3,967 research outputs found

    Monitoring of the primary drying of a lyophilization process in vials

    Get PDF
    An innovative and modular system (LyoMonitor) for monitoring the primary drying of a lyophilization process in vials is illustrated: it integrates some commercial devices (pressure gauges, moisture sensor and mass spectrometer), an innovative balance and a manometric temperature measurement system based on an improved algorithm (DPE) to estimate sublimating interface temperature and position, product temperature profile, heat and mass transfer coefficients. A soft-sensor using a multipoint wireless thermometer can also estimate the previous parameters in a large number of vials. The performances of the previous devices for the determination of the end of the primary drying are compared. Finally, all these sensors can be used for control purposes and for the optimization of the process recipe; the use of DPE in a control loop will be shown as an exampl

    The imperial war museum’s social interpretation project

    Get PDF
    This report represents the output from research undertaken by University of Salford and MTM London as part of the joint Digital R&D Fund for Arts and Culture, operated by Nesta, Arts Council England and the AHRC. University of Salford and MTM London received funding from the programme to act as researchers on the Social Interpretation (SI) project, which was led by the Imperial War Museum (IWM) and their technical partners, The Centre for Digital Humanities, University College London, Knowledge Integration, and Gooii. The project was carried out between October 2011 and October 2012

    Proposal of a System for Estimating the Assembly Time in Small and Medium-Sized Enterprises

    Get PDF
    This paper presents the results of the development of a specialized modifiable system for estimating the assembly time in practice. The proposal is mainly intended for small and medium-sized enterprises, which require the application of sophisticated and cost-effective solutions given the arising competitiveness in the assembly sector. The ATES system, i.e., Assembly Time Estimation System, which was created in Excel, was tested in the LEANLAB laboratory. The results correspond with current trends in this area and suggest directions for further development, especially in the field of 3D CAD systems and virtual reality

    Fine Tuning of Automated Assembly Machines Using Video Analysis

    Get PDF
    Human/machine interaction is of still importance in the age of automation. Automated assembling devices are customizable products that need basic settings before installation. Capabilities of operators have to be taken into consideration in this process. This paper presents a procedure based on video recording to determine time data for machine settings. It allows the engineers to forecast the expected capacity of individual workstation and the entire production line. A case study from industry is used to illustrate the application of the system

    Influence of Succinimide Dispersants on Film Formation, Friction and Antiwear Properties of Zinc Dialkyl Dithiophosphate

    Get PDF
    ZDDP (zinc dialkyldithiophosphate) is arguably the most successful antiwear additive ever employed in crankcase engine lubricants. It was originally used as an antioxidant and shortly afterwards recognized for its antiwear and extreme pressure properties. Unfortunately, another critical additive polyisobutylsuccinimide-polyamine (PIBSA-PAM), which is used as a dispersant in engine oils, is known to be antagonistic to ZDDP in terms of film formation, friction and wear. The mechanisms of this antagonism have been widely studied, but they are still not well understood. Furthermore, in order to protect engine exhaust catalysts from sulphated ash, phosphorus and sulphur (SAPS) and extend drain intervals of engine lubricants, a progressive reduction in ZDDP quantity but a growth in the use of PIBSA-PAM is required. The aim of this study is to explore the mechanisms and practical effects of the antagonism between ZDDP and PIBSA-PAM. Of particular interest is the impact on performance of the ratio of ZDDP to PIBSA-PAM, as measured by P:N ratio. Since ZDDP is a very effective antiwear additive, it produces only very low or "mild" rates of wear. To study this requires a new way to measure mild wear behaviour of formulated oils. Several techniques have been applied in this study to investigate the film formation, friction and wear properties of ZDDP- and/or PIBSA-PAM-containing oils. These include a new mild wear testing method, which is tested and developed using a range of different types of additives. It is found that the ratio of P:N plays a strong role in determining tribofilm formation and friction of ZDDP/PIBSA-PAM blends. However it plays a much weaker role in determining wear behaviour. It is found that some PIBSA-PAMs have considerable friction-reducing properties in their own right. The results suggest that PIBSA-PAM may interfere with the behaviour of ZDDP in several ways: by forming a ZDDP/ PIBSA-PAM complex at the metal surfaces to reduce the local activity of ZDDP; by PIBSA-PAM partially removing the ZDDP film; possibly also by PIBSA-PAM blocking ZDDP from metal surfaces. The newly-developed wear testing method can be used conveniently and effectively to study mild wear properties not just of ZDDP but of a wide range of other additives

    Economic criteria for optimizing the number and load factor of mining transformers

    Get PDF
    Purpose. This article discusses how to choose the optimal number and load factor, respectively the economic power in the first year of mining power transformers operation. The analysis is carried out based on technical-economic criteria. In this regard, two economic criteria are proposed for a detailed analysis, namely the minimum updated total expenses criterion and the minimum power and energy losses criterion. Methods. For determining the number and the optimal load factor, the paper presents mathematical models for the two eco-nomic criteria used. The results obtained by the presented methods are simulated using Matlab for several series of under-ground mining transformers. Also, it is assumed that the load remains constant over the year. Findings. The article confirms the possibility of using the analyzed economic criteria for establishing the optimal number of mining transformers as well as the optimal load factor, respectively the optimal power for the first year of operation. The difficulty of the research is related to the loss time assessment. Also, the paper presents the performed comparative analysis of the two implications. Originality. This research provides a novel approach, by the detailed presentation of the two criteria used for describing the objective functions which have to be minimized in order to gain the optimum, referring strictly to mining transformers, which represents a novelty for power engineering in mining. Practical implications. The methods described in the article can be successfully used in the case of new mining power networks which are going to be designed, and in the case of those currently in operation. Economic criteria analysed also provide results for the economical regime of mining transformers which corresponds to minimum energy loss. Therefore, this case also results in significant energy savings, i.e. lower economic criteria used.Мета. У статті обговорюється проблема вибору оптимального числа шахтних трансформаторів, визначення коефіцієнта їх навантаження і рентабельності протягом першого року експлуатації. Методика. Для визначення кількості трансформаторів і оптимального коефіцієнта їх навантаження запропонована математична модель на базі двох використаних економічних критеріїв: мінімальні скориговані загальні витрати та мінімальні втрати потужності й енергії. Отримані результати лягли в основу моделі, побудованої за допомогою Matlab для декількох серій підземних шахтних трансформаторів. Прийнято, що навантаження зберігається постійним протягом року. Результати. У статті підтверджена можливість використання аналізованих економічних критеріїв для визначення оптимального числа шахтних трансформаторів і оптимального коефіцієнта їх навантаження а, отже, оптимальної потужності протягом першого року їх експлуатації. Складність дослідження полягала в оцінці часових втрат. Крім того, у статті були представлені результати та порівняльний аналіз двох використаних економічних критеріїв. Встановлено, що оптимальним рішенням є використання трансформатора з номінальною потужністю, найближчою до теоретичного значення, отриманого в результаті розрахунків SNTmax. Результати, отримані при моделюванні, показують, що значення факторів навантаження, відповідно, оптимальної потужності шахтних трансформаторів, вище, ніж у поверхових, оскільки відношення втрат вище. Наукова новизна. Дослідження засноване на інноваційному підході, при якому детальне представлення двох критеріїв використано для опису об’єктивних функцій, що підлягають мінімізації, з метою отримання оптимальних рішень для шахтних трансформаторів. Даний підхід є принципово новим у галузі гірничої електроенергетики. Практична значимість. Методи, запропоновані в статті, можуть бути успішно застосовані як у разі проектування нових шахтних електричних мереж, так і для мереж, які вже перебувають в експлуатації. Аналізовані економічні критерії дозволяють встановити найбільш економічний режим експлуатації шахтних трансформаторів, при якому втрати енергії будуть мінімальні, що, в свою чергу, призведе до її суттєвої економії.Цель. В статье обсуждается проблема выбора оптимального числа шахтных трансформаторов, определения коэффициента их нагрузки и рентабельности в течение первого года эксплуатации. Методика. Для определения количества трансформаторов и оптимального коэффициента их нагрузки предложена математическая модель на базе двух использованных экономических критериях: минимальные скорректированные общие издержки и минимальные потери мощности и энергии. Полученные результаты легли в основу модели, построенной с помощью Matlab для нескольких серий подземных шахтных трансформаторов. Принято, что нагрузка сохраняется постоянной в течение года. Результаты. В статье подтверждена возможность использования анализируемых экономических критериев для определения оптимального числа шахтных трансформаторов и оптимального коэффициента их нагрузки и, следовательно, оптимальной мощности в течение первого года их эксплуатации. Сложность исследования заключалась в оценке временных потерь. Кроме того, в статье были представлены результаты и сравнительный анализ двух использованных экономических критериев. Установлено, что оптимальным решением является использование трансформатора с номинальной мощностью, ближайшей к теоретическому значению, полученному в результате расчетов SNTmax. Результаты, полученные при моделировании, показывают, что значения факторов нагрузки, соответственно, оптимальной мощности шахтных трансформаторов, выше, чем у поверхностных, поскольку отношение потерь выше. Научная новизна. Исследование основано на инновационном подходе, при котором детальное представление двух критериев использовано для описания объективных функций, подлежащих минимизации с целью получения оптимальных решений для шахтных трансформаторов. Данный подход является принципиально новым в области горной электроэнергетики Практическая значимость. Методы, предложенные в статье, могут быть успешно применены как в случае проектирования новых шахтных электрических сетей, так и для сетей, уже находящихся в эксплуатации. Анализируемые экономические критерии позволяют установить наиболее экономичный режим эксплуатации шахтных трансформаторов, при котором потери энергии будут минимальны, что, в свою очередь, приведет к ее существенной экономии.The authors state that this research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

    JAG: Reliable and Predictable Wireless Agreement under External Radio Interference

    Get PDF
    Wireless low-power transceivers used in sensor networks typically operate in unlicensed frequency bands that are subject to external radio interference caused by devices transmitting at much higher power.communication protocols should therefore be designed to be robust against such interference. A critical building block of many protocols at all layers is agreement on a piece of information among a set of nodes. At the MAC layer, nodes may need to agree on a new time slot or frequency channel, at the application layer nodes may need to agree on handing over a leader role from one node to another. Message loss caused by interference may break agreement in two different ways: none of the nodes uses the new information (time slot, channel, leader) and sticks with the previous assignment, or-even worse-some nodes use the new information and some do not. This may lead to reduced performance or failures. In this paper, we investigate the problem of agreement under external radio interference and point out the limitations of traditional message-based approaches. We propose JAG, a novel protocol that uses jamming instead of message transmissions to make sure that two neighbouring nodes agree, and show that it outperforms message-based approaches in terms of agreement probability, energy consumption, and time-to-completion. We further show that JAG can be used to obtain performance guarantees and meet the requirements of applications with real-time constraints.CONETReSens

    Modular and reconfigurable transient modeling and simulation design support tool for MEE/MEA power systems

    Get PDF
    There is a well-recognised need for robust simulation tools to support the design and evaluation of future More-Electric Engine and Aircraft (MEE/MEA) design concepts. Design options for these systems are increasingly complex, and normally include multiple power electronics converter topologies and machine drive units. In order to identify the most promising set of system configurations, a large number of technology variants need to be rapidly evaluated. This paper will describe a method of MEE/MEA system design with the use of a newly developed transient modeling, simulation and testing tool aimed at accelerating the identification process of optimal components, testing novel technologies and finding key solutions at an early development stage. The developed tool is a Matlab/Simulink library consisting of functional sub-system units, which can be rapidly integrated to build complex system architecture models
    corecore