Engineering Commons^™

Evaluation Of Several Maintenance Methods For Continuously Reinforced Concrete Pavements, Eldon J. Yoder

JTRP Technical Reports

No abstract provided.

An Investigation Of Recycling Bituminous Pavements, Volume 1 : Interim Report, James L. Mckinney

JTRP Technical Reports

No abstract provided.

The System Mgo‐Mgcl2‐H2o At 23°C, Ladawan Urwongse, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Solubilities of MgO in aqueous HC1 solutions at 23°±3°C were measured and combined with analyses of neat magnesium oxychloride cements, cured in sealed containers, to construct an equilibrium phase diagram for the system MgO‐MgCl2‐H₂O. Specific gravities and acidities of solutions saturated with MgO and relative humidities of vapor phases over sealed samples were measured and combined with XRD data to define the compositions in equilibrium with two crystalline phases. Studies of relative reaction rates indicated that the 5–1–8 phase crystallizes more rapidly than the 3·1·8 phase and that cements near the 3·1·8 composition react rapidly with atmospheric CO …

Phase Relations In Magnesium Oxysulfate Cements, Ladawan Urwongse, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Solubilities of MgO in H₂SO₄ solutions were measured and X‐ray analyses of over 100 neat cement samples were used to construct an isothermal phase diagram for the system MgO‐H₂SO₄‐H₂O at 23°±3°C. The phases MgO, Mg(OH)₂, 3Mg(OH)₂ MgSO₄·8H₂O (3·1·8), MgSO₄·7H₂O, MgSO₄·6H₂O, and MgSO₄·H₂O were stable at 23°C. The phases Mg(OH)₂· MgSO₄·5H₂O (1·1·5) and MgSO₄·4H₂O were observed but are considered to be metastable, resulting …

Interframe Television Coding Using Gain And Displacement Compensation, J. A. Stuller, A. N. Netravali, J. D. Robbins

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Presents Algorithms for Predicting Luminance Changes in Successive Television Frames. the Changes Can Result When Objects in a TV Scene Move or When Illumination Varies. by a Gradient Search Technique, Which Seeks to Minimize a Functional of the Interframe Prediction Error, We Estimate Two Parameters Associated with These Luminance Changes—displacement and Gain. using the Estimates of These Parameters, We Also Develop, for Interframe Coding, Adaptive Predictors and a Segmentor to Determine Which Pels Need to Be Transmitted. We Describe Several Coder Variations and Compare Them by Computer Simulations using Three Substantially Different Scene Sequences. for These Sequences, Gain …

County Road Management - Guidelines For Boards Of County Commissioners, Jean E. Hittle

Indiana Local Technical Assistance Program (LTAP) Publications

The purpose of these guidelines is to provide new County Commissioners in Indiana with a basic orientation of their duties and responsibilities in the management of county road systems. It is also a convenient reference to review.

Influence Of Interposed Ventilation Pressure Upon Artificial Cardiac Output During Cardiopulmonary Resuscitation In Dogs, Charles F. Babbs, W D. Voorhees, K R. Fitzgerald, H R. Holmes, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

This study was conducted to determine the effects of high pressure interposed ventilations during cardiopulmonary resuscitation (CPR). Cardiac output was measured by a modified indicator dilution technique in eight anesthetized, intubated mongrel dogs. Positive pressure ventilations (12/min, 80% O2) were interposed after every five chest compressions (performed at 62/min) by a mechanical chest compressor (Thumper®). On repeated trials in the same animal, ventilation pressures from 10-50 cm of H2O were tested in randomized sequence, while the technique of chest compression was held constant. Arterial blood gases immediately after resuscitation were monitored. Increasing ventilation pressure had surprisingly little effect on cardiac …

Evaluation Of The Operating Internal Resistance And Capacitance Of Intact Trapezoidal Waveform Defibrillators, Charles F. Babbs, Sj Whistler, La Geddes

Weldon School of Biomedical Engineering Faculty Publications

No abstract provided.

Regional Blood Flow During Cardiopulmonary Resuscitation In Dogs, W D. Voorhees, Charles F. Babbs, W A. Tacker

Weldon School of Biomedical Engineering Faculty Publications

To determine differences in regional blood flow during cardiopulmonary resuscitation (CPR) versus normal cardiac function, we measured regional blood flow to sev~ral organs in 19 pentobarbital-anesthetized dogs (6-12 kg). Regional blood flow was measured during sinus rhythm in 5 dogs and during electrically induced ventricular fibrillation with CPR in the other 14 dogs. Regional blood flow and cardiac output were measured using radioactively labelled polystyrene microspheres of 15 ±3P diameter, injected into the left ventricle. Adequacy of microsphere mixing at low cardiac outputs was verified by comparing flow rates to paired organs. Cardiac output was 175 ml/kg/min during sinus rhythm …

Therapeutic Indices For Transchest Defibrillator Shocks: Effective, Damaging, And Lethal Electrical Doses, Charles F. Babbs, Willis A. Tacker, John F. Vanvleet, Joe D. Bourland, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

Although prospective studies of defibrillator shock overdose cannot be performed in man, the therapeutic indices of various defibrillating current waveforms can be measured in animals. We determined the ratios TD50/ED50 and LD50/ ED50 (where TD50 = median "toxic" or damageinducing dose, ED50 = median effective or defibrillating dose, and LD50 = median lethal dose) as measures of the therapeutic index for damped sine wave defibrillator shocks in dogs. Death of an animal and/or any degree of cardiac damage found by gross or microscopic examination were defined as harmful effects of shock, analogous to drug toxicity. In terms of peak current, …

An Animal Model For Testing Automatic Defibrillators, J D. Bourland, Charles F. Babbs, W A. Tacker, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

A promising therapy for ventricular fibrillation--a life-threatening cardiac arrhythmia--is the implantation of an automatic defibrillator. A critical component of such a device is the system that detects the presence of ventricular fibrillation. Automatic systems for detecting ventricular fibrillation have been tested with arrhythmias produced by electric shocks in normal canine hearts, but have not been tested with spontaneous arrhythmias in hyperirritable hearts. We have developed an animal model to create arrhythmias without electrical stimulation and have used it to test our automatic defibrillator. This model permits evaluation of both reliability to diagnose ventricular fibrillation and reliability to reject other tachyarrhythmias.

A New Technique For Repeated Measurement Of Cardiac Output During Cardiopulmonary Resuscitation, L A. Geddes, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

We have developed a method for measurement of cardiac output during CPR with ventricular fibrillation. The method avoids the problems encountered when conventional techniques are used under the conditions of very low cardiac output. The method consists of injecting 5% saline as the indicator into the left ventricle and detecting its appearance in the descending aorta by withdrawing blood through an electrically calibrated conductivity cell. The adequacy of indicator mixing has been verified by obtaining dilutions curves simultaneously from the brachial and femoral arteries. Cardiac output can be determined even when output is as low as 7 ml/min/kg during CPR …

Influence Of Adrenergic Drugs Upon Vital Organ Perfusion During Cpr, H R. Holmes, Charles F. Babbs, W D. Voorhees, W A. Tacker, B De Garavilla

Weldon School of Biomedical Engineering Faculty Publications

To determine whether adrenergic drugs administered during cardiopulmonary resuscitation (CPR) alter the distribution of artificial card:l.ac output, we measu"red regional blood flow and cardiac output using radioactive microspheres in 12 dogs. Ventricular fibrillation was induced electrically and CPR was immediately begun with a mechanical chest compressor and ventilator (Thurn per ( R) ) at 60 compressions/min, with a ventilation:compression ratio of 1:5, a compression duration of 0.5 sec, and a ventilation pressure of 20 em H 2 o. Compression force was sufficient to develop 40-50 mmHg peak intraesophageal pressure. After 30 sec of CPR, either 0.9% saline vehicle or 50 …

Dependence Of Defibrillation Threshold Upon Extracellular/Intracellular K+ Concentrations, Charles F. Babbs, S J. Whistler, G Yim, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

The effect of increasing extracellular potassium concentration (K_o) upon electrical ventricular defibrillation threshold was investigated in pentobarbital anesthetized dogs treated with intravenous potassium chloride. Defibrillation threshold fell during potassium intoxication. The percent decrease in defibrillation threshold was linearly related to the logarithm of K_o and to the potassium equilibrium potential, E_K, calculated from measured extracellular and intracellular potassium concentrations of ventricular muscle. In dogs supported by left ventricular bypass in order to maintain the circulation during potassium intoxication, the values of K_o and E_K required for spontaneous, K⁺ induced defibrillation (electrical defibrillation …

Dynamic Intraesophageal Imagining Of The Heart With Ultrasound, N E. Fearnot, Charles F. Babbs, J D. Bourland, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

Real-time images of the heart from within the esophagus are produced by a new intraesophageal ultrasonic sector scanner. Sixty images per second are displayed on a gray scale CRT in real-time and recorded on standard videotape for review. By interactive positioning of the esophageal probe, heart ventricles, atria, and valves can be visualized and their dynamics can be studied. The esophageal probe comprises four 5 MHz PZT-5 piezoelements of 6.35 mm diameter, mounted on a shaft that rotates at 900 rpm. The piezoelements are pulsed at a 5 kHz rate and the echoes are processed electronically.

New Versus Old Theories Of Blood Flow During Cpr, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Today, the physiology of blood flow during external chest compression appears more complicated than had previously been imagined. New evidence requires that at least two possible mechanisms be considered for generating artificial circulation by external chest compression. The first is the classical mechanism in which the heart propels blood because it is squeezed between the sternum and the spine. The second is a more recently appreciated mechanism in which the entire thorax acts as a pump because of global intrathoracic pressure changes. The first might be called the cardiac pump mechanism and the second might be called the thoracic pump …

The Effects Of Added Softening Agents Upon The Behavior Of Cold Recycled Asphalt Mixtures : Interim Report, Akio Iida

JTRP Technical Reports

No abstract provided.

The Fabric Of A Medium Plastic Clay Compacted In The Laboratory And In The Field : Interim Report, Dean Matthews White

JTRP Technical Reports

No abstract provided.

Additives To Control Slaking In Compacted Shales : Interim Report, Mariappa Surendra

JTRP Technical Reports

No abstract provided.

Electronic Properties Of Metal Chloride Intercalants Of Graphite*, **, John A. Woollam, M. B. Dowell, A. Yavrouian, A. G. Lozier, G. Matulka

Department of Electrical and Computer Engineering: Faculty Publications

The Shubnikov-deHaas (SdH) effect has been used to study the electronic properties of graphite intercalated with PdC1₂ (stage 3), FeC1₃ (stages 2, 4, 6, and 11), CuC1₂ (stage 1), and WC1₆ (stage 5). For the palladium chloride, ferric chloride, and copper chloride intercalants the SdH spectra are similar: these show frequencies of approximately, 27, 80, 380, and 550 Tesla for fields parallel to the c-axis. The effective masses have been measured for each of these carriers, and are of the order of 0.1 m₀, where m₀ is the free electron mass. These carriers …

Missouri National Recreational River Nebraska And South Dakota General Design

United States Army Corps of Engineers, Omaha District

The purpose of this document is to serve as a general design memorandum (GDM) that provides the basic data and delineates the general procedure for implementation of the authorized project. This document provides an extension of the conceptual management program identified in the Management Plan and provides an update of the project cost estimate from 1978 to 1980 price levels.

General scopes of work, based on information available from ongoing studies is presented for recreation, cultural, visual, and fish and wildlife resources and for the bank preservation program.

The other resources outlined in the Management Plan, though not considered essential …

Final Environmental Impact Statement Missouri National Recreational River Nebraska And South Dakota

United States Army Corps of Engineers, Omaha District

The Missouri River from Gavins Point Dam to Ponca State Park, Nebraska, is one of the few remaining relatively natural, braided reaches of the Missouri River. The Corps of Engineers and the Heritage, Conservation, and Recreation Service have investigated public concerns related to streambank erosion control and recreational development along this river reach. Two plans were initially considered and one was selected for detailed study. The selected plan consists of development of the river reach as a recreation river under the Wild and Scenic Rivers Act. This plan would meet all streambank erosion control and recreational development needs and would …

Flora And Fauna A Biliography With Abstracts Or Partial Summaries

United States Army Corps of Engineers, Omaha District

The Missouri River from Gavins Point Dam to Ponca State Park, Nebraska was designated, on 10 November 1978, a National Recreational River. The purpose of the designation is to preserve and protect the river reach and to make its resources available for public use.

The Secretary of the Interior has been mandated to administer the river. Acting through the Assistant Secretary for Fish, Wildlife, and Parks, the Secretary of the Interior has entered into a written cooperative agreement with the Secretary of the Army (acting through the Chief of Engineers) to provide for construction and maintenance of erosion control work …

Design Of Vegetative Filters For Feedlot Runoff Treatment In Humid Areas, D. H. Vanderholm, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The vegetative filter approach uses overland flow or shallow channelized flow to treat feedlot runoff by infiltration, dilution and filtration. Based on extensive monitoring of four field systems in Illinois over a two year period, acceptable performance standards were selected. Design criteria to meet the standards were developed for both the overland flow vegetative filters and the channelized or serpentine terrace filters. A major design criterion for both types of vegetative filters is the time required for applied runoff to flow the length of the filter.

An alternative to using zero-discharge treatment systems to control feedlot runoff is to replace …

Home Sewage Treatment Systems, Elbert C. Dickey, Robert P. Pharris, Phillip W. Harlan, Gary Hosek

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Homeowners in areas not served by municipal sewage treatment systems face a problem of providing safe and effective wastewater treatment systems for their homes.

There are several methods currently available for proper treatment of home sewage, including septic tank absorption fields, mounds, lagoons, aerobic treatment units and others. These systems and their advantages and disadvantages are discussed in this NebGuide.

Treatment and disposal of domestic sewage is of concern because of the variety of pathogenic organisms contained in sewage. These include bacteria, viruses, and other microorganisms that come from the digestive tract, respiratory tract, and skin of man. Some of …

Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The Water and Power Resources Service is considering dredging in Black Canyon to create a larger forebay to accommodate higher peak discharges and reverse flows for proposed modifications to Hoover Dam. The Black Canyon area from Hoover Dam to Willow Beach supports a heavily utilized trout fishery and is important habitat for the razorback sucker (Xyrauchen texanus) and possibly bonytail chub (Gila elegans). The Water and Power Resources Service initiated this investigation to determine what effect dredging and higher peak-discharges would have on the ecology of Black Canyon.

The Dufour Effect. Iii. Direct Experimental Determination Of The Heat Of Transport Of Carbon Tetrachloride-Cyclohexane Liquid Mixtures, Richard L. Rowley, Frederick H. Horne

Faculty Publications

The heat of transport of carbon tetrachloride-cyclohexane liquid mixtures has been determined directly by Dufour effect experiments. The technique employs a withdrawable ''liquid gate'' to create a nonturbulent, sharp diffusional interface. The partial differential equations governing the barycentric velocity, composition, and temperature distributions are solved with a Crank-Nicholson implicit numerical scheme. This allows inclusion of the composition and temperature dependence of the thermodynamic and transport parameters. For mean mole fraction of carbon tetrachloride x1 between 0.34 and 0.55 and for mean temperature T between 295.13 and 296.43 degreesK, the best least squares fit of the data for the heat of …

Evaluation Of Available Herbicides And Herbicide Mixtures For Control Of Brush And Milkweed Along Roadsides : Interim Report, D. James Morré

JTRP Technical Reports

No abstract provided.

Computer Assisted Instruction Wood Identification Program, Dave Moyer

Graduate Research Papers

In the development of wood identification skills, certain factors are important. These include: mastery of both terminology and technique, repetitive practice experiences, and an individualized approach in both guidance and feedback to the learner. The use of the computer as a programmed instructional aid provides for an individualized approach to learning, simulated teacher-student interaction, and feedback and reinforcement to stimulate learning. The problem of this activity is to develop a computer assisted instructional program to enable the learning of techniques for identifying selected samples of hardwoods.

Acuta Enews December 1979, Vol. 8, No.12

ACUTA Newsletters

In This Issue

THE 1980'S: A TELECOMMUNICATION OPPORTUNITY

BITS & PIECES

THE USER'S CHOICE

COMMUNICATIONS SYSTEMS FOR EXTENDED CONTROL