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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.
421

Variabilidade subinercial das correntes na plataforma continental ao largo de Cabo Frio (RJ): observações / Subtidal variability of the currents on the continental shelf off Cabo Frio (RJ): observations

Santos, Luis Felipe Silva 05 March 2010 (has links)
Este trabalho foi desenvolvido dentro do contexto da hidrodinâmica da plataforma continental, com o objetivo de estudar a variabilidade subinercial das correntes no extremo norte na Plataforma Continental Sudeste brasileira. A região de estudo está localizada nas proximidades de Cabo Frio (RJ) e Arraial do Cabo (RJ) (aproximadamente 23º S / 42º W). Apesar de ser uma região bastante conhecida e estudada, em função do fenômeno da ressurgência costeira que ocorre em suas proximidades, pouco se conhece sobre a circulação subinercial nessa localidade. Devido à importância das correntes subinerciais, por serem responsáveis pelo transporte de substâncias dissolvidas ou em suspensão nas águas, tais como sedimentos, nutrientes e poluição, este trabalho tenta contribuir com um maior conhecimento desses campos de corrente, a partir da análise, no domínio do tempo e da frequência, de séries temporais de intensidade e direção das correntes e do vento local. Foram utilizados dados coletados no Projeto DEPROAS (Dinâmica do Ecossistema de Plataforma da Região Oeste do Atlântico Sul) a partir de correntógrafos e ADCP fundeados, numa radial em frente a Cabo Frio, sobre as isóbatas de 50, 100 e 200 m, bem como de uma bóia e de uma estação meteorológicas. Trabalhamos com as séries temporais do inverno de 2001 e do inverno e verão de 2003. A partir desse estudo foi possível verificar que a variabilidade subinercial domina o fluxo das correntes na região, principalmente na direção paralela à batimetria. Como no restante da PCSE, verificou-se um balanço geostrófico na direção normal à topografia, responsável por um fluxo paralelo às isóbatas, em especial na PCM e nas profundidades intermediárias afastadas das camadas limite. Foi observado que a corrente costeira, forçada por processos baroclínicos e pelo vento, típica da parte central da PCSE, atinge o extremo norte da plataforma continental, induzindo um fluxo mais frequente com sentido SE, nas camadas intermediária e de fundo, principalmente no inverno. Verificou-se também que os ventos locais têm baixa correlação com as correntes, exceto nos níveis superficiais, evidenciando a importância das forçantes remotas na dinâmica da região, somado à influência da atividade vortical ciclônica gerada na região pela Corrente do Brasil, com influência até a PCM. Evidências de eventos de ressurgência/subsidência apareceram ao longo de todos os períodos estudados, com ocorrência preferencial a W desta localidade. / This work was developed within the context of the continental shelf hydrodynamics, with the aim of studying the subtidal variability of the currents in the far north of the South Brazil Bight (SBB). The area of the study is located in the vicinity of Cabo Frio (RJ) and Arraial do Cabo (RJ) (approximately 23º S / 42º W). Despite being a well known and studied region, due to the coastal upwelling phenomenon that occurs in its vicinity, little is known about the subtidal variability in this location. Given the importance of the subtidal currents, that are responsible for the transport of substances dissolved or suspended in water, such as sediments, nutrients and pollution, this work tries to contribute to a better understanding of these current~ fields, by the analysis in the time and frequency domain, from time series of the currents and local wind intensity and direction. We used data collected in DEPROAS Project (Western South Atlantict Platform Ecosystem Dynamics) from current meters and an ADCP moored in front of Cabo Frio, on the isobaths of 50, 100 and 200 m, and from a buoy and a weather station. We worked with time series of 2001 winter and 2003 winter and summer. From this study it was found that the subtidal variability dominates the flow in the region, mainly in the parallel direction of the bathymetry. As in the rest of the SBB, there was a geostrophic balance in the normal direction of the topography, which accounts for a flow parallel to isobaths, particularly in the middle shelf and in intermediate depths of the remote boundary layer. It was observed that the coastal current forced by baroclinic processes and by the wind, typical of the central part of the SBB reaches the northern edge of the SBB, leading to a more frequent flow in the southeast direction, in the intermediate layers and the bottom, especially in the winter. It was also found that the local winds have low correlation with the currents, except on the superficial layers, indicating the importance of remote forcing in the dynamics of the region, coupled with the influence of cyclonic vortical activity in the region, generated by the Brazil Current, reaching the middle shelf. Upwelling and downwelling evidences were observed in all time series, with the preferential location occurring west of Cabo Frio.
422

Microbiological and Sensory Effects of Milk Processed for Extended Shelf Life and the Development of Rapid Methods to Quantitate Spores and Lipase Activity

Blake, Michael R. 01 May 1996 (has links)
The initial aim of this work was to evaluate processing conditions for extended shelf life (ESL) milk to have a shelf life at refrigeration temperature of 60 d. Milk was processed on a pilot-scale ultra-high-temperature processing plant and evaluated for microbial and sensory quality over 60 d at 7°C storage. Results of this study showed that lower process temperatures were preferable to minimize cooked flavors and that the minimum safe processing temperature was 134°C for 4 s as determined by the destruction of bacterial spores in the processed milk. Consumer preference panel results indicated that consumers preferred milk processed at 134°C for 4 s (those recommended in this study for ESL processing) to commercial UHT milk although there was a slight preference for pasteurized milk. The critical sensory characteristic of the processed milk was a cooked flavor, which decreased with lower processing temperature and shorter storage time; however, a significant increase in flavors that could be associated with lipolytic activity was also noted. This study highlighted deficiencies in existing methods for determining heat-stable bacterial products in thermal-processed foods. No rapid, sensitive assay for detection of heat-stable spores or lipases in milk exists. If such assays were available, it would allow processors to determine Lipase activity and bacterial spore counts before processing and direct raw milk with low spore counts and low lipolytic activity into long-shelf-life products. To this end, assays to rapidly quantitate spores and lipolytic activity in milk were developed. The lipase assay relies on the hydrolysis of p-nitrophenyl caprylate liberating a yellow color that is detected using reflectance colorimetry. The assay is sensitive to 5 mUnits/ml and is linearly correlated to spectrophotometry (r2 = 0.93) and release of titratable free fatty acids (r2 = 0.92 to 0.97). An immunocapture, enzyme-linked immunoassay coupled with a fluorescent detection system was developed for and resulted in a prototype spore assay using Bacillus stearothermophilus spores. This organism was selected because it is extremely heat resistant, is commonly found in milk, and is associated with spoilage of milk and milk products. The assay was able to quantitate spores down to 103 cfu/ml in milk and other products in about 1.5 h. Other detection limits could be set if needed.
423

藥品安定性儲存條件及有效期限之研究

吳林明 Unknown Date (has links)
藥品安定性試驗的目的乃在於確保該藥品具有優良藥品之特性,以保障消費者之權益。而藥品安定性試驗的品質良窳實取決於當地政府機關對其試驗之要求準則而定。近年來,我國不斷的在藥品安定性試驗方面進行研究和推擴,以提升國內市面上藥品之品質。本論文主要探討兩個主題:一是有關台灣在進行藥品安定性研究時,所規定藥品存放環境的溫度及溼度,以擬定出適合台灣環境之藥品儲存的溫溼度存放標準。二是針對藥品長期安定性試驗有效期限估算之軟體開發,使藥廠對藥品安定性試驗有效期限估算之研究分析更加便利。
424

Application of high pressure processing for extending the shelf-life of fresh lactic curd cheese

Daryaei, Hossein, s3088498@student.rmit.edu.au January 2008 (has links)
Outgrowth of spoilage yeasts and moulds and post-processing acidification can limit the shelf-life of some fermented dairy products including fresh lactic curd cheeses. The possibility of using high pressure processing (HPP) for controlling these problems was investigated in a commercially manufactured fresh lactic curd cheese (pH 4.3-4.4) and fermented milk models (pH 4.3-6.5). The effects of HPP at 300 and 600 MPa on inactivation of glycolytic enzymes of lactic acid bacteria were also evaluated. Fresh cheeses made from pasteurised bovine milk using a commercial Lactococcus starter preparation were treated with high pressures ranging from 200 to 600 MPa (less than or equal to 22°C, 5 min) under vacuum packaging conditions and subsequently stored at 4°C for 8 weeks. Treatment at greater than or equal to 300 MPa substantially reduced the viable count of Lactococcus and effectively prevented the outgrowth of yeasts and moulds for 6 to 8 weeks without adversely affecting the sensory and textural attributes of the product. However, it had no significant effects (p less than 0.01) on variation of titratable acidity during storage. Fermented milk models were prepared by individually growing Lactococcus lactis subsp. lactis C10, Lactococcus lactis subsp. cremoris BK5, Streptococcus thermophilus TS1, Lactobacillus acidophilus 2400 and Lactobacillus delbrueckii subsp. bulgaricus 2517 in UHT skim milk and diluting the resulting fermented milk with UHT skim milk up to pH 6.5. Pressure treatment of the milk models at pH 5.2 resulted in substantial inhibition of post-processing acidification during storage and markedly reduced the viable count of Lactococcus at both 300 and 600 MPa and other bacteria only at 600 MPa. Treatment of the milk model at 600 MPa decreased the viable counts of Candida zeylanoides and Candida lipolytica (wildtype spoilage yeasts of lactic curd cheese, added as challenge cultures) from 105 CFU mL-1 to below the detection limit (log 0 CFU mL-1) at all pH levels tested (pH 4.3-6.5) and effectively controlled their outgrowth for 8 weeks. Treatment of milk model at 300 MPa had a similar effect only on C. zeylanoides. The viable count of C. lipolytica was reduced by 2.6, 2.4 and 2.3 logs by treatment at 300 MPa at pH levels of 4.3, 5.2 and 6.5, respectively, which subsequently recovered by 2.9, 2.8 and 3.2 logs within 3 weeks. Glycolytic enzymes of various starter bacteria showed different responses to pressure treatment. The lactate dehydrogenase in L. lactis subsp. lactis and Lb. acidophilus was quite resistant to pressures up to 600 MPa, but it was almost completely inactivated in S. thermophilus at pressure levels as low as 300 MPa. The â-galactosidase in Lb. acidophilus was more pressure stable than â-galactosidase in S. thermophilus and Phospho-â-galactosidase in L. lactis subsp. lactis. The findings of this study suggests HPP at 300-600 MPa as an effective method for controlling the outgrowth of some spoilage yeasts and moulds in fresh lactic curd cheeses. The results obtained with selected lactic acid bacteria in fermented milk models can be used to assist in establishing HPP operating parameters for development of new generation cultured dairy products, of reduced acidity and extended shelf-life.
425

Hermes Technologies : En entreprenöriell process

Rahimi, Foad January 2005 (has links)
<p>Detta examensarbete beskriver problem och hinder som uppstår vid nyföretagande och entreprenörskap. Arbetet initierades i en period som karaktäriserades av stora nedskärningar inom den svenska högteknologi industrin och väldigt få examensarbeten var tillgängliga.</p><p>Den entreprenöriella processen och tankesättet har varit väldigt tongivande för det svenska samhället. Denna anda har producerat flera stora internationella storföretag. Även om inte alla entreprenörer når de internationella företag i storlek så har småföretagen en minst lika viktig roll för utvecklingen av samhället med det kreativa tankesättet och synen på affärsmöjligheter.</p><p>Rapporten består av litteraturstudie och en fallstudie Hermes Technologies. Med hjälp av modeller kring den entreprenöriella processen, teorier om de psykografiska förhållandena på högteknologiska marknader samt teorier kring skapandet av en markand och prissättning samt analysverktygen Affärsplattformen har en teoretisk bas byggts upp för att sedan appliceras på en fallstudie.</p><p>Teorin framhäver hur viktigt upptäckten av affärsmöjligheten är för framgång tillsammans med ett kreativt hanterande av resurserna.</p><p>Fallstudien består av uppstarten till grundandet av ett högteknologiskt utvecklingsföretag inom marknaden för Electronic Shelf Labeling system, ESL-system. Casestudien genomfördes vid ProNova Science Park i Norrköping som en del i pilotprojektet ”FörInkubatorn” vilket senare utvecklades till Drivbänken. Genom att tillämpa teorin på fallstudien framkom det att flera faktorer för att med framgång genomföra grundandet av Hermes Technologies saknades eller var bristfälliga.</p><p>Här framgår även hur grundandet av Hermes Technologies har genomförts. Vidare framförs hur detaljhandeln ställer sig inför införandet av ESL-system istället för dagens pappersmarkeringar.</p><p>Analysen klargjorde vilka faktorer som låg till grund för ett misslyckade samt vilka åtgärder som krävdes för att uppnå en mer tillfredsställande nivå. Erfarenhet var den ensamt största bristfälliga faktorn som resulterade i att projektet inte lyckades. För att kunna påverka denna faktor krävs det ofta flertaliga försök inom nyföretagande.</p><p>Resultatet påvisar att de teorier, som används i litteraturstudien, bör användas tillsammans med varandra för att uppnå bästa resultat vid nystartandet av ett företag. Detta kommer av att man på detta vis belyser problemet från flera infallsvinklar vilket ytterligare klargör de hinder som kan uppkomma eller har uppstått.</p>
426

Requirements Specifications Simplified and Adapted

Martinsson, Christoffer January 2008 (has links)
<p>Systems development projects and their documents are more or less standardized and can mainly be applied on systems that are supposed to be built from scratch, or updated. In pace with the number of IT-systems are increasing worldwide there is no need for every organization to build their own IT-system. Nowadays it is also possible to purchase licenses which allow the purchaser to modify or add functions to the system. Along with those changes, there have been an increased amount of “rapid development methods” such as Agile and “Quick and Dirty” solutions, but these methods and perspectives are mainly focusing on entire systems development processes, as the old ones, but quicker.</p><p>If a company purchases an off-the-shelf system with source code available, there is no real need to go through a proper systems development process. During interviews with a small company that has acquired a system as mentioned above, the researcher realized that only one single document is needed, the requirements specification. Today’s requirements specifications can be either well detailed or less, but a project still needs the details specified. Combining a known agile development process with IEEE’s standardized requirements specification, a new way to proceed with projects based on one single document (the requirements specification) has been made. This document also has a focus on simplicity for the inexperienced readers, but with the depth that every developer has got a use for.</p>
427

Hermes Technologies : En entreprenöriell process

Rahimi, Foad January 2005 (has links)
Detta examensarbete beskriver problem och hinder som uppstår vid nyföretagande och entreprenörskap. Arbetet initierades i en period som karaktäriserades av stora nedskärningar inom den svenska högteknologi industrin och väldigt få examensarbeten var tillgängliga. Den entreprenöriella processen och tankesättet har varit väldigt tongivande för det svenska samhället. Denna anda har producerat flera stora internationella storföretag. Även om inte alla entreprenörer når de internationella företag i storlek så har småföretagen en minst lika viktig roll för utvecklingen av samhället med det kreativa tankesättet och synen på affärsmöjligheter. Rapporten består av litteraturstudie och en fallstudie Hermes Technologies. Med hjälp av modeller kring den entreprenöriella processen, teorier om de psykografiska förhållandena på högteknologiska marknader samt teorier kring skapandet av en markand och prissättning samt analysverktygen Affärsplattformen har en teoretisk bas byggts upp för att sedan appliceras på en fallstudie. Teorin framhäver hur viktigt upptäckten av affärsmöjligheten är för framgång tillsammans med ett kreativt hanterande av resurserna. Fallstudien består av uppstarten till grundandet av ett högteknologiskt utvecklingsföretag inom marknaden för Electronic Shelf Labeling system, ESL-system. Casestudien genomfördes vid ProNova Science Park i Norrköping som en del i pilotprojektet ”FörInkubatorn” vilket senare utvecklades till Drivbänken. Genom att tillämpa teorin på fallstudien framkom det att flera faktorer för att med framgång genomföra grundandet av Hermes Technologies saknades eller var bristfälliga. Här framgår även hur grundandet av Hermes Technologies har genomförts. Vidare framförs hur detaljhandeln ställer sig inför införandet av ESL-system istället för dagens pappersmarkeringar. Analysen klargjorde vilka faktorer som låg till grund för ett misslyckade samt vilka åtgärder som krävdes för att uppnå en mer tillfredsställande nivå. Erfarenhet var den ensamt största bristfälliga faktorn som resulterade i att projektet inte lyckades. För att kunna påverka denna faktor krävs det ofta flertaliga försök inom nyföretagande. Resultatet påvisar att de teorier, som används i litteraturstudien, bör användas tillsammans med varandra för att uppnå bästa resultat vid nystartandet av ett företag. Detta kommer av att man på detta vis belyser problemet från flera infallsvinklar vilket ytterligare klargör de hinder som kan uppkomma eller har uppstått.
428

The Ross Sea Response to Evolving Ocean-Ice Interactions in a Changing Climate

Wiederwohl, Christina 1980- 14 March 2013 (has links)
Early 1990s to late 2000s freshening (ΔS ≈ -0.001–0.002) and warming (Δθ ≈ 0.02°C–0.035°C) of bottom waters was detected in the southern Pacific Ocean, and Ross Sea source waters progressively freshened during the past four decades. This study investigates potential freshwater anomaly sources and quantifies their effect. Glacial melt water inputs to the GCT increased by 1.3 km^3 per decade (1976– 2007), more rapidly so after 2000 (6.8 km^3 per decade), freshening local Shelf Water by 0.0004 per decade. Lighter basal melt inputs to the LAT started in 1994 and also picked up after 2000 to 14.9 km^3 per decade, lowering the local Antarctic Surface Water salinity by -0.017 per decade. Upstream in the Amundsen Sea surface water freshened by -0.03 per decade (1994–2007) mostly (50%) from larger melt water inputs from the Pine Island (17.7 km^3 per decade) and Dotson (14.8 km^3 per decade) glaciers. Two decades of steady (1978-2000) strengthening of sea ice productivity (200 km^3 per decade) within the Ross Sea Polynya suddenly reversed to weakening (-98.6 km^3 per decade) and resulted in Shelf Water freshening (-0.02 per decade) thereafter. To fully account for the observed variability in Ross Sea waters, the progressive (1992- 2011) adjustment of the density field and induced advective contributions are estimated based on a simplified three-layer stratification. Eastern (western) inflow (outflow) of light surface (dense shelf) water increased by 28% (15%) to 1.11 Sv (1.01 Sv) by 2011; whereas a sluggish intermediate inflow (0.02 Sv) of Modified Circumpolar Deep Water turned into outflow after 2007, thus contributing 0.09 Sv by 2011 to the ventilation of deep waters farther offshore. The estimated evolution of overturning and advective salt fluxes in the Ross Sea yield overall freshening of water masses similar to those derived from observations. Volumetric mean salinities declined at -0.07 per decade for Antarctic Surface Water, -0.05 per decade for Modified Circumpolar Water, and -0.03 per decade for Shelf Water. Outflow intensification of Shelf Water mixtures is also consistent with bottom water property changes (freshening and warming) measured farther downstream in the southern Pacific Ocean.
429

Resource Modeling and Allocation in Competitive Systems

An, Na 05 April 2005 (has links)
This thesis includes three self-contained projects: In the first project Bidding strategies and their impact on the auctioneer's revenue in combinatorial auctions, focusing on combinatorial auctions, we propose a simple and efficient model for evaluating the value of any bundle given limited information, design bidding strategies that efficiently select desirable bundles, and evaluate the performance of different bundling strategies under various market settings. In the second project Retailer shelf-space management with promotion effects, promotional investment effects are integrated with retail store assortment decisions and shelf space allocation. An optimization model for the category shelf-space allocation incorporating promotion effects is presented. Based on the proposed model, a category shelf space allocation framework with trade allowances is presented where a multi-player Retailer Stackelberg game is introduced to model the interactions between retailer and manufacturers. In the third project Supply-chain oriented robust parameter design, we introduce the game theoretical method, commonly used in supply-chain analysis to solve potential conflicts between manufacturers at various stages. These manufacturing chain partners collaboratively decide parameter design settings of the controllable factors to make the product less sensitive to process variations.
430

Effect Of High Hydrostatic Pressure On Quality Factors And Shelf Life Of Atlantic Mackerel (scomber Scombrus) And Red Mullet (mullus Barbatus)

Senturk, Tugce 01 September 2011 (has links) (PDF)
The ability of high hydrostatic pressure (HHP) to extend the shelf life of Atlantic mackerel (Scomber scombrus) and red mullet (Mullus barbatus) was assessed in this study. For that purpose, fillets of both atlantic mackerel and red mullet were subjected to pressure treatments at 200, 300, 400 MPa at 5, 10, 15&deg / C for 5 and 15 minutes. The influence of the treatments on Trimethylamine Nitrogen (TMA-N) level, lipid oxidation stability (Thiobarbituric Acid, TBA level) was investigated as well as color changes. The suitable combinations for Atlantic mackerel were determined as 200 MPa, 15&deg / C for 5 min and 400 MPa, 5&deg / C for 5 min / and for red mullet 200 MPa, 15&deg / C for 5 min. In the second stage, the shelf life of fish samples, which were treated with these conditions and stored at 4&deg / C, were studied by measurement of pH, color, sensorial features (appearance and odor), TMA-N, TBA, Total Volatile Basic Nitrogen (TVB-N), Histamine and Total Mesophilic Aerobic Count (TMAC) formations. Based on these analyses, the unpressurised mackerel samples were acceptable up to only 7 days compared to 17 and 19 days after 200 and 400 MPa treatments / respectively. For red mullet samples pressurization at 200 MPa extended the shelf life an additional 3 days (from 1 week to 10 days). HHP treatment in combination with chilled storage can improve the shelf life and quality of fish.

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