المؤلفون: J. Snuverink, R. Ainsworth, S. T. Boogert, F. J. Cullinan, A. Lyapin, Y. I. Kim, K. Kubo, S. Kuroda, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa, G. R. White

المصدر: Physical Review Accelerators and Beams, Vol 19, Iss 9, p 091002 (2016)

مصطلحات موضوعية: Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798

الوصف: Wakefields are an important factor in accelerator design, and are a real concern when preserving the low beam emittance in modern machines. Charge dependent beam size growth has been observed at the Accelerator Test Facility (ATF2), a test accelerator for future linear collider beam delivery systems. Part of the explanation of this beam size growth is wakefields. In this paper we present numerical calculations of the wakefields produced by several types of geometrical discontinuities in the beam line as well as tracking simulations to estimate the induced effects. We also discuss precision beam kick measurements performed with the ATF2 cavity beam position monitor system for a test wakefield source in a movable section of the vacuum chamber. Using an improved model independent method we measured a wakefield kick for this movable section of about 0.49 V/pC/mm, which, compared to the calculated value from electromagnetic simulations of 0.41 V/pC/mm, is within the systematic error.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2469-9888Test

الوصول الحر: https://doaj.org/article/4671463eadbe4b7088d60eec62628487Test

المؤلفون: E. Marin, R. Tomás, P. Bambade, K. Kubo, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa, A. Seryi, G. R. White, M. Woodley

المصدر: Physical Review Special Topics. Accelerators and Beams, Vol 17, Iss 2, p 021002 (2014)

مصطلحات موضوعية: Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798

الوصف: The Accelerator Test Facility 2 (ATF2) aims to test the novel chromaticity correction scheme which is implemented in the final focus systems of future linear colliders such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). The ATF2 nominal and ultralow β^{*} lattices are designed to vertically focus the beam at the focal point, or usually referred to as interaction point (IP), down to 37 and 23 nm, respectively. The vertical chromaticities of the nominal and ultralow β^{*} lattices are comparable to those of ILC and CLIC, respectively. When the measured multipole components of the ATF2 magnets are considered in the simulations, the evaluated spot sizes at the IP are well above the design values. In this paper we describe the analysis of the high order aberrations that allows identifying the sources of the observed beam size growth. In order to recover the design spot sizes three solutions are considered, namely final doublet replacement, octupole insertion, and optics modification. Concerning the future linear collider projects, the consequences of magnetic field errors of the focusing quadrupole magnet of the final doublet are also addressed.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1098-4402Test

الوصول الحر: https://doaj.org/article/4c1b9405b6244683aca9b89f3ba5be51Test

المؤلفون: Y. Renier, P. Bambade, T. Tauchi, G. R. White, S. Boogert

المصدر: Physical Review Special Topics. Accelerators and Beams, Vol 16, Iss 6, p 062803 (2013)

مصطلحات موضوعية: Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798

الوصف: The Accelerator Test Facility 2 (ATF2) commissioning group aims to demonstrate the feasibility of the beam delivery system of the next linear colliders (ILC and CLIC) as well as to define and to test the tuning methods. As the design vertical beam sizes of the linear colliders are about few nanometers, the stability of the trajectory as well as the control of the aberrations are very critical. ATF2 commissioning started in December 2008, and thanks to submicron resolution beam position monitors (BPMs), it has been possible to measure the beam position fluctuation along the final focus of ATF2 during the 2009 runs. The optics was not the nominal one yet, with a lower focusing to make the tuning easier. In this paper, a method to measure the noise of each BPM every pulse, in a model-independent way, will be presented. A method to reconstruct the trajectory’s fluctuations is developed which uses the previously determined BPM resolution. As this reconstruction provides a measurement of the beam energy fluctuations, it was also possible to measure the horizontal and vertical dispersion function at each BPMs parasitically. The spatial and angular dispersions can be fitted from these measurements with uncertainties comparable with usual measurements.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1098-4402Test

الوصول الحر: https://doaj.org/article/4cf7f90c6fe749f58952ec11e8deea3cTest

المؤلفون: Y. I. Kim, R. Ainsworth, A. Aryshev, S. T. Boogert, G. Boorman, J. Frisch, A. Heo, Y. Honda, W. H. Hwang, J. Y. Huang, E-S. Kim, S. H. Kim, A. Lyapin, T. Naito, J. May, D. McCormick, R. E. Mellor, S. Molloy, J. Nelson, S. J. Park, Y. J. Park, M. Ross, S. Shin, C. Swinson, T. Smith, N. Terunuma, T. Tauchi, J. Urakawa, G. R. White

المصدر: Physical Review Special Topics. Accelerators and Beams, Vol 15, Iss 4, p 042801 (2012)

مصطلحات موضوعية: Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798

الوصف: The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1098-4402Test

الوصول الحر: https://doaj.org/article/1041bcef33bf468c8926883be48ce900Test

المؤلفون: Kathleen M. Randolph, Edgar L. Dillon, J. Rathmacher, S. Schuette, Shanon L. Casperson, G. R. White, Randall J. Urban, Melinda Sheffield-Moore, Kristofer Jennings, Maurice Willis, V. Hoang, William J. Durham, Morteza Janghorbani

المصدر: Journal of Cachexia, Sarcopenia and Muscle

مصطلحات موضوعية: Sarcopenia, Pathology, medicine.medical_specialty, Cachexia, medicine.diagnostic_test, business.industry, Urinary system, Proteolysis, Skeletal muscle, Cancer, medicine.disease, 3. Good health, medicine.anatomical_structure, Tracer, Physiology (medical), medicine, Biomarker (medicine), Original Article, Orthopedics and Sports Medicine, business, Myofibril, Human

الوصف: Background Skeletal muscle loss accompanying aging or cancer is associated with reduced physical function and predicts morbidity and mortality. 3-Methylhistidine (3MH) has been proposed as a biomarker of myofibrillar proteolysis, which may contribute to skeletal muscle loss. Methods We hypothesized that the terminal portion of the isotope decay curve following an oral dose of isotopically labeled 3MH can be measured non-invasively from timed spot urine samples. We investigated the feasibility of this approach by determining isotope enrichment in spot urine samples and corresponding plasma samples and whether meat intake up to the time of dosing influences the isotope decay. Results Isotope decay constants (k) were similar in plasma and urine, regardless of diet. Post hoc comparison of hourly sampling over 10 h with three samples distributed over 10 or fewer hours suggests that three distributed samples over 5–6 h of plasma or urine sampling yield decay constants similar to those obtained over 10 h of hourly sampling. Conclusion The findings from this study suggest that an index of 3MH production can be obtained from an easily administered test involving oral administration of a stable isotope tracer of 3MH followed by three plasma or urine samples collected over 5–6 h the next day.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::22a7f0c498efc40e4179c5c5f217f59fTest
https://doi.org/10.1007/s13539-013-0117-7Test

المؤلفون: Yohann G. R. White, Theo G. M. Sandfort

المصدر: International Journal of Sexual Health. 28:259-260

مصطلحات موضوعية: Gender Studies, Reproductive Medicine, Social Psychology, Public Health, Environmental and Occupational Health, Dermatology

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a6327505c09c9ba70f8b0d676d364586Test
https://doi.org/10.1080/19317611.2016.1227014Test

المؤلفون: D. Duncan, J. Lough, F.A. Narducci, G. R. White, J.P. Davis

المصدر: Journal of Modern Optics. 56:2013-2021

مصطلحات موضوعية: Physics, Quantum optics, Atom interferometer, business.industry, Magnetometer, Measure (physics), Atomic and Molecular Physics, and Optics, law.invention, Magnetic field, Optics, law, Atom (measure theory), Physics::Atomic Physics, business, Local field, Quantum

الوصف: In this article, we highlight some of the problems inherent in fielding an atom interferometer sensor, specifically an atom interferometer gradient magnetometer of the type recently proposed [Davis, J.P.; Narducci, F.A. J. Mod. Opt. 2008, 55, 3173–3185]. In particular, we focus on the problems created by stray magnetic fields. We review some of the quantum optic techniques to measure local magnetic fields for the purpose of nulling them. We also present our implementation of a technique to non-destructively measure the temperature of an atom cloud. We highlight our implementation of these techniques and present our measurements.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::55079cb2c1d7bc50089cf50f50929df3Test
https://doi.org/10.1080/09500340903243455Test

المؤلفون: Y G R, White

المصدر: The West Indian medical journal. 62(2)

مصطلحات موضوعية: Humans, HIV Infections, Tuberculosis, Pulmonary

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::397bb1f1b30287383003b9a00891ede5Test
https://pubmed.ncbi.nlm.nih.gov/24564057Test

المؤلفون: G. R. White

المصدر: International Urogynecology Journal And Pelvic Floor Dysfunction. 8:288-292

مصطلحات موضوعية: medicine.medical_specialty, medicine.anatomical_structure, business.industry, Urology, Vagina, Obstetrics and Gynecology, Medicine, Pelvic fascia, Anatomy, business, Surgery, White line

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a714a0755663f5ae5ef3515d353533abTest
https://doi.org/10.1007/bf02765486Test

المؤلفون: C D Mantell, G R White, J P Collins

المصدر: Medical Education. 31:77-80

مصطلحات موضوعية: Affirmative action, Medical education, Student population, Absolute number, business.industry, education, Medical school, General Medicine, Indigenous, Education, Mathematics education, Medicine, Maori Population, business, Graduation

الوصف: SUMMARY An affirmative-action programme was introduced in Auckland in 1972 to increase the proportion and absolute number of entrants to medical school from the indigenous or Maori population and those of Pacific Island ancestry. One hundred and forty-seven students have entered the course through this programme, the percentage of females being higher than that of the non-affirmative category. Seventy-five have graduated – a graduation rate of 78%. Twenty-seven (18%) have been lost from the course mainly through academic failure, This loss is much higher than the 8% found for the remaining medical student population. The subsequent careers of those lost from the course has been satisfactory, some graduating from other faculties and some from polytechnics. Although such a programme remains controversial it has enabled a large number of persons to enter medical school who would not have been able to do so through the standard admitting process.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::dc6c04e1e1aae15f8a1e20eab402faf1Test
https://doi.org/10.1111/j.1365-2923.1997.tb02462.xTest