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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.
51

Shelf-life: designing and analysing stability trials

Kiermeier, Andreas January 2003 (has links)
All pharmaceutical products are required by law to display an expiry date on the packaging. The period between the date of manufacture and expiry date is known as the label shelf-life. The label shelf-life indicates the period of time during which the consumer can expect the product to be safe and effective. Methods for determining the label shelf-life from stability data are discussed in the guidelines on the evaluation of stability data issued by the International Conference for Harmonization. These methods are limited to data that can be analysed using linear model methods. Furthermore, in the situation where a number of batches are used to determine a label shelf-life, the current regulatory method (unintentionally) penalizes good statistical design. In addition, the label shelf-life obtained this way may not be a reliable guide to the properties of future batches produced under similar conditions. In this thesis it is shown that the current definition of the label shelf-life may not provide the consumer with the desired level of confidence that the product is safe and effective. This is especially the case when the manufacturer has performed a well designed stability study with many assays. Consequently, a new definition for the label shelf-life is proposed, such that the consumer can be confident that a certain percentage of the product will meet the specification by the expiry date. Several methods for obtaining such a label shelf-life under linear model and generalized linear model assumptions are proposed and evaluated using simulation studies. The new definition of label shelf-life is extended to allow a label shelf-life to be obtained from stability studies that make use of many batches, such that a proportion of product over all batches can be assured to meet specifications by the expiry date. Several methods for estimating the label shelf-life in the multi-batch case are proposed and evaluated with the help of simulation studies. / Thesis (Ph.D.)--School of Agriculture and Wine, 2003.
52

Structure and stratigraphy of tertiary and quaternary strata, Heceta Bank, Central Oregon shelf

Muehlberg, Gary Edward 10 May 1971 (has links)
Graduation date: 1971
53

Statistical foraminiferal ecology from seasonal samples, central Oregon continental shelf

Gunther, Fredrick John 28 October 1971 (has links)
This study examined the foraminifera and the ecologic conditions of the benthic environment of the Oregon shelf and the uppermost slope (75-550 m depth) between 143°45' N and 144°40' N. Seasonal collections monitored the near-bottom marine environment and the sedimentary substrate at 16 stations. The foraminiferal benthic fauna was examined from eight seasonal stations and two additional stations. Use of a multiple corer provided randomly selected subsarnples of the sediment for ecologic and faunal analyses. Use of water bottles that triggered upon bottom impact provided measurements of the water as close to the bottom as 0. 6 m. Computerized data processing and statistical analyses aided the ecologic and faunal evaluations. The environmental study showed the existence of considerable variation in the hydrography of near-bottom waters, especially between summer and winter (upwelling and non-upwelling) collections at the same station. Upwelling conditions directly affect the benthic Redacted for Privacy environment. In addition, the water at any one place, at least dciring upwelling, was so well mixed that vertical stratification did not exist between 0.6 and 5.0 m off the bottom. Statistically significant sea-. sorial variations in surface sediments at the same station were not observed. The living benthic foraminiferal fauna exhibited considerable within-station variation both in species composition and in specimen size of selected species. The percent abundance of individual dominant species varied in adjacent cores (subsamples) by amounts up to 46%. Living specimens of a single species were found that were three times as large as the smallest living specimen from the same sample, yet there was no evidence of a multimodal size distribution resulting from age classes. The author suggests that the dominant species are aggregated and that the aggregations are colonies of asexually produced siblings. Lack of fit of species-frequency curves to the lognormal distribution indicated that relatively few species are fit to reproduce in a particular environment; most juvenile specimens that enter a particular environment belong to species that will not thrive there and either die or simply maintain growth with little chance of reproductive success. The existence of colonial aggregations of individuals is considered to provide the best explanation of the observed variations between adjacent samples. However, the observed variations could be due to sampling error or to substrate microheterogeneity. A possible natural community of 15 dominant species has been determined for those species that form a consistent part of each other's biologic environment. The community crossed the depth and substrate boundaries upon which the stations were selected and appeared to be a general community for the Oregon outer shelf. The limits of the community appear to be determined mostly by water depth, with approximate boundaries at 75-100 m and somewhere between 200-500 m. Regression analyses to determine the ecologic control on the foraminiferal fauna did not indicate a close correspondence between faunal parameters and environmental variables. Regression analyses to determine the ecologic control on mdividual species indicated that most species depended upon a set of two to four environmental variables rather than upon one single limiting factor. The set for each species was different. Temperature. phosphate concentration and oxygen concentrations were common hydrographic members of sets; percent silt, percent sand, percent clay, organic carbon content and organic nitrogen were common sedimentary members of sets. / Graduation date: 1972
54

The dynamics of mean circulation on the continental shelf /

Shaw, Ping-Tung Peter. January 1900 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982. / Vita. Includes bibliographical references (p. 221-225).
55

Evaluation of Shelf-Life Improvements of Wet Pack Clingstone Peaches Designed for Military Operation Rations by Addition of Calcium Salts

Morse, Lee Charles 01 August 2011 (has links)
When available, wet pack peaches are produced by repackaging sliced and/or diced canned clingstone peaches into a 5-ounce MRE pouch, followed by a thermal process. In this study, wet pack diced peaches were processed in 5-ounce pouches using canned, fresh, and frozen peaches as the raw material. Calcium chloride was added at 0.0 or 0.5% (w/w) to the pouches. The pouches were then stored at 37°C for six months or 50°C for six weeks. The peaches were evaluated for texture, drained weight, pH, brix and sensory evaluations.The canned peaches were not significantly different from wet pack peaches processed using frozen and fresh peaches for overall liking when stored at 37°C for six months. Based on the inability of panelists to differentiate between peach types for overall liking, this study suggests that producers should continue to use canned clingstone peaches as the peach source for wet pack peaches.When calcium chloride was applied to wet pack peaches before thermal processing at 0.5% w/w, a significant increase was seen in the firmness of wet pack peaches after processing. Peaches treated with calcium chloride did not lose firmness as quickly when stored at 50°C for six weeks, but showed no difference in firmness loss rates when stored at 37°C for six months. Sensory analysis of the samples stored at 37°C for six months showed an improvement in firmness scores but a drastic decline in overall acceptance due to the impact of flavor scores.viMultiple levels of calcium chloride showed increased firming effects as the percentage of calcium chloride increased, with negative effects on flavor as the percentage increased. Flavor was not significantly affected by calcium chloride at 0.125% in sensory analysis. This study concludes that to optimize flavor and firmness of wet pack peaches, calcium chloride should only be added at a level up to 0.125%(w/w) that will result in a final pH ≥3.85.
56

The dynamics of mean circulation on the continental shelf /

Shaw, Ping-Tung Peter. January 1982 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Supervised by Gabriel T. Csanady. Vita. Includes bibliographical references (leaves 221-225).
57

Relationships between nutrients and dissolved oxygen concentrations on the Texas-Louisiana shelf during summer of 2004

Lahiry, Sudeshna 02 June 2009 (has links)
Hypoxia (dissolved oxygen concentrations less than 1.4 ml/l) is a recurrent seasonal phenomenon on the Louisiana Shelf, caused by the combined effects of nutrient loading by the Mississippi and Atchafalaya River System (MARS), and density stratification. In 2004, three shelf wide cruises (in April, June and August) were conducted on the Louisiana Shelf to understand the mechanisms controlling hypoxia on the shelf, and examine the relationship between dissolved oxygen and nutrient concentrations during the hypoxic periods. The shelf was divided into three geographically separate zones: A (off the mouth of the Mississippi River), B (off the Terrebonne Bay) and C (off the mouth of the Atchafalaya). Each zone was different in terms of the physical and biochemical processes occurring there. In April, no hypoxia was observed on the shelf because of water column mixing by winds, even though high discharge occurred from the MARS. Nutrients were abundant in the surface waters but present only in little amounts at the bottom. In June, the water column was highly stratified. Because of the presence of upwelling favorable winds no vertical mixing occurred and caused extensive hypoxia on the shelf. Dissolved oxygen concentrations were negatively correlated with nutrients at the bottom of the water column. Nutrients were considerably higher at the bottom than at the surface (except for zone A, where high nutrients were seen even at the bottom), indicating remineralization below the pycnocline. Resuspension of organic material and remineralized nitrogen were sustaining hypoxia far from the river sources. In August, hypoxia was patchy on the Louisiana Shelf. Correlations between dissolved oxygen and nutrient concentration varied seasonally with highest correlations occurring during hypoxic conditions in June and August. The spatial distribution of nutrients and other oceanographic parameters, such as light transmission, fluorescence, and dissolved oxygen concentrations, indicate seasonal variability of biochemical processes that are related to physical processes that affect stratification.
58

Jämförelse av off-the-shelf-hårdvara för realtidsapplikationer / Comparison of off-the-shelf hardware for real-time applications

Engström, Hampus, Ring, Christoffer January 2013 (has links)
Vid implementering av realtidsapplikationer krävs det att man kan använda hårdvaran på ett deterministiskt vis. En realtidsapplikation ställer stora krav på körtider och hur applikationen schemaläggs. Det är därför av största vikt att kontrollera om de uppfyller dessa krav. I detta examensarbete har tre system för realtidsapplikationer jämförts och en analys av framförallt sina beräkningsförmågor och hur pass deterministiskt de uppför sig gällande körtider har gjorts. Även andra aspekter så som utvecklingsmiljöer för mjukvara, tillbehör och effektförbrukning har jämförts.
59

Consumer’s Perceptions of Values Regarding Different Shelf Levels in Terms of Price

Mumtaz, Saqib Ali, Rahman, Md.Asifur January 2011 (has links)
Retail shelves acts as extrinsic cues which influence consumers’ perceptions and facilitates them in their purchase dilemma. This study is about determining any possible association between vertical shelf levels and consumers’ perception of values. The assumption that consumers perceive a product at higher place as of higher value (quality) was analyzed by means of primary data and further explained by cue utilization theory. The research attempts to quantify values (extrinsic cue effect) by means of prices of the products. Here, both shelf levels and price are considered as extrinsic cues. In other words, this research analyzed the influence of one extrinsic cue on the other and thus how this affects consumer perception of the product’s value. For this purpose, a primary research was conducted involving consumer group of Swedish people (N=90) and price data was collected for three products placing at different shelf levels. Results from the questionnaire were analyzed by means of one way ANOVA test. The results disapproved hypothesis that was tested yet showed a positive trend for one the value product e.g., coffee. On the basis of result, it can be deduced that further research with different experimental techniques could be applied on the same subject matter to bring more accurate results.
60

Evaluation of a Deep Plan Office Space Daylit with an Optical Light Pipe and a Specular Light Shelf

Upadhyaya, Kapil 15 May 2009 (has links)
This research developed the Optical Light Pipe (OLP) as a feasible solution to solve the problem of insufficient daylighting in deep plan office spaces for predominantly sunny climates. It further combined the OLP with a Specular Light Shelf (SLS) to achieve uniform daylighting. This research was performed with an experimental setup of two 1:4 scale models of deep plan office spaces, modified from an earlier research on optical light pipe at College Station, TX. Blinds and shading devices were installed on the south façade to provide daylight to the front zone of a 20 feet by 30 feet office module. The back zone was daylit by the OLP hidden in the plenum. The existing OLP design was optimized through computer aided ray-tracing. The SLS design was based on an earlier prototype designed at Lawrence Berkeley National Labs (LBNL). Results were based on observations made on clear and cloudy sky days between February 3rd and March 17th. The OLP achieved more than 300 lux of average workplane illuminance for 7.4 hours, when global horizontal illuminance was greater than 40,000 lux. It also achieved 200 lux of illuminance higher than an earlier prototype (Martins-Mogo, 2005) on workplane between 1000hrs and 1630hrs. It exhibited a glare free daylight distribution with luminance ratios well within prescribed limits on most of the vertical surfaces, with a relatively uniform illuminance distribution on back taskplane. OLP was better than windows with blinds and shading at providing diffuse daylight in backzone on a cloudy day, when global horizontal illuminance was greater than 20,000 lux. The OLP used in combination with SLS achieved more than 500 lux of average workplane illuminance for 6 hours, when global horizontal illuminance was greater than 40,000 lux. SLS also produced more uniform illuminance levels on the workplane at all times and on the leftwall at most times. However, it produced non-uniform luminance distribution on walls and ceiling and luminance ratios higher than allowable limits on the sidewall for some morning hours, and hence needed further refinement in design.

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