926 resultados para LABORATORY SIMULATOR
Resumo:
The purpose of this study was to estimate the energy cost of linear (EC) and vertical displacement (ECvert), mechanical efficiency and main stride parameters during simulated ski mountaineering at different speeds and gradients, to identify an optimal speed and gradient that maximizes performance. 12 subjects roller skied on a treadmill at three different inclines (10, 17 and 24 %) at three different speeds (approximately 70, 80 and 85 % of estimated peak heart rate). Energy expenditure was calculated by indirect calorimetry, while biomechanical parameters were measured with an inertial sensor-based system. At 10 % there was no significant change with speed in EC, ECvert and mechanical efficiency. At 17 and 24 % the fastest speed was significantly more economical. There was a significant effect of gradient on EC, ECvert and mechanical efficiency. The most economical gradient was the steepest one. There was a significant increase of stride frequency with speed. At steep gradients only, relative thrust phase duration decreased significantly, while stride length increased significantly with speed. There was a significant effect of gradient on stride length (decrease with steepness) and relative thrust phase duration (increase with steepness). A combination of a decreased relative thrust phase duration with increased stride length and frequency decreases ECvert. To minimize the energy expenditure to reach the top of a mountain and to optimize performance, ski-mountaineers should choose a steep gradient (~24 %) and, provided they possess sufficient metabolic scope, combine it with a fast speed (~6 km h(-1)).
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Automation was introduced many years ago in several diagnostic disciplines such as chemistry, haematology and molecular biology. The first laboratory automation system for clinical bacteriology was released in 2006, and it rapidly proved its value by increasing productivity, allowing a continuous increase in sample volumes despite limited budgets and personnel shortages. Today, two major manufacturers, BD Kiestra and Copan, are commercializing partial or complete laboratory automation systems for bacteriology. The laboratory automation systems are rapidly evolving to provide improved hardware and software solutions to optimize laboratory efficiency. However, the complex parameters of the laboratory and automation systems must be considered to determine the best system for each given laboratory. We address several topics on laboratory automation that may help clinical bacteriologists to understand the particularities and operative modalities of the different systems. We present (a) a comparison of the engineering and technical features of the various elements composing the two different automated systems currently available, (b) the system workflows of partial and complete laboratory automation, which define the basis for laboratory reorganization required to optimize system efficiency, (c) the concept of digital imaging and telebacteriology, (d) the connectivity of laboratory automation to the laboratory information system, (e) the general advantages and disadvantages as well as the expected impacts provided by laboratory automation and (f) the laboratory data required to conduct a workflow assessment to determine the best configuration of an automated system for the laboratory activities and specificities.
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Since its inception in 1994 as a purely online university, the Universitat Oberta de Catalunya(UOC) has been able to position itself among the main universities of the Catalan and Spanish university systems. Most of the students at the UOC (currently more than 60,000) are adults who have a profile that could hardly fit into the traditional university system, thus finding in the UOC an opportunity to start or continue their higher education grades, in a very innovative environment. The intensive use of ICT for both theteaching/learning processes and management allowsresearchers and practitioners to obtain data aboutwhat takes place in the UOC Virtual Campus, which is continuously being improved according to suchfindings.
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This paper reports the results of a three-year study of the effectiveness of mini-projects in a first year laboratory course in chemistry at a Scottish university. A mini-project is a short, practical problem which requires for its solution the application of the knowledge and skills developed in previously completed set experiments. A number of recommendations have been made about the most appropriate ways of introducing mini-projects into undergraduate laboratory course. The main hypothesis of this survey was concerned with the value of mini-projects in laboratory courses formulated within the context of Information Processing Theory.
Resumo:
COD discharges out of processes have increased in line with elevating brightness demands for mechanical pulp and papers. The share of lignin-like substances in COD discharges is on average 75%. In this thesis, a plant dynamic model was created and validated as a means to predict COD loading and discharges out of a mill. The assays were carried out in one paper mill integrate producing mechanical printing papers. The objective in the modeling of plant dynamics was to predict day averages of COD load and discharges out of mills. This means that online data, like 1) the level of large storage towers of pulp and white water 2) pulp dosages, 3) production rates and 4) internal white water flows and discharges were used to create transients into the balances of solids and white water, referred to as “plant dynamics”. A conversion coefficient was verified between TOC and COD. The conversion coefficient was used for predicting the flows from TOC to COD to the waste water treatment plant. The COD load was modeled with similar uncertainty as in reference TOC sampling. The water balance of waste water treatment was validated by the reference concentration of COD. The difference of COD predictions against references was within the same deviation of TOC-predictions. The modeled yield losses and retention values of TOC in pulping and bleaching processes and the modeled fixing of colloidal TOC to solids between the pulping plant and the aeration basin in the waste water treatment plant were similar to references presented in literature. The valid water balances of the waste water treatment plant and the reduction model of lignin-like substances produced a valid prediction of COD discharges out of the mill. A 30% increase in the release of lignin-like substances in the form of production problems was observed in pulping and bleaching processes. The same increase was observed in COD discharges out of waste water treatment. In the prediction of annual COD discharge, it was noticed that the reduction of lignin has a wide deviation from year to year and from one mill to another. This made it difficult to compare the parameters of COD discharges validated in plant dynamic simulation with another mill producing mechanical printing papers. However, a trend of moving from unbleached towards high-brightness TMP in COD discharges was valid.
Resumo:
From an analysis of a learning model based on the theory of information processing four hypothesis were developed for improving the design of laboratory courses. Three of these hypotheses concerned specific procedures to minimise the load on students' working memories (or working spaces) and the fourth hypothesis was concerned with the value of mini-projects in enhancing meaningful learning of the knowledge and skills underpinning the set experiments. A three-year study of a first year undergraduate chemistry laboratory course at a Scottish university has been carried out to test these four hypotheses. This paper reports the results of the study relevant to the three hypotheses about the burden on students' working spaces. It was predicted from the learning model that the load on students working space should be reduced by appropriate changes to the written instructions and the laboratory organisation and by the introduction of prelab-work and prelab-training in laboratory techniques. It was concluded from research conducted over the three years period that all these hypothesised changes were effective both in reducing the load on students' working spaces and in improving their attitudes to the laboratory course.
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The layout design process of the packaging laboratory at Lappeenranta University of Technology is documented in this thesis. Layout planning methods are discussed in general. The systematic layout planning procedure is presented in more detail as it is utilised in the case of layout planning of the packaging laboratory. General demands for research laboratory are discussed both from the machine and product perspectives. The possibilities for commercial food processing in the laboratory are discussed from the point of view of foodstuff processing regulations and hygiene demands. The layout planning process is documented and different layout possibilities are presented. Different layout drafts are evaluated and one layout draft is developed to be the final layout of the packaging laboratory. Guideline for technical planning and implementation based on the final layout is given
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When laboratory intercomparison exercises are conducted, there is no a priori dependence of the concentration of a certain compound determined in one laboratory to that determined by another(s). The same applies when comparing different methodologies. A existing data set of total mercury readings in fish muscle samples involved in a Brazilian intercomparison exercise was used to show that correlation analysis is the most effective statistical tool in this kind of experiments. Problems associated with alternative analytical tools such as mean or paired 't'-test comparison and regression analysis are discussed.
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This thesis describes the process of the integration of a real-time simulator environment with a motion platform and a haptic device as a part of the Kvalive project. Several programs running on two computers were made to control the different devices of the environment. User tests were made to obtain information of needed improvements to make the simulator more realistic. Also new ideas for improving the simulator and directions of further research were obtained with the help of this research.
Resumo:
In the paper machine, it is not a desired feature for the boundary layer flows in the fabric and the roll surfaces to travel into the closing nips, creating overpressure. In this thesis, the aerodynamic behavior of the grooved roll and smooth rolls is compared in order to understand the nip flow phenomena, which is the main reason why vacuum and grooved roll constructions are designed. A common method to remove the boundary layer flow from the closing nip is to use the vacuum roll construction. The downside of the use of vacuum rolls is high operational costs due to pressure losses in the vacuum roll shell. The deep grooved roll has the same goal, to create a pressure difference over the paper web and keep the paper attached to the roll or fabric surface in the drying pocket of the paper machine. A literature review revealed that the aerodynamic functionality of the grooved roll is not very well known. In this thesis, the aerodynamic functionality of the grooved roll in interaction with a permeable or impermeable wall is studied by varying the groove properties. Computational fluid dynamics simulations are utilized as the research tool. The simulations have been performed with commercial fluid dynamics software, ANSYS Fluent. Simulation results made with 3- and 2-dimensional fluid dynamics models are compared to laboratory scale measurements. The measurements have been made with a grooved roll simulator designed for the research. The variables in the comparison are the paper or fabric wrap angle, surface velocities, groove geometry and wall permeability. Present-day computational and modeling resources limit grooved roll fluid dynamics simulations in the paper machine scale. Based on the analysis of the aerodynamic functionality of the grooved roll, a grooved roll simulation tool is proposed. The smooth roll simulations show that the closing nip pressure does not depend on the length of boundary layer development. The surface velocity increase affects the pressure distribution in the closing and opening nips. The 3D grooved roll model reveals the aerodynamic functionality of the grooved roll. With the optimal groove size it is possible to avoid closing nip overpressure and keep the web attached to the fabric surface in the area of the wrap angle. The groove flow friction and minor losses play a different role when the wrap angle is changed. The proposed 2D grooved roll simulation tool is able to replicate the grooved aerodynamic behavior with reasonable accuracy. A small wrap angle predicts the pressure distribution correctly with the chosen approach for calculating the groove friction losses. With a large wrap angle, the groove friction loss shows too large pressure gradients, and the way of calculating the air flow friction losses in the groove has to be reconsidered. The aerodynamic functionality of the grooved roll is based on minor and viscous losses in the closing and opening nips as well as in the grooves. The proposed 2D grooved roll model is a simplification in order to reduce computational and modeling efforts. The simulation tool makes it possible to simulate complex paper machine constructions in the paper machine scale. In order to use the grooved roll as a replacement for the vacuum roll, the grooved roll properties have to be considered on the basis of the web handling application.
Resumo:
This paper reports how laboratory projects (LP) coupled to inquiry-based learning (IBL) were implemented in a practical inorganic chemistry course. Several coordination compounds have been successfully synthesised by students according to the proposed topics by the LP-IBL junction, and the chemistry of a number of metals has been studied. Qualitative data were collected from written reports, oral presentations, lab-notebook reviews and personal discussions with the students through an experimental course with undergraduate second-year students at the Universidad Nacional de Colombia during the last 5 years. Positive skills production was observed by combining LP and IBL. Conceptual, practical, interpretational, constructional (questions, explanations, hypotheses), communicational, environmental and application abilities were revealed by the students throughout the experimental course.
The accuracy of manually recorded time study data for harvester operation shown via simulator screen
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An undergraduate experiment that illustrates the phenomenon of perichromism-the sensitivity of a dye to its microenvironment, as assessed by color changes of its solutions-is described. An easily prepared perichromic imine is synthesized and characterized, and its solvatochromism, thermochromism, halochromism, and preferential solvation in binary solvent mixtures are demonstrated by visual inspection of its solutions. The results are rationalized by invoking solute - solvent interactions in the various media.
Resumo:
A two-step experiment is proposed for a third year class in experimental organic chemistry. Over a period of five weeks, the students synthesized calix[4]pyrrole, a receptor that is highly selective for fluoride, and a pyridinium N-phenolate dye. Subsequently, the students used the synthesized compounds to investigate a displacement assay on the basis of the competition in acetonitrile between fluoride and the dye for calix[4]pyrrole. The experiment increased the students' skills in organic synthesis and in the characterization of organic compounds, provided a very attractive and accessible illustration of important supramolecular phenomena, and allowed the study of a chromogenic chemosensor.