NALLA-2 : Strain measurements

Strains were monitored for NALLA2 Structural components at critical locations : 60 locations for wing, 50 for fuselage, 6 each for horizontal tail, vertical tail, landing gear and nose gear and 20 locations for wing fuselage joint. While the wing fuselage joint was tested upto the ultimate load, the rest of the components were loaded upto the limit load only. The measured strains have proved the linear behaviour upto the limit Load, with zero yield, validating the structural integrity, of the components

Estimating epidemiological and economic burden and community derived disability weights for snake bite in Kerala: a study protocol

BACKGROUND: In India, lack of data and underreporting of cases and deaths due to snakebite makes it difficult to estimate its socio-economic burden. Previous studies measuring economic burden of snakebite in low-and-middle-income countries (LMICs) using different approaches have been conducted, but none in India. The proposed study aims to provide evidence on disability weights, epidemiological and economic burden due to snakebites in Kerala state, India. PROTOCOL: The study is a community based cross-sectional study recruiting victims of snakebite occurring over a 12 month period prior to start of the study , across Ernakulam district, Kerala state, India. For the community-derived disability weights,70 adult patients who were treated within a 3 month period prior to commencement of the study at Amrita Institute of Medical Sciences, Kochi or Little Flower Hospital, Angamaly would be interviewed. The study will measure annual incidence, mortality, treatment cost of snakebites along with community-derived disability weights for snakebites in Ernakulam district.. Standard methods for analysis and reporting of mortality, morbidity, Years of Lives Lost (YLL), Years lived with disability (YLD), disability weights, and costs of treatment will be calculated. The study will be started in April 2021 and is expected to be completed by July2021. DISCUSSION: This protocol is the first published for estimating epidemiological, economic burden and community derived disability weights for snakebites in India. Besides, the Global Burden of Disease has not attached a particular disability weight to snakebite and this would be an attempt to do so. The protocol has been developed using guidelines for cross-sectional studies, cost of illness studies and international guidelines for conducting community derived disability weights. The evidence generated by this study will contribute significantly to knowledge regarding the epidemiology, economic burden and community-derived disability weights for snakebites in India and other countries where incidence of snakebite is high

NALLA2: Adhesive bond quality evaluation

The bond quality of the adhesively bonded skin-core construction (Glass Fibre Reinforced Plastic, GFRP, skin and Styrofoam core) of the Wing and Fuselage of all-composite aircraft, NALLA2, is evaluated. Bond Tester Model70 of Fokker VFW, The Netherlands, is employed. Test results before and after the static testing of these components indicated the changes in bond quality in the skin-core adhesive joints

Structural static testing of LCA rudder

Structural static strength test was conducted on the CFRP Composite Co-cured rudder for LCA, to demonstrate the structural integrity of the rudder and to experimentally determine the deflections and strains at selected locations and to correlate the test values with those obtained by theoretical analysis. The rudder was loaded upto the limit load (2614.0 kgs) and a limit reaction load (652.2 kgs) was also simultaneously applied. The load Vs deflection / strain behaviour was obtained. The rudder successfully withstood the limit load without any failure and the corresponding maximum tip deflection was 37.16 mm. The maximum strain recorded was 1998 micro strain on the shear web of the front spar of the rudder. The torque monitored on the link rod was 3874.20 N-m and the applied torque was 3675.17 N-m. Both the deflections and strains were well within design requirements. It was therefore concluded that the structural behaviour of the rudder is satisfactory and it was cleared for flight trials. This report deals with the results of the static testing of the rudder

Static testing of bridge deck plate prototypes

This report gives details of the static tests conducted on two types of prototypes : a) Sandwich type with aluminium alloy honeycomb core and Redux bonded GFRP face sheets and b) All GFRP integral web typ

Improved procedure for the determination of apparent strain

An improved procedure for theoretically determining the apparent strain is proposed. Based on the results of an experimental study into the behaviour of high temperature strain gages in a varying thermal environment a theoretical formula is developed. One of the significant features of the proposed formula lies in its ability to predict the apparent strain without actually carrying out the experiment, provided the relevant strain gage material parameters as also the coefficient of thermal expansion of the specimen material are known. A comparison study of the results obtained by using the proposed formula with the experimentally determined results shows excellent agreement. Its application to the development of improved temperature compensated gages is also indicated

Non destructive evaluation of repair schemes for advanced13; composite structures

This report primarily pertains to the non-destructive13; evaluation of candidate CFRP components chosen for the demonstration of various repair schemes . Nondestructive13; evaluation involved through transmission C-scan inspection . The purpose here was two-fold : to map the extent of damage and to assess the efficacy of the repair scheme . A few destructive tests were also performed in the case of bonded scarf repair of CFRP laminates for assessing the repair schem

Nonlinear responses of soil respiration to precipitation changes in a semiarid temperate steppe

Extreme precipitation events are predicted to occur more frequently and will have significant influences on terrestrial ecosystem carbon (C) cycling in the future. However, response patterns of soil respiration to precipitation changes remain uncertain in terrestrial ecosystems. A field experiment with seven precipitation treatments (i.e. from −60% to +60% of ambient precipitation to form a drought to wet precipitation gradient) was conducted over three growing seasons (2010–2012) in a semiarid temperate steppe of Northern China. Results showed a nonlinear response pattern of soil respiration along the experimental precipitation gradient, with soil respiration suppressed by decreased precipitation and enhanced by increased precipitation. Over the three growing seasons, soil respiration was reduced more under the three drought treatments (by 45.8, 32.8, and 15.9% under the −60, −40, and −20% treatments, respectively) than stimulated under the three wet treatments (by 8.9, 14.3, and 18.5% under the +20, +40, and +60% treatments, respectively). Our results indicate that soil respiration was more sensitive to decreased than increased precipitation treatments. The nonlinear and asymmetric responses of soil respiration to precipitation changes should be built into ecosystem models to project ecosystem C cycling associated with climate change