• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.89-96
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• 1997

The purpose of this study was to determine the effect of Ga-Al-As (Gallium-Aluminum-Arsenid) laser radiation on the tail-flick latency in rat. Thirty Sprague-Dawley male and female rats Were divided into five groups : that is control, laser 15sec radiation, laser 30sec radiation, laser 60sec radiation, and Tramadol Hcl injection groups. The continuous Ga-Al-As laser with, wave length 780-830nm and diameter of probe in the 3mm, averse output of 100mw radiation was applied to the meridian point(Gv 1 : Governing vessel) of the rats. Tail-flick latency were measured with hot plate at $55^{\circ}C$ : before treatment and immediately, 30 minutes, 1 hour, 2 hours, 24 hours, 24 hours and 48 hours after treatment. The result were as follows ; 1. The tail-flick latency according to time varition, control group was not significance. 2. The tail-flick latency according to time varition, laser 15 sec irradiate rats in post-treared was significance(P<0.05). 3. The tail-flick latency according to time varition, laser 30 sec irradiate rats group was not significance. 4. The tail-flick latency according to time varition, laser 60 sec irradiate rats in post 30 minute was significance(P<0.05). 5. The tail-flick latency according to time varition, Tramadol Hcl injection rats in post-treated (P<0.05), post 30 minute(P<0.05), post 60 minute (P<0.01) and 2 hour(P<0.05) was significance. This study suggest that Ga-Al-As (Gallium-Aluminum-Arsenid) laser applied to meridian point of the rat with 15 sec, 30 sec, and 60 set radiation could induc no analgesic effect, but Tramadol Hcl injection rat is good analgesic effect.

• Journal of Korean Society of Steel Construction
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• v.27 no.4
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• pp.377-386
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• 2015

In this study, inelastic buckling strength of HSA800 steel columns were tested to investigate the applicability of current column curve (KBC2009, 2010 AISC-LRFD) to HSA800 steel. Key test variables included width-thickness ratio, plate-edge restraints, and column slenderness ratio. Specimens made of ordinary steel (SM490) were also tested for comparison purposes. All the concentrically loaded HSA800 specimens exhibited sufficient buckling strength compared to the current column curve, but some of SM490 specimens showed understrength. This difference can be explained by the lower residual stress present in HSA800 specimens.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.1-6
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• 1998

Background: The role of nitric oxide(NO) in analgesia from opioids is controversial. On the one hand, IV morphine analgesia is enhanced by IV injection of NO synthase inhibitors. On the other hand, IV morphine results in increased release of NO in the spinal cord. There have been no behavioral studies examining the interaction between IV morphine and intrathecal injection of drugs which affect NO synthesis. Method: Rats were prepared with chronic lumbar intrathecal catheters and were tested withdrawal latency on the hot plate after 3~5 days of surgery. Antinociception was determinined in response to a heat stimulus to the hind paw before and after IV injection of morphine, 2.5 mg/kg. Twenty minutes after morphine injection, rats received intrathecal injection of saline or the NO synthase inhibitors, L-NMMA or TRIM, the NO scavenger, PTIO, or the NO synthase substrate, L-Arginine. Intrathecal injections, separated by 15 min, were made in each rats and measurements were obtained every 5 min. Result: Mophine produced a 60~70% maximal antinociceptive response to a heat stimulus in all animals for 60 min in control experiments. Intrathecal injection of idazoxane decreased antinociception of IV morphine. The NO synthase inhibitors and the NO scavenger produced dose-dependent decreases in antinociceptive effect of morphine, whereas saline as a control group and L-Arginine as the NO substrate had no effect on antinociception of morphine. Conclusion: The present study supports the evidences that systemic morphine increase the nitrite in cerebrospinal fluid and dorsal horn. These data suggest that the synthesis of NO in the spinal cord may be important to the analgesic effect of IV morphine and increased NO in spinal cord has different action from the supraspinal NO.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.5
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• pp.417-422
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• 2013

The aim of this study was to evaluate the synergistic potentiation effect of ineffective doses of dexmedetomidine on antinociception induced by morphine and fentanyl in acute pain model in rats. Seventy albino Wistar rats were separated into 7 groups. Data for the control and sham groups were recorded. The ineffective dose of dexmedetomidine was investigated and found to be 3 ${\mu}g/kg$. Each group was administered the following medications: 3 mg/kg morphine (intraperitoneal) to Group 3, 5 ${\mu}g/kg$ fentanyl (intraperitoneal) to Group 4, dexmedetomidine 3 ${\mu}g/kg$ (subcutaneously) to Group 5, dexmedetomidine 3 ${\mu}g/kg$ (subcutaneous)+3 mg/kg morphine (intraperitoneal) to Group 6 and finally 3 ${\mu}g/kg$ dexmedetomidine (subcutaneous)+5 ${\mu}g/kg$ fentanyl (intraperitoneal) to Group 7. Just before the application and 15, 30, 60, 90 and 120 min after the administration of medication, two measurements of tail flick (TF) and hot plate (HP) tests were performed. The averages of the measurements were recorded. TF and HP latencies were the main outcomes. The analgesic effect of the combinations with dexmedetomidine+morphine (Group 6) and dexmedetomidine+fentanyl (Group 7), compared to the analgesic effect of morphine alone and fentanyl alone was significantly higher at 15, 30, 60 and 90 minutes after administration. In this study, dexmedetomidine in ineffective doses, when combined with morphine and fentanyl, potentiates the effects of both morphine and fentanyl.

• Computers and Concrete
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• v.18 no.3
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• pp.319-336
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• 2016

In this study, both two- and three-dimensional (2D and 3D) finite-volume-based models were developed to analyze the heat transfer mechanisms through the porous structures of cellular concretes under steady-state heat transfer conditions and to investigate the differences between the 2D and 3D modeling results. The 2D and 3D reconstructed pore networks were generated from the microstructural information measured by 3D images captured by X-ray computerized tomography (X-CT). The computed effective thermal conductivities based on the 2D and 3D calculations performed on the reconstructed porous structures were found to be nearly identical to those evaluated from the 2D cross-sectional images and the 3D X-CT images, respectively. In addition, the 3D computed effective thermal conductivity was found to agree better with the measured values, in comparison with the 2D reconstruction and real cross-sectional images. Finally, the thermal conductivities computed for different reconstructed porous 3D structures of cellular concretes were compared with those obtained from 2D computations performed on 2D reconstructed structures. This comparison revealed the differences between 2D and 3D image-based modeling. A correlation was thus derived between the results of the 3D and 2D models.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.2
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• pp.119-123
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• 2012

In the present study, the antinociceptive profiles of $Agrimonia$ $pilosa$ $Ledeb$ extract were examined in ICR mice. $Agrimonia$ $pilosa$ $Ledeb$ extract administered orally (200 mg/kg) showed an antinociceptive effect as measured by the tail-flick and hot-plate tests. In addition, $Agrimonia$ $pilosa$ $Ledeb$ extract attenuated the writhing numbers in the acetic acid-induced writhing test. Furthermore, the cumulative nociceptive response time for intrathecal (i.t.) injection of substance P (0.7 ${\mu}g$) was diminished by $Agrimonia$ $pilosa$ $Ledeb$ extract. Intraperitoneal (i.p.) pretreatment with yohimbine (${\alpha}_2$-adrenergic receptor antagonist) attenuated antinociceptive effect induced by $Agrimonia$ $pilosa$ $Ledeb$ extract in the writhing test. However, naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) did not affect antinociception induced by $Agrimonia$ $pilosa$ $Ledeb$ extract in the writhing test. Our results suggest that $Agrimonia$ $pilosa$ $Ledeb$ extract shows an antinociceptive property in various pain models. Furthermore, this antinociceptive effect of $Agrimonia$ $pilosa$ $Ledeb$ extract may be mediated by ${\alpha}_2$-adrenergic receptor, but not opioidergic and serotonergic receptors.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.31-37
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• 2015

PURPOSES : To design a pre-heater for warm in-place recycling equipment, three different heating systems were evaluated to determine their thermal efficiency. METHODS: In this study, a $30cm{\times}30cm{\times}15cm$ wheel-tracking specimen was used to measure the inner temperature as a function of the heating system. The inner temperature of the specimen was measured with a data logger at the surface, and at depths of 1cm, 2cm, 3cm, 4cm, and 5cm. To evaluate the thermal efficiency, the researchers used three different types of equipment, namely, IR, a heating wire, and a gas burner. RESULTS: The IR heating system exhibits a higher level of performance than the others to achieve the target temperature at a depth of 5cm in the specimen. The gas burner system was capable of heating the surface to a temperature of up to $600^{\circ}C$. The other types, however, cannot heat the surface up to 600. The thermal efficiencies were measured based on the laboratory conditions. CONCLUSIONS: To find the most effective system for application to the development of a pre-heater for warm in-place recycling, various systems (IR, heating wire, gas burner) were examined in the laboratory. As a result, it was found that the hot plate of a gas burner system provides the highest temperature at the surface of the asphalt but, of all the systems, the IR system provides the best internal temperature increase rate. Furthermore, a gas burner can age the asphalt binder of the surface layer as a result of the high temperature. However, the gas burner cannot attain the target temperature at 5cm. The IR system, on the other hand, is effective at increasing the internal temperature of asphalt.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.620-625
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• 2002

Considering the fuel consumption of car, a light structure of aluminum alloys is desired for car body nowadays. However, fusion welding of aluminum alloys has some problems of reduction of joint efficiency, porosity formation and hot cracking. ill the present work, investigation to improve the joint performance of laser welded joint has been carried out by addition of Cu, Ni, and Zr to A6N01 alloy welds. Aluminum alloy plate of 2.0mm in thickness with filler metal bar was welded by twin beam Nd:YAG laser facility (total power:5kW). The filler metals were prepared by changing the chemical compositions for adding the elements into the weld metal. Thirteen filler metal bars were prepared and pre-placed into the base metal before welding. Ar gas shielding with a flow rate of 10 l/min was used. The defocusing distance is kept at 0 mm. At travel speeds of 3 to 9 m/min and at laser power of 5kW (front beam 2kW rear beam 3kW), full penetration welds were obtained, whereas at travel speeds of 12 to 18 m/min and same power, partial penetration was observed. The joint efficiency of laser-welded joint was improved by the addition of Cu, Ni, and Zr due to the solid solution hardening, grain refining and precipitation hardening. The type of hardening has been further considered by metallurgical examination.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.561-569
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• 2002

Laser has been called a "Quantum Machine" because of its mechanism of generation since the development on July 7,1960.by T.H.Maiman. We can now use this machine as a tool for manufacturing in industries. At present, 45kW CO2 laser, 10kW Nd:YAG laser, 6kW LD pumped YAG laser and 4kW direct diode laser facilities are available for welding a heavy steel plate of 40mm in thickness and for cutting metals at high speed of 140m/min. Laser Materials Processing is no longer a scientific curiosity but a modern tool in industries. Lasers in manufacturing sector are currently used in welding, cutting, drilling, cladding, marking, cleaning, micro-machining and forming. Recently, high power laser diode, 10kW LD pumped YAG laser, 700W fiber laser and excimer laser have been developed in the industrialized countries. As a result of large numbers of research and developments, the modem laser materials processing has been realized and used in all kinds of industries now. In the present paper, metallurgical studies on laser materials processing such as porosity formation, hot cracking and the joint performances of steels and aluminum alloys and dissimilar joint are discussed after the introduction of laser facilities and laser applications in industries such as automotive industry, electronics industry, and steel making industry. The wave towards the use of laser materials processing and its penetration into many industries has started in many countries now. Especially, development of high power/quality diode laser will be accelerate the introduction of this magnificent tool, because of the high efficiency of about 50%, long life time and compact.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1517-1523
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• 2020

The widely used medical isotope technetium-99 m (^99mTc) is a daughter of Molybdenum-99 (⁹⁹Mo), which is mainly produced using dedicated research reactors from the nuclear fission of uranium-235 (²³⁵U). ^99mTc has been used for several decades, which covers about 80% of the all the nuclear diagnostics procedures. Recently, the instability of the supply has become an important topic throughout the international radioisotope communities. The aging of major ⁹⁹Mo production reactors has also caused frequent shutdowns. It has triggered movements to establish new research reactors for ⁹⁹Mo production, as well as the development of various ⁹⁹Mo production technologies. In this context, a new research reactor project was launched in 2012 in Korea. At the same time, the development of fission-based ⁹⁹Mo production process was initiated by Korea Atomic Energy Research Institute (KAERI) in 2012 in order to be implemented by the new research reactor. The KAERI process is based on the caustic dissolution of plate-type LEU (low enriched uranium) dispersion targets, followed by the separation and purification using a series of columns. The development of proper waste treatment technologies for the gaseous, liquid, and solid radioactive wastes also took place. The first stage of this process development was completed in 2018. In this paper, the results of the hot test production of fission ⁹⁹Mo using HANARO, KAERI's 30 MW research reactor, was described.