• Clean Technology
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• v.24 no.3
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• pp.212-220
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• 2018

Oxy-fuel combustion is considered as a promising greenhouse gas reduction technology in power plant. In this study, the behaviors of NO and $SO_2$ were investigated under the condition that in-furnace $deNO_x$ and $deSO_x$ methods are applied in oxy-fuel circulating fluidized bed combustion condition. In addition, the generation trends of $SO_3$, $NH_3$ and $N_2O$ were observed. For the purpose, limestone and urea solution were directly injected into the circulating fluidized bed combustor. The in-furnace $deSO_x$ method using limestone could reduce the $SO_2$ concentration in exhaust gas from ~403 to ~41 ppm. At the same experimental condition, the $SO_3$ concentration in exhaust gas was also reduced from ~3.9 to ~1.4 ppm. This trend is mainly due to the reduction of $SO_2$. The $SO_2$ is the main source of the formation of $SO_3$. The negative effect of $CaCO_3$ in limestone, however, was also appeared that it promotes the NO generation. The NO concentration in exhaust gas reduced to ~26 - 34 ppm by appling selective non-catalytic reduction method using urea solution. The $NH_3$ concentration in exhaust gas was appeared up to ~1.8 ppm during injection of urea solution. At the same time, the $N_2O$ generation also increased with increase of urea solution injection. It seems that the HNCO generated from pyrolysis of urea converted into $N_2O$ in combustion atmosphere. From the results in this study, the generation of other pollutants should be checked as the in-furnace $deNO_x$ and $deSO_x$ methods are applied.

• Clean Technology
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• v.24 no.3
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• pp.198-205
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• 2018

This study investigated the influence of catalyst preparation on the activity of $Co-CeO_2$ catalyst for $N_2O$ decomposition. $Co-CeO_2$ catalysts were synthesized by co-precipitation and incipient wetness impregnation. In order to estimate the performance of the as prepared catalysts, direct catalytic $N_2O$ decomposition test was carried out under $250{\sim}375^{\circ}C$. As a result, the catalyst prepared by co-precipitation (CoCe-CP) showed an enhanced performance on $N_2O$ decomposition reaction even in the presence of $O_2$ and/or $H_2O$, whereas the impregnation catalyst (CoCe-IM) did not. In order to investigate the difference in catalytic activity, characterization such as XRD, BET, TEM, $H_2-TPR$, $O_2-TPD$, and XPS was conducted. It is confirmed that the particle size and specific surface area were changed depending on the catalyst preparation method and the synthesis process influenced the physical properties of the catalysts. In addition, the improvement in the activity of the catalyst prepared by co-precipitation is due to the enhanced reduction from $Co^{3+}$ to $Co^{2+}$ and the improved oxygen desorption rate. However, it has been confirmed that the surface electron state and binding energy, which are related to $N_2O$ decomposition, do not change depending on the preparation method.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.183-192
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• 2016

A total of 228 dental hygienists working in dental hospitals and clinics in the Busan and Gyeongnam areas were surveyed between August 1, 2015, and October 15, 2015. The factors influencing infection control awareness and implementation levels among the dental hygienists were investigated to prepare basic data with the goal of establishing guidelines for systemic infection control. Treatment preparation support for infection control positively correlated with equipment and facility support (r=0.4343, p<0.01), treatment skill and information support (r=0.231, p<0.01), infection control education support (r=0.266, p<0.01), infection control awareness (r=0.354, p<0.01), and infection control implementation levels (r=0.442, p<0.01). Equipment and facility support positively correlated with treatment skill and information support (r=0.418, p<0.01), infection control education support (r=0.422, p<0.01), infection control awareness (r=0.404, p<0.01), and infection control implementation levels (r=0.454, p<0.01). Infection control education support positively correlated with infection control awareness (r=0.348, p<0.01) and infection control implementation levels (r=0.405, p<0.01). Infection control awareness positively correlated with the infection control implementation level (r=0.879, p<0.01). The factors influencing the awareness of infection control include treatment preparation support, equipment and facility support, treatment skill and information support, and infection control education support. The influencing the infection control implementation level include treatment preparation support, equipment and facility support, infection control education support, and treatment skill and information support. To enhance the awareness of infection control and implementation levels amongdental hygienists, an infection control system must be established and implemented A rigorous system for evaluating dental clinics must also be established to ensure an ideal dental treatment environment and to protect patients' health and safety.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.235-241
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• 2013

This work was carried to evaluate effect of different raising periods on fatty acids and amino acids properties of Korean native commercial ducks. Korean native ducks (n = 90) from National Institute of Animal Science (RDA, Korea) were divided into 6 groups (15 birds/group) and were fed with meat-type duck diets for 8 wk old. When ducks grew at specific wk (6, 7 and 8 weeks), 2 ducks per group were slaughtered at 6, 7 and 8 wk old. Myristic acid (C14:0) and palmitic acid (C16:0) of saturated fatty acid (SFA) were the highest and arachidonic acid of unsaturated fatty acid (USFA) was the lowest at the age of 6 weeks old (P<0.05) at the age of 6 weeks old among treatments. Stearic acid of SFA was the highest at the age of 7 weeks old among treatments. There was no significant difference on other fatty acids among treatments. SFA and USFA have significant difference at the age of 8 weeks (P<0.05). Histidine, leucine, lysine, methionine, phenylalanine and threonine of essential amino acid increased with passing weeks (P<0.05). There was no significant difference on isoleucine and valine (P>0.05). Every non-essential amino acids were the highest at the age of 8 weeks among treatments (P<0.05). In conclusion, fatty acid contents and amino acid contents increased until the age of 8 weeks old, but further research was needed because of deficiency of data to suggest the correct shipping time.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.171-178
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• 2013

The purpose of this study was to evaluate the sperm viability, normal acrosome and mitochondrial activity in the frozen-thawed fowl semen by different cryoprotectants. The experiment was carried out on 10 sexually adult roosters of Ogye. The semen was collected twice a week and pooled semen was diluted 1:1 EK extender containing no cryoprotectant at $5^{\circ}C$. After equilibration for 30 minutes, diluted chicken semen was diluted 1:1 extender containing either 7% dimethylacetamide (DMA), 7% dimethylformamide (DMF) or 7.5% methylacetamide (MA) at final concentration and was put in 0.5 mL plastic straws and frozen for 30 minutes by exposure to liquid nitrogen vapor 4 cm above the surface of liquid nitrogen, followed by plunging into liquid nitrogen. Frozen semen was thawed in water bath at $5^{\circ}C$ for 2 minutes. For cytometric analysis, the frozen-thawed semen was diluted with EK extender to a final concentration of 90 million spermatozoa per mL. Sperm membrane integrity was evaluated as SYBR-14 and propidium iodide (PI). Acrosome integrity was assessed with fluorescein isothiocyanate-labeled PSA and PI. The percentage of mitochondrial function was estimated by using Rhodamine123 (R123) and PI. In conclusion, freezing rooster semen by using 7% DMF as cryoprotectant was significantly highest in rates of survival and mitochondrial function while its rate of damage of acrosome was significantly lowest. As a result, DMF is the cryoprotectant that has the lowest influences on sperm membranes and acrosome integrity. Therefore it could be used for freezing method of animal genetic conservation method for poultry diversity.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.253-261
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• 2016

Egg quality is a very important factor for both consumers and producers. Factors affecting egg quality include strain and age of hens; egg storage temperature, time, and humidity; laying season; and feeding. This study aimed to determine the effect of hen age and egg storage time on egg quality. A total of 700 eggs obtained from Hyline Brown commercial layers were used for this experiment, and they were separated into two hen age groups (30 vs. 60 weeks) with eight treatments and four storage times (day 0, 10, 20, and 30). The egg weight; shell color, thickness, and density; albumen height; Haugh unit (HU); yolk color; and the yolk and albumen pH and viscosity were measured for the egg quality assessment. The results showed that the age of the hen and egg storage time significantly affected almost all parameters of the internal and external egg quality. The shell thickness, albumen height, HU, yolk color, pH of yolk and albumen, and yolk viscosity significantly decreased with increasing hen age. The egg shell color was significantly lighter in eggs from 60-week-old hens than in those from 30 weeks-old hens. The egg weight; shell weight, thickness, and density; albumen height, HU; and albumen viscosity significantly decreased, but the yolk color and pH of the yolk and albumen increased with increasing egg storage time. The interaction effects between the storage time and hen age were significant in shell thickness, albumen height, yolk color, and yolk and albumen pH and viscosity. The eggs obtained from 60-week-old hens showed significantly lower shell thickness, albumen height, and HU values, which are considered typical egg quality measurements, than values of eggs from 30-week-old hens. Therefore, increasing hen age and egg storage time caused the deterioration of egg quality. In conclusion, this study demonstrated that hen age is the major factor affecting the quality of fresh eggs, whereas the storage time is the determinant factor affecting the quality of stored eggs.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.143-151
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• 2020

This study investigated the effects of the addition of commercial enzyme products to broiler feed with reduced levels of metabolizable energy and crude protein on the growth performance, blood profiles, and cecal microflora. A total of 750 seven-day-old male Ross 308 broiler chicks were randomly allotted to five treatment groups with six replicates (25 birds/replicate) for 28 days. A corn-wheat-soybean meal-based diet was formulated to meet or exceed the nutrient recommendations and used as the control diet. Experimental diets with metabolizable energy reduced by 100 kcal/kg and crude protein by 1% were formulated containing four different commercial enzyme products. Feed intake and weight gain were not affected by the dietary treatments; however, feed conversion ratios were significantly lower (P<0.01) in the control group than in the other treatment groups during the entire experimental period. There were no significant differences in the blood profiles and cecal microflora between the dietary treatments. However, the viscosity of jejunal contents in chicks fed a diet with enzyme B was significantly lower than that in the other groups. The tentative marketing age was unaffected by any of the dietary treatments, and ranged from 26.39 d to 26.84 d. Collectively, the use of commercial enzymes contributed to a similar weight gain as that in chicks fed diets with reduced energy and crude protein levels; however, it failed to maintain the feed conversion ratio.

• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.33-60
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• 2020

Along with the rapid advance in internet technologies, ubiquitous mobile device usage has enabled consumers to access real-time information and increased interaction with others through various social media. Consumers can now get information more easily when making purchase decisions, and these changes are affecting the brand landscape. In a digitally connected world, brand image is not communicated to the consumers one-sidedly. Rather, with consumers' growing influence, it is a result of co-creation where consumers have an active role in building brand image. This explains a reality where people no longer purchase products just because they know the brand or because it is a famous brand. However, there has been little discussion on the matter, and many practitioners still rely on the traditional measures of brand indicators. The goal of this research is to present the limitations of traditional definition and measurement of brand and brand image, and propose a more direct and adequate measure that reflects the nature of a connected world. Inspired by the proverb, "A man is known by the company he keeps," the proposed measurement offers insight to the position of brand (or brand image) through co-purchased product networks. This paper suggests a framework of network analysis that clusters brands of cosmetics by the frequency of other products purchased together. This is done by analyzing product networks of a brand extracted from actual purchase data on Amazon.com. This is a more direct approach, compared to past measures where consumers' intention or cognitive aspects are examined through survey. The practical implication is that our research attempts to close the gap between brand indicators and actual purchase behavior. From a theoretical standpoint, this paper extends the traditional conceptualization of brand image to a network perspective that reflects the nature of a digitally connected society.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.105-116
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• 2017

Murals in villages revitalize communities and spaces, and are economically efficient. Central and local governments are therefore actively undertaking Mural Village Projects but there are some issues and concerns about the projects for the provision of uniformed landscapes for the regions that are the result of a short-term completion of projects, and instead of cohesion, cause destruction of place identities. In addition, the problem of sustainable landscape management that is the result of low community involvement can be pointed out because the murals are products of government-led projects. The study covered the context of landscape and space change processes from a critical perspective, and focused on Ihwa-dong Mural Village, which is considered the first mural village in Korea and has begun to undergo drastic changes due to attention received from media. The purposes of this study are as follows. First, the study provides data about difference of place identity perception and landscape preference between residents and tourists in Ihwa-dong Mural Village. Second, this paper evaluates the current Mural Village Projects and finds alternative directions to improve the projects by using these data. This paper analyzed tourist hot spots in Ihwa-dong Mural Village by using SNS analysis, a field study and focus group interviews. The difference of place identity perception and landscape preference was examined among three groups: residents, new residents who are invited by Mural Village Projects, and tourists. This study showed that many tourists are focused on landscape areas that were not intentionally constructed projects. In addition, the locations of preferred landscapes and stores overlapped. Meanwhile, using qualitative data analysis, it was found that residents perceived the area as being an under-privileged location, while the murals, a non-daily landscape, largely affected place identity perception of new residents and tourists. For landscape preference, tourists preferred outdoor rest areas, while new residents and residents preferred less. Additionally, new residents and tourists preferred an area's night view while residents made no mention of this. Related to the direction of the projects, three groups showed their dependence on the government. This empirical study is significant from a participatory design perspective and in analyzing the issues for mural villages' landscapes, which are spreading across the nation and proceeding without criticism in urban regeneration. Implications for urban planners and suggestions for the future projects are given.

• Food Science and Preservation
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• v.15 no.4
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• pp.512-517
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• 2008

Fermentation characteristics of chestnut-added yakju prepared using various proportions of raw materials such as rice koji, rice flour, cornflour koji and cornflour were investigated. The pH of chestnut-added yakju prepared with cornflour koji and saccharified cornflour showed a higher value than that of chestnut-yakju prepared with rice koji and saccharified rice flour. The total acid content of chestnut-added yakju prepared with rice koji and saccharified rice flour was higher than that of chestnut-added yakju prepared using cornflour koji and sacharified cornflour. The reducing of sugar in chestnut-added yakju prepared with saccharified rice flour or saccharified cornflour was rapid at the first brewing stage, decreased dramatically after 2 days, and then decreased slowly after 5 days of fermentation. The value of L and a, the Hunter values, were high in chestnut-added yakju prepared with cornflour koji, and value b was high in chestnut-added yakju with rice koji. The content of iso-amyl alcohol was the highest of seven kinds of fusel oil found in chestnut-added yakju. Ethanol content increased to $17.6{\sim}18.2%$(v/v) after 8 days of fermentation. The content of lactic acid was the highest of all organic acids in the chestnut-added yakju. Sensory test results on chestnut-added yakju prepared with saccharifed corn flour showed that if rice flour is used as a sugar supplement for chestnut, the yakju prepared using koji had better flavor and taste. If cornflour was used in the preparation of chestnut-added yakju, the used of saccharified cornflour offered superior flavor and taste.