936 resultados para Quality control system


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Two simple sensitive and reproducible spectrophotometric methods have been developed for the determination of metronidazole either in pure form or in their tablets. The proposed methods are based on the reduction of the nitro group to amino group of the drug. The reduction of metronidazole was carried out with zinc powder and 5 N hydrochloric acid at room temperature in methanol. The resulting amine was then subjected to a condensation reaction with aromatic aldehyde namely, vanillin and p-dimethyl amino benzaldehyde (PDAB) to yield yellow colored Schiff's bases. The formed Schiff's bases are quantified spectrophotometrically at their absorption maxima at 422 nm for vanillin and 494 nm for PDAB. Beer's law was obeyed in the concentration ranges 10 to 65 µg mL-1 and 5 to 40 µg mL-1 with a limit of detection (LOD) of 0.080 µg mL-1 and 0.090 µg mL-1 for vanillin and PDAB, respectively. The mean percentage recoveries were found to be 100.05 ± 0.37 and 99.01 ± 0.76 for the two methods respectively. The proposed methods were successfully applied to determine the metronidazole in their tablet formulations and the results compared favorably to that of reference methods. The proposed methods are recommended for quality control and routine analysis.

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Software systems are expanding and becoming increasingly present in everyday activities. The constantly evolving society demands that they deliver more functionality, are easy to use and work as expected. All these challenges increase the size and complexity of a system. People may not be aware of a presence of a software system, until it malfunctions or even fails to perform. The concept of being able to depend on the software is particularly significant when it comes to the critical systems. At this point quality of a system is regarded as an essential issue, since any deficiencies may lead to considerable money loss or life endangerment. Traditional development methods may not ensure a sufficiently high level of quality. Formal methods, on the other hand, allow us to achieve a high level of rigour and can be applied to develop a complete system or only a critical part of it. Such techniques, applied during system development starting at early design stages, increase the likelihood of obtaining a system that works as required. However, formal methods are sometimes considered difficult to utilise in traditional developments. Therefore, it is important to make them more accessible and reduce the gap between the formal and traditional development methods. This thesis explores the usability of rigorous approaches by giving an insight into formal designs with the use of graphical notation. The understandability of formal modelling is increased due to a compact representation of the development and related design decisions. The central objective of the thesis is to investigate the impact that rigorous approaches have on quality of developments. This means that it is necessary to establish certain techniques for evaluation of rigorous developments. Since we are studying various development settings and methods, specific measurement plans and a set of metrics need to be created for each setting. Our goal is to provide methods for collecting data and record evidence of the applicability of rigorous approaches. This would support the organisations in making decisions about integration of formal methods into their development processes. It is important to control the software development, especially in its initial stages. Therefore, we focus on the specification and modelling phases, as well as related artefacts, e.g. models. These have significant influence on the quality of a final system. Since application of formal methods may increase the complexity of a system, it may impact its maintainability, and thus quality. Our goal is to leverage quality of a system via metrics and measurements, as well as generic refinement patterns, which are applied to a model and a specification. We argue that they can facilitate the process of creating software systems, by e.g. controlling complexity and providing the modelling guidelines. Moreover, we find them as additional mechanisms for quality control and improvement, also for rigorous approaches. The main contribution of this thesis is to provide the metrics and measurements that help in assessing the impact of rigorous approaches on developments. We establish the techniques for the evaluation of certain aspects of quality, which are based on structural, syntactical and process related characteristics of an early-stage development artefacts, i.e. specifications and models. The presented approaches are applied to various case studies. The results of the investigation are juxtaposed with the perception of domain experts. It is our aspiration to promote measurements as an indispensable part of quality control process and a strategy towards the quality improvement.

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The aim of this study was to evaluate the application possibility of tabular CUSUM control charts in the quality control of chemical variables in surface water. It was performed bibliographic and field research to collect water samples from 2003 to 2009, totaling 30 samples, some monthly and others semi-annual in order to observe the variables that regulate water quality. It was found that these charts may be applied to control the quality of river water; showing to be effective in the perception of changes during the process, especially for small samples (n=1) which there is no repetition as in this research. It was also concluded that the Mandurim River does not presents significant levels of pollution.

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ABSTRACTObjective:to analyze the implementation of a trauma registry in a university teaching hospital delivering care under the unified health system (SUS), and its ability to identify points for improvement in the quality of care provided.Methods:the data collection group comprised students from medicine and nursing courses who were holders of FAPESP scholarships (technical training 1) or otherwise, overseen by the coordinators of the project. The itreg (ECO Sistemas-RJ/SBAIT) software was used as the database tool. Several quality "filters" were proposed to select those cases for review in the quality control process.Results:data for 1344 trauma patients were input to the itreg database between March and November 2014. Around 87.0% of cases were blunt trauma patients, 59.6% had RTS>7.0 and 67% ISS<9. Full records were available for 292 cases, which were selected for review in the quality program. The auditing filters most frequently registered were laparotomy four hours after admission and drainage of acute subdural hematomas four hours after admission. Several points for improvement were flagged, such as control of overtriage of patients, the need to reduce the number of negative imaging exams, the development of protocols for achieving central venous access, and management of major TBI.Conclusion: the trauma registry provides a clear picture of the points to be improved in trauma patient care, however, there are specific peculiarities for implementing this tool in the Brazilian milieu.

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Objective The objective of this study is to assess the performance of cytopathology laboratories providing services to the Brazilian Unified Health System (Sistema Único de Saúde - SUS) in the State of Minas Gerais, Brazil. Methods This descriptive study uses data obtained from the Cervical Cancer Information System from January to December 2012. Three quality indicators were analyzed to assess the quality of cervical cytopathology tests: positivity index, percentage of atypical squamous cells (ASCs) in abnormal tests, and percentage of tests compatiblewith high-grade squamous intraepithelial lesions (HSILs). Laboratories were classified according to their production scale in tests per year≤5,000; from 5,001 to 10,000; from 10,001 to 15,000; and 15,001. Based on the collection of variables and the classification of laboratories according to production scale, we created and analyzed a database using Microsoft Office Excel 97-2003. Results In the Brazilian state of Minas Gerais, 146 laboratories provided services to the SUS in 2012 by performing a total of 1,277,018 cervical cytopathology tests. Half of these laboratories had production scales≤5,000 tests/year and accounted for 13.1% of all tests performed in the entire state; in turn, 13.7% of these laboratories presented production scales of > 15,001 tests/year and accounted for 49.2% of the total of tests performed in the entire state. The positivity indexes of most laboratories providing services to the SUS in 2012, regardless of production scale, were below or well below recommended limits. Of the 20 laboratories that performed more than 15,001 tests per year, only three presented percentages of tests compatible with HSILs above the lower limit recommended by the Brazilian Ministry of Health. Conclusion The majority of laboratories providing services to the SUS in Minas Gerais presented quality indicators outside the range recommended by the Brazilian Ministry of Health.

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The assembly and maintenance of the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. The VV is made of stainless steel, which has poor machinability and tends to work harden very rapidly, and all the machining operations need to be carried out from inside of the ITER VV. A general industrial robot cannot be used due to its poor stiffness in the heavy duty machining process, and this will cause many problems, such as poor surface quality, tool damage, low accuracy. Therefore, one of the most suitable options should be a light weight mobile robot which is able to move around inside of the VV and perform different machining tasks by replacing different cutting tools. Reducing the mass of the robot manipulators offers many advantages: reduced material costs, reduced power consumption, the possibility of using smaller actuators, and a higher payload-to-robot weight ratio. Offsetting these advantages, the lighter weight robot is more flexible, which makes it more difficult to control. To achieve good machining surface quality, the tracking of the end effector must be accurate, and an accurate model for a more flexible robot must be constructed. This thesis studies the dynamics and control of a 10 degree-of-freedom (DOF) redundant hybrid robot (4-DOF serial mechanism and 6-DOF 6-UPS hexapod parallel mechanisms) hydraulically driven with flexible rods under the influence of machining forces. Firstly, the flexibility of the bodies is described using the floating frame of reference method (FFRF). A finite element model (FEM) provided the Craig-Bampton (CB) modes needed for the FFRF. A dynamic model of the system of six closed loop mechanisms was assembled using the constrained Lagrange equations and the Lagrange multiplier method. Subsequently, the reaction forces between the parallel and serial parts were used to study the dynamics of the serial robot. A PID control based on position predictions was implemented independently to control the hydraulic cylinders of the robot. Secondly, in machining, to achieve greater end effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. This thesis investigates the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two schemes of intelligent control for a hydraulically driven parallel mechanism based on the dynamic model: (1) a fuzzy-PID self-tuning controller composed of the conventional PID control and with fuzzy logic, and (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self-tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel mechanism based on rod length predictions. The serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should be controlled to hold the hexa-element. Thirdly, a finite element approach of multibody systems using the Special Euclidean group SE(3) framework is presented for a parallel mechanism with flexible piston rods under the influence of machining forces. The flexibility of the bodies is described using the nonlinear interpolation method with an exponential map. The equations of motion take the form of a differential algebraic equation on a Lie group, which is solved using a Lie group time integration scheme. The method relies on the local description of motions, so that it provides a singularity-free formulation, and no parameterization of the nodal variables needs to be introduced. The flexible slider constraint is formulated using a Lie group and used for modeling a flexible rod sliding inside a cylinder. The dynamic model of the system of six closed loop mechanisms was assembled using Hamilton’s principle and the Lagrange multiplier method. A linearized hydraulic control system based on rod length predictions was implemented independently to control the hydraulic cylinders. Consequently, the results of the simulations demonstrating the behavior of the robot machine are presented for each case study. In conclusion, this thesis studies the dynamic analysis of a special hybrid (serialparallel) robot for the above-mentioned special task involving the ITER and investigates different control algorithms that can significantly improve machining performance. These analyses and results provide valuable insight into the design and control of the parallel robot with flexible rods.

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This thesis studies the use of machine vision in RDF quality assurance and manufacturing. Currently machine vision is used in recycling and material detection and some commer- cial products are available in the market. In this thesis an on-line machine vision system is proposed for characterizing particle size. The proposed machine vision system is based on the mapping between image segmenta- tion and the ground truth of the particle size. The results shows that the implementation of such machine vision system is feasible.

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Press forming is nowadays one of the most common industrial methods in use for producing deeper trays from paperboard. Demands for material properties like recyclability and sustainability have increased also in the packaging industry, but there are still limitations related to the formability of paperboard. A majority of recent studies have focused on material development, but the potential of the package manufacturing process can also be improved by the development of tooling and process control. In this study, advanced converting tools (die cutting tools and the press forming mould) are created for production scale paperboard tray manufacturing. Also monitoring methods that enable the production of paperboard trays with enhanced quality, and can be utilized in process control are developed. The principles for tray blank preparation, including creasing pattern and die cutting tool design are introduced. The mould heating arrangement and determination of mould clearance are investigated to improve the quality of the press formed trays. The effect of the spring back of the tray walls on the tray dimensions can be managed by adjusting the heat-related process parameters and estimating it at the mould design stage. This enables production speed optimization as the process parameters can be adjusted more freely. Real-time monitoring of pressing force by using multiple force sensors embedded in the mould structure can be utilized in the evaluation of material characteristics on a modified production machinery. Comprehensive process control can be achieved with a combination of measurement of the outer dimensions of the trays and pressing force monitoring. The control method enables detection of defects and tracking changes in the material properties. The optimized converting tools provide a basis for effective operation of the control system.

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The awareness and concern of our environment together with legislation have set more and more tightening demands for energy efficiency of non-road mobile machinery (NRMM). Integrated electro-hydraulic energy converter (IEHEC) has been developed in Lappeenranta University of Technology (LUT). The elimination of resistance flow, and the recuperation of energy makes it very efficient alternative. The difficulties of IEHEC machine to step to the market has been the requirement of one IEHEC machine per one actuator. The idea is to switch IEHEC between two actuators of log crane using fast on/off valves. The control system architecture is introduced. The system has been simulated in co-simulation using two different software. The simulated responses of pump-controlled system is compared to the responses of the conventional valve-controlled system.

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The development of new procedures for quickly obtaining accurate information on the physiological potential of seed lots is essential for developing quality control programs for the seed industry. In this study, the effectiveness of an automated system of seedling image analysis (Seed Vigor Imaging System - SVIS) in determining the physiological potential of sun hemp seeds and its relationship with electrical conductivity tests, were evaluated. SVIS evaluations were performed three and four days after sowing and data on the vigor index and the length and uniformity of seedling growth were collected. The electrical conductivity test was made on 50 seed replicates placed in containers with 75 mL of deionised water at 25 ºC and readings were taken after 1, 2, 4, 8 and 16 hours of imbibition. Electrical conductivity measurements at 4 or 8 hours and the use of the SVIS on 3-day old seedlings can effectively detect differences in vigor between different sun hemp seed lots.

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The software Seed Vigor Imaging System (SVIS®), has been successfully used to evaluate seed physiological potential by automated analyses of scanned seedlings. In this research, the efficiency of this system was compared to other tests accepted for assessing cucumber (Cucumis sativus L.) seed vigor of distinct seed lots of Supremo and Safira cultivars. Seeds were subjected to germination, traditional and saturated salt accelerated aging, seedling emergence, seedling length and SVIS analyses (determination of vigor indices and seedling growth uniformity, lengths of primary root, hypocotyl and whole seedlings). It was also determined whether the definition of seedling growth/uniformity ratios affects the sensitivity of the SVIS®. Results showed that analyses SVIS have provided consistent identification of seed lots performance, and have produced information comparable to those from recommended seed vigor tests, thus demonstrating a suitable sensitivity for a rapid and objective evaluation of physiological potential of cucumber seeds. Analyses of four-days-old cucumber seedlings using the SVIS® are more accurate and growth/uniformity does not affect the precision of results.

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The successful performance of company in the market relates to the quality management of human capital aiming to improve the company's internal performance and external implementation of the core business strategy. Companies with matrix structure focusing on realization and development of innovation and technologies for the uncertain market need to select thoroughly the approach to HR management system. Human resource management has a significant impact on the organization and use a variety of instruments such as corporate information systems to fulfill their functions and objectives. There are three approaches to strategic control management depending on major impact on the major interference in employee decision-making, development of skills and his integration into the business strategy. The mainstream research has focus only on the framework of strategic planning of HR and general productivity of firm, but not on features of organizational structure and corporate software capabilities for human capital. This study tackles the before mentioned challenges, typical for matrix organization, by using the HR control management tools and corporate information system. The detailed analysis of industry producing and selling electromotor and heating equipment in this master thesis provides the opportunity to improve system for HR control and displays its application in the ERP software. The results emphasize the sustainable role of matrix HR input control for creating of independent project teams for matrix structure who are able to respond to various uncertainties of the market and use their skills for improving performance. Corporate information systems can be integrated into input control system by means of output monitoring to regulate and evaluate the processes of teams, using key performance indicators and reporting systems.

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The objectives of this master’s thesis were to understand the importance of bubbling fluidized bed (BFB) conditions and to find out how digital image processing and acoustic emission technology can help in monitoring the bed quality. An acoustic emission (AE) measurement system and a bottom ash camera system were evaluated in acquiring information about the bed conditions. The theory part of the study describes the fundamentals of BFB boiler and evaluates the characteristics of bubbling bed. Causes and effects of bed material coarsening are explained. The ways and methods to monitor the behaviour of BFB are determined. The study introduces the operating principles of AE technology and digital image processing. The empirical part of the study describes an experimental arrangement and results of a case study at an industrial BFB boiler. Sand consumption of the boiler was reduced by optimization of bottom ash handling and sand feeding. Furthermore, data from the AE measurement system and the bottom ash camera system was collected. The feasibility of these two systems was evaluated. The particle size of bottom ash and the changes in particle size distribution were monitored during the test period. Neither of the systems evaluated was ready to serve in bed quality control accurately or fast enough. Particle size distributions according to the bottom ash camera did not correspond to the results of manual sieving. Comprehensive interpretation of the collected AE data requires much experience. Both technologies do have potential and with more research and development they may enable acquiring reliable and real-time information about the bed conditions. This information could help to maintain disturbance-free combustion process and to optimize bottom ash handling system.

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Dentro de las actividades para el control de calidad en el laboratorio, los resultados finales de un analito en particular son considerados productos intermedios, dada la pertinencia otorgada al aseguramiento de la calidad como fin último de los programas de gestión de la calidad. Esta concepción precisa el establecimiento de instrumentos integrales para la detección de eventos como la contaminación cruzada y la adopción de medidas para evitar que se afecte la marcha analítica. Objetivo: el objetivo principal fue establecer un sistema para el monitoreo y control de la contaminación cruzada en el laboratorio de análisis microbiológico de alimentos. Materiales y métodos: la metodología empleada consistió en desarrollar diagramas de flujo para los procedimientos sobre el control de las poblaciones de mesófilos aerobios y mohos provenientes de la contaminación en los ambientes, superficies, material estéril y medios de cultivos. Dichos diagramas incluyeron un árbol de decisiones, diseñado para efectuar acciones de control con base en los intervalos de tolerancia, establecidos como herramienta objetiva hacia la toma de decisiones que normalicen los recuentos de las poblaciones microbianas en cuestión. Resultados: los límites de alerta más estrictos se obtuvieron para las poblaciones de mesófilos aerobios y mohos en los diferentes controles, excepto para el ambiente del área de preparación de medios y los correspondientes al material estéril. Conclusión: el proceso desarrollado permitió complementar el sistema de control de calidad interno en el laboratorio, al disponer de un medio objetivo para el cierre de no conformidades por contaminación cruzada.

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Las organizaciones en la actualidad deben encontrar diferentes maneras de sobrevivir en un tiempo de rápida transformación. Uno de los mecanismos usados por las empresas para adaptarse a los cambios organizacionales son los sistemas de control de gestión, que a su vez permiten a las organizaciones hacer un seguimiento a sus procesos, para que la adaptabilidad sea efectiva. Otra variable importante para la adaptación es el aprendizaje organizacional siendo el proceso mediante el cual las organizaciones se adaptan a los cambios del entorno, tanto interno como externo de la compañía. Dado lo anterior, este proyecto se basa en la extracción de documentación soporte valido, que permita explorar las interacciones entre estos dos campos, los sistemas de control de gestión y el aprendizaje organizacional, además, analizar el impacto de estas interacciones en la perdurabilidad organizacional. ​