• Progress in Superconductivity and Cryogenics
• /
• v.21 no.3
• /
• pp.1-5
• /
• 2019

The superconductor stability theories are consistently described by the integral formula. If the defined stability function is a simple decreasing function, it becomes a cryogenic stability condition. If the stability function has a maximum value and a minimum value, and the maximum value is less than 0, then it is a cold-end recovery condition. If the maximum value is more than 0, it can be shown that the unstable equilibrium temperature, that is, the MPZ (minimum propagation zone) temperature distribution can exist. The MPZ region is divided into two regions according to the current ratio. At the low current ratio, the maximum dimensionless temperature is greater than 1, and at the relatively high current ratio, the maximum dimensionless temperature is less than 1. In order to predict the minimum quench energy, the dimensionless energy was obtained for the MPZ temperature distribution. In particular, it was shown that the dimensionless energy can be obtained even when the MPZ maximum temperature is 1 or more.

• Journal of the Korean Society of Radiology
• /
• v.17 no.4
• /
• pp.507-514
• /
• 2023

The purpose of this study is to find a formula that can easily calculate the effective photon energy in the X-ray beam of mammography. The tube voltage measured for each set tube voltage was obtained using the X2 MAM Sensor. The mass attenuation coefficient for aluminum of the aluminum filter was obtained from the half value layer measurement from each measured tube voltage X-ray beam. The mass attenuation coefficient of aluminum obtained from each measured tube voltage X-ray beam was corresponded to the mass attenuation coefficient of aluminum for each photon energy obtained from NIST. The photon energy corresponding to the matching mass attenuation coefficient was determined as the effective photon energy. The formula for calculating the determined effective photon energy was obtained by polynomial matching of the effective photon energy for each tube voltage in the Origin pro 2019b statistical program as y = 28.98968-1.91738x + 0.07786x2-0.000946717x3. Here, x is the measuring tube voltage and y is the effective photon energy. The calculation formula of the effective photon energy of the mammography X-ray beam obtained in this study is considered to be very useful in obtaining the interaction coefficient between the X-ray beam and a certain substance in clinical practice.

• Journal of Nutrition and Health
• /
• v.27 no.10
• /
• pp.1048-1057
• /
• 1994

Nonobese NIDDM patients were studied were studied with respect to changes in visceral protein status, serum glucose and lipids and insulin secretion capacity before and after intake of enteral formula. Patients with renal or hepatic disease, gastrectomy, malabsorption, weight gain over past 6 months and poorly controlled blood glucose level were excluded. Eighteen patients served as case and administered, in addition of their usual diet, 400ml of enteral formula for 8 weeks. Another 18 patients participated in controls and had usual food intake for 8 weeks. In the begining, the levels of fasting and postprandial glucose, glycated hemoglobin, triglyceride, HDL, LDL, total cholesterol, albumin, total protein and transferrin and glucose response area on oral glucose tolerance test were not different between two groups. The response areas of insulin, C-peptide and free fatty acid and serum IGF-1 level were higher in the case than in the control group. Energy intake of patients given enteral formula exceeded their estimated energy requirements(108%) and they consumed a mean of 112g protein per day. Patients given enteral formula showed an increase in body weight(4.4%), serum transferrin(10%), IGF-1(13%) and triglyceride(34%) while controls showed no changes in those parameters at 8 weeks compared to initial values. There were no significant changes after 8 weeks in the levels of glucose, glycated hemoglobin, HDL, LDL, total cholesterol, total protein and albumin and response areas of glucose, insulin, C-peptide and free fatty acid in both groups compared to initial values. This study suggests that nutrition supplement with enteral formula can increase body weight and visceral protein status in nonobese NIDDM patients without changes in blood glucose. However, excessive calorie intake could temporarily increase serum triglyceride. In addition, this study indicates that serum transferrin and IGF-1 are more sensitive indicators to changes of protein intake than serum albumin and total protein.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.4
• /
• pp.257-262
• /
• 1986

Thixotropy is a time-dependent shear-thinning phenomenon. We derived a new thixotropic formula which is based on the generalized viscosity formula of Ree and Eyring, $f={\Sigma}\frac{X_i}{{\alpha}_i}sinh^{-1}$ () (Refer to the text concerning the notation.) The following is postulated: (1) thixotropy occurs when small flow units attached to a large flow unit separate from the latter under stress (2) elastic energy(${\omega}$) is stored on the large flow unit during the flow process, and (3) the stored energy contributes to decrease the activation energy for flow. A new thixotropic formula was derived by using these postulations, $f={\frac}{X_0{\beta}_0}{\alpha_0}{\dot{s}}+{\frac}{X_1{\beta}_1}{{\alpha}_1}{\dot{s}}+{\frac}{X_2}{{\alpha_x}}sinh^{-1}$[$({\beta}_0)_2$ exp $(-C_2{\dot{s}}^2/RT){\cdot}{\dot{s}}$] f is the shear stress, and s is the rate of shear. In case of concentrated solutions where the Newtonian flow units have little contribution to the viscosity of the system, the above equation becomes, $f=\frac{X_2}{\alpha_2}sinh^{-1}$[$({\beta}_0)_2$ exp $(-C_2{\dot{s}}^2/RT){\cdot}{\dot{s}}$]. In order to confirm these formulas, we applied to TiO2(anatase and rutile)-water, printing ink and mayonnaise systems. Good agreements between the experiment and theory were observed.

• Journal of Korean Home Economics Education Association
• /
• v.23 no.3
• /
• pp.121-138
• /
• 2011

This research examined the amounts and methods change of recommended energy intake(REI) from 1962's recommended dietary intakes for Korean to 2010's dietary reference intakes for Koreans. REI is composed of 3 factors, such basal metabolic rate(or Resting Energy Expenditure, REE), activity energy, and thermogenic effect of foods. The first 1962 calculation formula of REI was weight based formula, that of 95's was the weight based REE multiplied by activity coefficient, and the recent one of 2005's(Estimated Energy Requirement: EER) was age, height. weight, and the activity level applying formula derived from the energy expenditure data by doubly labeled water technique(DLW). During the 50 years or so, REIs were reduced in all age groups, according to the activity(labor) strength and hour were reduced. The individual REI calculation method was introduced in 1995, and individual REI calculation was recommended since to prevent obesity. For the better REI estimation for Koreans, REI calculation formula derived from our peoples' DLW energy expenditure data is required.

• Journal of Nutrition and Health
• /
• v.26 no.3
• /
• pp.325-337
• /
• 1993

Korean breast-fed(BF) and formula-fed (FF) infants(n=31) were studied at their age of 1, 2 and 3 months to compare their intakes of energy, protein, lipid and lactose. Formulas had more energy, protein and lipid than breast milk, but the former had less lactose than the latter. The milk consumption of the FF infants was, however, greater than that of the BF infants with wide individual variation. As a result, the FF infants took in more energy, protein and lipid than the BF infants except lactose. The total daily caloric intakes(kcal/day) of the BF infants were 521.418 and 425 at their age of 1, 2 and 3 months respectively, and those of the FF infants were 676.752 and 723(at their age of 1, 2 and 3 months respectively). Daily protein intakes(g/days) of the BF infants were 9.5, 8.0 and 7.6 at their age of 1, 2 and 3 months respectively, and those of the FF infants were 13.9, 15.5 and 14.8(at their age of 1, 2 and 3 months respectively). The energy and protein of both the BF and the FF infants were deficient compared to the present Recommended Nutrient Allowances, and the deficiency of the BF infants was greater than that of the FF infants. But the energy intakes per kg of body weight of the FF infants at their age of 1 and 2 months were more than the present recommended energy allowances. And the protein intake per kg of body weight of the FF infant at the age of 1 month was the same as the present recommended protein allowances.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.04a
• /
• pp.281-286
• /
• 2008

Current feed-in tariffs(FIT) of Electricity generating from new and renewable energy sources are reappraised with the corrected formula of levelized generation cost(LGC) of utility power. The LGC of new and renewable electricity should be formulated in explicitly reflecting the capital cost and corporate tax during the economic life cycle based on its realistic application data. An applicable term of the FITs should, especially, be equal to the economic life cycle. The revised FITs issued in 2006 were, however, derived from the incorrect formula described in the study of KERI(Korea Electrotechnology Research Institute), and consequently misestimated. The reappraisal values for FIT of new and renewable electricity were shown and interpreted in this paper. An FIT of PV more than 30 kW, for example, should be 972.86 won/kWh instead of current 677.38 won/kWh increasing 43.6%. An upward revision of other FITs for new and renewable electricities should also be required in the range of 8.6% to 47.3%.

• Journal of Drive and Control
• /
• v.17 no.2
• /
• pp.28-37
• /
• 2020

It is difficult to analytically derive the relationship among volumetric displacement, flowrate, torque, and rotation speed regarding an instantaneous position of gerotor hydraulic pumps/motors. This can be explained by the geometric shape of the rotors, which is highly complicated. Herein, an analytical method for the instantaneous torque, rotation speed, flowrate, and volumetric displacement of a pump/motor is proposed. The method is based on two physical concepts: energy conservation and torque equilibrium. The instantaneous torque of a pump/motor shaft is determined for the posture of rotors from the torque equilibrium. If the torque equilibrium is combined with the energy conservation between the hydraulic energy of the pump/motor and the mechanical input/output energy, the formula for determining the instantaneous volumetric displacement and flowrate is derived. The numerical values of the instantaneous volumetric displacement, torque, rotation speed, and flowrate are calculated via the MATLAB software programs, and they are illustrated for the case in which inner and outer rotors rotate with respect to fixed axes. The degrees of torque fluctuation, speed fluctuation, and flowrate fluctuation can be observed from their instantaneous values. The proposed formula may provide a better understanding of the design or analysis process of gerotor pumps/motors.

• Solar Energy
• /
• v.10 no.1
• /
• pp.92-97
• /
• 1990

The electrochemical approach to the characteristics of black chrome solar selective coatings has been reviewed. Based on the formula of the ChromOnyx bath solution manufactured by Harshaw Company, the chromic acid-propionic acid bath solutions have been prepared by KIER. Comprehensive review of the black chrome electrodeposition mechanism also has been performed on the role played by constituents in the bath solution during electrodeposition. The optical properties such as absorption and emittance of electrodeposited black chrome coatings obtained from the new formula and their surface analysis will be reported in detail.

• Structural Engineering and Mechanics
• /
• v.80 no.5
• /
• pp.585-594
• /
• 2021

Ductility is very important parameter in seismic design of RC members such as beams where it allows RC beams to dissipate the seismic energy. In this field, the curvature ductility has taken a large part of interest compared to the deflection ductility. For this reason, the present paper aims to propose a general formula for predicting the deflection ductility factor of RC beams under mid-span load. Firstly, the moment area theorem is used to develop a model in order to calculate the yield and the ultimate deflections; then this model is validated by using some results extracted from previous researches. Secondly, a general formula of deflection ductility factor is written based on the developed deflection expressions. The new formula is depended on curvature ductility factor, beam length, and plastic hinge length. To facilitate the use of this formula, a parametric study on the curvature ductility factor is conducted in order to write it in simple manner without the need for curvature calculations. Therefore, the deflection ductility factor can be directly calculated based on beam length, plastic hinge length, concrete strength, reinforcement ratios, and yield strength of steel reinforcement. Finally, the new formula of deflection ductility factor is compared with the model previously developed based on the moment area theorem. The results show the good performance of the new formula.