• Journal of the Korean Vacuum Society
• /
• v.17 no.6
• /
• pp.538-543
• /
• 2008

Recently a nano-scale diamond is possible to manufacture forms of powder(below 100 nm) by new processing of explosion or deposition method. Using a sintering of nano-scale diamond is possible to manufacture of grinding tools. We have need of a processing development of coated uniformly inorganic to prevent an abnormal grain growth of nano-crystal and bonding obstacle caused by sintering process. This paper, in order to improve the sintering property of nano-scale diamond, we coated ZnO thin films(thickness: $20{\sim}30\;nm$) in a vacuum by ALD(atomic layer deposition) Economically, in order to deposit ZnO all over the surface of nano-scale diamond powder, we used a new modified fluidized bed processing replaced mechanical vibration effect or fluidized bed reactor which utilized diamond floating owing to pressure of pulse(or purge) processing after inserted diamond powders in quartz tube(L: 20 mm) then closed quartz tube by porosity glass filter. We deposited ZnO thin films by ALD in closed both sides of quartz tube by porosity glass filter by ALD(precursor: DEZn($C_4H_{10}Zn$), reaction gas: $H_2O$) at $10^{\circ}C$(in canister). Processing procedure and injection time of reaction materials set up DEZn pulse-0.1 sec, DEZn purge-20 sec, $H_2O$ pulse-0.1 sec, $H_2O$ purge-40 sec and we put in operation repetitive 100 cycles(1 cycle is 4 steps) We confirmed microstructure of diamond powder and diamond powder doped ZnO thin film by TEM(transmission electron microscope) Through TEM analysis, we confirmed that diamond powder diameter was some $70{\sim}120\;nm$ and shape was tetragonal, hexagonal, etc before ALD. We confirmed that diameter of diamond powders doped ZnO thin film was some $70{\sim}120\;nm$ and uniform ZnO(thickness: $20{\sim}30\;nm$) thin film was successfully deposited on diamond powder surface according to brightness difference between diamond powder and ZnO.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1529-1535
• /
• 1999

This study was done for the extraction of carotenoid from Phaffia rhodozyma in combination with PEF and other methods. PEF treatment conditions were $30{\sim}80\;kV/cm,\;100{\sim}1000\;Hz\;and\;100{\sim}1000\;{\mu}s$. In order to increase permeability of yeast cell wall, various methods such as freezing-thawing, mechanical treatment, solvents, permeabilizing agents, and yeast cell wall lytic enzyme were used before PEF treatment. The combination of PEF $(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ and conventional methods such as solvent and freezing-thawing pre-treatment had no effects on the extraction of carotenoid pigments. The extent of extracted carotenoid by the PEF $treatment(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ combined with yeast cell wall lytic enzyme and mechanical pre-treatment increased 52% and 69.8% more than the sum of that by each treatment, respectively. Permeabilizing agents, especially Tween 20 and capric acid, enhanced the extraction efficiency of carotenoid pigments from P. rhodozyma cells. These results indicated the feasibility for the continuous extracting carotenoid pigments from P. rhodozyma by PEF combined with other permeabilizing methods.

• Journal of Life Science
• /
• v.16 no.7 s.80
• /
• pp.1071-1079
• /
• 2006

The purpose of this study was to observe the effects of the feeding physiological activity substance in feral peach(Prunus Persica Batsch var. davidiana Max.) extract intake on the improvement of the lipid compositions, apolipoprotein and blood pressure level in spontaneously hypertensive rats(SHR, Wistar strain, male) fed the experimental diets for 33 days. Concentrations of total cholesterol, triglyceride(TG), LDL-cholesterol, free cholesterol and atherosclerotic index in serum were significantly lower in the feral peach extract intake groups[groups 5g% Ex.(basal diet+feral peach 5.0g% extract), 10g% Ex.(basal diet+feral peach 10.0g% extract)] than those in the group Control(basal diet+water). In the ratio of HDL-cholesterol concentration to total cholesterol and HDL-cholesterol concentration, feral peach 5.0g%, 10.0g% extract intake groups(group 5g% Ex. and 10g% Ex.) were higher percentage than in the group Control. However, concentrations of total cholesterol and TC in liver and brain were significantly lower in the groups 5g% Ex. and 10g% Ex. than those in the group Control. But the concentrations of apolipoprotein (Apo) A-I and Apo A-II in serum were significantly higher in the feral peach 5.0g% and 10.0g% extract intake groups(5g% Ex. and 10g% Ex.) than in the control group. However, concentrations of Apo C-II, Apo C-III, Apo E and ratio of Apo B to Apo A-I in serum were fairly reduced in the groups 5g% Ex. and 10g% Ex. than in the control group. The levels of systolic and diastolic blood pressure were significantly lower in feral peach 5g% Ex. and 10g% Ex. groups than control group. However, no significance was found in the effect of among the groups(groups 5g% Ex. and 10g% Ex.). From these results, physiological activity substance in feral peach(Prunus persica Batsch var. davidiana Max.) extracts were effective on the improvement of the lipid compositions and cardiovascular heart disease, hypertension in spontaneously hypertensive rats. And particularly, feral peach extracts were more effective as a therapeutic regimen for the control of blood pressure in hypertension.

• Journal of Life Science
• /
• v.21 no.12
• /
• pp.1732-1739
• /
• 2011

This study was carried out to investigate the effect of lotus root and leaf powder on the quality characteristics of pork patty stored at $3^{\circ}C$ for 9 days. The pork patties were of four types: nothing added(control, T0), 0.5% lotus root powder added (T1), 0.25% lotus root and 0.25% lotus leaf powder added (T2), and 0.5% lotus leaf powder added (T3). The $a^*$ value tended to decrease with longer storage period (p<0.05). The $L^*$ and $a^*$ value of T3 had the lowest value among the samples, the $b^*$ value T2 and T3 were higher than those of T0 and T1 (p<0.05). Water holding capacity decreased with longer storage period (p<0.05), the water holding capacity, cooking loss, increase rate of thickness and decrease rate of diameter were not significantly different among the samples. Hardness and chewiness increased and springiness decreased with longer storage period (p<0.05). The pH creased with longer storage period (p<0.05), but the VBN content not changed during storage. The TBARS values increased with longer storage period (p<0.05), and those of T0, T1, T2 and T3 were 4.57, 1.85, 0.43 and 0.41 mg MA/kg, respectively, after 9 days of the storage. The result suggest that the addition of lotus root and leaf powder at the same time, or addition of lotus leaf powder can be applied to pork patty to its functionality.

• Journal of Preventive Medicine and Public Health
• /
• v.9 no.1
• /
• pp.1-10
• /
• 1976

This study was conducted in order to observe some descriptive epidemiological findings and causes of life-long labour force loss in the rural population of Korea, and to consider, on the basis of these observations, some principles of the necessary control measures. The total number of subjects in the study was 27,172, all family members of 4,174 households. The study population was located in the 81 counties, out of a total of 138 counties, where the college students conducted service activities during the summer of 1974. In each village area where these service activities were conducted, one household per student interviewer was randomly selected. Student interviewers were instructed on the contents of the questionnaire prior to the survey. The main contents of the questionnaire form included address, name, sex and age of each family members, and present life-long labour force loss, if any, of each family member. In cases of current labour force loss, the age of onset and causes were recorded. Of the total households surveyed, 8.9% had family members (1-4 in number) with life-long labour force loss. Of the total persons surveyed, the crude prevalence rate for life-long labour force loss was 15.1 per 1,000; and the age-standardized prevalence rates for male and female were 16.3 per 1,000 and 13.4 per 1,000, respectively. The rates, in both sexes, were gradually increased as the ages were increased. The prevalence rates per 1,000, in order, for life-long labour force loss by the causes were 10.2 for senility, 2.4 for impairment of extremities, 1.2 for chronic diseases of internal organs, 0.5 for other conditions of muosculoskeletal system, 0.4 for blindness in both eyes, 0.2 for impairment of spine, 0.2 for psychoses, and 0.1 for epilepsy. Among them the causes of impairment of extremities were stroke, poliomyelitis, accidents, arthritis and injury due to war operation, in that order of higher relative frequency. The frequency ratios by age of onset were also observed by the causes and sex.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.9
• /
• pp.1439-1445
• /
• 2013

The aim of this study was to investigate the quality characteristics of rice cookies specifically prepared with rice flour following enzyme treatment. In this study, three types of specific enzyme treatments, that is, ${\alpha}$-amylase, ${\beta}$-amylase, and cellulose+${\beta}$-glucanase were applied on the effect of rice flour with respect to desired quality characteristics of the rice cookies. Based on our study results, we have found that the density of dough in the rice cookies was not significantly different between that of the non-enzyme treated (control) and the enzyme treated group. However, we found that the spread factor of rice cookies, prepared with rice flour treated with ${\beta}$-amylase, was higher than that of the control. It was also found that the moisture content of rice cookies (with added enzyme-treated rice flour) was 3.20 to 3.90%; however, this range is much lower than that observed in the control. Further, we observed that Hunter color's L-values were significantly higher for the control than those of the enzyme-treated cookies. We also found that hardness of enzyme-treated cookies was comparatively better than that of the control. In addition, the sensory acceptability scores of the enzyme-treated cookies were found to be significantly higher than the control in decisive parameters such as aroma, appearance, flavor, taste, texture, and overall acceptability. Based on our findings, we suggest that ${\alpha}$-amylase treated rice flour is an effective ingredient for improving the overall quality of rice cookies.

• Journal of the Korean Ceramic Society
• /
• v.39 no.9
• /
• pp.857-862
• /
• 2002

Porous ceramic supports with immobilized microorganisms for the water purifier were synthesized by firing green compacts of mixed powder comprising of fly ash, bentonite and an additive of yeast powder at 800∼1,000$^{\circ}C$ for 1h and the pore and mechanical properties of specimens were investigated. The compressive strength was increased in FB (Fly Ash + Bentonite) specimens while pore properties was decreased with increasing the bentonite content and sintering temperature. The compressive strength, bulk density, apparent density, porosity, mean pore size, pore volume and specific surface area of FB specimens at 800∼1,000$^{\circ}C$ were 89.6∼128.9 kgf/$cm^2$, 1.25∼1.43, 1.61∼1.78, 27.2∼62.2%, 7.9∼25.6 ${\mu}m$, 8.9∼$22.2{\times}10^{-5}\;cm^3/g$ and 35.2∼134.3 $m^2/g$, respectively. The pore properties of FBY (FB+yeast powder) specimens were superior to that of FB specimens, however compressive strength was decreased with increasing yeast powder content. The overall properties of 9F1B1Y (9F1B+10% of yeast powder) specimens at 900$^{\circ}C$ for 1 h were 98.7 kgf/$cm^2$, 1.20, 1.67, 68.1%, 48.9 ${\mu}m$, $29.5{\times}10^{-5}\;cm^3/g$ and 152.2 $m^2/g$, respectively. In this study, it was revealed that 9F1B1Y specimen demonstrated better S. saprophyticus adherence properties n their surface pores. Consequently, the microorganisms immobilized on porous ceramic supports showed better water purifying performance with many pores and adequate strength.

• Journal of Biomedical Engineering Research
• /
• v.25 no.6
• /
• pp.599-604
• /
• 2004

Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

• KEPCO Journal on Electric Power and Energy
• /
• v.6 no.3
• /
• pp.305-313
• /
• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.3
• /
• pp.21-29
• /
• 2016

In this paper, we developed a flexible transparent capacitive pressure sensor which can recognize X and Y coordinates and the size of force simultaneously by sensing a change in electrical capacitance. The flexible transparent capacitive pressure sensor was composed of 3 layers which were top electrode, pressure sensing layer, and bottom electrode. Silver nanowire(Ag NW)/poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) hybrid film was used for top and bottom flexible transparent electrode. The fabricated capacitive pressure sensor had a total size of 5 inch, and was composed of 11 driving line and 19 sensing line channels. The electrical, optical properties of the Ag NW/PEDOT:PSS and capacitive pressure sensor were investigated respectively. The mechanical flexibility was also investigated by bending tests. Ag NW/PEDOT:PSS exhibited the sheet resistance of $44.1{\Omega}/square$, transmittance of 91.1%, and haze of 1.35%. Notably, the Ag NW/PEDOT:PSS hybrid electrode had a constant resistance change within a bending radius of 3 mm. The bending fatigue tests showed that the Ag NW/PEDOT:PSS could withstand 200,000 bending cycles which indicated the superior flexibility and durability of the hybrid electrode. The flexible transparent capacitive pressure sensor showed the transmittance of 84.1%, and haze of 3.56%. When the capacitive pressure sensor was pressed with the multiple 2 mm-diameter tips, it can well detect the force depending on the applied pressure. This indicated that the capacitive pressure sensor is a promising scheme for next generation flexible transparent touch screens which can provide multi-tasking capabilities through simultaneous multi-touch and multi-force sensing.