1,609 research outputs found
Use of High Fidelity Fission Models in Criticality Calculations
The use of Monte Carlo, random number sampling, for neutron transport has been used for about half a century. There are many benchmarks that have been used to validate neutronics codes, mostly for critical systems. Critical systems are systems where the neutron population from one generation to the next is the same. Subcriticality is when there are less neutrons in the next generation and supercriticality is when there are more neutrons in the next generation than there were in the previous. To calculate criticality, a set number of neutrons are started in a system. Those neutrons interact and the number that were created for the next cycle are compared to that of the previous cycle. This is done for a certain amount of cycles after the source has converged, which is necessary due to the stochastic nature. Another method of tracking neutrons is called a fixed source problem. In this case the neutrons are only tracked from start to finish and can be useful in dosimetry cases. This method relies on all the particles ultimately being captured, by larger nuclei, or leaking out of the system. For a critical or supercritical systems this may be impossible, due to the divergence of the neutron population. Therefore, it was proposed to use the previously mentioned method for neutron transport. This allows for the use of high fidelity fission event models. This would allow for more accurate fission event modeling and thus results for these fission events
An exploration of heart rate and perceived exertion differences between class and competition in freestyle-disco dance
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US and UK Routes to Employment: Strategies to Improve Integrated Service Delivery to People with Disabilities
In this report, the authors examine the experience of the United States and United Kingdom in developing effective strategies for providing integrated service delivery. The report examines what works and what doesn't work, and provides a roadmap to improving services for individuals with disabilities. While more research is needed, the report identifies 12 strategies to strengthen integrated service delivery systems, and to assist individuals with disabilities in gaining and maintaining productive employment. Implementing these strategies can benefit clients, who have the opportunity to realize their potential more fully; the taxpayer, who is paying less for disability assistance; and society at large, which gains the productive skill of talented individuals
Experimental investigation of optical atom traps with a frequency jump
We study the evolution of a trapped atomic cloud subject to a trapping
frequency jump for two cases: stationary and moving center of mass. In the
first case, the frequency jump initiates oscillations in the cloud's momentum
and size. At certain times we find the temperature is significantly reduced.
When the oscillation amplitude becomes large enough, local density increases
induced by the anharmonicity of the trapping potential are observed. In the
second case, the oscillations are coupled to the center of mass motion through
the anharmonicity of the potential. This induces oscillations with even larger
amplitudes, enhancing the temperature reduction effects and leading to
nonisotropic expansion rates while expanding freely.Comment: 8 figures, Journal of Physics B: At. Mol. Op. Phy
Landlord Tenant Relations: A Report of the Landlord Tenant Relations Subcommittee of the North-Central Regional Land Tenure Committee
The magnitude and characteristics of the population of cancer survivors: Using populationbased estimates of cancer prevalence to inform service planning for survivorship care
© 2014 Sharp et al. Background: Rising cancer incidence and survival mean that the number of cancer survivors is growing. Accumulating evidence suggests many survivors have long-term medical and supportive care needs, and that these needs vary by survivors' socio-demographic and clinical characteristics. To illustrate how cancer registry data may be useful in survivorship care service planning, we generated population-based estimates of cancer prevalence in Ireland and described socio-demographic and clinical characteristics of the survivor population. Methods: Details of people diagnosed with invasive cancer (ICD10 C00-C96) during 1994-2011, and who were still alive on 31/12/2011, were abstracted from the National Cancer Registry, and tabulated by cancer site, sex, current age, marital status, initial treatment, and time since diagnosis. Associations were investigated using chi-square tests. Results: After excluding non-melanoma skin cancers, 17-year cancer prevalence in Ireland was 112,610 (females: 58,054 (52%) males: 54,556 (48%)). The four most prevalent cancers among females were breast (26,066), colorectum (6,598), melanoma (4,593) and uterus (3,505) and among males were prostate (23,966), colorectum (8,207), lymphoma (3,236) and melanoma (2,774). At the end of 2011, 39% of female survivors were aged <60 and 35% were ≥70 compared to 25% and 46% of males (p < 0.001). More than half of survivors of bladder, colorectal and prostate cancer were ≥70. Cancers with the highest percentages of younger (<40) survivors were: testis (50%); leukaemia (females: 28%; males: 22%); cervix (20%); and lymphoma (females: 19%; males: 20%). Fewer female (57%) than male (64%) survivors were married but the percentage single was similar (17-18%). More female (25%) than male survivors (18%; p < 0.001) were ≥10 years from diagnosis. Overall, 69% of survivors had undergone cancer-directed surgery, and 39%, 32% and 18% had received radiotherapy, chemotherapy and hormone therapy, respectively. These frequencies were higher among females than males (surgery: 82%, 54%; radiotherapy: 42%, 35%; chemotherapy: 40%, 22%; hormone therapy: 23%, 13%). Conclusions: These results reveal the socio-demographic and clinical heterogeneity of the survivor population, and highlight groups which may have specific medical and supportive care needs. These types of population-based estimates may help decision-makers, planners and service providers to develop follow-up and after-care services to effectively meet survivors' needs
Palliative care and Parkinson's disease : meeting summary and recommendations for clinical research
Introduction: Palliative care is an approach to caring for patients and families affected by serious illnesses that focuses on the relief of suffering through the management of medical symptoms, psychosocial issues, advance care planning and spiritual wellbeing. Over the past decade there has been an emerging clinical and research interest in the application of palliative care approaches to Parkinson’s disease (PD) and outpatient palliative care services are now offered by several movement disorders centers. Methods: An International Working Group Meeting on PD and Palliative Care supported by the Parkinson’s Disease Foundation was held in October 2015 to review the current state of the evidence and to make recommendations for clinical research and practice. Results: Topics included: 1) Defining palliative care for PD; 2) Lessons from palliative care for heart failure and other chronic illnesses; 3) Patient and caregiver Needs; 4) Needs assessment tools; 5) Intervention strategies; 6) Predicting prognosis and hospice referrals; 7) Choice of appropriate outcome measures; 8) Implementation, dissemination and education research; and 9) Need for research collaborations. We provide an overview of these discussions, summarize current evidence and practices, highlight gaps in our knowledge and make recommendations for future research. Conclusions: Palliative Care for PD is a rapidly growing area which holds great promise for improving outcomes for PD patients and their caregivers. While clinical research in this area can build from lessons learned in other diseases, there is a need for observational, methodological and interventional research to address the unique needs of PD patients and caregivers
Itinerant G-type antiferromagnet SrCr2As2 studied by magnetization, heat capacity, electrical resistivity, and NMR measurements
The physical properties of itinerant antiferromagnetic (AFM) SrCrAs
with body-centered tetragonal ThCrSi structure were investigated in
single crystalline and polycrystalline forms by electrical resistivity ,
heat capacity , magnetic susceptibility versus
temperature~ and magnetization versus applied magnetic field
isotherm measurements as well as As and Cr nuclear magnetic
resonance (NMR) measurements in the wide temperature range = 1.6--900 K.
From the and As NMR measurements, the G-type AFM state below
= 615(15) K has been determined, consistent with the previous
neutron-diffraction measurements. Direct evidence of magnetic ordering of the
Cr spins was shown by the observation of the Cr NMR spectrum under =
0. From the measurements on single-crystal SrCrAs under the
two different magnetic field directions and in the AFM state,
the Cr ordered moments are shown to align along the axis in the G-type AFM
state. The metallic state is directly evidenced by the , , and
NMR measurements, and the density of states at the Fermi energy in the AFM state is estimated to be 7.53 states/eV f.u. for both
spin directions which is almost twice the bare estimated
from first-principles calculations, suggesting an enhancement of the
conduction-carrier mass by a factor of two in the AFM state. The is found to be nearly constant below at least 100 K and is
independent of . The is found to show -linear behavior above
and exhibits positive curvature below where significant
loss of spin-disorder scattering upon magnetic ordering is observed.Comment: 14 pages, 12 figures, accepted for publication in Phys. Rev.
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