With technology changing at a dramatic pace, entrepreneurs may assume that acquiring the newest production equipment available is the best option. But that is not always the case. It is important to first assess the needs in order to decide whether new or remanufactured production equipment is the best alternative. Investment on production equipment can be initiated due to existing equipment cannot handle capacity; products evolve and changes needed to meet market requirement; to continuously improve production system; or the general requirements for quality, environment, economy and safety. However, the study reveals that it has received only limited attention from academics and practitioners regarding to whether decide to remanufacture or new acquire production equipment. Further, the framework visualizes the complexity of managing decision-making between production equipment remanufacturing and new acquisition. The study employs qualitative method by conducting literature review, interviews, brainstorming sessions, benchmarking, and observation to build the theoretical framework and collect empirical data. The thesis identifies the differences between production equipment remanufacturing and new acquisition; distinguishes the different levels of production equipment, proposes a new definition of production equipment remanufacturing; and analyses factors should be considered for the decision-making process. Altogether, the findings provide strong evidence to propose a decision-making checklist in decisions between production equipment remanufacturing and new acquisition.

Injection molding is widely used to manufacture plastic parts with good surface finish, dimensional stability and low cost. The common examples of parts manufactured by injection molding include toys, utensils, and casings of various electronic products. The process of mold design to generate these complex shapes is iterative and time consuming, and requires great expertise in the field. As a result, a significant amount of the final product cost can be attributed to the expenses incurred during the product’s design. After designing the mold segments, it is necessary to machine these segments with minimum cost using an efficient tool-path. The tool-path planning process also adds to the overall mold cost. The process of injection molding can be simplified and made to be more cost effective if the processes of mold design and tool-path generation can be automated. This work focuses on the automation of mold design from a given part design and the automation of tool-path generation for manufacturing mold segments. The hypothesis examined in this thesis is that the automatic identification of mold features can reduce the human efforts required to design molds. It is further hypothesised that the human effort required in many downstream processes such as mold component machining can also be reduced with algorithmic automation of otherwise time consuming decisions. Automatic design of dies and molds begins with the part design being provided as a solid model. The solid model of a part is a database of its geometry and topology. The automatic mold design process uses this database to identify an undercut-free parting direction, for recognition of mold features and identification of parting lines for a given parting direction, and for generation of entities such as parting surfaces, core, cavity and side-cores. The methods presented in this work are analytical in nature and work with the extended set of part topologies and geometries unlike those found in the literature. Moreover, the methods do not require discretizing the part geometry to design its mold segments, unlike those found in the literature that result in losing the part definition. Once the mold features are recognized and parting lines are defined, core, cavity and side-cores are generated. This work presents algorithms that recognize the entities in the part solid model that contribute to the design of the core, cavity and side-cores, extract the entities, and use them in the design of these elements. The developed algorithms are demonstrated on a variety of parts that cover a wide range of features. The work also presents a method for automatic tool-path generation that takes the designed core/cavity and produces a multi-stage tool-path to machine it from raw stock. The tool-path generation process begins by determining tool-path profiles and tool positions for the rough machining of the part in layers. Typically roughing is done with large aggressive tools to reduce the machining time; and roughing leaves uncut material. After generating a roughing tool-path for each layer, the machining is simulated and the areas left uncut are identified to generate a clean-up tool-path for smaller sized tools. The tool-path planning is demonstrated using a part having obstacles within the machining region. The simulated machining is presented in this work. This work extends the accessibility analysis by retaining the topology information and using it to recognize a larger domain of features including intersecting features, filling a void in the literature regarding a method that could recognize complex intersecting features during an automated mold design process. Using this information, a larger variety of new mold intersecting features are classified and recognized in this approach. The second major contribution of the work was to demonstrate that the downstream operations can also benefit from algorithmic decision making. This is shown by automatically generating roughing and clean-up tool-paths, while reducing the machining time by machining only those areas that have uncut material. The algorithm can handle cavities with obstacles in them. The methodology has been tested on a number of parts.

Residential on-site wastewater systems (OWS) are a potential source of phosphorus (P) which can negatively impact surface water quality in rural watersheds. The magnitude of P loading from OWS is typically not monitored, and is further complicated when agricultural land-uses are intermixed with residential dwellings. Watershed-scale computer simulations are commonly used tools for evaluating the impacts of land-use changes on P loading. Existing models simulate OWS P treatment via vertical flow transport in native soils. However, in Nova Scotia (NS) OWS designs rely pre-dominantly on lateral flow and imported sand filter media. In this thesis, a watershed-scale computer modeling framework for simulating P loads from agriculture and lateral flow OWS designs was developed and tested. The framework consists of the P on-site wastewater simulator (POWSIM), designed specifically for this study, which is used in conjunction with the Soil and Water Assessment Tool (SWAT) model. The POWSIM loading tool has three computational components: (i) OWS disposal field design type selection and treatment media mass calculation; (ii) disposal field P treatment dynamics; and (iii) soil subsurface plume P treatment dynamics. The active P treatment media mass and dynamics equations were developed from numerical modeling (HYDRUS-2D) and lateral flow sand filter (LFSF) OWS disposal field experiments. A 2-part piecewise linear model was found to best represent LFSF P treatment processes. Testing of the modeling framework in the mixed land-use Thomas Brook Watershed (TBW) in NS demonstrated improved simulation of baseflow total P (TP) loads in both a predominantly residential subcatchment and one dominated by agriculture over the SWAT model without POWSIM. Different residential and agricultural development and beneficial management practice (BMP) scenarios were evaluated in the TBW. Agricultural BMPs were most effective at reducing cumulative TP loads while OWS BMPs were best at mitigating in-stream eutrophication impacts. The 50 year simulation period for the various scenarios found peak OWS TP loading occurring between 25 and 50 years, suggesting that modeling for many decades is required for proper evaluation. This study highlights the importance in identifying specific water quality issues that need to be targeted prior to implementing a BMP strategy.

In this study, a three-axes PC numerical control system for industrial applications has been developed. With this system, fast and cheap prototyping of designed objects can be realized. The system consists of software and a hardware which includes an XYZ positioning table and three step motors controlling this table. A proper drive circuit for the stepper motors is utilized. The software digitizes two dimensional drawings of three dimensional objects and generates the control signals for the XYZ positioning table. The software is developed under Microsoft Studio Visual Basic 6.0 environment regardless of the OS of the PC. The parallel port of the PC has been utilized for generating the necessary control signals for the stepper motors.

This study includes examination of the machinability characteristics of two medium carbon steel types (SAE 1040 and SAE 1050) as a result of spherodizing treatment. Both steel types were handled into four categories according to their spherodizing treatment parameters (temperature and time). Microstructural investigation, hardness and ultrasonic sound velocity measurement (with both longitudinal and transverse waves) of these steels were performed, and effect of applied heat treatments on microstructure, hardness and ultrasonic sound velocity was investigated. Pulse-echo method has been used for ultrasonic sound velocity measurements, and measurements were performed with 5 and 10 MHz longitudinal and 5 MHz transverse wave probes. Tool life criterion was used for determining the machinability characteristics of the steels. For this purpose, flank wear land measurements were performed on the cutting tools. Results have showed that, by appliying heat treatment it is possible to change the microstructure, hardness, ultrasonic sound velocity and machinability characteristics of a steel.

This thesis introduces a visual composition approach for JavaBeans components, in compliance with the Component Oriented Software Engineering (COSE) process. The graphical modeling tool, COSECASE, is enhanced with the ability to build a system by integrating domain-specific components. Such integration is implemented by defining connection points and interaction details between components. The event model of the JavaBeans architecture is also added to the capabilities.

A three dimensional wing design tool with analysis functions has been developed with embedded Euler/Navier-Stokes flow solver and a three dimensional hyperbolic grid generator. A graphical user interface has been constructed using PYTHON script language and the tool was enhanced with pre-processing and post-processing capabilities. Analysis and design procedures are demonstrated with automatic grid generation, automatic series solution and automatic graphs and reports generation.

This dissertation focuses on the economic and environmental benefits of planting switchgrass as a bioenergy feedstock. The first chapter presents a dynamic optimization model of fertilizer and land allocation between switchgrass and corn to estimate economic benefits. Subsequent chapters utilize Geographic Information System (GIS)-based Soil and Water Assessment Tool (SWAT) to be calibrated to evaluate the environmental (nutrient and sediment loading) effects of land use conversion to switchgrass production on water quality and analyze the Water Quality Trading (WQT) program with cost-effectiveness ratios ordered for abatements of nutrient loadings in an East Tennessee watershed.

The use of new tools for mathematics at school wins increasingly Importance. It follows from this that they are consquences as well as on aims and contents of mathematics at school us like on methods in the lessons. It is not unusual, that students and parents and also university professors are to be feared, that the calculation competence is decreasing with the use of CAS. In the lesson should be showed a possible way to developing such competences in the beginning phase of the learning process in Algebra. The examples refer to a level of school mathematics for students in the middle school age. The methods tell apart phases with and without CAS and shows a didactic principles of mathematics lessons in the case of use of CAS handheld technology.

In this study, the new predictive model for the micro-grinding process was developed by consolidating mechanical and thermal effects within the single grit interaction model at microscale material removal. The size effect of micro-machining was also included in the proposed model. In order to assess thermal effects, the heat partition ratio was experimentally calibrated and compared with the prediction of the Hahn model. Then, on the basis of this predictive model, a comparison between experimental data and analytical predictions was conducted in view of the overall micro-grinding forces in the x and y directions. Although there are deviations in the predicted micro-grinding forces at low depths of cut, these differences are reduced as the depth of cut increases. On the other hand, the optimization of micro machine tools was performed on the basis of the proposed design strategy. Individual mathematical modeling of key parameters such as volumetric error, machine working space, and static, thermal, and dynamic stiffness were conducted and supplemented with experimental analysis using a hammer impact test. These computations yield the optimal size of miniaturized machine tools with the technical information of other parameters.