Academic literature on the topic 'Drum mills'
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Journal articles on the topic "Drum mills"
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Fistes, Aleksandar, and Gavrilo Tanovic. "The effect of using the drum detachers in the industrial wheat flour mills." Acta Periodica Technologica, no. 44 (2013): 49–56. http://dx.doi.org/10.2298/apt1344049f.
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The work is concerned with the effects of applying the drum detachers as flake disrupters in industrial wheat flour mills. The stocks entering and leaving the drum detachers applied on the different reduction passages in two industrial mills were intercepted and employed in the experiments. The changes in the flour release and flour ash content were followed. The results show that the drum detachers are effective in disrupting the flakes formed in the smooth roller mills grinding zone. However, the contribution of the drum detachers to the overall milling efficiency is in close correlation with the nature of the formed flakes. If the flakes are primarily composed of endosperm particles, the employment of drum detacher results in a statistically significant increase of the flour yields without deterioration of flour quality. If flakes, formed on the end passages of the reduction system, contain large portion of branny particles, the increase of the flour ash content following the drum detacher is statistically significant.
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Meshcheriakov, L., A. Kozhevnykov, and S. Prykhodchenko. "Intellectual agents of targets in analytical constructing of optimum systems of management of drum mills." Collection of Research Papers of the National Mining University 64 (2021): 264–72. http://dx.doi.org/10.33271/crpnmu/64.264.
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Purpose. Justification of the rational use of intellectual agents in forming of the quasi-optimal systems of management furnaces of complexes of type drum mills as observers of complete order. A method of research consists of decision of the best laws management by the mining complexes by the use of methods of the analytical constructing of optimum regulators withthe input in their structures of such essences as intellectual agents as observers of complete order. Results of research. Management by the mining and processing complexes it is perspective to carry out on the basis of the quasi-optimal systems of management. Taking into account properties and sensitiveness of intellectual agents, expediently to include them at the analytical constructing of regulators in the structure of observers of complete order. This increases in accordance with securing functional of quality criterion of exactness of optimum stabilization of rational technology of process of growing shallow in the drum mills. Scientific novelty. A new structure is set of the quasi-optimal system of management by the technological dynamics of drum mills with the asymptotic observer of complete order. Of efficiency of recognition and operative management it is suggested to carry the rise out on the basis of functional possibilities of intellectual agents of targets, as which an observer comes forward of complete order in aggregate with the considered technological processes in the mining and processing complexes. Practical value. Results of researches allow to recommend a rational chart of quasi-optimal management by the drum mills in accordance with the set criterion. In the spectrum of the active power consumable by the drive electric motor technological constituents are selected, which are conditioned by the difficult vibrations of ore mass of filling of drum. Their maximal values are selected ekstremum by detector and are watched by the observer of complete order with the optimum stabilization. This allows to secure intensification of return of the prepared class.
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SHARP, W. B. A. SANDY, and W. A. BILLY JONES. "Evaluation of near-drum thinning data in recovery boiler generating bank tubes." July 2016 15, no. 7 (August 1, 2016): 491–500. http://dx.doi.org/10.32964/tj15.7.491.
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Near-drum thinning affects the fireside surface of recovery boiler generating bank tubes near the surface of the mud drum. Although sophisticated thickness scanning equipment has been developed to rapidly make tens of thousands of thickness measurements in the portion of a tube that is vulnerable to near-drum thinning, methods for using these data to evaluate fitness-for-service have not shown similar advances. Non-destructive testing companies typically use a technician’s subjective judgment to identify the “thinnest reliable" thickness measurement on each tube. Some mills decide whether tubes can continue in operation or should be plugged or replaced based on this single thickness measurement. However, finite element analysis of the remaining strength of individual tubes thinned in the near-drum area suggests that it is essentially impossible to identify the weakest tubes from simple empirical rules. In the absence of an industry standard for evaluating these data, different mills could reach different conclusions about the fitness-for-service of a tube from the same data set. This paper reviews the technology for scanning the thickness of generating bank tubes and discusses approaches that have been used to identify the tubes most weakened by near-drum thinning and to evaluate the fitness-for-service of individual tubes.
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Chyrkun, Dzmitry Ivanovich, Aliaksandr Eduardovich Leudanski, Vladimir Grigorievich Golubev, Didar Sarsenbekuly, and Serik Arginbaevich Kumisbekov. "ANALYSIS OF INDUSTRIAL DRUM MILLS’ OPERATION AND WAYS OF THEIR IMPROVEMENT." SERIES CHEMISTRY AND TECHNOLOGY 6, no. 432 (December 15, 2018): 102–8. http://dx.doi.org/10.32014/2018.2518-1491.32.
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Vynohradov, Borys, Veronika Karpenko, Olena Lahoshna, Kostiantyn Bas, and Iryna Slovska. "The ways to enhance durability and bearing capacity of the open gear drum mills." Mining of Mineral Deposits 15, no. 3 (September 2021): 87–94. http://dx.doi.org/10.33271/mining15.03.087.
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Purpose is substantiating ways to enhance durability and bearing capacity of open gears of ore-pulverizing drum mills as well as efficiency of engineering solutions concerning the increase in their unit power at the expense of drive improvement. Methods. Results of continual experiments and theoretical studies have been generalized as for the abrasion of working surfaces of open gear teeth of drum mills and factors influencing load distribution in terms of a tooth rim width. Findings. Comparative analysis between domestic mills and the best world-class products has been carried out. Ways of solving problems to design large-capacity mills with a gearbox drive have been demonstrated. Influence of hardness of working teeth surfaces on their durability has been evaluated quantitatively. The factors, governing load distribution in terms of tooth rim width, have been analyzed. Use of self-adjusting gear drives for open gears has been evaluated. Originality. Functional relation between stress-strain properties of working surface of teeth; the number of running-in modes, determined by operational conditions; and durability of open gear has been identified. The factors, influencing load distribution in terms of tooth rim width, have been considered. Practical implications. It has been shown that use of such open gears, where hardness of working surface of gear teeth is (500-600) H1B1 and that of a tooth rim one is (260-300) H2B2, makes it possible to provide almost wear-free operation. Moreover, it is the required condition for the performance of a tooth rim with two drive gears.
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Pershin, V. F., G. B. Zhumagaliyeva, A. G. Tkachev, A. A. Pasko, and A. M. Vorobyev. "Production of graphene concentrates based on synthetic oils in rod drum mills." IOP Conference Series: Materials Science and Engineering 693 (November 28, 2019): 012035. http://dx.doi.org/10.1088/1757-899x/693/1/012035.
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Mikulionok, Іgor, Аnton Karvatskii, Serhii Leleka, and Olena Ivanenko. "Roll crushers and mills (Design review)." Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, no. 1 (March 29, 2022): 30–43. http://dx.doi.org/10.20535/2617-9741.1.2022.254157.
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The classification of roll crushers and mills for the disintegration of lumpy and loose materials processed at the enterprises of chemical, mining, construction, food and electrode industries, as well as in metallurgy, has been developed. A critical review of the most typical designs of roll crushers and mills proposed by scientists, designers and inventors of the world’s leading countries has been performed. The designs are analyzed according to the number of rolls, type of roll surface, shape of rolls, relative speed of working surface of rolls, possibility of roll surface temperature control, availability of additional working elements, as well as roll surface material.
Analysis of the designs of roll crushers and mills for the disintegration of lumpy and granular materials shows that they exist in numerous standard sizes, but conventional two-roll crushers with smooth, fluted and toothed rolls remain the most demanded by industry. In this case, the most promising area for improvement of roll crushers and mills is to develop designs of crushing elements for the working surface of rolls and materials for their manufacture.
In the future, it is planned to analyze the designs of other types of crushing equipment widespread in industry, such as jaw crushers and drum mills, as well as ways to improve their efficiency.
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Ostanovsky, Alexander. "IMPROVING THE EFFICIENCY OF FUNCTIONING OF DYNAMIC AUTOGENOUS MILLS DUE TO CYCLICAL DRUM BRAKE." University News. North-Caucasian Region. Technical Sciences Series, no. 2 (June 2016): 84–89. http://dx.doi.org/10.17213/0321-2653-2016-2-84-89.
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Koval', G. I., and Т. G. Kаrimоvа. "Calculation of roll calibration of rolling-forging mills using the rolling pattern “smooth drum – circle”." Bulletin of the South Ural State University Series ‘Metallurgy’ 16, no. 1 (2016): 72–77. http://dx.doi.org/10.14529/met160110.
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Федоренко, Mikhail Fedorenko, Бестужева, Olga Bestuzheva, Бондаренко, and Yuliya Bondarenko. "DETERMINATION OF RATIONAL PARAMETERS OF ROTARY SURFACE TREATMENT ROTATION WHEN RESTORING LARGE PARTS." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 1, no. 12 (November 11, 2016): 121–25. http://dx.doi.org/10.12737/22647.
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In various industries for production of cement, lime, gypsum, ceramic products for grinding solid materials using ball tube mills. In the process of operation under load of the mill, the wear of the main bearings of the drum tube mills – axles, with the result that on the surface appear different defects. The quality and performance of cement plants are directly dependent on the accuracy of its reconstruction, repair and content validity, determining largely technical and economic effect from the use of modern technical devices. Mill work in the area of large dynamic loads, leading to loss of efficiency and as a result long downtime to repair. With a view to their reduction, currently, to restore industrial equipment used in portable machines. Optimization of processing of surfaces of rotation when restoring large parts will allow you to obtain a rational combination of the varied parameters.
Dissertations / Theses on the topic "Drum mills"
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Гопка, Олександр Юрійович. "Трубний млин 4.6х10 з модернізацією корпусу." Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/26951.
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Метою роботи є пошук варіантів модернізація корпусу трубного
млина в літературних джерелах і патентах. В даній роботі розглядається модернізація футеровки барабану трубного млина, яка забезпечує підвищення ефективності подрібнення за рахунок ступінчатої футеровки. Також було розглянуто модернізацію корпусу яка забезпечує покращення
теплового режиму в робочій камері.Під час роботи було проведено параметричні та кінематичні
розрахунки млина та розрахунки на міцність окремих його вузлів.
Виконані креслення вузлів, загального вигляду. Було розроблено правила з техніки безпеки на виробництві, Розроблено систему автоматизації процесу помелу в трубному млині, а також рекомендації з технології монтажу та експлуатації машини. Були розробленні програми для автоматизованого виконання креслень вузлів трубного млина, в результаті були отримані 3D моделі. Отриману 3D модель використали для проведення розрахунків на міцність в системі Ansys. Виконані розрахунки, а також модернізації дипломної роботи можна використовувати для роботи з подальшим вдосконалення трубних млинів.The aim of the work is to search for options for upgrading the body of the pipe mill in the literature and patents. In this paper, we consider the modernization of the lining of the drum of the tube mill, which provides an increase in the efficiency of grinding by means of a stepped lining. It was also reviewed the modernization of the housing which provides improved thermal conditions in the working chamber. During the work, parametric and kinematic calculations of the mill and strength calculations of its individual nodes were carried out. Completed drawings of nodes, general view. Was developed rules on safety in production, developed a system for automation of the grinding process in a tube mill, as well as recommendations on the technology of installation and operation of the machine. Programs were developed for automated execution of pipe mill assembly drawings, and 3D models were obtained as a result. The resulting 3D model was used to perform strength calculations in the Ansys system. This pipe mill can be used for grinding asbestos cement. Calculations are made, as well as the modernization of the thesis can be used for work with the subsequent improvement of pipe mills.
Целью работы является поиск вариантов модернизация корпуса трубной мельницы в литературных источниках и патентах. В данной работе рассматривается модернизация футеровки барабана трубной мельницы, которая обеспечивает повышение эффективности измельчения за счет ступенчатой футеровки. Также была рассмотрена модернизация корпуса которая обеспечивает улучшение теплового режима в рабочей камере. Во время работы было проведено параметрические и кинематические расчеты мельницы и расчеты на прочность отдельных его узлов. Выполнены чертежи узлов, общего вида. Было разработаны правила по технике безопасности на производстве, Разработана система автоматизации процесса помола в трубном мельнице, а также рекомендации по технологии монтажа и эксплуатации машины. Были разработаны программы для автоматизированного выполнения чертежей узлов трубного мельницы, в результате были получены 3D модели. Полученную 3D модель использовали для проведения расчетов на прочность в системе Ansys. Данную трубную мельницу можно использовать для измельчения асбестоцемента. Выполнены расчеты, а также модернизации дипломной работы можно использовать для работы с последующим совершенствования трубных мельниц.
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Orozco, Luisa. "Modélisation numérique et rhéologie des milieux granulaires à particules fragmentables en vue d’application aux broyeurs à boulets." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS101.
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Une étape cruciale de la fabrication des combustibles nucléaires est le co-broyage des oxydes d’uranium et de plutonium pour obtenir une taille ciblée et un mélange homogène de particules. Cependant, le changement de l’échelle du laboratoire à celle de la production reste essentiellement empirique. Le but de cette thèse de doctorat est de modéliser et caractériser les écoulements granulaires dans des tambours rotatifs et d’élucider les mécanismes de broyage de l’échelle des particules à celle du procédé. A l’aide de simulations granulaires, et d’un critère de décohésion dynamique basé sur la mécanique de la rupture, on étudie la fragmentation de partic- ules sous impact. La dissociation de ces particules se fait au niveau d’une tessellation en cellules sous-jacentes fragmentables. Les analyses développées portent notamment sur : les propriétés d’écoulements granulaires dans le régime de cascade en fonction des paramètres du système; l’effet de la taille et du nombre de corps broyants sur le processus de broyage; l’évolution de la frag- mentation dans les écoulements en tambour rotatif. Nos simulations révèlent plusieurs relations bien définies entre différentes variables caractérisant l’écoulement (profil de surface, épaisseur d’écoulement, fluctuations de force, glissement aux parois), l’évolution de la taille des particules et les paramètres du système (vitesse de rotation, taille du tambour, taux de remplissage). Ces travaux conduisent à la définition d’un paramètre sans dimension qui peut être utilisé pour la mise à l’échelle des écoulements dans les tambours tournants et les broyeurs à bouletsA crucial step of nuclear fuel manufacture is the co-milling of uranium and plutonium oxides to obtain a targeted particle size and excellent mixing. However, the scale-up from the laboratory to plant production is still mainly empirical. The goal of this doctoral thesis is to model and characterize granular flows in rotating drums and to elucidate the mechanisms of particle grinding across scales. By means of particle dynamics simulations and a particle breaking model involving the tessellation of breakable particles into cells and a dynamic debonding criterion based on fracture mechanics, we investigate single- particle impacts, the properties of granular flows in the cascading regime in a rotating drum as a function of system parameters, the effect of the size and amount of grinding media on the grinding process, and the evolution of particle breakage in granular flows of breakable particles. Our simulations reveal several well- defined relationships between flow variables such as surface profile, flowing thickness, force fluctuations and wall slip, as well as with system parameters such as rotation speed, drum size and filling degree, and with particle fracture during flow. We identify a dimensionless parameter that can be used for the scale-up of rotating drums
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Chieng, Heng Liang Norman, and n/a. "Amorphous drug preparation using ball milling." University of Otago. School of Pharmacy, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081209.162001.
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Polymorphism and crystallinity are now recognised as important issues in drug development. This is shown by the increased amount of research in this area over recent years. In pharmaceutical development milling is an important unit operation for size reduction to improve powder handling, processing and dissolution rate. The aim of this thesis was to investigate the effect of ball milling (and cryo-milling) on the solid state properties, including amorphous drug formation, of pharmaceutical solids.
Milling was carried out using an oscillatory ball mill (Mixer Mill MM301, Retsch GmbH & Co., Germany). In cryo-milling the milling jars were immersed in liquid nitrogen for three min before milling. XRPD was used as the main technique to evaluate the milled samples. Ranitidine hydrochloride (RAN) and indomethacin (INDO) were the model drugs used in this study.
It was found that upon milling, RAN form 1 converts to RAN form 2 via an amorphous phase. A faster amorphization rate was observed when the crystalline samples were cryo-milled. Amorphous ranitidine hydrochloride was characterized to have a glass transition (T[g]) range of 13 to 30 �C and a crystallization exotherm (T[c]) between 30 and 65 �C. Conversion was found to occur faster when the temperature of the solid powder was greater than the T[c]. Under various storage conditions, similarly, crystallization of the amorphous phase mainly led to RAN form 2. However, some form 1 and amorphous phase was also detected on the XRPD diffractograms. Using partial least squares regression, the amount of solid form components in the ternary RAN mixtures were successfully quantified. RAN form 2 did not convert to form 1 under any milling (including cryo-milling) or storage conditions used in this study. Overall, RAN form 2 was found to be the thermodynamically stable form and the two (RAN) polymorphs are likely to be a monotropic pair.
In a co-milling study of INDO and RAN, the two crystalline drugs were successfully converted into a single amorphous phase after 60 min of co-milling in a cold room (4 �C). The T[g] range (26-44 �C) was also characterized for these mixtures. DRIFTS spectra of the co-milled amorphous samples indicated an interaction had occurred between the carboxylic acid carbonyl (HO-C=O) and benzonyl amide (NC=O) of the INDO molecule with the aci-nitro (C=NO₂) of RAN. Depending on the ratio of INDO to RAN, in general, the amorphous mixtures were stable at 4 �C after 30 days of storage. Crystallization was faster when the binary mixtures were stored at higher temperature or contained higher amounts of RAN in the mixture. Although XRPD and DRIFTS suggested an interaction between the two drugs, co-crystal formation was not observed between INDO and RAN.
Ball milling can be used to produce amorphous drug. The rate and extent of amorphization is dependent on the milling conditions. A faster rate of amorphization was observed when the crystalline drugs were cryo-milled. Amorphous drug formation can be made either alone or in combination with another crystalline drug. Amorphization could offer a significant improvement on the dissolution profile and the bioavailability of the poorly water soluble drug - indomethacin. Furthermore, ball milling can also be used to produce a homogenous mix between solids. The �goodmix� effect can be used for seed-induced crystallization or, when the XRPD or Raman data were combined with partial least squares regression, to create a reliable calibration model for quantitative analysis.
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Ясір, Юсеф Хуссейн Аль Хатіб, Юсеф Хуссейн Аль Хатиб Ясир, and Yousef Hussin Al Khatib Yasir. "Інтелектуальна ідентифікація станів барабанних млинів на основі спектральних методів формування інформаційних ознак." Thesis, Видавництво НГУ, 2013. http://ir.nmu.org.ua/handle/123456789/2920.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за
спеціальністю 05.13.07 – Автоматизація процесів керування. ДВНЗ “Національний
гірничий університет”. Дніпропетровськ, 2013.Диссертация на соискание ученой степени кандидата технических наук по специальности 05.13.07 – Автоматизация процессов управления. – ГВУЗ “Национальный горный университет”. Днепропетровск, 2013.
Ph D. thesis on the 05.13.07 specialism area – Automation of control processes. SHEI “National Mining University”. Dnipropetrovsk, 2013.
Дисертація присвячена рішенню актуальної наукової задачі – автоматизації процесів управління технічним станом конструктивних елементів броні футеровки барабанних млинів мокрого самоподрібнення шляхом застосування моментной ідентифікації у якості інформаційного засібу автоматизації на основі встановлення нових закономірностей формування моментних характеристик та їх спектрів сигналів активної потужності привідного електродвигуна барабанного млина. Вирішення цієї задачі дозволяє підвищити ефективність подрібнення за рахунок підтримки броні барабана в технологічно раціональному стані, підвищити продуктивність та надійність процесу подрібнення, знизити ресурсні і енергетичні витрати. Науково обґрунтовані інформаційне забезпечення, функціонально- алгоритмічні структури та програмне забезпечення до систем автоматичного контролю і регулювання процесів зносу конструктивних елементів броні футеровки барабанних млинів. Результати роботи впроваджені в проектній документації і можуть бути використані на залізорудних збагачувальних фабриках у гірничо-металургійній промисловості.
Диссертация посвящена решению актуальной научной задачи – автоматизации процессов управления техническим состоянием конструктивных элементов брони футеровки барабанных мельниц мокрого самоизмельчения путем применения моментной идентификации в качестве информационного средства автоматизации на основе установления новых закономерностей формирования моментных характеристик и их спектров сигналов активной мощности приводного электродвигателя барабанной мельницы. Решение этой задачи позволяет повысить эффективность измельчения за счет поддержания брони футеровки барабана в технологически рациональном состоянии, повысить производительность, надежность процесса измельчения, снизить ресурсные и энергетические затраты. Установлено, что для энергоинформационных сигналов активной мощности потребляемой приводными электродвигателями БМ ММС 70*23 фильтрация фрикативных составляющих полностью выполняется уже на третьем уровне моментной иерархии, что обусловливает из этого уровня повышение точности определения периодических составляющих. Установлено, что впервые примененные в работе числовые оценки тесноты статистических моментних связей случайных значений энергоинформационных сигналов потребляемой активной мощности барабанных мельниц являются новыми знаниями по всем основным признакам и могут быть использованы как информационные естества при формировании предметных областей систем интеллектуальной поддержки принятия решений для задач автоматизации процессов управления БМ в условиях неопределенности состояния последних. Использование раскрытых закономерностей технологических и технических параметров процесса измельчения через аппроксимирующие функции регрессии условных математических ожиданий определило возможность представления БМ в разных режимах через линейные и нелинейные модели. Впервые установлено, что показатели информационных характеристик, в виде количества и характера экстремумов моментних функций, что используют центральные моменты парных степеней подобные, однако при увеличение степени повышается чувствительность моментной функции, что дает дополнительную информацию для увеличения точности идентификации. Информационные характеристики моментних функций, что используют центральные моменты непарных степеней аналогично подобны. Установлено, что расширение информационного обеспечения автоматизации процессов управления БМ за счет использования моментних функций степеней, больше четвертого порядка для парного ряда и пятого порядка для непарного ряда не дает существенного прироста информации при идентификации технологических состояний барабанных мельниц Установлены числовые зависимости характеристик экстремумов спектральных оценок моментных функций непрерывных случайных сигналов активной мощности потребляемой приводными электродвигателями барабанных мельниц ММС 70*23 при разных технологических состояниях по заполнению барабана измельчаемой рудой. Впервые установлено, что автоматизация процесса измельчения в барабанных мельницах на основе метода интеллектуальной идентификации нелинейных объектов нечеткими базами знаний обеспечивает в пределах допустимой достоверности выполнение оперативного контроля степени износа брони барабана, что позволяет повысить точность и надежность определения предаварийных и аварийных ситуаций в барабанных мельницах. Разработанное информационное и программное обеспечение направлено на сбор, сохранение и использование знаний, с целью решения прикладных задач интеллектуальной идентификации и принятия решений относительно оперативных состояний барабанных мельниц. Программа содержит все экранные формы, необходимые для настройки экспертной системы. Основные научные положения и результаты работы приняты к внедрению в проект ОАО Проектное и проектно-конструкторский институт «Металлургавтоматика» при проектировании автоматизации секции 10, 12 РОФ-2 ОАО «Арселор Миттал Кривой Рог» (проект № 0476).
The thesis is devoted to solving such a relevant scientific problem as automation of control of structural components of coating armour of drum mills of wet self-grinding through moment identification as information technique of automation based on identification of new laws of moment characteristics forming as well as their spectra of active power of the drum mill drive motor. The problem solving helps to improve grinding efficiency owing to keeping armour of a drum in technologically rational conditions. That will help to improve efficiency as well as reliability of grinding process, and to reduce both resource and power consumption. Data support, functional and algorithmic structures are scientifically grounded as well as software for the systems of automatic control and control of wear of structural elements of drum mills coating armour. The results are implemented in project documents; they can be applied at iron-ore preparators of ore mining and smelting industry.
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Gonzalez, Mabel Gonzalez. "Factors related to prescription drug abuse among young adults in Florida." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2821.
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A lack of available data exists regarding environmental factors related to prescription drug abuse (PDA), which could explain the ineffectiveness of efforts to reduce PDA in Florida. Prescription drug abuse among adults older than age 18 varies with the level of education achieved, and these metrics potentially reflect socioeconomic differences. The purpose of this quantitative study was to examine the connections between contextual aspects of prescription opioid abuse among Florida's middle and high school students to understand youth PDA in relation to their environments. This study consisted of a secondary analysis of existing PDA data (dependent variable) in relation to a number of independent variables, including the incidence of female-headed households, the nature of residential environment, adherence to religious precepts, and students' ability to achieve educational goals. Incidence of female-headed households, the nature of residential environment, and adherence to religious precepts were not found to predict youth PDA. The only finding of significance was that PDA predicted lowered students' ability to achieve educational goals (p = .015). Data collected from this study might be used by school counselors and administrators when developing drug abuse prevention, intervention, and educational programs, thereby leading to positive social change in helping to reduce PDA among youth.
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Korde, Sachin A. "Solvent free technologies for polymer based crystal engineering and drug delivery." Thesis, University of Bradford, 2015. http://hdl.handle.net/10454/14132.
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Current research focuses on the effect of different continuous solid state shear based processing for the production of pharmaceutical amorphous system and cocrystals for poorly water soluble APIs. The S3M technology is getting first time reported for its application in pharmaceutical field and it is considered as technology with good potential for development of pharmaceutical dosage forms. The main objectives of this study include the effect of two solid state shear processes on the product properties in case of solid dispersions and cocrystals. Hot melt extrusion technology has been widely explored for the production of pharmaceutical solid dispersions and cocrystals, it would be helpful to compare how the new invented S3M technology will differ from the existing solid state shear process. The S3M has been also explored for the advantages over HME process in terms of residence time, plasticiser free dispersions, effect of process on degradation of drugs during processing. For this purpose, the process and material modifications during operation of these two technologies was important aspects of this study. The pharmaceutical drugs chosen for the solid dispersion purpose were carbamazepine, ibuprofen, glibenclamide which are BCS class II drugs and paracetamol from BCS class III drug was selected as model drug for solid dispersion manufacturing with PVP. VA64, HPMCP HP55, HPMCAS, Ethyl cellulose as polymers. In case of cocrystals selected drugs were carabamazepine, caffeine, paracetamol and ibuprofen with co-formers nicotinamide, saccharin, salicylic acid, glutaric acid, oxalic acid, maleic acid. The selections of co-formers were done on the basis of functional group complementarity between drug and co-former. All the details about the pairs for cocrystals and for solid dispersions are given in experimental section. Carbamazepine has been explored in depth for solid dispersions with different polymers and with different co-formers in case of cocrystals. The effect of process variables and amount of shear applied during processing was deciding factor in product output and quality. The end product in case of both the solid dispersions and cocrystals varied in their physicochemical, morphological and drug release properties HME process needed addition of plasticisers during preparation of solid dispersions whereas S3M was plasticiser free process which gave good insight on how this will affect the product performance during evaluation studies. The solid dispersions in case of HME were had smooth surfaces and which are non-porous in nature whereas in case of S3M the solid dispersions were highly porous in nature. The differences in the structural and morphological features of solid dispersions somehow did not affect the drug release of drug during in-vitro dissolution studies and both the solid dispersions did not show much difference in drug release. In case of cocrystals processing on S3M it was observed that the S3M process is dependent on the use of polymer as process aid. For this purpose PEO, PVP VA64 and HPMCP HP55 were selected as model polymer as process aid during processing of cocrystals, out of which PEO has been explored widely as processing aid due to its process suitability, low melting and ability to withstand high shear during processing. PVP VA64 was used only in case of carbamazepine cocrystals with salicylic acid and HPMCP HP55 in case of caffeine cocrystals with maleic acid. The effect of concentration of PEO in case of carbamazepine cocrystals as processing aid was studied (concentration range 5%, 10%, 15%, 25% w/w). The concentration of PEO in case of HME cocrystals had direct effect on the drug release of drug dissolution studies which was reduced in case of higher concentration of PEO (25% w/w), which was not observed in case of S3M processes carbamazepine cocrystals. The product in case of cocrystals by S3M was thread like structures whereas in case of HME cocrystals were in form of screw shaped compact mass. The difference in morphological and structural properties of cocrystals did not had major effect on drug release in case of S3M process but in case of HME processed cocrystals the higher amount of polymer slowed the drug release. The degradation studies in case of drugs carbamazepine, paracetamol were carried out whereas in case of polymer for HPMCP HP55 were carried out. It was found that HME processed samples showed higher degradation as compared to S3M processed one in both the cases solid dispersions and cocrystals. This can be attributed to high residence time in case of HME as compared to S3M process. The effect of two high shear processes HME and S3M had significant effect on the morphological and structural properties of the solid dispersions and cocrystals. The variation in the structural and morphological properties did not have direct effect on the drug release of drug during dissolution studies. HME and S3M both the processes had some positive and some negative aspects within them for processing of pharmaceutical dispersions and cocrystals. In case of HME the use of plasticiser is mandatory to maintain low torque levels during processing and to avoid blockage of extruder barrel, whereas in case of S3M the process is plasticiser independent and processing of solid dispersion is very easy as compared to HME with low residence time. Processing of plain drug or co-former was easy in case of HME whereas in case of S3M processing it was mandatory to use polymer as processing aid specially during processing of cocrystals. In case of process controls HME has excellent control over the process parameters which can be controlled and manipulated as per requirement, whereas S3M technology needs to have technical modifications to have better control over its processing parameters. The S3M can be a revolutionary technology for pharmaceutical industry once it is upgraded with better control and optimised process parameters.
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Carmler, Alexander. "Questioning the unquestionable : A normative study of the values, argumentation and logic of the Swedish drug policy." Thesis, Södertörns högskola, Statsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-45717.
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Sweden’s drug policy still invokes the ideas of zero-tolerance and prohibition despite the high reported number of drug-related deaths and arrest rates for using drugs in Sweden in the latest years. To reach knowledge about why prohibition of illegal drugs has remained such a strong staple of Swedish politics for the latest 60 years, this study asks questions about which ideas and arguments constituting the Swedish drug policy, examines the logical coherence of these, and proposes an alternative policy route which aims to mitigate the shortcomings of the current policy. The drug policy field is extensive and studies from different nations show that drug policies that move away from prohibitionist ideas have succeeded in both reducing drug-related mortality rates and reducing the stigma that is attached to either using or abusing psychoactive drugs. Because of an identified unclarity of why the prohibitionary ideas in Sweden have remained despite recent developments, this study aims to fill a gap in existing research by normatively analyzing the ideas in the policy. Since these ideas have great importance in restrictions of individual liberty and public health considerations, knowledge about them is essential to create because liberty and public health are fundamental aspects in any democratic society. The research endeavor performs an internal validity check as the methodological approach to check the internal logic and arguments of the policy and uses a theory of liberty to shed light on the trade-offs between liberty and public health. What is discovered is that the Swedish drug policy builds on inconsistent arguments and incoherent logic and has a moralizing intent that allows for restrictions on individual liberty to reach a utopian vision of a drug-free society. Also, this study shows that it is possible to create a policy that can mitigate the harms caused by the current by adhering to the principle that individual liberty should stretch as far as possible when no harm is caused to another. The implications of this are that it will be harder to justify the zero-tolerance approach in the future and that future policy must look to other policy approaches rather than build policy on assumptions based on outdated moralism.
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Trávníček, Dušan. "Vliv alkoholu a jiných psychotropních látek na bezpečnost v dopravě." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-232883.
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The objective of the thesis is based on statistical data to assess the degree of risk of abuse of psychotropic substances in transport. The work is divided into two parts. The theoretical part is mainly a search, dealing with the issue. The practical part has analyzed statistical data and the questionnaire survey, whose results are compared with the results of statistical data.
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Hamman, Gert J. M. "An investigation of Steckel mill coiler drum failure mechanisms." Thesis, 2008. http://hdl.handle.net/10210/602.
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Coiler drums are integral components of the Steckel mill reversing hot strip rolling process. A Steckel mill produces hot rolled strip steel from cast slabs, which are heated before being converted, via roughing, to a transfer bar, of which the thickness is subsequently reduced to the desired gauge by means of a reverse rolling process performed by the Steckel mill. Coiler drums are located inside two Steckel furnaces, which are positioned on both sides of the mill stand. As the strip thickness is reduced during each pass, the length increases. In order to obtain high rolling speeds and retain temperature, the strip is successively coiled and uncoiled, under tension, onto and from the heated coiler drums during processing. As coiler drums have a high unit cost and a significant impact on the quality of the finished product, coiler drum performance is important to Steckel mill operators. The high cost is associated with the high alloy composition of the casting and the specialised manufacturing process required for the production of coiler drums. Deterioration of the coiler drum condition over its service lifespan can adversely affect the quality of the final product, namely coiled strip. This investigation was therefore undertaken to gain insight into coiler drum failure mechanisms, which will benefit Steckel mill operators, mill suppliers and coiler drum suppliers.Professor R.F. Laubscher
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Lee, Chang-Hsing, and 李長興. "Drum-Buffer-Rope Theories Application on Production Control of Professional False Twisted Texturing Mill." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/14117553710297138525.
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碩士逢甲大學
紡織工程所
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The purpose of this paper is to compare the benefits of two ways of production linedesign. One is traditional capacity design, and the other is DBR（Drum-Buffer-Rope, DBR）protective capacity design. A good manufacturing system is enable to reduce production cycle time and raises the reliability of due day. In order to reach the objectives, manufacturing system must overcome the effects of various variable events, random fluctuation on production line, and minimum of the production cost as well. In view of the foregoing, traditional production system pursues capacity balance and places work-in-process (WIP) inventory in front of every machines to protect overall line, which will lead to production cycle time raise and lower the reliability of due day. Meanwhile, the DBR production system pursues flow balance and work adjusts. In general, DBR investment will greater than traditional capacity balance, but it will show good results in lowering WIP, cycle time, and due day. As to the results, how many the benefits will be? In order to answer the benefits, this research builds a simulation production line (DBR system) with software to simulate and analyze the results of both production line design concepts. It shows that the DBR system gets better results than traditional system as a whole.
Books on the topic "Drum mills"
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Akademik Milli Dram Teatrı (Azerbaijan). Azärbaycan Dövlät Akademik Milli Dram Teatrının foto-salnamäsi. Bakı: Letterpress, 2010.
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Üç äsrin yüz otuz ili: Akademik Milli Dram Teatrı bu gün. Bakı: Qapp-Poliqraf, 2003.
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Hakantürk. Abdullah Çatlı kimdir?: 3 Kasım 1996 Susurluk. Kayseri [Turkey]: Geçit Yayınevi, 1997.
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Ellis, Walter. Prince of darkness: A jazz fiction inspired by the music of Miles Davis. London: 20/20, 1998.
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Sixty miles of border: An American lawman battles drugs on the Mexican border. New York: Berkley Books, 2012.
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Sesenta millas de frontera: Un agente estadounidense lucha contra las drogas en la frontera con México. New York: Berkley Books, 2013.
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Raḣimli, Ilḣam. Azärbaycan Dövlät Akademik Milli Dram Teatrı: Teatrın 1873-2012-ci illär arasındakı yaradıcılıq yolunun salnamäsi, 3 cilddä. Bakı: Tähsil, 2013.
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Control, United States Congress House Select Committee on Narcotics Abuse and. Pill mills, Medicaid fraud, and the diversion of pharmaceuticals: Hearing before the Select Committee on Narcotics Abuse and Control, House of Representatives, One Hundred Second Congress, second session, July 29, 1992. Washington: U.S. G.P.O., 1992.
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Raḣimli, Ilḣam. Azärbaycan teatr antologiyası: Iki cilddä. Bakı: Azärbaycan Respublikası Mädäniyyät vä Turizm Nazirliyi, 2013.
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Bir vatan, iki reis: Abdullah Çatlı, Muhsin Yazıcıoğlu. İstanbul: Güz Yayınları, 2011.
Find full textBook chapters on the topic "Drum mills"
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Addison, R. F., and J. Y. Wilson. "CYP 1A Concentrations as an Indicator of Exposure of Fish to Pulp-Mill Effluents." In Molecular and Applied Aspects of Oxidative Drug Metabolizing Enzymes, 259–70. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4855-3_18.
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Leigh Thompson, W. "Dix, Cent, Mille." In Clinical Drug Trials And Tribulations, Revised And Expanded. Informa Healthcare, 2002. http://dx.doi.org/10.1201/9780203909560.ch6.
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Bartilow, Horace A. "The Corporate Elite and the Drug Enforcement Regime." In Drug War Pathologies, 68–106. University of North Carolina Press, 2019. http://dx.doi.org/10.5149/northcarolina/9781469652559.003.0004.
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The legislative deliberations of Plan Colombia and the Mérida Initiative also supported elite theories of the state and showed that corporate campaign contributions and the reciprocal relationships between corporate elites and the federal government also influence American counternarcotic aid flows. This chapter uses the Heckman selection estimator to ascertain whether these outcomes are also generalizable. First, it uses principal component factor analysis to create an index to operationalize C. Wright Mills’ concept of an interlocking directorate, which measures the interconnections among corporate board of directors for the corporations in the data set and their interconnections with policy think tanks and the U.S. government. The statistical findings provide evidence that corporate campaign contributions, corporate inter-locks with think tanks and the federal government, and an interlocking directorate systematically increased U.S. counternarcotic aid to eighty recipient countries. And since drug enforcement policy making toward Colombia and Mexico also demonstrated that congressional funding for the drug war is a source of corporate revenues, the chapter concludes by utilizes a time-series cross section statistical analysis that shows that increasing levels of counternarcotic aid flows increases corporate capital accumulation again confirming that the case study findings are generalizable.
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Singh, Prabhakar, Sudhakar Singh, and Rajesh Kumar Kesharwani. "Resealed Erythrocytes as Drug Carriers and Its Therapeutic Applications." In Pharmaceutical Sciences, 459–85. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1762-7.ch018.
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In this pharma innovative world, there are more than 30 drug delivery systems. Today's due to lacking the target specificity, the present scenario about drug delivery is emphasizing towards targeted drug delivery systems. Erythrocytes are the most common type of blood cells travel thousands of miles from wide to narrow pathways to deliver oxygen, drugs and nutrient during their lifetime. Red blood cells have strong and targeted potential carrier capabilities for varieties of drugs. Drug-loaded carrier erythrocytes or resealed erythrocytes are promising for various passive and active targeting. Resealed erythrocyte have advantage over several drug carrier models like biocompatibility, biodegradability without toxic products, inert intracellular environment, entrapping potential for a variety of chemicals, protection of the organism against toxic effects of the drug, able to circulate throughout the body, ideal zero-order drug-release kinetics, no undesired immune response against encapsulated drug etc. Resealed erythrocytes are rapidly taken up by macrophages of the Reticuloendothelial System (RES) of the liver, lung, and spleen of the body and hence drugs also. Resealed erythrocytes method of drugs delivery is secure and effective for drugs targeting specially for a longer period of time. This chapter will explain the different method of drug loading for resealed erythrocytes, their characterization, and applications in various therapies and associated health benefits.
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"The Liberty Principle." In What is Freedom?, edited by Toby Buckle, 89–99. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197572214.003.0006.
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In this interview John Skorupski gives an overview of John Stuart Mill and his liberty principle. Rather than an exact legal criterion, Skorupski argues that the liberty principle is best understood as a series of considerations to apply when thinking about social and political questions. Does their behavior harm others? Are they paying their fair share toward society? Would interfering with them be in the common good? Skorupski discusses two specific examples in detail to explicate these points: drug use and nonconforming sexual lifestyles. After discussing how the liberty principle applies to these, the discussion ends with the argument that Mill intended to establish not just a political principle but a moral vision of the world.
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Whitehead, Kevin. "Movies within Movies and New Orleans Comes Back 2008–2019." In Play the Way You Feel, 293–338. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190847579.003.0011.
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In the 2000s and 2010s, screen jazz stories explored new forms to tell a new century’s jazz stories—longform television included. The surreal comedy Be Kind Rewind critiques jazz narrative conventions, with a movie within a movie: a new trend in jazz pictures. Born to Be Blue depicts a Chet Baker biopic within the biopic. A Miles Davis biopic is configured as a self-contained double feature, dividing his charming and evil personas. Nina Simone and Joe Albany biopics likewise focus on lulls in their careers. Queen Latifah plays Bessie Smith in a sexually frank biopic. Damien Chazelle’s Whiplash is hysterical like a too-fast drum solo, and his La La Land echoes Scorsese’s New York, New York in various particulars. As the jazz film approached the music’s centenary on record, new stories keep harking back to early ones—even the earliest, drawing connections back to The Jazz Singer.
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Singh, Vanila, and Rachel Katonak. "Non-Opioid Alternatives to Managing Chronic Pain." In A Public Health Guide to Ending the Opioid Epidemic, 55–64. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190056810.003.0007.
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While public health practitioners generally focus on the primary prevention of illness and disease by developing programs and policies that promote health and well-being, an understanding of chronic pain and its treatment is important for public health professionals working to address the opioid crisis. There are unintended consequences of well-intentioned policies that may restrict prescribing behavior or otherwise interrupt or change access to opioids. For example, one consequence of expanding state prescription drug monitoring programs has been concern by providers that “legitimate” pain patients may be subjected to increased suspicion and stigma and not able to obtain needed medications. State and federal efforts to shut down “pill mills” are vital to addressing diversion and criminal behavior, but pain patients who are also seen in these clinics may have an interruption in their treatment or access to medication. Understanding chronic pain treatment and non-opioid alternatives to pain management is an important part of developing sound public health policies to prevent opioid use disorder and its sequelae. This chapter presents these alternatives and the evidence base for each.
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"Dix, Cent, Mille: Proof of Principle with $10 Million, 100 Patients, and 1000 Days." In Clinical Drug Trials and Tribulations, Revised and Expanded, 112–29. CRC Press, 2002. http://dx.doi.org/10.1201/9780203909560-11.
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Celosse, Karin. "Interactions Between Personality Traits of Law Enforcement and Corrections Officers, and Attitudes Toward Felony Drug Offenders." In Ethical Standards and Practice in International Relations, 128–56. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-2650-6.ch006.
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Punitive attitudes in criminal justice staff towards felony drug offenders, as related to level of social dominance orientation, right wing authoritarianism, protestant work ethic orientation, and openness to change were examined. These traits were hypothesized to be factors contributing to continued acceptance of a paradigm emphasizing use penalties and punishment to address substance abuse. The study utilized 28 law enforcement officers, 14 corrections officers, and 58 non-criminal justice individuals. Data was collected using Altemeyer abbreviated RWA scale, SDO-6 scale, Miles and Garrett protestant work ethic scale, attitudes to organizational change, officer's attitude survey, and researcher designed survey. Results indicated both moderating and mediating effects between variables, except in the case of openness to change. To reduce unwanted behaviors, focus needs to be on assisting criminal justice staff with challenges in a more psychologically healthy manner.
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Li, Jie Jack. "Merck’s Triumph." In Triumph of the Heart. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780195323573.003.0009.
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Merck was not the first to discover a statin (Akira Endo at Sankyo was), but it was the first company to bring one successfully to market. In September 1987, the FDA approved Merck’s Mevacor (lovastatin) for marketing in the United States while Sankyo’s mevastatin was resting in peace in the big graveyard of drugs that failed to reach the market. In 2007, Merck & Co. was ranked the third largest pharmaceutical company in the world, both by capital and by revenue, behind only Pfizer and GlaxoSmithKline. The drug juggernaut traces its origin to a humble apothecary shop in Darmstadt, a central German city 20 miles south of Frankfurt. In 1668, 47-year-old apothecary Friedrich Jacob Merck purchased the Engelapotheke (Angel Pharmacy) in the Hessian town and began trading fine chemicals. Most popular was laudanum, an alcoholic solution of opium, which was in every physician’s medicine chest and used as a “panacea” for many illnesses. In 1827, Heinrich E. Merck inherited the family business and established a chemical laboratory named “E. Merck & Co.” beside the Angel Pharmacy. There, he pioneered the commercial large-scale production of various medicinal alkaloids, including veratrine, codeine, atropine, quinine, coniine, and morphine. In 1860, Albert Niemann, working in Friedrich Wöhler’s laboratory in Göttingen, Germany, isolated the active principle of coca leaves as a white crystalline alkaloid and christened it “cocaine.” Since new compounds were routinely tasted, Wöhler recorded that “cocaine was a substance which had a somewhat bitter taste and exerted a numbing influence upon the gustatory nerve, so that they became almost completely insensitive.” Capitalizing on its financial success with alkaloids, E. Merck began to isolate cocaine from coca leaves in the early 1880s and aggressively marketed it as a pain killer. Interestingly, Sigmund Freud, the father of psychoanalysis, enthusiastically took part in exploring cocaine’s medical utilities. After procuring some cocaine from E. Merck, the young neurologist swallowed a small quantity of the drug, which calmed his stomach and boosted his libido. Freud also applied some cocaine locally to himself and found that it temporarily paralyzed the sensitivity of a certain area without any marked effect on the central nervous system.
Conference papers on the topic "Drum mills"
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Arteaga-Arcos, J. C., J. Trujillo-Reyes, D. J. Delgado-Herna´ndez, A. Santamari´a-Ortega, O. A. Chimal-Valencia, and H. T. Yee-Madeira. "HEM as an Environmental Friendly Alternative to Produce UFC." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63850.
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High fineness is one of the most important characteristics of the Ultrafine Cements (UFC) with maximum particle size below 20 μm. Usually, UFC is obtained once the Ordinary Portland Cement (OPC) is grinded in common grinding devices e.g. drum mills; however this is a time consuming process, as it becomes complicated to reduce such a size once the particles have reached ultrafine powder dimensions. Some modern grinding devices as High Energy-Ball Mills (HEM) and shaker mills, have been used for ultrafine grinding-processes, especially at the advanced materials processing research field, but not in the cement industry. The most suitable combination of parameters (time, ball/powder (B/P) ratio and milling speed) was determined after the characterization of processed cement powder, in order to obtain UFC at laboratory level. The optimal combination of parameters produced an UFC having a maximum particle size below 15 μm. The HEM horizontal-rotary-ball-mill device used herein is not only intended for laboratory purposes, but also has one of the advantages of a direct-scaling-up, as it could be used for industrial purposes by means of more capacity mills. Furthermore, it is more efficient than both a shaker mill and a traditional ball milling device. As a result, if this kind of device is used instead of the traditional ball mill, the environmental impact due to the UFC production process could be minimized. This represents an environmental friendly alternative process for obtaining UFC from OPC.
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Stoimenov, Nikolay, Dimitar Karastoyanov, and Luben Klochkov. "Study of the factors increasing the quality and productivity of drum, rod and ball mills." In RECENT ADVANCES ON ENVIRONMENT, CHEMICAL ENGINEERING AND MATERIALS. Author(s), 2018. http://dx.doi.org/10.1063/1.5060704.
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Zhumagalieva, Gaukhar, Vladimir Pershin, Alexey Tkachev, Alexandr Vorobiev, Alexandr Pasko, and Evgeny Galunin. "Using a rod drum mill for graphene masterbatch production." In 6TH INTERNATIONAL CONFERENCE ON PRODUCTION, ENERGY AND RELIABILITY 2018: World Engineering Science & Technology Congress (ESTCON). Author(s), 2018. http://dx.doi.org/10.1063/1.5079341.
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Mesnier, Aline, Maroua Rouabah, C. Cogné, Roman Peczalski, Séverine Vessot-Crastes, Pascal Vacus, and Julien Andrieu. "Mechanical and thermal segregation of milli-beads during contact heating in a rotary drum. DEM modeling and simulation." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7423.
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The flow mechanics and heat transfer phenomena within a bed of milli-metric size spherical beads rotated and heated by contact in a horizontal drum were simulated by means of commercial discrete element software EDEM. Mono-dispersed and bi-dispersed beds (two particle sizes or two particle densities) were considered. The mechanical segregation index (standard deviation of local bed compositions) and the thermal segregation index (standard deviation of beads temperatures) were calculated for the different types of bed and same operating conditions. The thermal segregation was found to be enhanced by mechanical segregation and was much stronger for bi-dispersed beds than for monodispersed one. Keywords: rotating drum; particulate solid; segregation; contact heat transfer; DEM simulation.
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Marra, Dominic. "Optimizing Boiler Generating Bank Tube Reliability Through the Use of IRIS Non Destructive Testing." In 12th Annual North American Waste-to-Energy Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/nawtec12-2223.
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The boilers’ generating bank (convective) section began suffering repeated random failures at the Miami-Dade County Resources Recovery Facility. The plant embarked on an optimization program to better identify and target the failures using non destructive ultrasonic Internal Rotary Inspection Services (IRIS) testing. Through the use of the IRIS nondestructive testing method, the plant was able to identify 3 major contributors to tube failures by mapping out the locations of the tube wastage across all 4 boilers at the facility. The testing allowed optimizing the use of resources allocated to this area of the boiler and resulted in a considerable drop of unscheduled downtime and increase in generating bank tube reliability. The IRIS testing method involves an ultrasonic probe that is lowered down the inside of the tubes. The tubes are flooded with water in order to get a full 360-degree thickness survey of the tubes from top to bottom, (steam drum to mud drum). The data for over 4.7 miles (7.5 Km) of linear tube per boiler is recorded digitally and presented on a CD. By pinpointing the location and severity of tube wastage across the entire generating bank section, the root cause of the failures could be identified. An integrated solution was developed involving a combination of tube replacements, shielding, tube plugging, and soot blower optimization. This paper summarizes the results of the testing and optimization program.
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Popovich, David P., M. H. Hu, Jonathan L. Barkich, and Peter R. Nelson. "Increased Concern for Degradation of Upper Steam Drum Internals Leading to Monitoring and Modifications Considerations." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48938.
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Pressurized water reactor plant steam generator upper internals have been monitored in accordance with accepted industry practice and on schedules based on the history of good inspection results with isolated cases of failures in a small percentage of plants worldwide. The current practice is, in general, to perform a small sample qualitative visual inspection. The causal factors for the historical events are indicators but, in general, not directly applicable to the current rationale for increased quantitative surveillance. There is an emerging trend toward increased indications of degradation with identifiable causal factors similar to but distinct from the traditional failure mechanisms. Primary and secondary moisture separation components and feedwater ring degradation is increasing as calculated by traditional models and according to qualitative and quantitative inspection results. Two established objective criteria for the performance functions for the steam drum components under consideration are: moisture carryover < 0.25% and material loss of 62.5 mils from nominal component thickness of 0.25 inches. These traditional acceptance criteria can be re-established based on an engineering evaluation of failure modes and effects. Two changes that have increased the concern for unacceptable degradation of steam drum components in recent years are 1) the chemistry improvements to reduce flow assisted corrosion (FAC) in the feed train piping with the concomitant reduction in entrained iron transport into steam generators, and 2) the increase in water-steam flow velocities that result from power uprates. The reduction of entrained particulate into the steam generators is positive with respect to fewer corrodents introduced but may have an unintended and previously under-analyzed effect of the transport of entrained particulate into the upper regions of the tube bundle and into the moisture separation components. The first indications of degraded moisture separator components have begun to emerge and warrant consideration of an increased surveillance program for selected plants. This paper discusses how recent changes in the operating parameters and secondary water chemistry control have created conditions for concern for exceeding the traditional moisture carryover criteria and erosion-corrosion of upper steam drum components, especially in light of extended life operation. Examples of recent developments in inspection results and considerations for improved materials, increased and improved surveillance techniques, and replacement strategies will be presented.
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Yuan, Sichen, Wuming Jing, and Hao Jiang. "A Deployable Tensegrity Microrobot for Minimally Invasive Interventions." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-67009.
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Abstract Micro-, and milli-scale robots have emerged as next generation of intelligent technology for minimally invasive diagnosis and treatment. Recent minimally invasive interventions call for robots that work as tiny “surgeons” or drug delivery “vehicles” to achieve inner body diagnostic, surgical, and therapeutic practices, without any trauma or discomfort. Most traditional medical robots are large, and lack effective locomotion design, which prevent them from entering small entrances and moving smoothly in small working areas, such as long and narrow passages. Presented in this paper is a design of an innovative milli-scale deployable tensegrity microrobot for minimally invasive interventions. The robot is made of a deployable tensegrity structure integrated by self-stress. A folded size of the robot is small for easily entering a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damages when burrowing through tightly packed tissues or high-pressure environments. Locomotion of the tensegrity microrobot is designed to mimic a crawling motion of an earthworm, which grants the robot an ability to move well through small working areas. The robot is also an untethered agent. Morphing for deployment and locomotion of the robot is actuated by magnetic forces generated by its active members that serve as electromagnetic coils.
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Lonsdale, Cameron, and Steven Dedmon. "Fatigue Testing of Microalloyed AAR Class C Wheel Steel." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13366.
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Railroad wheels guide a freight car along the rails while supporting mechanical loads, and also serve as the brake drum in the air brake system of a freight car. Since a 36-inch diameter freight car wheel experiences approximately 560 revolutions per mile, and since many North American freight cars accrue 100,000 miles per year in service, fatigue properties of steel are very important. Further, elevated tread temperatures resulting from tread braking are known to significantly reduce the yield strength of the wheel steel at the tread surface. This paper describes fatigue testing of AAR rim quenched Class C wheel steel manufactured with microalloy additions. Small amounts of selected alloy elements were purposely added to develop a wheel steel with improved high temperature yield strength. Rotating bending fatigue tests, conducted at a well-known professional testing laboratory, were performed at ambient and elevated temperatures using complete stress reversal (R = -1) cycling. Stress-life (S-N) curves were constructed and the microalloy steel results were compared to existing fatigue data, and to results for typical Class C steel with no microalloy additions. Past research work is briefly reviewed. Test results are discussed with emphasis on the implications for service performance of wheel steel.
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Kobayashi, Isao, and Mitsutoshi Nakajima. "Micro/Nanochannel Emulsification for Generating Monosize Droplets." In ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75238.
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Emulsification is an important process in various fields including foods, pharmaceuticals, cosmetics, and chemicals. Emulsification operation is commonly conducted using conventional emulsification devices, such as high-speed blenders, colloid mills, high-pressure homogenizers, and ultrasonic homogenizers. However, these emulsification devices result in the production of polydisperse emulsions with wide droplet size distributions and poor controllability in droplet size and its distribution. In contrast, monodisperse emulsions consisting of monosize droplets have received a great deal of attentions over the past decade due to their high-tech applications, e.g., monosize microparticles as spacers for electronic devices and monosize micro-carriers for drug delivery systems (DDS). Our group proposed microchannel (MC) emulsification as a promising technique to produce monodisperse emulsions in the mid 1990s. Micro/Nanochannel (MNC) emulsification enables generating monosize droplets with the smallest coefficient of variation (CV) of below 5% using MC and nanochannel (NC) arrays of unique geometry. The resultant droplet size, which ranged from 0.5 to 200 μm, can be precisely controlled by channel geometry. Droplet generation for MNC emulsification is very mild and does not require any external shear stress; a dispersed phase that passed through channels is transformed spontaneously into monosize droplets inside a continuous-phase domain. The aim of this paper is to present recent developments in MNC emulsification chips, particularly focusing on asymmetric straight-through MC arrays for large-scale production of monodisperse emulsions. Asymmetric straight-through MC array chips were fabricated using a silicon-on-insulator wafer. Numerous asymmetric straight-through MCs each consisting of a microslot and a narrow MC were positioned in the central region of the chip. Monosize droplets were stably generated via asymmetric straight-through MCs at high production rates. Below a critical droplet production rate, monosize droplets were generated via asymmetric straight-through MCs, with droplet size and size distribution independent of the droplet productivity. The use of a large asymmetric straight-through MC array chip achieved the mass production of monosize tetradecane oil droplets at ∼1 L/h. The simulation results using CFD (computational fluid dynamics) agreed well with the experimental results and provided useful information, such as the movement of the oil-water interface during droplet generation. Monosize submicron droplets were also obtained using NC emulsification chips made of single-crystal silicon.
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Blankenhorn, James A. "West Valley Demonstration Project High Level, Transuranic, and Greater Than Class C Wastes." In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59048.
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Located in the scenic hills of Western New York, 35 miles south of Buffalo, the 68 hectare West Valley Demonstration Project (WVDP) is a unique and challenging environmental cleanup project that currently manages High Level, Transuranic, and Greater than Class C wastes. Before the U.S. Department of Energy (DOE) assumed the responsibility of cleaning up the site, the site was the location of the only commercial spent nuclear fuel (SNF) reprocessing facility to operate in the United States. Operated by Nuclear Fuels Services from 1966–72, the site was owned by the State of New York and licensed by the Atomic Energy Commission. During operations, the plant reprocessed approximately 640 metric tons of commercial and defense nuclear fuel. When commercial operations were discontinued and the facilities were returned to New York State, there were nearly 2,271,247 liters (nearly 600,000 gallons) of liquid high-level radioactive waste (HLW) in an underground storage tank, there were approximately 750 unprocessed fuel assemblies, and there was a highly contaminated Main Plant Process Building (MPPB). The West Valley Demonstration Project Act of 1980 (the Act) authorized DOE to conduct a cleanup of the site, in cooperation with the New York State Energy Research and Development Authority (NYSERDA), the State agency responsible for managing the property. The Nuclear Regulatory Commission (NRC) license was placed in abeyance and DOE arrived on site in 1981. Since that time, several significant cleanup milestones have been completed, including vitrification (solidification in a glass matrix) of the high level liquid waste, containing approximately 15 million curies, into 275 high level waste canisters and the disposition of more than 19,000 subsequent drums of low-level radioactive waste (LLW); the shipment of the remaining 125 SNF assemblies that were in storage on site; and the shipment of more than 304,800 cubic meters (1,000,000 cubic feet) of LLW for offsite disposal. More recent accomplishments at West Valley have included deactivation and decontamination of the still-very-contaminated MPPB, management of the underground high level waste tanks (4) and their associated vaults (3), and processing and packaging of both legacy waste and waste generated as a result of decommissioning activities. This paper focuses on the high level, greater than Class C, and Transuranic waste challenges at West Valley and the options to address those challenges.