• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.108-108
• /
• 2009

Precipitation hardening nickel base alloys strengthened by intermetallic compounds are extensively used to manufacture on the components of the hot section of gas turbine engines. To ensure structural stability and maintenance of strength properties for a long time, nickel alloys are normally subjected to complex alloying with elements to form ${\gamma}'$(gamma prime). Such alloys have a limited weldability, are normally welded in high temperature. However, laser welding have a merit that applies in room temperature as easy control of welding parameter and heat input. In this study, $CO_2$ laser welding is applied on STS304 plate with good ductility and precipitation hardening nickel base alloy (GTD111DS) used blade material. Also, several welding parameters are applied on powder, power and travel speed. There are no cracks in Rene 80 and IN 625 powder when STS304 plate is used. But IN 625 powder has no cracks and Rene 80 have some cracks in welds with GTD111DS substrate. Adjusting of welding parameter is tried to apply Rene 80 having a good strength compare to IN 625. In the result of adjusted welding parameter, optimized welding parameters are set with low power, low feed rate and high welding speed. Tensile strength of GTD111DS substrate with Rene 80 powder is same and over than the one of base metal in room temp and high temp($760^{\circ}C$).

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.7
• /
• pp.151-157
• /
• 2020

This study is to find out the effectiveness by Infant CPR method of a single rescuer. It was conducted for 51 general public. And typical infant CPR method by a single rescuer and a new method, CPR with two thumb chest compressions wrapped in both hands over the head were compared. SPSS 22.0 was used as an analysis method and to compare the both CPR methods, Paired t-test was used. As a result of the study, the average chest compression depth(39.38±1.07 mm) by CPR with two thumb chest compressions wrapped in both hands over the head was significantly high(p<0.001). Ease of mouth-to-mouth resuscitation(p<0.001), convenience of CPR method(p<0.001), and finger pain level(p<0.001) had a significant difference. As for the preference of the CPR method, 80.4%(41 people) preferred CPR with two thumb chest compressions wrapped in both hands over the head. In this study, CPR with two thumb chest compressions wrapped in both hands over the head showed more effective results than typical CPR method. However, as a virtual study using mannequins, further research is needed to apply high-quality CPR methods to field.

• Fire Science and Engineering
• /
• v.6 no.1
• /
• pp.90-98
• /
• 1992

Over the last 100 years since the introduction of electricity, the nation has faced ever increasing demand for electricity as consequence of the rapid economic growth. The expanded consumption ratio for electricity naturally increased the possibility for electricity related accident mainly iii the form of electrically ignited fire and human injuries from electric shock. Under such circumstances, the presented study sets a focus on analysing the causes of the electrically related fire accidents happened in the nation over the last 10 years(in the 80's) to provide a scientific basis for identifying the cause of electric fires. Identification of the cause of fire ignited electrically may be approached either by studying accident related electrical properties or by investigating power instruments at the place of the accient. In the present paper, the former approach is taken especially on investigating the consequences of over current induced by short circuiting of high power instruments which is reported as the primary cause electricity related fire accidents. In order to provide reliability of the identification method, microscopic photograph's are taken for the cross sections of the electrical materials(fuse, wire, plug socket and plug) after being exposed to over current and heated by external means respectively. The results are consequently compared and analysed.

• Research in Community and Public Health Nursing
• /
• v.16 no.4
• /
• pp.527-533
• /
• 2005

Purpose: The purpose of this study was to validate waist circumference (WC) and waist to hip ratio (WHR) corresponding to body mass index (BMI) of $25kg/m^2$ and to survey the prevalence of hypertension according to obesity in female college students. Method: Weight, height, waist and hip circumferences and blood pressure were measured for each of 286 female college students in J City, Chungbuk. Results: The subjects' mean BMI was $21.4kg/m^2$, and the estimated prevalence of obesity was 11.2%. The subjects, the 80th-90th percentile of whom had BMI exceeding $25kg/m^2$, were found to have WC of 75-78.1 cm and WHR of 0.79-0.80, respectively. Of the subjects with obesity($BMI{\geq}25kg/m^2$), 53.1% exhibited abdominal obesity ($WC{\geq}80cm$) and 40.6% had WHR over 0.80. Systolic and diastolic blood pressure were correlated with BMI, WC, and WHR. The prevalence rate of hypertension in subjects with obesity($BMI{\geq}25kg/m^2$) was 25%. Additionally, the prevalence rate of hypertension in subjects with abdominal obesity ($WC{\geq}80cm$) was 39.1%. Conclusions: Our study indicates that WC corresponding to BMI of $25kg/m^2$ in female subjects in their twenties is different from that of adult women. We also found that the prevalence rate of hypertension in subjects with abdominal obesity was high. Therefore. we suggest further studies to determine the cutoff value of WC for evaluating abdominal obesity and to investigate the long-term effects of obesity on women in their twenties.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.19 no.2
• /
• pp.195-201
• /
• 2016

An experimental study has been found the air guide grooves for reducing drag. When a bullet is fired and move in the air, the drag is generated. The vortex which is one of the types of drag hinders the movement of the bullet. To solve this phenomenon, cut a negative grooves that we are called the air guiding grooves at the back of bullet. The grooves bullet has identified that the drag compared to conventional ammunition(KM80 and K193) is reduced to 4.480 and 4.054 : 10 % through a Finite Analysis Program($Ansys^{TM}$). Even pressure center was retreating 0.72 % compared to a Bullet(KM80 and K193). Effect obtained with these results is the accuracy of the grooves bullet in a shooting test was improved by over 32 %(KM80: 2.86, air guide grooves : 1.94) compared to conventional ammunition(KM80 and K193). In addition, muzzle velocity is increased 73 m/s. This is expected to be extended the velocity and effective range of bullet. Also, the velocity of the grooves bullet is increased when moving in the air while the velocity of the bullet(KM80 and K193) is reduced. The gas ejected from the muzzle to be balanced and stable flight of the Bullet. Given these effects, we can reckon the air guide grooves have positive influence.

• BMB Reports
• /
• v.28 no.4
• /
• pp.359-362
• /
• 1995

The highly polymorphic variable number of tandem repeat (VNTR) loci in the human genome are informative markers for the genetic characterization of individuals in the paternity test and forensic science as well as for the study of human disease. In this study, VNTR loci D1S80 and D2S123 have been amplified by PCR and the amplified length polymorphic alleles were detected with a discontinuous vertical PAGE system and silver staining. For explicit DNA typing, PCR optimization, in which amplification efficiencies are similar over a wide range of allele sizes, non-specific amplifications are minimal, and new longer alleles have high amplification efficiency, has been performed by changing the PCR reaction buffer composition and thermal cycling conditions. It turned out that adding an appropriate amount of Tween 20 and NP40 to the PCR reaction buffer and raising the annealing temperature to $68^{\circ}C$ in thermal cycling made it possible for optimal VNTR loci amplification. A modified PAGE system for VNTR separation was established. Under these conditions, new longer alleles in the 01580 locus were discovered and 025123 pattern changes in colorectal tumors were observed. These technical tips are valuable for detecting various amplified fragment length polymorphisms.

• Journal of Hospice and Palliative Care
• /
• v.4 no.1
• /
• pp.26-40
• /
• 2001

Purpose : The purpose of this study was to develop task guidelines for hospice team members. The task range of all personnel who work for hospice institutions was identified, and a tool describing roles and tasks of the hospice team members was developed based on review of related literature, both domestic and international. Methods : The content validity of the tool was assured by an expert panel through two phases of discussion. The first phase of the study included a survey conducted from December 1999 to January 2000 for a total of 126 hospice experts and practitioners affiliated with domestic hospice institutions. The second phase of the study included 35 subjects. The data were collected using a survey when the investigators visited each hospice institution. The data were analyzed using descriptive statistics. Results : 1) In the first phase of the study, all items scored over 80 points in CVI were selected as the roles and tasks of hospice coordinator, nurse, pastor, social worker, pharmacist, nutritionist, therapist, volunteer, and nurse aide. However, two items were excluded because they scored below 80 points: an item describing eligibility of a physician, a person who has a license for managing anesthetic agents was scored as 78.6 points, and an item describing the eligibility of the team leader of volunteers, a person educated at the graduate level was scored as 74.7 points. 2) In the second phase of the study, all items scored over 80 points in CVI were selected as the roles and tasks of hospice nurse, pastor, social worker, pharmacist, nutritionist, therapist, volunteer, and nurse aide. Of the roles of the hospice coordinator, however, the item scored as 77.9 points, assess and plan a patients physical, social, emotional, and spiritual status, and, of the roles of the team leaders of volunteers, the item scored as 78.6, attend a team meeting once a week and participate in building an standard nursing plan for patients were included in the tool since they scored over 80 points in the first phase of the study. Conclusion : The developed task guideline should be further modified and revised based on the findings of a preliminary application in the actual field. There is also a need of continuous research for developing more culturally-appropriate task guidelines for hospice team members.

• Nuclear Engineering and Technology
• /
• v.54 no.2
• /
• pp.709-731
• /
• 2022

Loss of fracture resistance due to thermal aging degradation is a potential limiting factor affecting the long-term (80+ year) viability of nuclear reactors. To evaluate the effects of decades of aging in a practical time frame, accelerated aging must be employed prior to mechanical characterization. In this study, a variety of chemically and microstructurally diverse austenitic stainless steels were aged between 0 and 30,000 h at 290-400 ℃ to simulate 0-80+ years of operation. Over 600 static fracture tests were carried out between room temperature and 400 ℃. The results presented include selected J-R curves of each material as well as K_0.2mm fracture toughness values mapped against aging condition and ferrite content in order to display any trends related to those variables. Results regarding differences in processing, optimal ferrite content under light aging, and the relationship between test temperature and Mo content were observed. Overall, it was found that both the ferrite volume fraction and molybdenum content had significant effects on thermal degradation susceptibility. It was determined that materials with >25 vol% ferrite are unlikely to be viable for 80 years, particularly if they have high Mo contents (>2 wt%), while materials less than 15 vol% ferrite are viable regardless of Mo content.

• The Monthly Technology and Standards
• /
• s.12
• /
• pp.67-78
• /
• 2003

In order to keep a characteristic corrugated fibreboard of fruits and flowers, temperature and humidity change of corrugated fibreboard are analyzed. According to relative humidity rises at fixed temperature, bursting strength of corrugated fibreboard was fallen and double wall corrugated fibreboard appeared greatly the bursting strength decline rate than double faced corrugated fibreboard and edgewise compressive strength of paper more than humidity 80% in rapidly fall. A column crush test of paper became decrease in the high temperature and ordinary temperature strength did over humidity 70% rapidly fallen and strength decrease happened by low temperature 80% slowly fallen and later rapidly. According to ISO standard temperature humidity conditioning (23$\pm$2 , 50$\pm$2%) change, pulp composition difference as to the ring crush strength of a physical strength and generally compare to KS standard increased 5∼8% for the compressive strength, and wet strength reagent was increased 4% inside and out.

• Atmosphere
• /
• v.20 no.3
• /
• pp.319-332
• /
• 2010

Sensitivity experiments of WRF model using different planetary boundary layer (PBL) and land surface model (LSM) parameterizations are evaluated for prediction of wind fields within the surface layer. The experiments were performed with three PBL schemes (YSU, Pleim, MYJ) in combination with three land surface models (Noah, RUC, Pleim). The WRF model was conducted on a nested grid from 27-km to 1-km horizontal resolution. The simulations validated wind speed and direction at 10 m and 80 m above ground level at a 1-km spatial resolution over the South Korea. Statistical verification results indicate that Pleim and YSU PBL schemes are in good agreement with observations at 10 m above ground level, while the MYJ scheme produced predictions similar to the observed wind speed at 80 m above ground level. LSM comparisons indicate that the RUC model performs best in predicting 10-m and 80-m wind speed. It is found that MYJ (PBL) - RUC (LSM) simulations yielded the best results for wind field in the surface layer. The choice of PBL and LSM parameterization will contribute to more accurate wind predictions for air quality studies and wind power using WRF.