• Title/Summary/Keyword: Wet condition

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Optimum Storage Temperature for Spring Sowing of Panax ginseng Seeds (봄파종을 위한 인삼 종자 저장 적정 온도 연구)

  • Suh, Su Jeoung;Jang, In Bae;Jang, In Bok;Moon, Ji Won;Yu, Jin
    • Korean Journal of Medicinal Crop Science
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    • v.27 no.6
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    • pp.390-396
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    • 2019
  • Background: Usually ginseng seeds are sown during autumn and spring. Sowing in spring often results in poorer seedling establishment than in autumn. One of the reasons for poor germination could be cold-treatment condition for breakage of physiological dormancy during winter. Here we tested the effects of storage temperature used during cold treatment on germination. Methods and Results: Germination properties were observed after dehiscent seeds were stored as wet and dry at 2℃, -2℃, -3.5℃ and alternating temperature (AT). Seed dryness and storage temperature affected germination properties (p < 0.01). Wet and AT condition germinated highest, and wet and -3.5℃ condition germinated lowest, which was 91.2% and 1.4% respectively. Mean germination time (MGT) of the wet and AT condition was faster than other treatments at 2.4 days, and the dry and -2℃ condition was the longest. Germination performance index (GPI) was highest for wet and AT condition (37.7%) and the lowest for wet and -3.5℃ condition (0.5%). The growth of above-ground and below-ground were the best for wet and 2℃ condition, and wet seeds showed better growth than dry seeds (p < 0.01). Conclusions: For cold treatment, ginseng seeds may not be stored below -2℃ for successful germination during spring sowing.

Failure Mechanism Analysis and Performance Change of Ballistic Resistance Material on Wet Condition (침수조건에 따른 방탄재료의 성능변화와 파괴거동 분석)

  • Tae, Won-Seok;Kim, Gun-In
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.6
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    • pp.803-810
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    • 2013
  • In this paper, we have verified the performance of ballistic resistance material on wet condition. Considering Korea terrain, soldiers may face many rivers and streams. However, bullet-proof jacket has no waterproofing and there's no water-proof standard in Military. Wearing wet bullet-proof jacket, soldiers can't be protected properly because of the decrement of jacket. Thus, we measure the performance of existing material on wet condition and analyze failure mechanism in order to indicate factors to improve bullet-proof jacket.

Comparison study of nanosecond laser induced wet and dry ablation of PMMA (나노초 레이저를 이용한 PMMA의 습식 및 건식어블레이션 비교 연구)

  • lee, Ho
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.3
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    • pp.243-250
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    • 2019
  • The nanosecond laser assisted ablation have been investigated. The biocompatable polymer PMMA was employed as the target material and the two distinctive surface conditions were test. The first surface condition is a dry surface for which the target surface is exposed to air and the second surface condition is the wet surface for which the target surface is covered with dehydrated water. The ablation volume, the laser induced acoustic wave, the laser induced plasma were investigated for both wet and dry condition. The nanosecond laser pulse ablatied more on the wet surface compared to the dry surface. The enhanced ablation of wet surface is attributed to the confined acoustic wave and the laser-induced plasma in the liquid layer.

A Comparison of Effect between Wet Gauze with Cold Normal Saline and Wet Gauze with Cold Water on Postoperative Thirst, Oral Cavity Condition, and Saliva pH (생리식염수 냉수 거즈와 일반 냉수 거즈의 수술 후 갈증, 구강상태, 타액 산성도에 미치는 효과 비교)

  • Moon, Yang Hee;Lee, Yeon Hee;Jeong, Ihn Sook
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.22 no.4
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    • pp.398-405
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    • 2015
  • Purpose: This study was aimed to compare the effect between wet gauze with cold normal saline and wet gauze with cold water on thirst, oral cavity condition, and saliva pH among postoperative patients. Methods: This study was a quasi-experimental study with 56 participants. The experimental group received wet gauze with cold normal saline, and control group received wet gauze with cold water for three times at 15 minute intervals. Data were collected using visual analog scale for thirst, oral assessment guide for oral cavity condition and acidity tape for saliva pH. Measurement were made before applying the gauze and at 15min, 30min, and 45min after applying gauze. Data were analyzed using repeated measured ANOVA. Results: Thirst, oral cavity condition, and saliva pH improved in both groups with increasing number of gauze application. Thirst for the experimental group improved more than for the control group (F=4.29, p=.009), oral cavity condition except saliva, and saliva pH were not significantly different between the groups. Conclusion: This study results indicated that nurses can apply wet gauze with cold normal saline to reduce thirst and saliva acidity, and to improve the oral cavity condition for postoperative patients.

Drilling Characteristics of PVC Materials (PVC 재료의 드릴링 특성)

  • Byun, J.Y.;Park, Na-Ram;Chung, S.W.;Kwon, S.H.;Kwon, S.G.;Park, J.M.;Kim, J.S.;Choi, Won-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.1
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    • pp.70-77
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    • 2015
  • This paper develops and evaluates a mechanical machining process which involves drilling on PVS material. According to the material, two treatment experiments were conducted, one involving drilling in a wet condition or using a lubricant and one involving drilling in a dry condition with no lubricant. Drilling in a dry condition showed better performance in terms of the cutting time than in the wet condition. Otherwise, the wet condition has several advantages. The lubricant influenced the burr diameter size and minimized the temperature on the surface of the work piece. During the wet condition drilling process, a smaller burr diameter size was noted as compared to the dry condition. The temperature showed a linear correlation with the drill bit size, where a least-square analysis provided an $R^2$valuewhichexceeded 0.95. The wet condition required more cutting time than the dry condition. In this condition, the water provides a lubrication effect. A thin layer between the cutting edges and the surface of the work piece is formed. The chip formation is affected by the drilling depth. The color on the tips of the chips was darker than in the initial condition. No correlation between the drilling depth and the bore roughness was noted, but the variation of the cutting speed or the RPM influenced the roughness of the bore. The optimum cutting speed ranged from 40 RPM to 45 RPM in the condition which provided the finest roughness surface.

Improvement of Wet-end Performance and Paper Strength with Polyvinylamine

  • Son, Dong-Jin;Kim, Bong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.5 s.113
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    • pp.63-69
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    • 2005
  • This study was performed to introduce recently developed polyvinylamine as a wet-end process and paper strength improving aids. As a retention and drainage aids, high cationic charged polyvinylamine was more effective at the BCTMP and ONP stock condition than LBKP stock condition. As a dry tensile strength aid, dual system of polyvinylamine with anionic polyacrylamide was the best at the LBKP or ONP stock conditions. On the other hand, polyvinyl amine alone was better than dual system of polyvinylamine with anionic polyacrylamide at the BCTMP condition. As a wet tensile strength aid, polyvinylamine single system and dual system of polyvinylamine with anionic polyacrylamide were good at LBKP, BCTMP and ONP stock conditions. However, poly(aminoamide)-epichlorohydrin resin was good at LBKP and ONP stock conditions but efficiency of poly(aminoamide)-epichlorohydrin resin was remarkably decreased at BCTMP stock condition.

Analysis on the Optimum Location of an Wet Air Cleaner in a Livestock House using CFD technology (전산유체역학 기법을 이용한 돈사 내 습식 공기 정화기의 적정 위치 설계)

  • Kwon, Kyeong-Seok;Lee, In-Bok;Hwang, Hyun-Seob;Bitog, Jessie.P.;Hong, Se-Woon;Seo, Il-Hwan;Choi, Ji-Sun;Song, Sang-Hyeon;Moon, Oun-Kyung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.3
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    • pp.19-29
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    • 2010
  • In South Korea, as the living standard has been getting higher, meat consumption is steadily increasing. To meet the country's demand, livestock houses become larger and wider with increased raising density. In larger livestock houses, pollutants such as flake of pig skin, excrement, odor, various dusts and noxious gas like ammonia are excessively accumulated inside the facility. These will cause weak immunity for the pigs, diminution of productivity and degeneration of working condition. These problems can be solved through the ventilation performance of the facility. In the winter time, ventilation must be controlled to minimum to maintain a suitable thermal condition. However, this affects the other internal environmental condition because of the minimum ventilation. The installation of "wet air cleaner" especially in the winter time can be an alternative solution. For efficient application of this machine, there is a need to understand the existing ventilation condition and analyze the interaction of existing ventilation system with the wet air cleaner considering its appropriate location. In this study, the existing ventilation system as well as the internal environmental condition negatively inside the facility with the wet air cleaner has been studied using CFD technology. The CFD simulation model was validated from the study conducted by Seo et al. (2008). Results show that the elimination rate of ammonia was 39.4 % and stability could be improved to 35.1 % (Comparing case 5 to 1 where wet air cleaner machine was not used). It can therefore be concluded that case 5 shows the optimum location of a wet air cleaner in the livestock house.

Studies on wet polishing characteristic of rice (습식연미 도정특성에 관한 연구)

  • Lee, B.Y.;Son, J.R.;Yoon, I.H.;Kim, Y.B.
    • Applied Biological Chemistry
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    • v.35 no.6
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    • pp.475-478
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    • 1992
  • Series of study were conducted to investigated the condition of wet polishing and quality of wet polished rice. The optimal condition for wet polishing was determined to be 0.5% added water after removal bran layer of 95% by normal milling. Its polishing yield was 0.75% lower than normal polishing, and the moisture content of wet and normal polished rice was the same, but the whiteness of wet polished rice was higher by 3.5% than that of normal polished rice and the lightness was very good. The total solid as washing wet polished rice in water and the total solid in residual liquid of cooked wet polished rice was about 0.30 and 2% lower than those of normal polished rice, respectively. The storability of wet polished rice was better than that of normal polished rice.

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The Effect of Dissolution Condition on the Yield, Molecular Weight, and Wet- and Electro-spinnability of Regenerated Silk Fibroins Prepared by LiBr Aqueous Solution

  • Cho, Hee-Jung;Um, In-Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.20 no.2
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    • pp.99-105
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    • 2010
  • In this paper, the regenerated silk fibroins were dissolved in LiBr aqueous solution with different dissolution temperature and time, and the effects of the dissolution condition on the regeneration yield, molecular weight, wet spinnability, and electrospinnability of regenerated silk fibroin were investigated. The regeneration yield, molecular weight distribution, and wet spinnability of regenerated silk fibroin were nearly affected by the dissolution temperature and time. However, the electrospinning performance of silk fibroin was influenced by the dissolution condition implying the electrospinning of silk fibroin is more sensitive process than the wet spinning in the range tested in this study. While $25^{\circ}C$ of dissolution temperature resulted in a good electrospinnability of regenerated silk fibroin, the electrospinnability was slightly deteriorated when silk fibroin was dissolved at $60^{\circ}C$ for 6 hours. Also, though the fiber diameters of electrospun silk fibroin produced by the dissolution at $25^{\circ}C$ for 6 hours and 24 hours were 443 and 451 nm, respectively, that at $60^{\circ}C$ for 5 min was reduced to 411 nm. The fiber diameter was more decreased to 393 nm when the dissolution time increased up to 6 hours at $60^{\circ}C$.

Evaluation of Applicability of Circuit-analog Radar Absorbing Structures for High Temperature in 350℃ and Hot-wet Environment (고온용 Circuit-analog 전파흡수구조의 350℃ 및 열 수분 환경에서의 적용성 평가)

  • Min-Su Jang;Ho-Beom Kim;Heon-Suk Hong
    • Composites Research
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    • v.36 no.5
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    • pp.335-341
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    • 2023
  • We proposed a high-temperature circuit-analog radar absorbing structures (CA-RAS), and evaluated radar absorption performance and tensile properties in 350℃ and a hot-wet environment. The CA-RAS was implemented with a glass/cyanate ester composites and a square resistive pattern layer, and reflection loss was measured by 350℃ and after exposure of hot-wet condition using free space measurement. And the tensile strength at 350℃ and after exposure of hot-wet condition was measured according to the ASTM D638. The proposed CA-RAS showed a 4 GHz of -dB bandwidth and -20 dB of a peak value at 350℃. In addition, there was no deterioration in absorption performance after exposure to a hot-wet condition. The tensile strength value of more than 95% compared to the strength of the glass/cyanate ester composite was confirmed at 350℃ and after exposure of hot-wet condition. Through this, the applicability of CA-RAS proposed in this study was confirmed as a load bearing structure for stealth weapon exposed to high temperature and hot-wet environment.