17 research outputs found

    Повышение точности обработки с применением активного контроля

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    An important task of modern mathematical statistics with its methods based on the theory of probability is a scientific estimate of measurement results. There are certain costs under control, and under ineffective control when a customer has got defective products these costs are significantly higher because of parts recall.When machining the parts, under the influence of errors a range scatter of part dimensions is offset towards the tolerance limit. To improve a processing accuracy and avoid defective products involves reducing components of error in machining, i.e. to improve the accuracy of machine and tool, tool life, rigidity of the system, accuracy of the adjustment. In a given time it is also necessary to adapt machine.To improve an accuracy and a machining rate there, currently  become extensively popular various the in-process gaging devices and controlled machining that uses adaptive control systems for the process monitoring. Improving the accuracy in this case is compensation of a majority of technological errors. The in-cycle measuring sensors (sensors of active control) allow processing accuracy improvement by one or two quality and provide a capability for simultaneous operation of several machines.Efficient use of in-cycle measuring sensors requires development of methods to control the accuracy through providing the appropriate adjustments. Methods based on the moving average, appear to be the most promising for accuracy control since they include data on the change in some last measured values of the parameter under control.В процессе обработки деталей под влиянием погрешностей происходит смещение поля рассеивания размеров деталей к границе допуска. Для повышения точности обработки и предотвращения получения брака необходимо уменьшать составляющие погрешности обработки: повышать точность станка и инструмента, стойкость инструмента, жесткость системы, точность настройки. Так же через определенное время необходимо произвести поднастройку станка. Но увеличение количества поднастроек снижает производительность, а повышенные требования к станку и инструменту приводят к значительному повышению стоимости обработки. Поэтому задача формирования рациональных методик контроля, позволяющих обеспечивать как некоторый заданный выходной уровень качества, так и его повышение, остаётся актуальной. В современном производстве в области управления технологическим процессом при помощи средств активного контроля задача повышения точности может быть решена выбором рационального алгоритма управления путем введения корректировок. Методы, основанные на управлении по скользящей средней, представляются наиболее перспективными для управления точностью, поскольку они включают в себя информацию об изменении нескольких по-следних измеренных значений контролируемого параметра

    Оценка влияния гидродинамической кавитационной обработки темных нефтепродуктов на выход фракций, выкипающих до 400 °С

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    Objectives. The reduction of the anthropogenic burden on the environment is generally associated with the transition to alternative energy sources. However, some of these have only regional significance, while the effectiveness of others remains doubtful. On this point, innovative processes aimed at increasing the depth of oil refining may be equally important for reducing the carbon footprint. Wave-based technologies such as cavitation may also be included in these processes. Among the various methods for inducing such cavitation phenomena in oil refining, hydrodynamic approaches are especially promising. It has been shown that the treatment effectiveness increases with greater pressure or when augmenting the number of cavitation processing cycles. The aim of this work is to identify the factor (i.e., pressure gradient or number of treatment cycles) having the greatest influence on the change of the characteristics of the oil product.Methods. Cavitation phenomena were created by pumping dark oil products through a diffuser. The pressure gradient ranged from 20 to 50 MPa, while the number of cavitation processing cycles varied from 1 to 10. The influence of cavitation conditions on the change of fractional composition of petroleum products was analyzed. Target fractions are those having a boiling point up to 400°C.Results. It is shown that increased pressure generated in the diffuser leads to a linear increase in the yield of desired cuts. The dependence of the yield of these fractions on the number of processing cycles is described by the growth model with saturation. A proposed equation describes the influence of pressure and number of cycles on the yield of the fractions from initial boiling point temperature (TIBP) to 400°C following cavitation processing of dark oil products. Some of the coefficients of this equation have been associated with the physicochemical characteristics of the feedstock.Conclusions. An equation for predicting the maximum possible yield of the TJBP-400°C fraction as a result of cavitation processing under different conditions of the process is proposed according to the physicochemical characteristics of the feedstock. The prediction error did not exceed 12%. The equation analysis and comparison of energy consumption between different process regimes shows that a higher yield of the target product is achieved by increasing pressure gradient rather than the number of processing cycles.Цели. Снижение антропогенной нагрузки человечества на окружающую среду связывают с использованием альтернативных источников энергии. Однако часть из них имеет только региональное значение, а эффективность других дискуссионна. Для сокращения углеродного следа не меньший интерес представляют инновационные процессы, направленные на увеличение глубины переработки нефти. К числу таких процессов можно отнести и волновые технологии, частным случаем которых является кавитация. Кавитационные явления для нефтепереработки создают различными методами, наиболее перспективным из которых считаются гидродинамические. Установлено, что эффективность воздействия возрастает как при повышении давления при прокачке нефтепродукта, так и при увеличении количества актов воздействия. Цель данной работы - какой из двух факторов - градиент давлений или количество циклов воздействия - оказывает большее влияние на изменение характеристик нефтепродукта.Методы. Явление кавитации создавали, прокачивая темные нефтепродукты через диффузор. Давление варьировалось от 20 до 50 МПа, а количество актов воздействия - от 1 до 10. Анализировалось влияние условий кавитации на изменение фракционного состава нефтепродуктов. В качестве целевых рассматривались фракции, выкипающие до 400 °C.Результаты. Показано, что выход целевых фракций линейно увеличивается при повышении давления, возникающего в диффузоре. Зависимость выхода этих фракций от количества циклов обработки описывается моделью роста с насыщением. Предложено уравнение, описывающее влияние давления и количества циклов на выход фракции от температуры начала кипения (ТНК) до 400 °С после кавитационной обработки темных нефтепродуктов. Установлена связь некоторых из коэффициентов этого уравнения с физико-химическими характеристиками исходного сырья.Выводы. Предложено уравнение, позволяющее по физико-химическим характеристикам исходного сырья предсказать максимально возможный выход фракции ТНК-400 °С в результате кавитационной обработки при различных условиях ведения процесса. Ошибка прогнозирования не превышает 12%. Анализ полученного уравнения и сопоставление энергозатрат при различных режимах ведения процесса показывают, что больший выход целевого продукта достигается в результате увеличения давления, а не числа циклов обработки

    Месалазин-индуцированная эозинофильная пневмония у мальчика 15 лет с язвенным колитом

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    One of the most difficult categories of patients is patients with inflammatory bowel disease. A clinical case of the development of mesalazine-induced eosinophilic pneumonia in a 15-year-old boy with ulcerative colitis is presented. The patient suffered an acute respiratory disease, which caused the aggravation of ulcerative colitis and, accordingly, an increase in the dose of mesalazine. Against this background, the child had active complaints of heaviness in the chest to the left. Eosinophilia was noted in the blood. Analysis of clinical symptoms, X-ray data, microscopic examination of the pleural fluid, the results of spiral computed tomography of the chest allowed a differential diagnosis of the main symptoms and associated identified pulmonary lesions with mesalazine.Одной из сложных категорий пациентов являются пациенты с воспалительными заболеваниями кишечника. Представлен клинический случай развития месалазин-индуцированной эозинофильной пневмонии у мальчика 15 лет с язвенным колитом. Пациент перенес острое респираторное заболевание, которое повлекло обострение язвенного колита и, соответственно, увеличение дозы месалазина. На этом фоне у ребенка появились активные жалобы на тяжесть в грудной клетке слева. В крови отмечалась эозинофилия. Анализ клинических симптомов, данные рентгенологического исследования, микроскопического исследования плевральной жидкости, результаты спиральной компьютерной томографии грудной клетки позволили провести дифференциальный диагноз основных симптомов и связать выявленные легочные поражения с воздействием месалазина

    Tablet Development for a Hydroscopic Drug Using Solid Dispersion

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    Introduction. Traumatic brain injury is a damage to the brain from an external mechanical force, possibly leading to permanent or temporary impairment of cognitive, physical, and psychosocial functions. It is a leading cause of death and disability among children and young adults. In connection with the above, the objective of developing new, more effective nootropic and antiasthenic drugs in the framework of restorative neurology is considered as one of the priority tasks of medical science in Russia.Aim. Development the composition and technology of tablets containing a hygroscopic substance using solid dispersions.Materials and methods. The pharmaceutical substance of a diethylaminoethanol derivative having antihypoxic, neuroprotective, adaptogenic and antioxidant effects is a hygroscopic powder. PEG 6000 was chosen as a matrix for solid dispersion production. Solid dispersions were obtained by high shear mixing and hot-melt extrusion. The technological properties of granulate and the quality indicators of the tablets were determined according to the methods described in the State Pharmacopoeia of the Russian Federation (14th edition).Results and discussion. The lactose mixed with the DEAE-PEG composition alloy improve the technological properties of granulate.Conclusion. A decrease water-absorbing ability of DEAE was achieved using PEG 6000 as a matrix carrier. The increase PEG content did not lead to a significant change in the kinetics of the release of DEAE from tablets

    Development of the Composition and Technology of New Neuroprotective Drug Tablets Using Fractional Factorial Design

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    Introduction. The creating an effective and safe domestic neuroprotective medicines with a complex of pleiotropic effects realized through specific orphan receptors (SUCNR1, HCA2) of glial cells, is a pressing problem of modern pharmacology and a promising possibility of pharmacotherapy of brain injury and cerebrovascular diseases. Ideally, the medicine should helps restore lost cognitive functions and physical performance after damage to the central nervous system, and its use should improve the quality of life of patients and reduce the risk of complications.Aim. To develop composition and technology of a new medicine tablets with neuroprotective effect, using fractional factorial design of experiment and the Harrington desirability function.Materials and methods. The shape and size of particles, physicochemical (solubility, melting point) and technological properties (bulk density, compressibility factor, fractional composition, hygroscopicity) of the pharmaceutical substance of DEAE derivative were studied according to the methods described in the State Pharmacopoeia of the Russian Federation (14th edition). A three-factor fractional plan based on the 4 × 4 Latin square design for selection a scientifically based composition of solid dosage form was chosen. 16 experiments to test the significance of the factors were carried out. The tablets obtained according to the planning matrix were investigated for disintegration; tablet crush resistance, friability, and hygroscopicity. To optimize the quality of the tablets, the generalized Harrington desirability function was used.Results and discussion. The study of the physicochemical and technological properties of the DEAE derivative substance showed that it is a highly hygroscopic, amorphous, white or pale yellow, odourless powder, prone to the formation of agglomerates. The powder is very easily soluble in water. Taking into account the values of the general desirability function, the best result was shown by sample № 4 consisting of mannitol, calcium stearate, and partially pregelatinized maize starch.Conclusion. The physicochemical and technological properties of the DEAE derivative were studied. The DEAE derivative is a highly hygroscopic substance. Via the method of mathematical planning of the experiment the composition of DEAE derivative tablets was selected and scientifically grounded: DEAE derivative 60 mg, mannitol, partially pregelatinized maize starch, calcium stearate. The average tablet weight is 300 mg. The parameters of pressing tablets were selected

    The antimicrobial activity and toxicity od alkyltetrahydroisoquinolones

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    The antibacterial and antifungal activity against gram-positive and gram-negative bacteria and Candida albicans fungal strain for alkyltetrahydroisoquinoline derivatives were evaluated. It was established, that 1,11-bis(6,7-Dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)undecan shows pronounced antibacterial properties against all the microorganism strains and strong antifungal activity against Candida albicans with greater inhibition area than the reference drug. IC50 value of the compound is 2,1±0,1 μg/ml, LD50 value is 324,9±18,2 mg/kg

    Mesalazin-induced eosinophilic pneumonia in a 15-year-old boy with ulcerative colitis

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    One of the most difficult categories of patients is patients with inflammatory bowel disease. A clinical case of the development of mesalazine-induced eosinophilic pneumonia in a 15-year-old boy with ulcerative colitis is presented. The patient suffered an acute respiratory disease, which caused the aggravation of ulcerative colitis and, accordingly, an increase in the dose of mesalazine. Against this background, the child had active complaints of heaviness in the chest to the left. Eosinophilia was noted in the blood. Analysis of clinical symptoms, X-ray data, microscopic examination of the pleural fluid, the results of spiral computed tomography of the chest allowed a differential diagnosis of the main symptoms and associated identified pulmonary lesions with mesalazine
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