Dislocation loops in overheated free-standing smectic films

Static and dynamic phenomena in overheated free-standing smectic-A films are studied using a generalization of de Gennes' theory for a confined presmectic liquid. A static application is to determine the profile of the film meniscus and the meniscus contact angle, the results being compared with those of a recent study employing de Gennes' original theory. The dynamical generalization of the theory is based on on a time-dependent Ginzburg-Landau approach. This is used to compare two modes for layer-thinning transitions in overheated films, namely "uniform thinning" vs. nucleation of dislocation loops. Properties such as the line tension and velocity of a moving dislocation line are evaluated self-consistently by the theory.Comment: 16 pages, 8 figure

Nonlinear Mid-Infrared Metasurface based on a Phase-Change Material

The mid-wave infrared (MWIR) spectral region (3–5 µm) is important to a vast variety of applications in imaging, sensing, spectroscopy, surgery, and optical communications. Efficient third-harmonic generation (THG), converting light from the MWIR range into the near-infrared, a region with mature optical detection and manipulation technologies, offers the opportunity to mitigate a commonly recognized limitation of current MWIR systems. In this work, the possibility of boosting THG in the MWIR through a metasurface design is presented. Specifically, a 30-fold enhancement in a highly nonlinear phase-change material Ge2Sb2Se4Te1 (GSST) is demonstrated by patterning arrays of subwavelength cylinders supporting a magnetic dipolar resonance. The unprecedented broadband transparency, large refractive index, and remarkably high nonlinear response, together with unique phase-change properties, make GSST-based metasurfaces an appealing solution for reconfigurable and ultra-compact nonlinear devices operating in the MWIR

Подходы к оценке полноты и качества регистров потомков облучённого населения

Uncertainties of radiation risk of late radiation exposure effects in humans are to a great extent determined by completeness and quality of epidemiological data. The registry of the studied cohort is of fundamental importance for the cohort studies. Particular difficulties appear in the course of development of the exposed population offspring registry as these people in contrast to their parents were not affected by radiation exposure. The formation of the cohort of the exposed population offspring has its peculiarities and requires evaluation of its completeness and quality. The objective of this research is to study the value of the sex ratio as a possible criterion to assess the completeness and quality of the registry of the Techa River Cohort offspring. The register of descendants of the irradiated population at the end of 2019 included information on 25930 persons. The formation of the register of descendants of the population irradiated on the Techa River was started in the mid-1950s. At the same time, various documents were used to confirm the fact of birth of a child in irradiated persons. In the Techa River population the proportion of offspring with exposed mother and unexposed father is 22.2%, those with exposed father and unexposed mother made up 13.9%; the proportion of in utero exposed offspring is 44.6%. In accordance to the widely accepted published data it was to be expected that the number of male 1st-generation offspring in the cohort would be lower. However, the results of the conducted research show no changes in the sex ratio among offspring relative to the population-based control. Moreover, it was stated that the sex ratio in the population of the 1st-generation offspring of the exposed residents of the Techa River settlements should not be viewed as secondary. The assumption about the influence of the pre-conceptional exposure of the parents as well as that of the in utero exposure on changes in the sex ratio was not confirmed. It is shown that the decrease in the value of the sex ratio is associated with misreporting of the male 1st -generation offspring who died in childhood and at young age. The value of the sex ratio in groups formed based on the character and dose of exposure, depended mainly on the source of information used in the course of the offspring registry development.Неопределенности оценок радиационного риска отдаленных последствий облучения человека в значительной степени определяются полнотой и качеством эпидемиологических данных. Основополагающее значение для когортных исследований имеет регистр исследуемой когорты. Особые сложности возникают при формировании регистра потомков облученных лиц, которые, в отличие от их родителей, не подвергались радиационному воздействию. Формирование когорты потомков облучённых лиц имеет свои особенности и требует оценки ее полноты и качества. Целью работы является изучение показателя соотношения полов как возможного критерия для оценки полноты и качества регистра потомков когорты реки Течи. Регистр потомков облучённого населения на конец 2019 г. включал сведения на 25 930 лиц. Формирование регистра потомков облучённого на реке Теча населения было начато в середине 1950-х гг. При этом использовались разнообразные документы, подтверждающие факт рождения ребёнка у облучённых лиц. В популяции реки Течи доля потомков, зачатых только облучённой матерью, составляет 22,2%, только облучённым отцом — 13,9%, доля потомков, подвергшихся внутриутробному облучению, составляет 44,6%. В соответствии с общепринятыми данными литературы, в когорте потомков первого поколения следовало ожидать уменьшение рождения мальчиков. Однако по результатам проведенной работы у потомков не отмечено изменения соотношения полов при сравнении с популяционным контролем. Более того, установлено, что соотношение полов в популяции потомков первого поколения облучённого на реке Тече населения нельзя рассматривать как вторичное. Не нашло подтверждения предположение о влиянии преконцептивного облучения родителей, а также внутриутробного облучения на изменение соотношения полов. Показано, что снижение показателя соотношения полов связано с недоучётом потомков первого поколения мужского пола, умерших в детском и молодом возрасте. Величина соотношения полов в группах, сформированных в зависимости от характера и дозы облучения, зависела, главным образом, от источников информации, использованных при формировании регистра потомков

СРАВНИТЕЛЬНЫЙ АНАЛИЗ РЕЗУЛЬТАТОВ ЭКСПЕРТИЗЫ СОСТОЯНИЯ ЗДОРОВЬЯ ОБЛУЧЁННЫХ ГРАЖДАН В ЧЕЛЯБИНСКОМ МЭС ЗА ПЕРИОД С 1990 ПО 2015 Г.

The article presents a comparative analysis of the key performance indicators of the Chelyabinsk Regional Interdepartmental Expert Council on ascertainment of the causal relationship of diseases with radiation exposure over the periods 1990-2009 and 2010-2015. The sources of information were annual reports of the Chelyabinsk Interdepartmental Expert Council as well as its standard protocols of meetings and decisions. During the period under review, all groups of the population served underwent natural aging process; the proportion of reconsidered cases increased mainly due to the cases considered for disability and death of the exposed individuals. The causal relationship was determined more often during the period 2010–2015 than in earlier periods: 43,3% and 67,1% respectively. Positive decisions were taken most often regarding the persons with malignant neoplasms (62.9% of the total number of the positively considered decisions). The relationship of disability and death with radiation exposure during 2010–2015 was established more often, whereas the proportion of postponed cases decreased significantly.Представлен сравнительный анализ основных показателей деятельности Челябинского регионального межведомственного экспертного совета по установлению причинной связи заболеваний с радиационным воздействием в период с 1990 по 2009 г. и в период с 2010 по 2015 г. Источниками информации являлись годовые отчёты о деятельности Челябинского межведомственного экспертного совета, стандартные протоколы заседаний и решения межведомственного экспертного совета. За рассматриваемый период произошло естественное постарение всех групп обслуживаемого населения, возросла доля дел, рассматриваемых повторно, в основном за счёт дел, рассматриваемых по поводу инвалидности или смерти облучённых лиц. В период 2010–2015  гг. причинная связь устанавливалась чаще, чем в более ранние сроки: 43,3% и 67,1% соответственно. Наиболее часто положительные решения принимались в отношении лиц со злокачественными новообразованиями (62,9% от общего числа принятых положительных решений). Связь инвалидности и смерти с радиационным воздействием в 2010–2015 гг. устанавливалась чаще, тогда как доля отложенных дел значительно уменьшилась

BCFL logging: an approach to acquire and preserve admissible digital forensics evidence in cloud ecosystem

Log files are the primary source of recording users, applications and protocols, activities in the cloud ecosystem. Cloud forensic investigators can use log evidence to ascertain when, why and how a cyber adversary or an insider compromised a system by establishing the crime scene and reconstructing how the incident occurred. However, digital evidence acquisition in a cloud ecosystem is complicated and proven difficult, even with modern forensic acquisition toolkit. The multi-tenancy, Geo-location and Service-Level Agreement have added another layer of complexity in acquiring digital log evidence from a cloud ecosystem. In order to mitigate these complexities of evidence acquisition in the cloud ecosystem, we need a framework that can forensically maintain the trustworthiness and integrity of log evidence. In this paper, we design and implement a Blockchain Cloud Forensic Logging (BCFL) framework, using a Design Science Research Methodological (DSRM) approach. BCFL operates primarily in four stages: (1) Process transaction logs using Blockchain distributed ledger technology (DLT). (2) Use a Blockchain smart contract to maintain the integrity of logs and establish a clear chain of custody. (3) Validate all transaction logs. (4) Maintain transaction log immutability. BCFL will also enhance and strengthen compliance with the European Union (EU) General Data Protection Regulation (GDPR). The results from our single case study will demonstrate that BCFL will mitigate the challenges and complexities faced by digital forensics investigators in acquiring admissible digital evidence from the cloud ecosystem. Furthermore, an instantaneous performance monitoring of the proposed Blockchain cloud forensic logging framework was evaluated. BCFL will ensure trustworthiness, integrity, authenticity and non-repudiation of the log evidence in the cloud

ЭЛЕКТРОМАГНИТНЫЙ МОНИТОРИНГ В АФТЕРШОКОВЫЙ ПЕРИОД ЧУЙСКОГО ЗЕМЛЕТРЯСЕНИЯ 2003 г. В ГОРНОМ АЛТАЕ: МЕТОДИКА ИЗМЕРЕНИЙ, РЕЗУЛЬТАТЫ

The article considers the method of observations, interpretation of data and results of electromagnetic monitoring with a controlled source for one of the seismically active regions of Siberia – Mountain (Gorny) Altai. The monitoring is carried out during the aftershock period in the epicentral zone of the destructive Chuya earthquake of 2003 with M=7.3. For regular observations, a measurement technique has been developed with several modifications of the transient electromagnetics method (TEM) to determine variations in electrical resistivity and anisotropy coefficient. The long-term series of these two geoelectric parameters of the section are presented, compared with the characteristics of the ongoing seismic events. The analysis shows that variations in electrical resistance and electrical anisotropy reflect the development and gradual attenuation of aftershock activity of a powerful earthquake. The advantages of the TEM method and the chosen methodology for monitoring in complex areas are reflected.В статье рассмотрена методика наблюдений, интерпретации данных и результаты электромагнитного мониторинга с контролируемым источником для одного из сейсмоактивных регионов Сибири – Горного Алтая. Мониторинг выполняется в афтершоковый период в эпицентральной зоне разрушительного Чуйского землетрясения 2003 г. с М=7.3. Для регулярных наблюдений разработана методика измерений несколькими модификациями метода зондирования становлением электромагнитного поля (ЗСБ) для определения вариаций удельного электрического сопротивления и коэффициента анизотропии. Приведены многолетние ряды этих двух геоэлектрических параметров разреза, сопоставленные с характеристиками происходящих сейсмических событий. В результате анализа показано, что вариации электросопротивления и коэффициента электрической анизотропии отражают развитие и постепенное затухание афтершоковой активности мощного землетрясения. Отражены преимущества метода ЗСБ и выбранной методики для мониторинга в сложно построенных районах

Ultrabright room-temperature single-photon emission from nanodiamond nitrogen-vacancy centers with sub-nanosecond excited-state lifetime

Ultrafast emission rates obtained from quantum emitters coupled to plasmonic nanoantennas have recently opened fundamentally new possibilities in quantum information and sensing applications. Plasmonic nanoantennas greatly improve the brightness of quantum emitters by dramatically shortening their fluorescence lifetimes. Gap plasmonic nanocavities that support strongly confined modes are of particular interest for such applications. We demonstrate single-photon emission from nitrogen-vacancy (NV) centers in nanodiamonds coupled to nanosized gap plasmonic cavities with internal mode volumes about 10 000 times smaller than the cubic vacuum wavelength. The resulting structures features sub-nanosecond NV excited-state lifetimes and detected photon rates up to 50 million counts per second. Analysis of the fluorescence saturation allows the extraction of the multi-order excitation rate enhancement provided by the nanoantenna. Efficiency analysis shows that the NV center is producing up to 0.25 billion photons per second in the far-field

Molecular simulation of chevrons in confined smectic liquid crystals

Chevron structures adopted by confined smectic liquid crystals are investigated via molecular dynamics simulations of the Gay-Berne model. The chevrons are formed by quenching nematic films confined between aligning planar substrates whose easy axes have opposing azimuthal components. When the substrates are perfectly smooth, the chevron formed migrates rapidly towards one of the confining walls to yield a tilted layer structure. However, when substrate roughness is included, by introducing a small-amplitude modulation to the particle- substrate interaction well-depth, a symmetric chevron is formed which remains stable over sufficiently long runtimes for detailed structural information, such as the relevant order parameters and director orien- tation, to be determined. For both smooth and rough boundaries, the smectic order parameter remains non-zero across the entire chevron, implying that layer identity is maintained across the chevron tip. Also, when the surface-stabilised chevron does eventually revert to a tilted layer structure, it does so via surface slippage, such that layer integrity is maintained throughout the chevron to tilted layer relaxation process. </p