Computerized Analysis of Stress-Strain Consolidation Data

A computerized, mathematical algorithm is described and presented for analyzing the semilogarithmic stress-strain (time-independent) properties of standard, controlled-gradient, and controlled-rate-of-strain consolidation tests. This algorithm is an automation of manual graphical procedures currently used in engineering practice to obtain stress-strain information necessary for use in time-independent settlement analysis. The Casagrande and Schmertmann constructions are analytically represented to determine the preconsolidation stress and the in situ, compressibility coefficients of compression and expansion. Values for each of these parameters range between a probable and minimum value. The point of maximum curvature is determined for the Casagrande construction by use of the mathematical definition of the radius of curvature or by the analytical representation of a newly proposed graphical approach. The location of the point of maximum curvature has been found to depend on the arithmetic scale factors used for the horizontal and vertical directions in the semilogadthmic representation of the consolidation curves. The mathematical algorithm is written in Fortran N for use with the IBM 370/165 computer and the Calcomp 663 drum plotter. The computer program has proven effective in the reduction and analysis of stress-strain data from more than 40 controlled and 30 standard consolidation tests

Posterior stabilized knee design biomechanical considerations

Numerous posterior stabilized knee systems are available for primary and revision total knee arthroplasty. Design of these systems requires an understanding of the articulating geometries and kinematic/kinetic biomechanical considerations of the normal knee. The findings for the normal knee are integrated into the design of a prosthetic system. The natural femoral, tibial and patella articulating geometries are defined to enable subsequent kinematic and kinetic analyses. The articulating geometries are characterized from review of anthropometric studies of the tibiofemoral and patellofemoral joint. The kinematic analysis of the natural knee defines knee motion in terms of rotation, adduction/abduction, range of motion and femoral rollback. Typical activities for total knee recipients are characterized under these headings. Instant center theory is also applied to the natural knee as it facilitates linking natural knee motion and prosthetic motion analysis. Natural knee kinetics for the gait cycle is characterized. The maximum gait cycle compressive and shear loads and knee motions attained from clinical studies using force plate, cinematography and computer optimization techniques are reviewed. The resultant loads and motions obtained from the studies form a benchmark used to establish laboratory testing parameters. The kinematic and kinetic analysis for generic posterior stabilized design is studied. Interaction of the femoral cam, tibial spine, femoral condyles and tibia plateau geometry are reviewed for a proposed and existing posterior stabilized geometry. Additional posterior stabilized design issues including: subluxation resistance, range of motion, bone conservation for the femoral housing resection, internal/external femoral rotation, tibial polyethylene insert modularity with the tibial tray and tibial polyethylene insert conformity with the femoral condyles are reviewed. A survey of designs on the market indicates a wide range of results for bone conservation for the femoral housing resection, internal/external rotation, and degree of conformity

Analysis of Time-Deflection Consolidation Data

A computerized statistical curve-fitting algorithm has been developed for determining the time-dependent properties of conventional (load-incremental) consolidation test data. Analytical models of the graphical methods developed by Taylor and Casagrande and of the Naylor-Doran method of successive approximations determtne values for the coefficients of consolidation, permeability, and the values of deflection corresponding to the begimltng and endtng of primary consolidation. The coefficients of volume change and secondary compression are also calculated. A modified statistical definition is used to select the linear portions of the data curves and is applicable to other data-fitting problems. After the Naylor-Doran method has been used, the coefficient of consolidation cy is calculated according to a definition independent of errors in the deflection at the begining of primary consolidation do. Input instructions, codtng sheets, example problems, a flow chart, and source listing are provided. The computer program is in Fortran N for the IBM 370/165 computer and Calcomp 663 drum plotter and has proven to be extremely effective in the analysis of over 30 sets of time-deflection consolidation test data

Computerized Analysis of Moisture-Density Data

A mathematical algorithm is described and presented for estimating optimum moisture content and maximum dry density from moisture-density data obtained from ASTM Standard Test Methods D 698 and D 1557, which are often, even though incorrectly, referred to as the Standard Proctor Test and Modified Proctor Test, respectively. However, the algorithm can be used to analyze moisture-density data obtained by non-standard procedures. The algorithm is written in Fortran IV for use with the IBM 370/165 computer and Calcomp 663 drum plotter. Documentation of this computer program includes detailed input instructions, coding sheets, flow chart, variable descriptions, example problem, example output, and example job control cards

Corrective Measures for Unstable Bridge-Approach Embankment US 68, Licking River, Blue Licks

In January 1979, an in-depth investigation of the unstable bridge-approach embankment, Figure 1, on US 68 over the Licking River in the north central portion of Nicholas County (MP 91-68-B0027) was begun by the Division of Research. This investigation was a continuation of a project initiated by the Division of Materials in 1967. This site is approximately 0.3 miles (0.5 km) north of Stony Creek Road and approximately 7.5 miles (12.0 km) north of Carlisle and 0.8 miles (1.3 km) southwest of Blue Licks Battlefield State Park. The bridge is a three-span, continuous, welded plate girder structure with span lengths of 160, 2004 and 160 feet (48.8, 61.0, and 48.8 m) at a 0 degree skew. The bridge is aligned at north 47 degrees east. The pier foundations are spread footings on rock; the abutments utilize 12 point-bearing (53 steel-type) piles. The roadway emerges from a cut of approximately 20 to 40 feet (6.1 to 12.2 m} near Stations 217 + 50 and 221 + 00 on the right and left, respectively. The nearby bridge approach embankment rests partly on a bench of limestone and partly on an alluvium river bank. Maximum height of the embankment is about 100 feet (30.5 m)

Matt Excell - Trial Lawyer Extraordinary

One day, in the civil assignment room, Matt Excell said to me: When the Lord made that lawyer (pointing to one) he hand-carved him, and when He was making him (pointing to another) He was called to the telephone. If his own definition were to be applied to Matthew B. Excell, he was a lawyer hand-carved by God. This story pertains to the period in which I knew, worked and lived with him in court and in the preparation of cases for court

Combating School Truancy: Current Practices and Recommendations for Improvement

School truancy poses a significant problem for the U.S. educational system and our society. Truant students suffer negative effects not only in their education, but also in their potential future financial earnings and even their life expectancy. Despite the recognition of the problem in the United States, efforts to curb truancy have proben largely ineffective. As exploratory case study, which consisted of semi-structured interviews with five participants - four principals and one district superintendent - examined the perceptions of current truancy intervention programs and ways to improve them. The most common practice for combating truancy involved the employment of truancy officers. However, participants indicated that the most effective ways to curb truancy were by taking more proactive approaches within students\u27 homes and by forming partnerships with different agencies, such as the police and court system

Thrifty Viability and Traditional Mortgage Lending: A Simultaneous Equations Analysis of the Risk-Return Trade-Off

A number of studies have argued that the thrift industry is not viable as it is presently structured and regulated because mortgage yields are inadequate to cover interest and operating costs. This hypothesis suggests that observed profitability is primarily the result of the tendency of the industry to "ride" the yield curve by borrowing short and lending long. To evaluate this argument, we construct a simultaneous-equations model of thrift risk (maturity gap positions) and return (net interest margin). We find support for the notion that the industry could not be reasonably profitable if it did not take on significant interest-rate risk. For instance, a zero gap position produces a return on assets of only 19 basis points and a return on equity of only 4%. We also estimate the amount of interest-rate risk the industry can employ to increase returns on equity and assets. Our estimates show that over 50% of thrift profits earned during this period are the result of negative gap positions and interest-rate speculation. As earlier research shows, changes in regulations affecting thrift asset and liability choices can be counterproductive.

The Efficacy of Peripheral Opioid Antagonists in Opioid-Induced Constipation and Postoperative Ileus: A Systematic Review of the Literature.

Opioid-induced constipation has a negative impact on quality of life for patients with chronic pain and can affect more than a third of patients. A related but separate entity is postoperative ileus, which is an abnormal pattern of gastrointestinal motility after surgery. Nonselective μ-opioid receptor antagonists reverse constipation and opioid-induced ileus but cross the blood-brain barrier and may reverse analgesia. Peripherally acting μ-opioid receptor antagonists target the μ-opioid receptor without reversing analgesia. Three such agents are US Food and Drug Administration approved. We reviewed the literature for randomized controlled trials that studied the efficacy of alvimopan, methylnaltrexone, and naloxegol in treating either opioid-induced constipation or postoperative ileus. Peripherally acting μ-opioid receptor antagonists may be effective in treating both opioid-induced bowel dysfunction and postoperative ileus, but definitive conclusions are not possible because of study inconsistency and the relatively low quality of evidence. Comparisons of agents are difficult because of heterogeneous end points and no head-to-head studies