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Articles 2011 - 2040 of 2082

Full-Text Articles in Engineering

Experimental Spinal Fusion With Recombinant Human Bone Morphogenetic Protein-2 Without Decortication Of Osseous Elements, Harvinder Sandhu, Linda E.A. Kanim, Jeffrey M. Toth, J. Michael Kabo, David Liu, Rick B. Delamarter, Edgar G. Dawson Jun 1997

Experimental Spinal Fusion With Recombinant Human Bone Morphogenetic Protein-2 Without Decortication Of Osseous Elements, Harvinder Sandhu, Linda E.A. Kanim, Jeffrey M. Toth, J. Michael Kabo, David Liu, Rick B. Delamarter, Edgar G. Dawson

Biomedical Engineering Faculty Research and Publications

Study Design. L4-L5 intertransverse process fusions were produced with 58 μg, 230 μg, or 920 μg of recombinant human bone morphogenetic protein-2 in 20 dogs. Eleven had traditional decortication of posterior elements before insertion of the implant. Nine were left undecorticated. All animals were evaluated 3 months after surgery.

Objectives. To determine whether decortication is a prerequisite for successful fusion in the presence of osteoinductive proteins such as bone morphogenetic protein-2.

Summary of Background Data. Recombinant osteoinductive proteins can induce de novo bone in ectopic soft-tissue sites in the absence of bone marrow elements. Traditional methods for achieving spinal fusion …


Generic, Geometric Finite Element Analysis Of The Transtibial Residual Limb And Prosthetic Socket, Barbara Silver-Thorn, Dudley S. Childress Apr 1997

Generic, Geometric Finite Element Analysis Of The Transtibial Residual Limb And Prosthetic Socket, Barbara Silver-Thorn, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

Finite element analysis was used to investigate the stress distribution between the residual limb and prosthetic socket of persons with transtibial amputation (TTA). The purpose of this study was to develop a tool to provide a quantitative estimate of prosthetic interface pressures to improve our understanding of residual limb/prosthetic socket biomechanics and prosthetic fit. FE models of the residual limb and prosthetic socket were created. In contrast to previous FE models of the prosthetic socket/residual limb system, these models were not based on the geometry of a particular individual, but instead were based on a generic, geometric approximation of the …


Public Perceptions Of The Midwest’S Pavements - Minnesota - Phase I (Winter Ride), University Of Wisconsin - Extension, Wisconsin Survey Research Laboratory, Marquette University, Department Of Civil, Construction, And Environmental Engineering Jan 1997

Public Perceptions Of The Midwest’S Pavements - Minnesota - Phase I (Winter Ride), University Of Wisconsin - Extension, Wisconsin Survey Research Laboratory, Marquette University, Department Of Civil, Construction, And Environmental Engineering

Transportation Research Center: Public Perception of Midwest Pavements

The Minnesota Winter Ride Survey was designed to gauge the extent to which motorists were tolerant of the rougher ride of pavements on rural two-lane highways in the winter. Survey objectives, therefore, were centered around this focal question of winter ride tolerance. A telephone survey was conducted during the first quarter of the year (January 15 to March 15, 1997) by the Wisconsin Survey Research Laboratory (WSRL), which simultaneously conducted a similar survey in Wisconsin. Random digit dial samples were drawn for both states according to accepted sampling procedure. The survey data set provided by WSRL included 417 respondents.

Analysis …


Membrane Analogy For Saint-Venant Torsion: New Results, Stephen M. Heinrich Nov 1996

Membrane Analogy For Saint-Venant Torsion: New Results, Stephen M. Heinrich

Civil and Environmental Engineering Faculty Research and Publications

The Saint-Venant torsion problem for a twisted shaft may be formulated in terms of the Prandtl stress function (PSF) or the conjugate warping function (CWF), each of which may be interpreted as the transverse deflection of a thin membrane via the well-known membrane (soap-film) analogies. The deflection of the PSF membrane is associated with a uniform transverse pressure loading, whereas the CWF membrane is nonpressurized—its deformation is due solely to imposed deflections along its edge. The utility of the PSF analogy stems from the simple relationships that exist between the geometry of the deformed membrane (slope, enclosed volume) and the …


Effective Doses Of Recombinant Human Bone Morphogenetic Protein-2 In Experimental Spinal Fusion, Harvinder Sandhu, Linda E.A. Kanim, J. Michael Kabo, Jeffrey M. Toth, Erik N. Zeegen, David Liu, Rick B. Delamarter, Edgar G. Dawson Sep 1996

Effective Doses Of Recombinant Human Bone Morphogenetic Protein-2 In Experimental Spinal Fusion, Harvinder Sandhu, Linda E.A. Kanim, J. Michael Kabo, Jeffrey M. Toth, Erik N. Zeegen, David Liu, Rick B. Delamarter, Edgar G. Dawson

Biomedical Engineering Faculty Research and Publications

Study Design

Nineteen dogs underwent L4-L5 intertransverse process fusions with either 58 μg, 115 μg, 230 μg, 460 μg, or 920 μg of recombinant human bone morphogenetic protein-2 carried by a polylactic acid polymer. A previous study (12 dogs) compared 2300 μg of recombinant human bone morphogenetic protein-2, autogenous iliac bone, and carrier alone in this model. All fusions subsequently were compared.

Objectives

To characterize the dose-response relationship of recombinant human bone morphogenetic protein-2 in a spinal fusion model.

Summary of Background Data

Recombinant osteoinductive morphogens, such as recombinant human bone morphogenetic protein-2, are effective in vertebrate diaphyseal defect and …


A Review Of Prosthetic Interface Stress Investigations, Barbara Silver-Thorn, John W. Steege, Dudley S. Childress Jul 1996

A Review Of Prosthetic Interface Stress Investigations, Barbara Silver-Thorn, John W. Steege, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

Over the last decade, numerous experimental and numerical analyses have been conducted to investigate the stress distribution between the residual limb and prosthetic socket of persons with lower limb amputation. The objectives of these analyses have been to improve our understanding of the residual limb/prosthetic socket system, to evaluate the influence of prosthetic design parameters and alignment variations on the interface stress distribution, and to evaluate prosthetic fit. The purpose of this paper is to summarize these experimental investigations and identify associated limitations. In addition, this paper presents an overview of various computer models used to investigate the residual limb …


Parametric Analysis Using The Finite Element Method To Investigate Prosthetic Interface Stresses For Persons With Trans-Tibial Amputation, Barbara Silver-Thorn, Dudley S. Childress Jul 1996

Parametric Analysis Using The Finite Element Method To Investigate Prosthetic Interface Stresses For Persons With Trans-Tibial Amputation, Barbara Silver-Thorn, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

A finite element (FE) model of the below-knee residual limb and prosthetic socket was created to investigate the effects of parameter variations on the interface stress distribution during static stance. This model was based upon geometric approximations of anthropometric residual limb geometry. The model was not specific to an individual with amputation, but could be scaled to approximate the limb of a particular subject. Parametric analyses were conducted to investigate the effects of prosthetic socket design and residual limb geometry on the residual limb/prosthetic socket interface stresses. Behavioral trends were illustrated via sensitivity analysis.

The results of the parametric analyses …


Analysis Of Support Conditions Under Joined Concrete Slabs Along Ush 18/151, James Crovetti Mar 1995

Analysis Of Support Conditions Under Joined Concrete Slabs Along Ush 18/151, James Crovetti

Transportation Reports with the Wisconsin Department of Transportation

The Wisconsin Department of Transportation has been constructing jointed concrete pavements incorporating open graded permeable base (OGPB) layers for a number of years. The OGPB layer has been constructed using non-stabilized, asphalt stabilized, and cement stabilized aggregates of varying gradations. Test sections have been established throughout the State of Wisconsin and have been monitored for performance for the last 5 years. To date, little if any performance variations after limited trafficking have been noted for jointed PCC sections constructed over OGPB layers as compared to those constructed over conventional dense graded aggregate base layers.

Data was collected along USH 18/151 …


Estimation Of The Pulmonary Capillary Transport Function In Isolated Rabbit Lungs., Said H. Audi, J H. Linehan, Gary S. Krenz, C A. Dawson, S B. Ahlf, David L. Roerig Mar 1995

Estimation Of The Pulmonary Capillary Transport Function In Isolated Rabbit Lungs., Said H. Audi, J H. Linehan, Gary S. Krenz, C A. Dawson, S B. Ahlf, David L. Roerig

Biomedical Engineering Faculty Research and Publications

Recently, we presented a method for estimating the pulmonary capillary volume and transport function based on the use of a reference indicator and two or more indicators that rapidly equilibrate (radially) with the tissue (i.e., the concentrations in the vascular and extravascular spaces at a given axial location are in equilibrium) during transit through the capillaries in a bolus-injection indicator dilution method (S. H. Audi, G. S. Krenz, J. H. Linehan, D. A. Rickaby, and C. A. Dawson. J. Appl. Physiol. 77: 332-351, 1994). The objectives of the present study were 1) to determine whether [14C]diazepam …


Knowledge‐Based Expert System For Concrete Mix Design, Yong Bai, Serji N. Amirkhanian Jun 1994

Knowledge‐Based Expert System For Concrete Mix Design, Yong Bai, Serji N. Amirkhanian

Civil and Environmental Engineering Faculty Research and Publications

In the United States, the American Concrete Institute method (ACI 211) is the most widely used concrete mix design. However, ACI 211 does not consider all factors regarding concrete mix design. The acceptance of a freshly mixed concrete depends on concrete quality control test results. If the results indicate that the concrete does not meet the specification, mix design adjustment must be made. Concrete mix design and adjustment are somewhat complicated and time‐consuming tasks that are performed best by experienced persons. In this project, a rule‐based expert system was developed to assist the user in concrete mix design, including the …


Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid May 1994

Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid

Biomedical Engineering Faculty Research and Publications

The envelope of the backscattered signal from tissues can exhibit non‐Rayleigh statistics if the number density of scatterers is small or if the variations in the scattering cross sections are random. The K distribution which has been used extensively in radar, is introduced to model this non‐Rayleigh behavior. The generalized K distribution is extremely useful since it encompasses a wide range of distributions such as Rayleigh, Lognormal, and Rician. Computer simulations were conducted using a simple one‐dimensional discrete scatteringmodel to investigate the properties of the echo envelope. In addition to cases of low number densities, significant departures from Rayleigh statistics …


Immittance Spectroscopy Of Smart Components And Novel Devices, Mohammad Anwarul Alim, Sanjida Khanam, Martin A. Seitz Jan 1994

Immittance Spectroscopy Of Smart Components And Novel Devices, Mohammad Anwarul Alim, Sanjida Khanam, Martin A. Seitz

Electrical and Computer Engineering Faculty Research and Publications

AC small-signal immittance spectroscopy is employed as a viable tool to demonstrate electrical characterization, performance improvement, and quality assurance issues of smart materials-based components and novel devices. The variation in the ac response, complemented via dc measurements within a range of tolerating temperature, delineates competing phenomena occurring in the microstructures of these engineering material systems. The results are presented in a generic manner with possible explanations on the mechanisms for two selected Debye-like (nearly ideal) and non-Debye (non-ideal) low-capacitance resistors. This spectroscopic approach allows systematic development of a representative equivalent circuit, considered to be the characteristic of the devices and …


Development Of Knowledge-Based Systems For Aluminum Welding, R. J. Napolitano, H. Kulluk, Mark L. Nagurka, R. P. Martukanitz, P. B. Dickerson Nov 1992

Development Of Knowledge-Based Systems For Aluminum Welding, R. J. Napolitano, H. Kulluk, Mark L. Nagurka, R. P. Martukanitz, P. B. Dickerson

Mechanical Engineering Faculty Research and Publications

No abstract provided.


Accident Analysis Of Ice Control Operations, David Kuemmel, Rashad Hanbali Jun 1992

Accident Analysis Of Ice Control Operations, David Kuemmel, Rashad Hanbali

Transportation Research Center: Accident Analysis of Ice Control Operations

Highway maintenance involves all work necessary to assure that the highway system is kept safe, open to traffic, and in proper working order. During winter, the removal of snow and ice from streets, roads, and highways is a major maintenance operation. With more than 135 million motor vehicles registered in the United States and roughly four million miles of roads and streets, local governments must be prepared to deal with the removal of snow and ice to insure public safety, and to reduce the adverse impact on the affected area’s economy.

Snow and ice covered roads can paralyze the functioning …


Analysis Of Algorithms For Velocity Estimation From Discrete Position Versus Time Data, Ronald H. Brown, Susan C. Schneider Phd, Michael G. Mulligan Feb 1992

Analysis Of Algorithms For Velocity Estimation From Discrete Position Versus Time Data, Ronald H. Brown, Susan C. Schneider Phd, Michael G. Mulligan

Electrical and Computer Engineering Faculty Research and Publications

Algorithms for constructing velocity approximations from discrete position versus time data are investigated. The study is limited to algorithms suitable to provide velocity information in discrete-time feedback control systems such as microprocessor-based systems with a discrete position encoder. Velocity estimators based on lines per period, reciprocal-time, Taylor series expansion, backward difference expansions, and least-square curve fits are presented. Based on computer simulations, comparisons of relative accuracies of the different algorithms are made. The least-squares velocity estimators filtered the effect of imperfect measurements best, whereas the Taylor series expansions and backward difference equation estimators respond better to velocity transients.


Accident Analysis Of Ice Control Operations - Abstract, David Kuemmel, Rashad Hanbali Jan 1992

Accident Analysis Of Ice Control Operations - Abstract, David Kuemmel, Rashad Hanbali

Transportation Research Center: Accident Analysis of Ice Control Operations

This widely publicized study by Marquette University was the first of its kind in North America to document, with statistical validity, the direct benefits of deicing operations. It was patterned after a German study of the Technical University at Darmstadt during the late 1980s.

The Marquette study was conducted during the winter of 1990-1991 in four states: New York, Illinois, Minnesota and Wisconsin. It covered a network of 520 miles of randomly selected twolane undivided highways and 50 miles of multi-lane divided freeways in the four states. The sections included were primarily rural or sub-urban.

Data collection included estimated hourly …


Instrumentation And Control For A Microprocessor-Based Coronary Perfusion System, Daniel L. Priester Oct 1991

Instrumentation And Control For A Microprocessor-Based Coronary Perfusion System, Daniel L. Priester

Master's Theses (1922-2009) Access restricted to Marquette Campus

No abstract provided.


A Computer Simulation Model Of Waterhyacinth And Weevil Interactions, Kunter S. Akbay, F. G. Howell, J. W. Wooten Jan 1991

A Computer Simulation Model Of Waterhyacinth And Weevil Interactions, Kunter S. Akbay, F. G. Howell, J. W. Wooten

Mechanical Engineering Faculty Research and Publications

A personal computer simulation model termed "INSECT" has been developed to evaluate biological control of waterhyacinth (Eichhornia crassipes (Mart.) Solms.) by two species of weevil (Neochetina eichhorniae Warner, and N. bruchi Hustache). The model results were compared with the data from three different locations. For each data set, the simulated plant biomass, adult and larva populations were plotted against the 95% confidence intervals of the actual field observations. In many cases, the simulation results were within the 95% confidence intervals, and especially during the growing season, they indicated trends similar to those seen in the field data. However, there were …


Using Optimization And Simulation Techniques To Estimate Initial Weevil Populations, Kunter S. Akbay Jan 1991

Using Optimization And Simulation Techniques To Estimate Initial Weevil Populations, Kunter S. Akbay

Mechanical Engineering Faculty Research and Publications

In this paper, a mathematical programming and simulation method is used to estimate the number of weevils (Neochetina bruchi Hustache, and N. eichhorniae Warner) necessary to initialize the INSECT model which simulates the biological control of waterhyacinth by the weevils. The objective is to estimate the initial input values for the adult population so that the sum of the absolute differences between the observed and the simulated numbers of weevils is minimized. In general, the simulated values using the initial values obtained from the mathematical programming problem were within the 95% confidence intervals of the actual field observations. Also, in …


Space Structures: Issues In Dynamics And Control, H. Benaroya, Mark L. Nagurka Oct 1990

Space Structures: Issues In Dynamics And Control, H. Benaroya, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

A selective technical overview is presented on the vibration and control of large space structures, the analysis, design, and construction of which will require major technical contributions from the civil/structural, mechanical, and extended engineering communities. The immediacy of the U.S. space station makes the particular emphasis placed on large space structures and their control appropriate. The space station is but one part of the space program, and includes the lunar base, which the space station is to service. This paper attempts to summarize some of the key technical issues and hence provide a starting point for further involvement. The first …


Stress Interference In A Transversely Isotropic Body Under Axisymmetric Loading, Stephen M. Heinrich, J. Y. Wang Mar 1989

Stress Interference In A Transversely Isotropic Body Under Axisymmetric Loading, Stephen M. Heinrich, J. Y. Wang

Civil and Environmental Engineering Faculty Research and Publications

An unbounded homogeneous transversely isotropic body of revolution containing two twin spheroidal cavities is subjected to an axisymmetric loading. The axis of loading symmetry coincides with the axis of elastic symmetry of the material and the axis of revolution of the body. The elasticity solution is obtained in series form utilizing the displacement potential representation for the equilibrium of transversely isotropic solids, and numerical results are presented for the cases of two spherical cavities perturbing uniaxial and hydrostatic tension fields in certain hexagonal crystals and in isotropic materials. Of primary interest is the influence of cavity spacing and material type …


Cotgame: Cotton Insect Pest Management Simulation Game, Kunter S. Akbay, R.W. Mcclendon, L. G. Brown Sep 1988

Cotgame: Cotton Insect Pest Management Simulation Game, Kunter S. Akbay, R.W. Mcclendon, L. G. Brown

Mechanical Engineering Faculty Research and Publications

An interactive version of the Cotton and Insect Management (CIM) model was developed to aid individuals in improving their insect pest management decision making skills. This version, COTGAME, allowed the user to encounter situations and make decisions during the simulated cotton crop growing season. The intermediate results of these decisions were immediately delivered in the form of a report on the current status of the crop and insect populations. Based on the information presented in this status report, the user would make additional management decisions and take tactical actions. Once the harvest date had been reached, the economics of the …


Multistep Measurement Of Plantar Pressure Alterations Using Metatarsal Pads, An-Hsiung Chang, Ziad U. Abu-Faraj, Gerald F. Harris, Joe Nery, Michael J. Shereff Dec 1986

Multistep Measurement Of Plantar Pressure Alterations Using Metatarsal Pads, An-Hsiung Chang, Ziad U. Abu-Faraj, Gerald F. Harris, Joe Nery, Michael J. Shereff

Biomedical Engineering Faculty Research and Publications

Metatarsal pads are frequently prescribed for nonoperative management of metatarsalgia due to various etiologies. When appropriately placed, they are effective in reducing pressures under the metatarsal heads on the plantar surface of the foot. Despite the positive clinical reports that have been cited, there are no quantitative studies documenting the load redistribution effects of these pads during multiple step usage within the shoe environment. The objective of this study was to assess changes in plantar pressure metrics resulting from pad use. Ten normal adult male subjects were tested during a series of 400-step trials. Pressures were recorded from eight discrete …


On The Uniqueness Of Solution Of Magnetostatic Vector‐Potential Problems By Three‐Dimensional Finite‐Element Methods, O. A. Mohammed, W. A. Davis, B. D. Popovic, T. W. Nehl, Nabeel Demerdash Jan 1982

On The Uniqueness Of Solution Of Magnetostatic Vector‐Potential Problems By Three‐Dimensional Finite‐Element Methods, O. A. Mohammed, W. A. Davis, B. D. Popovic, T. W. Nehl, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In this paper, particular attention is paid to the impact of finite‐element approximation on uniqueness and to approximations implicit in finite element formulations from the uniqueness requirements standpoint. It is also shown that the flux density is unique without qualifications. The theoretical and numerical uniqueness of the magnetic vector potential in three‐dimensional problems is also given. This analysis is restricted to linear, isotropic media with Dirichlet Boundary conditions. As an interesting consequence of this analysis it is shown that, under usual conditions adopted in obtaining three‐dimensional finite‐element solutions, it is not necessary to specify div Ā in order that Ā …


Ceramic To Metal Bonding, Spencer A. Marrese Oct 1980

Ceramic To Metal Bonding, Spencer A. Marrese

Master's Essays (1922 - )

Various theories for ceramic to metal bonding are discussed. Theories prior to the mid-1960's are categorized as either mechanical or chemical in nature with the main emphasis being a bibliography of articles on the topic which have been listed as appendices. Current theories are discussed as they relate to a Battelle Memorial Institute study conducted in the late 1950's. Major factors affecting the ceramic-metal interfacial region, as related to surface or firing changes, are reviewed from current research.


Direct Observation Of Stacking Faults In Single Crystal T102 (Rutile) By Transmission Electron Microscopy, Michael R. Williams Jan 1970

Direct Observation Of Stacking Faults In Single Crystal T102 (Rutile) By Transmission Electron Microscopy, Michael R. Williams

Master's Essays (1922 - )

This study was undertaken to evaluate the stacking fault energy of single crystal rutile and to develop a model for the dislocation reaction.


Frictional Behavior Of Flat Sliding Surfaces, Elmer J. Weiter Aug 1957

Frictional Behavior Of Flat Sliding Surfaces, Elmer J. Weiter

Bachelors’ Theses

The objectives of this thesis are four in number. The first is to advance the basic understanding of the frictional behavior of materials in flat surface sliding, especially in the breakaway region where the coefficient of static friction is predominant. The second is to present an apparatus incorporating the use of flat contact surfaces, to provide accurate determination of the coefficient of static friction and some of the kinetic characteristics. The third is to establish a procedure of testing such that the static frictions is accurately analyzed to include variations with time and wear. The fourth objective is to establish …


Soft X-Rays, William F. Roherty Jun 1950

Soft X-Rays, William F. Roherty

Bachelors’ Theses

Traditionally, radiation of those wavelengths produced by a potential of from 2 to 25kv. has been classified as "Grenz" or "soft" x-rays. The peculiar property of this radiation is its low penetrating power. While being transparent to more energetic radiation, animal tissue and similar materials are sufficiently opaque to Grenz rays as to be studied in detail. Since the radiation is of the continuous type, it can be made soft enough to reveal any object, providing, of course, that the tube window and object medium be not opaque. Soft x-rays are produced in exactly the same manner as others, except …


Calibration Of Pearson Type Eagle Mounting Spectrograph Of 1.5 Meter Length With Grating Lines 15,000 Per Inch, James F. Sullivan May 1949

Calibration Of Pearson Type Eagle Mounting Spectrograph Of 1.5 Meter Length With Grating Lines 15,000 Per Inch, James F. Sullivan

Bachelors’ Theses

The spectrograph which has been calibrated is a Pearson modification of the Eagle mounting. It was originally built for industry but was never set up in a working condition nor was the dispersion of its grating ever calibrated. The ultimate purpose of this thesis was to fulfill the requirements, and to set up the conditions so that the spectrograph could be used for quantitative purposes. This included the measurement of the dispersion of lines performed by the grating, and the recognition of lines of the iron spectrum in order that a quantitative constant could be made.


8-Inch Gun Housing: Stresses In Side Walls And Rear Plate, Gerald W. Kinzelman Jun 1948

8-Inch Gun Housing: Stresses In Side Walls And Rear Plate, Gerald W. Kinzelman

Bachelors’ Theses

Mr. Phileas H. Girouard, Chief Engineer of the Bureau of Ordnance, Washington, D. C., requested the author of this thesis to determine whether the 8-inch gun housing would safely withstand the forces imposed. It is the purpose of the thesis to show the reasoning followed by the author in proving that the housing was acceptable as designed. Mr. Sidney Hersh assisted in the computations.

The solution to this problem was urgently required before a prototype could be built and tested. At a later date, and independently of the author, a prototype of the housing was tested under the direction of …