• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.83-94
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• 2009

The aim of this study was to investigate the shear bond strength between zirconia ceramic and resin cement according to various surface treatments. The surface of each zirconia ceramic was subjected to one of the following treatments and then bonded Rely X Unicem or Rely X ARC resin cement; (1) Rocatec system and $50{\mu}m$ surface polishing, (2) No treatment and $50{\mu}m$ surface polishing, (3) Rocatec system and $1{\mu}m$ surface polishing, (4) No treatment and $1{\mu}m$ surface polishing. Each of eight bonding group was tested in shear bond strengths by universal testing machine(Z020, Zwick, Ulm, Germany) with crosshead speed of 1mm/min. The results were as follows; 1. Rocatec treatment groups showed greater bonding strengths than No Rocatec groups. There was significant difference of among groups(P<0.001) 2. For Rocatec groups, $50{\mu}m$ surface roughness groups showed greater bonding strengths than $1{\mu}m$ surface roughness groups.(P<0.001) But for No Rocatec groups, There was no significant difference of among groups(P>0.05) 3. Rely X Unicem groups showed greater bonding strengths than Rely X ARC groups. There was significant difference of among groups(P<0.01) Within the conditions of this study, Rocatec treatment was an effective way of increasing zirconia bonds to a resin cement, even in the case of self-adhesive resin cement.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.249-277
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• 2015

Regulation (EC) No 261/2004 ("Regulation") is a common rule on compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights. In some recent cases of European nations, passengers sued the air carrier in order to obtain monetary compensation under Article 7(1) of the Regulation. Some courts dismissed the actions on the grounds that, unlike denied boarding or cancellation of the flight, the Regulation provides no compensation in relation to delayed flights. However, Court of Justice of the European Union(CJEU) ruled that Regulation 261/2004 must be interpreted to mean that passengers whose flights are delayed have a right to compensation in cases when the loss of time is equivalent to, or is in excess of three hours - where the passengers eventually reached their final destination three hours or more later than the originally scheduled arrival time. It is true that a strict interpretation of the regulation would suggest that passengers whose flight has merely been delayed are not entitled to compensation. They should only be offered assistance in accordance with the Articles 6 and 9. Nevertheless, the Court recognized the same right to the same compensation for passengers of flights delayed by more than three hours as that explicitly provided for passengers of cancelled flights. On the one hand, the Court bases this ruling on the recitals of the Regulation, in which the legislature links the question of compensation to that of a long delay, while indicating that the Regulations seek to ensure a high level of protection for passengers regardless of whether they are denied boarding or their flight is cancelled or delayed. On the other hand, the Court interprets the relevant provisions of the Regulation in light of the general principle of equal treatment. Furthermore, the Court delivered a ruling that the loss of time inherent in a flight delay, which constitutes an inconvenience within the intention of Regulation No 261/2004 and which cannot be categorized as 'damage occasioned by delay' within the meaning of Article 19 of the Montreal Convention, cannot come within the scope of Article 29 of that convention. Consequently, under this view, the obligation under Regulation No 261/2004 intended to compensate passengers whose flights are subject to a long delay is in line with Article 29 of the Montreal Convention. Although the above interpretation of the Court can be a analogical interpretation, the progressive attitude of the Regulation and the view of Court forward to protect passengers' interest is a leading role in the area of international air passenger transportation. Hopefully, after the model of the positive support in Europe, Korea can establish a concrete rule for protecting passengers' right and interest.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.3-54
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• 2013

Nowadays, major advanced countries in aviation technology are putting their effort to develop commercial and civil Unmanned Aircraft System(UAS) due to its highly promising market demand in the future. The market scale of commercial and civil UAS is expected to increase up to approximately 8.8 billon U.S. dollars by the year 2020. The usage of commercial and civil UAS covers various areas such as remote sensing, relaying communications, pollution monitoring, fire detection, aerial reconnaissance and photography, coastline monitoring, traffic monitoring and control, disaster control, search and rescue, etc. With the introduction of UAS, changes need to be made on current Air Traffic Management Systems which are focused mainly manned aircrafts to support the operation of UAS. Accordingly, the legislation for the UAS operation should be followed. Currently, ICAO's Unmanned Aircraft System Study Group(UASSG) is leading the standardization process of legislation for UAS operation internationally. However, some advanced countries such as United States, United Kingdom, Australia have adopted its own legislation. Among these countries, United States is most forth going with President Obama signing a bill to integrate UAS into U.S. national airspace by 2015. In case of Korea, legislation for the unmanned aircraft system is just in the beginning stage. There are no regulations regarding the operation of unmanned aircraft in Korea's domestic aviation law except some clauses regarding definition and permission of the unmanned aircraft flight. However, the unmanned aircrafts are currently being used in military and under development for commercial use. In addition, the Ministry of Land, Infrastructure and Transport has a ambitious plan to develop commercial and civil UAS as Korea's most competitive area in aircraft production and export. Thus, Korea is in need of the legislation for the UAS operation domestically. In this regards, I personally think that Korea's domestic legislation for UAS operation will be enacted focusing on following 12 areas : (1)use of airspace, (2)licenses of personnel, (3)certification of airworthiness, (4)definition, (5)classification, (6)equipments and documents, (7)communication, (8)rules of air, (9)training, (10)security, (11)insurance, (12)others. Im parallel with enacting domestic legislation, korea should contribute to the development of international standards for UAS operation by actively participating ICAO's UASSG.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.775-785
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• 1999

Background : The herbicide paraquat can cause severe lung injury and fibrosis in experimental animals. In this study we have investigated the changes in lung endothelin-1(Et-1) levels and immunohistochemical localization in relation to treatment with cyclophosphamide and methylprednisolone in paraquat induced pulmonary fibrosis in guinea pigs. Material and methods : 29 male Hartley guinea pigs were divided into 4 groups. Group I was normal control. Paraquat was instilled into the lung of guinea pig of group II, III and IV unilaterally. Group II was treated with cyclophosphamide and methylprednisolone. Group III was treated with methlprednisolone. Group IV was not treated. The degree of fibrosis was evaluated by H-E stains and Masson's trichrome stains and cell activity was assessed by Et-1 immunohistochemical stains. Statistical evaluation was performed using the Kruskawallis oneway analysis. Results : Paraquat induced an increase in numbers of fibroblasts and total amount of lung collagen in Group IV compared to the normal controls. There was no significant difference in total numbers of fibroblasts between any of paraquat instilled groups, but there was significant increase in total amount of collagen in Group IV compared to group II and III (p<0.05). The treatment of cyclophosphamide and methyprednisolone suppressed the growths of both fibroblasts and collagen, but this suppression was stastically significant only in the case of collagen Et-1 immunoreactivities of bronchial epithelium, type II pneumocytes, endothelial cells and fibroblast in group II and III were decreased compared to those in group IV. Conclusion : These results demonstrate that Et-1 is an important contributing factor in the pathogenesis of pulmonary fibrosis. Et-1 is synthesized and released by bronchial epithelium, Type II pneumocyte, endothelial cells, alveolar macrophages and fibroblasts. Especially they are associated with alveolar macrophage and fibroblasts. We conclude that combined therapy of cyclophosphamide and methylprednisolone are more effective in the control of Et-1 expression and collagen deposition.

• Tuberculosis and Respiratory Diseases
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• v.51 no.5
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• pp.437-447
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• 2001

Background: TNF-alpha is related to the generation of lung fibrosis in patients with UIP. The precise mechanism leading to lung fibrosis by TNF-alpha is unknown. However, the activation of a transcription factor like AP-1(down stream of c-jun N-terminal kinase, JNK) by TNF-alpha may be related to the induction of fibrogenic cytokines like PDGF or IGF-I. Furthermore, JNK was reported to be activated in the radiation-induced lung fibrosis model. This study examined JNK activity in patients with UIP. Methods : The expression of phosphorous JNK(p-JNK), macrophage/monocyte specific markers, CD68, and cytokeratin was evaluated by immunohistochemical(IHC) staining of lung tissues from patients with UIP and lung cancer. An in vitro kinase assay was performed with alveolar macrophages obtained by a bronchol-avleolar lavage from patients with UIP and healthy persons as the control. Results : The IHC stain showed that p-JNK is expressed in the almost all of the alveolar macrophages and smooth muscle cells in patients with UIP. In case of the normal areas of the lung from patients with lung cancer, the alveolar macrophages showed little p-JNK expression. Interestingly, increased JNK activity was not found in the in vitro kinase assay of the alveolar macrophages obtained from both patients with UIP and healthy persons as the control. Furthermore, 10 ng/mL of TNF-alpha failed to increase the JNK activity of the alveolar macrophages in both patients with UIP and healthy people. Conclusion : The JNK was activated constitutionally in patients with UIP. However, the role of JNK in the pathogenesis of lung fibrosis needs to be clarified.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.767-774
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• 1999

Background : Tuberculous mediastinal lymphadenitis (TML) is a relatively commonly encountered in Korea. However, there were no datas available on TML without other combined tuberculous infections in Korea. We retrospectively analyzed clinical manifestations, radiologic findings, Chest CT scan findings, the duration of treatment, and follow up Chest CT scan findings of 23 cases who had only TML. Method : 23 cases from 1991 to 1997 with TML confirmed by biopsy and had no other combined tuberculous infections were studied retrospectively. Results : Of the 23 cases, 7 cases were male and 16 female. The male to female ratio was 1 : 2.4. Mean age was 31 years and the most prevalent age group was the 3rd decade(43%). The most common presenting symptoms were fever(39%) followed by no symptom, cough, swallowing difficulty, and chest discomfort. On simple chest X-ray, mediastinal enlargement were noted in 20 cases(90%). The most frequently involved site was the paratracheal node in 11 cases with the right to left side involvement ratio being 4.6 : 1. On chest CT scan, the most commonly enlarged node was the paratracheal node(33%) followed by the subcarinal(20%), hilar(13%), tracheobronchial (8%), subaortic(8%), supraclavicular(8%) and anterior. mediastinal nodes. 6 cases were dropt out due to incomplete follow up. Thirteen cases were treated with HERZ regimen and the mean duration of treatment was 14 months. Three cases were treated with second line drug regimens(Tarivid, Pyrazinamide, Streptomycin plus Ethambutol or Para-aminosalicylic acid) for 18 months. In HERZ groups, one case was recurred after 10 months later and retreatment was done by same HERZ regimen during 12 months. Follow up chest CT scan after completion of treatment were done in 13 cases and that revealed more than a 50% decrease in size in 77% of the cases and no interval change in 23% of the cases. Conclusion : In cases of TML without other combined tuberculous infection, the minimal duration of treatment was required 12 months by HERZ regimen and 18 months by a 2nd line regimen or more. Further studies will be needed to confirm the treatment duration for TML without other combined tuberculous infections.

• Tuberculosis and Respiratory Diseases
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• v.55 no.5
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• pp.516-521
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• 2003

The Aspergillus species produces metabolic products that play a significant role in the destructive processes in the lung. We experienced a case of chronic necrotizing pulmonary aspergillosis caused by an Aspergillus niger infection, which contained numerous calcium oxalate crystals in the necrotic lung tissue. A 46-year-old man, who had a history of pulmonary tuberculosis, presented with high fever, intermittent hemoptysis and pulmonary infiltrations with a cavity indicated by the chest radiograph. Despite being treated with several antibiotics and anti-tuberculosis regimens, the high fever continued. The sputum cultures yielded A. niger repeatedly, and intravenous amphotericin B was then introduced. The pathological specimen obtained by a transbronchial lung biopsy revealed numerous calcium oxalate crystals in a background of acute inflammatory exudates with no identification of the organism. Intravenous amphotericin B was continued at a total dose of 1600 mg, and at that time he was afebrile, although the intermittent hemoptysis continued. On the $63^{rd}$ hospital day, a massive hemoptysis (about 800 mL) developed, which could not be controlled despite embolizing the left bronchial artery. He died of respiratory failure the next day. It is believed that the oxalic acid produced by A. niger was the main cause of the patient's pulmonary injury and the ensuing massive hemoptysis.

• Tuberculosis and Respiratory Diseases
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• v.60 no.1
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• pp.72-75
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• 2006

Background : This report reviews our experience with persistent air leaks in the peumothorax that were not considered candidates for surgical treatment in order to evaluate the efficacy and risks of the OK-432 plus autoblood or OK-432 pleurodesis. Material & Methods : From March 2004 to July 2005, 8 consecutive patients who had an air leak in the pneumothorax over 5 days and had been treated with OK-432 plus autoblood or OK-432 pleurodesis. The patients were not considered candidates for surgical treatments because the chest CT findings revealed severe chronic lung disease with multiple bullae and/or bullous changes. A prolonged air leak with/without dead space was treated with either OK-432 plus autoblood or OK-432 pleurodesis. The efficacy and side effects of OK-432 pleurodesis were assessed by determining the duration of the air leak, the number of pleurodesis, the patients' symptoms, measurements of the white blood cell count and the c-reactive protein level. Results : All of eight patients were male and the mean age was $72.4{\pm}8.5$. The mean number of pleurodesis was $1.9{\pm}1.1$ and the mean duration of the air leak was $4.6{\pm}4.6days$ after pleurodesis. Side effects after pleurodesis were encountered in 7 patients, which included a chilling sensation in 7 cases, chest pain in 5 cases, headache in 3 cases, local heat sensation in 2 cases, and fever in 1 case. Leukocytosis was observed in 6 patients, and the mean of WBC count and CRP were $14500{\pm}2100$ and $21.9{\pm}11.4mg/dL$, respectively. Conclusion : Either OK-432 plus autoblood or OK-432 pleurodesis has acceptable side effects, and can be considered a treatment option for persistent air leaks in the pneumothorax that are not candidates for surgical treatment.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.15-21
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• 2003

Background : There are many risk factors for osteoporosis in patients with chronic obstructive pulmonary disease(COPD). These include smoking, a low body mass index, insufficient exercise, and the use of glucocortcoids. However, there is lack of data on the incidence of osteoporosis according to the different glucocorticoid administration methods in patients with COPD. This study compared the incidence of osteoporosis according to the different administration methods of glucocorticoid. Methods : A matched case-controlled study (gender, age, cumulative steroid dose and pack-years of smoking) was conducted. Forty-five patients with documented COPD for at least a 3 year duration and a cumulative glucocorticoid dose above 1,000 mg were enrolled in study. The patients were classified into the following three groups. First, fifteen patients received continuous inhaled glucocorticoid with intermittent oral steroids but had no admission history due to an acute exacerbation(Group I). Secondly, fifteen patients received a multiple course of oral steroids with additional inhaled glucocorticoid but had no admission history due to their acute exacerbation(Group II). Lastly, fifteen patients received intermittent oral or inhaled glucocorticoids and had an admission history due to the acute exacerbation with intravenous steroid treatment for at least 2 weeks per year(Group III). The enrolled patients had apulmonary function test and bone densitometry performed at the lumbar spine and femoral neck. Results : The patients from Group III had significantly high incidence of osteoporosis in the lumbar and femoral neck compared to Group I and Group II (p<0.01). Conclusion : The incidence of osteoporosis in patients with COPD appears to be strongly affected by the method of steroid administration. This result suggests that intravenous steroid administration is strongly associated with the risk of osteoporosis.

• Journal of Energy Engineering
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• v.29 no.2
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• pp.68-78
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• 2020

According to the new climate change agreement, technology development to reduce greenhouse gases is actively conducted worldwide, and research on energy efficiency improvement in the field of power generation and transmission and distribution is underway [1,2]. Economic analysis of the operation method of storing and supplying surplus electricity using energy storage devices, and using energy storage devices as a frequency adjustment reserve power in regional cogeneration plants has been reported as the most profitable operation method [3-7]. Therefore, this study conducted an economic analysis for the installation of energy storage devices in the combined heat and power plant in the Czech Republic. The most important factor in evaluating the economics of battery energy storage devices is the lifespan, and the warranty life is generally 10 to 15 years, based on charging and discharging once a day. For the simulation, the ratio of battery and PCS was designed as 1: 1 and 1: 2. In general, the primary frequency control is designed as 1: 4, but considering the characteristics of the cogeneration plant, it is set at a ratio of up to 1: 2, and the capacity is simulated at 1MW to 10MW and 2MWh to 20MWh according to each ratio. Therefore, life was evaluated based on the number of cycles per year. In the case of installing a battery energy storage system in a combined heat and power plant in the Czech Republic, the payback period of 3MW / 3MWh is more favorable than 5MW / 5MWh, considering the local infrastructure and power market. It is estimated to be about 3 years or 5 years from the simple payback period considering the estimated purchase price without subsidies. If you lower the purchase price by 50%, the purchase cost is an important part of the cost for the entire lifetime, so the payback period is about half as short. It can be, but it is impossible to secure profitability through the economy at the scale of 3MWh and 5MWh. If the price of the electricity market falls by 50%, the payback period will be three years longer in P1 mode and two years longer in P2 and P3 modes.