30 research outputs found

    Designing Problem Based Learning (PBL) Problem Scenario for Statistic Using Linear and Non-linear Multimedia Presentation

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    Problem Based Learning (PBL) is an instructional method that is known to offer students with knowledge suitable for problem solving. In order to test this assertion the process of problem based learning is described and measured against three principle of learning: activation of prior knowledge, elaboration and encoding specificity. Using PBL method, students’ understanding with regards to the problem scenario is very significant process. One of the main defining characteristic of PBL, which distinguishes it from some other method, is that the problem is presented to the students first at the start learning process. Traditionally, problem scenario is presented in a printed text, which is not tempting for student to understand the motive behind it. Information and Communication Technology (ICT) on the other hand has widely accepted in many areas which include education as well. By applying multimedia presentation as a discipline in ICT, it is believed that it could helps in designing the effective problem scenario. The purpose of this study is to design and test the effectiveness of PBL problem scenario for subject Statistic using linear and non-linear multimedia presentation. Linear presentation is known as no navigation control is involved through that process while nonlinear presentation uses user interactivity to control the presentation. This paper discusses the early storyboard design and the icons that used

    DEVELOPMENT OF RESEARCH FRAMEWORK FOR PBL PROBLEM SCENARIO USING LINEAR & NON-LINEAR MULTIMEDIA

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    Problem Based Learning (PBL) is an instructional approach to provide student with knowledge suitable for problem solving. To support the research, PBLStat courseware is developed based on the PBL approach. In PBL approach, problem scenario is first presented during the learning process. Problem scenario helps to maintain student interest in course so it is important to create a good problem that can cause students‘ inquiry and drive students to solve the problems. The purpose of this paper is to highlight the development of research framework for PBL problem scenario presentation. Problem scenario can be presented using linear and non-linear multimedia categories. The framework of study contains the description of research control modes, content and output. The control modes of the research are consisting of two independent variables which are linear problem scenario and non-linear problem scenario. Content is the phase of courseware‘s development. The ADDIE model is used to complete the development of courseware. Finally is the research output, this is to evaluate student‘s preferences and performances based on the problem scenario categorization. There are four research instrument tools has been created to answer the research question which are questionnaire, observation, interview and PBLStat

    Heat resistant and tensile properties of glass fiber reinforced polymer composites

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    The study focuses on E glass fiber laminate with vinyl ester resin. Two types of fiber glass are used namely chopped strand mat (CSM) and woven roving (WR). The objective of this research is to determine the thermal conductivity, specific heat capacity and Modulus Young of glass fiber-reinforced polymer (GFRP) prepared by vacuum bagging resin infusion process. The samples of GFRP were exposed to cooking gas fire for 5 minutes and 10 minutes for fire test. The tensile test was also conducted for the three samples and the microstructure was analyzed using Scanning Electron Microscope (SEM) after tensile testing. The result discovered that WR sample was better than CSM sample because CSM sample yield an average value of 0.236 W/mK for thermal conductivity and 521.6 J/KgK for specific heat capacity while WR sample give a value of 0.205 W/mK for thermal conductivity and 589.5 J/KgK for specific heat capacity. The Modulus Young of WR sample is higher (24.2 GPa) compared with CSM sample (16.1 GPa). From SEM micrograph, the failure occurred on the samples were matrix cracking and fibers separation. From the fire and tensile test conducted, the damage occurred on the samples were quite the same with the failure of the reinforcement and matrix. The findings could be used in the building construction as engineers always looking for the best material as they may have the possibilities of fire exposure and tension load as well as this is a part of the safety requirement for buildings

    Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16

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    Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP

    Physical, optical and radiative properties of CaSO4–B2O3–P2O5 glasses doped with Sm3+ions

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    Trivalent rare earth ions doped borosulfophosphate glasses are in high demand owing to their several unique attributes that are advantageous for applications in diverse photonic devices. Thus, Sm3+ ion doped calcium sulfoborophosphate glasses with composition of 25CaSO4–30B2O3–(45−x)P2O5–xSm2O3 (where x = 0.1, 0.3, 0.5, 0.7 and 1.0 mol%) were synthesized using melt-quenching technique. X-ray diffraction confirmed the amorphous nature of the prepared glass samples. Differential thermal analyses show transition peaks for melting temperature, glass transition and crystallization temperature. The glass stability is found in the range 91 °C to 116 °C which shows increased stability with addition of Sm2O3 concentration. The Fourier transform infrared spectral measurements carried out showed the presence of vibration bands due to P–O linkage, BO3, BO4, PO4, P–O–P, O–P–O, S–O–B, and B–O–B unit. Glass density showed increase in value from 2.179 to 2.251 g cm−3 with increase in Sm2O3 concentration. The direct, indirect band gap and Urbach energy calculated were found to be within 4.368–4.184 eV, 3.641–3.488 eV and 0.323–0.282 eV energy ranges, respectively. The absorption spectra revealed ten prominent peaks centered at 365, 400, 471, 941, 1075, 1228, 1375, 1477, 1528 and 1597 nm corresponding to 4D3/2,6H5/2→4I11/2,6P3/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2 transitions respectively. Photoluminescence spectra monitored at the excitation of 398 nm exhibits four emission bands positioned at 559, 596,643 and 709 nm corresponding to 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions respectively. The nephelauxetic parameters calculated showed good influence on the local environment within the samarium ions site and the state of the Sm–O bond. The Judd–Ofelt intensity parameters calculated for all glass samples revealed that Ω6> Ω4> Ω2. The emission cross-section and the branching ratios values obtained for 4G5/2→6H7/2 transition indicate its suitability for LEDs and solid-state laser application

    The role of dysprosium ions on the physical and optical properties of lithium-borosulfophosphate glasses

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    Achieving outstanding physical and optical properties of borosulfophosphate glasses via controlled doping of rare earth ions is the key issue in the fabrication of new and highly-efficient glass material for diverse optical applications. Thus, the effect of replacing P2O5 by Dy2O3 on the physical and optical properties of Dy3+-doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O-30B2O3-15SO3-(40 - x)P2O5-xDy2O3 (where 0.0 mol.% ≤ x ≪ 1.0 mol.%) has been investigated. The glass samples were synthesized from high-purity raw materials via convectional melt-quenching technique and characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), density and UV-vis-NIR absorption measurements. The amorphous nature of the prepared glass samples was confirmed by XRD patterns whereas the EDX spectrum depicts elemental traces of O, C, B, S, P and Dy. The physical parameters such as density, refractive index, molar volume, polaron radius and field strength were found to vary nonlinearly with increasing Dy2O3 concentration. UV-vis-NIR absorption spectra revealed seven absorption bands with most dominant peak at 1269 nm (6H15/2 →6F11/2 +6H9/2). From the optical absorption spectra, the optical bandgap and Urbach's energy have been determined and are related with the structural changes occurring in these glasses with increase in Dy2O3 content. Meanwhile, the bonding parameters (δ) evaluated from the optical absorption spectra were found to be ionic in nature. The superior features exhibited by the current glasses nominate them as potential candidate for nonlinear optical applications

    Impact of Eu3+ on the luminescent, physical and optical properties of BaSO4 – B2O3 – P2O5 glasses

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    The investigations of the impact on the luminescent, physical and optical properties of Alkaline earth metal borophosphate glasses doped with rare earth (RE) ions became demanding owing to their several distinct features that are advantageous for applications in diverse photonic devices. A new series of BaSO4 – B2O3 – P2O5 glasses doped Eu3+ with different compositions of 25BaSO4 – 30B2O3 – (45-x) P2O5 – xEu2O3 (where x = 0.1, 0.3, 0.5, 0.7, 1.0, 2.0 and 2.1 mol%) were prepared by melt – quenching technique. X-ray diffraction and scanning electron microscope examined the amorphous state of the prepared glasses. Differential thermal analyser was used to determine the transition peaks. Some of their physical properties have been calculated. The direct band gap, indirect band gap and urbach energy were found to be within (4.654–4.199 eV), (3.902–3.656 eV) and (0.576–0.428 eV). The absorption spectra in the UV–vis and near infrared region revealed seven prominent peaks centred at 379, 393, 414, 463, 532, 2091 and 2206 nm corresponding to 7F0 → 5G2, 5L6, 5D3, 5D2, 5D1, 7F0 → 7F6 and 7F1 → 7F6 transitions respectively. Photoluminescence spectra monitoring at the excitation of 391 nm exhibits four emissions band positioned at 591, 613, 655 and 701 nm corresponding to 5D0 → 7F1, 7F2, 7F3 and 7F4 transition of Eu3+ ions. Judd-ofelt parameters have been calculated. The decay time of 5D0 level decreases from 2.02 to 1.52 ms. The excellent features demonstrated by the current glasses affirm their suitability for solid state lasers and red LEDs applications

    The impact of auditor education level on the relationship between auditor busyness and audit quality in Turkey

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    In this study, I examine the effect of auditor education level on the relationship between auditor busyness and audit quality using Turkish listed firms. Prior studies regarding auditor busyness have not considered how auditor busyness affects audit quality in the case of auditors who are less educated or more educated. I created some interaction variables using busyness and auditor education level. Additionally, the sample was split into two groups based on auditor education level. The main estimation results show that auditor busyness (auditor education level) negatively (positively) affects audit quality. Auditor formal education level minimises the negative effect of auditor busyness on auditor quality. Also, I found that the negative effect of auditor busyness on audit quality is more pronounced in the case of less educated auditors

    Structural, optical and physical properties of Dy3+ ions in barium sulphate borophosphate glasses for generation of white light

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    Glasses in the 25BaSO4-30B2O3-(45 -x)P2O5-xDy2O3 system with x = 0.1, 0.3, 0.5, 0.7 and 1.0 mol% have been prepared by the melt quenching approach with the aim of using it for optical and white light application. The structural properties are examined by Fourier transform infrared and Raman spectroscopy. The amorphous state of the glasses matrices is determined by X-ray diffraction. Direct and indirect energy bandgap have been evaluated via the data found from UV-visible-near IR spectroscopy. The spectral absorption, emission and excitation are measured, and it is found that the glass doped Dy2O3 ions display good UV-excited luminescence of 4F9/2 6H15/2 and 4F9/2 6H13/2 transition around 480-500 and 570-600 nm corresponding to blue and yellow regions respectively. The physical parameters of the glasses have also been calculated. Infrared and Raman of the borosulfophosphate glasses revealed intense spectrum which is characterized by distinct bands
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