• Textile Coloration and Finishing
• /
• v.12 no.2
• /
• pp.89-95
• /
• 2000

Effect of twist-setting time, temperature and cylinder layer for the physical properties of the twist yarn were investigated by separated 9 layer from yarn cylinder. Obtained results were as follow. Shrinkage of the yarn in middle layer shows high value with heat-permeation and in inner's shows low value because of cylinder hardness. And then yarn thermal shrinkage in outer layers shows more or less high value because twist yarn in the outer layer sets more faster. Concerning to the difference on the yam physical properties among cylinder layers, the changes on physical properties shows significant differences from the 7th layer to the last one. Linear density, T.P.M and initial modulus decreases but snarl index increases.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.333-336
• /
• 2006

A new forming method for metal/ other metal two-layer tubes by multi-billet extrusion (MBE) is introduced. The forming possibilities of two-layer tubes CDA 365(inner)/Al 1100(outer) and Al 2014(inner)/Al 1100(outer) by MBE are investigated according to the given frictional condition and die profile. The results show that two-layer tube composed by two types tube as abovementioned can be manufactured by MBE. Some stated variables in the forming process such as effective stress and normalized pressure at welding surface are analyzed by FEM code ($DEFORM^{TM}$-3D)

• Journal of the Korean institute of surface engineering
• /
• v.35 no.4
• /
• pp.193-198
• /
• 2002

Alloys of XD45 (Ti45A12Nb2Mn-0.8vol%TiB$_2$) and XD47 (Ti47A12Nb2Mn-0.8vol%TiB$_2$) were oxidized between 800 and $1000^{\circ}C$ in air, and their oxidation characteristics were studied. The oxide scales consisted primarily of an outer $TiO_2$ layer, an intermediate $Al_2$$O_3$-rich layer, and an inner mixed layer of ($TiO_2$+$Al_2$$O_3$). Nb tended to present at the lower part of the oxide scale, whereas Mn at the upper part of the oxide scale. The Pt marker tests indicated that the outer oxide layer grew primarily by the outward diffusion of Ti and Mn, and the inner mixed layer by the inward transport of oxygen.

• Korean Journal of Metals and Materials
• /
• v.50 no.3
• /
• pp.218-223
• /
• 2012

Fe-(8.5, 18.5, 28.3, 36.9) wt% Cr alloys were corroded between 600 and $800^{\circ}C$ for up to 70 h in a 1 atm gas mixture that consisted of 0.0242 atm of $H_2S$, 0.031 atm of water vapor, and 0.9448 atm of nitrogen gas. Their corrosion resistance increased with an increment in the Cr content. The Fe-8.5%Cr alloy corroded fast, forming thick, fragile, nonadherent scales that consisted primarily of an outer FeS layer and an inner (Fe, Cr, O, S)-mixed layer. The outer FeS layer grew into the air by the outward diffusion of $Fe^{2+}$ ions, whereas the inner mixed layer grew by the inward diffusion of oxygen and sulfur ions. At the interface of the outer and inner scales, voids developed and cracking occurred. The Fe-(18.5, 28.3, 36.9)% Cr alloys displayed much better corrosion resistance than the Fe-8.5Cr alloy, because thin $Cr_2O_3$ or $Cr_2S_3$ scales formed.

• Ocean and Polar Research
• /
• v.25 no.4
• /
• pp.459-468
• /
• 2003

Annual variation of water qualities in the Shihwa Lake were observed 18 times from June 1996 to October 2001. We studied at the station of the upper streams and near the water gate of lake. After the flow of the outer seawater through the water gate, the surface salinity in Shihwa Lake increased to the range of 25-30 psu in both stations after October 1998. Due to the declination of the salinity differences between the surface and the bottom water, the pycnocline in which had existed until 1997 has weakened, and made the water column mix vertically. This led to the improvement of anoxic/hypoxic environment at bottom waters after April 1998. However, despite the continuous flow of the outer seawater, the concentrations of chlorophyll-a at surface layer were varied from $2{\mu}g/l\;to\;60{\mu}g/l$, and these values indicated the eutrophication. The following organic matter load was greatly influencing the surface layer's COD concentration. During the rainy season, the salinity at the surface layer to the below 15 psu resulting in stratification between the surface and bottom layer. Organic matters that were provided from the surface layer to the bottom layer due to active primary production in the year exhausted dissolved oxygen at the bottom layer, and the bulks of organic matters at bottom gave rise to hypoxic or anoxic environment. It was observed that the enrichment of ammonia and phosphate were main factors to worsen the water quality of the Shihwa Lake. The results of examining the annual variations in Shiwha Lake through principal component analysis shown that water characteristics in the rainy season were similar with those before input of outer sea water.

• Journal of Pharmacopuncture
• /
• v.12 no.2
• /
• pp.21-29
• /
• 2009

Objective : This study was carried to identify the anatomical component of FTMM(Foot Taeyang Meridian Muscle) in human lower limb, and further to help the accurate application to real acupuncture. Methods : FTM at the surface of the lower limb was labelled with latex. And cadaver was stripped off to demonstrate muscles, nerves and the others and to display the internal structures of FTMM, being divided into outer, middle, and inner layer. Results : FTMM in human lower limb is composed of muscles, nerves, ligaments etc. The internal composition of the FTMM in human lower limb are as follows : 1) Muscle : Gluteus maximus. biceps femoris, semitendinosus, gastrocnemius, triceps calf, fibularis brevis tendon, superior peroneal retinacula, calcaneofibular ligament, inferior extensor retinaculum, abductor digiti minimi, sheath of flexor tendon at outer layer, biceps femoris, semimembranosus, plantaris, soleus, posterior tibialis, fibularis brevis, extensor digitorum brevis, flexor digiti minimi at middle layer, and for the last time semimembranosus, adductor magnus, plantaris, popliteus, posterior tibialis, flexor hallucis longus, dorsal calcaneocuboidal ligament at inner layer. 2) Nerve : Inferior cluneal nerve, posterior femoral cutaneous n., sural cutaneous n., proper plantar branch of lateral plantar n. at outer layer, sciatic nerve, common peroneal n., medial sural cutaneous n., tibial n. at middle layer, and for the last time tibial nerve, flexor hallucis longus branch of tibial n. at inner layer. Conclusions : This study proves comparative differences from already established studies from the viewpoint of constituent elements of FTMM in the lower limb, and also in the aspect of substantial assay method. We can guess that there are conceptional differences between terms (that is, nerves which control muscles of FTMM and those which pass near by FTMM) in human anatomy.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.2 s.233
• /
• pp.220-227
• /
• 2005

In this study, stress-displacement analytic solutions are obtained by a shear lag modeling method constructed for the spliced joint area with a splicing gap in the fiber metal laminate (FML). This gap can be empty or be filled with an adhesive material of elastic modulus $E_a$. Two splicing types are considered for spliced shear models, one for spliced in the center metal layer, the other for spliced in the outer metal layer. It is shown that from the viewpoint of the load transfer efficiency and the avoidability of disbond generation due to the shear and axial stresses at the interface between metal layer and composite layer of the gap-front in the spliced area, the center spliced type (k=2) is much preferable to the outer spliced type (k=1).

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.7
• /
• pp.518-528
• /
• 2008

The effects of surface roughness on a turbulent boundary layer (TBL) were investigated using particle image velocimetry (PIV). The roughness elements used were periodically arranged two-dimensional spanwise rods, and the roughness height was ${\kappa}/{\delta}$. Introduction of the roughness elements increased the wake strength and the turbulent stress not only in the roughness sublayer but also in the outer layer. This indicates the existence of interaction between inner and outer layers for 2D rod-roughened wall. Roughness effects on a turbulence structure near the wall were obtained by PIV measurements. Iso-contours of mean velocities and Reynolds stresses in the roughness sublayer showed a very good agreement with previous DNS results.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2015.05a
• /
• pp.128-129
• /
• 2015

Al-rich coatings were prepared on hot rolled low carbon steel by hot dipping method in molten Al-bath to investigate the corrosion resistance with the possible outcomes and defects of aluminized coatings in air and $Ar-0.2%SO_2$ mixed gases. Coating microstructure was composed of an inner Al-Fe intermetallic layer and outer Al-rich layer. Aluminum oxidized preferentially to the thin, outer, protective ${\alpha}-Al_2O_3$ layer, without forming the nonprotective iron/sulfur-oxide layer after heating at $800^{\circ}C$ for 20 h, in both the gases and provided the resistance against corrosion.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2015.05a
• /
• pp.122-122
• /
• 2015

Al-rich coatings were prepared on hot rolled low carbon steel by hot dipping method in molten Al-bath to investigate the corrosion resistance with the possible outcomes and defects of aluminized coatings in air and $Ar-0.2%SO_2$ mixed gases. Coating microstructure was composed of an inner Al-Fe intermetallic layer and outer Al-rich layer. Aluminum oxidized preferentially to the thin, outer, protective ${\alpha}-Al_2O_3$ layer, without forming the nonprotective iron/sulfur-oxide layer after heating at $800^{\circ}C$ for 20h, in both the gases and provided the resistance against corrosion.