• Resources Recycling
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• v.10 no.3
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• pp.29-36
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• 2001

Cyclic voltammetry has been applied in the basic studies for the treatment and recovery of heavy metal component contained in wastewater by electrochemical reduction. The electrochemical behaviors of zinc ion for zinc metal electrode and carbon elec-trode were characterized by voltammograms and it was showed that zinc ions were reduced to metallic form below -0.76 V vs SHE. The change in the features of crystalline form of metallic zinc upon oxidation and reduction reaction was observed by X-ray diffraction method and the Am analysis verified that zinc ions were reduced to metal on copper plate. The results of this study were regarded to be important and meaningful in the treatment of heavy metal containing wastewater and, as a result, in the obtainment of metallic product by electrochemical method.

• Korean Journal of Materials Research
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• v.26 no.11
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• pp.583-589
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• 2016

In this study, recrystallization behaviors in the two-phase (${\alpha}+{\gamma}$) region of micro-alloyed steels such as Base, Nb, TiNbV and CAlN were investigated in terms of flow stress, microstructure and associated grain boundary characteristics. The flow stress of all specimens reached peak stress and gradually decreased, which means that recrystallization or recovery of proeutectoid deformed ferrite and recovery or transformation to ferrite of deformed austenite occurred by thermal activation. The precipitation of carbide or nitride via the addition of micro-alloying elements, because it reduced prior austenite grain size upon austenitization, promoted transformation of austenite to ferrite and increased flow stress. The strain-induced precipitation under deformation in the two-phase region, on the other hand, increased the flow stress when the micro-alloying elements were dissolved during austenitization. The recrystallization of the Nb specimen was more effectively retarded than that of the TiNbV specimen during deformation in the two-phase region.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.62-70
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• 2005

The nanoindenter and AFM have been used for nanofabrication, such as nanolithography, nanowriting, and nanopatterning, as well as measurement of mechanical properties and surface topology. Nanoscale indents can be used as cells for molecular electronics and drug delivery, slots for integration into nanodevices, and defects for tailoring the structure and properties. Therefore, it is very important to make indents of desired morphology (shape, size and depth). Indents of different shapes can be obtained by using indenters of different geometries such as a cube comer and conical and spherical tips. The depth and size of indents can be controlled by making indentations at different indentation loads. However, in case of viscoplastic viscoelastic materials such as polymethylmethacrylate (PMMA) the time dependent deformation (TDD) should also be considered. In this study, the effect of process parameters such as loading rate and hold-time at peak load on the indent morphology (maximum penetration depth, elastic recovery, transient creep recovery, residual depth pile-up height) of PMMA were studied for hyperfine pattern fabrication.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.22-31
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• 1989

In this paper, we analyze the performance of the IEEE 802.4 token passing bus protocol through a simulation model of the protocol. In order to analyze performance of the protocol in the initialization, transition and fault recovery states as well as in the steady state, the protocol functions are divided into five processes each of which can effectively simulate protocol behaviors according to the variations of protocol parameters. From the simulation study, we obtain protocol parameters which severely influence the protocol performance and find out that proper selection of the protocol parameter values for token passing is very important to obtain good performance of the protocol when the priority scheme is used.

• Women's Health Nursing
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• v.28 no.2
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• pp.145-153
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• 2022

Purpose: This study aimed to investigate the influencing factors of breast cancer recurrence by comparing the risk factors and lifestyle patterns related to breast cancer in Korean women with and without recurrence. Methods: This cross-sectional survey comprised 241 Korean women diagnosed with breast cancer who had received follow-up treatment. Participants were recruited from a university hospital in Seoul and an online social media platform for breast cancer patients. Data were collected either via online or a paper survey, using a structured questionnaire that included general and disease-related characteristics and lifestyle behaviors. Data were analyzed using descriptive statistics, univariate analysis, and logistic regression. Results: Recurrence of breast cancer was influenced by four factors; childbirth experience, consumption of green/yellow vegetables, drinking behavior, and recovery from fatigue after sleep. Prevalence of recurrent breast cancer was associated with no childbirth experience (OR=2.29, p=.010), fewer green/yellow vegetables (OR=0.71, p=.008), drinking behavior (OR=0.24, p=.001), and a lower level of recovery from fatigue after sleep (OR=0.51, p<.001). Conclusion: Aside from having experienced childbirth, this study identified several modifiable factors that influence breast cancer recurrence. Increasing green/ yellow vegetable intake, alleviating fatigue, and reducing alcohol intake are important. Intervention strategies in clinical research and practice can be applied to address risk factors and reduce the prevalence of recurrent breast cancer.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.43-49
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• 2024

In early 2020, as the COVID-19 pandemic hit the world, widespread changes occurred throughout society. COVID-19 also brought changes in consumers' consumption behaviors and preferences. This study aims to find out how the current status of the tourism industry and the coffee industry has changed since the end of COVID-19 by conducting big data analysis focusing on the search frequency of Naver, Google, and the following, which are representative social networks in Korea. Designating "Coffee Industry + Tourism Industry" as the representative keyword, January 1, 2020 to December 31, 2020, the time of each COVID-19 outbreak, was set before the COVID-19 type, and January 1, 2023 to December 31, 2023 was set after the end of COVID-19. Based on the analyzed search binder big data analysis within the period, we would like to find out how the current status of the tourism industry and the coffee industry has changed since the end of COVID-19. Finaly, the coffee and tourism industries are on the path of recovery and growth. In particular, the rise in coffee consumption, the recovery of the number of tourists, the emphasis on local tourism, and the strengthening of links with global markets are prominent.

• Resources Recycling
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• v.26 no.4
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• pp.88-94
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• 2017

The recovery of gold in cyclone type electrolytic cell was conducted from solution for stripping gold of PCB by cyanide. The electrolytic recovery behaviors of gold was investigated by reaction time and addition of electrolytic sodium hypochlorite (NaOCl) and gold plating additive (KG-120). Because the electrolysis generated NaOCl reacted with the cyanide in the leachate by alkaline chlorination, more than 99% of the cyanide was removed at a $NaOCl(g)/CN^-(g)$ ratio of 1.0. When NaOCl was added during the recovery of the gold from cyanide leachate in the cyclone electrolytic cell, the recovery of gold was 98% at the ratio of $NaOCl(g)/CN^-(g)$ from 0.5 to 2.5 in 480 minutes and decreased rapidly over the ratio of 3.0. Gold was recovered more than 99% by adding 1.5 and 4.5%(v/v) of KG-120 with NaOCl in 480 minutes. In particular, when the concentration of KG-120 was 3.5 and 4.5%(v/v), more than 96% of gold was recovered within 240 minutes and the initial recovery rate was relatively faster. The optimum concentration of KG-120 is 3.5%(v/v) considering the economic feasibility and efficiency.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.11-23
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• 2023

This study aims to investigate the relationship between service recovery justice, residual emotions, and customer behavior. It empirically verifies that low justice in service recovery affects residual emotions and, in turn, has an impact on customers' negative behaviors. Furthermore, this research distinguishes customer-brand relationship quality into emotional relationship quality and cognitive relationship quality and seeks to validate that the type of relationship quality may influence the extent to which the justice of recovery processes affects residual emotions. Data was collected through surveys, and hypotheses were tested using structural equation modeling. The research findings indicate that among the dimensions of service recovery justice, procedural justice and interactional justice significantly influence residual emotions. Moreover, residual emotions have a significant impact on both the intention to revisit and the intention to engage in negative word-of-mouth. In addition, the impact of distributive justice and procedural justice on residual emotions was found to be higher for cognitive relationship quality than emotional relationship quality, and the impact of interactional justice on residual emotions was found to be higher for emotional relationship quality than cognitive relationship quality.

• Journal of Oriental Neuropsychiatry
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• v.24 no.4
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• pp.419-434
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• 2013

Objectives: The object of this study is to observe the cognition and motor function recovery effects of Joojakwhan (JJW), a traditional Korean poly-herbal formula for treating various neuropsychiatric diseases such as dementia, for the mildly stroke rats, with 60 minutes of reperfusion transient middle cerebral artery occlusion (tMCAO). Methods: In the present study, 125, 250 and 500 mg/kg of JJW were orally administered, once per day for 10 continuous days 2 hours after the tMCAO. The body weight changes, infarct sizes under 2% 2, 3, 5-triphenyl tetrazolium chloride (TTC) stain, sensorimotor functions and cognitive motor behavior tests were serially monitored with cerebral caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP)-immunoreactivities and histopathological changes. The effects of tMCAO on sensorimotor functions were evaluated by using of limb placing and body-swing tests, and the cognitive motor behaviors were also observed with water maze tests. Results: From the results of tMCAO, with marked decreases of body weights, disorders of sensorimotor functions increases the limb placing test scores, and decrease the numbers and percentages of body swings to the ipsilateral sides. The cognitive motor behaviors increases the distances and time to reach the escape platform which included the inhibitions of the decreases with repeated trials that were observed with focal cerebral cortex infarct volumes. In addition, the marked increases of the atrophy, numbers of degeneration, caspase-3- and PARP-immunoreactive cells around peri-infarct ipsilateral cerebral cortex were also observed in tMCAO controls when compared with the sham control rats, respectively. Conclusions: The results obtained from this study suggest that oral administrations of JJW indicate obvious cognitions and motor function recoveries of the rats with tMCAO, mild strokes, which are mediated by neuro-protective effects through known antioxidant effects of components.

• Child Health Nursing Research
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• v.24 no.4
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• pp.353-363
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• 2018

Purpose: The purpose of this study was to investigate pediatric nurses' perceptions regarding in end-of-life care and turnover intention. Methods: A cross-sectional descriptive study was performed among 111 hospital nurses. Pediatric nurses' perceptions of obstacles and supportive behaviors were measured using the Pediatric Nurses' Perceptions of End of Life Care Questionnaire which was translated into Korean and turnover intention was measured using the Korean Nurse Turnover Intention Scale (K-NTIS). Results: The supportive behavior with the highest perceived magnitude was 'Physicians who are compassionate, but very clear about prognosis.' The obstacle with the highest perceived magnitude was 'Instigating painful treatments when there is no hope of recovery.' Pediatric nurses' perceptions of obstacles in end-of-life care showed statistically significant differences depending on whether nurses received end-of-life care education (t=2.02, p=.046). The perception of obstacles in end-of-life care was positively correlated with turnover intention (intensity r=.28, p=.002) (frequency r=.20, p=.027). Conclusion: These results suggest that pediatric nurses' perception of obstacles and supportive behaviors in end-of-life care need to be assessed when considering turnover intention. Furthermore, psychological counseling should be offered to nurses to prevent burnout and reduce moral distress which is correlated with the turnover rate.