The Fourier Spectral Method For The Sivashinsky Equation.

In this paper, a Fourier spectral method for solving the Sivashinsky equation with periodic boundary conditions is developed. We establish semi-discrete and fully discrete schemes of the Fourier spectral method. A fully discrete scheme is constructed in such a way that the linear part is treated implicitly and the nonlinear part explicitly. We use an energy estimation method to obtain error estimates for the approximate solutions. We also perform some numerical experiments

Quantized Hall conductance in graphene by nonperturbative magnetic-field-containing relativistic tight-binding approximation method

In this study, we conducted a numerical investigation on the Hall conductance ($\sigma_{Hall}$) of graphene based on the magnetic energy band structure calculated using a nonperturbative magnetic-field-containing relativistic tight-binding approximation (MFRTB) method. The nonperturbative MFRTB can revisit two types of plateaus for the dependence of $\sigma_{Hall}$ on Fermi energy. One set is characterized as wide plateaus (WPs). These WPs have filling factors (FFs) of 2, 6, 10, 14, etc. and are known as the half-integer quantum Hall effect. The width of WPs decreases with increasing FF, which exceeds the decrease expected from the linear dispersion relation of graphene. The other set is characterized by narrow plateaus (NPs), which have FFs of 0, 4, 8, 12, etc. The NPs correspond to the energy gaps caused by the spin-Zeeman effect and spin-orbit interaction. Furthermore, it was discovered that the degeneracy of the magnetic energy bands calculated using the nonperturbative MFRTB method leads to a quantized $\sigma_{Hall}$

Assessing the determinants of rice farmers' adaptation strategies to climate change in Bangladesh

Purpose - This paper examines rice farmers' selection of adaptation strategies to cope with and offset the effects of climate change and the determinants of those selections in Rajshahi, a severely drought-prone district of Bangladesh. Design/methodology/approach - Farm level micro-data was obtained from 550 rice growers in the 2010-2011 farming season. A multinomial logit (MNL) model was utilised to assess the determinants of adaptation strategies practised by farmers in response to climate change. Findings - Results from the MNL model indicate that gender, age, education of household heads, household assets, annual farm income, farm size, tenure status, farmer-to-farmer extension, access to credit, access to subsidy, and access to electricity, all affect farmers' selection of adaptation strategies for climate change. Originality/value - This is the first study of its kind to analyse the determinants of adaptation strategies for climate change by farmers in drought-prone areas of Bangladesh. This study provides direction for policy makers in order to strengthen the adaptation strategies of farmers and guide policies accordingly. These strategies have the potential to minimise the adverse effects of climate change

On the Convergence of the Homotopy Analysis Method for Inner-Resonance of Tangent Nonlinear Cushioning Packaging System with Critical Components

Homotopy analysis method (HAM) is applied to obtain the approximate solution of inner-resonance of tangent cushioning packaging system based on critical components. The solution is obtained in the form of infinite series with components which can be easily calculated. Using a convergence-control parameter, the HAM utilizes a simple method to adjust and control the convergence region of the infinite series solution. The obtained results show that the HAM is a very accurate technique to obtain the approximate solution

Phytochemical investigations of Campsis radicans L.

Petroleum ether, dichloromethane and ethyl acetate soluble fractions were obtained through partitioning the crude methanolic extract of the leaves of Campsis radicans L. (Family. Bignoniaceae) followed by the chromatographic separation of secondary metabolites from them. A total of five triterpene compounds i.e., corosolic acid methyl ester (1), β-amyrin (2), arjunolic acid (3), maslinic acid (4) and 28-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl]-2α,3α,19α-trihydroxy-12-en-28-ursolic acid (5) were isolated from the dichloromethane fractions and their structures were characterized by 1H NMR spectroscopy and compared the NMR data with published values

The Potential Short- and Long-Term Disruptions and Transformative Impacts of 5G and Beyond Wireless Networks: Lessons Learnt from the Development of a 5G Testbed Environment

The capacity and coverage requirements for 5 th generation (5G) and beyond wireless connectivity will be significantly different from the predecessor networks. To meet these requirements, the anticipated deployment cost in the United Kingdom (UK) is predicted to be between £30bn and £50bn, whereas the current annual capital expenditure (CapEX) of the mobile network operators (MNOs) is £2.5bn. This prospect has vastly impacted and has become one of the major delaying factors for building the 5G physical infrastructure, whereas other areas of 5G are progressing at their speed. Due to the expensive and complicated nature of the network infrastructure and spectrum, the second-tier operators, widely known as mobile virtual network operators (MVNO), are entirely dependent on the MNOs. In this paper, an extensive study is conducted to explore the possibilities of reducing the 5G deployment cost and developing viable business models. In this regard, the potential of infrastructure, data, and spectrum sharing is thoroughly investigated. It is established that the use of existing public infrastructure (e.g., streetlights, telephone poles, etc.) has a potential to reduce the anticipated cost by about 40% to 60%. This paper also reviews the recent Ofcom initiatives to release location-based licenses of the 5G-compatible radio spectrum. Our study suggests that simplification of infrastructure and spectrum will encourage the exponential growth of scenario-specific cellular networks (e.g., private networks, community networks, micro-operators) and will potentially disrupt the current business models of telecommunication business stakeholders - specifically MNOs and TowerCos. Furthermore, the anticipated dense device connectivity in 5G will increase the resolution of traditional and non-traditional data availability significantly. This will encourage extensive data harvesting as a business opportunity and function within small and medium-sized enterprises (SMEs) as well as large social networks. Consequently, the rise of new infrastructures and spectrum stakeholders is anticipated. This will fuel the development of a 5G data exchange ecosystem where data transactions are deemed to be high-value business commodities. The privacy and security of such data, as well as definitions of the associated revenue models and ownership, are challenging areas - and these have yet to emerge and mature fully. In this direction, this paper proposes the development of a unified data hub with layered structured privacy and security along with blockchain and encrypted off-chain based ownership/royalty tracking. Also, a data economy-oriented business model is proposed. The study found that with the potential commodification of data and data transactions along with the low-cost physical infrastructure and spectrum, the 5G network will introduce significant disruption in the Telco business ecosystem

A Suitable method to detect potential fraud of bringing Malayan box turtle (Cuora amboinensis) meat into the food chain

Malayan box turtle (Cuora amboinensis) has been a wildlife-protected vulnerable turtle species in Malaysia since 2005. However, because of its purported usage in traditional medicine, tonic foods and feeds, clandestine black market trade is rampant. Several polymerase chain reaction (PCR) assays for the taxonomic detection and classification of turtle species have been proposed. These assays are based on long-length target amplicons which are assumed to break down under compromised states and, hence, might not be suitable for the forensic tracing and tracking of turtle trafficking. For the first time this paper develops a very short-amplicon-length PCR assay (120 bp) for the detection of Malayan box turtle meat in raw, processed and mixed matrices, and experimental evidence is produced that such an assay is not only more stable and reliable but also more sensitive than those previously published. We checked the assay specificity against 20 different species and no cross-species detection was observed. The possibility of any false-negative detection was eliminated by a universal endogenous control for eukaryotes. The assay detection limit was 0.0001 ng of box turtle DNA from pure meat and 0.01% turtle meat in binary and ternary admixtures and commercial meatballs. Superior target stability and sensitivity under extreme treatments of boiling, autoclaving and microwave cooking suggested that this newly developed assay would be suitable for any forensic and/or archaeological identification of Malayan box turtle species, even in severely degraded specimens. Further, in silico studies indicated that the assay has the potential to be used as a universal probe for the detection of nine Cuora species, all of which are critically endangered

The One Step Optimal Homotopy Analysis Method to Circular Porous Slider

An incompressible Newtonian fluid is forced through the porous of a circular slider which is moving laterally on a horizontal plan. In this paper, we introduce and apply the one step Optimal Homotopy Analysis Method one step OHAM to the problem of the circular porous slider where a fluid is injected through the porous bottom. The effects of mass injection and lateral velocity on the heat generated by viscous dissipation are investigated by solving the governing boundary layer equations using one step optimal homotopy technique. The approximate solution for the coupled nonlinear ordinary differential equations resulting from the momentum equation is obtained and discussed for different values of the Reynolds number of the velocity field. The solution obtained is also displayed graphically for various values of the Reynolds number and it is shown that the one step OHAM is capable of finding the approximate solution of circular porous slider

Small-Scale Turkey Farming in Bangladesh: Farming Practices, Profitability and Supply Chain Mapping

The study was conducted to know the existing turkey production system, supply chain mapping, and identifying the prospects and problems of turkey rearing in some selected areas of Bangladesh during October 2019 to December 2019. A total of 100 turkey raisers were surveyed following convenience method of sampling technique. The primary data were collected, analyzed accordingly and tabular presentation method was applied with the help of simple descriptive statistical measures e.g. frequency distributions, percentage, sum and means to illustrating the results. Profitability analysis was done on the basis of variable cost, fixed cost, return by using arithmetic means and percentages. The study revealed that 87 male and 13 female respondents were surveyed, of them cent percent found educated. About 56% turkey keeper’s main occupation was business, 27% service and 12% in farming while 88.57% involved with farming as secondary sources of income. Average landholding for homestead, cultivable and non-cultivable was 24.40, 129.71 and 29.47 decimal, respectively. About 59% farms started for commercial purpose, 32% for non-commercial purpose and 9% for both. About 60% respondents kept less than 50 turkeys and only 2% kept 501-1000 turkeys. Among the surveyed farms55% stopped their operation and 45% farms found running their business. Among the running farms cent percent were small-scale group. The average feed intake was 192.13 grams per day per bird at 20 weeks of age. Turkey laid on an average 139 eggs a year irrespective of variety and for hatching poults, the fertility and hatchability rate found between 65 to 100% and 50 to 90%, respectively. About 28% farmers experienced the deaths of turkey because of Cold, Pox, Ranikhet, Bird flu and unknown cases and 69.47% farmers took veterinary advice from Upazila Livestock Hospital and rest from other sources. Farmers to consumers were the most common and widely used marketing channel for egg, chick and adult turkey. The market intermediaries of turkey farm carried out different marketing functions e.g. buying and selling, pricing, transportation, sorting, distribution and market information. The average net return and benefit-cost ratio was BDT 127838.04 and 1.38, respectively for 50 turkeys per year. In the study, turkey rearing found some comparative benefit over chicken and ducks e.g. higher weight gain, forage eater, lower diseases rate and suitability for the country. The main problem of turkey rearing identified as market instability, lack of quality turkey feed, higher feed price, lack of proper marketing facility and training on turkey farming. In conclusion, the small-scale turkey farming could be a viable source of income for the rural people of Bangladesh after taking some remedial steps by the Government of Bangladesh for the aforesaid hindrances faced by the turkey farmers

Genetic Divergence in Advanced Lines of Oilseed Rape (Brassica napus ssp oleifera L.)

A field experiment was conducted with 22 Brassica napus L. advanced lines at the experimental farm of Sher-e-Bangla Agricultural University, Dhaka from November 2008 to March 2009 to asses genetic diversity among advanced lines of Brassica napus L. Different multivariate analysis techniques were used to classify 22 Brassica napus genotypes. The genotypes were grouped into four clusters. The highest inter-cluster distance was observed between clusters II and IV whereas the maximum intra-cluster distance was found in cluster II. Therefore, the genotypes belonging to cluster I and cluster II, cluster II and cluster III and cluster III and cluster IV have been selected for future hybridization program. The role of number of secondary branches per plant and number of siliqua per plant in both vectors were important components for genetic divergence in these materials. Considering group distance and other agronomic performance the inter-genotypic crosses between G1 and G2, G2 and G6; G6 and G7; G6 and G8 and G7 and G8 might be suggested for future hybridization program