183 research outputs found

    Torsion nonminimally coupled to the electromagnetic field and birefringence

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    In conventional Maxwell--Lorentz electrodynamics, the propagation of light is influenced by the metric, not, however, by the possible presence of a torsion T. Still the light can feel torsion if the latter is coupled nonminimally to the electromagnetic field F by means of a supplementary Lagrangian of the type l^2 T^2 F^2 (l = coupling constant). Recently Preuss suggested a specific nonminimal term of this nature. We evaluate the spacetime relation of Preuss in the background of a general O(3)-symmetric torsion field and prove by specifying the optical metric of spacetime that this can yield birefringence in vacuum. Moreover, we show that the nonminimally coupled homogeneous and isotropic torsion field in a Friedmann cosmos affects the speed of light.Comment: Revtex, 12 pages, no figure

    The Mu3e experiment: Toward the construction of an HV-MAPS vertex detector

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    The Mu3e experiment searches for the lepton flavor violating decay μ+  e+ e+ e\mu^+~\rightarrow~e^+~e^+~e^- with an ultimate aimed sensitivity of 1 event in 101610^{16} decays. This goal can only be achieved by reducing the material budget per tracking layer to X/X00.1%X/X_0 \approx 0.1 \%. High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) which are thinned to 50 μm serve as sensors. Gaseous helium is chosen as coolant. Results of recent studies related to the sensor prototypes, the helium cooling, and module prototyping are presented. The recent chip submission MuPix10 has proven its functionality regarding efficiency and time resolution. The helium cooling system for the inner tracker could be verified using a full-scale prototype. A complete prototype equipped with MuPix10 chips will be tested inside the Mu3e magnet in summer 2021

    The Mu3e experiment: Toward the construction of an HV-MAPS vertex detector

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    The Mu3e experiment searches for the lepton flavor violating decay μ+  e+ e+ e\mu^+~\rightarrow~e^+~e^+~e^- with an ultimate aimed sensitivity of 1 event in 101610^{16} decays. This goal can only be achieved by reducing the material budget per tracking layer to X/X00.1%X/X_0 \approx 0.1 \%. High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) which are thinned to 50 μm50\ \mu m serve as sensors. Gaseous helium is chosen as coolant. Results of recent studies related to the sensor prototypes, the helium cooling, and module prototyping are presented. The recent chip submission MuPix10 has proven its functionality regarding efficiency and time resolution. The helium cooling system for the inner tracker could be verified using a full-scale prototype. A complete prototype equipped with MuPix10 chips will be tested inside the Mu3e magnet in summer 2021.Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS2021), 15-18 March 2021. C21-03-15.

    ERiK methodological report III. Conceptualisation and design of the ERiK-surveys 2022

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    The ERiK-Methodological Report III is the third in a series of methodological reports related to the ‘Entwicklung von Rahmenbedingungen in der Kindertagesbetreuung – indikatorengestützte Qualitätsbeobachtung (ERiK)’ study. The report focuses on the conception, sample selection, and survey designs of the ERiK-Surveys 2022. Together with the ERiK-Methodological Report I and II, that cover the ERiK Surveys 2020, it provides comprehensive background information on the ERiK-Surveys conducted in 2022 and describes their progression until December 31, 2021. The subsequent steps, such as implementing the ERiK-Surveys 2022, will be described in a later report. (DIPF/Orig.

    Cranial and ventricular size following shunting or endoscopic third ventriculostomy (ETV) in infants with aqueductal stenosis: further insights from the International Infant Hydrocephalus Study (IIHS)

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    Purpose: The craniometrics of head circumference (HC) and ventricular size are part of the clinical assessment of infants with hydrocephalus and are often utilized in conjunction with other clinical and radiological parameters to determine the success of treatment. We aimed to assess the effect of endoscopic third ventriculostomy (ETV) and shunting on craniometric measurements during the follow-up of a cohort of infants with symptomatic triventricular hydrocephalus secondary to aqueductal stenosis. Methods: We performed a post hoc analysis of data from the International Infant Hydrocephalus Study (IIHS)—a prospective, multicenter study of infants (\u3c 24 months old) with hydrocephalus from aqueductal stenosis who were treated with either an ETV or shunt. During various stages of a 5-year follow-up period, the following craniometrics were measured: HC, HC centile, HC z-score, and frontal-occipital horn ratio (FOR). Data were compared in an analysis of covariance, adjusting for baseline variables including age at surgery and sex. Results: Of 158 enrolled patients, 115 underwent an ETV, while 43 received a shunt. Both procedures led to improvements in the mean HC centile position and z-score, a trend which continued until the 5-year assessment point. A similar trend was noted for FOR which was measured at 12 months and 3 years following initial treatment. Although the values were consistently higher for ETV compared with shunt, the differences in HC value, centile, and z-score were not significant. ETV was associated with a significantly higher FOR compared with shunting at 12 months (0.52 vs 0.44; p = 0.002) and 3 years (0.46 vs 0.38; p = 0.03) of follow-up. Conclusion: ETV and shunting led to improvements in HC centile, z-score, and FOR measurements during long-term follow-up of infants with hydrocephalus secondary to aqueductal stenosis. Head size did not significantly differ between the treatment groups during follow-up, however ventricle size was greater in those undergoing ETV when measured at 1 and 3 years following treatment

    Развитие стресс-менеджмента в системе управления персоналом предприятия на примере ОАО "Томскнефть" ВНК

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    Стресс-менеджмент и его методика позволяют быстро и эффективно решить стрессовую ситуацию возникшую в организации. Развитие стресс-менеджмента в системе управления персоналом предприятия позволит сформировать конструктивное отношение к стрессовым ситуациям на рабочем месте. Большую часть своего времени современный человек проводит на работе. Высокая нагрузка на работе; недостаточное количество сна; конфликты на работе; отсутствие контроля; отсутствие эмоциональной поддержки со стороны сослуживцев приводят к выявлению у человека одного из синдромов: "boreout" или "burnout". В данной работе были сформированы методические указания конструктивного отношения к стрессовым ситуациям и методам саморегулирования.Stress management and its methodology allow to quickly and effectively solve the stressful situation that arose in the organization. The development of stress management in the personnel management system of the enterprise will allow to form a constructive attitude to stressful situations in the workplace. Most of his time a modern man spends at work. High work load; Insufficient sleep; Conflicts at work; Lack of control; The lack of emotional support from co-workers lead to the identification of a person in one of the syndromes: "boreout" or "burnout". In this work, methodical instructions for a constructive attitude to stressful situations and methods of self-regulation have been formed

    Lustre in WAN Environment and Development

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