• Journal of Surface Science and Engineering
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• v.34 no.5
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• pp.421-428
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• 2001

New WC-CrN superlattice film was deposited on Si substrate (500$\mu\textrm{m}$) using cathodic arc ion plating system. The microstructure and mechanical properties of the film depend on the superlattice period (λ). In the X-ray diffraction analysis (XRD), preferred orientation of microstructure was changed according to various superlattice periods(λ). During the Transmission Electron Microscope analysis (TEM), microstructure and superlattice period (λ) of the WC - CrN superlattice film was confirmed. Hardness and adhesion of the deposited film was evaluated by nanoindentation test and scratch test, respectively. As a result of nanoindentation test, the hardness of WC - CrN superlattice film was gained about 40GPa at superlattice period (λ) with 7nm. Also residual stress with various superlattice period (λ) was measured on Si wafer (100$\mu\textrm{m}$) by conventional beam-bending technique. The residual stress of the film was reduced to a value of 0.2 GPa by introducing Ti - WC buffer layers periodically with a thickness ratio ($t_{buffer}$/$t_{buffer+superlattice}$ ). To the end, for the evaluation of oxidation resistance at the elevated temperature, CrN single layer and WC - CrN superlattice films with various superlattice periods on SKD61 substrate was measured and compared with the oxidation resistance.

• Earthquakes and Structures
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• v.22 no.3
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• pp.263-275
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• 2022

Structural collapses can occur as a result of a dynamic amplification of either, the building's seismic response or the ground shaking by local site effects; one of the reasons is a resonance effect due to the proximity of the structural elastic fundamental period TE and the soil fundamental period TS. We evaluate the vulnerability to resonance effects in Guadalajara, México, in a three-step schema: 1) we define structural systems in the building environment of western Guadalajara, in terms of their construction materials and structural components; 2) we estimate TE with different equations, to obtain a representative value in elastic conditions for each structural system; and, 3) we evaluate the resonance vulnerability by the analysis of the ratio between TE and TS. We observe that the larger the soil fundamental period, the higher the resonance vulnerability for buildings with height between 17 and 39 m. For the sites with a low TS, the most vulnerable buildings will be those with a height between 2 and 9 m. These results can be a helpful tool for disaster prevention, by avoiding the construction of buildings with certain heights and structural characteristics that would result in a dangerous proximity between TE and TS.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.3
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• pp.193-201
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• 2023

A developed code based on the unified conservation laws of incompressible/compressible fluids is applied to analyze similarity in pressure oscillations caused by pulsating air pockets in sloshing tanks. It is shown that the nondimensional time histories of pressure show good agreements under Froude and geometric similarities, provided that there are no pulsating entrapped air pockets. However, the nondimesional period of pressure oscillation due to the pulsating air pocket becomes longer as the size of the sloshing tank increases. The discrepancy in the nondimensional period is attributed to the compressibility bias of the entrapped air. To get rid of the compressibility bias, the ullage pressure in a sloshing tank is adjusted based on the Bagnold's impact number. The variation in the period of pressure oscillation according to the ullage pressure is explained based on the spring-mass system. It is shown that the nondimensional period of pressure oscillation is virtually constant when the ullage pressure is adjusted based on the Bagnold's impact number, regardless of tank size. It is found that the Bagold's impact number should be the same, if the time history of pressure is important while an entrapped air pocket pulsates.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.82-91
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• 1989

This study was carried out to get the basic information of irrigation plans for the red pepper, such as optimum irrigation level and irrigation requirement in Taegu and Kyungpook province. In this study, red peppers were cultivated in 6 PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each plot to measure the soil water pressure head. Field measurements were made during the period June 6 to October 31, 1988 at the experimental farm of Kvungpook National University. Six levels of irrigation were used. They were PF 1.8-2.0, PF 2.2-2.4, PF 2.8-3.0, FC-PF.1.7, FC-PF 2.2, and FC-PF 2.7. The results obtained from this study are summarized as follows : 1. In case of irrigation levels of narrow ranges of water contents, the higher the soil water content was, the larger the ET was. Hut in case of the irrigation levels returning to the field capacity, the lager the PF value of irrigation point was, the larger the ET was. Considering ET, yield and weight per fruit, the latter is much better than the former irrigation method. 2. The mean daily ET and mean ET ratio for each 10-day period showed that the maximum value occured in the last of August. The ranges of those were 3.74-14.64 mm/day and 0.87-3.40, respectively. These values showed that small during the early stage of growth, large during the middle stage and getting smaller in the last stage. 3. In case of irrigation levels of narrow ranges of water contents, the increase of irrigation water supplied increased the ET. The relationship between the two showed nearly straight line. Most of irrigated water was consumed as ET and the rest as percolation. But, in case of irrigation levels returning to the field capacity, the higher the PF value of irrigation point was, the larger the ET ratio was. However, their relationship didn't show straight line. 4. The irrigation level of PC - PP 2.7 was found to be the optimum irrigation level with respect to the yield, the weight per fruit, stem length, irrigation requirement and percolation quantity. In this case, mean daily ET and mean ET ratio were 6.79 mm/day (total 10052 mm) and 1.67, respectively. The maximum mean daily ET and mean ET ratio for 10-day period were 14.64 mm/day and 3.40, respectively, in the last of August, and the maximum daily ET was 2126 mm/day on August 24. 5. In case of PC - PP 2.7 which is found the optimum irrigation level, mean irrigation water required, mean ET and mean percolation water quantity were 7.44 mm/day, 6.79 mm/day(91.3% of irrigation water), and 0.38 mm/day (5.5% of it), respectively.

• Neonatal Medicine
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• v.17 no.2
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• pp.254-261
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• 2010

Little is known about neonatal mitochondrial disease, though mitochondrial metabolic disorders may often present in the neonatal period because of the high energy requirement of neonate. In newborn period, common presentations are not specific and the disease course may be rapid and fatal. In this study, we report three cases of neonatal mitochondrial disease. The first case was strongly suspected because of sudden seizure and mental change with severe lactic acidosis, and multiorgan failure. Plasma lactate/pyruvate (L/P) ratio was increased to 55.6 with marked lactic aciduria and increased plasma alanin up to 2,237 nmol/mL. In the second patient, a peritoneal dialysis was performed for acute adrenal and renal failure, but metabolic acidosis persisted. Plasma L/P ratio was increased to 23.9, and MRC I (mitochondrial respiratory chain defect) was diagnosed through the enzymatic analysis of the muscles. The third case showed repetitive episode of lactic acidosis during the first two months of life, hypotonia, failure to thrive and feeding difficulties. We found markedly increased cerebrospinal fluid L/P ratio up to 57 though plasma L/P ratio(19.4) was borderline with increased plasma lactate. The lactate peak was prominent in brain magnetic resonance spectroscopy (MRS). MRC II was confirmed through muscle biopsy. Plasma lactate level and lactate peak of brain MRS were normalized after conservative treatment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.70-81
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• 2024

In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

• Herbal Formula Science
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• v.16 no.1
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• pp.169-183
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• 2008

In this study, we measured body mass index, visceral fat ratio and 6 parts of body, neck circumference, circumference of upper arm, chest circumference, abdomen circumference, hip circumference, and thigh circumference by bioimpedence analysis system, after taking Gyeongshingangjeehwan16 (GGEx16) in five months except the first period before taking GGEx16 on 49 women who are obesity or high-level obesity. In order to examine the significance test for the effect of obesity improvement of GGEx16, we practices repeated measure ANOVA with values of measurement variables in 6 monthly times. As a result of all measurement variables, there were significant difference (P-value=0.001). Therefore, we can say that GGEx16 is effective about obesity improvement. As it dramatically decreased between second measure period and first measure period for all measure variables, we can see that there were the most effect of GGEx16 in the first time after taking GGEx16. It is known that a important measurement variable to have a effect for obesity improvement about two variable which are body mass index and visceral fat ratio is waist circumference through correlation analysis. The result of whether there are differences to effect of obesity improvement for GGEx16 around the climacteric, there were significant difference for the effect of obesity improvement for GGEx16 around the climacteric about all parts of body (P-value=0.001). There were also powerfully difference in effect of obesity improvement for GGEx16 around the climacteric about all parts of body (P-value=0.001). Especially, the climacteric before is more effective than the climacteric after in the aspect of the effect of GGEx16.

• Journal of the Korean Dietetic Association
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• v.21 no.3
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• pp.181-193
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• 2015

This study investigated anthropometric and biochemical characteristics, nutrient intakes, and bone density of Korean elderly men (over 65 yrs). Data on bone density and anthropometric (height, weight, waist circumference, body mass index and blood pressure) and biochemical (total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and hemoglobin) characteristics, nutrient intakes, and nutrient density were obtained from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES, 2008~2011). Subjects were categorized into smoking and non-smoking groups, and smoking groups were divided into three groups by smoking period (under 20 yrs, 21~40 yrs and over 41 yrs). Serum triglyceride concentrations of the smoking group aged 21~40 yrs were higher than those of other groups (P<0.01), whereas other biochemical factors were not different. Intake ratios of energy, protein, phosphorus and sodium in subjects were over 100% of Dietary Reference Intake for Koreans (KDRI). Nutrient densities according to intakes of thiamin, riboflavin, and niacin per 1,000 kcal were significantly different among the groups (P<0.05). Bone density of subjects decreased according to smoking period (T-score of total femur in non-smoking group -0.3108, and -0.2918, -0.4941, -0.6847 in smoking group, respectively). Ratio of osteoporosis was 38.1% in the non-smoking group and 44.4%, 51.1%, and 64.0% in the smoking group, respectively. The findings of the present study show that smoking may be associated with bone health, higher ratio of osteoporosis, and low nutrient density in elderly men. Therefore, practical and systematic non-smoking programs are required to improve the bone density of elderly men as well as maintain healthy bone levels and desirable lifestyle.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.9-17
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• 2019

Cement hydrates and the related characteristics change with ages, and the behaviors are much related with chloride diffusion. In this work, 30% replacement ratio with FA(Fly Ash) and GGBFS(Ground Granulated Blast Furnace Slag) are considered for concrete with three levels of W/B (Water to Binder ratio) and 2 years of curing period. Chloride diffusion coefficients from accelerated condition are obtained at 5 measurement period (28days, 56days, 180days, 365days, and 730days), and the results are compared with porosity, binding capacity, and permeability from program-DUCOM. The similar changing pattern between chloride diffusion and permeability is observed since permeability is proportional to the square of porosity. Curing period is grouped into 4 periods and the changing ratios are investigated. Cement hydrate characteristics such as porosity, permeability, and diffusion coefficient are dominantly changed at the early ages (28~56 days), and diffusion coefficient in OPC concrete with low W/B continuously changes to 180days.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.378-383
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• 2016

The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = $483{\pm}25.7kg$) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. $BW=486{\pm}27.5kg$) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.