Comparison of Chemical Filters for the Control of Airborne Molecular Contamination

2007 ◽  
Vol 50 (2) ◽  
pp. 52-72 ◽  
Author(s):  
Chris Muller

Airborne molecular contamination (AMC) continues to grow as a major contamination control issue for microelectronics manufacturers. Because of this growth, chemical filter manufacturers are offering a large number of AMC control options from which the facility, process, and contamination control engineers must determine the best solution for their specific AMC control application(s). This paper will present information on the various types of chemical filters available, filter strengths and weaknesses, and the results of independent performance evaluations for a number of different chemical filter types. Several AMC control strategies employing chemical filtration will be discussed. Other topics include an introduction to gaseous contaminants and a definition of AMC; classifications of AMC; contaminants common to cleanroom applications, their sources, and effect; implementing AMC control—a three-step methodology for optimum control of AMC; gas-phase air filtration principles—adsorption, absorption, chemisorption, and factors affecting each; dry-scrubbing air filtration media—plain and chemically impregnated adsorbents; chemical filtration equipment designs—thin-bed and deep-bed systems; and AMC monitoring—passive and real-time reactivity monitors.

Author(s):  
E. M. Ratnikov ◽  
D. O. Milko

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.


Author(s):  
Dennis Sherwood ◽  
Paul Dalby

Another key chapter, examining reactions in solution. Starting with the definition of an ideal solution, and then introducing Raoult’s law and Henry’s law, this chapter then draws on the results of Chapter 14 (gas phase equilibria) to derive the corresponding results for equilibria in an ideal solution. A unique feature of this chapter is the analysis of coupled reactions, once again using first principles to show how the coupling of an endergonic reaction to a suitable exergonic reaction results in an equilibrium mixture in which the products of the endergonic reaction are present in much higher quantity. This demonstrates how coupled reactions can cause entropy-reducing events to take place without breaking the Second Law, so setting the scene for the future chapters on applications of thermodynamics to the life sciences, especially chapter 24 on bioenergetics.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Jorge Lopez-Jimenez ◽  
Nicanor Quijano ◽  
Alain Vande Wouwer

Climate change and the efficient use of freshwater for irrigation pose a challenge for sustainable agriculture. Traditionally, the prediction of agricultural production is carried out through crop-growth models and historical records of the climatic variables. However, one of the main flaws of these models is that they do not consider the variability of the soil throughout the cultivation area. In addition, with the availability of new information sources (i.e., aerial or satellite images) and low-cost meteorological stations, it is convenient that the models incorporate prediction capabilities to enhance the representation of production scenarios. In this work, an agent-based model (ABM) that considers the soil heterogeneity and water exchanges is proposed. Soil heterogeneity is associated to the combination of individual behaviours of uniform portions of land (agents), while water fluxes are related to the topography. Each agent is characterized by an individual dynamic model, which describes the local crop growth. Moreover, this model considers positive and negative effects of water level, i.e., drought and waterlogging, on the biomass production. The development of the global ABM is oriented to the future use of control strategies and optimal irrigation policies. The model is built bottom-up starting with the definition of agents, and the Python environment Mesa is chosen for the implementation. The validation is carried out using three topographic scenarios in Colombia. Results of potential production cases are discussed, and some practical recommendations on the implementation are presented.


2021 ◽  
Vol 25 (5) ◽  
Author(s):  
Jeanne Moldenhauer

Warning letters and regulatory inspection observation reports (e.g., FDA 483) often provide useful information for assessing risks in your facility and preparing for upcoming inspections. Starting with the updates to the European Union’s Annex 1 for the Manufacture of Sterile Drugs there has been an increased focus on contamination control strategies in facilities. A contamination control strategy is an integral part of pharmaceutical manufacturing, whether sterile or non-sterile. For this article we are going to look at a series of observations for a vaccine production facility and how we might learn from these observations. Highlighted are some of the contamination control issues. The FDA 483 Report was published in redacted form.


Author(s):  
Руслан Юрьевич Павлов

Актуальность статьи связана с поиском новых способов и методов повышения эффективности борьбы с преступностью, оперативного раскрытия преступлений, а также с набирающим популярность среди криминалистов направлением «криминалистического мышления», овладение навыками которого будет способствовать наиболее полноценному и объективному расследованию уголовных дел. Проблемным в настоящее время является недостаточное качество следствия и необходимость повышения когнитивных способностей следователей (дознавателей). Задачей исследования являлось выявление факторов, влияющих на развитие и формирование криминалистического мышления следователей. Цель работы - провести анализ составных частей процесса становления следователя и особенностей его практической деятельности, влияющих на когнитивные способности с точки зрения криминалистики, путем изучения и сравнения имеющихся материалов по данной тематике. Анализу подвергнуты личностные качества следователя, особенности образовательного процесса и влияние опыта на результаты работы, а также факторы, сопутствующие следственной деятельности (организация труда, уровень стресса, нагрузки и т. д.). Результат проведенного исследования выражен в определении проблемных факторов, влияющих на формирование криминалистического мышления следователя (дознавателя) и возможных путей их преодоления, важности такого мышления, которое остается знанием, постоянно сориентированным в сторону практики. The relevance of the article is related to the search for new ways and methods to improve the effectiveness of the fight against crime, the prompt detection of crimes, as well as the trend of «forensic thinking», which is gaining popularity among criminalists, mastering the skills of which will contribute to the most complete and objective investigation of criminal cases. Problems at present are insufficient quality of investigation and the need to improve the cognitive abilities of investigators (inquirers). The task of the study was to identify factors that influence the development and formation of forensic thinking of investigators. The purpose of the work is- to analyze the components of the process of formation of an investigator and features of his practical activities affecting the cognitive abilities in terms of forensics by studying and comparing existing materials on this topic. The analysis is subjected to the personal qualities of an investigator, the peculiarities of the educational process and the impact of experience on the results of work, as well as factors associated with the investigative activity (organization of work, stress and stress levels, etc.). The result of the study is expressed in the definition of problematic factors affecting the formation of forensic thinking of an investigator (inquirer) and possible ways to overcome them, the importance of such thinking, which remains knowledge, constantly oriented towards practice


2015 ◽  
Vol 8 (1) ◽  
pp. 61-84
Author(s):  
David Koppitz ◽  
Milan Půček ◽  
František Ochrana ◽  
Michal Plaček

Abstract The paper aims to carry out a comparative analysis of heating of school facilities under the administration of municipalities in Macedonia, Moldova and Kosovo and to test the factors that affect the heating costs of school facilities. For a definition of the theoretical fundament parts of the theory of fiscal federalism are used. Subsequently five hypotheses are put forward that are verified using the method of benchmarking. The theoretical conclusions and recommendations may be used for a more effective implementation of public policies within the surveyed countries.


1993 ◽  
Vol 28 (11-12) ◽  
pp. 9-14 ◽  
Author(s):  
Troy D. Vassos

The need to optimize treatment plant performance and to meet increasingly stringent effluent criteria are two key factors affecting future development of instrumentation, control and automation (ICA) applications in the water and wastewater industry. Two case studies are presented which highlight the need for dynamic modelling and simulation software to assist operations staff in developing effective instrumentation control strategies, and to provide a training environment for the evaluation of such strategies. One of the limiting factors to date in realizing the potential benefits of ICA has been the inability to adequately interpret the large number of existing instrumentation inputs available at treatment facilities. The number of inputs can exceed the number of control loops by up to three orders of magnitude. The integration of dynamic modelling and expert system software is seen to facilitate the interpretation of real-time data, allowing both quantitative (instrumented) and qualitative (operator input) information to be integrated for process control. Improvements in sensor reliability and performance, and the development of biological monitoring sensors and control algorithms are also discussed.


Author(s):  
Олена Миколаївна Афанасьєва ◽  
Валерія Вячеславівна Кошарна

The paper explores the key factors affecting the corporate culture formation and development. Recently, the issues of corporate culture, especially in large organizations, trigger the focused attention of a number of management theorists and practitioners. It is a relatively new and insufficiently researched concept, both in this country and abroad. People make the foundation of any company, conversely any organization directs its activities towards a person fostering a multifaceted diversity of organizational culture brought in by each employee. This wide spectrum of variety is shaped by the uniqueness of each individual. Each person’s genetic background is exceptional which stems from people’s diversity of the universe. Ukrainian national individualism specified by the nature of social life plays a dual role in building a corporate culture domain of domestic business structures. Given the equity capital formation under the indirect ownership-based principle of “from individual to collective”, this feature of a national character contributes to corporate philosophy tailoring. The paper suggests a definition of the “corporate culture” concept as a set of values, beliefs, opinions, perceptions, expectations, symbols as well as behavior norms and patterns, traditions, rituals, etc. that have developed in the organization or its divisions during its life cycle and which are accepted by the majority of employees. The system of leadership based on encouraging practices is proved to be most effective. Diligent, initiative performance of management instructions, hard creative work in this case depend on the remuneration policy. Thus, incentives should be meaningful for a performer and feasible for a firm. Insights to a range of theoretical and practical aspects in building employee’s corporate culture are provided. The personnel particular role in facilitating the enterprise performance efficiency is revealed. The paper verifies the need to implement coaching in terms of effective training practices for staff development.


2021 ◽  
Author(s):  
Paolo Scarabaggio ◽  
Raffaele Carli ◽  
Graziana Cavone ◽  
Nicola Epicoco ◽  
Mariagrazia Dotoli

This paper proposes a stochastic non-linear model predictive controller to support policy-makers in determining robust optimal strategies to tackle the COVID-19 secondary waves. First, a time-varying <i>SIRCQTHE </i>epidemiological model (considering Susceptible, Infected, Removed, Contagious, Quarantined, Threatened, Healed, and Extinct compartments of individuals) is defined to get reliable predictions on the pandemic dynamics on a regional basis. A stochastic Model Predictive Control problem is then formulated to select the necessary control actions to minimize the arising socio-economic costs. <br>In particular, considering the unavoidable uncertainty characterizing this decision-making process, we ensure that the capacity of the network of regional healthcare systems is not violated in accordance with a chance constraint approach.<br>Furthermore, since the infection rate depends on people’s mobility, differently from the related literature, we model the control actions as interventions affecting the mobility levels associated to different socio-economic categories.<br><div>The effectiveness of the presented method in properly supporting the definition of diversified regional strategies for tackling the COVID-19 spread is tested on the network of Italian regions using real data from the Italian Civil Protection Department. However, provided the availability of reliable data, the proposed approach can be easily extended to cope with other countries' characteristics and different levels of the spatial scale.</div><div><br></div><div>Preprint of paper submitted to IEEE Transactions on Automation Science and Engineering (<em>T-ASE</em>)</div>


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