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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Desenvolvimento de um controlador de irrigação para áreas experimentais / Development of an irrigation controller for experimental areas

Camargo, Antonio Pires de 29 August 2012 (has links)
Em áreas experimentais, é comum ser necessário individualizar a quantidade de água aplicada em cada unidade (vaso ou canteiro), podendo haver variações desta quantidade ao longo dos eventos de irrigação. Este controle individualizado constitui uma tarefa repetitiva e trabalhosa que geralmente é efetuada manualmente por meio de válvulas instaladas na entrada de cada unidade. A execução manual de tais tarefas está sujeita a erros como imperfeições no controle de tempos de operação, limitações de dimensões e critérios relacionados à pesquisa e, principalmente, implicam em desperdício de tempo e recursos para o pesquisador. Por outro lado, as soluções comercializadas para automação do controle da irrigação apresentam-se em dois extremos. As soluções com preço acessível não são versáteis o suficiente para atender aos requisitos de experimentos envolvendo irrigação, e quando empregadas implicam em uma série de restrições para a definição de tratamentos na pesquisa. Já as soluções sofisticadas, que seriam aptas para uso nas mais diversas situações, apresentam custo restritivo. Acerca disto, esta pesquisa teve como objetivo o desenvolvimento de um sistema constituído de módulos microprocessados e aplicativo supervisório, empregados para o controle automático e individualizado da irrigação em unidades existentes em áreas experimentais. A solução proposta foi desenvolvida em duas etapas. A primeira etapa visou o desenvolvimento de um sistema de controle malha aberta, dedicado ao acionamento individualizado de atuadores (válvulas solenóides e motobombas), sendo operado segundo intervalos de tempo informados pelo usuário. A segunda etapa visou o desenvolvimento de um sistema automatizado para monitoramento e controle individualizado da irrigação em áreas experimentais. O sistema proposto dispõe de recursos de hardware e software que asseguram versatilidade, escalabilidade e confiabilidade, sendo capaz de atender aos requerimentos de diferentes tarefas ou experimentos. / Irrigation scheduling at experimental areas is determined by several factors, which are mainly related to features of each unit (container or bed) and criteria set by researchers. Many times the experimental areas are greenhouses and depending on the research may be necessary provide mechanisms for monitoring sensors and controlling actuators on each unit in order to supply individual water requirements. Once irrigation requirements vary in time and among units, this individual irrigation management becomes a repetitive and laborious task when sensors and actuators are operated manually. Commercial systems for automated irrigation controlling in Brazil can be characterized in two extremes, when applied on experimental areas. Irrigation controllers sold at affordable and feasible prices have basic functionalities and don\'t have enough versatility for using at most of irrigation researches. In the other hand, there are some sophisticated solutions for automating irrigation systems which have plenty of technology and could be implemented at any experimental area. Although, these kind of automated systems are very expensive and most of times are unfeasible for using at irrigation researches. Based on the summarized situation, this thesis presents the development of an automated system comprised of microprocessed modules and Supervisory Control and Data Acquisition (SCADA), implemented for actuators controlling and sensor\'s data acquisition at irrigation experimental areas. The first research\'s stage describes the development of an openloop control system that was a dedicated solution for actuators controlling. The second stage described a closed-loop control system designed for irrigation controlling at experimental areas. The developed solutions have features of hardware and software that ensure versatility, scalability, and reliability.
372

Automation of the bank operation system in the Hong Kong offices of a multi-national bank: a case approach.

January 1993 (has links)
by Thomas Li Yuen-cheuk, Tina Yeung Chi-yin. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1993. / Chapter I. --- INTRODUCTION --- p.1 / Chapter II. --- METHODOLOGY & TERMINOLOGY --- p.2 / Methodology --- p.2 / Terminology --- p.4 / Chapter III. --- BACKGROUND INFORMATION --- p.6 / Company Statistics --- p.6 / Situation Before the Automation Project --- p.7 / Major Trends in Banking in the 90's --- p.8 / Chapter IV. --- THE NEW SYSTEM --- p.11 / Characteristics of the New System (SYSCO) --- p.11 / Functional Overview --- p.18 / Chapter V. --- "THE IMPLEMENTATION TEAM, PLAN AND PROCESS" --- p.36 / Life Time for SYSCO --- p.36 / Implementation Plan --- p.37 / Why Hong Kong is Chosen as the Second Pioneer Site? --- p.38 / The Project Organisation --- p.39 / Implementation Schedule --- p.42 / Chapter VI. --- IMPLEMENTATION DIFFICULTIES --- p.45 / Chapter VII. --- POST-IMPLEMENTATION RESULTS --- p.57 / Sampling --- p.57 / Findings and Interpretations --- p.58 / Chapter VIII. --- CONCLUSION --- p.72 / Lession to Learn --- p.72 / Conclusive Remarks --- p.75 / APPENDIX / Chapter I. --- User Opinion Survey Questionnaire --- p.77 / Chapter II. --- Customer Opinion Survey Questionnaire --- p.80
373

Compact iris verification on portable computing platform.

January 2003 (has links)
Chun, Chun Nam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 73-75). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.ii / ACKNOWLEDGEMENTS --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.v / LIST OF TABLES --- p.vii / Chapter 1 --- INTRODUCTION --- p.01 / Chapter 1.1 --- Iris Texture as A Biometric Password --- p.01 / Chapter 1.1.1 --- Advantages --- p.02 / Chapter 1.1.2 --- Previous Work --- p.04 / Chapter 1.1.3 --- Operation Procedures --- p.06 / Chapter 1.1.3.1 --- Image Acquisition --- p.07 / Chapter 1.1.3.2 --- Iris Localization --- p.07 / Chapter 1.1.3.3 --- Image Encoding and Database Matching --- p.08 / Chapter 1.2 --- Motivation and Research Objective --- p.09 / Chapter 1.3 --- Thesis Outline --- p.11 / Chapter 2 --- IMAGE ACQUISITION --- p.13 / Chapter 2.1 --- Difficulties on Image Acquisition --- p.13 / Chapter 2.2 --- Our Iris Image Acquisition Setting --- p.13 / Chapter 3 --- PRE-PROCESSING --- p.15 / Chapter 3.1 --- Isolating the Region of Interest --- p.15 / Chapter 3.1.1 --- Conscious and Unconscious Recognition --- p.15 / Chapter 3.1.2 --- Iris Boundary Detection --- p.16 / Chapter 3.2 --- Iris-ring Unfolding and Normalization --- p.19 / Chapter 3.2.1 --- Eccentric-polar Coordinate System --- p.20 / Chapter 3.2.2 --- Iris-ring Unfolding --- p.22 / Chapter 3.2.3 --- Normalization --- p.22 / Chapter 3.3 --- Data Binarization --- p.24 / Chapter 4 --- RADON TRANSFORM BASED ENCODING AND MATCHING --- p.27 / Chapter 4.1 --- Radon Transform based Encoding --- p.28 / Chapter 4.2 --- Iris Code Matching --- p.32 / Chapter 4.2.1 --- Regional Correlation --- p.32 / Chapter 5 --- PALM-TOP IMPLEMENTATION ON COMPUTING PLATFORM --- p.36 / Chapter 5.1 --- Image Acquisition --- p.37 / Chapter 5.1.1 --- Desktop Version --- p.37 / Chapter 5.1.2 --- Palm-top Version --- p.37 / Chapter 5.2 --- Iris Localization --- p.39 / Chapter 5.2.1 --- Desktop Version --- p.39 / Chapter 5.2.2 --- Palm-top Version --- p.39 / Chapter 5.3 --- Image Encoding --- p.41 / Chapter 5.3.1 --- Desktop Version --- p.41 / Chapter 5.3.2 --- Palm-top Version --- p.41 / Chapter 5.4 --- Palm-Top Computer Application --- p.42 / Chapter 5.4.1 --- Palm-top Computer Setting --- p.42 / Chapter 5.4.2 --- Software Selection --- p.42 / Chapter 5.4.3 --- Technical Problems --- p.43 / Chapter 5.4.3.1 --- Problem 1: Memory Limitation --- p.43 / Chapter 5.4.3.2 --- Problem 2: Image Format --- p.44 / Chapter 5.4.3.3 --- Problem 3: Origin of Image --- p.44 / Chapter 5.5 --- Our Iris Recognition Platform --- p.44 / Chapter 6 --- EXPERIMENTAL RESULTS --- p.47 / Chapter 6.1 --- The Test Data --- p.47 / Chapter 6.2 --- Experiment One: Eccentric Polar Coordinates System Recognition Performance --- p.48 / Chapter 6.2.1 --- Performance Measure of Recognition --- p.48 / Chapter 6.2.2 --- Experimental Result --- p.49 / Chapter 6.3 --- Experiment Two: Radon Transform-based Recognition System Performance --- p.53 / Chapter 6.3.1 --- Intra-group Similarity vs. Inter-group Similarity --- p.54 / Chapter 6.3.2 --- Performance Comparison with an Existing System --- p.57 / Chapter 6.4 --- Experiment Three: The Resolution of Image in the Eccentric-polar Coordinates System --- p.58 / Chapter 7 --- CONCLUSION AND FUTURE WORK --- p.62 / Chapter 7.1 --- Conclusion --- p.62 / Chapter 7.2 --- Future Work --- p.63 / APPENDIX A --- p.66 / APPENDIX B --- p.67 / BIBLIOGRAPHY --- p.73
374

Truss climbing robot for space station: design, analysis, and motion control. / CUHK electronic theses & dissertations collection

January 2012 (has links)
近年來,空間機器人被廣泛應用於低地球軌道的空間服務中,其中包括太空船艙內、艙外的活動。因應艙外的活動,空間機器人經常以地面工業用機械臂的形式設計,並擁有相似的關節配置。空間機械臂的關節配置,主要可以分成兩類。第一類是六自由度空間機械臂,例如,太空梭遙控機械手系統SRMS,工程試驗衛星七號RTS-VII '和日本實驗模組遙控器系統JEMRMS 。另一類是七自由度空間機械臂,例如,歐洲機械臂ERA和空間站遠距離機械手系統SSRMS。他們不但能在空間站上完成不同的操作任務,而且能於空間站上進行攀爬。 / 在一個自由飄浮的環境中,空間機械臂的運動會影響太空站的姿態。因此,空間站的姿態穩定對維持太陽能板的接收和系統通訊的信號強度發揮非常重要的作用。大部份太空站姿態穩定的研究都集中於對機械臂的操作運動進行控制。然而,針對機械臂的移動進行優化的研究卻不多。由於空間機械臂的工作空間有限,在空間站上的移動能力是必要的,因此該運動對空間站的影響是無法避免。 / 有見及此,本論文提出一種新型空間站移動技術,從而減低因機械臂移動時對空間站造成的干擾。在維持現有空間機械臂的關節配置下,提出種結合驅動輸和傳統機械手抓優點的新型手抓概念。為了實現這種新型手抓概念,本論文提出了種新型的支架攀爬機械人,名為Frambot' 並在Frambot上實現了新式手抓的設計與應用。Frambot 的設計主要針對不能進行包圍性抓緊的方型析架進行攀爬,手抓的握持力是通過壓縮彈簧而產生,實現低能耗攀爬,提高Ftambot在析架上的工作時間。為了提高Ftambot在析架攀爬時的穩定性,本論文在Ftambot設計了個簡單、不需要傳感器反饋的傾斜修正結構。另外,在Frambot 的平臺上實驗了新式的攀爬運動,從而證明利用驅動輪的原理在析架上進行攀爬的可行性。 / 基於這種新型的手抓,本文為空間機械臂設計出新式空間站移動步履,並分析新式空間站移動步履對空間站造成的干擾。由於傳統的空間機器人系統建模是針對於機械臂的操作運動,因此本文針對機械臂利用驅動輪移動時,對空間站的姿態變化進行建模,並建立一個實驗平臺去對該模型進行驗證。此外,利用空間機械臂的系統模型,對新式的移動步履進行動態運動仿真。透過和傳統的移動步履進行比較,總結出新式的移動步履在空間站的姿態影響和能量需要都是最低的。 / 在一個自由飄浮的環境中,空間機械臂的步履時間越長,對太空站的干擾就越大。另外,空間站的能源是有限的,所以減低空間機臂對空間站的能耗十分重要。本論文考慮到實際的應用,空間機械臂需要移動到空間站上不同的地點完成操作任務,因此提出了空間機械臂在桁架移動時的路徑規規劃方案,目的在於對路徑的總長度和能量需求進行優化。本文提出的路徑規劃演算法,透過利用遺傳演算法,對開型和閉合路徑進行優化。此外,在演算法中引多個新的概念,從而改善遺傳演算法的收斂速度和結果。最後,通過不同類型的仿真,對路徑規劃演算法的性能進行評估。 / The application of space robots has become more popular in performing tasks such as Intra and Extra Vehicular Activities (EVA) in Low Earth Orbit. For EVA, space robots were always designed as a chain-like manipulator with a joint configuration similar to on the earth robotic arm. Based on their joint configuration, they can be classified into two main categories. The first one is the six degrees of freedom (DOF) robotic arm including Shuttle Remote Manipulator System (SRMS), Engineering Test Satellite No. 7 (ETSVII), the Main Arm (MA) and the Small Fine Arm (SFA) of Module Remote Manipulator System (JEMRMS). The other group is the seven-DOF space robotic arm which includes European Robotic Arm (ERA) and Space Station Remote Manipulator System (SSRMS), or Canadarm2. They not only perform manipulation tasks, but also be able to navigate on the exterior of the International Space Station (ISS). / In a free floating environment, motions of a space robotic arm cause the attitude change of a space station because of their dynamic coupling effect. Hence, the stabilization of the space station attitude is important to maintain the electrical energy generated by the solar panels and the signal strength for communication. Most of research in this area focuses on the motion control of a space manipulator through the study of Generalized Jacobian Matrix. Little research has been conducted specifically on the design of locomotion mechanism of a space manipulator. / This dissertation proposes a novel methodology for the locomotion on a space station which aims to lower the disturbance on a space station. Without modifying the joint configuration of conventional space manipulators, the use of a new gripping mechanism is proposed which combines the advantages of active wheels and conventional grippers. To realize the proposed gripping mechanism, this dissertation also presents the design of a novel frame climbing robot (Frambot) which is equipped with the new gripping mechanism, named movable gripper (MovGrip). It is capable of climbing non-enclosable rectangular trusses and the gripping force is generated by the compression of springs. Therefore, the energy consumption in static gripping is zero which allows itself to stay on a truss for a long time. To enhance the climbing stability, a simple and sensor-free auto-tilting correction mechanism is designed. Based on the robot prototype, novel climbing gaits are designed and realized and this verifies the feasibility of using wheels motion in climbing trusses. / With the use of the proposed gripping mechanism, new gaits are designed for space manipulators and the corresponding disturbance on a space station is analyzed. Since conventional modeling of a space station system focuses on manipulation tasks, this dissertation extends the model to formulate the dynamic coupling effect during wheels navigation. To verify the formulations, an experimental platform is designed and developed. Based on the system model, the proposed gaits are simulated and the results are compared with conventional gaits. From the simulation results, it can be concluded that the proposed gaits are better than conventional gaits in terms of minimum dynamic disturbance and energy demand on a space station. / In a free floating environment, the longer a gait is performed, the greater the disturbance is generated on a space station. Also, the energy source of a space station is limited and the minimization of the energy consumption of a robot is important. Therefore, this dissertation also proposes a path planning algorithm which aims to minimize the total traveling distance and energy demand when a space manipulator is commanded to reach a target position for certain missions. For the proposed algorithm, both closed and open paths are considered and the optimizations are based on the conventional genetic algorithm. To enhance the convergent rate and final solutions, several novel concepts are introduced. Different simulation are performed and the results are presented to evaluate the performance of the proposed path planning algorithm. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chung, Wing Kwong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 164-172). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Related Work --- p.2 / Chapter 1.3 --- Motivation of the Dissertation --- p.9 / Chapter 1.4 --- Organization of the Dissertation --- p.10 / Chapter 2 --- Design Principles of Movable Gripper --- p.12 / Chapter 2.1 --- Preliminary Gripper Design --- p.12 / Chapter 2.2 --- Static Model: Gripping Force --- p.14 / Chapter 2.3 --- Dynamic Model: Tractive Force --- p.19 / Chapter 2.4 --- Anti-slip Strategy --- p.23 / Chapter 2.4.1 --- Vertical Truss Climbing --- p.24 / Chapter 2.4.2 --- Horizontal Truss Climbing --- p.27 / Chapter 2.4.3 --- Right-side-up Truss Climbing --- p.29 / Chapter 2.4.4 --- Arbitrary gripping orientation analysis --- p.31 / Chapter 3 --- Design of a Novel Frame Climbing Robot --- p.36 / Chapter 3.1 --- Introduction --- p.36 / Chapter 3.2 --- Mechanical Design --- p.40 / Chapter 3.2.1 --- Gripper Jaw --- p.42 / Chapter 3.2.2 --- Parallel Gripping Mechanism --- p.43 / Chapter 3.2.3 --- Rotation Axis of Wheels --- p.44 / Chapter 3.2.4 --- Body Linkage --- p.45 / Chapter 3.3 --- Design of Climbing Gaits --- p.48 / Chapter 3.3.1 --- Motion simulation --- p.48 / Chapter 3.4 --- Experiments and Results --- p.52 / Chapter 3.4.1 --- Grasp’s Contact --- p.52 / Chapter 3.4.2 --- Tilting Correction Capability --- p.53 / Chapter 3.4.3 --- Load Carrying Capability --- p.53 / Chapter 3.4.4 --- Performance of Frambot --- p.57 / Chapter 3.5 --- Summary --- p.60 / Chapter 4 --- Modeling Analysis: Robot and Space Station --- p.61 / Chapter 4.1 --- Introduction --- p.61 / Chapter 4.2 --- Modeling of a space station system --- p.62 / Chapter 4.3 --- Kinematics --- p.66 / Chapter 4.4 --- Linear and Angular Momentums --- p.68 / Chapter 4.5 --- Dynamics --- p.69 / Chapter 4.6 --- Modeling Analysis --- p.71 / Chapter 4.7 --- Summary --- p.84 / Chapter 5 --- Modeling Analysis: Disturbance in Space Station --- p.85 / Chapter 5.1 --- Introduction --- p.85 / Chapter 5.2 --- Categories of Locomotion --- p.86 / Chapter 5.2.1 --- Joint Configurations --- p.86 / Chapter 5.2.2 --- Linear Locomotion --- p.87 / Chapter 5.2.3 --- Turning --- p.88 / Chapter 5.2.4 --- Exterior Transition --- p.93 / Chapter 5.3 --- Analysis of Dynamic Disturbance --- p.96 / Chapter 5.3.1 --- Linear Locomotion --- p.97 / Chapter 5.3.2 --- Turning --- p.103 / Chapter 5.3.3 --- Exterior Transition --- p.107 / Chapter 5.4 --- Analysis of Energy Demand --- p.113 / Chapter 5.5 --- Summary --- p.117 / Chapter 6 --- Global Path Planning --- p.122 / Chapter 6.1 --- Shortest Distance Path Planning --- p.124 / Chapter 6.1.1 --- Problem Description --- p.127 / Chapter 6.1.2 --- The Framework of Genetic Algorithm --- p.128 / Chapter 6.1.3 --- Simulation Study and Discussion --- p.135 / Chapter 6.2 --- Minimum Energy Demand Path Planning --- p.144 / Chapter 6.2.1 --- Problem Description --- p.147 / Chapter 6.2.2 --- The Framework of Genetic Algorithm --- p.148 / Chapter 6.2.3 --- Simulation Study and Discussion --- p.154 / Chapter 6.3 --- Summary --- p.159 / Chapter 7 --- Conclusions --- p.160 / Chapter 7.1 --- Contributions --- p.160 / Chapter 7.1.1 --- Design a New Gripping Mechanism for Truss Climbing Robot --- p.160 / Chapter 7.1.2 --- Design and Develop a Novel Truss Climbing Robot --- p.161 / Chapter 7.1.3 --- Formulate and Analyze the Disturbance on a Space Station Under different Gaits --- p.161 / Chapter 7.1.4 --- Develop a Global Path Planning Algorithm for the Minimization of Total Traveling Distance and Energy Demand --- p.162 / Chapter 7.2 --- Recommendation for Future Research --- p.162 / Chapter 7.2.1 --- Design Optimization --- p.162 / Chapter 7.2.2 --- Autonomous Truss Climbing --- p.163 / Chapter 7.2.3 --- Multicriteria Path Planning Algotirhm --- p.163
375

Experimental Testing of a Computer Aided Heat Treatment Planning System

Vaidya, Rohit Subhash 27 August 2003 (has links)
"Heat treatment is an important manufacturing process, which controls the mechanical property of metal parts, therefore contributes to the product quality. A Computerized Heat Treatment (CHT) system has been developed to model and simulate the heat transfer in furnace. When the part load and thermal schedule information is given with part and furnace specifications, the temperature profiles of parts in furnace can be calculated based on heat transfer principle. Therefore the part load and thermal schedule can be optimized to remove unnecessary delay time while the quality of heat treatment is ensured. In the thesis, the functions of CHT are enhanced with the capability of modeling and simulating the heat treatment processes with random part load and continuous furnaces. Methods to model random load and continuous furnace have been developed. Case studies with industry real data have been conducted to validate the system and to show effectiveness of the system. The system development is also introduced in the thesis."
376

Designing and implementing a computer conferencing system to manage and track articles through the revision process

Dock, Patricia January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
377

A form based personalized bulk mailing system

Lin, Huiling January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
378

Design of the IDO for the intelligent data object management system (IDOMS) project

Rykowski, Ronna Wynne January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries / Department: Computer Science.
379

Engineering chemistry : integrated control strategies and Internet-enabled tools for chemical synthesis

Fitzpatrick, Daniel Ewert January 2017 (has links)
The use of enabling technologies and continuous methods to enhance chemical synthesis is a vibrant area of research, gaining increasing attention from laboratories in academia and industry. Yet many prominent synthesis procedures have not changed for decades and require significant manual intervention from bench chemists, which may lead to the waste of both human and material resources. The research described herein details how chemistry has been bridged with engineering to address this issue in a world increasingly focussed on sustainability and efficiency. This thesis is divided into four chapters. The first describes the development of a novel Internet-based process control system which is applied to automate a cycling catalytic process. The capability of the system to conduct multi-dimensional self-optimisation processes is shown, where it is integrated with an on-line mass spectrometer and inline infrared spectrometer to drive optimisation against customisable multicomponent evaluation functions. Chapter 2 details the successful synthesis of the anti-cancer drug candidate AZ82. The control system is applied to assist with a number of these steps, including facilitating the integration between batch and flow processes on a single reactor platform. A new distillation unit to assist with downstream solvent switching is also described. In Chapter 3, the cloud-based nature of the control system is exploited by moving it to servers residing in Tokyo. The ability of the system to accelerate the drug development process is highlighted with the autonomous self-optimisation and synthesis of four active pharmaceutical ingredient targets: tramadol, lidocaine, bupropion and isoniazid. In the case of bupropion, the system maintained steady-state operation of a telescoped two-step process for an extended period. A researcher in Los Angeles was able to initiate and monitor all processes, via Japan, in real-time as they occurred in our laboratory in Cambridge, UK. Finally, Chapter 4 describes the development of a new parallel column supercritical fluid chromatography (SFC) unit that is capable of separating a multicomponent product stream continuously exiting a flow reactor. The versatility of the SFC unit is showcased with the telescoped synthesis of isoniazid in which all stages, including the SFC process itself, are managed by the control system without researcher intervention.
380

Desenvolvimento de um controlador de irrigação para áreas experimentais / Development of an irrigation controller for experimental areas

Antonio Pires de Camargo 29 August 2012 (has links)
Em áreas experimentais, é comum ser necessário individualizar a quantidade de água aplicada em cada unidade (vaso ou canteiro), podendo haver variações desta quantidade ao longo dos eventos de irrigação. Este controle individualizado constitui uma tarefa repetitiva e trabalhosa que geralmente é efetuada manualmente por meio de válvulas instaladas na entrada de cada unidade. A execução manual de tais tarefas está sujeita a erros como imperfeições no controle de tempos de operação, limitações de dimensões e critérios relacionados à pesquisa e, principalmente, implicam em desperdício de tempo e recursos para o pesquisador. Por outro lado, as soluções comercializadas para automação do controle da irrigação apresentam-se em dois extremos. As soluções com preço acessível não são versáteis o suficiente para atender aos requisitos de experimentos envolvendo irrigação, e quando empregadas implicam em uma série de restrições para a definição de tratamentos na pesquisa. Já as soluções sofisticadas, que seriam aptas para uso nas mais diversas situações, apresentam custo restritivo. Acerca disto, esta pesquisa teve como objetivo o desenvolvimento de um sistema constituído de módulos microprocessados e aplicativo supervisório, empregados para o controle automático e individualizado da irrigação em unidades existentes em áreas experimentais. A solução proposta foi desenvolvida em duas etapas. A primeira etapa visou o desenvolvimento de um sistema de controle malha aberta, dedicado ao acionamento individualizado de atuadores (válvulas solenóides e motobombas), sendo operado segundo intervalos de tempo informados pelo usuário. A segunda etapa visou o desenvolvimento de um sistema automatizado para monitoramento e controle individualizado da irrigação em áreas experimentais. O sistema proposto dispõe de recursos de hardware e software que asseguram versatilidade, escalabilidade e confiabilidade, sendo capaz de atender aos requerimentos de diferentes tarefas ou experimentos. / Irrigation scheduling at experimental areas is determined by several factors, which are mainly related to features of each unit (container or bed) and criteria set by researchers. Many times the experimental areas are greenhouses and depending on the research may be necessary provide mechanisms for monitoring sensors and controlling actuators on each unit in order to supply individual water requirements. Once irrigation requirements vary in time and among units, this individual irrigation management becomes a repetitive and laborious task when sensors and actuators are operated manually. Commercial systems for automated irrigation controlling in Brazil can be characterized in two extremes, when applied on experimental areas. Irrigation controllers sold at affordable and feasible prices have basic functionalities and don\'t have enough versatility for using at most of irrigation researches. In the other hand, there are some sophisticated solutions for automating irrigation systems which have plenty of technology and could be implemented at any experimental area. Although, these kind of automated systems are very expensive and most of times are unfeasible for using at irrigation researches. Based on the summarized situation, this thesis presents the development of an automated system comprised of microprocessed modules and Supervisory Control and Data Acquisition (SCADA), implemented for actuators controlling and sensor\'s data acquisition at irrigation experimental areas. The first research\'s stage describes the development of an openloop control system that was a dedicated solution for actuators controlling. The second stage described a closed-loop control system designed for irrigation controlling at experimental areas. The developed solutions have features of hardware and software that ensure versatility, scalability, and reliability.

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