• Clean Technology
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• v.16 no.4
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• pp.258-264
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• 2010

This study estimated the possibility of phosphate removal characteristics to utilize EAF(electric arc furnace) slag as submarine cover material. The major phosphate removal mechanism was a certain formation of HAP precipitation occurred by the ionization reaction between $Ca^{2+}$ and $OH^-$, which were leached from the EAF Slag. Another phosphate removal mechanism was the adsortion of EAF slag surface. As a result of $PO_4{^-}-P$ removal characteristics using continuous column reactor, $PO_4{^-}-P$ concentration decreased rapidly after 3 days and 10 days later, it show under 0.5 ppm. The result as applied in real sea water, shows that the phosphate removal effects were 93~98% by the subaqueous sediment removal using the EAF slag. In conclusion, EAF slag is useful in $PO_4{^-}-P$ removal and control and it is possible to use without additional process like crush and selection.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.404-413
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• 2023

In this research, we studied the development of a SUS304 microneedle array based on microfabrication technology and the applicability of Parylene-C thin film, a medical polymer material. First of all, four materials commonly used in the field of medical engineering (SUS304, Ti, PMMA, and PEEK) were selected and a 5 ㎛ Parylene-C thin film was deposited. The applicability of Parylene-C coating to each material was confirmed through SEM analysis, contact angle measurement, surface roughness(Ra) measurement, and adhesion test according to ASTM standards for each specimen. Parylene-C thin film was deposited based on chemical vapor deposition (CVD), and a 5 ㎛ Parylene-C deposition process was established through trial and error. Through characteristic experiments to confirm the applicability of Parylene-C, SUS304 material, which is the easiest to apply Parylene-C coating without pretreatment was selected to develop a microneedle array based on CNC micromachining technology. The CNC micromachining process was divided into a total of 5 steps, and a microneedle array consisting of 19 needles with an inner diameter of 200 ㎛, an outer diameter of 400 ㎛, and a height of 1.4 mm was designed and manufactured. Finally, a 5 ㎛ Parylene-C coated microneedle array was developed, which presented future research directions in the field of microneedle-based drug delivery systems.

• The Journal of the Acoustical Society of Korea
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• v.27 no.2
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• pp.57-65
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• 2008

Setting parameters of Ultrasonic scanners influence the quality of ultrasonic images. In order to obtain optimized images sonographers need to understand the effects of the setting parameters on ultrasonic images. The present study considered typical four parameters including TGC (Time Gain Control), Gain, Frequency, DR (Dynamic Range). LCS (low contrast sensitivity) was chosen to quantitatively compare the quality of the images. In the present experiment LCS targets of a standard ultrasonic test phantom (539, ATS, USA) were imaged using a clinical ultrasonic scanner (SA-9000 PRIME, Medison, Korea). Altering the settings in the parameters of the ultrasonic scanner, 6 LCS target images (+15 dB, +6 dB, +3 dB, -3 dB, -6 dB, -15 dB) to each setting were obtained, and their LCS values were calculated. The results show that the mean pixel value (LCS) is the highest at the max setting in TGC, mid to max in gain and pen mode in frequency and 40-66 dB in DR. Among all images, the image being the highest in LCS was obtained at the setting of DR 40 dB. It is expected that the results will be of use in setting the parameters when ultrasonically examining masses often clinically found In either solid lesions (similar to +15, +6, +3 dB targets) or cystic lesions (similar to -15, -6, -3 dB targets).

• Transactions of Materials Processing
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• v.28 no.3
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• pp.145-153
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• 2019

The objective of this study is to analyze the mechanical splicing characteristic of the threaded bar according to the contact conditions of the transverse rib. In order to consider the contact conditions of the rib, selection of the main variables including the gap of the core diameter ($l_c$), rib angle (${\theta}$), and the number of contacts ($C_N$) of transverse rib was done. So as to analyze the splicing characteristic of the D51 threaded bar, a finite element (FE) simulation of the tensile test was conducted using the designed D51 threaded bar and coupler. Through FE simulation results, it was verified that the mechanical slicing characteristics varied based on the main design variables ($l_c$, ${\theta}$, and $C_N$). It was further confirmed that it was important to determine the $C_N$ in consideration of $l_c$. Additionally, the tensile test results of the D25 and D51 threaded bar combined with the couplers were similar to FE simulation results. Furthermore, to quantitatively evaluate FE simulation and test results, the calculation equation for the contacted projection area ratio (R) of the transverse rib was proposed. To secure a mechanical splicing joint of the threaded bar, it was established that the R calculated using the proposed equation had to be greater or equal to 40%.

• Journal of Biomedical Engineering Research
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• v.43 no.6
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• pp.382-389
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• 2022

In this study, the accuracy of the orthognathic surgical guides with single-stage split path was upgraded to realize orthognathic surgical guides with two-stage split path and simulated surgery was performed to verify its accuracy. As a result, the average error distance between the simulation model and the scan model was + 0.289 / - 0.468 mm (standard deviation 0.128), which was confirmed to be within ± 0.5 mm, which is a clinically acceptable level. Also, there was no significant difference compared with the average value of + 0.313 / - 0.456 mm (average standard deviation 0.106) of the conventional single-stage split path type device. It is judged that the use of this device can contribute to the reduction of surgical time and increase in accuracy since a separate finishing operation for bone preparation is unnecessary.

• The Journal of Internal Korean Medicine
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• v.42 no.6
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• pp.1184-1198
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• 2021

Objectives: The aim of this study was to investigate the latest clinical studies on Korean medicine treatment of post-concussion syndrome (PCS) in the Chinese National Knowledge Infrastructure Database (CNKI). Methods: We searched the last 10 years of clinical studies discussing Oriental medicine-based treatments for PCS in the CNKI database. The search focused on the authors, publication year, type of study, purpose of the study, method and duration of treatment, evaluation criteria, and results of each article. Results: Of the 22 selected studies, 1 was a non-randomized controlled trial (nRCT), 2 were case series, and 19 were randomized controlled trials (RCTs). Treatments included oral herbal medicine in 16 studies, oriental medicine through external use in 2 studies, acupuncture in 3 studies, and traditional Chinese medicine injection in 2 studies. The most frequently used herb was Cnidii Rhizoma (川芎). All 22 studies confirmed the efficacy of Oriental medicine treatments. Conclusion: More varied and scientifically designed clinical studies are required to develop treatments for PCS. The results of this study could be used as basic data for further PCS studies.

• Journal of Industrial Convergence
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• v.21 no.5
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• pp.31-41
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• 2023

We examine the relationship between abusive supervision and work-family conflict, and the moderating effects of employee's resilience and perceived organizational support. We collected the employees' sample(n=136) and conducted multiple hierarchical regression analysis. Abusive supervision has a significant positive effect on work-family conflict. Subordinate's resilience has a buffer effect on the main relationship, but perceived organizational support has no significant moderating effect. This study will be helpful for employees who are suffered from work-family conflict.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.475-477
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• 2019

Stem cell research arose from the need to explore new therapeutic possibilities for intractable and lethal diseases. Although musculoskeletal disorders are basically nonlethal, their high prevalence and the relative ease of performing clinical trials have facilitated the clinical application of stem cells in this field. On the other hand, despite the plethora of in vitro and preclinical studies in stem cell research for regenerative medicine in the musculoskeletal system, few reliable clinical studies have been published. Stem cell therapy can be applied locally for bone, cartilage, and tendon regeneration. The candidate disease modalities in bone regeneration include large bone defects, nonunion of fractures, and osteonecrosis. Focal osteochondral defect and osteoarthritis are the current targets for cartilage regeneration. For tendon regeneration, bone-tendon junction problems, such as rotator cuff tears are hot topics in clinical research. To date, the literature supporting stem cell-based therapies comprises mostly case reports or case series.

• 한국노년학
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• v.38 no.4
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• pp.1057-1081
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• 2018

This study analyzed the case of elderly care cluster in Gwangjin-gu to explore the possibilities of social economy as a provider of community-based social services. Community-based means the approach by which community organizations build a voluntary and collaborative network to enhance collective problem-solving abilities. Therefore, it is very likely that the social economy that emphasizes people, labor, community, and democratic principles can contribute to community-based social services. This study analyzed social economic network by using four characteristics of social economy suggested by OECD community economy and employment program as an analysis framework. The results of this study are as follows: First, it is found that social economy would hardly supply community-based social services through network cooperation because of a large variation in community identity, investment to new product, and labor protection. Second, community users are not the consumers of the social economy and the products of the social economy stay in market products only for the organizations in social economy. In order to create good services that meet the needs of residents, community development approaches are required at the same time. The importance of community space where local residents and social economy meet is derived. Third, public support such as purchasing support has weakened the ecosystem of social economy by making the distinction between public economy and social economy more obscure. On the other hand, public investment in community infrastructure is an indirect aid to social economy to communicate with residents and to promote good supply and consumption. In the end, community-based social services need a platform where the social economy and the people meet. This type of public investment can create the ecosystem of the social economy.

• Food Engineering Progress
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• v.15 no.4
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• pp.346-354
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• 2011

This study was carried out to fortify the antimicrobial activity of yoghurt by adding liquorice extract to it. The liquorice extracts (1 mg/mL) showed relatively high antibacterial activity against H. pylori KCCM 40449 (p < 0.05). The solvent liquorice extracts of minimal inhibitory concentrations (MIC) against H. pylori KCCM 40449 were 25- 100 ${\mu}g$/mL. Lactobacillus amylovorus DU-21 with high EPS production ability were inoulated to milk after the addition of different amounts of liquorice extracts (0.0%, 0.05%, 0.1% and 0.2%). The physico-chemical characteristics of yoghurts added with liquorice extracts were examined. The initial pH, titratable acidity, viscosity and viable cell counts of the yoghurt added liquorice extracts were 3.41-3.51, 1.021-1.091%, 1,686-1,930 cp and 9.41-9.38 Log CFU/mL, respectively. The viscosity and syneresis of yoghurt were better than that of the control. Antimicrobial activity against H. pylori KCCM 40449 increased with increasing addition of liquorice extract. However, the sensory score of yoghurt added with different amounts of liquorice extracts was lower than that of the control (p < 0.05). As a result of the sensory evaluations, the flavor, taste, texture, color and overall acceptability of the yoghurt with 0.05% liquorice extract were found to be much better than those of the other groups (p < 0.05). Overall, the optimal amount of liquorice extract added in the manufacture of yoghurt was 0.05% of the total weight. Further studies on increment of antimicrobial activity and palatability of liquorice extract added yoghurt are necessary.