• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.1
• /
• pp.91-108
• /
• 1985

Turbulent flow and heat transfer in the 180.deg. bend with square cross section were analizied numerically by using k-.epsilon. 2 eqatiuon model with applications of QUICK scheme and PSL method. Results with PSL method show the more agreements with experimental data than those with wall function. However these results also show that it is very difficult to predict the 3-dimensional turbulent flow with strong secondary flow accuratly by standard k-.epsilon. equation model, and therefore it is necessary to introduce the higher order turbulent model or to correct the standard k-.epsilon. model for the more accurate predictions of these types of flow.

• Archives of Reconstructive Microsurgery
• /
• v.19 no.1
• /
• pp.68-79
• /
• 2010

Lower abdominal tissue is regarded as an ideal donor site for the breast reconstruction because it provides large skin territory and huge amount of soft tissues enough to the breast size. However it is not easy for the surgeon to reconstruct the really natural breast, and needs the learning curve with long time experience. Author represent the various reconstruction procedures for the breast using lower abdominal tissue such as muscle sparing free TRAM, DIEP, and SIEA free flaps to reinsure like breast. Indications, and selection of reconstructive methods, surgical timing, selection of donor sites and recipient vessel of these flaps were reviewed. In addition, detailed procedures, surgical tips and secondary adjuvant procedures are described for more symmetry of reconstructed breast. The muscle sparing free TRAM, DIEP, and SIEA free flaps would be enough to provide supple, huge amount of well vascularized tissue for the breast, if these flaps were selected for the appropriate indication according to patient's general condition, obesity, the opposite breast and abdominal tissue condition. Lower abdominal tissue was able to provide versatile designs with sufficient adipose tissue without compromising the integrity of abdominal wall.

• Journal of Chest Surgery
• /
• v.35 no.11
• /
• pp.839-841
• /
• 2002

Generally, patients who have airway compression with severe kyphoscoliosis can be improved through surgery for the thoracolumbar deformity. However, abnormal thoracic configuration due to severe kyphoscoliosis can cause respiratory distress secondary to severe compression of central airway in uncorrectable case. We tried to elevate the chest wall and obtained relatively good result in case of airway compression with abnormal thoracic configuration which was difficult to correct.

• Journal of computational fluids engineering
• /
• v.4 no.2
• /
• pp.9-16
• /
• 1999

The present study investigates flow character and heat transfer behaviors of viscoelastic non-Newtonian fluid in a 2:1 rectangular duct. An axially-constant heat flux on bottom wall and peripherally constant temperature boundary condition(H1) was adopted. The Reiner-Rivlin fluid model is used as the normal stress model for the viscoelastic fluid and temperature-dependent viscosity model is adopted. The present results show a signifiant change of the main flow field which causes a large heat transfer enhancement. This phenomena can be explained by the combined effect of buoyancy, temperature-dependent viscosity and viscoelastic property on the flow.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.5
• /
• pp.588-594
• /
• 1998

Heat transfer characteristics of distance between impinging surface and a plane jet were experi-mentally investigated. The local heat transfer coefficients were measured by a thermochromic liq-uid crystal(TLC) The jet Reynolds number studied was varied over the range from 10,000310 to 30,000310 the nozzle-to-plate distance (H/B) from 4 to 10. It was observed that the Nusselt number increases with Reynolds number the occurrence of the secondary peak in the Nusselt number is within the potential core region the potential core of the jet flow can reach the impinging surface so that the wall jet can a transition from laminar to turbulent flow resulting in a sudden increase in the heat transfer rate.

• Journal of Korean Foot and Ankle Society
• /
• v.13 no.1
• /
• pp.109-112
• /
• 2009

Calciphylaxis is a rare disease that appear in patients with secondary hyper-parathyroidism or chronic renal failure or that show defect in calcium phosphate metabolism which is characterized by fibrin deposit or calcification of medial wall of vessels causing gradual ischemic skin necrosis. Calciphylaxis is a disease with poor prognosis as skin necrosis can progress rapidly. If left untreated, calciphylaxis will progress to sepsis with high mortality. The treatment is controversial but kidney transplantation or parathyroidectomy is suggested to recover calcium-phosphate metabolism. The authors have experienced calciphylaxis in a patient with chronic renal failure caused by DM nephropathy with characteristic skin lesion and rapid skin necrosis. We describe this case with documentary reviews.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.4
• /
• pp.569-576
• /
• 2020

This study investigated the characteristics of microfibril angle(MFA) in order to see if there was any difference in pine tree lumber quality among the three mountain areas surrounding the Taebaek Mountains in Korea - Yeongdong (Goseong-gun), Yeongseo (Hongcheon-gun) and Yeongnam (Bonghwa-gun). Pine trees of each mountain area were divided into earlywood and latewood in relation to heartwood part (1959 ~ 1961, 3 annual rings) and sapwood part (2002 ~ 2004, 3annual rings), and measured at tangential section. The microfibril angle showed significant differences between mountain areas. In general, Goseong Mountain was found to have 37.35°, followed by Hongcheon Mountain 32.42° and Bonghwa Mountain 25.75°, in order. The sapwood part had larger angle than heartwood part; and earlywood, than latewood. Variation within a single annual ring tended to be smaller from earlywood toward latewood.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.4
• /
• pp.87-94
• /
• 2000

The morphological properties of the traditional handmade papers made in Korea, China and Japan were identified using CLSM(Confocal Laser Scanning Microscope). It was shown that the primary and secondary wall of the Hanji fibers were separated. The lumen of the fibers was not observed. Dochim, a traditional way of Hanji calendering, was turned out to accelerate the separation of the two walls, by which the unique effects of Dochim could be obtained. There were no separation of the two walls in Chinese handmade paper and Japanese handmade paper. Lumen was not observed in Senji fibers but it was observed in Whasi fibers. It was postulated that the morphological properties of the fibers are closely related with the calligraphic writings or drawings properties of handmade papers.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.8 no.3
• /
• pp.56-64
• /
• 2000

A friction force measurement system using the floating liner method was developed to study the frictional behavior of piston rings. The measurement system was carefully designed to control the effect of the piston secondary motion and the temperature of cylinder wall and oil. The friction force between the barrel shaped piston ring and the cylinder liner, was measured under the condition of flooded oil supply. The measured friction forces were classified into five frictional modes with regard to the combination of predominant lubrication regimes(boundary, mixed and hydrodynamic lubrication) and stroke regions(midstroke and dead centers). The modes could be identified on the Stribeck diagram of the friction coefficients and the dimensionless number of ㎼/p, where the friction coefficients are evaluated at near the midstroke and dead centers.

• Journal of Magnetics
• /
• v.13 no.4
• /
• pp.177-181
• /
• 2008

A very simple a.c. magnetic susceptometer for use in a helium closed cycle cryostat is reported in this paper. This simple setup has only a single bobbin-less copper coil, instead of the primary coil and two secondary coils typically used in mutual-inductance types. The single bobbin-less copper coil is directly mounted on the cryostat cold head. A sample is attached on the inside wall of the copper coil using a thermal contact material and its a.c. magnetic susceptibility is obtained from the measurement of the self-inductance of the sample coil using an LCR meter or an impedance analyzer. Experimental details are described and illustrative measurements on magnetic and superconducting materials as a function of temperature are included. The performances and limitations of this simple a.c. magnetic suceptometer are also discussed.