Identification of the chemical composition of essential oils is very important for ensuring the quality of finished herbal products. The objective of the study was to analyze the chemical components present in the essential oils of five Beilschmiedia species (i.e. B. kunstleri, B. maingayi, B. penangiana, B. madang, and B. glabra) by multivariate data analysis using principal component analysis (PCA) and hierarchical clustering analysis (HCA) methods. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 108 chemical components were successfully identified from the essential oils of five Beilschmiedia species. The essential oils were characterized by high proportions of ?-caryophyllene (B. kunstleri), ?-cadinene (B. penangiana and B. madang), and ?-eudesmol (B. maingayi and B. glabra). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that ch.....

755 hits

This study evaluated the benchmarking process of active queue management (AQM) methods, which consider a multicriteria decision-making (MCDM) problem using multidimensional criteria. Academic studies have benchmarked the AQM methods using MCDM techniques. However, these studies have used existing MCDM techniques, which face considerable theoretical challenges. The latest MCDM method called fuzzy decision by opinion score (FDOSM) was published in the Journal of Applied Soft Computing in 2020 to address the theoretical challenges of the existing MCDM methods. However, FDOSM continues�to encounter serious issues. That is, it exclusively depends on the direct aggregation MCDM approach based on arithmetic mean (AM) operator. However, performing other operators (i.e., geometric mean, harmonic mean, and root mean square), in addition to applying other MCDM approaches (i.e., distance measurement and compromise rank), may result in different ranking results. Hence, this study mainly proposes .....

1067 hits

This paper aims to propose a grouping framework for benchmarking the active queue management (AQM) methods of network congestion control based on multicriteria decision-making (MCDM) techniques to assist developers of AQM methods in selecting the best AQM method. Given the current rapid development of the AQM techniques, determining which of these algorithms is better than the other is difficult because each algorithm performs better in a specific metric(s). Current benchmarking studies benchmark the AQM methods from a single incomplete prospective. In each proposed AQM method, the benchmarking was achieved with reference to some evaluation measures that are relatively close to the desired goal being followed during the development of the AQM methods. Furthermore, the benchmarking frameworks of AQM methods are complicated and challenging because of the following reasons: (1) the technical details of the AQM methods are adapted and the input parameters are selected according to the sens.....

1030 hits

Water has been proven to be an effective additive to enhance the growth rate and purity of the synthesized carbon nanotubes (CNTs) in the chemical vapor deposition (CVD) method. Due to similar CNT growth parameters in CVD and flame environment, it is expected that a similar effect can be replicated in CNT flame synthesis to a certain degree. The present study analyzes the effect of water addition to the fuel stream toward the CNT growth in methane diffusion flame under atmospheric conditions. Water vapor was introduced into the fuel gas by passing the methane gas through a water bubbler, and the growth condition was analyzed based on a cross-sectional analysis of the grown CNT on top of nickel wire. The water addition to the fuel reduces the axial extent of the growth region due to the reduction in flame height. Even though the spatial distribution of the growth region in the flame with water additive changes compared to that of the flame without water, the average growth region temper.....

819 hits

Urban green space is one of the most essential components in contributing to ecological balance and environmental sustainability. Due to rapid urbanization in the last few decades, massive reduction of urban vegetation cover (VC) has increased the land surface temperature (LST) and hampered the environmental sustainability. This study aims to identify the VC cover loss on LST increase in Rajshahi City Corporation (RCC) area using geospatial techniques. The study established the relationship between VC loss and LST increase using transformation analysis and micro-level directional mapping in ArcGIS 10.6 software. Multi-temporal Landsat TM/OLI satellite images were used for the years 1990, 2000, 2010 and 2020, to classify land use/land cover (LULC) classes, the transition between VC and urban area (UA), directional distribution of UA and VC, and variation of ward wise LST distribution due to VC loss in the study area. The maximum likelihood supervised classification algorithm was used to.....

1406 hits

An electrochemical cholesterol sensor based on emulsion photo-polymerized methacrylic acid molecularly imprinted polymers (MIPs) microspheres modified screen-printed electrode (SPE) has been developed. Electrochemical quantitation of cholesterol concentration was performed by means Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV) technique by using redox couple of potassium ferricyanide [K3Fe(CN)6]. A decrement in the electrochemical CV and SWV signal indicated that the cholesterol molecules were bound to the microspheres? cavities of the biomimetic MIPs sensor, and formed an electron transfer barrier to the redox species from electron transfer at the electrode surface. Under optimal conditions, the electrochemical MIPs microsensor could detect cholesterol concentration in the linear response range of 0.5 mg L-1 to 50.0 mg L-1 with a limit of detection (LOD) at 0.1 mg L-1. The MIPs microspheres-modified carbon SPE electrode providing good operational stability to cholesterol s.....

850 hits

Background: Tropomyosin is a major allergen in crustaceans, including mud crab species, but its molecular and allergenic properties in Scylla olivacea are not well known. Thus, this study aimed to produce the recombinant tropomyosin protein from S. olivacea and subsequently investigate its IgE reactivity. Methods and Results: The tropomyosin gene was cloned and expressed in the Escherichia coli system, followed by SDS-PAGE and immunoblotting test to identify the allergenic potential of the recombinant protein. The 855-base pair of tropomyosin gene produced was found to be 99.18% homologous to Scylla serrata. Its 284 amino acids matched the tropomyosin of crustaceans, arachnids, insects, and Klebsiella pneumoniae, ranging from 79.03 to 95.77%. The tropomyosin contained 89.44% alpha-helix folding with a tertiary structure of two-chain alpha-helical coiled-coil structures comprising a homodimer heptad chain. IPTG-induced histidine tagged-recombinant tropomyosin was purified at the size of.....

1125 hits

Purpose: The purpose of this paper is to explore the direct effect of classical predictors of an individual?s behaviour, namely, attitude, subjective norms (SN) and perceived behavioural control (PBC) on the intention to deal with Islamic banks. The study extended the Theory of Planned Behaviour (TPB) by introducing the customers? religiosity paradigm as a moderator between the classical predictors of the theory and the intention to deal with Islamic banks. Design/methodology/approach: By applying the Theory of Planned Behaviour (TPB) framework, data were collected from conventional banks to investigate the potential Islamic bank customers? intention. Using self-administered questionnaires, the data were collected from conventional banks in Muscat. A total of 1,000 questionnaires were distributed; however, only 638 were found usable. The structural equation modelling (SEM) was used to test the hypothesis and analyse the prediction values of the model in the TPB framework. It is also us.....

744 hits

This paper presents a state variable feedback (SVF) control with proportional gain to control a one-link flexible manipulator incorporating payload. The dynamic model of a one-link flexible manipulator is developed through a finite element method. The system is uncertain due to the variation of payloads and numbers of elements. There is a challenge in designing a controller for each number of elements. To obtain the effectiveness of the controllers, a combination of SVF control-based LQR controls with proportional gain is developed for a flexible link manipulator with payload variations. An assessment is conducted to examine the input tracking controller capability of the hub angular position, deflection, hub velocity and end-point residual of the one-link flexible manipulator. The responses of the system are shown in domains of time and frequency, while the SVF control with proportional gain schemes is also discussed. This study finds that the payload effects on the response incorpora.....

792 hits

Rises in land surface temperature (LST) significantly impacted by land use/land cover (LULC) changes. The increase in LST massively impacted the urban biodiversity, ecosystem and population health. This study aims to estimate the changes in LULC classes and identify their impacts on LST in Dhaka city, Bangladesh using Landsat satellite images from 2000 to 2020. Based on the past estimated change maps of LULC and LST, the study finally predicted the future LULC and LST scenario for the year 2030. The support vector machine algorithm was applied to perform the LULC classification. Artificial neural network and cellular automata algorithms were used to predict the LST and LULC changes for 2030. Results suggested a significant reduction in vegetation cover (5%) and an increase in built-up area (14%) from 2000 to 2020. Due to this massive increase in built-up areas, the LST increment took place by 7.24 �C in the last two decades. The maximum temperature was recorded in built-up areas (34 .....

1031 hits