• Title/Summary/Keyword: Thermal pre-treatment

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Improvement of the Quality of Dried Wild Vegetables by Micro Oil Sprayed Thermal Air Technique

  • Yonghyun Kim;Yunmi Park;Chul-Woo Kim;Uk Lee;Hyun Ji Eo
    • Korean Journal of Plant Resources
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    • v.35 no.6
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    • pp.778-784
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    • 2022
  • Wild vegetables, such as Cirsium setidens, and Aster scaber, are commonly distributed as dried materials because the wild vegetables lose their freshness quickly after harvest and distribution. Dried wild vegetables require rehydration to use as a food ingredient, and the quality of rehydrated wild vegetables is affected by pre-drying and drying methods. Here, we introduce the newly developed pre-drying and drying method, termed "micro oil sprayed thermal air (MOTA) technique". The three wild vegetables processed by the MOTA technique showed improved rehydration rate and reduced time to achieve maximum rehydration rate. Color characteristics were also improved in C. setidens. These results indicate that the MOTA technique improves the overall quality of rehydrated wild vegetables. It is expected that our findings could enhance the marketability of dried wild vegetables by improving overall quality and reducing preparation time.

A Study on Pre-treatment and Performance Evaluation for Printing RFID Antenna with Conductive Paste (RFID 안테나용 전도성 프린팅을 위한 PET 직물의 최적 전처리 공정연구 및 성능평가)

  • Hong, Jinpyo;Jung, Chando;Yoon, Seokhan;Choi, Sanghyun
    • Textile Coloration and Finishing
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    • v.25 no.4
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    • pp.287-291
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    • 2013
  • Nowadays, terms such as 'Smart Textile', 'Intelligent Textile' and 'Wearable Computing' are commonly used in everyday contexts. And radio-frequency identification (RFID) is the use of a wireless non-contact system that uses radio-frequency electromagnetic fields to transfer data from a tag attached to an object, for the purposes of automatic identification and tracking. These products are required technologies which are textile treatments, printing, ink, etc. Durability of textile substrates is an essential marker for conductive ink printing process. Especially, heat stability is important, since conductive ink should be processable (annealing, curing) at temperatures below $150^{\circ}C$. This study was application of RFID on textiles. The textile pre-treatment processes should be carried out to use RFID antenna on textiles.

A Methodological Study of the Wear-Resistant Property Improvement on the Thermal Spray Coating for Capstan (Capstan용 용사코팅의 내마모 특성 향상 방안)

  • 어순철
    • Journal of Powder Materials
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    • v.7 no.2
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    • pp.63-70
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    • 2000
  • Thermal spray coating process has proven to be effective at producing hard, dense, wear resistance coatings on the relatively mild substrates. Among several spraying techniques, HVOF (High Velocity Oxygen Fuel) and plasma coating processes, which are preferentially used for the wear resistance application such as capstans, have been applied in this study. The effects of pre-treatment, it-process and post-treatment parameters on the wear and mechanical properties of WC+12%Co, Cr3C2 and Al2O3 powder coatings have been investigated and correlated with the microstructures. The results indicated that the carbide coating was more preferable to the oxide coatings and the post-treatments consisting of vacuum annealing and sealing on carbide coatings led to significant improvements in wear resistance, adhesive strength and coating phase stabilization over the other processing techniques in this application.

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Effect of Passive Temperature Therapy of the Femoral Muscles on the Countermovement Jump Performance

  • Lee, Jintaek;Panday, Siddhartha Bikram;Byun, Kyungseok;Lee, Jusung;Hwang, Jinny;Moon, Jeheon
    • Korean Journal of Applied Biomechanics
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    • v.29 no.4
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    • pp.227-235
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    • 2019
  • Objective: The purpose of this study was to evaluate the effect of passive-acute temperature therapy of the femoral muscle and dynamic warm-up on the countermovement jump performance. Method: Twenty male track and field athletes from national team underwent three treatments applied on the femoral muscles; cold temperature treatment, thermal treatment and dynamic warm-up. The variables extracted at 2 time points (pre-measurement and post measurement) were the temperature of the left and right femoral muscle, displacement & velocity of centre of mass, peak power out, range of motion and moment & power of the knee joint. Results: There was a statistically significant difference in the temperature of the femoral muscle according to measurement time which was high in the order of thermal treatment, dynamic treatment and cold treatment. The jump height was the highest in the dynamic warm-up with no statistically significant difference for the range of motion of the knee joint. The peak power out at dynamic warm-up and the power of the knee joint were statistically significant according to the treatment and measurement time. Conclusion: Local cold and thermal treatment of femoral muscles at ambient temperature did not improve jump performance, while dynamic warm-up was considered to be effective for maintaining the performance of the activities that require strong muscular power.

LIMITED OXIDATION OF IRRADIATED GRAPHITE WASTE TO REMOVE SURFACE CARBON-14

  • Smith, Tara E.;Mccrory, Shilo;Dunzik-Gougar, Mary Lou
    • Nuclear Engineering and Technology
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    • v.45 no.2
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    • pp.211-218
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    • 2013
  • Large quantities of irradiated graphite waste from graphite-moderated nuclear reactors exist and are expected to increase in the case of High Temperature Reactor (HTR) deployment [1,2]. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 ($^{14}C$), with a half-life of 5730 years. Fachinger et al. [2] have demonstrated that thermal treatment of irradiated graphite removes a significant fraction of the $^{14}C$, which tends to be concentrated on the graphite surface. During thermal treatment, graphite surface carbon atoms interact with naturally adsorbed oxygen complexes to create $CO_x$ gases, i.e. "gasify" graphite. The effectiveness of this process is highly dependent on the availability of adsorbed oxygen compounds. The quantity and form of adsorbed oxygen complexes in pre- and post-irradiated graphite were studied using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Xray Photoelectron Spectroscopy (XPS) in an effort to better understand the gasification process and to apply that understanding to process optimization. Adsorbed oxygen fragments were detected on both irradiated and unirradiated graphite; however, carbon-oxygen bonds were identified only on the irradiated material. This difference is likely due to a large number of carbon active sites associated with the higher lattice disorder resulting from irradiation. Results of XPS analysis also indicated the potential bonding structures of the oxygen fragments removed during surface impingement. Ester- and carboxyl-like structures were predominant among the identified oxygen-containing fragments. The indicated structures are consistent with those characterized by Fanning and Vannice [3] and later incorporated into an oxidation kinetics model by El-Genk and Tournier [4]. Based on the predicted desorption mechanisms of carbon oxides from the identified compounds, it is expected that a majority of the graphite should gasify as carbon monoxide (CO) rather than carbon dioxide ($CO_2$). Therefore, to optimize the efficiency of thermal treatment the graphite should be heated to temperatures above the surface decomposition temperature increasing the evolution of CO [4].

Variation in Physicochemical Properties and Anaerobic Digestion Efficiency by Thermal-alkali Pre-treatment (THAP) Factors (열화학적 가수분해 영향인자에 따른 물리화학적 특성 변화 및 혐기성소화 효율 평가)

  • Park, Seyong;Han, Sungkuk;Song, Eunhey;Kim, Choonggon;Lee, Wonbae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.3
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    • pp.27-39
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    • 2019
  • In this study, thermal-alkali pre-treatment (THAP) optimal condition and co-digestion efficiency with THAP of the mixture food waste and sewage sludge were evaluated for improving the performances of co-digestion for mixed food waste and sewage sludge. The optimal condition of THAP was evaluated for solubilization COD, CST(Capillary Suction Time), TTF(Time to Filter), and volatile fatty acids (VFAs) with THAP temperature and NaOH concentration. In addition, the co-digestion of mixed food waste and sewage sludge were evaluated using biochemical methane potential (BMP) test. The optimal THAP reaction temperature and NaOH concentration of food waste and sewage sludge were $140^{\circ}C$ and 60 meq/L to solubilization COD over 20%, CST and TTF under 60sec and VFAs concentration over 12,000 mg-COD/L, respectively. The optimal condition of co-digestion of mixed food waste and sewage sludge equal to THAP condition. Therefore, it was determined that the optimal condition of THAP reaction temperature and NaOH concentration for co-digestion of mixed food waste and sewage sludge were $140^{\circ}C$ and 60 meq/L, respectively.

Effect of Carbon Nanotube Pre-treatment on Dispersion and Electrical Properties of Melt Mixed Multi-Walled Carbon Nanotubes / Poly(methyl methacrylate) Composites

  • Park Won Ki;Kim Jung Uyun;Lee Sang-Soo;Kim Junkyung;Lee Geon-Woong;Park Min
    • Macromolecular Research
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    • v.13 no.3
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    • pp.206-211
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    • 2005
  • Multi-walled carbon nanotubes (MWNTs) pre-treated by concentrated mixed acid or oxidized at high temperature were melt mixed with poly(methyl methacrylate) (PMMA) using a twin screw extruder. The morphologies and electrical properties of the MWNT/PMMA composites were investigated. The thermally treated MWNTs (t-MWNTs) were well dispersed, whereas the acid treated MWNTs (a-MWNTs) were highly entangled, forming large-sized clusters. The resulting electrical properties of the composites were analyzed in terms of the carbon nanotube (CNT) dispersion. The experimental percolation threshold was estimated to be $3 wt\%$ of t-MWNTs, but no percolation occurred at similar concentrations in the a-MWNT composites, due to the poor dispersion in the matrix.

Remediation of Petroleum-Contaminated Soil by a Directly-Heated Thermal Desorption Process (직접 가열식 열탈착 공정을 이용한 유류오염토양의 정화)

  • Min, Hyeong-Sik;Yang, In-Ho;Jeon, Sang-Jo;Kim, Han-S.
    • Journal of Soil and Groundwater Environment
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    • v.14 no.5
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    • pp.62-70
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    • 2009
  • A field soil highly contaminated with petroleum hydrocarbons (JP-8 and diesel fuels) was employed for its remediation by a lab-scale thermal desorption process. The soil was collected in the vicinity of an underground storage tank in a closed military base and its contamination level was as high as 4,476 ppm as total petroleum hydrocarbon (TPH). A lab scale directly-heated low temperature thermal desorption (LTTD) system of 10-L capacity was developed and operated for the thermal treatment of TPH contaminated soils in this study. The desired operation temperature was found to be approximately $200-300^{\circ}C$ from the thermal gravimetric analysis of the contaminated field soils. The removal efficiencies higher than 90% were achieved by the LTTD treatment at $200^{\circ}C$ for 10 min as well as at $300^{\circ}C$ for 5 min. As the water content in the soils increased and therefore they were likely to be present as lumps, the removal efficiency noticeably decreased, indicating that a pre-treatment such as field drying should be required. The analysis of physical and chemical properties of soils before and after the LTTD treatment demonstrated that no significant changes occurred during the thermal treatment, supporting no needs for additional post-treatments for the soils treated by LTTD. The results presented in this study are expected to provide useful information for the field application and verification of LTTD for the highly contaminated geo-environment.

Changes of Facial Temperature and Blood Flow Rates by Treatment of Miso Facial Rejuvenation Acupuncture (미소안면침이 안면 피부 온도와 혈류량에 미치는 영향)

  • Kim, Tae Yeon;Bak, Jong Phil;Kim, Yong Min
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.4
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    • pp.481-486
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    • 2013
  • To investigate the effects of facial temperature and blood flow rates generated by Miso Facial Rejuvenation Acupuncture treatment. Ten women in their twenties to fifties with no skin diseases were recruited. Miso Facial Rejuvenation Acupuncture(MFRA) was performed on the both sides of their face. We measured their facial temperature using Digital Infrared Thermal Imaging(DITI) and blood flow rates using Laser Doppler Perfusion Imaging(LDPI) at pre-treatment, immediately, twenty and sixty minutes after treatment. We analyzed data using student's t-test(p<0.05). After MFRA treatment, facial temperature on the measurement area increased immediately from $30.5{\pm}1.0^{\circ}C$ to $31.5{\pm}1.0^{\circ}C$, a statistically significant increase. Sixty minutes after treatment, facial temperature on the measurement area decreased a little bit($30.2{\pm}0.6^{\circ}C$), but there was no statistical significance. After MFRA treatment, facial blood flow rates on the measurement area increased immediately from $165.1{\pm}52.3$ PU to $342.7{\pm}51.3$ PU, a statistically significant increase. Sixty minutes after treatment, facial blood flow rates measurement area were recovered almost at the same level as before treatment. MFRA treatment could increase facial temperature and blood flow rates.

Study on Physical Properties of Polyvinylidene fluoride Paint Coated Steel by Thermal Treatment Condition under Continuous Mass Production (P.V.D.F 페인트 도장강판의 연속공정하의 열처리 조건에 따른 물성 변화 연구)

  • Jeong, Min-Yeong;Kim, Yong-Hui;Lee, Bo-Ryong;Mun, Man-Bin
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.187-187
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    • 2015
  • Polyvinylidene fluoride (PVDF) 코팅은 뛰어난 내후성으로 인해 Pre-painted metal에 많이 응용되며 주로 고가의 건축물 외장재에 적용되고 있는데, 수지의 열가소성 특성으로 인해 도막경화시 Baking 온도 및 냉각속도가 도막의 결정화도에 영향을 주어 가공특성이 상이하게 변함을 확인 하였다.

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