• Journal of the Korean Institute of Gas
• /
• v.17 no.1
• /
• pp.7-12
• /
• 2013

As emission regulation for vehicle has been reinforced, many researches carried out for HCNG(hydrogen-natural gas blends) fuel to the conventional compressed natural gas (CNG) engine. However, abnormal combustion such as backfire, pre-ignition or knocking can be caused due to high combustion speed of hydrogen and it can result in over heating of engine or reduction of thermal efficiency and power output. In the present study, improvement of combustion performance was observed with HCNG fuel since it can extend a flammability limit. Knocking characteristics for CNG and HCNG fuel were investigated. Feasibility of HCNG fuel was evaluated by checking the knock margin according to excess air ratio. The operation of engine with HCNG was stable at minimum advance for best torque(MBT) spark timing and knock phenomena were not detected. However, it is necessary to prepare higher knock tendency since possibility of knock is higher with HCNG fuel.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.3
• /
• pp.516-530
• /
• 2012

Gasohol which is the mixture of gasoline and ethanol, is used to gasoline vehicles worldwide currently. This study is performed by the methods of the review of references, and includes the background introduced, manufacturing processes, amounts produced, original properties, specifications, ways of applied currently, regulations and policies as a fuel for gasoline vehicles on individual countries through the scope of worldwide, especially focused on bioethanol and gasoline. By the reason above, it is prepared by focused on multiple angles for the person who want to getting information and searching desired ways in the future regarding to bioethanol and gasohol. It is concluded that gasohol is one of the useful renewable energies, and must to take a step forward by the approaching of multiple points, and finally showed some directions by the way of comparing of the situations and references nowaday.

• The Korean Journal of Pharmacology
• /
• v.1 no.1 s.1
• /
• pp.37-46
• /
• 1965

1. In the tortoise, Amyda japonica, a cold-blooded animal readily available in this country, the role of catecholamines in the regulation of free fatty acids(FFA) metabolism was investigated in both in vivo and in vitro studies. 2. Norepinephrine elevated both FFA and glucose levels in plasma. 3. When $50{\mu}g/kg$ of Epinephrine, Norepinephrine and Isopropylarterenol were administered intravenously, the relative effectiveness of mobilizing FFA was in the descending order of potency-Epinephrine, Norepinephrine and Isopropylarterenol. 4. In order to exclude the 'tonic influence of the endogenous catecholamines', reserpine was given to some animals. Two days after the reserpine-treatment, glucose showed a significant increase over the solely vehicle treated controls, FFA but an insignificant one. Excised auricles from those animals showed a diminished response to tyramine. Seven days after the treatment, however, when the depletion of catecholamines from the tissue stores seemed to be complete, judged from the absence of the response of isolated auricles to tyramine, both FFA and glucose levels were definitely lowered. 5. In in vitro experiments Epinephrine enhanced the FFA-release from the adipose tissue. The effect increased proportionately with the concentration until a maximal effect was attained at a concentration of 1x $10^5$ g/ml. 6. The order of potency in releasing FFA from adipose tissue in vitro was the same as in vitro, i.e., Epinephrine, Norepinephrine and Isopropylarterenol, but the differences were much less marked. 7. Ergotamine exerted no lipolytic action, but inhibited the lipolytic effect ef Epinephrine significantly. 8. Nethalide showed a slight lipolytic effect per se but inhibited the Epinephrine-induced lipolysis significantly. 9. Catecholamines play an important role in regulating FFA metabolism in the cold-blooded animal, just as in the warm-blooded animals, and the tortoise, Amyda japonica, may be used in the studies of fat metabolism as well as the rat.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.5
• /
• pp.523-528
• /
• 1997

Peripheral benzodiazepine receptor(PBR) has been indentified in various peripheral tissues including kidney. The physiological and pharmacological functions of PBR are still uncertain, althought it has been suggested that these are associated with the regulation of stress/anxiety response. Diazepam progeny, which were exposed to diazepam perinatally, was reported to be an animal model of chronic anxiety. However, PBR in the diazepam progenies are not known yet. In the present study, therefore, we examined the changes of PBR in the stress/anxiety response. Dams of rats were given injection of diazepam or vehicle during puerperium. Diazepam progenies showed increased level of anxiety on the performance of elevated plus maze, and increased Bmax of PBR. Saturation experiments followed by scatchard analysis of the results showed that the increase in the density of PBR and the affinity of the PBR remained unchanged. Forced swim stress increased anxiety on the plus maze in both groups of rats. In contrast to control, diazepam progenies did not show further upregulation of renal PBR immediately after swimming stress, but still higher than control. From the above results, it may be concluded that upregulation of renal PBR is associated with chronic anxiety as well as stress-induced response.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.32 no.1
• /
• pp.12-25
• /
• 2016

Recently, research investment in the improvement of food safety as a food source and specializing of nutritional source of edible insects is being actively conducted. Cricket especially has been attracting considerable interest in entomophagy; however, research on the safety assessment of cricket is limited. This study investigated the effects of cricket ethanol extract when orally administrated in Sprague-Dawley rats. Here, we performed a 4 wk repeated oral dose toxicity test in Sprague-Dawley rats following the Organization for Economic Cooperation and Development test guidelines 407 under Good Laboratory Practice regulation. Rats were randomly allocated 4 groups: vehicle control, 250, 500, 1,000 mg/kg test groups and administrated based on body weight for 28 d. The animals were observed for mortalities and clinical signs, body weight changes, food and water consumption. At the end of treatment period, blood and urine were collected and analyzed. Subsequently, the animals were sacrificed and subjected to gross pathological examination and organ weight measurement. The organs were preserved for histopathological examination. The results showed that there were no systemic toxicological effects related with the cricket ethanol extract in the 4 wk oral repeated dose toxicity study. It is considered that NOAEL of cricket ethanol extract is greater than 1,000 mg/kg/d and there was no target organ detected.

• The Korean Journal of Air & Space Law and Policy
• /
• v.35 no.3
• /
• pp.65-93
• /
• 2020

With the development of information and communication technology, the unmanned aerial vehicle industry began to attract attention as a new growth industry as it entered the fourth industrial revolution. As the size of the unmanned aerial vehicles and the scope of airspace vary from small drones to large unmanned aerial vehicles, the developed countries such as USA and Europe are developing plans for the integrated operation of manned and unmanned aerial vehicles. ICAO is also working on amendments to the relevant ICAO annexes to establish international standards and recommendations for unmanned aerial vehicles. Korea also needs to prepare for the integrated operation of manned and unmanned aerial vehicles that will come in the future, and for this purpose, it is necessary to review and revise the national regulation systems for the safe operation of unmanned aerial vehicles. This study analyzes the amendments of related annexes discussed on the Remotely Piloted Aircraft System (RPAS) pannel, and suggests the direction of revision of the Aviation Safety Act for the safe operation of unmanned aerial vehicles in comparison with the existing Aviation Safety Act.

• Biomedical Science Letters
• /
• v.14 no.3
• /
• pp.131-137
• /
• 2008

Adipogenesis is a complex sequence of events that culminates in the differentiation of fibroblast-like preadipocytes into specialized lipid-filled adipocytes and also involves a cascade of expression of many transcription factors such as peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ and CCAAT/enhancer-binding proteins (C/EBPs). $PPAR{\gamma}$ and C/EBPs transcriptionally transactivate adipocyte specific genes, including fatty acid transport protein (FAT/CD36) and leptin. To determine whether $17{\beta}$-estradiol modulates $C/EBP{\alpha}$ actions on adipogenesis in high fat diet-fed female ovariectomized (OVX) C57BL/6 mice, mice were treated with $17{\beta}$-estradiol for 7 days and the effects of $17{\beta}$-estradiol on adipose tissue mass and expression of adipocyte specific gene as well as $C/EBP{\alpha}$ were measured. Compared to vehicle-treated OVX control mice, OVX mice treated with $17{\beta}$-estradiol for 7 days had lower adipose tissue weights that were similar to weights in high fat diet-fed sham-operated (Sham) mice. OVX mice showed the increased expression of $C/EBP{\alpha}$ mRNA compared with Sham mice. However, $17{\beta}$-estradiol treatment in OVX mice inhibited OVX induced-$C/EBP{\alpha}$ activation, indicating that $17{\beta}$-estradiol may act as an inhibitor of $C/EBP{\alpha}$ action. Moreover, $17{\beta}$-estradiol decreased mRNA levels of adipocyte marker genes, such as lipoprotein lipase, FAT/CD36 and leptin, to levels in Sham mice. These results suggest that down-regulation of adipogenesis by $17{\beta}$-estradiol may be due to reduced adipose $C/EBP{\alpha}$ activities in female OVX C57BL/6 mice.

• Journal of Power System Engineering
• /
• v.20 no.6
• /
• pp.93-98
• /
• 2016

Environmental problems are issued throughout all over the world and which are needed the strength management. In case of the diesel cars are also being developing and studying continuously about various after-treatments device such as EGR, LNT, SCR, DPF and DOC etc. which are used for decreasing $NO_X$ and PM. The air temperature goes up to $39^{\circ}C$ in summer and goes down to $-20^{\circ}C$ in winter because of the location. These changing of the temperature can effect to the engine and harmful exhaust gas discharged and it seems to make the increase - decrease different. The result of the evaluate while changing between the test-mode and the air temperature, which expresses that WLTC-mode is 2.2 times and FTP_75 mode is 4.1~6 times increase to the comparison NEDC-mode of the current regulation. The exhaust characteristic of $NO_X$ by the changing temperature increases in the low temperature and 4.3 times in $14^{\circ}C$ and 21.3 times in $-7^{\circ}C$ with maximum when it compares to $23^{\circ}C$. The fuel efficiency of the different weight car and engine with same data is about 5.7 % in maximum.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.6
• /
• pp.723-730
• /
• 2013

The speed-limit regulation on a turnout is the main factor inhibiting the speed-up of conventional lines. The specified speed for a train moving through a turnout system is lower than that for a train traveling over the general track. This is done to ensure the running safety of a railway vehicle moving through a turnout. In this study, the shape change example of the guard rail component of a turnout in the Daegu Metropolitan Transit Corporation (DTRO) system was studied. A theoretical examination of the geometrical interaction formula according to wheel/rail shape at the turnout was conducted. Running safety analysis by changing the length of the guard rail on the F10/F12 turnout using the developed analysis techniques (by VI-Rail) was achieved, and the effect on railway safety was examined accordingly.

• Journal of Pharmacopuncture
• /
• v.17 no.1
• /
• pp.59-69
• /
• 2014

Objectives: In homeopathy, it is claimed that more homeopathically-diluted potencies render more protective/curative effects against any disease condition. Potentized forms of Condurango are used successfully to treat digestive problems, as well as esophageal and stomach cancers. However, the comparative efficacies of Condurango 6C and 30C, one diluted below and one above Avogadro's limit (lacking original drug molecule), respectively, have not been critically analyzed for their cell-killing (apoptosis) efficacy against lung cancer cells in vitro, and signalling cascades have not been studied. Hence, the present study was undertaken. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were conducted on H460-non-small-cell lung cancer (NSCLC) cells by using a succussed ethyl alcohol vehicle (placebo) as a control. Studies on cellular morphology, cell cycle regulation, generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential (MMP), and DNA-damage were made, and expressions of related signaling markers were studied. The observations were done in a "blinded" manner. Results: Both Condurango 6C and 30C induced apoptosis via cell cycle arrest at subG0/G1 and altered expressions of certain apoptotic markers significantly in H460 cells. The drugs induced oxidative stress through ROS elevation and MMP depolarization at 18-24 hours. These events presumably activated a caspase-3-mediated signalling cascade, as evidenced by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot and immunofluorescence studies at a late phase (48 hours) in which cells were pushed towards apoptosis. Conclusion: Condurango 30C had greater apoptotic effect than Condurango 6C as claimed in the homeopathic doctrine.