Strengthening of Load Bearing Masonry Wall Panels with Externally Bonded Precast Textile Reinforced Concrete Laminate

241-245Textile Reinforced Concrete (TRC) has gained worldwide popularity as a strengthening material for masonry structures in the recent years. As of today, the application of TRC for masonry strengthening is either by cast-in-place methodology or by spraying method. The present work is a first-of-its kind study, which explores the feasibility of using externally bonded precast TRC laminate for strengthening of load bearing brick masonry wall panels. The binder used in TRC itself is used as adhesive for adhering the TRC laminate to masonry wall panels. Experimental investigations were carried out on unstrengthened and strengthened brick masonry wall panels under axial compression and combined axial compression and shear loading. The influence of TRC strengthening system is assessed by examining the performance indicators such as strength, stiffness and deformation. Based on the investigations, the use of externally bonded precast TRC laminate is found to be a feasible solution to strengthen brick masonry walls to have the required structural adequacy

Strengthening of Load Bearing Masonry Wall Panels with Externally Bonded Precast Textile Reinforced Concrete Laminate

Textile Reinforced Concrete (TRC) has gained worldwide popularity as a strengthening material for masonry structures in the recent years. As of today, the application of TRC for masonry strengthening is either by cast-in-place methodology or by spraying method. The present work is a first-of-its kind study, which explores the feasibility of using externally bonded precast TRC laminate for strengthening of load bearing brick masonry wall panels. The binder used in TRC itself is used as adhesive for adhering the TRC laminate to masonry wall panels. Experimental investigations were carried out on unstrengthened and strengthened brick masonry wall panels under axial compression and combined axial compression and shear loading. The influence of TRC strengthening system is assessed by examining the performance indicators such as strength, stiffness and deformation. Based on the investigations, the use of externally bonded precast TRC laminate is found to be a feasible solution to strengthen brick masonry walls to have the required structural adequacy

Variable Stars in Galactic Globular Clusters

Based on a search of the literature up to May 2001, the number of known variable stars in Galactic globular clusters is approximately 3000. Of these, more than 2200 have known periods and the majority (approximately 1800) are of the RR Lyrae type. In addition to the RR Lyrae population, there are approximately 100 eclipsing binaries, 120 SX Phe variables, 60 Cepheids (including population II Cepheids, anomalous Cepheids and RV Tauri) and 120 SR/red variables. The mean period of the fundamental mode RR Lyrae variables is 0.585, for the overtone variables it is 0.342 (0.349 for the first-overtone pulsators and 0.296 for the second-overtone pulsators) and approximately 30% are overtone pulsators. These numbers indicate that about 65% of RR Lyrae variables in Galactic globular clusters belong to Oosterhoff type I systems. The mean period of the RR Lyrae variables in the Oosterhoff type I clusters seems to be correlated with metal abundance in the sense that the periods are longer in the more metal poor clusters. Such a correlation does not exist for the Oosterhoff type II clusters. Most of the Cepheids are in clusters with blue horizontal branches.Comment: 45 pages, 10 figures, to be published in AJ November 200

An Observational study to Compare Prophylactic and Therapeutic Surfactant Administration in Preterm Babies and Retinopathy of Prematurity

AIM AND OBJECTIVES: To compare Prophylactic versus Therapeutic surfactant administration in preterm babies and retinopathy of prematuriy. STUDY DESIGN: Prospective Observational study. STUDY CENTRE: • Department of Ophthalmology, Government Rajaji Hospital, Madurai. • Neonatal intensive care unit,Institute of Paediatrics, Government Rajaji Hospital, Madurai. STUDY DESIGN: Prospective Observational study. STUDY CENTRE: • Department of Ophthalmology, Government Rajaji Hospital, Madurai. •Neonatal intensive care unit,Institute of Paediatrics, Government Rajaji Hospital, Madurai. Informed Consent for the study is obtained in written statement from parents or guardian of all the babiesbefore enrolment for the study. SELECTION OF STUDY SUBJECTS: 100 babies fulfilling the eligibility criteria referred from Neonatology Intensive Care Unit, GRH, Madurai whom were given surfactant therapy. METHODOLOGY: The various parameters recorded were weight at birth, gestational age, age of post conception, risk factors such as anaemia, long term exposure to oxygen, neonatal jaundice, mechanical ventilation, use of any surfactant, Respiratory Distress Syndrome, sepsis, multiple births, multiple blood transfusions, and intraventricular haemorrhage. Gestational age was calculated according to last menstrual period or according to the date mentioned by first trimester USG abdomen. In our study the screening protocol for ROP was followed based on the guidelines by National Neonatology Forum (NNF). The first retinal examination would be held at 4 to 5 weeks from the birth. Retina examined with binocular indirect ophthalmoscope with+20 D lens. Patient information and retinal findings recorded in the ROP screening case sheet. For categorising ROP, revised ICROP guidelines and classification was used. Followup schedule individualised based on the retinal findings and it would be continued till retina vascularises completely or ROP regression noted or until treated according to the ETROP guidelines. In our study, “Mild ROP”- was termed for ROP where the severity is not sufficient to meet the criteria for treatment according to “ETROP” and CRYO-ROP study and, “Severe ROP”- was termed for either the Type 1 ROP based on “ETROP study” findings or the threshold ROP, Aggressive ROP, stage 4 ROP (partial RD) or stage 5 ROP(total RD) that validates treatment. Babies in our study will be categorised into two groups as follows: GROUP 1: Preterm low birth weight babies who received prophylactic surfactant therapy. GROUP 2: Preterm low birth weight babies who received therapeutic surfactant therapy. PROCEDURE: - Procedure explained to babie’s parents or the guardian. - Informed written consent to be obtained. - Oral feeds to be curtailed one hour before the procedure. - Clean hands with disinfectant is the priority. - Anterior segment of the eye would be examined before retinal examination to look for pupil size, tunica vasculosalentis, pupillary light reflex and lens status. - Both the eyes are dilated with the mydriatics, as a combination of tropicamide 0.5% and phenylephrine 2.5% eye drops has to be prepared by diluting tropicamide 0.8% and phenylephrine 5% eye drop in tear substitutes in 50:50, and used two to three times about 10-15 minutes apart. STATISTICAL ANALYSIS: The information collected regarding all the selected cases were recorded in a Master Chart. Data analysis was done with the help of computer by using SPSS 16 software. Using this software, percentages, means, standard deviations were calculated and 'p' values were calculated from Student ‘t’ test for raw data and chi square test for consolidated data to test the significance of difference between variables. A 'p' value less than 0.05 is taken to denote significant relationship SUMMARY OF RESULTS: Among 100 babies taken for the study, 20 had severe ROP ; 16 had mild ROP and 54 had No ROP. Among 100 babies analysed, 54 were males and 46 were females. Group 1 had 22 males and 22 females also Group 2 had 32 males and 24 females. There was no significant association of gender between the groups, since the ‘p’ value was 0.611. The mean gestational age in group 1 and group 2 were 30.818 weeks and 31.719 weeks respectively and there is no significant difference in gestational age between the two groups.(P = 0.242). The mean birth weight in group 1 and group 2 were 1.412 grams and 1.542 grams respectively and significant difference was found between the two groups.(P = 0.011). Among 100 babies, 58 were normal vaginal delivery and 32 were LSCS. Group 1 had 28 NVD cases and 16 LSCS cases and group 2 had 40 NVD cases and 16 LSCS cases. There was no significant association between two types of mode of delivery in both the groups. (P = 0.54) *In this study, prophylactic surfactant is given to 44 babies and therapeutic surfactant to 56 babies * In Group 1, among male and female occurrence of severity of ROP shows P value as 0.678 and in Group 2 its 0.406.both are not statistically significant. * In Group 1, occurrence of Severe ROP on comparing gestational age 30 weeks shows p value 0.234. In Group 2, occurrence of severe ROP in group 2 shows p value 0.318.both are not statistically significant. In Group 1, occurrence of Severe ROP on comparing birth weight 1.25 shows p value 0.105. In Group 2, occurrence of sever ROP in group 2 shows p value 0.809.Both are not statistically significant. Among 100 babies, 20 were severe ROP cases, 16 mild ROP cases and 54 were No ROP cases. Group 1 had 2 severe ROP cases, 6 mild ROP cases, 36 No ROP cases .Group 2 had 18 severe ROP cases, 10 mild ROP cases and 36 No ROP cases. The incidence of severe ROP was found to be more among surfactant given babies. Statistical analysis showed, there is significant association between retinal findings in both the groups. (P < 0.001). CONCLUSION: Our study showed that babies who had prophylactic Surfactant administration compared to therapeutic surfactant administration showed reduced incidence in severity of ROP. When Surfactant administration is present in preterm low birth weight babies, and if its therapeutic also it should be considered as an independent risk factor for ROP. Followup and screening to be increased in babies who had therapeutic surfactant administration in postnatal period. When surfactant administered babies are screened for ROP regularly, it will help to detect the ROP timely and treatment can be delivered at its earliest. Thus reducing the devastating sequeale of ROP. It is also helpful to avoid unnecessary stressful examination on preterm infants who are not at risk of developing “severe ROP”. Our study result helps the ophthalmologists and the neonatologists to look into the surfactant administered babies with special care and attention ,and to predict and closely followup for retinopathy changes much earlier before it is being diagnosed by the regular ophthalmic examination .It will help to intervene early and to prevent sight threatening complications. This study shows significant association between therapeutic surfactant administration and severe ROP than prophylactic surfactant administration. Also shows the need for mechanical ventilation is more in therapeutic surfactant babies which can increase the risk of ROP

Performance of Concrete Filled in Cold Form Steel Sheet with Shear Connector under Pure Bending

172-175This paper investigates Performance of concrete filled in cold form steel sheet with shear connector under pure bending. A model is created  using <span style="mso-bidi-font-weight: bold;mso-bidi-font-style:italic">ABAQUS to predict the performance of concrete filled in cold form steel sheet with shear connector to find moment carrying capacity ultimate point. The concrete filled in cold form steel sheet<span style="mso-bidi-font-weight:bold; mso-bidi-font-style:italic"> beam investigated and compared by finite element programme ABAQUS against experimental and theoretical data<span style="mso-bidi-font-weight:bold; mso-bidi-font-style:italic">. The reinforced concrete beam shuttered with the cold formed steel sheet and stud T shaped shear connectors were welded on three sides of the beam. Bracings were provided on the top of the beam in the pure bending region. The moment capacity depends on the parameter of q, which is ratio of force in shear connectors and force in bottom reinforcement. The experiment was carried out with various spacing of shear such as 75,100,125 and 150mm, we found that beams of 75mm spacing of shear connector takes higher ultimate load. The comparison of ultimate bending moment vs. spacing of shear connector for the beams analyzed with experimental, theoretical and ABAQUS value gives 75 mm spacing attain the good ultimate strength of the beam. </span

RECOVERY AND REUSE OF FINE AGGREGATE FROM DEBRIS OF BUILDING DEMOLITION

ABSTRACT Demolition of unsafe buildings and structures requiring extensive modifications is more common now a days. Almost 30% of new constructions are coming up on the demolition site. Handling of demolition debris has become a challenging issue in all the developing countries including India. The growth rate in the construction sector is 1.5 times in 5 years. While the demand for aggregates is increasing day-by-day, the natural resources like sand, gravel etc. are decreasing around the world. The need for the recycle of aggregate recovered from the debris is the need of the hour to meet the rising demand. Various studies have been reported on the subject. The present study reports the developed empirical relations between the area of the building and different items of materials in the debris for the estimation of quantity generation. Experimental results on the strength of concrete for different proportions of replacement of fine aggregate recovered from the debris are presented. The study results encourage the use of fine aggregate recycle in concrete

Identification of Recharge Processes in Groundwater in Hard Rock Aquifers of Madurai District Using Stable Isotopes

Stable isotopes of H and O are the integral parts of water molecule and serve as ideal tracers to understand the recharge processes in groundwater. Hence, a study has been conducted in hard rock aquifers of Madurai District of Tamilnadu to identify the recharge processes using stable isotopes. A total of 54 groundwater samples were collected representing the entire district from various lithounits during post monsoon. Samples were analysed for pH, EC, Ca2+, Mg2+, Na+, K+, Cl− HCO3−, SO42−, PO43−, H4SiO4, F−, δ18O and δD. Cl− and HCO3− were the dominant ions in groundwater samples. Average values of Cl− and HCO3− ranged from 247 and 244 mg/L in fissile hornblende biotite gneiss, 262 and 268 mg/L in Charnockite, 75 and 185 mg/L in quartzite, 323 and 305 mg/L in granite, 524 and 253 mg/L in floodplain alluvium rock types. Geochemical signatures of groundwater were used to identify the chemical processes that control hydrogeochemistry. Interpretation of δ18O and δD indicates recharge from the meteoric water in charnockite, quartzite, granite and some samples of fissile hornblende biotite gneiss. It is also inferred that recharge take place from evaporated water in floodplain alluvium and fissile hornblende biotite gneiss

Determination of the utility of groundwater with respect to the geochemical parameters: a case study from Tuticorin District of Tamil Nadu (India)

In modern living, rapid development has created an increase in demand for groundwater. An endeavor has been made to understand the hydrogeochemical parameters to determine the utility of groundwater. This situation is severe in coastal hard rock aquifers due to the influence of salinity ingression and other anthropogenic influence. A total of 135 groundwater samples were collected from the coastal aquifer of the Tuticorin district and analyzed for major cations and anions during premonsoon (PRM) and postmonsoon (POM). The ions analyzed were used to determine the drinking, agricultural and domestic utility of groundwater. The electrical conductivity (EC) contour shows that the groundwater quality is poor along the coast. The parameters were compared with WHO (Guidelines for drinking water quality recommendations, WHO, Geneva, 2004) standard for drinking purpose. A groundwater classification method has been developed for groundwater in the area using a dynamic water quality index (WQI). On the basis of the WQI so computed, groundwater in the area has been spatially classified into “excellent,” “good,” “poor” and “very poor” to “Unsuitable” water types variation lithologywise. Corrosivity ratio and hardness were noted to be higher and found to be unsuitable in majority of the regions for domestic purpose. Higher fluoride concentration was noted in the central part of the study area represented by complex geology comprising of the hornblende biotite gneiss and charnockite. Sodium percentage (Na%), sodium absorption ratio, residual sodium carbonate, Wilcox (Classification and use of irrigation waters, US Department of Agriculture, Washington, 1955), permeability index, residual sodium bicarbonate, magnesium hazard, Kelly’s ratio and potential salinity also indicate that most of the groundwater samples are not suitable for irrigation purposes

Epigenetic and transcriptional regulation of cytokine production by Plasmodium falciparum-exposed monocytes

Abstract Plasmodium falciparum infection causes the most severe form of malaria, where excessive production of proinflammatory cytokines can drive the pathogenesis of the disease. Monocytes play key roles in host defense against malaria through cytokine production and phagocytosis; however, they are also implicated in pathogenesis through excessive proinflammatory cytokine production. Understanding the underlying molecular mechanisms that contribute to inflammatory cytokine production in P. falciparum-exposed monocytes is key towards developing better treatments. Here, we provide molecular evidence that histone 3 lysine 4 (H3K4) methylation is key for inflammatory cytokine production in P. falciparum-exposed monocytes. In an established in vitro system that mimics blood stage infection, elevated proinflammatory TNF and IL-6 cytokine production is correlated with increased mono- and tri-methylated H3K4 levels. Significantly, we demonstrate through utilizing a pharmacological inhibitor of H3K4 methylation that TNF and IL-6 expression can be suppressed in P. falciparum-exposed monocytes. This elucidated epigenetic regulatory mechanism, controlling inflammatory cytokine production, potentially provides new therapeutic options for future malaria treatment