• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.44-48
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• 2021

Semiconductor inspection equipment makes components using materials with insulating properties for functional inspection including current and voltage of semiconductor parts. A representative insulating material is plastic, and plastic is made of a component through an injection process using plastic pellet. When plastic pellets contain excessive moisture, problems such as performance degradation and product surface defects occur. To prevent this, pre-drying is essential, and the heat convective type is the most applied. However, the heat convective type has a problem of low consumption efficiency and a long drying time. Recently, many studies have been conducted on a drying method using microwaves due to high energy efficiency. In this paper, drying was performed using a microwave for drying PC pellets. Energy consumption and drying efficiency analyzed by set up an experimental apparatus of heat convective, microwave, and hybrid(heat convective + microwave) types. It was confirmed that energy consumption and drying efficiency were high when drying using microwaves, and it was confirmed that the hybrid method improved drying performance compared to the heat convective method. It is expected that the research results of this paper can be used as basic data for drying plastic pellets using microwave.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.256-260
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• 2001

This study was initially performed to investigate current red-pepper drying methods commonly being adopted on red-pepper cultivation farm area. Based on the informations obtained from the field survey, an experiment of red-pepper drying was carried out to verify the actual drying potential of plastic covered solar house similar to the conventional pipe frame greenhouses covered with one or two layer of plastic film. Some results obtained from field survey and drying experiment for red-pepper are summarized as follows; 1. Various patterns of red-pepper drying process were found; 1) complete natural drying with red-pepper exposed in outdoor air, 2) hot air drying by dry chamber only, 3) combination drying by hot air dryer together with plastic covered passive solar house, 4) drying with plastic covered solar house unit. 2. The average air temperatures of outdoor and solar house during drying experiment period were $26.9-30.8\;and\;28.6-33.8^{\circ}C$, respectively, and the maximum air temperatures of those two were $34.2-36.4\;and\;39.8\;-52.3^{\circ}C$, respectively. Horizontal solar intensity during experiment period was $18.49-23.96\;MJ/m^{2}$, and relative humidity of outdoor and experimental solar house were 56 - 66% and 64 - 70%, respectively. 3. The weight of red-pepper during drying experiment period was decreased almost linearly from initial moisture content of 85% to final moisture content of 14%.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.1191-1196
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• 2006

Analysis of drying characteristics has been carried out with one-dimensional model in the dryer using the principle of the refraction of radiation. The dryer is composed of hot water tank, a plastic film conveyer belt, drying material, etc. The model considers the conduction and radiation within the plastic film and drying material. The film is semitransparent to radiation and the drying material is assumed to be semitransparent or opaque to radiation. The results shows that the effect of radiative transfer on the drying rate is relatively large when the thickness of drying material is small and the water temperature is high. When the material is thin, the drying rate by only conduction is also enhanced so that drying time can considerably be reduced.

• 설비공학논문집
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• 제18권8호
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• pp.678-685
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• 2006

Analysis of drying characteristics has been carried out with one-dimensional model in the dryer using the principle of the refraction of radiation. The dryer is composed of hot water tank, plastic film conveyer belt, drying material, etc. The model considers the con-duction and radiation within the plastic film and drying material. The film is semitransparent to radiation and the drying material is assumed to be semitransparent or opaque to radiation. The results show that the effect of radiative transfer on the drying rate is relatively large when the thickness of drying material is small and the water temperature is high. When the material is thin, the drying rate due to conduction is also enhanced and the drying time can considerably be reduced.

• 한국건축시공학회지
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• 제16권3호
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• pp.211-217
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• 2016

본 연구에서는 2015년 가을철 실제 시공중인 고층 아파트를 대상으로 1중 백색 버블시트로 타설된 콘크리트의 표면을 덮어주는 버블시트 피복양생 공법과 표면을 노출한 채로 양생없이 유지하는 표면노출 방법간을 비교하여 소성 및 건조수축균열의 저감정도를 분석하였다. 실험 결과, 버블시트를 시공하였을 경우, 수화열 및 적산온도는 표면노출보다 약간 높았고, 바닥 균열의 갯수, 길이, 최대 균열폭, 균열 면적 모두 현저하게 적은 값이 측정되었다. 따라서 가을철 버블시트를 타설된 콘크리트 표면에 적용 할 경우에는 소성 및 건조수축균열을 획기적으로 방지할 수 있는 효과적인 표면피복 양생공법인 것으로 판단되었다.

• Design & Manufacturing
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• 제15권4호
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• pp.32-36
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• 2021

In this study, the cause of the decrease in transmittance of the outer lens among the causes of the decrease in the amount of light in the automobile headlamp was identified, and the improvement method was selected to determine the effect. The causes of defects that lower the transmittance of the outer lens are divided into a moisture problem and a haze problem. The moisture problem is caused by the temperature difference between the inside and the outside of the head lamp, and the haze problem occurs when the heat inside the head lamp evaporates the haze component contained in the plastic material and attaches it to the outer lens. In order to improve the haze problem that occurs in plastic raw materials, the structures of the bulb light source type headlamp and the LED chip light source type headlamp were analyzed. Among them, the housing material of the LED chip light source type headlamp, which is structurally prone to haze gas, was selected as the test target. In the mass-production injection process of the housing, the drying process was selected as a method to minimize haze gas without adding a separate production process. After extracting a sample every drying time at a constant drying temperature, the sample was put into a haze tester and the residual amount of haze gas was measured. As a result, it was confirmed that the residual amount of Haze gas in the material decreased as the drying time increased.

• 콘크리트학회논문집
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• 제12권6호
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• pp.109-117
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• 2000

CFRD(Concrete Faced Rockfill Dam) face slab concrete has a much capability to occur crack due to drying shrinkage, plastic shrinkage and bad compaction etc. Because of these cracks of concrete induce structural problem and decrease durability of dam, it is need to reduce crack of face slab concrete. This is an experimental study to analyze the influence factors on crack properties of CFRD face slab concrete. For this purpose, various mix proportion of CFRD face slab concrete and concrete using PPF(polypropylene fiber0 and fly ash was selected. And tests for drying shrinkage, bonding strength, water permeability and plastic shrinkage were performed, and then CFRD D and PPC of those mix proportion were placed in CFRD field. According to test results, it was found that the bonding strength of C1(compact sufficiently) was higher about 10~20% than that of C2(compact insufficiently). And the engineering properties of PPC(concrete using PPF) and FAC(concrete using fly ash) were better than those of the others ; the permeability of PPC and FAC after 8 weeks curing was little lower than that of CFRD D, and plastic shrinkage crack of PPC and FAC was lower 40~60% than crack of CFRD D.

• Journal of Biosystems Engineering
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• 제34권6호
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• pp.420-424
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• 2009

Since the sesame pod gets open gradually from the lower to upper parts of the stem due to its different maturity during cutting and binding of sesame, at the conventional work for shattering, the procedures of drying and shattering are repeated two or three times. Therefore, in this study, a drying stand with transparent plastic cover was developed to complete the drying and shattering at the same time. Owing to the developed drying stand, simple drying work, the area for drying was reduced prevention of sesame seeds from loss and rain are available. The performance of developed drying stand was evaluated. Before the drying stand was developed, the conventional method and shattering machine for shattering sesame required at least three times of operation for complete shattering. But After drying stand was developed, the complete shattering works was possible with only one time shattering operation. Finally, the developed drying stand could prevent approximately 5% of the total sesame seed production from loss during drying and shattering works.

• Advances in materials Research
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• 제13권2호
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• pp.115-128
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• 2024

Concrete is the most significant material in the construction industry which is required to construct several facilities like roads, buildings, and bridges etc. which leads to the economic development of a country. But now days, in view of sustainable development and environmental problems, plastic waste management is one of the major environmental issues due to its non-biodegradable nature which allows it to stay in the landfills until they are cleaned up. To overcome all these concerns, plastic waste may be used as a substitute of natural fine and coarse aggregate in concrete and a valuable solution to utilize the plastic items which causes several problems. In order to, present study is focused on the affecting properties of concrete as workability, compressive strength, and tensile strength of concrete with using plastic waste and without using plastic waste. Based on the detailed literature, it was observed that the plastic waste is not affecting the quality and consistency of concrete. However, as the number of PVC particles in the mixture increased, the drying shrinkage values decreased and the inclusion of plastic flakes can mitigate drying shrinkage cracking which leads the higher durability of concrete. Based on the comprehensive literature, it was also observed that the plastic aggregate found to be suitable for low and medium strength concrete. However, the investigation on the application of plastic aggregate in the high strength concrete is found limited. It was concluded that the optimum percentage of the plastic aggregate was found about 20%.

• Archives of Plastic Surgery
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• 제40권4호
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• pp.374-379
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• 2013

Background To date, various types of acellular dermal matrix (ADM) have been developed for clinical use. AlloDerm is the most familiar type of ADM to most surgeons in breast reconstruction. It is prepared by freeze-drying. CG CryoDerm is the first form of ADM that requires no drying process. Therefore, theoretically, it has a higher degree of preservation of the dermal structures than AlloDerm. We conducted this study to compare the clinical course and postoperative outcomes of patients who underwent direct-to-implant breast reconstructions using AlloDerm and those who did using CG CryoDerm. Methods We performed a retrospective analysis of the medical records in a consecutive series of 50 patients who underwent direct-to-implant breast reconstruction using AlloDerm (n=31) or CryoDerm (n=19). We then compared the clinical course and postoperative outcomes of the two groups based on the overall incidence of complications and the duration of drainage. Results The mean follow-up period was 16 months. There were no significant differences in the overall incidence of complications (seroma, infection, skin flap necrosis, capsular contracture, and implant loss) between the two groups. Nor was there any significant difference in the duration of drainage. Conclusions CG CryoDerm has the merits of short preparation time and easy handling during surgery. Our results indicate that CG CryoDerm might be an alternative allograft material to AlloDerm in direct-to-implant breast reconstruction.