• Corrosion Science and Technology
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• 제22권1호
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• pp.10-20
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• 2023

Because of its inexpensive cost, mild steel is frequently employed as a construction material in different industries. Unfortunately, because of its limited resistance to corrosion, a protective layer must be applied to keep it from decaying in acidic or basic environments. The presence of heteroatoms, such as nitrogen, oxygen, and pi-electrons in the Schiff base could cause effective adsorption on the mild steel surface, preventing corrosion. The weight loss method and scanning electron microscopy (SEM) were used to investigate the inhibitory effects of APIDO on mild steel in a 1 M hydrochloric acid environment. The efficiency of inhibition increased as the inhibitor concentration increased and decreased as the temperature increased. The SEM analysis confirmed that the corrosion inhibition of APIDO proceeded by the formation of an organic protective layer over the mild steel surface by the adsorption process. Simulations based on the density functional theory are used to associate inhibitory efficacy with basic molecular characteristics. The findings acquired were compatible with the experimental information provided in the research.

• 대한약침학회지
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• 제22권4호
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• pp.279-283
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• 2019

Hominis placenta pharmacopuncture, a treatment that injects Hominis placenta extract into acupoints, has been suggested in the literature and researches that it could be used for cognitive decline. We experienced a case of mild neurocognitive disorder treated with Hominis placenta pharmacopuncture. Hominis placenta pharmacopuncture could be a possible treatment modality producing substantial clinical result in cognitive function which is assessed with Mini-Mental State Examination-Dementia Screening (MMSE-DS), Korean Version of Montreal Cognitive Assessment (MoCA-K), and Korean-Dementia Rating Scale (K-DRS). A 84-year-old man with mild neurocognitive disorder received Hominis placenta pharmacopuncture on GV20, CV12, and bilateral ST36 for a month. The results of neuropsychological examination showed increase in scores after treatment of Hominis placenta pharmacopuncture. Before treatment, they were 15 points for MoCA-K, and 120 points for K-DRS (7.6%), but after treatment, they elevated by 21 points for MoCA-K and 137 points for K-DRS (100%). MMSE-DS score was 28 points, unchanged before and after treatment. It did not cause any side-effect. Hominis placenta pharmacopuncture could be a safe option for treating mild neurocognitive disorder.

• 대한통합의학회지
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• 제4권1호
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• pp.21-29
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• 2016

Purpose : The purpose of this study was to evaluate the influence of LOTCA-G and ADL by individualized cognitive program in elderly with vascular dementia, alzheimer dementia and mild cognitive impairment. Method : The subjects of this study, old man and woman diagnosed with vascular dementia, alzheimer dementia and mild cognitive impairment, 24 patients were picked up, who were agreed with this research and were having hospital care for 3weeks at nursing care centers. Individualized cognitive program was applied to 8 patients of vascular dementia, 8 patients of alzheimer dementia and 8 patients of mild cognitive impairment. Cognitive function measured by LOTCA-G and performance measured by FIM. The SPSS Ver. 22.0 statistical program was used for data processing. The significance level for statistical inspection was set as 0.05. Result : In comparison of LOTCA-G was significant increased after intervention and among three groups were significant difference. But FIM was no significant difference after intervention and among three groups were no significant difference. Conclusion : Therefore, the individualized cognitive program is useful to improve the cognitive function in elderly with dementia and mild cognitive impairment.

• 한국해안해양공학회지
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• 제19권6호
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• pp.521-532
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• 2007

완경사 파랑식의 유도에 Galerkin방법을 사용하여 수심 의존함수에 대한 Sturm-Liouville 미분식을 엄밀하게 구성하였다. 구한 방정식의 종속변수에 대한 전형적인 변수변환으로 수심, 해저경사 그리고 해저곡률에 대한 항들로 구성된 변형 Helmholtz식을 얻었다. 수치실험을 통해 이 항들이 지형에 의한 파랑변형에 주요한 역할을 보이고 이들의 상대적인 크기에 의해 수정 완경사 파랑식(MMSE)에 비해 완경사 파랑식(MSE)의 적용성이 제한됨을 입증하였다.

• Journal of Welding and Joining
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• 제15권5호
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• pp.104-114
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• 1997

The microstructure and bond strength were investigated on the SiC/SiC and SiC/mild steel joints brazed by Ag-5at%Ti alloy. Ag-5at%Ti-2at%Fe and -5at%Fe brazing alloys were also used to see the effects of Fe addition on the bond strength of SiC/SiC brazed joints. Brazing temperature and brazing gap were selected and examined as brazing variables. The microstructure of SiC/SiC brazed joints was affected by Fe addition to the Ag-5at%Ti alloy, but the bond strength was not. Increasing brazing temperature also changed the microstructure of $Ti_5Si_3$ reaction layer and brazing alloy matrix of the SiC/SiC and SiC/mild steel joints, but not the bond strength. Brazing gap had a great effects on the bond strength. Decreasing brazing gap from 0.2 mm to 0.1 mm in SiC/SiC brazing increased the bond strength from 187 MPa to 263 MPa and, in SiC/mild steel brazing, from 189 MPa to 212 MPa. It was concluded that the most important parameter on the bond strength in SiC/SiC and SiC/mild steel brazing was the relative ratio between brazing gap and specimen size.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.333-337
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• 2001

The pharmacokinetic changes of diltiazem (DTZ) and its main metabolite, deacetyldiltiazem (DAD) were studied after oral administration of DTZ to normal rabbits and mild and medium folate-induced renal failure rabbits. DTZ 10 mg/kg was given to the rabbits either orally (n=6). Plasma concentrations of DTZ and DAD were determined by a high performance liquid chromatography assay. The area under the plasma concentration-time curves (AUC) and maximum plasma concentration ($C_{max}$) of DTZ were significantly increased in mild and medium folate-induced renal failure rabbits. The metabolite ratio of the DTZ to DAD were significantly decreased in mild and medium folate-induced renal failure rabbits. The volume of distribution ($V_{d}$) and total body clearance ($CL_{t}$) of DTZ were significantly decreased in mild and medium folate-induced renal failure rabbits. The elimination rate constant ($\beta$) of DTZ was significantly decreased in folate-induced renal failure rabbits, but that of DAD was significantly increased. These findings suggest that the hepatic metabolism of DTZ was inhibited and the $V_{d}$, $CL_{t}$ and $\beta$ of DTZ were significantly decreased in mild and medium folate-induced renal failure rabbits.

• 대한치매학회지
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• 제17권3호
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• pp.120-129
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• 2018

Background and Purpose: Prospective memory (PM) has a known relationship with frontal function, and PM decline has been observed in amnestic mild cognitive impairment (aMCI). Cerebral small vessel disease, as evidenced by white matter hyperintensities (WMHs), is linked to frontal dysfunction. This study was undertaken to evaluate the relationship between PM decline and WMHs in patients with aMCI. Methods: Of 74 enrollees with aMCI, 69 completed this prospective study. We compared total scores and sub-scores of the Prospective and Retrospective Memory Questionnaire (PRMQ) administered at baseline and 3 months later, stratifying patients by degree of WMHs. Results: A significant decline was seen in PRMQ total scores and PM scores at the 3-month mark in patients with moderate (vs. mild) degrees of WMHs ($-2.8{\pm}7.2$ vs. $0.2{\pm}7.1$; p=0.032). In addition, patients with moderate (vs. mild) degrees of deep WMHs (DWMHs) showed greater PM decline, whereas PM loss in patients with mild, moderate, or severe degrees of periventricular WMHs (PVWMHs) did not differ significantly. Conclusions: Findings of this study indicate that the burden of WMHs is consistently implicated in PM deterioration experienced by patients with aMCI, and signifies greater PM decline, especially in instances of extensive DWMHs. Greater attention to the change of PM is therefore needed in aMCI patients with WMHs.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.400-412
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• 2022

Hydrogen with high chemical reactivity and combustion efficiency, is expected to reduce greenhouse gas and CO emission. However, there is a problem of increase in NOx emission due to hydrogen combustion. MILD combustion technology has been proposed to resolve NOx emission. In this study, the characteristics of MILD combustion and NOx formation by flue gas recirculation (KV) in CH₄-H₂ mixture were analyzed and predicted using 0D premixed combustion model. The ignition delay time became shorter as the hydrogen co-firing rate increased, and longer as the recirculation rate increased. For NOx emission, EINO decreased as the KV increased, but EINO increased as the hydrogen co- firing rate increased. In particular, EINO was predicted to increase significiently above 80% hydrogen. Through the pathway analysis of NO formation, it was found that the influence of N₂O intermediate route and NNH route was enhanced for hydrogen co-firing.

• Corrosion Science and Technology
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• 제23권1호
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• pp.20-32
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• 2024

Metal corrosion in acidic environments is a major issue in various industrial applications. This study evaluates the 4-piperonylideneaminoantipyrine (PPDAA) corrosion inhibition efficiency for mild steel in a hydrochloric acid (HCl) solution. The weight loss method was used to determine the corrosion inhibition efficiency at different concentrations and immersion time periods. Results revealed that the highest inhibition efficiency (94.3%) was achieved at 5 mM concentration after 5 hours of immersion time. To inspect the surface morphology of the inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl. Density functional theory (DFT) calculations were performed to investigate the molecular structure and electronic properties of the inhibitor molecule to understand the corrosion inhibition mechanism. Theoretical results showed that the inhibitor molecule can adsorb onto the mild steel surface through its nitrogen and oxygen atoms, forming a protective layer that prevents HCl corrosive attack. These findings highlight the potential of PPDAA as an effective corrosion inhibitor for mild steel in HCl solution. Moreover, combining experimental and theoretical approaches provides insights into the mechanism of corrosion inhibition, which is essential for developing effective strategies to prevent metal corrosion in acidic environments.

• The Korean Journal of Physiology
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• 제30권2호
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• pp.231-236
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• 1996

In our previous study (Kim et al, 1991), GLUT 4 protein content correlated negatively with plasma glucose levels in skeletal muscles of STZ-induced diabetic rats. Thus, in this study, to confirm whether expression of GLUT 4 correlate negatively with degree of hyperglycemia, we measured levels of GLUT 4 mRNA in red and white gastrocnemius muscles in STZ-induced mild and severe diabetic rats. Rats were randomly assigned to control, mild, and severe diabetic groups, and the diabetes was induced by intraperitoneal administration of STZ. The experiment was carried out 10 days after STZ administration. Gastrocnemius red and white muscles were used fur the measurement of GLUT 4 expression. Plasma glucose levels of mild and severe diabetic rats were increased compared to control rats (control, mild, and severe diabetes; $6.4{\pm}0.32,\;9.4{\pm}0.68,\;and\;22.0{\pm}0.58$ mmol/L, respectively). Plasma insulin levels of mild and severe diabetic rats were decreased compared to control rats (control, mild, and severe diabetes; $198{\pm}37,\;l14{\pm}14,\;and\;90{\pm}15$ pmol/L, respectively). GLUT 4 mRNA levels of gastrocnemius red muscles in mild and severe diabetic rats were decreased compared to control rats ($64{\pm}1.2%\;and\;71{\pm}2.0%$ of control, respectively), but GLUT 4 mRNA levels in gastrocnemius white muscles were unaltered in diabetic rats. In summary, GLUT 4 mRNA levels were decreased in STZ-induced diabetic rats but did not correlated negatively with degree of hyperglycemia, and this result suggest that the regulatory mechanisms of decreased GLUT 4 mRNA levels are hypoinsulinemia and/or other metabolic factor but not hyperglycemia. And regulation of GLUT 4 expression in STZ-induced diabetes between red and white enriched skeletal muscles may be related to a fiber specific gene regulatory mechanism.