• Title/Summary/Keyword: Difference Pressure

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Effect of Plastic Container Vent Ratio on Strawberry Quality during Precooling and Storage (플라스틱 컨테이너 상자의 개공율에 따른 딸기의 예냉 및 저장효과)

  • Lee, Ho-Joon;Seo, Jeong-Ah;Choi, Jeong-Hee;Lee, Kang-Dae;Jeong, Moon-Cheol
    • Food Science and Preservation
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    • v.17 no.5
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    • pp.581-585
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    • 2010
  • The effects of plastic container vent ratio on fruit quality during strawberry precooling and storage were analyzed. Plastic containers ($520mm{\times}355mm{\times}182mm$) were manufactured with bottom and side vents at areal ratios of 5%, 10%, 15% and 20%. Fruit was loaded at a volume ratio of 80% prior to pressure cooling and storage at $5^{\circ}C$. The internal fruit temperature was $18^{\circ}C$ and the times taken to attain $2^{\circ}C$ after precooling were 1 hour 9 minutes, 1 hour 13 minutes, 2 hours 2 minutes, and 2 hours 51 minutes at vent ratios of 20%, 15%, 10%, and 5%, respectively. To mimic the current distribution system, precooled strawberries were packaged in tray wrapping and stored at $5^{\circ}C$. Changes in weight, bruising, extent of decay, and firmness, were measured. Weight loss, bruising, and decay were highest at a vent ratio of 20%, lowest at a vent ratio of 15%, and moderate at vent ratios of 5% and 10%. No significant among-treatment difference in fruit firmness was evident.

Physicochemical quality characteristics of hot water extracts of processed ginseng based on different heat treatments (열처리 방법에 따른 가공 인삼 열수추출물의 이화학적 품질 특성)

  • Kang, Yoon-Han;Zhou, Rui;Kim, Hyo Jin;Kim, Ji Eun;Shin, Il Shik
    • Food Science and Preservation
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    • v.25 no.1
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    • pp.155-163
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    • 2018
  • The present study was carried out to investigate the physicochemical properties of hot water extracts of red ginseng powder prepared by two-stage hot air drying method using steamed ginseng and steaming liquid for 2.5 h under high-temperature and high-pressure autoclave condition. The total polyphenols, total flavonoids, total sugar, acid polysaccharides and crude saponin in hot water extracts from red ginseng powder were analyzed and determined, and the flavor components of ginseng were measured using color difference meter and an electronic tongue. The total polyphenol, total flavonoid, total polysaccharide, and acid polysaccharide of the red ginseng hot water extract obtained by autoclaving (ARG) were 9.06 mg GAE/g, 3.38 mg NE/g, 35.22 g/100 g, and 10.90 g/100 g, respectively. The final contents of the total polyphenols, total flavonoids, crude saponin were higher than those determined using other red ginseng methods; the time required for steamed red ginseng production reduced. The total ginsenoside content of ginseng including Rb1 was 10.69 mg/g, which is the lowest ARG. The processing conditions affected the conversion to ginsenosides unique to red ginseng. Red ginseng and steaming liquid obtained from the autoclave are expected to be in need for non-food materials and products as well as foods by improving the flavor components through conversion of red ginseng components into low molecular weight.

The Effects of Guided Imagery Activities Using Music on Mood States, and Physiological Responses of Psychiatric Inpatients (음악을 사용한 지시적 심상이 입원 정신질환자의 기분상태 및 생리적 변화에 미치는 영향)

  • Cho, Hyun-joo;Moon, Ji-young
    • 재활복지
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    • v.20 no.1
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    • pp.113-130
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    • 2016
  • The purpose of this study is to determine the effects of guided imagery activities using music on both mood states and physiological responses of psychiatric inpatients. The experimental group was consisted of 27 psychiatric patients participating in the guided imagery activities using music for 11 minutes. Also, the control group was formed with 27 psychiatric patients with non-musical intervention. Mood states, blood pressure, pulse and skin temperature were checked before and after session. We could see the significant difference in the score of five areas-tension, depression, anger, vigor, fatigue-showed most differences in score. Also, the score of skin temperature of both experimental group and between two groups showed significant differences, too. Therefore, we can conclude that these results were showing that guided imagery activities using music was an effective nursing intervention method for altering mood state of psychiatric patients. Besides, it seemed to have physiological impact to make patients relax tension backed up by change of skin temperature.

Comparative Analysis of Annual Tropospheric Delay by Season and Weather (계절과 날씨에 따른 연간 대류권 지연오차량 변화)

  • Lim, Soo-Hyeon;Kim, Ji-Won;Park, Jeong-Eun;Bae, Tae-Suk;Hong, Sungwook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.1
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    • pp.1-7
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    • 2019
  • In this study, we estimated the tropospheric delay of GNSS (Global Navigation Satellite System) signals during passing through the atmosphere in relation to weather and seasonal factors. For this purpose, we chose four CORS (Continuously Operating Reference Station) stations from inland (CCHJ and PYCH) and on the coast (GEOM and CHJU). A total of 48 days for each station (one set of data for each week) were downloaded from the NGII (National Geographic Information Institute) and processed it using the scientific GNSS software. The average tropospheric delays in winter are less than 2,400 mm, which is about 200 mm less than those in summer. The estimated tropospheric delay shows a similar pattern from all stations except the absolute bias in magnitude, while a large delay was observed for the station located on the coast. In addition, the delay during the day was relatively stable in winter, and the average tropospheric delay was strongly related to the orthometric height. The inland stations have tropospheric delays by the precipitation rather than humidity due to dry weather and difference in temperature. On the contrary, it was primarily caused by the humidity on the sea. The correlation between temperature and water vapor pressure is 0.9 or larger for all stations, and the tropospheric delay showed a high linear relationship with temperature. It is necessary to analyze the GNSS data with higher temporal resolution (e.g. all RINEX data of the year) to improve the stability and reliability of the correlation results.

Effect of Aromatic Additives on the Coke Reduction and the Asphaltene Conversion in a Slurry-phase Hydrocracking (슬러리상 수첨분해 반응에서 아로마틱 유분 첨가에 따른 코크 저감 및 아스팔텐 전환 특성)

  • Lim, Suk Hyun;Go, Kang Seok;Nho, Nam Sun;Lee, Jae Goo
    • Korean Chemical Engineering Research
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    • v.57 no.2
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    • pp.244-252
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    • 2019
  • This study investigated the effect of addition of aromatics such as Toluene/LCO/resin on the coke depression and asphaltene conversion. The experiment was carried out with vacuum residue as a feedstock with Molybdenum dispersed catalysts under the slurry-phase hydrocracking condition (Temp. of $425^{\circ}C$, $H_2$ pressure of 80 bar at $80^{\circ}C$, reaction time of 4 hr, Mo-concentration of 500 ppm). As results, the coke reduction was shown to be similar irrespective of types of aromatics, while asphaltene was more converted to gas and maltene when LCO and resin with higher dipole moment were added. The addition of aromatics with change of reaction time showed no difference in terms of depression of coke formation. But the addition of LCO rather increased the coke yield after 2 hr. And it was found that asphaltene in liquid phase had the higher aromaticity index so that asphaltene is difficult to disperse in oil phase.

Evaluation of Soil Disturbance Due to Bucket Installation in Sand (모래지반에서 버켓기초 설치에 의한 지반교란 평가)

  • Kim, Jae-Hyun;Lee, Seung-Tae;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.34 no.11
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    • pp.21-31
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    • 2018
  • Bucket foundations are widely used in offshore areas due to their various benefits such as easy and fast installations. A bucket is installed using self-weight and the hydraulic pressure difference across the lid generated by pumping out water from inside the bucket. When buckets are installed in high permeable soil such as sands, upward seepage flow occurs around the bucket tip and interior, leading to a decrease in the effective stress in the soil inside the buckets. This process reduces the penetration resistance of buckets. However, the soil inside and outside the bucket can be disturbed due to the upward seepage flow and this can change the soil properties around the bucket. Moreover, upward seepage flow can create significant soil plug heave, thereby hindering the penetration of the bucket to the target depth. Despite of these problems, soil disturbance and soil plug heave created by suction installation are not well understood. This study aims to investigate the behavior of soil during suction installation. To comprehend the phenomena of soil plug heave during installation, a series of small-scale model tests were conducted with different testing conditions. From a series of tests, the effects of tip thickness of bucket, penetration rate, and self-weight were identified. Finally, soil properties inside the bucket after installation were approximated from the measured soil plug heave.

A Study on The Thickness Shrinkage of Injection Molded Parts with The Variation of Injection Mold Core and Molding Materials (사출금형코어 및 성형수지 변화에 따른 두께 방향 수축률에 관한 연구)

  • Shin, Sung-Hyun;Jeong, Eui-Chul;Kim, Mi-Ae;Chae, Bo-Hye;Son, Jung-Eon;Kim, Sang-Yoon;Yoon, Kyung-Hwan;Lee, Sung-Hee
    • Design & Manufacturing
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    • v.13 no.2
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    • pp.17-21
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    • 2019
  • In this study, selective laser sintered 3D printing mold core and metal core were used to investigate the difference of the thickness shrinkage from the gate of the injection molded part at a constant interval. SLS 3D printing mold core was made of nylon-based PA2200 powder and the metal core was manufactured by conventional machining method. As the PA2200 powder material has low strength, thermal conductivity and high specific heat characteristics compared with metal, molding conditions were set with the consideration of molten temperature and injection pressure. Crystalline resin(PP) and amorphous resin(PS) with low melting temperature and viscosity were selected for the injection molding experiment. Cooling time for processing condition was selected by checking the temperature change of the cores with a cavity temperature sensor. The cooling time of the 3D printing core was required a longer time than that of the metal core. The thickness shrinkage of the molded part compared to the core depth was measured from the gate by a constant interval. It was shown that the thickness shrinkage of the 3D printing core was 2.02 ~ 4.34% larger than that of metal core. In additions, in the case of metal core, thickness shrinkage was increased with distance from the gate, on the contrary, in the case of polymer core showed reversed aspect.

Effectiveness of Polyvinyl Acetate Sheeted with Carboxymethyl Cellulose as a Packing Material after Septoplasty (비중격성형술 후 Carboxymethyl Cellulose 시트로 둘러싼 Polyvinyl Acetate의 비 패킹 재료로서 유용성)

  • Kim, Sung-Dong;Kim, Dongwon;Kim, Deok-Soo;Kim, Ji-a;Lee, Dong-Joo;Cho, Kyu-Sup
    • Journal of Rhinology
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    • v.25 no.2
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    • pp.86-90
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    • 2018
  • Background and Objectives: Although polyvinyl acetate ($Merocel^{(R)}$) has been widely used as a packing material after septoplasty, removable nasal packing can increase patient discomfort, local pain, and pressure. Furthermore, the removal of nasal packing has been described as the most uncomfortable and distressing feature associated with septoplasty. The purpose of this study was to investigate the efficacy of polyvinyl acetate with carboxymethyl cellulose sheet ($Rhinocel^{(R)}$) nasal packing on patient subjective symptoms, degree of bleeding, hemostasis, and wound healing following septoplasty. Subjects and Method: Forty patients with nasal septum deviation requiring septoplasty were included. Following surgery, one nasal cavity was packed with $Rhinocel^{(R)}$ and the other one with $Merocel^{(R)}$. Patient subjective symptoms while the packing was in situ, hemostatic properties, pain on removal, degree of bleeding on removal, duration of hemostasis after removal, postoperative wound healing, and the cost of the pack were evaluated. Results: Although the two types of packing materials were equally effective in controlling postoperative bleeding after septoplasty, $Rhinocel^{(R)}$ was significantly more comfortable while in situ and less painful on removal than $Merocel^{(R)}$, which was associated with significantly more bleeding on removal and so more time was needed to control hemorrhage. There was no significant difference in postoperative wound healing or pack cost. Conclusion: The use of $Rhinocel^{(R)}$ after septoplasty has less discomfort, greater patient satisfaction, and less bleeding on removal with no adverse reactions compared to $Merocel^{(R)}$ packing. Therefore, $Rhinocel^{(R)}$ may be a useful packing material after septoplasty.

Influence of the Amount of Conductive Paste on the Electrical Characteristics of c-Si Photovoltaic Module (전도성 페이스트 도포량 변화에 따른 결정질 태양광 모듈의 전기적 특성에 대한 영향성 분석)

  • Kim, Yong Sung;Lim, Jong Rok;Shin, Woo Gyun;Ko, Suk-Whan;Ju, Young-Chul;Hwang, Hye Mi;Chang, Hyo Sik;Kang, Gi-Hwan
    • Korean Journal of Materials Research
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    • v.29 no.11
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    • pp.720-726
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    • 2019
  • Recently, research on cost reduction and efficiency improvement of crystalline silicon(c-Si) photovoltaic(PV) module has been conducted. In order to reduce costs, the thickness of solar cell wafers is becoming thinner. If the thickness of the wafer is reduced, cracking of wafer may occur in high temperature processes during the c-Si PV module manufacturing process. To solve this problem, a low temperature process has been proposed. Conductive paste(CP) is used for low temperature processing; it contains Sn57.6Bi0.4Ag component and can be electrically combined with solar cells and ribbons at a melting point of $150^{\circ}C$. Use of CP in the PV module manufacturing process can minimize cracks of solar cells. When CP is applied to solar cells, the output varies with the amount of CP, and so the optimum amount of CP must be found. In this paper, in order to find the optimal CP application amount, we manufactured several c-Si PV modules with different CP amounts. The amount control of CP is fixed at air pressure (500 kPa) and nozzle diameter 22G(outer diameter 0.72Ø, inner 0.42Ø) of dispenser; only speed is controlled. The c-Si PV module output is measured to analyze the difference according to the amount of CP and analyzed by optical microscope and Alpha-step. As the result, the optimum amount of CP is 0.452 ~ 0.544 g on solar cells.

A pilot study of high flux membrane process for responding to influent turbidity changes in reservoir water (호소수 탁도변화 대응을 위한 고플럭스 막여과공정의 Pilot 연구)

  • Kang, Joonseok;Seong, Jayeong;Yoo, Jewan;Kim, Hyungsoo;Lee, Jaekyu;Jeon, Minhyuk;Cheon, Jihoon
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.6
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    • pp.393-402
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    • 2020
  • In the membrane process, it is important to improve water treatment efficiency to ensure water quality and minimize membrane fouling. In this study, a pilot study of membrane process using reservoir water was conducted for a long time to secure high flux operation technology capable of responding to influent turbidity changes. The raw water and DAF(Dissolved Air Flotation) treated water were used for influent water of membrane to analyze the effect of water quality on the TMP (Trans Membrane Pressure) and to optimize the membrane operation. When the membrane flux were operated at 70 LMH and 80 LMH under stable water quality conditions with an inlet turbidity of 10 NTU or less, the TMP increase rates were 0.28 and 0.24 kPa/d, respectively, with minor difference. When the membrane with high flux of 80 LMH was operated for a long time under inlet turbidity of 10 NTU or more, the TMP increase rate showed the maximum of 43.5 kPa/d. However, when the CEB(Chemically Enhanced Backwash) cycle was changed from 7 to 1 day, it was confirmed that the TMP increase rate was stable to 0.23 kPa/d. As a result of applying pre-treatment process(DAF) on unstability water quality conditions, it was confirmed that the TMP rise rates differed by 0.17 and 0.64 kPa/d according to the optimization of the coagulant injection. When combined with coagulation pretreatment, it was thought that the balance with the membrane process was more important than the emphasis on efficiency of the pretreatment process. It was considered that stable TMP can be maintained by optimizing the cleaning conditions when the stable or unstable water quality even in the high flux operation on membrane process.