Catalytically activated quantum-size Pt/Pd bimetallic core–shell nanoparticles decorated on ZnO nanorod clusters for accelerated hydrogen gas detection

Hassan, Kamrul,Chung, Gwiy-Sang Elsevier 2017 Sensors and actuators. B Chemical Vol.239 No.-

<P><B>Abstract</B></P> <P>This paper presents theoretical and experimental investigations of quantum-sized (3/3nm) Pt/Pd bimetallic core-shell nanoparticle (NP)-decorated ZnO nanorod (NR) clusters (Pt/Pd-ZnO NRs) on silicon (Si) substrate for accelerated hydrogen (H<SUB>2</SUB>) gas detection. Quantum-size core–shell NP synthesis, metal loading, and Pt/Pd bimetal composition were all carefully controlled by varying the deposition conditions used in the pulsed laser deposition (PLD) system. Theory suggests that the structural arrangement of bimetallic Pt shell around a Pd core can be advantageous in H<SUB>2</SUB> sensing compared to the converse arrangement. Experimental analysis showed that the as-fabricated sensor exhibited a high response magnitude of 58% (10,000ppm), a fast response time of 5s, and a broad detection range from 0.2 to 40,000ppm at the operating temperature of 100°C. The fabricated sensor also exhibited a good selectivity and a negligible humidity effect over the entire detection range. The superior sensing features of the sensor can be attributed to the enhancement of hydrogen-induced changes in the work function of the Pt/Pd-ZnO NR network. More importantly, the atomic arrangements and chemical potentials of the core–shell interfacial region play vital role in accelerating the H<SUB>2</SUB> sensing properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ZnO NR clusters was synthesized by sol-gel and hydrothermal process. </LI> <LI> Quantum size (3/3nm) Pt/Pd bimetal decorated on ZnO NR clusters by PLD method. </LI> <LI> Computational analysis of bimetallic nanoparticles for hydrogen sensing. </LI> <LI> Feasibility of H<SUB>2</SUB> sensing properties is investigated. </LI> <LI> The mechanism for H<SUB>2</SUB> response was described by diffusion pathway. </LI> </UL> </P>

Fast and reversible hydrogen sensing properties of Pd-capped Mg ultra-thin films modified by hydrophobic alumina substrates

Hassan, Kamrul,Chung, Gwiy-Sang Elsevier 2017 Sensors and actuators. B, Chemical Vol.242 No.-

<P><B>Abstract</B></P> <P>This work reports on the hydrogen sensing abilities of palladium (Pd)-capped magnesium (Mg) bimetallic ultra-thin films, which were prepared by RF magnetron sputtering. The metal loading and the composition of the quantum-sized Pd-capped Mg nanoparticles (NPs) were carefully controlled by varying the deposition conditions of the RF magnetron sputtering system. The as-fabricated structure shows hydrogenation at room temperature and dehydrogenation at increased temperatures. The change in electrical resistance during the hydrogenation/dehydrogenation process is found to be reversible. Along with this, the as-fabricated sensor also showed remarkable advantages, such as a large detection range (1–40,000ppm) and fast response time. For a 10,000ppm (1vol.%) H<SUB>2</SUB> concentration at room temperature, a response time of 6s was observed. The fabricated sensor also exhibited good selectivity and a negligible humidity effect over the entire detection range. These Pd-capped Mg bimetallic ultra-thin films deposited on alumina (Al<SUB>2</SUB>O<SUB>3</SUB>) substrates can be used as a fast response, affordable, and low-temperature hydrogen sensing material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Quantum size Pd-capped Mg bimetallic nanoparticles were deposited on alumina substrate as an ultra-thin film manner by RF magnetron sputtering system. </LI> <LI> Computational analysis of bimetallic nanoparticles/ultra-thin films for hydrogen sensing. </LI> <LI> Feasibility of H<SUB>2</SUB> sensing properties is investigated. </LI> <LI> The mechanism for H<SUB>2</SUB> response was described by diffusion pathway. </LI> </UL> </P>

Population Age Structure and Real Exchange Rate in OECD Countries: An Empirical Analysis

Kamrul Hassan,Ruhul Salim,Harry Bloch 인하대학교 정석물류통상연구원 2020 JOURNAL OF INTERNATIONAL LOGISTICS AND TRADE Vol.18 No.1

This article examines the impact of population age structure on the real exchange rate. Data on a panel of 22 OECD (Organization of Economic Cooperation and Development) countries over 1980-2015 period are used to estimate the empirical model. Using fixed effect model the paper finds that different age cohorts have a significant influence on the real exchange rates in the sample countries. The results are mostly consistent with the theoretical framework discussed in the paper and also with the findings of previous studies in this area. These results have important policy implications given the fact that the population is ageing in almost all the OECD economies these days.

Biogeography-based Interference Mitigation Scheme for OFDMA System in Heterogeneous Network

Mohammad Kamrul Hasan,Ahmad Fadzil Ismail,Aisha-Hassan Abdalla,Wahidah Hashim,Shayla Islam 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10

In Heterogeneous Network (HetNet), the small base station such as femtocells are deployed in indoor and multiple business complexes in order to extend the coverage and capacity. The deployment of co-channel (i.e. shared channel) for femtocells along with macrocell induces the severe interference issues. This is because of effects on SINR and thereby capacity become deteriorated. Therefore, this paper investigates the interference mitigation techniques and come out with a proposal to improve the Signal to Interference Noise Ratio (SINR) performance as well as total capacity in Heterogeneous Network (HetNet).The simulation results show that the achieved capacity is maximized than the existing technique.

A Numerical Framework for the Analysis of Handoff Delay Component in Proxy NEMO Environment

Shayla Islam,Aisha-Hassan A. Hashim,Azween Abdullah,Mohammad Kamrul Hasan 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.8

Network Mobility Basic Support Protocol (NEMO-BSP), the existing IETF standard for mobile network support, signifies an important portion for future heterogeneous wireless access networks. The reason is to provide continuous Internet connectivity during movement of Mobile Router (MR) in NEMO. This paper conducted a quantitative analysis on the handoff delay component of NEMO-BSP as well as its existing enhancements, i.e., Fast NEMO (F-NEMO) handoffs, and an Extension of F-NEMO (EF-NEMO), using the numerical framework. The mathematical scenario includes two access routers, one local home agent and up to 20 MRs that interrelate by two different wireless access networks are mainly WiFi and WiMAX. The analysis offers quantitative outcomes of the performance enhancements achieved via the proposed improvements concerning handoff delay gain, packet loss, and packet loss ratio. The numerical results assist in understanding the influence of link switching delay, mobility rate, and radius on the handoff delay gain, packet loss, and packet loss ratio. The results of this analysis will also be aided to pick an appropriate mobility management scheme for Proxy NEMO environment.

A review on sensors and systems in structural health monitoring: current issues and challenges

Mahammad A. Hannan,Kamrul Hassan,Ker Pin Jern 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.5

Sensors and systems in Civionics technology play an important role for continuously facilitating real-time structure monitoring systems by detecting and locating damage to or degradation of structures. An advanced materials, design processes, long-term sensing ability of sensors, electromagnetic interference, sensor placement techniques, data acquisition and computation, temperature, harsh environments, and energy consumption are important issues related to sensors for structural health monitoring (SHM). This paper provides a comprehensive survey of various sensor technologies, sensor classes and sensor networks in Civionics research for existing SHM systems. The detailed classification of sensor categories, applications, networking features, ranges, sizes and energy consumptions are investigated, summarized, and tabulated along with corresponding key references. The current challenges facing typical sensors in Civionics research are illustrated with a brief discussion on the progress of SHM in future applications. The purpose of this review is to discuss all the types of sensors and systems used in SHM research to provide a sufficient background on the challenges and problems in optimizing design techniques and understanding infrastructure performance, behavior and current condition. It is observed that the most important factors determining the quality of sensors and systems and their reliability are the long-term sensing ability, data rate, types of processors, size, power consumption, operation frequency, etc. This review will hopefully lead to increased efforts toward the development of low-powered, highly efficient, high data rate, reliable sensors and systems for SHM.

A review on sensors and systems in structural health monitoring: current issues and challenges

Hannan, Mahammad A.,Hassan, Kamrul,Jern, Ker Pin Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.22 No.5

Sensors and systems in Civionics technology play an important role for continuously facilitating real-time structure monitoring systems by detecting and locating damage to or degradation of structures. An advanced materials, design processes, long-term sensing ability of sensors, electromagnetic interference, sensor placement techniques, data acquisition and computation, temperature, harsh environments, and energy consumption are important issues related to sensors for structural health monitoring (SHM). This paper provides a comprehensive survey of various sensor technologies, sensor classes and sensor networks in Civionics research for existing SHM systems. The detailed classification of sensor categories, applications, networking features, ranges, sizes and energy consumptions are investigated, summarized, and tabulated along with corresponding key references. The current challenges facing typical sensors in Civionics research are illustrated with a brief discussion on the progress of SHM in future applications. The purpose of this review is to discuss all the types of sensors and systems used in SHM research to provide a sufficient background on the challenges and problems in optimizing design techniques and understanding infrastructure performance, behavior and current condition. It is observed that the most important factors determining the quality of sensors and systems and their reliability are the long-term sensing ability, data rate, types of processors, size, power consumption, operation frequency, etc. This review will hopefully lead to increased efforts toward the development of low-powered, highly efficient, high data rate, reliable sensors and systems for SHM.

Adaptive multiple tuned mass dampers based on modal parameters for earthquake response reduction in multi-story buildings

Rahman, Mohammad Sabbir,Hassan, Md Kamrul,Chang, Seongkyu,Kim, Dookie SAGE Publications 2017 ADVANCES IN STRUCTURAL ENGINEERING - Vol.20 No.9

Value Chain Analysis for Tourism Services in Bandarban District, Bangladesh

Syed Rashidul Hasan,Kamrul Hassan 세계문화관광학회 2020 International Journal of Culture and tourism Resea Vol.13 No.1

Bandarban is a hidden paradise in Bangladesh away from the hustle and bustle of city life. Though not developed for tourism activities yet, today or tomorrow it will be one of the heavens for eco-tourism. Tourism is seasonal in pattern in Bandarban. Proper management of available tourism resource can ensure poverty alleviation and economic development of the destination. From this paper it was found that Bandarban is a destination for young people as it attracts them for adventure tourism. Almost all of them visit Bandarban without taking any service from tour operator or travel agent. Most of them travel to Bandarban with their friend circle. Purpose of their visit is adventure (70%) and leisure and recreation (26%). This study highlighted the current scenario of Bandarban, identified the tourism resources as mean of economic development, enlisted the zones of tourism development in Bandarban, SWOT analysis and developed value chain mapping in order to uplift the tourism business and community of the destination. Finally, the study tried to identify the huge potentials vis-à-vis the limitations of developing tourism sector in that hilly region of Bandarban in Bangladesh.

Compressive Behaviour of Geopolymer Concrete-Filled Steel Columns at Ambient and Elevated Temperatures

Tao, Zhong,Cao, Yi-Fang,Pan, Zhu,Hassan, Md Kamrul Council on Tall Building and Urban Habitat Korea 2018 International journal of high-rise buildings Vol.7 No.4

Geopolymer concrete (GPC), which is recognised as an environmentally friendly alternative to ordinary Portland cement (OPC) concrete, has been reported to possess high fire resistance. However, very limited research has been conducted to investigate the behaviour of geopolymer concrete-filled steel tubular (GCFST) columns at either ambient or elevated temperatures. This paper presents the compressive test results of a total of 15 circular concrete-filled steel tubular (CFST) stub columns, including 5 specimens tested at room temperature, 5 specimens tested at elevated temperatures and the remaining 5 specimens tested for residual strength after exposure to elevated temperatures. The main variables in the test program include: (a) concrete type; (b) concrete strength; and (c) curing condition of geopolymer concrete. The test results demonstrate that GCFST columns have similar ambient temperature behaviour compared with the conventional CFST counterparts. However, GCFST columns exhibit better fire resistance than the conventional CFST columns. Meanwhile, it is found that the GCFST column made with heat cured GPC has lower strength loss than other columns after exposure to elevated temperatures. The research results highlight the possibility of using geopolymer concrete to improve the fire resistance of CFST columns.