scholarly journals Nanometer-scale photon confinement inside dielectrics

2021 ◽  
Author(s):  
Marcus Albrechtsen ◽  
Babak Vosoughi Lahijani ◽  
Rasmus Christiansen ◽  
Vy Nguyen ◽  
Laura Casses ◽  
...  
Keyword(s):  
Single Photon ◽  
Near Field ◽  
Critical Role ◽  
Diffraction Limit ◽  
Optical Measurements ◽  
Nanometer Scale ◽  
Common Definition ◽  
Photon Confinement ◽  
Definition Of ◽  
Mode Volume

Abstract Optical nanocavities confine and store light, which is essential to increase the interaction between photons and electrons in semiconductor devices, enabling, e.g., lasers and emerging quantum technologies. While temporal confinement has improved by orders of magnitude over the past decades, spatial confinement inside dielectrics was until recently believed to be bounded at the diffraction limit. The conception of dielectric bowtie cavities (DBCs) shows a path to photon confinement inside semiconductors with mode volumes bound only by the constraints of materials and nanofabrication, but theory was so far misguided by inconsistent definitions of the mode volume and experimental progress has been impeded by steep nanofabrication requirements. Here we demonstrate nanometer-scale photon confinement inside 8 nm silicon DBCs with an aspect ratio of 30, inversely designed by fabrication-constrained topology optimization. Our cavities are defined within a compact device footprint of 4 lambda^2 and exhibit mode volumes down to V = 3E-4 lambda^3 with wavelengths in the lambda = 1550 nm telecom band. This corresponds to field localization deep below the diffraction limit in a single hotspot inside the dielectric. A crucial insight underpinning our work is the identification of the critical role of lightning-rod effects at the surface. They invalidate the common definition of the mode volume, which is prone to gauge meretricious surface effects or numerical artefacts rather than robust confinement inside the dielectric. We use near-field optical measurements to corroborate the photon confinement to a single nanometer-scale hotspot. Our work enables new CMOS-compatible device concepts ranging from few- and single-photon nonlinearities over electronics-photonics integration to biosensing.

SIMILARITIES AND DIFFERENT FEATURES OF HAND GESTURES IN AMERICAN AND KYRGYZ CULTURES

2019 ◽  
pp. 19-22
Author(s):  
Avtandil kyzy Ya
Keyword(s):  
Everyday Life ◽  
Facial Expressions ◽  
Main Part ◽  
Body Language ◽  
Hand Gestures ◽  
Common Definition ◽  
The World ◽  
The Common ◽  
Definition Of ◽  
Different Cultures

Abstract: This paper highlights similarities and different features of the category of kinesics “hand gestures”, its frequency usage and acceptance by different individuals in two different cultures. This study shows its similarities, differences and importance of the gestures, for people in both cultures. Consequently, kinesics study was mentioned as a main part of body language. As indicated in the article, the study kinesics was not presented in the Kyrgyz culture well enough, though Kyrgyz people use hand gestures a lot in their everyday life. The research paper begins with the common definition of hand gestures as a part of body language, several handshake categories like: the finger squeeze, the limp fish, the two-handed handshake were explained by several statements in the English and Kyrgyz languages. Furthermore, this article includes definitions and some idioms containing hand, shake, squeeze according to the Oxford and Academic Dictionary to show readers the figurative meanings of these common words. The current study was based on the books of writers Allan and Barbara Pease “The definite book of body language” 2004, Romana Lefevre “Rude hand gestures of the world”2011 etc. Key words: kinesics, body language, gestures, acoustics, applause, paralanguage, non-verbal communication, finger squeeze, perceptions, facial expressions. Аннотация. Бул макалада вербалдык эмес сүйлѳшүүнүн бѳлүгү болуп эсептелген “колдордун жандоо кыймылы”, алардын эки башка маданиятта колдонулушу, айырмачылыгы жана окшош жактары каралган. Макаланын максаты болуп “колдордун жандоо кыймылынын” мааниси, айырмасы жана эки маданиятта колдонулушу эсептелет. Ошону менен бирге, вербалдык эмес сүйлѳшүүнүн бѳлүгү болуп эсептелген “кинесика” илими каралган. Берилген макалада кѳрсѳтүлгѳндѳй, “кинесика” илими кыргыз маданиятында толугу менен изилденген эмес, ошого карабастан “кинесика” илиминин бѳлүгү болуп эсептелген “колдордун жандоо кыймылы” кыргыз элинин маданиятында кѳп колдонулат. Андан тышкары, “колдордун жандоо кыймылынын” бир нече түрү, англис жана кыргыз тилдеринде ма- селен аркылуу берилген.Тѳмѳнкү изилдѳѳ ишин жазууда чет элдик жазуучулардын эмгектери колдонулду. Түйүндүү сѳздѳр: кинесика, жандоо кыймылы, акустика,кол чабуулар, паралингвистика, вербалдык эмес баарлашуу,кол кысуу,кабыл алуу сезими. Аннотация. В данной статье рассматриваются сходства и различия “жестикуляции” и частота ее использования, в американской и кыргызской культурах. Следовательно, здесь было упомянуто понятие “кинесика” как основная часть языка тела. Как указано в статье, “кинесика” не была представлена в кыргызской культуре достаточно хорошо, хотя кыргызский народ часто использует жестикуляцию в повседневной жизни. Исследовательская работа начинается с общего определения “жестикуляции” как части языка тела и несколько категорий жестикуляции, таких как: сжатие пальца, слабое рукопожатие, рукопожатие двумя руками, были объяснены несколькими примерами на английском и кыргызском языках. Кроме того, эта статья включает определения слов “рука”, “рукопожатие”, “сжатие” и некоторые идиомы, содержащие данных слов согласно Оксфордскому и Академическому словарю, чтобы показать читателям их образное значение. Данное исследование было основано на книгах писателей Аллана и Барбары Пиз «Определенная книга языка тела» 2004 года, Романа Лефевра «Грубые жестикуляции мира» 2011 года и т.д. Ключевые слова: кинесика, язык жестов, жесты, акустика, аплодисменты, паралингвистика, невербальная коммуникация, сжатие пальца, чувство восприятия, выражение лиц.

scholarly journals A theoretical and numerical approach for selecting miniaturized antenna topologies on magneto-dielectric substrates

2015 ◽  
Vol 7 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Alex Pacini ◽  
Alessandra Costanzo ◽  
Diego Masotti
Keyword(s):  
Near Field ◽  
Dielectric Materials ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Microwave Range ◽  
Dielectric Substrates ◽  
Full Wave ◽  
Miniaturized Antenna ◽  
Wavelength Radiation ◽  
Definition Of

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.

scholarly journals Public Personnel Management Process Capability Assessment

2019 ◽  
Vol 49 (1) ◽  
pp. 111-140 ◽  
Author(s):  
Ebru Gökalp ◽  
Onur Demirörs ◽  
P. Erhan Eren
Keyword(s):  
Personnel Management ◽  
Critical Role ◽  
Process Capability ◽  
Software Process Improvement ◽  
Management Process ◽  
Process Definition ◽  
Multiple Case ◽  
Generate Process ◽  
The Government ◽  
Definition Of

Personnel management plays a critical role in the success of public organizations. Our literature review shows that there is a lack of systematic guidance on how to improve Public Personnel Management Process (PPMP) quality. Software Process Improvement and Capability Determination (SPICE) is a process assessment framework that is successfully used by software organizations during the past two decades. The framework can also be used as a baseline to generate process capability models for different specific domains/sectors. We have utilized this approach for the government domain and we developed the process definition of PPMP. To observe the benefits and usability of the model, we have performed a multiple case study, including the assessments of three organizations’ PPMP capability levels and the development of action plans for PPMP improvement. The findings show that the proposed approach is applicable for identifying the PPMP capability levels and is capable of providing a roadmap for moving to the next level.

Ultra-broadband unidirectional launching of surface plasmon polaritons by a double-slit structure beyond the diffraction limit

Nanoscale ◽  
2014 ◽  
Vol 6 (22) ◽  
pp. 13487-13493 ◽  
Author(s):  
Jianjun Chen ◽  
Chengwei Sun ◽  
Hongyun Li ◽  
Qihuang Gong
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Near Field ◽  
Diffraction Limit ◽  
Plasmonic Waveguide ◽  
Plasmon Polaritons ◽  
Double Slit

Based on the near-field interference of two slit apertures in a subwavelength plasmonic waveguide, an ultra-broadband unidirectional SPP launcher beyond the diffraction limit was experimentally realized. This ultra-small SPP launcher has important applications in high-integration plasmonic circuits.

A case for multiple views of function in design based on a common definition

2013 ◽  
Vol 27 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Amaresh Chakrabarti ◽  
V. Srinivasan ◽  
B.S.C. Ranjan ◽  
Udo Lindemann
Keyword(s):  
State Change ◽  
Multiple Views ◽  
System Environment ◽  
Common Definition ◽  
Effect Model ◽  
Before And After ◽  
Definition Of

AbstractFunctions are important in designing. However, several issues hinder progress with the understanding and usage of functions: lack of a clear and overarching definition of function, lack of overall justifications for the inevitability of the multiple views of function, and scarcity of systematic attempts to relate these views with one another. To help resolve these, the objectives of this research are to propose a common definition of function that underlies the multiple views in literature and to identify and validate the views of function that are logically justified to be present in designing. Function is defined as a change intended by designers between two scenarios: before and after the introduction of the design. A framework is proposed that comprises the above definition of function and an empirically validated model of designing, extended generate, evaluate, modify, and select of state-change, and an action, part, phenomenon, input, organ, and effect model of causality (Known as GEMS of SAPPhIRE), comprising the views of activity, outcome, requirement–solution–information, and system–environment. The framework is used to identify the logically possible views of function in the context of designing and is validated by comparing these with the views of function in the literature. Describing the different views of function using the proposed framework should enable comparisons and determine relationships among the various views, leading to better understanding and usage of functions in designing.

International Law and Administrative Insulation: A Comparison of Refugee Status Determination Regimes in the United States, Canada, and Australia

2012 ◽  
Vol 37 (04) ◽  
pp. 933-968 ◽  
Author(s):  
Rebecca Hamlin
Keyword(s):  
United States ◽  
International Law ◽  
Control Policy ◽  
The United States ◽  
Border Control ◽  
Refugee Status ◽  
Common Definition ◽  
Political Debates ◽  
Political Interference ◽  
Definition Of

International law provides nations with a common definition of a refugee, yet the processes by which countries determine who should be granted refugee status look strikingly different, even across nations with many institutional, cultural, geographical, and political similarities. This article compares the refugee status determination regimes of three popular asylum seeker destinations—the United States, Canada, and Australia. Despite these nations' similar border control policies, asylum seekers crossing their borders access three very different systems. These differences have less to do with political debates over admission and border control policy than with the level of insulation the administrative decision-making agency enjoys from political interference and judicial review. Bureaucratic justice is conceptualized and organized differently in different states, and so states vary in how they draw the line between refugee and nonrefugee.

scholarly journals When does proton pump inhibitor treatment become long term? A scoping review

2021 ◽  
Vol 8 (1) ◽  
pp. e000563
Author(s):  
Peter Fentz Haastrup ◽  
Dorte Ejg Jarbøl ◽  
Wade Thompson ◽  
Jane Møller Hansen ◽  
Jens Søndergaard ◽  
...  
Keyword(s):  
Proton Pump Inhibitor ◽  
Proton Pump ◽  
Cochrane Library ◽  
Clinical Context ◽  
Eligibility Criteria ◽  
Proton Pump Inhibitor Treatment ◽  
Common Definition ◽  
Definition Of ◽  
Inhibitor Treatment

ObjectiveProton pump inhibitor (PPI) use has risen substantially, primarily driven by ongoing use over months to years. However, there is no consensus on how to define long-term PPI use. Our objectives were to review and compare definitions of long-term PPI use in existing literature and describe the rationale for each definition. Moreover, we aimed to suggest generally applicable definitions for research and clinical use.DesignThe databases PubMed and Cochrane Library were searched for publications concerning long-term use of PPIs and ClinicalTrials.gov was searched for registered studies. Two reviewers independently screened the titles, abstracts, and full texts in two series and subsequently extracted data.ResultsA total of 742 studies were identified, and 59 met the eligibility criteria. In addition, two ongoing studies were identified. The definition of long-term PPI use varied from >2 weeks to >7 years. The most common definition was ≥1 year or ≥6 months. A total of 12/61 (20%) of the studies rationalised their definition.ConclusionThe definitions of long-term PPI treatment varied substantially between studies and were seldom rationalised.In a clinical context, use of PPI for more than 8 weeks could be a reasonable definition of long-term use in patients with reflux symptoms and more than 4 weeks in patients with dyspepsia or peptic ulcer. For research purposes, 6 months could be a possible definition in pharmacoepidemiological studies, whereas studies of adverse effects may require a tailored definition depending on the necessary exposure time. We recommend to always rationalise the choice of definition.

Updating the knowledge of the flower flies (Diptera: Syrphidae) from Chile: Illustrated catalog, extinction risk and biological notes

Zootaxa ◽  
2021 ◽  
Vol 4959 (1) ◽  
pp. 1-178
Author(s):  
RODRIGO M. BARAHONA-SEGOVIA ◽  
PAMELA RIERA ◽  
LAURA PAÑINAO-MONSÁLVEZ ◽  
VICENTE VALDÉS GUZMÁN ◽  
PATRICIA HENRÍQUEZ-PISKULICH
Keyword(s):  
Extinction Risk ◽  
Critical Role ◽  
Floral Biology ◽  
Iucn Red List ◽  
Decomposition Of Organic Matter ◽  
Management Plans ◽  
Flower Flies ◽  
Iucn Red List Criteria ◽  
Definition Of ◽  
First Time

Syrphidae, more commonly known as flower flies, are considered one of the most important Diptera families worldwide because of their critical role in pollination, biological control and decomposition of organic matter. The study of these flies in Chile has stagnated due to a lack of local experts as well as the absence of an updated catalog of species. This study is an attempt to remedy the latter of these issues by providing an illustrated and updated catalog to the Syrphidae of Chile. Species are presented under currently accepted names, with synonyms and previous combinations listed and original references. Type localities, world and Chilean distribution by geopolitical Chilean regions, taxonomic and biological notes, a complete record of bibliographic references and extinction risk under IUCN Red List criteria are provided. This catalog recognizes 132 species of Syrphidae, belonging to four subfamilies (Eristalinae, Microdontinae, Pipizinae and Syrphinae), 13 tribes and 47 genera. A total of 46 species (34.84 %) is restricted to the geopolitical territory of Chile. Eight species are considered exotic, one is considered incertae sedis and three are based on doubtful records. Seventeen species of 10 different genera (Copestylum Macquart, 1846; Dolichogyna Macquart, 1842; Eosalpingogaster Hull, 1949b; Eupeodes Osten Sacken, 1877; Meromacrus Rondani, 1848; Palpada Macquart, 1834; Paragus Latreille, 1804; Sphiximorpha Rondani, 1850; Sterphus Philippi, 1865 and Toxomerus Macquart, 1855) are reported from Chile for the first time. A total of 44 species (33.33 %) reported from Chile are directly threatened by human activities such as agriculture, forestry, mining and/or urbanization and indirectly by climate change. The gaps found in the geographic distribution of Chilean flower fly species and what it means for its use by disciplines such as ecology, floral biology and agronomy, are discussed. In addition, the use of this illustrated catalog for biological conservation, the potential definition of priority areas and ecosystem management plans based on this group of Diptera are also discussed. 

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