Displaying publications 561 - 580 of 2919 in total

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  1. Sahari J, Sapuan SM, Zainudin ES, Maleque MA
    Carbohydr Polym, 2013 Feb 15;92(2):1711-6.
    PMID: 23399210 DOI: 10.1016/j.carbpol.2012.11.031
    In recent years, increasing environmental concerns focused greater attention on the development of biodegradable materials. A thermoplastic starch derived from bioresources, sugar palm tree was successfully developed in the presence of biodegradable glycerol as a plasticizer. Sugar palm starch (SPS) was added with 15-40 w/w% of glycerol to prepare workable bioplastics and coded as SPS/G15, SPS/G20, SPS/G30 and SPS/G40. The samples were characterized for thermal properties, mechanical properties and moisture absorption on exposure to humidity were evaluated. Morphological studies through scanning electron microscopy (SEM) were used to explain the observed mechanical properties. Generally, the addition of glycerol decrease the transition temperature of plasticized SPS. The mechanical properties of plasticized SPS increase with the increasing of glycerol but up to 30 w/w%. Meanwhile, the water absorption of plasticized SPS decrease with increasing of glycerol.
    Matched MeSH terms: Temperature*
  2. Rahman IA, Saad B, Shaidan S, Sya Rizal ES
    Bioresour Technol, 2005 Sep;96(14):1578-83.
    PMID: 15978990
    Phosphoric acid (H(3)PO(4)) and sodium hydroxide (NaOH) treated rice husks, followed by carbonization in a flowing nitrogen were used to study the adsorption of malachite green (MG) in aqueous solution. The effect of adsorption on contact time, concentration of MG and adsorbent dosage of the samples treated or carbonized at different temperatures were investigated. The results reveal that the optimum carbonization temperature is 500 degrees C in order to obtain adsorption capacity that is comparable to the commercial activated carbon for the husks treated by H(3)PO(4). It is interesting to note that MG adsorbed preferably on carbon-rich than on silica rich-sites. It is found that the behaviour of H(3)PO(4) treated absorbent followed both the Langmuir and Freundlich models while NaOH treated best fitted to only the Langmuir model.
    Matched MeSH terms: Hot Temperature*
  3. Gul A, Khan I, Shafie S, Khalid A, Khan A
    PLoS One, 2015;10(11):e0141213.
    PMID: 26550837 DOI: 10.1371/journal.pone.0141213
    This study investigated heat transfer in magnetohydrodynamic (MHD) mixed convection flow of ferrofluid along a vertical channel. The channel with non-uniform wall temperatures was taken in a vertical direction with transverse magnetic field. Water with nanoparticles of magnetite (Fe3O4) was selected as a conventional base fluid. In addition, non-magnetic (Al2O3) aluminium oxide nanoparticles were also used. Comparison between magnetic and magnetite nanoparticles were also conducted. Fluid motion was originated due to buoyancy force together with applied pressure gradient. The problem was modelled in terms of partial differential equations with physical boundary conditions. Analytical solutions were obtained for velocity and temperature. Graphical results were plotted and discussed. It was found that temperature and velocity of ferrofluids depend strongly on viscosity and thermal conductivity together with magnetic field. The results of the present study when compared concurred with published work.
    Matched MeSH terms: Hot Temperature; Temperature
  4. Nawi SN, Wahib NF, Zulkepely NN, Amin YB, Min UN, Bradley DA, et al.
    Sensors (Basel), 2015;15(8):20557-69.
    PMID: 26307987 DOI: 10.3390/s150820557
    Study has been undertaken of the thermoluminescence (TL) yield of various tailor-made flat cross-section 6 mol% Ge-doped silica fibers, differing only in respect of external dimensions. Key TL dosimetric characteristics have been investigated, including glow curves, dose response, sensitivity, fading and reproducibility. Using a (60)Co source, the samples were irradiated to doses within the range 1 to 10 Gy. Prior to irradiation, the flat fibers were sectioned into 6 mm lengths, weighed, and annealed at 400 °C for 1 h. TL readout was by means of a Harshaw Model 3500 TLD reader, with TLD-100 chips (LiF:Mg, Ti) used as a reference dosimeter to allow the relative response of the fibers to be evaluated. The fibers have been found to provide highly linear dose response and excellent reproducibility over the range of doses investigated, demonstrating high potential as TL-mode detectors in radiation medicine applications. Mass for mass, the results show the greatest TL yield to be provided by fibers of the smallest cross-section, analysis indicating this to be due to minimal light loss in transport of the TL through the bulk of the silica medium.
    Matched MeSH terms: Temperature*
  5. Muraoka M, Susuki N, Yamaguchi H, Tsuji T, Yamamoto Y
    J Vis Exp, 2016 Mar 21.
    PMID: 27023374 DOI: 10.3791/53956
    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.
    Matched MeSH terms: Hot Temperature*
  6. Abdullah BM, Zubairi SI, Huri HZ, Hairunisa N, Yousif E, Basu RC
    PLoS One, 2016;11(3):e0151603.
    PMID: 27008312 DOI: 10.1371/journal.pone.0151603
    Presently, plant oils which contain high percentage of linoleic acid 1 are perceived to be a viable alternative to mineral oil for biolubricant applications due to their biodegradability and technical properties. In order to get biodegradable lubricant, triester derivatives compounds (1-5) were synthesized and characterized. The processes involved were monoepoxidation of linoleic acid 2, oxirane ring opening 3, esterification 4 and acylation 5. The structures of the products were confirmed by FTIR, 1H and 13C-NMR and LC-MS. The results that showed lowest temperature properties were obtained for triester 5, with a pour point value (PP) of -73°C, highest onset temperature (260°C) and lowest volatility at 0.30%. Viscosity index (VI) increased for the ester's synthetic compounds (2, 3, 4, 5), while the PP decreased. This behavior is the result of the increase of the chain length of the branching agents. Triester based linoleic acid has improved properties such as low-temperature and tribological properties. These results will make it feasible for plant oil to be used for biolubricants, fuels in chain saws, transmission oil and brake fluid.
    Matched MeSH terms: Cold Temperature*
  7. Tripathy A, Pramanik S, Manna A, Shah NF, Shasmin HN, Radzi Z, et al.
    Sensors (Basel), 2016;16(3):292.
    PMID: 26927116 DOI: 10.3390/s16030292
    Armalcolite, a rare ceramic mineral and normally found in the lunar earth, was synthesized by solid-state step-sintering. The in situ phase-changed novel ceramic nanocrystals of Ca-Mg-Ti-Fe based oxide (CMTFOx), their chemical reactions and bonding with polydimethylsiloxane (PDMS) were determined by X-ray diffraction, infrared spectroscopy, and microscopy. Water absorption of all the CMTFOx was high. The lower dielectric loss tangent value (0.155 at 1 MHz) was obtained for the ceramic sintered at 1050 °C (S1050) and it became lowest for the S1050/PDMS nanocomposite (0.002 at 1 MHz) film, which was made by spin coating at 3000 rpm. The excellent flexibility (static modulus ≈ 0.27 MPa and elongation > 90%), viscoelastic property (tanδ = E″/E': 0.225) and glass transition temperature (Tg: -58.5 °C) were obtained for S1050/PDMS film. Parallel-plate capacitive and flexible resistive humidity sensors have been developed successfully. The best sensing performance of the present S1050 (3000%) and its flexible S1050/PDMS composite film (306%) based humidity sensors was found to be at 100 Hz, better than conventional materials.
    Matched MeSH terms: Temperature; Transition Temperature
  8. Bangash JI, Khan AW, Abdullah AH
    J Med Syst, 2015 Sep;39(9):91.
    PMID: 26242749 DOI: 10.1007/s10916-015-0268-5
    A significant proportion of the worldwide population is of the elderly people living with chronic diseases that result in high health-care cost. To provide continuous health monitoring with minimal health-care cost, Wireless Body Sensor Networks (WBSNs) has been recently emerged as a promising technology. Depending on nature of sensory data, WBSNs might require a high level of Quality of Service (QoS) both in terms of delay and reliability during data reporting phase. In this paper, we propose a data-centric routing for intra WBSNs that adapts the routing strategy in accordance with the nature of data, temperature rise issue of the implanted bio-medical sensors due to electromagnetic wave absorption, and high and dynamic path loss caused by postural movement of human body and in-body wireless communication. We consider the network models both with and without relay nodes in our simulations. Due to the multi-facet routing strategy, the proposed data-centric routing achieves better performance in terms of delay, reliability, temperature rise, and energy consumption when compared with other state-of-the-art.
    Matched MeSH terms: Body Temperature*
  9. Urbieta MS, Donati ER, Chan KG, Shahar S, Sin LL, Goh KM
    Biotechnol Adv, 2015 Nov 1;33(6 Pt 1):633-47.
    PMID: 25911946 DOI: 10.1016/j.biotechadv.2015.04.007
    Thermophiles and hyperthermophiles are present in various regions of the Earth, including volcanic environments, hot springs, mud pots, fumaroles, geysers, coastal thermal springs, and even deep-sea hydrothermal vents. They are also found in man-made environments, such as heated compost facilities, reactors, and spray dryers. Thermophiles, hyperthermophiles, and their bioproducts facilitate various industrial, agricultural, and medicinal applications and offer potential solutions to environmental damages and the demand for biofuels. Intensified efforts to sequence the entire genome of hyperthermophiles and thermophiles are increasing rapidly, as evidenced by the fact that over 120 complete genome sequences of the hyperthermophiles Aquificae, Thermotogae, Crenarchaeota, and Euryarchaeota are now available. In this review, we summarise the major current applications of thermophiles and thermozymes. In addition, emphasis is placed on recent progress in understanding the biodiversity, genomes, transcriptomes, metagenomes, and single-cell sequencing of thermophiles in the genomic era.
    Matched MeSH terms: Hot Temperature*
  10. Chan CS, Chan KG, Tay YL, Chua YH, Goh KM
    Front Microbiol, 2015;6:177.
    PMID: 25798135 DOI: 10.3389/fmicb.2015.00177
    The Sungai Klah (SK) hot spring is the second hottest geothermal spring in Malaysia. This hot spring is a shallow, 150-m-long, fast-flowing stream, with temperatures varying from 50 to 110°C and a pH range of 7.0-9.0. Hidden within a wooded area, the SK hot spring is continually fed by plant litter, resulting in a relatively high degree of total organic content (TOC). In this study, a sample taken from the middle of the stream was analyzed at the 16S rRNA V3-V4 region by amplicon metagenome sequencing. Over 35 phyla were detected by analyzing the 16S rRNA data. Firmicutes and Proteobacteria represented approximately 57% of the microbiome. Approximately 70% of the detected thermophiles were strict anaerobes; however, Hydrogenobacter spp., obligate chemolithotrophic thermophiles, represented one of the major taxa. Several thermophilic photosynthetic microorganisms and acidothermophiles were also detected. Most of the phyla identified by 16S rRNA were also found using the shotgun metagenome approaches. The carbon, sulfur, and nitrogen metabolism within the SK hot spring community were evaluated by shotgun metagenome sequencing, and the data revealed diversity in terms of metabolic activity and dynamics. This hot spring has a rich diversified phylogenetic community partly due to its natural environment (plant litter, high TOC, and a shallow stream) and geochemical parameters (broad temperature and pH range). It is speculated that symbiotic relationships occur between the members of the community.
    Matched MeSH terms: Hot Temperature; Temperature
  11. Raman S, Shahla A
    Aust N Z J Obstet Gynaecol, 1992 May;32(2):117-9.
    PMID: 1520194
    A prospective study of temperature drop in 141 normal term newborn infants delivered vaginally at the labour ward, University Hospital, Kuala Lumpur were studied. The effect of various manoeuvres on the temperature drop were also studied. They were randomized into 3 study groups, 63 cases where the babies were wiped with dry cloth alone, 37 cases where the babies were put into a plastic bag immediately after birth and lastly 41 cases where the babies were wiped with dry cloth and then inserted into a plastic bag. There was significant temperature drop in all the 3 groups maximum in the first 15 minutes and the fall continued for 1 hour after delivery (p less than 0.001). This shows that in an air-conditioned labour ward in a tropical country the temperature fall in newborn infants can be significant. This study also showed that plastic is a poor insulator against significant temperature drop.
    Matched MeSH terms: Body Temperature*
  12. Farra Amira Mohamed, Aimi Nadia Ramli,, Noorlis Ahmad
    MyJurnal
    Demand for milk has increased in Malaysia due to the increased in awareness of healthy foods consumption.
    Hence, research of milk is crucial to ensure that it is not contaminated with Escherichia coli. This study
    evaluated the survival of Escherichia coli at different temperature and haemolysin activity of Escherichia
    coli on blood agar. A total of 8 samples of raw fresh and pasteurized milk were collected from nearby farm
    and market in Negeri Sembilan, Malaysia. After an overnight exposure to four different temperatures of
    0
    0C, 280C, 350C and 450C, the bacteriological test of milk was evaluated for the presence of Escherichia
    coli. Overall, all raw fresh milk sampled exceeded the acceptable limit of bacterial count of 1 x 105 CFU/ml.
    Raw fresh milk recorded the highest count at 35oC with 4.4 x 107 CFU/ml and the lowest at 0oC with 8.3 x
    104 CFU/ml. The presence of Escherichia coli was detected in 7/20(35%) of the total raw fresh milk
    samples. All pasteurized milk showed no presence of Escherichia coli due to the effectiveness of heat
    treatment. Haemolysin test showed no haemolytic activity. Milk contaminated with Escherichia coli can
    cause diarrheal, gastrointestinal diseases and urinary infection. Hence, it is important to study the survival
    rate of Escherichia coli and its pathogenicity in milk to ensure public safety.
    Matched MeSH terms: Hot Temperature; Temperature
  13. Jeevananthan C, Muhamad NA, Jaafar MH, Hod R, Ab Ghani RM, Md Isa Z, et al.
    BMJ Open, 2020 11 04;10(11):e039623.
    PMID: 33148753 DOI: 10.1136/bmjopen-2020-039623
    INTRODUCTION: The current global pandemic of the virus that emerged from Hubei province in China has caused coronavirus disease in 2019 (COVID-19), which has affected a total number of 900 036 people globally, involving 206 countries and resulted in a cumulative of 45 693 deaths worldwide as of 3 April 2020. The mode of transmission is identified through airdrops from patients' body fluids such as during sneezing, coughing and talking. However, the relative importance of environmental effects in the transmission of the virus has not been vastly studied. In addition, the role of temperature and humidity in air-borne transmission of infection is presently still unclear. This study aims to identify the effect of temperature, humidity and air quality in the transmission of SARS-CoV-2.

    METHODS AND ANALYSIS: We will systematically conduct a comprehensive literature search using various databases including PubMed, EMBASE, Scopus, CENTRAL and Google Scholar to identify potential studies. The search will be performed for any eligible articles from the earliest published articles up to latest available studies in 2020. We will include all the observational studies such as cohort case-control and cross-sectional studies that explains or measures the effects of temperature and/or humidity and/or air quality and/or anthropic activities that is associated with SARS-CoV-2. Study selection and reporting will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Meta-Analysis of Observational Studies in Epidemiology guideline. All data will be extracted using a standardised data extraction form and quality of the studies will be assessed using the Newcastle-Ottawa Scale guideline. Descriptive and meta-analysis will be performed using a random effect model in Review Manager File.

    ETHICS AND DISSEMINATION: No primary data will be collected, and thus no formal ethical approval is required. The results will be disseminated through a peer-reviewed publication and conference presentation.

    PROSPERO REGISTRATION NUMBER: CRD42020176756.

    Matched MeSH terms: Temperature*
  14. Isa IN, Dom SM
    J Vet Med Sci, 2016 Oct 1;78(9):1399-1403.
    PMID: 27211519
    Elevated temperatures can induce changes in red blood cell (RBC), white blood cell (WBC) and platelet (PLT) counts. Ultrasound heating during obstetric scans has the potential to increase body temperature owing to the phenomenon of absorption. We conducted a study to determine the thermal effects of prenatal ultrasound on RBCs, hemoglobin concentration (Hb), WBCs and PLTs in young rabbits. We selected 69 rabbits that were 1 month of age and 73 that were 5 months of age, and allocated them to four groups. The control group consisted of four pregnant does that were allowed to have a full term delivery without any ultrasound exposure. The experimental groups were subjected to one-time ultrasound exposure for 30, 60 and 90 min in the middle of each gestational stage accordingly. RBCs and Hb showed significant reductions in the experimental groups of 1- and 5-month-old rabbits (P<0.05). In addition, WBCs and PLTs yielded significant differences in the 1-month group that were not observed in the 5-month group (P>0.05). The highest values recorded were those of the WBCs of 1-month-old subjects that received 90 min of exposure at the second stage of gestation. The PLTs were the lowest values recorded in 1-month-old subjects following 90 min of ultrasound exposure at the third stage of gestation. These findings suggest that hematological fluctuations during the early stages of postnatal life persisted until 1 month of age and recovered thereafter, as the subjects progressed into adulthood. Therefore, ultrasound heating can cause significant, yet reversible effects on the hematological parameters of rabbits.
    Matched MeSH terms: Body Temperature; Temperature
  15. Mazumder SK, Ghaffar MA, Tomiyama T, Das SK
    Respir Physiol Neurobiol, 2019 10;268:103253.
    PMID: 31301383 DOI: 10.1016/j.resp.2019.103253
    This study tested the oxygen consumption rates (OCR), energy, and thermal coefficient of juvenile Lutjanus malabaricus (60 fish, size: 4.53 ± 1.14 g) at four temperatures of 22, 26, 30 and 34 °C. During 30 days of experimental period 5 fish tank-1 were reared at four temperatures with three replicates in intermittent flow respirometers in a recirculatory system under laboratory conditions. As expected, oxygen consumption rates increased significantly (P 
    Matched MeSH terms: Temperature*
  16. Rezk MG, Foroozesh J
    Heliyon, 2019 Jul;5(7):e02057.
    PMID: 31384679 DOI: 10.1016/j.heliyon.2019.e02057
    This paper investigates the phase behavior and mutual interactions between a light crude oil and CO2 at high pressures and high temperatures (HPHT). To do so, we have measured PVT properties of the CO2-oil system at HPHT using a PVT setup. We have also tried to present a detailed methodology for measuring PVT properties of CO2-oil systems and highlight the difficulties such as oil vaporization by CO2 during the experiments. A crude oil sample, collected from a Malaysian oil field, was used here. Our experiments indicated that, CO2 solubility in the oil increased at higher pressures when measured at a fixed temperature. Our experiments also showed that increasing the test temperature would reduce CO2 solubility in the oil, while its effect is more significant at higher pressures. The swelling factor (SF) measurements showed an increasing trend with pressure up to a certain value so-called extraction pressure, at which, the SF started to be reduced even became less than one. The measurements of oil viscosity indicated that CO2 dissolution in the oil sample could reduce the mixture viscosity up to 61%. The interfacial tensions between CO2 and the crude oil at different pressures were also measured while the results were used to estimate the minimum miscibility pressure (MMP) and the first contact miscibility (FCM) pressure. The IFT measurements at various pressures displayed a reduction trend as a result of more CO2 dissolution in the oil but with two different slopes. That is, at lower pressure values, the measured IFTs were sharply reduced with pressure, while the reduction rate of the IFT became less when pressures exceeded the extraction pressure. This study helps with determining the optimum pressure and temperature conditions of CO2-oil systems to have a minimum IFT, a maximum CO2 solubility and SF, and a minimum oil viscosity that are favorable for CO2-enhanced oil recovery projects. Additionally, the methodology presented here gives guidelines on how to design PVT experiments of CO2-oil systems for petroleum and chemical engineering applications.
    Matched MeSH terms: Hot Temperature; Temperature
  17. Zainon SNM, Azmi WH
    Micromachines (Basel), 2021 Feb 11;12(2).
    PMID: 33670250 DOI: 10.3390/mi12020176
    Many studies have shown the remarkable enhancement of thermo-physical properties with the addition of a small quantity of nanoparticles into conventional fluids. However, the long-term stability of the nanofluids, which plays a significant role in enhancing these properties, is hard to achieve, thus limiting the performance of the heat transfer fluids in practical applications. The present paper attempts to highlight various approaches used by researchers in improving and evaluating the stability of thermal fluids and thoroughly explores various factors that contribute to the enhancement of the thermo-physical properties of mono, hybrid, and green nanofluids. There are various methods to maintain the stability of nanofluids, but this paper particularly focuses on the sonication process, pH modification, and the use of surfactant. In addition, the common techniques to evaluate the stability of nanofluids are undertaken by using visual observation, TEM, FESEM, XRD, zeta potential analysis, and UV-Vis spectroscopy. Prior investigations revealed that the type of nanoparticle, particle volume concentration, size and shape of particles, temperature, and base fluids highly influence the thermo-physical properties of nanofluids. In conclusion, this paper summarized the findings and strategies to enhance the stability and factors affecting the thermal conductivity and dynamic viscosity of mono and hybrid of nanofluids towards green nanofluids.
    Matched MeSH terms: Hot Temperature; Temperature
  18. Hanson SM, Mutebi JP, Craig GB, Novak RJ
    J Am Mosq Control Assoc, 1993 Mar;9(1):78-83.
    PMID: 8468578
    Eggs of temperate Aedes albopictus populations are cold hardy and can diapause, but tropical populations are not cold hardy and cannot diapause. Heterozygotes possess intermediate diapause and cold hardiness. Males of a tropical strain from Malaysia with a distinctive genetic marker were released into an existing temperate population in East St. Louis, Illinois. Subsequent egg samples from the release site had genetic marker frequency of up to 24%. Reduced cold hardiness and decreased diapause incidence were also observed in the release site population. No such changes occurred at a nearby control site. The rank order of overwintering survival of eggs at the release site was: Aedes triseriatus > temperate Ae. albopictus > hybrid temperate/tropical Ae. albopictus > tropical Ae. albopictus. Eggs collected from the release population the next summer showed total absence of the genetic marker; presumably carriers were removed by the winter.
    Matched MeSH terms: Cold Temperature*
  19. Umi Nadrah Amran, Farah Wahida Ahmad Zaiki
    MyJurnal
    Introduction: Doppler mode ultrasound is widely used in prenatal scanning and known to produce a higher acoustic
    output which later leads to higher heat energy conversion compared to other ultrasound modes. It has been reported
    that the use of Doppler imaging might increase the temperature of tissues, thus, when Doppler is used in combination with 2D ultrasound, the risks of bioeffects tend to increase more. It is also known that prolonged exposure to
    ultrasound during pregnancy can cause irreversible biological destructions to the fetus. Despite the benefits of using
    Doppler ultrasound, its potential adverse effects have received scant attention in the research literature. Therefore,
    this study aimed to examine a correlation between gestational stages (GS) and newborn rabbit’s body weight at different prenatal Doppler ultrasound exposure durations. Methods: Twelve pregnant New Zealand white rabbits (NZWR)
    were exposed once using three different Doppler ultrasound exposure durations (30, 60, 90 minutes exposure) at
    three different GSs (1st, 2nd, and 3rd GS). After delivery, the mean weights of the 62 newborns were statistically analysed. Results: Strong negative and positive correlation between newborn’s body weight at different GSs and Doppler
    ultrasound exposure durations with a significant result found in 60 minutes exposure (p =
    Matched MeSH terms: Hot Temperature; Temperature
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