211 research outputs found
Modelos matemáticos e computadorizados da mudança dos parâmetros da camada de grão durante o movimento do grão através da zona de microondas e convecção
In the process of drying the grain in a dense layer in motion, the grain moves through the grain dryer. The movement of the grain layers is usually uneven. In addition, it is likely that the temperature and consumption of the desiccant agent will not remain the same throughout the height of the drying zone. The specific power of the microwave field in the drying zone can also alter. All these factors affect the speed and uniformity of drying of the grain layer throughout the drying zone.In the first stage, an analysis of the theoretical studies on the subject was carried out. It was determined that to date there has not been presented any work in which mathemati-cal models of heat and humidity exchange in a dense layer of grain in motion with con-sideration of the relative vertical movement of the layers. Therefore, it is necessary to develop such a mathematical model.As an initial configuration for the development of a mathematical description of the drying process, it was deemed appropriate to use the configuration of the microwave and convection zone developed by the authors.The equal probability of combination of parameters of the desiccant agent temperature, its relative humidity, the velocity and distance from the caryopsis to the waveguide was assumed. From this point, we developed a computerized microwave and convection drying model that takes into account this type of change in the parameters.The results of the grain drying simulation demonstrated the efficiency of the computer model obtained, reflecting the influence of fluctuations in grain parameters and the microwave field in the drying process.To evaluate the accuracy of the obtained model, it is necessary to carry out experimental studies.En el proceso de secado del grano en una capa densa en movimiento, el grano se mueve en la secadora de grano. El movimiento de las capas de grano suele ser desigual. Además, es probable que la temperatura y el consumo del agente desecante no permanezcan iguales a lo largo de la altura de la zona de secado. La potencia específica del campo de microondas en la zona de secado también puede alterar. Todos estos factores afectan la velocidad y la uniformidad de secado de la capa de grano en toda la zona de secado.En la primera etapa, llevamos a cabo un análisis de los estudios teóricos sobre el tema. Hemos modelos matemáticos de intercambio de calor y humedad en una capa de grano densa en movimiento con consideración del movimiento vertical relativo de las capas. Por lo tanto, es necesario desarrollar tal modelo matemático.Como configuración inicial para el desarrollo de una descripción matemática del proceso de secado, consideramos conveniente utilizar la configuración de la zona de microondas y convección desarrollada por los autores.Se supuso la probabilidad igual de combinación de parámetros de la temperatura del agente desecante, su humedad relativa, la velocidad y la distancia de la cariopse a la guía de ondas. A partir de ello, desarrollamos un modelo computarizado de secado por microondas y convección que toma en consideración este tipo de cambio en los parámetros.Los resultados de la simulación de secado de grano demostraron la aptitud del modelo computarizado obtenido, reflejando la influencia de las fluctuaciones en los parámetros de grano y el campo de microondas en el proceso de secado.Para evaluar la precisión del modelo obtenido, es necesario realizar estudios experimentales.No processo de secagem do grão em uma camada densa em movimento, o grão se move no secador de grãos. O movimento das camadas de grãos é geralmente irregular. Além disso, é provável que a temperatura e o consumo do agente de secagem não permaneçam os mesmos ao longo da altura da zona de secagem. A potência específica do campo de microondas na zona de secagem também pode ser alterada. Todos esses fatores afetam a velocidade e a uniformidade de secagem da camada de grãos em toda a zona de secagem.Na primeira etapa, realizamos uma análise dos estudos teóricos sobre o assunto. Determinamos que até hoje não houve trabalhos em que modelos matemáticos de troca de calor e umidade em uma camada de grão denso em movimento são contemplados considerando o movimento vertical relativo das camadas. Portanto, é necessário desenvolver um modelo matemático desse tipo.Como configuração inicial para o desenvolvimento de uma descrição matemática do processo de secagem, consideramos conveniente utilizar a configuração da zona de microondas e convecção desenvolvida pelos autores.A probabilidade igual de combinação de parâmetros de temperatura do agente dessecante, sua umidade relativa, a velocidade e a distância entre o cariopse e o guia de ondas foi assumida. A partir disso, desenvolvemos um modelo computadorizado de secagem por microconvecção e convecção que leva em conta esse tipo de mudança nos parâmetros.Os resultados da simulação de secagem de grãos demonstraram a adequação do modelo computacional obtido, refletindo a influência das flutuações nos parâmetros de grãos e do campo de microondas no processo de secagem.Para avaliar a precisão do modelo obtido, é necessário realizar estudos experimentais
Trepanacija i povećan parijetalni foramen na lubanjama otkrivenima na otočju Loyalty
The goal of this study is a comprehensive examination of openings discovered on two skulls in the collection of skeletal remains from the Loyalty Islands (Melanesia). The skull № 1524 displayed an evidence of successful trepanation, and the skull № 7985 revealed openings that were reminiscent of a trepanation, however, we are inclined to believe that in the latter case we are dealing with a rare genetic anomaly - enlarged parietal foramen.Cilj je ovog istraživanja opsežan pregled otvora otkrivenih na dvjema lubanjama u zbirci skeletnih ostataka s otočja Loyalty (Melanezija). Lubanja br. 1524 dokaz je uspješne trepanacije, a otvori lubanje br. 7985 podsjećaju na trepanaciju, međutim skloni smo vjerovati da se u potonjem slučaju susrećemo s rijetkom genetskom anomalijom – povećanim parijetalnim foramenom
Non-metric variation in red vole populations within the East-Ural Radioactive Track (EURT) zone
Boosting Heterogeneous Catalyst Discovery by Structurally Constrained Deep Learning Models
The discovery of new catalysts is one of the significant topics of
computational chemistry as it has the potential to accelerate the adoption of
renewable energy sources. Recently developed deep learning approaches such as
graph neural networks (GNNs) open new opportunity to significantly extend scope
for modelling novel high-performance catalysts. Nevertheless, the graph
representation of particular crystal structure is not a straightforward task
due to the ambiguous connectivity schemes and numerous embeddings of nodes and
edges. Here we present embedding improvement for GNN that has been modified by
Voronoi tesselation and is able to predict the energy of catalytic systems
within Open Catalyst Project dataset. Enrichment of the graph was calculated
via Voronoi tessellation and the corresponding contact solid angles and types
(direct or indirect) were considered as features of edges and Voronoi volumes
were used as node characteristics. The auxiliary approach was enriching node
representation by intrinsic atomic properties (electronegativity, period and
group position). Proposed modifications allowed us to improve the mean absolute
error of the original model and the final error equals to 651 meV per atom on
the Open Catalyst Project dataset and 6 meV per atom on the intermetallics
dataset. Also, by consideration of additional dataset, we show that a sensible
choice of data can decrease the error to values above physically-based 20 meV
per atom threshold
Multi-Watt Average Power Nanosecond Microchip Laser and Power Scalability Estimates
We demonstrated up to 2 W average power, CW-pumped, passively- Q-switched, 1.5 ns monolithic MCL with single-longitudinal mode-operation. We discuss laser design issues to bring the average power to 5-1 OW and beyond
The efficacy of a brief intervention in reducing hazardous drinking in working age men in Russia: the HIM (Health for Izhevsk men) individually randomised parallel group exploratory trial
BACKGROUND: Russia has particularly low life expectancy for an industrialised country, with mortality at working ages having fluctuated dramatically over the past few decades, particularly among men. Alcohol has been identified as the most likely cause of these temporal variations. One approach to reducing the alcohol problem in Russia is 'brief interventions' which seek to change views of the personal acceptability of excessive drinking and to encourage self-directed behaviour change. Very few studies to evaluate the efficacy of brief interventions in Russia have been conducted. Motivational Interviewing (MI) is a person-centred counselling style which can be adapted to brief interventions in which help is offered in thinking through behaviour in the context of values and goals, to decide whether change is needed, and if so, how it may best be achieved. METHODS: This paper reports on an individually randomised two-armed parallel group exploratory trial. The primary hypothesis is that a brief adaptation of MI will be effective in reducing self-reported hazardous and harmful drinking at 3 months. Participants were drawn from the Izhevsk Family Study II, with eligibility determined based on proxy reports of hazardous and harmful drinking in the past year. All participants underwent a health check, with MI subsequently delivered to those in the intervention arm. Signed consent was obtained from those in the intervention arm only at this point. Both groups were then invited for 3 and 12 month follow ups. The control group did not receive any additional intervention. RESULTS: 441 men were randomised. Of these 61 did not have a health check leaving 190 in each trial arm. Follow up at 3 months was high (97% of those having a health check), and very similar in the two trial arms (183 in the intervention and 187 in the control). No significant differences were detected between the randomised groups in either the primary or the secondary outcomes at three months in the intention to treat analyses. The unadjusted odds ratio (95% CI) for the effect of MI on hazardous and harmful drinking was 0.77 (0.51, 1.16). An adjusted odds ratio of 0.52 (0.28, 0.94) was obtained in the pre-specified per protocol analysis. CONCLUSIONS: This trial demonstrates that it is possible to engage Russian men who drink hazardously in a brief intervention aimed at reducing alcohol related harm. However the results with respect to the efficacy are equivocal and further, larger-scale trials are warranted. TRIAL REGISTRATION: ISRCTN: ISRCTN82405938
Examining the influence of corporate website favorability on corporate image and corporate reputation: findings from fsQCA
This study uses the attribution and signaling theory perspective to scrutinize the key impacts of the determinants of corporate website favorability. In addition, this paper examines the main influences of satisfaction and attractiveness on corporate image and reputation, observes the role that the demographics of consumers (gender and age) play in such relationships, and proposes a research model along with research tenets. To examine these tenets, the conceptual framework was empirically evaluated through the perceptions of 563 consumers toward the financial setting in Russia (563). This study employs complexity theory, which integrates the principle of equifinality. To examine the data, this research employs fuzzy set qualitative comparative analysis (fsQCA) and confirmatory factor analysis (CFA). Additionally, this study makes a managerial contribution to the understanding of marketing and communication managers and website designers regarding the associations among corporate website favorability, its antecedents, and its consequences
НЕПОСРЕДСТВЕННЫЕ И ОТДАЛЕННЫЕ РЕЗУЛЬТАТЫ ЭНДОПРОТЕЗИРОВАНИЯ ПРИ РАССЛОЕНИЯХ И АТЕРОСКЛЕРОТИЧЕСКИХ АНЕВРИЗМАХ ГРУДНОЙ АОРТЫ
Objective: to analyze the results of endovascular stent-graftingin dissections and atherosclerotic aneurysms of descending part of thoracic aorta.Material and method: in this analysis includes 28 patients with dissections and atherosclerotic aneurysms of descending part of thoracic aorta. Acute aortic dissection type 3 was occurred in 10 patients and two of them were complicated with rupture into the left pleural cavity. 10 patients with chronic aortic dissection type bunderwent operations and one of them was complicated with rupture into the left pleural cavity. Among 8 operated patients due to chronic aneurysms of descending part of thoracic aorta, 4 patients were manifested with symptoms of hemothorax. In 3 patients with aortic dissection type 1 in long-term period, endovascular stent-grafting was performed concerning with the dilatation of descending thoracic aorta and patent false lumen. During in-hospital and long-term periods immediate clinical results, serious clinical complications and long-term survival were compared.Results: technical success of endovascular stent-grafting was achieved in 100 % of cases. In-hospital mortality was 4 (14,2 %) and 30-day mortality was 3 (10,7 %). Events of paraplegia, TIA (Transient Ischemic Attack), prosthetic infection were not found in our research. Two clinical occurrences of vascular approach site complication were found; one case of endoleak type 1 and stent-graft dislocation which required repeated endovascular stent-grafting and one case of endoleak type 2 which was performed subclaviancarotid bypass and ligation of left subclavian artery. Prolong intubation was needed in 5 patients (18,5 %).conclusion: Endovascular stent-grafting in dissections and atherosclerotic aneurysms of descending part of thoracic aorta contributes good immediate clinical results associating with less quantity of serious complications.ЦЕЛЬ ИССЛЕДОВАНИЯ: анализ результатов эндопротезирования (ЭП) при расслоениях и атеросклеротических аневризмах нисходящего отдела грудной аорты.МАТЕРИАЛЫ И МЕТОДЫ: в анализ были включены 28 пациентов с расслоениями и атеросклеротическими аневризмами нисходящего отдела грудной аорты. Острое расслоение 3 типа было у 10 пациентов, из них у 2 пациентов имелось осложнение в виде прорыва в левую плевральную полость. С хроническим расслоением В типа прооперировано 10 пациентов, из них у 1 – прорыв в левую плевральную полость. Из 8 пациентов, оперированных по поводу хронической атеросклеротической аневризмы нисходящего отдела грудной аорты, у 4 симптомы манифестировали в виде гемоторакса. У 3 пациентов с расслоением аорты 1 типа в отдаленном периоде выполнялось эндопротезирование в связи с дилатацией нисходящей рудной аорты и функционирующим ложным просветом. В госпитальном и отдаленном периодах сравнивались непосредственные клинические результаты, серьезные клинические осложнения и отдаленная выживаемость.РЕЗУЛЬТАТЫ. Технический успех ЭП был достигнут в 100 % случаев. Госпитальная летальность составила 4 (14,2 %), 30-дневная летальность – 3 (10,7 %). Случаев параплегии, ОНМК, инфекции эндографта в нашем исследовании не было. Наблюдалось два клинических случая развития осложнений в месте сосудистого доступа; один случай эндолика 1 типа и дислокация стент-графта, требующего повторного эндопротезирования, и один эндолик 2 типа, проведено подключично-сонное шунтирование, перевязка левой подключичной артерии. Продленная интубация потребовалась у 5 пациентов (18,5 %).ВЫВОДЫ: эндопротезирование при расслоениях и атеросклеротических аневризмах нисходящего отдела грудной аорты дает хороший непосредственный клинический результат, сопровождается меньшим количеством серьезных осложнений
Polarized blazar X-rays imply particle acceleration in shocks
Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier1,2,3, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree ΠX of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock
X-ray Polarization Observations of BL Lacertae
Blazars are a class of jet-dominated active galactic nuclei with a typical
double-humped spectral energy distribution. It is of common consensus the
Synchrotron emission to be responsible for the low frequency peak, while the
origin of the high frequency hump is still debated. The analysis of X-rays and
their polarization can provide a valuable tool to understand the physical
mechanisms responsible for the origin of high-energy emission of blazars. We
report the first observations of BL Lacertae performed with the Imaging X-ray
Polarimetry Explorer ({IXPE}), from which an upper limit to the polarization
degree 12.6\% was found in the 2-8 keV band. We contemporaneously
measured the polarization in radio, infrared, and optical wavelengths. Our
multiwavelength polarization analysis disfavors a significant contribution of
proton synchrotron radiation to the X-ray emission at these epochs. Instead, it
supports a leptonic origin for the X-ray emission in BL Lac.Comment: 17 pages, 5 figures, accepted for publication in ApJ
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