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Articles 8101 - 8130 of 11222

Full-Text Articles in Engineering

Acuta Enews June 1999, Vol.28, No. 6 Jun 1999

Acuta Enews June 1999, Vol.28, No. 6

ACUTA Newsletters

In This Issue

Winners Announced in Student Papers Contest

Conference Offers Many Choices

Dues Notices Mailed

Does It Make Sense?

Board Report

Share Your Expertise

DC at a Glance

Positions Available

Welcome New Members


Biodegradation Of Thermoplastic And Hermosetting Polyesters From Z-Protected Glutamic Acid, R M. Tadros, Hossein Noureddini, Delmar C. Timm Jun 1999

Biodegradation Of Thermoplastic And Hermosetting Polyesters From Z-Protected Glutamic Acid, R M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomolecular Engineering

In a previous article,1 the development and molecular characterization of three polyesters from N-carbobenzyloxy-L-glutamic acid (ZGluOH) were reported. The polymers were a linear, heterochain polyester (ZGluOH and ethylene glycol), a crosslinked heterochain polyester (ZGluOH and diglycidyl ether of 1,4-butanediol), and a crosslinked, heterochain aromatic polyester (ZGluOH and diglycidyl ether of bisphenol A). In this manuscript, results of biodegradation studies are reported. The three polymers hydrolyzed to low molecular weight oligomers similar to the monomers with lipase. When exposed to a mixed culture of micro-organisms, the first two resins degraded to biomass and respiratory gases. The crosslinked heterochain aromatic polyester resisted …


Z-Protected Glutamic Acid-Based Biodegradable Thermoplastic And Thermosetting Polyesters: Synthesis And Characterization, R. M. Tadros, Hossein Noureddini, Delmar C. Timm May 1999

Z-Protected Glutamic Acid-Based Biodegradable Thermoplastic And Thermosetting Polyesters: Synthesis And Characterization, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

Biodegradable polymers were formed from N-benzyloxycarbonyl-L-glutamic acid with the comonomers ethylene glycol, diglycidyl ether of 1,4-butanediol, and diglycidyl ether of bisphenol A. The three polymers were a linear and a cross-linked heterochain polyester and a cross-linked polyester that contained aromatic units within its network chains. The thermoplastic resin and the soluble fractions for the thermosetting resins were characterized by gel permeation chromatography. Conversions for carboxylic acid were determined by titrations. A quality, 22,000 molecular weight thermoplastic resin was formed. The two thermosets were cured past their gel points. Gelation analysis revealed that the relative rate constants for the sequential oxirane/acid …


Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander, Anuradha Subramanian May 1999

Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander, Anuradha Subramanian

Department of Chemical and Biomolecular Engineering: Patents

A method is disclosed for coupling a ligand within a porous support. The method involves mixing ligand and porous support under conditions sufficient to suppress coupling conditions of the ligand to the porous support while enhancing the relative rate of diffusion, to the rate of reaction, of the ligand into and within the porous support, and then altering the conditions to enhance rapid coupling of the ligand within the porous support. The alteration from diffusion conditions to coupling conditions involves a change in the reaction solution of pH, ionic strength, temperature, coupling competitor, such that a relatively lower Thiele Modulus …


Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander May 1999

Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

A method is disclosed for coupling a ligand within a porous support. The method involves mixing ligand and porous support under conditions sufficient to suppress coupling conditions of the ligand to the porous support while enhancing the relative rate of diffusion, to the rate of reaction, of the ligand into and within the porous support, and then altering the conditions to enhance rapid coupling of the ligand within the porous support. The alteration from diffusion conditions to coupling conditions involves a change in the reaction solution of pH, ionic strength, temperature, coupling competitor, such that a relatively lower Thiele Modulus …


Variable Angle Of Incidence Analysis Of Magneto-Optic Multilayers, William A. Mcgahan, Liang-Yao Chen, John A. Woollam May 1999

Variable Angle Of Incidence Analysis Of Magneto-Optic Multilayers, William A. Mcgahan, Liang-Yao Chen, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

We have applied the technique of variable angle of incidence spectroscopic ellipsometry (VASE) to the analysis of multilayered magneto-optic structures. With this instrument we measure the complete pseudodielectric tensor (diagonal and off-diagonal elements) for the sample of interest at variable angles of incidence. We have also developed computer software to perform a best-fit analysis of the measured data, providing optical constants, Voigt parameters, and layer thicknesses for the individual layers in the sample. Additionally, given an estimate of the material parameters, this software will provide an estimate of the optimum spectral range and angles of incidence for accurate characterization of …


Acuta Enews May 1999, Vol. 28, No. 5 May 1999

Acuta Enews May 1999, Vol. 28, No. 5

ACUTA Newsletters

In This Issue

Board Approves Slate of Nominees

Moderators & Monitors Needed in Nashville!

Board Report

Who Pays for Cellular Calls?

DC at a Glance

Positions Available

Welcome New Members


Directivity Patterns Of Acoustic Radiation From Bowed Violins, Lily M. Wang, Courtney B. Burroughs May 1999

Directivity Patterns Of Acoustic Radiation From Bowed Violins, Lily M. Wang, Courtney B. Burroughs

Durham School of Architectural Engineering and Construction: Faculty Publications

Directivity patterns of acoustic radiation have been measured in the far-field of a violin, excited with an open-frame mechanical bowing machine. Analysis of the directivity patterns confirms that, at frequencies below 600 Hz, the violin radiates omnidirectionally, while above 600 Hz, certain trends are apparent as the patterns become increasingly complex. It is noted that when different strings are excited, the far-field radiation patterns observed at nearly the same frequency are similar, even in higher frequency ranges where modal overlap is high. When the difference in frequency between two directivity patterns exceeds some fraction of a semitone, though, the measured …


Simulation Modeling Presentations: The Life Cycle, Edward Yellig, Paul Savory May 1999

Simulation Modeling Presentations: The Life Cycle, Edward Yellig, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

A typical large scale simulation modeling project spans many months and encompasses activities such as problem definition, data collection, model development, experimentation, and scenario analysis. During the life cycle of a simulation project, numerous presentations are made to many different types of audiences. The purpose of these presentations will vary from seeking project approval, requesting information, discussing simulation model features, verifying the model, validating the model, presenting the experimental results, and offering model conclusions. This paper will discuss presentation techniques we used during a year-long simulation-modeling project. We will highlight techniques used for defining the purpose of each presentation, identifying …


Direct Chip Attach For Low Alpha Emission Interconnect System, Ravi F. Saraf Apr 1999

Direct Chip Attach For Low Alpha Emission Interconnect System, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An interconnect system that has low alpha particle emission characteristics for use in an electronic device includes a semiconductor chip that has an upper surface and spaced apart electrically resistive bumps positioned on conductive regions of the upper surface, the electrically resistive bumps are made of a composite material of a polymer and metal particles, and a substrate that has conductive regions bonded to the electrically resistive bumps in a bonding process wherein the electrically resistive bumps convert to electrically conductive bumps after the bonding process.


In Situ Stem Technique For Characterization Of Nanoscale Interconnects During Electromigration Testing, Ismail Gobulukoglu, Brian W. Robertson Apr 1999

In Situ Stem Technique For Characterization Of Nanoscale Interconnects During Electromigration Testing, Ismail Gobulukoglu, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

A technique for observing microstructure and morphology changes during annealing or electromigration of 100 nm-scale and smaller interconnects is presented. The technique is based on dynamic in situ characterization using a UHV field-emission scanning transmission electron microscope (STEM) and can enable full microstructural characterization (images, diffraction patterns and compositions) during electromigration testing. Initial steps in the validation of the approach include in situ electron-beam OMCVD of Al-containing wires and observation of these wires. Although the deposition conditions were not optimized. Al-containing wires, with high edge acuity, thickness uniformity, and with minimum interconnect widths as small as 15 nm have successfully …


Mar 1999, Tractor Museum Mar 1999

Mar 1999, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Additional Funds Donation to Camp Creek Threshers Renovation Status


Transgenic Mammals Expressing Human Coagulation Factor Viii , William H. Velander Mar 1999

Transgenic Mammals Expressing Human Coagulation Factor Viii , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

A non-human transgenic mammalian animal, as described above, contains an exogenous double stranded DNA sequence stably integrated into the genome of the animal, which comprises cis-acting regulatory units operably linked to a DNA sequence encoding human Factor VIII protein and a signal peptide, where the cis-acting regulatory units are active in mammary gland cells and the signal peptide is active in directing newly expressed Factor VIII into the milk of the animal. The promoter may be a milk protein promoter such as for whey acidic protein, casein, lactalbumin, or beta-lactoglobulin promoter. The transgenic mammals are preferably farm animals, for example, …


Acuta Enews April 1999, Vol.28, No. 4 Mar 1999

Acuta Enews April 1999, Vol.28, No. 4

ACUTA Newsletters

In This Issue

Calling-Party-Pays Cellular to Get Legislative Push from Cellular Industry

Midwest Local Events

Achievements Award Nominations

Van Houweling to Speak on Internet2

Michael Zastrocky Described Enterprise 2004

Board Report

Near-TV-Quality Over Net

DC at a Glance

Positions Available

Welcome New Members


Acuta Enews March 1999, Vol.28, No. 3 Mar 1999

Acuta Enews March 1999, Vol.28, No. 3

ACUTA Newsletters

In This Issue

Austin Peay Survives Tornado

Nominate Now for Board of Directors

Tips to Make Your Presentation Better

President's Message

ACUTA Spring Seminars

Preparing Competitive Proposals

Board Report

DC at a Glance

Positions Available

Welcome New Members


Liquid-Phase Catalytic Oxidation Of Unsaturated Fatty Acids , Hossein Noureddini, M Kanabur Mar 1999

Liquid-Phase Catalytic Oxidation Of Unsaturated Fatty Acids , Hossein Noureddini, M Kanabur

Papers in Biomaterials

Liquid-phase catalytic oxidation of oleic acid with hydrogen peroxide in the presence of various transition metal/metal oxide catalysts was studied in a batch autoclave reactor. Azelaic and pelargonic acids are the major reaction products. Tungsten and tantalum and their oxides in supported and unsupported forms were used as catalysts. Alumina pellets and Kieselguhr powder were used as supports for the catalysts. Tungsten, tantalum, molybdenum, zirconium, and niobium were also examined as catalysts. Tertiary butanol was used as solvent. Experimental results concluded that tungsten and tungstic oxide are more suitable catalysts in terms of their activity and selectivity. The rate of …


A Mutant Of Chlamydomonas Reinhardtii With Reduced Rate Of Photorespiration, Kensaku Suzuki, Tarlan G. Mamedov, Toraoyoshi Ikawa Feb 1999

A Mutant Of Chlamydomonas Reinhardtii With Reduced Rate Of Photorespiration, Kensaku Suzuki, Tarlan G. Mamedov, Toraoyoshi Ikawa

Papers in Biochemical Engineering

Photorespiration rates under air-equilibrated conditions (0.04% CO2 and 21% O2) were measured in Chlamydomonas reinhardtii wild-type 2137, a phosphoglycolate-phosphatase-deficient (pgpl) mutant and a suppressor double mutant (7FR2N) derived from the pgpl mutant. In both cells grown under 5% CO2 and adapted air for 24 h in the suppressor double mutant, the maximal rate of photorespiration (phosphoglycolate synthesis) was only about half of that in either the wild type or the pgpl mutant (18-7F) cells. In the progeny, the reduced rate of photorespiration was accompanied by increased photosynthetic affinity for inorganic carbon and the capacity for growth …


Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf Feb 1999

Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electrically conductive paste which includes a thermoplastic polymer, a conductive metal powder and an organic solvent system is disclosed. The invention further encompasses an electrically conductive composite which includes the aforementioned thermoplastic and metal, wherein the metal represents at least about 30% by volume, based on the total volume of the composite. The composite is formed from the paste under elevated temperature. The paste is employed in processes which involve electrically connecting electrical and electronic components under process conditions which convert the paste to the composite.


Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf Feb 1999

Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electrically conductive paste which includes a thermoplastic polymer, a conductive metal powder and an organic solvent system is disclosed. The invention further encompasses an electrically conductive composite which includes the aforementioned thermoplastic and metal, wherein the metal represents at least about 30% by volume, based on the total volume of the composite. The composite is formed from the paste under elevated temperature. The paste is employed in processes which involve electrically connecting electrical and electronic components under process conditions which convert the paste to the composite.


Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf Feb 1999

Lead Free Conductive Composites For Electrical Interconnections, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electrically conductive paste which includes a thermoplastic polymer, a conductive metal powder and an organic solvent system is disclosed. The invention further encompasses an electrically conductive composite which includes the aforementioned thermoplastic and metal, wherein the metal represents at least about 30% by volume, based on the total volume of the composite. The composite is formed from the paste under elevated temperature. The paste is employed in processes which involve electrically connecting electrical and electronic components under process conditions which convert the paste to the composite.


Acuta Enews February 1999, Vol.28, No. 2 Feb 1999

Acuta Enews February 1999, Vol.28, No. 2

ACUTA Newsletters

In This Issue

Call for Nominations: ACUTA Board of Directors 1999-2000

Levine, McDonalds to Speak at Seminars

Network Challenges for the 21st Century

Overheard on the Listserve

Board Report

Distance Ed Institutes

DC at a Glance

Welcome New Members

Positions Available

A Leader Is a Big Thinker- The Magnet That Attracts Others


Bovine Follicular Dynamics, Oocyte Recovery,And Development Of Oocytes Microinjected With A Green Fluorescent Protein Construct, M S. Chauhan, S Nadir, T L. Bailey, A W. Pryor, S P. Butler, D R. Notter, William H. Velander, F C. Gwazdauskas Jan 1999

Bovine Follicular Dynamics, Oocyte Recovery,And Development Of Oocytes Microinjected With A Green Fluorescent Protein Construct, M S. Chauhan, S Nadir, T L. Bailey, A W. Pryor, S P. Butler, D R. Notter, William H. Velander, F C. Gwazdauskas

Papers in Biotechnology

The present study was carried out to 1) evaluate the viability of in vitro fertilized zygotes after microinjection of DNA, 2) assess the influence of oocyte quality upon the development rate of embryos when injected with DNA, and 3) determine the integration frequency of green fluorescent protein DNA into microinjected embryos. Oocytes were aspirated from ovaries of nine nonlactating Holsteins and were categorized into grades A, B, C, and D. At 16 h after in vitro fertilization, approximately half of the pronuclear stage presumptive zygotes were classified as having 1 pronucleus or 2 pronuclei, and they were microinjected with DNA …


Jan 1999, Tractor Museum Jan 1999

Jan 1999, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Museum Open House Officer Elections UN Museum


Method And Apparatus For Production Of Levulinic Acid Via Reactive Extrusion, Viswasrao Ghorpade, Milford Hanna Jan 1999

Method And Apparatus For Production Of Levulinic Acid Via Reactive Extrusion, Viswasrao Ghorpade, Milford Hanna

Industrial Agricultural Products Center: Publications and Information

The present invention relates to a continuous process for preparing levulinic acid from starch in a reactive extrusion process. In a preferred embodiment, the extrusion takes place in a twin-screw extruder having a plurality of temperature zones wherein the starch slurry is preconditioned, extruded, filter pressed, reboiled, vacuum distilled, condensed, centrifuged, whereby the waste effluent from the centrifugation is reprocessed upstream to the preconditioning stage.


Acuta Enews January 1999, Vol.28, No. 1 Jan 1999

Acuta Enews January 1999, Vol.28, No. 1

ACUTA Newsletters

In This Issue

High Priorities for '99

Board Report

Making Choices: ATM vs. Gigabit Ethernet

Overheard on the Listserve: Is VoIP for Me?

DC at a Glance

Positions Available

Welcome New Members

Universal Translations Service

Use Telephone Wires To Create a Household Network

Information, Please

High Speed Networking

ACUTA Member Needs Assessment: Members are Highly Satisfied with ACUTA Services


Compliance Testing Of Iowa’S Skid-Mounted Sign Device, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Dean L. Sicking Jan 1999

Compliance Testing Of Iowa’S Skid-Mounted Sign Device, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Dean L. Sicking

Mid-America Transportation Center: Final Reports and Technical Briefs

A wide variety of traffic control devices are used in work zones, some of which are nont ormally found on the roadside or in the traveled way outsideofthe work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Due to the placement of the traffic control devices, the devices themselves may be potentially hazardous to both workers and errant vehicles. The impact performance of many work zone traffic control devices is mainly unknown and to date limited crash testing has been conducted under the criteria of National Cooperative Highway …


Influence Of Aqueous And Solid-Phase Fe(Ii) Complexants On Microbial Reduction Of Crystalline Iron(Iii) Oxides, Matilde Urrutia, Eric E. Roden, John M. Zachara Jan 1999

Influence Of Aqueous And Solid-Phase Fe(Ii) Complexants On Microbial Reduction Of Crystalline Iron(Iii) Oxides, Matilde Urrutia, Eric E. Roden, John M. Zachara

United States Department of Energy: Publications

The influence of aqueous (NTA and EDTA) and solidphase (aluminum oxide, layer silicates) Fe(II) complexants on the long-term microbial reduction of synthetic goethite by Shewanella alga strain BrY was studied. NTA enhanced goethite reduction by promoting aqueous Fe(II) accumulation, in direct proportion to its concentration in culture medium (0.01-5 mM). In contrast, EDTA failed to stimulate goethite reduction at concentrations e1 mM, and 5 mM EDTA enhanced the final extent of reduction by only 25% in relation to nonchelator controls. The minor effect of EDTA compared to NTA, despite the greater stability of the Fe(II)- EDTA complex, likely resulted from …


Test 1895: Case Ih Cx 70/C 70 Diesel, Nebraska Tractor Test Lab Jan 1999

Test 1895: Case Ih Cx 70/C 70 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


Test 1894: Case Ih Cx 60/ C 60 Diesel, Nebraska Tractor Test Lab Jan 1999

Test 1894: Case Ih Cx 60/ C 60 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


Nebraska Summary: S296 New Holland Ts 110, Nebraska Tractor Test Lab Jan 1999

Nebraska Summary: S296 New Holland Ts 110, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …