The molecular design of a new solvent for the absorption of carbon dioxide

Gas absorption, the removal of one or more constitutents from a gas mixture, is widely used in chemical processes. In many gas absorption processes, the gas mixture is already at high pressure and in recent years organic solvents have been developed for the process of physical absorption at high pressure followed by low pressure regeneration of the solvent and recovery of the absorbed gases. Until now the discovery of new solvents has usually been by expensive and time consuming trial and error laboratory tests. This work describes a new approach, whereby a solvent is selected from considerations of its molecular structure by applying recently published methods of predicting gas solubility from the molecular groups which make up the solvent molecule. The removal of the acid gases of carbon dioxide and hydrogen sulfide from methane or hydrogen was used as a commercially important example. After a preliminary assessment to identify promising moecular groups, more than eighty new solvent molecules were designed and evaluated by predicting gas solubility. The other important physical properties were also predicted by appropriate theoretical procedures, and a commercially promising new solvent was chosen to have a high solubility for acid gases, a low solubility for methane and hydrogen, a low vapour pressure, and a low viscosity. The solvent chosen, of molecular structure Ch3-COCH2-CH2-CO-CH3, was tested in the laboratory and shown to have physical properties, except for vapour pressures, close to those predicted. That is gas solubilities were within 10% but lower than predicted. Viscosity within 10% but higher than predicted and a vapour pressure significantly lower than predicted. A computer program was written to predict gas solubility in the new solvent at the high pressures (25 bar) used in practice. This is based on the group contribution method of Skold Jorgensen (1984). Before using this with the new solvent, Acetonyl acetone, the method was show to be sufficiently accurate by comparing predicted values of gas solubility with experimental solubilities from the literature for 14 systems up to 50 bar. A test of the commercial potential of the new solvent was made by means of two design studies which compared the size of plant and approximate relative costs of absorbing acid gases by means of the new solvent with other commonly used solvents. These were refrigerated methanol(Rectisol process) and Dimethyl Ether or Polyethylene Glycol(Selexol process). Both studies showed in terms of capital and operating cost some significant advantage for plant designed for the new solvent process.

Expert system design for cold form sections

The concept of an Expert System (ES) has been acknowledged as a very useful tool, but few studies have been carried out in its application to the design of cold rolled sections. This study involves primarily the use of an ES as a tool to improve the design process and to capture the draughtsman's knowledge. Its main purpose is to reduce substantially the time taken to produce a section drawing, thereby facilitating a speedy feedback to the customer. In order to communicate with a draughtsman, it is necessary to use sketches, symbolic representations and numerical data. This increases the complexity of programming an ES, as it is necessary to use a combination of languages so that decisions, calculations, graphical drawings and control of the system can be effected. A production system approach is used and a further step has been taken by introducing an Activator which is an autoexecute operation set up by the ES to operate an external program automatically. To speed up the absorption of new knowledge into the knowledge base, a new Learning System has been constructed. In addition to developing the ES, other software has been written to assist the design process. The section properties software has been introduced to improve the speed and consistency of calculating the section properties. A method of selecting or comparing the most appropriate section for a given specification is also implemented. Simple loading facilities have been introduced to guide the designer as to the loading capacity of the section. This research has concluded that the application of an ES is beneficial and with the activator approach, automated designing can be achieved. On average a complex drawing can be displayed on the screen in about 100 seconds, where over 95% of the initial section design time for repetitive or similar profile can be saved.

The application of knowledge based expert systems to mechanical engineering design

Investigation of the different approaches used by Expert Systems researchers to solve problems in the domain of Mechanical Design and Expert Systems was carried out. The techniques used for conventional formal logic programming were compared with those used when applying Expert Systems concepts. A literature survey of design processes was also conducted with a view to adopting a suitable model of the design process. A model, comprising a variation on two established ones, was developed and applied to a problem within what are described as class 3 design tasks. The research explored the application of these concepts to Mechanical Engineering Design problems and their implementation on a microcomputer using an Expert System building tool. It was necessary to explore the use of Expert Systems in this manner so as to bridge the gap between their use as a control structure and for detailed analytical design. The former application is well researched into and this thesis discusses the latter. Some Expert System building tools available to the author at the beginning of his work were evaluated specifically for their suitability for Mechanical Engineering design problems. Microsynics was found to be the most suitable on which to implement a design problem because of its simple but powerful Semantic Net Knowledge Representation structure and the ability to use other types of representation schemes. Two major implementations were carried out. The first involved a design program for a Helical compression spring and the second a gearpair system design. Two concepts were proposed in the thesis for the modelling and implementation of design systems involving many equations. The method proposed enables equation manipulation and analysis using a combination of frames, semantic nets and production rules. The use of semantic nets for purposes other than for psychology and natural language interpretation, is quite new and represents one of the major contributions to knowledge by the author. The development of a purpose built shell program for this type of design problems was recommended as an extension of the research. Microsynics may usefully be used as a platform for this development.

Computer simulation of form-roll design

Changes in modern structural design have created a demand for products which are light but possess high strength. The objective is a reduction in fuel consumption and weight of materials to satisfy both economic and environmental criteria. Cold roll forming has the potential to fulfil this requirement. The bending process is controlled by the shape of the profile machined on the periphery of the rolls. A CNC lathe can machine complicated profiles to a high standard of precision, but the expertise of a numerical control programmer is required. A computer program was developed during this project, using the expert system concept, to calculate tool paths and consequently to expedite the procurement of the machine control tapes whilst removing the need for a skilled programmer. Codifying the expertise of a human and the encapsulation of knowledge within a computer memory, destroys the dependency on highly trained people whose services can be costly, inconsistent and unreliable. A successful cold roll forming operation, where the product is geometrically correct and free from visual defects, is not easy to attain. The geometry of the sheet after travelling through the rolling mill depends on the residual strains generated by the elastic-plastic deformation. Accurate evaluation of the residual strains can provide the basis for predicting the geometry of the section. A study of geometric and material non-linearity, yield criteria, material hardening and stress-strain relationships was undertaken in this research project. The finite element method was chosen to provide a mathematical model of the bending process and, to ensure an efficient manipulation of the large stiffness matrices, the frontal solution was applied. A series of experimental investigations provided data to compare with corresponding values obtained from the theoretical modelling. A computer simulation, capable of predicting that a design will be satisfactory prior to the manufacture of the rolls, would allow effort to be concentrated into devising an optimum design where costs are minimised.

Computer aided design and manufacture of form-rolls

Cold roll forming of thin-walled sections is a very useful process in the sheet metal industry. However, the conventional method for the design and manufacture of form-rolls, the special tooling used in the cold roll forming process, is a very time consuming and skill demanding exercise. This thesis describes the establishment of a stand-alone minicomputer based CAD/CAM system for assisting the design and manufacture of form-rolls. The work was undertaken in collaboration with a leading manufacturer of thin-walled sections. A package of computer programs have been developed to provide computer aids for every aspect of work in form-roll design and manufacture. The programs have been successfully implemented, as an integrated CAD/CAM software system, on the ICL PERQ minicomputer with graphics facilities. Thus, the developed CAD/CAM system is a single-user workstation, with software facilities to help the user to perform the conventional roll design activities including the design of the finished section, the flower pattern, and the form-rolls. A roll editor program can then be used to modify, if required, the computer generated roll profiles. As far as manufacturing is concerned, a special-purpose roll machining program and postprocessor can be used in conjunction to generate the NC control part-programs for the production of form-rolls by NC turning. Graphics facilities have been incorporated into the CAD/CAM software programs to display drawings interactively on the computer screen throughout all stages of execution of the CAD/CAM software. It has been found that computerisation can shorten the lead time in all activities dealing with the design and manufacture of form-rolls, and small or medium size manufacturing companies can gain benefits from the CAD/CM! technology by developing, according to its own specification, a tailor-made CAD/CAM software system on a low cost minicomputer.

Lubrication efficiency and die design in wire drawing

With the competitive challenge facing business today, the need to keep cost down and quality up is a matter of survival. One way in which wire manufacturers can meet this challenge is to possess a thorough understanding of deformation, friction and lubrication during the wire drawing process, and therefore to make good decisions regarding the selection and application of lubricants as well as the die design. Friction, lubrication and die design during wire drawing thus become the subject of this study. Although theoretical and experimental investigations have been being carried out ever since the establishment of wire drawing technology, many problems remain unsolved. It is therefore necessary to conduct further research on traditional and fundamental subjects such as the mechanics of deformation, friction, lubrication and die design in wire drawing. Drawing experiments were carried out on an existing bull-block under different cross-sectional area reductions, different speeds and different lubricants. The instrumentation to measure drawing load and drawing speed was set up and connected to the wire drawing machine, together with a data acquisition system. A die box connected to the existing die holder for using dry soap lubricant was designed and tested. The experimental results in terms of drawing stress vs percentage area reduction curves under different drawing conditions were analysed and compared. The effects on drawing stress of friction, lubrication, drawing speed and pressure die nozzle are discussed. In order to determine the flow stress of the material during deformation, tensile tests were performed on an Instron universal test machine, using the wires drawn under different area reductions. A polynomial function is used to correlate the flow stress of the material with the plastic strain, on which a general computer program has been written to find out the coefficients of the stress-strain function. The residual lubricant film on the steel wire after drawing was examined both radially and longitudinally using an SEM and optical microscope. The lubricant film on the drawn wire was clearly observed. Therefore, the micro-analysis by SEM provides a way of friction and lubrication assessment in wire drawing.

Proliferative diabetic retinopathy (R3) referrals from the digital diabetic retinopathy screening program:urgency of appointment in the hospital eye service achieved and needed?

DESIGN. Retrospective analysis PURPOSE. To assess the clinical characteristics and outcomes of patients identified with proliferative diabetic retinopathy (PDR) referred from the screening program to the hospital eye services (HES) METHODS. a retrospective analysis of urgently referred PDR cases to Birmingham Heartlands HES from august 2008 until July 2010 RESULTS. 130 urgent diabetic retinopathy referrals were made and reviewed. 103 (68% male, 80% type 2 diabetes) were referred for PDR with a mean age of 59 years, mean diabetes duration of 17.8years. 69% were on insulin treatment at the time of the screening, with mean HbA1c of 10.4% (range-5.7 to 16.5%). 65% of the patients were offered appointments at HES within two weeks after referral from the screening. 50.5% of the patients were seen in the HES within 2 weeks, 22 and 16 % were seen 2-4 and 4-8 weeks after referral respectively. 6 patients never attended ophthalmology examination during the two years of review. Of all the attendees, 56% were booked for pan retinal photocoagulation (PRP) & 9(9.3%) for macular laser respectively on their 1st HES visit. 75% of the patients were newly diagnosed PDR and 26 had previous PRP laser but lost to follow up. 63 patients ( 66%) received either PRP or macular laser treatment (85.7% of which is PRP). 63% of the PRP treatment was performed within a month of first HES attendance. Retinopathy grading discrepancy between the screening program and HES was noted in 20% (21 patients). CONCLUSIONS. This data suggests that the digital screening programme is appropriately identifying high risk patients with PDR with timely PRP laser treatment in the majority of patients but raises concern over patients lost to follow up (hence failsafe tracking of appointment attendance), and review of grading discrepancies between the ophthalmology and screening service.

Case based design of knitwear

In the developed world we are surrounded by man-made objects, but most people give little thought to the complex processes needed for their design. The design of hand knitting is complex because much of the domain knowledge is tacit. The objective of this thesis is to devise a methodology to help designers to work within design constraints, whilst facilitating creativity. A hybrid solution including computer aided design (CAD) and case based reasoning (CBR) is proposed. The CAD system creates designs using domain-specific rules and these designs are employed for initial seeding of the case base and the management of constraints. CBR reuses the designer's previous experience. The key aspects in the CBR system are measuring the similarity of cases and adapting past solutions to the current problem. Similarity is measured by asking the user to rank the importance of features; the ranks are then used to calculate weights for an algorithm which compares the specifications of designs. A novel adaptation operator called rule difference replay (RDR) is created. When the specifications to a new design is presented, the CAD program uses it to construct a design constituting an approximate solution. The most similar design from the case-base is then retrieved and RDR replays the changes previously made to the retrieved design on the new solution. A measure of solution similarity that can validate subjective success scores is created. Specification similarity can be used as a guide whether to invoke CBR, in a hybrid CAD-CBR system. If the newly resulted design is suffciently similar to a previous design, then CBR is invoked; otherwise CAD is used. The application of RDR to knitwear design has demonstrated the flexibility to overcome deficiencies in rules that try to automate creativity, and has the potential to be applied to other domains such as interior design.

Information-Analytical System for Design of New Inorganic Compounds

The principles of design of information-analytical system (IAS) intended for design of new inorganic compounds are considered. IAS includes the integrated system of databases on properties of inorganic substances and materials, the system of the programs of pattern recognition, the knowledge base and managing program. IAS allows a prediction of inorganic compounds not yet synthesized and estimation of their some properties.

Digital Art and Design

The desire to create unique things and give free rain to one's imagination served as a powerful impetus to the development of digital art and design software. The commoner was the use of computers the wider variety of professional software was developed. Nowadays the creators and computer designers are receiving more and more new and advanced programs that allow their ideas becoming virtual reality. This research paper looks at the history of the development of graphic editors from the simplest to the most modern and advanced. This brief survey includes the history of different graphic editors’ creation, their features and abilities. This paper highlights the two basic branches of graphic editors – these that are in free use and commercial graphic editors design software. The researcher selected the most powerful and influential graphic editors design software brands like Paint.NET and GIMP among free software and commercial Adobe Photoshop. This paper also dwells upon the way digital art transferred from the exclusively professional business into the hobby for ordinary users. This research paper bears implications for those who are interested in features and potentiality of most popular graphic editors design software.

Rebirth of a neighborhood: In streetscape design

This study involves one of the eight neighborhoods in the City of Miami named Little Havana. Little Havana, once a flourishing Hispanic community during the 1960s through the 1980s, is now experiencing housing deterioration, economic disinvestment, and increased social needs. ^ Although the City developed a Community Development Plan for the neighborhood addressing the neighborhood problems, needs, and objectives, it failed to address and take advantage of the area's prominent commercial street, Calle Ocho, as a cultural catalyst for the revitalization of the neighborhood. With an urban study and understanding of the area's needs for transit system improvements, program analysis, and a valuable architectural inventory, an intervention project can be developed. The project will capitalize on the area's historical and cultural assets and serve as a step towards altering the area's decline and revitalizing the street and community to recapture the energy present during the early years of the massive Cuban migration. ^

Effectiveness of the Teaching Enrichment Activities to Minorities (TEAM) program at increasing underrepresented students in gifted programs

This study examined the effectiveness of the TEAM (Teaching Enrichment Activities to Minorities) program in preparing and identifying underrepresented students for entrance into the gifted program. Miami-Dade County Public Schools (M-DCPS) developed the TEAM program as an intervention program aimed at developing student's thinking skills and critical thinking skills in all subject areas and prepare students for possible placement into the gifted program. ^ A systematic sampling strategy was utilized to select three TEAM schools from each of the six regions in M-DCPS for the sample, for a total of 18 schools. A pool of the students that participated in the TEAM program in 2003-2004 in the 18 schools selected were identified as the TEAM Sample students. A matching sample was created from 18 public schools in Miami-Dade County that did not implement the TEAM program in 2003-2004. The Matching Sample created a match for 806 students in the TEAM sample, for a total of 1612 subjects for the study. ^ This study used a logistical regression design to analyze the relationships of multiple independent variables, including: ethnicity, limited English proficiency, gender, free/reduced lunch status, grade level, reading achievement, mathematics achievement, and participation TEAM on the dependent variables of referral for the gifted program and eligibility into the gifted program. The first analysis found the variables of grade level, participation in TEAM, reading achievement, and mathematics achievement were all significant variables in determining if a student was referred for the gifted program. The second analysis found the variables of grade level, gender, free/reduced lunch status, reading achievement, and mathematics achievement were all significant variables in determining if a student was eligible for the gifted program. ^ Recommendations based on the results of this study include the expansion of the TEAM program in M-DCPS to include additional grade levels and schools. Additionally, adopting a broadened definition of giftedness and reviewing the screening and placement policies for potentially gifted students is recommended. Adopting multicultural and broader definitions of giftedness and constructing better tools and programs, such as TEAM, for assessing and identifying potential gifted students, represent small steps towards creating equitable education for all students. ^

An integrated framework for ensuring the quality of software design

Software development is an extremely complex process, during which human errors are introduced and result in faulty software systems. It is highly desirable and important that these errors can be prevented and detected as early as possible. Software architecture design is a high-level system description, which embodies many system features and properties that are eventually implemented in the final operational system. Therefore, methods for modeling and analyzing software architecture descriptions can help prevent and reveal human errors and thus improve software quality. Furthermore, if an analyzed software architecture description can be used to derive a partial software implementation, especially when the derivation can be automated, significant benefits can be gained with regard to both the system quality and productivity. This dissertation proposes a framework for an integrated analysis on both of the design and implementation. To ensure the desirable properties of the architecture model, we apply formal verification by using the model checking technique. To ensure the desirable properties of the implementation, we develop a methodology and the associated tool to translate an architecture specification into an implementation written in the combination of Arch-Java/Java/AspectJ programming languages. The translation is semi-automatic so that many manual programming errors can be prevented. Furthermore, the translation inserting monitoring code into the implementation such that runtime verification can be performed, this provides additional assurance for the quality of the implementation. Moreover, validations for the translations from architecture model to program are provided. Finally, several case studies are experimented and presented.

Customization of the design of antenna using genetic algorithm and finite-difference time-domain technique

Antenna design is an iterative process in which structures are analyzed and changed to comply with certain performance parameters required. The classic approach starts with analyzing a "known" structure, obtaining the value of its performance parameter and changing this structure until the "target" value is achieved. This process relies on having an initial structure, which follows some known or "intuitive" patterns already familiar to the designer. The purpose of this research was to develop a method of designing UWB antennas. What is new in this proposal is that the design process is reversed: the designer will start with the target performance parameter and obtain a structure as the result of the design process. This method provided a new way to replicate and optimize existing performance parameters. The base of the method was the use of a Genetic Algorithm (GA) adapted to the format of the chromosome that will be evaluated by the Electromagnetic (EM) solver. For the electromagnetic study we used XFDTD™ program, based in the Finite-Difference Time-Domain technique. The programming portion of the method was created under the MatLab environment, which serves as the interface for converting chromosomes, file formats and transferring of data between the XFDTD™ and GA. A high level of customization had to be written into the code to work with the specific files generated by the XFDTD™ program. Two types of cost functions were evaluated; the first one seeking broadband performance within the UWB band, and the second one searching for curve replication of a reference geometry. The performance of the method was evaluated considering the speed provided by the computer resources used. Balance between accuracy, data file size and speed of execution was achieved by defining parameters in the GA code as well as changing the internal parameters of the XFDTD™ projects. The results showed that the GA produced geometries that were analyzed by the XFDTD™ program and changed following the search criteria until reaching the target value of the cost function. Results also showed how the parameters can change the search criteria and influence the running of the code to provide a variety of geometries.

Cognitive and noncognitive variables that predict Florida community college radiography program graduates' success on the Registry

This study examined the predictive merits of selected cognitive and noncognitive variables on the national Registry exam pass rate using 2008 graduates (n = 175) from community college radiography programs in Florida. The independent variables included two GPAs, final grades in five radiography courses, self-efficacy, and social support. The dependent variable was the first-attempt results on the national Registry exam. The design was a retrospective predictive study that relied on academic data collected from participants using the self-report method and on perceptions of students' success on the national Registry exam collected through a questionnaire developed and piloted in the study. All independent variables except self-efficacy and social support correlated with success on the national Registry exam ( p < .01) using the Pearson Product-Moment Correlation analysis. The strongest predictor of the national Registry exam success was the end-of-program GPA, r = .550, p < .001. The GPAs and scores for self-efficacy and social support were entered into a logistic regression analysis to produce a prediction model. The end-of-program GPA (p = .015) emerged as a significant variable. This model predicted 44% of the students who failed the national Registry exam and 97.3% of those who passed, explaining 45.8% of the variance. A second model included the final grades for the radiography courses, self efficacy, and social support. Three courses significantly predicted national Registry exam success; Radiographic Exposures, p < .001; Radiologic Physics, p = .014; and Radiation Safety & Protection, p = .044, explaining 56.8% of the variance. This model predicted 64% of the students who failed the national Registry exam and 96% of those who passed. The findings support the use of in-program data as accurate predictors of success on the national Registry exam.