Engineering Commons^™

Withdrawal Strength Of Ring-Shank Nails Embedded In Southern Pine Lumber, M J. Skulteti, D A. Bender, S G. Winistorfer, David Pollock

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Ring-shank nails are used extensively in post-frame construction due to their superior performance, yet surprisingly little testing has been done on nail sizes above 12d. Experience in the post-frame industry suggests that published allowable design values for ring-shank nails may be overly conservative and need revision. The goal of the research reported herein was to characterize the withdrawal strength of ring-shank nails embedded in Southern Pine lumber. Three sizes ofgalvanized and ungalvanized (bright) ring-shank nails from two manufacturers were studied. Ring-shank nails had approximately twice the withdrawal resistance of smooth-shank nails of the same diameter. Galvanizing slightly reduced withdrawal strength …

A Quantitative Method Of Measuring Cell-Substrate Adhesion Areas, R. G. Richards, G. Rh Owen, B. A. Rahn, I. Ap Gwynn

Cells and Materials

Variability in measurements of the 'cell adhesion strength' of fibroblasts to substrates using mechanical disruption techniques causes difficulty in determining precisely the position, in the cytoskeleton-focal adhesion-matrix -substrate interface, where failure has occurred. In the present study, a quantitative in vitro procedure for measuring the total area and percentage of fibroblast adhesion to biomaterials, using the scanning electron microscope (SEM), is described. The amount of adhesion ofL929 and Balb/c3T3 fibroblasts to discs of stainless steel, commercially pure titanium, and polyethylene terepthalate (Thermanox) was quantified. Cells were fixed, stained with heavy metals, dehydrated and embedded in resin. The resin blocks were …

Beta-Tricalcium Phosphate Resorption By Monocytes In Biphasic Calcium Phosphate: An In Vitro Study, Wolf Bohne, Jean A. Pouëzat, Dorothea Pouëzat, Guy Daculsi

Cells and Materials

A macroporous biphasic calcium phosphate (BCP) of 60.7% carbonated dense non-porous hydroxyapatite (HA)/39.3% dense microporous ß-tricalcium phosphate (ß-TCP) was immersed during 15 days in a supplemented a-MEM (minimal essential medium) solution with and without dog bone marrow cells obtained by punction. The aim of the study was to demonstrate the time-related changes in the BCP fractions by means of X -ray diffraction, infrared spectroscopy and scanning electron microscopy, and to investigate the cell populations. The HA/ß-TCP ratios varied according to immersion duration and cell presence. If any, there was a slight preponderance of ß-TCP …

Transmission Electron Microscopical Study Of Fibroblast Attachment To Microtextured Silicone Rubber Surfaces, E. T. Den Braber, J. E. De Ruijter, H. J. E. Croes, L. A. Ginsel, J. A. Jansen

Cells and Materials

Cellular attachment has been suggested to be highly influenced by the micromorphology of the substratum surface. To test this hypothesis, smooth and microtextured silicone substrata were produced, which possessed parallel surface grooves with a groove and ridge width of 2.0 (SilD02), 5.0 (SilD05), and 10 µm (SilD10). Groove depth was approximately 0.5 µm. After culture of rat dermal fibroblasts (RDFs) on these substrata for 3 and 5 days, the samples were prepared and sectioned for transmission electron microscopy with a specially developed preparation technique. On the SilD02 and SilD05 surfaces, it was found that the RDFs attached to …

Mechanism For Formation Of Lamellar Constituents In Grain-Refined Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, John C. Mitchell, Stanley G. Vermilyea

Cells and Materials

Grain-refined Pd-Cu-Ga dental alloys solidify with a lamellar microstructural constituent that affects a variety of clinically relevant properties. While formation of this constituent has been attributed to eutectic solidification, an alternative mechanism of discontinuous precipitation has been proposed. Using a representative grain-refined Pd-Cu-Ga dental alloy, casting procedures involving two different rates of solidification were used: (a) A standard thin-walled coping configuration for a metal-ceramic restoration was cast into a room temperature mold, followed by rapid quenching into an ice-water mixture. (b) A thin plate specimen was cast into a standard elevated-temperature mold, with the same subsequent rapid quenching procedure. Neither …

Biofilms In Dental Unit Waterlines: Ultrastructural And Cytochemical Analysis, J. Barbeau, C. Avezard, E. Faucher, S. Zalzal, A. P. Prévost

Cells and Materials

Dental unit waterlines are heavily colonized by bacteria which contaminate the water used to perform intra-oral, and sometimes invasive, procedures. There is little information on the nature of the biofilm colonizing the flexible plastic tubing used to supply water to the different handpieces. We have therefore undertaken quantitative microbial analysis and ultrastructural studies of these biofilms by direct counting with the epifluorescent filter technique and by transmission and scanning electron microscopy after staining with ruthenium red and periodic acid-thiosemicarbazide-silver proteinate to visualize the composition and the distribution of exopolysaccharides and intracellular polysaccharides. The biofilm was revealed as a non-uniform structure …

Maximum Individual & Vicinity-Average Dose For A Geologic Repository Containing Radioactive Waste, Thomas H. Pigford

RISK: Health, Safety & Environment (1990-2002)

Explains the basis for his strong dissent to an NAS report on Yucca Mountain.

Surface Modifying Additives Reduce Thrombogenicity: An In Vitro And Clinical Evaluation, H. T. Spijker, J. Haan, R. Graaff, P. W. Boonstra, W. Van Oeveren

Cells and Materials

To improve the biocompatibility of biomaterials a new surface treatment has been described based on the addition of polysiloxane containing copolymers to the base polymer resin (surface modifying additives). In an in vitro and a clinical study, we compared the thrombogenicity of polyvinyl chloride (PVC) to PVC with these surface modifying additives (SMA).

In the in vitro study, adsorption of thrombin and fibrinogen, binding of platelets and platelet release were measured on the tubing and were found reduced on SMA-PVC.

For the clinical study, we examined tubing material and blood collected after cardiopulmonary bypass (CPB). Onto the tubing, the binding …

Osteoclast Differentiation In Cocultures Of Chondrogenic Cell Line Rcj 3.1c5.18 And Mouse Or Rat Bone Marrow: Dependence On Culture Substrate And Association With Alkaline Phosphatase Positive Marrow Stromal Cells, G. I. Anderson, J. N. M. Heersche

Cells and Materials

We investigated the formation of tartrate-resistant acid phosphatase positive (TRAP+) colonies and multinucleated cells (MNCs) in rat and mouse marrow cultures alone and cocultured with the chondrogenic cell line, RCJ3.1C5.18 on different substrata. In mouse marrow cultured in 35 mm dishes, few TRAP+ MNCs developed, while in rat marrow cultures, many TRAP+ MNCs, which possessed calcitonin receptors and resorbed bone, developed. In both rat and mouse cultures, TRAP+ MNC first appeared at Day 4 and grew in number up to Day 8. When both marrows were cocultured with RC3.1C5.18 cells, TRAP+ colony numbers increased relative to marrow alone. In marrow …

English-Chinese Bilingual Database And The Compilation Of Dictionary, Gan Ye, Nanjing University

Pepperdine University Libraries

No abstract provided.

Multi-Criteria Optimization - An Important Foundation Of Fuzzy System Design, Hung T. Nguyen, Vladik Kreinovich

Departmental Technical Reports (CS)

In many real-life design situations, there are several different criteria that we want to optimize, and these criteria are often in conflict with each other. Traditionally, such multi-criteria optimization situations are handled in an ad hoc manner, when different conflicting criteria are artificially combined into a single combination objective that is then optimized. The use of unnatural ad hoc tools is clearly not the best way of describing a very natural aspect of human reasoning. Fuzzy logic describes a much more natural way of handling multi-criterion optimization problems: when we cannot maximize each of the original conflicting criteria 100%, we …

Computers Of Generation Omega, Vladik Kreinovich

Departmental Technical Reports (CS)

To make computers faster, we must take smaller and smaller processing elements, and to analyze these elements, we need to take into consideration more and more subtle quantum effects. A. Stern has shown a natural way to use quantum field theory for computing. It turns out that if we take into consideration all quantum effects, then this idea leads to an even faster performance.

Spider: An Overview Of An Object-Oriented Distributed Computing System, Han-Sheng Yuh

Theses Digitization Project

The Spider Project is an object-oriented distributed system which provides a testbed for researchers in the Department of Computer Science, CSUSB, to conduct research on distributed systems.

Design And Implemetation Of Internet Mail Servers With Embedded Data Compression, Alka Nand

Theses Digitization Project

No abstract provided.

Effect Of Length On Compressive Strain Softening Of Concrete, Daniel C. Jansen, Surendra P. Shah

Civil and Environmental Engineering

The concept of localization during the postpeak of compressive strain softening is presented. To explore localization in compression, a feedback-control method using a linear combination of displacement and force that partially subtracts the elastic response of the specimen to give a stable feedback signal is used. Results are presented from two test series (45 and 90 MPa) that use this method to test cylinders with length-to-diameter ratios ranging from 2.0 to 5.5. It is shown that compression failure is in fact a localized phenomenon. The compressive fracture energy is divided into energy dissipated in the prepeak and the postpeak portions …

Assessment Of Cased-Borehole Seals Using An Ultrasonic Method, Nazli Yesiller, Craig H. Benson, Tuncer B. Edil, James Klima

Civil and Environmental Engineering

Tests were conducted in Wisconsin from 1994 through 1996 in several boreholes using an ultrasonic method that was developed at the University of Wisconsin-Madison to assess the integrity of annular seals. Initially, three model boreholes simulating monitoring wells were installed to evaluate the effectiveness of the ultrasonic method. Different types of seals were placed around the casings and defects were purposely introduced in the seals to test the ultrasonic method. The ultrasonic method was effective for detecting the presence of different types of seals and defects and also the changes in the condition of seals with time. Then tests were …

Ultrastructural Observations Of Peri-Implant Mucosa Morphology Around Different Types Of Abutment In Humans, C. Piacentini, P. Lanzarini, R. Rodriguez Y Baena, S. Rizzo, C. Brusotti

Cells and Materials

Scanning electron microscopy (SFM) and transmission electron microscopy (TEM) were used to examine the morphological aspects of peri-implant mucosa around abutments of differing geometry (biconical and cylindrical) and of differing surface micromorphology. The samples were taken from seven patients who had undergone implant surgery at least one year prior to the study. In samples from biconical abutments, SEM of the sulcular epithelium showed that it consisted of flattened polygonal cells with a surface resembling a honeycomb. Superficial desquamation was rarely found. In contrast, in the samples from cylindrical abutments, the sulcular epithelium showed extensive desquamation and surface irregularity, but not …

Fractals, Surface Roughness, And Fracture Toughness Of Dental Composite And Unfilled Resin Fracture Surfaces, James L. Drummond

Cells and Materials

The intent of this project was to evaluate whether or not there exists a correlation between fractal dimension, surface roughness, and fracture toughness of an unfilled resin and a filled composite. The fracture surfaces of the unfilled resin and the filled composite were examined using atomic force microscopy (AFM) and a surface roughness measuring device. The specimens examined were aged in distilled water or air at 37°C for up to 12 months. Line scans of 1.4 µm for the atomic force microscope and 0.25 mm for the surface analyzer across the fracture surface were conducted on each specimen. Comparisons …

Bone Marrow Cell Colonization Of, And Extracellular Matrix Expression On, Biodegradable Polymers, C. E. Holy, M. S. Shoichet, J. E. Davies

Cells and Materials

Poly(DL-lactide-co-glycolide)s (PLGAs) have been proposed as substrata for bone tissue engineering. In the experiments reported herein, we sought to identify the optimum lactide to glycolide ratio, from the series 85:15, 75:25, 50:50, or poly-(DL-lactide) (PLA), for the elaboration of bone matrix by cultured rat bone marrow cells (RBMC) on two-dimensional substrates. Having identified PLGA 75:25 as the optimum for bone matrix elaboration by RBMC, we produced three dimensional foams from this copolymer. For the two dimensional substrata, glass coverslips were spin-coated with one of the PLGAs, or PLA. Cultures were maintained for two weeks. We employed a new technique to …

Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai

Faculty Publications

Multilevel block coded modulation (BCM) schemes with unequal error protection (UEP) are investigated. These schemes are based on unconventional set partitions that greatly reduce the error coefficients associated with multi-stage decoding of conventional BCM, at the expense of smaller intra-set distances.

Anatomy Of A Strike: Waterford Glass 1990, Eddie Conlon

Conference papers

No abstract provided.

Characteristic Of A Broadband Ti:Linbo3, Optical Modulator With Buried Electrodes And Etched Grooves In The Buffer Layer, Jinyang Hu, Boyu Wu, Xiaomin Jin

Electrical Engineering

Traveling wave Ti:LiNbO₃ Mach-Zehnder optical modulators with buried electrodes and etched grooves in the SiO₂ buffer layer are analyzed by the finite element method. The tradeoff between the bandwidth BW and the half-wave voltage Vπ is discussed. The value of BW/V_π is used to weight the total performance of the modulator. Taking a thick buffer layer and etching deep grooves in the buffer layer are demonstrated as two effective methods to improve the performance of the modulator. A 3-dB optical bandwidth of 18 GHz with half-wave voltage 5V at a wavelength of 1.55 pm could be obtained …

The Airline Quality Rating 1997, Brent Bowen, Dean Headley, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 97-9

The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline performance on combined multiple factors important to consumers. Development history and calculation details for the AQR rating system are detailed in The Airline Quality Rating 1991 issued in April, 1991, by the National Institute for Aviation Research at Wichita State University. This current report, Airline Quality Rating 1997, contains monthly Airline Quality Rating scores for 1996. Additional copies are available by contacting Wichita State University or University of Nebraska at Omaha. The Airline Quality Rating 1997 is …

American "Kaizen" - A Perspective On American Management Theories, Kurt Henry Becker, J. Snow

Engineering Education Faculty Publications

No abstract provided.

Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai

Faculty Publications

The error performance of bandwith-efficient concatenated multilevel coded modulation (MCM) schemes for digital satellite broadcasting is analyzed. Nonstandard partitioning, multistage decoding, and outer Reed-Solomon (RS) codes are employed to provided unequal error protection capabilities.

A Lagrangian Dispersion Model For Predicting Co2 Sources, Sinks, And Fluxes In A Uniform Loblolly Pine (Pinus Taeda L.) Stand, Gabriel Katul, Ram Oren, David Ellsworth, Cheng-I Hsieh, Nathan Phillips, Keith Lewin

United States Department of Energy: Publications

A canopy Lagrangian turbulent scalar transport model for predicting scalar fluxes, sources, and sinks within a forested canopy was tested using CO₂ concentration and flux measurements. The model formulation is based on the localized near-field theory (LNF) proposed by Raupach [1989a, b]. Using the measured mean CO₂ concentration profile, the vertical velocity variance profile, and the Lagrangian integral timescale profile within and above a forested canopy, the proposed model predicted the CO₂ flux and source (or sink) profiles. The model testing was carried out using eddy correlation measurements at 9 m in a uniform 13 m tall …

The Agricultural Health Study: Factors Affecting Completion And Return Of Self-Administered Questionnaires In A Large Prospective Cohort Study Of Pesticide Applicators, Robert Tarone, Michael Alavanja, Sheila Hoar Zahm, Jay Lubin, Dale Sandler, Suzanne Mcmaster, Nathaniel Rothman, Aaron Blair

United States Environmental Protection Agency: Publications

Response rates were examined in a prospective epidemiologic study of individuals, mostly farmers, from Iowa and North Carolina seeking a pesticide applicator license during the period from 1994 through 1996. In the first year of enrollment 16,535 farmers (representing 77% of eligible farmer applicators) enrolled in the study by completing a 17-page questionnaire administered at a pesticide training session; 47% of the enrolled farmers completed and returned a much longer take-home questionnaire. The characteristics of farmers who completed only the enrollment questionnaire were quite similar to those of farmers who also completed and returned the take-home questionnaire. The most notable …

Quantitation Reference Compounds And Voc Recoveries From Soils By Purge-And-Trap Gc/Ms, Brian Schumacher, Steven Ward

United States Environmental Protection Agency: Publications

Unquantified volatile organic compound (VOC) losses occur in every phase of VOC determination including sample collection, transport, storage, preparation, and analysis. Current quality assurance/quality control measures, such as surrogate spikes and internal standards, do not account for losses that occur during sample handling nor do they account for soil matrix effects. An alternate approach, the quantitation reference compound (QRC) approach, is presented that involves direction injection of the QRCs onto the soil matrix to account for any matrix effects and losses during subsequent processing steps prior to sample analysis. Final VOC quantitation is based on the QRC instead of the …

A Cell Model For Ductile Fracture With Applications, C. Fong Shih, Li Cheng, J. Faleskog, Xiaosheng Gao

Mechanical Engineering Faculty Research

No abstract provided.

An Investigation Of The Hydrodynamic Effects Of Enteromorpha Clathrata Fouling On Hydrofoils, Brian J. Collino

Master's Theses - Daytona Beach

The purpose of this investigation was to determine the effects of biological fouling on hydrofoils. NACA 4412 and 4415 hydrofoil models with 6 inch chord and 8 inch span were used in this study. A water tunnel facility was designed and constructed to perform the tests, and the results were verified using computational fluid dynamic modeling. The CFD software package Fluent was used to create a two dimensional model of the water tunnel test section and hydrofoil. The model was meshed using a Laplacian grid smoothing technique that forced the structured grid lines to follow the same approximate contour as …