Soil organic carbon stock in natural and restored mangrove forests in Pichavaram south-east coast of India

801-808Mangrove ecosystem is one of the important coastal ecosystems providing ecological security of the coastal area and livelihood security to the coastal fishermen.  Besides it plays an important role in carbon sequestration as large amount of carbon is stored in the below ground biomass. The role of mangrove restoration in carbon stocking has not been studied comprehensively either globally or nationally. The aim of the present study is to quantify the soil organic carbon stock and carbon sequestration rate of the different age groups of restored and natural stands of Pichavaram mangroves forest. The soil organic carbon stock of the upper soil layer (0–90 cm) of six different sites from natural mangrove stands, 21years, 17 years, 16 years, 15 years and 12 years old stands were 146.1(Mg C ha-1), 99.29 (Mg C ha-1), 93.18 (Mg C ha-1), 57.41 (Mg C ha-1), 95.54 (Mg C ha-1) and 84.84 (Mg C ha-1), respectively. Carbon sequestration rate of Pichavaram mangrove forests ranged from 2.33 to 4.44 g C m-2 year-1. The result of the study reveals that soil organic carbon stock and burial rate were high in natural mangrove area than the restored areas. In this regard, restoration and rehabilitation of mangroves is required for preserving the ecologically important mangroves ecosystem to mitigate the impacts of climate change

Determination of the efficacy and side-effect profile of lower doses of intrathecal morphine in patients undergoing total knee arthroplasty

<p>Abstract</p> <p>Background</p> <p>Intrathecal (IT) morphine provides excellent post-operative analgesia, but causes multiple side effects including nausea and vomiting (PONV), pruritus and respiratory depression, particularly at higher doses. The lowest effective dose of spinal morphine in patients undergoing total knee arthroplasty is not known.</p> <p>Methods</p> <p>We evaluated the analgesic efficacy and side effect profile of 100 – 300 μg IT morphine in patients undergoing elective total knee replacement in this prospective, randomized, controlled, double-blind study. Sixty patients over the age of 60 undergoing elective knee arthroplasty were enrolled. Patients were randomized to receive spinal anaesthesia with 15 mg Bupivacaine and IT morphine in three groups: (i) 100 μg; (ii) 200 μg; and (iii) 300 μg.</p> <p>Results</p> <p>Both 200 μg and 300 μg IT morphine provided comparable levels of postoperative analgesia. However, patients that received 100 μg had greater pain postoperatively, with higher pain scores and a greater requirement for supplemental morphine. There were no differences between groups with regard to PONV, pruritus, sedation, respiratory depression or urinary retention.</p> <p>Conclusion</p> <p>Both 200 μg and 300 μg provided comparable postoperative analgesia, which was superior to that provided by 100 μg IT morphine in patients undergoing total knee arthroplasty. Based on these findings, we recommend that 200 μg IT morphine be used in these patients.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier NCT00695045</p

Ferrography — A procedure for measuring wear rate

377-381A contact fatigue phenomenon is most common failure seen in the structural components, which are under high-cyclic fatigue loads. Rail wheels, mating gears, ball bearing and wherever the formal contact between the two structural elements, are affected by contact fatigue failure, is commonly referred as pitting of surface. It can be seen that those structural elements are manufactured by powder metallurgy technology since it has more technical as well as commercial advantages over the conventionally made structural parts. Development in powder metallurgy manufacturing technologies, will give us confident to use of more powder metallurgy structural parts in place of conventional parts. Rolling-sliding contact fatigue (RSCF) experiments on powder metallurgy (PM) steels have been carried out in the laboratories with available experimental set-up. The lubrication oil is collected for regular interval and ferrography test is involved to predict the wear rate of the powder metallurgy steels. Wear morphology of porous steel is predicted

Influence of counterbody material on fretting wear behaviour of surface mechanical attrition treated Ti-6Al-4V

Surface mechanical attrition treatment (SMAT) was carried out on Ti-6Al-4V. Fretting wear tests were conducted using two counterbody materials (alumina and steel). SMAT resulted in surface nanocrystallization. Due to high hardness, low tangential force coeffl{ligature}cient (TFC) and more TiO 2 layer, fretting wear resistance of SMAT treated samples was higher than that of the untreated samples. TFC values obtained with alumina counterbody were higher than those obtained with steel counterbody. The fretting wear resistance of untreated and treated samples fretted against alumina was lower than that of the samples fretted against steel due to tribochemical reactions at the contact zone. © 2012 Elsevier Ltd