• 월간산업보건
• /
• s.353
• /
• pp.29-33
• /
• 2017

수산화나트륨(Sodium hydroxide)의 직업적 노출에 대한 TLV-Ceiling은 $2mg/m^3$으로 권고하였다. 권고수준은 수산화나트륨 에어로졸이 눈, 점막, 피부에 심한 자극을 유발하고 수산화나트륨 분진이 상기도 기관에 자극을 유발하는 농도에 근거하였다. 노출기준은 눈과 상기도 기관에 자극을 최소화하기 위하여 권고하였다. 고농도의 수산화나트륨에 장기간 노출되면 비강 궤양과 눈과 피부에 심한 손상을 유발할 수 있다. "피부", "감작제(SEN)", "발암성"의 경고주석을 권고하기에는 유용한 자료가 충분하지 않다.

• Journal of Welding and Joining
• /
• v.22 no.3
• /
• pp.39-44
• /
• 2004

최근 국내외적으로 환경규제가 강화되면서 소형선의 경우 FRP선의 폐선처리가 문제시되면서 알루미늄선에 대한 관심이 고조되고 있다. 이러한 알루미늄선의 건조는 철강재 등 여러 재료에 비해 알루미늄은 비강도가 높아 경량화에 의한 고속화가 가능하고 높은 내식성에 의한 유지보수가 용이하며, 폐선시 재활용이 가능하여 환경 친화적이라는 이점이 있기 때문이다.(중략)

• Proceedings of the Korea Contents Association Conference
• /
• 2006.11a
• /
• pp.788-791
• /
• 2006

The perception of English labial consonants was investigated via experiment where 40 Korean EFL learners identified nonwords with the target labial consonants [p, b, f, v] in 4 different prosodic locations. The results showed that there was a strong positional effect since the accuracy rates of the four target consonants differed by position. Specifically, the average accuracy rate for the target consonants was higher in the stressed intervocalic position and initial onset position than in the unstressed intervocalic position and final coda position. Further, the accuracy rate for [f] is was high in all prosodic locations except the unstressed intervocalic position. This is unexpected in markedness theory given that fricatives are assumed to be more difficult to learn than stops.

• Composites Research
• /
• v.14 no.1
• /
• pp.30-38
• /
• 2001

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the on-line cure monitoring during the cure process of the composite materials has become an important research area for the better quality and productivity. In this paper, the dielectric circuit of the Wheatstone bridge type for measuring the dissipation factor during cure of thermsetting resin matrix composite materials was designed and manufactured. Also, the dielectric sensor for the cure monitoring of high temperature cure composites was developed and tested. The residual thermal stresses of the dielectric sensor during high temperature cure were analyzed by the finite element method and its dielectric characteristics at high temperature cure were analyzed by the finite element method and its dielectric characteristics at high temperature were evaluated. The on-line cure monitoring of the BMI(Bismaleimide) resin was performed using the developed Wheatstone bridge type circuit and the high-temperature dielectric sensor.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.22 no.1
• /
• pp.25-33
• /
• 2016

Purpose: The purpose of this study was to examine the effects of frozen gauze with normal saline on thirst and the oral health of patients with nasal surgery. Methods: A quasi-experimental, nonequivalent control group pretest-post test design was used. Participants (n=52) received either gauze frozen with normal saline (n=26), or wet gauze (n=26). The subjective thirst level and oral health of the participants were assessed before the intervention, 30 minutes after the first intervention, 30 minutes after the second intervention, and 30 minutes after the third intervention. Results: After oral hygiene was provided twice, the thirst level was improved in patients receiving the gauze frozen with normal saline. After oral hygiene was provided a third time, the thirst level was improved in patients receiving the gauze frozen with normal saline. Conclusion: Gauze frozen with normal saline can be effective for oral hygiene in reducing the thirst level and improving the oral health in nasal surgery patients.

• Journal of Korean Association for Spatial Structures
• /
• v.11 no.3
• /
• pp.77-83
• /
• 2011

Laminated composite plates have shown their superiority over metals in applications requiring high specific strength, high specific modulus, and so on. Therefore, they have used in various industry. However, they have poor resistance to impact compared to typical metal materials. To resolve this problem by many researchers for a variety of studies have been attempted. This study investigates characteristic of impact behavior of laminated composite plates due to initial stress. Using finite element program which involved the indentation law, we investigate characteristic of impact behavior of laminated composite plates due to initial stress.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.6
• /
• pp.461-467
• /
• 2009

Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal, abnormal, and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time normal and several deformed nasal cavity models, which simulate surgical operation, Turbinectomy, are investigated numerically by the FVM general purpose code and PIV analysis. The comparisons of these results are appreciated. Dense CT data and careful treatment of model surface under the ENT doctor's advice provide more sophisticated cavity models. The Davis (LaVision Co.) code is used for PIV flow analysis. Average and RMS distributions have been obtained for inspirational and expirational nasal airflows in the normal and deformed nasal cavities.

• Journal of the Korean Institute of Gas
• /
• v.13 no.4
• /
• pp.15-21
• /
• 2009

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. Pressure vessels using this composite material have two main merits which are to cut down energy by reducing weight and to have long-term life due to corrosion resistance. In this paper, we developed optimal design module of laminate for CNG composite pressure vessel winding E-glass/epoxy based on Von-Mises yield criterion, Tsai-Hill theory and stress ratio using finite element method and ANSYS RSM(Response Surface Method).

• Journal of Yeungnam Medical Science
• /
• v.5 no.1
• /
• pp.135-139
• /
• 1988

The primary malignat melanoma of the nasal cavity and paranasal sinuses is extemely rare and accounts for only between 0.6 and 2.5% of the total 'number of malignat melanoma at all sites. In the nose, the left side is involved in 60% of cases and the most frequent site is the septum followed by the inferior and middle turbinates. In the sinuses, the maxillary sinus is the site of origin in 80% of cases, followed by ethmoid sinus. The tumors are sessile or polypoid, with variable color such as pink. white, brown or black. Of all tumors, 10~30% are amelanotic, requiring special stains for melanin. When primary site of melanoma is mucosal origin. treatment of primary lesion is often hampered by anatomic retrictions and large size, which results from the delayed diagnosis caused by their location. We report 4 cases of primary malignant melanoma of nasal cavity with review of literature.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.1
• /
• pp.104-117
• /
• 1999

The Composite materials has been used in the field of high technology industry because of high specific stiffness and high specific strength. Specially, the composite materials has been widely applied to the field of the aircraft and the transportation by the effectiveness of light weight due to low specific weight and reduction of the parts due to bonding, molding and so on. These advantages about the composite have led to study and apply in the transmission shaft for the aircraft and the drive shaft for the automobile. The composite material propeller shaft with the high vibrational stability was designed and analyzed. In order to verify the analysis, two types of experimental test which are the FFT analyzer with impact hammer and the rotational equipment were applied.