Isotropic thin-walled pressure vessel experiment

The objectives are: (1) to investigate the stress and strain distributions on the surface of a thin walled cylinder subject to internal pressure and/or axial load; and (2) to relate stress and strain distributions to material properties and cylinder geometry. The experiment, supplies, and procedure are presented

The Development of Techie Times

Summer 2020 provided the motivation and opportunity to move summer outreach programs into the virtual world. Faculty and students in the Purdue University School of Engineering Technology moved face-to-face programs into a middle school program called Techie Times. This program was designed to provide students with an organized platform occurring just before the school year started, allowing them to learn at home, working with family, or independently. The program was designed to take place nonconsecutively over eight days, covering five various STEM topics. Some of these activities were already a part of the middle school curriculum; others were not. That provided an opportunity to engage students and teach them principles that support various engineering technology curricula. Students were recruited from across the country. Students were placed into three cohorts sorted by biological age and then into smaller groups to enhance interactions. Volunteers moderated the smaller groups representing corporate engineering retirees, university professors, and others interested in helping. The volunteers were provided with information to support the principles being learned in the activity of the day. They asked the students to demonstrate what they did at home and then asked them questions about what they learned from the activity. In the older age groups, volunteers generated hypotheses and tested them to see if they worked, thus providing a challenge for the older and more experienced students. This camp proved to be well-timed on the summer calendar. Parents expressed their pleasure in their students becoming a bit more disciplined as they transitioned from their summer activities to the upcoming school year. This paper will review the program’s curriculum, observations by the parents/guardians, and feedback from the students. The program is an example of a well-transformed outreach program that engaged and enlightened students

SOUND SOURCE STRENGTH SENSITIVITY TO LOAD IMPEDANCES IN AN AIR-DUCT SYSTEM

会議名称 : The 19th International Congress on Noise Control Engineering : science for silence主催学会 : SA

Religious Identity, Religious Attendance, and Parental Control

Using a national sample of adolescents aged 10–18 years and their parents (N = 5,117), this article examines whether parental religious identity and religious participation are associated with the ways in which parents control their children. We hypothesize that both religious orthodoxy and weekly religious attendance are related to heightened levels of three elements of parental control: monitoring activities, normative regulations, and network closure. Results indicate that an orthodox religious identity for Catholic and Protestant parents and higher levels of religious attendance for parents as a whole are associated with increases in monitoring activities and normative regulations of American adolescents

Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects

Policies, Political-Economy, and Swidden in Southeast Asia

For centuries swidden was an important farming practice found across the girth of Southeast Asia. Today, however, these systems are changing and sometimes disappearing at a pace never before experienced. In order to explain the demise or transitioning of swidden we need to understand the rapid and massive changes that have and are occurring in the political and economic environment in which these farmers operate. Swidden farming has always been characterized by change, but since the onset of modern independent nation states, governments and markets in Southeast Asia have transformed the terms of swiddeners’ everyday lives to a degree that is significantly different from that ever experienced before. In this paper we identified six factors that have contributed to the demise or transformation of swidden systems, and support these arguments with examples from China (Xishuangbanna), Laos, Thailand, Malaysia, and Indonesia. These trends include classifying swiddeners as ethnic minorities within nation-states, dividing the landscape into forest and permanent agriculture, expansion of forest departments and the rise of conservation, resettlement, privatization and commoditization of land and land-based production, and expansion of market infrastructure and the promotion of industrial agriculture. In addition we note a growing trend toward a transition from rural to urban livelihoods and expanding urban-labor markets

Hardness Comparison of Polymer Specimens Produced with Different Processes

Development of new effective laboratory experiences to extend and reinforce knowledge from lectures plays an essential role in engineering technology education. This paper will address a set of labs based on hardness testing. A common mechanical property test, hardness testing measures the indent penetration or other surface characteristics of materials based on the hardness test type. The laboratory procedures and the testing specimens follow appropriate standards for materials testing. In an introductory materials course for the manufacturing and mechanical engineering technology degree programs at the campuses of Purdue University, polymer specimens are tested for their Shore Durometer hardness. The quality and manufacture of the specimens directly affects the final hardness test results. To help students understand this polymer property and the importance of the specimens’ respective manufacturing processes, samples made of the same material and size, but by different production methods were evaluated. Student tasks spanned polymer specimen design, processing, testing, and analysis. Sample production approaches and comparison of hardness values corresponding to each process are discussed for several polymer materials. Changes in student understanding of variability and their interest in experimental research will be explored