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Temperature Characteristics (temperature + characteristic)
Selected AbstractsAn investigation on thermal-recycling of recycled plastic resin (spherically symmetric analysis of abrupt heating processes of a micro plastic-resin particle)HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 4 2006Ryuji Yamakita Abstract A fundamental understanding of the physical properties of a micro plastic-resin particle subjected suddenly to hot combustion gas, such as the temperature history in the micro particle and its lifetime, is necessary for effectively realizing thermal recycling of recycled plastic resin. However, micro plastic particles have such small diameters, ranging from 100 µm to 200 µm, that the measurement of temperature histories within them is extremely difficult. In this paper, therefore, a spherically symmetric one-dimensional analysis is applied to the abrupt heating process of a micro plastic resin particle in a high temperature inert atmosphere. Variations of the temperature history and the lifetime with the ambient gas temperature and the initial particle diameter are numerically analyzed, by dividing the entire heating process into four independent periods; the solid heating period, the melting period, the liquid heating period, and the vaporization period. Effects of the Nusselt number on the particle lifetime are also discussed. It is found that, by suitably taking account of the influences of heat transfer properties, the proposed simplified analysis is useful for estimating the fundamental and overall temperature characteristics of a micro plastic resin particle under abrupt heating. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(4): 279,293, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20113 [source] Temperature-frequency characteristics simulation of piezoelectric resonators and their equivalent circuits based on three-dimensional finite element modellingINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2003N. Wakatsuki Abstract The electromechanical resonators made of piezoelectric crystals such as a quartz crystal are widely used for electronic devices. Their frequency,temperature characteristics are of primary importance for their applications to the frequency control devices. The present paper demonstrates numerical simulation for several types of resonators using 3-D Finite Element Modelling. The results are compared with the theoretical values whenever they are available. As they are electronic devices, the equivalent circuit representation is often favourable for describing the admittance at the electrical terminals which enables the circuit analysis including the effect of the temperature change by using commercially available circuit simulators. Copyright © 2003 John Wiley & Sons, Ltd. [source] Influence of operating conditions on friction and temperature characteristics of a wet clutch engagementLUBRICATION SCIENCE, Issue 2 2000Mikael HolgersonArticle first published online: 9 MAR 200 Abstract To optimise the gear change in automatic transmissions, more knowledge is needed of the engagement behaviour of wet clutches. A factorial design investigation of the engagement of a wet clutch has been carried out. The friction and temperature characteristics have been studied. The experiments were carried out in an apparatus that can vary sliding velocity, drive torque, inertia, force rate, and lubricant flow. The results show how these parameters affect the response data: engagement time, developed energy, temperature rise, maximum torque, maximum power, static friction, dynamic friction, and initial friction. There are interaction effects between some of the input parameters, but they are relatively small. The friction coefficient varies over time but is independent of the input parameters, except for dynamic friction, which decreases with increasing sliding velocity, drive torque, and inertia. The temperature rise was found to be proportional to developed energy and both these were most affected by sliding velocity. The drive torque and force rate have the greatest effect on the engagement time. [source] Temperature characteristic analysis of a ferrite phase shifter in a grooved waveguideMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2001Wenquan Che Abstract A rigorous analysis of the temperature characteristics of a ferrite phase shifter in a grooved waveguide is carried out by using a combination of analytical and numerical methods. The numerical results are found to be in agreement with our measurements. The results obtained provide valuable guidance for the simulation of the property of the device in the high-power case and for the optimization of the design of the device. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 156,159, 2001. [source] Synthesis and characterization of radio-opaque thermosensitive poly[N -isopropylacrylamide-2,2,-(ethylenedioxy)bis(ethylamine)-2,3,5-triiodobenzamide]POLYMER INTERNATIONAL, Issue 8 2009Christine M Leon Abstract BACKGROUND:In situ gelling polymers, like poly(N -isopropylacrylamide) (poly(NIPAAm)), have many potential medical applications due to their biocompatibility and thermosensitivity. RESULTS: Radio-opaque thermosensitive poly(NIPAAm) grafted with 10.7 wt% 2,2,-(ethylenedioxy)bis(ethylamine)-2,3,5-triiodobenzamide was successfully synthesized and characterized. The conjugated polymer showed good visibility with X-ray fluoroscopy. The polymer had a lower critical solution temperature of 30 °C after conjugation with triiodobenzamide as determined by cloud point determination and a transition peak temperature of 33.3 ± 0.57 °C as determined by differential scanning calorimetry. CONCLUSION: The polymer synthesized was highly visible under X-rays, based upon the percentage incorporation of triiodobenzamide. After conjugation of the NIPAAm to the triiodobenzamide through a bis(ethylamine) linkage, the resultant polymer retained lower critical solution temperature characteristics in a temperature region that makes it physiologically useful. Copyright © 2009 Society of Chemical Industry [source] Effect of solvent on the viscosity changes of coal-oil slurry under high temperature,high pressure during heatingASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Yingjie Ren Abstract Heating coal-oil slurry is an important step in direct coal liquefaction. Some physical and chemical properties and the viscosity of coal-oil slurry will be the changes in the heating process. A self-manufactured rotary viscometer that can measure the viscosity of coal slurry at high-pressure temperature was designed. Two kinds of solvents including anthracene oil, Shenhua recycled oil (the catalytic hydrogenation products of Shenhua direct coal liquefaction) and Yanzhou coal were used. The results show that the viscosity of Yanzhou coal-anthracene oil and Shenhua recycled oil slurry decrease firstly with the decreasing of solvent viscosity, then increase with measuring temperature for the absorption and volatilization of the solvent in atmosphere. Both of them have a viscosity peak with increasing measuring temperature in atmosphere. However, the Yanzhou coal-anthracene oil slurry has a viscosity peak at about 583 K under high pressure during heating, while the Yanzhou coal-Shenhua recycled oil slurry does not have a viscosity peak, but coke deposits appear at 623 K and above, under high pressure. In addition, the viscosity,temperature characteristics of thermally treated coal-oil slurry at different temperatures are the same; both have a viscosity peak with increasing heating temperature at the same measuring temperature. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Use of stomatal conductance and pre-dawn water potential to classify terroir for the grape variety KékfrankosAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2009Zs. ZSÓFI Abstract Background and Aims:, A 3-year study was carried out in order to evaluate the ecophysiology, yield and quality characteristics of Vitis vinifera L. cv. Kékfrankos (syn. Limberger) at Eger-Nagyeged hill (steep slope) and at Eger-K,lyuktet, (flat) vineyard sites located in the Eger wine region, Hungary. The aim of this paper was to analyse the effect of ,vintage' and ,terroir' on the seasonal changes of Kékfrankos ecophysiology and its possible relationship with yield and wine composition. Methods and Results:, Grapevine physiological responses (midday- and pre-dawn water potential, pressure,volume analysis and gas-exchange), growing stages, yield and wine composition of each vineyard were studied. Lower grapevine water supply was detected at Eger-Nagyeged hill in each season due to its steep slope and soil characteristics. Pressure-volume curves indicated that there was no osmotic adjustment in the leaves of this variety. Higher osmotic concentration was measured at turgor loss and full turgor in the leaves of the unstressed vineyard (Eger-K,lyuktet,) presumably due to higher photosynthetic activity. Differences in soil water content of the vineyards resulted in a slightly altered cell wall elasticity. Stomatal conductance, transpiration rate and photosynthetic production per unit leaf area were affected by water availability. Lower yield in Eger-Nagyeged hill was partly associated with decreased photosynthetic production of the canopy. Improved wine quality of Eger-Nagyeged hill was due to moderate water stress which induced higher concentration of anthocyanins and phenolics in the berries. The duration of the phenological stages was dependent on vintage temperature characteristics rather than on vineyard site. Conclusion:, There was a close relationship between environmental conditions, Kékfrankos gas-exchange, water relations, yield and wine composition. Water deficit plays an important role in creating a terroir effect, resulting in decreased yield, better sun exposure of leaves and clusters and thus higher concentration of phenolics and anthocyanins. Although quality is mainly influenced by vintage differences, vineyard characteristics are able to buffer unfavourable vintage effects even within a small wine region. Significance of the Study:, Stomatal conductance, pre-dawn water potential and climatic data may be reliable parameters for terroir classification, although variety,terroir interactions must always be considered. [source] Helix-coil energetics for helix formers and breakers reflect context and temperature: Mutants of helically robust, guest-sensitive homopeptide hostsBIOPOLYMERS, Issue 5 2009Khaled A. Nasr Abstract The natural amino acids are primarily helix breakers at the low assignment temperatures characteristic of many studies, but recent genomic analyses of thermophilic proteins suggest that at high temperatures, some breakers may become strong helix formers. Moreover, the breaker/former inventory has not been previously characterized at the physiologically relevant temperature of 37°C. The versatility of 13CO NMR chemical shifts as helicity reporters allows construction of two mutant peptide series, tailored to expand the range of temperature assignments for helical propensities and derived from the core hosts tL-Ala9XxxAla9 - tL and tL-AlaNva4XxxNva4Ala9 - tL, Nva = norvaline. For three limiting guests Xxx, the helix former Nva and the breakers Gly and Pro, we report wXxx[T] assignments at seven temperatures from 2 to 80°C, validating our reasoning and paving the way for assignment of a definitive wXxx[T] data-base. © 2008 Wiley Periodicals, Inc. Biopolymers 91: 311,320, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | |||||||||||||