Effect of using performance-based approach for seismic design of tall building diaphragms

This paper presents how performance-based design (PBD) approaches can help to improve the structural performance and cost effectiveness in design of floor diaphragms of tall buildings under earthquakes. In contrast to the prescriptive design approaches, performance-based design provides a systematic methodology for assessing the performance capability of overall building system and its components. The performance-based design explicitly evaluates the response of the building under the potential seismic hazard, considering the probable site-specific seismic demands as well as the uncertainties in the post-yielding response and behaviour of the building under seismic events. Case study of 57-story reinforced concrete residential building with 4 basement levels is presented. The building was designed for Design Basis Earthquake (DBE) level in accordance with traditional code-based design procedures at the preliminary design stage. After preliminary design, the performance of the building was checked explicitly at Service Level Earthquake (SLE) (43-year return period) and Maximum Considered Earthquake (MCE) level (2475-year return period), using linear and nonlinear response history procedures. Diaphragm design forces at podium level and tower levels were explicitly checked at site-specific MCE level event rather than application of code-specified modification factors to estimate the forces and deformation under code-specified earthquake level. Cost effectiveness of the design was evaluated by comparison of the indicative quantities and parameters between the code-based design and the modified design based on PBD

Diversity and Abundance of Copepods in Taninthayi Coastal Waters, Myanmar

Diversity and abundance of copepods occurring in Taninthayi coastal waters were studied and analyzed from the samples collected by R/V DR. FRIDTJOF NANSEN during the Myanmar ecosystem survey 2018. Seventy-nine copepods species belonging to calanoids (51 species), cyclopoids (21 species), and harpacticoids (7 species) were identified in the copepods community of Taninthayi coastal waters. Copepods species number and density were high at the nearshore stations (Sts 799, 842, 788) and low at the offshore stations (Sts 846, 802, 823). The resulted diversity index values of copepods were varied from 2.61 to 3.78 in species diversity index (H'), from 0.89 to 0.97 in the evenness index (E'), and from 2.51 to 7.50 in species richness index (D'). According to the correlation matrix, the abundance of copepods was positively correlated with temperature, chlorophyll a and fluorescence, and negatively correlated with salinity and oxygen

Market surveys and social media provide confirmation of the endangered giant freshwater whipray Urogymnus polylepis in Myanmar

The giant freshwater whipray Urogymnus polylepis is a threatened species that is vulnerable to riverine and coastal marine pressures. Despite its threatened status, the range of U. polylepis is still being determined. In this study, photographic evidence of U. polylepis in Myanmar was provided through market surveys (2017-2018) and social media (Sharks and Rays of Rakhine Facebook page, 2021). Urogymnus polylepis is exposed to fisheries and habitat degradation pressures in Myanmar; therefore, conservation management is likely needed to ensure populations persist into the future

Nutrient composition of 19 fish species from Sri Lanka and potential contribution to food and nutrition security

Fish is an important part of the Sri Lankan diet. However, existing data on the nutrient composition of fish in Sri Lanka is highly outdated and limited. The aim of this study was to report the nutrient composition of commonly consumed marine fish species in Sri Lanka and assess the potential contribution of selected key nutrients in fish to recommended nutrient intakes (RNI). Fish were sampled during a survey with research vessel Dr. Fridtjof Nansen around Sri Lanka. Species were categorised as either small (25 cm, n = 7), and three composite samples from each species were analysed using accredited methods. Small species commonly consumed whole contained significantly higher concentrations of micronutrients such as calcium (960 mg/100 g), iron (3.3 mg/100 g), zinc (2.1 mg/100 g), vitamin A (295 μg/100 g), and EPA and DHA (0.14 and 0.32 g/100 g, respectively) than larger species where only the fillet is consumed. Several species were identified to contribute ≥25 % of the RNI of women of reproductive age for multiple essential nutrients. These data may represent an important contribution to the future development of the Sri Lankan food composition database.publishedVersio

Nutrient Composition of Demersal, Pelagic, and Mesopelagic Fish Species Sampled Off the Coast of Bangladesh and Their Potential Contribution to Food and Nutrition Security—The EAF-Nansen Programme

Fish is a major part of the Bangladeshi diet, but data on the nutrient composition of marine fish species are sparse. Mesopelagic fish may be a new potential resource of food and nutrients; however, nutrient composition data are lacking. The aim of this study was to provide nutrient composition data of fish species sampled off the coast of Bangladesh and determine their potential contribution to recommended nutrient intakes (RNI). Seven species from the pelagic, mesopelagic, and demersal zones were sampled from the coast of Bangladesh with Dr. Fridtjof Nansen in 2018. Three pooled samples containing 15-840 individuals from each species were analysed at the Institute of Marine Research, Norway. The demersal species contained substantially lower concentrations of nearly all nutrients, whereas the mesopelagic species generally were more nutrient dense. All species, except for the demersal species Bombay duck (9% dry matter), were found to contribute ≥100% to the RNI of vitamin B12, eicosapentaenoic acid, docosahexaenoic acid, and selenium. All species, except for the demersal fish species, contributed ≥25% to the RNI of six or more nutrients. The data presented in this paper are an important contribution to the Bangladeshi food composition table and contribute to the understanding of fish as an important source of micronutrients