Aerodynamics Investigation of Faceted Airfoils at Low Reynolds Number

The desire and demand to fly farther and faster has progressively integrated the concept of optimization with airfoil design, resulting in increasingly complex numerical tools pursuing efficiency often at diminishing returns; while the costs and difficulty associated with fabrication increases with design complexity. Such efficiencies may often be necessary due to the power density limitations of certain aircraft such as small unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs).;This research, however, focuses on reducing the complexity of airfoils for applications where aerodynamic performance is less important than the efficiency of manufacturing; in this case a Hybrid Projectile. By employing faceted sections to approximate traditional contoured wing sections it may be possible to expedite manufacturing and reduce costs.;We applied this method to the development of a low Reynolds number, disposable Hybrid Projectile requiring a 4.5:1 glide ratio, resulting in a series of airfoils which are geometric approximations to highly contoured cross-sections called ShopFoils. This series of airfoils both numerically and experimentally perform within a 10% margin of the SD6060 airfoil at low Re.;Additionally, flow visualization has been conducted to qualitatively determine what mechanisms, if any, are responsible for the similarity in performance between the faceted ShopFoil sections and the SD6060. The data obtained by these experiments did not conclusively reveal how the faceted surfaces may influence low Re flow but did indicate that the ShopFoil s did not maintain flow attachment at higher angles of attack than the SD6060. Two reasons are provided for the unexpected performance of the ShopFoil: one is related to downwash effects, which are suspected of placing the outer portion of the span at an effective angle of attack where the ShopFoils outperform the SD6060; the other is the influence of the tip vortex on separation near the wing tips, which possibly provides a \u27comparative advantage\u27 to the ShopFoil because it has more to gain from a reduction in its pressure drag component

Rinaldo D’Aquino rimatore della scuola siciliana

The article focuses on Rinaldo d’Aquino, a noble rhymer of the Sicilian School, calling into question some biographical information handed down from critical tradition and analyzing some of his compositions

Direct foam writing in microgravity

Herein we report 2D printing in microgravity of aqueous-based foams containing metal oxide nanoparticles. Such hierarchical foams have potential space applications, for example for in situ habitat repair work, or for UV shielding. Foam line patterns of a TiO2-containing foam have been printed onto glass substrates via Direct Foam Writing (DFW) under microgravity conditions through a parabolic aircraft flight. Initial characterization of the foam properties (printed foam line width, bubble size, etc.) are presented. It has been found that gravity plays a significant role in the process of direct foam writing. The foam spread less over the substrate when deposited in microgravity as compared to Earth gravity. This had a direct impact on the cross-sectional area and surface roughness of the printed lines. Additionally, the contact angle of deionized water on a film exposed to microgravity was higher than that of a film not exposed to microgravity, due to the increased surface roughness of films exposed to microgravity

Willingness to use a Supervised Injection Site Among Participants of Syringe Exchange Program

PURPOSE: Supervised injection sites (SIS) allow individuals to inject pre-obtained substances under the supervision of staff trained to provide harm reduction education, sterile injection drug equipment, and respond to an overdose. Implementation of SIS in countries such as Canada and Australia has shown to reduce the frequency of fatal overdoses, infectious disease transmission, and public syringe disposal. The purpose of this study was to better understand current syringe exchange program (SEP) participants’ willingness to use a SIS. SUBJECTS: The study population of interest includes participants of a Michigan SEP that are actively using injection drugs. The study included a convenience sample of 31 participants. METHODS: A needs assessment survey was developed in collaboration with a local SEP, and participants were recruited as they came in to the organization for services. Variables of interest include drug use characteristics, willingness to use a SIS, and perceived barriers to SIS use. Descriptive statistics were calculated for survey responses. RESULTS: The majority of participants were white, male, and under the age of 40. Injection drug use behaviors included injecting in a private place (51.6%), using heroin (96.8%), and a history of drug overdose (64.5%). The majority reported willingness to use a SIS if one was offered at their local SES, and identified criminal repercussions as the biggest barrier to accessing such service. CONCLUSIONS: Findings show current SEP participants support the development of a SIS. The results will assist the organization to best serve their participants and make decisions regarding program development in the future

Using analytics to improve delivery performance

Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, 2014. In conjunction with the Leaders for Global Operations Program at MIT.Thesis: S.M., Massachusetts Institute of Technology, Engineering Systems Division, 2014. In conjunction with the Leaders for Global Operations Program at MIT.Cataloged from PDF version of thesis.Includes bibliographical references (page 49).Delivery Precision is a key performance indicator that measures Nike's ability to deliver product to the customer in full and on time. The objective of the six-month internship was to quantify areas in the supply chain where the most opportunities reside in improving delivery precision. The Nike supply chain starts when a new product is conceived and ends when the consumer buys the product at retail. In between conception and selling, there are six critical process steps. The project has provided a method to evaluate the entire supply chain and determine the area that has the most opportunity for improvement and therefore needs the most focus. The first step in quantifying the areas with the most opportunity was to identify a framework of the supply chain. The framework includes the target dates that must be met in order to supply product to the customer on schedule and the actual dates that were met. By comparing the target dates to the actual dates, the area of the supply process that caused the delay can be identified. Next a data model was created that automatically compares the target dates to actual dates for a large and specified set of purchase orders. The model uses the framework and compiles all orders to quantify the areas in the supply chain that create the most area for opportunity. The model was piloted on the North America geography, Women's Training category, Apparel product engine, and Spring 2013 season, for orders shipped to the Distribution Center (DC). The pilot showed that the most area for opportunity lies in the upstream process (prior to the product reaching the consolidator). In particular the pilot showed that the area with the most opportunity for the sample set was the PO create process. This conclusion was also confirmed with the Running category. The method developed during the internship provides Nike with a method to measure the entire supply chain. By quantifying the areas in the process, Nike can focus and prioritize their efforts on those areas that need the most improvement. In addition the model created can be scaled for any region, category, or product engine to ultimately improve delivery precision across the entire company.by Tacy J. Napolillo.M.B.A.S.M

Alternative definition of 'early gastric cancer': Stage A of Dukes' classification

[No abstract available