75 research outputs found

    The research of sapropels as the drilling fluids in dispersed phase (Lake Kirek)

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    This research describes the application of Kirek Lake sapropel as a drilling fluid in dispersed phase which could replace traditionally used clay powders in drilling fluids. Sapropel is century-old bed silt of freshwater lakes of more than 12 000 years, i.e. Holocene. It consists of natural organic and inorganic substances and chemically is a complex multicomponent biogenic genesis system. Humic complexes and wulfonic acids, polysaccharides, carbonic and protein polymers comprise sapropel suspension texture. This article introduces formulations and laboratory research of sapropel suspensions and thermal activation

    Synthesis of Carboxymethyl Starch for increasing drilling mud quality in drilling oil and gas wells

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    This paper describes the impact of carboxymethyl starch preparation conditions on physicochemical properties of polysaccharide reagent, widely used as fluid loss reducing agent in drilling mud. Variation of the main parameters of carboxymethylation is researched in the experiment. The following conditions such as temperature and reaction time, amount of water, as well as ratio of NaOH to monochloracetic acid define the characteristics of carboxymethyl starch. The degree of substitution is defined for polysaccharides, as well as the characteristics of samples have been studied by infrared spectroscopy. Rheological characteristics and fluid loss indicator have been investigated to study the impact of the reagents on drilling mud quality

    Arbitrary trajectory foot planner for bipedal walking

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    © 2017 by SCITEPRESS - Science and Technology Publications, Lda. All Rights Reserved. This paper presents a foot planner algorithm for bipedal walking along an arbitrary curve. It takes a parametrically defined desired path as an input and calculates feet positions and orientations at each step. Number of steps that are required to complete the path depends on a maximum step length and maximum foot rotation angle at each step. Provided with results of the foot planner, our walking engine successfully performs robot locomotion. Verification tests were executed with AR601M humanoid robot

    Comparing fiducial marker systems in the presence of occlusion

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    © 2017 IEEE. A fiducial marker system is a system of unique 2D (planar) marker, which is placed in an environment and automatically will be detected with a camera with a help of a corresponding detection algorithm. Application areas of these markers include industrial systems, augmented reality, robots navigation, human-robot interaction and others. Marker system designed for such different applications must be robust to such factors as view angles, occlusions, changing distances, etc. This paper compares three existing systems of markers: ARTag, AprilTag, and CALTag. As a benchmark, we use their reliability and detection rate in presence of occlusions of various types and intensity. The paper presents experimental comparison of these markers. The marker detection was performed with a simple inexpensive Web camera

    Long-Wave Instability of Advective Flows in Inclined Layer with Solid Heat Conductive Boundaries

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    We investigate the stability of the steady convective flow in a plane tilted layer with ideal thermal conductivity of solid boundaries in the presence of uniform longitudinal temperature gradient. Analytically found the stability boundary with respect to the long-wave perturbations, find the critical Grashof number for the most dangerous among them of even spiral perturbation.Comment: in Russian, 18 pages, 5 figures, submited to Appl. mechanics and physics, RAS Siberian brunch, Novosibirsk, Russia; Key words: advective flow, oblique layer, a longitudinal temperature gradient, long-wave instabilit

    Determination of optimal technology for manufacturing dental surgical guides

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    © Published under licence by IOP Publishing Ltd. This article describes methods of manufacturing surgical guides - their creation in rapid prototyping installations and milling machine grinding. Implantation was carried out using the obtained guides and derating level of installed implants was defined. The work compares existing technologies of surgical guides production and defines a clear advantage of using laser stereolithography technology for product manufacture in quantities greater than one

    Synthesis of Carboxymethyl Starch for increasing drilling mud quality in drilling oil and gas wells

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    This paper describes the impact of carboxymethyl starch preparation conditions on physicochemical properties of polysaccharide reagent, widely used as fluid loss reducing agent in drilling mud. Variation of the main parameters of carboxymethylation is researched in the experiment. The following conditions such as temperature and reaction time, amount of water, as well as ratio of NaOH to monochloracetic acid define the characteristics of carboxymethyl starch. The degree of substitution is defined for polysaccharides, as well as the characteristics of samples have been studied by infrared spectroscopy. Rheological characteristics and fluid loss indicator have been investigated to study the impact of the reagents on drilling mud quality

    Acute Adhesive Small Bowel Obstruction: a Comparative Analysis of Open and Laparoscopic Surgery

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    Background. Acute adhesive small bowel obstruction (AASBO) is a common surgical emergency requiring immediate interventions. AASBO is a usual indication for both small bowel resection and adhesiolysis. Postoperative adhesions cause 60% of small bowel obstructions.Materials and methods. An analysis of treatment outcomes is presented for 197 acute adhesive small bowel obstruction patients; 63 patients had urgent laparotomy, and 134 were scheduled for laparoscopy. The examination included physical, laboratory, radiological methods (abdominal radiography, ultrasound, CT scan), laparoscopy and intra-abdominal pressure monitoring.Results and discussion. Of 134 patients scheduled for laparoscopic adhesiolysis, only 46.2% had laparoscopy completed, and 53.8% required conversion to laparotomy. The main rationale for conversion were massive adhesions, intraoperative haemodynamic instability, a need for intestinal decompression, as well as rare complications. Laparoscopic operations were reported with the lower vs. laparotomy rates of surgical complications (6.4  vs. 12.69%), mortality (6  vs. 6.3%), shorter hospital stays (6.5 vs. 12 days) and operation times (75 vs. 118 min, respectively).Conclusion. Laparoscopic surgery in acute adhesive small bowel obstruction was feasible in 31.47% patients and in 46.2% — after a diagnostic laparoscopy; however, a thorough patients selection for laparoscopic adhesiolysis is necessary. The first estimated should be the patient’s haemodynamic stability, the severities of condition, adhesions and comorbid cardiorespiratory pathology. Grade I—II adhesions are an indication for laparoscopic surgery

    ВЫЯВЛЕНИЕ НЕБЛАГОПРИЯТНЫХ ФАКТОРОВ, СПОСОБСТВУЮЩИХ РАЗВИТИЮ МИОПИИ У СТУДЕНТОВ МЕДИЦИНСКИХ КОЛЛЕДЖЕЙ

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    To define the risk factors of myopia development among the students the authors got acquainted with spreading of the pathology among the students and their parents. 313 students of Tuimaizy medical college (at the age of 16 to 22 ys) and their parents (n = 579) participated in the study. Attention was paid to the internal factors (heredity, family atmosphere, quality of life) and to the external factors (the life, intensity in studying) -the factors promoting development of myopia. Special psychomedico-pedagogical commission has been organized for better health protection of the organ of vision in teenagers in Tuimaizy medical college.С целью определения факторов риска развития миопии среди студентов была изучена распространенность данного заболевания у студентов и их родителей. Проведено исследование студентов Туймазинского медицинского колледжа в возрасте от 16 до 22 лет, всего 313 человек, и их кровных родителей - 579 человек. В процессе исследования были выявлены следующие факторы: внутренние (наследственно-семейная среда, качество жизни) и внешние (образ жизни, интенсивность учебного процесса), способствующие возникновению или дальнейшему развитию миопии. Для укрепления здоровья органа зрения подростков на базе Туймазинского медицинского колледжа организована психолого-медико-педагогическая комиссия. Ведется комплексная работа, в которой участвуют психолог, преподаватели колледжа, фельдшер, офтальмолог, что обеспечивает массовую профилактику близорукости среди студентов

    Başkortostan Cumhuriyeti Toratau Jeoparki bal arısı (apis mellifera) popülasyonunda tergit rengi değişimi

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    A phenetic analysis of the honey bee population of the Toratau Geopark (Russia) was performed. Over 1,000 worker and drone bee samples were collected from 250 colonies in 59 apiaries on the territory of the Toratau Geopark (Gafuriysky, Ishimbaysky, Meleuzovsky, and Sterlitamaksky districts of the Republic of Bashkortostan). Six phenes in worker bees and four phenes in drone bees were recognized. The phenes E, 1R, 2R, and 3R in workers and Is, I, and O-gray in drones were predominant in the honey bee population of the Toratau Geopark, which were associated with subspecies of the Clineage. These phenes can be used as indicators of introgressive hybridization in the local dark European honey bee population. The phenes allow for quick evaluation of certain honey bee colonies hybridization states.Toratau Jeoparkı'ndaki (Rusya) bal arısı popülasyonunun fenetik analizi yapılmıştır. Toratau Jeoparkı topraklarındaki (Başkurdistan Cumhuriyeti'nin Gafuriysky, Ishimbaysky, Meleuzovsky ve Sterlitamaksky bölgeleri) 59 arılıktaki 250 koloniden 1.000'den fazla işçi ve erkek arı örneği toplanmıştır. İşçi arılarda altı fen ve erkek arılarda dört tergit rengi tespit edilmiştir. İşçilerde E, 1R, 2R ve 3R ve erkek arılarda Is, I ve O-gri fenleri Toratau Jeoparkı'ndaki bal arısı popülasyonunda baskındı ve bunlar C soyunun alt türleriyle ilişkiliydi. Bu tergit rengi, yerel koyu Avrupa bal arısı popülasyonunda içsel melezleşmenin göstergeleri olarak kullanılabilir. Bu tergit renkleri, belirli bal arısı kolonilerinin melezleşme durumlarının hızlı bir şekilde değerlendirilmesine olanak sağlamaktadır.The article was prepared with supporting the grant of the head of the Republic of Bashkortostan Radiy Khabirov, grant title "Study of the Bashkir bee population on the territory of the Toratau Geopark
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