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Thermal and dynamic mechanical properties of cellulose nanofibers reinforced epoxy composites

Saba N, Safwan A, Sanyang ML, Mohammad F, Pervaiz M, Jawaid M, et al.

Int J Biol Macromol, 2017 Sep;102:822-828.
PMID: 28455253 DOI: 10.1016/j.ijbiomac.2017.04.074

The current study presents about the effect of cellulose nanofibers (CNFs) filler on the thermal and dynamic mechanical analysis (DMA) of epoxy composites as a function of temperature. In this study hand lay-up method was used to fabricate CNF reinforced Epoxy nanocomposites with CNF loading of 0.5%, 0.75%, and 1% into epoxy resin. The obtained thermal and DMA results illustrates that thermal stability, char content, storage modulus (E'), loss modulus (E") and glass transition temperature (Tg) increases for all CNF/epoxy nanocomposites compared to the pure epoxy. Thermal results revealed that 0.75% offers superior resistance or stability towards heat compared to its counterparts. In addition, 0.75% CNF/epoxy nanocomposites confers highest value of storage modulus as compared to 0.5% and 1% filler loading. Hence, it is concluded that 0.75% CNFs loading is the minimal to enhance both thermal and dynamic mechanical properties of the epoxy composites and can be utilized for advance material applications where thermal stability along with renewability are prime requirements.

Matched MeSH terms: Temperature*; Transition Temperature
Fulltext Analysis of cryostat for small angle neutron scattering at small research triga reactor by using computational fluid dynamic(CFD)

Azraf Azman, Mohd Rizal Mamat@Ibrahim, Anwar Abdul Rahman, Megat Harun Al Rashid Megat Ahmad, Abdul Aziz Mohamed, Muhammad Rawi Mohd Zin, et al.

Journal of Nuclear and Related Technologies, 2011;2011(2):1-7.
MyJurnal

The temperature profile of a cryogenic system for cooling of beryllium filter of a small-angle neutron scattering (SANS) instrument of TRIGA MARK II PUSPATI research reactor was investigated using computational fluid dynamics (CFD) modeling and simulation. The efficient cooling of beryllium filter is important for obtaining higher cold neutron transmission for the SANS instrument. This paper presents the transient CFD results of temperature distributions via the thermal link to the beryllium and simulation of heat
flux. The temperature simulation data are also compared with the experimental results for the cooling time and distribution to the beryllium.

Matched MeSH terms: Cold Temperature; Hot Temperature; Temperature
Fulltext Flat plate solar collectors and applications: a review

Bande, Y. M., Mariah, N. A.

Pertanika Journal of Science & Technology, 2014;22(2):365-385.
MyJurnal

In this study, various methods and applications of flat plate solar collectors are discussed and pictorial representations are presented. Low temperature applications of flat plate collectors are identified in solar cooking, solar water heating, space and air heating, industrial heating plants and in agricultural produce drying processes. Basic equations, as presented by many researchers in the performances of flat plate collectors, are also presented. The review discusses the analysis of losses from flat plate collectors towards obtaining the overall heat loss coefficient which indicate the performance of flat plate collectors.

Matched MeSH terms: Body Temperature Regulation; Cold Temperature; Temperature
Projected changes of future climate extremes in Malaysia

Meng Sei Kwan, Fredolin T. Tangang, Liew Juneng

Sains Malaysiana, 2013;42:1051-1059.

Mitigating and adapting to the impacts of climate change at regional level require downscaled projection of future climate states. This paper examined the possible changes of future climate extremes over Malaysia based on the IPCC SRES A1B emission scenario. The projected changes at 17 stations were produced by bias correcting the UKMO PRECIS downscaling simulation output. The simulation expected higher probability of rainfall extreme occurrences over the west coast of Peninsular Malaysia during the autumn transitional monsoon period. In addition, possible early monsoon rainfall was projected for certain stations located over East Malaysia. The simulation also projected larger increase of warm temperature extremes but smaller decrease of cold extremes, suggesting asymmetric expansion of the temperature distribution. The impact of the elevated green house gases (GHG) is higher in the night time temperature extremes as compared to the day time temperature extremes. The larger increment of warm night frequencies as compared to the warm day suggests smaller diurnal temperature ranges under the influence of higher greenhouse gases. Stations located in East Malaysia were projected to experience the largest increase of warm night occurrence.

Matched MeSH terms: Cold Temperature; Hot Temperature; Temperature
Effects of limited moisture content and storing temperature on retrogradation of rice starch

Ding L, Zhang B, Tan CP, Fu X, Huang Q

Int J Biol Macromol, 2019 Sep 15;137:1068-1075.
PMID: 31260761 DOI: 10.1016/j.ijbiomac.2019.06.226

The objective of this study is to investigate the effects of limited moisture content and storing temperature on the retrogradation of rice starch. Starch was gelatinized in various moisture contents (30-42%) and rice paste was stored at different temperatures (4 °C, 15 °C, 30 °C, -18/30 °C and 4/30 °C). X-ray diffraction (XRD) analysis revealed that after retrogradation, the crystalline type of rice starch changed from A-type to B + V type. The B-type crystallinity of retrograded rice starch under 30 °C was the highest among the five temperature conditions, and an increase in B-type crystallinity with increasing moisture content was observed. Differential scanning calorimetry (DSC) results revealed that rice starch retrogradation consists of recrystallization of amylopectin and amylose, and is mainly attributed to amylopectin. The higher moisture content was favorable for amylopectin recrystallization, whereas the moisture content had little effect on the amylose recrystallization. The optimal temperature for amylopectin and amylose recrystallization was 4 °C and 15 °C, respectively. The amylopectin recrystallization enthalpy of rice starch stored at 4/30 °C was mediated between 4 °C and 30 °C but always higher than that at -18/30 °C. On the whole, after being heated at 42% moisture content and stored at 4 °C, rice starch showed the maximum total retrogradation enthalpy (8.44 J/g).

Matched MeSH terms: Temperature*; Transition Temperature
Fulltext Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

Jamil SNAM, Daik R, Ahmad I

Materials (Basel), 2014 Sep 01;7(9):6207-6223.
PMID: 28788187 DOI: 10.3390/ma7096207

A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA) and FN were 55%-71%, 85%-91% and 76%-79%, respectively. It was found that with the same comonomer feed (10%), the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C). AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C). By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%). It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C). In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1%) and AN/EHA copolymer (38.0%).

Matched MeSH terms: Hot Temperature; Temperature; Transition Temperature
Fulltext Natural convection heat transfer in an oscillating vertical cylinder

Khan I, Ali Shah N, Tassaddiq A, Mustapha N, Kechil SA

PLoS One, 2018;13(1):e0188656.
PMID: 29304161 DOI: 10.1371/journal.pone.0188656

This paper studies the heat transfer analysis caused due to free convection in a vertically oscillating cylinder. Exact solutions are determined by applying the Laplace and finite Hankel transforms. Expressions for temperature distribution and velocity field corresponding to cosine and sine oscillations are obtained. The solutions that have been obtained for velocity are presented in the forms of transient and post-transient solutions. Moreover, these solutions satisfy both the governing differential equation and all imposed initial and boundary conditions. Numerical computations and graphical illustrations are used in order to study the effects of Prandtl and Grashof numbers on velocity and temperature for various times. The transient solutions for both cosine and sine oscillations are also computed in tables. It is found that, the transient solutions are of considerable interest up to the times t = 15 for cosine oscillations and t = 1.75 for sine oscillations. After these moments, the transient solutions can be neglected and, the fluid moves according with the post-transient solutions.

Matched MeSH terms: Hot Temperature*; Temperature
Thermo-Responsive Polymer-siRNA Conjugates Enabling Artificial Control of Gene Silencing around Body Temperature

Honda Y, Onodera S, Takemoto H, Harun NFC, Nomoto T, Matsui M, et al.

Pharm Res, 2023 Jan;40(1):157-165.
PMID: 36307662 DOI: 10.1007/s11095-022-03414-8

PURPOSE: Controlling small interfering RNA (siRNA) activity by external stimuli is useful to exert a selective therapeutic effect at the target site. This study aims to develop a technology to control siRNA activity in a thermo-responsive manner, which can be utilized even at temperatures close to body temperature.
METHODS: siRNA was conjugated with a thermo-responsive copolymer that was synthesized by copolymerization of N-isopropylacrylamide (NIPAAm) and hydrophilic N,N-dimethylacrylamide (DMAA) to permit thermally controlled interaction between siRNA and an intracellular gene silencing-related protein by utilizing the coil-to-globule phase transition of the copolymer. The composition of the copolymer was fine-tuned to obtain lower critical solution temperature (LCST) around body temperature, and the phase transition behavior was evaluated. The cellular uptake and gene silencing efficiency of the copolymer-siRNA conjugates were then investigated in cultured cells.
RESULTS: The siRNA conjugated with the copolymer with LCST of 38.0°C exhibited ~ 11.5 nm of the hydrodynamic diameter at 37°C and ~ 9.8 nm of the diameter at 41°C, indicating the coil-globule transition above the LCST. In line with this LCST behavior, its cellular uptake and gene silencing efficiency were enhanced when the temperature was increased from 37°C to 41°C.
CONCLUSION: By fine-tuning the LCST behavior of the copolymer that was conjugated with siRNA, siRNA activity could be controlled in a thermo-responsive manner around the body temperature. This technique may offer a promising approach to induce therapeutic effects of siRNA selectively in the target site even in the in vivo conditions.

Matched MeSH terms: Body Temperature*; Temperature
Durability of induced heat tolerance by short-term heat challenge at broilers marketing age

Soleimani AF, Kasim A, Alimon AR, Zulkifli I

Pak J Biol Sci, 2008 Sep 01;11(17):2163-6.
PMID: 19266934

A trial was conducted to determine the influence of short-term exposure to high ambient temperature at 28 and 35 days of age on deep body temperatures (Tb) and subsequent growth of birds until 42 days of age. A total of 90 day old chicks were reared in stainless steel battery cages and were assigned at random into 18 pens of 5 birds each, with 9 pens containing males and another 9 pens containing females. Three treatment groups, each represented by 3 male and 3 female pens, were represented by T1 without any heat exposure, T2 with heat exposure starting at day 28 and T3 with heat exposure starting at day 35. Heat stress was defined as 180 min exposure to 35 +/- 1 degrees C. Tb and body weights were measured at 35, 37 and 39 days of age immediately following heat exposure. Heat stress resulted in higher Tb and Onset of heat stress at 28 days resulted in significantly lower Tb than onset of heat stress at 35 days. Lower Tb in T2 than T3 permitted recovery in body weight at 42 days. Sexes responded similarly to heat stress.

Matched MeSH terms: Body Temperature Regulation/physiology*; Hot Temperature*
Fulltext Seed/Catalyst-Free Growth of Gallium-Based Compound Materials on Graphene on Insulator by Electrochemical Deposition at Room Temperature

Rashiddy Wong F, Ahmed Ali A, Yasui K, Hashim AM

Nanoscale Res Lett, 2015 Dec;10(1):943.
PMID: 26055478 DOI: 10.1186/s11671-015-0943-y

We report the growth of gallium-based compounds, i.e., gallium oxynitride (GaON) and gallium oxide (Ga2O3) on multilayer graphene (MLG) on insulator using a mixture of ammonium nitrate (NH4NO3) and gallium nitrate (Ga(NO3)3) by electrochemical deposition (ECD) method at room temperature (RT) for the first time. The controlling parameters of current density and electrolyte molarity were found to greatly influence the properties of the grown structures. The thicknesses of the deposited structures increase with the current density since it increases the chemical reaction rates. The layers grown at low molarities of both solutions basically show grain-like layer with cracking structures and dominated by both Ga2O3 and GaON. Such cracking structures seem to diminish with the increases of molarities of one of the solutions. It is speculated that the increase of current density and ions in the solutions helps to promote the growth at the area with uneven thicknesses of graphene. When the molarity of Ga(NO3)3 is increased while keeping the molarity of NH4NO3 at the lowest value of 2.5 M, the grown structures are basically dominated by the Ga2O3 structure. On the other hand, when the molarity of NH4NO3 is increased while keeping the molarity of Ga(NO3)3 at the lowest value of 0.8 M, the GaON structure seems to dominate where their cubic and hexagonal arrangements are coexisting. It was found that when the molarities of Ga(NO3)3 are at the high level of 7.5 M, the grown structures tend to be dominated by Ga2O3 even though the molarity of NH4NO3 is made equal or higher than the molarity of Ga(NO3)3. When the grown structure is dominated by the Ga2O3 structure, the deposition process became slow or unstable, resulting to the formation of thin layer. When the molarity of Ga(NO3)3 is increased to 15 M, the nanocluster-like structures were formed instead of continuous thin film structure. This study seems to successfully provide the conditions in growing either GaON-dominated or Ga2O3-dominated structure by a simple and low-cost ECD. The next possible routes to convert the grown GaON-dominated structure to either single-crystalline GaN or Ga2O3 as well as Ga2O3-dominated structure to single-crystalline Ga2O3 structure have been discussed.

Matched MeSH terms: Temperature
Barium(II)-2,4-dinitrophenolate-18-crown-6 at 183 K

Usman A, Chantrapromma S, Fun HK

Acta Crystallogr C, 2002 Jan;58(Pt 1):m45-7.
PMID: 11781470

The title compound, bis(2,4-dinitrophenolato-kappa2O,O')(1,4,7,10,13,16-hexaoxadecane-kappa6O)barium(II), [Ba(C6H3N2O5)2(C12H24O6)], is a 1:1 complex of barium(II)-2,4-dinitrophenolate and 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6). Its structure is located on a crystallographic inversion centre. The temperature dependence of the crystal structure has been studied. The monoclinic beta angle of the P2(1)/n space group increases with increasing temperature. The packing structure of the complex is stabilized by intermolecular C-H...O interactions.

Matched MeSH terms: Temperature
Destructive heat and cooling prayer: Malay humoralism in pregnancy, childbirth and the postpartum period

Laderman C

Soc Sci Med, 1987;25(4):357-65.
PMID: 3686085 DOI: 10.1016/0277-9536(87)90274-7

Malaya, an ancient crossroads of trade, was the recipient of Chinese and Ayurvedic humoral ideas and, later, those of medieval Islam. These ideas were readily accepted by Malays, since they are highly congruent with pre-existing notions among aboriginal peoples of Malaya involving a hot-cold opposition in the material and spiritual universe and its effects upon human health. Islamic Malays have adapted these aboriginal beliefs to correspond to the Greek-Arabic humoral model in matters concerning foods, diseases, and medicines. Although Malay theories of disease causation include such concepts as soul loss and spirit attack, along with 'naturalistic' ideas such as dietary imbalance and systemic reactions to foods, all of these theories can either be reinterpreted in humoral terms, or, at least, are congruent with the basic tenets of Islamic humoral pathology. Behaviors and beliefs regarding human reproduction, however, while essentially following a humoral pattern, diverge from Islamic, as well as traditional Chinese and Indian Ayurvedic, humoral theories. Unlike any other major humoral doctrine, Malay reproductive theory (like that of non-Islamic aboriginal peoples of Malaya) equates coldness with health and fertility and heat with disease and sterility. These ideas, in turn, are related to beliefs regarding the nature of the spirit world: the destructiveness of spiritual heat and the efficacy of cooling prayer.

Matched MeSH terms: Cold Temperature*; Hot Temperature*
Removal and recovery attempt of liquid crystal from waste LCD panels using subcritical water

Izhar S, Yoshida H, Nishio E, Utsumi Y, Kakimori N

Waste Manag, 2019 Jun 01;92:15-20.
PMID: 31160022 DOI: 10.1016/j.wasman.2019.04.060

With the advancement of the fourth industrial revolution, the demand for LCD has widely accelerated as monitoring screens for computers and cell phones. Consequently, old LCD panels are expected to end up as a tremendous amount of e-waste. Apart from transparent electrodes and transistor, waste LCD panel also contains hazardous liquid crystal compound that can contaminate the landfill site. Thus, removing the material from waste LCD was investigated. In this study, water at subcritical state was applied at temperatures between 100 and 360 °C. Initially, the liquid crystals were extracted using toluene and were used to compare with subcritical water. The specific compounds of the liquid crystals were not identified. The liquid crystals (12 mg/g-LCD) were entirely removed from the LCD panel when treated above 300 °C by means of extraction with the subcritical water. Although liquid crystal was successfully removed, recovery was complicated due to the degradation of liquid crystals above 250 °C. A recovery of 70% was obtained at 250 °C without deformation of the molecules. Consequently, this study has shown that although it is not practical to recover LC from LCD panel waste using subcritical water, liquid crystals can be removed efficiently. This method is auspicious in reducing hazardous liquid crystal from waste LCD panel before their disposals at landfill sites.

Matched MeSH terms: Temperature
A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent

Samsudin MH, Hassan MA, Idris J, Ramli N, Mohd Yusoff MZ, Ibrahim I, et al.

Waste Manag Res, 2019 May;37(5):551-555.
PMID: 30727859 DOI: 10.1177/0734242X18823953

A one-step self-sustained carbonization of coconut shell biomass, carried out in a brick reactor at a relatively low temperature of 300-500°C, successfully produced a biochar-derived adsorbent with 308 m2/g surface area, 2 nm pore diameter, and 0.15 cm3/g total pore volume. The coconut shell biochar qualifies as a nano-adsorbent, supported by scanning electron microscope images, which showed well-developed nano-pores on the surface of the biochar structure, even though there was no separate activation process. This is the first report whereby coconut shell can be converted to biochar-derived nano-adsorbent at a low carbonization temperature, without the need of the activation process. This is superior to previous reports on biochar produced from oil palm empty fruit bunch.

Matched MeSH terms: Temperature
The influence of atmospheric electrical factors on the healthy and sick man

de Langen CD

Malayan Medical Journal, 1934;9:1-10.

Matched MeSH terms: Temperature
Fulltext Microstrain, particle size and lattice constant of CaCO3 ceramic by Rietveld analysis

Irzaman, Jamal, Z., Idris, M.S., Kurnia, D., Barmawi, M.

Journal of Nuclear and Related Technologies, 2007;2005(1):43-46.
MyJurnal

The specimens used were CaCO3 (Sigma Aldrich, purity 99.9 %). We have 23 parameters and 20 iterations, including two theta zero error, scale factor, thermal effect, coefficients for polynomial describing the background; U, V, W and mixing parameters of the profile peak function, lattice constants, positional parameters and overall isotropic temperature factors. Most the samples show that the crystal structure are rhombohedral with lattice constants a = b = 4.981 Å, c = 17.044 Å and space group is R3C. The microstrain (K) and the particle size (V) of CaCO3 ceramic were calculated using 10 the full width at half maximum (FWHM) of diffraction peaks from (0 1 2), (1 0 4), (0 0 6), (1 1 0), (1 1 3), (2 0 2), (0 1 8), (1 1 6), (2 2 1 ), (1 2 2) crystal planes are 2.1 x 10-2 and
362 nm, respectively.

Matched MeSH terms: Temperature
Fulltext Influence of calcination parameters on CaCu3Ti4O12 formation and its microstructure

Julie Juliewatty Mohamed, Mohd Riduan, Hutagalung, Sabar Derita, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2007;2007(1):171-176.
MyJurnal

Dielectric material CaCu3Ti4O12 (CCTO) prepared by solid state technique, was calcined at different temperatures (700 - 1000 o C) for 6 and 12 hours. The calcined powder were analysed by XRD to identify the CCTO formation. Then the microstructure was observed by SEM. The CCTO single phase formation was firstly detected on sample calcined at 700 o C for 12 hours. The microstructure obtained shows the particles were spherical in shape. The grain getting larger as calcination temperature was increased.

Matched MeSH terms: Temperature
Fulltext Intermetallic phase formation and thickness of tin-zinc based lead-free solders

Mayappan, Ramani, Ahmad Badri Ismail, Zainal Arifin Ahmad, Hussain, Luay Bakir, Ariga, Tadashi

Journal of Nuclear and Related Technologies, 2007;2007(1):143-148.
MyJurnal

In this study the intermetallic (IMC) thickness of Sn-Pb, Sn-Zn and Sn-Zn-Bi solders on copper (Cu) substrate were measured at different temperatures using reflow methods. Cu6Sn5 intermetallic phase was detected between Sn-Pb solder and Cu substrate. The J-Cu5Zn8 phase was detected between Sn-Zn and Sn-Zn-Bi lead-free solders with Cu substrate. The thickness of the intermetallics increases with temperature. The IMC thickness for Sn-8Zn-3Bi solder is lower than Sn-9Zn solder for all the soldering temperatures, indicating that Bi has suppressed the initial IMC formation.

Matched MeSH terms: Temperature
Fulltext Study of CNG combustion under internal combustion engines conditions part I: using quasi-dimensional modelling

Bakhshan, Y., Shahrir Abdullah

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

An in-house quasi-dimensional code has been developed which simulate the overlap, intake, compression, combustion, as well as expansion and exhaust processes of a homogeneous charged internal combustion engine (ICE). A detailed chemical kinetic mechanism, constituting of 39 species and 148 elementary reactions, has been used in conjunction with above code to study the combustion of CNG under IC engine conditions. Two different criteria, based on pressure rise and mass of fuel burned, are used to detect the onset of ignition. Parametric studies are conducted to show the effect of compression ratio, initial pressure, intake temperature and equivalence ratio, on the time of ignition and fuel burning rate. The results obtained from the modelling show a good agreement with the experimental data.

Matched MeSH terms: Temperature
Fulltext Optimisation of Biomethane production by anaerobic digestion of food waste

Nurul Shahida Osman, Zainon Mohd Noor, Zatilfarihiah Rasdi, Iwana Izni Zainuddin, Noor Azrimi Umor

Pertanika Journal of Science & Technology, 2017;25(107):101-110.
MyJurnal

Food waste is a mixture of organic residues that affect fermentation process. Thus, appropriate parameters should be optimised to ensure high biomethane production. In this research, response surface methodology (RSM) was utilised for building models, evaluating the significance of several independent factors (pH, temperature, substrate concentration and inocula size) and determining optimum conditions for desirable responses (biomethane yield). The RSM and contour plots set the optimum working factors in order to accomplish the desired biomethane yield. Results suggest that biomethane yield can be increased when pH and temperature are increased. Thus, the main effects of parameters are pH and temperature.

Matched MeSH terms: Temperature

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