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Acute and chronic toxicity of nickel to nitrifiers at different temperatures

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Journal of Environmental Sciences 2019年第8期31卷 169-178页

作者： Xiaoguang Liu mohammad M.I.chowdhury Masuduz Zaman Mingu Kim George Nakhla Department of Civil and Environmental Engineering University of Western Ontario Department of Chemical and Biochemical Engineering University of Western Ontario

This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants(K_(I,Ni)) for ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors(SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μ_(max), b, and K_o of AOB were 0.16 day^(-1), 0.098 day^(-1) and 2.08 mg O_2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen(DO)(7 mg/L) and long solids retention time(SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible.

关键词： Nickel inhibition Temperature Nitrifying culture Activated sludge Toxicity

Deposition behavior and tribological properties of diamond-like carbon coatings on stainless steels via chemical vapor deposition

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1335-1343页

作者： Labani Mustafi M.M.Rahman mohammad Nur E Alam Al Nasim mohammad Asaduzzaman chowdhury M.H.Monir School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Engineering RMIT UniversityMelbourneVictoria 3001Australia Dhaka University of Engineering and Technology Gazipur 1707Bangladesh

A systematic investigation was carried out to observe the deposition rate of a diamond-like carbon(DLC) coating on two stainless steel substrates by chemical vapor deposition(CVD). The objective of this research is to study the deposition behavior of the DLC coating and its tribological properties in different combinations of methane(CH_4) and nitrogen, which were used as precursor gases. The results reveal that the deposition rate increases with increasing CH_4 content up to 50 vol%. The hardness of the DLC-deposited layer also increases while the friction coefficient decreases with increasing CH_4 gas content up to 50% in the precursor gas mixture.

关键词： diamond-like carbon chemical vapor deposition methane and nitrogen gas mixtures deposition rate hardness friction coefficient

Movement Optimization for a Cyborg Cockroach in a Bounded Space Incorporating Machine Learning

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Cyborg and Bionic Systems 2023年第1期4卷 427-440页

作者： Mochammad Ariyanto chowdhury mohammad Masum Refat Kazuyoshi Hirao Keisuke Morishima Department of Mechanical Engineering Graduate School of EngineeringOsaka UniversitySuita 565-0871Japan Department of Mechanical Engineering Faculty of EngineeringDiponegoro UniversitySemarang50275Indonesia

Cockroaches can traverse unknown obstacle-terrain,self-right on the ground and climb above the ***,they have limited motion,such as less activity in light/bright areas and lower ***,the movement of the cyborg cockroaches needs to be optimized for the utilization of the cockroach as a cyborg *** study aims to increase the search rate and distance traveled by cockroaches and reduce the stop time by utilizing automatic stimulation from machine *** machine learning classifiers were applied to classify the offline binary classification of the cockroach movement based on the inertial measuring unit input *** time-domain features were chosen and applied as the classifier *** highest performance of the classifiers was implemented for the online motion recognition and automatic stimulation provided to the cerci to trigger the free walking motion of the cockroach.A user interface was developed to run multiple computational processes simultaneously in real time such as computer vision,data acquisition,feature extraction,automatic stimulation,and machine learning using a multithreading *** the basis of the experiment results,we successfully demonstrated that the movement performance of cockroaches was importantly improved by applying machine learning classification and automatic *** system increased the search rate and traveled distance by 68%and 70%,respectively,while the stop time was reduced by 78%.

关键词： computer classifier obstacle

A comparative study of the antioxidant,antimicrobial,cytotoxic and thrombolytic potential of the fruits and leaves of Spondias dulcis

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Asian Pacific Journal of Tropical Biomedicine 2013年第9期3卷 682-691页

作者： shawkat Md.Aminul Islam kh Tanvir Ahmed mohammad Kawsar Manik Md.Arif Wahid chowdhury shafayat ibne kamal Department of Pharmacy East West University

Objective:To investigate the antioxidant,antimicrobial,cytotoxic and thrombolytic property of the fruits and leaves of Spondias dulcis（***）.Methods:Methanolic extracts of fruits and leaves of *** were partitioned with chloroform and *** antioxidant potential of the crude extract and partitioned fractions were evaluated in terms of total phenolic content,total flavonoid content,DPPH radical scavenging potential,reducing potential and total antioxidant capacity by specific standard *** antimicrobial activity was evaluated using disc diffusion *** cytotoxicity was evaluated by using brine shrimp lethality bioassay and compared with vincristine *** thrombolytic activity was compared with ***:The methanolic fruit extract exhibited the highest phenolic content,flavonoid content and antioxidant capacity,among the other extracts,with the highest DPPH radical scavenging activity at a concentration of 10μg/mL(IC50:1.91μg/mL)and maximum reducing power at a concentration of 100μg/ml.(EC50:3.58μg/mL).Though all extract showed moderate antimicrobial activity against the bacterial strains,weak or no activity against *** range of LC50value of all extracts was 1.335-14.057μg/mL which was far lower than the cut off index for *** extracts exhibited statistically significant（P<0.001）thrombolytic ***:Our study suggested that *** exhibits antimicrobial activities against a wide variety of strains while it possesses significant antioxidant,cytotoxic and thrombolytic aclivily.

关键词： Spondias dulcis Antioxidant activity Antimicrobial activity Cytotoxic activity Thrombolytic activity DPPH IC_(50) LC_(50

Variable selection strategies and its importance in clinical prediction modelling

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Family Medicine and Community Health 2020年第1期8卷 37-43页

作者： mohammad Ziaul Islam chowdhury Tanvir C Turin Department of Community Health Sciences Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada Department of Family Medicine Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada

Clinical prediction models are used frequently in clinical practice to identify patients who are at risk of developing an adverse outcome so that preventive measures can be initiated.A prediction model can be developed in a number of ways;however,an appropriate variable selection strategy needs to be followed in all *** purpose is to introduce readers to the concept of variable selection in prediction modelling,including the importance of variable selection and variable reduction *** will discuss the various variable selection techniques that can be applied during prediction model building(backward elimination,forward selection,stepwise selection and all possible subset selection),and the stopping rule/selection criteria in variable selection(p values,Akaike information criterion,Bayesian information criterion and Mallows’Cp statistic).This paper focuses on the importance of including appropriate variables,following the proper steps,and adopting the proper methods when selecting variables for prediction models.

关键词： criterion backward subset

Shadow banking:a bibliometric and content analysis

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Financial Innovation 2021年第1期7卷 1586-1614页

作者： Ridoy Deb Nath mohammad Ashraful Ferdous chowdhury Department of Business Administration Shahjalal University of Science and TechnologySylhetBangladesh

This study reports on our systematic review of 2008–2021 literature on shadow *** present an overview of the shadow banking sector,wherein we discuss the definitions,evolution,functions,and specific activities that comprise *** conducted a bibliometric analysis using the VOSviewer bibliometric tool on articles collected from the Scopus database,after which we conducted content analysis on top articles from leading sources,and identified four major streams of shadow banking ***,we identified gaps in the literature and proposed seven research questions to be addressed in future studies to advance knowledge of the shadow banking *** findings of this review may serve as a robust reference for scholars researching various aspects of shadow banking to develop our understanding of this sector.

关键词： Shadow banking Review study Bibliometric analysis Content analysis VOSviewer

Enhancing Septic Shock Detection through Interpretable Machine Learning

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Computer Modeling in Engineering & Sciences 2024年第12期141卷 2501-2525页

作者： Md Mahfuzur Rahman Md Solaiman chowdhury mohammad Shorfuzzaman Lutful Karim Md Shafiullah Farag Azzedin Department of Information and Computer Science King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Department of Electrical and Computer Engineering North South UniversityDhaka1229Bangladesh Department of Computer Science Taif UniversityTaif21974Saudi Arabia College of Applied Arts and Technology Seneca PolytechnicTorontoM2J 2X5Canada Department of Control&Instrumentation Engineering King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

This article presents an innovative approach that leverages interpretable machine learning models and cloud computing to accelerate the detection of septic shock by analyzing electronic health *** traditional methods,which often lack transparency in decision-making,our approach focuses on early detection,offering a proactive strategy to mitigate the risks of *** integrating advanced machine learning algorithms with interpretability techniques,our method not only provides accurate predictions but also offers clear insights into the factors influencing the model’s ***,we introduce a preference-based matching algorithm to evaluate disease severity,enabling timely interventions guided by the analysis *** innovative integration significantly enhances the effectiveness of our *** leverage a clinical health dataset comprising 1,552,210 Electronic Health Records(EHR)to train our interpretable machine learning models within a cloud computing *** techniques like feature importance analysis and model-agnostic interpretability tools,we aim to clarify the crucial indicators contributing to septic shock *** transparency not only assists healthcare professionals in comprehending the model’s predictions but also facilitates the integration of our system into existing clinical *** validate the effectiveness of our interpretable models using the same dataset,achieving an impressive accuracy rate exceeding 98%through the application of oversampling *** findings of this study hold significant implications for the advancement of more effective and transparent diagnostic tools in the critical domain of sepsis management.

关键词： Sepsis prediction machine learning cloud computing

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煤-树脂混合物残炭的形貌分析(英文)

新型炭材料 2004年第4期19卷 293-297页

作者： imtiaz Ahmad mohammad Ishaq mohammad Arsala Khan mohammad Shakir Ullah Ali Bahader Department of Chemistry University of Peshawar N.W.F.P. 25000 Pakistan Department of Chemistry University of Peshawar N.W.F.P. 25000 Pakistan Department of Chemistry University of Peshawar N.W.F.P. 25000 Pakistan Department of Chemistry University of Peshawar N.W.F.P. 25000 Pakistan Department of Chemistry University of Peshawar N.W.F.P. 25000 Pakistan

　借助扫描电子显微镜研究了原煤及其各种树脂混合物经微型反应釜中350℃和400℃处理后所获残炭的形貌。结果表明:富氢煤的显微组分被分解,而丝炭和角质等煤的显微组分难分解。添加诸如高密、低密聚丙烯及聚苯乙烯等树脂后可加速煤的显... 详细信息

　借助扫描电子显微镜研究了原煤及其各种树脂混合物经微型反应釜中350℃和400℃处理后所获残炭的形貌。结果表明:富氢煤的显微组分被分解,而丝炭和角质等煤的显微组分难分解。添加诸如高密、低密聚丙烯及聚苯乙烯等树脂后可加速煤的显微组分的分解,并改变了其残炭的显微形貌。

关键词：煤残炭树脂形貌分析显微组分

Allometric relationship for estimating above-ground biomass of Aegialitis rotundifolia Roxb. of Sundarbans mangrove forest, in Bangladesh

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Journal of Forestry Research 2012年第1期23卷 23-28页

作者： mohammad Raqibul Hasan Siddique Mahmood Hossain Md. Rezaul Karim chowdhury Forestry and Wood Technology Discipline Khulna University Khulna-9208 Bangladesh

Tree biomass plays a key role in sustainable management by providing different aspects of ecosystem. Estimation of above ground biomass by non-destructive means requires the dex;elopment of allometric equations. Most researchers used DBH （diameter at breast height） and TH （total height） to develop allometric equation for a tree. Very few spe- cies-specific allometric equations are currently available for shrubs to estimate of biomass from measured plant attributes. Therefore, we used some of readily measurable variables to develop allometric equations such as girth at collar-height （GcH） and height of girth measuring point （GMH） with total height （TH） for A. rotundifolia, a mangrove species of Sundarbans of Bangladesh, as it is too dwarf to take DBH and too ir- regular in base to take Girth at a fixed height. Linear, non-linear and logarithmic regression techniques were tried to determine the best re- gression model to estimate the above-ground biomass of stem, branch and leaf. A total of 186 regression equations were generated from the combination of independent variables. Best fit regression equations were determined by examining co-efficient of determination （R：）, co-efficient of variation （Cv）, mean-square of the error （Ms^r）, residual mean error （Rmax）, and F-value. Multiple linear regression models showed more efficient over other types of regression equation. The performance of regression equations was increased by inclusion of GMn as an independ- ent variable along with total height and GCH.

关键词： Aegialitis rotundifolia allometry biomass mangroves sundarbans