Heat Resistance Characteristics Research Articles

Heat Resistant Characteristics of Major Royal Jelly Protein 1 (MRJP1) Oligomer.

Soluble royal jelly protein is a candidate factor responsible for mammiferous cell proliferation. Major royal jelly protein 1 (MRJP1), which consists of oligomeric and monomeric forms, is an abundant proliferative protein in royal jelly. We previously reported that MRJP1 oligomer has biochemical heat resistance. Therefore, in the present study, we investigated the effects of several heat treatments (56, 65 and 96°C) on the proliferative activity of MRJP1 oligomer. Heat resistance studies showed that the oligomer molecular forms were slightly maintained until 56℃, but the molecular forms were converted to macromolecular heat-aggregated MRJP1 oligomer at 65℃ and 96℃. But, the growth activity of MRJP1 oligomer treated with 96°C was slightly attenuated when compared to unheated MRJP1 oligomer. On the other hand, the cell proliferation activity was preserved until 96℃ by the cell culture analysis of Jurkat cells. In contrast, those of IEC-6 cells were not preserved even at 56°C. The present observations suggest that the bioactive heat-resistance properties were different by the origin of the cells. The cell proliferation analysis showed that MRJP1 oligomer, but not MRJP2 and MRJP3, significantly increased cell numbers, suggesting that MRJP1 oligomer is the predominant proliferation factor for mammiferous cells.

Development of a High-PerformanceFlexible Substrate for Flexible Electronics:Joining TAC Films and an Ultra-Thin Glassby Using TEOS-DAC Synthesized by the Sol-Gel Method

A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS-DAC (TEOS: tetraethyl orthosilicate, DAC: diacethy cellulose) adhesive resin synthesized by sol-gel method by means of thermo-compression bonding. This substrate has high transparency in visible-light region (90%), high flexibility (torsion strength and bending strength) and high gas barrier characteristics due to an ultra thin glass. The newly-developed substrate is superior to the substrates fabricated with commercially available adhesive resin in the same way in characteristics of heat resistance, transparency and flexibility.

1ϕ 2 W MCCB의 기준 비교 및 내열 특성 평가에 관한 연구

1ϕ 2 W MCCB의 기준 비교 및 내열 특성 평가에 관한 연구

Deep‐blue, low‐threshold amplified spontaneous emitting and high thermal stability binaphthyl derivates

We have investigated the photoluminescent characteristics of binaphthyl derivates, 4′′,4′′′‐N,N‐diphenylamine‐4,4′‐diphenyl‐1,1′‐binaphthyl (BN1), 4′′, 4′′′‐(9‐(9H‐9‐carbazole)‐4, 4′‐diphenyl‐1, 1′‐binaphthyl (BN2) and 4, 4′‐bis(9‐(p‐fluorophenyl)‐9H‐3‐carbazole))‐1, 1′‐binaphthyl (BN3) and found their amplified spontaneous emission (ASE) from neat films. The ASE threshold of pumping energy, Eth = 4.4, 3.8, 5.3 µJ cm−2 were obtained under optical excitation at 355 nm for the neat films of BNs, 1, 2, and 3, respectively. Moreover, the lasing of those non‐doped films exhibited deep‐blue emission, whose peak spectra of BNs 1, 2, and 3 were 438, 421, and 428 nm, respectively. We have also studied the thermal‐stability of BN1 by annealing at 250 °C for 30 min and found that the ASE threshold stayed almost unchanged compared to untreated film, demonstrating its high heat resistance characteristics. The characteristics of decreased tendency to crystallize and weaker intermolecular interactions in the solid state of BNs make them potential candidates for approaching electrically pumped organic laser diodes.

Thermochemical transformations of polycarbosilane precursors into a ceramic matrix

The possibility of preparing polymeric ceramic-forming precursors from polycarbosilane and oligosilazane was examined. Oligosilazane as a component of polycarbosilane formulations acts as a curing agent, ensuring curing at 150–300°C in the absence of oxygen and modifier. Pyrolysis of the cross-linked copolymer in argon yields an inorganic matrix whose yield is 1.3 times higher than that of pyrolyzates of the starting components. The major phase of the ceramic products obtained, according to the results of X-ray diffraction and chemical analyses, is X-ray amorphous silicon carbide. The ceramic obtained is highly resistant to thermal oxidation (up to 1400°C). The composition of the ceramic and the heat resistance and service characteristics of ceramic-matrix composite materials prepared on its basis using the “polymer technology” can be controlled by varying the ratio of the initial oligomers.

Numerical Simulation of Heat Transfer Enhanced Tube Inserted Delta-Wing

Heat transfer and resistance characteristics of a tube inserted delta-winglet (inclination angle is 10 °) are studied by numerical simulation. The results show that the delta-winglet enhance the heat transfer of the enhancement tube inserted delta-winglet and improve the PEC with modest pressure drop penalties. Compared with based tubes, the delta-wings structure enhance the heat transfer 19.52%-31%.

Experimental Investigation of Heat Transfer and Resistance Characteristics of a Finned Oval-Tube Heat Exchanger With Different Air Inlet Angles

The air inlet flow direction is not orthogonal to the heat exchanger surface in many cases. To study the performance of the heat transfer and pressure drop of a heat exchanger with different air inlet angles, this paper shows the experimental system about a finned oval-tube heat exchanger inclined toward the air incoming flow direction. The heat transfer and pressure drop characteristics of four air inlet angles (90°, 60°, 45°, and 30°) are studied separately for the Reynolds number ranging from 1300 to 13000 in this study. The experimental correlations of Nusselt number and resistance coefficient of the air side are acquired. The results show that the overall heat transfer coefficients become smaller and smaller with the decrease of the air inlet angles, while the pressure drops have significant changes. The heat transfer performances of the heat exchanger under the three inclined air inlet angles are worse than that at 90°. Among the three inclined angles, the performance at 45° is the best under identical mass flow rate criterion and at low Reynolds number under identical pressure drop criterion; that at 60° is the best at large Reynolds under identical pressure drop criterion. Finally, some conclusions are attained about the effects of the air inlet angles on the heat transfer and pressure drop performance of the finned oval-tube heat exchanger.

Numerical study on heat transfer and resistance characteristics of supercritical water inside internally-ribbed tube

The effects of structural parameters for internally-ribbed tube on heat transfer and flow characteristics of supercritical water were studied numerically. The results show that the heat transfer and pressure loss increases with the increase of mass flow or heat flux. The Heat transfer and resistance coefficients of supercritical water increase with the spiral rising angle decrease or rib height increase, while rib width has a weak influence on heat transfer and pressure drop.

프런트 필라 트림의 내열특성 향상을 위한 순차적 실험계획법과 인공신경망 기반의 최적설계

Optimal mount position of a front pillar trim considering heat resistant characteristics can be determined by two methods. One is conventional approximate optimization method which uses the statistical design of experiments (DOE) and response surface method (RSM). Generally, approximated optimum results are obtained through the iterative process by a trial and error. The quality of results depends seriously on the factors and levels assigned by a designer. The other is a methodology derived from previous work by the authors, which is called sequential design of experiments (SDOE), to reduce a trial and error procedure and to find an appropriate condition for using artificial neural network (ANN) systematically. An appropriate condition is determined from the iterative process based on the analysis of means. With this new technique and ANN, it is possible to find an optimum design accurately and efficiently.

Experimental study of the effect of air inlet angle on the air-side performance for cross-flow finned oval-tube heat exchangers

An experimental system was built to study the heat transfer and resistance characteristics of two finned oval-tube heat exchangers (HE1: Double rows of tubes, HE2: Three rows of tubes.) inclined towards the air incoming flow direction. Four air inlet angles (90°, 60°, 45° and 30°) are investigated separately to acquire the heat transfer and pressure drop performances for Reynolds number ranging from 1300 to 13,000. The experimental correlations of Nusselt number and resistance coefficient of the air side are obtained, and the comprehensive comparisons of heat transfer performance are carried out. The results show that whether the heat transfer performance for heat exchangers positioned obliquely is improved or not is depended on not only their inclined angles, but also their structures.

Study on Heat Transfer and Resistance Characteristics of H-Type Finned Tube

Three-dimensional numerical study is performed for heat transfer and resistance characteristics as well as comprehensive performance of two kinds H-type (single and double) finned tube. It is found that the heat transfer and resistance characteristics as well as comprehensive performance of H-type finned tube are influenced by the Reynolds number of gas. With the growth of Reynolds number, the air-side Nusselt number rises gradually and the heat transfer performance gets better and better, whereas the air-side Euler number drops step by step until close to a fixed value. The comprehensive performances of both single H-type finned tube and double ones are weaken progressively. When Reynolds number value is same, the convective heat transfer, pressure drop, air-side Nusselt number and Euler number of single H-type finned tube are bigger than those of double ones. The single H-type finned tube expression is much better than double ones in comprehensive performance and heat transfer.

Numerical Simulation of Heat Transfer Characteristics in Longitudinal Flow Circular Fin Tube Based on Fluent

Numerical simulation method were performed to comparatively study the heat transfer and resistance characteristics of smooth tubetransversal and longitudinal flow circular fin tube and longitudinal flow slotted umbrella fin tube; researched the flowheat transfer and resistance characteristics of longitudinal flow slotted umbrella fin tube with five different fin angle. Results show that, with the same piping mode and Re number, heat transfer coefficient of longitudinal flow slotted umbrella fin tube is 1.4~1.8 times of smooth tube, heat transfer coefficient of transversal and longitudinal flow circular fin tube is 1.1~1.5 times of smooth tube, longitudinal flow slotted umbrella fin tube with α=105° has the best heat transfer coefficient; the resistance of longitudinal flow slotted umbrella fin tube is 0.25~0.75 times of transversal flow circular fin tube, and higher than longitudinal flow circular fin tube, longitudinal flow slotted umbrella fin tube with α=105° has the lowest resistance of all slotted umbrella fin tubes.

A study on the characteristics of a rubber blend of fluorocarbon rubber and hydrogenated nitrile rubber

In this study, the physical and chemical characteristics of a rubber blend of fluorocarbon rubber (FKM) and hydrogenated Nitrile Butadiene rubber (HNBR) were investigated based on the blend ratio for the purpose improving thermal resistance of HNBR and the low-temperature resistance of FKM. The blended FKM and HNBR materials showed better heat resistance, oil resistance, and fuel resistance than those of the 100phr HNBR materials. Blended materials with added compatibilizer (KBM503) showed improved basic physical properties than those of the materials without the agent. This result agreed with a scanning electron microscopy image. The thermal properties of the blended materials based on the FKM and HNBR blend ratio were studied by Thermo Gravimetric Analysis (TGA) and differential scanning calorimetry (DSC). The TGA results showed improved heat resistance characteristics for the blended materials than those of the HNBR materials. The DSC results also showed improved characteristics of low temperature resistance with increasing HNBR contents.

The Heat-resistance Characteristics of Silicone Rubber Tube for Beverage Use and the Effect of Heat-resistance Reagent

The Heat-resistance Characteristics of Silicone Rubber Tube for Beverage Use and the Effect of Heat-resistance Reagent

Clostridium sporogenes PA 3679 and its uses in the derivation of thermal processing schedules for low-acid shelf-stable foods and as a research model for proteolytic Clostridium botulinum.

The putrefactive anaerobe Clostridium sporogenes PA 3679 has been widely used as a nontoxigenic surrogate for proteolytic Clostridium botulinum in the validation of thermal processes for low-acid shelf-stable foods, as a target organism in the derivation of thermal processes that reduce the risk of spoilage of such foods to an acceptable level, and as a research model for proteolytic strains of C. botulinum. Despite the importance of this organism, our knowledge of it has remained fragmented. In this article we draw together the literature associated with PA 3679 and discuss the identity of this organism, the phylogenetic relationships that exist between PA 3679 and various strains of C. sporogenes and proteolytic C. botulinum, the heat resistance characteristics of PA 3679, the advantages and limitations associated with its use in the derivation of thermal processing schedules, and the knowledge gaps and opportunities that exist with regard to its use as a research model for proteolytic C. botulinum. Phylogenetic analysis reviewed here suggests that PA 3679 is more closely related to various strains of proteolytic C. botulinum than to selected strains, including the type strain, of C. sporogenes. Even though PA 3679 is demonstrably nontoxigenic, the genetic basis of this nontoxigenic status remains to be elucidated, and the genetic sequence of this microorganism appears to be the key knowledge gap remaining to be filled. Our comprehensive review of comparative heat resistance data gathered for PA 3679 and proteolytic strains of C. botulinum over the past 100 years supports the practice of using PA 3679 as a (typically fail-safe) thermal processing surrogate for proteolytic C. botulinum.

Heat transfer and resistance characteristics of conical spiral tube bundle based on field synergy principle

Conical spiral tube bundle are universally used in heat transfer enhancement in heat exchangers. The heat transfer and resistance of the tube bundle are affected greatly by the conical structure, so the analysis of it is necessary. In order to a further evaluation, the heat transfer and resistance characteristics of conical spiral tube bundle are investigated with regression analysis based on numerical simulation data. The correlations of heat transfer and pressure drop of conical spiral tube bundle are proposed both in laminar and turbulent fluid flow. On the based of the field synergy principle, the synergy of four vectors, the velocity, the velocity gradient, the temperature gradient and the pressure gradient, are calculated and discussed via the user defined function (UDF) program. The synergy angles β and θ, which respectively denote the performance of heat transfer enhancement and pressure drop of the conical spiral tube bundle, are analyzed. Finally, the comprehensive performance of the conical spiral tube is evaluated by the synergy angle γ and all of the three synergy angles of conical spiral tube bundle are compared to both bare tube and thin cylinder-interpolated tube. The analysis of the synergy angles shows that the heat transfer enhancement and pressure drop of conical spiral tube bundle are smaller than that of the thin cylinder-interpolated tube, while the comprehensive performance of conical spiral tube bundle is greater. The analysis of the heat transfer and pressure drop of conical spiral tube is valuable and instructional on the design and optimum of conical spiral tube bundle heat exchangers.

S191011 超軽量CFRPアブレータの耐熱特性に関する数値シミュレーション

For a re-entry capsule which carries out the atmospheric entry, the ablator is used for the thermal protection material. In order to design the heat protection system of the capsule, it is necessary to understand the thermal behavior by heating tests and numerical simulations. In this study, the ablation analysis program was developed to simulate the heat-resistant characteristics of the ablator. The ultra-light weight CFRP ablator(=LATS) was developed recently and arc-heated tests of the LATS ablator were carried out. Test results (measured data of temperature, mass loss, etc.) are compared with those of ablation analysis. It is confirmed that mathematical model used in the ablation program can express the heat-resistant behavior of the LATS faily well.

다공성 PTFE 복합소재의 마모 및 윤활 특성 연구

Because of excellent mechanical properties, such as good friction coefficient and heat resistance characteristics, PTFE parts have been widely used in the industries. However, the poor wear resistance of PTFE has been a main problem limiting wider applications. In this study, to improve the poor wear resistance of PTFE, porous PTFE composites were prepared by mixing additives(sodium bicarbonate and graphite) with PTFE powder. The friction coefficient, wear resistance and lubricating property of porous PTFE composites were measured and the results were compared with those of untreated PTFE.

Ventilated facade systems classification. Influence of ”Thermal bridges” on their heat-resistant characteristics

Ventilated facade systems classification. Influence of ”Thermal bridges” on their heat-resistant characteristics

Analyses of marine-derived tocopherol in processed foods containing fish

The contents of marine-derived tocopherol (MDT) and other types of tocopherols in processed foods containing fish were analysed. Almost all the processed foods contained MDT, and the %MDT values, calculated using the equation 100×[MDT]/([MDT]+[α-tocopherol]), where [MDT] and [α-tocopherol] are the contents of MDT and α-tocopherol, respectively, ranged from 0% to 19%. The %MDT values of the processed foods were nearly identical to those of raw fish meat (0–20%). The heat-resistance characteristics of MDT in fish meat treated with three heating processes, boiling, grilling and frying were investigated. All heating processes brought about a decrease in the MDT and α-tocopherol contents and the rate at which the contents of MDT and α-tocopherol decreased were similar across the heating processes. The heat-resistance characteristics of MDT are thought to be similar to those of α-tocopherol. The study results indicate that processed foods containing fish may also influence the MDT content in the human body.