• Journal of Adhesion and Interface
• /
• v.10 no.3
• /
• pp.141-147
• /
• 2009

In this study, the high performance hybrid chemical filter (HPHCF) was prepared by web spray using hot melt adhesive. The material of HPHCF was conditionally made of ion exchange resin and PP non-woven fabric. The optimum temperature and pressure for manufacturing of HPHCF conditions were such as $170^{\circ}C$ and 50 psi, respectively. The characteristics of preparated HPHCF and their adsorption properties of ammonia gas were investigated. The ion exchange capacity (IEC) of HPHCF was increased with increasing the resin contents and their values were higher than pure resin and ion exchange fabrics. The removal efficiency for ammonia gas increased with the increase of packing density of hybrid ion exchange fabrics in the column. It showed 13 min which the adsorption breakthrough time was slower than resin and fibers. The maximum value of adsorption for ammonia gas was 98 percent. And also, the velocity was increased with increasing concentration and flow rate of ammonia gas.

• Journal of the Korean Society of Safety
• /
• v.28 no.2
• /
• pp.26-30
• /
• 2013

The purpose of this study is to find risk factors by analyzing the operation principle of a photo coupler (P/C) used to remove the noise of electronic devices and establish a base for the performance improvement of developed products. It was found from the P/C circuit analysis of normal products that they were equipped with an electrolytic condenser of $0.1{\mu}F$ to smooth system signals. Due to the epoxy resin packing the external part of the P/C, this study experienced a limit to visually examine the damage to it. It could be seen from the analysis of electric characteristics of the P/C that the forward voltage ($V_f$) and reverse current ($I_r$) were 1.3 V and 10 uA, respectively. In addition, it is required that the breakdown voltage (VCE) between the collector (C) and emitter (E) be maintained at less than 35 V. The and of the damaged product #1 were comparatively good. However, the measurement of was 100.0 uA. From this, it is thought that a short circuit occurred to the internal circuit. Moreover, from the fact that the of the damaged product #2 was open circuit and the measurement of was 0.0 uA, it is thought that the collector and emitter was separated or insulation resistance was significantly high. Furthermore, from the fact that the of the damaged product #3 was open circuit and the measurement of was 0.0 uA, it is thought that the space between the collector (C) and emitter (E) failed to meet the design standard or that they were separated. Therefore, it is thought that fabricating the P/C by increasing the reverse current 10 mA to 50 mA will prevent its malfunction.

• Korean Journal of Occupational Health Nursing
• /
• v.20 no.1
• /
• pp.93-103
• /
• 2011

Purpose: This study was conducted to assess reported industrial accidents and non-reported industrial accidents that took place in 63 small and medium sized manufacturing industries located in Daegu and Gyeongsangbuk-do in the year of 2009. Methods: During the period from January to December 2009, the number of industrial accidents that happened each month was examined according to the characteristics of industry, industrial accidents, workers with industrial accidents, treatment, as well as causes and treatment of the non-reported. Results: The total incidence rate of industrial accidents was 3.48%, of which only 0.31% reported. The incidence rate in packing and distribution among manufacturing workplace, and in the industry with 50~99 employees, was higher than the other groups. Of the non-reported, over 80% in required under 10 days of medical treatment, and 56% in required cost of less than 100,000 won. Kappa values were 0.771 concurrence in opinions for causes of non-reported, and 0.571 concurrence in opinions for management termination of non-reported between the employees and employer. Conclusion: It is suggested that more supportive policy and precise, nationwide survey on the actual state of industrial accidents, including non-reported cases, be implemented to efficiently manage industrial accidents.

• Journal of Korean Society for Atmospheric Environment
• /
• v.23 no.3
• /
• pp.265-276
• /
• 2007

The primary objective of this study is to investigate the effect of media on the performance of biofilters. Two types of experiments were carried out in this study. The first type of experiment used a biofilter with the media composed of three different packing materials of compost, peatmoss and GAC(granular activated carbon), whereas the second type used a biofilter with the media composed of compost only. It was found from the two experiments that the biofilter composed of compost, peatmoss and GAC showed better performance than the one composed of compost only with the higher toluene removal efficiency, lower pressure drop, and more uniform media moisture content. In particular, no appreciable media compression occurred for the biofilter composed of compost, peatmoss and GAC, whereas significant media compression took place in the biofilter composed of compost only. As suggested by the other researchers, it is likely that GAC may be responsible for the higher toluene removal efficiency in the case of the biofilter composed of mixed media especially for the early stage of biofiltration due to its adsorption capability of toluene of such high concentration as 300 ppm. It was also regarded that GAC may playa major role in maintaining lower media pressure drop in the case of the mixed media than the media with compost only because of its mechanical strength resisting to the compression. Nonetheless, further refined experiments may need to draw more accurate conclusion. The results of the additional test run using the same mixed media showed that the biofilter system using the mixed media can be consistently operated for more than 100 days very stably despite sudden change in operating conditions of temperature and flow rate.

• Journal of the Korean Dietetic Association
• /
• v.11 no.1
• /
• pp.11-20
• /
• 2005

This study was conducted to investigate preference for convenience food and dietary attitude in college students in Seoul and Kyunggi-do area. This study used a questionnaires as instrument tool. Thequestionnaire consisted of socio-demographic characteristics of the subjects, the valuation of preference for convenience, the concern of nutrition, and the dietary attitude. The subject were 199 males and 137 females. The mean age of subjects was 22.4$\pm$2.3year. The results have been summarized as follows Male students preferred more convenience food than females. Male students liked chicken, ice cream, ramyeon, pizza·hamburgerandfemalestudentslikedchicken,pizza, ice cream, ramyeon·hamburger. The kinds of convenience foods for a substitute meal were ramyeon, hamburger, bread, potato in male group and female group had frequently ramyeon, hamburger, bread, rice cake for a substitute meal. Male students were more likely to eat ramyeon (p<0.01) and purchased sabalmyeon The subjects used to purchase sabalmyeon as main convenience food at convenient store The score of preference for convenience food in male group was higher than female group. The score of attitude toward balanced diet in female group was higher than male group(p<0.01). In scores of concern for nutrition information, balanced diet, and nutrition knowledge, Female group had higher scores of concern for nutrition information, balanced diet, and nutrition knowledge than that of male group (p<0.01).There was no significant difference in the degree of preference for packing types, however, Male group tended to prefer more micro wave type than female group. The persons to affect the consumption of convenience food were friends. There was no significant difference in the time of purchase convenience food, however, Male tended to purchase convenience food at the time of snack than female group. As a results, proper nutritional education and qualitative development of convenience food are required in order to improve the consuming attitude of consumers and their preference for convenience food.

• Fire Science and Engineering
• /
• v.30 no.2
• /
• pp.98-105
• /
• 2016

A fire risk assessment in rack-type warehouse is typically determined based on the following factors: 1. flammability and fire loads for storage of goods, packing materials, and pallet, 2. a ceiling height of warehouse indoor spaces, and 3. height, arrangement, and spacing for storage racks. For appropriately extinguishing and protecting the fire in warehouses, therefore, it is necessary to classify combustibles considering the previously mentioned factors and to develop design Standards for sprinkler system. As the first step to apply automatic sprinkler system to domestic warehouses, this study investigated characteristics for commodity distribution and warehouse configuration using 28 warehouses in five distribution complexes located in Gyeonggi-do, South Korea. In addition, this study analyzed Standards for commodity distribution adopted in USA, Europe, and Japan. Using the field survey analysis, this study was aimed to provide baseline data to prepare for Commodity Classification Standard for warehouses in South Korea.

• The Journal of the Korea Contents Association
• /
• v.5 no.6
• /
• pp.163-171
• /
• 2005

Many food companies cooperate with the existing food until it reaches from the start of the 90s recently. which began to develop suitable new functional foods in the characteristic of each product So that consumers' consciousness may also get interested in the functional foods with which a as specific ingredient and as specific as possible are expected while the expectation for health and a long life becomes high. from which it consisted of and the propriety of functionality became the important point of a new-product-development strategy. A packing design also takes the advantage of development of such functional foods. therefore the seen research, with general consideration of such functional foods Who is going to investigate to the product communication-of-information method and differentiation strategy of more desirable functional foods by analyzing and seeing the functional characteristics which each product has to the fermented milk enjoyed and drunk, and these expression strategies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.12
• /
• pp.1028-1032
• /
• 2009

In this study, the influences of silicon-based gas barrier films fabricated by using a facing target sputtering(FTS) system on the gas permeability for flexible displays have been investigated. Under these optimum conditions on the $SiO_x$ film with oxygen concentration($O_2/Ar+O_2$) of 3.3% and the $SiO_xN_y$ film with nitrogen concentration($N_2/Ar+O_2+N_2$) of 30% deposited by the FTS system, it was found that the films were grown about 4 times higher deposition rate than that of the conventional sputtering system and showed high transmittance about 85% in the visible light range. Particularly, the polyethylene naphthalate(PEN) substrates with the $SiO_x$ and/or $SiO_xN_y$ films showed the enhanced properties of decreased water vapor transmission rate (WVTR) over $10^{-1}\;g/m^2{\cdot}day$ compared with the PEN substrate without any gas barrier films, which was due to high packing density in the Si-based films with high plasma density by FTS process and/or the denser chemical structure of Si-N bond in the $SiO_xN_y$ film.

• Polymer(Korea)
• /
• v.31 no.6
• /
• pp.479-484
• /
• 2007

In this study, the hybrid ion exchange fibers (HIEF) were prepared by using web spraying muthod with hot melt adhesive. Characteristics of HIEF and their adsorption properties for ammonia gas were investigated. The ion exchange capacity (IEC) of HIEF was increased with increasing the resin contents and their values were higher than those of pure resin and ion exchange fabrics. The removal efficiency for ammonia gas increased with an increase in packing density of hybrid ion exchange fabrics in the column. The adsorption breakthrough time was 270 min, which was slower than those of the resin and fibers. The maximum value of adsorption for ammonia gas was 94%. The breakthrough time was also increased with increasing the concentration and flow rate of ammonia gas. The reaction constant(k) for ammonia gas was increased with increasing the concentration and flow rate of the gas, while it was decreased an the mass was increased.

• Carbon letters
• /
• v.28
• /
• pp.24-30
• /
• 2018

Coke aggregates and carbon artifacts were produced to investigate the interactions of coke and pitch during the kneading process. In addition, the kneading ratio of the coke and binder pitch for the coke aggregates was controlled to identify the formation of voids and pores during carbonization at $900^{\circ}C$. Experiments and thermogravimetric analysis revealed that carbon yields were improved over the theoretical yield calculated by the weight loss of the coke and binder pitch; the improvement was due to the binding interactions between the coke particles and binder pitch by the kneading process. The true, apparent, and bulk densities fluctuated according to the kneading ratio. This study confirmed that an excessive or insufficient kneading ratio decreases the density with degradation of the packing characteristics. The porosity analysis indicated that formation of voids and pores by the binder pitch increased the porosity after carbonization. Image analysis confirmed that the kneading ratio affected the formation of the coke domains and the voids and pores, which revealed the relations among the carbon yields, density, and porosity.