Study of Seismic Base Isolation of Bridge Considering Soil Structure Interaction

In this paper, a comprehensive study of seismic response of base isolated bridge is made by varying different parameters such as soil stiffness, embedment depth, hydrodynamic pressure and earthquake response spectrum. The object is to determine effect of soil-structure interaction on seismic response when isolation by elastomeric bearing is provided between superstructure and substructure. Elastomeric bearing is seen to be effective in reducing seismic response of substructure on rocky site. The increase in embedment depth also causes reduction in bending moments and shear forces in the substructure. The use of elastomeric bearing in place of Rocker-Roller bearing is seen to be beneficial from seismic considerations

Seismic Behaviour of Bridges Considering Soil-Structure Interaction

The soil-structure interaction has significant effect on seismic response of bridges in many situations. The choice of soil springs for response determination is an important consideration. This paper presents a comparative assessment of the seismic response of bridge substructure by four different types of frequency independent soil springs namely, Beredugo-Novak, Wolf, Bycroft-Parmelee and Terzaghi. The variation of equivalent weighted damping and equivalent seismic coefficient is also studied. The Terzaghi\u27s soil springs obtained by modulus of subgrade reaction approach are most flexible as compared to others. The responses are seen to be comparable with springs other than Terzaghi. The equivalent damping in higher modes is increased due to energy dissipation in soil. The codal provisions of equivalent seismic coefficient variation below scour level are generally unconservative

On the origin of the artesian groundwater and escaping gas at Narveri after the 2001 Bhuj earthquake

At Narveri, north of Khavada in the Great Rann of Kachchh, an outflow of groundwater continued even more than four months after the Bhuj earthquake of 26 January 2001, although at a considerably reduced rate compared to that immediately following the earthquake. Air or gas bubbling through the freshly oozing water has also been observed. We had collected a large number of samples from different parts of Gujarat, where post-earthquake groundwater outpourings were reported. Narveri, however, was the only site where the samples showed dissolved helium concentrations, significantly above the air equilibration value. Based on measurements of helium, radon, chloride, sulphate and sodium concentrations and temperature, we suggest that the flowing water and escaping gases at Narveri have a deep confined source with a reservoir age in excess of ~ 104 years

Medical research and ethics - Revisited

Ethics in the medical research is known since many years; however, there have been new developments in this area recently. A phenomenal improvement in the health-care system, leading to increased life expectancy, and thereby, newer lifestyle and other health-related diseases has opened avenues for newer drugs and health-care technology. However, these have to be tried and tested in the context of the disease epidemiology, health-care delivery and of course, medical ethics. Monitoring and evaluation of the treatment regimes of well documented effective medicines is also required. This is the core of medical research. With the ever increasing concept of evidence-based medical system, and thereby, a rapid rise in the number of clinical trials; the role of medical ethics is potentially increasing to keep the patient

Behavior of Buildings in August 21, 1988 Bihar-Nepal Earthquake

A moderate size earthquake rocked Bihar-Nepal border at 4.40 hrs. on August 21, 1988 causing wide spread devastation leading to loss of many lives and economic loss to the people of that region. The paper describes the study of damages occurred in masonry buildings, reinforced concrete buildings and liquefaction of the soil. The weakness of construction causes of damage and lessons learnt from the performance of structures are highlighted. The traditional and old structures without any earthquake resistance measures has suffered greater damage. The new reconstruction and strengthening measures must take into consideration the experience of failure of structures

Thoracoscopic oesophageal atresia/tracheo-oesophageal fistula (OA/TOF) repair is associated with a higher stricture rate: a single institution’s experience

Purpose: Thoracoscopic OA/TOF repair was first described in 1999. Currently, less than 10% of surgeons routinely employ minimally access surgery. Our primary aim was to review our immediate-, early- and long-term outcomes with this technique compared with the open approach. Methods: A retrospective review of all patients undergoing primary OA/TOF (Type C) repair at our institution from 2009 was conducted. Outcome measures included length of surgery, conversion rate from thoracoscopy, early complications such as anastomotic leak and post-operative complications such as anastomotic strictures needing dilatations. Fisher’s exact and Kruskal–Wallis tests were used for statistical analysis. Results: 95 patients in total underwent OA/TOF repair during the study period of which 61 (64%) were completed via an open approach. 34 were attempted thoracoscopically of which 11 (33%) were converted. There was only one clinically significant anastomotic leak in our series that took place in the thoracoscopic group. We identified a significantly higher stricture rate in our thoracoscopic cohort (72%) versus open surgery (43%, P < 0.05). However, the median number of dilations (3) performed was not significantly different between the groups. There was one recurrent fistula in the thoracoscopic converted to open group. Our median follow-up was 60 months across the groups. Conclusion: In our experience, the clinically significant leak rate for both open and thoracoscopic repair as well as recurrent fistula is much lower than has been reported in the literature. We do not routinely perform contrast studies and are, thus, reporting clinically significant leaks only. The use of post-operative neck flexion, ventilation and paralysis is likely to be protective towards a leak. Thoracoscopic OA/TOF repair is associated with a higher stricture rate compared with open surgery; however, these strictures respond to a similar number of dilatations and are no more refractory. Larger, multicentre studies may be useful to investigate these finding further

Self-medication amongst pregnant women in a tertiary care teaching hospital in India

Background: Self-medication is a popular practice in developing countries where there is no strict regulation of drugs sold in local pharmacies. General public is usually unaware of the adverse effects of drugs used for common illness and continue using them without prescription during pregnancy. This study was carried out to know the extent of self-medication practised by pregnant women and various factors associated with it.Methods: A questionnaire based, cross-sectional study of pregnant women visiting the OB GYN-OPD of a tertiary care teaching hospital was conducted. 303 eligible subjects were questioned and statistical analysis was carried out.Results: Total 16.5% women were found to be self-medicating during pregnancy for common conditions like headache (26%), fever (23%) and common cold (19%). Odds Ratio between the self-medicating and non-self-medicating groups for variables like age (<25 years; ≥25 years), education (illiterate; literate) and gestational age (<20 weeks; ≥20 weeks) are 1.6, 2 and 1.73 respectively. Women with a history of self-medicating before pregnancy were significantly more likely to continue doing so during pregnancy (p value <0.00001).Conclusions: A significant proportion of pregnant women have been found to self-medicate without knowing the adverse effects of the drug used. Thus, spreading awareness against this health-predicament is necessary

Failure to normalize lymphopenia following trauma is associated with increased mortality, independent of the leukocytosis pattern

INTRODUCTION: Following trauma and systemic inflammatory response syndrome (SIRS), the typical response is an elevation of the total complete blood count (CBC) and a reduction of the lymphocyte count. This leukocytosis typically returns to normal within 48 hours. The persistence of a leukocytosis following trauma is associated with adverse outcomes. Although lymphocyte anergy and dysfunction following trauma is associated with increased risk for infection and sepsis, there is a paucity of data regarding the impact of a persistence of a low lymphocyte count in trauma patients. METHODS: This is a retrospective review of prospectively collected data from trauma patients collected over the 5 years of September 2003 to September 2008. Patients were included if the injury severity score (ISS) was >/=15, and they survived at least 3 days. Demographic data, mechanism and injury severity score, mortality, and length of stay were collected from the medical record. Laboratory values for the first 4 hospital days were collected. Leukocyte, neutrophil and lymphocyte counts were extracted from the daily complete blood count (CBC). Patients were then grouped based on response (elevation/depression) of each component of the CBC, and their return, or failure thereof, to normal. Proportional hazards regression with time-varying covariates as well as Kaplan-Meier curves were used to predict risk of death, time to death and time to healthy discharge based on fluctuations of the individual components of the CBC. RESULTS: There were 2448 patients admitted over the 5 years included in the analysis. When adjusting for age, gender and ISS the relative risk of death was elevated with a persistent leukocytosis (2.501 (95% CI = 1.477-4.235)) or failure to normalize lymphopenia (1.639 (95% CI = 10.17-2.643)) within the first 4 days following admission. Similar results were seen when Kaplan-Meier curves were created. Persistent lymphopenia was associated with shortest time to death. Paradoxically in survivors persistent lymphopenia was associated with the shortest time to discharge. CONCLUSIONS: Persistently abnormal CBC responses are associated with a higher mortality following trauma. This is the first report noting that a failure to normalize lymphopenia in severely injured patients is associated with significantly higher mortality

Corrections to the Nonrelativistic Ground Energy of a Helium Atom

Considering the nuclear motion, the authors give out the nonrelativistic ground energy of a helium atom by using a simple but effective variational wave function with a flexible parameter $k$. Based on this result, the relativistic and radiative corrections to the nonrelativistic Hamiltonian are discussed. The high precision value of the helium ground energy is evaluated to be -2.90338 a.u., and the relative error is 0.00034%.Comment: 8 pages, no figures, 2 table