Advanced collapsible tank for liquid containment

Tanks for bulk liquid containment will be required to support advanced planetary exploration programs. Potential applications include storage of potable, process, and waste water, and fuels and process chemicals. The launch mass and volume penalties inherent in rigid tanks suggest that collapsible tanks may be more efficient. Collapsible tanks are made of lightweight flexible material and can be folded compactly for storage and transport. Although collapsible tanks for terrestrial use are widely available, a new design was developed that has significantly less mass and bulk than existing models. Modelled after the shape of a sessible drop, this design features a dual membrane with a nearly uniform stress distribution and a low surface-to-volume ratio. It can be adapted to store a variety of liquids in nearly any environment with constant acceleration field. Three models of 10L, 50L, and 378L capacity have been constructed and tested. The 378L (100 gallon) model weighed less than 10 percent of a commercially available collapsible tank of equivalent capacity, and required less than 20 percent of the storage space when folded for transport

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,

Advanced underwater lift device

Flexible underwater lift devices ('lift bags') are used in underwater operations to provide buoyancy to submerged objects. Commercially available designs are heavy, bulky, and awkward to handle, and thus are limited in size and useful lifting capacity. An underwater lift device having less than 20 percent of the bulk and less than 10 percent of the weight of commercially available models was developed. The design features a dual membrane envelope, a nearly homogeneous envelope membrane stress distribution, and a minimum surface-to-volume ratio. A proof-of-concept model of 50 kg capacity was built and tested. Originally designed to provide buoyancy to mock-ups submerged in NASA's weightlessness simulators, the device may have application to water-landed spacecraft which must deploy flotation upon impact, and where launch weight and volume penalties are significant. The device may also be useful for the automated recovery of ocean floor probes or in marine salvage applications

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

Lime Stabilization of Pavement Subgrade Soils of Section AA-19 of the Alexandria-Ashland Highway

The purposes of this study were to evaluate the effects of hydrated lime on the soils from Section AA-19 of the Alexandria-Ashland Highway and determine if the engineering properties of the soils from Section AA-19 could be improved by lime stabilization. Soil samples used in the study were obtained by· the Kentucky Transportation Research Program on March 25, 1986. Three bag samples were collected from Section AA-19 (Lewis County, Kentucky) of the Alexandria-Ashland Highway, Stations 1630 (Sample A), 1495 (Sample B), and 1675+50 (Sample C), respectively. Based on a review of the geology of Section AA-19, the three sampling sites are directly underlain by the Crab Orchard Formation. The study was authorized by contract dated April 4, 1986 (Purchase Order No. ML86-1248), between the Kentucky Transportation Research Program, College of Engineering, University of Kentucky, and the Dravo Lime Company of Maysville, Kentucky. Authorization to proceed with the work was given by Mr. Ward Blakefield of the Dravo Lime Company. The scope and specific engineering services to be performed are outlined in the purchase order contract. Preliminary test results (1) were submitted to the Dravo Lime Company on July 30, 1986

Mechanical & Engineering Properties of a Cherty Paleozoic Material

The Divide Cut Section 3A of the Tennessee-Tombigbee Waterway is located in Tishomingo County, Mississippi. Construction of this portion of the canal required the excavation of a cherty residuum. This material (hereafter referred to as cherty Paleozoic material) is a member of the Fort Payne Formation, of the Mississippian Period, of the Paleozoic era. The purpose of this study was to determine the mechanical and engineering properties of the material, including its abrasiveness. Also, the mineralogy of the material was to be determined and a particular effort was made to determine if the material could be classified as Tripoli. On June 22, 1982, a test pit was excavated east of the canal at Station 13179+75. The excavation was made with a tracked backhoe to a depth of approximately 16.4 feet. Excavation was done and samples were collected under the direct supervision of two geotechnical engineers of the Kentucky Transportation Research Program of the University of Kentucky. The soil profile encountered at the test pit is illustrated in Figure 1. The location of sampling depths is listed in the same figure. All samples collected were sealed immediately to prevent a loss of moisture while being transported to the laboratory

Effects of Water on Slope Stability

A brief state-of-the-art review of the effects of water on slope stability and the techniques for analysis is presented. The effective stress principle and basic considerations of slope stability, including design factors of safety, are discussed briefly. The derivations and effects of seepage forces and rapid drawdown on effective stress are also presented. Various conditions of external loading produce changes in effective stress. These changes are discussed and limiting conditions which should be analyzed are mentioned. Limitations of total stress analyses are discussed in detail. It appears that, for soils having a liquidity index of 0.36 or greater (normally consolidated), the undrained shear strength gives factors of safety close to the actual factor of safety. For soils with a liquidity index less than 0.36 (overconsolidated), the undrained shear strength gives factors of safety that are too high; but the strength parameters can be corrected by the empirical relationship presented herein. Data also show that the difference between vane and calculated shear strength increased as the plasticity index and (or) the liquid limit increased. An empirical relationship for correcting vane shear strength is presented. A discussion of effective stress analysis, including differences between peak and residual φ angles for normally consolidated and overconsolidated soils, is presented. The residual φ angle decreases logarithmically with increasing clay fraction. The critical state of a clay is also defined. Sheer strength parameters of a clay tested in that state correspond to the theoretical strength of an overconsolidated clay which has undergone a process of softening. To test a clay in the critical state, it is suggested herein the soil should be remolded to a moisture content equal to 0.36 times the plastic index plus the plastic limit. Water may cause unstable conditions in earth slopes due to changes in geometry. Erosion of the toe or the slope can induce damaging stress. Piping through heaving or erosion of subsurface layers can cause damage. Construction of side-hill embankments can cause danuning, resulting in a rise in the water table. Methods of water detection are also summarized. These include tracers, electrical resistivity, and water table observations. The tatter method apparently is the most successful. A discussion of ways to monitor water pressures, including the types and operations of piezometers, is given. Finally, suggested guidelines for the design of earth slopes are included

Some Uncertainties of Slope Stability Analyses

Some practical limitations of total stress and effective stress analyses are discussed. For clays having a liquidity index of 0.36 or greater, φ-equal-zero analyses based on laboratory undrained shear strengths give factors of safety close to the actual factor of safety. However, based on field vane strengths, φ-equal-zero analyses may yield factors of safety which may be too high. The difference between field vane and calculated shear strengths increased as the plasticity index increased. For clays having a liquidity index less than 0.36, φ-equal-zero analyses using laboratory undrained shear strengths give factors of safety that are much too high; but the strength parameters can be corrected by the empirical relationship presented herein. An empirical relationship for correcting vane shear strength is also presented. A method is proposed for predicting the probable success of a φ-equal-zero analysis. Data suggest that overconsolidated clays and clay shales or clays having a liquidity index less than 0.36 pose the greatest slope design dilemma. An effective stress analysis based on peak triaxial shear strength parameters generally yields factors of safety which are too high; residual shear strength parameters frequently yield factors of safety which are too low. To approximate the theoretical strength of an overconsolidated clay which has undergone a process of softening, the effective stress parameters might be obtained from triaxial tests performed on remolded, normally consolidated clay. It is suggested the soil be remolded to a moisture content equal to the plastic limit plus the product of 0.36 and the plasticity index

Mechanical and Engineering Properties of a Cherty Paleozoic Material

In September 1982, Research Report UKTRP-82-16 was issued to document the sampling of a cherty Paleozoic material from a test pit on Divide Cut Section 3A of the Tennessee-Tombigbee Waterway. Results of laboratory testing of the samples were also reported. Subsequent to the issuance of Report UKTRP-82-16, additional testing and analyses have been completed. The purpose of this report is to document the results of those tests and analyses

Geotechnical, Hydrologic, and Hydraulic Investigation of Mill Creek Dam-Phase II

The general scope of this study, Phase II, was to assess the safety of Mill Creek Dam. Findings obtained from detailed geotechnical, hydraulic, and hydrological investigations are presented. The structural stability, as well as the hydrological and hydraulic stability, were investigated. Specifically, objectives of the study were as follows: 1. To determine the engineering characteristics of the clay core, shells, and random fill. 2. To evaluate the potential for piping. 3. To evaluate seepage conditions at the site. 4. To evaluate the structural stability of the earth and rockfill dam. 5. To evaluate erodability. 6. To assess geologic conditions at the site. 7. To evaluate existing and required spillway hydraulics and hydrology of the site. 8. To analyze requirements for a drawdown facility. 9. To evaluate alternative remedial measures that could be used to correct deficiencies in the dam. This study presents data relating to the degree of safety and alternative remedial schemes. Information presented herein will aid in the final selection of the remedial method and in implementing remedial construction. Development of detailed remedial plans, however, was not within the scope of this study