Mechanical properties of neat polymer matrix materials and their unidirectional carbon fiber-reinforced composites

The mechanical properties of two neat resin systems for use in carbon fiber epoxy composites were characterized. This included tensile and shear stiffness and strengths, coefficients of thermal and moisture expansion, and fracture toughness. Tests were conducted on specimens in the dry and moisture-saturated states, at temperatures of 23, 82 and 121 C. The neat resins tested were American Cyanamid 1806 and Union Carbide ERX-4901B(MPDA). Results were compared to previously tested neat resins. Four unidirectional carbon fiber reinforced composites were mechanically characterized. Axial and transverse tension and in-plane shear strengths and stiffness were measured, as well as transverse coefficients of thermal and moisture expansion. Tests were conducted on dry specimens only at 23 and 100 C. The materials tested were AS4/3502, AS6/5245-C, T300/BP907, and C6000/1806 unidirectional composites. Scanning electron microscopic examination of fracture surfaces was performed to permit the correlation of observed failure modes with the environmental test conditions

Static tensile and tensile creep testing of five ceramic fibers at elevated temperatures

Static tensile and tensile creep testing of five ceramic fibers at elevated temperature was performed. J.P. Stevens, Co., Astroquartz 9288 glass fiber, Nippon Carbon, Ltd., (Dow Corning) Nicalon NLM-102 silicon carbide fiber, and 3M Company Nextel 312, 380, and 480 alumina/silica/boria fibers were supplied in unsized tows. Single fibers were separated from the tows and tested in static tension and tensile creep. Elevated test temperatures ranged from 400 to 1300 C and varied for each fiber. Room temperature static tension was also performed. Computer software was written to reduce all single fiber test data into engineering constants using ASTM Standard Test Method D3379-75 as a reference. A high temperature furnace was designed and built to perform the single fiber elevated temperature testing up to 1300 C. A computerized single fiber creep apparatus was designed and constructed to perform four fiber creep tests simultaneously at temperatures up to 1300 C. Computer software was written to acquire and reduce all creep data

Airspeed Measurements

This paper presents the results of a research project initiated as part of an ASCI 309 EV Home- Aerodynamics class held on Tuesday evenings during the 11/W1 term. The objective was to measure the airspeed of an automobile using techniques commonly used to measure the airspeed of light aircraft. The outcome of the recently completed project can form the basis for a research project for the next ASCI 309, ASCI 310, ASCI 509, or ASCI 510 course. It should be noted that use is made of material presented in the prerequisite courses: Math 112-Calculus (partial derivatives of multivariate functions), Math 211-Statistics (calculations of the mean and variance), and Phys 102-Physics (Conservation of Energy, Fluid Mechanics, and unit conversions) which lets the student consolidate and apply previously unrelated knowledge

Resolving the Issue of How Reliability is Related to Statistical Power: Adhering to Mathematical Definitions

Reliability in classical test theory is a population-dependent concept, defined as a ratio of true-score variance and observed-score variance, where observed-score variance is a sum of true and error components. On the other hand, the power of a statistical significance test is a function of the total variance, irrespective of its decomposition into true and error components. For that reason, the reliability of a dependent variable is a function of the ratio of true-score variance and observed-score variance, whereas statistical power is a function of the sum of the same two variances. Controversies about how reliability is related to statistical power often can be explained by authors’ use of the term “reliability” in a general way to mean “consistency,” “precision,” or “dependability,” which does not always correspond to its mathematical definition as a variance ratio. The present note shows how adherence to the mathematical definition can help resolve the issue and presents some derivations and illustrative examples that have further implications for significance testing and practical research

Water Issues That Affect Affordability And Safety In A Community: The Camden Ohio Experience

This study describes the trials and tribulations of an Ohio township involved in maintaining utility rates at an affordable level while dealing with salt intrusion in drinking water wells that supply the Village. Emphasis is on the political, regulatory, and financial issues faced by management. This research deals exclusively with utility rate and water supply issues within the Village of Camden in Ohio when salt is discovered in the fresh water system. The analysis also discusses affordability as village officials decide whether to improve the existing well field, develop a new well field, or purchase water from an alternative supply

Strain energy release rate as a function of temperature and preloading history utilizing the edge delamination fatique test method

Static laminate and tension-tension fatigue tests of IM7/8551-7 composite materials was performed. The Edge Delamination Test (EDT) was utilized to evaluate the temperature and preloading history effect on the critical strain energy release rate. Static and fatigue testing was performed at room temperature and 180 F (82 C). Three preloading schemes were used to precondition fatigue test specimens prior to performing the normal tension-tension fatigue EDT testing. Computer software was written to perform all fatigue testing while monitoring the dynamic modulus to detect the onset of delamination and record the test information for later retrieval and reduction

Last Georgic, or James Grahame’s Revision of Eighteenth-Century Rural Labour

No abstrac

Collaborating with library staff: opportunities for technical communicators

Poster session presented at the International Professional Communication Conference, October 1-3, 2007, Seattle, Washington

First Record and Habitat Notes for the Genus Lightiella (Crustacea, Cephalocarida, Hutchinsoniellidae) from the British Virgin Islands

The crustacean class Cephalocarida, as currently understood, is comprised of five genera and ten species (Hessler and Elofsson 1996, Hessler and Wakabara 2000). Although in some instances numerous specimens have been collected in a single locale (e.g., the nearly 120 specimens of Lightiella incisa Gooding, 1963 from Puerto Rico studied by Sanders and Hessler (1964), and the numerous specimens of Hutchinsoniella macracantha Sanders, 1955 now known from Buzzards Bay, Massachusetts, see Hessler and Sanders 1973:193), most reports are based on very few specimens. For example, the original description of the genus Hutchinsoniella Sanders, 1955 was based on only eight specimens from Long Island Sound, New York (Sanders 1955); the genus Sandersiella was originally described by Shiino (1965) on the basis of only one specimen from Japan; the genus Chiltoniella Knox and Fenwick, 1977 was based on two specimens from New Zealand (Knox and Fenwick 1977), and the genus Lightiella Jones, 1961 was based on seven specimens from San Francisco Bay (Jones 1961). Lightiella moniotae was described for a single individual from New Caledonia (Cals and Delamare-Deboutteville 1970); Sandersiella calmani for two specimens from Peru (Hessler and Sanders 1973); and Sandersiella bathyalis for two specimens from the deep ocean off southwest Africa (Hessler and Sanders 1973). The single eastern Caribbean record (Barbados) of a cephalocarid also was based on two specimens (Gooding 1963), although Gooding also discussed two specimens from Puerto Rico in that account. Cephalocarids are of such interest morphologically and phylogenetically, and are found so infrequently, that their presence anywhere is noteworthy. As part of an ongoing survey of the cryptic marine invertebrates of certain Caribbean islands, we obtained a single specimen of a cephalocarid from Guana Island, British Virgin Islands, that matches most closely the description by Gooding (1963) of L. incisa. The find is of interest not only because it is the first record for the far eastern Caribbean other than Gooding’s (1963) two type specimens from Barbados, but also because of the unusual habitat in which it was found