• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.25-29
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• 2021

This paper demonstrates the utility of the Ni-Pd and carbon-nanotube (Ni-Pd-CNT)-based nanoalloy to improve the α-Ga₂O₃ crystal quality using the halide-vapor-phase epitaxy (HVPE) method. As result, the overall thickness of the α-Ga₂O₃ epitaxial layer increased from a Ni electroless plating time of 40 s to 11 ㎛ after growth. In addition, the surface morphologies of the α-Ga₂O₃ epilayers remained flat and crack-free. The full-width half-maximum results of the X-ray diffraction analysis revealed that the ($10{\bar{1}}4$) diffraction patterns decreased with increasing nominal thickness.

• Journal of Electrochemical Science and Technology
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• v.13 no.4
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• pp.472-478
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• 2022

Solar energy harvesting is practiced by various nations for the purpose of energy security and environment preservation in order to reduce overdependence on oil. Converting solar energy into electrical energy through Photovoltaic (PV) module can take place either in on-grid or off-grid applications. In recent time Lithium battery is exhibiting its presence in on-grid applications but its role in off-grid application is rarely discussed in the literature. The preliminary capacity and Peukert's study indicated that the battery quality is good and can be subjected for life cycle test. The capacity of the battery was 10.82 Ah at 1 A discharge current and the slope of 1.0117 in the Peukert's study indicated the reaction is very fast and independent on rate of discharge. In this study Lithium Iron Phosphate battery (LFP) after initial characterization was subjected to life cycle test which is specific to solar off-grid application as defined in IEC standard. The battery has delivered just 6 endurance units at room temperature before its capacity reached 75% of rated value. The low life of LFP battery in off-grid application is discussed based on State of Charge (SOC) operating window. The battery was operated both in high and low SOC's in off-grid application and both are detrimental to life of lithium battery. High SOC operation resulted in cell-to-cell variation and low SOC operation resulted in lithium plating on negative electrode. It is suggested that to make it more suitable for off-grid applications the battery by default has to be overdesigned by nearly 40% of its rated capacity.

• 월간산업보건
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• s.356
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• pp.16-25
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• 2017

Chromium exists at various valences, including elemental, trivalent, and hexavalent chromium, and undergoes reduction-oxidation reactions in the environment. Since hexavalent chromium is known as a human carcinogen, it is most important to evaluate the oxidationreduction characteristics of the hexavalent chromium species. Although hexavalent chromium can be reduced to trivalent state, the detailed information on this in workplace environments is limited. The purpose of this study was to investigate hexavalent chromium reduction in time in various conditions. A pilot chrome plating operation was prepared and operated in a laboratory for this study. There was evidence that the hexavalent chromium was reduced by time after mist generation. The percentage ratio (with 95% confidence intervals in parentheses) of hexavalent chromium to total chromium was almost 100% (99.1 ; 102.3) immediately after mist generation, and was reduced to 87.4% (84.8 ; 89.9) at 1 hour and 81.0% (78.3 ; 83.5) at 2 hours, respectively. Another test indicated that hexavalent chromium collected on PVC filters was also reduced by time after sampling. Hexavalent chromium was reduced to 90.8% (88.2 ; 93.3) at 2 hours after sampling. It also was found that hexavalent chromium was reduced during storage in air. It is recommended that air samples of hexavalent chromium be protected against reduction during storage.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.535-541
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• 2017

On the basis of 200 ppm of Ag and 120 l/h of feed flow rate, we built a pilot plant of an ion exchange fiber system having an double tube type ion exchange chamber with strong base ion exchange fiber (FIVAN A-6) which was designed to replace fibers easily and to eliminate the need for a fixture. The following results were obtained for the double tube type of ion exchange fiber system with an ion exchange capacity of 4.6 meq/g for Ag. The adsorption process was operated in the range of 40~90 l/h after confirming the effect of the flow rate and, pH did not affect formation of complex ion of Ag in the range of pH 7~12. In the case of backwash process, the recovery rate of Ag was tested in the range of 60~120 l/h and comparative experiments were carried out using NaOH, $NH_4Cl$, and NaCl as the chemicals for backwash. Although the desorption time was shortened at higher concentration, the desorption efficiency per mol was lowered. Therefore, it was confirmed that the desorption time and the concentration should be well balanced to operate economically. The desorption pattern of the backwash process is slower than the adsorption process and takes a lot of time. The results showed that the Ag adsorption ratio was 99.5% or more and the Ag recovery ratio was 96% or more, and commercialization was possible.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.439-444
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• 2016

In the present study, the performance of culture methods using two selective agars and real-time PCR were compared for selective isolation of Cronobacter in powdered infant formula and dried pumpkin. Two food samples were spiked with the pathogen and then preenriched in distilled water. A small portion of preenrichment (10 mL) was incubated in Enterobacteriaceae enrichment both, followed by inoculation onto Druggan-Forsythe-Iversen agar (DFI agar) and Cronobacter sakazakii chromogenic plating agar (R&F agar). The preenrichment and enrichment (1 mL each) was used in real-time PCR assay. In powdered infant formula (PIF), no statistical difference was observed between both culture methods and real-time PCR with preenrichemt (p > 0.05). However, the number of positives obtained by R&F agar and real-time PCR was much higher than that of culture method using DFI agar in dried pumpkin (p < 0.05). In particular, R&F agar yielded a significantly greater selectivity than DFI agar in dried pumpkin (p < 0.05). Real-time PCR and R&F agar, which are currently recommended by US FDA, could be used as an alternative detection tools for the isolation of Cronobacter in PIF and ingredient of child foods such as dried pumpkin that has high number of competing natural microflora.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.4
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• pp.103-133
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• 2007

The purpose of this study is to investigate whether customer satisfaction is affected by the expenditure for the customer satisfaction such as advertising, promotion, and training. This study also investigate whether the financial performance of the firm is affected by the customer satisfaction. The major findings are summarized as following. First, the customer satisfaction is affected by the expenditure for the customer satisfaction such as promotion, training. But customer satisfaction is not affected by advertising cost. Second, considering the time-lag and incremental valiables, the relationship between customer satisfaction and expenditure for the customer satisfaction is not founded. Third, the customer satisfaction affects positively on the corporate financial performance, such as ratio of operating income to sales, ratio of net income to sales, return on total assets, and return on equity. Finally, considering the time-lag the relationship between customer satisfaction and financial performance is not founded. Considering the incremental valiables, the relationship between customer satisfaction and financial performance is founded when ratio of operating income to sales and return on total assets are used financial performance. These findings imply that the expenditure for promotiom and training is needed to increase the customer satisfaction. Also improvement customer satisfaction is needed to increase the financial performance. The limitations of this study are as following. First, this study could not consider the other variables that would affect on the relationship among expenditure for customer satisfaction, level of customer satisfaction, and financial performance. Second, the results of this study are difficult to generalize because this study is focused on the service industry.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.83-92
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• 1999

Chitosan was prepared from chitin which was abstracted from wasted crab shells. Then itaconic acid was graft-copolymerized onto chitosan using ceric ammonium nitrate as a reaction initiator. To investigate the optimal grafting conditions, the influences of several factors on the grafting were studied, i. e., the concentrations of CAN and itaconic acid, the reaction temperature and time. And to find out its flocculation ability. the flocculation test was carried out with a metal plating factory waste water. The state of graft-copolymer was identified through IR spectra analysis. The optimal grafting conditions and flocculation results were shown to be : concentration of ceric ammonium nitrate is $3.5{\times}10^3M$, reaction temperature is $40^{\circ}C$ and reaction time is 4hrs with 0.25M of the monomer(itaconic acid). Though flocculation tests using chitosan, grafted chitosan and cation, CODcr. metal ions removal rates were measured. The order of superiority is Itaconic acid grafted chitosan>Chitosan>Cationic polymer.

• Resources Recycling
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• v.11 no.2
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• pp.3-13
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• 2002

The characteristics of cyanide decomposition in aqueous phase by hydrogen peroxide have been explored in an effort to develop a process to recycle waste water. The self-decomposition of $H_2O$$_2$at pH 10 or below was minimal even in 90 min., with keeping about 90% of $H_2O$$_2$undissociated. On the contrary, at pH 12 only 9% of it remained during the same time. In the presence of copper catalyst at 5 g Cu/L, complete decomposition of $H_2$O$_2$was accomplished at pH 12 even in a shorter time of 40 min. The volatility of free cyanide was decisively dependent on the solution pH: the majority of free cyanide was volatilized at pH 8 or below, however, only 10% of it was volatilized at pH 10 or above. In non-catalytic cyanide decomposition, the free cyanide removal was incomplete in 300 min. even in an excessive addition of $H_2$$O_2$at a $H_2$$O_2$/CN molar ratio of 4, with leaving behind about 8% of free cyanide. On the other hand, in the presence of copper catalyst at a Cu/CN molar ratio of 0.2, the free cyanide was mostly decomposed in only 16 min. at a reducedH202/CN molar ratio of 2. Ihe efnciency of HBO2 in cyanide decomposition decreased with increasing addition of H2O2 since the seu-decomposition rate of $H_2$$O_2$increased. At the optimum $H_2$$O_2$/mo1ar ratio 0.2 of and Cu/CN molar ratio of 0.05, the free cyanide could be completely decomposed in 70 min., having a self-decomposition rate of 22 mM/min and a H$_2$$O_2$ efficiency of 57%.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.90-95
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• 2010

The application of livestock manure to cropland is a practice that has been used for centuries. Agricultural crops can utilize nutrients from manure, and the producer can utilize land for disposal, although in a "sustainable system" the concept is manure utilization and not waste disposal. However, meeting regulatory criteria regarding microbial quality remains an expensive and time consuming process. The purpose of this study was to quantify the level of environmental impact of soil moisture and temperature on fecal coliform (Escherichia coli or E. coli) survival in upland soils for sound application of livestock manure. Samples were collected up to 30 days depending on the given conditions. The inactivation rate of E. coli increased linearly with increased temperature while the inactivation rate gradually decreased with decreased soil moisture level. The overall findings of this study showed that the temperature was the limited factor on E. coli survival in soils over soil moisture content. This study will provide useful and practical guidelines to applicators of soil in deciding appropriate handling and time frames for land application for sustainable agriculture.

• Journal of the Korean Society of Food Culture
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• v.28 no.4
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• pp.348-355
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• 2013

This study intends to provide preliminary data for improving dining experience in the restaurants of Bamboo food village and help draw up guidelines for the improvement of these dining venues by surveying customer perception and satisfaction in 15-restaurants of the food village. The restaurants were surveyed mainly for satisfaction of the menu, especially, on the signature dishes of Damyang, "ddeokgalbi" (grilled short rib balls) and "daetongbab"-the grilled short rib balls and bamboo rice. The two dishes were more liked by people in the the 20- to 29-year age group with a score of 3.92 and 4.11, respectively. Although the 30-49 age group showed the highest satisfaction score on the fixed price menu, there was no statistically significant difference. The age group of 20-29 also showed the highest satisfaction on plating and table setting with a score of 4.09 and 4.04, respectively, and there was significant difference among age groups in this regard (p<0.05). All the age groups surveyed answered "time-honored taste" should be captured when working on menus, which suggests it should be the first choice for the restaurants in the food village when they develop their menus. When it comes to the restaurant environment, satisfaction on sanitary conditions was significantly different among the groups with a score of 4.21 given by 30-49 age group and 3.88 by the 50 and over group (p<0.05). In the category of service satisfaction, the two aforementioned age groups again showed significant difference in catering to customer needs with a score of 3.99 and 3.63, respectively (p<0.05), whereas welcoming customers and serving food was scored without statistical difference by age. Being asked what needs to be done to strengthen competitive advantage of the restaurants, all the age groups answered "taste" would matter the most while the 20 to 29 and 30 to 49 age groups picked "hygiene" and the 50 and over selected "table setting and ambience" next, which was statistically different with a p value of <0.05. Regarding the competitive advantage of the Korean restaurants in Damyang Bamboo food village, the first two younger groups (20 to 29 and 30 to 49) chose "table setting and ambience" and the eldest (50 and over) age group answered "location wise advantage," indicating significant difference by age. More than 80 percent of the people surveyed were willing to revisit the venues, which suggests improving restaurant environment in Bamboo food village and offering customers a better experience are very likely to build a image of culinary tourism for Damyang.