• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.2
• /
• pp.17-23
• /
• 2004

A cylindrical constant volume combustion bomb is used to investigate the combustion characteristics and to analyze the heat quantity of homogeneous charge methane-air mixture under various initial pressures, excess air ratios and ignition times. As the overall pressure increase, the values of maximum combustion pressure, maximum heat release rate and cumulative heat release have been increased. But it is not very meaningful to compare with some values such as maximum combustion pressure, maximum heat release rate and cumulative heat release for different overall pressure due to the different heat energy of supplied fuel. So the each value is needed to be compared with normalized value, which is divided by the entered fuel energy. To analyze the heat quantity, some definitions including the CHR ratio, the UHC ratio and the HL ratio are needed and are calculated. As the overall pressure increase, the CHR ratios and the UHC ratios have been decreased, while the HL ratios have been increased. The CHR ratio of 300 ms has the higher value than that of 10000ms, and the HL ratios of 300 ms have a lower value.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.1 no.1
• /
• pp.13-25
• /
• 2014

In the current study, a drug-eluting stent coated with biodegradable polymers and sirolimus was developed by using an ultrasonic nanocoater and characterized in aspects of surface smoothness and coating thickness. In addition, in vitro release profiles of sirolimus by changing top coating layer with different biodegradable polymers were investigated. Smooth surfaces with variable thickness could be fabricated by optimizing polymer concentration, flow rate, nozzle-tip distance, gas pressure, various solvents and ultrasonic power. Smooth surface could be generated by using volatile solvents (acetone, chloroform, and methylene chloride) or post-treating with solvent vapor. Coating thickness could be controlled by varying injection volume or polymer concentration, and higher concentration could reduce the coating time while obtaining the same thickness. The thickness measurement was the most effectively performed by a conventional cutting method among three different methods that were investigated in this study. Release profiles of sirolimus were effectively controlled by changing polymers for top layer. PLGA made the release rate 3 times faster than PDLLA and PLLA and all top layers prevented burst release at the initial phase of profiles. Our results will provide useful and informative knowledge for developing drug-eluting stents, especially coated with biodegradable polymers.

• Korean Journal Plant Pathology
• /
• v.11 no.4
• /
• pp.344-347
• /
• 1995

Factors affecting on the ascospore release of Mycosphaerella nawae, the causal organism of persimmon leaf casting disease, were investigated. The ascospore release of the pathogen occurred following the precipitation of rain. The ascospore release started from the beginning of raining, reached maximum at 2 hours after the precipitation of rain, and then decreased abruptly. When the inoculum source (a file of infected leaves) was submerged in water to imitate raining conditions, 92.5% of the total ascospores were released within 1 hour after submerging, 5.8% were after 2 hours, 1.4% were after 4 hours, 0.1% were after 8 hours, and none detected after 10 hours. The inoculum source overwintered in the field released ascospores much more and earlier than the inoculum source kept in the greenhouse. The first ascospore release was about 10 days earlier, and the amount of the total liberated spores was 3∼4 times higher in the field inoculum source than the greenhouse nioculum source. The early defoliated leaves (in early October) in the previous year produced ascospores twice more than the late defoliated leaves (in early November) produced.

• The Korean Journal of Physiology and Pharmacology
• /
• v.6 no.2
• /
• pp.81-85
• /
• 2002

Conventional views of synaptic transmission generally overlook the possibility of 'postfusional-control' the regulation of the speed or completeness of transmitter release upon vesicular fusion. However, such regulation often occurs in non-neuronal cells where the dynamics of fusion-pore opening is critical for the speed of transmitter release. In case of synapses, the slower the transmitter release, the smaller the size and rate-of-rise of postsynaptic responses would be expected if postsynaptic neurotransmitter receptors were not saturated. This prediction was tested at hippocampal synapses where postsynaptic AMPA-type glutamate receptors (AMPAR) were not generally saturated. Here, we found that the small miniature excitatory postsynaptic currents (mEPSCs) showed significantly slower rise times than the large mEPSCs when the sucrose-induced mEPSCs recorded in cyclothiazide (CTZ), a blocker for AMPAR desensitization, were sorted by size. The slow rise time of the small mEPSCs might result from slow release through a non-expanding fusion pore, consistent with postfusional control of neurotransmitter release at central synapses.

• Archives of Pharmacal Research
• /
• v.12 no.3
• /
• pp.186-190
• /
• 1989

The release rates of methotrexate (MTX) from MTX-human serum albumin (HSA) conjugate, and 5-fluorouracil (5-FU) from 5-FU acetic acid (AA)-HSA conjugate were determined after incubation of the conjugates in various conditions. The concentrations of 5-FU released from the conjugate increased monoexponentially, however those of MTX increased biexponentially in all studies. It indicated that there are two distinct types of MTX-HSA linkage, weakly and tightly bound linkages. The release rates of 5-FU were lower than those of MTX in all studies indicating that the bond of 5-FU-AA-HSA conjugate is very stable, which is supported by the higher value of activation energy (39. 9 vs 10. 7 Kcal/mole) using Arrhenius equation. The release rates of MTX and 5 -FU from the conjugates increased with incubation temperatures. Proteolytic enzyme and liver homogenates accelerated significantly the release rates of MTX and 5-FU. Approximately 1.30 and 22.0% of MTX were released after 12 hours of incubation in the absence and presence of protease, respectively. The corresponding values for 5-FU were released after 12 hours of incubation with rat liver homogenates which were diluted 6 times with phosphate buffer of pH 6.0. The MTX-HSA and 5-FU-AA-HSA conjugates were very stable in rat plasma.

• The Korean Journal of Pesticide Science
• /
• v.8 no.4
• /
• pp.319-324
• /
• 2004

Pesticide formulations for controlled release were pepared with hollow silica microspheres. The hollow microsphere, which was obtained through calcination for the core removed after silica coating, showed maximum impregnation of benfuracarb up to 2.7 times of its mass in comparison with those obtained through the other core removal method. The release test of the pesticide formulation, when used with ESO(Epoxidized Soybean Oil) as a binder, showed ideal release pattern with steady release rate from the day 10 to 30 retaining the benfuracarb concentration in the water around 1.65 ppm.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.4 no.1
• /
• pp.19-29
• /
• 2009

Objectives: The purpose of this study is to evaluate the therapeutic effect of acupuncture treatment of acute ankle sprain combined with positional release therapy. Methods: A prospective randomized single blind study between positional release group and knee flexed supine position group was conducted. Patients with ankle sprain within 48 hours were evaluated by Ankle injury grade chart(AIGC). In group A, positional release therapy was combined with acupuncture, whereas in group B, acupuncture was conducted in knee flexed supine position. The treatment was planned for a duration of 1 week, 3times a week. In AIGC scores, VAS, weight bearing time and weight bearing time in blind were followed up and compared. Results and Conclusion: The VAS score decreased in both group. Weight bearing time increased in group B, weight bearing time in blind increased in group A. Comparing the therapeutic effect of each group, group A had significant effectiveness in weight bearing time in blind. So we may conclude that Acupuncture treatment combined with positional release therapy is effective and recommandable at early stage of ankle sprain.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.15 no.2
• /
• pp.69-79
• /
• 2009

Purpose : to investigate the effectiveness of joint mobilization and myofascial release on the neck pain and to provide the effective treatment. Methods : Twenty-two subjects with neck pain participated in the experiment. All subjects were randomly assigned to a joint mobilization group(n=11) or a myofascial release group(n=11). Both groups received treatment for 15 minutes four times during 2 weeks. Cervical range of motion(CROM) instrument was used to measure range of neck motion, and Algometer was used to measure tenderness. All measurements of the subjects were measured at pre-treatment and post-treatment. Results : 1. The range of neck right side-bending motion of the myofascial release group was significantly increased(P<0.05), and the range of neck extension, right side-bending, left side-bending, right rotation motion of the joint mobilization group was significantly increased(P<0.05). 2. There was no significant improvement of tenderness in both groups(p>0.05). Conclusion : These data suggest that joint mobilization is more effective against increasing the range of motion than myofascial release, but myofascial release is more beneficial to tenderness than joint mobilization although it does not have a significant difference in the tenderness because there was a little improvement.

• Journal of the Korean Society of Physical Medicine
• /
• v.14 no.1
• /
• pp.15-23
• /
• 2019

PURPOSE: This study was conducted to investigate the effects of the myofascial meridians release technique on pain and postural control of college students with forward head posture and to compare the intervention effects of the Grastone massage and the Rollfing massage. METHODS: Thirty subjects with forward head posture were randomly and equally allocated to experimental group I (myofascial meridians release technique using Grastone massage, n=15) or experimental group II (myofascial meridians release using Rollfing massage, n=15). All subjects underwent 30 minutes of different myofascial meridians release techniques in addition to general physical therapy (hot pack: 15 min, interferential current therapy: 15 min, ultra sound: 5 min) three times a week for a total of 6 weeks. Outcome was measured before and after 4 weeks of intervention. RESULTS: In both groups, the numerical rating scale of pain was significantly decreased after intervention, with experimental group I showing a greater decrease than experimental group II. The neck disability index decreased significantly after intervention in both groups, with experimental group I showing a significantly greater decrease than the controls. The distance of the head forward displacement did not differ significantly between the two groups (p>.05). CONCLUSION: This study suggests that the Grastone method combined with the myofascial meridians release technique is a more effective intervention for improvement of pain and postural control in adults with moderate forward head posture.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.4
• /
• pp.486-492
• /
• 2016

This study investigates the relationship between environmental factors, such as semilunar rhythm and atmospheric pressure, and the release of Marphysa sanguinea larvae. During artificial seed production in a temperature-regulated culture system, there was an increase in the number of released larvae at tide times between 3-4 and 9-11. Numbers of larvae released were significantly correlated with tidal rhythms. Atmospheric pressure also appeared to influence larval release, with increased numbers released when a period of high atmospheric pressure followed a period of low pressure.