1,721 research outputs found

    On the Spectrum of Isotropic Turbulence

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    Measurements of the spectrum and correlation functions at large Reynolds number (RN ~ 10^5 based on the grid mesh) have been made, as well as a series of accurate spectrum measurements at lower Reynolds number (RN ~ 10^4). The results are compared with the theoretical laws proposed in recent years. It is found that the measurements at large Reynolds numbers exhibit a range of frequencies where the spectrum is nearly of the form n^- 5/3. The largest part of the spectrum in the initial stage of decay at the lower Reynolds number was found to follow closely the simple spectrum A/[B + n^2] , where A and B are constants and n is the frequency of fluctuation. At x/M = 1000 (where x is the distance behind the grid and M is the mesh size) the spectrum approaches a Gaussian distribution. The second, fourth, and sixth moments of the spectrum have been computed from the measurements and are discussed In relation to theoretical results. The significance of the number of zeros of the fluctuating velocity u(t) is discussed and examples of measurements for the determination of the microscale of turbulence [lambda] from zero counts are given

    6-(4-Chloro­phen­yl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde

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    The 4-chloro­phenyl residue in the title compound, C20H16ClNO, is oriented at a dihedral angle of 53.6 (3)° towards the phenyl ring and 42.0 (9)° towards the pyrrole ring of the pyrrolizine template. The phenyl ring is oriented at a dihedral angle of 45.4 (4)° towards the pyrrole ring

    On Upper Bounds for Toroidal Mosaic Numbers

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    In this paper, we work to construct mosaic representations of knots on the torus, rather than in the plane. This consists of a particular choice of the ambient group, as well as different definitions of contiguous and suitably connected. We present conditions under which mosaic numbers might decrease by this projection, and present a tool to measure this reduction. We show that the order of edge identification in construction of the torus sometimes yields different resultant knots from a given mosaic when reversed. Additionally, in the Appendix we give the catalog of all 2 by 2 torus mosaics.Comment: 10 pages, 111 figure

    6-(4-Meth­oxy­phen­yl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde

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    The 4-meth­oxy­phenyl residue in the title compound, C21H19NO2, is oriented at a dihedral angle of 54.6 (5)° with respect to the phenyl ring and at a dihedral angle of 52.5 (8)° with respect to the pyrrole ring of the pyrrolizine system. The phenyl ring is oriented at a dihedral angle of 36.2 (5)° with respect to the pyrrole ring. The meth­oxy group makes a C—C—O—C torsion angle of 3.8 (9)° with the attached benzene ring

    Информационная система учета и анализа предпочтений покупателей смартфонов ООО «Сатурн»

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    Объектом исследования является процесс организации анкетирования среди покупателей смартфонов ООО «Сатурн». Цель и задачи исследования работы: проектирование и разработка информационной системы для ООО «Сатурн», по анкетированию покупателей с целью анализа предпочтений при выборе смартфонов. В процессе исследования проведен анализ предприятия, постановка проектной задачи, и поиск инновационных вариантов, теоритический анализ, инженерный расчет, конструкторская разработка, техническое и организационное проектирование. В результате исследования разработана информационная система, реализующая функции: 1. Учет номенклатуры смартфонов. 2. Учет анкет покупателя. 3. Анализ критериев выбора смартфонов покупателем. Среда разработки: 1С: Предприятие 8.3 Степень внедрения: опытная эксплуатация.Object of research is process of the organization of questioning among buyers of smartphones of LLC Saturn. Purpose and research problems of work: design and development of information system for LLC Saturn, on questioning of buyers for the purpose of the analysis of preferences at the choice of smartphones. In the course of research the analysis of the enterprise, statement of a design task, and search of innovative options, the theoretical analysis, engineering calculation, design development, technical and organizational design is carried out. As a result of research the information system realizing functions is developed: 1. Accounting of the nomenclature of smartphones. 2. Accounting of questionnaires of the buyer. 3. Analysis of criteria of the choice of smartphones by the buyer. De

    Towards quantitative tissue absorption imaging by combining photoacoustics and acousto-optics

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    We propose a strategy for quantitative photoacoustic mapping of chromophore concentrations that can be performed purely experimentally. We exploit the possibility of acousto-optic modulation using focused ultrasound, and the principle that photons follow trajectories through a turbid medium in two directions with equal probability. A theory is presented that expresses the local absorption coefficient inside a medium in terms of noninvasively measured quantities and experimental parameters. Proof of the validity of the theory is given with Monte Carlo simulations.Comment: 14 pages, 5 figure

    Increased Executive Functioning, Attention, and Cortical Thickness in White-Collar Criminals

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    Very little is known on white collar crime and how it differs to other forms of offending. This study tests the hypothesis that white collar criminals have better executive functioning, enhanced information processing, and structural brain superiorities compared to offender controls. Using a case-control design, executive functioning, orienting, and cortical thickness was assessed in 21 white collar criminals matched with 21 controls on age, gender, ethnicity, and general level of criminal offending. White collar criminals had significantly better executive functioning, increased electrodermal orienting, increased arousal, and increased cortical gray matter thickness in the ventromedial prefrontal cortex, inferior frontal gyrus, somatosensory cortex, and the temporal-parietal junction compared to controls. Results, while initial, constitute the first findings on neurobiological characteristics of white-collar criminals It is hypothesized that white collar criminals have information-processing and brain superiorities that give them an advantage in perpetrating criminal offenses in occupational settings

    Correlative In Situ Multichannel Imaging for Large-Area Monitoring of Morphology Formation in Solution-Processed Perovskite Layers

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    To scale up production of perovskite photovoltaics, state-of-the-art laboratory recipes and processes must be transferred to large-area coating and drying systems. The development of in situ monitoring methods that provide real-time feedback for process control is pivotal to overcome this challenge. Herein, correlative in situ multichannel imaging (IMI) obtaining reflectance, photoluminescence intensity, and central photoluminescence emission wavelength images on areas larger than 100 cm2 with subsecond temporal resolution using a simple, cost-effective setup is demonstrated. Installed on top of a drying channel with controllable laminar air flow and substrate temperature, IMI is shown to consistently monitor solution film drying, perovskite nucleation, and perovskite crystallization. If the processing parameters differ, IMI reveals characteristic changes in large-area perovskite formation dynamics already before the final annealing step. Moreover, when IMI is used to study >130 blade-coated devices processed at the same parameters, about 90% of low-performing devices contain coating inhomogeneities detected by IMI. The results demonstrate that IMI should be of value for real-time 2D monitoring and feedback control in industrial-scale, high-throughput fabrication such as roll-to-roll printing
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