• 운동영양학회지
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• 제25권1호
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• pp.23-29
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• 2021

[Purpose] This preliminary study aimed to develop a regression model to estimate the non-exercise activity thermogenesis (NEAT) of Korean adults using various easy-to-measure dependent variables. [Methods] NEAT was measured in 71 healthy adults (male n = 29; female n = 42). Statistical analysis was performed to develop a NEAT estimation regression model using the stepwise regression method. [Results] We confirmed that age^A, weight^B, heart rate (HR)_average^C, weight × HR_average^D, weight × HR_sum^E, systolic blood pressure (SBP) × HR_rest^F, fat mass ÷ height^2G, gender × HR_average^H, and gender × weight × HR_sum^I were important variables in various NEAT activity regression models. There was no significant difference between the measured NEAT values obtained using a metabolic gas analyzer and the predicted NEAT. [Conclusion] This preliminary study developed a regression model to estimate the NEAT in healthy Korean adults. The regression model was as follows: sitting = 1.431 - 0.013 × (A) + 0.00014 × (D) - 0.00005 × (F) + 0.006 × (H); leg jiggling = 1.102 - 0.011 × (A) + 0.013 × (B) + 0.005 × (H); standing = 1.713 - 0.013 × (A) + 0.0000017 × (I); 4.5 km/h walking = 0.864 + 0.035 × (B) + 0.0000041 × (E); 6.0 km/h walking = 4.029 - 0.024 × (C) + 0.00071 × (D); climbing up 1 stair = 1.308 - 0.016 × (A) + 0.00035 × (D) - 0.000085 × (F) - 0.098 × (G); and climbing up 2 stairs = 1.442 - 0.023 × (A) - 0.000093 × (F) - 0.121 × (G) + 0.0000624 × (E).

• 공업화학
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• 제16권5호
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• pp.664-671
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• 2005

Alkyl ethoxylates, 비이온 계면활성제, 물, d-limonene으로 이루어진 3성분 계에 보조계면활성제를 첨가한 경우, 단일상의 마이크로에멀젼이 보다 낮은 온도와 넓은 온도 영역에서 형성되었다. 특히 n-propanol을 LA-7 계면활성제계에 첨가할 경우 가장 넓은 온도 영역에서 단일상의 마이크로에멀젼이 형성되며, 보조계면활성제/계면활성제 비율이 0.3 이상인 조건에서 단일상의 마이크로에멀젼이 형성되기 시작하였다. 음이온 계면활성제 SDS를 첨가한 혼합 계면활성제 계의 경우, $30{\sim}65^{\circ}C$까지의 온도 영역에서 단일상의 마이크로에멀젼을 형성함으로써 비이온 계면활성제 계의 온도 변화에 따른 민감성을 저하시킬 수 있었다. 또한 형성된 단일상의 마이크로에멀젼은 $30{\sim}60^{\circ}C$의 온도 영역에서 pH와 경도에 대한 영향을 받지 않으며, 산화방지제에 대한 영향도 매우 작았다. 보조계면활성제와 첨가제 등에 대한 상평형 실험을 통하여 선정한 후보 세정제들은 $30{\sim}40^{\circ}C$의 온도에서 abietic acid에 대한 우수한 세정력을 나타내었다.

• International Journal of Automotive Technology
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• 제3권4호
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• pp.157-163
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• 2002

It is well recognized that the ultrasonic method is one of the most common and reliable nondestructive testing (NDT) methods for the quantitative estimation of defects in welded structures. However, NDT techniques applying for adhesively bonded joints have not been clearly established yet. In this paper, the detection of interface crack by the ultrasonic method was applied for the measurement of interfacial crack length in the adhesively bonded joints of double-cantilever beam (DCB). An optimal condition of transmission coefficients and experimental accuracy by the ultrasonic method in the adhesively bonded joints have been investigated and discussed. The experimental values are in good agreement with the computed results by boundary element method (BEM) and Ripling's equation.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.99-105
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• 2003

A liquid-liquid extraction followed by evaporative concentration method was used to determine the concentration of normal, or straight chain, saturated hydrocarbons (NSH) $(C_{10}\;to\;C_{24})$ and polycyclic aromatic hydrocarbons (PAH) here defined as: fluorene, anthracene, pyrene, chrysene and perylene, in the Buriganga River water of Bangladesh. Samples were collected from 5 and 25 cm depth of water at the southern, middle and northern parts of the river at Postogolla, Sadarghat and Sowarighat stations. Hydrocarbons were extracted from 450 mL of water into 75 mL n-hexane and then concentrated into 1 or 2 mL solution by evaporation. These solutions were analyzed by gas chromatography. The highest and lowest concentrations were determined as $257\;{\mu}gL^{-1}\;for\;C_{13}\;and \;0.24\;{\mu}g\;L^{-1}\;for\;C_{22}$ at 5 ㎝ depth of water, at the northern part of the Sowarighat and southern part of the Postogolla, respectively. This method could allow the analysis of water for $C_{22}$ as low as $0.24\;{\mu}g\;L^{-1}$.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1406-1411
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• 2005

The creep rupture data for type 316LN stainless steels were collected through literature survey or experimental data produced in KAERI. Using these data, polynomial equations for predicting creep life were obtained by Larson-Miller (L-M), Orr-Sherby-Dorn (O-S-D) and Manson-Haferd (M-H) etc. time-temperature parametric (TTP) methods. Standard error of estimate (SEE) values for the each parameter was obtained with different temperatures through the statistical process of the creep data. The results of L-M, O-S-D and M-H methods showed good creep-life prediction, but M-H method showed better agreement than L-M and O-S-D methods. Especially, it was found that SEE values of M-H method at $700^{\circ}C$ were lower than that of L-M and O-S-D methods.

• Steel and Composite Structures
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• 제19권6호
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• pp.1549-1560
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• 2015

This paper presents the characterization of fatigue crack in the A283 Grade C steel using the MMM method by identifying the effects of magnetic flux leakage towards the crack growth rate, da/dN, and crack length. The previous and current research on the relation between MMM parameters and fatigue crack effect is still unclear and requires specific analysis to validate that. This method is considered to be a passive magnetic method among other Non-Destructive Testing (NDT) methods. The tension-tension fatigue test was conducted with a testing frequency of 10 Hz with 4 kN loaded, meanwhile the MMM response signals were captured using a MMM instrument. A correlation between the crack growth rate and magnetic flux leakage produces a sigmoid shape curve with a constant values which present the gradient, m value is in the ranges of 1.4357 to 4.0506, and the y-intercept, log C in the ranges of $4{\times}10^{-7}$ to 0.0303. Moreover, a linear relation was obtained between the crack length and magnetic flux leakage which present the R-Squared values is at 0.830 to 0.978. Therefore, MMM method has their own capability to investigate and characterize the fatigue crack effects as a main source of fracture mechanism for ferrous-based materials.

• 열처리공학회지
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• 제18권5호
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• pp.312-317
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• 2005

The precipitation process in Cu-0.2 wt.%Cr-0.05 wt.%Zr alloys has been studied by electrical electrical resistivity measurements. The kinetics of precipitation could be well described by Johnson-Mehl-Avrami equation, $f(t)=1-\exp(-kt^n)$. The values of n were found to be in the range of 0.36~0.42 at first stage and 1.3~1.6 at second stage. The activation energy was determined by cross-cut method and was 80~89 kJ/mol. The value is similar to the energy for the migration of either a vacancy or a vacancy-solute complex through the lattice.

• 한국표면공학회지
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• 제34권5호
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• pp.510-515
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• 2001

It was first time that low frequency R.F. derived plasma enhanced MOCVD with frimethylborate precursor was used to fabricate a new ternary compound $BO_{x}$ $N_{y}$ . The formation of BON molecule was resulted from nitrogen nitrifying B-O, and forming the angular molecule structure proved by XPS and FT-IR results. The relationship between hardness and film thickness was studied. An thickness-independent hardness was fond about 10 GPa. The empirical calculation of band-gap and UV test result showed that our deposited $BO_{x}$ $N_{y}$ thin film was semiconductor material with 3.4eV of wide band gap. The electrical conductivity, $4.8$\times$10^{-2}$ /($\Omega$.cm)$^{-1}$ also confirmed that $BO_{x}$ $N_{y}$ has a semiconductor property. The roughness detected from the as-grown films showed that there was no serious bombarding effect due to anion in the plasma occurring in the RF frequency derived plasma.

• 한국토양비료학회지
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• 제24권4호
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• pp.278-285
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• 1991

우분(牛糞)을 속성(速成)으로 부숙(腐熟)시켜 양질(良質)의 유기질비료(有機質肥料)로 제조(製造)해서 그 제품(製品)의 부숙(腐熟)이 량호(良好)하게 되었는가 여부(與否)를 판단(判斷)할 수 있는 기준(基準)인 부숙도(腐熟度) 잠정(暫定) 기준치(基準値) 설정시험(設定試驗)에서 여지(濾紙) Chromatography법(法), CEC 법(法) 및 환원당율(還元糖率)을 중점(重點)으로 연구한 결과(結果)는 다음과 같다. 가. 퇴적내(堆積內) 부숙온도(腐熟溫度) 측정(測定)은 부숙도(腐熟度)의 간접적(間接的)인 기준(基準)으로 가장 적합(適合)할 것으로 생각되었다. 나. 건물중(乾物重)의 2% T-N함량(含量)과 20이하(以下)의 C/N율(率)을 부숙도(腐熟度)의 잠정기준치(暫定基準値)로 설정(設定)하는 것은 인난(因難)할 것으로 사료(思料)되었다. 다. 여지(濾紙) Chromatography법(法)는 주재료(主材料)가 우분(牛糞)이고 충전제(充塡劑)가 나무껍질, 나무조각, 톱밥인 목질계통(木質系統)이기때문에 Chromatography가 선명(鮮明)하게 나타나지 않아 부숙도(腐熟度)의 기준치(基準値)로 적용(適用)할 수 없었다. 라. CEC 함량(含量)은 부숙(腐熟)이 진행(進行)될수록 높아졌으며, 부숙온도(腐熟溫度)가 높았던 처리구(處理區)에서 CEC함량(含量)이 높아 '88년(年)에는 우분(牛糞)+나무껍질구>우분(牛糞)+볏짚구이고, '89년 우분(牛糞)+나무조각구>우분(牛糞)+볏짚구이며, '90년 우분(牛糞)+볏짚구>우분(牛糞)+톱밥구가 높았다. 마. 환원당율(還元糖率)('90년(年))은 부숙온도(腐熟溫度)가 가장 높았던 우분(牛糞)+볏짚구 보다 우분(牛糞)+톱밥구가 더 낮았는데 이는 우분(牛糞)과 톱밥의 분리(分離)가 잘 되지 않아서 제품(製品)의 T-Cg함량(含量)이 높았기 때문에 나타난 것으로 보여졌다.

• 한국자기학회지
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• 제5권3호
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• pp.203-209
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• 1995

보자력이 다른 NiFe와 Co를 자성층으로 하고 Cu를 사잇층으로 하는 $glass\[Cu_{x\AA}\NiFe_{50\AA}\Cu_{x\AA}\Co_{50\AA}](X;\=\;8,\;10,\;14,\;18,\;22,\;26,\;28,\;38,\;48,\;58\;\AA)$ 다층박막을 D.C magnetron sputtering 방법으로 제작하여 사잇층인 Cu 두께, 적층횟수 및 열처리가 자기저항비에 미치는 영향과 자기 곡선의 변화에 대해 연구하였다. 자기저항 측정시 인가 자장은 전류의 방향과 수평, 수직하게 인가하여 측정하였다. Cu 두께가 대략 $10\;\AA$에서 최대 자기저항비를 보이고 있으며, 두께가 증가함에 따라 진동하는 경향은 나타냈다. 적층횟수에 따라서는 적층횟수가 증가함에 따라 증가하였으며, 단지 4층의 경우에는 오히려 3층 보다 감소하였다. 열처리의 경우 온도의 증가에 따라 증가하다가 $250^{\circ}C$ 이상에서는 다시 감소하는 것을 나타났다.