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Description
It is widely recognized that dietary protein induces greater satiety compared to carbohydrate and fat. Two separate trials were conducted to assess the use of protein as a dietary approach to manage energy intake (EI). The first, crossover trial, examined 24– hour EI after consuming a high protein bar (HP) vs. a high carbohydrate (HC) bar upon awakening on two separate days and a control, no bar day. Of the 54 participants who entered the trial, 37 subjects completed the study in its entirety. Results showed there was no significant difference in mean EI between the intervention days when the bars were consumed and the control day. The subjects consumed 1752±99 kcal on the control day, and 1846±75 and 1891±110 kcal on the days the HP and HC bars were consumed, respectively (P=0.591). However, compared to the control day, snack bar ingestion was significantly related to an increase in EI for the subjects who self-reported high weekly physical activity levels (n=11) (+22%; P=0.038 and +45%; P=0.030, HP and HC bars, respectively). These data suggest that individuals who have moderate to low physical activity levels compensate for the ingestion of energy bars (regardless of protein content) over a 24–hour period. The second parallel-arm, pilot trial examined the effect of 6 g daily gelatin ingestion vs. control on EI and weight change in healthy, overweight and obese women who initiated a walking program. Of the 37 women who entered the trial, 28 completed the six week trial. The results showed activity level (steps/d) increased in both groups (+ 22%, P=0.022). There was a significant group difference in mean EI at week 6 vs. baseline (–174±612 kcal/d and +197±320 kcal/d, P=0.001; gelatin and control groups, respectively). However, there was no significant between group difference for changes in weight, percent body fat and waist circumference. Those subjects having baseline Disinhibition scores of ≥12 gained significantly more weight throughout the study vs. those scoring <12 (P=0.004). These results indicate that daily gelatin ingestion may be a practical strategy for controlling EI among overweight and obese women initiating an exercise program.
ContributorsTrier, Catherine M (Author) / Johnston, Carol S. (Thesis advisor) / Swan, Pamela D. (Committee member) / Mayol-Kreiser, Sandra N. (Committee member) / Appel, Christy L. (Committee member) / Gaesser, Glenn A. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home is collected for use elsewhere within the microgrid footprint. The surplus power that would have been discarded becomes a community asset, and is used to run intermittent services. In this paper, the modeled community does not have parking adjacent to each home allowing for the installment of a privately owned slower Level 2 charger, making EV ownership option untenable. A solution is to provide a Level 3 DC Quick Charger (DCQC) as the intermittent service. The addition of batteries and Fuel Cells are meant to increase load leveling, reliability, and instill limited island capability.
ContributorsPatterson, Maxx (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Macia, Narciso (Committee member) / Peng, Xihong (Committee member) / Arizona State University (Publisher)
Created2013
Description
Background: Previous research suggests a healthy eater schema (i.e., identifying yourself as a healthy eater) may be a useful concept to target in interventions. A "stealth" intervention that discussed the moral issues related to food worked better at promoting healthful eating than an intervention focused on the health benefits. No research has explored the relationship between moral foundations, a theoretical model focused on delineating core "foundations" for making a moral decision, and healthy eater self-identity or self-efficacy. Purpose: We explored the relationship between moral foundations (i.e., harm/care, fairness/reciprocity, in-group/loyalty, authority/respect, & purity/sanctity) and health eater self-identity and fruit and vegetable self-efficacy (FVSE). Methods: 542 participants completed an online cross-sectional survey, which included moral foundations (i.e., MFQ), political views, healthy eater self-identity (i.e., HESS), and FVSE measures. Logistic regression was used to assess the relationship between moral foundations between healthy eater self-identity after controlling for age, gender, major, BMI, and political beliefs. OLS regression was used to explore the relationship between self-efficacy and the moral foundations after controlling for the covariates. Results: 75.6% of the sample were college students, with a mean age of 25.27 (SD=8.61). 25.1% of students were nutrition majors. Harm/care, authority/respect, and ingroup/loyalty were significantly associated with healthy eater schema, (i.e., OR=1.7, p<.001, OR=1.5, p=.009, and OR=1.4, p=.027, respectively). Ingroup/loyalty, authority/respect, and purity/sanctity were related to FVSE (p=.006, p=.002, p=.04, respectively). Conclusion: Among college students, harm/care and authority/respect were associated with a healthy eater schema. Future research should explore possible uses of these moral foundations in interventions (e.g., a plant-based diet based on reduced harm to animals or eating fewer processed views based on "traditional" values).
ContributorsKiser, Sarah (Author) / Hekler, Eric B. (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2013
Description
The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy mar-ket, considered to be an effective solution to promote energy efficiency. In the urban en-vironment, the electricity, water and natural gas distribution networks are becoming in-creasingly interconnected with the growing penetration of the CHP-based DG. Subse-quently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and sit-ing for a larger test bed with the given information of energy infrastructures. In this con-text, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The pro-posed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation per-formances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electrici-ty, gas, and water system models were developed individually and coupled by the devel-oped CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical output and recovered thermal output, which are affected by multiple factors and thus analyzed in different case studies. The results indicate that the designed typical gas system is capable of supplying sufficient natural gas for the DG normal operation, while the present water system cannot support the complete recovery of the exhaust heat from the DG units.
ContributorsZhang, Xianjun (Author) / Karady, George G. (Thesis advisor) / Ariaratnam, Samuel T. (Committee member) / Holbert, Keith E. (Committee member) / Si, Jennie (Committee member) / Arizona State University (Publisher)
Created2013
Description
The Solid State Transformer (SST) is an essential component in the FREEDM system. This research focuses on the modeling of the SST and the controller hardware in the loop (CHIL) implementation of the SST for the support of the FREEDM system demonstration. The energy based control strategy for a three-stage SST is analyzed and applied. A simplified average model of the three-stage SST that is suitable for simulation in real time digital simulator (RTDS) has been developed in this study. The model is also useful for general time-domain power system analysis and simulation. The proposed simplified av-erage model has been validated in MATLAB and PLECS. The accuracy of the model has been verified through comparison with the cycle-by-cycle average (CCA) model and de-tailed switching model. These models are also implemented in PSCAD, and a special strategy to implement the phase shift modulation has been proposed to enable the switching model simulation in PSCAD. The implementation of the CHIL test environment of the SST in RTDS is described in this report. The parameter setup of the model has been discussed in detail. One of the dif-ficulties is the choice of the damping factor, which is revealed in this paper. Also the grounding of the system has large impact on the RTDS simulation. Another problem is that the performance of the system is highly dependent on the switch parameters such as voltage and current ratings. Finally, the functionalities of the SST have been realized on the platform. The distributed energy storage interface power injection and reverse power flow have been validated. Some limitations are noticed and discussed through the simulation on RTDS.
ContributorsJiang, Youyuan (Author) / Ayyanar, Raja (Thesis advisor) / Holbert, Keith E. (Committee member) / Chowdhury, Srabanti (Committee member) / Arizona State University (Publisher)
Created2014
Description
The increase in obesity since the 1980's has been associated with fast-food consumption. In hopes that calorie labeling will be an effective tool to combat obesity, congress included a provision in the Patient Protection and Affordable Care Act of 2010 (ACA) that will require all restaurants with twenty or more locations to post calorie information for each menu item. Current research has provided mixed results regarding the effectiveness of calorie labeling, but overall seems to suggest that calorie labeling may only be effective among certain populations. In September, 2012 McDonald's began to post calorie labels on their menu boards before it was federally mandated under the ACA. This policy provided the opportunity to study the impact of calorie labeling on the purchasing behavior of McDonald's patrons. This cross-sectional study was designed to determine if self-perception of diet, self-perception of health, smoking, physical activity, fruit and vegetable intake, or knowledge of daily calorie requirements is associated with the likelihood of noticing or using calorie labels, or total calories purchased. In addition, relationships between noticing or using calorie labels with total calories purchased were also examined. Receipts and survey responses were collected from 330 participants who purchased food and beverage items from 27 different McDonald's locations within a 20 mile radius of downtown Phoenix, Arizona. Results indicated that only 16.1% of the sample reported using calorie labels, and those who reported using calorie labels purchased an average of 136 fewer calories. Multivariate analysis indicated there were no statistically significant relationships between self-perception of diet, self-perception of health, smoking, physical activity, fruit and vegetable intake, or knowledge of daily calorie requirements with the likelihood of noticing or using calorie labels, or total calories purchased. However, it is possible that the small sample size of participants using calorie labeling precluded any statistically significant relationships among these variables from emerging. Further research with larger sample sizes should be conducted, to investigate individual level factors that may be associated with use of calorie labeling.
ContributorsBrown, Alan (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Bruening, Meredith (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Arizona State University (Publisher)
Created2013
Description
Type 2 diabetes affects approximately 7.3% of Americans, leading to debilitating and life-threatening comorbidities. Estrogen and testosterone levels have been linked to inflammatory and oxidative stress markers, as well as glucose and insulin concentrations. The present study was designed to determine the link between sex differences, glucose control, and inflammation and oxidative stress related to daily almond ingestion among subjects with type 2 diabetes. Subjects were randomized to an intervention group, which received 1.5 oz. almonds daily for 12 weeks, or to the matched control group, which maintained their current diet. No significant differences were found in changes in glucose control in response to ingestion of almonds. However, CRP was significantly reduced by an average of 36.2% in those that received almonds daily (p = 0.017). Although not significant, women randomized to the intervention group appeared to have improvements in insulin resistance compared to women with no dietary change. Results suggest that the addition of almonds to the diet may be an effective intervention for managing inflammation associated with type 2 diabetes. The addition of almonds to the diet is a low cost intervention that is easily implemented into daily lifestyle. Due to the small sample size, additional studies are needed to determine the impact and mechanisms of almond ingestion in subjects with type 2 diabetes.
ContributorsPetersen, Katherine Nicole (Author) / Karen, Sweazea (Thesis advisor) / Carol, Johnston (Committee member) / Christy, Lespron (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study evaluates two photovoltaic (PV) power plants based on electrical performance measurements, diode checks, visual inspections and infrared scanning. The purpose of this study is to measure degradation rates of performance parameters (Pmax, Isc, Voc, Vmax, Imax and FF) and to identify the failure modes in a "hot-dry desert" climatic condition along with quantitative determination of safety failure rates and reliability failure rates. The data obtained from this study can be used by module manufacturers in determining the warranty limits of their modules and also by banks, investors, project developers and users in determining appropriate financing or decommissioning models. In addition, the data obtained in this study will be helpful in selecting appropriate accelerated stress tests which would replicate the field failures for the new modules and would predict the lifetime for new PV modules. The study was conducted at two, single axis tracking monocrystalline silicon (c-Si) power plants, Site 3 and Site 4c of Salt River Project (SRP). The Site 3 power plant is located in Glendale, Arizona and the Site 4c power plant is located in Mesa, Arizona both considered a "hot-dry" field condition. The Site 3 power plant has 2,352 modules (named as Model-G) which was rated at 250 kW DC output. The mean and median degradation of these 12 years old modules are 0.95%/year and 0.96%/year, respectively. The major cause of degradation found in Site 3 is due to high series resistance (potentially due to solder-bond thermo-mechanical fatigue) and the failure mode is ribbon-ribbon solder bond failure/breakage. The Site 4c power plant has 1,280 modules (named as Model-H) which provide 243 kW DC output. The mean and median degradation of these 4 years old modules are 0.96%/year and 1%/year, respectively. At Site 4c, practically, none of the module failures are observed. The average soiling loss is 6.9% in Site 3 and 5.5% in Site 4c. The difference in soiling level is attributed to the rural and urban surroundings of these two power plants.
ContributorsMallineni, Jaya Krishna (Author) / Govindasamy, Tamizhmani (Thesis advisor) / Devarajan, Srinivasan (Committee member) / Narciso, Macia (Committee member) / Arizona State University (Publisher)
Created2013
Description
ABSTRACT Deciding what to eat can be difficult. There are multiple different diets which are popular today, and all of them say different things about which foods optimize health, and which foods are destructive. The situation become more complicated when the suggestions are all purportedly based on relevant science, and all have had demonstrated positive impacts on overall wellbeing. Even when we do have good information, financial factors, geography, and time constraints can prevent us from acting on it. In an attempt to portray the difficulties involved in eating well, I start by analyzing what each of six diets - The Paleo Diet, The Perfect Health Diet, the vegetarian diet, the vegan diet, the Mediterranean Diet, and the Traditional Asian Diet - says about what we should be eating. I then explore what the science says about what we should be eating, and whether this science lines up with the diets, by discussing an extensive review of books and literature on nutrition. Lastly, in order to gain an understanding of factors which discourage us from eating well, I tracked my consumption habits for a week using My Fitness Tracker, and noted any reasons that I chose to eat or not eat certain foods. I supplemented this with a discussion of the shortcomings of the Healthy, Hunger-Free Kids Act, and the types of factors that prevent people from acting on information. In conclusion, diets should be praised for attempting to align American eating habits with the best scientific information, but the vast amount of information and the difficulty involved in eating well may ultimately prevent people from doing so.
ContributorsWhitson, Grant (Author) / Robert, Jason (Thesis advisor) / Hurlbut, Ben (Committee member) / Wharton, Chris (Committee member) / Arizona State University (Publisher)
Created2014
Description
A robust, fast and accurate protection system based on pilot protection concept was developed previously and a few alterations in that algorithm were made to make it faster and more reliable and then was applied to smart distribution grids to verify the results for it. The new 10 sample window method was adapted into the pilot protection program and its performance for the test bed system operation was tabulated. Following that the system comparison between the hardware results for the same algorithm and the simulation results were compared. The development of the dual slope percentage differential method, its comparison with the 10 sample average window pilot protection system and the effects of CT saturation on the pilot protection system are also shown in this thesis. The implementation of the 10 sample average window pilot protection system is done to multiple distribution grids like Green Hub v4.3, IEEE 34, LSSS loop and modified LSSS loop. Case studies of these multi-terminal model are presented, and the results are also shown in this thesis. The result obtained shows that the new algorithm for the previously proposed protection system successfully identifies fault on the test bed and the results for both hardware and software simulations match and the response time is approximately less than quarter of a cycle which is fast as compared to the present commercial protection system and satisfies the FREEDM system requirement.
ContributorsIyengar, Varun (Author) / Karady, George G. (Thesis advisor) / Ayyanar, Raja (Committee member) / Holbert, Keith E. (Committee member) / Arizona State University (Publisher)
Created2014