Development of mechanized ultrasonic scanning system

Mechanized ultrasonic scanning system for testing butt welds in large aluminum propellant tank

Research and development of the dry tape battery concept Quarterly report no. 2, 9 Sep. - 8 Dec. 1965

Magnesium-aluminum chloride, hydrogen chloride- trichlorotriazinetrione system for dry tape batterie

Has the introduction of “Project Maths” at post-primary level affected the attitudes of first-year higher education engineering students in Ireland?

Mathematics is increasingly a focus of educational studies nationally and internationally, due to the growing need of mathematical skills in today’s technological, economical, and industrial world (European Commission 2011, Conway and Sloane 2005). It is widely known that mathematics is a core subject for science and engineering disciplines. As Project Maths was implemented on a phased basis over a four-year period, our study is directed upon testing the mathematical skills and investigating first year engineering students' attitudes towards mathematics over the course of the implementation. In this paper, we give a detailed overview of the results of a pilot attitudinal survey conducted in 2012 on a cohort of students who studied phase one of Project Maths. Overall, the results show quite a negative attitude towards mathematics, a fact that is naturally of concern among a cohort of engineering students who will rely heavily upon mathematics for the duration of their studies and beyond. Possible reasons for these attitudes will be further investigated in the following years, along with comparisons as to whether there are any improvements in students' mathematical skills and attitudes evident in the data we collect

Non linear finite element simulation of complex bulge forming processes

Bulge forming is a manufacturing process that is becoming increasingly important as a technology that can be used to produce seamless, lightweight and near-net-shape industrial components. The process is being increasingly applied in the automotive and aerospace industries where the demands for increased structural strength and decreased vehicle weight make it a very attractive manufacturing method. This work is concerned with increasing knowledge of the deformation mechanisms during bulge forming processes using numerical simulation. A number of complex bulge forming operations which have not been satisfactorily analysed in published research were identified and subsequently analysed using commercial finite element software. A non-linear explicit solution method was used in each case. The processes chosen for simulation were: hydraulic bulge forming of cross joints, bulge forming using a solid bulging medium, bulge forming of bimetallic tubes and the behaviour of the die during these bulge forming processes. In each case a number of process parameters were varied and their effect on the process identified. Where possible the finite element results were validated against results from experimental trials. It was found that the simulations predicted the experimental results with accuracy, thus indicating that the models developed here can be used with confidence to predict the behaviour of bulge forming operations. From the results of the finite element simulations it was concluded that when designing processes to bulge form cross joint components that compressive axial loading should be used in conjunction with pressure loading where possible, friction between the die and workpiece should be kept to a minimum where maximum branch height is required and greater tube thickness should be used when seeking to reduce stress and thinning behaviour in the formed component. The results also indicate that, where possible a solid bulging medium should be used as it results in much more favorable forming conditions, which can allow the realisation of greater branch heights. The simulations of bulge forming of bimetallic tubes showed that the relative thickness of the two metal layers has a significant effect on the shape of the final component. It was also found that varying the relative strength of the two metallic layers had a significant effect on the branch height obtained. The development of stress in the die during various bulge forming process was detailed at various stages during the process. It was found that generally a stress concentration moves towards the die bend as the process progresses. The effect of using different die materials was examined and it was concluded that certain materials are unsuitable for use as die materials due to the fact that their yield stress is exceeded during the forming process

Research and development of the dry tape battery concept Quarterly report no. 1, 9 Jun. - 8 Sep. 1965

Cell discharge measurements for dry tape battery couple - anode and cathode development in aqueous and nonaqueous electrolyte

Pennsylvania Folklife Vol. 26, No. 2

• Battalion Day: Militia Exercise and Frolic in Pennsylvania Before the Civil War • Folklore in the Library: Cherished Memories of Old Lancaster • Widows\u27 Wills for Philadelphia County, 1750-1784: A Study of Pennsylvania German Folklife • Forest County Lore • The Big Valley Amish of Central Pennsylvania: A Community of Cultural Contrasts • Maurice A. Mook (1904-1973): An Appreciation • Collectanea: Ore-Mining and Basket-Making in Maxatawny ; The Sharadin Tannery at Kutztown ; Occult Lore Recorded in Cumberland County • German Immigrants in America as Presented in Travel Accounts • The Pie and Related Forms in Pennsylvania Cuisine: Folk-Cultural Questionnaire No. 46https://digitalcommons.ursinus.edu/pafolklifemag/1071/thumbnail.jp

Scaling behavior of self-avoiding walks on percolation clusters

The scaling behavior of self-avoiding walks (SAWs) on the backbone of percolation clusters in two, three and four dimensions is studied by Monte Carlo simulations. We apply the pruned-enriched Rosenbluth chain-growth method (PERM). Our numerical results bring about the estimates of critical exponents, governing the scaling laws of disorder averages of the end-to-end distance of SAW configurations. The effects of finite-size scaling are discussed as well.Comment: 6 page

Ethnic differences in hepatitis A and E virus seroprevalence in patients attending the Emergency Department, Paramaribo, Suriname

Background Hepatitis A virus (HAV) and hepatitis E virus (HEV) have enteric modes of transmission and are common causes of acute hepatitis in low- and middle-income countries. HEV is also characterised as a zoonotic infection and is prevalent in high-income countries. Data on HAV and HEV prevalence in Suriname, a middle-income country in South America, are scarce. Methods Serum samples of 944 and 949 randomly selected patients attending the Emergency Department at the Academic Hospital of Paramaribo, the capital of Suriname, were analysed for anti-HAV antibodies (anti-HAV) and anti-HEV antibodies (anti-HEV), respectively. Determinants of anti-HAV and anti-HEV positive serology were evaluated using multivariable logistic regression. Results Anti-HAV prevalence was 58.3% (95% CI 55.4 to 61.4%) and higher prevalence was independently associated with belonging to the Tribal or Indigenous population and older age. Anti-HEV prevalence was 3.7% (95% CI 2.6 to 5.0%) and higher prevalence was associated with Tribal and Creole ethnicity and older age. Conclusions In Suriname, exposure to HAV is consistent with a very low endemic country and exposure to HEV was rare. Both viruses were more prevalent in specific ethnic groups. As anti-HAVantibodies were less frequently found in younger individuals, they could be susceptible to potential HAV outbreaks and might require HAV vaccination.Immunogenetics and cellular immunology of bacterial infectious disease

Differential trajectories of hypometabolism across cognitively-defined Alzheimer’s disease subgroups

Disentangling biologically distinct subgroups of Alzheimer’s disease (AD) may facilitate a deeper understanding of the neurobiology underlying clinical heterogeneity. We employed longitudinal [18F]FDG-PET standardized uptake value ratios (SUVRs) to map hypometabolism across cognitively-defined AD subgroups. Participants were 384 amyloid-positive individuals with an AD dementia diagnosis from ADNI who had a total of 1028 FDG-scans (mean time between first and last scan: 1.6 ± 1.8 years). These participants were categorized into subgroups on the basis of substantial impairment at time of dementia diagnosis in a specific cognitive domain relative to the average across domains. This approach resulted in groups of AD-Memory (n = 135), AD-Executive (n = 8), AD-Language (n = 22), AD-Visuospatial (n = 44), AD-Multiple Domains (n = 15) and AD-No Domains (for whom no domain showed substantial relative impairment; n = 160). Voxelwise contrasts against controls revealed that all AD-subgroups showed progressive hypometabolism compared to controls across temporoparietal regions at time of AD diagnosis. Voxelwise and regions-of-interest (ROI)-based linear mixed model analyses revealed there were also subgroup-specific hypometabolism patterns and trajectories. The AD-Memory group had more pronounced hypometabolism compared to all other groups in the medial temporal lobe and posterior cingulate, and faster decline in metabolism in the medial temporal lobe compared to AD-Visuospatial. The AD-Language group had pronounced lateral temporal hypometabolism compared to all other groups, and the pattern of metabolism was also more asymmetrical (left < right) than all other groups. The AD-Visuospatial group had faster decline in metabolism in parietal regions compared to all other groups, as well as faster decline in the precuneus compared to AD-Memory and AD-No Domains. Taken together, in addition to a common pattern, cognitively-defined subgroups of people with AD dementia show subgroup-specific hypometabolism patterns, as well as differences in trajectories of metabolism over time. These findings provide support to the notion that cognitively-defined subgroups are biologically distinct

Detection of blast-related traumatic brain injury in U.S. military personnel

BACKGROUND: Blast-related traumatic brain injuries have been common in the Iraq and Afghanistan wars, but fundamental questions about the nature of these injuries remain unanswered. METHODS: We tested the hypothesis that blast-related traumatic brain injury causes traumatic axonal injury, using diffusion tensor imaging (DTI), an advanced form of magnetic resonance imaging that is sensitive to axonal injury. The subjects were 63 U.S. military personnel who had a clinical diagnosis of mild, uncomplicated traumatic brain injury. They were evacuated from the field to the Landstuhl Regional Medical Center in Landstuhl, Germany, where they underwent DTI scanning within 90 days after the injury. All the subjects had primary blast exposure plus another, blast-related mechanism of injury (e.g., being struck by a blunt object or injured in a fall or motor vehicle crash). Controls consisted of 21 military personnel who had blast exposure and other injuries but no clinical diagnosis of traumatic brain injury. RESULTS: Abnormalities revealed on DTI were consistent with traumatic axonal injury in many of the subjects with traumatic brain injury. None had detectible intracranial injury on computed tomography. As compared with DTI scans in controls, the scans in the subjects with traumatic brain injury showed marked abnormalities in the middle cerebellar peduncles (P<0.001), in cingulum bundles (P = 0.002), and in the right orbitofrontal white matter (P = 0.007). In 18 of the 63 subjects with traumatic brain injury, a significantly greater number of abnormalities were found on DTI than would be expected by chance (P<0.001). Follow-up DTI scans in 47 subjects with traumatic brain injury 6 to 12 months after enrollment showed persistent abnormalities that were consistent with evolving injuries. CONCLUSIONS: DTI findings in U.S. military personnel support the hypothesis that blast-related mild traumatic brain injury can involve axonal injury. However, the contribution of primary blast exposure as compared with that of other types of injury could not be determined directly, since none of the subjects with traumatic brain injury had isolated primary blast injury. Furthermore, many of these subjects did not have abnormalities on DTI. Thus, traumatic brain injury remains a clinical diagnosis. (Funded by the Congressionally Directed Medical Research Program and the National Institutes of Health; ClinicalTrials.gov number, NCT00785304.