Исследование характеристик пробоя твердых горючих ископаемых при воздействии джоулева тепла и частичных разрядов

Актуальность темы: оценка целесообразности применения электрофизического способа конверсии твердых горючих ископаемых. Объект исследования является тепловой и триинговый пробой в горючих сланцах. Пробой как способ формирования нагревательного элемента в толще пласта, для дальнейшей термической конверсии органических компонентов породы. Цель исследовательской работы: экспериментальное определение влияния времени воздействия частичных разрядов и джоулева тепла на напряжение и механизм пробоя. В ходе исследования была проведена серия опытов по пробою горючего сланца, выявлены зависимости характеризующие тепловой и триинговый пробой.Relevance of the topic: evaluation of the expediency of using the electro- physical method of conversion of solid fossil fuels. Object of a research is thermal and treeing breakdown in oil shales. Thermal breakdown as a method of forming a heating element in the shale formation, for further thermal conversion of organic formation components. Aim of the study is the experimental determination of the partial discharges action time influence and Joule heat influence on the voltage and the mechanism of breakdown. During the course of study, a series of experiments on the breakdown of oil shale was conducted, and dependences characterizing the thermal and triage breakdown were revealed

Методика использования виртуальной среды SolidWorks Simulation для формирования компетенций будущих инженеров

Формирование способности ассоциировать напряженно-деформированное состояние конструкций и моделей С

Androgenic suppression combined with radiotherapy for the treatment of prostate adenocarcinoma: a systematic review

<p>Abstract</p> <p>Background</p> <p>Locally advanced prostate cancer is often associated with elevated recurrence rates. Despite the modest response observed, external-beam radiotherapy has been the preferred treatment for this condition. More recent evidence from randomised trials has demonstrated clinical benefit with the combined use of androgen suppression in such cases. The aim of this meta-analysis is to compare the combination of distinct hormone therapy modalities versus radiotherapy alone for overall survival, disease-free survival and toxicity.</p> <p>Methods</p> <p>Databases (MEDLINE, EMBASE, LILACS, Cochrane databases and ClinicalTrials.gov) were scanned for randomised clinical trials involving radiotherapy with or without androgen suppression in local prostate cancer. The search strategy included articles published until October 2011. The studies were examined and the data of interest were plotted for meta-analysis. Survival outcomes were reported as a hazard ratio with corresponding 95% confidence intervals.</p> <p>Results</p> <p>Data from ten trials published from 1988 to 2011 were included, comprising 6555 patients. There was a statistically significant advantage to the use of androgen suppression, in terms of both overall survival and disease free survival, when compared to radiotherapy alone. The use of long-term goserelin (up to three years) was the strategy providing the higher magnitude of clinical benefit. In contrast to goserelin, there were no trials evaluating the use of other luteinizing hormone-releasing hormone (LHRH) analogues as monotherapy. Complete hormonal blockade was not shown to be superior to goserelin monotherapy.</p> <p>Conclusions</p> <p>Based on the findings of this systematic review, the evidence supports the use of androgen suppression with goserelin monotherapy as the standard treatment for patients with prostate cancer treated with radiotherapy, which are at high risk of recurrence or metastases.</p

Giovanni Boccaccio. Italienisch-deutscher Kulturtransfer von der Frühen Neuzeit bis zur Gegenwart

Italien und Deutschland – kaum zwei andere Kulturen in Europa sind so stark miteinander verbunden wie diese beiden, sei es geschichtlich oder kulturell. Am wirkmächtigsten war sicherlich die Übernahme des Gedankenguts der italienischen Renaissance, in deren Folge Wissen aus gesellschaftlichen, wissenschaftlichen und kulturellen Bereichen den Weg nach Deutschland fand, darunter auch die Kenntnis von Giovanni Boccaccios Werken, die sich auf deutschsprachige Kontexte auswirkten. Der vorliegende Tagungsband versammelt die Beiträge zur gleichnamigen Tagung „Giovanni Boccaccio. Italienisch-deutscher Kulturtransfer von der Frühen Neuzeit bis zur Gegenwart“ (Bamberg, 21. bis 23. November 2013), die sich mit vielfältigen Aspekten der Boccaccio-Rezeption auseinandersetzen

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Organokatalytische Chromanonsynthese und enantioselektive Synthese von Isochromanonen und polysubstituierten Cyclohexanderivaten

In this work a new organocatalytic variation for a Friedel-Crafts-type reaction of indoles with chromanones and a cyclopropanation of chromanones has been developed. Moreover, it was developed an enantioselective organocatalytic one-pot reaction of polysubstituted cyclohexanecarbaldehydes with six stereocenters from three different components. It was also possible to synthesize isochromanonderivatives by an organocatalytic procedure and thus to create an access for the synthesis of natural products. The best results for the cyclopropanation of chromanones (1) were achieved with sparteine and potassium carbonate. By varying the reaction conditions and the processing method the yield can be increased to 77% and a dr of 78:22 by using K2CO3 (Fig. 1). It was successfully performed a Friedel-Crafts-type reaction of indoles 6 and 3-nitro-chromanones 4. For this reaction was used N,N'-dimethylthiourea (5) (Fig. 2). A chiral catalyst 8 was also successfully used in this reaction (Fig. 3). The problem was the measurement of the enantiomeric excess because the products decompose on the HPLC. Also using chiral auxiliary reagents within an NMR measurement the enantiomeric excess could not be determined. Using 10 mol% of the catalyst 8 it was obtained a dr greater than 95:5 and it was measured a rotation value of -12.8 degrees. This result proves an enantiomeric excess in this reaction. It was developed an asymmetric organocatalytic one-pot reaction, which can be handled very flexible and simple. By means of this one-pot reaction sequence could easily be synthesized highly substituted cyclohexanecarbaldehydes 13 with six stereocenters (Fig. 4). The resulting cyclohexanes wear many functional groups such as a hydroxygroup, an ester, and a nitrogroup, which make further reactions possible. The first step of this one-pot reaction, the Michael addition, was initiated by the bifunctional thioureacatalyst 12. Followed by the amine-catalyzed Michael / aldol addition by means of an iminium / enamine activation were obtained good yields (22-70%) by generating three new bonds and six stereocenters. On this way excellent diastereoselectivities of >95:5 and enantioselectivities 91-98% were obtained. It could be demonstrated a simple organocatalytic access for isochromanones 16. This takes place by means of proline as catalyst by an intramolecular aldol addition. The standard system, the 2-carboxybenzaldehyde-2-oxopropylester, was obtained in quantitative yield with a diastereoselectivity of 5:1 and an enantiomeric excess 82% (Fig. 5). After recrystallization only one diastereomer with an enantiomeric excess of 90% was obtained. Furthermore, it was already possible to use some varied substrates, but they were not converted with the same success as the standard system. All other examples were either in yield or the stereoselectivity less successful. This should be improved in future studies

A comprehensive simulation tool for the analysis of password policies

Modern organizations rely on passwords for preventing illicit access to valuable data and resources. A well designed password policy helps users create and manage more effective passwords. This paper offers a novel model and tool for understanding, creating, and testing password policies. We present a password policy simulation model which incorporates such factors as simulated users, accounts, and services. This model and its implementation enable administrators responsible for creating and managing password policies to test them before giving them to actual users. It also allows researchers to test how different password policy factors impact security, without the time and expense of actual human studies. We begin by presenting our password policy simulation model. We next discuss prior work and validate the model by showing how it is consistent with previous research conducted on human users. We then present and discuss experimental results derived using the model