• Resources Recycling
• /
• v.12 no.3
• /
• pp.13-24
• /
• 2003

The production characteristics of activated carbon from waste walnut shell have been investigated by taking activation temperature, activation time, amount of activating agent, and kind of activating agent as the major influential factors. The adsorption capacity of the activated carbon which was produced using phosphoric acid as the activating agent increased with activation temperature and showed its greatest value at about $550^{\circ}C$. Yield for activated carbon was observed to decrease continuously as the activation temperature was raised. The optimal activation time for the highest adsorption capacity was found to be about 2 hr, and as the activation time increased the yield for activated carbon was showed to decrease continuously. The increase in the amount of activating agent resulted in the increase of the yield for activated carbon, however, excessive amount of activating agent deteriorated its adsorption capacity reversely. The variations of the microstructure of activated carbon observed by SEM with several influential factors, correlated very well with its changes in the adsorbability with the same factors and the kind of activating agent was found to play an important role in the determination of the adsorption capacity of activated carbon. To investigate the adsorption characteristics of the produced activated carbon, the adsorption reactions of $Cu^{2+}$ ion were examined using the produced activated carbon as the adsorbent. In general, the kinetics of the adsorption of $Cu^{2+}$ ion was observed to follow a 2nd-order reaction and the rate constant for adsorption reaction increased as the initial concentration of adsorbate was diminished. The equilibrium adsorption of $Cu^{2+}$ was explained well with Freundlich model and its adsorption reaction was found to be endothermic. The activation energy for adsorption was calculated to be 13.07 kcal/mol, which implied that the adsorption reaction was very irreversible, and several thermodynamic parameters of adsorption reaction were estimated using van't. Hoff equation and thermodynamic relationships.

• Journal of the Korean Institute of Gas
• /
• v.18 no.5
• /
• pp.47-51
• /
• 2014

This paper is to analyze and study the fire examples in respect of intake and exhaust, alternator tuning and inflow of inflammables on exhaust part in a car. In the first example, the driver diverted the intake and exhaust system for tuning of a car. Stopping a car to rest for moment, the flammable styrofoam scrap go into exhaust pipe that installed with exhaust manifold newly. It certified the fact that catched fire gradually, furthermore enlarged the fire by leaking fuel. In the second example, the driver enlarged the generator performance to divert the audio system in side room., it knew the fact that the electric wiring connected with generator gave the cause of outbreak a fire by overheating. In the third example, the serviceman replaced the engine oil using funnel-shaped, he put the a bottle of plastic pat onto engine cover carelessly. Consequentially, it found the fire occurrence in the engine room. Therefore, the driver never divert the intake and exhaust and generator construction of a car abnormally. Also, repairing and inspecting a car, the serviceman have a care to not occur the fire by inflammables.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.3
• /
• pp.182-187
• /
• 2011

In this paper, PBTI characteristics of NMOSFETs with La incorporated HfSiON and HfON are compared in detail. The charge trapping model shows that threshold voltage shift (${\Delta}V_{\mathrm{T}}$) of NMOSFETs with HfLaON is greater than that of HfLaSiON. PBTI lifetime of HfLaSiON is also greater than that of HfLaON by about 2~3 orders of magnitude. Therefore, high charge trapping rate of HfLaON can be explained by higher trap density than HfLaSiON. The different de-trapping behavior under recovery stress can be explained by the stable energy for U-trap model, which is related to trap energy level at zero electric field in high-k dielectric. The trap energy level of two devices at zero electric field, which is extracted using Frenkel-poole emission model, is 1,658 eV for HfLaSiON and 1,730 eV for HfLaON, respectively. Moreover, the optical phonon energy of HfLaON extracted from the thermally activated gate current is greater than that of HfLaSiON.

• Journal of Korean Society of Rural Planning
• /
• v.26 no.3
• /
• pp.67-77
• /
• 2020

The purpose of this study was to determine the problems of reclamation sites and the prospects of farming in reclamation areas seen by local governments and the KRC branches in Chungnam, Jeonbuk, and Jeonnam provinces. A mail survey method was used. The survey items were set for 15 items regarding the reclamation site situation, problems, and prospects. Seventy-five copies of the questionnaire were distributed to the local government, and 90 copies were sent to the KRC 165 copies in total. In response to the questionnaire, 72 recipients of the local governments responded, showing a 96% response rate, and 74 (82.2%) of the KRC responded. The overall response rate was 88.5%. The opinions on the rental method of the reclaimed land were found to differ according to the geographic conditions of the reclaimed land, the construction conditions, and the time. Regarding the survey on crops preferred for cultivation, rice was highest in both local governments (61%) and KRC (46%). When cultivating field crops in reclaimed land, 56% of local governments and 57% of KRC considered salinity as the most problematic or resolvable problem. Regarding growing other field crops in reclaimed land, salt and drainage problems were recognized as the biggest obstacles in all reclaimed land. As for technologies that need to be applied first for the future agriculture of reclamation land, KRC responded with automatic water management (48%) and local governments responded with unmanned agricultural machinery (32%). In order to diversify the land use in the reclamation area, it is necessary to reduce salt damage and ensure systematic maintenance, employing, for example, automatic water management facilities and drainage improvement methods. The results of this study can set a land use direction for reclamation sites and provide useful information for use in various forms.

• Korean Security Journal
• /
• no.42
• /
• pp.229-249
• /
• 2015

As the post-cold war era and globalization go on, national security problems which were not traditional national security problems such as terrorism, crime, environmental disasters, economic crises, cyber-terrorism, diseases, and energy problems threat humanity and nations and demands changes. Also, with the change, the concept of "big government" has emerged as the role of nation expanded. The modern society sees every country change from small government to big government in order to realize the establishment of welfare state. A comprehensive interpretation of security is needed in order to comprehensive protection of citizens beyond outside invasion such as crime, new disaster, terrorism. In Korea, incidents such as Cheonan-Ham, Yeonpeyong-Do, foot-and-mouth disease, Ddos terrorism, pirates hostages, mad cow disease, AI are happening and the humanitarian support for North Korea and the summit of South and North Korea are at a standstill. Also, National emergency management system, comprehensive emergency management center, countrol tower, national security system, cooperation with citizens, establishment of legal and institutional system are needed. The importance of this research is on the reestablishment of new national security and emergency management system according to the comparison between the national security and counter-terrorism system of Korea and that of the United States which is a leading country in this field. Also, the establishment of national emergency management act is needed as a statute for effective function as currently various laws and administrative organizations are dispersed.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.25 no.2
• /
• pp.78-88
• /
• 2012

Objectives: Paeonia japonica has been widely used for gynecopathy and analgesic effects in Korean Traditional Medicine. The aim of the present study is to determine the antioxidant effect of Paeonia japonica extracts(PJE) by using mouse embryonic fibroblast cells(MEF cells). Methods: We evaluated Radical Scavenging Activity of PJE by the DPPH assay. Protective effect of the PJE on the hydrogen peroxide($H_2O_2$) induced oxidative damage of MEF cells was analyzed by the MTT assay. The Morphological changes of MEF cells induced by P. japonica, $H_2O_2$ and P. japonica+$H_2O_2$ was evaluated by DAPI staining. And effect of PJE on the rate of apoptosis in MEF cells was measured using flow cytometry with Annexin V-FITC and PI double staining. Results: We observed that PJE contain significant DPPH radical scavenging activity. Cell viability of oxidative damaged cells treated with various concentrations of $H_2O_2$ was increased by treatment with PJE. Flow cytometric analysis of the cells treated with $H_2O_2$ in the absence or presence of PJE showed that the crumbled G1 peak was accumulated by the treatment with $H_2O_2$ alone, but restored by addition of PJE. Portion of cells that undergo apoptosis mediated by oxidative stress was decreased by treatment of PJE. The nuclear fragmentation occurred in the oxidative damaged MEF cells was also decreased by PJE treatment. Conclusions: Taken together, our results suggest that PJE exhibits significant antioxidant activity and functions to inhibit cell death mediated by oxidative damage induced apoptotic pathways.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.24 no.4
• /
• pp.105-113
• /
• 2011

Objectives: To examine the current status of clinical research in oriental medicine, and to assess 'risk of bias'(ROB) of randomized clinical trials(RCTs) in oriental medicine in Korea. Methods: Special committee for EBM, KOMS(Korean Oriental Medicine Society) reviewed 17 journals related to oriental medicine in Korea (from the first issue to May 2010), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2010), and PubMed (1966 to May 2010). Then we selected eligible RCTs in terms of oriental medicine, and assessed 'risk of bias'. Results: We reviewed 12,653 articles from the 17 journals, and 41 articles from CENTRAL and PubMed. After non-clinical articles were excluded, 1,004 articles were left. Among them, the number of eligible studies in terms of oriental medicine was 306. In these eligible studies, 130 were RCTs. Of RCTs, 69 were on acupuncture, 25 on herbal medicine. The proportion of 'unclear' is high in the criteria of 'Allocation concealment', 'Blinding of participants and personnel', 'Blinding of outcome assessment' and 'Other bias'. On the other hand, 'low' has high in the criteria of 'Incomplete outcome data' and 'Selective reporting'. Conclusions: Risk of bias on oriental medicine is unclear in terms of 'allocation concealment' and 'blinding'. For high-quality research in oriental medicine, further research should be needed on randomization and blinding in the RCTs.

• Archives of Plastic Surgery
• /
• v.38 no.4
• /
• pp.472-476
• /
• 2011

Purpose: Traditional transcutaneous incision and transconjunctival incision methods are commonly used in the lower blepharoplasty. The transconjunctival method leaves no visible scars nor does it change the shape of lower eyelid contour and the surgical technique is not difficult. However removal of excess baggy skin is not possible through this method. Therefore, the transconjunctival incision method is useful only for patients who still have normal elasticity of the lower eyelids and fat that is protruding only anterocaudally. The Author will introduce a technique, which complements the limitations of these two methods mentioned above. Methods: The author combined the transconjunctival approach and lower blepharoplasty with only the excised skin flap method. This method does not go beyond the previous methods but does apply the advantages of them. Results: From March 2007 to October 2010, this new technique was performed in a total of 62 patients. Fat was removed and repositioned through transconjunctival incision. Drooped skin was excised as in the traditional blepharoplasty but only the skin flap was elevated. This prevents post-operative complications such as ectropion, sclera show, and deformation of the shape of the lower eyelids or under-resection of fat. All patients were satisfied with the post-operative appearance. Conclusion: The author was able to get satisfactory results while avoiding complications of traditional transcutaneous technique with this combined technique of the transconjunctival approach and the lower blepharoplasty method of skin flaps only.

• Journal of the Korean Wood Science and Technology
• /
• v.9 no.3
• /
• pp.16-23
• /
• 1981

This study has been carried out to make a comparative study for the adhesive control methods specifically developed for application to formaldehyde. The method for formaldehyde determination used in this report is the improved chromo tropic acid determination. The results are summarized as follows: 1. The soaking treatment in aqueous solution of urea wok the most scavenging effect on the formaldehyde release from a plywood sample glued with a urea formaldehyde adhesive, and other removal treatment such as resorcinol, albumine-, and hardener-treatment gave significant reduction too. 2. In glue shear strength of dry test, 2% of resorcinol treatment and soaking treatment showed the highest strength and all the other treatment met the standard, but in hot water soaking test, 2% of resorcinol treatment gave the best results, on the other hand, adding the hardener showed the lowest strength and failed in meeting the standard. 3. Air dried moisture content of all treated plywood met the standard which calls for 13% or bellow. 4. In this comparative study, we can make a strong combination each other or go into the details of one treatment for the best result through the more study.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.39 no.1 s.119
• /
• pp.38-47
• /
• 2007

This study was carried out to develop a new application field and obtain the basic data of citrus peel as waste in Jeju island and traditional Hanji for producing functional Hanji. The results measuring physical and optical properties, water vapor permeance and antibacterial activity are as follows. It was revealed that apparent density go as down but bulk raise up in the structural view of Hanji with increasing of the addition various Korean citrus peel (citrus unshiu, cheonggyun and hanrabong peel, and citrus unshiu peel powder) percentages, and that the density of Hanji added citrus unshiu peel was higher, but bulk was lower in compared with Hanji added other kinds of peel. Those Hanji added citrus unshiu peel, cheonggyun peel, hanrabong peel and citrus unshiu powder were very great not only in the strength (breaking length, burst index, tear index and folding endurance) but also in water vapor permeant rate in comparison with Hanji. The pHs of Hanji were neutrality (7 to 8). The brightness of the Hanji added various citrus peel percentages was low in compared to Hanji, and the 40% addition of hanrabong peel was the lowest. When 40% hanrabong peel was added to Hanji, it was very yellow in the color degree. When cheonggyun peel was added to Hanji manufacture, water vapor permeant rate was highly effective. It is known that vacant space of intrafiber was reduced by image analysis of Hanji and the additions of peel of citrus unshiu, cheonggyun and hanrabong were distributed equally in the interior of Hanji. The antibacterial activity of Hanji added citrus unshiu peel is more than 98%. After all, it would be able to increase utilization of Hanji, extensively. Namely, production of high quality Hanji added functional materials is expected for new valuable industry of citrus peel and Hanji.