119 research outputs found
Case Study on the Rehabilitation of a Distressed Retaining Wall
Earth retaining structures usually need careful monitoring after construction in order to detect any signs of distress. In cases where failure is likely to occur, appropriate remedial techniques need to adopted, backed by a detailed analysis. This paper presents a case study on the rehabilitation of a retaining wall that was constructed for a bypass road project. The structure showed clear signs of distress immediately after completion and hence could not be opened for traffic. Preliminary finite element analysis of the wall showed values of factor of safety that are lesser than permissible values. The values of factor of safety obtained from limit equilibrium analyses based on overturning, sliding and bearing pressure were also inadequate. Soil nailing with grouted nails has been suggested as a remedial measure for this case. The results of the finite element analysis of the wall reinforced with grouted nails are presented in this paper. Results show that the soil nailing technique is effective in the rehabilitation of the wall
FUZZY OPTIMIZATION MODELING IN THE ANALYSIS OF HUMAN HEALTH CARE BASED ON LINEAR PROGRAMMING PROBLEM
Communicable diseases are the diseases which can be spread from one person to the other. It can also spread from infected animals. The transfer of the infection can occur through air, water, surfaces which are contaminated or through the direct contact. Moreover, Communicable Diseases are common among people nowadays days. In this paper, Fuzzy Optimization Model is developed based on Linear Programming Problem to control the communicable diseases with minimum curing time and dosage by distributing the various treatments to the disease population in order to reduce the human productivity loss. Finally, to demonstrate the feasibility of the proposed optimization model, an analytic technique is given for some four combinable diseases with four types of treatments
Case Study on the Rehabilitation of a Distressed Retaining Wall
Earth retaining structures usually need careful monitoring after construction in order to detect any signs of distress. In cases where failure is likely to occur, appropriate remedial techniques need to adopted, backed by a detailed analysis. This paper presents a case study on the rehabilitation of a retaining wall that was constructed for a bypass road project. The structure showed clear signs of distress immediately after completion and hence could not be opened for traffic. Preliminary finite element analysis of the wall showed values of factor of safety that are lesser than permissible values. The values of factor of safety obtained from limit equilibrium analyses based on overturning, sliding and bearing pressure were also inadequate. Soil nailing with grouted nails has been suggested as a remedial measure for this case. The results of the finite element analysis of the wall reinforced with grouted nails are presented in this paper. Results show that the soil nailing technique is effective in the rehabilitation of the wall
ANALYSIS AND DESIGN OF REINFORCED EARTH WALL FOR SHORE PROTECTION SYSTEM AGAINST TSUNAMI
The evaluation and design of coastal shore protection works for tsunamis assumed considerable importance following the impact of the 26th December 2004 tsunami in India and other countries of Asia. The lack of proper guidelines made matters worse and resulted in the great damage that occurred. Subsequent surveys indicated that scour resulting from high water velocities was one of the prime reasons in the damage of simple structures. In some cases, it became apparent that sea walls were helpful in minimizing the degree of damage. The objective of the present study is to illustrate how proper design analysis for expected wave heights as well as the use of flexible systems such as geocells, are likely to provide better shoreline protection. Protective systems can be designed that can withstand wave forces that correspond to a variety of incidence probabilities. The present study illustrates such an analytical design approach that is necessary for a shoreline protection system and provides references to relevant wave height data for the east coast of India
Prophylactic combined supplementation of choline and docosahexaenoic acid attenuates vascular cognitive impairment and preserves hippocampal cell viability in rat model of chronic cerebral hypoperfusion ischemic brain injury
Background: Stroke is the second cause of mortality in the world and third leading cause of disability in surviving victims. Cerebral ischemic cascade involves multiple pathways that can result in motor and cognitive deficits. The current treatment strategy focuses mainly on motor recovery, and the management of post-stroke cognitive impairment is largely neglected. Similarly, very few studies have explored the prophylactic combined synergetic treatment strategies that have the potential to target multiple pathways in the ischemic cascade to alleviate vascular cognitive impairment (VCI) in the event of an ischemic stroke. Choline and docosahexaenoic acid (Cho-DHA) are both essential neuronal membrane phospholipid precursors, known to be important in enhancing cognitive functions. The objective of present study was to explore the prophylactic efficacy of combined Cho-DHA supplementation (Cho-DHA suppl.) in attenuating VCI in a rodent model of ischemic brain injury.Methods: An 10-months-old male Wistar rats were subdivided into four groups (n=8/group); normal control (NC), bilateral common carotid artery occlusion (BCCAO) induced ischemic brain injury group, sham BCCAO (S-BCCAO) group, and prophylactic combined Cho-DHA suppl. BCCAO group. Subsequently, all groups of rats were tested for cognition and neuro-morphological changes in the hippocampus.Results: BCCAO rats showed significant learning and memory deficits (p<0.05) and neuronal injury compared to S-BCCAO and NC rats. These cognitive deficits and neuronal injury were significantly (p<0.01) attenuated in Cho-DHA suppl. BCCAO rats.Conclusion: Prophylactic combined Cho-DHA suppl. may be envisaged as an effective preventive strategy to attenuate VCI and neuronal injury in high-risk individuals susceptible for a future event of an ischemic stroke
Evaluation of Reference Evapotranspiration Estimation Methods and Development of Crop Coefficient Models
ABSTRACT This study is an attempt to find best alternative method to estimate reference evapotranspiration (ETo
Stochastic evolution of cosmological parameters in the early universe
We develop a stochastic formulation of cosmology in the early universe, after
considering the scatter in the redshift-apparent magnitude diagram in the early
epochs as an observational evidence for the non-deterministic evolution of
early universe. We consider the stochastic evolution of density parameter in
the early universe after the inflationary phase qualitatively, under the
assumption of fluctuating factor in the equation of state, in the
Fokker-Planck formalism. Since the scale factor for the universe depends on the
energy density, from the coupled Friedmann equations we calculated the two
variable probability distribution function assuming a flat space geometry.Comment: 10 page
Plasma and cellular fibronectin: distinct and independent functions during tissue repair
Fibronectin (FN) is a ubiquitous extracellular matrix (ECM) glycoprotein that plays vital roles during tissue repair. The plasma form of FN circulates in the blood, and upon tissue injury, is incorporated into fibrin clots to exert effects on platelet function and to mediate hemostasis. Cellular FN is then synthesized and assembled by cells as they migrate into the clot to reconstitute damaged tissue. The assembly of FN into a complex three-dimensional matrix during physiological repair plays a key role not only as a structural scaffold, but also as a regulator of cell function during this stage of tissue repair. FN fibrillogenesis is a complex, stepwise process that is strictly regulated by a multitude of factors. During fibrosis, there is excessive deposition of ECM, of which FN is one of the major components. Aberrant FN-matrix assembly is a major contributing factor to the switch from normal tissue repair to misregulated fibrosis. Understanding the mechanisms involved in FN assembly and how these interplay with cellular, fibrotic and immune responses may reveal targets for the future development of therapies to regulate aberrant tissue-repair processes
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy
Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations.
Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves.
Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p 90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score.
Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
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