• Carbon letters
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• v.10 no.3
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• pp.202-207
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• 2009

Pitch-based carbon fiber tows were prepared from naphtha cracking bottom oil by reforming and carbonization. The relationship between exothermic heat and carbon contents of the fiber was investigated by changing the carbonization conditions. The carbon contents and the crystallinities of isotropic pitch-based carbon fibers were 86.8~93.8 wt% and 33.7~40.1%, respectively, which were linearly proportional to the increase of carbonization temperature from 700 to $1000^{\circ}C$. The exothermic heat (temperature increase) of fiber tows was measured in a short time, which was also linearly proportional to the increase of carbon contents due to the increase of crystallinity, even though the crystallinity was low. Therefore, the carbon contents or carbonization degree of fibers can rapidly and indirectly be estimated by measuring the surface temperature increase of fibers.

• The Journal of the Korean dental association
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• v.10 no.8
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• pp.531-534
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• 1972

The author measured exothermic temperature of the 5 kinds of zinc phosphate cement and 3 kinds of copper phosphate cement during setting process. Cements were mixed on the glass slab with flexible steel spatula at room temperature (25.8℃) for one minute (spatulating speed was 100 strokes per minute) and placed in the incubator of which temperature was held at 37℃ and thermometer was inserted into the cement mass. The powder liquid ration was 3.0gm:1ml and 1.5gm:1ml. The results were as follows. 1) The heat generated after mixing these cements was under 47.22℃. 2) The range of thermal change of the zinc phosphate cements during setting process was wider than copper phosphate cements. 3) The exothermic temperature from the thin mix was higher than thick mix. 4) The exothermic temperature of the zinc phosphate cements was higher than copper phosphate cements.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3808-3814
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• 2023

The thermal stability of nitric acid solutions after contact with non-irradiated and irradiated tributyl phosphate (TBP) and its solution in Isopar-M has been studied. It has been established that exothermic processes occur during heating due to the interaction of soluble radiolysis products and the decomposition of the extractant with nitric acid. Such processes can occur at temperatures below 100 ℃, but unlike a thermal explosion that occurs in seconds, they are longer in time and are accompanied by weak heat evolution. Their intensity depends on the composition of the extractant, the concentration of HNO₃, and the volume ratio of the organic and aqueous phases. The presence of extractant degradation products in raffinates does not pose a risk of a rapid evolution of gaseous products during evaporation, however, the presence of reducing agents can significantly increase the intensity of the exothermic decomposition of raffinates.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.297-302
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• 2022

An exothermic oil absorbent sheet with calcium chloride crystals can be fabricated, by dipping a clean polypropylene fabric in calcium carbonate and hydrochloric acid solution and drying it. The exothermic oil absorbent sheet applied to the seawater surface, releases heat by the dissociation of calcium chloride. The dissociation heat liquefies the solidified low-sulfur fuel oil at a low temperature, and converts it to a state at which it can be absorbed. The optimum mole concentrations of calcium carbonate and hydrochloric acid required for the exothermic oil absorbent sheet, are 0.25 M and 0.5 M, respectively. The oil absorption capacity of the exothermic oil absorbent sheet for low sulfur fuel oil depends on the seawater temperature. But, it is highly excellent at 4.5-7.08 g/g at 10℃, the average seawater temperature during the winter in Korea. The exothermic oil absorbent sheet is an excellent alternative in absorbing low-sulfur fuel oil in winter and removing it from seawater.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.1
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• pp.37-43
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• 2022

In this study, we investigated the optical, electrical and exothermic characteristics of ITO/Ag/ITO multilayer structures prepared with various Ag thicknesses on quartz and PI substrates. The transparent conducting properties of the ITO/Ag/ITO multilayer films depended on the thickness of the mid-layer metal film. The ITO/Ag (14 nm)/ITO showed the highest Haccke's figure of merit (FOM) of approximately 19.3×10^-3 Ω^-1. In addition, the exothermic property depended on the substrate. For an applied voltage of 3.7 V, the ITO/Ag (14 nm)/ITO multilayers on quartz and PI substrates were heated up to 110℃ and 200℃, respectively. The bending tests demonstrated a comparable flexibility of the ITO/Ag/IT multilayer to other transparent electrodes, indicating the potential of ITO/Ag/ITO multilayer as a flexible transparent conducting heater.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.639-642
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• 1990

본 EXOTHERMIC BATCH 공정은 두 개의 FLUID BED REACTOR로 구성되며 여기서 다종의 제품이 생산된다. 각 제품은 그 제품 자체의 특징 온도 패턴을 갖게 되며 허용한계를 벗어나지 않는 제품을 생산하기 위해서는 그 특징 온도 패턴대로 제어되어야 하며 실패할 경우 그 배치를 포기하여야만 한다. 초기의 배치제어시스템에서는 램프 제너레이터(RAMP GENERATOR) 기능이 있는 공기식 계기가 사용되었으며 제품을 변경하기 위해서는 각 제품마다 일일이 그 특징 패턴을 수동으로 입력시켜 주어야만 했다. 이 과정에서 한 개의 파라미터를 실수하면 사용할 수 없는 제품이 된다. 다종 제품의 화학공정에서는 품질과 생산량 향상에 의한 이득 증대에 그 목표를 두고 있으며, 이와 같은 목표를 달성하기 위한 해결책은 운전자의 개입을 감소시켜주는 제어시스템으로 개선하는 것이었다. 본 논문에서는 배치공정에 있어서의 프로그래머블 콘트롤러(PROGRAMMABLE CONTROLLER)의 응용에 관하여 논술하고자 한다.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.139-144
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• 2007

The fires were occasionally occurred by the quicklime, used in soil conditioners and stall disinfectant, in the stables and shed especially during the rainy season. Accordingly, we observed that spontaneous ignition by the exothermic reaction was happened through the revival experiments. As a results of revival experiments, we confirmed that fire had been occurred by exothermic energies in the case of heat accumulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.555-555
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• 2012

The thermal stability of poly(sodium 4-styrenesulfonate) intercalated graphite oxide has been investigated using a differential scanning calorimeter. The poly(sodium 4-styrenesulfonate) intercalated graphite oxide composite shows a prominent exothermic reaction near $207^{\circ}C$ and an endothermic reaction near $453^{\circ}C$. Graphite oxide is responsible for the exothermic reaction while the endothermic reaction is caused by the poly(sodium 4-styrenesulfonate) used in the synthesis of poly(sodium 4-styrenesulfonate) intercalated graphite oxide. The onset temperature of the exothermic reaction of poly(sodium 4-styrenesulfonate) intercalated graphite oxide decreased by $92^{\circ}C$ in comparison with that of graphite oxide, indicating the addition of poly(sodium 4-styrenesulfonate) in the composite has diminished the thermal stability of graphite oxide.

• Proceedings of the KIEE Conference
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• 2006.10b
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• pp.167-170
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• 2006

$TiO_{2}-Nb_{2}O_{5}$ sol was prepared using sol-gel method. DTA properties of gel powder had endothermic reaction due to evaporation of propanol and water about $78^{\circ}C$, had exothermic reaction due to propanol combustion about $290^{\circ}C$ and had exothermic reaction due to changing of $TiO_2$ phase about $640^{\circ}C$. Capacitance of thin films increased according to increasing relative humidity, whereas it decreased according to increasing measured frequency.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.52-59
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• 2016

For almost of concrete structures by placing in cold weather, it is very important that the selection of curing method at early aged construction stage. The Exothermic curing method with hot wire and rapid hardening cement is used mostly to prevent the initial cracks and the strength decrease. Most of the construction sites, however, have not been applied to the optimal curing method caused by the simple approaches and the empirical judgements. Therefore, this paper has proposed a evaluation algorithm of the exothermic curing method for representing heating temperature, period, position of hot wire by analyzing the transient heat transfer solution. This has been implemented, moreover, using an object oriented programming language to develop structural analysis system taking account risk parameters. This system is composed of input module, database module, database store module, analysis module, and result generation module. Linkage interface between the central database and each of the related module is implemented by the visual c# concept. Graphic user interface and the relational database table are supported for user's convenience.