Displaying publications 1 - 20 of 747 in total

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  1. Mehrnoush A, Mustafa S, Yazid AM
    Molecules, 2011 Dec 08;16(12):10202-13.
    PMID: 22158589 DOI: 10.3390/molecules161210202
    A 'Heat treatment aqueous two phase system' was employed for the first time to purify serine protease from kesinai (Streblus asper) leaves. In this study, introduction of heat treatment procedure in serine protease purification was investigated. In addition, the effects of different molecular weights of polyethylene glycol (PEG 4000, 6000 and 8000) at concentrations of 8, 16 and 21% (w/w) as well as salts (Na-citrate, MgSO₄ and K₂HPO₄) at concentrations of 12, 15, 18% (w/w) on serine protease partition behavior were studied. Optimum conditions for serine protease purification were achieved in the PEG-rich phase with composition of 16% PEG6000-15% MgSO₄. Also, thermal treatment of kesinai leaves at 55 °C for 15 min resulted in higher purity and recovery yield compared to the non-heat treatment sample. Furthermore, this study investigated the effects of various concentrations of NaCl addition (2, 4, 6 and 8% w/w) and different pH (4, 7 and 9) on the optimization of the system to obtain high yields of the enzyme. The recovery of serine protease was significantly enhanced in the presence of 4% (w/w) of NaCl at pH 7.0. Based on this system, the purification factor was increased 14.4 fold and achieved a high yield of 96.7%.
    Matched MeSH terms: Hot Temperature*
  2. Lee BQ, Khor SM
    Compr Rev Food Sci Food Saf, 2015 Jan;14(1):48-66.
    PMID: 33401813 DOI: 10.1111/1541-4337.12120
    Soy sauce, a dark-colored seasoning, is added to enhance the sensory properties of foods. Soy sauce can be consumed as a condiment or added during the preparation of food. There are 3 types of soy sauce: fermented, acid-hydrolyzed vegetable protein (acid- HVP), and mixtures of these. 3-Chloropropane-1,2-diol (3-MCPD) is a heat-produced contaminants formed during the preparation of soy sauce and was found to be a by-product of acid-HVP-produced soy sauce in 1978. 3-MCPD has been reported to be carcinogenic, nephrotoxic, and reproductively toxic in laboratory animal testing and has been registered as a chemosterilant for rodent control. 3-MCPD is classified as a possible carcinogenic compound, and the maximum tolerated limit in food has been established at both national and international levels. The purpose of this review is to provide an overview on the detection of 3-MCPD in soy sauce, its toxic effects, and the potential methods to reduce its concentration, especially during the production of acid-HVP soy sauce. The methods of quantification are also critically reviewed with a focus on efficiency, suitability, and challenges encountered in analysis.
    Matched MeSH terms: Hot Temperature
  3. Wang D, Wong SI, Sunarso J, Xu M, Wang W, Ran R, et al.
    ACS Appl Mater Interfaces, 2021 May 05;13(17):20105-20113.
    PMID: 33886260 DOI: 10.1021/acsami.1c02502
    Hydrocarbon-fueled solid oxide fuel cells (SOFCs) that can operate in the intermediate temperature range of 500-700 °C represent an attractive SOFC device for combined heat and power applications in the industrial market. One of the ways to realize such a device relies upon exploiting an in situ steam reforming process in the anode catalyzed by an anti-carbon coking catalyst. Here, we report a new Ni and Ru bimetal-doped perovskite catalyst, Ba(Zr0.1Ce0.7Y0.1Yb0.1)0.9Ni0.05Ru0.05O3-δ (BZCYYbNRu), with enhanced catalytic hydrogen production activity on n-butane (C4H10), which can resist carbon coking over extended operation durations. Ru in the perovskite lattice inhibits Ni precipitation from perovskite, and the high water adsorption capacity of proton conducting perovskite improves the coking resistance of BZCYYbNRu. When BZCYYbNRu is used as a steam reforming catalyst layer on a Ni-YSZ-supported anode, the single fuel cell not only achieves a higher power density of 1113 mW cm-2 at 700 °C under a 10 mL min-1 C4H10 continuous feed stream at a steam to carbon (H2O/C) ratio of 0.5 but also shows a much better operational stability for 100 h at 600 °C compared with those reported in the literature.
    Matched MeSH terms: Hot Temperature
  4. Chuo SC, Nasir HM, Mohd-Setapar SH, Mohamed SF, Ahmad A, Wani WA, et al.
    Crit Rev Anal Chem, 2020 Sep 20.
    PMID: 32954795 DOI: 10.1080/10408347.2020.1820851
    Naturally active compounds are usually contained inside plants and materials thereof. Thus, the extraction of the active compounds from plants needs appropriate extraction methods. The commonly employed extraction methods are mostly based on solid-liquid extraction. Frequently used conventional extraction methods such as maceration, heat-assisted extraction, Soxhlet extraction, and hydrodistillation are often criticized for large solvent consumption and long extraction times. Therefore, many advanced extraction methods incorporating various technologies such as ultrasound, microwaves, high pressure, high voltage, enzyme hydrolysis, innovative solvent systems, adsorption, and mechanical forces have been studied. These advanced extraction methods are often better than conventional methods in terms of higher yields, higher selectivity, lower solvent consumption, shorter processing time, better energy efficiency, and potential to avoid organic solvents. They are usually designed to be greener, more sustainable, and environment friendly. In this review, we have critically described recently developed extraction methods pertaining to obtaining active compounds from plants and materials thereof. Main factors that affect the extraction performances are tuned, and extraction methods are chosen in line with the properties of targeted active compounds or the objectives of extraction. The review also highlights the advancements in extraction procedures by using combinations of extraction methods to obtain high overall yields or high purity extracts.
    Matched MeSH terms: Hot Temperature
  5. Arris FA, Thai VTS, Manan WN, Sajab MS
    Foods, 2020 Nov 29;9(12).
    PMID: 33260330 DOI: 10.3390/foods9121769
    Process-based contaminants in food-particularly in vegetable oils-have been a topic of interest due to their potential health risk on humans. Oral consumption above the tolerable daily intake might result in health risks. Therefore, it is critical to correctly address the food contaminant issues with a proper mitigation plan, in order to reduce and subsequently remove the occurrence of the contaminant. 3-monochloropropane-1,3-diol (3-MCPD), an organic chemical compound, is one of the heat- and process-induced food contaminants, belonging to a group called chloropropanols. This review paper discusses the occurrence of the 3-MCPD food contaminant in different types of vegetable oils, possible 3-MCPD formation routes, and also methods of reduction or removal of 3-MCPD in its free and bound esterified forms in vegetable oils, mostly in palm oil due to its highest 3-MCPD content.
    Matched MeSH terms: Hot Temperature
  6. 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
  7. Henna Lu, F.S., Tan, P.P
    MyJurnal
    This aim of this research is to investigate thermal stability of virgin coconut oil, (VCO) which was heated at 190°C upon 40 days storage as compared to extra virgin olive oil (EVOO). The changes in fatty acids composition through (GC), Fourier Transform Infrared (FTIR) spectra, iodine value (IV) and total phenolic content were determined throughout the period of study. Results from GC showed that there was significant changes (P
    Matched MeSH terms: Hot Temperature
  8. Taufiq-Yap, Y. H., Ong, P. S., Zainal, Z.
    MyJurnal
    In this work, 10 mol% yttrium-doped ceria powders, Ce0.9Y0.1O1.95, were synthesised using a new mechanical technique, mechanochemical reaction, in which both impact action and shearing forces were applied for efficient fine grinding, subsequently leading to higher homogeneity of the resultant powders. Ce0.9Y0.1O1.95 prepared using this new technique was systematically compared with a sample of the same prepared using conventional solid-state methodology. X-ray diffraction analysis showed all prepared samples were single phase with a cubic fluorite structure. Generally, Y2O3-doped CeO2 electrolytes prepared by mechanochemical reactions were stable at a lower temperature (1100 °C) compared with a sample of the same synthesised using the conventional solid-state method. Characterisations using differential thermal analysis (DTA) and thermogravimetric analysis (TGA) showed no thermal changes and phase transitions, indicating all materials were thermally stable. The electrical properties of the samples investigated by AC impedance spectroscopy in the temperature range 200–800 ˚C are presented and discussed. Scanning electron microscopy (SEM) was used to study the morphology of the materials. Fine-grained powders with uniform grain-size distribution were obtained from the mechanochemical reaction.
    Matched MeSH terms: Hot Temperature
  9. Wakabayashi H, Wijayanto T, Lee JY, Hashiguchi N, Saat M, Tochihara Y
    PMID: 24490869 DOI: 10.1186/1880-6805-33-5
    This study investigated the effect of hydration differences on body fluid and temperature regulation between tropical and temperate indigenes exercising in the heat.
    Matched MeSH terms: Hot Temperature
  10. Sadeghinezhad E, Kazi SN, Dahari M, Safaei MR, Sadri R, Badarudin A
    Crit Rev Food Sci Nutr, 2015;55(12):1724-43.
    PMID: 24731003 DOI: 10.1080/10408398.2012.752343
    Heat exchanger performance degrades rapidly during operation due to formation of deposits on heat transfer surfaces which ultimately reduces service life of the equipment. Due to scaling, product deteriorates which causes lack of proper heating. Chemistry of milk scaling is qualitatively understood and the mathematical models for fouling at low temperatures have been produced but the behavior of systems at ultra high temperature processing has to be studied further to understand in depth. In diversified field, the effect of whey protein fouling along with pressure drop in heat exchangers were conducted by many researchers. Adding additives, treatment of heat exchanger surfaces and changing of heat exchanger configurations are notable areas of investigation in milk fouling. The present review highlighted information about previous work on fouling, influencing parameters of fouling and its mitigation approach and ends up with recommendations for retardation of milk fouling and necessary measures to perform the task.
    Matched MeSH terms: Hot Temperature*
  11. Cheong JKK, Yap S, Ooi ET, Ooi EH
    Comput Methods Programs Biomed, 2019 Jul;176:17-32.
    PMID: 31200904 DOI: 10.1016/j.cmpb.2019.04.028
    BACKGROUND AND OBJECTIVES: Recently, there have been calls for RFA to be implemented in the bipolar mode for cancer treatment due to the benefits it offers over the monopolar mode. These include the ability to prevent skin burns at the grounding pad and to avoid tumour track seeding. The usage of bipolar RFA in clinical practice remains uncommon however, as not many research studies have been carried out on bipolar RFA. As such, there is still uncertainty in understanding the effects of the different RF probe configurations on the treatment outcome of RFA. This paper demonstrates that the electrode lengths have a strong influence on the mechanics of bipolar RFA. The information obtained here may lead to further optimization of the system for subsequent uses in the hospitals.

    METHODS: A 2D model in the axisymmetric coordinates was developed to simulate the electro-thermophysiological responses of the tissue during a single probe bipolar RFA. Two different probe configurations were considered, namely the configuration where the active electrode is longer than the ground and the configuration where the ground electrode is longer than the active. The mathematical model was first verified with an existing experimental study found in the literature.

    RESULTS: Results from the simulations showed that heating is confined only to the region around the shorter electrode, regardless of whether the shorter electrode is the active or the ground. Consequently, thermal coagulation also occurs in the region surrounding the shorter electrode. This opened up the possibility for a better customized treatment through the development of RF probes with adjustable electrode lengths.

    CONCLUSIONS: The electrode length was found to play a significant role on the outcome of single probe bipolar RFA. In particular, the length of the shorter electrode becomes the limiting factor that influences the mechanics of single probe bipolar RFA. Results from this study can be used to further develop and optimize bipolar RFA as an effective and reliable cancer treatment technique.

    Matched MeSH terms: Hot Temperature*
  12. Adam SK, Das S, Jaarin K
    Int J Exp Pathol, 2009 Jun;90(3):321-7.
    PMID: 19563614 DOI: 10.1111/j.1365-2613.2009.00658.x
    Hypercholesterolaemia, increase in lipid peroxidation and hyperhomocysteinaemia may contribute to the pathogenesis of atherosclerosis. This study was performed to examine the effects of repeatedly heated palm oil mixed with 2% cholesterol diet on atherosclerosis in oestrogen-deficient postmenopausal rats. Ovariectomy causes disruption of tunica intima layer of the rat aorta simulating a postmenopausal condition in females. Twenty-four ovariectomized female Sprague-Dawley rats were divided into four groups. The control group received 2% cholesterol diet without palm oil. A diet with 2% cholesterol content fortified with fresh, once-heated and five-times-heated palm oil was given to the other treatment groups. The rats were sacrificed at the end of 4 months of study and the aortic arch tissue was processed for histomorphometry and electron microscopy. On observation, there was disruption of the intimal layer of the ovariectomized rat aorta. There was no obvious ultrastructural change in the aorta of the rats fed with fresh palm oil. The ultrastructural changes were minimal with once-heated palm oil, in which there was a focal disruption of the endothelial layer. The focal disruption was more pronounced with five-times-heated palm oil. The results of this study show that the ingestion of fresh palm oil may have a protective effect on the aorta but such a protective action may be lost when the palm oil is repeatedly heated. The study may be clinically important for all postmenopausal women who are susceptible to atherosclerosis.
    Matched MeSH terms: Hot Temperature
  13. Al-Hada NM, Saion EB, Shaari AH, Kamarudin MA, Flaifel MH, Ahmad SH, et al.
    PLoS One, 2014;9(8):e103134.
    PMID: 25093752 DOI: 10.1371/journal.pone.0103134
    A facile thermal-treatment route was successfully used to synthesize ZnO nanosheets. Morphological, structural, and optical properties of obtained nanoparticles at different calcination temperatures were studied using various techniques. The FTIR, XRD, EDX, SEM and TEM images confirmed the formation of ZnO nanosheets through calcination in the temperature between 500 to 650 °C. The SEM images showed a morphological structure of ZnO nanosheets, which inclined to crumble at higher calcination temperatures. The XRD and FTIR spectra revealed that the samples were amorphous at 30 °C but transformed into a crystalline structure during calcination process. The average particle size and degree of crystallinity increased with increasing calcination temperature. The estimated average particle sizes from TEM images were about 23 and 38 nm for the lowest and highest calcination temperature i.e. 500 and 650 °C, respectively. The optical properties were determined by UV-Vis reflection spectrophotometer and showed a decrease in the band gap with increasing calcination temperature.
    Matched MeSH terms: Hot Temperature*
  14. Sadri R, Hosseini M, Kazi SN, Bagheri S, Abdelrazek AH, Ahmadi G, et al.
    J Colloid Interface Sci, 2018 Jan 01;509:140-152.
    PMID: 28898734 DOI: 10.1016/j.jcis.2017.07.052
    In this study, we synthesized covalently functionalized graphene nanoplatelet (GNP) aqueous suspensions that are highly stable and environmentally friendly for use as coolants in heat transfer systems. We evaluated the heat transfer and hydrodynamic properties of these nano-coolants flowing through a horizontal stainless steel tube subjected to a uniform heat flux at its outer surface. The GNPs functionalized with clove buds using the one-pot technique. We characterized the clove-treated GNPs (CGNPs) using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). We then dispersed the CGNPs in distilled water at three particle concentrations (0.025, 0.075 and 0.1wt%) in order to prepare the CGNP-water nanofluids (nano-coolants). We used ultraviolet-visible (UV-vis) spectroscopy to examine the stability and solubility of the CGNPs in the distilled water. There is significant enhancement in thermo-physical properties of CGNPs nanofluids relative those for distilled water. We validated our experimental set-up by comparing the friction factor and Nusselt number for distilled water obtained from experiments with those determined from empirical correlations, indeed, our experimental set-up is reliable and produces results with reasonable accuracy. We conducted heat transfer experiments for the CGNP-water nano-coolants flowing through the horizontal heated tube in fully developed turbulent condition. Our results are indeed promising since there is a significant enhancement in the Nusselt number and convective heat transfer coefficient for the CGNP-water nanofluids, with only a negligible increase in the friction factor and pumping power. More importantly, we found that there is a significant increase in the performance index, which is a positive indicator that our nanofluids have potential to substitute conventional coolants in heat transfer systems because of their overall thermal performance and energy savings benefits.
    Matched MeSH terms: Hot Temperature
  15. Onwude DI, Hashim N, Chen G, Putranto A, Udoenoh NR
    J Sci Food Agric, 2021 Jan 30;101(2):398-413.
    PMID: 32627847 DOI: 10.1002/jsfa.10649
    BACKGROUND: Combined infrared (CIR) and convective drying is a promising technology in dehydrating heat-sensitive foods, such as fruits and vegetables. This novel thermal drying method, which involves the application of infrared energy and hot air during a drying process, can drastically enhance energy efficiency and improve overall product quality at the end of the process. Understanding the dynamics of what goes on inside the product during drying is important for further development, optimization, and upscaling of the drying method. In this study, a multiphase porous media model considering liquid water, gases, and solid matrix was developed for the CIR and hot-air drying (HAD) of sweet potato slices in order to capture the relevant physics and obtain an in-depth insight on the drying process. The model was simulated using Matlab with user-friendly graphical user interface for easy coupling and faster computational time.

    RESULTS: The gas pressure for CIR-HAD was higher centrally and decreased gradually towards the surface of the product. This implies that drying force is stronger at the product core than at the product surface. A phase change from liquid water to vapour occurs almost immediately after the start of the drying process for CIR-HAD. The evaporation rate, as expected, was observed to increase with increased drying time. Evaporation during CIR-HAD increased with increasing distance from the centreline of the sample surface. The simulation results of water and vapour flux revealed that moisture transport around the surfaces and sides of the sample is as a result of capillary diffusion, binary diffusion, and gas pressure in both the vertical and horizontal directions. The nonuniform dominant infrared heating caused the heterogeneous distribution of product temperature. These results suggest that CIR-HAD of food occurs in a non-uniform manner with high vapour and water concentration gradient between the product core and the surface.

    CONCLUSIONS: This study provides in-depth insight into the physics and phase changes of food during CIR-HAD. The multiphase model has the advantage that phase change and impact of CIR-HAD operating parameters can be swiftly quantified. Such a modelling approach is thereby significant for further development and process optimization of CIR-HAD towards industrial upscaling. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Hot Temperature
  16. Azlan CA, Mohd Nasir NF, Saifizul AA, Faizul MS, Ng KH, Abdullah BJ
    Australas Phys Eng Sci Med, 2007 Dec;30(4):288-91.
    PMID: 18274069
    Percutaneous image-guided needle biopsy is typically performed in highly vascular organs or in tumours with rich macroscopic and microscopic blood supply. The main risks related to this procedure are haemorrhage and implantation of tumour cells in the needle tract after the biopsy needle is withdrawn. From numerous conducted studies, it was found that heating the needle tract using alternating current in radiofrequency (RF) range has a potential to minimize these effects. However, this solution requires the use of specially designed needles, which would make the procedure relatively expensive and complicated. Thus, we propose a simple solution by using readily available coaxial core biopsy needles connected to a radiofrequency ablation (RFA) generator. In order to do so, we have designed and developed an adapter to interface between these two devices. For evaluation purpose, we used a bovine liver as a sample tissue. The experimental procedure was done to study the effect of different parameter settings on the size of coagulation necrosis caused by the RF current heating on the subject. The delivery of the RF energy was varied by changing the values for delivered power, power delivery duration, and insertion depth. The results showed that the size of the coagulation necrosis is affected by all of the parameters tested. In general, the size of the region is enlarged with higher delivery of RF power, longer duration of power delivery, and shallower needle insertion and become relatively constant after a certain value. We also found that the solution proposed provides a low cost and practical way to minimizes unwanted post-biopsy effects.
    Matched MeSH terms: Hot Temperature/therapeutic use
  17. Huda AS, Taib S, Ghazali KH, Jadin MS
    ISA Trans, 2014 May;53(3):717-24.
    PMID: 24593986 DOI: 10.1016/j.isatra.2014.02.003
    Infrared thermography technology is one of the most effective non-destructive testing techniques for predictive faults diagnosis of electrical components. Faults in electrical system show overheating of components which is a common indicator of poor connection, overloading, load imbalance or any defect. Thermographic inspection is employed for finding such heat related problems before eventual failure of the system. However, an automatic diagnostic system based on artificial neural network reduces operating time, human efforts and also increases the reliability of system. In the present study, statistical features and artificial neural network (ANN) with confidence level analysis are utilized for inspection of electrical components and their thermal conditions are classified into two classes namely normal and overheated. All the features extracted from images do not produce good performance. Features having low performance reduce the diagnostic performance. The study reveals the performance of each feature individually for selecting the suitable feature set. In order to find the individual feature performance, each feature of thermal image was used as input for neural network and the classification of condition types were used as output target. The multilayered perceptron network using Levenberg-Marquardt training algorithm was used as classifier. The performances were determined in terms of percentage of accuracy, specificity, sensitivity, false positive and false negative. After selecting the suitable features, the study introduces the intelligent diagnosis system using suitable features as inputs of neural network. Finally, confidence percentage and confidence level were used to find out the strength of the network outputs for condition monitoring. The experimental result shows that multilayered perceptron network produced 79.4% of testing accuracy with 43.60%, 12.60%, 21.40, 9.20% and 13.40% highest, high, moderate, low and lowest confidence level respectively.
    Matched MeSH terms: Hot Temperature
  18. Fatima N, Karimov KS, Qasuria TA, Ibrahim MA
    J Alloys Compd, 2020 Dec 30;849:156702.
    PMID: 32834521 DOI: 10.1016/j.jallcom.2020.156702
    In this research, due to the present pandemic of COVID-19, we are proposing a stable and fixed semitransparent photo-thermoelectric cell (PTEC) module for green energy harvesting. This module is based on the alloy of Bismuth Telluride Selenide (Bi2Te3Se), designed in a press tablet form and characterized under solar energy. Here, both aspects of solar energy i.e., light and heat are utilized for both energy production and water heating. The semitransparent PTEC converts heat energy directly to electrical energy due to the gradient of temperature between two electrodes (top and bottom) of thermoelectric cells. The PTEC is 25% transparent, which can be varied according to the necessity of the utilizer. The X-ray diffraction of material and electric characterization of module i.e., open-circuited voltage (VOC) and Seebeck coefficient were performed. The experimental observations disclose that in the proposed PTEC module with an increment in the average temperature (TAvg) from 34 to 60 °C, results in the rise of VOC ∼ 2.4 times. However, by modifying the size of heat-absorbing top electrode and by increasing the temperature gradient through the addition of water coolant under the bottom electrode, an uplift in the champion device results in as increment of VOC ∼5.5 times and Seebeck coefficient obtained was -250 μV/0C, respectively. Results show that not only the selection of material but also the external modifications in the device highly effective the power efficiency of the devices. The proposed modules can generate electric power from light and utilize the penetrating sunlight inside the room and for the heating of the water which also acts as a coolant. These semitransparent thermoelectric cells can be built-in within windows and roofs of buildings and can potentially contribute to green energy harvesting, in situations where movement is restricted locally or globally.
    Matched MeSH terms: Hot Temperature
  19. Sulong MR, Abdul Rahman RN, Salleh AB, Basri M
    Protein Expr. Purif., 2006 Oct;49(2):190-5.
    PMID: 16769222
    An organic solvent tolerant (OST) lipase gene from Bacillus sphaericus 205y was successfully expressed extracellularly. The expressed lipase was purified using two steps purification; ultrafiltration and hydrophobic interaction chromatography (HIC) to 8-fold purity and 32% recovery. The purified 205y lipase revealed homogeneity on denaturing gel electrophoresis and the molecular mass was at approximately 30 kDa. The optimum pH for the purified 205y lipase was 7.0-8.0 and its stability showed a broad range of pH value between pH 5.0 to 13.0 at 37 degrees C. The purified 205y lipase exhibited an optimum temperature of 55 degrees C. The activity of the purified lipase was stimulated in the presence of Ca2+ and Mg2+. Ethylenediaminetetraacetic acid (EDTA) has no effect on its activity; however inhibition was observed with phenylmethane sulfonoyl fluoride (PMSF) a serine hydrolase inhibitor. Organic solvents such as dimethylsulfoxide (DMSO), methanol, p-xylene and n-decane enhanced the activity. Studies on the effect of oil showed that the lipase was most active in the presence of tricaprin (C10). The lipase exhibited 1,3 positional specificity.
    Matched MeSH terms: Hot Temperature
  20. Chan WP, Veksha A, Lei J, Oh WD, Dou X, Giannis A, et al.
    J Environ Manage, 2019 Mar 15;234:65-74.
    PMID: 30616190 DOI: 10.1016/j.jenvman.2018.12.107
    A novel, cost-effective and real-time process monitoring and control system was developed to maintain stable operation of waste-to-energy gasification process. It comprised a feedback loop control that utilized the differential temperatures of the oxidation and reduction zones in the gasifier to determine the regional heat-flow (endothermic or exothermic), to assess the availability of oxidizing agent (for instance, air or O2) at the char bed and to calculate the fuel feeding rate. Based on the correlations developed, the air-to-fuel ratio or the equivalence air ratio (ER) for air gasification could be instantaneously adjusted to maintain stable operation of the gasifier. This study demonstrated a simplification of complex reaction dynamics in the gasification process to differential temperature profiling of the gasifier. The monitoring and control system was tested for more than 70 h of continuous operation in a downdraft fixed-bed gasifier with refuse-derived fuel (RDF) prepared from municipal solid wastes (MSW). With the system, fuel feeding rate could be adjusted accurately to stabilize the operating temperature and ER in the gasifier and generate syngas with consistent properties. Significant reductions in the fluctuations of temperature profiles at oxidation and reduction zones (from higher than 100 °C to lower than 50 °C), differential temperatures (from ±200 to ±50 °C) in gasifier and the flow rate (from 16 ± 6.5 to 12 ± 1.8 L/min), composition of main gas components, LHV (from 6.2 ± 3.1 to 5.7 ± 1.6 MJ/Nm3) and tar content (from 8.0 ± 9.7 to 7.5 ± 4.2 g/Nm3) of syngas were demonstrated. The developed gasifier monitoring and control system is adaptable to various types (updraft, downdraft, and fluidized-bed) and scales (lab, pilot, large scale) of gasifiers with different types of fuel.
    Matched MeSH terms: Hot Temperature
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