• Title/Summary/Keyword: Cleaning System

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Comparison of the Frequency of Pain Occurrence by Using Different Calcium Hydroxide Pastes and Root Canal Sealers (수종의 수산화칼슘 근관 첩약제와 레진계 근관 실러의 사용 후 통증 발생 빈도에 관한 연구)

  • Kwak, Sang Won;Kim, Hyeon-Cheol
    • The Journal of the Korean dental association
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    • v.56 no.5
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    • pp.254-262
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    • 2018
  • Objectives: This study aimed to compare the postoperative pain and clinical performance after applying three different intracanal medicaments and root canal sealers. Materials and Methods: Sixty-five patients requiring root canal treatment due to symptomatic apical periodontitis were included in this study. After a glide path preparation by using PathFile, each canal was shaped with ProTaper Next file system. After the canal cleaning and shaping procedure, the canal was dried and each intracanal medicaments were adjusted (Calcipex II, TRC-paste, Metapaste). At the next visit, the patients were requested to answer the absence of the pain after the procedure. Once the patients showed no symptom, the canal was obturated with each corresponded root canal sealers (AH plus, Radic-sealer, ADseal). The patients were recalled after 1 week, 1, 3, and 6 months to check the postoperative pain or unexpected clinical signs. One-way ANOVA and Duncan's post hoc comparison, and Chi-square test were used for statistical analysis to evaluate any differences among tested materials. Results: The average number of visits for intracanal medication was 2.69, 2.65, and 2.61 for Calcipex II, TRC-paste, and Metapaste. There were no statistically differences in post-obturation pain among three groups obturated with different root canal sealers (P > 0.05). Conclusions: Under the limitations of this study, three tested intracanal medicaments and epoxy resin root canal sealers showed clinically acceptable similar results.

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The surface propery change of multi-layer thin film on ceramic substrate by ion beam sputtering (이온빔 스퍼터링법에 의한 다층막의 표면특성변화)

  • Lee, Chan-Young;Lee, Jae-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.259-259
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    • 2008
  • The LTCC (Low Temperature Co-fired Ceramic) technology meets the requirements for high quality microelectronic devices and microsystems application due to a very good electrical and mechanical properties, high reliability and stability as well as possibility of making integrated three dimensional microstructures. The wet process, which has been applied to the etching of the metallic thin film on the ceramic substrate, has multi process steps such as lithography and development and uses very toxic chemicals arising the environmental problems. The other side, Plasma technology like ion beam sputtering is clean process including surface cleaning and treatment, sputtering and etching of semiconductor devices, and environmental cleanup. In this study, metallic multilayer pattern was fabricated by the ion beam etching of Ti/Pd/Cu without the lithography. In the experiment, Alumina and LTCC were used as the substrate and Ti/Pd/Cu metallic multilayer was deposited by the DC-magnetron sputtering system. After the formation of Cu/Ni/Au multilayer pattern made by the photolithography and electroplating process, the Ti/Pd/Cu multilayer was dry-etched by using the low energy-high current ion-beam etching process. Because the electroplated Au layer was the masking barrier of the etching of Ti/Pd/Cu multilayer, the additional lithography was not necessary for the etching process. Xenon ion beam which having the high sputtering yield was irradiated and was used with various ion energy and current. The metallic pattern after the etching was optically examined and analyzed. The rate and phenomenon of the etching on each metallic layer were investigated with the diverse process condition such as ion-beam acceleration energy, current density, and etching time.

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Research on Consumer Recognition of Korean Traditional Costume, Hanbok (한복의 소비자 인식에 관한 연구)

  • Cho, Woo-Hyun;Kim, Mun-Young
    • Journal of the Korean Society of Costume
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    • v.60 no.2
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    • pp.130-143
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    • 2010
  • Hanbok industry is not based on a consumer-oriented market system, which is related to poor competitiveness in various areas, such as product planning, marketing, and flow of raw materials. The purpose of this paper is to design and conduct an empirical study on important aspects of consumers. experiences and perspectives about Hanbok, and thereby aims to provide much-needed guidance about ways to promote the Hanbok market. Out of 1065 questionnaires distributed, a total of 1039 was returned with responses and used for analyses. The respondent sample included consumers of various background characteristics in their residential areas, age, gender, education levels, and income levels. Cronbach's alpha and a factor analysis were employed for the reliability and the construct validation of the survey instrument. One-way ANOVA associated with post-hoc comparison tests was used to investigate differences across different demographic subgroups of consumers. The results show that consumers generally view Hanbok as one of the formal dresses, worn one or two times per year for traditional events or ceremonies. Consumers tend to show negative opinions about the pricing, and the inconvenience in cleaning and wearing Hanbok. However, consumers think very highly of the aesthetic values, the gracious styles, and the iconic identity of nationalism of Hanbok. This study suggests that Hanbok for modern consumers should be considered as clothing for a ritual, rather than clothing to reconstruct to be fitted to modern daily lives. Hanbok should be promoted as part of up-scaled and differentiated traditional cultures, as clothing that represents and enhances the traditional elegance and beauty unique to the Korean people.

A Numerical Study on Coughed Particle Dispersion and Deposition in Negative Pressure Isolation Room according to Particle Size (음압격리병실에서의 기침 토출입자의 입경에 따른 확산 및 침적에 대한 수치해석 연구)

  • Jung, Minji;Hong, Jin Kwan
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.24 no.2
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    • pp.37-44
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    • 2018
  • Purpose: This study investigates the influences of coughing direction and healthcare worker's location on the transport characteristics of coughed particles in airborne infection isolation room (AIIR), which is commonly called negative pressure isolation room, with a downward ventilation system. Methods: Computational Fluid Dynamics (CFD) was used to simulate the airflow and for tracing the behavior of particles. Results: The results show that the airflow pattern and coughing direction have a significant influence on the characteristics of particle dispersion and deposition. When healthcare workers are in the isolation room with the patient who is lying on the bed, it is recommended to be located far from the anteroom to reduce the exposures from infectious particles. And when the patient is lying, it is more effective in removing particles than when the patient is in Fowler's position. Although it is an isolation room that produces unidirectional flow, coughing particles can spread to the whole room and a large number of particles can be deposited onto patient, bed, side rails, healthcare worker, ceiling, floor, and sidewall. Implications: Following the patients' discharge or transfer, terminal cleaning of the vacated room, furniture, and all clinical equipment is essential. Also, it is necessary to establish detailed standard operating procedure (SOP) in order to reduce the risk of cross-contamination.

Estimation of Completeness of Cancer Registration for Patients Referred to Shiraz Selected Centers through a Two Source Capture Re-capture Method, 2009 Data

  • Sharifian, Roxana;SedaghatNia, Mohammad Hossein;Nematolahi, Mohtram;Zare, Najaf;Barzegari, Saeed
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.13
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    • pp.5549-5556
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    • 2015
  • Background: Cancer has important social consequences with cancer registration as the basis of moving towards prevention. The present study aimed to estimate the completeness of registration of the ten most common cancers in patients referred to selected hospitals in Shiraz, Iran by using capture-recapture method. Materials and Methods: This cross-sectional analytical study was performed in 2014 based on the data of 2009, on a total of 4,388 registered cancer patients. After cleaning data from two sources, using capture-recapture common findings were identified. Then, the percentage of the completeness of cancer registration was estimated using Chapman and Chao methods. Finally, the effects of demographic and treatment variables on the completeness of cancer registration were investigated. Results: The results showed that the percentages of completeness of cancer registration in the selected hospitals of Shiraz were 58.6% and 58.4%, and influenced by different variables. The age group between 40-49 years old was the highest represented and for the age group under 20 years old was the lowest for cancer registration. Breast cancer had the highest registration level and after that, thyroid and lung cancers, while colorectal cancer had the lowest registration level. Conclusions: According to the results, the number of cancers registered was very few and it seems that factors like inadequate knowledge of some doctors, imprecise diagnosis about the types of cancer, incorrectly filled out medical documents, and lack of sufficient accuracy in recording data on the computer cause errors and defects in cancer registration. This suggests a necessity to educate and teach doctors and other medical workers about the methods of documenting information related to cancer and also conduct additional measures to improve the cancer registration system.

Development of MBR System Commercialization Technology Using a Membrane with a Good Fouling Resistance (막 오염 저항성이 우수한 분리막을 이용한 MBR 시스템의 실증화 기술개발)

  • Choi, J.H.;Lee, J.B.;Kim, I.C.
    • Membrane Journal
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    • v.18 no.1
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    • pp.35-43
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    • 2008
  • In this study, we tried to solve membrane fouling with membranes made by fine nano-particle in MBR process. And we confirmed good fouling resistance in pilot test. In this test, we confirmed our membrane with titania out-standing quality by testing in the pilot long-term test by comparing to other company product. Our membrane keep up steadily $20{\sim}25 L/m^2{\cdot}hr$ high flux in $7,000{\sim}13,000mg/L$ MLSS high sludge concentration. In addition to this quality, we studied membrane flux character related membrane arrangement, membrane-air line arrangement, air-line hole size, cleaning solution concentration, treatment method, etc. Using the optimization of this additional parameter, we tried to search method of maximizing membrane quality.

An Analysis about the Behavior of the Wiper Blade Including Incompressibility (비압축성을 고려한 와이퍼 블레이드의 거동 해석)

  • Chung, Won-Sun;Song, Hyun-Seok;Park, Tae-Won;Jung, Sung-Pil;Kim, Wook-Hyeon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.2
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    • pp.83-90
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    • 2010
  • The windshield wiper consists of 4 parts: a blade, an arm, a linkage and a motor. The wiper blade makes contact with the windshield and is designed to be operated normally at an angle of 30~50 degrees to the front glass. If the contact pressure between the wiper blade and windshield surface is too high, noise and wear of the rubber will result. On the other hand, if the contact pressure is too low, the performance will do badly, since foreign substances such as dust and stains will not be removed well. The pressure and friction of the wiper blade has a great influence on its effectiveness in cleaning the front window. This is due to the contact of the rubber with the window. This paper presents the dynamic analysis method to estimate the performance of the flat type blade of the wiper system. The blade has a nonlinear characteristic since the rubber is an incompressible hyper-elastic and visco-elastic material. Thus, Structural dynamic analysis using a complex contact model for the blade is performed to find the characteristics of the blade. The flexible multi-body dynamic model is verified by the comparison between test and analysis result. Also, the optimization using the central composite design table is performed.

Effect of Rotating Speed and Air Flow Rate on Material Removal Characteristics in Abrasive Fluidized Bed Machining of Polyacetal (폴리아세탈의 입자유동베드 가공에서 회전속도와 공기 유량이 재료제거 특성에 미치는 영향)

  • Jang, Yangjae;Kim, Taekyoung;Hwang, Heondeok;Seo, Joonyoung;Lee, Dasol;Lee, Hyunseop
    • Tribology and Lubricants
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    • v.33 no.5
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    • pp.214-219
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    • 2017
  • Abrasive fluidized bed machining (AFBM) is similar to general abrasive fluidized machining (AFM) in that it can perform polishing of the outer and inner surfaces of a 3-dimensional shape by the flow of particles. However, in the case of AFM, the shear force generated by the flow of the particles causes material removal, while in AFBM, the abrasive particles are suspended in the chamber to form a bed. AFBM can be used for deburring, polishing, edge contouring, shot peening, and cleaning of mechanical parts. Most studies on AFBM are limited to metals, and research on application of AFBM to plastic materials has not been performed yet. Therefore, in this study, we investigate the effect of rotating speed of the specimen and the air flow rate on the material removal characteristics during AFBM of polyacetal with a horizontal AFBM machine. The material removal rate (MRR) increases linearly with increase of the rotating speed of the main shaft because of the shear force between the particles of the fluidized bed and the rotation of the workpiece. The reduction in surface roughness tends to increase as the rotating speed of the main shaft increases. As the air flow rate increases, the MRR tends to decrease. At a flow rate of 70 L/min or more, the MRR remains almost constant. The reduction of the surface roughness of the specimen is found to decrease with increasing air flow rate.

Evaluation of Indoor Air Quality Improvement by Formaldehyde Emission Rate in School Indoor Environment Using Mass Balance (물질수지를 이용한 학교 실내환경의 포름알데히드(HCHO) 배출량 산정에 의한 실내공기질 개선 평가)

  • Yang, Won-Ho;Son, Bu-Soon;Kim, Dae-Won;Kim, Young-Hee;Byeon, Jae-Cheol;Jung, Soon-won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.3
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    • pp.160-165
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    • 2005
  • Schools have significant and serious indoor environmental health problem, of which indoor air quality (IAQ) in school building may affect the health of the students and indirectly affect learning performance. Schools are of special concern when regarding indoor exposure to air pollutants, because students are particularly sensitive to pollutants and spend a significant amount of time in that environment. Therefore researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide(TiO2) coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde emission rate in school indoor environments by far-Infrared ray coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor air quality.

The Dyeing Properties and Antibiosis of Fabrics Dyed with Agastache rugosa Extract (배초향 추출액을 이용한 염색포의 염색성 및 항균성)

  • Park, Young-Hee
    • Journal of Fashion Business
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    • v.16 no.1
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    • pp.16-25
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    • 2012
  • As the test results for surface color, dyeing durability, antibiosis of cotton fabrics and silk fabrics dyed with Agastache rugosa extract, the following conclusions were obtained. The surface color of all the dyed fabrics was confirmed mostly as a GY system. As the result of chrominance(${\Delta}E_{ab}$) measurement, in the case of cotton fabrics the dyed fabrics treated with $Al_2(SO_4)_3$ mordant showed the highest value and in the case of silk fabrics the non-mordant dyed fabrics showed the highest value. The dyeing durability of test fabrics dyed with Agastache rugosa extract are as follows. As the test results of colorfastness to laundry for cotton dyed fabrics, the discoloration degree showed 1st-2nd grade and the contamination degree showed 4th-5th grade. As the test result of colorfastness to dry cleaning for silk dyed fabrics, the contamination degree showed from 1st to 3rd-4th grade. As the test results of colorfastness to acid artificial perspiration, the discoloration degree showed from 1st to 3rd-4th grade and the contamination degree showed from 3rd to 4th-5th grade. As the test results of colorfastness to alkaline artificial perspiration, the discoloration degree showed from 1st to 4th grade and the contamination degree showed from 3rd to 4th-5th grade. The colorfastness to sunlight showed from 1st to 2nd grade. The colorfastness to rubbing showed from 3rd to 4th-5th grade in dry process and from 2nd-3rd to 4th-5th grade in wet process. As the test results of antibiosis, the decrease rate of germs to virus Klebsiella pneumoniae and Staphylococcus aureus showed at least more than 99% after the wash of 10 times. As the test results of antifungal activity to mycete Trichophyton mentagrophytes and Aspergillus niger, the both cotton and silk dyed fabrics didn't gain the significant antifungal effect.