Zero-valent iron amended biochar(ZVIB)has been proposed as a promising material in immobilizing heavy metals in paddy fields.In this study,the impacts of p H of ZVIB(p H 6.3 and p H 9.7)and watering management techniq...Zero-valent iron amended biochar(ZVIB)has been proposed as a promising material in immobilizing heavy metals in paddy fields.In this study,the impacts of p H of ZVIB(p H 6.3 and p H 9.7)and watering management techniques(watering amount in the order of CON(control,5/72)>3/72>1-3/72>3/100>1/72,with 5/72,for example,representing irrigation given to 5 cm above soil surface in 72 hr regular interval)on As and Cd bioavailability for rice and its grain yield(Yield BR)were investigated in a pot experiment.Brown rice As(As BR)content was irrelative to the watering treatments,while significantly decreased(>50%)with the addition of both ZVIB materials.The diminutions of brown rice Cd(Cd BR)content as well as the Yield BR were highly dependent on both the soil amendment materials’p H and watering amount.Among all the watering treatments,3/72 treatment(15%less irrigation water than the CON)with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As BR(50%)and Cd BR contents(19%)as well as for significant increment(12%)of the Yield BR.Although high pH(9.7)ZVIB application could also efficiently decrease As and Cd contents in brown rice,it might risk grain yield lost if appropriate(e.g.3/72 in our study)watering management technique was not chosen.Therefore,ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.展开更多
This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance sur...This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .展开更多
River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss...River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.展开更多
Background: The COVID-19 pandemic had a significant impact on every aspect of life. Like other chronic diseases, pediatric rheumatic diseases (PRDs) also faced unique challenges during the pandemic, including limited ...Background: The COVID-19 pandemic had a significant impact on every aspect of life. Like other chronic diseases, pediatric rheumatic diseases (PRDs) also faced unique challenges during the pandemic, including limited access to care, concerns regarding infection risk, drug shortages and social isolation. Objective: The objective of the study was to identify the impact of the COVID-19 pandemic on the management course of children with rheumatic diseases. Methods: This cross-sectional study was conducted in the department of paediatrics, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from April 2021 to March 2022. Two hundred and twenty patients were enrolled. A predesigned questionnaire was completed which included socio-demographic, clinical and laboratory parameters. Disease activity was assessed clinically and from laboratory profile. Data were calculated manually and by using SPSS version 22. Z-proportion test and chi square test were done when applicable. Results: Among the enrolled PRD cases 87.7% were Juvenile Idiopathic Arthritis (JIA), 7.7% were Systemic Lupus Erythematosus (SLE) and 4.6% were other cases. Irregular follow-ups were found in 69.9% JIA cases, 82.4% SLE cases and 60% other PRD cases. Poor drug compliance was present in 18.2% of cases. A significant number of patients had higher disease activity or flare during the COVID-19 pandemic. Conclusion: During COVID-19 pandemic most (70.5%) of the PRD patients were irregular in their follow-ups. Poor drug compliance was also more than in the pre-COVID period. Disease activity status significantly worsened during this period.展开更多
In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray ...In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90,BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7(municipal waste dumping) and 8(medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5(Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9(urban), 10(sub-urban), 11(rural) while sites-7 and 8(urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites -7 and 8. Values of incremental lifetime cancer risk were from 10to 10showed no carcinogenic health risk by road dusts contaminated with the heavy metals.展开更多
The aggregation behavior of the mixture of cetyltrimethylammonium chloride(CTAC), a cationic surfactant, and moxifloxacin hydrochloride(MFH), a fourth-generation fluoroquinolone antibiotic drug, has been studied using...The aggregation behavior of the mixture of cetyltrimethylammonium chloride(CTAC), a cationic surfactant, and moxifloxacin hydrochloride(MFH), a fourth-generation fluoroquinolone antibiotic drug, has been studied using the conductivity technique in aqueous and alcoholic(EtOH, 1-PrOH, and 2-BuOH)media. The study was performed at several temperatures between 298.15 and 323.15 K at 5 K intervals.The assembly has been characterized by evaluating the micellar parameters, such as the critical micelle concentration(CMC) and the counter ion binding(β), of the CTAC + MFH mixture. The values of the CMC for the assembly of the CTAC + MFH mixture were reliant on the composition of alcohols in the mixed solvents and the temperature. The CMC values of the CTAC + MFH mixture increased with increasing temperature;that is, assembly was delayed by increased temperature. The micellization of the CTAC + MFH mixed system was delayed in alcoholic media. The observed-ΔG0mvalues for the association of the CTAC + MFH mixed system demonstrated a spontaneous aggregation process under all study conditions.Based on the-ΔH^(0)_(m) and +ΔS^(0)_(m) values, the association of the CTAC + MFH mixture is exothermic and the interaction forces acting between the CTAC and MFH species are hydrophobic, ion–dipole, and electrostatic interactions. The transfer properties and enthalpy–entropy compensation were also assessed and described comprehensively.展开更多
Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extrac...Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extracts against the late blight disease incidence and severity in experimental potato field at University of Rajshahi, Bangladesh during 2019-2020. Crude aqueous extract of leaves of <i>Syzygium</i> <i>cumini</i>, <i>Psidium</i> <i>guajava</i>, <i>Eucalyptus</i> <i>globusus</i>, <i>Carica</i> <i>papaya</i> and <i>Lawsonia</i> <i>inermis</i>;fruits of <i>Terminalia</i> <i>bellirica</i>, <i>T.</i> <i>chebula</i> and <i>Piper</i> <i>nigrum</i>;flower buds of <i>Syzygium</i> <i>aromaticum</i> and cloves of <i>Allium</i> <i>sativum</i> were used at 5% (w/v) concentration for evaluation. Out of ten botanicals, <i>Syzygium</i> <i>cumini</i> leaves extract was found most effective in controlling the late blight disease incidence and severity up to 66 DAS (days after sowing) and increased the potato yield by 71.29% compare to untreated control. The efficacy of <i>Lawsonia</i> <i>inermis</i> extract against late blight disease was found promising and increased the potato yield by 48.51%. Other four botanical extracts (<i>Terminalia</i> <i>chebula</i>, <i>Piper</i> <i>nigrum</i>, <i>Syzygium</i> <i>aromaticum</i> and <i>Carica</i> <i>papaya</i>) showed moderate efficacy <span>against the incidence and severity of late blight disease, and increased 30% </span>more potato yield compare to control. These results suggest that botanical extract of <i>Syzygium</i> <i>cumini</i> ha<span style="font-family:;" "="">s</span><span style="font-family:;" "=""> a great potential as an alternative </span><span style="font-family:;" "="">of</span><span style="font-family:;" "=""> chemical fungicides to control the late blight disease of potato in</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">eco-friendly way.</span>展开更多
The assessment of the radiological concentration of <sup>134</sup>Cs and <sup>137</sup>Cs owing to hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh is presente...The assessment of the radiological concentration of <sup>134</sup>Cs and <sup>137</sup>Cs owing to hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh is presented here in this work. The concentration of <sup>134</sup>Cs and <sup>137</sup>Cs was estimated in different pathways consisting of the ingestion of plants, milk, and meat. The highest air concentration has been determined at 65 m distance from the core of the reactor. The maximum concentration passed off without delay simply after the accident in various directions. Local meteorological information such as average wind velocity and wind frequency were analyzed. Considering all directions, the highest concentration has been observed in the “S” direction. The concentrations of <sup>134</sup>Cs and <sup>137</sup>Cs were determined in ground, vegetation, milk and meat. The concentration of <sup>137</sup>Cs is investigated to be higher than the <sup>134</sup>Cs. The concentration of <sup>134</sup>Cs and <sup>137</sup>Cs was found to be lower in vegetation, milk, and meat than that of ground concentration. Overall, in this study, the concentration in meat has been investigated to be lower. In case of a reactor accident, the concentration assessment due to the ingestion of vegetables, milk, and meat will be a valuable guide for insuring radiological protection across the research reactor at AERE, Savar, Bangladesh.展开更多
<strong>Background: </strong>Disseminated Intravascular Coagulation (DIC) is a life threatening complication frequently observed in acute leukemia. Among the morphological varieties of Acute Myeloid Leukae...<strong>Background: </strong>Disseminated Intravascular Coagulation (DIC) is a life threatening complication frequently observed in acute leukemia. Among the morphological varieties of Acute Myeloid Leukaemia (AML), Acute Promyelocytic Leukaemia (APL) is well established to cause DIC. But there have been reports noted that abnormal DIC parameters also commonly observed in the patients with non-APL AML. This study evaluated the DIC parameters & DIC score according to International Society of Thrombosis and Haemostasis (ISTH) in newly diagnosed non-APL AML patients. <strong>Materials and Methods:</strong> This cross-sectional observational study was conducted in the Department of Haematology, BSMMU, Dhaka, Bangladesh. 48 newly diagnosed non-APL AML patients were enrolled. Platelets count was measured by auto analyzer (Sysmax XT 2000i/Pentra ABX-120DX) as well as checked manually. Prothrombin time, fibrinogen, D-Dimer were measured using STAGO Coagulation analyzer. The ISTH-DIC scoring system was used to calculate DIC score. The statistical analysis was carried out using the Statistical Package for Social Sciences version 24.0 for Windows. Chi-Square test & Fisher exact test was used for categorical variables. Unpaired t-test was used to compare mean between groups. For all statistical tests, p-value less than 0.05 was considered as statistically significant. <strong>Results: </strong>By analyzing 48 newly diagnosed patients with non-APL AML, found that DIC developed in 14.6% patients at presentation. Among the DIC parameters, PT and D-dimer were significantly higher in patients presented with DIC. Patients with DIC exhibit lower expression of CD117, CD34, HLA-DR and statistically significant association with negative expression of HLA-DR (p-value 0.034). No significant association was found between presence of DIC and age, gender, bleeding at presentation, morphological type, WBC count or peripheral blast percentage.<strong> Conclusion:</strong> Abnormalities of DIC parameters in common in patients with AML. A sign展开更多
The effects of initial concentrations of PNP, doses of TiO2, cations and anions have been investigated to find out the conditions for the maximum degradation of PNP in presence of 254 nm UV light. The rate of photocat...The effects of initial concentrations of PNP, doses of TiO2, cations and anions have been investigated to find out the conditions for the maximum degradation of PNP in presence of 254 nm UV light. The rate of photocatalytic degradation of PNP was increased with increasing TiO2 dose until the dose concentration reached at a value 0.4 g/100 mL. Further increase of TiO2 decreased the degradation. The maximum degradation of PNP was found with the catalyst dose 0.4 g/100 mL at pH 3. The degradation of PNP was decreased with increasing of PNP concentration. About 90% degradation of PNP was observed when 1.0 × 10﹣4 M PNP was irradiated for 2 hours in 0.4 g/100 mL of TiO2 suspension. The effect of Cu(II) and Fe(II) ions on the degradation was also investigated. Addition of Cu(II) ions enhances the percent degradation but excess of Cu(II) ions decreases the degradation. Under the same experimental conditions, the presence of and is found to be detrimental to the photodegradation of PNP. Hydrogen ion concentration of reaction mixture was found to increase continuously during photodegradation suggesting mineralization of PNP.展开更多
The system of linear equations plays a vital role in real life problems such as optimization, economics, and engineering. The parameters of the system of linear equations are modeled by taking the experimental or obse...The system of linear equations plays a vital role in real life problems such as optimization, economics, and engineering. The parameters of the system of linear equations are modeled by taking the experimental or observation data. So the parameters of the system actually contain uncertainty rather than the crisp one. The uncertainties may be considered in term of interval or fuzzy numbers. In this paper, a detailed study of three solution techniques namely Classical Method, Extension Principle method and α-cuts and interval Arithmetic Method to solve the system of fuzzy linear equations has been done. Appropriate applications are given to illustrate each technique. Then we discuss the comparison of the different methods numerically and graphically.展开更多
The spot-diffusing technique provides better performance compared to conventional diffuse system for indoor optical-wireless communication (OWC) system. In this paper, the performance of an OW spot-diffusing communica...The spot-diffusing technique provides better performance compared to conventional diffuse system for indoor optical-wireless communication (OWC) system. In this paper, the performance of an OW spot-diffusing communication system using Neuro-Fuzzy (NF) adaptive multi-beam transmitter configuration has been proposed. The multi-beam transmitter generates multiple spots pointed in different directions, hence, forming a matrix of diffusing spots based on position of the receiver and receiver mobility. Regardless of the position of the transmitter and receiver, NF controller target the spots adaptively at the best locations and allocates optimal power to the spots and beam angle are adapted in order to achieve better signal-to-noise plus interference ratio (SNIR). Maximum ratio combining (MRC) is used in the imaging receiver. The proposed OW spot-diffusing communication system is compared with other spot-beam diffusion methods proposed in literature. Performance evaluation revels that the proposed NF based OW spot-diffusing communication system outperforms other spot-beam diffusion methods.展开更多
In this paper,the problem of time varying telecommunication delays in passive teleoperation systems is addressed.The design comprises delayed position,velocity and position-velocity signals with the local position and...In this paper,the problem of time varying telecommunication delays in passive teleoperation systems is addressed.The design comprises delayed position,velocity and position-velocity signals with the local position and velocity signals of the master and slave manipulators.Nonlinear adaptive control terms are employed locally to cope with uncertain parameters associated with the gravity loading vector of the master and slave manipulators.Lyapunov-Krasovskii function is employed for three methods to establish asymptotic tracking property of the closed loop teleoperation systems.The stability analysis is derived for both symmetrical and unsymmetrical time varying delays in the forward and backward communication channel that connects the local and remote sites.Finally,evaluation results are presented to illustrate the efectiveness of the proposed design for real-time applications.展开更多
The peripheral rivers of Dhaka city became highly polluted because of industrialization and urbanization to a greater extent in the last few decades.Thus,an attempt has been taken to measure 48 elements in water of th...The peripheral rivers of Dhaka city became highly polluted because of industrialization and urbanization to a greater extent in the last few decades.Thus,an attempt has been taken to measure 48 elements in water of the river Buriganga using the ICP-MS method for the first time.Accordingly,it could be the reference values for future research in Bangladesh.Out of the 48 elements,the following metals are given more attention because of their detrimental effects on living organisms and for discussing their aquatic chemistry in polluted water body:Be,Na,Al,Cr,Mn,Fe,Ni,Cu,Zn,Cd,Ba,Hg,Pb,Bi and U.Results revealed that metals’concentrations in water in the monsoon were less than that of the winter,however,Cr and Fe were found at below detection limits in the winter that is unexpected.Physicochemical parameters of the river water such as pH,dissolved oxygen play vital roles for hydrolysis reactions in the stagnant water body.Hydrolyzed products of metal ions having low values of solubility products(K sp),for example,iron(III)hydroxide,chromium(III)hydroxide,phase out through precipitation reactions.This study also detects and quantifies total concentrations of Hg and U in water of the river Buriganga for the first time.PCA and correlation matrix results provided potential sources of the relevant metals.Mechanisms of hydrolysis and precipitation reactions for metal ions in the polluted river water are also discussed.展开更多
Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5...Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) &ARING;, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.展开更多
Fully developed turbulent water-flow structure over one-side repeated-ribs in narrow two-dimensional rectangular channels was investigated experimentally by Particle Image Velocimetry （PIV） and analytically by the s...Fully developed turbulent water-flow structure over one-side repeated-ribs in narrow two-dimensional rectangular channels was investigated experimentally by Particle Image Velocimetry （PIV） and analytically by the standard k-ε and nonlinear k-ε turbulent models. Two rib-pitch to height ratios （p/k） of 10 and 20 were investigated while the rib height was held constant at 4 mm. The rib height-to-channel equivalent diameter ratio （k/De） was 0.1. The streamwise mean velocity and turbulent kinetic energy distributions at six selected axial stations from the center rib for the two Reynolds number （Re） of 7,000 and 20,000 were obtained and compared with the predicted one. The performance ability in predicting separating and reattaching turbulent water-flow between the standard K-ε and nonlinear k-ε models had yielded no clear conclusion. A large-scale turbulent eddy was generated by the rib promoter and then propagated into the mainstream flow, which led to the deformation of the velocity profile. The turbulent kinetic energy was increased about two times higher at p/k = 20 than that at p/k =10 under the two Reynolds numbers. The effect of the p/k value and the Reynolds number （Re） on reattachment length （XR） was investigated and showed that the p/k and Re had no significant effect on the reattachment length beyond a critical value of Re = 15,000 where XR was found to be approximately 4 times of the rib height under water-flow condition.展开更多
Objectives: To compare the outcomes of Percutaneous Nephrolithotomy (PCNL) with or without nephrostomy tube. Materials & Methods: This prospective comparative study intended to compare the outcomes between PCNL wi...Objectives: To compare the outcomes of Percutaneous Nephrolithotomy (PCNL) with or without nephrostomy tube. Materials & Methods: This prospective comparative study intended to compare the outcomes between PCNL without nephrostomy tube and PCNL with nephrostomy tube. A total of 50 cases of renal stone disease planned for PCNL in Dhaka Medical College Hospital from July 2015 to June 2017, were included in this study according to the statistical calculation. Cases were randomly allocated to group A (PCNL without nephrostomy tube) and group B (PCNL with nephrostomy tube). Each group consisted of 25 patients. The outcome variables were post operative pain, requirement of analgesic, leakage of urine and post operative hospital stay. Data were analyzed and compared by statistical tests. Results: No significant differences were found regarding age (p = 0.95), sex (p = 0.55) and operation time (p = 0.36) between two groups. Post operative pain (p p p p Conclusions: Percutaneous nephrolithotomy without nephrostomy tube is better than percutaneous nephrolithotomy with nephrostomy tube in selective cases. It significantly reduces post operativepain, analgesic requirement and postoperative hospital stay. So percutaneous nephrolithotomy without nephrostomy tube is safe and effective.展开更多
The aim of this paper is to find the numerical solutions of the second order linear and nonlinear differential equations with Dirichlet, Neumann and Robin boundary conditions. We use the Bernoulli polynomials as linea...The aim of this paper is to find the numerical solutions of the second order linear and nonlinear differential equations with Dirichlet, Neumann and Robin boundary conditions. We use the Bernoulli polynomials as linear combination to the approximate solutions of 2nd order boundary value problems. Here the Bernoulli polynomials over the interval [0,1] are chosen as trial functions so that care has been taken to satisfy the corresponding homogeneous form of the Dirichlet boundary conditions in the Galerkin weighted residual method. In addition to that the given differential equation over arbitrary finite domain [a,b] and the boundary conditions are converted into its equivalent form over the interval [0,1]. All the formulas are verified by considering numerical examples. The approximate solutions are compared with the exact solutions, and also with the solutions of the existing methods. A reliable good accuracy is obtained in all cases.展开更多
基金the National Key Research and Development Program of China(No.2017YFD0801003)。
文摘Zero-valent iron amended biochar(ZVIB)has been proposed as a promising material in immobilizing heavy metals in paddy fields.In this study,the impacts of p H of ZVIB(p H 6.3 and p H 9.7)and watering management techniques(watering amount in the order of CON(control,5/72)>3/72>1-3/72>3/100>1/72,with 5/72,for example,representing irrigation given to 5 cm above soil surface in 72 hr regular interval)on As and Cd bioavailability for rice and its grain yield(Yield BR)were investigated in a pot experiment.Brown rice As(As BR)content was irrelative to the watering treatments,while significantly decreased(>50%)with the addition of both ZVIB materials.The diminutions of brown rice Cd(Cd BR)content as well as the Yield BR were highly dependent on both the soil amendment materials’p H and watering amount.Among all the watering treatments,3/72 treatment(15%less irrigation water than the CON)with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As BR(50%)and Cd BR contents(19%)as well as for significant increment(12%)of the Yield BR.Although high pH(9.7)ZVIB application could also efficiently decrease As and Cd contents in brown rice,it might risk grain yield lost if appropriate(e.g.3/72 in our study)watering management technique was not chosen.Therefore,ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.
文摘This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .
文摘River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.
文摘Background: The COVID-19 pandemic had a significant impact on every aspect of life. Like other chronic diseases, pediatric rheumatic diseases (PRDs) also faced unique challenges during the pandemic, including limited access to care, concerns regarding infection risk, drug shortages and social isolation. Objective: The objective of the study was to identify the impact of the COVID-19 pandemic on the management course of children with rheumatic diseases. Methods: This cross-sectional study was conducted in the department of paediatrics, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from April 2021 to March 2022. Two hundred and twenty patients were enrolled. A predesigned questionnaire was completed which included socio-demographic, clinical and laboratory parameters. Disease activity was assessed clinically and from laboratory profile. Data were calculated manually and by using SPSS version 22. Z-proportion test and chi square test were done when applicable. Results: Among the enrolled PRD cases 87.7% were Juvenile Idiopathic Arthritis (JIA), 7.7% were Systemic Lupus Erythematosus (SLE) and 4.6% were other cases. Irregular follow-ups were found in 69.9% JIA cases, 82.4% SLE cases and 60% other PRD cases. Poor drug compliance was present in 18.2% of cases. A significant number of patients had higher disease activity or flare during the COVID-19 pandemic. Conclusion: During COVID-19 pandemic most (70.5%) of the PRD patients were irregular in their follow-ups. Poor drug compliance was also more than in the pre-COVID period. Disease activity status significantly worsened during this period.
基金the financial support by the National Natural Science Foundation of China (42042050, U2005207)Natural Science Foundation of Fujian Province, China (2020J0141)。
文摘In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90,BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7(municipal waste dumping) and 8(medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5(Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9(urban), 10(sub-urban), 11(rural) while sites-7 and 8(urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites -7 and 8. Values of incremental lifetime cancer risk were from 10to 10showed no carcinogenic health risk by road dusts contaminated with the heavy metals.
基金funded by Institutional Fund Projects (IFPIP:515-961-1443)technical and financial support provided by the Ministry of Education and King Abdulaziz University, DSR, Jeddah, Saudi Arabia。
文摘The aggregation behavior of the mixture of cetyltrimethylammonium chloride(CTAC), a cationic surfactant, and moxifloxacin hydrochloride(MFH), a fourth-generation fluoroquinolone antibiotic drug, has been studied using the conductivity technique in aqueous and alcoholic(EtOH, 1-PrOH, and 2-BuOH)media. The study was performed at several temperatures between 298.15 and 323.15 K at 5 K intervals.The assembly has been characterized by evaluating the micellar parameters, such as the critical micelle concentration(CMC) and the counter ion binding(β), of the CTAC + MFH mixture. The values of the CMC for the assembly of the CTAC + MFH mixture were reliant on the composition of alcohols in the mixed solvents and the temperature. The CMC values of the CTAC + MFH mixture increased with increasing temperature;that is, assembly was delayed by increased temperature. The micellization of the CTAC + MFH mixed system was delayed in alcoholic media. The observed-ΔG0mvalues for the association of the CTAC + MFH mixed system demonstrated a spontaneous aggregation process under all study conditions.Based on the-ΔH^(0)_(m) and +ΔS^(0)_(m) values, the association of the CTAC + MFH mixture is exothermic and the interaction forces acting between the CTAC and MFH species are hydrophobic, ion–dipole, and electrostatic interactions. The transfer properties and enthalpy–entropy compensation were also assessed and described comprehensively.
文摘Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extracts against the late blight disease incidence and severity in experimental potato field at University of Rajshahi, Bangladesh during 2019-2020. Crude aqueous extract of leaves of <i>Syzygium</i> <i>cumini</i>, <i>Psidium</i> <i>guajava</i>, <i>Eucalyptus</i> <i>globusus</i>, <i>Carica</i> <i>papaya</i> and <i>Lawsonia</i> <i>inermis</i>;fruits of <i>Terminalia</i> <i>bellirica</i>, <i>T.</i> <i>chebula</i> and <i>Piper</i> <i>nigrum</i>;flower buds of <i>Syzygium</i> <i>aromaticum</i> and cloves of <i>Allium</i> <i>sativum</i> were used at 5% (w/v) concentration for evaluation. Out of ten botanicals, <i>Syzygium</i> <i>cumini</i> leaves extract was found most effective in controlling the late blight disease incidence and severity up to 66 DAS (days after sowing) and increased the potato yield by 71.29% compare to untreated control. The efficacy of <i>Lawsonia</i> <i>inermis</i> extract against late blight disease was found promising and increased the potato yield by 48.51%. Other four botanical extracts (<i>Terminalia</i> <i>chebula</i>, <i>Piper</i> <i>nigrum</i>, <i>Syzygium</i> <i>aromaticum</i> and <i>Carica</i> <i>papaya</i>) showed moderate efficacy <span>against the incidence and severity of late blight disease, and increased 30% </span>more potato yield compare to control. These results suggest that botanical extract of <i>Syzygium</i> <i>cumini</i> ha<span style="font-family:;" "="">s</span><span style="font-family:;" "=""> a great potential as an alternative </span><span style="font-family:;" "="">of</span><span style="font-family:;" "=""> chemical fungicides to control the late blight disease of potato in</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">eco-friendly way.</span>
文摘The assessment of the radiological concentration of <sup>134</sup>Cs and <sup>137</sup>Cs owing to hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh is presented here in this work. The concentration of <sup>134</sup>Cs and <sup>137</sup>Cs was estimated in different pathways consisting of the ingestion of plants, milk, and meat. The highest air concentration has been determined at 65 m distance from the core of the reactor. The maximum concentration passed off without delay simply after the accident in various directions. Local meteorological information such as average wind velocity and wind frequency were analyzed. Considering all directions, the highest concentration has been observed in the “S” direction. The concentrations of <sup>134</sup>Cs and <sup>137</sup>Cs were determined in ground, vegetation, milk and meat. The concentration of <sup>137</sup>Cs is investigated to be higher than the <sup>134</sup>Cs. The concentration of <sup>134</sup>Cs and <sup>137</sup>Cs was found to be lower in vegetation, milk, and meat than that of ground concentration. Overall, in this study, the concentration in meat has been investigated to be lower. In case of a reactor accident, the concentration assessment due to the ingestion of vegetables, milk, and meat will be a valuable guide for insuring radiological protection across the research reactor at AERE, Savar, Bangladesh.
文摘<strong>Background: </strong>Disseminated Intravascular Coagulation (DIC) is a life threatening complication frequently observed in acute leukemia. Among the morphological varieties of Acute Myeloid Leukaemia (AML), Acute Promyelocytic Leukaemia (APL) is well established to cause DIC. But there have been reports noted that abnormal DIC parameters also commonly observed in the patients with non-APL AML. This study evaluated the DIC parameters & DIC score according to International Society of Thrombosis and Haemostasis (ISTH) in newly diagnosed non-APL AML patients. <strong>Materials and Methods:</strong> This cross-sectional observational study was conducted in the Department of Haematology, BSMMU, Dhaka, Bangladesh. 48 newly diagnosed non-APL AML patients were enrolled. Platelets count was measured by auto analyzer (Sysmax XT 2000i/Pentra ABX-120DX) as well as checked manually. Prothrombin time, fibrinogen, D-Dimer were measured using STAGO Coagulation analyzer. The ISTH-DIC scoring system was used to calculate DIC score. The statistical analysis was carried out using the Statistical Package for Social Sciences version 24.0 for Windows. Chi-Square test & Fisher exact test was used for categorical variables. Unpaired t-test was used to compare mean between groups. For all statistical tests, p-value less than 0.05 was considered as statistically significant. <strong>Results: </strong>By analyzing 48 newly diagnosed patients with non-APL AML, found that DIC developed in 14.6% patients at presentation. Among the DIC parameters, PT and D-dimer were significantly higher in patients presented with DIC. Patients with DIC exhibit lower expression of CD117, CD34, HLA-DR and statistically significant association with negative expression of HLA-DR (p-value 0.034). No significant association was found between presence of DIC and age, gender, bleeding at presentation, morphological type, WBC count or peripheral blast percentage.<strong> Conclusion:</strong> Abnormalities of DIC parameters in common in patients with AML. A sign
文摘The effects of initial concentrations of PNP, doses of TiO2, cations and anions have been investigated to find out the conditions for the maximum degradation of PNP in presence of 254 nm UV light. The rate of photocatalytic degradation of PNP was increased with increasing TiO2 dose until the dose concentration reached at a value 0.4 g/100 mL. Further increase of TiO2 decreased the degradation. The maximum degradation of PNP was found with the catalyst dose 0.4 g/100 mL at pH 3. The degradation of PNP was decreased with increasing of PNP concentration. About 90% degradation of PNP was observed when 1.0 × 10﹣4 M PNP was irradiated for 2 hours in 0.4 g/100 mL of TiO2 suspension. The effect of Cu(II) and Fe(II) ions on the degradation was also investigated. Addition of Cu(II) ions enhances the percent degradation but excess of Cu(II) ions decreases the degradation. Under the same experimental conditions, the presence of and is found to be detrimental to the photodegradation of PNP. Hydrogen ion concentration of reaction mixture was found to increase continuously during photodegradation suggesting mineralization of PNP.
文摘The system of linear equations plays a vital role in real life problems such as optimization, economics, and engineering. The parameters of the system of linear equations are modeled by taking the experimental or observation data. So the parameters of the system actually contain uncertainty rather than the crisp one. The uncertainties may be considered in term of interval or fuzzy numbers. In this paper, a detailed study of three solution techniques namely Classical Method, Extension Principle method and α-cuts and interval Arithmetic Method to solve the system of fuzzy linear equations has been done. Appropriate applications are given to illustrate each technique. Then we discuss the comparison of the different methods numerically and graphically.
文摘The spot-diffusing technique provides better performance compared to conventional diffuse system for indoor optical-wireless communication (OWC) system. In this paper, the performance of an OW spot-diffusing communication system using Neuro-Fuzzy (NF) adaptive multi-beam transmitter configuration has been proposed. The multi-beam transmitter generates multiple spots pointed in different directions, hence, forming a matrix of diffusing spots based on position of the receiver and receiver mobility. Regardless of the position of the transmitter and receiver, NF controller target the spots adaptively at the best locations and allocates optimal power to the spots and beam angle are adapted in order to achieve better signal-to-noise plus interference ratio (SNIR). Maximum ratio combining (MRC) is used in the imaging receiver. The proposed OW spot-diffusing communication system is compared with other spot-beam diffusion methods proposed in literature. Performance evaluation revels that the proposed NF based OW spot-diffusing communication system outperforms other spot-beam diffusion methods.
基金supported by Natural Sciences and Engineering Research Council of Canada (NSERC) Research Fellowship,Canada Research Chairs Program and University of Ottawa Research Chair Program
文摘In this paper,the problem of time varying telecommunication delays in passive teleoperation systems is addressed.The design comprises delayed position,velocity and position-velocity signals with the local position and velocity signals of the master and slave manipulators.Nonlinear adaptive control terms are employed locally to cope with uncertain parameters associated with the gravity loading vector of the master and slave manipulators.Lyapunov-Krasovskii function is employed for three methods to establish asymptotic tracking property of the closed loop teleoperation systems.The stability analysis is derived for both symmetrical and unsymmetrical time varying delays in the forward and backward communication channel that connects the local and remote sites.Finally,evaluation results are presented to illustrate the efectiveness of the proposed design for real-time applications.
基金support by the National Natural Science Foundation of China(42042050,U2005207)Natural Science Foundation of Fujian Province,China(2020J0141).
文摘The peripheral rivers of Dhaka city became highly polluted because of industrialization and urbanization to a greater extent in the last few decades.Thus,an attempt has been taken to measure 48 elements in water of the river Buriganga using the ICP-MS method for the first time.Accordingly,it could be the reference values for future research in Bangladesh.Out of the 48 elements,the following metals are given more attention because of their detrimental effects on living organisms and for discussing their aquatic chemistry in polluted water body:Be,Na,Al,Cr,Mn,Fe,Ni,Cu,Zn,Cd,Ba,Hg,Pb,Bi and U.Results revealed that metals’concentrations in water in the monsoon were less than that of the winter,however,Cr and Fe were found at below detection limits in the winter that is unexpected.Physicochemical parameters of the river water such as pH,dissolved oxygen play vital roles for hydrolysis reactions in the stagnant water body.Hydrolyzed products of metal ions having low values of solubility products(K sp),for example,iron(III)hydroxide,chromium(III)hydroxide,phase out through precipitation reactions.This study also detects and quantifies total concentrations of Hg and U in water of the river Buriganga for the first time.PCA and correlation matrix results provided potential sources of the relevant metals.Mechanisms of hydrolysis and precipitation reactions for metal ions in the polluted river water are also discussed.
文摘Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) &ARING;, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.
文摘Fully developed turbulent water-flow structure over one-side repeated-ribs in narrow two-dimensional rectangular channels was investigated experimentally by Particle Image Velocimetry （PIV） and analytically by the standard k-ε and nonlinear k-ε turbulent models. Two rib-pitch to height ratios （p/k） of 10 and 20 were investigated while the rib height was held constant at 4 mm. The rib height-to-channel equivalent diameter ratio （k/De） was 0.1. The streamwise mean velocity and turbulent kinetic energy distributions at six selected axial stations from the center rib for the two Reynolds number （Re） of 7,000 and 20,000 were obtained and compared with the predicted one. The performance ability in predicting separating and reattaching turbulent water-flow between the standard K-ε and nonlinear k-ε models had yielded no clear conclusion. A large-scale turbulent eddy was generated by the rib promoter and then propagated into the mainstream flow, which led to the deformation of the velocity profile. The turbulent kinetic energy was increased about two times higher at p/k = 20 than that at p/k =10 under the two Reynolds numbers. The effect of the p/k value and the Reynolds number （Re） on reattachment length （XR） was investigated and showed that the p/k and Re had no significant effect on the reattachment length beyond a critical value of Re = 15,000 where XR was found to be approximately 4 times of the rib height under water-flow condition.
文摘Objectives: To compare the outcomes of Percutaneous Nephrolithotomy (PCNL) with or without nephrostomy tube. Materials & Methods: This prospective comparative study intended to compare the outcomes between PCNL without nephrostomy tube and PCNL with nephrostomy tube. A total of 50 cases of renal stone disease planned for PCNL in Dhaka Medical College Hospital from July 2015 to June 2017, were included in this study according to the statistical calculation. Cases were randomly allocated to group A (PCNL without nephrostomy tube) and group B (PCNL with nephrostomy tube). Each group consisted of 25 patients. The outcome variables were post operative pain, requirement of analgesic, leakage of urine and post operative hospital stay. Data were analyzed and compared by statistical tests. Results: No significant differences were found regarding age (p = 0.95), sex (p = 0.55) and operation time (p = 0.36) between two groups. Post operative pain (p p p p Conclusions: Percutaneous nephrolithotomy without nephrostomy tube is better than percutaneous nephrolithotomy with nephrostomy tube in selective cases. It significantly reduces post operativepain, analgesic requirement and postoperative hospital stay. So percutaneous nephrolithotomy without nephrostomy tube is safe and effective.
文摘The aim of this paper is to find the numerical solutions of the second order linear and nonlinear differential equations with Dirichlet, Neumann and Robin boundary conditions. We use the Bernoulli polynomials as linear combination to the approximate solutions of 2nd order boundary value problems. Here the Bernoulli polynomials over the interval [0,1] are chosen as trial functions so that care has been taken to satisfy the corresponding homogeneous form of the Dirichlet boundary conditions in the Galerkin weighted residual method. In addition to that the given differential equation over arbitrary finite domain [a,b] and the boundary conditions are converted into its equivalent form over the interval [0,1]. All the formulas are verified by considering numerical examples. The approximate solutions are compared with the exact solutions, and also with the solutions of the existing methods. A reliable good accuracy is obtained in all cases.
