• Biomedical Science Letters
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• v.10 no.4
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• pp.501-506
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• 2004

Extended spectrum β-lactamase (ESBL) generated Enterobacteriaceae including Escherichia coli is responsible for resisting antibiotics, which is clinical problem. This study was performed to investigate the isolation rates of 111 strains having positive of VITEK ESBL test 111 ESBL-strains in each month and season and statistically to determine their patterns of antibiotic test. One hundred eleven ESBL-strains were collected among 1,688 strains of E. coli isolated from various clinical specimen of one general hospital in Busan during 2002 to 2003. Month rates of ESBL-strains were 0％ to 13.3％, while the seasonal rates were highest at autumns during two years. The resistance to ampicillin, cefazolin, azteronam, ceftriaxone, and cefepime were 100％ in 2002. In ampicillin and cefazolin the resistances were 100％ during the two years. There were significant differences of cefoxitin and piperacillin/tazobactam between the two years but not significant between specimens. Four groups were divided according to the pattern of resistance and then the highest group had 93∼100％ of the resistance to 8 drugs but not resistant to imipenem.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.71-76
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• 1996

Recently, large scale concrete structures exposed to severe environment are increasingly built in various locations. The corrosion may affect severely the durability and service life of such a concrete structure. It is, therefore, necessary to develop durable concrete to enhance the corrosion resistance. The corrosion resistance of concrete can be identified through accelerated corrosion test. The purpose of the present paper is, therefore, to devise a reasonable and accurate method to predict the amount of corrosion of reinforcing steels. The proposed method which is basically based on the concept of Faraday's Law, determines the corroded amount of a re-bar according to accelerated corrosion time. The corrosion is accelerated by employing the potentiometric corrosion test arrangement. The effects of admixtures in concrete including fly ash and silica fume have been also studied to explore the relative corrosion resistance of concrete.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.46-49
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• 2003

Aluminum based metal matrix composites(MMCs) are well known for their high specific strength, stiffness and hardness. They are gaining further importance because of their high wear resistance. In this study, Al/Saffil-20%, Al/Saffil-5%/Al2O3(particle type)-15% and Al/Saffil-5%/SiC(particle type)-15% hybird MMCs' wear behavior were characterized by the pin-on-disk test under various normal load The superior wear resistance was exhibited at Al/Saffil-5%/SiC(particle type)-15% MMCs. And this MMCs' predominant wear mechanism is subsurface cracking in the low load wear regime. Others(Al/Saffil-20%, Al/Saffil-5%/Al2O3(particle type)-15%) showed the similar wear resistance with each other at the same test condition. In the low load & room temperature condition, the wear resistance was improved due to the high hardness of the ceramic reinforcements. As the test load increased, the wear properties were governed by the wear properties of matrix.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.267-272
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• 2014

In this paper, we analyze the characteristics for the driving shock resistance of the military vehicle through the bump test. Prior to the experiment, theoretical analysis was performed by using the SRS(shock response spectrum) and VRS(vibration response spectrum) analysis method. And we estimated the characteristics for the driving shock resistance of the military vehicle. Bump test was performed using the acceleration sensor and the driving test at a different speed. We evaluated the characteristics for the driving shock resistance of the military vehicle based on the result. And predicted values were compared with the theoretical analysis. In addition, we evaluated the results of the theoretical prediction of the SRS and the VRS analysis. And we evaluate the suitability of the prediction method at military vehicle shock analysis.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1813-1815
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• 1997

In this study, in order to develop outdoor insulating materials, SIN(simultaneous interpenetrating polymer network) was introduced to Epoxy resin and the environment resistance was investigated. Six kinds of specimen were manufacture by filler($SiO_2$) content. SEM was untilized in order to confirm their network structure changes. Also, tracking test, UV test and acid rain test were carried out investigate the environment resistance characteristic. Therefore it was confirmed that simultaneous interpenetrating polymer network specimens were more excellent than single network structure specimens. But, acid rain almost never changed resistance.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.339-351
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• 2007

Salmonella infections cause the diseases in poultry and some zoonotic Salmonella can be transmitted to human through poultry products, resulting in food-borne disease. This study was conducted to obtain some useful information for the control of salmonellosis in human. Twenty four Salmonella spp were isolated from poultry carcasses, and they were examined with several methods such as serotyping, antimicrobial resistance test and random amplified polymorphic DNA(RAPD) to identify their characteristics. In serotyping test of 24 strains S enteritidis was 17 (70.8%), followed by S schwarzengrund 3 (12.5%), untyped strain 4 (16.7%). In the results of antimicrobial resistance test, 23 (95.8%) isolates were resistant to at least one antimicrobial agent, generating eight different resistance patterns. In RAPD analysis using URP-6 primer to differentiate Salmonella isolates within a serotype, 4 serogroups were divided into 10 RAPD types: 5 types in S enteritidis, 2 types in S schwarzengrund and 3 types in the remainder.

• Journal of Technologic Dentistry
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• v.21 no.1
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• pp.43-53
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• 1999

The mechannical properties and corrosion resistance of alloy added commercially pure titanium for dental implants have been investigated. Ti, To-65Zr, Ti-10.1Ta and Ti-17Sn alloys were melthed in arc furnace and the corrosion resistance of Ti alloys was evaluated by anodic polarization test. The microstructure and mechanical properties of Ti alloy were analysed by optical micrograph. hardness tester and instron. In isothermal test, Ti-10.1Ta and Ti-17Sn alloys exhibited the best oxidation resistance below $1100^{\circ}C$. Ti65Zr, Ti-10.1Ta and Ti-17Sn alloys showed better rockwell hardness compared with commercially pure. Ti As the result of the anodic polarization test in 5%HCl, it 5%HCl, it was known knows that Ti-65Zr, alloy showed a rapid decrease in current density at higher potenial in comparision with other Ti alloys.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.211-219
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• 2003

The main study experiments to obtain engine torque of the vehicle during performance test of the recent automobile. Torque was measured through the engine dynamometer to produces engine torque of the vehicle but the research method calculated engine torque of the vehicle without the engine dynamometer. The performance of the vehicle receive various running resistance. The study certificates performance of certification before a certification of used vehicle didn't carry out and certificate. This way evaluated on road test and chassis dynamometer The result of the study shows that it is much possible to apply the test. After comparing the engine torque of road driving with that of chassis dynamometer, the results are approximately the same. When rapidly speeded up, the road-load vehicle can pitch in some degrees, which may result in the fluctuations of acceleration, and then affect on the engine torque. Therefore it is confirmed that this method is easier way to measure the performance of vehicles.

• Journal of Welding and Joining
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• v.30 no.3
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• pp.57-65
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• 2012

The interest of austenitic heat resistant stainless steels containing high Si has increased because they have higher resistance of oxidation and higher strength at high temperature than STS 310. This study carried out Varestraint test for evaluation of solidification cracking sensitivity of 14 different stainless steels. As a result of Varestraint test, all specimens solidified as primary ferrite, and solidification crack sensitivity increased with adding $N_2$ to shielding gas. Nb and W had beneficial effect on solidification crack resistance in case of less than FN 2 containing, but crack sensitivity increased with Nb and W in case of more than FN 2. Ce had beneficial effect on solidification crack resistance but impaired weld bead appearance.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.45-54
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• 2003

The density and strength of wood is affected by degradations and defects, such as voids and knots. Old wooden structures such as traditional cultural properties have been deteriorated by these types of defects. They were evaluated by a visual observation that is difficult to evaluate the inner deterioration in structures. In this study, three nondestructive testing techniques were investigated to detect the wooden structural members. Ultrasonic stress wave tests, drilling resistance tests and visual inspections were used to examine the structural wood members. Patterns of Resistograph using by drilling resistance tests could indicate the features of internal wood such as voids, knots, decay, fungi, and so on. The technique just like as ultrasonic stress wave tests, however, difficult to detect exactly area where small amounts of internal deterioration in logs are. In spite of results of ultrasonic stress wave test, the internal deterioration of wooden structural members could be evaluated by the relationship between ultrasonic stress wave tests and drilling resistance tests.