Displaying publications 141 - 160 of 737 in total

Abstract:
Sort:
  1. Lim HP, Liew WYH, Melvin GJH, Jiang ZT
    Materials (Basel), 2021 Mar 29;14(7).
    PMID: 33805462 DOI: 10.3390/ma14071677
    This paper reviews the phase structures and oxidation kinetics of complex Ti-Al alloys at oxidation temperatures in the range of 600-1000 °C. The mass gain and parabolic rate constants of the alloys under isothermal exposure at 100 h (or equivalent to cyclic exposure for 300 cycles) is compared. Of the alloying elements investigated, Si appeared to be the most effective in improving the oxidation resistance of Ti-Al alloys at high temperatures. The effect of alloying elements on the mechanical properties of Ti-Al alloys is also discussed. Significant improvement of the mechanical properties of Ti-Al alloys by element additions has been observed through the formation of new phases, grain refinement, and solid solution strengthening.
    Matched MeSH terms: Hot Temperature
  2. Pramanik A, Basak AK, Littlefair G, Debnath S, Prakash C, Singh MA, et al.
    Heliyon, 2020 Dec;6(12):e05554.
    PMID: 33344787 DOI: 10.1016/j.heliyon.2020.e05554
    Titanium alloys are difficult to machine using conventional methods, therefore, nonconventional processes are often chosen in many applications. Electrical discharge machining (EDM) is one of those nonconventional processes that is used frequently for shaping titanium alloys with their respective pros and cons. However, a good understanding of this process is very difficult to achieve as research results are not properly connected and presented. Therefore, this study investigates different types of EDM processes such as, wire EDM, die-sink EDM, EDM drill and hybrid EDM used to machine titanium alloys. Machining mechanism, tool electrode, dielectric, materials removal rate (MRR), and surface integrity of all these processes are critically analysed and correlated based on the evidence accessible in literature. Machining process suffer from lower material removal rate and high tool wear while applied on titanium alloys. Formation of recast layer, heat affected zone and tool wear is common in all types of EDM processes. Additional challenge in wire EDM of titanium alloys is wire breakage under severe machining conditions. The formation of TiC and TiO2 are noticed in recast layer depending on the type of dielectrics. Removal of debris from small holes during EDM drilling is a challenge. All these restricts the applications EDMed titanium alloys in high-tech applications such as, aerospace and biomedical areas. Most of these challenges come up due to extraordinary properties such as, low thermal conductivity, high melting point and high hardness, of titanium alloys. Though hybrid EDM has been introduced and there is some work on simulation of EDM process, further developments in EDM of this alloy is required for widening the application of this methods.
    Matched MeSH terms: Hot Temperature
  3. Chieng BW, Ibrahim NA, Then YY, Loo YY
    Polymers (Basel), 2017 Jun 02;9(6).
    PMID: 30970882 DOI: 10.3390/polym9060204
    A renewable resource, epoxidized jatropha oil (EJO), was used as a green plasticizer and added to poly(lactic acid) (PLA). EJO was compounded into PLA at different contents. The addition of 3 wt % EJO to the PLA demonstrates significant improvement in flexibility, which leads to a percentage increase of about 7000% in elongation at break. This tensile result was confirmed by surface morphology analysis with clear proof of plastic deformation in EJO-plasticized PLA. EJO imparts a good heat stabilization effect. Thermal stability of PLA was enhanced upon addition of EJO, which is due to their good interaction and plasticizer dispersion within the PLA matrix. This EJO-plasticized PLA has wide applications in various industries, such as packaging of food and non-food products.
    Matched MeSH terms: Hot Temperature
  4. Lund LA, Omar Z, Khan I
    Heliyon, 2019 Mar;5(3):e01345.
    PMID: 30949601 DOI: 10.1016/j.heliyon.2019.e01345
    This study investigates the numerical solutions of MHD boundary layer and heat transfer of the Williamson fluid flow on the exponentially vertical shrinking sheet, having variable thickness and thermal conductivity under effects of the velocity and thermal slip parameters. It is also assumed that shrinking/stretching velocity, as well as the wall temperature, has the exponential function form. In this study, the continuity, momentum and energy equations with buoyancy parameter and Hartmann number are incorporated especially in the Williamson fluid flow case. Similarity transformation variables have been employed to formulate the ordinary differential equations (ODEs) from partial differential equations (PDEs). The resultant ODEs are solved by shooting method with Runge Kutta of fourth order method in Maple software. The effects of the different applied non-dimensional physical parameters on the boundary layer and heat transfer flow problems are presented in graphs. The effects of Williamson parameter, Prandtl number, and slip parameters on velocity and temperature profiles have been thoroughly demonstrated and discussed. The numerical results show that the buoyancy force and the slip parameters contribute to the occurrence of the dual solutions on the boundary layer and heat transfer flow problems. Furthermore, the stability analysis suggests that the first solution is stable and physically possible.
    Matched MeSH terms: Hot Temperature
  5. Liu C, Zhao M, Zheng Y, Cheng L, Zhang J, Tee CATH
    Langmuir, 2021 Jan 26;37(3):983-1000.
    PMID: 33443436 DOI: 10.1021/acs.langmuir.0c02758
    When two or more droplets coalesce on a superhydrophobic surface, the merged droplet can jump spontaneously from the surface without requiring any external energy. This phenomenon is defined as coalescence-induced droplet jumping and has received significant attention due to its potential applications in a variety of self-cleaning, anti-icing, antifrosting, and condensation heat-transfer enhancement uses. This article reviews the research and applications of coalescence-induced droplet jumping behavior in recent years, including the influence of droplet parameters on coalescence-induced droplet jumping, such as the droplet size, number, and initial velocity, to name a few. The main structure types and influence mechanism of the superhydrophobic substrates for coalescence-induced droplet jumping are described, and the potential application areas of coalescence-induced droplet jumping are summarized and forecasted.
    Matched MeSH terms: Hot Temperature
  6. Farawahida Abdul Halim, Jinap Selamat, Nor Khaizura Mahmud @ Ab Rashid, Chin, C. K., Nik Iskandar Putra Samsudin, Norlia, M.
    MyJurnal
    The aims of the present work were to determine the prevalence of Aspergillus spp. and occurrence of aflatoxins (AFs) along the peanut sauce processing line from different peanut sauce
    companies in Malaysia, and to determine to which extent peanut sauce processing steps
    employed by the peanut sauce industries could efficiently reduce AFs in peanut sauce. Peanut
    and chili samples were collected at each processing step along the peanut sauce production
    from three peanut sauce companies which were different in companies’ profile. Peanut
    samples from Companies B (87.5%) and C (100%) were contaminated with AFs. Of these,
    12.5% (Company B) and 75% (Company C) samples exceeded the Malaysian regulatory limit.
    None of the samples from Company A was contaminated. The steps efficient in reducing AFs
    in peanut sauce identified in the present work were (i) safety monitoring of raw materials, (ii)
    sorting of raw materials, and (iii) heat treatment of raw materials.
    Matched MeSH terms: Hot Temperature
  7. Lee JY, Saat M, Chou C, Hashiguchi N, Wijayanto T, Wakabayashi H, et al.
    J Therm Biol, 2010 Feb;35(2):70-76.
    PMID: 28799915 DOI: 10.1016/j.jtherbio.2009.11.002
    The purpose of this study was to investigate ethnic differences in cutaneous thermal sensation thresholds and the inter-threshold sensory zone between tropical (Malaysians) and temperate natives (Japanese). The results showed that (1) Malaysian males perceived warmth on the forehead at a higher skin temperature (Tsk) than Japanese males (p<0.05), whereas cool sensations on the hand and foot were perceived at a lower Tsk in Malaysians (p<0.05); (2) Overall, the sensitivity to detect warmth was greater in Japanese than in Malaysian males; (3) The most thermally sensitive body region of Japanese was the forehead for both warming and cooling, while the regional thermal sensitivity of Malaysians had a smaller differential than that of Japanese; (4) The ethnic difference in the inter-threshold sensory zone was particularly noticeable on the forehead (1.9±1.2C for Japanese, 3.2±1.6°C for Malaysians, p<0.05). In conclusion, tropical natives had a tendency to perceive warmth at a higher Tsk and slower at an identical speed of warming, and had a wider range of the inter-threshold sensory zone than temperate natives.
    Matched MeSH terms: Hot Temperature
  8. Raziff HHA, Tan D, Tan SH, Wong YH, Lim KS, Yeong CH, et al.
    Phys Med, 2021 Feb;82:40-45.
    PMID: 33581616 DOI: 10.1016/j.ejmp.2021.01.067
    PURPOSE: To investigate the efficacy of a newly-developed laser-heated core biopsy needle in the thermal ablation of biopsy tract to reduce hemorrhage after biopsy using in vivo rabbit's liver model.

    MATERIALS AND METHODS: Five male New Zealand White rabbits weighed between 1.5 and 4.0 kg were anesthetized and their livers were exposed. 18 liver biopsies were performed under control group (without tract ablation, n = 9) and study group (with tract ablation, n = 9) settings. The needle insertion depth (~3 cm) and rate of retraction (~3 mm/s) were fixed in all the experiments. For tract ablation, three different needle temperatures (100, 120 and 150 °C) were compared. The blood loss at each biopsy site was measured by weighing the gauze pads before and after blood absorption. The rabbits were euthanized immediately and the liver specimens were stained with hematoxylin-eosin (H&E) for further histopathological examination (HPE).

    RESULTS: The average blood loss in the study group was reduced significantly (p 

    Matched MeSH terms: Hot Temperature
  9. Teh, Chiew Peng, Tan, Aileen Shau Hwai, Vengatesen, Thiyagarajan
    Trop Life Sci Res, 2016;27(11):111-116.
    MyJurnal
    The influence of the cool and warm temperatures on early life development and
    survival of tropical oyster, Crassostrea iredalei was studied. D-hinged larvae (day 1 larvae)
    were reared to three different temperatures (20°C, 27°C, and 34°C) for nine days. Oyster
    larvae reared in temperature 27°C, acted as control (ambient temperature). The highest
    survival rate occurred when the larvae were reared in 20°C and 27°C. Larvae reared at
    34°C exhibited reduced survival but increase in the growth rate. The growth rate in larvae
    reared in high temperature (34°C) was significantly higher compared to larvae reared in
    20°C and 27°C (p
    Matched MeSH terms: Hot Temperature
  10. Li Y, Shaheen SM, Rinklebe J, Ma NL, Yang Y, Ashraf MA, et al.
    J Hazard Mater, 2021 08 15;416:126012.
    PMID: 34492887 DOI: 10.1016/j.jhazmat.2021.126012
    The rapid thermal cracking technology of biomass can convert biomass into bio-oil and is beneficial for industrial applications. Agricultural and forestry wastes are important parts of China's energy, and their high-grade utilization is useful to solve the problem of energy shortages and environmental pollution. To the best of our knowledge, the impact of nanocatalysts on converting biowastes for bio-oil has not been studied. Consequently, we examined the production of bio-oil by pyrolysis of Aesculus chinensis Bunge Seed (ACBS) using nanocatalysts (Fe2O3 and NiO catalysts) for the first time. The pyrolysis products of ACBS include 1-hydroxy-2-propanone (3.97%), acetic acid (5.42%), and furfural (0.66%). These chemical components can be recovered for use as chemical feedstock in the form of bio-oil, thus indicating the potential of ACBS as a feedstock to be converted by pyrolysis to produce value-added bio-oil. The Fe2O3 and NiO catalysts enhanced the pyrolysis process, which accelerated the precipitation of gaseous products. The pyrolysis rates of the samples gradually increased at DTGmax, effectively promoting the catalytic cracking of ACBS, which is beneficial to the development and utilization of ACBS to produce high valorization products. Combining ACBS and nanocatalysts can change the development direction of high valorization agricultural and forestry wastes in the future.
    Matched MeSH terms: Hot Temperature
  11. Lohrey S, Chua M, Gros C, Faucet J, Lee JKW
    Sci Total Environ, 2021 Nov 10;794:148260.
    PMID: 34328123 DOI: 10.1016/j.scitotenv.2021.148260
    Extreme heat is an increasing climate threat, most pronounced in urban areas where poor populations are at particular risk. We analyzed heat impacts and vulnerabilities of 1027 outdoor workers who participated in a KAP survey in Hanoi, Vietnam in 2018, and the influence of their mitigation actions, their knowledge of heat-risks, and access to early warnings. We grouped respondents by their main income (vendors, builders, shippers, others, multiple jobs, and non-working) and analyzed their reported heat-health impacts, taking into consideration socioeconomics, knowledge of heat impacts and preventive measures, actions taken, access to air-conditioning, drinking amounts and use of weather forecasts. We applied linear and logistic regression analyses using R. Construction workers were younger and had less knowledge of heat-health impacts, but also reported fewer symptoms. Older females were more likely to report symptoms and visit a doctor. Access to air-conditioning in the bedroom depended on age and house ownership, but did not influence heat impacts as cooling was too expensive. Respondents who knew more heat exhaustion symptoms were more likely to report impacts (p < 0.01) or consult a doctor (p < 0.05). Similarly, those who checked weather updates were more likely to report heat impacts (p < 0.01) and experienced about 0.6 more symptoms (p < 0.01). Even though occupation type did not explain heat illness, builders knew considerably less (40%; p < 0.05) about heat than other groups but were twice as likely to consult a doctor than street vendors (p < 0.01). Knowledge of preventive actions and taking these actions both correlated positively with reporting of heat-health symptoms, while drinking water did not reduce these symptoms (p < 0.01). Child carers and homeowners experienced income losses in heatwaves (p < 0.01). The differences support directed actions, such as dissemination of educational materials and weather forecasts for construction workers. The Red Cross assisted all groups with cooling tents, provision of drinks and health advice.
    Matched MeSH terms: Hot Temperature
  12. Luqman Chuah, A., Russly A.R., Keshani, S.
    MyJurnal
    Rheology is the science of deformation and flow behavior of fluid. Knowledge of rheological properties of fluid foods and their variation with temperature and concentration have been globally important for industrialization of food technology for quality, understanding the texture, process engineering application, correlation with sensory evaluation, designing of transport system , equipment design (heat exchanger and evaporator ), deciding pump capacity and power requirement for mixing. The aim of this study was to determine the rheological behavior of pomelo juice at different concentrations (20-60.4%) and temperatures (23-60°C) by using a rotational rotational Haake Rheostress 600 rheometer. Pomelo juice was found to exhibit both Newtonian and Non-Newtonian behavior. For lower concentration the Newtonian behavior is observed while at higher concentration Non-Newtonian behavior was observed. Standard error (SE) method was selected on the basis to carry out the error analysis due to the best fit model. For the four models the values of SE show that the Herschel-Bulkley and Power Law models perform better than the Bingham and Casson models but Herschel-Bulkley model is true at higher concentration. The rheological model of pomelo juice, incorporating the effects of concentration and temperature was developed. The master-curve was investigated for comparing data from different products at a reference temperature of 40°C. Multiple regression analysis indicated Master-Curve presents good agreement for pomelo juice at all concentrations studied with R2>0.8.
    Matched MeSH terms: Hot Temperature
  13. Lanyau, Tonny, Mohd Fazli Zakaria, Zaredah Hashim, Mohd Fairus Abdul Farid, Mohammad Suhaimi Kassim
    MyJurnal
    PUSPATI TRIGA Reactor (RTP) is the only nuclear research reactor in Malaysia. It has been safely operated and maintained since 28 June 1982. Over 28 years of operation, some of the reactor systems have been upgraded or replaced to ensure the functionality and safety of the reactor. One of the major reactor systems which is primary cooling system is used to remove heat generated in the reactor core. The former primary cooling system consisting of single unit of shell-and-tube heat exchanger, three centrifugal pumps and piping system was replaced with a new system due to decreasing of the cooling performance. The new primary cooling system, consisting of two units of the 1.5-MW plate-type heat exchangers, new three primary pumps and new piping system was installed in accordance to the specified AELB requirements and guidelines of Nuclear Malaysia Safety, Health and Environment Committee (JKSHE). This paper summarises the replacement process of the former RTP primary cooling system. The activities involved preparation before and during construction and installation phases as well as safety consideration based on International Atomic Energy Agency (IAEA), Atomic Energy Licensing Board (AELB) requirements and Occupational Health and Safety Act (Act 514) were discussed and evaluated.
    Matched MeSH terms: Hot Temperature
  14. Muhamat Omar, Zalina Laili, Julia Abdul Karim, Zarina Masood, Nik Marzukee Nik Ibrahim, Mohd Abd Wahab Yusof
    MyJurnal
    A study to assess the concentration of radionuclides in spent resins of the PUSPATI TRIGA Mark II reactor coolant purification system has been carried out. Fresh spent resins collected and analysed in May 2010, after the changing of leaked heat exchanger in Sept. 2009 was found to contain 24Na, 122Sb, 51Cr, 124Sb, 58Co, 65Zn, 54Mn and 60Co. Old spent resins removed in 2001 and 2002 but analysed in 2010 indicated the presence of 60Co and 152Eu as radionuclides with half-lives of < 1 year might have already been decayed out. These results can be used to establish radionuclide inventory of the spent resins as part of radiation protection programme.
    Matched MeSH terms: Hot Temperature
  15. Normah, I., Cheow, C.S., Chong, C.L.
    MyJurnal
    Refined bleached and deodorized palm oil (RBDPO) was crystallized from the melt in a thermally controlled water bath at 14 and 22°C for 90 min. Slurries were withdrawn after 5, 15, 30, 60 and 90 min of crystallization for crystal morphology studies. Crystallization was also performed in a similar manner using a Labmax reactor connected to a FBRM detector to obtain the information on crystal count and size distribution during crystallization. Based on the shape of the crystals viewed under the microscope, all crystals appeared as needle shaped spherulitic β´- form at both crystallization temperatures studied. Crystals were slightly larger with increase in crystallization time and at higher crystallization temperature (22°C). Crystals size range between 4.34 to 22.29µm. FBRM recorded high count of crystals with increased in crystallization time and at lower temperature (14°C).
    Matched MeSH terms: Hot Temperature
  16. Inada S, Shinagawa K, Illias SB, Sumiya H, Jalaludin HA
    Sci Rep, 2016 09 15;6:33454.
    PMID: 27628271 DOI: 10.1038/srep33454
    The miniaturization boiling (micro-bubble emission boiling [MEB]) phenomenon, with a high heat removal capacity that contributes considerably to the cooling of the divertor of the nuclear fusion reactor, was discovered in the early 1980s. Extensive research on MEB has been performed since its discovery. However, the progress of the application has been delayed because the generation mechanism of MEB remains unclear. Reasons for this lack of clarity include the complexity of the phenomenon itself and the high-speed phase change phenomenon in which boiling and condensation are rapidly generated. In addition, a more advanced thermal technique is required to realize the MEB phenomenon at the laboratory scale. To the authors' knowledge, few studies have discussed the rush mechanism of subcooled liquid to the heating surface, which is critical to elucidating the mechanism behind MEB. This study used photographic images to verify that the cavitation phenomenon spreads to the inside of the superheated liquid on the heating surface and thus clarify the mechanism of MEB.
    Matched MeSH terms: Hot Temperature
  17. Mohd. Adzahan, N., Benchamaporn, P.
    MyJurnal
    The application of non-thermal processing technology (NTP) is increasing within the food industry. The absence of heat in this technology offer some advantages such as the sensory and nutritional attributes of the product remaining unaffected, thus yielding products with better quality compared to traditional processing methods. Suitability of technology for a certain application varies according to the nature of the reason and the purpose for processing. Some NTP has long been used in the food industry in Southeast Asia, but most are still at the initial stage of research. Despite several existing challenges, these technologies have the potential to be taken up as an alternative to processing of value-added food products especially now when consumer and trade demands as well as economic strength in the region is changing.
    Matched MeSH terms: Hot Temperature
  18. Ullah I, Khan I, Shafie S
    Sci Rep, 2017 04 25;7(1):1113.
    PMID: 28442747 DOI: 10.1038/s41598-017-01205-5
    Unsteady mixed convection flow of Casson fluid towards a nonlinearly stretching sheet with the slip and convective boundary conditions is analyzed in this work. The effects of Soret Dufour, viscous dissipation and heat generation/absorption are also investigated. After using some suitable transformations, the unsteady nonlinear problem is solved by using Keller-box method. Numerical solutions for wall shear stress and high temperature transfer rate are calculated and compared with previously published work, an excellent arrangement is followed. It is noticed that fluid velocity reduces for both local unsteadiness and Casson parameters. It is likewise noticed that the influence of a Dufour number of dimensionless temperature is more prominent as compared to species concentration. Furthermore, the temperature was found to be increased in the case of nonlinear thermal radiation.
    Matched MeSH terms: Hot Temperature
  19. Cheng-Yong H, Yun-Ming L, Abdullah MM, Hussin K
    Sci Rep, 2017 03 27;7:45355.
    PMID: 28345643 DOI: 10.1038/srep45355
    This paper presents a comparative study of the characteristic of unfoamed and foamed geopolymers after exposure to elevated temperatures (200-800 °C). Unfoamed geopolymers were produced with Class F fly ash and sodium hydroxide and liquid sodium silicate. Porous geopolymers were prepared by foaming with hydrogen peroxide. Unfoamed geopolymers possessed excellent strength of 44.2 MPa and degraded 34% to 15 MPa in foamed geopolymers. The strength of unfoamed geopolymers decreased to 5 MPa with increasing temperature up to 800 °C. Foamed geopolymers behaved differently whereby they deteriorated to 3 MPa at 400 °C and increased up to 11 MPa at 800 °C. Even so, the geopolymers could withstand high temperature without any disintegration and spalling up to 800 °C. The formation of crystalline phases at higher temperature was observed deteriorating the strength of unfoamed geopolymers but enhance the strength of foamed geopolymers. In comparison, foamed geopolymer had better thermal resistance than unfoamed geopolymers as pores provide rooms to counteract the internal damage.
    Matched MeSH terms: Hot Temperature
  20. Talib, R.A., Nor, M.Z.M., Noranizan, M.A., Chin, N.L., Hashim, K.
    MyJurnal
    This work describes the effects of different cooking temperatures in repetitive cooking-chilling (RCC) process on resistant starch (RS) content in fish crackers prepared in a ratio of 1:1 fish to sago starch formulation. In this work, three sets of four RCC cycles were performed on fish crackers, in which each set was cooked at fixed temperatures of 100, 115 and 121°C, respectively. The chilling temperature was fixed at 4°C in all cases. Subjecting the fish crackers to a higher cooking temperature for up to 4 cycles of RCC can increase the RS content. However, quality degradation was observed in the characteristics of the fish crackers. During the first RCC cycle, cooking at a higher temperature had caused the crackers to crack and burst. Besides, defragmentation to the shape of the fish cracker gels was also observed during the first RCC cycle, coupled with softer texture and high moisture content. When the products were subjected to frying, their linear expansion decreased, the texture became harder and the colour turned darker. This work demonstrated that the application of higher cooking temperature up to 4 RCC cycles was able to enhance the RS content in the fish crackers, but it was less able to attain the product's perfect shape. On the contrary, fish crackers that were exposed to lower cooking temperatures contained lower RS but with less shape damage.
    Matched MeSH terms: Hot Temperature
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links