Investigation of Shear Stud Performance in Flat Plate Using Finite Element Analysis

Three types of shear stud arrangement, respectively featuring an orthogonal, a radial and a critical perimeter pattern, were evaluated numerically. A numerical investigation was conducted using the finite element software ABAQUS to evaluate their ability to resist punching shear in a flat plate. The finite element analysis here is an application of the nonlinear analysis of reinforced concrete structures using three-dimensional solid finite elements. The nonlinear characteristics of concrete were achieved by employing the concrete damaged plasticity model in the finite element program. Transverse shear stress was evaluated using finite element analysis in terms of shear stress distribution for flat plate with and without shear stud reinforcement. The model predicted that shear studs placed along the critical perimeter are more effective compared to orthogonal and radial patterns

Inductive cum targeted yield model based Integrated fertilizer prescriptions for tomato (Solanum lycopersicum L.) under drip fertigation on an alfisol

Soil test crop response (STCR) correlation studies under Integrated Plant Nutrition System were conducted in the western agro-climatic zone of Tamil Nadu during 2020-2021 to devise the fertilizer prescription equations for tomato (Solanum lycopersicum L.)  under drip fertigation on an alfisol. The equations were derived by following Ramamoorthy’s Inductive cum targeted yield model. The nutrient requirement of N, P2O5 and K2O for producing one quintal of tomato fruit was found to be 0.22, 0.11, 0.27 kg respectively. The per cent contribution of nutrients were 37.93, 46.73 and 29.53 of N, P2O5 and K2O from soil (Cs) and 47.84, 31.12 and 74.13 of N, P2O5 and K2O from fertilizers (Cf) respectively. Two organic sources were applied viz., FYM (Farm Yard Manure) and Biocompost and the per cent contribution of nutrients from FYM were 38.36, 13.22 and 52.17 of N, P2O5 and K2O and from biocompost were 43.34, 10.90 and 57.00 of N, P2O5 and K2O respectively. Fertilizer adjustment equations were formulated for STCR-NPK alone, STCR-IPNS (FYM) and STCR-IPNS (Biocompost) by applying the basic parameters such as NR, Cs, Cf, Cfym, Cbiocompost. A ready reckoner of fertilizer doses for a set of soil test values at yield targets 80 and 90 t ha-1 was computed. The findings also showed that the adoption of STCR-IPNS could save more fertilizers

A Material Model Approach on the Deflection and Crack Pattern in Different Panels of the RCC Flat Plate using Finite Element Analysis

Three reinforced cement concrete (RCC) flat plate panels, namely interior, edge, and corner panels, were considered for evaluating the deflection and crack development from the column. In this study, a numerical analysis was conducted for a steel fibre-reinforced flat plate with steel fibre volumes of 0.3% and 0.4%. The study was conducted on real- and scaled-sized flat plates. We used the ABAQUS software to model and evaluate the deflection and crack patterns. An experimental study was conducted on the scaled-sized specimens to validate the finite element analysis (FEA) results. This study presents the punching shear behaviour of various panels of a flat plate with and without steel fibres. The deflection values obtained from the FEA and experiment were compared, and we found that the interior panel exhibited better results when compared to edge and corner panels. A minimum of three sided support is preferred for the stability of a larger-sized flat plate. The interior panels provided better strength and load-bearing capacity when compared to edge and corner panels. Crack patterns for different panels of a flat plate with different steel fibre volumes were analysed by comparing the FEA and experimental results. The development of cracks moved away from the column face on addition of steel fibres and changed its brittle nature. The results indicate that the crack developed from the column face is away from the critical distance d/2 from the slab-column junction (specimens with fibre), further demonstrating the stability of the structure. Doi: 10.28991/CEJ-2022-08-03-05 Full Text: PD

Development and in-vitro Evaluation of a Topical Drug Delivery System Containing Betamethazone Loaded Ethyl Cellulose Nanospheres

Purpose: Lipid nanospheres are used for the passive targeting of cosmetic agents to skin, thereby achieving major benefits such as reduction of total dose and avoidance of systemic absorption. The present study was carried out to exploit the feasibility of using polymeric nanospheres as an alternative and cheaper carrier for targeting corticosteroids to the skin. Methods: Nanospheres were prepared from ethyl cellulose by a modified method of desolvation and cross linking. The drug betamethazone was incorporated into nanospheres and the drug: polymer ratio was evaluated to determine the carrier capacity of the polymer. In-vitro release studies of drug-loaded nanospheres were carried out by the centrifugal ultrafiltration method. The kinetics of release was determined and fitted to an empirical equation. The release of drug from drug-loaded nanospheres dispersing in a conventional cream was evaluated. A comparative in-vitro diffusion study was carried out between a commercial brand of cream and the cream incorporating nanospheres. Results: Formulation of nanospheres of betamethazone by a modified method produced discrete particles. Studies on drug:polymer ratio showed a linear relationship between drug concentration and percentage of loading. The in-vitro release of drug-loaded nanospheres was found to be first order. The comparative in-vitro diffusion study between the commercial cream and the formulated cream showed a marked reduction in release rate from nanospheres-bound cream. Conclusion: Formulated topical cream containing nanospheres of betamethazone was found to be a potential dermal delivery system for sustaining the release of the drug. Keywords: Nanospheres, desolvation and cross-linking method, ethyl cellulose, betamethazone, in-vitro diffusion studies.> Tropical Journal of Pharmaceutical Research Vol. 4 (2) 2005: pp. 495-50

Post-harvest soil nutrient prediction in hybrid castor (Ricinus communis l.) Cropping sequence using a multivariate analysis technique

In the era of precision agriculture, the fertilizer prescription based on the soil fertility status is much required.  Analyzing the soil after each crop is necessary for fertilizer recommendation and developing an alternative technique to forecast the soil available nutrient value rather than analyzing the soil. Multiple linear regression (MLR) equation was developed using filed experiment data to predict the soil available nutrient in castor cropping sequence. The post-harvest soil available nutrient was considered as the dependent variable and the initially available soil nutrient values, fertilizer added, yield and nutrient uptake of castor as an independent variable. In general, the post-harvest soil nutrient model's prediction accuracy was notable and had a coefficient of determination of less than 0.90. By calculating the RMSE (root means square error), R2 value, the ratio performance to deviation (RPD) and, RE (relative error) the performance of the MLR model was confirmed.Using the validated model, post-harvest soil available nutrients were predicted and compared with laboratory tested soil available nutreints. It turned out that the established model is more precisely effective and equally precise. Fertilizer recommendation could be made to subsequent crop after hybrid castor using the predicted soil available nutrients

Impact of forest types on soil properties

Soil and vegetation have a complex interrelationship, in which one influences the other. Both in naturalforests as well as man-made plantations cycling of nutrients is an important aspect as considerableamount of nutrients are returned through litter fall are made available for re-absorption. The natureand amount of organic matter produced depends on the dominant tree species present and the sitecharacteristics of the area, which regulate the physico-chemical properties of soil. Thus, the percentagereturn of nutrient varies with species, site conditions and topography.The present study investigates the effect offorest types on soi I properties. Soil samples were collectedfrom different forest types covering different forest ecosystems viz., dry deciduous forest, moistdeciduous, shola forest, grassland, pine plantation, eucalyptus + wattle plantation, each at three depthsviz., 0-15, 15-30 and 30-45 ern and were analyzed for their physical and chemical properties.The soil pH ranged from 3.52 to 7.60 and the dry deciduous forest registered a maximum pH of 6.54and the minimum was recorded in shola forest. With increase in depth, there was a slight increase inpH under dry deciduous forest, pine plantation and eucalyptus + wattle plantation. Dry deciduousforest registered a maximum EC of 0.946 d'Sm+at top layer followed by shola forests. In general,grassland recorded lower EC values than other vegetations. Organic carbon content was higherunder shola forest. With increasing depth, there was a progressive reduction in organic carbon.Soi I avai lable nitrogen was in the range of 229 kg ha' to 1919 kg ha -I. A higher value of availablenitrogen was recorded in grassland soils followed by shola forest. Available nitrogen was found tooccur in a decreasing order with soil depth in all the study sites excluding sholas and grasslands. Thehighest available phosphorus was recorded in sholas and minimum was found in moist deciduousforest. With increasing depth, there was a great reduction in soil available phosphorus in all locations.This may be due to increased uptake anclless contribution of P by the litters. Soil available potassiumranged from 90 kg ha' to 941 kg ha-' The maximum amount of potassium was recorded in teaplantations and the minimum was under pine plantations. With increasing depth soil potassiumdecreased drastically.Bulk density (80) increased with increasing depth in all vegetations. Sholas recorded lesser BO. Thisis because of more organic matter addition to the top layer of the ground floor. Particle density (PO)oftop layer of grassland was the lowest followed by sholas. Like BO, PO also increased with increasingdepth of soil. Percent pore space was maximum in the top layers of shola forest and it decreased withincreasing depth.From this study a very good fertility status of soil was observed under sholas and grasslands. Thelower amount of nutrients was recorded under dry deciduous and moist deciduous forest and this isbecause of higher absorption of nutrients by the trees and erosional losses. Hence it is concluded thatthe soil physical and chemical properties are markedly influenced by vegetation.

Impact Resistance and Strength Reliability of Fiber-reinforced Concrete in Bending under Drop Weight Impact Load

This paper presents an experimental investigation on the Impact failure energy and strength reliability of fiber reinforced concrete (FRC) by using a simple drop weight test which was based on the testing procedure recommended by ACI committee 544. Two different steel fibers were used as the reinforcing material in various volume fractions such as 0%, 0.5%, 1.0% and 1.5% with a water cement ratio of 0.42. Furthermore, the two-parameter weibull distribution was used to analyze the experimental data in order to sort out a variation of test results. Using the weibull distribution, the impact failure strength reliability, in other words, the probability distribution according to which the concrete will fail, was obtained. The results indicated that the concrete containing a 1.5% volume fraction of fiber gave the best performance followed by 1.0% and 0.5% under impact loading. It was proven that the probabilistic distributions of the impact failure energy of seven types of samples approximately follow two-parameter Weibull distribution