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Computational Modelling Of Free Surface Flow In Intake Structures Using Flow 3d SoftwareAybar, Akin 01 June 2012 (has links) (PDF)
Intakes are inlet structures where fluid is accelerated to a certain flow velocity to provide required amount of water into a hydraulic system. Intake size and geometry affects the formation of flow patterns, which can be influential for hydraulic performance of the whole system. An experimental study is conducted by measuring velocity field in the hydraulic model of the head pond of a hydropower plant to investigate vortex formation. Vortex strength based on potential flow theory is calculated from the measured velocity field. It was shown that vortex strength increases with the submergence Froude number. The free surface flow in the head pond is simulated using Flow-3D software. Vortex strength calculations are repeated using the computational velocity distributions and compared to experimentally obtained values. Similar computations were carried on with some idealized pond geometries such as rectangular and circular.
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Determining biological sources of variation in residual feed intake in Brahman heifers during confinement feeding and on pastureDittmar (III), Robert Otto 10 October 2008 (has links)
Objectives were to characterize residual feed intake (RFI) and determine the
phenotypic correlation between performance, feed efficiency, and other biological
measurements in Brahman heifers, as well as the relationship between RFI determined in
confinement and measurements of grazing activity on pasture. Three separate 70 d
feeding trials were performed, and RFI was determined as the residual between actual
and predicted dry matter intake (DMI) for a given level of production. Brahman heifers
(n = 103; 5-to-9 mo of age) were individually limit-fed a pelleted 12% CP complete
ration daily in Calan gates. Weekly body weight (BW) and DMI data were collected, and
predicted DMI was determined by linear regression of actual DMI on mid-test metabolic
BW. Ytterbium chloride was used to evaluate digestive kinetics, and fecal samples were
collected to determine fecal volatile fatty acids (VFA) concentration and determine
apparent dry matter digestibility (DMD) utilizing acid insoluble ash as an internal
marker. Measurements of temperament were evaluated on all heifers at weaning. High (n
= 6) and low (n = 6) RFI heifers (Exp. I) grazed fescue and ryegrass to determine
variation in grazing behavior, DMI, and apparent DMD. Data from all three experiments were pooled, and RFI was not correlated with
average daily gain (ADG), DMI, BW, partial efficiency of gain, feed conversion ration,
fecal VFA concentration, or any measures of temperament. There were no significant
differences in digestive kinetics between the RFI efficiency groups. Fecal samples taken
for acid detergent insoluble ash (ADIA) determination were not collected at frequent
enough intervals to account for weekly variation in fecal ADIA concentration. Pasture
measurements were not different between the efficiency groups for heifers evaluated for
grazing behavior, as well as estimated intake as a proportion of BW, or apparent DMD.
Results of this study suggest that Bos indicus cattle appear to have similar efficiency
traits as Bos taurus and Bos indicus influenced cattle, making this measure of efficiency
equally as valid for use in both types of cattle. This indicates that selection based on RFI
can be made to increase feed efficiency without affecting ADG or BW in Brahman
cattle.
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Organic Carbon Reduction in Seawater Reverse Osmosis (SWRO) Plants, Jeddah, Saudi ArabiaAlshahri, Abdullah 12 1900 (has links)
Desalination is considered to be a major source of usable water in the Middle East, especially the Gulf countries which lack fresh water resources. A key and sometimes the only solution to produce high quality water in these countries is through the use of seawater reverse osmosis (SWRO) desalination technology. Membrane fouling is an economic and operational defect that impacts the performance of SWRO desalination technology. To limit this fouling phenomenon, it is important to implement the appropriate type of intake and pre-treatment system design.
In this study, two types of systems were investigated, a vertical well system and a surface-water intake at a 9m depth. The purpose of this investigation is to study the impact of the different intake systems and pre-treatment stages in minimizing the concentrations of algae, bacteria, natural organic matter (NOM) and transparent exopolymer particles (TEP), in the feed water prior to pre-treatment, through the pre-treatment stages, and in the product water and concentrate.
Water samples were collected from the surface seawater, the intakes (wells for site A, 9 m depth open ocean intake at site B), after the media filter, after the cartridge filter, and from the permeate and reject streams. The measured parameters included physical parameters, algae, bacteria, total organic carbon (TOC), fractions of dissolved NOM, particulate and colloidal TEP.
The results of this study prove that the natural filtration and biological treatment of the seawater which occur in the aquifer matrix are very effective in improving the raw water quality to a significant degree. The results demonstrated that algae and biopolymers were 100% removed, the bacterial concentrations were significantly removed and roughly 50% or greater of TOC concentrations was eliminated by the aquifer matrix at site A. The aquifer feeding the vertical wells reduced TEP concentrations, but to differing degree.
There is a slight decrease in the concentrations of, algae, bacteria, TOC, NOM, and TEP in the feed water at 9 m depth compared to the surface seawater at site B. The pre-treatment was of significant effectiveness and the improvements in reducing the membrane fouling potential were quite high and strong at this site. Investigation of the permeate stream showed some breakthrough of bacteria which is of concern because it may indicate a problem within the membrane system (e.g., broken seal and perforation). The aquifer feeding the wells in the subsurface system plays a main role in the improvement of water quality, so the pre-treatment seems less effective in site A plant. This proves that the subsurface intake is better than open ocean intake in terms of providing better raw water quality and ultimately reducing membrane biofouling.
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Recalled Fruit and Vegetable Intake while Growing up and its Association with Adult Fruit and Vegetable Intake among U.S. Adults - Analysis of the Food Attitudes and Behaviors SurveyHill, Mary D 07 May 2011 (has links)
ABSTRACT
MARY D. HILL
Recalled fruit and vegetable intake while growing up and its association with adult fruit and vegetable intake among U.S. adults – analysis of the food attitudes and behaviors survey
(Under the direction of DR. KYMBERLE STERLING)
High dietary intake of fruits and vegetables (FVs) is associated with a lower risk for chronic disease including certain cancers, optimal child growth, and weight management. More than 72 million U.S. adults are obese; therefore, fruit and vegetable intake is important in weight management. Using data from the Food Attitude and Behavior survey, this study will address the following questions: is there a correlation between recalled fruit and vegetable intake during childhood and adult fruit and vegetable intake among U.S. adults? Secondly, is reported fruit and vegetable consumption associated with sociodemographic variables and other health-related behaviors? Results indicated there is a positive correlation between recalled FV intake and reported FV intake in adults. Therefore, public health practitioners should develop initiatives to increase the amount of FV intake in children so that these FV consumption habits may continue in adulthood.
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The Effects of Substrate Oxidation on Post-exercise Food Intake in Pre-pubertal, Normal-weight Boys and MenHunschede, Sascha 12 July 2013 (has links)
The relationship between substrate oxidation (RER) and food intake (FI) is undefined. This study examined the effects of RER modified by a glucose pre-load (GL), exercise (EX) and GL with EX on, FI and energy balance (NEB) in normal-weight boys (9-12 y) and men (20-30 y). Subjects (15 boys, 15 men) were randomized with treatments of either water or GL followed by either EX or rest. Measures included RER, energy expenditure (EE)(kcal/kg), subjective appetite, FI(kcal/kg) measured at a pizza lunch and NEB (kcal/kg). FI(kcal/kg) was reduced by GL(p < 0.0001), and further decreased with GL ingested prior to EX(p = 0.0254). RER was increased with GL(p < 0.0001) and EX(p = 0.0043), and was higher in men compared to boys (p = 0.007). There was no association between RER and FI(kcal/kg). In conclusion, there was no relationship between RER and FI, suggesting that FI is not affected by substrate oxidation.
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The Effects of Substrate Oxidation on Post-exercise Food Intake in Pre-pubertal, Normal-weight Boys and MenHunschede, Sascha 12 July 2013 (has links)
The relationship between substrate oxidation (RER) and food intake (FI) is undefined. This study examined the effects of RER modified by a glucose pre-load (GL), exercise (EX) and GL with EX on, FI and energy balance (NEB) in normal-weight boys (9-12 y) and men (20-30 y). Subjects (15 boys, 15 men) were randomized with treatments of either water or GL followed by either EX or rest. Measures included RER, energy expenditure (EE)(kcal/kg), subjective appetite, FI(kcal/kg) measured at a pizza lunch and NEB (kcal/kg). FI(kcal/kg) was reduced by GL(p < 0.0001), and further decreased with GL ingested prior to EX(p = 0.0254). RER was increased with GL(p < 0.0001) and EX(p = 0.0043), and was higher in men compared to boys (p = 0.007). There was no association between RER and FI(kcal/kg). In conclusion, there was no relationship between RER and FI, suggesting that FI is not affected by substrate oxidation.
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Phenotypic Characterization of Feed Efficiency and Feeding Behavior Traits in Performance Tested Bulls Fed a Corn Silage-Based DietMoreno Rajo, Jose Gilberto 02 October 2013 (has links)
Objectives of this study were to characterize feed efficiency traits and examine phenotypic relationships with feeding behavior traits in bulls. Performance, feed intake and feeding behavior traits were measured in bulls (n = 5,165) representing 2 breeds (4100 Angus and 952 Red Angus). Intake and feeding behavior traits were measured for 70-d using a GrowSafe system while fed a corn silage based diet (ME = 2.50 Mcal/kg DM). BW was measured at 14-d intervals. Residual feed intake (RFI) was calculated as the difference between actual DMI and that expected from regression of DMI on mid-test BW0.75 (MBW) and ADG, and residual gain (RG) as the difference between actual ADG and that expected from regression of ADG on MBW and DMI. Residual gain and intake (RIG) was computed as the sum of -1 x RFI and RG, both standardized to a variance of 1.
Results from the study indicate that RFI was correlated with DMI (r = 0.71, P < 0.0001) but not MBW or ADG, whereas, RG was correlated with ADG (r = 0.87, P < 0.0001) but not MBW or DMI. RFI was negatively correlated with G:F (r = -0.53, P < 0.0001) and RG (r = -0.40, P < 0.0001). Feeding bout (FB) frequency and duration were correlated with RFI (r = 0.30, 0.36; P < 0.001), but were not significant or weakly correlated (r < 0.10) with RG and G:F. Meal criterion and duration were both correlated (r = -0.13, 0.22; P < 0.0001) with RFI, but not with RG or G:F. Bulls with low RFI spent less time at the feed bunk (129 vs 151 ± 31.2 min/d) and had fewer FB events (79 vs 91 ± 23.4 events/d) than high-RFI bulls. Low-RFI bulls had longer (P < 0.001) meal criterion (9.9 vs 8.5 ± 6.6 min) indicating they took longer to initiate new meals, and had longer meal durations (223 vs 244 ± 43.5 min/d) than high-RFI bulls. Bulls have distinctive feeding behavior patterns that contribute to between-animal variation in RFI, but not associated with RG or G:F.
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An investigation on body composition, dietary intakes and physical activity in girls aged 8-11 years in Saudi ArabiaAlkutbe, Rabab Bade January 2017 (has links)
Introduction: Obesity has become a major world-wide health issue. Social-economic status, physical activity levels and dietary intake may influence the weight status in children. However, these issues have not been examined together in studies of young girls in Saudi Arabia. Aim: This study aimed to investigate energy and nutrient intakes, physical activity and social economic status of girls aged 8-11 years in western Saudi Arabia according to their BMI. Methods: This study was conducted in two phases, phase one was a pilot study where 32 girls were selected to assess the suitability of body composition, dietary intake (food diary, food frequency questionnaire) and physical activity measurement tools (pedometer, physical activity questionnaire). The findings of this phase were employed in phase 2; the diet diary and accelerometer were nominated as assessment tools. In phase two, girls (n= 234) participated from different schools. Waist circumference, height and weight were measured and BMI was calculated. Girls were classified according to BMI centile charts (CDC). Dietary intake was measured via a 4-day food diary and accelerometers were used to assess the intensity and time spent in physical activity. Results: A total of 30% of the sample were classified obese or overweight. There was a significant difference in the mean daily energy intake between the BMI groups with the obese group having the highest energy, fat, carbohydrate and protein intake (obese group: 2677 ± 804 kcal/d; healthy weight group: 1806 ± 403 kcal/d, p< 0.001), but the percentage contribution of the macronutrients to energy intake remained the same across the BMI groups. Carbohydrate intake was shown to be the main contributor to predict obesity levels. VI There were no differences in number of steps taken per day or time spent in moderate/ vigorous intensity exercise according to BMI category. Most of the girls did not meet daily physical activity guidelines (5969 to 6773 steps per day and 18.5 - 22.5 mins per day of moderate- vigorous activity). Intake of sweets and sugary drinks, and total energy intake were significantly higher in the high income group compared to the low income group. However, family income was not associated with BMI status. Conclusion: The results of this study suggest that obesity in girls aged 8-11 years is linked to excessive energy intake from all macronutrients and the majority of girls in all weight categories are inactive. Research should be conducted to develop interventions to promote dietary change and activity that is culturally acceptable for girls in Saudi Arabia.
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Estimativa de ingestão do corante artificial amarelo crepúsculo e quantificação em alimentos consumidos pela população brasileiraFeitosa, Luana Carolina Alves January 2016 (has links)
Para avaliar os possíveis efeitos que os corantes artificiais podem causar à saúde, é de grande importância possuir dados relativos à exposição a estas substâncias. O fato de diversos estudos apontarem problemas de saúde relacionados ao consumo do corante artificial Amarelo Crepúsculo (AC) justifica a necessidade de verificar se a ingestão desta substância, através do consumo de alimentos industrializados, ultrapassa a Ingestão Diária Aceitável (IDA). O objetivo deste trabalho foi estudar e caracterizar a ingestão de AC pela população brasileira. Para isso, primeiramente foram verificados quais os alimentos comercializados por uma das maiores redes de supermercados do país que continham AC na sua formulação. Foi avaliada a ingestão média destes alimentos utilizando as Pesquisas de Orçamento Familiar (POF, 2008-2009) e determinada a Ingestão Diária Máxima Teórica (IDMT) de AC, através dos valores estipulados pela legislação brasileira para a concentração máxima permitida deste corante nos diferentes grupos de alimentos. Posteriormente foram realizadas analises, através de Cromatografia Líquida de Alta Eficiência (CLAE), para avaliar o teor de Amarelo Crepúsculo em refrescos em pó, refrigerantes, bebidas isotônicas, gelatinas e balas, e verificar as faixas de utilização deste corante e a adequação à legislação vigente. Através dos dados obtidos, verificou-se que a IDMT para AC, considerando o consumo médio per capita de alimentos, não supera a IDA para nenhuma das distribuições populacionais estudadas. No entanto, ao considerar a prevalência de consumo alimentar, a IDMT é superior à IDA para adolescentes de 10 a 18 anos (277% da IDA), adultos (181% da IDA) e idosos (140% da IDA) das áreas urbanas e rurais e nas cinco regiões do país Em relação às amostras analisadas, pode-se constatar que, considerando-se as médias obtidas, os produtos que mais contêm AC são na ordem: Refrigerantes (7,91 mg/100 mL); Bebidas Isotônicas (6,22 mg/100 mL); Refrescos em pó (5,96 mg/100 mL); Gelatinas (5,92 mg/100 mL) e Balas (menor que 1,25 mg/100 g). Através da realização deste trabalho, conclui-se que considerando o consumo médio per capita a ingestão diária representa entre 14 e 31% da IDA, não representando risco à saúde. No entanto, verificou-se que alguns indivíduos de todos os grupos populacionais podem estar ingerindo o corante em quantidades superiores às recomendadas. Cabe destacar que a POF (2008-2009), utilizada como fonte de dados nesta pesquisa, entrevistou crianças a partir dos 10 anos de idade. Visto que neste estudo o consumo de AC aumentou ao diminuir a faixa etária, é provável que esta tendência se aplique para crianças com menos de 10 anos. Diante do exposto, torna-se necessário um maior rigor no emprego e na fiscalização do uso de Amarelo Crepúsculo em produtos alimentares, visto que o consumo elevado deste corante pode ocasionar reações adversas aos seus consumidores. / To evaluate the possible effects that artificial dyes can cause health is very important to have data on exposure to these substances. The fact that several studies suggest health problems related to the consumption of artificial dye Sunset Yellow (SY) justifies the need to verify that the ingestion of this substance through consumption of processed foods, exceeds the Acceptable Daily Intake (ADI). The aim of this study was to evaluate and characterize the SY intake by the Brazilian population. For this, they were first checked which foods marketed by one of the country's largest supermarket chains containing SY in its formulation. the average intake of these foods using the Household Budget Surveys were evaluated (HBS 2008-2009) and determined the Theory Maximum Daily Intake (TMDI) SY, through the values set by the Brazilian legislation for the maximum permitted concentration of the dye in the different groups of food. Later analyzes were performed by High Performance Liquid Chromatography (HPLC) to evaluate the Yellow Twilight content in powdered drinks, soft drinks, isotonic drinks, gelatins and candy, and check the use of bands of this dye and the adequacy of legislation current. Through the data, it was found that the TMDI for SY, considering the average per capita consumption of food does not exceed the ADI for any of the studied population distributions. However, when considering the prevalence of food consumption, the TMDI is higher than the ADI for adolescents 10-18 years (277% of ADI), adults (181% of ADI) and the elderly (140% ADI) in urban areas and rural and in five regions of the country. Regarding the samples, it can be seen that, considering the averages, the products that contain SY are in order: Soft drinks (7.91 mg/100 mL); Isotonic drinks (6.22 mg/100 mL); powdered drinks (5.96 mg/100 mL); Gelatins (5.92 mg/100 mL) and candy (below 1,25 mg/100 g) Through this work, it is concluded that considering the average consumption per capita daily intake is between 14 and 31% of ADI and do not represent a health risk. However, it was found that some individuals of all population groups may be ingesting the dye in amounts greater than those recommended. It should be noted that the HBS (2008-2009), used as a data source in this research, interviewed children from 10 years old. Since in this study the use of SY increased by reducing the age, it is likely that this trend will apply to children under 10 years. Given the above, it is necessary a greater rigor in applying and monitoring the use of Sunset Yellow in food products, as the high consumption of this dye can cause adverse reactions to their consumers.
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Corantes artificiais: estudo da estimativa de ingestão por crianças e da percepção de adultos residentes no Rio Grande do SulValente, Marina Coelho Hofmeister January 2018 (has links)
Os corantes são substâncias adicionadas para conferir ou intensificar a cor dos alimentos. Sendo a aparência dos alimentos fundamental para a escolha do consumidor, a indústria justifica o uso de corantes como forma de melhorar a aparência dos mesmos e aumentar o consumo. Os corantes artificiais adquiriram seu espaço no mercado por terem a vantagem de ser mais estáveis ao processamento, possuírem maior poder tintorial e serem mais baratos do que os naturais. Contudo, estudos ao longo dos anos têm apontado que corantes alimentares artificiais podem estar relacionados a problemas de saúde, principalmente em crianças. Nesse contexto, o presente estudo visou verificar qual a percepção da população do Rio Grande do Sul (RS) em relação a esse tipo de aditivo, através de um questionário online de opinião. Além disso, a pesquisa também procurou estudar o consumo de corantes artificiais por crianças residentes no Rio Grande do Sul. No estudo de percepção (n = 531) foi verificada uma baixa percepção de benefício e alta percepção de perigo dos corantes artificiais, principalmente por pessoas do gênero feminino, pessoas com filho e pessoas de maior faixa etária. Contudo, apesar da sua opinião sobre corantes artificiais, o consumidor não parece afetar o seu padrão de consumo, uma vez que os respondentes afirmaram consumir produtos com esse tipo de aditivo Foi verificado também uma alta desconfiança por parte do público quanto a regulamentação da área de alimentos e falta de conhecimento do consumidor em relação aos rótulos dos alimentos. No estudo de consumo de corantes artificiais por crianças (n = 218), os resultados demonstraram que embora a maioria das crianças (~90%) consuma corantes em quantidades inferiores aquelas estipuladas como seguras, algumas extrapolam o consumo em níveis que podem acarretar em risco à saúde. Em média, os corantes mais consumidos com relação à IDA foram: o Bordeaux (~29% da IDA), Amarelo crepúsculo (~6,5% da IDA), Amarelo Tartrazina (~3,1% da IDA) e Azul Brilhante (~2,8% da IDA). O corante Bordeaux foi o que apresentou maior porcentagens de crianças que ultrapassaram a sua IDA (7,3%). O principal alimento responsável pelo consumo é o refresco em pó. O estudo demonstrou que algumas crianças estão colocando em risco sua saúde ao consumir quantidades elevadas de corantes artificiais. / Dyes are added substances to confer or intensify the color of food. As the appearance of food is fundamental to consumer’s choice, the industry justifies its use as a way to improve their appearance and increase consumption. Artificial dyes have acquired their space in the market because they have the advantage of being more stable to the processing, possessing greater color power and being cheaper than the natural ones. However, studies over the years have pointed out that artificial food colorings may be related to health problems, especially in children. In this context, the present study aimed to verify the perception of the population of Rio Grande do Sul (RS) in relation to this type of additive, through an online opinion questionnaire. In the study of perception (n = 531), a low perception of benefit and a high perception of the risk of artificial dyes were observed, mainly by people of the female gender, people with children and people of greater age. However, in spite of his opinion about artificial colors, the consumer does not seem to affect his consumption pattern, since the respondents stated that they consume products with this type of additive There was also a high public distrust regarding the regulation of the food area and lack of consumer knowledge about food labels. In the study of artificial colorants consumption by children (n = 218), the results showed that although most children (~ 90%) consume dyes in amounts lower than those stipulated as safe, some extrapolate consumption to levels that may be at risk the health. On average, the most consumed dyes with respect to IDA were: Bordeaux (~ 29% of IDA), Sunset Yellow (~ 6.5% of IDA), Yellow Tartrazine (~ 3.1% of IDA) and Bright Blue ~ 2.8% of the ADI). The Bordeaux dye showed the highest percentage of children who exceeded their ADI (7.3%). The main food that is responsible for consumption is soft drink powder. The study showed that some children are putting their health at risk by consuming high amounts of artificial colorants.
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