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An ab initio investigation of vibrational, thermodynamic, and optical properties of Sc_2AlC mAX compound

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Chinese Physics B 2016年第10期25卷 103-108页

作者： m A Ali m T Nasir m r khatun A K m A Islam S H Naqib Department of Physics Chittagong University of Engineering and Technology Department of Arts & Sciences Bangladesh Army University of Science and Technology Department of Physics University of Rajshahi International Islamic University Chittagong

The structural vibrational, thermodynamical, and optical properties of potentially technologically important, weakly coupled mAX compound, Sc2 Al C are calculated using density functional theory(DFT). The structural properties of ScAlC are compared with the results reported earlier. The vibrational, thermodynamical, and optical properties are theoretically estimated for the first time. The phonon dispersion curve is calculated and the dynamical stability of this compound is investigated. The optical and acoustic modes are observed clearly. We calculate the Helmholtz free energy(F), internal energy(E), entropy(S), and specific heat capacity(Cv) from the phonon density of states. Various optical parameters are also calculated. The reflectance spectrum shows that this compound has the potential to be used as an efficient solar reflector.

关键词： mAX compound phonon dispersion thermodynamical properties optical properties

modelling the Effect of Self-Immunity and the Impacts of Asymptomatic and Symptomatic Individuals on COVID-19 Outbreak

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Computer modeling in Engineering & Sciences 2020年第12期125卷 1033-1060页

作者： m.H.A.Biswas m.A.Islam S.Akter S.mandal m.S.khatun S.A.Samad A.K.Paul m.r.khatun mathematics Discipline Science Engineering and Technology SchoolKhulna UniversityKhulna9208Bangladesh Department of mathematics Bangabandhu Sheikh Mujibur Rahman Science and Technology UniversityGopalganj8100Bangladesh

COVID-19 is one of themost highly infectious diseases ever emerged and caused by newly discovered severe acute respiratory syndrome coronavirus 2(SArS-CoV-2).It has already led the entire world to health and economic *** has invaded the whole universe all most every *** present study demonstrates with a nine mutually exclusive compartmental model on transmission dynamics of this pandemic disease(COVID-19),with special focus on the transmissibility of symptomatic and asymptomatic infection from susceptible ***,the compartmental model has been investigated with mathematical analysis and computer simulations in order to understand the dynamics of COVID-19 ***,mathematical analysis of the model has been carried out in broadly by illustrating some well-known methods including exactness,equilibrium and stability analysis in terms of basic reproduction *** investigate the sensitivity of the model with respect to the variation of the parameters’***,computer simulations are performed to illustrate the *** analysis reveals that the death rate from coronavirus disease increases as the infection rate increases,whereas infection rate extensively decreases with the increase of quarantined *** quarantined individuals also lead to increase the concentration of recovered ***,the infection rate of COVID-19 increases more surprisingly as the rate of asymptomatic individuals increases than that of the symptomatic ***,the infection rate decreases significantly due to increase of self-immunity rate.

关键词： COVID-19 asymptomatic and symptomatic individuals selfimmunity mathematical model basic reproductive ratio numerical simulations

Field performance of alternate wetting and drying furrow irrigation on tomato crop growth, yield, water use efficiency, quality and profitability

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Journal of Integrative Agriculture 2016年第10期15卷 2380-2392页

作者： Khokan Kumer Sarker m.A.r.Akanda S.K.Biswas D.K.roy A.khatun m.A.Goffar Irrigation and Water management Division Bangladesh Agricultural Research Institute Horticulture research Centre Bangladesh Agricultural Research Institute

Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.

关键词： alternate furrow irrigation alternate drying process tomato yield quality water use efficiency net return

Investigation of adequate closed form travelling wave solution to the space-time fractional non-linear evolution equations

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Journal of Ocean Engineering and Science 2022年第3期7卷 292-303页

作者： mohammad Asif Arefin m.Ayesha khatun m.Hafiz Uddin mustafa Inc Department of mathematics Jashore University of Science and TechnologyJashore 7408Bangladesh Department of Computer Engineering Biruni UniversityIstanbulTurkey Department of mathematics Science FacultyFirat UniversityElazigTurkey Department of medical research China Medical University HospitalChina Medical UniversityTaichungTaiwan

This work aims to construct exact solutions for the space-time fractional(2+1)-dimensional dispersive longwave(DLW)equation and approximate long water wave equation(ALW)utilizing the twovariable(G′/G,1/G)-expansion method and the modified riemann-Liouville fractional *** recommended equations play a significant role to describe the travel of the shallow water *** fractional complex transform is used to convert fractional differential equations into ordinary differential *** wave solutions have been successfully achieved using the proposed approach and the symbolic computer maple *** maple package program was used to set up and validate all of the computations in this *** choosing particular values of the embedded parameters,we pro-duce multiple periodic solutions,periodic wave solutions,single soliton solutions,kink wave solutions,and more forms of soliton *** achieved solutions might be useful to comprehend nonlinear *** is worth noting that the implemented method for solving nonlinear fractional partial dif-ferential equations(NLFPDEs)is efficient,and simple to find further and new-fangled solutions in the arena of mathematical physics and coastal engineering.

关键词： riemann-Liouville fractional derivative Space-time fractional(2+1)-dimensional dispersive long wave equation Approximate long water wave equation Wave transformation The two-variable(G′/G,1/G)-expansion method

Introduction of Zika virus in Bangladesh:An impending public health threat

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Asian Pacific Journal of Tropical medicine 2017年第9期10卷 925-928页

作者： A.K.m.muraduzzaman Sharmin Sultana Tahmina Shirin Selina khatun mdTarikul Islam mahmudur rahman Department of Virology Institute of EpidemiologyDisease Control&Research(IEDCR)DhakaBangladesh Department of Epidemiology Institute of EpidemiologyDisease Control&Research(IEDCR)DhakaBangladesh Laboratory of Genetics and Genomics Institute for Developing Science and Health InitiativesDhakaBangladesh Institute of Epidemiology Disease Control&Research(IEDCR)DhakaBangladesh

Objective: To explore the presence of Zika virus(ZIKV) in Bangladesh and to understand the associated risk ***: A retrospective sero-surveillance was performed on stored serum samples of dengue surveillance conducted from 2013 to 2016. real time rT-PCr was performed on randomly selected acute serum samples to detect the Zika virus nucleic ***: Of 200 samples screened, one was found positive for ZIKV by real time rTPCr and further confirmed by genome sequencing. The case was a 65 years old male from a metropolitan city of Bangladesh who had no history of travel outside *** analysis of partial E gene sequences from Bangladeshi isolates demonstrated a close relationship with ZIKV from Brazil and current South American strains clustering within a monophyletic clade distinct from African ***: Presence of ZIKV raises serious public health concerns in Bangladesh owing to its association with congenital anomalies/neurological-manifestations. We,therefore, recommend every suspected viral fever patient, particularly pregnant women be screened for ZIKV infection to rule out yet another emerging infection in Bangladesh.

关键词： Zika virus Bangladesh Public health impact

Novel PCr primers to diagnose visceral Leishmaniasis using peripheral blood, spleen or bone marrow aspirates

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Asian Pacific Journal of Tropical medicine 2017年第8期10卷 819-824页

作者： mahbuba khatun S m Sabbir Alam Abed Hussain Khan mAnwar Hossain Jalaluddin Ashraful Haq mdShariful Alam Jilani mohammad Tariqur rahman muhammad manjurul Karim Department of microbiology University of Dhaka Department of medicine Bangabandhu Sheikh Mujib Medical University Department of microbiology Ibrahim Medical College & BIRDEM Hospital Faculty of Dentistry University of Malaya

Objective: To establish a suitable method of diagnosis of visceral Leishmania sis(VL) using peripheral blood, spleen or bone marrow aspirates. methods: Peripheral blood, bone marrow and spleen aspirate samples were collected from clinically suspected VL patients(n=26). A new PCr primer pair(mK1F/r) was designed targeting kinetoplast mini circle DNA sequences of Leishmania donovani, and Leishmania infantum, and was used to diagnose VL along with some other established primers for VL in polymerase chain reactions. Test was validated by comparing with several other diagnostic methods. results: The designed primer set showed 100% specificity and 98% sensitivity in detecting VL using blood samples, when compared with more invasive samples: bone marrow or spleen aspirates. Conclusions: The newly designed primer mK1F/r could be a better alternative for PCr based diagnosis of VL using less invasive sample, peripheral blood instead of bone marrow or spleen aspirates.

关键词： Visceral Leishmaniasis Kala-Azar Leishmania species PCr detection New primer

Natural radioactivity measurement and Assessment of radiological Hazards in Some Building materials Used in Bangladesh

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Journal of Environmental Protection 2018年第10期9卷 1034-1048页

作者： m. Azmary khatun J. Ferdous m. m. Haque Department of Physics University of Rajshahi Rajshahi Bangladesh Health Physics Division Atomic Energy Center (AEC) Dhaka Bangladesh

The radioactivity concentrations of 226ra, 232Th and 40K in 24 samples of natural and manufactured building materials commonly used in Bangladesh were measured using HPGe gamma ray spectrometer. The results in the present study were compared with the world average and also with the reported data available in literature. The radium equivalent activity, the absorbed dose rate, annual effective dose, external and internal hazard indices, gamma index, alpha index, annual gonadal dose equivalent and excess lifetime cancer risk were also evaluated to assess the potential radiation hazards associated with these building materials. All samples under investigation were found to be within the recommended safety limit and do not pose any significant radiation hazards. This study can be used as a reference for more extensive studies of the same subject in future.

关键词： Natural radioactivity Building materials HPGe Detector radiation Hazards

Essential Gene(s) Targeted by Peptide Nucleic Acids Kills <i>mycobacterium smegmatis</i>in Culture and in Infected macrophages

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Advances in Infectious Diseases 2021年第2期11卷 156-164页

作者： md. Ariful Islam mst. minara khatun Nammalwar Sriranganathan Stephen m. Boyle Center for One Health research Virginia-Maryland College of Veterinary Medicine Virginia Tech Blacksburg VA USA Department of microbiology & Hygiene Bangladesh Agricultural University Mymensingh Bangladesh

Background: Antisense peptide nucleic acids (PNAs) exhibit growth inhibitory effects on bacteria by inhibiting the expression of essential genes and could be promising therapeutic agents for treating bacterial infecti... 详细信息

m>Background:m> Antisense peptide nucleic acids (PNAs) exhibit growth inhibitory effects on bacteria by inhibiting the expression of essential genes and could be promising therapeutic agents for treating bacterial infections. A study was carried out to determine the efficacy of several antisense PNAs in inhibiting extracellular and intracellular growth of m>mycobacterium smegmatism>. m>methods: m>Six PNAs obtained from a commercial supplier were tested to evaluate the inhibitory effect on bacterial growth by inhibiting the expression of the following essential genes: m>inhA m>(a fatty acid elongase), m>rpsLm> (ribosomal S12 protein), m>gyrAm> (DNA gyrase), m>pncAm> (pyrazinamidase), m>polAm> (DNA polymerase I) and m>rpoCm> (rNA polymerase m>βm> subunit) of m>m. smegmatism>. Each PNA was tested at 20 μm, 10 μm, 5 μm and 2.5 μm concentrations to determine whether they caused a dose dependent killing of m>m. smegmatism> cultured in middlebrook 7H9 broth or in a J774A.1 murine macrophage cell line.m> results:m> In middlebrook broth, the strong growth inhibitory effect against m>m. smegmatism> was observed by PNAs targeting the m>inhA m>and m>rpsLm> genes at all four concentrations. The PNAs targeting them> pncAm>, m>polAm> andm> rpoCm> genes were found to exhibit strong growth inhibition against m>m. smegmatism> but only at 20 μm concentration. No growth inhibition of m>m. smegmatis m>was seen in pure culture when treated with PNAs targeting gyrA and a mismatch PNA targeting dnaG (DNA primase). All six PNAs showed killing of m>m. smegmatis m>in J774A.1 macrophage cell line that were statistically significant (p m>Conclusion:m> It may be concluded from this study that PNAs could be potential therapeutics for mycobacterial infections.

关键词： middlebrook 7H9 Broth Culture J774A.1 murine macrophage Cell Line Antisense Therapy Peptide Nucleic Acid Cell Penetrating Peptide mycobacterium

Image Noise Analysis of a Large ring PET Scanner

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International Journal of medical Physics, Clinical Engineering and radiation Oncology 2017年第2期6卷 208-215页

作者： m. m. Ahasan S. Akter r. khatun m. F. Uddin A. N. monika m. A. rahman m. N. Khanam Institute of Nuclear medical Physics AERE Savar Bangladesh medical Physics Division Atomic Energy Centre Dhaka Bangladesh Infertility Unit Department of Gynae & Obs BSMMU Dhaka Bangladesh

Image noise analysis of a large ring PET scanner “macro PET” performed using two different phantoms, namely a Jaszczak SPECT phantom and a uniform cylindrical phantom. In the present work, simple 2D filtered back projection was used to reconstruct all the images, and in almost all the cases a Hamming filter of cutoff frequency 0.4 and a 256 by 256 matrix with zoom factors from 1 to 4 were used in order to investigate the imaging capabilities of the new scanner and the influence of filter and cut-off frequency on the filtered back projected images. results indicate that 11.1 mm cold rod in the Jaszczak phantom images can consistently be seen. The Coefficient of variation (CV) results for Hann and Hamming filters are very similar and increase approximately in linear fashion with higher cutoff frequency. The value of CV for the Parsen filter is lower than the value for Hann and Hamming filters. It concludes that all filters with low cut off-frequency (0.6) would suppress image noise but decrease contrast.

关键词： PET Sinogram Filter & CV