On the performance of GPU accelerated q-LSKUM based meshfree solvers in Fortran, C++, Python, and Julia

This report presents a comprehensive analysis of the performance of GPU accelerated meshfree CFD solvers for two-dimensional compressible flows in Fortran, C++, Python, and Julia. The programming model CUDA is used to develop the GPU codes. The meshfree solver is based on the least squares kinetic upwind method with entropy variables (q-LSKUM). To assess the computational efficiency of the GPU solvers and to compare their relative performance, benchmark calculations are performed on seven levels of point distribution. To analyse the difference in their run-times, the computationally intensive kernel is profiled. Various performance metrics are investigated from the profiled data to determine the cause of observed variation in run-times. To address some of the performance related issues, various optimisation strategies are employed. The optimised GPU codes are compared with the naive codes, and conclusions are drawn from their performance.Comment: 42 pages, 3 figure

Fracture properties of GGBFS-blended fly ash geopolymer concrete cured in ambient temperature

Fracture characteristics are important part of concrete design against brittle failure. Recently, fly ash geopolymer binder is gaining significant interest as a greener alternative to traditional ordinary Portland cement (OPC). Hence it is important to understand the failure behaviour of fly ash based geopolymers for safe design of structures built with such materials. This paper presents the fracture properties of ambient-cured geopolymer concrete (GPC). Notched beam specimens of GPC mixtures based mainly on fly ash and a small percentage of ground granulated blast furnace slag were subjected to three-point bending test to evaluate fracture behaviour. The effect of mixture proportions on the fracture properties were compared with control as well as OPC concrete. The results show that fracture properties are influenced by the mixture compositions. Presence of additional water affected fracture properties adversely. Fracture energy is generally governed by tensile strength which correlates with compressive strength. Critical stress intensity factor varies with the variation of flexural strength. Geopolymer concrete specimens showed similar load–deflection behaviour as OPC concrete specimens. The ambient cured GPC showed relatively more ductility than the previously reported heat cured GPC, which is comparable to the OPC specimens. Fly ash based GPC achieved relatively higher fracture energy and similar values of KIC as compared to those of OPC concrete of similar compressive strength. Thus, fly ash based GPC designed for curing in ambient condition can achieve fracture properties comparable to those of normal OPC concrete

Rational design of hierarchically porous sulfonic acid and silica hybrids with highly active sites for efficient catalytic biodiesel synthesis

Catalysis is the vertebra of most of commercial processes, which utilizes chemical reactions to transform reagents into value added chemicals. Biodiesel synthesis from animal fats and edible vegetable oils via transesterification over homogeneous catalysts is recently taken into account of untenable by the emerging biofuel industries, particularly by virtue of food vs. fuel counteraction, economic and environmental challenges blended with the feedstocks as well as catalytic systems, respectively. Therefore, present efforts concern with the preparation of a novel PTSA-Si catalyst and its relevance for biodiesel synthesis from non-food castor oil. It has been manifested from the experimental outcomes, the most relevant reaction parameters are, 5% PTSA-Si (w/w), 65 ​°C reaction temperature, 1:11 O:M molar ratio and 10 ​h reaction time for 98.56% biodiesel yield. The PTSA-Si was appropriately analyzed using FT-IR, SEM, XRD, BET, TGA-DTA and TPD-NH3 analysis. Since, castor oil and castor biodiesel were analyzed using FT-IR, 1H &13C NMR analysis. Besides, biodiesel physico-chemical properties were predicted and associated with ASTM fuel standards

Fracture Mechanics Model for Analysis of Plain and Reinforced High-Performance Concrete Beams

In developing a one-dimensional analysis and design procedure for reinforced concrete structures, research is generally based on yield phenomena and the plastic flow of steel in tension and concrete in compression. The ability of concrete to resist tension is considered in the form of tension stiffening or is completely disregarded. This procedure does not account for the influence of structural size in changing the failure mode and the stress distribution across the uncracked or cracked ligament. The key factor affecting this stress distribution is found to be the strain-softening modulus. This paper presents an improved model that is based on the fundamental equilibrium equation for the progressive failure of plain concrete beams. The concrete stress-strain relationship in tension is derived by calculating the peak tensile stress, and softening modulus for different depths of beams on the basis of the fracture parameters obtained with the size effect law. Thus, the proposed model uses the peak tensile stress and the softening modulus, which vary depending on the size of the beam. To study the effect of the strength of high-performance concrete (HPC) on the concrete tensile stress-strain relationship, the experimental load-deflection plots of different-sized beams are compared with those obtained by using the proposed analytical model for eight different mixes made with locally available fly ash and slag. The model is also extended for lightly reinforced concrete beams,and the results are compared with those in the literature and are found to be in good agreement

Long term studies on FRP strengthened concrete specimens

465-472This paper presents the results of long term studies on fiber reinforced polymer (FRP) strengthened concrete cylinders and reinforced concrete (RC) beams. The specimens strengthened with one and two layers of carbon or glass fibers are tested for long term performance under natural seasonal environmental conditions. The results of compression test on cylinders and flexural test on RC beam exposed for duration of zero (unexposed), one and two years have been reported. From the results it is observed that the ultimate load carrying capacity of the RC specimens strengthened with CFRP are more when compared with GFRP strengthened specimens exposed to a period of one and two years. This study recommends that the strengthening with CFRP will serve better in long term performance when compared with GFRP

Genetic Inheritance of Anthocyanin Pigmentation in Rice (Oryza sativa L.)

Rice is an important cereal crop that belongs to the grass family Poaceae. A unique feature of purple-coloured anthocyanin pigmentation is possessed by some of the rice varieties and the accumulation of anthocyanin in plants offers resistance to UV radiation and brings out responses to various biotic and abiotic stresses. Knowledge of the inheritance of pigmentation will aid breeders in developing appropriate selection strategies to improve the trait under consideration. In order to study the inheritance of anthocyanin pigmentation, an experiment involving the F1 and segregated F2 populations obtained by crossing the two Oryza sativa subsp. indica varieties, viz., BPT-5204 (non-pigmented) and HY-256 Purple (pigmented), was conducted during three consecutive growing seasons at AICRIP, ARS (Paddy), Sirsi. Hybridization between the female parent, BPT-5204 and male parent, HY-256 Purple, was done during summer 2021 and the seeds obtained from hybridization constituted the F1 generation and were sown during kharif 2021. The same were subjected to selfing to obtain seeds to generate the F2 population, which were evaluated along with the parents and F1 plants during summer 2022. Observations on the presence or absence of anthocyanin pigmentation for different morphological traits, viz., leaf blade, leaf tip, leaf margin, midrib, juncture and junctura back, were recorded in the parents, F1’s and F2 populations in such a way that the presence of pigmentation was recorded as purple, while its absence was recorded as non-pigmented or green. Purple-coloured anthocyanin pigmentation was absent in all the characters in the F1 plant. Similarly, varied segregation for pigmentation was observed and documented in 1276 plants that constituted the F2 generation. The data was analyzed for colour pigmentation to determine the fitness with diverse segregation ratios and to determine the mode of inheritance by chi-square test, which revealed the involvement of two to three genes with different gene interactions