960 resultados para Work Measurement


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A system for the NDI' testing of the integrity of conposite materials and of adhesive bonds has been developed to meet industrial requirements. The vibration techniques used were found to be applicable to the development of fluid measuring transducers. The vibrational spectra of thin rectangular bars were used for the NDT work. A machined cut in a bar had a significant effect on the spectrum but a genuine crack gave an unambiguous response at high amplitudes. This was the generation of fretting crack noise at frequencies far above that of the drive. A specially designed vibrational decrement meter which, in effect, measures mechanical energy loss enabled a numerical classification of material adhesion to be obtained. This was used to study bars which had been flame or plasma sprayed with a variety of materials. It has become a useful tool in optimising coating methods. A direct industrial application was to classify piston rings of high performance I.C. engines. Each consists of a cast iron ring with a channel into which molybdenum, a good bearing surface, is sprayed. The NDT classification agreed quite well with the destructive test normally used. The techniques and equipment used for the NOT work were applied to the development of the tuning fork transducers investigated by Hassan into commercial density and viscosity devices. Using narrowly spaced, large area tines a thin lamina of fluid is trapped between them. It stores a large fraction of the vibrational energy which, acting as an inertia load reduces the frequency. Magnetostrictive and piezoelectric effects together or in combination enable the fork to be operated through a flange. This allows it to be used in pipeline or 'dipstick' applications. Using a different tine geometry the viscosity loading can be predoninant. This as well as the signal decrement of the density transducer makes a practical viscometer.

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The further development of the use of NMR relaxation times in chemical, biological and medical research has perhaps been curtailed by the length of time these measurements often take. The DESPOT (Driven Equilibrium Single Pulse Observation of T1) method has been developed, which reduces the time required to make a T1 measurement by a factor of up to 100. The technique has been studied extensively herein and the thesis contains recommendations for its successful experimental application. Modified DESPOT type equations for use when T2 relaxation is incomplete or where off-resonance effects are thought to be significant are also presented. A recently reported application of the DESPOT technique to MR imaging gave good initial results but suffered from the fact that the images were derived from spin systems that were not driven to equilibrium. An approach which allows equilibrium to be obtained with only one non-acquisition sequence is presented herein and should prove invaluable in variable contrast imaging. A DESPOT type approach has also been successfully applied to the measurement of T1. T_1's can be measured, using this approach significantly faster than by the use of the classical method. The new method also provides a value for T1 simultaneously and therefore the technique should prove valuable in intermediate energy barrier chemical exchange studies. The method also gives rise to the possibility of obtaining simultaneous T1 and T1 MR images. The DESPOT technique depends on rapid multipulsing at nutation angles, normally less than 90^o. Work in this area has highlighted the possible time saving for spectral acquisition over the classical technique (90^o-5T_1)_n. A new method based on these principles has been developed which permits the rapid multipulsing of samples to give T_1 and M_0 ratio information. The time needed, however, is only slightly longer than would be required to determine the M_0 ratio alone using the classical technique. In ^1H decoupled ^13C spectroscopy the method also gives nOe ratio information for the individual absorptions in the spectrum.

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This study is concerned with several proposals concerning multiprocessor systems and with the various possible methods of evaluating such proposals. After a discussion of the advantages and disadvantages of several performance evaluation tools, the author decides that simulation is the only tool powerful enough to develop a model which would be of practical use, in the design, comparison and extension of systems. The main aims of the simulation package developed as part of this study are cost effectiveness, ease of use and generality. The methodology on which the simulation package is based is described in detail. The fundamental principles are that model design should reflect actual systems design, that measuring procedures should be carried out alongside design that models should be well documented and easily adaptable and that models should be dynamic. The simulation package itself is modular, and in this way reflects current design trends. This approach also aids documentation and ensures that the model is easily adaptable. It contains a skeleton structure and a library of segments which can be added to or directly swapped with segments of the skeleton structure, to form a model which fits a user's requirements. The study also contains the results of some experimental work carried out using the model, the first part of which tests• the model's capabilities by simulating a large operating system, the ICL George 3 system; the second part deals with general questions and some of the many proposals concerning multiprocessor systems.

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The objective of this thesis is to investigate, through an empirical study, the different functions of the highways maintenance departments and to suggest methods by means of which road maintenance work could be carried out in a more efficient way by utilising its resources of men, material and plant to the utmost advantage. This is particularly important under the present circumstances of national financial difficulties which have resulted in continuous cuts in public expenditure. In order to achieve this objective, the researcher carried out a survey among several Highways Authorities by means of questionnaire and interview. The information so collected was analysed in order to understand the actual, practical situation within highways manintenance departments, and highlight any existing problems, and try to answer the question of how they could become more efficient. According to the results obtained by the questionnaire and the interview, and the analysis of these results, the researcher concludes that it is the management system where least has been done, and where problems exist and are most complex. The management of highways maintenance departments argue that the reasons for their problems include both financial and organisational difficulties, apart from the political aspect and nature of the activities undertaken. The researcher believes that this ought to necessitate improving the management's analytical tools and techniques in order to achieve the most effective way of performing each activity. To this end the researcher recommends several related procedures to be adopted by the management of the highways maintenance departments. These recommendations, arising from the study, involve the technical, practical and human aspects. These are essential factors of which management should be aware - and certainly should not neglect - in order to achieve its objectives of improved productivity in the highways maintenance departments.

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Coke oven liquor is a toxic wastewater produced in large quantities by the Iron and Steel, and Coking Industries, and gives rise to major effluent treatment problems in those industries. Conscious of the potentially serious environmental impact of the discharge of such wastes, pollution control agencies in many countries have made progressively more stringent quality requirements for the discharge of the treated waste. The most common means of treating the waste is the activated sludge process. Problems with achieving consistently satisfactory treatment by this process have been experienced in the past. The need to improve the quality of the discharge of the treated waste prompted attempts by TOMLINS to model the process using Adenosine Triphosophnte (ATP) as a measure of biomass, but these were unsuccessful. This thesis describes work that was carried out to determine the significance of ATP in the activated sludge treatment of the waste. The use of ATP measurements in wastewater treatment were reviewed. Investigations were conducted into the ATP behaviour of the batch activated sludge treatment of two major components of the waste, phenol, and thiocyanate, and the continuous activated sludge treatment of the liquor itself, using laboratory scale apparatus. On the basis of these results equations were formulated to describe the significance of ATP as a measured activity and biomass in the treatment system. These were used as the basis for proposals to use ATP as a control parameter in the activated sludge treatment of coke oven liquor, and wastewaters in general. These had relevance both to the treatment of the waste in the reactor and to the settlement of the sludge produced in the secondary settlement stage of the treatment process.

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Off-highway motive plant equipment is costly in capital outlay and maintenance. To reduce these overheads and increase site safety and workrate, a technique of assessing and limiting the velocity of such equipment is required. Due to the extreme environmental conditions met on such sites, conventional velocity measurement techniques are inappropriate. Ogden Electronics Limited were formed specifically to manufacture a motive plant safety system incorporating a speed sensor and sanction unit; to date, the only such commercial unit available. However, problems plague the reliability, accuracy and mass production of this unit. This project assesses the company's exisiting product, and in conjunction with an appreciation of the company history and structure, concludes that this unit is unsuited to its intended application. Means of improving the measurement accuracy and longevity of this unit, commensurate with the company's limited resources and experience, are proposed, both for immediate retrofit and for longer term use. This information is presented in the form of a number of internal reports for the company. The off-highway environment is examined; and in conjunction with an evaluation of means of obtaining a returned signal, comparisons of processing techniques, and on-site gathering of previously unavailable data, preliminary designs for an alternative product are drafted. Theoretical aspects are covered by a literature review of ground-pointing radar, vehicular radar, and velocity measuring systems. This review establishes and collates the body of knowledge in areas previously considered unrelated. Based upon this work, a new design is proposed which is suitable for incorporation into the existing company product range. Following production engineering of the design, five units were constructed, tested and evaluated on-site. After extended field trials, this design has shown itself to possess greater accuracy, reliability and versatility than the existing sensor, at a lower unit cost.

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An initial aim of this project was to evaluate the conventional techniques used in the analysis of newly prepared environmentally friendly water-borne automotive coatings and compare them with solvent-borne coatings having comparable formulations. The investigation was carried out on microtuned layers as well as on complete automotive multi-layer paint systems. Methods used included the very traditional methods of gloss and hardness and the commonly used photo-oxidation index (from FTIR spectral analysis). All methods enabled the durability to weathering of the automotive coatings to be initially investigated. However, a primary aim of this work was to develop methods for analysing the early stages of chemical and property changes in both the solvent-borne and water-borne coating systems that take place during outdoor natural weathering exposures and under accelerated artificial exposures. This was achieved by using dynamic mechanical analysis (DMA), in both tension mode on the microtomed films (on all depths of the coating systems from the uppermost clear-coat right down to the electron-coat) and bending mode of the full (unmicrotomed) systems, as well as MALDI-Tof analysis on the movement of the stabilisers in the full systems. Changes in glass transition temperature and relative cross-link density were determined after weathering and these were related to changes in the chemistries of the binder systems of the coatings after weathering. Concentration profiles of the UV-stabilisers (UVA and HALS) in the coating systems were analysed as a consequence of migration in the coating systems in separate microtomed layers of the paint samples (depth profiling) after weathering and diffusion co-efficient and solubility parameters were determined for the UV stabilisers in the coating systems. The methods developed were used to determine the various physical and chemical changes that take place during weathering of the different (water-borne and solvent-borne) systems (photoxidation). The solvent-borne formulations showed less changes after weathering (both natural and accelerated) than the corresponding water-borne formulations due to the lower level of cross-links in the binders of the water-borne systems. The silver systems examined were more durable than the blue systems due to the reflecting power of the aluminium and the lower temperature of the silver coatings.

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Purpose – This paper aims to respond to John Rossiter's call for a “Marketing measurement revolution” in the current issue of EJM, as well as providing broader comment on Rossiter's C-OAR-SE framework, and measurement practice in marketing in general. Design/methodology/approach – The paper is purely theoretical, based on interpretation of measurement theory. Findings – The authors find that much of Rossiter's diagnosis of the problems facing measurement practice in marketing and social science is highly relevant. However, the authors find themselves opposed to the revolution advocated by Rossiter. Research limitations/implications – The paper presents a comment based on interpretation of measurement theory and observation of practices in marketing and social science. As such, the interpretation is itself open to disagreement. Practical implications – There are implications for those outside academia who wish to use measures derived from academic work as well as to derive their own measures of key marketing and other social variables. Originality/value – This paper is one of the few to explicitly respond to the C-OAR-SE framework proposed by Rossiter, and presents a number of points critical to good measurement theory and practice, which appear to remain underdeveloped in marketing and social science.

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The leadership categorisation theory suggests that followers rely on a hierarchical cognitive structure in perceiving leaders and the leadership process, which consists of three levels; superordinate, basic and subordinate. The predominant view is that followers rely on Implicit Leadership Theories (ILTs) at the basic level in making judgments about managers. The thesis examines whether this presumption is true by proposing and testing two competing conceptualisations; namely the congruence between the basic level ILTs (general leader) and actual manager perceptions, and subordinate level ILTs (job-specific leader) and actual manager. The conceptualisation at the job-specific level builds on context-related assertions of the ILT explanatory models: leadership categorisation, information processing and connectionist network theories. Further, the thesis addresses the effects of ILT congruence at the group level. The hypothesised model suggests that Leader-Member Exchange (LMX) will act as a mediator between ILT congruence and outcomes. Three studies examined the proposed model. The first was cross-sectional with 175 students reporting on work experience during a 1-year industrial placement. The second was longitudinal and had a sample of 343 students engaging in a business simulation in groups with formal leadership. The final study was a cross-sectional survey in several organisations with a sample of 178. A novel approach was taken to congruence analysis; the hypothesised models were tested using Latent Congruence Modelling (LCM), which accounts for measurement error and overcomes the majority of limitations of traditional approaches. The first two studies confirm the traditional theorised view that employees rely on basic-level ILTs in making judgments about their managers with important implications, and show that LMX mediates the relationship between ILT congruence and work-related outcomes (performance, job satisfaction, well-being, task satisfaction, intragroup conflict, group satisfaction, team realness, team-member exchange, group performance). The third study confirms this with conflict, well-being, self-rated performance and commitment as outcomes.

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This thesis begins with a review of the literature on team-based working in organisations, highlighting the variations in research findings, and the need for greater precision in our measurement of teams. It continues with an illustration of the nature and prevalence of real and pseudo team-based working, by presenting results from a large sample of secondary data from the UK National Health Service. Results demonstrate that ‘real teams’ have an important and significant impact on the reduction of many work-related safety outcomes. Based on both theoretical and methodological limitations of existing approaches, the thesis moves on to provide a clarification and extension of the ‘real team’ construct, demarcating this from other (pseudo-like) team typologies on a sliding scale, rather than a simple dichotomy. A conceptual model for defining real teams is presented, providing a theoretical basis for the development of a scale on which teams can be measured for varying extents of ‘realness’. A new twelve-item scale is developed and tested with three samples of data comprising 53 undergraduate teams, 52 postgraduate teams, and 63 public sector teams from a large UK organisation. Evidence for the content, construct and criterion-related validity of the real team scale is examined over seven separate validation studies. Theoretical, methodological and practical implications of the real team scale are then discussed.

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There is increasing evidence that non-enzymatic post-translational protein modifications might play key roles in various diseases. These protein modifications can be caused by free radicals generated during oxidative stress or by their products generated during lipid peroxidation. 4-Hydroxynonenal (HNE), a major biomarker of oxidative stress and lipid peroxidation, has been recognized as important molecule in pathology as well as in physiology of living organisms. Therefore, its detection and quantification can be considered as valuable tool for evaluating various pathophysiological conditions.The HNE-protein adduct ELISA is a method to detect HNE bound to proteins, which is considered as the most likely form of HNE occurrence in living systems. Since the earlier described ELISA has been validated for cell lysates and the antibody used for detection of HNE-protein adducts is non-commercial, the aim of this work was to adapt the ELISA to a commercial antibody and to apply it in the analysis of human plasma samples.After modification and validation of the protocol for both antibodies, samples of two groups were analyzed: apparently healthy obese (n=62) and non-obese controls (n=15). Although the detected absolute values of HNE-protein adducts were different, depending on the antibody used, both ELISA methods showed significantly higher values of HNE-protein adducts in the obese group. © 2013 The Authors.

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The main purpose of this research is to develop and deploy an analytical framework for measuring the environmental performance of manufacturing supply chains. This work's theoretical bases combine and reconcile three major areas: supply chain management, environmental management and performance measurement. Researchers have suggested many empirical criteria for green supply chain (GSC) performance measurement and proposed both qualitative and quantitative frameworks. However, these are mainly operational in nature and specific to the focal company. This research develops an innovative GSC performance measurement framework by integrating supply chain processes (supplier relationship management, internal supply chain management and customer relationship management) with organisational decision levels (both strategic and operational). Environmental planning, environmental auditing, management commitment, environmental performance, economic performance and operational performance are the key level constructs. The proposed framework is then applied to three selected manufacturing organisations in the UK. Their GSC performance is measured and benchmarked by using the analytic hierarchy process (AHP), a multiple-attribute decision-making technique. The AHP-based framework offers an effective way to measure and benchmark organisations’ GSC performance. This study has both theoretical and practical implications. Theoretically it contributes holistic constructs for designing a GSC and managing it for sustainability; and practically it helps industry practitioners to measure and improve the environmental performance of their supply chain. © 2013 Copyright Taylor and Francis Group, LLC. CORRIGENDUM DOI 10.1080/09537287.2012.751186 In the article ‘Green supply chain performance measurement using the analytic hierarchy process: a comparative analysis of manufacturing organisations’ by Prasanta Kumar Dey and Walid Cheffi, Production Planning & Control, 10.1080/09537287.2012.666859, a third author is added which was not included in the paper as it originally appeared. The third author is Breno Nunes.

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Simultaneous strain and temperature measurement for advanced 3-D braided composite materials using fibre-optic sensor technology is demonstrated, for the first time. These advanced 3-D braided composites can virtually eliminate the most serious problem of delamination for conventional composites. A tandem in-fibre Bragg-grating (FBG)/extrinsic Fabry-Perot interferometric sensor (EFPI) system with improved accuracy has been used to facilitate simultaneous temperature and strain measurement in this work. The non-symmetric distortion of the optical spectrum of the FBG, due to the combination of the FBG and the EFPI, is observed for the first time. Experimental and theoretical studies indicate that this type of distortion can affect the measurement accuracy seriously and it is mainly caused by the modulation of the periodic output of the EFPI. A simple method has been demonstrated to improve the accuracy for detection of the wavelength-shift of the FBG induced by temperature change. A strain accuracy of ∼ ±20 με and a temperature accuracy of ∼ ±1 °C have been achieved, which can meet the requirements for practical applications of 3-D braided composites. © 2002 Elsevier Science Ltd. All rights reserved.

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The purpose of this work is the development of database of the distributed information measurement and control system that implements methods of optical spectroscopy for plasma physics research and atomic collisions and provides remote access to information and hardware resources within the Intranet/Internet networks. The database is based on database management system Oracle9i. Client software was realized in Java language. The software was developed using Model View Controller architecture, which separates application data from graphical presentation components and input processing logic. The following graphical presentations were implemented: measurement of radiation spectra of beam and plasma objects, excitation function for non-elastic collisions of heavy particles and analysis of data acquired in preceding experiments. The graphical clients have the following functionality of the interaction with the database: browsing information on experiments of a certain type, searching for data with various criteria, and inserting the information about preceding experiments.

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The development of the distributed information measurement and control system for optical spectral research of particle beam and plasma objects and the execution of laboratory works on Physics and Engineering Department of Petrozavodsk State University are described. At the hardware level the system is represented by a complex of the automated workplaces joined into computer network. The key element of the system is the communication server, which supports the multi-user mode and distributes resources among clients, monitors the system and provides secure access. Other system components are formed by equipment servers (CАМАC and GPIB servers, a server for the access to microcontrollers MCS-196 and others) and the client programs that carry out data acquisition, accumulation and processing and management of the course of the experiment as well. In this work the designed by the authors network interface is discussed. The interface provides the connection of measuring and executive devices to the distributed information measurement and control system via Ethernet. This interface allows controlling of experimental parameters by use of digital devices, monitoring of experiment parameters by polling of analog and digital sensors. The device firmware is written in assembler language and includes libraries for Ethernet-, IP-, TCP- и UDP-packets forming.