• Restorative Dentistry and Endodontics
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• v.1 no.1
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• pp.34-38
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• 1975

Artificial canals were prepared by means of engine reamer on the slab which was made of clear acrylic resin. The shape of this canal is similar to the natural canal, the size is almost same as Kerr File No. 70, and the length is about 20mm. Sealer, Zine oxide eugenol mixture was prepared as matched to spatula test. Lentulo filler was inserted as deep as middle portion and apical one-third portion of the canal and the dental engine was driven in the speed of 1,000 and 3,000 r.p.m. in 30 seconds and 60 seconds with feeding of the sealer. The author measured the excess flow of the canal sealer from Lentulo end. Following are the results obtained from this study. 1. Lentulo insertion at the middle portion 1,000 r.p.m. in 30 seconds case: 0.21mm Same as above in 60 seconds: 0.20mm 2. Lentulo insertion at apical-thirds. 1,000 r.p.m. in 30 seconds: 0.22mm. Same as above in 60 seconds: 0.20mm. 3. Lentulo insertion at middle portion. 3,000 r.p.m. in 30 seconds: 0.14mm Same as above in 60 seconds: 0.25mm. 4. Lentulo insertion at apical-thirds, 3,000 r.p.m. in 30 seconds: 0.11mm Same as above in 60 seconds: 0.27mm.

• Journal of the Korean institute of surface engineering
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• v.21 no.2
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• pp.53-67
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• 1988

The high temperature corrosion of Fe-C alloys were studied at I atm SO gas in the temperature range 500~80$0^{\circ}C$ by means of a thermogravimetric analysis. The Na2SO4 induced high tempwrature corrosion rate was also measured at atm O2 gas under above the temperature renge. The reaction products were identified with the aid of X-ray diffraction technique, and micostruction of the alloy/scale interface was observed with a optical microscope and SEM. The experimental results were disussed by the themodeynamic calcutions. Under above the experimental condition. the reaction rates decrbon with increasing carbon content. The transfer of Fe ion was limited by a residue of carbon precipitated at alloy scale interface due to the oxidation of Fe-C alloys at alloy surface. The effect of cold working on reaction rate was different between the Fe containing low carbon and Fe-C Alloy containing carbon above 0,73 wt%. In a cold worked iron containing low carbon content, the crystallization of metal surface leads to the poor adherence between the alloy and the cavity formed between the alloy and scale. The outward diffusion of ion through the scale is estimated to be hindered by the cavity formed between the scale, consequently decreasing reaction rate. In the case Fe-C containing carbon above 0.73 Wt% alloy, the reaction rate was little affected by cold working, because the effect of content on reaction rats is greater than the effect of cold working.

• Research in Community and Public Health Nursing
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• v.24 no.3
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• pp.368-376
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• 2013

Purpose: The purpose of this study was to identify the current urinary incontinence states in women above middle age dwelling in rural areas and their coping with the problems. Methods: The participants were 261 women above middle age. Data were collected from February to May, 2012 using a structured questionnaire. The data were analyzed with the SPSS/WIN 20 program. Results: The frequency of urinary incontinence in women above middle age was 45.4%. There were significant differences in urinary incontinence due to age, education, job status, frequency of delivery, and menstrual status. And, there were significant relations among urinary symptoms, difficulty of ADL, incontinence stress and depression. Frequently used coping-methods with urinary incontinence were washing frequently in order to avoid awful smell, paying attention to perineal cleaning, and going to restroom frequently. Conclusion: Community nurses who are in charge of primary health care ought to assess urinary incontinence and develop a urinary incontinence program that includes psychological and social factors.

• Korean Journal of Materials Research
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• v.19 no.12
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• pp.644-648
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• 2009

Temperature dependency of resistivity of the carbon black-polyethylene composites below and above percolation threshold is studied based on the electrical conduction mechanism. Temperature coefficient of resistance of the composites below percolation threshold changed from minus to plus, increasing volume fraction of carbon black; this trend decreased with increasing volume fraction of carbon black. The temperature dependence of resistivity of the composites below percolation threshold can be explained with a tunneling conduction model by incorporating the effect of thermal expansion of the composites into a tunneling gap. Temperature coefficient of resistance of the composites above percolation threshold was positive and its absolute value increased with increasing volume fraction of carbon black. By assuming that the electrical conduction through percolating paths is a thermally activated process and by incorporating the effect of thermal expansion into the volume fraction of carbon black, the temperature dependency of the resistivity above percolation threshold has been well explained without violating the universal law of conductivity. The apparent activation energy is estimated to be 0.14 eV.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.2
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• pp.211-221
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• 2010

Purpose : The purpose of this study is to find out the effects of combined exercise including walking and yoga on cognitive functions in the elderly women. Methods : Sixteen elderly women aged above 65 are invited in this study. Each subject participated in exercise three times a week for eight weeks from July 14th to September 13th in 2008. The changes between pre and post exercise are analyzed by Wilcoxon sign rank test and repeated ANOVA test with SPSS (ver 17.0) package program. Results : After exercise, In the below 23 points group, only interference STROOP test (p<.05) among sub items of Cognition Scale for Older Adults (CSOA) is improved significantly. In the above 24 points group, words memory (p<.05), delayed recall (p<.05), and picture naming (p<.05) among sub items of CSOA are improved significantly. But it is no different to the change patterns among two groups. Conclusion : These results show that combined exercise including walking and yoga is helpful to improve cognitive functions. And we find that exercise is helpful in the above 24 points elderly women more than in the below 23 points.

• Korean Journal of Metals and Materials
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• v.50 no.6
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• pp.413-418
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• 2012

This study was carried out to investigate the effect of reverse transformation on the mechanical properties in high manganese austenitic stainless steel. Over 95% of the austenite was transformed to deformation-induced martensite by 70% cold rolling. Reverse transformation became rapid above an annealing temperature of $550^{\circ}C$, but there was no significant transformation above $700^{\circ}C$. In addition, with an increasing annealing time at $700^{\circ}C$, reverse transformation was induced rapidly, but the transformation was almost completed at 10 min. There was a rapid decrese in strength and hardness with annealing at temperature above $550^{\circ}C$, while elongation increased rapidly above $600^{\circ}C$. At $700^{\circ}C$, hardness and strength decreased rapidly, and elongation increased steeply with an increasing reverse treatment time up to 10 min, whereas there were no significant change with a treatment time after 10 min. The reverse-transformed austenite showed an ultra-fine grain size less than $0.2{\mu}m$, which made it possible to strengthen the high manganese austenitic stainless steel.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.353-363
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• 2019

This paper presents a comprehensive simulation and assessment of gas dispersion above sea from a subsea release using a Computational Fluid Dynamics (CFD) approach. A 3D CFD model is established to evaluate the behavior of flammable gas above sea, and a jack-up drilling platform is included to illustrate the effect of flammable gas cloud on surface vessels. The simulations include a matrix of scenarios for different surface release rates, distances between surface gas pool and offshore platform, and wind speeds. Based on the established model, the development process of flammable gas cloud above sea is predicted, and the dangerous area generated on offshore platform is assessed. Additionally, the effect of some critical factors on flammable gas dispersion behavior is analyzed. The simulations produce some useful outputs including the detailed parameters of flammable gas cloud and the dangerous area on offshore platform, which are expected to give an educational reference for conducting a prior risk assessment and contingency planning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.948-953
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• 2021

To find the optimal eggs to larvae transforming temperature of walleye pollock Theragra chalcogramma, we investigated their hatching pattern, mortality, and larval deformities. Results showed that the hatching quality decreased as the water temperature increased and dropped sharply above 13℃. The highest hatching rate was achieved at 7℃, whereas the lowest was at 15℃. Dead eggs were not observed at 7℃; however, dead egg ratios were significantly high at 4.5℃ and above 13℃ (P<0.05). Mortality of larvae after hatching was not observed at 4.5℃, but was significantly high above 13℃. The DNA content of the larvae did not show any significant difference at all water temperatures; however, RNA content was the highest at 7℃ and was significantly low above 11℃. In addition, RNA/DNA ratio was the highest at 7℃. Larval deformities after hatching were low at 7-11℃ and higher at higher or lower water temperature. Therefore, the hatching index and larval health index of Walleye pollock eggs in this study show that 7℃ to 11℃ seems to be the optimal transforming water temperature range.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.194-195
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• 2021

Due to urban regeneration projects or changes in the living environment, there is an increasing need to demolish old buildings that have lost their functions. Demolition of above ground and underground structures is an important construction project that greatly affects the construction period and safety of the entire process. However, it is difficult for the safety officer to manage the demolition work due to the lack of specific and diverse data applicable to the site of the demolition plan. Therefore, in this study, items that need to be improved in structural safety when the above-ground and underground structures are demolished are reviewed and organized. For the main contents of structural safety management in demolition work, 1) structural review reflecting the order of demolition work, 2) installation and dismantling of steel pipe scaffolding and dust nets, 3) installation and dismantling of system scaffolding, 4) installation and dismantling of fall prevention nets, 5) jack support Installation and dismantling, 6) movement of equipment, movement and planning between floors, 7) equipment for demolition of structures, height of remnants, 8) site cleanup, and 9) equipment operators were categorized and arranged.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.3
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• pp.75-84
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• 1999

Systematic studies for the effect of the linewidth enhancement factor, the confinement factor, the internal loss and the cavity length on the single mode gain difference and the frequency detuning are performed for $\lambda$/4 phase shifted DFB lasers above threshold. The above threshold characteristics are mainly determined by the linewidth enhancement factor, not by the confinement factor or the parameter defined by the product of the linewidth enhancement factor and the confinement factor. The normalized internal loss defined by the product of the internal loss and the cavity length mainly determines the above threshold characteristics compared to that of the internal loss or the cavity length alone. The effect of the cavity length on threshold characteristics is larger than that of the internal loss in the case of the same normalized internal loss. The above threshold characteristics of quantum well lasers are more resistant to the variations of the confinement factor and the normalized internal loss than those of bulk lasers due to the small linewidth enhancement factor.