• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.53-59
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• 2013

Since 1990s, the major recycling methods for mechanical recycling of FRP(Fiber Reinforced Plastics)boats has involved shredding and grinding of the scrap FRP in a new recycled product. But still it leads to secondary problem such as air pollution, unacceptable shredding noise level and few limited applications. This study is to propose a newly advanced method which is more efficient and environment friendly waste FRP regenerating system. As extracting FRP layer and making the recycled fiber for recycled-fiber reinforced concrete(RFRC) from waste FRP, the recycling process has some merits in a sense of the recycling energy and the environmental effects. In this study, for those tasks, spectro-chemical differentiation method and coloring water-soluble dye treatment makes the roving layer more distinguishable photophysically. Also that has remarkably reduced safety hazards and energy. Using the mechanical properties of polymers and composite, FRP with the orthotropic and laminated plastic structure has been easily separated in the new extracting system. Also the new method has introduced five kind of separating manuals for the some different compositions of FRP boats. The roving fiber of laminated glass-fiber layer is as good as the polyvinyl fiber which is cost-high commercial fiber to increasing strength of concrete products. The early study has shown the effectiveness of laminated glass-fiber layer which also is chemical-resistant due to the resin coating. These results imply that more efficient and environment friendly recycled glass fiber can be better applied to the fiber reinforced concrete(FRC) substitute and this study also has shown wide concrete applications with RFRC from the waste FRP boat.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.320-328
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• 2016

Among biogenic volatile organic compounds (BVOCs) in the natural ecosystem, monoterpenes, along with isoprene, play important roles in atmospheric chemistry and make significant impacts on air pollution and climate change, especially due to their contribution to secondary organic aerosol production and photochemical ozone formation. It is essential to measure monoterpene concentrations accurately for understanding their oxidation processes, emission processes and estimation, and interactions between biosphere and atmosphere. Thus, traceable calibration standards are crucial for the accurate measurement of monoterpenes at ambient levels. However, there are limited information about developing calibrations standards for monoterpenes in pressured cylinders. This study describes about developing primary standard gas mixtures (PSMs) for monoterpenes at about 2 nmol/mol, near ambient levels. The micro-gravimetric method was applied to prepare monoterpene (${\alpha}$-pinene, 3-carene, R-(+)-limonene, 1,8-cineole) PSMs at $10{\mu}mol/mol$ and then the PSMs were further diluted to 2 nmol/mol level. To select an optimal cylinder for the development of monoterpene PSMs, three different kinds of cylinders were used for the preparation and were evaluated for uncertainty sources including long-term stability. Results showed that aluminum cylinders with a special internal surface treatment (Experis) had little adsorption loss on the cylinder internal surface and good long-term stability compared to two other cylinder types with no treatment and a special treatment (Aculife). Results from uncertainty estimation suggested that monoterpene PSMs can be prepared in pressured cylinders with a special treatment (Experis) at 2 nmol/mol level with an uncertainty of less than 4%.

• Journal of Conservation Science
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• v.34 no.3
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• pp.211-225
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• 2018

The Stupa of the State Preceptor Jigwang from the Beopcheonsaji temple site in Wonju (National Treasure No. 101) was built in the Goryeo Period (around the 11th century), with very excellent style and techniques. It was returned to the Korea after being taken to Osaka of Japan without notice in 1912, and was severely damaged during the Korean War. Subsequently, the Stupa was restored using restoration materials like mortar, and relocated to the National Palace Museum of Korea. Surface contaminants in the Stupa primarily existed around the restoration materials. Black discoloration, which indicates a high discoloration grade, signified a high possession rate in the north and inner regions of the Stupa, which may be related to the relative moisture maintenance time. Most surface contaminants were calcite and gypsum; the black discoloration area underwent secondary discoloration due to air pollution. Moreover, the stone properties exhibited a relatively low discoloration grade, exhibiting crystallized contaminants that partly covered the rock-forming minerals. Overall, the Stupa deteriorated due to discoloration and being covered by lime materials, which were dissolved as the mortar degraded. Hence, it required contaminants removal, surface cleaning and desalination during conservation treatment, in order to control the rate of physicochemical deterioration by contaminants.

• Analytical Science and Technology
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• v.27 no.1
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• pp.1-10
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• 2014

The $PM_{10}$ and $PM_{2.5}$ samples were collected at Gosan Site of Jeju Island, and analyzed, in order to investigate the size distribution and pollution characteristics of their components. $NH{_4}{^+}$, nss-$SO{_4}^{2-}$, $K^+$, and $CH_3COO^-$ were mostly existed in fine particles. Meanwhile, $NO{_3}{^-}$ was distributed in both fine and coarse particles, and $Na^+$, $Cl^-$, $Mg^{2+}$, nss-$Ca^{2+}$ were rich in coarse particle mode. The concentrations of nss-$Ca^{2+}$ and $NO{_3}{^-}$ were increased 36.7 and 3.2 times in coarse particles, and 15.0 and 3.1 times in fine particles during the Asian Dust periods. Especially, the concentrations of crustal elemental species such as Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba were highly increased for those periods. In the haze events, the concentrations of secondary air pollutants were increased 1.3~2.6 and 1.5~4.2 times in coarse and fine particles, respectively. Moreover, the remarkable increase of $NO{_3}{^-}$ concentration was also observed in fine particle mode. The factor analysis showed that the composition of coarse particles was influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, the fine particles were influenced by anthropogenic sources, followed by marine and soil sources.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.6.2-7
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• 1977

Hoarseness, caused by any condition that interfers with normal phonatory function of larynx, is the most important symtom of the laryngeal disease. The air pollution is the serious social problom today due to irritation of the respiratory mucosa and secondary respiratory disease. It is significant to study whether, in resent years, the patients with complant of hoarseness has being increased or decreased, compare to past years. The authors report a statistical analysis on 400 cases with chief complain of horseness at the Department of Otolaryngology, Hanil Hospital during past 7 years from Jan. I, 1970 to Dec. 31, 1976. The results were as follows; 1) Among total out patients of 14, 731 who visited to the department of otolaryngology, the patients with hoarseness numbered to 400(2.7%). 2) Among total of 400 cases, male were 211 and female were 189. The incidence was slightly higher in male than female with ratio 1.1 to 1 in sex distribution. 3) The uderlying diseases causing hoarseness in order of frequency were Acute Laryngitis (158 cases, 39.5%), Chronic Laryngitis (103 cases, 27.3 %), Vccal Nodule (37 cases, 9.3%), Vocal cord paralysis (34 cases, 8.5%), Laryngeal Polyp (32 cases, 8%), Laryngeal Ca. (13 cases, 3.5%), and Laryngeal Tbc. (9 cases, 2.3%). Particulary, Laryngeal Ca., Laryngeal polyp and Laryngeal Papilloma were extremely high in male but the remainings were equally distributed in sex group distribution. 4) The highest incidence occurred in 3rd decade (113 cases, 28.5%), the next 4th and 2nd decade in the age group distribution. Acute and Chronic Laryngitis were widely distributed in age group distribution but the highest incidence was noted between 3rd and 4th decade (145 cases, 55.5%). The highest incidence was 3rd decade in Laryngeal polyp, 3rd and 4th decade in Vocal Nodule, 4th and 5th decade in Laryngeal Tbc. and Vocal cord paralysis and 5th decade in Laryngeal Ca. 5) The underlying disease causing hoarsness were evenly occurred in monthly distribution but relatively high incidence was observed between April and June (35.5%) compared to winter. 6) In durational distribution, the highest incidence was within 10 days (26%) from onset to consultation. 317 cases (80%) were visited to the clinic within 1 year.

• Resources Recycling
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• v.29 no.2
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• pp.55-61
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• 2020

Selective catalytic reduction (SCR) has been a promising technology to reduce the air pollution caused by nitrogen oxides (NOx) in several industries. The consumption of SCR catalysts increases every year as technology evolves, however those have a limited lifespan and usually end up in landfills after they deactivate. Currently, the most widely used catalyst for and stationary applications is V₂O₅-WO₃/TiO₂ which can contain around 50% wt V₂O₅ and 7-10% wt of WO₃. The vast uses for both vanadium and tungsten and the worldwide interest in recycling methods that allow for the extraction of metals from secondary sources represent the major motivation for this research. The extraction time, pH dependency, extraction concentration studies were carried out using Aliquat 336 in exxol D80 as the extractant. It was determined that to optimize the extraction of both metals 30min of contact time with an organic phase containing 0.5mol/L of Aliquat 336 are needed at a slightly acidic pH (~5.0). In addition, counter McCabe-Thiele studies allowed us to determine that one stage is necessary for the removal of 99% of vanadium while 2 stages are necessary for the extraction of tungsten and counter current simulations proved that the theoretical approach was correct.