Digital Commons Network^™

Urban Growth Trends: 1980-1990, University Of New Mexico Bureau Of Business And Economic Research

BBER Publications

A report made by the University of New Mexico's Bureau of Business and Economic Research for the City of Albuquerque for population trends experienced during the period of 1980-1990.

Unobserved Ability, Efficiency Wages, And Interindustry Wage Differentials, Mckinley L. Blackburn, David Neumark

Faculty Publications

One competitive-market explanation of interindustry wage differentials that is not challenged by the persistence of these differentials is that they are due to differences across workers in unobserved ability or quality. In contrast, this paper explores the unobserved ability hypothesis by using test scores as error-ridden indicators of ability, and family background variables as instruments.This approach avoids two potential problems with using first-difference methods to remove omitted-ability bias from wage equation estimates of industry effects the exacerbation of measurement error from misclassification of industry, and selectivity with respect to industry changes. However, this approach may introduce other problems, for two …

The Influence Of Pore Fluids On Shear Strength And Stress-Strain Behavior Of Granular Soils, Prasanna Ratnaweera

Dissertations

When a dry granular soil is subjected to an external load, the stresses are transferred through mineral to mineral contacts. The shear strength of such a soil is governed by its contact properties. Presence of a thin layer of fluid between mineral to mineral contacts in a saturated soil will alter its contact properties. Therefore any change in the physical properties of pore fluid can logically be reasoned to influence the deformation characteristics of granular soils.

To investigate the influence of pore fluid viscosity on shear strength and stress-strain behavior of a soil, a series of consolidated drained triaxial tests …

Expert System For The Injection Molding Of Engineering Thermoplastics, Tzy-Cherng Jan

Dissertations

Injection molding of engineering thermoplastics is the most widely used manufacturing method in industry. It is a priority to maintain a deviation-free operating environment to ensure high quality, low cost manufacture. An expert system for the injection molding of engineering thermoplastics has been investigated. The system can be used to attenuate the deviations experienced during the injection molding of engineering thermoplastics. The system is coded in C programming language.

The resolution procedures of this system include two stages such as the definition of declarative knowledge and the procedure of corrective actions. In the definition of declarative knowledge, all of the …

A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng

Dissertations

Several nitroxides have been prepared for study of their image enhancement capability. These nitroxides contain different nitroxyl moieties within one molecule. On MRI examination for the nitroxides prepared, TEMPO and HPTPO are better due to their better water solubility, even though some of the others have more nitroxyl centers available. The intensity response is linear with respect to concentration in the range studied in most of the cases except for HPTPO, whose intensity finally reaches maximum when its concentration is higher than 10 mM.

Three sources of biomass, namely, liver microsomes, whole-cell yeast and a bacterial activated sludge consortium, have …

Renal Stone Formation In Patients With Inflammatory Bowel Disease, R. Caudarella, E. Rizzoli, L. Pironi, N. Malavolta, G. Martelli, G. Poggioli, G. Gozzetti, M. Miglioli

Scanning Microscopy

Kidney stones are more common in patients with inflammatory bowel disease (IBD) than in the general population. The main lithogenetic risk factors were evaluated in patients affected by Crohn's disease and ulcerative colitis. Our results show the presence of several factors, besides hyperoxaluria, in patients with IBD although their behaviour appears different in Crohn's disease and ulcerative colitis at pre- and post-operative stages. Before surgery in patients with Crohn's disease we found a decreased citrate (p < 0.001) and magnesium (p < 0.005) excretion together with a low urinary volume (p < 0.001) and pH (p < 0.005). After surgery patients with Crohn's disease showed a further reduction of magnesium and citrate. Patients with ulcerative colitis before surgery showed a reduced citrate excretion (p < 0.05) and a more acidic pH (p < 0.05) than healthy subjects. Surgical treatment of proctocolectomy with ileal pouch-anal anastomosis seems to increase the risk of stone formation; in fact, after surgery we observed a relevant decrease of urinary volume (p < 0.001), pH (p < 0.0001) and urinary excretion of citrate (p <0.0001) as well as magnesium (p < 0.005). Patients with IBD seem to be at greater risk of stone formation than patients with idiopathic calcium lithiasis; in fact, they show a lower excretion of citrate (p < 0.001) and magnesium (p < 0.001) together with a low urinary pH (p < 0.001) and volume (p < 0.001). Urinary volume reduction is probably one of the major risk factors together with the decrease of small molecular weight inhibitors that is a constant finding in all patients with IBD.

The Murray Ledger And Times, October 31, 1992, The Murray Ledger And Times

The Murray Ledger & Times

No abstract provided.

The Weekly Challenger, October 31, 1992, The Weekly Challenger, Et Al

Weekly Challenger Newspaper Collection

The October 31, 1992, issue of The Weekly Challenger.

A Study Of Annular Slurry Jet For Abrasive Waterjet Cutting, Thomas Kuriakose

Theses

The objective of this project is to study the performance of an annualr slurry jet nozzle for abrasive waterjet cutting. This nozzle has been invented by Avraham. Harnoy, Department of Mechanical Engineering, NJIT and presented to the patent committee of NJIT in May 1990. This study includes design and development of prototyes and testing of their performance. Moreover, it includes initial theoretical study of the flow behavior.

The idea is based on the merging of a high velocity pure waterjet with an annular jet of a slurry of water and abrasives at low velocity. The two jets merge outside the …

Design For Productivity Using Gd&T, Srihari G. Acharya

Theses

No abstract provided.

Quantitative Measurement Of Pyrolysis And Combustion Species Concentration By Molecular-Beam-Sampling-Mass-Spectrometry, Xian Zhong

Theses

A molecular-beam-sampling apparatus utilizing both a time-of-flight mass spectrometer with vacuum ultraviolet (VUV) photoionization and a quadrupole mass spectrometer with electron impact ionization is described. These systems are used to analyze reactants and products, as well as reactive intermediates, from flow tube experiments at reduced pressures and elevated temperatures. It is shown that the quadrupole signal sensitivity can be predicted using literature cross sections which are based upon the atom hybridization within the various molecules. Measurements of the VUV photoionization sensitivity for stable species led to development of a group additivity approach to predict cross sections. This approach was extended …

Errors In Constant-Velocity Shaft Couplings, Philip M. Remington

Theses

A Multiloop spatial system of rotations is used to represent a shaft coupling, allowing a transmission plane which may deviate from the plane of symmetry to be specified. The plane of transmission, for intersecting input and output shaft axes, is the locus of intersections of screw axes that compose the system. By prescribing the transmission plane outside of the plane of symmetry (commonly called the "homokinetic plane" or "bisecting plane") to pecified orientations, a phase shift between the input and output shaft rotational displacements will he quantified. The rotational phase shift between the input and output shafts can be evaluated …

A Theoretical Study Of The Subband Structures And Tunneling In Polytype Heterostructures, Hong Chen

Theses

A theoretical study of the electronic and optical properties in polytype heterostructures is presented in this thesis.

In the first part of the thesis (Chap. 2 and Chap. 3), an explicit expression for calculating the subband structure and tunneling is formulated by the incorporation of the envelope function approximations and the transfer matrix technique. It is based on the k*p theory as done to date, but contains two significant improvements: a more realistic treatment of the spatial and energetic dependance of effective masses and band edges; the availability of the calculations, in favor of direct numerical evaluation, to various quantum …

Uses And Applications Of Artificial Intelligence In Manufacturing, Manojkumar H. Desai

Theses

The purpose of the THESIS is to provide engineers and personnels with a overview of the concepts that underline Artificial Intelligence and Expert Systems. Artificial Intelligence is concerned with the developments of theories and techniques required to provide a computational engine with the abilities to perceive, think and act, in an intelligent manner in a complex environment.

Expert system is branch of Artificial Intelligence where the methods of reasoning emulate those of human experts. Artificial Intelligence derives it's power from its ability to represent complex forms of knowledge, some of it common sense, heuristic and symbolic, and the ability to …

Cost Deployment Based On Quality Function Deployment, John Goceljak

Theses

A methodology for Cost Deployment based on Quality Function Deployment (QFD) architecture is developed and explained. Following a comprehensive review of Quality Function Deployment terminology and composition, a house-of-quality is developed, and matrix correlation methodologies are discussed. Current applications are presented to illustrate the scope and adaptability of this quality assurance tool. In addition, an exercise in product design and review is conducted to illustrate a unique approach to cost deployment. Quality Function Deployment issues, including software, consulting, and preferred practices are also presented.

Automatic Surface Mount Solder Joints Inspection, Zhu Liu

Theses

This thesis reports the research results on automatic inspection of solder joints on printed circuit boards. The previous work on this subject has been advanced significantly in the following three aspects. With the support of AT&T Bell Lab, the most updated surface mount solder joints are inspected in this work instead of larger simulation solder joints or traditional through hole solder joints in the previous work. A small set of features is extracted for surface mount solder joints in both infrared and visual light inspection. A new image processing software named Khoros has been applied to improve the quality of …

Posterior Stabilized Knee Design Biomechanical Considerations, Donald E. Mcnulty

Theses

Numerous posterior stabilized knee systems are available for primary and revision total knee arthroplasty. Design of these systems requires an understanding of the articulating geometries and kinematic/kinetic biomechanical considerations of the normal knee. The findings for the normal knee are integrated into the design of a prosthetic system.

The natural femoral, tibial and patella articulating geometries are defined to enable subsequent kinematic and kinetic analyses. The articulating geometries are characterized from review of anthropometric studies of the tibiofemoral and patellofemoral joint.

The kinematic analysis of the natural knee defines knee motion in terms of rotation, adduction/abduction, range of motion and …

Design For Manufacturability And Assembly, Srinivas Mullapudi

Theses

This report presents a study of the various concepts of design for manufacturability and assembly with some case studies, and examples.

The goal of DFM is reduction of parts and simplifying assembly process. A simple faucet has been studied and attempts have been made at re-designing the same using the techniques of design for manufaturability as postulated by Boothroyd, Dewhurst and Henry Stoll.

The Design And Manufacture Of Institutional Trays Using Simultaneous Engineering, Antonio Schmidt

Theses

This study evaluates thermoformed trays as used in the food service industry. The resin used in fabricating trays is a blend of Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). The life of the trays is presently between 1 to 3 years. The trays are used in correctional facilities and hospitals. The handling of the tray is not abusive. The trays are pulled out of service once they exhibit stress cracking.

To further understand the unpredictable life of the thermoformed trays an understanding of the behavior of the plastics is required and the method of comparing one resin from another, as …

Three-Dimensional Beam-Columns, Mohammad Hassan Shams

Theses

This thesis explores several special cases of three-dimensional beam-columns and suggests that the method of finite differences can be used when a solution of general case is required. The thesis begins with a review of the three-dimensional beam-column equations and then shows how these equations can be used to generate the member stiffness matrix for the nonlinear analysis of three-dimensional frames. Examples are included which discuss the differences between the analytical and numerical solutions.

Application Of Desktop Manufacturing System (Sla) For The Manufacturing Of A Centrifugal Pump Impeller Using Cad (I-Deas), Wasimuddin Azam Muhammad Syed

Theses

Desktop Manufacturing (DTM) systems which combine personal computer, laser and other technologies are being used to sculpt objects from computer generated models created on computer aided design (CAD) workstations. As a member of DTM systems, StereoLithography Apparatus (SLA) transforms 3-dimensional designs into a 3-D output. This can substantially reduce the time required to produce a prototype through the process of photopolymerization. The process involves the transfer of a liquid plastic monomer into a solid polymer by exposing it to ultraviolet light.

Although the process looks productive, inefficiencies can occur, if incorrect parameters are selected before its application for a particular …

Modeling, Evaluation, And Control Of A Flexible Manufacturing Cell Using Petri Nets, Glenn Arthur Thorniley

Theses

This thesis describes the usefulness of Petri nets in modeling, evaluating, and controlling a Flexible Manufacturing Cell (FMC). The basics of Petri net theory are explained and a specific FMC is examined. First, the FMC is modeled. The purpose of modeling is to facilitate the evaluation and provide a framework on which the control methodologies can be applied. The objective of the evaluation is to determine how the FMC would benefit most by replacing or adding equipment. Several ideas on control are combined to form a useful framework for the designing of the control net. With this framework the control …

Character Recognition Using String Matching, Xiaozhi Ye

Theses

To handle noisy and distorted pattern is the use of similarity or distance measures. A similarity or distance measure can be defined between a representation of an unknown pattern and a representation of a prototype pattern. Recognition of the unknown pattern can be carried out on the basis of the maximum-similarity or minimum distance criterion (Bunke 1990) This approach is proposed to recognize the noisy or distorted character image. In this work, a directly string representation of the pattern ( prototype as well as unknown input) using the histogram method, a decision procedure for classification is the well known Levenshtein …

Thermal Decomposition Of Dichloromethane In Absence And Presence Of Added Oxygen And/Or Methane, Hong-Ming Chiang

Theses

Thermal decomposition experiments on dichloromethane in absence and presence of added O₂ and/or ₄ and in argon bath gas were conducted in a tubular flow reactor. The thermal reactions were studied at 1 atmosphere pressure with residence times of 0.3 - 2.0 seconds in the temperature range from 680 to 840 °C.

The degradation of dichloromethane and the decomposition product distributions were studied in both oxidative and pyrolytic reaction environments. The slowest decay of dichloromethane occurred when CH₄ was present and 02 was absent. The concentration of all products, (except HCl, CO, and CO₂ in the oxidation), …

Synthesis Of Bisphenol A Bis-2-Hydroxypropylmethacrylate (Bisgma) And Diethylchlorophosphate And 2-Hydroxyethylmethacrylate (Decp-Hema) And Preparation Of Dental Adhesives, Da Xie

Theses

BisGMA and DECP-HEMA were separately synthesized from Bisphenol A and glycidyl methacrylate and from diethylchlorophosphate and 2-hydroxyethyl-methacrylate. The structure of the monomer, BisGMA, was further analyzed by means of chromatography, VPO, IR, FTIR and GC-MASS.

Based on the main monomers, BisGMA, DECP-HEMA and an organosilane compound, a dental adhesive has been formulated. Although the tervile strength of the adhesive has been found to be not as good as the adhesive formulated by a previous worker (student), its applicability to teeth is more suitable for clinic practice.

User Interface And Data Structure Design For Architectural Expert System, Yonghua Ma

Theses

Computers are currently used to generate drawings in the architectural design process. This thesis anticipates the development of an Architectural Expert System, which could provide assistance in the decision-making processes in architectural design. The focus is on the design of the user interface of such a system. Architectural object-oriented data hierarchies are created. Also, a set of drawing tools, which assist the user in the creation of architectural objects such as walls, windows, and doors, are provided.

Automatic Motion Analysis Of Colliding Spheres, John Vijayakumar Caesar

Theses

Motion analysis is useful to compute linear and angular velocities and acceleration of an object from a sequence of images. This thesis is part of an investigation to compute the translation and rotation velocities needed to determine the collision parameters of two colliding spheres. This involves the tracking of the spheres and feature points on the spheres over a time interval. An experimental setup releases two spheres such that they collide and a high speed imaging system, i.e., Kodak Ektapro 1000 is utilised to record the motion of the spheres. The imaging system is capable of recording at a speed …

Shop Floor Planning And Control In Integrated Manufacturing Systems, Tahir Mahmood

Theses

The implementation of a shop floor planning and control system is a prerequisite in establishing an effective computer integrated manufacturing system. A shop floor control system integrates management production goals with the capabilities and limitations of the manufacturing plant. Shop floor planning begins with a long term rough cut capacity plan and evolves into near term, capacity requirements and input/output plans. Shop floor control provides a status of in-process operations and a measure of the plants success in executing the plan. Effective use of technology on shop floor increases the efficiency of the manufacturing plant. Simulation is an important tools …

Design And Implementation Of Two Text Recognition Algorithms, Madhumathi Yendamuri

Theses

This report presents two algorithms for text recognition. One is a neural-based orthogonal vector with pseudo-inverse approach for pattern recognition. A method to generate N orthogonal vectors for an N-neuron network is also presented. This approach converges the input to the corresponding orthogonal vector representing the prototype vector. This approach can restore an image to the original image and thus has error recovery capacility. Also, the concept of sub-networking is applied to this approach to enhance the memory capacity of the neural network. This concept drastically increases the memory capacity of the network and also causes a reduction of the …

The Durability Of Hot Mix Asphalt With Petroleum Contaminated Soils, Bonnie H. Dubose

Theses

Petroleum contaminated soils are considered solid waste They must be taken to solid waste facilities such as landfills or some other method must be found to deal with them. Landfills are becoming limited and is looked upon by the government as the least attractive option. One method that looks promising is to use petroleum contaminated soils in Hot Mix Asphalt Concrete.

In the research program the following are examined: 1) Investigation of material properties of the petroleum contaminated soil and aggregates 2) The proper procedure to produce a design blend of asphalt concrete. 3) Establishing the test procedure protocol to …