44 research outputs found
On rational functions with Golden Ratio as fixed point
The existence of an equivalence subset of rational functions with Fibonacci numbers as coefficients and the Golden Ratio as fixed point is proven. The proof is based on two theorems establishing basic relationships underlying the Fibonacci Sequence, Pascal\u27s Triangle and the Golden Ratio. Equations from the two theorems are related to each other and seen to generate the equivalence subset of rational functions. Proof by induction on these equations constitutes the proof of the existence of this subset of rational functions. It is found that this subset of rational functions possesses interesting mathematical properties, particularly that of convergence to the Golden Ratio at the limit. Further investigation showed that this subset of rational functions possesses algebraic structures that would take us into the realms of abstract algebra and complex analysis. The study concludes that the findings are significant as an addition to mathematical knowledge, and as a possible tool for biological research. In this respect, recommendations are made for further research with a view to applications in the sciences and education
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A multiple solution, laboratory-scale delivery system and its applications
Researchers around the world use various solution-based deposition techniques to deposit thin films with multiple layers that typically require multiple rounds of deposition. Some such techniques include successive ionic layer adsorption and reaction (SILAR), and layer-by-layer (LBL) deposition.
One of the main issues with deposition of these types of films is the labor intensive aspect. The SILAR and LBL techniques typically take from tens of minutes to hours for deposition. The laborious processes hinder the application of these techniques for the fabrication of more complex film structures such as functionally graded films.
The need for a programmable and more flexible process inspired the research and development for a laboratory scale system that could deliver the precursor solutions on-demand. The system features an in-situ mixing capability that is ideal for the fabrication of functionally graded thin films. The prototype system presented in this work is currently called multiple solution delivery system. This system was originally envisioned to be paired with a spin coater such that a researcher could program recipes in the system and spin coater, start operation and leave the system to deliver the solutions when necessary. This would allow the researcher to spend time on other, more cognitively challenging endeavors while the deposition took place. It would also relieve the researcher from the duty of preparing several solutions of different concentrations as the system could mix solutions to create a delivered solution of different concentrations for different layers.
After intensive research into available systems, and several rounds of discussion on the system requirements, it was decided that a custom system was most appropriate. A design process was used to design the system. A syringe pump based delivery system was chosen for the ease of varying reservoir size and resolution of dispensing. The system went through multiple revisions, pre and post construction. The final embodiment was calibrated, further tested for mixing and paired with a spin coater for thin film deposition. Documentation, in the form of a component list, operations manual and commented code, was also prepared and is presented
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Industrially-situated project-based learning : a study of feedback and diffusion
The Virtual Chemical Vapor Deposition (CVD) Process Development Project provides the context for the two areas of the research presented in this dissertation. The first area, generally referred to as feedback in this dissertation, focuses on student learning and the interactions of students and instructors that take place in the project, specifically focused on characterizing feedback and determining the influence of feedback as student teams progress towards completing the project. The characteristics of feedback found in this project are presented within a situative perspective using the analytical framework of episodes. The characteristics include: a list and categorization of episode themes, the structure and flow of episodes during the coaching session, the sub-structure present within individual episodes, and the types of feedback present. This dissertation shows how these characteristics frame participation in a community of practice and can be used as tools to scaffold instructor feedback in project-based learning. Episodes analysis is also used to investigate how feedback on professional skills can help to enculturate students into a community of practice and influence their fluency with professional skills and engagement in more technical activities. The second area examines the spread of this innovative project from its home institution to
other institutions. In this area an analysis of the spread of the Virtual CVD Process Development Project in the high school setting is presented. The project was found to provide versatility for instructors and afford student learning in the areas of motivation, cognition, and epistemological beliefs.
These two areas inform each other. As the project is assessed at different institutions, it is continually improved and the sensitivity of different aspects of the project is explored, e.g., the aspects of the project that are crucial to maintain effectiveness are identified. One of these aspects is the feedback that takes place in the project. As the project is further examined at the home institution in depth, more can be learned about the best ways it can be delivered. This information informs scaffolding that then can be provided to faculty at other institutions such that they can attend to crucial aspects of the project in the most efficient, effective manner, improving not only the probability of successful adaptation, but also the likelihood that the project will further diffuse to other institutions
Basic Study on Flood Management Assessment in Metro Manila, Philippines
Flooding is the most frequent and damaging natural hazard worldwide. The resulting impact of flood disasters on society depends on the economic strength of the affected country prior to the disaster. The larger the disaster and the smaller the economy, the more significant is the impact. This is very clearly seen in developing countries, like the Philippines, where weak economies become much weaker after a devastating flood event. In 2009, tropical storm Ondoy, brought heavy rainfalls that produced destructive floods in the northern islands of the Philippines, leaving inconceivable damages, especially in Metro Manila, which caused the Philippine government to re-evaluate its decades\u27 worth of flood management strategies. Deliberate strategies for flood damage reduction, as well as environmental protection, may aid a country (or a community) to efficiently manage scarce resources for flood mitigation. Nevertheless, many governments lack an adequate institutionalized system for applying cost effective and reliable technologies for disaster prevention, early warnings, and mitigation, mainly due to lack of systematic and reliable flood management assessment strategies. In Metro Manila, important decision elements, such as stakeholders\u27 perception and environmental protection are often overlooked in the development of sustainable flood mitigation plans. Stakeholders can significantly contribute in achieving the desired level of prevention and protection in flood disaster-prone regions. Knowledge of the local conditions and understanding of the public\u27s perception can significantly help address the prioritization issues involved in flood management planning. However, the integration of the stakeholders\u27 perception in the appraisal of flood management systems has not yet been clearly established. In the case of environmental protection, environmental impact assessment (EIA) can provide a certain level of awareness on the benefits of environmentally sound and sustainable urban development. However, the common practice of EIA in the Philippines is generally qualitative and lacks clear methodology in evaluating multi-criteria systems. A study that deals with flood management assessment in Metro Manila is thus necessary to find solutions that may help cope with these inadequacies. This study focuses on the following main objectives: 1) to develop a heuristic analytical strategy that helps identify priority concerns in the flood management systems of Metro Manila using a perception-based appraisal, and 2) to develop a systematic and rational evaluation scheme that would help incorporate environmental assessment in the appraisal of flood mitigation measures. To achieve the first objective, an analytical assessment approach was developed to identify and analyze the flood management gaps using the questionnaire-based stakeholders\u27 perception obtained during the aftermath of the tropical storm Ondoy. For the second objective, a quantitative analytical approach was developed for EIA to further enhance the evaluation process in the planning of flood mitigation projects. This dissertation is composed of six chapters: Chapter 1 is the introduction, which contains the background, motivation, and objectives of this study. A comprehensive review of literature and a description of the scopes and methods were presented in this chapter. Chapter 2 focuses on the performance of the flood management systems in Metro Manila. A brief description of the flood management systems used in Metro Manila, before and during the aftermath of tropical storm Ondoy, was provided. The nature and characteristics of the tropical storm, as well as its effects on the flood management systems, were presented in this chapter. A multi-criteria gap analysis technique was developed to examine the flood disaster risk reduction (FDRR) management systems, which is demonstrated using a questionnaire-based database to obtain an explicit representation of the systems\u27 strengths and weaknesses. In this study, 14 out of 17 municipalities in Metro Manila were investigated. Results revealed that small to medium scale flood management gaps exist within the 14 assessed municipalities. Chapter 3 further explores the potential of a multi-criteria gaps assessment technique in the evaluation of FDRR management systems in Metro Manila. Perception-based assessment is inherently vague and imprecise, which often operates in a fuzzy environment. To cope with this, a fuzzy-based analytical approach was proposed to handle the uncertainties in the evaluation process of flood management gaps. The new approach is demonstrated using the same database in Chapter 2. The results reveal that the municipal-based FDRR management systems in Metro Manila are insufficient in terms of flood disaster prevention, preparedness, response and recovery. Larger gaps were found in the emergency response mechanism of the disaster preparedness management system. Chapter 4 deals with the EIA of nine planned structural flood mitigation measures (SFMMs) in Metro Manila. A modified rapid impact assessment matrix (RIAM) technique was proposed to systematically and quantitatively evaluate the socioeconomic and environmental impacts of the planned SFMMs. The distribution of impacts of each SFMM was estimated for each environmental component of the 4 environmental categories. Based on the results, most of the negative and positive impacts of SFMMs occur during their construction and operation phases, respectively. The modified RIAM approach provided a clear panoramic view of the environmental impacts of each assessed SFMM. Chapter 5 presents a new EIA approach that provides enhancement to the modified RIAM technique in Chapter 4. A utility-based assessment approach using the RIAM technique, coupled with a recursive evidential reasoning approach, was proposed to rationally and systematically evaluate the ecological and socio-economic impacts of 4 planned SFMMs in Metro Manila. This new approach quantitatively characterized the overall impact of each of the planned SFMMs which can provide the means for benefit maximization and optimization. Results show that the overall environmental contributions of each of the planned SFMMs is generally positive, which indicate that the utility of their positive impacts would generally outweigh their negative ones. The results also indicated that the planned river channel improvements have higher environmental benefits than the planned open channels. Chapter 6 presents the overall conclusions and recommendations for the assessment of flood management systems in Metro Manila, including the future research works.首都大学東京, 2014-09-30, 博士(工学), 甲第421号首都大学東
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Mixed Spices at Culinary Doses Have Prebiotic Effects in Healthy Adults: A Pilot Study.
Spices were used as food preservatives prior to the advent of refrigeration, suggesting the possibility of effects on microbiota. Previous studies have shown prebiotic activities in animals and in vitro, but there has not been a demonstration of prebiotic or postbiotic effects at culinary doses in humans. In this randomized placebo-controlled study, we determined in twenty-nine healthy adults the effects on the gut microbiota of the consumption daily of capsules containing 5 g of mixed spices at culinary doses by comparison to a matched control group consuming a maltodextrin placebo capsule. The 16S ribosomal RNA sequencing data were used for microbial characterization. Spice consumption resulted in a significant reduction in Firmicutes abundance (p < 0.033) and a trend of enrichment in Bacteroidetes (p < 0.097) compared to placebo group. Twenty-six operational taxonomic units (OTUs) were different between the spice and placebo groups after intervention. Furthermore, there was a significant negative correlation between fecal short-chain fatty acid propionate concentration and Firmicutes abundance in spice intervention group (p < 0.04). The production of individual fecal short-chain fatty acid was not significantly changed by spice consumption in this study. Mixed spices consumption significantly modified gut microbiota, suggesting a prebiotic effect of spice consumption at culinary doses
FEDSM2006-98347 FIXED VALVE PIEZOELECTRIC MICROPUMP FOR MINIATURE THERMAL MANAGEMENT MODULE
ABSTRACT In this paper, we discuss implementation of a micropump with fixed-geometry Tesla-type valves in a closed-loop forced convection thermal management system. The micropump was integrated with a heat sink in a stacked array and fabricated using a photochemical etching process. Two different micropump cavity diameters of 10-mm and 15-mm were fabricated and tested. For each cavity diameter, there were three valve sizes ranging from 140-µm to 340-µm in width. For the best-performing micropump we also evaluated the impact of varying the aspect ratio by adding and removing layers within the micropump. Our results indicated that as the diameter or cavity depth increased the performance of the pump in terms of block load pressure and flow rate degraded. Also, decreasing the valve width for each cavity diameter and height tended to increase the block load pressure and the resulting flow rate. For a pump with 140-µm valve width and an optimal cavity height of 550-µm (11-layers), the maximum flow and pressures obtained for a single pump subassembly were nearly 1.1-mL/min and 0.8-psi. A stack of 4 micropump subassemblies provided more than 5.5 mL/min flow rate and 0.5-psi pressure. The micropump power consumption was less than 50-mW per subassembly, and including the driving electronics power conversion, it consumed less than 0.5-W of power under these conditions. The thermal performance of an integrated liquid cooling module on standard Pentium P4 microprocessor running at up to 40-W was comparable to an off-the-shelf heatsink, but in a package less than 1/10 the size. This unit is currently being considered for blade server applications
Optimizing Microwave-assisted Crude Butter Extraction from Carabao Mango (Mangifera indica) Kernels
Carabao mangoes are among the highly produced fruit crops in the Philippines. The processing and consumption of carabao mangoes leave a significant amount of waste seeds. Mango kernel butter extracted from waste seed kernels is a potential additive to cosmetic products or as a cocoa butter substitute. This study determined the pretreatment conditions that produce optimum yield prior to the mechanical extraction of the crude butter. Moreover, this study provided a general sensory evaluation of the finished product. Microwave power (160, 500, and 850 W), microwave exposure time (2.0, 3.5, and 5.0 min), and size levels (1.5, 3.0, and 4.5 mm) were tested for their effects on the yield of the mechanically extracted crude butter in wet basis percentage. The optimization procedures resulted to optimum pretreatment conditions of 160 W, 4.25 min, and 1.5 mm. Size level was the most significant factor in the crude butter yield. Sensory evaluation of the crude butter extracted at optimum pretreatment conditions through acceptance test by a test panel resulted to below neutral scores in visual appearance and odor, and above neutral score in texture, indicating the potential of mango butter as a good substitute to cocoa butter in cosmetic products
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Pomegranate Juice and Extract Consumption Increases the Resistance to UVB-induced Erythema and Changes the Skin Microbiome in Healthy Women: a Randomized Controlled Trial.
In vitro and animal studies have demonstrated that topical application and oral consumption of pomegranate reduces UVB-induced skin damage. We therefore investigated if oral pomegranate consumption will reduce photodamage from UVB irradiation and alter the composition of the skin microbiota in a randomized controlled, parallel, three-arm, open label study. Seventy-four female participants (30-45 years) with Fitzpatrick skin type II-IV were randomly assigned (1:1:1) to 1000 mg of pomegranate extract (PomX), 8 oz of pomegranate juice (PomJ) or placebo for 12 weeks. Minimal erythema dose (MED) and melanin index were determined using a cutometer (mexameter probe). Skin microbiota was determined using 16S rRNA sequencing. The MED was significantly increased in the PomX and PomJ group compared to placebo. There was no significant difference on phylum, but on family and genus level bacterial composition of skin samples collected at baseline and after 12 week intervention showed significant differences between PomJ, PomX and placebo. Members of the Methylobacteriaceae family contain pigments absorbing UV irradiation and might contribute to UVB skin protection. However, we were not able to establish a direct correlation between increased MED and bacterial abundance. In summary daily oral pomegranate consumption may lead to enhanced protection from UV photodamage