Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Student: Vlachová Hana Consultant: Doc. RNDr. Milan Řehula, CSc. Determination of optimal compression forces and speed of compression for the production of aciclovir tablets. This thesis deals with the characterisation of impact compression process on hardness of the tablets. The theoretical part of the thesis describes the effective substance - aciclovir. It also describes compression equations which explain process of compression and factors influencing terminal weight and hardness of tablets. The aim of the experimental part of the work is to measure physical properties of the tablets and find compression forces and speed of compression which are suitable for compression tablets. Tablets were pressed using Kilian Synthesis 700 machine at six compression forces in the range from 4 kN to 14 kN. The height, weight and hardness of each tablet were measured immediately after dressing and note to help for later calculation. The result of the study was to determine the impact of compression forces and compression speed on tablet hardness and weight. Tablet weight decreses with increasing comppession forces. Hardness increases with increasing compression forces. The range of radial hardness...

The final objective of the present work is the accurate prediction of the dynamic stiffness behaviour of complex rubber parts using finite element simulation tools. For this purpose, it becomes necessary to perform a complex rubber compound material characterisation and modelling work; this needs two important previous steps. These steps are detailed in the present document together with a theoretical review of viscoelastic visco-elasto-plastic models for elastomers. Firstly, a new characterisation method is proposed to determine the degree of cure of rubber parts. It is known that the degree of cure of rubbers bears heavily on their mechanical properties. This method consists of the correlation of swelling results to rheometer data achieving a good agreement. Secondly, the influence of the strain rate used in static characterisation tests is studied. In this step, a new characterisation method is proposed. The latter characterisation method will be used to fit extended hyperelastic models in Finite Element Analysis (FEA) software like ANSYS. The proposed method improves the correlation of experimental data to simulation results obtained by the use of standard methods. Finally, the overlay method proposed by Austrell concerning frequency dependence of the dynamic modulus and loss angle that is known to increase more with frequency for small amplitudes than for large amplitudes is developed. The original version of the overlay method yields no difference in frequency dependence with respect to different load amplitudes. However, if the element in the viscoelastic layer of the finite element model are given different stiffness and loss properties depending on the loading amplitude level, frequency dependence is shown to be more accurate compared to experiments. The commercial finite element program Ansys is used to model an industrial metal rubber part using two layers of elements. One layer is a hyper viscoelastic layer and the other layer uses an elasto-plastic model with a multi-linear kinematic hardening rule. The model, being intended for stationary cyclic loading, shows good agreement with measurements on the harmonically loaded industrial rubber part.

This thesis attempts to revise the existing historiography of British Columbia by first. establishing the growth and presence of a significant and diversified manufacturing sector between 1860 and 1890 and second. by charting the relative and absolute decline of the secondary manufacturing sector between 1890 and 1915. It adds to the literature which argues that British Columbia has been an industrial society since before the 1880's. Even by 1890 a higher percentage of British Columbians were engaged in manufacturing than elsewhere in Canada and output per capita in British Columbia exceded that of any other province. Comparing total manufactured output. British Columbia moved from the seventh largest producer to third among Canadian provinces in the three decades after 1880. Through the whole study period British Columbia factories tended to be larger than their counterparts elsewhere in Canada. The core of the thesis describes the manufacturing sectors of British Columbia. both primary and secondary. at an aggregate level utilizing census. directory. tax. and credit data. In attempting to account for the pattern of growth and decline it considers the two main approaches to Canadian political economy. the export base (staple) approach and the dependency approach and concludes that a third, "production system." approach inspired by recent work in economic anthropology provides a better framework to discern the causal factors. Utilizing the production system framework this thesis explores some of the reasons for the decline of the secondary manufacturing sector after 1890 by using one of the central industries. the boiler and engine industry. as a case study. The thesis ' identifies three factors that were important in explaining the decline of the boiler and engine industry: discriminatory railway rates. high labour costs and. the transfer of iii ownership of much of the economy from local to non-local capitalists. This thesis reveals that although regional manufacturers were responding to the relative prices of transport and labour. these prices were the product of the interaction of social and institutional factors located both within and without the region. The third factor. the shift of ownership outside the region. is an example of how structural changes affect the whole economy. These three factors also point to a revised understanding of how regional industries are linked to one another and how frontier regions or "peripheries" are linked to the metropole. The increasing amount of ownership of the resource extractive. primary processing and transportation industries by non-locals meant that linkages that formerly connected these sectors to local manufacturers. were transferred outside the region. The thesis concludes that these linkages are socially. rather than technologically defined. The thesis argues that the de-industrialization of British Columbia was one aspect of a larger process which. viewed from central Canada. has been called "centralization". Set in a global context the British Columbia experience was one part of an international process which saw industry concentrate in other regions like southeastern Ontario. the American northeast. and parts of Great Britain as it left regions which then became the "periphery". / Graduate

In modern manufacturing technology with increasing automation of manufacturing processes and operations, the need for automated measurement has become much more apparent. Computer measuring machines are one of the essential instruments for quality control and measurement of complex products, performing measurements that were previously laborious and time consuming. Inspection of sculptured surfaces can be time consuming since, for exact specification, an almost infinite number of points would be required. Automated measurement with a significant reduction of inspected points can be attempted if prior knowledge of the part shape is available. The use of a vision system can help to identify product shape and features but, unfortunately, the accuracy required is often insufficient. In this work a vision system used with a Coordinate Measuring Machine (CMM), incorporating probing, has enabled fast and accurate measurements to be obtained. The part features have been enhanced by surface marking and a simple 2-D vision system has been utilised to identify part features. In order to accurately identify all parts of the product using the 2-D vision system, a multiple image superposition method has been developed which enables 100 per cent identification of surface features. A method has been developed to generate approximate 3-D surface position from prior knowledge of the product shape. A probing strategy has been developed which selects correct probe angle for optimum accuracy and access, together with methods and software for automated CMM code generation. This has enabled accurate measurement of product features with considerable reductions in inspection time. Several strategies for the determination and assessment of feature position errors have been investigated and a method using a 3-D least squares assessment has been found to be satisfactory. A graphical representation of the product model and errors has been developed using a 3-D solid modelling CAD system. The work has used golf balls and tooling as the product example.

Thesis (M.B.A.)--Boston University

In an environment of world competition in manufacturing, the application of information technology (IT) is seen an important component in the achievement of performance improvement. Computer Integrated Manufacturing (CIM) is interpreted as the realisation of an IT strategy for manufacturing to achieve competitive advantage. The thesis identifies the growing problems of change and uncertainty in manufacturing which make effective, centralised, monolithic control ever more difficult to achieve by automation. An alternative, more manageable approach is deonstrated in which artificial intelligence (AI) is distributed across an enterprise in order to carry out decision making at the locations where it would naturally take place. The concept of an intelligent nodal architecture has been defined, differentiating between the functions of decision making, recording business transactions and enabling communication. A detailed case study was undertaken of a manufacturer of printed circuit boards to investigate the criteria for effective application of the intelligent architecture to decision making procedures. In the process, the IDEF-O analytical methodology was critically appraised, and the conclusion reached that design based on top-down analysis is inferior to evolutionary design of manufacturing systems. A simulator to support the proposed intelligent architecture was developed using object-oriented, hypermedia software, and tested with a small scale factory model. The simulator, then applied to the case study, demonstrated the potential for improving performance using Kanban techniques implemented by means of distributed intelligent nodes. It was also observed that AI based simulation could provide better planning tools than centralised systems such as MRP (Manufacturing Resource Planning). In conclusion, evidence was provided to support the use of distributed intelligence in manufacturing automation and an intelligent architecture proposed and tested using simulation. The research shows potential for commercial development.

No description available.

Thorough investigation and planning are essential steps in the deployment of Flexible Manufacturing Systems. At the present time, the most popular method of planning and analysis of these systems is computer-based modelling and simulation of which many varieties are commercially available. Ideally, during the modelling phase, the modeller should pay particular attention to such important details as reliability, damage propagation patterns, condition monitoring scenarios and the supervision aspects of these system as these factors are critical to the operation and performance of any envisaged configuration of FMS or its subsystems. In practice however, these are among the most neglected aspects of the models being constructed at the present time. This is in part because the present generation of commercially available simulation languages and environments are in many respects ill-equipped to deal with the challenges posed by the modelling of FMS. This thesis investigates the potential suitability of contemporary reliability and fault-mode description and analysis tools for inclusion within simulation models. Contemporary research work in analytical arid simulation-based reliability and fault-mode modelling and analysis of computer-integrated and flexible manufacturing systems have been investigated. A number of guidelines for the development of CIM and FMS simulation models have been developed. Four standard FMS models are developed and utilized as application examples in thesis. Analytical reliability techniques have been re-examined with special reference to the modelling of computer-integrated and flexible manufacturing systems. The potential sources of error and pitfalls of discrete-event simulation modelling have been outlined. The effect of the host languages, the different simulation time advancement modes, and the traditionally prescribed break-down modelling techniques have been investigated. Contemporary technology, programming and modelling concepts have been illustrated using PCModel and PROLOG. Fundamentals of "accurate" knowledge-based simulation modelling have been described and an alternative object-like structural implementation in a declarative environment has been proposed for the simulation models and tools. A detailed examination of the pre-requisites for the accurate simulation of reliability, fault-mode, and condition monitoring aspects of FMS has been performed. Some of the reliability and fault-mode modelling and analysis tools have been considered for their potential suitability as discrete-event simulation tools. Various possible resource-aging modes, health monitoring modules, and repairability /maintenance models have been developed. Micro-failure modelling and analysis has been proposed as an alternative to the traditional macro-failure modelling and analysis. Techniques for modelling of systems incorporating combinations of new and used equipment have been developed. A multi-phase development and demonstration of simulation models incorporating the tools and concepts proposed and cultivated during the course of the research has been undertaken. In each case, the model's evolution and the subsequent variations in its behaviour have been followed and examined from its bare-bone prototype to its fully developed stage. The research results in better understanding of reliability, condition monitoring and knowledge representation issues in simulation.

The dynamics of fluid flow unveils complicated dynamical behaviour. Systems such as a dripping tap are no exception. Flow through a nozzle produces three different modes: periodic dripping, chaotic dripping and jetting streams. This research concentrates on a study of the chaotic behaviour of a dripping tap. This involves both mathematical model studies and experimental studies. In addition, the work involves the development of an experimental facility to allow future study of the system in microgravity conditions. The facility to achieve microgravity conditions is a Drop Tower type, which uses a novel approach to achieve these conditions. The novelty is in the use of linear electromagnetic motors. The facility was built and is in the final stage of the commissioning process, and when it is ready it will allow up to 2.12 s of test time. The mathematical model uses an existing Mass-Spring-Damper model, with Reynolds numbers between 4 to 175, and a step size of 0.4. The results showed multiple bifurcation regions appearing before chaotic regions. Similarly, experimental results showed that some instabilities exist in this region. The model also explained and showed multiple bifurcations and an increase in dripping time due to instabilities, and has identified that those processes are due either to perturbations of the system or due to initial instabilities of the system. These results were confirmed by experiment. To achieve the required experimental goals a test module was developed whose requirements were set to fulfil the microgravity experiment conditions, in case future research is required. The experimental results showed some similarities with the mathematical model. At the same time, there was found to be quite a lot of disagreement. Results identified two different limit cycle attractors in periodic dripping mode: strong single-point attractors and regional attractors. Also, limit cycle attractors and strange attractors in chaotic mode were identified. More importantly, it has been identified that the chaotic region consists of areas where the system is stable (and produces a single region attractor), and others where the system is not (and this produces strange attractors), and there are points where, depending on the disturbances to the system, both types can be observed. The work done has led to several discoveries and achievements. Although the Drop Tower project could not be completed it may nonetheless be considered as a success. The facility has been fully assembled and calibrated to meet the set of design requirements, and to some extent was commissioned allowing future progress to discover modification requirements. The study of the Mass-Spring-Damper model led to the conclusion that the model is oversimplified and in its current state should be used only for descriptive purposes, when illustrating chaotic behaviour. Additionally, it was found that the model predicts bifurcations outside the experimentally determined chaotic region. Nevertheless, the work identified some possible improvements to the model. Experimentally it was found that the region of chaotic behaviour is located around a Reynolds number of 43 in contrast to what was previously reported. The study of the periodic dripping region showed that the system, if disturbed, can develop history dependent phenomena (where the subsequent drop periods follow a well identified sequence). Satellite drops were discovered to exist beyond the previously predicted value of flow rate. It was discovered that the fluid supply system can have a major effect on the drop dynamics (different types of post-detachment developments were found - termed here regular residual mass and wetted mass - along with the discovery of different types of drop detachment (regular mass, mid-size drops and jets) coexisting within the chaotic region. The drop horizontal disturbance study led to the unconfirmed discovery of two modes of vibrations, where the system response follows a standard damped response and an amplitude modulated damped response.

In order to meet increasingly strict regulations on vehicle emissions, manufacturers are seeking ways to produce vehicles that emit less pollution and consume less fuel. Eco-driving is the optimisation of velocity and gear selection in existing vehicles to reduce fuel consumption and such reductions can be made at relatively low development costs compared to powertrain modification. However, the driving experience of a premium vehicle could be compromised if the vehicle behaviour differs from that which is expected by the driver and the acceptance of such fuel saving measures may be diminished. Therefore, in order to maintain the driving experience the contribution of this work is the development and implementation of an optimal control algorithm based on Dynamic Programming which optimises, in real time, the vehicle velocity and gear selection based on a vehicle and upcoming road model while consideration is given to objective measures of driveability. The algorithm is deployed on a Raspberry Pi miniature computer with connection to the vehicle data network. Fuel savings and time savings are identified with the optimisation algorithm both with and without violating constraints on driveability, first in simulation and finally in a real-time, in-vehicle eco-driving feedback system. Primarily the application of this system is in internal combustion engine passenger vehicles in both urban and extra-urban road situations, however the approach is deliberately flexible to allow development for other powertrain configurations.