281 research outputs found
Применение геотермии для выделения перспективных зон нефтегазоносности нижнеюрского резервуара (пласта Ю16) Нюрольской мегавпадины
Modelling cyclists’ comfort zones from obstacle avoidance manoeuvres
This paper introduces a framework for modelling the cyclist’s comfort zone. Unlike the driver’s comfort zone, little is known about the cyclist’s. The framework draws on existing literature in cognitive science about driver behaviour to explain experimental results from cycling field trials, and the modelling of these results. We modelled braking and steering manoeuvres from field data of cyclists’ obstacle avoidance within their comfort zone. Results show that when cyclists avoided obstacles by braking, they kept a constant deceleration; as speed increased, they started to brake earlier, farther from the obstacle, maintaining an almost constant time to collision. When cyclists avoided obstacles by steering, they maintained a constant distance from the object, independent of speed. Overall, the higher the speed, the more the steering manoeuvres were temporally delayed compared to braking manoeuvres. We discuss these results and other similarities between cyclist and driver behaviour during obstacle avoidance. Implications for the design of acceptable active safety and infrastructure design are also addressed
Модернизация теплообменных аппаратов различной производительности на основе численного моделирования
Выпускная квалификационная работа 104 с., 49 рис., 10 табл., 20 источников, 3 прил.
Ключевые слова: математическое моделирование, теплообменник, топливный газ, интенсификаторы теплообмена, принудительная конвекция, турбулентность, расчетная сетка, присоединительный вихрь, тепловой поток, геометрическая модель.
Объектом исследования является теплообменный аппарат, применяемый для нагрева топливного газа перед подачей его на горелочные устройства.
Цель работы - исследование интенсифицированного теплообмена при турбулентном течении теплоносителя в прямых круглых трубах с итенсификаторами теплообмена и анализ эффективности различных турбулизаторов.Final qualifying work 104 p., 49 fig., 10 tab., 20 sources, 3 application.
Keywords: mathematical modeling, heat exchanger, fuel gas, to vary the heat transfer, forced convection, turbulence, computational grid, connecting a whirlwind, heat flow, the geometric model.
The object of research is the heat exchanger that is used to heat the fuel gas before it is fed to the burners.
Objective - research intensified heat exchange in turbulent flow of coolant in straight circular pipes with itensifikatorami heat exchange and analysis of the effectiveness of different turbulence.
The study was carried out mathematical modeling of the object of study with the use of ANSYS package applications, analysis of the results and evaluation of the effectiveness of different types of turbulence
Social and Economic Activity of the Elder Generation in Tomsk Region
Social and economic activity of the Russian elder generation has a contradictory nature. On the one hand, Russian pensioners often continue working beyond the existing comparatively low retirement age, on the other hand, in terms of involvement in volunteering, political activities, and even in care for children and grandchildren they lag significantly behind the average European level. Explaining it only by the lack of time does not seem plausible, since in many European countries, the employment rates, involvement in unpaid work and caring for other family members are all higher than in Russia. In our study we attempt to identify reasons for lower social and economic activity of older adults in Russia as compared with European countries. We use data of Tomsk regional survey (2015, N=400) for accessing older adults' social activity. Data analysis on Tomsk region suggests that employment (as an activity) and education (as a prerequisite) contribute to higher involvement in social interactions in later life
Restricted gene flow and genetic drift in recently fragmented populations of an endangered steppe bird
Identifying the genetic processes derived from habitat fragmentation is critical for the conservation of endangered species. We conducted an integrated analysis of genetic patterns in the endangered Dupont’s lark (Chersophilus duponti), a circum-Mediterranean songbird threatened by the loss and fragmentation of natural steppes in recent decades. After sampling all the remaining Spanish populations and the two clos¬est North African ones, we found that the Mediterranean Sea acts as a major barrier against gene flow and that recent habitat fragmentation is isolating Spanish populations at different spatial scales. While we found a historical signal of gene flow among Spanish regions, a coalescent model supported that the ancestral panmictic population is evolving into several different units in the absence of current gene flow, genetic drift being more intense in the smaller and more isolated populations. Moreover, small-scale spa¬tial autocorrelation analyses showed that genetic differentiation is also acting within populations. The spatial genetic structure, significant levels of inbreeding and high relatedness within patches raise con¬cerns on the viability of most of the extant populations. We highlight the urgency for steppe patches to be protected, expanded and reconnected, considering the genetic clusters identified here rather than the previously considered eco-geographic regions occupied by the species. Meanwhile, translocations could be considered as a complementary, faster management action to attenuate the crowding and genetic effects of population fragmentation and the extinction risk of small populations without compromising the current local adaptations, culture diversity and genetic clusters already known for the species.Peer Reviewe
Evaluation of nitrogen- and silicon-vacancy defect centres as single photon sources in quantum key distribution
We demonstrate a quantum key distribution (QKD) testbed for room temperature
single photon sources based on defect centres in diamond. A BB84 protocol over
a short free-space transmission line is implemented. The performance of
nitrogen-vacancy (NV) as well as silicon-vacancy defect (SiV) centres is
evaluated and an extrapolation for next-generation sources with enhanced
efficiency is discussed.Comment: 14 pages, 5 figure
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