarce. Secondly, there had been plenty of studies in the literature that focused on two or three level supply chains whilst considering a number of uncertain factors (e.g. customer demand) or a single supply chain performance indicator (e.g. cost). However, the research on multiple stage supply chain systems with multiple uncertainties and multiple objectives based on real industrial cases had been spared and deserved more attention. One reason was due to the lack of reliable industrial data that required an enormous effort to collect the primary data and there was a serious concern about data confidentiality from the industry aspect. This study employed two SME manufacturing companies as case studies. The first one was in the Aluminium industry and another was in the Chemical industry. The aim was to better understand the characteristics of the supply chains in Chinese SMEs through performing in-depth case studies, and built models and tools to evaluate different strategies for improving their supply chain performance. The main contributions of this study included the following aspects. Firstly, this study generalised a supply chain model including a domestic supply chain part and an international supply chain part based on deep case studies with the emphasis on identifying key characteristics in the case supply chains, such as uncertainties, constraints and cost elements in association with flows and activities in the domestic supply chain and the international supply chain. Secondly, two important SCM issues, i.e. the integrated raw material procurement and finished goods production planning, and the international sales planning, were identified. Thirdly, mathematical models were formulated to represent the supply chain model taking into account multiple uncertainties. Fourthly, several operational strategies utilising the concepts of just-in-time, safety-stock/capacity, Kanban, and vendor managed inventory, were evaluated and compared with the case company's original strategy in various scenarios through simulation methods, which enabled quantification of the impact of information sharing on supply chain performance. Fifthly, a single objective genetic algorithm was developed to optimise the integrated raw material ordering and finished goods production decisions under (s, S) policy (a dynamic inventory control policy), which enabled the impact of coordinated management on supply chain performance to be quantified. Finally, a multiple objectives genetic algorithm considering both total supply chain cost and customer service level was developed to optimise the integrated raw material ordering and finished goods production with the international sales plan decisions under (s, S) policy in various scenarios. This also enabled the quantification of the impact of coordinated management on supply chain performances.

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