304 research outputs found

    Case Study: Unsaturated Embankment Failure on Soft Soils

    Get PDF
    This paper describes the application of unsaturated soil mechanics to an interstate connecting-ramp embankment that failed during construction. Specifically, matric suction is incorporated into the calculation of the tension crack (TC) depth induced by desiccation and strain incompatibility and the contribution of matric suction to embankment shear strength. The results are compared with field observations to assess the viability of unsaturated soil mechanics in modeling compacted embankments in stability analyses. Results from this study suggest that using unsaturated shear strength parameters while introducing a TC in the compacted fill yields a reasonable inverse analysis of this interstate embankment. This may be preferred in slope stability analyses to the current practice of using an undrained shear strength (i.e., cohesion) for the unsaturated compacted fill and including a TC to generate a reasonable factor of safety

    An Assessment of State Agencies’ Practices in Managing Geotechnical Risks in Design-Build Projects

    Get PDF
    State highways agencies policies and procedures for articulating geotechnical information and requirements on Design-Build (DB) projects is a means to manage geotechnical risks. Successful approaches and practices to managing geotechnical risk not only reduce the level of geotechnical uncertainty for both the owner and the competing design-builder, but also distribute the remaining geotechnical risk between the parties. This paper discusses the differences in regard to geotechnical risk management, aspects of the DB procurement process, and contract aspects between state departments of transportation (DOT) with experience delivering projects using DB versus those who are not as experienced. Results are presented from two independent sources of information; one was obtained through literature review of aspects related to geotechnical requirements and management of DB projects, and the other was through an online-survey of 38 DOTs. Results of the study statistically demonstrate the value of DB experience in managing geotechnical risks, and accordingly presents a set of recommended practices for agencies that are relatively new to DB project delivery, during both procurement and contract formation

    Behavior of hybrid high-strength fiber reinforced concrete slab-column connections under the effect of high temperature

    Get PDF
    AbstractConcrete can be modified to perform in a more ductile form by the addition of randomly distributed discrete fibers in the concrete matrix. The combined effect of the addition of two types of fibers (steel fiber and polypropylene fiber with different percentages) to concrete matrix, which is called hybrid effect is currently under investigation worldwide. The current research work presents the conducted experimental program to observe the behavior of hybrid high strength reinforced concrete slab-column connections under the effect of high temperature. For this purpose, ten slab-column connections were casted and tested. The experimental program was designed to investigate the effect of different variables such as concrete mixture, column location and temperature fighting system. All specimens were exposed to a temperature of 500°C for duration of two hours. To observe the effect of each variable, specimens were divided into four groups according to the studied parameters. The test results revealed that using hybrid high strength concrete HFHSC produced more strength in punching failure compared with high strength concrete HSC when exposed to elevated temperature. Fighting by air had higher initial crack load compared with that for without fighting and fighting by water. On the other hand, fighting by water decreased the ultimate load

    The prevalence of blinding trachoma in northern states of Sudan.

    Get PDF
    BACKGROUND: Despite historical evidence of blinding trachoma, there have been no widespread contemporary surveys of trachoma prevalence in the northern states of Sudan. We aimed to conduct district-level surveys in this vast region in order to map the extent of the problem and estimate the need for trachoma control interventions to eliminate blinding trachoma. METHODS AND FINDINGS: Separate, population based cross-sectional surveys were conducted in 88 localities (districts) in 12 northern states of Sudan between 2006 and 2010. Two-stage cluster random sampling with probability proportional to size was used to select the sample. Trachoma grading was done using the WHO simplified grading system. Key prevalence indicators were trachomatous inflammation-follicular (TF) in children aged 1-9 years and trachomatous trichiasis (TT) in adults aged 15 years and above. The sample comprised 1,260 clusters from which 25,624 households were surveyed. A total of 106,697 participants (81.6% response rate) were examined for trachoma signs. TF prevalence was above 10% in three districts and between 5% and 9% in 11 districts. TT prevalence among adults was above 1% in 20 districts (which included the three districts with TF prevalence >10%). The overall number of people with TT in the population was estimated to be 31,072 (lower and upper bounds = 26,125-36,955). CONCLUSION: Trachoma mapping is complete in the northern states of Sudan except for the Darfur States. The survey findings will facilitate programme planning and inform deployment of resources for elimination of trachoma from the northern states of Sudan by 2015, in accordance with the Sudan Federal Ministry of Health (FMOH) objectives

    Measures of women's empowerment based on individual-level data: a literature review with a focus on the methodological approaches

    Get PDF
    BackgroundQuantifying women's empowerment has become the focus of attention of many international organizations and scholars. We aimed to describe quantitative indicators of women's empowerment that are based on individual-level data.MethodsIn this scoping review, we searched PubMed, Scopus, Web of Science, Science Direct, Google, and Google Scholar for publications describing the operationalization of measures of women's empowerment.ResultsWe identified 36 studies published since 2004, half of them since 2019, and most from low- and middle-income countries. Twelve studies were based on data from the Demographic and Health Surveys and used 56 different variables from the questionnaires (ranging from one to 25 per study) to measure the overall empowerment of women 15–49 years. One study focused on rural women, two included married and unmarried women, and one analyzed the couple's responses. Factor analysis and principal component analysis were the most common approaches used. Among the 24 studies based on other surveys, ten analyzed overall empowerment, while the others addressed sexual and reproductive health (4 studies), agriculture (3) and livestock (1), water and sanitation (2), nutrition (2), agency (1), and psychological empowerment (1). These measures were mainly based on data from single countries and factor analysis was the most frequently analytical method used. We observed a diversity of indicator definitions and domains and a lack of consensus in terms of what the proposed indicators measure.ConclusionThe proposed women's empowerment indicators represent an advance in the field of gender and development monitoring. However, the empowerment definitions used vary widely in concept and in the domains/dimensions considered, which, in turn influence or are influenced by the adopted methodologies. It remains a challenge to find a balance between the need for a measure suitable for comparisons across populations and over time and the incorporation of country-specific elements

    A randomized comparison between three types of irrigating fluids during transurethral resection in benign prostatic hyperplasia

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Central nervous system changes, circulatory and electrolyte imbalances are the main complications of endoscopic transurethral resection of the prostate (TURP) which is known as transurethral resection (TUR) syndrome, which occurs as result of excessive absorption of irrigating fluid. We compare glycine 1.5% versus glucose 5% and normal saline 0.9% as irrigating solutions during TURP in patients with moderate to severe bladder outlet obstruction due to benign prostatic hyperplasia (BPH).</p> <p>Methods</p> <p>Three hundred sixty patients with symptomatic BPH were randomized into a prospective, controlled trial comparing the three irrigation modalities. One-hundred twenty patients used glycine 1.5% solution as irrigating fluid (glycine group), 120 patients used glucose 5% solution (glucose group) and 120 patients used normal saline 0.9% solution (saline group). Patient's demographics, operation time, hospital stay, postoperative amino acid glycine assay, postoperative serum cardiac troponin I and perioperative complications were noted.</p> <p>Results</p> <p>No difference was found between the groups in the immediate postoperative levels of hemoglobin and hematocrite. A high glycine level was associated with the TUR syndrome. Seventeen patients had TUR syndrome; all were in glycine group and they had the highest postoperative amino acid glycine levels. Slight increase in serum sodium (142.6 ± 12.6 mmol/l) was detected in saline group. Transient Hyperglycemia (170 ± 35.9 mg/dl) and hypokalemia (3.67 ± 0.92 mmol/l) occurred in the immediate postoperative period in the glucose group.</p> <p>Conclusion</p> <p>Endoscopic TURP performed using either glucose 5% or saline 0.9% irrigating solution during and after surgery is associated with lower incidence of TUR syndrome, lower catheterization period, shorter hospital stay and no cardiac toxicity in comparison with glycine 1.5% solution.</p> <p>Trial Registration</p> <p>This clinical trail had been approved and registered in PACT Registry; with identification number for the registry is ATMR2010010001793131.</p
    • …
    corecore