• Corrosion Science and Technology
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• v.14 no.1
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• pp.19-24
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• 2015

Flow Accelerated Corrosion (FAC) causes unexpected accidents in a secondary side of a nuclear power plant. The secondary side pipes are mainly carbon steel tubes that have a protective magnetite ($Fe_3O_4$) layer on the inner surface. The stability of the protective magnetite layer depends on the parameters related to the FAC phenomena such as pH, temperature, flow rate, surface roughness etc. The dissolution of magnetite is basically the electrochemical reaction, but the most of the experiments of magnetite dissolution were carried out thermodynamically to determine the solubility of magnetite. The knowledge of the electrochemical properties of magnetite is required to understand the dissolution process of magnetite. This paper reviews the manufacture of the magnetite ($Fe_3O_4$) electrode, and summaries the electrochemical properties of the magnetite.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1285-1292
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• 2016

Background: It is well established that mutations in the BRCA1 gene are a major risk factor for breast cancer. Induction of cancer cell death and inhibition of survival are the main principles of cancer therapy. In this context, autophagy may have dual roles in cancer, acting on the one hand as a tumor suppressor and on the other as a mechanism of cell survival that can promote the growth of established tumors. Therefore, understanding the role of autophagy in cancer treatment is critical. Moreover, defects in apoptosis, programmed cell death, may lead to increased resistance to chemotherapy. Purpose: The aim of the present study was to detect BRCA1 gene mutations in order to throw more light on their roles as risk factors for breast cancer in Egypt. Secondly the role of autophagy and apoptosis in determining response to a fluorouracil, doxorubicin, cyclophosphamide (FAC) regimen was investigated. Materials and Methods: Forty-five female breast cancer cases and thirty apparently healthy females were enrolled in the present study. Serum levels of autophagic biomarkers, Beclin 1 and LC3 as well as the serum levels of apoptosis biomarkers Bcl-2 and Caspase-3 were measured before and after chemotherapy. Results: BRCA1 mutations were found in 5 (16.7%) and 44 (99.8%) of the controls and cancer patients, the most frequent being 5382insC followed by C61G and 185 delAG. The results revealed that chemotherapy caused elevation in serum concentration levels of the autophagic biomarkers (Beclin 1 and LC3). This elevation was associated with a significant decrease in serum concentration levels of Bcl-2 and significant increase in caspase-3 concentration levels (apoptotic markers). Conclusions: The results of the present study indicate a very high level of BRCA mutations in breast cancer cases in Egypt and point to involvement of autophagic and apoptotic machinery activation in response to FAC chemotherapy.

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1595-1603
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• 2002

In this paper we have presented the results of diffusion behavior of model systems for eight liquid n-alkanes ($C_{12}$-$C_{44}$) in a canonical (NVT) ensemble at several temperatures using molecular dynamics simulations. For these n-alkanes of small chain length n, the chains are clearly <$R_{ee}^2$>/6<$R_g^2$>>1 and non-Gaussian. This result implies that the liquid n-alkanes over the whole temperatures considered are far away from the Rouse regime, though the ratio becomes close to the unity as n increases. Calculated self-diffusion constants $D_{self}$ are comparable with experimental results and the Arrhenius plot of self-diffusion constants versus inverse temperature shows a different temperature dependence of diffusion on the chain length. The global rotational motion of n-alkanes is examined by characterizing the orientation relaxation of the end-to-end vector and it is found that the ratio ${\tau}1/{\tau}2$ is less than 3, the value expected for a isotropically diffusive rotational process. The friction constants ${\xi}$of the whole molecules of n-alkanes are calculated directly from the force auto-correlation (FAC) functions and compared with the monomeric friction constants ${\xi}_D$ extracted from $D_{self}$. Both the friction constants give a correct qualitative trends: decrease with increasing temperature and increase with increasing chain length. The friction constant calculated from the FAC's decreases very slowly with increasing temperature, while the monomeric friction constant varies rapidly with temperature. By considering the orientation relaxation of local vectors and diffusion of each site, it is found that rotational and translational diffusions of the ends are faster than those of the center.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4270-4274
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• 2011

A method is proposed for determining chromium content in the carbon steel pipes of a nuclear power plant (NPP) to evaluate wall thinning caused by flow-accelerated corrosion (FAC). A flat file was used to obtain filings samples. To assess sampling quality, a disk form of SRM 1227 was ground with the flat file, and the amount of Cr in the filings was determined by ICP-AES. The content of chromium in the filings of SRM 1227 was estimated as six times higher than the certified value due to the contamination of chromium in the file. To eliminate chromium contamination from the file, it was coated with WC-12Co using high-velocity oxygen-fuel (HVOF) spraying systems. After obtaining filings samples using the coated file, Cr content in four types of disk-form SRMs was determined by ICP-AES. The recoveries of Cr in the disk-form SRMs were in the range of 95.4-102.6%, with relative standard deviations from 0.43 to 3.0%. The Cr contents in the filings collected from the used outlet headers of the nuclear power plants using the flat file coated were in the range of 0.11-0.19%.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.194-200
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• 1998

The difference in leaf bud flushing times of Quercus species and their hybrids was compared among the trees from natural forest, seedlings from natural pollination and artificial crossing. In the natural forest of the Hiruzen experimental forest of Tottori University, Japan, Quercus species flushed in the order of Q. crispula > Q. anguste-lepidota > Q. takatorensis ${\fallingdotseq}$ Q. serrate > Q. dentata. The flushing time of seedlings from natural pollination was in the order of Q. aliena ${\fallingdotseq}$ Q. crispula > Q. angustelepidota > Q. takatorensis ${\fallingdotseq}$ Q. serrate > Q. dentata. The flushing times of $F_1$ hybrids by artificial crossing were between those of parental species. From the result of interspecific hybridization, it is shown that the earliness of flushing in Quercus species is a genetic character considered hereditable to progenies.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.53-58
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• 2010

Purpose: Our goal was to determine the difference in motor recovery between two stroke types: the corona radiata (CR) infarct type and the intracerebral hemorrhage (ICH) type, by using assessment methods for motor functions. Methods: Forty subjects who were diagnosed as having had a stroke with an infarct (men: 11, women: 9, mean age: $62.25{\pm}7.59$) or a stroke with an ICH (men: 12, women: 8, mean age: $59.75{\pm}6.11$) were recruited. In all subjects, motor functions of the affected extremities were measured 2 times: at stroke onset (initial) and 6 months after the onset (final) by the motricity index (MI), the modified Brunnstrom classification (MBC), and functional ambulatory category (FAC). We compared the final assessment with the initial one. Results: Motor functions of all patients improved with the passing of time. All scores of motor function assessment in the ICH type were higher than in the infarct type. Comparing the initial assessment with the final one, upper MI and MBC scores of the upper extremities were significantly different between the two stroke types (p<0.05), but lower MI and FAC scores of the lower extremities were not (p>0.05). Conclusion: These findings imply that patterns of motor recovery in patients with either the infarct type or the ICH type of stroke change for the better over time. The degree of motor recovery in the ICH type was better than in the infarct type. Therefore, one can introduce clinical interventions by the aspect of progress in functional motor recovery.

• The Journal of Korean Physical Therapy
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• v.25 no.3
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• pp.126-131
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• 2013

This case report described a single case of adult stoke patient due to Moyamoya disease through long-term follow-up observation, which included his demographics, brain images, and change of motor function and functional activities. The subject was the 54-year-old male diagnosed with left hemiparesis from a stroke due to multifocal encephalomalacia in both hemispheres. At the time of the stroke attack, he took brain surgery intervention including external ventricular drain. Physical and occupational therapy for stroke rehabilitation were admitted including muscle strengthening exercises, functional activity/ADL training, neurofacilitative techniques with bobath or proprioceptive neuromuscular facilitation concepts, and compensatory strategy. Patient's MRI showed that right frontal lobe, right peri-ventricular area, left parietal, and left occipital lobes were damaged, and MRA showed that abnormal collateral vessel was richly developed in both hemispheres by occlusion of proximal internal carotid arteries in both sides. His motor strength was improved from poor to good grade in all of upper and lower limb motions, that MBC was improved from stage 1 to stage 5. In FAC and barthel index, at the initial evaluation, he could not perform any functional movement, but his FAC and barthel index were on 3 and 14 points at present, respectively. During long-term follow-up for approximately 4 years, the subject's functional motor ability was improved, as similar with recovery progression of usual stroke patient. We believe that this single case report will provide clinical information and concern regarding Moyamoya disease with physical therapist, in terms of such as epidemiology, pathogenesis, diagnostic procedures, clinical features, recovery process, and prognosis.

• Nuclear Engineering and Technology
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• v.42 no.5
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• pp.568-575
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• 2010

Flow Accelerated Corrosion is an active degradation mechanism of CANDU feeder. The tight bend downstream to Gray loc weld connection, close to reactor face, suffers significant wall thinning by FAC. Extensive in-service inspection of feeder wall thinning is very difficult because of the intense radiation field, complex geometry, and space restrictions. Development of a knowledge-based inspection program is important in order to guarantee that adequate wall thickness is maintained throughout the whole life of feeder. Research results and plant experiences are reviewed, and the plant inspection databases from Wolsong Units One to Four are analyzed in order to support developing such a knowledge-based inspection program. The initial thickness before wall thinning is highly non-uniform because of bending during manufacturing stage, and the thinning rate is non-uniform because of the mass transfer coefficient distributed non-uniformly depending on local hydraulics. It is obvious that the knowledge-based feeder inspection program should focus on both fastest thinning locations and thinnest locations. The feeder wall thinning rate is found to be correlated proportionately with QV of each channel. A statistical model is proposed to assess the remaining life of each feeder using the QV correlation and the measured thicknesses. W-1 feeder suffered significant thinning so that the shortest remaining life barely exceeded one year at the end of operation before replacement. W-2 feeder showed far slower thinning than W-1 feeder despite the faster coolant flow. It is believed that slower thinning in W-2 is because of higher chromium content in the carbon steel feeder material. The average Cr content of W-2 feeder is 0.051%, while that value is 0.02% for W-1 feeder. It is to be noted that FAC is reduced substantially even though the Cr content of W-2 feeder is still very low.

• Corrosion Science and Technology
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• v.12 no.3
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• pp.125-131
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• 2013

The most common pipe wall thinning degradation mechanisms that can occur in the steam and feedwater systems are FAC (Flow Acceleration Corrosion), cavitation, flashing, and LDIE (Liquid Droplet Impingement Erosion). Among those degradation mechanisms, FAC has been investigated by many laboratories and industries. Cavitation and flashing are also protected on the piping design phase. LDIE has mainly investigated in aviation industry and turbine blade manufactures. On the other hand, LDIE has been little studied in NPP (Nuclear Power Plant) industry. This paper presents the development of prediction system for pipe wall thinning caused by LDIE in terms of erosion rate based on air-water ratio and material. Experiment is conducted in 3 cases of air-water ratio 0.79, 1.00, and 1.72 using the three types of the materials of A106B, SS400, and A6061. The main control parameter is the air-water ratio which is defined as the volumetric ratio of water to air (0.79, 1.00, 1.72). The experiments were performed for 15 days, and the surface morphology and hardness of the materials were examined for every 5 days. Since the spraying velocity (v) of liquid droplets and their contact area ($A_c$) on specimens are changed according to the air-water ratio, we analyzed the behavior of LDIE for the materials. Finally, the prediction equations(i.e. erosion rate) for LDIE of the materials were determined in the range of the air-water ratio from 0 to 2%.

• 모자간호학회지
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• v.4 no.1
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• pp.68-79
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• 1994

This study measured variables influencing the breast feeding patterns of lactating mothers over a 40 day period In 1993 in the Jeonla area. The Methodology used was a questionnaire covering 92 items based on statistical discriminant analysis. The results were as follows : The successful group was measured against the unsuccessful group over a 4month lactation period ; The successful group was measured over a 4month lactation period ; the unsuccessful less than 4month lactation period. Principal factor analysis was used to generate comparative data factors which were ; 1) nonunderstanding of mother's breast feeding, 2) physical and psychological stress, 3) insufficient milk supply, 4) mother's negative acceptance of baby, 5) lack of spousal support, 6) sore nipple and breast pain, 7) baby's negative acceptance, 8) lack of familial support, 9) baby's diarrhea and watery milk. Discriminant statistical analysis of sever factors included ; 1) insufficient milk supply 2) sore nipple and breast pain, 3) pre-natal planning of breast feeding method, 4) mother's occupation 5) breast feeding method of previous infant, 6) nipple type, and 7) infant birth order. This analysis predicted a 78.9% successful breast feeding. Criterion correlation analysis revealed ; D=-1.780+.165$\times$(Fac3)+.135$\times$(Fac6)+.927$\times$(prenatal planning of breast feeding method)+.900$\times$(mother's occupation)+.675$\times$ (breast feeding method of previous infant)+1.0l4$\times$(nipple type)+.378$\times$(infant birth order). We classified the unsuccessful group as more than .63937 and the successful group less than -.82742 of the D value obtained from the above criterion correlation in order to check the success or the non-success of breast feeding mothers. The rate of correct classification of the grouped cases employing a statistical discriminant analysis was significantly improved to 78.9% when these cases were compared with the actual grouped classification.