• Journal of environmental and Sanitary engineering
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• v.18 no.1
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• pp.23-29
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• 2003

The effect of ozone oxidation on bio-degradability of leachate was studied. Ozone oxidation process was used as pre-treatment process to enhance performance of biological process in treating landfill leachate. Optimum ozone injection rate and contact time in this experiment was $160{\;}mg{\;}O_/{\ell}{\cdot}hr$ and 45 minutes, respectively. Bio-degradability was enhanced 5.08% by ozone oxidation. The ratio of ozone demand/DOC concentration was $0.049~0.091{\;}mg{\;}O_3/mg{\;}DOC$. The increase of bio-degradability depending on ozone injection rate(D) and contact time(T) can be expressed as follows ; The rate of bio-degradation of DOC was increased proportionally with the increase of ozone injection rate and contact time irrespective of landfill site age. The increase of bio-degradability by ozone addition was not satisfactory. It is hard to expect significant increase in bio-degradability by ozone treatment only. Thus, it is evaluated that ozone oxidation can not increase biodegradability significantly in concentrated wastewater composed of complex organic compound such as leachate.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.1-6
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• 2005

The effect of ozone oxidation on biodegradability of leachate was studied. Ozone oxidation process was used as pre-treatment process to enhance performance of biological process in treating landfill leachate. Optimum ozone dosing rate and contact time in this experiment was $160mg\;O_3/L$ hr and 45 minutes, respectively. Biodegradability was enhanced 5.08% by ozone oxidation. The ratio of ozone demand/DOC concentration was $0.049{\sim}0.091mg\;O_3/mg$ DOC. The increase of biodegradability depending on ozone dosing rate(D) and contact time(T) can be expressed as follows ; ${\Delta}E=0.00479{\cdot}D^{0.773}{\cdot}T^{0.800}$ The biodegradation rate of DOC was increased proportionally with the increase of ozone dosing rate and contact time irrespective of landfill site age. The increase of biodegradability by ozone addition was not satisfactory. It is hard to expect significant increase in biodegradability by ozone treatment only. Thus, it is evaluated that ozone oxidation can not increase biodegradability significantly in concentrated wastewater composed of complex organic compound such as leachate.

• Elastomers and Composites
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• v.33 no.1
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• pp.27-36
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• 1998

The surface of wiper blade(W/B) rubber was chlorinated by chemical treatment method using the hydrochloric acid(HCI) and sodium hypochlorite(NaOCl). From the results of contact angle measurement, friction coefficient measurement, and ATR-IR spectra, the surface characteristics of chlorinated W/B rubber with time of chlorination were studied. Contact angles for W/B rubber with increasing time of chlorination and chlorine concentration were measured for the water and ethylene glycol. From the results, contact angle fell rapidly with increasing time of chlorination and chlorine concentration, reaching a constant value after about 10min. And the wettability of W/B rubber surface by means of chlorination has been improved. For an unchlorinated W/B rubber, the friction coefficient with time of chlorination decreased from 1.27 to 0.20~0.23 on full chlorination. As the results it was considered that abrasion resistance of W/B rubber surface has been also improved. The values of pH and $Cl^-$ ion concentration in a chlorine treatment solution decreased as the extent of chlorination of W/B rubber surface increased. From the results of ATR-IR spectra, it was observed that C=C double band of W/B rubber surface transformed into C-Cl band, but quantitative determination of the extent of chlorination was not feasible because of the complexity of chlorination reactions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.790-793
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• 2011

In this study, the surface modification for a silicon(Si) mold using $CHF_3$ inductively coupled plasma(ICP). The conditions under that plasma was treated a input ICP power 600 W, an operating gas pressure of 10 mTorr and plasma exposure time of 30 sec. The Si mold surface became hydrophobic after plasma treatment in order to $CF_x$(X= 1,2,3) polymer. However, as the de-molding process repeated, it was investigated that the contact angle of Si surface was decreased. So, we attempted to investigate the degradation mechanism of the accurate pattern transfer with increasing the count of the de-molding process using scanning electron microscope (SEM), contact angle, and x-ray photoelectron spectroscopy (XPS) analysis of Si mold surface.

• The Journal of Korea Robotics Society
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• v.16 no.2
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• pp.172-178
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• 2021

The COVID-19 pandemic has been reshaping the world by accelerating non-contact services and technologies in various domains. Hospitals as a healthcare system lie at the center of the dramatic change because of their fundamental roles: medical diagnosis and treatments. Leading experts in health, science, and technologies have predicted that robotics and artificial intelligence (AI) can drive such a hospital transformation. Accordingly, several government-led projects have been developed and started toward smarter hospitals, where robots and AI replace or support healthcare personnel, particularly in the diagnosis and non-surgical treatment procedures. This article inspects the remaining element of healthcare services, i.e., surgical treatment, focusing on evaluating whether or not currently available laparoscopic surgical robotic systems are sufficiently preparing for the era of post-COVID-19 when contactless is the new normal. Challenges and future directions towards an effective, fully non-contact surgery are identified and summarized, including remote surgery assistance, domain-expansion of robotic surgery, and seamless integration with smart operating rooms, followed by emphasis on robot tranining for surgical staff.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1506-1514
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• 2022

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.

• Journal of Life Science
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• v.21 no.5
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• pp.713-719
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• 2011

In this study, we evaluated whether Lunasin Enriched Soybean (LES) suppressed 1-chloro-2,4-dinitrochlorobenzene (DNCB) induced allergic contact dermatitis in vivo. In the group treated with DNCB alone, erythema and hemorrhage in the skin were observed, while the application of LES after DNCB treatment modulated erythema and hemorrhage similar to the untreated group. In histopathological analysis of the skin, DNCB-treated groups showed increased skin thickness compared to the untreated groups, while the treatment of LES dose-dependently modulated skin thickness. Also, hypertrophy and hyperkeratosis of the epidermis, intracellular edema and infiltration of inflammatory cells were observed in the group treated with DNCB alone, while treatment of LES inhibited these inflammatory changes. DNCB also induced a significant up-regulation of iNOS and COX-2 expression, as compared to the untreated groups. However, the treatment of LES significantly decreased the down-regulation of iNOS and COX-2 expression, as compared to DNCB-treated groups. Also, LES reduced the IgE level in DNCB-stimulated groups. And lunasin from LES translocated the nucleus of the cells in the skin of Sprague-Dawley rats. Taken together, it is thought that LES has the potential to be used as an alternative treatment for allergic contact dermatitis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.2
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• pp.128-132
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• 2008

Background: Laryngeal contact granuloma is an inflammatory hypertrophic granulation tissue arising at around the vocal process of arytenoid cartilage. Various approaches are currently used for the treatment, but a solid guideline has not been established. Objectives: We aimed to compare the each treatment modality in the hope of suggesting a guideline for the successful management of laryngeal contact granuloma. Method: Eighty-seven treatment cases of 56 patients were analyzed. Cases having recent intubation history were excluded from the study. All patients received vocal hygiene education. Proton pump inhibitors (PPI, N = 33) or H2 receptor antagonists ($H_{2}RA$, N =26) were used as a first-line treatment. Among the non-responders to $H_{2}RA$, 11 cases received PPI as a second-line therapy. Eight cases received botulinum toxin injection and 9 cases had laryngomicrosurgical removal. Results: As an initial therapy, response rate to PPI and $H_{2}RA$ was 60.6% and 38.5% respectively, which was not statistically different (p=0.091). Response rate of PPI as the second-line therapy was 36.3% (p=0.162 when compared to that of first-line PPI therapy). Response rate of Botulinum toxin injection was 75%. All cases of surgical removal recurred in a relatively short period (mean 1.9months). Conclusion: In patients having laryngeal contact granuloma, combined therapy with vocal hygiene education and PPI medication would provide more than 60% of therapeutic response. Botulinum toxin injection is highly effective even in non-responders to antireflux therapy. The only indications of surgery are to resolve diagnostic doubt or to treat acute airway compromise.

• Tribology and Lubricants
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• v.35 no.6
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• pp.350-355
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• 2019

Surface energy is an important factor in determining the performance of application components in terms of preventing adhesion failure between thin films. In this regard, numerous attempts have been made to acquire the desired surface energy through chemical treatment or by using micro/nanostructures. However, such approaches are expected to provide extreme values of surface energy, which may not be suitable in achieving the enhanced performance of applications. In this study, we propose a method to control surface energy by using bilayer metallic film heterostructures. We measure the water contact angle of incompatible (Ni/Ag) and compatible (Zn/Ag) metal pairs under several experimental factors, including thickness, time, and temperature. Furthermore, we conduct Auger electron spectroscopy measurements to investigate the atomic concentration with respect to depth after the change in the water contact angle. The experimental results reveal that three parameters, namely, compatibility, film thickness, and environmental temperature, are major factors in controlling the water contact angle. Thus, we experimentally demonstrate that controlling these three parameters can provide the approximate desired water contact angle. This result is expected to aid in the performance enhancement of a wide range of application components, where control of surface energy is required.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.175-182
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• 1990

This study was performed to investigate the influence of occlusal change on the masticatory muscle activity. 8 students without any symptom of T.M.J. dysfunction, any history of prosthodontic or orthodontic treatment on dental college of WonKwang Univ. were participated in this study. The activity of masseter and anterior temporal muscles were measured by bioelectric processor(EM2, Myotronics, Inc., U.S.A.) during voluntary maximal clenching on natural teeth, by splint with bilateral posterior surface contact, by splint with unilateral posterior surface contact, and by splint without unilateral posterior teeth contact. The obtained results were as follows ; 1. The loss of posterior contact on noe side resulted in change of the activity of anterior temporal and masseter muscle during clenching on ipsilateral side, but there was no change of muscle activity on contralateral side. 2. The activity of anterior temporal and masseter muscle during clenching were not affected by the pattern of occlusal contact. 3. There were no difference between the activity of anterior temporal and masseter miuscle during clenching by natural teeth and by occlusal splint.