• Korean Journal of Community Nutrition
• /
• v.2 no.3
• /
• pp.376-387
• /
• 1997

The elderly are the most rapidly growing segment of the population in Korea and the largest consumers of expensive medical care. It is reasonable to believe that improving the nutritional status would be beneficial to reducing morbidity and to impro- ving the quality of their lives. This study was conducted to assess the health status and the Nutritional Risk Index of the elderly, and to provide the basic data for the Elderly Nutrition Improvement Program at the Public Health Center. One hundred and forty seven(76 males. 71 females) aged 60 years and over living in Suwon, were assessed with anthropometric measurements, body fat analysis, blood pressure measurements, and a set of questionnaires about health and other related variables. Over half of them had less than a junior middle school education and were considered low income. The percentage of overweight and obese subjects was 33% by the BMI(Body Mass Index), and the prevalence of hypertension was 28$\%$(males) and 31$\%$(females). They had a lot of self-recognized health problems, the male elderly complained about more than the female elderly. In the case of psychological health status, however, the female elderly showed a higher proportions of depression than the male elderly(p$\ll$0.05). In social health status, the elderly had good relationships with friends and collegues, whereas they had poor relationships with their families. They had many nutritional risk factors, and smoking was the most prevalent risk factor for the male elderly and anemia was for the female elderly. The results of this study suggest that Elderly Nutrition Improvement Programs should be planned that can be easily followed. It would be helpful to design a program focusing on individual phychological and social health status, this would increase the efficiency of the program.

• Asian Journal of Atmospheric Environment
• /
• v.11 no.2
• /
• pp.107-113
• /
• 2017

This study describes (1) the impact of positive sampling artifacts caused by not only a filter-based sampling, but also a denuder-based sampling in the determination of particle-phase organic carbon (POC), (2) the effect of sample flow rate on positive artifacts, and (3) an optimum flow rate that provides a minimized negative sampling artifact for the denuder-based sampling method. To achieve the goals of this study, four different sampling media combinations were employed: (1) Quartz filter-alone (Q-alone), (2) quartz filter behind quartz-fiber filter (QBQ), (3) quartz filter and quartz filter behind Teflon filter (Q-QBT), and (4) quartz filter behind carbon-based denuder (Denuder-Q). The measurement of ambient POC was carried out in an urban area. In addition, to determine gas-phase OC (GOC) removal efficiency of the denuder, a Teflon filter and a quartz filter were deployed upstream and downstream of the denuder, respectively with varying sample flow rates: 5, 10, 20, and 30 LPM. It was found that Q-alone sampling configuration showed a higher POC than QBQ, Q-QBT, and Denuder-Q by 12%, 28%, and 23%, respectively at a sample flow rate of 20 LPM due to no correction for positive artifact caused by adsorption of GOC onto the filter. A lower quantity of GOC was collected from the backup quartz filter on QBQ than that from Q-QBT. This was because GOC was not in equilibrium with that adsorbed on the front quartz filter of QBQ during the sampling period. It is observed that the loss of particle number and mass across the denuder increases with decreasing sample flow rate. The contribution o f positive arti facts to POC decreased with increasing sample flow rate, showing 29%, 25%, and 22% for 10, 20, and 30 LPM, respectively. The 20 LPM turns out to be the optimum sample flow rate for both filter and denuder-based POC sampling.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.6
• /
• pp.81-91
• /
• 2013

A novel design process of a parallel multi-flow type air-cooled condenser of a dual-loop waste heat recovery system with Rankine steam cycles for improving the fuel efficiency of gasoline automobiles has been investigated focusing on reduction of the pressure drop inside the micro-tubes. The low temperature condenser plays a role to dissipate heat from the system by condensing the low temperature loop working fluid sufficiently. However, the refrigerant has low evaporation temperature enough to recover the waste from engine coolant of about $100^{\circ}C$ but has small saturation enthalpy so that excessive mass flow rate of the LT working fluid, e.g., over 150 g/s, causes enormously large pressure drop of the working fluid to maintain the heat dissipation performance of more than 20 kW. This paper has dealt with the scheme to design the low temperature condenser that has reduced pressure drop while ensuring the required thermal performance. The number of pass, the arrangement of the tubes of each pass, and the positions of the inlet and outlet ports on the header are most critical parameters affecting the flow uniformity through all the tubes of the condenser. For the purpose of the performance predictions and the parametric study for the LT condenser, we have developed a 1-dimensional user-friendly performance prediction program that calculates feasibly the phase change of the working fluid in the tubes. An example is presented through the proposed design process and compared with an experiment.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.25 no.1
• /
• pp.35-41
• /
• 2017

The use of engineering plastics in automotive components is increasing with the trend towards improving the car strength and reducing weight. Among the different choices of materials, engineering plastic emerged as the necessary material for achieving lower costs, reduced weight and improved production efficiency. To produce the automotive parts, it is important to predict defect and validation of injection molding prior to design. Injection molding analysis and structural analysis are widely applied as a part of the design process when developing automotive parts. Injection molding analysis, in particular, involves a highly complicated mechanism that requires deep knowledge of polymer properties as well as an analytic approach different from that used for a general isotropic material when the molded material is used as a structural material. This is because the parts made of polymer have pre-stress factors such as intrinsic deformation and residual stress. The most important factors for injection molded plastic products are injection molding condition and cavity design, taking into account ease of molding, mass production and application. Despite optimal injection molding conditions and cavity design, however, glass fiber orientation is critically linked to strength reduction. The application of injection molding and structural coupled analysis provides a low-cost solution for product molding and structural validation, all prior to the actual molding. The purpose of this study involves the validation, pre-study, and solution of defect in injection-molded polymer automotive parts using the simulation software for injection molding and structural coupled analysis. Finally, this thesis provides validation of an injection molding and structural coupled analytic mechanism that can demonstrate the effect of glass fiber orientation on mechanical strength. Design improvement ideas for the injection molded product of PPS (Poly Phenylene Sulfide)+40% glass fiber are also suggested.

• Analytical Science and Technology
• /
• v.16 no.2
• /
• pp.134-142
• /
• 2003

Comparison of a microwave-assisted extraction with sonication extraction was performed for arsenic speciation in fish tissue with chromatographic separation and inductively coupled plasma mass spectrometry detection. The detection limits of arsenicals with ultrasonic nebulizerand cross-flow nebulizer were shown to be similar. The arsenicals investigated were arsenobetaine (AsB), arsenite [As(III)], dimethylarsine acid (DMA), monomethylarsonic acid (MMA), arsenate [As(v)], and phenylarsonic acid (PAA). Quantitative extraction of arsenicals from dogfish muscle, DORM-2, standard reference material of NRCC (National Research Council of Canada) was achieved using 50% (v/v) methanol-water in both extraction methods. Extraction efficiency of arsenobetaine in both methods is greater than 82% with RSDs on replicates of less than 5%. The concentrations of AsB determined in extract of microwave assisted extraction and sonication methods were $14.18{\pm}0.42mg\;kg^{-1}$ and $13.54 {\pm}0.84mg\;kg^{-1}$, respectively. And the concentrations of DMA were $0.45{\pm}0.06mg\;kg^{-1}$ and $0.44{\pm}0.06mg\;kg^{-1}$, respectively.

• Proceedings of KOSOMES biannual meeting
• /
• 2006.05a
• /
• pp.85-92
• /
• 2006

Crude oil is complex mixture if thousands of different organic compound formed from a variety of organic materials that are chemically converted under differing geological conditions over long periods of time. Also oil composition varies according to crude source, refining, processing, handling and storage. The oil fingerprint method is application if specific knowledge of petrochemicals and use if sophisticated analytical equipment and techniques to identify the source(s) if oil pollution. KCG currently utilizes four primary analytical techniques: Gas Chromatography (GC), Fluorescence Spectroscopy(FL), Infrared Spectroscopy(IR) and Gas Chromatography mass spectrometer(GC/MS). Of all these techniques, GC technique are most widely used Gas Chromatography is used as a primary analytical method because high reliableness, high separating efficiency and repeatability.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.12
• /
• pp.1257-1262
• /
• 2005

Organo-chlorinated pesticides have been seldom measured in Korea because their use was banned for more than two decades. Nevertheless, the environmental persistency of these pesticides requires regular monitoring. Only organo-phosphorus pesticides are currently being monitored in Korea. Simultaneous determination of organo-chlorinated and organo-phosphorus pesticides was attempted using gas chromatography/mass spectrometer detector. Pressurized fluid extraction(PFE) was used in sample preparation. PFE showed equivalent extraction efficiency to traditional soxhlet extraction with less solvent use and less sample preparation time. Average recovery of spiked pesticides to soil and lawn samples was 62% ranging 52 to 154%. Method detection levels(MDLs) for these pesticides ranged from 3.4 to 10.5 ${\mu}g/kg$. Endosulfan, fenitrothion, and diazinon were found in the samples from 5 different golf courses out of 9 courses.

• Analytical Science and Technology
• /
• v.13 no.3
• /
• pp.297-303
• /
• 2000

Isotope-dilution inductively coupled plasma mass spectrometry was used to determine trace amounts of Cd, Cu, Pb, Ni and Zn in sediment. Sediment samples were dissolved by microwave digestion with addition of mixed acid ($HNO_3$, HF and $HClO_4$). Lead was determined after separation of alkaline and alkaline earth metals by an ammonium pyrrolidenedithiocarbarmate (APDC) solvent extraction. The other elements were determined after separation of iron, tin and titanium by hydroxide precipitation. Recovery efficiency of the analyte elements was not satisfactory, but most of matrix elements causing the isobaric interference could be effectively eliminated by the separation. Good agreement was achieved with the certified values in the analysis of the two sediment reference materials.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.12
• /
• pp.76-82
• /
• 2005

An experimental study on an axial-type micro turbine which consists of maximum 6 stages is conducted to measure aerodynamic characteristics on each stage. This turbine has a 2.0 flow coefficient, 3.25 loading coefficient and 25.8mm mean diameter. The solidity of stators and rotors is within a 0.67~0.75, and the off-design performance is measured by changing the load after adjusting the mass flowrate and the total pressure to constant at inlet. A maximum specific output power of 2kW/kg/sec is obtained in one stage, but the increment of the specific output power with increasing stages is alleviated. In case of torque, the increment of the torque maintains to constant at low RPM region, but its increment become dull at high RPM region. The efficiency of the micro turbine becomes low because the tip gap effect is great due to the small blade, but it could be improved by increasing the stages.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.151-156
• /
• 2018

As industry and medicine developed, many people became interested in the quality of life. As the concern for health became higher, vegetarian or vegetable oils became more popular than meat. With the development of processes primarily using nickel catalysts today, the shelf life of vegetable oils has increased and mobility has become more convenient. Currently nickel catalysts for the curing of oil are dominated by foreign companies in the world market. On the other hand, the mass production technology of domestic nickel catalyst is backward, and the entire amount is imported from foreign countries. Therefore, there is a need for active research and development of a catalyst that can be commercialized in korea. In this study, nickel as a main active catalyst was used as a base for hydrogen curing reaction, and the effect of rare earth on catalytic activity was investigated. A certain amount of rare earths could induce the dispersion of nickel to increase efficiency and use as co-catalyst.