• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.276-283
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• 2008

To provide the research strategy for protection of children's health from hazardous chemical, we reviewed the hazardous chemicals can be exposed through maternity, children's life style and living environment. Recently, diseases related with children's living condition were focused as asthma, atopy, childhood developmental disability, congenital malformations and obesity. Children can be exposed to hazardous chemicals through an ambient air, water, soil, food, toys and other factors such as floor dust. Also children's health was deeply related with a wrong life style and neglectful caring by a lack of knowledge and information of harmful ones at parents and child care center's nursers. According to the previous study, the chemical risk factor of children's health were identified as inorganic arsenic, bisphenol A, 2,4-D, dichlorvos, methylmercury, PCBs, pesticide, phthalates, PFOA/PFOS, vinyl chloride, et al. Domestic studies for identification of causality between children exposure to chemicals and resulted hazardous effects were not implemented. The confirmation of chemical risk factors through simultaneously performing toxicological analysis, human effect study, environmental/human monitoring, and risk assessment is needed for good risk management. And also, inter-agency collaboration and sharing information can support confirming scientific evidence and good decision making.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.119-126
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• 2012

Purpose: To study changes in coating and lens materials after chemically etched different polymer based glass lenses in short-term and ambient condition using hydrofluoric acid. Methods: Vinyl ester polymer (Lens A) and thiourethane polymer (Lens B), both dyed in gray 70%, were etched in hydrofluoric acid solution for 5, 10, or 15 min. The mechanical properties, degrees of damages in hard coating, anti-reflection coating, and other coatings, rates of refractive index and light transmission of both polymer types were evaluated. Results: Rates of refractive index of both lens types were not changed significantly after chemical etching. However, anti-reflection coatings and hard coatings were removed and lens surfaces were damaged. As a results, UV light transmission of lenses increased and mechanical properties decreased. Chemical etching notably changed various properties of thiourethane polymer materials. Conclusions: Depending on types of polymer materials, chemical reactions by hydrofluoric acid were dissimilar. Thus, various properties of les materials were altered differently.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.573-583
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• 2005

Fugitive dust, which is emitted in the ambient air without first passing through a stack or duct designed to control flow, is frequently generated by means of wind erosion from storage yards at Pohang Steel Wokrs. The size distribution of fugitive dust is mostly in the range of coarse particulate which is deposited as soon as emitted and less harm to human health; however $20\%$ of fugitive dust contains PM 10 known as one of most harmful airborne pollutant. Consequently, effective control and reduction of fugitive dust is strongly requested by the local society, but it is not easy so far because the generation and dispersion of fugitive dust highly depends on meteorological conditions, and it being occurred for irregularity. This research presented a fugitive dust control system for each meteorological condition by providing statistical prediction data obtained from a statistical analysis on the probability of generating the threshold velocity at which the fugitive dust begins to occur, and the frequency occurring by season and by time of the wind direction that can generate atmospheric pollution when the dispersed dust spreads to adjacent residential areas. The research also built a fugitive dust detection system which monitors the weather conditions surrounding storage yards and the changes in air quality on a real-time basis and issues a warning message by identifying a situation where the fugitive dust disperses outside the site boundary line so that appropriate measures can be taken on a timely basis. Furthermore, in respect to the spraying of water to prevent the generation of fugitive dust from the storage piles at the storage yard, an advanced statistical meteorological analysis on the weather conditions in Pohang area and a case study of fugitive dust dispersion toward outside of working field during $2002\∼2003$ were carried out in order to decide an optimal water-spraying time and the number of spraying that can prevent the origin of fugitive dust emission. The results of this research are expected to create extremely significant effects in improving surrounding environment through actual reduction of the fugitive dust produced from the storage yard of Pohang Steel Works by providing a high-tech warning system capable of constantly monitoring the leakage of fugitive dust and water-spray guidance that can maximize the water-spraying effects.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.608-611
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• 2011

Laser-induced combustions and explosions generated by high laser irradiances were explored by Laser-Induced Breakdown Spectroscopy (LIBS) in rich, and stoichiometric conditions. The laser used for target ablation is a Q-switched Nd:YAG laser with 7 ns pulse duration at wavelength of 1064 nm laser energies from 40 mJ to 2500 mJ ($6.88{\times}10^{10}-6.53{\times}10^{11}\;W/cm^2$). The plasma light source from aluminum detected by the echelle grating spectrometer and coupled to the gated ICCD(a resolution (${\lambda}/{\Delta}{\lambda}$) of 5000). This spectroscopic study has been investigated for obtaining both the atomic signals of aluminum (fuel) - oxygen (oxidizer) and the calculated ambient condition (plasma temperature and electron density). The essence of the paper is observing specific electron density ratio which can support the processes of combustion and explosion between ablated aluminum plume and oxygen from air by inducing high power laser.

• Journal of Distribution Science
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• v.16 no.6
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• pp.65-75
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• 2018

Purpose - The exhibition is one of the critical distribution channels that leads to mass sales of products. Servicescape is considered as an effective means facilitating consumers' purchasing behavior. The objective of this research is to examine the effects of servicescape of the exhibition on consumer's purchasing behavior measured by time spent, the number of consultations, the number of items purchased, and amount of money spent. Research design, data, and methodology - Servicescape was divided into four main components: 'spatial layout/functionality', 'ambient condition', 'design/artifacts', and 'human factor'. Based on previous studies, this study hypothesized that servicescape dimensions first influence consumer's shopping duration and the number of consultations which in turn, affects consumer's actual purchase. A total of 407 samples were collected from attendees in Baby Expo taken place in Kyunggido, South Korea. The data were used to assess overall fit of the proposed model and test hypotheses using structural equation modeling. All the constructs had acceptable levels of composite reliability and convergent and discriminant validity. Results - The results showed that except for 'spatial layout/functionality', all components of servicescape had a significant influence on consumer's shopping duration in the exhibition. Except for 'design/artifacts', other factors of servicescape did not show a significant effect on 'the number of consultations'. Interestingly, 'design/artifacts' exerted a significant negative effect on 'the number of consultations'. As expected, 'time spent' and 'number of consultations' showed significant effects on both 'the number of items purchased' and 'amount of money spent'. Conclusions - The results offer some insights into the effect of servicescape on facilitating consumers' purchasing behavior in the context of the exhibition. Theoretically, this study provides a new type of conceptual framework that verifies the relationships between not only servicescape and purchasing behavior, but also purchasing behavior-related variables. In addition, this study supports the concept of a dark side of servicescape. With regards to practical implications, this study suggests that exhibition organizers should put more efforts in facilitating consumer's desire to stay. More importantly, organizers need to keep in mind that excessive emphasis on 'design/artifacts' to increase consumers' shopping duration can cause a side effect that reduces opportunities for interactions with customers.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.117-123
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• 1999

The analytical instrument method was applied to analyze malodorous sulfur compounds emitted from industrial fields. Six factories and two sites which release malodorous substances into ambient air were selected to determine the level of hydrogen sulfide($H_2S$), methylmercaptan(MeSH), dimethyl sulfide($Me_2S$), and dimethyl disulfide($Me_2S_2$) using automated thermal desorption system (STD400) and GC-FPD in summer and fall seasons of 1999. The Air sampler for ATD400 uses a small pump to draw sample and a mass flow controller to adjust sample amount without using a dilution apparatus. The trap temperature of ATD400 reached to $-80^{\circ}$ by supplying liquid nitrogen and $H_2S$ can be analyzed under this condition. The recovery rates of $H_2S$, MeSH, $Me_2S$, and $Me_2S_2$ of odorous sulfur compounds standard were shown 98.2%, 93.6%, 98.2%, 99.4% respectively. The concentrations of $Me_2S$ at outside boundary of G market, L factory, and J factory were 0.018ppm, 0.021ppm, 0.032ppm in summer, respectively. The concentration of $H_2S$ at Nanjido landfill was 1.167ppm in summer, but that of $H_2S$ was not detected in fall because of soil covering. The concentration of H2S and $Me_2S_2$ at inside of Chonggye stream were 0.564ppm and 1.045ppm in summer, while those of H2S and Me2S2 were 0.285ppm and 0.465ppm in fall, respectively.

• Geophysics and Geophysical Exploration
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• v.16 no.4
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• pp.275-283
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• 2013

The sea dike is the most important facility of reclamation projects, and plays an important role in securing freshwater in the reservoir. Systematic research on practical approaches and data analysis techniques are lacking even though some geophysical methods such as electrical resistivity and self-potential surveys are included within the inspection processes. Hence, geophysical methods were considered for improvement of precision safety diagnosis methods after problems in the maintenance system have been identified, such as safety checks and precision safety diagnoses. In addition, geophysical methods customized according to variations in ambient environmental limiting factors such as pore pressure changes by tidal fluctuation, compaction characteristics of the fill materials, and the surface condition of the embankment were suggested.

• Korean Journal of Materials Research
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• v.13 no.5
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• pp.279-284
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• 2003

The $CoSi_2$ process is widely employed in a salicide as well as an ohmic layer process. In this experiment, we investigated the characteristics of $CoSi_2$ films by combinations of I-type (TiN 100$\AA$/Co 150$\AA$), II-type(TiN 100$\AA$/Co 150$\AA$/Ti 50$\AA$), III-type(Ti 100$\AA$/Co 150$\AA$/Ti 50$\AA$), and IV-type(Ti 100$\AA$/Co 150$\AA$/Ti 100$\AA$). Sheet resistances of $CoSi_2$ show the lowest resistance with 2.9 $\Omega$/sq. in a TiN/Co condition and much higher resistances in conditions simultaneously applying Ti capping layers and Ti interlayers. Though we couldn't observe a $CoSi_2$roughness dependence on the film stacks from RMS values, Ti capping layers turned into 78∼94$\AA$ thick TiN layers of (200) preferred orientation at $N_2$ambient. In addition, Ti interlayers helped to form the epitaxial $CoSi_2$with (200) preferred orientation and ternary compounds of Co-Ti-Si. We propose that film structures of II-type and III-type may be appropriate in the salicide process and the ohmic layer process from the viewpoint of Co diffusion kinetics and the CoSi$_2$epitaxy.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.22-30
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• 2013

The reproductive performance of multivoltine breed 'Nistari' and bivoltine breeds as NB18, P5 and a bivoltine hybrid (NB18 ${\times}$ P5) of B. mori were studied in different seasons in terms of total number of eggs laid, unlaid and hatching efficiency of the laid eggs to critically assess the breeds / hybrid potentiality. The bivoltine hybrid showed better performance in all the seasons as compared to the breeds investigated, as expected due to possibility of hybrid vigour. Among the breeds, bivoltine P5 had a better egg laid performance in S1 (February - March), S2 (May - June) and S3 (September - October) seasons but with an increase in the number of unlaid eggs. The hatching percentage, although didn't show any definitive trend, still suggested a marginal better performance in the hybrid. Most importantly, egg laying rhythmicity was studied by mating the female moth at 6.00 a.m. for $3{\frac{1}{2}}$ hours, and subsequently allowing the laying of eggs both under BOD condition ($25{\pm}1^{\circ}C$ and $85{\pm}5%$ RH) and at ambient temperature ($23-28^{\circ}C$ and $74.7{\pm}5%$) separately. Maximum (90%) egg laid occurred from 3.30 to 7.30 pm (i.e. 4 - 6 h after decoupling). Similar laying patterns were observed when females where mated at 12 noon and decoupled at 3.30 pm, revealing that late photoperiod and early scotoperiod were favourable for egg laying in case of multivoltine breed and bivoltine prefers late photoperiod for egg laying.

• Plant Journal
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• v.13 no.1
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• pp.37-43
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• 2017

This study analyzed the change of gas turbine performance with air temperature decrease by the evaporation cooling system in summer season. Gas turbine performance was tested on the condition that ambient temperature is $29{\pm}1^{\circ}C$. As a result, Air temperature at the compressor inlet was decreased by $4.12^{\circ}C$ after the installation of evaporation cooling system. Decreased air temperature followed by increased air density affected gas turbine performance, Which increased compressor pressure ratio by 0.27, improved compressor efficiency of 0.29 %p, improved gas turbine enthalpy drop efficiency of 0.31 %p, improved the gas turbine efficiency by 0.44 %p, improved electric power output by 4,489 kW. On the other side, the influence of the humidity increase and flow resistance increase was negligible.