• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.57-65
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• 2008

Wastewater containing strong organic matter is very difficult to treat by utilizing general sewage treatment plant. but the wastewater is adequate to generate biomass energy (bio-gas; methane gas) by utilizing anaerobic digestion. EcoDays Plug Flow Reactor (E-PFR), which was already proved as an excellent aerobic wastewater treatment reactor, was adapted for anaerobic food wastewater digestion. This research was performed to improve the efficiency of bio-gas production and to optimize anaerobic wastewater treatment system. Food wastewater from N food waste treatment plant was applied for the pilot scale experiments. The results indicated that the efficiency of anaerobic wastewater treatment and the volume of bio-gas were increased by applying E-PFR to anaerobic digestion. The structural characteristics of E-PFR can cause the high efficiency of anaerobic treatment processes. The unique structure of E-PFR is a diaphragm dividing vertical hydraulic multi-stages and the inversely protruded fluid transfer tubes on each diaphragm. The unique structure of E-PFR can make gas hold-up space at the top part of each stage in the reactor. Also, E-PFR can contain relatively high MLSS concentration in lower stage by vertical up-flow of wastewater. This hydraulic flow can cause high buffering capacity against shock load from the wastewater in the reactor, resulting in stable pH (7.0~8.0), relatively higher wastewater treatment efficiency, and larger volume of bio-gas generation. In addition, relatively longer solid retention time (SRT) in the reactor can increase organic matter degradation and bio-gas production efficiency. These characteristics in the reactor can be regarded as "ideal" anaerobic wastewater treatment conditions. Anaerobic wastewater treatment plant design factor can be assessed for having 70 % of methane gas content, and better bio-gas yielding and stable treatment efficiency based on the results of this research. For example, inner circulation with generated bio-gas in the reactor and better mixing conditions by improving fluid transfer tube structure can be used for achieving better bio-gas yielding efficiency. This research results can be used for acquiring better improved regenerated energy system.

• The Korean Journal of Pain
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• v.2 no.2
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• pp.135-144
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• 1989

Celiac plexus block is recommended in patients with intractable upper abdominal cancer pain. The success rate of a celiac plexus block is variable among the authors. One of the causes of this is the anatomical variations of the celiac plexus. There has not been a study concerning anatomical observations of the celiac plexus in Korean cadavers. So, anatomical dissections were performed and observations were made of the celiac plexus and related structures in Korean cadavers. The results were as follows: 1) The subjects were 21 male bodies and 5 female bodies. The mean age at death was $69.9{\pm}15.5$ years (range 37~93). The mean height was $155.5{\pm}8.3\;cm$ (range 143~172). 2) The number of celiac ganglia ranged from 1~4. The mean numbers were $2.3{\pm}1.9$ in the right plexus and $1.9{\pm}0.8$ in the left, and the mean sizes were $18.9{\pm}7.7{\times}8.0{\pm}3.8\;mm^2$ and $18.5{\pm}8.3{\times}9.5{\pm}3.9\;mm^2$ respectively. 3) Celiac ganglia were most frequently located at the level of the upper third and middle third of L1 in both sides (65.5% in right, 64.0% in left). The vertical range of celiac ganglia ranged from 1 space, which is one third the height of one vertebral body, to 4 spaces. Mean vertical ranges were $1.5{\pm}0.6$ spaces in the right plexus and $1.6{\pm}0.7$ spaces in the left. The celiac ganglia located at the level of the upper third of L1 in the right and the lower third of L1 in the left side, had the largest vertical ranges respectively ($1.8{\pm}0.5$ spaces in right, $2.3{\pm}0.6$ spaces in left) 4) Right side celiac ganglia were located near the midline of the vertebrae compared to the left ones (mean 5.0 mm) The horizontal dimension was greater in the right ganglia ($24.2{\pm}9.2\;mm$) than in the left ganglia ($l8.8{\pm}7.0\;mm$). 5) There was no vertebral level difference between both celiac ganglia in most cases (60%). However, of the 40% of cases at different levels, in half of these (20%) the right ganglia were located higher than the left ganglia; and in the other 20%, this was reversed. 6) The origin sites of the celiac artery were most frequently in the upper third and middle third of L1 (61.6%). The celiac ganglia were usually located at the same level as the site of origin of the celiac artery (61.6% in right, 52.0% in left). 7) The vertebral level of the splanchnic nerves piercing the abdominal surface of the diaphragm was most frequently in the upper third and middle third of L1 (66.6% in right, 66.7% in left). 8) The level of the origin of diaphragmatic crura from the anterior surface of the vertebral bodies varied from the L1-L2 interspace to the L3-L4 interspace. Right crura most frequently originated at the level of the lower third of L2 to the upper third of L3 (57.6%), while left crura originated from the level of the L2-L3 interspace to the middle third of L3 (69.3%). From the above results, we realized that there were some anatomical variations of the celiac plexus and its relations to adjacent structures in Korean bodies. However, when the needle point is behind the anterior margin of the upper third of L1, it is possible to perform a successful retrocrural splanchnic nerve block.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.244-249
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• 2007

Deadweight piston gauge have been widely used as a fundamental instrument of precise pressure measurement because they are robust, accurate, potable, convenient to use and are able to realize the definition of pressure as farce per unit area. Basically, a deadweight piston gauge consists of a piston mounted vertically in a close-fitting cylinder filled with a gas and weights of known mass values. The pressure to be measured is applied to the base of the piston generating an upward vertical force, and is balanced by the downward gravitational force generated by weights. These instruments can be used to measure pressures above 10 kPa because of tare weights including piston. However, using a variable bell-jar pressure method and a newly developed weight loading device we can extend the application range of deadweight piston gauge to lower pressures. In this paper, we present the practical calibration results for two CDGs(Capacitance diaphragm gauge, MKS) with full-scale ranges of 1.33 kPa and 13.3 kPa, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.10-15
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• 2017

The refraction expansion joints have been newly developed by complementing the problems of shock, noise, replaceability, displacement in the direction perpendicular to bridge, vertical difference, which are problems of existing expansion joints. The Refraction expansion joints are characterized by continuous surfaces with small impact and low noise. The behavior of the Refraction expansion joints performs the bridge expansion behavior by rotation of the link. In the rotational behavior of the link, the bolt is the central axis of the behavior. Therefore, it can be said that the durability of the bolt is very important. However, the theoretical and experimental verification of the bolt durability of the Refraction expansion joint is lacking. In this paper, to verify the fatigue durability of the bolt, test specimens with a 300 mm Refraction expansion joint were fabricated. A strain gauge dedicated to the bolt was installed inside the manufactured test specimen bolt. The test method was applied in accordance with KS F 4425. The fatigue durability of the bolts assembled inside the diaphragm expansion joint was confirmed by the repeated fatigue test of 2,000,000 cycles.