121 research outputs found

    Traveling wave solutions of the (2+1)-dimensional Zoomeron equation and the Burgers equations via the MSE method and the Exp-function method

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    AbstractThe modified simple equation (MSE) method is promising for finding exact traveling wave solutions of nonlinear evolution equations (NLEEs) in mathematical physics. In this letter, we investigate solutions of the (2+1)-dimensional Zoomeron equation and the (2+1)-dimensional Burgers equation by using the MSE method and the Exp-function method. The competence of the methods for constructing exact solutions has been established

    Soft Soil Effect on Soft Storey Response

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    Multi-storied reinforced concrete frame (RCF) buildings with open first storey to provide parking space is common in Dhaka city, the capital of Bangladesh. Such buildings are likely to produce soft storey action when subjected to earthquake loadings. Bangladesh building code places Dhaka in a moderate earthquake zone with a zone coefficient (Z) value of 0.15. Several soft soil sites exist in the city, most of which have been created by filling up of low lands and water bodies without proper compaction. Such soft soil sites are likely to produce major site amplification effects during earthquakes. One-dimensional wave propagation using the computer program SHAKE is used for selected soft soil profile of Dhaka. In the absence of measured shear wave velocity data, empirical relations are used to obtain shear wave velocity from Standard Penetration Test (SPT) data. Ground motion time histories are obtained for different input motions. Due to the absence of strong motion records for Dhaka city, US and Japanese strong motion records for four different earthquakes were used as input (outcrop) motion. Two-dimensional finite element models of six and ten storied RCF buildings with and without infill walls in the ground floor are subjected to the ground motion obtained for the specific site. Infill wall action is approximated with equivalent strut action. Elastic transient time history analysis is conducted using the computer program ETABS. To account for the energy dissipation in the structural elements due to inelastic action during strong earthquakes, the seismic response obtained is divided by a factor equal to the reduction factor R specified in the building code. Results thus obtained are compared to demonstrate the significant effect of soft soil site on the seismic response of buildings with soft storey

    Water Purification and Disinfection by Using Solar Energy: Towards Green Energy Challenge

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    The aim of this work was to design a solar water treatment plant for household purpose. Water purification is the process of eradicating detrimental chemicals, biological poisons, suspended solids and gases from contaminated water. In this work we have reported an investigation of compact filter which is cost effective for developing countries and ease of maintenance. We have arranged a solar water disinfection system that improves the microbiological quality of drinking water at household level. We get 14 L pure water and 16 ml water vapour within 240 min by using filtration method. From our work we get hot water up to 49°C. The efficiency of the system at sunny days and cloudy days are 18.23% and 18.13% respectively. This simple solar hybrid system helps to remove turbidity as well as chemical and pathogenic contaminants from water sources in the most affordable, and expedient manner possibly

    Policy and scale factors influencing efficiency in dairy and poultry production in Bangladesh

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    Demand for animal products has been increasing rapidly in Bangladesh due to income and population growth and urbanisation. The expanding market has the potential to create income and employment opportunities for small-scale and poor livestock producers if they can produce and sell market-demanded products at competitive costs and prices. This opportunity may be lost if investment, fiscal and capital market policies are distorted in a way that favour large-scale producers. Therefore, the overall objective of this study was to assess the efficiency of dairy and poultry producers in Bangladesh to identify policy options for assisting small-scale operators to develop economically viable and ecologically sustainable production enterprises for participating in the rapidly-expanding urban and rural markets for milk, poultry and eggs. The theoretical framework was based on the premise that small-scale producers may be able to compete with large-scale producers in the expanding market if they fulfil two conditions: if smallholders earn higher profit/unit of output as they need to earn a reasonable income to stay in business with low volume of output, and if smallholders are more profit-efficient in the use of their limited resources, i.e. use fewer resources/unit of profit generated

    An Action Plan for Adaptation in Bangladesh Agriculture under Climate Change

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    This report is the outcome of a study titled 'An Action Plan for Adaptation in Bangladesh Agriculture under Climate Change', carried out with support from the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS). This report prepared by the Center for Environmental and Geographic Information Services (CEGIS) delineates an action plan to prioritize adaptation options after considering the inputs by experts and scrutiny by stakeholders. It aims to promote precision agriculture and commercialization of crop agriculture with strong institutional and financial footing to tackle climate change

    Infrared Dielectric Functions and Brillouin Zone Center Phonons of \u3cem\u3eα\u3c/em\u3e-Ga\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e compared to \u3cem\u3eα\u3c/em\u3e-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e

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    We determine the anisotropic dielectric functions of rhombohedral α-Ga2O3 by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high-frequency and static dielectric constants. We perform density functional theory computations and determine the phonon dispersion for all branches in the Brillouin zone, and we derive all phonon mode parameters at the Brillouin zone center including Raman-active, infrared-active, and silent modes. Excellent agreement is obtained between our experimental and computation results as well as among all previously reported partial information from experiment and theory. We also compute the same information for α-Al2O3, the binary parent compound for the emerging alloy of α-(AlxGa1−x)2O3, and use results from previous investigations [Schubert, Tiwald, and Herzinger, Phys. Rev. B 61, 8187 (2000)] to compare all properties among the two isostructural compounds. From both experimental and theoretical investigations, we compute the frequency shifts of all modes between the two compounds. Additionally, we calculate overlap parameters between phonon mode eigenvectors and discuss the possible evolution of all phonon modes into the ternary alloy system and whether modes may form single-mode or more complex mode behaviors

    Multi-Channel Multi-Radio Using 802.11 Based Media Access for Sink Nodes in Wireless Sensor Networks

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    The next generation surveillance and multimedia systems will become increasingly deployed as wireless sensor networks in order to monitor parks, public places and for business usage. The convergence of data and telecommunication over IP-based networks has paved the way for wireless networks. Functions are becoming more intertwined by the compelling force of innovation and technology. For example, many closed-circuit TV premises surveillance systems now rely on transmitting their images and data over IP networks instead of standalone video circuits. These systems will increase their reliability in the future on wireless networks and on IEEE 802.11 networks. However, due to limited non-overlapping channels, delay, and congestion there will be problems at sink nodes. In this paper we provide necessary conditions to verify the feasibility of round robin technique in these networks at the sink nodes by using a technique to regulate multi-radio multichannel assignment. We demonstrate through simulations that dynamic channel assignment scheme using multi-radio, and multichannel configuration at a single sink node can perform close to optimal on the average while multiple sink node assignment also performs well. The methods proposed in this paper can be a valuable tool for network designers in planning network deployment and for optimizing different performance objectives

    Identifying Recent Cholera Infections Using a Multiplex Bead Serological Assay

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    Estimates of incidence based on medically attended cholera can be severely biased. Vibrio cholerae O1 leaves a lasting antibody signal and recent advances showed that these can be used to estimate infection incidence rates from cross-sectional serologic data. Current laboratory methods are resource intensive and challenging to standardize across laboratories. A multiplex bead assay (MBA) could efficiently expand the breadth of measured antibody responses and improve seroincidence accuracy. We tested 305 serum samples from confirmed cholera cases (4 to 1083 d postinfection) and uninfected contacts in Bangladesh using an MBA (IgG/IgA/IgM for 7 Vibrio cholerae O1-specific antigens) as well as traditional vibriocidal and enzyme-linked immunosorbent assays (2 antigens, IgG, and IgA). While postinfection vibriocidal responses were larger than other markers, several MBA-measured antibodies demonstrated robust responses with similar half-lives. Random forest models combining all MBA antibody measures allowed for accurate identification of recent cholera infections (e.g., past 200 days) including a cross-validated area under the curve (cvAUC200) of 92%, with simpler 3 IgG antibody models having similar accuracy. Across infection windows between 45 and 300 days, the accuracy of models trained on MBA measurements was non-inferior to models based on traditional assays. Our results illustrated a scalable cholera serosurveillance tool that can be incorporated into multipathogen serosurveillance platforms. IMPORTANCE Reliable estimates of cholera incidence are challenged by poor clinical surveillance and health-seeking behavior biases. We showed that cross-sectional serologic profiles measured with a high-throughput multiplex bead assay can lead to accurate identification of those infected with pandemic Vibrio cholerae O1, thus allowing for estimates of seroincidence. This provides a new avenue for understanding the epidemiology of cholera, identifying priority areas for cholera prevention/control investments, and tracking progress in the global fight against this ancient disease

    Genomic landscape of prominent XDR Acinetobacter clonal complexes from Dhaka, Bangladesh

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    Background: Acinetobacter calcoaceticus-A. baumannii (ACB) complex pathogens are known for their prevalence in nosocomial infections and extensive antimicrobial resistance (AMR) capabilities. While genomic studies worldwide have elucidated the genetic context of antibiotic resistance in major international clones (ICs) of clinical Acinetobacter spp., not much information is available from Bangladesh. In this study, we analysed the AMR profiles of 63 ACB complex strains collected from Dhaka, Bangladesh. Following this, we generated draft genomes of 15 of these strains to understand the prevalence and genomic environments of AMR, virulence and mobilization associated genes in different Acinetobacter clones. Results: Around 84% (n = 53) of the strains were extensively drug resistant (XDR) with two showing pan-drug resistance. Draft genomes generated for 15 strains confirmed 14 to be A. baumannii while one was A. nosocomialis. Most A. baumannii genomes fell under three clonal complexes (CCs): the globally dominant CC1 and CC2, and CC10; one strain had a novel sequence type (ST). AMR phenotype-genotype agreement was observed and the genomes contained various beta-lactamase genes including blaOXA-23 (n = 12), blaOXA-66 (n = 6), and blaNDM-1 (n = 3). All genomes displayed roughly similar virulomes, however some virulence genes such as the Acinetobactin bauA and the type IV pilus gene pilA displayed high genetic variability. CC2 strains carried highest levels of plasmidic gene content and possessed conjugative elements carrying AMR genes, virulence factors and insertion sequences. Conclusion: This study presents the first comparative genomic analysis of XDR clinical Acinetobacter spp. from Bangladesh. It highlights the prevalence of different classes of beta-lactamases, mobilome-derived heterogeneity in genetic architecture and virulence gene variability in prominent Acinetobacter clonal complexes in the country. The findings of this study would be valuable in understanding the genomic epidemiology of A. baumannii clones and their association with closely related pathogenic species like A. nosocomialis in Bangladesh. 2022, The Author(s).This work was funded by North South University Conference Travel and Research Grants (NSU CTRG) Committee under the grant number: NSU-RP-18-042.Scopu
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