305 research outputs found
REACTIVITY EFFECTS OF STRUCTURAL MATERIALS IN THE BEM-II B
Reactivity effects of 93.2% enriched oralloy, molybdenum, iron, niobium, 310 stainless steel, 304 stainless steel, Inconel X, FeC rAl, zirconium, nickel, nichrome V, and chromium clad with FeCrAl, in the form of foils in the center cell of the BEM-II B minimum void, beryllium moderated critical experiment are reported. Nineteen-energy-level diffusion calculations with cell corrections from both coarse and fine energy detail were correlated with the measurements. The fine energy detail improved the correlation, mainly because resonance self- shielding and flux depression are more adequately treated, and residual discrepancies for the most part can be attributed to inadequacies in the cross section data. (auth
Percolative nature of the transition from 60 K to 90 K phase in YBa2Cu3O6+d
We have measured the heat capacity of YBa2Cu3O6+d for 0.7<d<0.8 between 1.8
and 300K. It was found that doping dependences of specific heat jump and
temperature of heat capacity jump contradict to the assumption of spatially
homogeneous electronic density. The results suggest that the transition from
60K to 90K phase has a percolative nature and the structure of underdoped 60K
phase can be considered as array of superconducting nanoclusters embedded in
the insulating matrix.Comment: Submitted to proceedings of M2S-IX 2009, Tokyo (Physica C
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Improving analytical understanding through the addition of information: Bayesian and hybrid mathematics approaches
Safety analysts frequently must provide results that are based on sparse (or even no) data. When data (or more data) become available, it is important to utilize the new information optimally in improving the analysis results. Two methods for accomplishing this purpose are Bayesian analysis, where "prior" probability distributions are modified to become "posterior" distributions based on the new data, and hybrid (possibilistic/probabilistic analysis) where possibilistic "membership" portrays the subjectivity involved and the probabilistic analysis is "frequentist." Each of these approaches has interesting features, and it is advantageous to compare and contrast the two. In addition to describing and contrasting these two approaches, we will discuss how features of each can be combined to give new advantages neither offers by itself
Synchronous N-S and E-W extension at the Tibet-to-Himalaya transition in NW Bhutan
Despite ~50 Myr of continuous continent-continent collision, contractional structures in the Himalayan-Tibetan orogen are today limited to the northern and southern margins of the system, while extension dominates much of the interior. On the Tibetan Plateau, Cenozoic E-W extension has been accommodated by strike-slip faults and extensional grabens, while N-S extension at the Tibet-to-Himalaya transition has been accommodated by the South Tibetan fault system (STFS). The genetic relationship between N-S and E-W extension is disputed, although age constraints indicate temporal overlap of at least 7 Myr. In NW Bhutan the two intersect where the STFS basal detachment is cut by the Yadong cross structure (YCS), an extensional half graben that provides a rare opportunity to constrain relative timings. We report U-Pb zircon dates from four STFS footwall leucogranites consistent with episodic magmatism during the middle-late Miocene and in situ U(-Th)-Pb monazite and xenotime dates from three metasedimentary rocks ranging from late Oligocene to middle Miocene. We suggest that amphibolite facies footwall metamorphism was ongoing at the time the basal STFS detachment initiated as a ductile structure in the middle-late Miocene. Late-stage granitic intrusions may reflect footwall melting during extensional exhumation along the STFS, but post-metamorphic and post-intrusion fabrics suggest that most displacement occurred after emplacement of the youngest granites. Some of the oldest YCS-related fabrics are found in a deformed 14 Ma leucogranite, implying middle Miocene ductile deformation. This observation, along with evidence for subsequent brittle YCS deformation, suggests that N-S and E-W extensional structures in the area had protracted and overlapping deformation histories
Genomic medicine without borders: which strategies should developing countries employ to invest in precision medicine? A new "fast-second winner" strategy
Genomic medicine has greatly matured in terms of its technical capabilities, but the diffusion of genomic innovations worldwide faces significant barriers beyond mere access to technology. New global development strategies are sorely needed for biotechnologies such as genomics and their applications toward precision medicine without borders. Moreover, diffusion of genomic medicine globally cannot adhere to a “one-size-fits-all-countries” development strategy, in the same way that drug treatments should be customized. This begs a timely, difficult but crucial question: How should developing countries, and the resource-limited regions of developed countries, invest in genomic medicine? Although a full-scale investment in infrastructure from discovery to the translational implementation of genomic science is ideal, this may not always be feasible in all countries at all times. A simple “transplantation of genomics” from developed to developing countries is unlikely to be feasible. Nor should developing countries be seen as simple recipients and beneficiaries of genomic medicine developed elsewhere because important advances in genomic medicine have materialized in developing countries as well. There are several noteworthy examples of genomic medicine success stories involving resource-limited settings that are contextualized and described in this global genomic medicine innovation analysis. In addition, we outline here a new long-term development strategy for global genomic medicine in a way that recognizes the individual country's pressing public health priorities and disease burdens. We term this approach the “Fast-Second Winner” model of innovation that supports innovation commencing not only “upstream” of discovery science but also “mid-stream,” building on emerging highly promising biomarker and diagnostic candidates from the global science discovery pipeline, based on the unique needs of each country. A mid-stream entry into innovation can enhance collective learning from other innovators' mistakes upstream in discovery science and boost the probability of success for translation and implementation when resources are limited. This à la carte model of global innovation and development strategy offers multiple entry points into the global genomics innovation ecosystem for developing countries, whether or not extensive and expensive discovery infrastructures are already in place. Ultimately, broadening our thinking beyond the linear model of innovation will help us to enable the vision and practice of genomics without borders in both developed and resource-limited settings
Relativistic versus Nonrelativistic Optical Potentials in A(e,e'p)B Reactions
We investigate the role of relativistic and nonrelativistic optical
potentials used in the analysis of () data. We find that the
relativistic calculations produce smaller () cross sections even in the
case in which both relativistic and nonrelativistic optical potentials fit
equally well the elastic proton--nucleus scattering data. Compared to the
nonrelativistic impulse approximation, this effect is due to a depletion in the
nuclear interior of the relativistic nucleon current, which should be taken
into account in the nonrelativistic treatment by a proper redefinition of the
effective current operator.Comment: Added one new figure, the formalism section has been enlarged and the
list of references updated. Added one appendix. This version will appear in
Phys. Rev. C. Revtex 3.0, 6 figures (not included). Full postscript version
of the file and figures available at
http://www.nikhefk.nikhef.nl/projects/Theory/preprints
The Effects of Disorder on the Quantum Hall State
A disorder-averaged Hartree-Fock treatment is used to compute the density of
single particle states for quantum Hall systems at filling factor . It
is found that transport and spin polarization experiments can be simultaneously
explained by a model of mostly short-range effective disorder. The slope of the
transport gap (due to quasiparticles) in parallel field emerges as a result of
the interplay between disorder-induced broadening and exchange, and has
implications for skyrmion localization.Comment: 4 pages, 3 eps figure
Hurricane Florence and suicide mortality in North Carolina: A controlled interrupted time-series analysis
Background Natural disasters are associated with increased mental health disorders and suicidal ideation; however, associations with suicide deaths are not well understood. We explored how Hurricane Florence, which made landfall in September 2018, may have impacted suicide deaths in North Carolina (NC). Methods We used publicly available NC death records data to estimate associations between Hurricane Florence and monthly suicide death rates using a controlled, interrupted time series analysis. Hurricane exposure was determined by using county-level support designations from the Federal Emergency Management Agency. We examined effect modification by sex, age group, and race/ethnicity. Results 8363 suicide deaths occurred between January 2014 and December 2019. The overall suicide death rate in NC between 2014 and 2019 was 15.53 per 100 000 person-years (95% CI 15.20 to 15.87). Post-Hurricane, there was a small, immediate increase in the suicide death rate among exposed counties (0.89/100 000 PY; 95% CI -2.69 to 4.48). Comparing exposed and unexposed counties, there was no sustained post-Hurricane Florence change in suicide death rate trends (0.02/100 000 PY per month; 95% CI -0.33 to 0.38). Relative to 2018, NC experienced a statewide decline in suicides in 2019. An immediate increase in suicide deaths in Hurricane-affected counties versus Hurricane-unaffected counties was observed among women, people under age 65 and non-Hispanic black individuals, but there was no sustained change in the months after Hurricane Florence. Conclusions Although results did not indicate a strong post-Hurricane Florence impact on suicide rates, subgroup analysis suggests differential impacts of Hurricane Florence on several groups, warranting future follow-up
Innovations in suicide prevention research (INSPIRE): a protocol for a population-based case–control study
Background Suicide deaths have been increasing for the past 20 years in the USA resulting in 45 979 deaths in 2020, a 29% increase since 1999. Lack of data linkage between entities with potential to implement large suicide prevention initiatives (health insurers, health institutions and corrections) is a barrier to developing an integrated framework for suicide prevention. Objectives Data linkage between death records and several large administrative datasets to (1) estimate associations between risk factors and suicide outcomes, (2) develop predictive algorithms and (3) establish long-term data linkage workflow to ensure ongoing suicide surveillance. Methods We will combine six data sources from North Carolina, the 10th most populous state in the USA, from 2006 onward, including death certificate records, violent deaths reporting system, large private health insurance claims data, Medicaid claims data, University of North Carolina electronic health records and data on justice involved individuals released from incarceration. We will determine the incidence of death from suicide, suicide attempts and ideation in the four subpopulations to establish benchmarks. We will use a nested case–control design with incidence density-matched population-based controls to (1) identify short-term and long-term risk factors associated with suicide attempts and mortality and (2) develop machine learning-based predictive algorithms to identify individuals at risk of suicide deaths. Discussion We will address gaps from prior studies by establishing an in-depth linked suicide surveillance system integrating multiple large, comprehensive databases that permit establishment of benchmarks, identification of predictors, evaluation of prevention efforts and establishment of long-term surveillance workflow protocols
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
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