Some Travelling Wave Solutions of KdV-Burgers Equation

In this paper we study the extended Tanh method to obtain some exact solutions of KdV-Burgers equation. The principle of the Tanh method has been explained and then apply to the nonlinear KdV- Burgers evolution equation. A finnite power series in tanh is considered as an ansatz and the symbolic computational system is used to obtain solution of that nonlinear evolution equation. The obtained solutions are all travelling wave solutions

Stock market prediction of Bangladesh using multivariate long short-term memory with sentiment identification

The prediction of stock market trends is a challenging task due to its dynamic and volatile nature. Research has shown that predicting the stock market, especially in developing nations like Bangladesh, is challenging due to the presence of multiple external factors in addition to technical ones. To address this, this study proposed a novel dataset that includes not only technical stock market data from 2014 to 2021, but also external factors such as news sentiment and other economic indicators like inflation, gross domestic product (GDP), exchange rate, interest rate, and current balance. The goal is to provide a comprehensive view of the Dhaka Stock Exchange (DSE), the largest stock market in Bangladesh. The main objective of this study is to predict the trend of DSE by taking into account both technical stock market data and relevant external factors, and to compare the predictions made with and without using external factors. The study utilized a multivariate long short-term memory (LSTM) neural network for the stock market trend prediction. The experimental results showed that the use of external factors improved the accuracy of the LSTM-based stock market trend predictions by approximately 24%

Relationship Between Salinity and Crop Production in Different Hydrological Regimes Downstream of Muhuri Regulator

A large landmass was formed at the downstream of Feni river due to the construction of Muhuri regulator at a cross dam in Mirsaraiupazila of Chittagong district. But this land is more vulnerable to storm and tidal surges leading to saline water intrusion. The study site was selected from this area to investigate the relationship between salinity and crop production. Soil samples were collected from different hydrological regimes such as old protected area, new protected area, unprotected area and affected area from topsoil, subsoil and substratum in both wet and dry period. Crop yield of the sampling plots were recorded through farmer’s interview. It was found that, salinity of the study area was less than 4 dS/m both in aman and rabi season. Rice is a semi-tolerant crop (it can tolerate salinity up to 4 dS/m). So no significant relationship between soil salinity and rice yield was observed. Farmers of this area mainly cultivate khesari crop in rabi season. A significant positive correlation (correlation coefficient 0.97) was found between the soil salinity and khesari yield in unprotected area. Water salinity inside the cross dam was around 0.1 dS/m (rabi season), which is considered excellent for irrigation. But outside the cross dam it ranged in between 4.8-5.4 dS/m in aman season and 12.4-20.8 dS/m in rabi season, which was extremely toxic for irrigation for the cultivation boro rice. Although soil salinity permits to cultivate HYV rice in a man season but water logging is the main constraint. HYV rice in boro season can be cultivated in old and new protected area by utilizing Feni river water inside the Muhuri regulator and closure dam for irrigation purpose. But in unprotected area, it can not be cultivated due lack of suitable irrigation water and tidal flooding. In the study area, non-irrigated crop like khesari can be grown successfully just after aman season by utilizing residual soil moisture

ESTIMATION OF COMBINING ABILITY AND HETEROSIS IN WHEAT

The study used a half-diallel mating fashion to identify combining ability (GCA and SCA) and heterosis of six wheat (Triticum aestivum L.) genotypes and their 15 F1 hybrids for morpho-physiological, yield, and yield-contributing traits. The present study was carried out in a randomized complete block design with three replications. The studied characters are heading days, maturity days, chlorophyll content, Plant height, Effective tillers plant-1, Total tillers plant-1, Spikes plant-1, Spike length, Filled spikelets spike-1, Unfilled spikelets spike-1, Grains spike-1, Thousand grain weight, Grain yield plant-1, Biological yield plant-1, and Harvest index Highly significant differences were observed among genotypes (parents and F1 hybrids) for all characters studied. The results also showed that the mean squares due to general (GCA) and specific (SCA) combining abilities were highly significant for all studied characters except harvest index, indicating the magnitude of both additive and non-additive gene effects in governing these traits. GCA/SCA ratios were greater than one for all characters except filled spikelets spike-1 and harvests index, indicating the dominance of additive gene effects, which play important roles in the inheritance of these characters. While the non-additive effect of the gene predominated in the inheritance of filled spikelets (spike-1) and harvests index, The parent BARI GOM-30 emerged as the best general combiner for total tillers plant-1, filled spikelets spike-1, grains spike-1, thousand-grain weight, grain yield plant-1, and harvest index. Bari Gom-28 was the best general combiner for heading days and maturity days, and Sourav was the best for effective tillers plant-1, spikes plant-1, and biological yield plant-1. The cross BARI GOM-30  SOURAV was the best specific combiner for effective tillers plant-1, total tillers plant-1, spikes plant-1, and PRODIP  SOURAV for filled spikelets spike-1. Bari GOM-33   Sourav emerged as the best specific combiner for grain yield plant-1 and Prodip    Ayt-5 for grain spike-1. Concerning heterotic effects in comparison to the midparent, the F1 hybrid BARI GOM-28  BARI GOM-33 showed maximum significant positive heterosis for chlorophyll content and biological yield plant-1 and BARI GOM-33  SOURAV for effective tillers plant-1, spikes plant-1, and grain yield plant-1. These parents and cross combinations could be used for the breeding program of wheat for potential yield. View Article DOI: 10.47856/ijaast.2022.v09i12.00

Steady MHD Free Convection Flow with Thermal Radiation past a Vertical Porous Plate Immersed in a Porous Medium

Abstract: The present study is concerned with thermal radiation in a steady two-dimensional MHD free convection flow through a porous vertical flat plate immersed in a porous medium. In the analysis a DarcyForchhemier model is considered while the fluid is taken to be gray, absorbing-emitting radiation. The nonlinear governing equations have been transformed by the usual similarity transformation to a system of ordinary differential equations. These dimensionless similar equations are then solved numerically employing the Nachtsheim-Swigert shooting iteration technique along with sixth order Runge-Kutta integration scheme. Finally the effects of the pertinent parameters are examined

光和周波および第二高調波分光によるSi(111)表面の水素脱離研究

Supervisor:水谷　五郎マテリアルサイエンス研究科博

About transverse vortex rings that can be used as elements of turbulence

Vorticity and velocity distributions of several vortex rings that can principally be used as elements of turbulence are obtained and compared. The comparison emphasis is mainly given to the viscous type of D- and Q-vorticies obtained by Lee and vortex obtained by Chou & Huang. Because of the analytical complexity of Chou & Huang vortex a simpler and more compact form of solution for this latter is attained which appears to be the same as the Q-vortex. The analytical considerations compared to the solution of Chou & Huang are shown in Appendix A. The longitudinal and transversal velocity correlations of D-vortex and Q-vortex are also calculated and compared with that of Chou & Huang vortex and also with the experimental results of Batchelor and Townsend.Sattar Md. Abdus. About transverse vortex rings that can be used as elements of turbulence. In: Bulletin de la Classe des sciences, tome 67, 1981. pp. 585-616

Numerical simulation of foaming in metal processing with population balance modeling

In this study computational fluid dynamic (CFD) model has been developed and numerical simulation has been carried out to predict the formation of foam, the number density of different bubble class, thermo-chemical reaction and multiphase flow phenomena. A new approach for the numerical simulation of foaming has been proposed and used in the present study. Numerical simulation of multiphase flow with bubble break-up and bubble coalescence model available in the open literature has also been incorporated in the CFD model. An anomaly was identified in the model of daughter bubble distribution available in the literature and rectified in the present study. Population balance modelling was used to track the number density of different bubble class. The decarburisation reaction with heat generation due to exothermic reaction was considered in the present study. The numerical prediction was based on Eulerian-Eulerian approach where the liquid phase was treated as a continuum and the gas phase (bubbles) was considered as a dispersed phase. A user subroutine was written in FORTRAN programming language to incorporate foam formation and destruction, bubble interactions and decarburisation into the main CFD software. The simulated results from the CFD models were validated against the experimental data available in the open literature