258 research outputs found
Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C
Ion implantation of Mn ions into hole-doped GaP has been used to induce
ferromagnetic behavior above room temperature for optimized Mn concentrations
near 3 at.%. The magnetism is suppressed when the Mn dose is increased or
decreased away from the 3 at.% value, or when n-type GaP substrates are used.
At low temperatures the saturated moment is on the order of one Bohr magneton,
and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the
magnetization provides an estimate Tc = 385K of the Curie temperature that
exceeds the experimental value, Tc = 270K. The presence of ferromagnetic
clusters and hysteresis to temperatures of at least 330K is attributed to
disorder and proximity to a metal-insulating transition.Comment: 4 pages, 4 figures (RevTex4
Modeling Heatshield Erosion Due to Dust Particle Impacts for a Martian Entry Vehicle
Because planetary missions to Mars take years from initial design to arrival at Mars, and because of the unpredictability of major global dust storms, the de-sign of the thermal protection system (TPS) of a Mars entry vehicle requires an estimation for the potential damage caused by dust particle impacts on the heat-shield. This paper will review previous analytical and experimental approaches to modeling dust particle ero-sion and will compare the legacy models against more modern computational techniques and new dust ero-sion models that will be based on upcoming experi-ments in the German Aerospace Center (DLR) GBK facility. The various models will be compared by incorporating them into the Icarus material response code applied to a representative vehicle entering the Martian atmosphere
Разработка технологии автоматической сварки под слоем флюса тавровых балок на установке Corimpex
Объектом исследования является обзор существующих способов сварки тавровых балок и разработка новой технологии сварки тавровых балок под слоем флюса на автоматической сварочной линии.
В результате проведенного исследования была разработана технология автоматической сварки тавровых балок под слоем флюса и технология правки остаточных деформаций балок непосредственно в процессе сварки, составлена циклограмма и маршрутно-операционная карта процесса сварки.The object of research is a review of existing methods of T-beam welding and the development of a new technology for T-beam welding on an automatic welding line.
As a result of the research, the technology of automatic submerged arc T-beam welding and the technology of correcting residual beam deformations directly in the welding process was developed, a cyclogram and operating map of the welding process was compiled
Повышение надежности линейной части магистрального газопровода
Цель работы – повышение надежности линейной части магистрального газопровода путем проведение капитального ремонта участка газопровода 372 – 383 км. Задачи работы: обоснование необходимости проведения капитального ремонта участка газопровода; разработка технологии проведения капитального ремонта маги-стрального газопровода; провести расчеты толщены стенки трубы, проверка трубопро-вода на прочность, проверка трубопровода на пластические деформации.The aim of the work is to increase the reliability of the linear part of the main gas pipeline by overhauling the section of the 372 - 383 km gas pipeline. Work tasks: necessity substantiation for major overhaul of the gas pipeline section; technologies for capital repairs of the mainstream gas pipeline development; Calculate the pipes wall thickness, check the pipeline strength, check the pipeline for plastic deformation
Production Trends, Collaboration, and Main Topics of the Integrative and Complementary Oncology Research Area: A Bibliometric Analysis
Background: The prevalence of cancer has increased over time worldwide. Nevertheless, the number of deaths has been
reduced during the past 2 decades. Thus, one-third of the cancer patients are users of complementary and alternative
therapies, looking for other types of interventions. The main aim of the present study is to understand the current status of
the research in integrative and complementary oncology. Three different aspects were analyzed: production trends, country
collaboration, and leading research topics. Methods: The dataset was obtained from the documents indexed under the
Integrative and Complementary Medicine category of the Web of Science database from 1976 to 2017. VOSviewer and
SciMAT software were employed to perform the bibliometric analysis. Results: The Journal of Ethnopharmacology, China
Medical University and the People’s Republic of China are the leading producers in the field. Regarding the collaboration,
the United States and China present a close connection. The scientific community is focused on the following topics:
apoptosis, breast cancer, oxidative stress, chemotherapy, and nuclear factor-Kappa-B (NF-Kappa-B). Conclusions: The
present article shows potentially important information that allows understanding of the past, present, and future of
research in integrative and complementary oncology. It is a useful evidence-based framework on which to base future
research actions and academic directions
Global and regional trends in particulate air pollution and attributable health burden over the past 50 years
Long-term exposure to ambient particulate matter (PM2.5, mass of particles with an aerodynamic dry diameter of < 2.5 μm) is a major risk factor to the global burden of disease. Previous studies have focussed on present day or future health burdens attributed to ambient PM2.5. Few studies have estimated changes in PM2.5 and attributable health burdens over the last few decades, a period where air quality has changed rapidly. Here we used the HadGEM3-UKCA coupled chemistry-climate model, integrated exposure-response relationships, demographic and background disease data to provide the first estimate of the changes in global and regional ambient PM2.5 concentrations and attributable health burdens over the period 1960 to 2009. Over this period, global mean population-weighted PM2.5 concentrations increased by 38%, dominated by increases in China and India. Global attributable deaths increased by 89% to 124% over the period 1960 to 2009, dominated by large increases in China and India. Population growth and ageing contributed mostly to the increases in attributable deaths in China and India, highlighting the importance of demographic trends. In contrast, decreasing PM2.5 concentrations and background disease dominated the reduction in attributable health burden in Europe and the United States. Our results shed light on how future projected trends in demographics and uncertainty in the exposure–response relationship may provide challenges for future air quality policy in Asia
Reduced-Order Modeling of Turbulent Reacting Flows with Application to Ramjets and Scramjets
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90621/1/AIAA-50272-117.pd
Simulation of a Shear Coaxial GO2/GH2 Rocket Injector with DES and LES Using Flamelet Models
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97098/1/AIAA2012-3744.pd
- …