• Journal of Surface Science and Engineering
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• v.31 no.1
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• pp.54-62
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• 1998

In this study, the behaviorof ion nitriding of AISI 304 stainless steel was investigated using plasma ion nitriding system. The characteristics of ion nitriding, and their micsoctrucyures, and physical properties were investigated as a function of process parmeteds. important conclusions can be summarzied as follows. Firstly, it was found that growth of nitride layer in ion nitriding are mainly affected by N2 partial pressures and nitriding temperatures for AISI 304 stainless steel. The $N_2$<\TEX> partial pressure plays on important role in ion nitriding since it determiness the incoming flux of nitrogen species onto specimen surface. Nitriding thmprrature is also important besauseit determines the diffusion rates of nitrogen through nitride layers. While both parameters affects the characteristics rateding are controlled by nitridingen diffusion nitration profiles of N and alloying elements such as Cr and Ni are observed through niride layers. Secondly, nitride layer consists of the upper white laywe having various nitride phases and the underneath diffusion layers. The thickness of white layer increases with $N_2$<\TEX> partial pressures and nitriding temperatures. The thinkness of diffusion layer is increasting nitriding temperatures. Finally, nitriding of stainless steels steel show slighly low their corrsionce prorerties. However, passivation properties, which is normally observed in stainless steels, were still observed aftre ion nitriding.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.115-120
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• 2003

This study was conducted to investigate the hematological changes of the dogs when administrated excessive amount of the Artemisia capillaris extract for a short period. In this experiment, clinically healthy dogs(n = 20, average weight = 7.68 kg) were divided into 2 groups : Artemisia capillaris rude juice extract group(CR) and concentrated extract group(CE). They were inserted stomach tube and administrated the extracts (5 ml/kg) for 8 days. The followings are the results of this experiment.: 1). The number of red blood cell(RBC) was significantly (p<0.05) decreased in CE group on day 4, 5, 6, whereas CJE group showed significantly (p<0.05) difference on day 5. 2). The packed cell volume(PCV) and hemoglobin concentration were significantly (p<0.05) decreased in both groups during experimental periods. 3). The met hemoglobin was significantly (p < 0.05) increased from 12 hrs after administration to day 8 in CJE group wheres, it was significantly (p<0.05) increased on day 6,7 in CE group.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.11-14
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• 2001

In this study, the relationship between metals (Cu, Cr, Cd, Zn. Pb, and Fe) 5 fractions and toxicity of soil samples from various contaminated sites in Korea were investigated. Metal toxicity of soils was tested using MetPLATE$^{TM}$ test kit, which is known as metal sensitive and organic insensitive. Significant amount of Fe was found in soils, and metal contents were in the order of Fe>Zn>Pb>Cu>Cr>Cd. Metal levels in organic fraction were rather high for all metals except Fe, and quite high percentages (35~79%) for residual fraction were observed for all metals. There were no significant relationships between the content of each metal fraction and toxicity which showed regression $R^2$in the range of 0.0003~0.414. However, correlation between toxicity and total metal contents showed regression coefficient $R^2$= 0.72. These results showed that the risk evaluation of metals in contaminated sites should be difficult to assess only by the contents of metal distribution because of the complexity of mixture of various metals.s.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.111-119
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• 1997

We met the continued population growth, contamination of both surface and groundwaters, deficiency of water resources, and increase of water demand. Wastewater reclamation and reusing system are important facilities in water resources planning aspect. The required water quality for reclamed wastewater varies with each application. This study was conducted to examine the possibilities of the wastewater reclamation and reusing on milk manufacturing wastewater. Biofiltration could reduce the COD$_{Cr}$, NH$_{3}$-N. Turbidty was reduced highly by coagulation. In conclusion, we identified the possibilities of wastewater reclamation and reusing on milk manufacturing wastewater's by biological activated carbon filter.

• Clinical and Experimental Pediatrics
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• v.63 no.4
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• pp.151-156
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• 2020

Background: Acute kidney injury (AKI) is one of the most significant postoperative complications of pediatric cardiac surgery. Because serum creatinine has limitations as a diagnostic marker of AKI, new biomarkers including neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18) are being evaluated to overcome these limitations and detect AKI at an early stage after cardiac surgery. Purpose: This study aimed to investigate the clinical usefulness of these biomarkers in young children. Methods: Thirty patients with congenital heart diseases who underwent cardiac surgery using cardiopulmonary bypass (CPB) were selected, and their urine and blood samples were collected at baseline and 6, 24, and 48 hours after surgery. Serum creatinine and blood urea nitrogen levels as well as NGAL, KIM-1, and IL-18 levels in urine samples were measured, and clinical parameters were evaluated. Results: Of the 30 patients, 12 developed AKI within 48 hours after cardiac surgery. In the AKI group, 8 of 12 (66.6%) met AKI criteria after 24 hours, and urine KIM-1/creatinine (Cr) level (with adjustment of urine creatinine) peaked at 24 hours with significant difference from baseline level. Additionally, urine KIM-1/Cr level in the AKI group was significantly higher than in the non-AKI group at 6 hours. However, urine NGAL/Cr and IL-18/Cr levels showed no specific trend with time for 48 hours after cardiac surgery. Conclusion: It is suggested that urine KIM-1/Cr concentration could be considered a good biomarker for early AKI prediction after open cardiac surgery using CPB in young children with congenital heart diseases.

• Journal of Environmental Science International
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• v.31 no.8
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• pp.677-689
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• 2022

In order to photocatalytically treat organic matter (COD_Cr) and chromaticity effectively, chemical coagulation and sedimentation processes were employed as a pretreatment of the leachate produced from landfill in Jeju Island. This was performed using FeCl₃·6H₂O as a coagulant. For the treated leachate, UV/TiO₂ and UV/TiO₂/H₂O₂ systems were investigated, using 4 types of UV lamps, including an ozone lamp (24 W), TiO₂ as a photocatalyst, and/or H₂O₂ as an initiator or inhibitor for photocatalytic degradation. In the chemical coagulation and sedimentation process using FeCl₃·6H₂O, optimum removal was achieved with an initial pH of 6, and a coagulant dosage of 2.0 g/L, culminating in the removal of 40% COD_Cr and 81% chromaticity. For the UV/TiO₂ system utilizing an ozone lamp and 3 g/L of TiO₂, the optimum condition was obtained at pH 5. However, the treated COD_Cr and chromaticity did not meet the emission standards (COD_Cr: 400 mg/L, chromaticity: 200 degrees) in a clean area. However, for a UV/TiO₂/H₂O₂ system using 1.54 g/L of H₂O₂ in addition to the above optimum UV/TiO₂ system, the results were 395 mg/L and 160 degrees, respectively, which were within the emission standard limits. The effect of the UV lamp on the removal of COD_Cr, and chromaticity of the leachate decreased in the order of ozone (24 W) lamp > 254 nm (24 W) lamp > ozone (14 W) lamp > 254 nm (14 W) lamp. Only COD_Cr and chromaticity treated with the ozone (24 W) lamp met the emission standards.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1018-1023
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• 2011

Alzinc is a ursine situated in the Ghazaouet town western part of the republic of Algeria. The purpose of this study was to determine the degree of contamination which soil and plants are burdened with some heavy metals: Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, then the accumulation of heavy metals in the soil and plant adjacent of area the alzinc ursine was detected and the interdependence of pollution among all three regions of the environment determined. This paper analyzes the heavy metal contents within a 2-years period in the soil and plants at the beginning of the vegetation period. The presence of Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, in the samples were analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Measurements of heavy metal contents were performed at three locations in soil and vegetative parts of three-plant types (plant alimentary) period during summer. The plant samples from the immediate environment of the dumpsite were highly contaminated with Zn, Cd and Mn. Three plants species: grape, artichoke and pepper, particularly, grape met some of the conditions to be classified as accumulators for Zn, Cu, Cd and Fe, consequently, she revealed a health risk for human and livestock due to the spread of the metal pollution from waste dumpsites to agricultural areas.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.9-14
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• 2014

Background: Cervical radiculopathy is the result of cervical nerve root pathology that may lead to chronic pain and disability. Although manual therapy interventions including cervical traction and neural mobilization have been advocated to decrease pain and disability caused by cervical radiculopathy, their analgesic effect has been questioned due to the low quality of research evidence. The purpose of this paper is to present the effect of manual therapy on pain, ROM, disability in a patient experiencing cervical radiculopathy. Methods: In this study, 30 participants who met the diagnostic criteria for cervical radiculopathy were randomized into two groups: group I (nerve mobilization group) & group II (Mckenzie exercise group). The experimental group was performed manual cervical traction and neural mobilization technique. The control group was performed manual cervical traction and cervical retraction, extension exercise. Assessments were performed to 30 participants before and after 4 weeks therapy. The components of assessments were pain intensity (PI), cervical rotation ROM (CR) and neck disability index (NDI). Results: After 4 weeks therapy, PI, CR and NDI were significantly reduced in both groups (p<.01). The PI, CR and NDI were no significantly reduced between group I and group II (p>.01). Conclusions: Manual therapy could reduce the symptoms of cervical radiculotpathy.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.77-91
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• 2017

Due to the lack of learning motivation, there is a need to seek ways to facilitate learning incentives because it's causing drop out and maladjustment of university life. This study is to examine whether the ARCS evaluation model developed by Keller (1983) is a valid model for evaluating the motivation level of local university students sample 276(male 116, female 157) in the Republic of Korea. To analyze the data, average statistic, one-way ANOVA and confirmative factor analysis were used. The conclusion of this study is as follows. First, the level of motivation per ARCS factor has demonstrated the highest relevance factor. Second, the level of motivation by the ARCS for the 1st and 3rd graders was appropriate. Differences in 'attention' and 'relevance' have only been observed for each year, and the 1st grade group was found to be larger than the 2nd grade cohort. Third, construct validity and convergent validity were obtained for measuring the level of motivation. The results of the verification of the variables also showed that the AVE and CR were met, and the model fit well was satisfactory. Based on the finding results, discussion and implication for further research were suggested.

• Clean Technology
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• v.17 no.4
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• pp.353-362
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• 2011

In our nature, the utilization of rainwater is essential for healthy water recirculation. This is one of the solutions of the increment of impermeability surface according to the development of new cities; this study of the improvement of rainwater quality has been carried on through the improvement of collecting and restoring system of rainwater. The southwestern region of Daejeon City, the rainwater coefficient of run off was 0.40 and this number had computed to 0.59 after the development. After filtration of rainwater, the heavy metal (Cu, As, Cr, Fe, Mn) contents level were lower than underground water. Moreover, collected rainwater showed better quality than underground water in following criteria; hardness, permanganate consumption quality, chloride, evaporation residue, sulfates and nitrate nitrogen. This water quality met the gray water quality standards. The rainwater quality was still suitable to use as bathroom flushing and gardening after 100 days of storage. This study proved that modification (installation of cover with gutter to existing rainwater collection system, proper filtering, and installation of underground storage tank) of collection system could improve quality of water and maintain this approximately 100 days.