A hedonic model of lamb carcass attributes

Lamb carcass value is widely reported to be a function of lean meat yield, which is the relationship between muscle, fat and bone. Five retailers and five wholesalers assessed 47 lamb carcasses from diverse genotypes and scored seven attributes. A hedonic model reveals that conformation attributes were more highly valued (16 c/kg) relative to yield characteristics (4 c/kg). Meat colour and fat distribution were significant for retailers, but less important for wholesalers. Genotype was not a strong indicator of conformation. Eye muscle area and depth were correlated with Fat C; however, these were not significant. These results indicate that carcass conformation, meat colour and fat distribution should be incorporated into carcass grading models.Hedonic, lamb, conformation and meat value, attributes, Livestock Production/Industries,

Metal matrix composite micromechanics: In-situ behavior influence on composite properties

Recent efforts in computational mechanics methods for simulating the nonlinear behavior of metal matrix composites have culminated in the implementation of the Metal Matrix Composite Analyzer (METCAN) computer code. In METCAN material nonlinearity is treated at the constituent (fiber, matrix, and interphase) level where the current material model describes a time-temperature-stress dependency of the constituent properties in a material behavior space. The composite properties are synthesized from the constituent instantaneous properties by virtue of composite micromechanics and macromechanics models. The behavior of metal matrix composites depends on fabrication process variables, in situ fiber and matrix properties, bonding between the fiber and matrix, and/or the properties of an interphase between the fiber and matrix. Specifically, the influence of in situ matrix strength and the interphase degradation on the unidirectional composite stress-strain behavior is examined. These types of studies provide insight into micromechanical behavior that may be helpful in resolving discrepancies between experimentally observed composite behavior and predicted response

Computational simulation of high temperature metal matrix composites cyclic behavior

A procedure was developed and is described which can be used to computationally simulate the cyclic behavior of high temperature metal matrix composites (HTMMC) and its degradation effects on the structural response. This procedure consists of HTMMC mechanics coupled with a multifactor interaction constituent material relationship and with an incremental iterative nonlinear analysis. The procedure is implemented in a computer code that can be used to computationally simulate the thermomechanical behavior of HTMMC starting from the fabrication process and proceeding through thermomechanical cycling, accounting for the interface/interphase region. Results show that combined thermal/mechanical cycling, the interphase, and in situ matrix properties have significant effects on the structural integrity of HTMMC

A new source detection algorithm using FDR

The False Discovery Rate (FDR) method has recently been described by Miller et al (2001), along with several examples of astrophysical applications. FDR is a new statistical procedure due to Benjamini and Hochberg (1995) for controlling the fraction of false positives when performing multiple hypothesis testing. The importance of this method to source detection algorithms is immediately clear. To explore the possibilities offered we have developed a new task for performing source detection in radio-telescope images, Sfind 2.0, which implements FDR. We compare Sfind 2.0 with two other source detection and measurement tasks, Imsad and SExtractor, and comment on several issues arising from the nature of the correlation between nearby pixels and the necessary assumption of the null hypothesis. The strong suggestion is made that implementing FDR as a threshold defining method in other existing source-detection tasks is easy and worthwhile. We show that the constraint on the fraction of false detections as specified by FDR holds true even for highly correlated and realistic images. For the detection of true sources, which are complex combinations of source-pixels, this constraint appears to be somewhat less strict. It is still reliable enough, however, for a priori estimates of the fraction of false source detections to be robust and realistic.Comment: 17 pages, 7 figures, accepted for publication by A

Microjansky sources at 1.4 GHz

We present a deep 1.4 GHz survey made with the Australia Telescope Compact Array (ATCA), having a background RMS of 9 microJy near the image phase centre, up to 25 microJy at the edge of a 50' field of view. Over 770 radio sources brighter than 45 microJy have been catalogued in the field. The differential source counts in the deep field provide tentative support for the growing evidence that the microjansky radio population exhibits significantly higher clustering than found at higher flux density cutoffs. The optical identification rate on CCD images is approximately 50% to R=22.5, and the optical counterparts of the faintest radio sources appear to be mainly single galaxies close to this optical magnitude limit.Comment: 6 pages, 4 figures, accepted by ApJ Letters 4 May 199

Dependence of Dust Obscuration on Star Formation Rates in Galaxies

Many investigations of star formation rates (SFRs) in galaxies have explored details of dust obscuration, with a number of recent analyses suggesting that obscuration appears to increase in systems with high rates of star formation. To date these analyses have been primarily based on nearby (z < 0.03) or UV selected samples. Using 1.4 GHz imaging and optical spectroscopic data from the Phoenix Deep Survey, the SFR-dependent obscuration is explored. The use of a radio selected sample shows that previous studies exploring SFR-dependent obscurations have been biased against obscured galaxies. The observed relation between obscuration and SFR is found to be unsuitable to be used as an obscuration measure for individual galaxies. Nevertheless, it is shown to be successful as a first order correction for large samples of galaxies where no other measure of obscuration is available, out to intermediate redshifts (z ~ 0.8).Comment: 9 pages (including 5 encapsulated postscript figures), aastex, uses emulateapj5.sty. Accepted for publication in Ap

Evaluation of Triaxial Testing Equipment and Methodologies of Three Agencies

To obtain reliable and consistent shear strength results, which are essential in the design of earth structures, from triaxial tests, careful attention, skill, and judgement must be given to testing procedures and equipment make-up. There are many sources of potential errors in the test, especially when pore pressures are monitored. Consequently, a question inevitably arises concerning tbe quality of triaxial test results obtained by different geotechnical laboratories. The intent of this study was to initiate and help establish a triaxial testing forum whereby any geotechnical laboratory engaged in triaxial testing can check the quality of their triaxial results, and therefore, evaluate their testing procedures and equipment make-up agamst the results obtained by other agencies. To initiate the forum, isotropically consolidated, undrained triaxial tests with pore pressure measurements were performed by three agencies -- the Divisions of Research and Materials of the Kentucky Department of Transportation and the Civil Engineering Department of the University of Kentucky -- on remolded, standardized kaolinite specimens. The triaxial results reported by each agency and analyses of all data by the Division of Research are reported and shows that the three participating agencies obtained about the same results. The forum will be useful to any governmental agency for accrediting any geotechnical laboratory performing work for that agency

Embankment Construction Using Shale

Shales have been used extensively in the construction of highway embankments, and other earthen structures, because of the vast amounts of these materials located in many areas of the country and the lack of economical and alternate available materials. Because shales exhibit a wide range of engineering properties and behaviors, many problems have occurred. Numerous shale embankment failures have occurred generally some 1 to 10 years after construction. Settlements of 1 to 3 feet (0.3 - 0.9 m) have been observed in many old embankments and required numerous asphaltic overlays. Shale embankments that settle continuously have been observed to fail eventually. Each year millions of dollars are spent repairing embankments built with shales. This report presents a discussion of some of the research conducted by the University of Kentucky Transportation Center in the seventies and eighties and attempts to address some of the problems that arise in constructing shale embankments. A brief overview of the engineering properties of shales located in Kentucky is presented. Some important factors that need to be considered in designing and building shale embankments are briefly discussed. Finally, a description of the construction of three experimental shale embankments in 1986 is given. These embankments were constructed to evaluate a special shale compaction provision adopted by the Kentucky Transportation Cabinet to avoid large long-term settlements and instabilities. Observations of long-term settlements of the embankments are presented

Stabilization of Subgrade Soil using Hydrated Lime Product

The Carbide/Graphite Group Inc. requested the University of Kentucky, Kentucky Transportation Center to do a feasibility study to determine if a hydrated lime product produced at their Calvet City, Kentucky facility can be used as a soil subgrade stabilizing agent

Construction and Performance of Trial Section of Treated Shoulders on the Mountain Parkway Extension

In October 1966, J.W. Spurrier, Assistant Operations Management Engineer, requested that the Research Division make a study of a two-mile section of the shoulders on the Mountain Parkway Extension in Wolfe County (from Mile Post 43.8 to Mile Post 45.8) and make recommendations for design and construction procedures for cement stabilization of the shoulders. In compliance with this request, in January 1967, Research Division personnel made a survey of the full length of shoulder on the Mountain Parkway Extension. Included in this survey were measurements of depth of the dense graded aggregate, penetrations of the shoulder subgrade soil and samples taken of the DGA and soil. Compressive strengths were measured on sampled material treated with cement. A memorandum reporting the results of the shoulder survey, compressive tests, and recommended cement treatment design and construction procedures was prepared in March 1967 (see Appendix A). A typical section of the shoulder, as originally constructed, is shown in Figure 1