2,297 research outputs found

    The Efficacy of Molecular Markers Analysis with Integration of Sensory Methods in Detection of Aroma in Rice

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    Allele Specific Amplification with four primers (External Antisense Primer, External Sense Primer, Internal Nonfragrant Sense Primer, and Internal Fragrant Antisense Primer) and sensory evaluation with leaves and grains were executed to identify aromatic rice genotypes and their F1 individuals derived from different crosses of 2 Malaysian varieties with 4 popular land races and 3 advance lines. Homozygous aromatic (fgr/fgr) F1 individuals demonstrated better aroma scores compared to both heterozygous nonaromatic (FGR/fgr) and homozygous nonaromatic (FGR/FGR) individuals, while, some F1 individuals expressed aroma in both leaf and grain aromatic tests without possessing the fgr allele. Genotypic analysis of F1 individuals for the fgr gene represented homozygous aromatic, heterozygous nonaromatic and homozygous nonaromatic genotypes in the ratio 20 : 19 : 3. Genotypic and phenotypic analysis revealed that aroma in F1 individuals was successfully inherited from the parents, but either molecular analysis or sensory evaluation alone could not determine aromatic condition completely. The integration of molecular analysis with sensory methods was observed as rapid and reliable for the screening of aromatic genotypes because molecular analysis could distinguish aromatic homozygous, nonaromatic homozygous and nonaromatic heterozygous individuals, whilst the sensory method facilitated the evaluation of aroma emitted from leaf and grain during flowering to maturity stages

    Characteristics of Mineral Oil-based Nanofluids for Power Transformer Application

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    Trends in the field of nanomaterial-based transformer oil show most of the conducted works have focused only on the transformer oil-based nanofluids but limited studies on the stability of transformer oil-based nanofluids. Since mineral oil-based nanofluids still can produce the sedimentation, thus the cold-atmospheric pressure plasma method is proposed to functionally modify the Silicon Dioxide (SiO2) nanofiller in order to enhance the electrical properties of the mineral oil-based nanofluids. The AC breakdown strength oil samples before and after modification were measured. It was found that the plasma treated nanofluids have higher AC breakdown voltage compared to pure oil and untreated nanofluids. Also, Fourier Transform Infrared (FTIR) Spectroscopy has been used in this study to analyse the physical changes of oil samples. It is envisaged that the added silica nanofiller has significant effect on electrical properties of the transformer oil-based nanofluids which would enable to the development of an improved class of liquid dielectric for the application of power transformer

    Wavelets operational methods for fractional differential equations and systems of fractional differential equations

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    In this thesis, new and effective operational methods based on polynomials and wavelets for the solutions of FDEs and systems of FDEs are developed. In particular we study one of the important polynomial that belongs to the Appell family of polynomials, namely, Genocchi polynomial. This polynomial has certain great advantages based on which an effective and simple operational matrix of derivative was first derived and applied together with collocation method to solve some singular second order differential equations of Emden-Fowler type, a class of generalized Pantograph equations and Delay differential systems. A new operational matrix of fractional order derivative and integration based on this polynomial was also developed and used together with collocation method to solve FDEs, systems of FDEs and fractional order delay differential equations. Error bound for some of the considered problems is also shown and proved. Further, a wavelet bases based on Genocchi polynomials is also constructed, its operational matrix of fractional order derivative is derived and used for the solutions of FDEs and systems of FDEs. A novel approach for obtaining operational matrices of fractional derivative based on Legendre and Chebyshev wavelets is developed, where, the wavelets are first transformed into corresponding shifted polynomials and the transformation matrices are formed and used together with the polynomials operational matrices of fractional derivatives to obtain the wavelets operational matrix. These new operational matrices are used together with spectral Tau and collocation methods to solve FDEs and systems of FDEs

    Analysis of Open Stub Resonator and its Application in Dual Isolation Band of SPDT Switch Design

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    In this paper, an analysis of open stub resonator is presented and its application in dual isolation band of Single Pole Double Throw (SPDT) switch is proposed. A mathematical model and the characteristic of the bandstop of the resonator were analyzed and discussed. The open stub resonator was implemented using the microstrip transmission line and able to switch between bandstop and allpass responses. Frequency bands of 2.3 and 3.5 GHz were chosen to demonstrate the dual isolation band in the switch design. The performance results of the SPDT switch showed that the isolation was greater than 30 dB, return loss was greater than 10 dB and insertion loss less than 2 dB at the center resonant frequency of 2.3 and 3.5 GHz. The potential application of the proposed dual isolation band of SPDT switch is for multi band RF front-end system such as WiMAX, LTE, WiFi and HyperLAN

    Tunable indium tin oxide thin film as saturable absorber for generation of passively Q-switched pulse erbium-doped fiber laser

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    A tunable Q-switched pulse erbium-doped fiber (EDF) laser using indium tin oxide (ITO) thin-film-based saturable absorber (SA) is proposed and demonstrated. The SA is formed by depositing an ITO layer using DC magnetron sputtering on the fiber ferrule, which can be easily fabricated in less than 200 s with thickness of 17.80 nm. The proposed tunable Q-switched pulse EDF laser is operated from 1540.0 to 1570.0 nm, covering a total wavelength of 30.0 nm. The generated output pulses displayed a repetition rate range between 21.70 and 94.34 kHz. The shortest pulse width retrieved is 3.22 ls at the maximum pump power of 378.6 mW, while the maximum pulse energy recorded is 30.29 nJ. To the best of the authors’ knowledge, this appears to be the first proposed tunable passively Q-switched pulse EDF laser using ITO that serves as SA, which can promote ITO film in the application of ultrafast photonics

    Peripheral interface controller-based maximum power point tracking algorithm for photovoltaic DC to DC boost controller

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    A method of developing a maximum power point tracking (MPPT) algorithm for photovoltaic (PV) utilizing a peripheral interface controller (PIC) is presented in this paper. The efficiency and adequacy of a PV depend on the temperature and the exposed position to the sun. Thus, there is an optimum point at which the operating power is at maximum. The goal is to operate the PV module at this point (MPP). It can be accomplished by using the MPPT algorithm designed with a DC-DC boost converter. The boost converter, MPPT circuit, PIC18F4550 microcontroller and PV panel are the main components used in this design. The current and voltage produced by the solar panel are observed continuously by a closed-loop control system. The microcontroller-based control system adjusts the duty cycle of the converter to extract the maximum power. With a DC input voltage of 15 V, the boost converter is capable of generating an output voltage of an approximately 60 Vdc at a maximum power of 213.42 W with minimum voltage ripple as compared to 84 W without the MPPT. It proved the effectiveness of the developed algorithm

    Peripheral interface controller-based maximum power point tracking algorithm for photovoltaic DC to DC boost controller

    Get PDF
    A method of developing a maximum power point tracking (MPPT) algorithm for photovoltaic (PV) utilizing a peripheral interface controller (PIC) is presented in this paper. The efficiency and adequacy of a PV depend on the temperature and the exposed position to the sun. Thus, there is an optimum point at which the operating power is at maximum. The goal is to operate the PV module at this point (MPP). It can be accomplished by using the MPPT algorithm designed with a DC-DC boost converter. The boost converter, MPPT circuit, PIC18F4550 microcontroller and PV panel are the main components used in this design. The current and voltage produced by the solar panel are observed continuously by a closed-loop control system. The microcontroller-based control system adjusts the duty cycle of the converter to extract the maximum power. With a DC input voltage of 15 V, the boost converter is capable of generating an output voltage of an approximately 60 Vdc at a maximum power of 213.42 W with minimum voltage ripple as compared to 84 W without the MPPT. It proved the effectiveness of the developed algorithm

    Characteristics of cellulose from oil palm mesocarp fibres extracted by multi-step pretreatment methods

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    Characteristics of cellulose isolated from oil palm mesocarp fiber (OPMF) using multi-step pretreatment methods were determined in this study. It was postulated that the succession of pretreatment steps for cellulose extraction from lignocellulosic biomass may affect the cellulose properties. Pretreatment steps involved in cellulose extraction were superheated steam (SHS) treatment, enzymatic hydrolysis and alkaline treatment. OPMF was subjected to SHS treatment to open up the fibres wall structure followed by enzymatic hydrolysis using xylanase for effectiveness enhancement the alkaline treatment afterwards. In order to obtain bleached cellulose, peracetic acid, a totally chlorine free (TCF) chemical was used. Cellulose obtained from these multi-step pretreatment methods had purity of 87.5 %, with crystallinity of 69.2 % and thermally stable up to 360°C.The Wood and Biofiber International Conference (WOBIC 2017), 21–23 November 2017, Selangor, Malaysi

    Sustainability assessment framework: a mini review of assessment concept

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    Sustainability assessment is viewed as a vital instrument to aid in the shift towards sustainability which is simply an appraisal method which integrates an iterative and pluralistic procedure. Sustainability assessment is viewed as a vital instrument to aid in the shift towards sustainability. Sustainability assessment is a rather complex appraisal technique conducted for supporting decision-making and policy in an extensive environmental, economic and social perspective. Sustainability assessment transcends a technical or scientific evaluation. Sustainability assessment tools are essentially a structured process encompassing different field-specific analytical methods and models. The growth of indicators in numerous fields has influenced sustainability assessment methodologies to a great extent. In general two broad approaches for sustainability can be distinguished, top-down and bottom-up. Despite the abundance and diversified procedures for evaluating sustainability, indicators based assessment is one of the most widely used platform. Many parties feel that the presence of conceptual inconsistencies and the absence of operational definitions have hampered attempts to appraise, let alone achieve, sustainability. Assessing the sustainability assessment schemes in a quantitative manner requires the identification and integration of diverse phenomena or indicators, in a framework consistent with the evolving concept of sustainability. In fact, integration of indicators for sustainability assessment, have been at the forefront of various political, academic and scientific researches. Existing sustainability assessments schemes typically provide interpretation in the form of comparative value analysis where impacts are scored based on pre-set values, utility analysis where impacts are ranked on a uniform scale and weighted, cost-benefit analysis where positive and negative impacts are apportioned to monetary values, multi-criteria analysis where quantitative as well as qualitative impacts are scaled on pre-set criteria or risk assessment where degrees in risk reduction is identified relative to pre-set risk thresholds. Consequently, the paper that follows provides an integrative analysis of existing sustainability assessment approaches. Such review not only offers a very valuable insight on the features of existing sustainability assessment schemes, but also highlighting gaps to a certain extent
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