• Title/Summary/Keyword: Air gun

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Antioxidant and Physicochemical Changes in Salvia plebeia R. Br. after Hot-air Drying and Blanching (열풍건조 및 데침 처리에 따른 배암차즈기(Salvia plebeia R. Br.)의 항산화 및 이화학적 특성 변화)

  • Jeong, Ji-Suk;Kim, Yong-Joo;Choi, Bo-Rum;Go, Geun-Bae;Son, Byeong-Gil;Gang, Suk-Won;Moon, Seung-Man
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.893-900
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    • 2014
  • The aim of this study was to investigate physicochemical changes in Salvia plebeia R. Br. (SPA) upon hot-air drying and blanching. After hot-air drying and blanching, total polyphenol and flavonoid contents were reduced from 96.64 mg and 48.40 mg gallic acid equivalent/g to 29.70 mg and 22.10 mg quercetin equivalent/g, respectively. DPPH radical scavenging activities at $25{\mu}g/mL$ of SPA were 94.5% for ascorbic acid, 84.3% for hot-air dried SPA, and 59.7% for blanched SPA and there was no significant difference between those of hot-air dried SPA and ascorbic acid as a positive control. Total sugar contents were 7.187% and 6.104% for hot-air dried SPA and blanched SPA, respectively. During the blanching process, sucrose and maltose contents decreased, whereas glucose and fructose contents increased. Glucose and fructose were converted into citric acid in blanched SPA, whereas sucrose and maltose were converted into tartaric acid, malic acid, and succinic acid. Fourteen kinds of amino acids were found, but methionine, lysine, glycine, histidine, and cysteine were absent. The proportion of essential amino acids was 61.76% upon hot-air drying, which was a relatively high amount. In addition, hot-air drying resulted in 1.40 mg/100 g of norvaline as well as 39.00 mg/100 g of GABA, which are non-amino acids. Therefore, Salvia plebeia R. Br. can be used not only as vegetables but also as highly useful and various health functional foods with antioxidant effects and excellent nutrition.

Enhanced Internal Quantum Efficiency and Light Extraction Efficiency of Light-emitting Diodes with Air-gap Photonic Crystal Structure Formed by Tungsten Nano-mask

  • Cho, Chu-Young;Hong, Sang-Hyun;Kim, Ki Seok;Jung, Gun-Young;Park, Seong-Ju
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.705-708
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    • 2014
  • We demonstrate the blue InGaN/GaN multiple quantum wells light-emitting diodes (LEDs) with an embedded air-gap photonic crystal (PC) which was fabricated by the lateral epitaxial overgrowth of GaN layer on the tungsten (W) nano-masks. The periodic air-gap PC was formed by the chemical reaction of hydrogen with GaN on the W nano-mask. The optical output power of LEDs with an air-gap PC was increased by 26% compared to LEDs without an air-gap PC. The enhanced optical output power was attributed to the improvement in internal quantum efficiency and light extraction efficiency by the air-gap PC embedded in GaN layer.

Optimum Design for an Air Current Pulverizing Blade Using the Computational Fluid Dynamics (CFD분석을 통한 기류식 분쇄기 날개부의 최적설계)

  • Kim, Gun-hoi;Kim, Han-bit
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.8
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    • pp.8-14
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    • 2020
  • In the air current pulverizing type grinding method, the blade wings fitted inside a casing are rotated at a high speed to generate a cornering air current, which facilitates the collision of materials with one another, leading to the pulverizing phenomenon. In contrast to mechanical grinding, grit pulverizing leads to fine grinding and less acid waste and degeneration of the material. Moreover, this approach prevents the loss of nutritional value, while allowing the milling grain to have an excellent texture. However, the existing air current pulverizing type machines consist of prefabricated blades, which cannot be rotated at a speed higher than 5,000 rpm. Consequently, the grinding process becomes time consuming with a low productivity. To overcome these problems, in this study, the shape and structure of the air current pulverizing type wings were optimized to allow rapid grinding at more than 8,000 rpm. Moreover, the optimal design for the ripening parts for the air current pulverizing type device was determined by performing a computational fluid dynamics analysis based on airflow analyses to produce machinery that can grinding materials to the order of micrometers.

Development of a Washing Machine for Paprika (착색단고추 세척기 개발)

  • Kim, Young-Keun;Yoon, Hong-Sun;Choe, Jung-Seub;Lee, Young-Hee
    • Journal of Biosystems Engineering
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    • v.36 no.5
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    • pp.361-368
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    • 2011
  • The amount of export of paprika has been increased rapidly in recent years. Therefore, its cultivation area has greatly increased in Korea according to current consumer's attraction. Moreover, it becomes one of the major exporting products while it recorded 53 million dollars, in 2009 resulting in 40% of the total vegetables export. Most of the products are exported to Japan, but it is necessary to prolong the quality preservation periods to export paprika to nations like U.S.A. or EU. However, to encourage an export to many countries, washing and disinfection became more important to deal with longer transportation and medical inspection. The non-chemical use is very important due to stronger regulation of safety to agricultural production. Accordingly, this study was performed to determine the optimum conditions and develop a prototype washing machine, hot water washing of paprika. The results were as follows : The working performance of the prototype was 938 kg/hr, and which was 1.5 times higher than the conventional air gun type washing machine. The operation cost of prototype was 30 won/kg, and 56% of the cost was reduced when compared with air gun type washing machine.

The bibliographical study on causing symptom and treatment of wind-coughing ( 風嗽 ) (풍수(風嗽)의 원인(原因) 증상(症狀) 치법(治法) 치방(治方)에 관(關)한 문헌적(文獻的) 고찰(考察))

  • Kim, Rack-Ki;Oh, Tae-Hwan;Jung, Sung-Gi;Rhee, Hyung-Koo
    • The Journal of Internal Korean Medicine
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    • v.12 no.2
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    • pp.129-137
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    • 1991
  • This study has been carried out to investigate the cause symptom and treatment of wind-coughing ( 風嗽 ) by referring to 38 literatures. The results were obtained as follows; 1. The factors causing wind-coughing ( 風嗽 ) is wind-air. The 1st factors are mistaking of transport lung-air ( 肺氣不宣 ) and cleaning lung (肺失淸肅). 2. The symptom of wind-coughing ( 風嗽 ) is as follows. Bi Saek Sung Jung ( 鼻塞聲重 ), Gu Gun Hu Yang ( 口乾喉痒 ), A Mi Kung I Hae ( 語未竟而咳 ), Maek Bu ( 脈浮 ), Jeang Han Jang Yul ( 憎寒壯熱 ), Ja Han OU Pung ( 自汗惡風 ), Bun Jo ( 煩躁 ), Bi Ryu Chung Chae ( 鼻流淸?), Ya Jung 11 Jyung ( 夜重日輕 ). 3. The treatment-method of wind-coughing ( 風嗽 ) is as follow. Bal San Bul Ga Ha ( 發散 不可下 ), So Pung San Han ( 疏風散寒 ), Chung Yul ( 淸熱 ), Sun Pae Ji Hae ( 宣肺止咳 ). 4. The treatment-herbs of wind-coughing ( 風嗽 ) is as follow. Kwan Dong Hwa San ( 款冬花散 ), Gun Bi Cho San ( 金沸草散 ), Sam Yo Tang ( 三拗湯 ), Ji Hae San ( 止嗽散 ), Hang So San ( 杏蘇散), Sang Kuk Yeam ( 桑菊飮).

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Study on Improvement of Air Conditioning Units for Anti Aircraft Gun Wheeled Vehicle (차륜형 대공포 냉방장치 성능개선 연구)

  • Jeon, Ki-Hyun;Lee, Dong-Hui;Lee, Boo-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.12
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    • pp.1099-1103
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    • 2013
  • A combat vehicle needs to have an air-conditioning unit. Accordingly, new combat systems have tended to apply an integrated heating, cooling, and ventilating system. The air conditioning unit used depends on the combat vehicle's purpose of use. In this study, we studied an air-conditioning unit for an armored combat vehicle as a special use and military specification and tried to improve the air-conditioning unit's performance.

Survey evaluation of thermal boundary condition in the inside and outside of double skin facade

  • Shin, Hyun-Cheol;Jang, Gun-Eik
    • KIEAE Journal
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    • v.15 no.4
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    • pp.29-35
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    • 2015
  • Purpose: Double skin facade is a representative advantageous passive technology of building skin in the aspect of energy saving and environment improvement, reduces heat loss with buffer space in winter season and enhances indoor air and comfort of residents by activating natural ventilation in mid-season. However, in summer season, temperature increase in the intermediate space due to solar energy from exterior transparent skin could be a potential problem; also, relatively weak buoyancy of air caused by low density difference between double-skin facade could increase cooling load as air of intermediate space in high temperature hangs. However, proof data is insufficient to objectify such phenomenon. Method: In this study, researchers surveyed air temperature of intermediate space and airflow and diagnosed its cause targeting on applied multistory facade in the building which gives thermal uncomfort to residents. Also, the researchers produced Solar-air heat transfer coefficient meter, measured thermal boundary condition of double-skin facade, and presented the result of measurement as an objectified verification material regarding overheating phenomenon in the intermediate space of double-skin facade in summer season. Result: Inefficient condition was verified that total heat increases and overheating due to insufficient natural ventilation in multistory facade. In addition, logic behind preceding research was objectified and verified regarding high temperature phenomenon in the intermediate space which could increase cooling load in summer season.

A Field Survey of Indoor Air Environment of Schools (학교 건물의 실내공기환경 실태조사 연구)

  • Chung, Min-Hee;Jung, Sun-Mi;Kim, Mi-Yeon;Kim, Gun-Woo;Park, Jin-Chul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.12
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    • pp.865-873
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    • 2007
  • Recently there has been more apprehensions about health and environment. Since the concern has been increased, it is realized that students need to study in comfort and clean environment, and plan to study in environmental friendly facilities. Hence it is needed for both indoor air quality performance evaluation and greening facilities in order to plan environmental friendly schools. Accordingly, this study analyzes the indoor air quality throughout field survey of schools to provide preliminary data to develop environmental friendly education facilities. This paper investigates and analyzes indoor environment standards and performances in schools. There will be included 15 existing schools and 5 newly built schools for survey in Seoul and Gyeonggi. Additionally, environmental problems are also investigated and analyzed by occupants' questionnaires through surveys.

Estimating the Growth Rate of Inbound Air Travelers to Jeju with ARIMA Time-Series - Using Golf Course Visitor Data - (ARIMA 시계열 모형을 이용한 제주도 인바운드 항공여객 증가율 예측 연구 - 제주지역 골프장 내장객 현황 데이터를 활용하여 -)

  • Gun-Hee Sohn;Kee-Woong Kim;Ri-Hyun Shin;Su-Mi Lee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.31 no.1
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    • pp.92-98
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    • 2023
  • This paper used the golf course visitors' data in Jeju region to forecast the growth of inbound air traveler to Jeju. This is because the golf course visitors were proven to bring the highest economic and production inducement effect to the Jeju region. Based on such a data, this paper forecast the short-term growth rate of inbound air traveler using ARIMA to the Jeju until December 2025. According to ARIMA (0,1,0) (0,1,1) model, it was analyzed that the monthly number of golf course visitors to Jeju has been increasing steadily even since COVID-19 pandemic and the number is expected to grow until the end of 2025. Applying the same parameters of ARIMA (0,1,0) (0,1,1) to inbound air travel data, it was found the growth rate of inbound air travelers would be higher than the growth rate of 2019 shortly without moderate variation even though the monthly number of inbound travelers to Jeju had been dropped during COVID-19 pandemic.

Design of Gun Launched Ramjet Propelled Artillery Shell with Inviscid Flow Assumption (비점성 유동을 가정한 포 발사 램제트 추진탄 설계)

  • Kang, Shinjae;Park, Chul;Jung, Woosuk;Kwon, Taesoo;Park, Juhyeon;Kwon, Sejin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.4
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    • pp.52-60
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    • 2015
  • Operation area of corps was expanded under military reformation, and extending range of 155 mm howitzer became important issue. New approach is needed to extend range to 80 kim. Ramjet engine is air breathing engine, and it can provide specific impulse several times more than solid rocket motor so that range is extended using same weight of propellant. If the ramjet engine is gun-launched system, it does not require any other booster because muzzle velocity is near Mach 3. Especially solid fuel ramjet (SFRJ) does not have any moving part so that it is favorable for gun-launching system which is under high stress during launching. In this paper, we design air intake, combustion chamber, and nozzle of 155 mm gun launched ramjet propelled artillery shell with inviscid flow assumption. We conduct parameter study to have range more than 80 km, and maximum high explosive volume.