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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.
81

Mode I Fracture Toughness Testing of Friction Stir Processed HSLA-65

Horschel, Jeffery D. 09 July 2008 (has links) (PDF)
In order to investigate the viability of friction stir welding for use in Naval construction, mode one elastic-plastic fracture toughness of friction stir processed HSLA-65 was determined using current ASTM 1820 and BS 7448 standards. Double-sided welds were used to achieve 12.7 mm thick samples. A constant feed rate of 100 mm/min was used for all welds. To explore the effect of weld parameters on toughness, welds were produced using two rotational speeds: 340 RPM and 490 RPM. The weld centerline, advancing side hardened region (ASHR), and TMAZ/HAZ regions were sampled, in addition to un-welded parent material. All elastic-plastic fracture toughness values were thickness dependent. For welds produced at 340 RPM, toughness ranged from 33% to 75% below parent material. By increasing the rotational speed to 490 RPM, weld toughness was likewise less than the parent material, but increased 12% to 50% relative to welds produced at 340 RPM. The lowest measured toughness was in the ASHR samples for both parameters. This region of the weld exhibited mixed mode stress-strain conditions and toughness 75% and 62% less than parent material. Toughness values for all samples failed to meet qualification requirements of both ASTM 1820 and BS 7448 due to non-uniform crack extension. Irregular crack extension was caused by the through thickness change in tensile properties due to welding and the affect this had on the plastic zone size compared to the thickness. Increased weld toughness from 340 RPM to 490 RPM was attributed to microstructural differences as a result of increased rotational speed. In addition, higher crack extensions were observed in the second weld pass relative to the first for both rotational speeds. This was attributed to weld tempering of the first pass by the second. The ASHR samples exhibited the highest crack extensions. In this location, the weld microstructure consisted of Widmanstatten ferrite, a microstructure known to be detrimental to toughness.
82

Nutritional Messaging: To Eat or Not to Eat?

Triptow, Christina 31 March 2022 (has links)
There is a great deal of diet-specific processed foods on the market today. With so many options it can become difficult for consumers to decide what products to purchase. This situation is further intensified by the plethora of contradictory messages found in food advertising, especially in weight loss and dieting food advertising, but also seen in government nutrition campaigns and all over the internet on platforms like social media, blogs, and so forth. These messages can be confusing and frustrating for consumers as they try to decipher which foods they should eat to reach their health or weight loss goals. The purpose of this study was to determine if these contradictory messages extend to the advertising claims found on diet-specific food product packaging. A content analysis was performed on 400 keto and vegan products to uncover the most commonly used advertising claims and verify their accuracy based on the information provided on the nutrition label and ingredients list. An analysis of the health impacts of nutrient content and food additives based on FDA guidelines was also conducted. Results indicated that contradictory messages do extend to the advertising claims on keto and vegan food product packaging and the lack of healthy food options among these products should be a concern for consumers. This study highlights the importance of shoppers approaching food product advertising claims with skepticism until they can be verified.
83

Effect of Environmental Enrichments on Fresh and Processed Meat Quality of Turkeys

Melinda Ashley Dennis (14237636) 09 December 2022 (has links)
<p>  </p> <p>Environmental enrichments have been investigated to determine impacts on turkey health and welfare; however, there is limited data to determine the impact of these enrichments on fresh or processed turkey meat quality. One hundred and forty-four turkeys were randomly assigned to six enrichment treatments: control (C), pecking block (PB), platform (P), platform + straw bale (PSB), straw bale (SB), and tunnel (T). Each treatment was replicated within two rooms in the same barn, with 24 pens total (n = 4 pens/treatment). At 19 weeks of age, turkeys were weighed (live weight, kg), and harvested over two days, with three birds from each pen per day (n=144). A subset of 96 turkeys were fabricated into wings, boneless thighs, drumsticks, and boneless breasts at 24 h postmortem in order to determine carcass cutting yields. From the breast and thigh, three, 1.25 cm samples were taken for pH, proximate analysis, and drip loss. From the breast, three, 2.54 cm samples were taken for instrumental color and sensory analysis, with all remaining breast sample used for further processed boneless turkey breast. Breast portions were pumped with a commercial brine (water, salt, brown sugar, sodium phosphate, sodium erythorbate, and sodium nitrite) to 110% by weight. Brined breast was then vacuum sealed and vacuum tumbled (9 rpm for 90 min, stopping every 15 min for 10 min). Tumbled breast was stuffed into a cellulose casing, thermally processed (internal temperature 68.3oC), and smoked to produce boneless turkey logs. From each log, eight, 1.25 cm slices were taken for packaged purge loss, expressed moisture, instrumental color, and texture and sensory analysis. All treatment levels were analyzed using PROC GLM (SAS 9.4, SAS Institute, Cary, NC). Statistical significance level was set at <em>P≤</em>0.05. For fresh turkey, results showed significant differences in live weight by treatment. SB turkeys weighed the least, PB turkeys weighed the most, and T, PSB, C, and P were intermediate in weight (<em>P=</em>0.008). Treatment did not impact the cut-out values for breasts (<em>P=</em>0.387), thighs (<em>P=</em>0.985), wings (<em>P=</em>0.211), and drumsticks (<em>P=</em>0.575). Treatment did not impact breast L* (<em>P=</em>0.777), a* (<em>P=</em>0.247), or b* (<em>P=</em>0.366) or thigh L* (<em>P=</em>0.936) and a* (<em>P=</em>0.067), but PSB thighs displayed the highest b* values and PB thighs displayed the lowest (<em>P=</em>0.037). Finally, for fresh turkey, treatment did not impact breast drip loss (<em>P=</em>0.766), thigh drip loss (<em>P=</em> 0.933), breast pH (<em>P=</em>0.197), or thigh pH (<em>P=</em>0.385). For processed turkey quality, treatment had no effect on a* (<em>P=</em>0.498) or b* (<em>P=</em>0.831) but was significant for L*. SB, T, P, and PSB had lighter color values, C had darker color values, and PB had intermediate values (<em>P=</em>0.024). Finally, for processed turkey quality, treatment did not impact processing yield (<em>P=</em>0.058) or packaged purge loss (<em>P=</em>0.581), but treatment impacted expressed moisture (<em>P=</em>0.041). PB, PSB, C, and T had higher expressed moisture loss, P had the lowest, and SB had intermediate expressed moisture loss (<em>P=</em>0.041).</p>
84

Product Formulation And Consumer Acceptability Of Processed Cheese Made With Different Types Of Cocoas And Chocolates & Product Formulation And Quantitative Descriptive Analysis Of Aged Cheddar Cheese With Different Types Of Chocolate Inclusions

Royyala, Vishal Kumar 13 December 2008 (has links)
The objectives of this research were to compare different types of cocoa and chocolates in the formulation of processed chocolate cheese and aged Cheddar cheese, and to evaluate sensory, physical, chemical and quality parameters of each. Four different varieties of chocolates were utilized along with other ingredients to prepare processed chocolate cheeses and were tested for consumer acceptability for their basic and critical attributes. Chocolate chips of four different types and proportions were incorporated into Cheddar cheese curd, ripened for 105 days, and a trained panel evaluated the sensory parameters. Results indicated that processed chocolate cheese made with Bordeaux chocolate was preferred the most by consumers, followed by those prepared with Ghirardelli, German and Dutch chocolates, respectively. This research provides a platform to pioneer the study of the sensory profiles of the processed chocolate cheeses. Development of a lexiconal study for the Cheddar cheeses with chocolate chips is also necessitated.
85

Developing Saturated Fat-reduced Processed Cheese Products

Huang, Huidong 01 September 2015 (has links)
No description available.
86

Are Cooking Interventions Effective at Improving Dietary Intake and Health Outcomes? A Systematic Review

Wunderlich, Kayla Marie 14 September 2022 (has links)
Existing systematic reviews have suggested that cooking interventions can be beneficial for improving dietary intake and health outcomes, with research indicating that the ability to prepare meals at home may prove to be more complex, and involve influencing factors (i.e., cooking self-efficacy, food agency [i.e., one's ability to procure and prepare food with the considerations of their physical, social and economic environment], and nutritional literacy/knowledge) for improving health outcomes. With the average American's diet consisting of about 60% of total energy coming from the consumption of ultra-processed foods, interventions that target increasing cooking skills and the frequency of consuming home-cooked meals may help to reduce reliance on processed foods, improve dietary intake quality, and reduce risk of weight gain, obesity, and related conditions. To date, there are no systematic reviews that have addressed the impact of cooking interventions on processed or ultra-processed food consumption. Therefore, this research systematically reviewed the body of literature focused on cooking interventions and dietary intake including processed food consumption and evaluated intervention's effectiveness at improving dietary intake and physical and mental health outcomes. English and full-text research articles published through January 2021 were obtained through PubMed, CINAHL using EBSCO, Web of Science from Clarivate, Scopus and PsycInfo. Overall, 55 articles were obtained after meeting the inclusion criteria and going through the data extraction process. Outcomes of interests to measure included fruit and vegetable consumption, body mass index (BMI), body weight, waist circumference, blood pressure, physical activity, and if the study measured psychosocial outcomes or processed food consumption. Results indicate that when analyzing the effect sizes for studies that reported mean data for each group (eg, intervention and control/comparison groups), 86% of studies measuring fruit intake found a positive effect size (Average: Cohen's d: 0.65, 95% CI: 0.30, 0.99); 90% of studies measuring vegetable intake found a positive effect size (Average: Cohen's d: 0.80, 95% CI: 0.37, 1.09); 82% of studies measuring BMI found a negative effect size (Average: Cohen's d: -0.20, 95% CI: -0.58, 0.17); 100% of studies measuring body weight had a negative effect size (Average: Cohen's d: -0.27, 95% CI: -0.77, 0.23); and 100% of studies measuring waist circumference had a negative effect size (Cohen's d: -0.16, 95% CI: -0.60,0.24). This systematic review will provide information on recently published studies that were not incorporated in prior reviews that can be utilized in future interventions that aim to improve health outcomes and reduce processed food consumption. / Master of Science / Prior systematic reviews have stated that cooking classes and demonstrations may be beneficial for improving an individual's diet and overall health. Research currently suggests that the ability to prepare meals at home may prove to be more difficult to assess, and involve other factors, (i.e., cooking confidence, one's ability to get and prepare food in their physical, social and economic environment, and nutritional knowledge) for improving physical and mental health. With the average American's diet consisting of about 60% of total energy coming from the consumption of ultra-processed foods, interventions that aim to improve cooking skills and how often someone consumes home-cooked meals may help to reduce reliance on processed foods, improve diet quality, and reduce risk of weight gain, obesity, and related conditions. To date, there are no systematic reviews that have explored cooking interventions effects on ultra-processed food consumption. This research systematically reviewed the body of literature focused on cooking interventions and dietary intake including processed food consumption and evaluated their effectiveness at improving dietary intake and physical and mental health outcomes. English and full-text research articles published through January 2021 were obtained through five online databases. Overall, 55 articles were included. Outcomes of interests included fruit and vegetable consumption, body mass index (BMI), body weight, waist circumference, blood pressure, physical activity, psychosocial outcomes, and processed food consumption. Results indicate that 86% of studies measuring fruit intake found their intervention to be effective in increasing fruit intake. A total of 90% of studies measuring vegetable intake found that their interventions were effective at improving vegetable intake. 82% of studies measuring BMI found that their interventions showed effectiveness at decreasing BMI. Both 100% of studies measuring body weight and waist circumference showed effectiveness at decreasing both measures. This systematic review will provide information on recently published studies that were not incorporated in prior reviews that can be utilized in future interventions that aim to improve health outcomes and reduce processed food consumption.
87

Effect of Semi-Solid Processing on Microstructural Evolution and Mechanical Behavior of Austenitic Stainless Steel

Samantaray, Diptimayee January 2015 (has links) (PDF)
In view of the significant advantages offered by semi-solid processing, such as reduction in number of intermediate processing steps and energy input, and the potential for improving component complexity, it is of paramount interest to develop indigenous technology for semi-solid forming of steels, especially nuclear grade steels. For adopting semisolid processing as an alternative method of manufacturing of steels, it is essential to study the amenability of the steel for the process, understand the fundamental mechanisms of micro structural evolution and evaluate the mechanical properties of the steel after processing. To achieve this goal, the present work attempts to appraise the amenability of a low-carbon variant of 18%Cr-8%Ni austenitic stainless steel (304L SS) for semi-solid processing. Among the many requirements of the feedstock in semi-solid processing, a key feature that makes it amenable for semi-solid processing is the unique microstructure containing solid spheroids in a liquid matrix, thereby enabling thixo-tropic behaviour in the alloy. To understand the micro structural evolution in the steel, during major steps of semi-solid processing (partial melting, soaking and solidification), several experiments are carried out by varying the key parameters such as temperature, soaking time and cooling rate. Experimental results are analyzed in details to specify the effects of these parameters on the microstructure of semi-solid processed steel. The analysis indicates different phase transformation sequences during solidification of the steel from its semi-solid state. On the basis of experimental results, mechanism for micro structural evolution during partial melting and subsequent solidification of 304L SS is proposed. The effect of soaking time on the size and shape of the solid globules is analyzed using the theory of anisotropic Ostwald ripening. The semi-solid processing parameters, such as soaking time and temperature, are found to have significant influence on the globule distribution, globule shape, ferrite distribution and dislocation density, which in turn govern the tensile behaviour and mechanical properties of the steel after processing. Semi-solid processed 304L SS exhibits lower yield strength, ultimate tensile strength and higher strain hardening in temperature range 303–873K compared to as-received (rolled and subsequently annealed) 304L SS. However, semi-solid processed steel shows higher uniform elongation and fracture strain compared to the as-received steel. A pronounced effect of semi-solid processing is also found on the high temperature plasticity and dynamic recrystallization pattern. This work demonstrates the amenability of 300 series austenitic stainless steels for semi-solid processing. The investigation provides the significant insight into the mechanism of micro structural evolution in austenitic stainless steels during semi-solid processing and the important information on the mechanical properties and plastic flow behavior of the semi-solid processed steel. The results give crucial inputs for the optimization of processing parameters for obtaining the desired property in the product, and also for deciding the potential industrial application of the process.
88

Valuation of country of origins of organic processed food: a comparative study of consumer demand for soymilk in the United States and China

Zheng, Yue January 1900 (has links)
Master of Science / Department of Agricultural Economics / Xianghong Li / Hikaru H. Peterson / The organic food market in the United States expanded rapidly at annual rates between 12% and 21% from 1997 to 2008, yet the adoption rate of organic farming remained stagnant. Industry sources suggest that the degree of outsourcing organic inputs has been increasing during the most recent years. Organic foods are available at traditional supermarkets and mass merchandisers. Many retailers now offer organic food products in their private labels. This study focuses on organic soymilk, which illustrates these recent trends. China, a major low income country which supplies organic agricultural ingredients to the U.S. , has raised food safety concerns fueled by recent incidents. Organic foods have been marketed in China as eco-products in an effort to promote safer foods to meet domestic needs. While organic soybean is one of China’s primary organic exports, China has been the leading importer of conventional soybeans with U.S. as its largest source, but most U.S. production is transgenic. China has a labeling policy on GM (genetically modified) products, which has been more tightly enforced in recent years. This thesis examines U.S. and Chinese consumers’ valuations of attributes of processed organic products, with an emphasis on eliciting their preferences of organic ingredients from different origins, in the case of soymilk. A survey was designed for each country. The U.S. survey was administered online nationwide. An enumerated survey was administered at three types of food retail channels in Beijing, Shanghai and Guangzhou in China. Respectively, 316 and 300 responses were collected from the U.S. and China. Choice experiment was used to elicit consumer values for various attributes of soymilk in both markets. The results show that consumers in both countries are willing to pay premiums for processed foods such as soymilk with organic and non-GMO ingredients. The premium for organic soybeans is significantly higher than that for non-GMO beans. The results also indicate that U.S. consumers hold strong preferences for organic soymilk produced with domestically produced soybeans. In terms of brand preferences, U.S. respondents are willing to pay more for national brands relative to store brands, with taste as a major differentiating factor. In contrast, Chinese consumers’ valuations depend greatly on nationalities of certifying agencies. U.S. certified organic product was perceived higher than EU or Chinese certified organic products, but Chinese-certified non-GMO products were preferred over those certified by U.S. agencies. Chinese consumers’ values varied by cities and retail types where respondents were surveyed.
89

IMPLEMENTATION OF DGPS AS A FLIGHT TEST PERFORMANCE MEASUREMENT TOOL

Pedroza, Albert 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The accurate determination of test aircraft position and velocity is a very strong requirement in several certification and development flight test applications. This requirement often requires availability of test ranges properly instrumented with optical or radar tracking systems, precision time for data reduction and dependency on environmental and meteorological conditions. The capabilities of GPS (Global Positioning System) technology, in terms of data accuracy, speed of data availability and reduction of test operating cost, moved Bombardier Flight Test Center to make an investment and integrate a system utilizing GPS for extensive use in flight and ground test activity. Through the use of differential GPS (DGPS) procedures, Bombardier Flight Test Center was able to implement a complete system which could provide real-time data results to a very acceptable output rate and accuracy. Furthermore, the system was capable of providing post-processed data results which greatly exceeded required output rate and accuracy. Regardless of the type of aircraft testing conducted, the real-time or post-processed data could be generated for the same test. After conducting various types of testing, Bombardier Flight Test Center has accepted the DGPS as an acceptable and proper flight and ground test measurement tool for its various aircraft test platforms.
90

Production of salami from meat of aquatic and terrestrial mammals

Koep, Karin Sarah Coles 03 1900 (has links)
Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005. / The aim of this study was to develop a product using alternative red meat species, aquatic and terrestrial mammals, which would be acceptable to the consumer and suitable from a food safety aspect. Many of these alternative species are harvested seasonally. A product which is shelf stable needs to be developed to provide a supply of this meat all year round. The species used in this investigation were the Cape fur seal (Arctocephalus pusillus pusillus), the Grey seal (Halichoerus grypus) from the northern hemisphere, the Minke whale (Balaenoptera acutorostrata), horse, beef, mutton, blesbok (Damaliscus dorcas phillipsi) and springbok (Antidorcas marsupialis). Muscle (m. pectoralis) of Cape fur seal pups has a higher percentage fat (4.2g/100g) than the bulls (2.4g/100g), but similar levels of protein (23.2g/100g). Bull blubber samples have a higher percentage protein (26.6g/100g) than the pups (14.6g/100g), but a lower fat percentage (67.1g/100 g) compared with the pups (77.2g/100g). In the Cape fur seal bull meat, saturated fatty acids (SFA) contribute 33mg/100g, monounsaturated fatty acids (MUFA) 29mg/100 g and polyunsaturated fatty acids (PUFA) 38mg/100g of the total fatty acid content. In pups, the three fractions are 39, 30 and 31 mg/100g for SFA, MUFA and PUFA, respectively. Salami,prepared using exclusively seal meat, or seal meat with beef and pork, was produced in a pilot study, using two commercially available starter cultures. The pH values of all three batches started off at ca. 5.6, and dropped to 4.3. Water activity readings started off at 0.96 and dropped to 0.91 after 21 days. Salami produced from the meat of the Grey (Havert) seal and Minke whale, using three starter cultures, had recorded pH values (in both species), which started off between 5.68 and 5.92, and dropped to between 4.5 and 4.8 over the 21 days. Water activity showed an initial value of 0.96, which dropped to 0.90 after 21 days. The final force (N/cm2) that was needed to compress the salami samples was double that of the initial force required for the same species and starter culture combination. The raw seal meat contained 349.6 (mg/100 g sample) SFA, 271.6 (mg/100g sample) MUFA and 175.8 (mg/100g sample) PUFA, whilst the raw whale meat contained 312.3, 251.9 and 179.6 (mg/100g sample) SFA, MUFA and PUFA respectively. Fifteen batches of salami were made from horse, beef, mutton, blesbok and springbok, respectively, and starter cultures of Lactobacillus curvatus DF 38 (batch I), active bacteriocin producing Lactobacillus plantarum 423 (batch II) and then a mutant variation of Lactobacillus plantarum 423m, which did not produce the bacteriocin (batch III). Batch I had a higher final pH value (4.66), after 23 days, whereas the values for batches II and III were similar (4.42 and 4.46 respectively). On day 23 the water activity value was 0.90 for all starter cultures. Horse salami, in batch I, was the leanest in terms of fat content (34.34g/100g salami), with mutton salami having the highest fat content (37.52g/100g salami). Blesbok salami had the highest fat content in batch II (42.77g/100g meat), with beef the leanest (35.71g/100g meat). Salami made from horse and springbok proved to be the most desirable in terms of chemical composition, especially fatty acid profiles, with regard to P: S and n-6: n-3 ratios. Similar growth patterns in colony forming units (cfu) were recorded for L. plantarum 423, L. plantarum 423m and L. curvatus DF38 in MRS broth (Merck) at 30oC, although batch I reached asymptotic growth earlier. The percentage of L. plantarum 423 compared with the total population of microflora in mutton salami remained almost the same (80-95% variety) during the entire fermentation and maturation process. In horse salami, L. plantarum 423 was present at relatively low cell numbers (55-50% on day 1 and before smoking), but increased to 70% after smoking and stabilized to 70-80% for the remaining fermentation period. In beef salami, cell numbers in batch II decreased slightly during the first five days (from 95 to 70%), followed by an increase to 90%. In springbok salami, cell numbers in batch II remained fairly stable at 80-90%. In blesbok salami, batch II slowly decreased during the first three days, from 88% to 70%, then increased to 92% after 12 days and stabilized for the rest of the fermentation period. Similar results were recorded for batch I. Analytical sensory evaluation concluded that the salami prepared using starter culture I resulted in end products with lower sensory qualities. Salami prepared using blesbok and mutton also resulted in end products with lower sensory qualities and was perceived as significantly lower in salami flavour (P≤0.05) and higher in venison-like and mutton-like flavour respectively. The blesbok samples were rated significantly higher (P≤0.05) in sour meat aroma, sour meat flavour and venison-like flavour than the rest of the samples. The blesbok salami was rated significantly lowest for colour compared with the rest of the samples. The tastes of the springbok and horse salami were significantly (P≤0.05) more acceptable than those of the beef and blesbok salami.

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