76 research outputs found
Determination of basic calculation and experimental parameters of device for bore hole cleaning
Purpose. To substantiate the design and operating technological parameters of the device for the interval bore hole cleaning departing from the set dependences of active jets formation in the flow through the blade element.
Methods. Application of bench and analytical research techniques allowed to establish the fundamental principles of active jets formation in the flow through the blade element of the designed device and the nature of their impact on the processed objects.
Findings. Bench testing of the device for the interval bore hole cleaning resulted in defining aspects of the mechanism of active fluid jets formation. We studied the distribution of speed components in the workflow. The use of tilted surface for the formation of the blade profile has been justified. As a result of studying the physical model of the device working body, we received data regarding its structural design. Information about the peculiar hydrodynamics of the flow around the blade node with respect to the process of removing clay-mud agglomerates has been provided. The indicators of the effectiveness of the designed device were designated.
Originality. The steady flow through the blade element and consequently the removal of clay-mud agglomerates is provided by well-defined structural design characteristics which determine hydrodynamic aspects of the unit operation.
Practical implications. The results of laboratory and analytical studies are the base for designing the operating parameters of the process of preparing a bore hole for casing running and subsequent plugging of the bore hole with a guaranteed provision of high technical and economic indicators. Data for the study of the flow mode through the blade element are the basis for the hydrodynamic calculation of the device for the interval cleaning.Мета. Обґрунтування конструктивного виконання технологічних і режимних параметрів роботи пристрою поінтервального очищення стовбура свердловини виходячи із встановлених закономірностей формування активних струменів рідини при обтіканні лопатевого елемента.
Методика. Стендовими і аналітичними прийомами досліджень встановлені основні принципи формування активних струменів при обтіканні лопатевого елемента проектованого пристрою і характер їх впливу на об’єкти обробки.
Результати. В результаті проведення стендових досліджень пристрою поінтервального очищення стовбура свердловини встановлені аспекти механізму формування активних струменів рідини. Вивчено розподіл швидкісних складових в робочому потоці. Обґрунтовано застосування гвинтової поверхні для утворення контуру лопаті. На основі розгляду фізичної моделі робочого органу пристрою отримані дані щодо його конструктивного оформлення. Наведено відомості про особливості гідродинаміки обтікання лопатевого вузла стосовно процесу видалення шламових скупчень. Визначені показники результативності застосування проектованого пристрою.
Наукова новизна. Стійкому режиму обтікання лопатевого органу і як наслідок видалення шламових скупчень відповідають цілком певні конструктивні характеристики, що визначають гідродинамічну сторону функціонування пристрою.
Практична значимість. Отримані результати лабораторних та аналітичних досліджень є базовими для проектування режимних параметрів процесу підготовки свердловини до спуску обсадної колони і подальшого тампонування стовбура з гарантованим забезпеченням високих техніко-економічних показників. Дані по вивченню режиму обтікання лопатевого елемента являють собою основу гідродинамічного розрахунку пристрою поінтервального очищення.Цель. Обоснование конструктивного исполнения и режимных технологических параметров работы устройства поинтервальной очистки ствола скважины, исходя из установленных закономерностей формирования активных струй жидкости при обтекании лопастного элемента.
Методика. Стендовыми и аналитическими приемами исследований установлены основополагающие принципы формирования активных струй при обтекании лопастного элемента проектируемого устройства и характер их воздействия на объекты обработки.
Результаты. В результате проведения стендовых исследований устройства поинтервальной очистки ствола скважины установлены аспекты механизма формирования активных струй жидкости. Изучено распределение скоростных составляющих в рабочем потоке. Обосновано применение винтовой поверхности для образования контура лопасти. На основе рассмотрения физической модели рабочего органа устройства получены данные относительно его конструктивного оформления. Приведены сведения об особенностях гидродинамики обтекания лопастного узла применительно процессу удаления шламовых скоплений. Обозначены показатели результативности применения проектируемого устройства.
Научная новизна. Устойчивому режиму обтекания лопастного органа и как следствие удаления шламовых скоплений соответствуют вполне определенные конструктивные характеристики, определяющие гидродинамическую сторону функционирования устройства.
Практическая значимость. Полученные результаты лабораторных и аналитических исследований являются базовыми для проектирования режимных параметров процесса подготовки скважины к спуску обсадной колонны и последующему тампонированию ствола с гарантированным обеспечением высоких технико-экономических показателей. Данные по изучению режима обтекания лопастного элемента представляют собой основу гидродинамического расчета устройства поинтервальной очистки.Авторы считают необходимым выразить слова признательности всем сотрудникам кафедр техники разведки месторождений полезных ископаемых (Национальный горный университет, Днепропетровск, Украина) и технологии и техники бурения скважин (Национальный исследовательский технический университет им. К.И. Сатпаева, Алматы, Казахстан), так или иначе принимавшим участие в проведении стендовых исследований
Evaluation of contamination of cow milk with various conditionally pathogenic microflora for mastitis: genera Staphylococcus
The food safety issue of livestock products concerning insemination by opportunistic and accompanying microflora has attracted increasing attention from specialists. The ever-increasing trade and export of dairy and meat products from Ukraine to the EU countries requires constant monitoring of inoculation with mesophilic-aerobic and facultatively anaerobic microorganisms and psychrophilic microorganisms, in particular the genera Listeria and Yersinia, which survive and multiply at low temperatures and in salted and fermented products and pose a threat to human health. Milk and lactic acid products make up a significant part of the diet of a modern person. Therefore, constant control of raw materials from dairy enterprises for the production of milk and directly at enterprises for its processing is a guarantee of food safety. At the stage of milk production, due to violations of technological cycles of production (mastitis and contamination with antibiotics) and the spread of several diseases in Ukraine (paratuberculosis, tuberculosis, leptospirosis, brucellosis), milk from a herd of dairy cows poses a significant threat to human health due to the danger of mastitis milk and milk containing the causative agents of tuberculosis, brucellosis, leptospirosis, and recently there are more and more reports about the association of bovine paratuberculosis and human short bowel syndrome (Crohn's disease) mainly among the young population of Europe, which may be due to extreme variability and adaptive capacity mycobacteria
Small hive beetle (Aethina tumida) threat on the horizon
Beekeeping is an agricultural industry that deals with breeding bees, obtaining honey, wax, and other products. Bees are used for pollination of many types of crops to increase their harvest. Beekeeping products are also used in medicine, pharmacology, chemical, and food industries. One of the essential aspects of successful beekeeping development is ensuring sustainable epizootic well-being from infectious and invasive bee diseases in Ukraine. About 3 million bee colonies are owned by private farms and amateur beekeepers, which give approximately 50-60 thousand tons of commercial honey and 1.2–1.4 thousand tons of wax per year at the current stage of beekeeping development in Ukraine. Honey and bee products from Ukraine received 15 prestigious awards in various categories at the 77th National Honey Show, held in London among many countries in 2008. In recent years, there has been a constant increase in the threat of new little-known invasive and infectious diseases that pose a significant danger to beekeeping worldwide. The invasion of the small hive beetle Aethina tumida belongs to quarantine and hazardous invasive diseases, which have destroyed many bee colonies in several countries worldwide (USA, Canada, African countries, Australia, some European countries – Italy, and Portugal). There are no effective methods of preventing and controlling the small hive beetle. The only way to prevent the invasion of the small hive beetle in Ukraine is constant monitoring and control at the state border of the movement of bee packages and bee products, which may pose a threat to introducing this invasive species into Ukraine
Electromagnetic torque of valve engine with nonmagnetic anchor
Получены расчетные соотношения электромагнитной момента секции вентильного двигателя с немагнитным якорем на интервале коммутации и определено ее общее выражение при 120-градусном законе коммутации. Произведена оценка пульсаций электромагнитного момента, обусловленных дискретной коммутацией секций якорной обмотки.The ratios for the electromagnetic moment calculation on the switching period in the section of the BLDC with a non-magnetic armature are obtained and general expression of the electromagnetic force at 120-degree switching law is determined. The estimation of the electromagnetic force ripple caused by discrete switching in the armature winding sections is performed
Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool
Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively
East Eurasian ancestry in the middle of Europe: Genetic footprints of Steppe nomads in the genomes of Belarusian Lipka Tatars
Medieval era encounters of nomadic groups of the Eurasian Steppe and largely sedentary East Europeans had a variety of demographic and cultural consequences. Amongst these outcomes was the emergence of the Lipka Tatars-a Slavic-speaking Sunni-Muslim minority residing in modern Belarus, Lithuania and Poland, whose ancestors arrived in these territories via several migration waves, mainly from the Golden Horde. Our results show that Belarusian Lipka Tatars share a substantial part of their gene pool with Europeans as indicated by their Y-chromosomal, mitochondrial and autosomal DNA variation. Nevertheless, Belarusian Lipkas still retain a strong genetic signal of their nomadic ancestry, witnessed by the presence of common Y-chromosomal and mitochondrial DNA variants as well as autosomal segments identical by descent between Lipkas and East Eurasians from temperate and northern regions. Hence, we document Lipka Tatars as a unique example of former Medieval migrants into Central Europe, who became sedentary, changed language to Slavic, yet preserved their faith and retained, both uni-and bi-parentally, a clear genetic echo of a complex population interplay throughout the Eurasian Steppe Belt, extending from Central Europe to northern China
Potential interactions between invasive Fusarium circinatum and other pine pathogens in Europe
Prevalence of Markers of Certain Blood-Borne Viral Infections in Pregnant Women and Their Partners in the Republic of Guinea
The aim of the work was to estimate the prevalence of HIV, HBV and HCV markers among pregnant women and their male partners in the Republic of Guinea.Materials and methods. The material of the study was blood plasma samples from 140 pregnant women living in Kindia prefecture and N’Zerekore prefecture, as well as 60 male partners who reported sexual contact with HIV-infected persons. The samples were examined for the presence of serological (HBsAg, HBeAg, antibodies anti-HBs IgG, anti-HBcore IgG, anti-HBe IgG, anti-HCV IgG, Ag/Ab-HIV) and molecular (HBV DNA, HCV RNA, HIV RNA) markers.Results and discussion. The age of the examined pregnant women ranged from 13 to 55 years and was on average (26.29±9.67) years. The age of men varied from 15 to 60 years, on average – (29.05±11.99) years. When assessing the prevalence of serological markers, antibodies to HCV were detected in 2.14 % cases in women and in 3.33 % cases in men. Antibodies to HIV were found in 6.43 % and 6.67 % women and men, respectively. Serological markers associated with HBV were detected in 80.71 % (HBsAg – 13.57 %) of women and 81.67 % (15 %) of men. In the pregnant women, HCV RNA was not detected, HIV RNA was revealed in 1 case, HBV DNA was identified in 26 cases (18.57 %), including 5 % HBsAg-negative hepatitis B cases. In the men group, HCV RNA and HIV RNA were detected in 3.33 % and 6.67 % cases, respectively. HBV DNA was determined in 16.67 % of men, including latent hepatitis B in one person. A significantly higher incidence of HIV in men compared to women is shown (χ2=3.907 at p<0.05). The relative risk of HIV infection in men is nine times higher than in women: RR=9.333; p=0.0291; 95 % CI: 1.065–81.815 %. Four out of five identified HIV infection cases were co-infected with HBV and/or HCV. There is an obvious need to introduce screening for HIV, HCV, HBV, including latent hepatitis B, into routine laboratory diagnostics during examination of pregnant women and their partners, followed by couples counseling and vaccination against hepatitis B virus
Comparative Analysis of the Antineoplastic Activity of C60 Fullerene with 5-Fluorouracil and Pyrrole Derivative In Vivo
Використання професійно-орієнтованих текстів у процесі вивчення іноземної мови студентами заочного відділення в немовних ВНЗ
Давиденко, О. Б. Використання професійно-орієнтованих текстів у процесі вивчення іноземної мови студентами заочного відділення в немовних ВНЗ / О. Б. Давиденко Гуманіт. вісн. НУК. – Миколаїв : НУК, 2010. – Вип. 3. – С. 117–118.Проаналізовано читання як засіб навчання. Розглянуті основні методи роботи з професійно-орієнтованими текстами студентами заочного відділенняReading as means of teaching is represented. The basic methods of working with the texts for specific purposes by part-time students are examined
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