In today's society, many women wear high-heeled shoes, but the effect of heel height on lumbar lordosis has not been clearly defined. The objective of this study was to identify the influence of heel height and general characteristics of subjects on lumbar lordosis. The subjects of this study were 40 healthy women who were students of the Department of Physical Therapy, College of Rehabilitation Science, Taegu University. Flexible ruler measurement was used to measure the lumbar lordosis at barefoot, 3 cm and 7 cm high-heeled standing positions. The results were as follows: 1) Significant statistical decrease in lumbar lordosis was observed as heel heights were increased from barefoot to 7 cm high heel. 2) There were no statistically significant differences between lumbar lordosis according to three different heel heights and weight, body mass index. 3) Lumbar lordosis measured at different heel heights was related to subject's height. With increasing subject's height, lumbar lordosis that measured from each heel height was significantly decreased. As heel heights were increased from barefoot to 7 cm high heel, significant statistical decrease in lumbar lordosis was observed in the subjects whose height were 151~160 cm. 4) Intrarater reliability on lumbar lordosis taken with a flexible ruler was good, with Cronbach values of 0.8971 for barefoot, 0.8107 for 3 cm and 0.9002 for 7 cm high-heeled standing positions.

The effect of Pb addition on microstructure and wear resistance was studied in rapidly solidified Al-20Si-5Fe-xPb(x=2, 4, 6 wt.%) alloys. The R/S Al-20Si-5Fe-xPb (x=2, 4, 6 wt.%) alloys showed a fine and homogeneous microstructure and an improved wear property compared with Al-20Si-5Fe alloy, while no significant change in UTS (Ultimate Tensile Strength) was shown. Contribution of the dispersoids on the wear property was discussed by showing the plastic deformation layers formed during wear track.

The quadriceps angle (Q angle) has been used to reflect the quadriceps muscle's force on the patella in the frontal plane. Previous investigations of the Q angle and it's relationship to knee disorders have yield equivocal results. The purpose of this study was to analyze the factors related to the Q angle and it's relation to other variables such as leg length, body weight, CTA (calcaneus to tibia angle), TOA (toe out angle), and pelvic width in normal subjects. The participants were 60 students (30 men and 30 women) who had no orthopedic and neurological impairments, aged from 20 to 29 years of age, with an average age of 22.1 years. Prior to participation, each subject was informed of the procedures of the experiment from a researcher and assistant researchers. The equipment used in this study were modified standard goniometer, ruler, marking pen, and Martin apparatus for pelvic width. In order to determine the statistical significance of the experiment, regression analysis, independent t-test, and Pearson correlation were used at the 0.05 level. The results were as follows: 1) It was found that the Q angle of women is greater than that of men's from both knees. 2) There was no significant difference between right and left quadriceps angle. 3) The Q angle decreased as the body weight (leg length) shifted from low to high. 4) It seems that factors related to the Q angle were body weight, CTA, and pelvic width, but there was no significant difference at the 0.05 level.

The microstructures and mechanical properties of submicron WC-Co cemented carbides were investigated in relation to cobalt content. To inhibit the WC grain growth during sintering, VC was added as a inhibitor in each alloy with 3 mass% to the cobalt content. The WC-(5, 8, 10, 15, 20) mass% Co compacts were sintered at for 30 min in vacuum. Some of WC-(5, 8, 10) mass% Co sintered compacts were HIPed with 120 atm at 130 for 1 hr. The shrinkages of all HIPed alloys were increased without depending on the cobalt contents and the sintered densities of them. The relative densities of the alloys were increased with the cobalt content and HIPing. The less the cobalt content, the larger the WC grain. Many contiguities of WC grains were found in WC-5 mass% Co alloy. The sizes and numbers of pores in the alloys were decreased by HIPing. And also the strength and the hardness of each alloy were increased. The maximum hardness was about 18.95 GPa in the WC-5 mass% Co alloy HIPed and the maximum transverse-rupture strength (T.R.S.) 3.2 GPa in the WC-20 mass% Co alloy sintered.

Fe 계 합금의 적층결함에너지를 감소시키는 거승로 알려진 vanadium이 Fe-20Cr-1.7C-1Si합금의 미세조직과 고온 마모저항성에 미치는 영향에 대하여 조사하였다. Fe-20Cr-1.7C-1Si-xV (x=0, 1, 3, 6, 10wt.%)조성에서 오스테나이트 기지상을 유지하면서 첨기될 수 있는 V의 최대 첨가량은 약 3wt.%이었으며 오스테나이트 기지상을 갖는 합금은 상온에서 낮은 적층결함에너지와 γ->α 변형유기 상변태에 의해 페라이트 합금보다 높은 마모저항성을 보인 것으로 생각된다.225˚C에서 α 생성량도 많은 것으로 보다 V은 Fe-20Cr-1.7C-1Si 합금의 온도에 따른 적층결함에너지 증가율를 억제하고 Md온도도 증가시킴으로써 고온 마모저항성을 증가시키는 것으로 생각된다.

현재까지 박막코팅 분야에 주로 이용해 오던 플라즈마 용융분사법을 이용하여 고밀도의 두꺼운 세라믹 침적물을 제조하였다. 용융점이 2910K인 ZrO2-20wt%Y2O3분말을 이용하여 최적조건에서 이론밀도의 약 97%의 침적물을 얻었다. 고밀도 침적에 영향을 미치는 변수는 챔버 내부압력, 플라즈마동력, 플라즈마 가스조성, 분사거리, 분말입자 크기 등이었으며, 침적밀도 및 침적된 splat의 형태는 분말의 용융정도 및 챔버 내부압력에 크게 좌우되었다. 높은 밀도으 침적물을 만들기 위해서는 분말을 완전히 용융시키는 것이 중요하며, 완전히 용융된 조건에서는 챔버 내부압력이 낮고 분말분사거리가 짧은 조건 즉, 분사되는 분말이 높은 모멘텀을 가질수록 침적물의 밀도가 증가함을 알 수 있었다. 실험에서 얻어진 결과는 ANOVA 통계방법으로 분석하여 단일변수의 영향뿐만 아니라 이들 변수가 서로 조합하여 밀도에 미치는 영향도 분석하였다.

LI2형 결정구조를 갖는 Ni-20at.%AI-10at%Fe 금속간화합물에 boron, zirconium 과 hafnium을 최고 0.5at.% 까지 첨가하여 항복강도, 연성, 파괴 등 기계적 성질의 변화를 인장시험과 X선분석 및 XPS분석 등을 통하여 관찰하였다. Ni-20at.% AI-10at.% Fe금속간화합물에 boron을 첨가하였을 때는 연신율의 현저한 증가가 나타났으나 zirconium이나 hafnium첨가의 경우에는 별다른 효과가 나타나지 않았다. Ni-20at.%AI-10at%Fe 금속간화합물의 경우, boron의 양이 증가할수록 인장연신율이 증가하였으며 0.1at.%의 boron을 첨가한 경우 최고 48.5%의 상온인장연신율을 나타내었다. 첨가물을 넣지 않은 경우와 zirconium과 hafnium을 첨가한 경우, 파괴모드는 입계파괴의 형태를 나타내었으나 boron을 첨가한 경우에는 파괴모드가 입계파괴에서 입내파괴로 변화되었다. XPS분석을 통하여 boron이 입계에 편석된 것을 관찰할 수 있었으며 이는 이미 제시된 여러가지 해석들과 일치하는 결과이다. 이로부터 boron의 첨가에 따른 인장연신율의 증가는 boron의 입계편석거동과 관련이 있음을 알 수 있다.