• Title/Summary/Keyword: pouring frequency

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Evaluation of the Time and Pouring Frequency Dependent Dimensional Stability of Additional Silicone Impression Materials. (인상채득 후 시간경과와 반복주입에 따른 부가중합형 실리콘 인상재의 체적변화)

  • Choi, Mee-ra
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.3
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    • pp.239-248
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    • 2007
  • The accuracy and dimensional stability of rubber impression materials are very important for the fitness of the final restoration. The purpose of this investigation was to evaluate the effects of the storage time and pouring frequency of the additional silicone materials on dimensional stability. Total 30 impressions were made of tooth prepared single crown. The dies had 1 buccolingual, 1 mesiodistal and 1 occlusogingival lines. Two additional silicone materials(examixfine, aquasil) were included. 15 specimens were made of each impression material and poured by type IV stone over times(1hour, 24hours, 72hours) after mixing. 5 impressions poured after 1 hour were used for second pouring after 24hours and third pouring after 72hours. The same examiner measured each specimen 3 times after lazer scanning. All statistical tests were performed with the level of significance set at 0.05. The results indicated that significant difference at any measuring point of stone dies except the buccolingual and mesiodistal lines of the specimen made at 1hour after mixing with examixfine when measurements at 1hour, 24hours and 72hours were campared. There were significant difference between two impression materials and at every measuring point of stone dies made at second and third pouring. The length of measuring point increased significantly as time passed by and increase of the pouring frequency. However, this results are clinically acceptable except the dies of the third pouring. Under the conditions of this study, the shrinkage rate of the additional silicone rubber impression materials significantly increased as time passed by and increase of the pouring frequency.

A Numerical Study of the Effect of Casting Temperature and Rotational Frequency of Mold on the Functionally Graded Microstructure in Centrifugal Casting of Hyper-eutectic Al-Si Alloy (과공정 Al-Si합금의 원심주조시 용탕온도와 금형회전수가 경사기능 조직에 미치는 영향에 대한 해석적 고찰)

  • Park, Jeong-Wook;Kim, Heon-Joo
    • Journal of Korea Foundry Society
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    • v.29 no.2
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    • pp.78-85
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    • 2009
  • Functionally graded microstructure of centrifugal cast Al-Si alloy, especially distribution of primary Si particles according to the changes of melt pouring temperature and rotation frequency was investigated by numerical simulation. Moving velocity of Si particles increased as the melt pouring temperature and rotational frequency of mold increased. Therefore, segregation tendency of primary Si particles toward inner side of cylindrical sample increased as the melt pouring temperature and rotational frequency of mold increased. Rich distribution region of particles was located at 0.9, 0.7, 0.4 mm from inner surface of cylindrical sample under the centrifugal cast condition of $750^{\circ}C$ melt pouring temperature and 1500, 2000 and 2500 rpm mold rotational frequencies, respectively, by numerical simulation.

Effect of Centrifugal Casting Parameters on The Distribution of Primary Si Particles of B390 Aluminum Alloy (B390 알루미늄 합금의 초정Si 입자분포에 미치는 원심주조 공정인자의 영향)

  • Park, Jeong-Wook;Kim, Heon-Joo
    • Journal of Korea Foundry Society
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    • v.28 no.1
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    • pp.25-30
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    • 2008
  • To develop a functionally graded microstructure of cylindrical liner, effect of centrifugal casting parameters such as pouring temperature of hyper-eutectic Al-Si alloy melt, mold pre-heating temperature, and rotational frequency of mold on distribution of primary Si particles across wall thickness were investigated. Segregation tendency of Si particles toward inner side of cylindrical liner increased as the increase of rotational frequency of mold, pouring temperature of melt and mold pre-heating temperature. Especially, distribution density of primary Si particles within 1.5 mm from inner surface of cylindrical liner was above 35% under the centrifugal casting condition of $750^{\circ}C$ melt pouring temperature, $300^{\circ}C$ mold pre-heating temperature, and 2500 rpm mold rotational frequency.

A Literature study on the external treatment of nose diseases (鼻病의 外治法에 關한 文獻的 考察)

  • Park, Sang-Gyun;Rho, Sek-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.10 no.1
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    • pp.139-158
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    • 1997
  • A Literature study on the external treatment of nose diseases, the results are as follows; 1. Nose was called "Cheun-bin(天牝)", was outer orifice of the lung, was the gate of vital energe(氣), The main function of nose is divided three pacts. One is the respiration, another is the sense of smell, the other is the sounding consonance. 2. Nose is concerned with The Lung(肺), The Spleen(脾), The Heart(心), The Stomach(胃), The Large intestine(大腸), The Bladder(膀胱) in the organs, is concerned with Lung Meridean, Large intestine Meridean, Stomach Meridean, Heart Meridean, Spleen Meridean, Governor Vessel Meridean etc. 3. The method on the external treatment of nose diseases is classified with obstructive method, pouring method, blowing method, attaching method, plaster method, rubbing method, cleansing method, poulticing method. In frequency of practical use, Obstructive method is used 276 cases, Blowing method is used 123 cases, Attaching method is used 103 cases, Plaster method is used 76 cases. 4. In frequency of the medicinal works on the external treatment of nose diseases, Herba Asari(細辛) is used 134 cases, Pedicellus Melo(瓜 ) is used 85 cases, Radix Aconiti Praeparata(附子) is used 52 cases, Herba Agastachis(麝香) is used 51 cases, Semen Armeniacae Amarurn(杏仁) is used 44 cases etc. In frequency of a prescription on the external treatment of nose diseases, Tongcho-san(通草散) is used 9 cases, $Sesin-go{\cdot}Sinyi-go{\cdot}Changpo-san$ are used 8 cases, $Kwache-san{\cdot}Wungwhang-san$ are used 7 cases etc.

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A Study on the Development of Induction Heating Mass Production System for Moisture Removal of Secondary Battery (이차전지 수분 제거용 유도가열 양산 시스템 개발에 관한 연구)

  • Wangeun Ji;Sunghwan Kim;Haiyoung Jung;Seok-Hyun Lee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.1
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    • pp.42-48
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    • 2023
  • Abstract: In this study, an induction heating system using resonance is developed to remove remaining moisture and contaminations which could be generated during fabricating secondary batteries. This system is composed of power supply and induction coil. Power supply needs an oscillator, zero crossing detection, frequency tracking function, and induction coil needs a dummy coil to obtain a uniform temperature distribution. It is very important to obtain a uniform heating temperature distribution of battery cell case in the induction heating system before pouring electrolyte into battery cell. Experimental results show a temperature distribution deviation of below 1℃ in the external position of battery cell cases. As well, the temperature of battery cell itself shows distribution of 40℃±3℃.

A Literature study on the external treatment of Nasal Polyps (비치(鼻痔)(Nasal polyp)의 외치법(外治法)에 대한 문헌적(文獻的) 고찰(考察))

  • Han, Na-Young;Seo, Hyung-Sik
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.3
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    • pp.208-219
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    • 2009
  • Object : Understanding the importance of the external treatment of nasal polyps and let know the necessity of development of the effect of herb medicine to use in these days. Method : I investigated about 12 oriental medical texts which recorded the external treatment of nasal polyps. I separated them to three part (prescription, herb medicine, the way of making the external application) and check the frequency. Also compared the external treatment of oriental medicine and western medicine. Result : 1. Prescription: There are 48 prescriptions -Nyosasan is used 4 cases, Gwajungsan is used 2 cases and others only 1 case each. 2. Herb-med: There are 67 herb medicines - Herba Asari(細辛) is used 15 cases, Pedicellus Melo (瓜蔕) is used 11 cases, Alunite(白礬) is used 10 cases, Realgar(雄黃)is used 9 cases. 3. The way of making the external application: obstructive method is used 19 cases, attaching method is used 9 cases, blowing method is used 8 cases, plaster method is used 7 cases, pouring method is used 3 cases. 4. The treatment takes about 1day to 15days and the soften nasal polyps like a water can be expect the positive prognosis. Conclusion: The external treatment is very important to treat nasal polyps. So we need to research more on eliminating the toxicity of the herb medicine and develop the convenient way of using the external treatment.

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An improved case by operating the traditional oriental medical remedy with mindfullness to the Hwa-Byung patient suffering from insomnia and physical symptoms (불면(不眠)과 신체증상(身體症狀)을 호소하는 화병 환자에게 한의학적(韓醫學的) 치료(治療)와 마음챙김명상을 병행하여 호전된 1례)

  • Park, Se-Hwan;Seok, Seon-Hee;Kim, Geun-Woo;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.231-244
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    • 2008
  • Insomnia is one of the highest frequency neuropsychosis of neuropsychiatry patients and is primarily caused by major depressive disorder. This case study is about a remedy for a 33 year-old woman who has insomnia and intense depressed mood caused by the continuous family jar. Also, she had the feeling of squeezing her body, pouring cold water into her body, anorexia and feeling cold and hot turn and turn. I operated mindfullness with accupuncture, herb-medication and aroma theraphy. Especially, mindfullness and Gagamguibi-tang were effective for relaxation and the sound sleep in quality and quantity. According to this study, the traditional oriental medical remedy such as accupuncture, herb-medication is effective for the cure of insomnia and mindfullness fortifies the oriental medical remedy.

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Inquiring Activities on the Acoustic Phenomena Using Sound Card in Personal Computer (사운드카드를 이용한 음향학 탐구학습 사례)

  • Lee, Seung-Koog;Lee, Jong-Rim;Kim, Hyun-Byuk;Kim, Young-H.
    • The Journal of the Acoustical Society of Korea
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    • v.30 no.5
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    • pp.249-254
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    • 2011
  • Inquiring activities on the acoustic phenomena have been carried out by using a sound card installed in a personal computer. A sound card is cheaper and more accessible to the students than the precision equipment such as a function generator or an oscilloscope. The students record the sounds from various acoustic phenomena to the sound card. Then they analyze the frequency spectrums of that sounds by using a program. Inquired phenomena include beat by two tuning forks, sound from Rijke tube, pouring sound, breaking of a wine glass and pop-up sound of a wine bottle. Through these activities students perform quantitative analysis of various phenomena due to superposition, resonance and standing wave.

RFID Technology Applications with PMIS for Managing RMC Truck Operations

  • Kim, Seung-Ho;Kim, Sang-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.5
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    • pp.468-481
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    • 2011
  • This research presents a strategy and information system to manage the logistics of delivery ready mixed concrete (RMC) under the integrated environment of PMIS+RFID. PMIS is system tool and technique used in construction sectors to delivery information. Information that can be extracted electronically in real time is more valuable than data gathered and maintained manually. RFID technology can help to improve data accuracy through supply chains and by identifying products and objects at specific points through automatic identification. The objectives of these two implementations can be able to improve the efficiency of logistics management for RMC truck process, and to verify the technical and practical feasibility of PMIS+RFID application in construction industry. This may be realistic given the dynamics of daily activities on construction sites. This research is focused on examples on real world case study, applications and research theme related and connected to PMIS+RFID technology. It demonstrated that PMIS+RFID technology has been automatically implemented and has shown process information about the RMC truck and the overall status information about it, both quickly and accurately. As a result, the construction site where needs 300 $m^3$ pouring (50 RMC trucks) per day can be reduced total 250 minutes. Moreover, this time saving is related to the labour cost saving. From the case studies, RFID+PMIS system was proven in terms of effectiveness rather than current method.

Traffic-induced vibrations at the wet joint during the widening of concrete bridges and non-interruption traffic control strategies

  • Junyong Zhou;Zunian Zhou;Liwen Zhang;Junping Zhang;Xuefei Shi
    • Computers and Concrete
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    • v.32 no.4
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    • pp.411-423
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    • 2023
  • The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.