36 research outputs found
The Unitary Gas and its Symmetry Properties
The physics of atomic quantum gases is currently taking advantage of a
powerful tool, the possibility to fully adjust the interaction strength between
atoms using a magnetically controlled Feshbach resonance. For fermions with two
internal states, formally two opposite spin states, this allows to prepare long
lived strongly interacting three-dimensional gases and to study the BEC-BCS
crossover. Of particular interest along the BEC-BCS crossover is the so-called
unitary gas, where the atomic interaction potential between the opposite spin
states has virtually an infinite scattering length and a zero range. This
unitary gas is the main subject of the present chapter: It has fascinating
symmetry properties, from a simple scaling invariance, to a more subtle
dynamical symmetry in an isotropic harmonic trap, which is linked to a
separability of the N-body problem in hyperspherical coordinates. Other
analytical results, valid over the whole BEC-BCS crossover, are presented,
establishing a connection between three recently measured quantities, the tail
of the momentum distribution, the short range part of the pair distribution
function and the mean number of closed channel molecules.Comment: 63 pages, 8 figures. Contribution to the Springer Lecture Notes in
Physics "BEC-BCS Crossover and the Unitary Fermi gas" edited by Wilhelm
Zwerger. Revised version correcting a few typo
Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015
Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context.
Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI).
Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa.
Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden.
Funding: Bill & Melinda Gates Foundation
Experimental testing of liquid boiling-up homogeneity near the boundary of the attainable superheating
ESTIMATION OF POWER AND SPATIAL CHARACTERISTICS OF THE ULTRAWIDEBAND RTS FOR RAISING OF THE BARRAGE HANDYCAPS
Проанализированы и обобщены возможности создания заградительных помех радиолиниям управления взрывными устройствами (РУВУ). Получена оценка энергетических и пространственных характеристик антенной системы сверхширокополосной (СШП) РТС блокирования РУВУ. Исходя из тактических соображений, в качестве антенной системы для излучения помехи с шириной спектра 100 МГц – 3 ГГц предлагается использовать зеркальную антенную систему с облучателем в виде конической спиральной антенны, диаметр антенны составляет 1,5 м, поляризация – круговая. Рассчитан коэффициент эффективности защиты.Проаналізовані і узагальнені можливості створення загороджувальних завад радіолініям керування вибуховими пристроями (РКВП). Отримана оцінка енергетичних і просторових характеристик антенної системи надширокосмугової (НШС) РТС блокування РКВП. Виходячи з тактичних міркувань, в якості антенної системи для випромінювання завади із шириною смуги спектру 100 МГц – 3 ГГц пропонується використовувати дзеркальну антенну систему з опромінювачем у вигляді конічної спіральної антени, діаметр антени складає 1,5 м, поляризація – колова. Розрахований коефіцієнт ефективності захисту.Possibility of barrage handycaps creation to radioline of the control by explosive devices (RCED) are analysed and generalized. The estimation of power and spatial characteristics of the antenna system is got ultrawideband RTS blocking of RCED. Coming from the tactical considering, as an antenna system for the radiation of handycaps with the spectrum width 100 MHz – 3 GHz it is suggested to utillize the mirror antenna system with an irradiator as conical spiral antenna, the diameter – 1,5 m, polarization - circle. The coefficient of defence efficiency equal one is expected
Method комплексирования of the passive channel with the informational system of the short-range surface-to-air missile system at its radio-electronic suppression
В работе рассмотрен новый подход к построению средств разведки и управления в зенитно-ракетном комплексе (ЗРК) ПВО Сухопутных войск, который заключается в применении пассивных радиотехнических систем, дополнительно введенных в состав комплексов, распределенных на местности. Представлена блоксхема алгоритма работы пассивной радиотехнической системы, созданной на базе батареи ЗРК ближнего действия.У роботі розглянутий новий підхід до побудови засобів розвідки і управління в зенітно-ракетному комплексі (ЗРК) ППО Сухопутних військ, який полягає в застосуванні пасивних радіотехнічних систем, додатково введених до складу комплексів, розподілених на місцевості. Представлена блок-схема алгоритму роботи пасивної радіотехнічної системи, створеної на базі батареї ЗРК ближньої дії.The new approach to construction of means of survey and management in the surface-to-air missile system air defence of Land forces which consists in application of the passive radio engineering systems in addition injected into composition of complexes, distributed on locality is in-process observed. The block diagramme of algorithm of work of the passive radio engineering system created on the basis of short-range battery ZRK is presented
Refinement of numerical values of distributions laws parameters of errors in course of coordinates measurement at difference-dalnomernom the passive location method
В работе разработан метод уточнения законов распределения ошибок измерения пространственных координат самолета, проведена оценка числовых значений параметров законов распределений. Определено, что наиболее часто ошибки измерения при разностно-дальномерном методе пассивной радиолокации подчиняются закону Шарлье.У роботі розроблений метод уточнення законів розподілу помилок виміру просторових координат літака, проведена оцінка числових значень параметрів законів розподілів. Визначено, що найчастіше помилки виміру при різницеводалекомірному методі пасивної радіолокації підкоряються закону Шарлье.The method of refinement of law of errors of measurement of space co-ordinates of the airplane is in-process developed, the estimation of numerical values of parametres of laws of distributions is spent. It is defined that most often measuring errors at difference-dalnomernom a method of passive radiolocation obey the law Sharle
Systems of disguise and immitacii of tank troops
Здійснено аналіз систем маскування та імітації, що застосовуються танковими військами. Розглянуто основні типи маскувальних засобів: покриття, сітки, фарби, піна, аерозолі. Відзначається, що для найбільш ефективного маскування доцільно використовувати комбінацію різних типів систем маскування.Осуществлен анализ систем маскировки и имитации, которые применяются танковыми войсками. Рассмотрены основные типы маскировочных средств: покрытия, сетки, краски, пена, аэрозоли. Отмечается, что для наиболее эффективной маскировки целесообразно использовать комбинацию разных типов систем маскировки.The analysis of the systems of disguise and imitation, which are used tank troops, is carried out. The basic types of disguise facilities are considered: coverages, nets, paints, suds, aerosols. It is marked that for the most effective disguise it is expedient to utillize combination of different types of the systems of disguise
Estimation of efficiency of battle actions of zenithal complex of short-range with the use of mobile system of passive radio-location
В статье проведена оценка эффективности боевых действий зенитного комплекса ближнего действия (ЗК БД) с использованием подвижной системы пассивной радиолокации.У статті проведена оцінка ефективності бойових дій зенітного комплексу ближньої дії (ЗК БД) з використанням рухливої системи пасивної радіолокації.In the article the estimation of efficiency of battle actions of zenithal complex of short-range (ЗК DB) is conducted with the use of mobile system of passive radio-location