1,501 research outputs found

    Removal of mercury (II) from aqueous solution by using rice residues

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    Sorption potential of rice residues for Hg(II) removal from aqueous solution was investigated. Rice husk (RH) and rice straw (RS) were selected and treated with sodium hydroxide (NaOH). The raw and modified adsorbents were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and BET surface area measurements. The effects of pH, initial ion concentration, and agitation time on the removal process were studied in batch adsorption experiments. Two simple kinetic models, which are pseudo-first-order and pseudo-second-order, were tested to investigate the adsorption mechanisms. The kinetic data fits to pseudo second order model with correlation coefficients greater than 0.99 for all adsorbents. The equilibrium data fitted well with the Langmuir compared to Freundlich isotherm models. Alkali-treated adsorbent obtained larger surface area and RH-NaOH showed highest adsorption capacity followed by RS-Pure > RH-Pure > RS-NaOH. The maximum removal efficiency obtained by RH-NaOH and RS-Pure was 42 mg/l (80%) at pH 6.5 and with 2 days contact time (for 50 mg/l initial concentration and 25 mg adsorbents)

    A modified bats echolocation-based algorithm for solving constrained optimisation problems

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    A modified adaptive bats sonar algorithm (MABSA) is presented that utilises the concept of echolocation of a colony of bats to find prey. The proposed algorithm is applied to solve the constrained optimisation problems coupled with penalty function method as constraint handling technique. The performance of the algorithm is verified through rigorous tests with four constrained optimisation benchmark test functions. The acquired results show that the proposed algorithm performs better to find optimum solution in terms of accuracy and convergence speed. The statistical results of MABSA to solve all the test functions also has been compared with the results from several existing algorithms taken from literature on similar test functions. The comparative study has shown that MABSA outperforms other establish algorithms, and thus, it can be an efficient alternative method in the solving constrained optimisation problems

    Malaysian and Indonesian Learners: They Are Judges of How They Learn English Most Effectively in and Out of Classrooms

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    The position of English is that of a Second Language in Malaysia and a Foreign Language in Indonesia. But the objective is the same that is to enable the learners to communicate effectively and efficiently in social and professional situations. Learners' beliefs and learners' strategies are also part of the learning processes. Strategies are ways of managing the complex information that the learners are receiving about the target language. This study aims to find out (i) the learners' beliefs on the importance of English (ii) what the learners will do (strategies) to manage their own learning. 100 respondents participated in the study. They responded to open ended questions. The results show that there are similarities and differences in the ways the Malaysian and Indonesian learners perceived the importance of English. They also have similarities and differences in their strategies to manage their own learning to achieve their goals. As a conclusion, even though the two countries adopted different language policy, the learners of English as a Second and Foreign Language have their own enthusiasms and they make judgements about how to learn the language effectively and they have the awareness of what language learning is like

    Ventricular arrhythmias classification and onset determination system

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    Accurately differentiating between ventricular fibrillation (VF) and ventricular tachycardia (VT) episodes is crucial in preventing potentially fatal missed interpretations that could lead to needless shock to the patients, resulting in damaging the heart. Apart from accurately classifying between VT and VF, the predetermination of the onset of the ventricular arrhythmias is also important in order to allow for more efficient monitoring of patients and can potentially save one’s life. Thus, this research intends to focus on developing a system called Classification and Onset Determination System (CODS) that is able to classify, track and monitor ventricular arrhythmias by using a method called Second Order Dynamic Binary Decomposition (SOD-BD) technique. Two significant characteristics (the natural frequency and the input parameter) were extracted from Electrocardiogram (ECG) signals that are provided by Physiobank database and analyzed to find the significant differences for each ventricular arrhythmia types and classify the ECGs accordingly (N, VT and VF). The outcome from these ECG extractions was also used to locate the onset of ventricular arrhythmia that is useful to predict the occurrence of the heart abnormalities. All the ECGs analysis, parameters extraction, classification techniques, and the CODS are developed using LabVIEW software

    Programming with C++ concepts

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    AbstractThis paper explores the definition, applications, and limitations of concepts and concept maps in C++, with a focus on library composition. We also compare and contrast concepts to adaptation mechanisms in other languages.Efficient, non-intrusive adaptation mechanisms are essential when adapting data structures to a library’s API. Development with reusable components is a widely practiced method of building software. Components vary in form, ranging from source code to non-modifiable binary libraries. The Concepts language features, slated to appear in the next version of C++, have been designed with such compositions in mind, promising an improved ability to create generic, non-intrusive, efficient, and identity-preserving adapters.We report on two cases of data structure adaptation between different libraries, and illustrate best practices and idioms. First, we adapt GUI widgets from several libraries, with differing APIs, for use with a generic layout engine. We further develop this example to describe the run-time concept idiom, extending the applicability of concepts to domains where run-time polymorphism is required. Second, we compose an image processing library and a graph algorithm library, by making use of a transparent adaptation layer, enabling the efficient application of graph algorithms to the image processing domain. We use the adaptation layer to realize a few key algorithms, and report little or no performance degradation

    New Features of Cervical Cells for Cervical Cancer Diagnostic System Using Neural Network.

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    Currently, Pap test is the most popular and effective test for cervical cancer. However, Pap test does not always produce good diagnostic performance. This problem has encouraged several studies to develop diagnosis system based on neural networks to increase the diagnostic performance

    Comparison of Weibull and normal probability distribution of flexural strength of dense and porous fired clay

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    In this research, dense and porous fired clay were produced at a firing temperature of 1300°C. The flexural strength data of the dense and the porous fired clay were determined using three point bending test. Two-parameter Weibull and normal probability distributions were used to estimate the reliability of the flexural strength data of the dense and the porous fired clay. From the result, the Weibull probability distribution scale parameter for the dense (36.31MPa) and Porous (18.85MPa) fired clay are higher than the mean strength value for the dense (33.84MPa) and the porous (17.87MPa) of the normal distribution. Distributions of flaws in the dense and the porous fired clay have a significant effect on the Weibull and normal distribution parameters. The fractured surface of the dense fired clay shows a random distribution of cracks while that of the porous fired clay shows a distribution of pores in the morphology. The normal distribution considers failure at 50% of the flexural strength data while Weibull probability distribution is failure at 62.3% of the strength data. Therefore, two-parameter Weibull is the suitable tool to model failure strength data of the dense and porous fired clay

    Cognitive function assessment in young adult using trail making and stroop tests

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    Cortical network between brain regions is one of the topics that being investigated by brain researchers. Methods that are used to investigate brain developments of cognitive function include Partial Directed Coherence (PDC) and the power spectrum of the brain activity. The purposes of this study were to determine the cortico-cortical functional connectivity between brain regions using PDC and to investigate the power spectrum of brain activity while performing cognitive function assessments. Twenty healthy young adults, age between 20 to 30 years old, were asked to perform two tasks/tests, Trail Making Test (TMTA-alphabet, TMTA-number, TMTB-mixed alphabets and numerical) and Stroop Task. An electroencephalogram (EEG) machine was used to record the brain signals, and the data were analyzed using PDC and Fast Fourier Transform (FFT). Our findings showed that not only frontal area but temporal and occipital area also generates information and the information was sent to various scalp location. Theta frequency was significantly increased at frontal area while gamma and high-gamma frequency bands were significantly increased at centroparieto-occipito-temporal regions. All of these areas are associated with cognitive function doing specific task
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