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38 results on '"Ahmed, Kawser"'

1. Adherence to inhalers and associated factors among adult asthma patients: an outpatient-based study in a tertiary hospital of Rajshahi, Bangladesh

Author

Rafi, Md. Abdur, Tahmin, Chowdhury Ibtida, Tashrik, Symom, Bonna, Atia Sharmin, Jannat, Ferdousy, Mily, Sabrina Jahan, Shrestha, Abhigan Babu, Seemanta, Senjuti, Rashid, Afsana, Mahjabeen, Mosarrat, Nura, Nurunnahar, Shahriar, Tasnim, Mahadi, Ashrafur Rahaman, Ahmed, Kawser, Hasan, Mohammad Jahid, Haque, Md. Azizul, and Hossain, Md. Golam

Published
2022
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2. Solid-state neutron detectors based on thickness scalable hexagonal boron nitride

Author

Ahmed, Kawser, Dahal, Rajendra, Weltz, Adam, Lu, James J. -Q., Danon, Yaron, and Bhat, Ishwara B.

Subjects
Physics - Instrumentation and Detectors
Abstract

This paper reports on the device processing and characterization of hexagonal boron nitride (hBN) based solid-state thermal neutron detectors, where hBN thickness varied from 2.5 to 15 microns. These natural hBN epilayers (with 19.9% B-10) were grown by a low pressure chemical vapor deposition process. Complete dry processing was adopted for the fabrication of these metal-semiconductor-metal (MSM) configuration detectors. These detectors showed intrinsic thermal neutron detection efficiency values of 0.86%, 2.4%, 3.15%, and 4.71% for natural hBN thickness values of 2.5, 7.5, 10, and 15 microns, respectively. Measured efficiencies are very close (more than 92%) to the theoretical maximum efficiencies for corresponding hBN thickness values for these detectors. This clearly shows the hBN thickness scalability of these detectors. A 15-micron thick hBN based MSM detector is expected to yield an efficiency of 21.4%, if enriched hBN (with ~100% B-10) is used instead of natural hBN. These results demonstrate that the fabrication of hBN thickness scalable highly efficient thermal neutron detectors is possible.

Published
2016
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3. Metalorganic chemical vapor deposition of hexagonal boron nitride on (001) sapphire substrates for thermal neutron detector applications

Author

Ahmed, Kawser, Dahal, Rajendra, Weltz, Adam, Lu, James J. -Q., Danon, Yaron, and Bhat, Ishwara B.

Subjects
Condensed Matter - Materials Science
Abstract

This paper reports on the growth and characterization of hexagonal boron nitride (hBN) and its use for solid-state thermal neutron detection. The hBN epilayers were grown by metalorganic chemical vapor deposition on sapphire substrates at a temperature of 1350 C. X-ray diffraction peak from the (002) hBN plane at a 2theta angle of 26.7 deg exhibited the c-lattice constant of 6.66 {\AA} for these films. A strong peak corresponding to the high frequency Raman active mode of hBN was found for the films at 1370.5/cm. hBN-based solid-state neutron detectors were fabricated and tested with a metal-semiconductor-metal configuration with an electrode spacing of 1 mm and hBN thickness of 2.5 micron. Fabricated detectors showed strong response to deep UV light as well. An intrinsic thermal neutron detection efficiency of 0.86% was measured, which is close to the theoretically expected efficiency of 0.87%. These results demonstrate that epitaxial hBN films are promising for thermal neutron detection applications.

Published
2016

4. Effects of sapphire nitridation and growth temperature on the epitaxial growth of hexagonal boron nitride on sapphire

Author

Ahmed, Kawser, Dahal, Rajendra, Weltz, Adam, Lu, James J. -Q., Danon, Yaron, and Bhat, Ishwara B.

Subjects
Condensed Matter - Materials Science
Abstract

This paper reports on the epitaxial growth of hexagonal boron nitride (hBN) films on sapphire substrates in a cold wall chemical vapor deposition (CVD) system where different sapphire nitridation and hBN growth temperatures were employed. A thin and amorphous nitridated layer was formed at a low temperature (850 C), which enabled subsequent epitaxial hBN growth at 1350 C. The influences of the sapphire nitridation temperature and the growth temperature on the film quality were analyzed by X-ray diffraction (XRD) measurements. Higher than optimum nitridation and growth temperatures improve the crystalline quality of the nitridated layer, but does not favor the epitaxial growth of hBN. hBN films grown at the optimum conditions exhibit the c-lattice constant of 6.66 {\AA} from the XRD {\theta}-2{\theta} scan, and the characteristic in plane stretching vibration at 1370.5/cm from Raman spectroscopy. X-ray photoelectron spectroscopy analysis confirmed the formation of stoichiometric hBN films with excellent uniformity., Comment: 4 pages, 4 figures

Published
2016

6. Extremism and Radicalization to Violence Prevention in Manitoba: A Resource for Educators

Author

Extremism and Radicalization to Violence Prevention in Manitoba (ERiM), Ahmed, Kawser, Mlodzinski, Linda, Anderson, Connie Wyatt, Poor, Marjorie, Extremism and Radicalization to Violence Prevention in Manitoba (ERiM), Ahmed, Kawser, Mlodzinski, Linda, Anderson, Connie Wyatt, and Poor, Marjorie

Abstract

Extremism and Radicalization to Violence Prevention in Manitoba (ERiM) is a made-in-Manitoba resource for educators. Funded by Public Safety Canada, this document was created in collaboration with educators and education stakeholders and intended for use in Manitoba schools. The purpose of this guide is to develop educator awareness, knowledge, and capacity in order to build resilience in youth and to help prevent radicalization to violence.

Published
2023

9. Identity and Representation: Does ‘Name’ Matter As An Element of Statehood?

Author

Ahmed, Kawser, Ahmed, Kawser, Ahmed, Kawser, and Ahmed, Kawser

Abstract

No state is born sans a name. The widely accepted view is that a state comprises its population, the geographical territory, the ruling government and capacity to enter into relations with other states. This paper argues that in addition to these traditionally recognised requirements, the name of a state, as the most suitable signifier of its identity, deserves to be recognised as an element of statehood. The reason for establishing a state is to create conditions as well as justification for exercising sovereign power, which ipso facto requires manifestation of its identity. This expected function seems impracticable at least in an international setting if a state does not have any name at all. The name of a state serves as the most efficacious vehicle for manifesting its identity as a legal entity. Moreover, practices concerning the name and naming of the prospective states show that it has been regarded as a crucial desideratum by the actors concerned in the course of attainment of statehood.&nbsp

Published
2021

11. Wetland Sanctuary Co-management and Conflict: An Exploratory Study of the Impacts of the Baikka Beel Project in Bangladesh

Author

Khan, Nahreen I., Ahmed, Kawser, Khan, Nahreen I., and Ahmed, Kawser

Abstract

In 2003, the Government of Bangladesh declared Baikka Beel, a 100-hectare wetland in the north-eastern part of the country, as a permanent wetland sanctuary conservation project intended to preserve its fish breeding and bio-diversity. Within the framework of the Borogangina Resource Management Organisation, a co-managed project was launched with the support of the USAID. Through a community husbandry initiative several NGOs and one multi-national company also took part in the project. Field research was conducted in 2012 to explore the socio-economic and environmental impacts of the co-managed project. The research revealed that the primary dependent group (i. e. the fishermen) who live in the surrounding vicinity were excluded from the co-management process and that the project impacted their economic, social, political and cultural lives considerably. The top-down approach apparently failed to persuade relevant stakeholders to buy in, resulting in a conflict among three relevant project stakeholder groups as they perceived and pursued their interests on a piecemeal basis.

Published
2022

13. Risk of adverse pregnancy outcomes prior to the onset of an autoimmune rheumatic disease: a systematic review.

Author

Muñoz, Candido Muñoz, Goulden, Bethan, Ahmed, Kawser, Alijotas-Reig, Jaume, and Giles, Ian

Subjects
ONLINE information services, SYSTEMATIC reviews, AUTOIMMUNE diseases, RISK assessment, PREGNANCY complications, AGE factors in disease, RHEUMATOID arthritis, RESEARCH funding, RHEUMATISM, MEDLINE, SYSTEMIC lupus erythematosus, DISEASE risk factors, DISEASE complications
Abstract

Objectives An increased risk of adverse maternal and foetal pregnancy complications (including pre-eclampsia, intrauterine growth restriction, and small for gestational age) is well described in women with autoimmune rheumatic disease (ARD) compared with the general population (GenPop). It is less clear, however, whether this risk of adverse pregnancy outcome (APO) also exists in women with 'preclinical ARD' (pre-ARD) before they are diagnosed with an ARD many years post-partum. Therefore, we have undertaken a systematic review of the available evidence on APO in patients who subsequently were diagnosed with a rheumatic disease to identify whether there is an increased risk in pre-ARD. Methods The present study was reported in accordance with the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard. A systematic literature review was performed using the online PubMed database. Pre-SLE and pre-RA patients were defined as those who, over the subsequent years, developed SLE or RA according to international classification criteria. Results A total of 176 articles were screened, and 27 original articles were selected for final analysis. Pre-RA was the most studied group, with 15 studies and a total of >1600 pregnancies, and pre-SLE was the second-most studied pre-ARD in pregnancy, with 14 studies and a total of >1000 pregnancies. We found that patients who subsequently developed SLE had an increased burden of poor pregnancy outcomes compared with pregnant women from the GenPop, but fewer APOs compared with pregnancies of women with SLE. In contrast, a similar rate of APOs was found when pre-RA pregnancies were compared with GenPop pregnancies. Conclusion Our findings of an increased risk of APO in certain pre-ARDs highlights the relevance of taking an obstetric history during the first rheumatology appointment and the need for novel screening strategies for the prediction of APOs. Further research is required to elucidate the immune basis of APOs in preclinical and clinical ARD. [ABSTRACT FROM AUTHOR]

Published
2023
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18. Spline parameterization based nonlinear trajectory optimization along 4D waypoints

Author

Ahmed, Kawser, Bousson, K., Coelho, Milca, and uBibliorum

Subjects
Nonlinear Programming, Trajectory Optimization, Spline Parameterization, 4D Waypoint Optimization
Abstract

Flight trajectory optimization has become an important factor not only to reduce the operational costs (e.g.,, fuel and time related costs) of the airliners but also to reduce the environmental impact (e.g.,, emissions, contrails and noise etc.) caused by the airliners. So far, these factors have been dealt with in the context of 2D and 3D trajectory optimization, which are no longer efficient. Presently, the 4D trajectory optimization is required in order to cope with the current air traffic management (ATM). This study deals with a cubic spline approximation method for solving 4D trajectory optimization problem (TOP). The state vector, its time derivative and control vector are parameterized using cubic spline interpolation (CSI). Consequently, the objective function and constraints are expressed as functions of the value of state and control at the temporal nodes, this representation transforms the TOP into nonlinear programming problem (NLP). The proposed method is successfully applied to the generation of a minimum length optimal trajectories along 4D waypoints, where the method generated smooth 4D optimal trajectories with very accurate results.

Published
2019

19. An Improved Extended Kalman Filter for Radar Tracking of Satellite Trajectories.

Author

de Freitas Coelho, Milca, Bousson, Kouamana, and Ahmed, Kawser

Subjects
KALMAN filtering, ARTIFICIAL satellite tracking, ESTIMATION theory, ARTIFICIAL satellites, RADARSAT satellites
Abstract

Nonlinear state estimation problem is an important and complex topic, especially for real-time applications with a highly nonlinear environment. This scenario concerns most aerospace applications, including satellite trajectories, whose high standards demand methods with matching performances. A very well-known framework to deal with state estimation is the Kalman Filters algorithms, whose success in engineering applications is mostly due to the Extended Kalman Filter (EKF). Despite its popularity, the EKF presents several limitations, such as exhibiting poor convergence, erratic behaviors or even inadequate linearization when applied to highly nonlinear systems. To address those limitations, this paper suggests an improved Extended Kalman Filter (iEKF), where a new Jacobian matrix expansion point is recommended and a Frobenius norm of the cross-covariance matrix is suggested as a correction factor for the a priori estimates. The core idea is to maintain the EKF structure and simplicity but improve its accuracy. In this paper, two case studies are presented to endorse the proposed iEKF. In both case studies, the classic EKF and iEKF are implemented, and the obtained results are compared to show the performance improvement of the state estimation by the iEKF. [ABSTRACT FROM AUTHOR]

Published
2021
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20. Wetland Sanctuary Co-management and Conflict: An Exploratory Study of the Impacts of the Baikka Beel Project in Bangladesh

Author

Khan, Nahreen I. and Ahmed, Kawser

Subjects
Ecology, Co-management, conflict escalation, natural resource management, Bangladesh, Ökologie, ddc:577, Ecology, Environment, Ökologie und Umwelt
Abstract

In 2003, the Government of Bangladesh declared Baikka Beel, a 100-hectare wetland in the north-eastern part of the country, as a permanent wetland sanctuary conservation project intended to preserve its fish breeding and bio-diversity. Within the framework of the Borogangina Resource Management Organisation, a co-managed project was launched with the support of the USAID. Through a community husbandry initiative several NGOs and one multi-national company also took part in the project. Field research was conducted in 2012 to explore the socio-economic and environmental impacts of the co-managed project. The research revealed that the primary dependent group (i. e. the fishermen) who live in the surrounding vicinity were excluded from the co-management process and that the project impacted their economic, social, political and cultural lives considerably. The top-down approach apparently failed to persuade relevant stakeholders to buy in, resulting in a conflict among three relevant project stakeholder groups as they perceived and pursued their interests on a piecemeal basis., International Quarterly for Asian Studies, Bd. 48 Nr. 3-4 (2017): Myanmar · Bangladesh · Indonesia · Korea · India

Published
2018
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22. Social conflict and peace-building: the perceptions, experiences, and contributions of leaders of selected community-based organizations in Winnipeg, Manitoba

Author

Senehi, Jessica (Peace and Conflict Studies) Haque, C, Emdad (Natural Resources Institute) Rahman, Mashiur (Biosystems Engineering), Byrne, Sean (Peace and Conflict Studies), Ahmed, Kawser, Senehi, Jessica (Peace and Conflict Studies) Haque, C, Emdad (Natural Resources Institute) Rahman, Mashiur (Biosystems Engineering), Byrne, Sean (Peace and Conflict Studies), and Ahmed, Kawser

Abstract

People perceive social conflict and conflict issues in different ways. My research is directed at understanding how leaders from some of Winnipeg’s Community-Based Organizations (CBOs; faith and ethno-cultural NGOs) perceive and experience social conflict and to explore their contributions toward peace-building and conflict transformation. Historically, Winnipeg has been home to a plethora of faith-based, ethno-cultural community organizations, and NGOs whose mission is to provide crucial basic and spiritual needs to people. Their contribution to the nurturing of both the spiritual and social needs of their communities is also remarkable. This qualitative research is based on semi-structured interviews and participant observation as research instruments to observe social events related to conflict and peace-building. Critical ethnographic and grounded theory approaches inform the methodology while drawing necessary inferences from relevant quantitative data. From this research, several key findings become evident: 1) CBO leaders have a high level of personal motivation and employ a wide range of tools, such as the social capital of their organizations, to intervene in social conflict issues for the purpose of peace-building; 2) of the three types of CBO (faith, ethno-cultural and NGOs), the Faith-Based Organizations (FBOs) are the most networked and involved in transforming social conflicts and contributing toward peace-building in Winnipeg; 3) some respondents seemed to indicate that not all projects are contributing equally in addressing social conflict issues; 4) social conflict issues appear to be rooted in an unjust social structure and a number of socio-economic-political and cultural policies; 5) research participants cited five complex, interrelated conflict issues in Winnipeg; 6) a grounded theoretical concept (Perception-Expectation-Frustration) was generated to explain social conflict; and 7) these everyday leaders are using a plethora of strategies as ev

Published
2017

23. 4D Fuel Optimal Trajectory Generation from Waypoint Networks

Author

Ahmed, Kawser and Bousson, Kouamana

Subjects
Dijkstra´S Algorithm, 4D Waypoint Navigation, Cost Index, Fuel Conservation, Engenharia e Tecnologia::Outras Engenharias e Tecnologias [Domínio/Área Científica], Base of Aircraft Data (Bada)
Abstract

Made available in DSpace on 2018-11-28T16:13:10Z (GMT). No. of bitstreams: 1 4679_9179.pdf: 2720176 bytes, checksum: 4e27c9dbfcda362e484a9b45b5317441 (MD5) Previous issue date: 2016-03-21

Published
2016

25. Generating Time Optimal Trajectory from Predefined 4D waypoint Networks

Author

Ahmed, Kawser, Bousson, K., and uBibliorum

Subjects
Fluid Flow and Transfer Processes, Trajectory Optimization, Computer science, Cruise, Aerospace Engineering, Trajectory optimization, Time Conservation, Reduction (complexity), Waypoint, Control and Systems Engineering, Control theory, 4D Waypoint Navigation, Trajectory, Cost index, Dijkstra’s Algorithm, Climb, Base of Aircraft Data (BADA), Electrical and Electronic Engineering, Descent (aeronautics), Dijkstra's algorithm, Simulation
Abstract

Submitted by BOUSSON (bousson@ubi.pt) on 2020-02-07T18:16:36Z No. of bitstreams: 1 2017 - KBousson (IREASE) - 4D Waypoint Networks.pdf: 2984244 bytes, checksum: 072981a65459871905c9fb1ff7916a73 (MD5) Approved for entry into archive by Pessoa (pfep@ubi.pt) on 2020-02-10T15:14:29Z (GMT) No. of bitstreams: 1 2017 - KBousson (IREASE) - 4D Waypoint Networks.pdf: 2984244 bytes, checksum: 072981a65459871905c9fb1ff7916a73 (MD5) Approved for entry into archive by Pessoa (pfep@ubi.pt) on 2020-02-10T15:22:39Z (GMT) No. of bitstreams: 1 2017 - KBousson (IREASE) - 4D Waypoint Networks.pdf: 2984244 bytes, checksum: 072981a65459871905c9fb1ff7916a73 (MD5) Made available in DSpace on 2020-02-10T15:22:39Z (GMT). No. of bitstreams: 1 2017 - KBousson (IREASE) - 4D Waypoint Networks.pdf: 2984244 bytes, checksum: 072981a65459871905c9fb1ff7916a73 (MD5) Previous issue date: 2017-08 info:eu-repo/semantics/publishedVersion

Published
2017

38. Heavy metal accumulation during the last 30 years in the Karnaphuli River estuary, Chittagong, Bangladesh

Author

Ke-liang Chen, Yonghang Xu, Seema Rani, Xiang Ye, Aijun Wang, and Ahmed Kawser

Subjects
Pollution, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Sedimentation rate, 010501 environmental sciences, Silt, 01 natural sciences, Metal, Catastrophic events, 0105 earth and related environmental sciences, media_common, geography, Multidisciplinary, geography.geographical_feature_category, Research, Sediment, Landslide, Estuary, Karnaphuli River estuary, Contamination, Sedimentation, Heavy metal, visual_art, Environmental chemistry, visual_art.visual_art_medium, Environmental science, Pollution load index
Abstract

Heavy metal contamination of aquatic environment has attracted global attention owing to its abundance, persistence, and environmental toxicity, especially in developing countries like Bangladesh. Five heavy metals, namely chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were investigated in surface and core sediments of the Karnaphuli River (KR) estuary in Chittagong, Bangladesh, in order to reveal the heavy metal contamination history in estuarine sediments and its response to catastrophic events and human activities. The surface sediment was predominantly composed of silt and sand, and the surface sediment was contaminated with Cr and Pb. Based on the 210Pb chronology, the sedimentation rate in the inter-tidal zone of KR estuary was 1.02 cm/a before 2007, and 1.14 cm/a after 2008. The core sediment collected from 8 to 20 cm below the surface mainly originated from terrestrial materials induced by catastrophic events such as cyclone, heavy rainfall and landslides in 2007 and 2008. The values of contamination factor (CF) showed that the sediment became moderately contaminated with Cr and Pb in the last 30 years. The variation and accumulation of heavy metals in core sediment before 2000 was mainly related to natural variations in sediment sources; however, in subsequent years, the anthropogenic inputs of heavy metals have increased due to rapid physical growth of urban and industrial areas in the Chittagong city. In general, the accumulation pattern of heavy metals after normalization to Aluminum in sediments of KR estuary indicated an accelerated rate of urbanization and industrialization in the last 30 years, and also suggested the influence of natural catastrophic event on estuarine environment.

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