Displaying publications 1 - 20 of 149 in total

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  1. Hussanan A, Zuki Salleh M, Tahar RM, Khan I
    PLoS One, 2014;9(10):e108763.
    PMID: 25302782 DOI: 10.1371/journal.pone.0108763
    In this paper, the heat transfer effect on the unsteady boundary layer flow of a Casson fluid past an infinite oscillating vertical plate with Newtonian heating is investigated. The governing equations are transformed to a systems of linear partial differential equations using appropriate non-dimensional variables. The resulting equations are solved analytically by using the Laplace transform method and the expressions for velocity and temperature are obtained. They satisfy all imposed initial and boundary conditions and reduce to some well-known solutions for Newtonian fluids. Numerical results for velocity, temperature, skin friction and Nusselt number are shown in various graphs and discussed for embedded flow parameters. It is found that velocity decreases as Casson parameters increases and thermal boundary layer thickness increases with increasing Newtonian heating parameter.
    Matched MeSH terms: Heating*
  2. Al-Waeli AHA, Sopian K, Kazem HA, Chaichan MT
    Environ Sci Pollut Res Int, 2023 Jul;30(34):81474-81492.
    PMID: 36689112 DOI: 10.1007/s11356-023-25321-0
    The bi-fluid photovoltaic thermal (PVT) collector was introduced to provide more heating options along with improved cooling capabilities for the PV module. Since its introduction, this type of PVT system has been investigated thoroughly in various original works. In this review paper, we intend to put the concept and applications of this technology into question and revise the main achievements and discoveries through research and development with a focus on climatic and operational parameters. The paper encompasses a critical review of the discussed research and future directions for PVT collectors. The main utilized operational modes are discussed in detail, which are (i) water used in both channels, (ii) water in one channel and air in the other, and (iii) air in both channels. The modes were found to lead to different enhancement and performance effects for the utilized photovoltaic modules. The impact of mass flow rate was also taken by keeping one working fluid constant while varying the other to obtain its impact on the energy and exergy efficiency of the collector. In some cases, the fluids were run simultaneously and, in other cases, independently.
    Matched MeSH terms: Heating*
  3. Thapa S, Zaki SA
    J Therm Biol, 2024 Feb;120:103809.
    PMID: 38364574 DOI: 10.1016/j.jtherbio.2024.103809
    The sub-Himalayan region extends over 2500 km, extending over several countries. Though the effects of climate change is widely anticipated in the diverse but fragile ecosystem of the Himalayas, very less research has been conducted on the indoor environment of the buildings in these regions. In this study, a pre-validated model of 3-storey concrete residential building was used to study the indoor performance and thermal comfort in the face of climate change in the 8 (eight) different hill towns (hill stations) located from west to the east. Rise in ambient and indoor conditions were evident as a part of climate change with colder locations being affected the most. The thermal comfort assessment using both the climate chamber based PMV model and adaptive models revealed the decrease in cold related discomfort and increase in hot related discomfort. On an overall, the indoor conditions improved in these cold locations. The indoor and outdoor thermal condition and thermal comfort plummeted significantly with latitude and elevation. The heating demand in the future climate reduced by about 50-70 % in warmer locations, while the cooling demand increased by as much as 1000-2000 % in cold locations, respectively. Additionally, it was seen that the thermal environment and comfort both declined more rapidly with elevation in the locations lying in the western Himalayas as compared to those in the eastern Himalayas.
    Matched MeSH terms: Heating*
  4. Xu D, Yang L, Zhao M, Zhang J, Syed-Hassan SSA, Sun H, et al.
    Environ Pollut, 2021 Feb 01;270:116120.
    PMID: 33341552 DOI: 10.1016/j.envpol.2020.116120
    Understanding the migration and conversion of nitrogen in wood-based panels (WBPs) during pyrolysis is fundamentally important for potentially transforming the N-containing species into valuable material-based products. This review firstly summarizes the commonly used methods for examining N evolution during the WBPs pyrolysis before probing into the association between the wood and adhesives.The potential effects of wood-adhesive interaction on the pyrolysis process are subsequently analyzed. Furthermore, the controversial statements from literature on the influence of adhesives on wood pyrolysis behavior are discussed, which is followed by the detailed investigation into the distribution and evolution of N-containing species in gas, liquid and char, respectively, during WBPs pyrolysis in recent studies. The differences in N species due to the heating sources (i.e. electrical heating vs microwave heating) are particularly compared. Finally, based on the characteristics of staged pyrolysis, co-pyrolysis and catalytic pyrolysis, the converting pathways for WBPs are proposed with an emphasis on the production of value-added chemicals and carbon materials, simultaneously mitigating NOx emission.
    Matched MeSH terms: Heating
  5. Mohammed MN, Omar MZ, Salleh MS, Alhawari KS, Kapranos P
    ScientificWorldJournal, 2013;2013:752175.
    PMID: 24194689 DOI: 10.1155/2013/752175
    Semisolid metal (SSM) processing or thixoforming is widely known as a technology that involves the formation of metal alloys between solidus and liquidus temperatures. For the procedure to operate successfully, the microstructure of the starting material must consist of solid near-globular grains surrounded by a liquid matrix and a wide solidus-to-liquidus transition area. Currently, this process is industrially successful, generating a variety of products with high quality parts in various industrial sectors. Throughout the years since its inception, a number of technologies to produce the appropriate globular microstructure have been developed and applied worldwide. The main aim of this paper is to classify the presently available SSM technologies and present a comprehensive review of the potential mechanisms that lead to microstructural alterations during the preparation of feedstock materials for SSM processing.
    Matched MeSH terms: Heating/methods*
  6. Salema AA, Ani FN
    Bioresour Technol, 2011 Feb;102(3):3388-95.
    PMID: 20970995 DOI: 10.1016/j.biortech.2010.09.115
    The purpose of this paper was to carry out microwave induced pyrolysis of oil palm biomass (shell and fibers) with the help of char as microwave absorber (MA). Rapid heating and yield of microwave pyrolysis products such as bio-oil, char, and gas was found to depend on the ratio of biomass to microwave absorber. Temperature profiles revealed the heating characteristics of the biomass materials which can rapidly heat-up to high temperature within seconds in presence of MA. Some characterization of pyrolysis products was also presented. The advantage of this technique includes substantial reduction in consumption of energy, time and cost in order to produce bio-oil from biomass materials. Large biomass particle size can be used directly in microwave heating, thus saving grinding as well as moisture removal cost. A synergistic effect was found in using MA with oil palm biomass.
    Matched MeSH terms: Heating/methods
  7. Yasin MH, Ishak A, Pop I
    Sci Rep, 2015;5:17848.
    PMID: 26647651 DOI: 10.1038/srep17848
    The steady two-dimensional stagnation-point flow and heat transfer past a permeable stretching/shrinking sheet with effects of viscous dissipation, Joule heating and partial velocity slip in the presence of a magnetic field is investigated. The partial differential equations are reduced to nonlinear ordinary differential equations by using a similarity transformation, before being solved numerically by shooting technique. Results indicate that the skin friction coefficient and the local Nusselt number increase as magnetic parameter increases. It is found that for the stretching sheet the solution is unique while for the shrinking sheet there exist nonunique solutions (dual solutions) in certain range of parameters. The stability analysis shows that the upper branch solution is stable while the lower branch solution is unstable.
    Matched MeSH terms: Heating
  8. Maazullah Khan, Abdurab, Muhammad Hanif, Mansoor Khan Khattak, Muhammad Ramzan
    Sains Malaysiana, 2018;47:1061-1067.
    Air heating by solar collectors is renewable technology providing hot air for different purposes. The present research
    emphasizes on analysis of energy, exergy and efficiency of a flat plate solar air heater. The analysis model was tested
    on five different air mass flow rates of 0.5 (Natural), 1.31, 2.11, 2.72 and 3.03 kgs-1 under three different tilt angles of
    25, 35 (Recommended) and 50o
    . The data was replicated three times making a total of 45 treatments. A two factorial
    completely randomized design was used to find if there is any significant difference among the treatments. The results
    showed that the solar collector gave better performance at air mass flow of 3.03 kgs-1 under tilt of 35o
    . At maximum
    air mass flow rate of 3.03 kgs-1and optimum tilt angle of 35o
    the maximum energetic efficiency of 51%, while minimum
    exergetic efficiency of 24% and maximum overall efficiency of 71% were recorded. It was concluded that to get maximum
    thermal efficiencies of 71% from flat plate solar collector used as an air heater must be operated at high air mass flow
    rates of 3.03 kgs-1under 35o
    tilt angle at Peshawar, Pakistan.
    Matched MeSH terms: Heating
  9. Teng SY, Loy ACM, Leong WD, How BS, Chin BLF, Máša V
    Bioresour Technol, 2019 Nov;292:121971.
    PMID: 31445240 DOI: 10.1016/j.biortech.2019.121971
    The aim of this study is to identify the optimum thermal conversion of Chlorella vulgaris with neuro-evolutionary approach. A Progressive Depth Swarm-Evolution (PDSE) neuro-evolutionary approach is proposed to model the Thermogravimetric analysis (TGA) data of catalytic thermal degradation of Chlorella vulgaris. Results showed that the proposed method can generate predictions which are more accurate compared to other conventional approaches (>90% lower in Root Mean Square Error (RMSE) and Mean Bias Error (MBE)). In addition, Simulated Annealing is proposed to determine the optimal operating conditions for microalgae conversion from multiple trained ANN. The predicted optimum conditions were reaction temperature of 900.0 °C, heating rate of 5.0 °C/min with the presence of HZSM-5 zeolite catalyst to obtain 88.3% of Chlorella vulgaris conversion.
    Matched MeSH terms: Heating
  10. Othuman Mydin MA, Zamzani NM, Ghani ANA
    Data Brief, 2019 Aug;25:104320.
    PMID: 31428668 DOI: 10.1016/j.dib.2019.104320
    Quantifying the elevated temperature strengths of cement-based material is crucial to the design of building structural systems for fire resistance purpose. This paper collates a database of elevated temperature axial compressive and flexural strengths of coir fibre reinforced foamed concrete exposed to heating temperatures of 105 °C, 200 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C and 800 °C. There were four densities of foamed concrete of 700, 1100, 1500 and 1900 kg/m3 were prepared and tested. The untreated coir fibre was added in foamed concrete in percentages of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and 0.6% by mix volume fraction. The database can aid in prediction of elevated temperature strengths of fibre reinforced foamed concrete which can be exploited to assist manufacturers to develop their products without having to perform numerous large-scale elevated temperature tests in the future.
    Matched MeSH terms: Heating
  11. M. Fahmi M. Yusof, Nornashriah A. Rashid, Reduan Abdullah
    MyJurnal
    The glow curve in TLD-100 was compared by applying long preheat time, short preheat time
    techniques and without preheat technique before the TLD readout. Fading effect of the TLD signal
    upon certain storage time with long preheat time (100°C, 10 minutes using the oven) and short
    preheat time techniques (100°C, 10 seconds using the reader) were also studied. 15 TLD-100 chips
    were used with 3 of the TLD chips were used for measuring background radiation. 12 TLD chips
    were annealed, irradiated, preheated long and short preheat time techniques) and analyzed. The TL
    signals output from TLD chips of without preheated were used as the control. Two sets of data were
    taken using TLD chips irradiated with 6 MV and 10 MV photon beams. TL signal output was
    recorded the highest for short preheat time, followed by long preheat time and no preheating. The
    TL signal loss upon certain storage time was also reduced when short preheat time technique was
    applied. By applying long preheat time technique the low temperature peak in the glow curve was
    completely removed for both energies. Whereas, TLD chips exposed to 6 MV and with short preheat
    time technique the low temperature peak did not disappear completely but decreased in intensity as
    compared to the control data by 19.80%, 37.69%, 48.19% and 100% at 24, 48, 72 and 96 hours
    after exposure prior to readout, respectively. Meanwhile, for 10 MV photon beam with short
    preheat time, the small peak intensity was reduced by 19.58% for readout at 24 hours after
    irradiation and 100% for 48,72 and 96 hours delayed time prior to readout. It was observed that
    the TLD-100 was highly dependent on preheat heating time before readout. Short preheat time
    technique was able to reduce post irradiation fading of TLD-100 dosimeters
    Matched MeSH terms: Heating
  12. Suseno S.H., Tajul, A.Y., Nadiah, W.A.
    MyJurnal
    Magnesol XL concentration (0.5, 1, 3 and 5%), heating temperature (25, 50, 70 and 90 ˚C) and time (5, 10, 15 and 20 mnt) during purification to the color properties (Lightness L*, redness a* and yellowness b*) of Sardinella lemuru oil were evaluated. Purification using Magnesol XL in any condition effectively increase the L* and a* value but reduced the b* value of the lemuru oil. Highest L* value (96.57) was achieved at the treatment temperature 90 ˚C, 5 % level of Magnesol XL concentration and 5 minutes process. Lowest a* value (more green color) was obtained at treatment 70 ˚C temperature, 5% level of concentration and 15 minutes, then lowest b* value was obtained at treatment 90 ˚C temperature, 5 % concentration and 5 minutes process. All the refined lemuru oil’s result had a hue angle higher than 90˚ representing the light greenish-yellow color.
    Matched MeSH terms: Heating
  13. Ong, C.A., Abdul Aziz, N., Taip, F.S., Ibrahim M.N.
    MyJurnal
    A study has been conducted on pink guava juice (PGJ) fouling deposit. Several ex-situ experimental rigs were set-up to obtain PGJ fouling deposit, while the best ex-situ experimental rig was also selected. PGJ was heated at 93°C and its fouling deposit was obtained after 1 hour of heating. Then, it was used for the ex-situ cleaning study at 1 litre min-1, at several temperatures (70, 80 and 90°C), and in some chemical concentrations (1.6 v/v% of Maxiclean CP6 or 0.325 % OH-; 1.8 v/v% of Maxiclean CP6 or 0.369 % OH-; 2.0 v/v% of Maxiclean CP6 or 0.44 % OH-). The best cleaning combinations were investigated. Carbohydrate is the main content in the fouling deposit. The morphology of the deposit was studied using SEM and it showed an aggregated structure. The cleaning process improved as the temperature increased with the increasing of the chemical solution concentration. The shortest cleaning time was 40 minutes, for cleaning using 2.0 v/v % of Maxiclean CP6 (0.44 % OH-) at 90°C.
    Matched MeSH terms: Heating
  14. Maskat, M.Y, Tan, S.M.
    MyJurnal
    Extract of mengkudu was heated using a bench-top tube heat exchanger at 30, 50, 70 and 90 o C for 0, 5, 10 and 15 min residence time. The treated mengkudu extract was then measured for pH, L * , a * , b * color parameters, clarity, viscosity and total polyphenol content. Results show that heating using temperature of 30 to 90 o C for 5 to 15 mins significantly (p
    Matched MeSH terms: Heating
  15. Arifin, N., Cheong, L.Z., Koh, S.P., Long, K., Tan, C.P., Yusoff, M.S.A., et al.
    ASM Science Journal, 2010;4(2):113-122.
    MyJurnal
    Several binary and ternary medium- and long-chain triacylglycerol (MLCT)-enriched margarine formulations were examined for their solid fat content, heating profile, polymorphism and textural properties. MLCT feedstock was produced through enzymatic esterification of capric and stearic acids with glycerol. The binary formulations were produced by mixing MLCT feedstock blend (40%–90%) and palm olein (10%–60%) with 10% increments (w/w). Solid fat profiles of commercial margarines were used as a reference to determine the suitability of the formulations for margarine production. The solid fat content of the binary formulations of MO 82 and MO 91 (M, MLCT, O, palm olein) were similar to the commercial margarines at 25°C which met the basic requirement for efficient dough consistency. Ternary formulations using reduced MLCT feedstock blend proportion (from 80%–90% to 60%–70%) were also developed. The reduction of MLCT feedstock blend was
    done as it had the highest production cost (3USD/kg) in comparison to palm olein (0.77USD/kg) and palm stearin (0.7USD/kg). The proportions of 5%–15% of palm stearin were substituted with palm olein in MO 64 and MO 73 (M, MLCT; O, palm olein) formulations with 5% increment (w/w). As a result, MOS 702010 and MOS 603010 (M, MLCT; O, palm olein; S, palm stearin) margarine formulations showed similar SFC % to the commercial margarines at 25ºC. These formulations were subsequently chosen to produce margarines. The onset melting and complete melting points of MLCT-enriched margarine formulations were high (51.04ºC –57.93ºC) due to the presence of a high amount of long chain saturated fatty acids. Most of the formulations showed β΄- crystals. MOS 702010 was selected as the best formulation due to values for textural parameters comparable (P
    Matched MeSH terms: Heating
  16. Loy ACM, Gan DKW, Yusup S, Chin BLF, Lam MK, Shahbaz M, et al.
    Bioresour Technol, 2018 Aug;261:213-222.
    PMID: 29665455 DOI: 10.1016/j.biortech.2018.04.020
    The thermal degradation behaviour and kinetic parameter of non-catalytic and catalytic pyrolysis of rice husk (RH) using rice hull ash (RHA) as catalyst were investigated using thermogravimetric analysis at four different heating rates of 10, 20, 50 and 100 K/min. Four different iso conversional kinetic models such as Kissinger, Friedman, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) were applied in this study to calculate the activation energy (EA) and pre-exponential value (A) of the system. The EA of non-catalytic and catalytic pyrolysis was found to be in the range of 152-190 kJ/mol and 146-153 kJ/mol, respectively. The results showed that the catalytic pyrolysis of RH had resulted in a lower EA as compared to non-catalytic pyrolysis of RH and other biomass in literature. Furthermore, the high Gibb's free energy obtained in RH implied that it has the potential to serve as a source of bioenergy production.
    Matched MeSH terms: Heating
  17. Muhammad Khairul Anuar Mohamed, Mohd Zuki Salleh, Roslinda Naza, Anuar Ishak
    Sains Malaysiana, 2012;41:1467-1473.
    In this study, the numerical solution of stagnation point flow over a stretching surface, generated by Newtonian heating in which the heat transfer from the surface is proportional to the local surface temperature is considered. The transformed boundary layer equations are solved numerically using the shooting method. Numerical solutions are obtained for the local heat transfer coefficient, the surface temperature and the temperature profiles. The features of the flow and heat transfer characteristics for various values of the Prandtl number, stretching parameter and conjugate parameter are analyzed and discussed.
    Matched MeSH terms: Heating
  18. Sirajuddin N, Md Jamil M
    Sains Malaysiana, 2015;44:811-818.
    Synthetic materials that are capable of healing upon damage are being developed at a rapid pace because of their
    many potential applications. Here, new healing chemically cross-linked hydrogel of poly(2-hydroxyethyl methacrylate)
    (pHEMA) was prepared. The healing hydrogel was achieved by heating above its glass transition (Tg
    ). The intermolecular
    diffusion of dangling chain and the chain slippage led to healing of the gel. The peaks in attenuated total reflectance
    (ATR) confirmed that hydrogel was formed while rheological studies had determined the minimum for healing temperature
    is 48.5o
    C. The results showed that ratio stress of the healable hydrogel can reach until 92 and 91% of first and second
    healing cycle, respectively. The morphology of the sample was carried out to evaluate the self-property of hydrogel.
    Matched MeSH terms: Heating
  19. Nelisa Ameera Mohamed Joeharry, Che Aziz Ali, Kamal Roslan Mohamed, Mohd Shafeea Leman
    Sains Malaysiana, 2018;47:1423-1430.
    A single sample from the logged section at eastern side of Gua Panjang limestone hill, southwest of Kampung Kubang
    Rasa Village, Merapoh, has yielded 5 very important conodont species. They are Hindeodus parvus erectus, Hindeodus
    parvus parvus, Hindeodus latidentatus latidentatus, Hindeodus latidentatus praeparvus, Hindeodus postparvus, Hindeodus
    eurypge and Isarcicella staeschi. These Early Triassic conodonts were obtained in a bioclastic dolostone sample, located
    2.5 m above bioclastic grainstone which yielded Late Permian foraminifera. The conodonts found were given Conodont
    Alteration Index (CAI) scale of 5, consistent with the heating of Main Range granitoid during Indosinian Orogeny.
    Limestone harbouring basal Triassic conodonts in Gua Panjang is interpreted to be deposited in an open shallow marine
    shelf environment.
    Matched MeSH terms: Heating
  20. Kabir G, Mohd Din AT, Hameed BH
    Bioresour Technol, 2017 Oct;241:563-572.
    PMID: 28601774 DOI: 10.1016/j.biortech.2017.05.180
    Oil palm mesocarp fiber (OPMF) and palm frond (PF) were respectively devolatilized by pyrolysis to OPMF-oil and PF-oil bio-oils and biochars, OPMF-char and PF-char in a slow-heating fixed-bed reactor. In particular, the OPMF-oil and PF-oil were produced to a maximum yield of 48wt% and 47wt% bio-oils at 550°C and 600°C, respectively. The high heating values (HHVs) of OPMF-oil and PF-oil were respectively found to be 23MJ/kg and 21MJ/kg, whereas 24.84MJ/kg and 24.15MJ/kg were for the corresponding biochar. The HHVs of the bio-oils and biochars are associated with low O/C ratios to be higher than those of the corresponding biomass. The Fourier transform infrared spectra and peak area ratios highlighted the effect of pyrolysis temperatures on the bio-oil compositions. The bio-oils are pervaded with numerous oxygenated carbonyl and aromatic compounds as suitable feedstocks for renewable fuels and chemicals.
    Matched MeSH terms: Heating
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