• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.62-70
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• 2005

In this study, the air-side heat transfer coefficients of several types of evaporators in the household freezer/refrigerators are investigated. The types considered in this work are: discrete flat plate fin-and-tube type(in-lined tube array), continuous flat plate fin-and-tube type(staggered tube array), and spine fin-and-tube type(in-lined tube array). The heat transfer correlations obtained from this study for each heat exchangers could expect heat transfer coefficients less than $5\%$ of errors. The result indicates that the air-side heat transfer performance of spine fin-and-tube type evaporator shows the highest value under dry conditions, but discrete flat plate fin-and-tube type evaporator shows the highest value among these three evaporators under frosting conditions.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.283-287
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• 2016

One of the most important factors for determining the thermal performance of an evaporative cooling system is the wettability of the evaporative heat exchanger surface. Evaporation of a widely spread water film on the heat exchanger surface promotes heat transfer between the "dry" air and "wet" air passages. Hydrophilic coating is generally applied on the heat exchanger surfaces to increase the wettability of the heat exchanger surface and the COP of the evaporative cooling system. In this paper, a simple lamellar patterned structure is suggested to maximize the spreading of a water film on the vertically oriented walls. The capillary height of the lamellar structured grooves is analyzed through a theoretical model, and the results are compared with the numerical analysis through a finite element analysis tool, SE-FIT. A good agreement between the theoretical model and the numerical analysis can be observed as long as the channel depth is comparable to or larger than the channel width of the lamellar structure.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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• pp.11-20
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• 2005

This study was carried out to investigate the influence of paper stock type and heat treatment on sizing effect. Various types of pulps were used to make handsheets sized internally with AKD(alkyl ketene dimer) and externally with CMC(carboxyl methyl cellulose). Most of the handsheets were treated with heat by dry oven $(100^{\circ}C,\;30min)$ to evaluate the effect of heat treatment on sizing development. Internal sizing development of newsprint was very bad, but the effect of heat treatment was much higher than those of NBKP, BCTMP. In case of surface sizing, newsprint was more effective compared to the other pulps. Considering above mentioned results, it seems that internal sizing slows down water into paper by molecular diffusion much more than capillary penetration, but surface sizing slows down capillary penetration. With regard to density, a higher thickness sheets showed high heat treatment effect on sizing, therefore it assumed that heat treatment effect on sizing had very close relationship with sheet density.

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.194-204
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• 1994

The purpose of this study was to evaluate the surface hardness of composite resins according to heat treatment. storage condition and storage time. In this study. two kinds of composite resin inlays and one kind of conventional posterior composite resin were used as experimental materials. One hundred eighty composite resin specimens were constructed from composite resin inlays and conventional posterior composite resin. The conditions of this study were heat treatment. storage condition and storage time. Hardness readings were taken from the top surface of each samples using the Vickers microhardness tester(MHT-l. Matsuzawa. Japan}. The following results from this study were obtained: 1. Regardless of storage condition. both composite resin inlay and conventional posterior composite resin have a higher surface hardness under heat treatment than not. 2. Composite resins with heat treatment have a higher surface hardness under dry storage than under water immersion. 3. In case of Clearfil Photo Posterior and Brilliant Enamel with heat treatment. there was no significant difference with time. but Clearfil CR Inlay with heat treatment. there was statistical difference after 24 hours. 4. Surface hardness of composite resins with coarse hybrid type was higher than that of composite resin with fine hybrid type.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.435-438
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• 1992

Data were collected on productive and reproductive performance of different $F_1$ crossbred cows (Deshi cows joined by A.I. to Sindhi, Sahiwal, Jersey or Holstein-Friesian Bull semen) reared by farmers in and around the Bangladesh Agricultural University campus at Mymensingh. The traits considered were birth weight, age at first heat, age at first calving, gestation length, post-partum heat period, milk yield, lactation length, dry period and calving interval. Data were analyzed statistically using a completely randomized design and Duncan's Multiple Range Test to compare and determine the significance of between individual group means. It was observed that the Holstein $\times$ Deshi had the highest birth weight (21.4 kg) followed by Sahiwal (17.6 kg), Jersey (16.7 kg) and Sindhi (16.1 kg). Shortest age at first heat (854 and 920 days) and age at first calving (1002 and 1201 days) were found for the Jersey $\times$ Deshi and Holstein $\times$ Deshi crosses respectively. The post-partum heat period were significantly different between breeds with Jersey and Holstein sired calves having the shortest intervals. There was no difference in the gestation length of the four crosses. Holstein $\times$ Deshi and Jersey $\times$ Deshi cows gave the highest milk yields due to longer lactation periods and higher daily milk production. Similarly, Holstein $\times$ Deshi and Jersey $\times$ Deshi crosses had significantly shorter dry periods and Jersey $\times$ Deshi had a shorter calving interval. From this study it may be concluded that exotic genotypes such as Holstein-Friesian and Jersey can perform very well under rural conditions in Bangladesh.

• Journal of the Korean Geosynthetics Society
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• v.12 no.1
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• pp.83-92
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• 2013

Backfill material with thermal resistivity which has $50^{\circ}C$-cm/Watt in wet and $100^{\circ}C$-cm/Watt in dry is requested to improve the power transfer capability for dissipation of heat production in underground power cables. In the field test performed by buried cable backfills, the backfill material developed from this study is compared with river sand and weathered soil (native soil) to investigate the effect of heat transfer in various seasons and locations of thermal sensors. As a result, the developed backfill material is faster approaching yielding temperature (critical heat) than that of river sand and weathered soil, and it has good dissipation capacity rather than other materials by keeping moisture content at dry season.

• Electronics and Telecommunications Trends
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• v.38 no.6
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• pp.41-51
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• 2023

Heat dissipation technology for semiconductors and electronic packaging has a substantial impact on performance and lifespan, but efficient heat dissipation is currently facing limited improvement. Owing to the high integration density in electronic packaging, heat dissipation components must become thinner and increase their performance. Therefore, heat dissipation materials are being devised considering conductive heat transfer, carbon-based directional thermal conductivity improvements, functional heat dissipation composite materials with added fillers, and liquid-metal thermal interface materials. Additionally, in heat dissipation structure design, 3D printing-based complex heat dissipation fins, packages that expand the heat dissipation area, chip embedded structures that minimize contact thermal resistance, differential scanning calorimetry structures, and through-silicon-via technologies and their replacement technologies are being actively developed. Regarding dry cooling using single-phase and phase-change heat transfer, technologies for improving the vapor chamber performance and structural diversification are being investigated along with the miniaturization of heat pipes and high-performance capillary wicks. Meanwhile, in wet cooling with high heat flux, technologies for designing and manufacturing miniaturized flow paths, heat dissipating materials within flow paths, increasing heat dissipation area, and reducing pressure drops are being developed. We also analyze the development of direct cooling and immersion cooling technologies, which are gradually expanding to achieve near-junction cooling.

• Food Science and Preservation
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• v.21 no.4
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• pp.544-548
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• 2014

This study was conducted to investigate the effects of various heat treatments on the microbial reduction and germination of red radish seeds for the development of effective and economical sterilization methods of improving microbial safety without reducting the germination rate. Hydrothermal treatment was conducted at 60, 65, 70, 75, 80, and $90^{\circ}C$ for 30 and 60 seconds, and dry heat treatment was performed at 70, 80, 90, and $100^{\circ}C$ for 5 minutes. In the seeds that underwent the hydrothermal treatment, time had little effect on the microbial reduction. There was no significant microbial reduction over time. However, there was significant microbial reduction as temperatures increased (p<0.001). The total plate count (TPC) was reduced by more than 3 logs, and Listeria monocytogenes was not detected at temperatures above $70^{\circ}C$. In the seeds that were subjected to the dry heat treatment, the TPC and the population of the L. monocytogenes were significantly reduced as the temperatures increased (p<0.001). After treatment at $100^{\circ}C$ for 5 minutes, the TPC and the L. monocytogenes were reduced by 3 logs. As with the microbial reduction, time had little effect on the germination. There were no significant changes in the germination after the hydrothermal treatment over time; but at the temperatures above $75^{\circ}C$, the germination rate significantly decreased as the temperature increased (p<0.001). When the seeds were soaked after the hydrothermal treatment, their germination was stimulated. The dry heat treatment at temperatures of $80^{\circ}C$ and higher significantly decreased the germination rate as the temperature increased (p<0.001). Dry heat treatment before the germination of the seeds soaked in distilled water for three hours significantly decreased the germination at temperatures greater than $90^{\circ}C$ (p<0.05). This study showed that appropriate heat treatments can increase the microbiological safety and germination of red radish seeds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.222-229
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• 2009

This study presents comparison of heat transfer and air side friction characteristics in a condenser condition of air conditioner between Louver fin-tube heat exchangers and aluminum parallel heat exchangers. All experiments are performed using an air-enthalpy type calorimeter, which is designed based on the method described in ASHRAE standards. The air velocities crossing the heat exchanger tubes are varied from 0.7 to 1.6 m/s with 0.3 m/s interval, maintaining air dry temperature and relative humidity at $20^{\circ}C$ and 60% respectively. Water temperature and flow rate inside the tube are $70^{\circ}C$ and 10 LPM, respectively. Experimental results show that the heat transfer performances of aluminum heat exchangers are 17-163% higher than those of Louver fin-tube heat exchangers based on the data per unit volume, mass, and heat transfer area, whereas air side pressure drops of aluminum heat exchangers are 19-81% lower.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.10-24
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• 2000

1. Objectives : Millions of people throuout the world are affected by some form of dry eye disorder. I made researches for more effective treatments for dry eye. 2. Methodes : I refered to occidental and oriental medical records. 3. The results were as follows : Common symptoms of dry eye are dryness, burning, irritation, grittiness, itching, fatigue of eye, photophobia, congestion, mattering and tear. Treatments of dry eye are to clear away heat and fire, remove dampness, replenish Um and promote production of body fluid, tonify the blood and replenish Ki. Acupunctre and moxibustion therapy of dry eye are as follows: Very busy points of traditional regular acupuncture are Sangsong, Chanjuk, Sajukkong, Chongmyong, Sabaek, Tongjaryo, Taeyang, Pungji, Tuimup, Paekoe, Un-gyo, Chonjong, Hapkok, Yangbaek, Kansu, Yanggye, Imup, Chok-samni, Taechung, Kwangmyong, Yang-gok, Uihui, Chohae, Haenggan. Less busy points of it are Oyo, Kuhu, Sungup, Konmyong, Konmyongl, Konmyong2, Sangmyong, SanghaChongmyong, Shinmyong, Osang, Shinjong, Yonghyang, Yaemyong, Chon-yu, Chon-ju, Kwallye, Naebi, Noeho, Tuyu, Mokchang, Ponshin, Shinhoe, Yepung, Okchim, Pungbu, Kokchon, Kollyun, Nae-gwan, Tae-nung, Samumgyo, Sokolkong, Shinsu, Um-gyo, Igan, Chongok, Choktaek, Kyonjungsu, Kokchi, Kongchoe, Kyuum, Kihae, Taekolkong, Taedon, Pino, Pisu, Sabong, Samgan, Kokchi, Shinmun, Shinmaek, Shimsu, Yangno, Aengmun, Yolgyol, Oegwan, Wijung, Chang-gan, Chungjo, Chungdo, Chigu, Chium, Chollyo, Tongni, Pungmun, Haryom. Very busy points of ear-acupuncture are Kan, Bi, Shin, An, Less busy points of it are Shim, Pye, Naebunbe, Mok1, Mok2, Shinmun, Ichom. Useful points of bleeding by needle are Taeyang meridian, Yangmyong meridian, Chono, Chonjong, Paekoe, Sangsong, Chanjuk, Sajukkong, nasal cavity. Useful points of moxibustion are Inchung, Huaryo, Shinchu, Pungmun, Kansu, Shimsu, Kokchi, Kongchoe, Sohae.