114 research outputs found
Technology Transition-Opportunities and Progress
Don Thompson in his introductory remarks, and many other speakers since then, have talked to the needs for NDE. These fall into three major categories: reliability of the complex constructs that seem increasingly to pervade our civilization; the role of NDE as an important factor in what I might call a rational approach to a conservation ethic or a total life cycle cost approach to systems;and the use of NDE as a tool for lower cost production. If we accept the validity of these and other needs let us consider the challenge posed by our keynote speaker
New Technology from ARPA/AFML
My purpose in this talk is to introduce the Poster Session that follows. We believe that most of the work presented in that session is ready for the next step of development. One of the key elements in this step is to find the window which can make use of these ·new pieces of technology. I truly appreciate the opportunity to hear the talks from the Air Force, Navy, and the Army which will help to identify some of these slots. I\u27d like to give a bit of our program philosophy that is important in this regard. On Wednesday, you heard so.e of the fundamentals of the ultrasonic work that we have been doing; work that has resulted in procedures which now are capable of producing .numbers that characterize a defect. In achieving this capability, there are a number of improvements in various elements of the ultrasonic apparatus that have a .useful identity of their own, i.e., they have a spinoff capability. Those are the elements that we wish to talk about this morning and to identify as having reached a proof-of-principle plateau, and, if you will, are ready now for the next question. In the context of Dr. Frank Kelley\u27s remarks and the needs identified by the Tri-Services, we must now seek to put them into specific problems for evaluation. As indicated also by Dr. Kelley, this is a very important step in developing a technology flow within the DoD. However, research must continue in order that future results may also be harvested. With this background in mind, I\u27d like to introduce some of the topics that you\u27ll see in the Poster Session that have been developed under ARPA/AFML sponsorship
The Middle Ground of the NDE R&D Spectrum
Our keynote talk today has several objectives: First, we want to call attention, as some of us have before, to the interdisciplinary nature of NDE science and technology and some approaches for fostering R&D in such a situation. Next, we want to describe the objective of the DARPA, Air Force (and now Navy) core program for developing a science base for NDE and how it has evolved during the past two years. Some changes have indeed taken place; we feel that they were both necessary and evolutionary. Many of you are probably familiar with these changes by now but there may be some residual concerns or questions in your minds. Since I was the initiating influence behind most of them, it is appropriate for you to hear me say what they are and what they arenât, and to have an opportunity to question us. Finally and most importantly, we want to enlist your participation in the difficult task of identifying exploratory development programsâand we will try to define this termâwhich will benefit from the growing science base that all of us are helping to develop. We hope to stimulate the interaction between people such as you and the consumers of the evolving NDE technology in order to identify reduction-to-practice possibilities that should be pursued
Metal matrix composite materials
COMPOSITF materials, especially metal matrix composite
materials are possible substitutes for metals in use today. However, because they can possess extremely high strengths, moduli and excellent high temperature prop-erties they may be employed most profitably in applicat-ions which do not presently exist,since no present mat-erial has the required capabilities.In addition, their present high cost and very early stage of development
make them unlikely candidates for materials substitut-
ion in the context of this meeting. This paper is orie-nted more towards the development of composite materials for aerospace structures
Development of a neutron radiography simulation model
Measurement models of NDE techniques have been developed with the purpose of proving the capabilities of NDE techniques for finding flaws. The models take NDE parameters such as ultrasonic frequency, probe diameter, and angle of incidence, and predict the response from the flaw. Models are also a part of quantitative NDE, i.e., the ability to size and characterize flaws and or materials
Deindustrialization in cities of the global south
Recent research by economists has shown that deindustrialization is more severe in Sub-Saharan Africa and Latin America than it ever was in the Organisation for Economic Co-operation and Development (OECD). Nevertheless, most research on deindustrialization is focused on the former centres of Fordist manufacturing in the industrial heartlands of the North Atlantic. In short, there is a mismatch between where deindustrialization is researched and where it is occurring, and the objective of this paper is to shift the geographical focus of research on deindustrialization to the Global South. Case studies from Argentina, India, Tanzania and Turkey demonstrate the variegated nature of deindustrialization beyond the North Atlantic. In the process, it is demonstrated that cities in the Global South can inform wider theoretical discussions on the impacts of deindustrialization at the urban scale
Ambient air pollution and the prevalence of rhinoconjunctivitis in adolescents: A worldwide ecological analysis
Whether exposure to outdoor air pollution increases the prevalence of rhinoconjunctivitis in children is unclear. Using data from Phase Three of the International Study of Asthma and Allergies in childhood (ISAAC), we investigated associations of rhinoconjunctivitis prevalence in adolescents with model-based estimates of ozone, and satellite-based estimates of fine (diameterâ<â2.5 ÎŒm) particulate matter (PM2.5) and nitrogen dioxide (NO2). Information on rhinoconjunctivitis (defined as self-reported nose symptoms without a cold or flu accompanied by itchy watery eyes in the past 12 months) was available on 505,400 children aged 13â14 years, in 183 centres in 83 countries. Centre-level prevalence estimates were calculated and linked geographically with estimates of long-term average concentrations of NO2, ozone and PM2.5. Multi-level models were fitted adjusting for population density, climate, sex and gross national income. Information on parental smoking, truck traffic and cooking fuel was available for a restricted set of centres (77 in 36 countries). Between centres within countries, the estimated change in rhinoconjunctivitis prevalence per 100 children was 0.171 (95% confidence interval: ââ0.013, 0.354) per 10% increase in PM2.5, 0.096 (ââ0.003, 0.195) per 10% increase in NO2 and ââ0.186 (ââ0.390, 0.018) per 1 ppbV increase in ozone. Between countries, rhinoconjunctivitis prevalence was significantly negatively associated with both ozone and PM2.5. In the restricted dataset, the latter association became less negative following adjustment for parental smoking and open fires for cooking. In conclusion, there were no significant within-country associations of rhinoconjunctivitis prevalence with study pollutants. Negative between-country associations with PM2.5 and ozone require further investigation
Metabolite profiles of medulloblastoma for rapid and non-invasive detection of molecular disease groups
\ua9 2024 The AuthorsBackground: The malignant childhood brain tumour, medulloblastoma, is classified clinically into molecular groups which guide therapy. DNA-methylation profiling is the current classification âgold-standardâ, typically delivered 3â4 weeks post-surgery. Pre-surgery non-invasive diagnostics thus offer significant potential to improve early diagnosis and clinical management. Here, we determine tumour metabolite profiles of the four medulloblastoma groups, assess their diagnostic utility using tumour tissue and potential for non-invasive diagnosis using in vivo magnetic resonance spectroscopy (MRS). Methods: Metabolite profiles were acquired by high-resolution magic-angle spinning NMR spectroscopy (MAS) from 86 medulloblastomas (from 59 male and 27 female patients), previously classified by DNA-methylation array (WNT (n = 9), SHH (n = 22), Group3 (n = 21), Group4 (n = 34)); RNA-seq data was available for sixty. Unsupervised class-discovery was performed and a support vector machine (SVM) constructed to assess diagnostic performance. The SVM classifier was adapted to use only metabolites (n = 10) routinely quantified from in vivo MRS data, and re-tested. Glutamate was assessed as a predictor of overall survival. Findings: Group-specific metabolite profiles were identified; tumours clustered with good concordance to their reference molecular group (93%). GABA was only detected in WNT, taurine was low in SHH and lipids were high in Group3. The tissue-based metabolite SVM classifier had a cross-validated accuracy of 89% (100% for WNT) and, adapted to use metabolites routinely quantified in vivo, gave a combined classification accuracy of 90% for SHH, Group3 and Group4. Glutamate predicted survival after incorporating known risk-factors (HR = 3.39, 95% CI 1.4â8.1, p = 0.025). Interpretation: Tissue metabolite profiles characterise medulloblastoma molecular groups. Their combination with machine learning can aid rapid diagnosis from tissue and potentially in vivo. Specific metabolites provide important information; GABA identifying WNT and glutamate conferring poor prognosis. Funding: Children with Cancer UK, Cancer Research UK, Children\u27s Cancer North and a Newcastle University PhD studentship
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