• Progress in Medical Physics
• /
• v.20 no.2
• /
• pp.80-87
• /
• 2009

Phase transformation, superelastic characteristics and variation of surface residual stress were studied for Nitinol shape memory alloy through application of UNSM technology, and life extension methods of stent were also studied by using elastic resilience and corrosion resistance. Nitinol wire of ${\phi}1.778$ mm showed similar surface roughness before and after UNSM treatment, but drawing traces and micro defects were all removed by UNSM treatment. It also changed the surface residual stress from tensile to compressive values, and XRD result showed less intensive austenite peak and clear martensite and additional R-phase peaks after UNSM treatment. Fatigue resistance could be greatly improved through removal of surface defects and rearrangement of surface residual stress from tensile to compressive state, and development of surface modification system to improve not only bio-compatability but also resistance to corrosion and wear will make it possible to develop vascular stent which can be used for circulating system diseases which run first cause of death of recent Koreans.

• Journal of Chest Surgery
• /
• v.39 no.12 s.269
• /
• pp.900-905
• /
• 2006

Background: Homografts and bioprostheses are most commonly used for Rastelli operation in congenital heart disease, but the limited durability is responsible for multiple reoperations associated with increased morbidity This study evaluated long-term results after Rastelli operation with a mechanical valved conduit. Material and Method: A total of 20 patients underwent Rastelli operation with mechanical valved conduit from January 1990 to July 1992. Operative mortality was 1 of 20 patients, and a retrospective review of 19 patients(10 males, 9 females) was done. Initial diagnosis was congenitally corrected transposition of great arteries(cc-TGA, n=4), complete TGA (n=2), ventricular septal defect with pulmonary atresia(VSD with PA, n=9), truncus arteriosus(n=2), double outlet right ventricle with pulmonary stenosis(DORV with PS, n=2). The mean age at Rastelli operation was $4.6{\pm}3.4$ years, and mean follow-up period was $12.8{\pm}2.7$ years. Patients underwent Rastelli opearation using 16 CarboMedics mechanical valve, and 3 Bjork-Shiley mechanical valve($17{\pm}2$ mm). Result: There were 15 reoperations for failed mechanical valved conduit. The freedom from reoperation at 5 and 10 years was 53% and 37%. Most patients were received oral anticoagulation with warfarin, and maintained the international normalized ratio(INR) of 1.5 to 2.0. There was no anticoagulation or thromboembolism related complication. There was a significant difference in the causes of a conduit failure between early(within 3 years) and late(after 3 years) failure groups. The six patients reported early prosthetic valve failure, mainly due to valvular dysfunction by thrombosis or pannus formation. The other nine patients reported late prosthetic valve failure, mainly due to dacron conduit stenosis at anastomosis sites, whereas their valvar motion was normal except 1 patient. Conclusion: To avoid early prosthetic valve failure, strict anticoagulation therapy would be helpful. About the late development of obstructive intimal fibrocalcific peels within the Dacron conduit, an improvement of conduit material is necessary to reduce late prosthetic valve failure. In selected patients, the long term results were satisfactory.

• Journal of Bio-Environment Control
• /
• v.24 no.3
• /
• pp.217-225
• /
• 2015

Local heating system providing hot air locally to growing parts including shoot apex and flower cluster which were temperature-sensitive organs of cherry tomato was developed to reduce energy consumption for greenhouse heating without decline of crop growth. Growing part following local heating system was composed of double duct distributer which connected inner and outer ducts with hot air heater and winder which moved ducts up and down following growing parts with plant growth. Growing part local heating system was compared with conventional bottom duct heating system with respect to distributions of air and leaf surface temperatures according to height, growth characteristics and energy consumption. By growing part local heating, air temperature around growing part was maintained $0.9{\sim}2.0^{\circ}C$ higher than that of lower part of crop and leaf surface temperature was also stratified according to height. Investigations on crop growth characteristics and crop yield showed no statistically significant difference except for plant height between bottom duct heating and growing part local heating. As a result, the growing part local heating system consumed 23.7% less heating energy than the bottom duct heating system without decrease of crop yield.

• Food Science and Preservation
• /
• v.10 no.1
• /
• pp.16-22
• /
• 2003

This study was conducted to find out effective MA (Modified Atmosphere) gas compositions on the oyster mushroom through statistical analysis of the respiration rate and MA storage for the various packaging materials. Under the various gas compositions, the oxygen consumption rate of oyster mushroom was from 28.9 to 161.4mgO$_2$/kg$.$hr and the carbon dioxide evolution rate was from 53.4 to 166.9 mgCO$_2$/kg$.$hr at 20$^{\circ}C$. The estimated MA condition of oyster mushroom were 2.5∼4.5%O$_2$and 11.5∼l3%CO$_2$by the RSREG(Response Surface Regression). The gas compositions of MA packaging are following that 0.03mm LDPE were 1.6∼3.0%O$_2$and 3.9∼5.3%CO$_2$,0.05mm LDPE were 1.2∼1.3%O$_2$and 9.0∼11.1%CO$_2$and Nylon+PE were 0.9∼1.2%O$_2$and 33.5∼39.6%CO$_2$. The weight loss increased at 0.03mm LDPE but has the lowest value at Nylon+PE. The hardness of pileus and stipe was decreased with storage periods. The $\Delta$E-value increased with storage period and seriously changed in early storage period at 12 and 20$^{\circ}C$. In the 0.05mm LDPE, the gas compositions of packaging were similar to estimated gas compositions from the RSREG and the storage quality was superior to the other packaging materials in weight loss, hardness, and color difference at 4, 12 and 20 $^{\circ}C$.

• Journal of agricultural medicine and community health
• /
• v.21 no.1
• /
• pp.61-73
• /
• 1996

This study conducted to determine the attitude on environment pollution by Pohang city citizens. 1,059 Pohang city citizens in the age group 20 and over were chosen and surveyed by officials's interview at Up, Myun and Dong during the period 6 September to 20 September 1995. The issue problems to be solved in Pohang city were traffic control 47.3%, environment pollution 22.7%, cultural institutions 11.6%, water service 9.9%, education system 5.1% and community security 2.1%. The 55.1% of subjects responded that responsibility for environment pollution is every citizens duty. The trash from houses were 'garbage'(48.1%), 'waste of life'(21.8%), 'reuse trash'(15.6%) and 'one use thing'(14.5%) in order. The 66.9% of subjects responded that the trash's standard envelopes can be easily tear and its texture is not good. The respondents sometimes or often had experienced foreign bodies, sediment in the water service supply. The 45.9% of the respondents use natural water as drinking water, and the water service supply(26.7%), underground water(17.0%) and buying water(9.3%) were followed. Pertaining to the air pollution(by percent) was pollution of the steel industry complex 78.0%, combustive gas 16.6% and construction dust 1.7%. The respondents at southern district complained of respiratory tract by air pollution and the respondents at northern district complained of the visual disturbance and the offensive odor(P<0.05). Water pollution problem is factory's wastewater 56.2%, home wastewater 36.4% and livestock's wastewater 5.6% in order. The respondents at southern district complained of the noise pollution by airplanes and factories at the afternoon and the respondents at northern district complained of the noise pollution by vehicles(P<0.05).

• Korean Journal of Food Science and Technology
• /
• v.52 no.1
• /
• pp.1-10
• /
• 2020

The present study identified the restrictions on the use of sous-vide products in the Korean HMR market for small and medium-sized manufacturing companies. A detailed literature review revealed that the HMR market in Korea is close to saturation. Notably, the technologically advanced products produced using sous-vide seem to display significant potential to overcome market saturation. The sous-vide method differs from conventional cooking techniques and is characterized by maintenance of food texture along with flavor enhancement. However, due to the unfamiliarity of the manufacturers with this method and the unclear food safety regulations, mass food manufacturing companies do not agree on using this method; hence, sous-vide production is usually undertaken by small/medium sized companies catering primarily through online marketing portals. This study highlights the various restrictions to the implementation of sous-vide production, and discusses several practical implications of sous-vide production that would help users of this technique enter the HMR market.

• Journal of Animal Environmental Science
• /
• v.15 no.3
• /
• pp.231-240
• /
• 2009

In this research pig house facilities what are 3,029 houses hold over 1000 heads were surveyed by scale and province. Full-time farms hold over 1000 heads breed total 7,229,892 heads. And farms breed 2,386.9 heads averagely. Pig houses were constructed august 1995 averagely. Each of houses have $3,017.2\;m^2$ scale. The construction type of pig house was winch-curtain type 77.2% which was most popular, confined type 51.3%, litter type 7.4% and loft type 4.6%. The winch-curtain type was popular than windowless type in pig farms which have 1,000-1,999 heads. But pig house construction type which have more than over 10,000 heads was windowless type more than winch-curtain type. Manure removing type was slurry 72.3% and scraper 38.5% in farms which have 1,000-1,999 heads. Manure removing type was slurry 83.3% in farms which have over 10,000 heads. Proportion of roof type of pig house was slate 51.2%, panel 46.1%. But in middle or small farms, slate type was only 25.0%. Proportion of wall type of pig house was 41.9%, block 21.9%, concrete 7.6%, winch-curtain 6.3%, and bnck 5.9%. Ventilation type of pig house was natural winch 46.1%, mechanical windowless 69.8% and mixed type 53.1%. So, mechanical windowless type was popular than natural winch type. Especially the farm scale is bigger the mechanical widowless type was more. Utilization period of pig house was 8.1 years about automatic feeder, 8.3 years about waterer, 8.2 years about electric facilities and 9.0 years about floor material. Thus, almost of facilities were used at least 8 years.

• Archives of design research
• /
• v.17 no.4
• /
• pp.241-250
• /
• 2004

In this research, the copper alloy plates C2200, C5210, C7701, C8113 were selected to make datum and to identify further usage of metal craft experimentation. For its experimentation, the general welding and TIG welding methods were researched; for 2nd experimentation, the Reticulation and Electroforming skill's differences in color and temperature were researched. With these methods 3 different kinds of works are introduced for sample studies. For this research, Dr. Lee, Dong-Woo who works in Poongsan Metal Co, supported 4 kinds of copper alloy metals. Which are Commercial bronze (Cu-Zn), Deoxidiged Copper(Cu-Sn-P), Nickel Silver (Cu-Ni-Zn), and White Bronze (Cu-Ni); they were applied partly and wholly by the method of Laminatin, Reticulation, Fusing, and Electroforming skills. In case of C2200, the brass, the A. C. TIG welding method is better under 2mm slight plate; the D.C. TIG welding is better upper 2mm plate; and 250~300$^{\circ}C$ is recommended for remain heat treatment. In case of C5210, not having Hydrogen in high temperature return period, doesn't need Oxygen in high temperature and hardening in comparative high temperature neither, it is good for welding. It contains Sn 2-9% ad P 0.03-0.4% generally; and in accordance with the growth rate of Sn contain amount, the harden temperature boundary become broad. In case of cold moment after welding, they are recommended that higher speed TIG welding, smaller melting site and less than 200$^{\circ}C$ for pre-heating temperature. In case of C7701, the 10-20% Ni, 15-30% Zn are widely used.. If it is upper 30% Zn, it become (${\alpha}+{\beta}$) system and adhesive power rate become lower, and the productivity become lower in low temperature but the productivity become higher in high temperature. Nickel Silver's resistance of electricity is well; and the heatproof and incorrodibility is good, too. Lastly, in case of C8113, good at persistence in salty and grind; high in strength of high temperature. In case of white brass, contain 10-30% Nickel and hardened in high temperature and become single phrase. For these reason, the crystallization particles easily become large, if the resistance become higher small amount of Pb, P, S separation rate become higher.

• Journal of Chest Surgery
• /
• v.31 no.7
• /
• pp.660-667
• /
• 1998

Background: This study is to evaluate the effectiveness and application of Lecompte procedure as a treatment for various complex cardiac anomalies with pulmonary outflow tract obstruction. Methods: Between July 1988 and December 1997, 44 patients underwent Lecompte procedure in Seoul National University Children's Hospital. The male to female ratio was 24 to 20 and the mean age was 29.2 months(range, 3 to 83). Of these patients, 28(63.6%) had transposition of great arteries with ventricular septal defect and pulmonary stenosis(or pulmonary atresia), 14(31.8%) had double outlet right ventricle with pulmonary stenosis(or pulmonary atresia), and so on. The principles of the technique are 1) extension of the ventricular septal defect or conal resection, 2) construction of a intracardiac tunnel connecting the left ventricle to the aorta, and 3) direct connection, without a prosthetic conduit, of the pulmonary trunk to the right ventricle. Results: There were 3 in-hospital deaths and their causes were sustained hypoxia, myocardial failure, and sepsis, respectively. There was 1 late death due to sepsis. Reoperations were performed in 6 patients who had pulmonary outflow tract obstructions(4 cases), residual muscular ventricular septal defect(1 case), and recurrent septic vegetation(1 case). The cumulative survival rates by the Kaplan-Meier method were 92.7%, 92.7%, and 92.7% at 1, 2, and over 4 years. The reoperation free survival rates were 92.7%, 92.7%, and 70.2% at 1, 3, and over 5 years. Among the risk factors for the operative death, aortic cross clamping time had statistical significance(p<0.05) and all the risk factors for the recurrent pulmonary stenosis such as age, pulmonary artery index, and materials used for the pulmonary outflow tract reconstruction had no statistical significance(p>0.05). Conclusions: Our review suggests that Lecompte procedure is an effective treatment modality for various complex cardiac anomalies with pulmonary outflow tract obstruction. Repair in early age is possible and the rates of mortality and morbidity are also acceptable.

• Journal of Food Hygiene and Safety
• /
• v.35 no.2
• /
• pp.136-145
• /
• 2020

This study was conducted to evaluate pesticide residues and foreign metallic matter on a total of 104 powdered agricultural products in Incheon. Residue testing for 373 pesticides was conducted by GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD and HPLC-UVD. Foreign metallic matter was detected by magnetic rod. As a result pesticide testing, 7 of the 104 products were found to be within the MRL of the pesticides. The detected pesticides were chlorpyrifos, etofenprox, fenoxanil, malathion, permethrin, tebuconazole and tetraconazole. As for foreign metallic matter, 16 samples were above the allowable limits set by Korean regulations. Therefore, the inspection of residual pesticides in raw material, and the removal of foreign metallic matter will require further stringent attention for the safety of powdered agricultural products.