141 research outputs found

    A review of ground heat exchangers for cooling application in the malaysian climate

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    The ground heat exchanger (GHE) is one of the energy sources that has been identified since the 1970s which is able to produce sustainable energy for cooling which is in passive side. GHEs are widely implemented around the world, especially in European countries and a few Asian countries. In Malaysia, application of GHE is still considered as a new passive cooling approach in building energy reduction. Therefore, this paper reviews several important ways of implementing GHE in order to supply passive cooling for any application. The review covers general implementation of the GHE for thermal comfort and agricultural greenhouse cooling. The ground temperature variation used in different researches is also reviewed in this paper as an important part of identifying potential GHE implementations. Design and performance aspects of the GHE are also reviewed. Finally, this paper summarizes the potential and benefit of GHE implementation in the Malaysian climate for cooling applications to reduce the energy used in buildings and greenhouse gas emission

    Crystal structure of 2-((1E)-{2-[bis(2-methylbenzylsulfanyl) methylidene]-hydrazin-1-ylidene}methyl)-6-methoxy-phenol

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    We thank the Department of Chemistry, Universiti Putra Malaysia for facilities. This research was funded by Universiti Putra Malaysia (UPM) and the Malaysian Government under the Geran UPM Scheme (RUGS No. IBT/2013/9419400), the Malaysian Fundamental Research Grant Scheme (FRGS No.01–02-13–1344FR) and the ScienceFund under the Ministry of Science, Technology and Innovation (MOSTI 06–01-04-SF1810). ENMY wishes to thank UPM for the award of a Graduate Research Fellowship.Peer reviewedPublisher PD

    A study of frequency and pulses for stepper motor controller system by using programmable logic controller

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    The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load

    Bis{4-methylbenzyl 2-[4-(propan-2-yl)benzylidene]hydrazinecarbodithioato-κ2N2,S}nickel(II): crystal structure and Hirshfeld surface analysis

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    The complete molecule of the title hydrazine carbodithioate complex, [Ni(C19H21N2S2)2], is generated by the application of a centre of inversion. The NiII atom is N,S-chelated by two hydrazinecarbodithioate ligands, which provide a trans-N2S2 donor set that defines a distorted square-planar geometry. The conformation of the five-membered chelate ring is an envelope with the NiII atom being the flap atom. In the crystal, p-tolyl-C—H...π(benzene-iPr), iPr-C—H...π(p-tolyl) and π–π interactions [between p-tolyl rings with inter-centroid distance = 3.8051 (12) Å] help to consolidate the three-dimensional architecture. The analysis of the Hirshfeld surface confirms the importance of H-atom contacts in establishing the packing

    A cinnamaldehyde Schiff base ofS-(4-methylbenzyl) dithiocarbazate: crystal structure, Hirshfeld surface analysis and computational study

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    The title dithiocarbazate ester (I), C18H18N2S2 [systematic name: (E)-4-methylbenzyl 2-[(E)-3-phenylallylidene]hydrazinecarbodithioate, comprises an almost planar central CN2S2 residue [r.m.s. deviation = 0.0131 Å]. The methylene(tolyl-4) group forms a dihedral angle of 72.25 (4)° with the best plane through the remaining non-hydrogen atoms [r.m.s. deviation = 0.0586 Å] so the molecule approximates mirror symmetry with the 4-tolyl group bisected by the plane. The configuration about both double bonds in the N—N=C—C=C chain is E; the chain has an all trans conformation. In the crystal, eight-membered centrosymmetric thioamide synthons, {...HNCS}2, are formed via N—H...S(thione) hydrogen bonds. Connections between the dimers via C—H...π interactions lead to a three-dimensional architecture. A Hirshfeld surface analysis shows that (I) possesses an interaction profile similar to that of a closely related analogue with an S-bound benzyl substituent, (II). Computational chemistry indicates the dimeric species of (II) connected via N—H...S hydrogen bonds is about 0.94 kcal mol−1 more stable than that in (I)

    Style of information usage and use of accounting information : a Malaysian study

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    Purpose &ndash; Since the 1990s, there has been a growing interest in style of information usage. However, most studies on style of information usage are conducted in developed countries. There is limited research on style of information usage in developing countries. The purpose of this paper is to fill the gap in the existing literature by examining relationships between style of information usage and use of financial and non-financial information in Malaysia. Design/methodology/approach &ndash; The authors adopted a survey method, for which a written questionnaire was prepared and mailed out to companies in Kuala Lumpur, Selangor, Terengganu and Pulau Pinang. Findings &ndash; Findings of the study show that diagnostic style of information usage is positively associated with use of financial information, while interactive style of information usage is positively associated with use of non-financial information. Further analysis on types of non-financial information used by managers who adopt interactive style of information usage reveals that customer-related non-financial information such as quality, customer satisfaction and flexibility play a more important role in their decision-making processes. Originality/value &ndash; The paper provides insights into relationships between style of information usage on and use of accounting information in developing countries. Findings of the study can be applied to assist management accountants in meeting managers&rsquo; information requirements.<br /

    The nexus between energy price changes and environmental quality in Malaysia

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    This paper provides new evidence by examining the impact of oil price changes on environmental quality. Having utilized three co-integrating estimators and a dataset from 1983 to 2014, we found that lower oil price can increase carbon emissions and reduce environmental quality. On the other hand, higher oil price can mitigate carbon emissions and improve environmental quality. We recommend the use of cleaner energy sources to improve environmental quality during lower oil price

    Adsorption study of ammonia nitrogen by watermelon rind

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    The utilization of fruit waste for low-cost adsorbents as a replacement for costly conventional methods of removing ammonia nitrogen from wastewater has been reviewed. The adsorption studies were conducted as a function of contact time and adsorbent dosage and it were carried out on four different adsorbents; fresh watermelon rind and modified watermelon rind with sodium hydroxide (NaOH), potassium hydroxide (KOH) and sulphuric acid (H2SO4). Adsorbents were tested for characterization by using zeta potential test and all samples shows negative values thus makes it favourable for the adsorption process. The batch experimental result showed that adsorption process is rapid and equilibrium was established within 40 minutes of contact time. The ammonia nitrogen removal rate amounted in range of 96% to 99%, and the adsorption capacities were in range of 1.21 to 1.24 mg/g for all four different types of adsorbents used

    Kritik al-Quran oleh Nasr Hamid Abu Zayd melalui terapan hermeneutics humanistic

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    Nasr Hamid Abu Zayd dikenali sebagai seorang tokoh yang lantang mengkritik al-Quran pada abad ini. Beliau mempunyai metode yang tersendiri ketika mentafsir al-Quran iaitu mengaplikasi hermeneutik dengan menerapkan elemen humanistic. Artikel ini bertujuan untuk menganalisis elemen humanistic yang dibawa oleh Abu Zayd dalam empat aspek iaitu definisi al-Quran, konsep bahawa wahyu, proses penurunan wahyu dan metode pentafsiran. Empat aspek tersebut dibandingkan secara berterusan dengan al-Quran dan al-Sunnah. Untuk mencapai validity data, artikel yang bersifat kualitatif ini menggunakan metode analisis kandungan yang terdiri daripada karyakarya Abu Zayd sebagai sumber pengumpulan data. Manakala analisis data menggunakan kaedah diskriptif dan perbandingan berterusan. Hasil kajian menunjukkan, elemen humanistic yang telah diterapkan kepada al-Quran telah mencetuskan implikasi terhadap al- Quran, konsep wahyu, tafsiran relatif dan liberalisasi hukum syariah
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