• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.246-252
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• 2018

A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.2
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• pp.119-124
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• 2014

In order to understand those factors to influence the hearing-impaired in connection with their using hearing aids, this study analyzed a total of 521 hearing-impaired people examined by a fourth-year Korea panel survey of employment for the disabled. For the analysis, the study, first, used Andersen-Newman service use model to categorize any influential factors into precedence factors, possibility factors and desire factors, and second, in order to look into how these factors would work on the hearing-impaired's using the hearing aids, the study conducted the logistic regression analysis. According to the results of the analysis, in terms of the precedence factors, when the hearing-impaired people are older and more highly-educated, they would be happier to use the hearing aids while when it comes to the possibility factors, when the gross income of these people is lower but when they are more willing to accept the fact that they have a disability, they would have a fewer problems with using the hearing aids. In addition, regarding the desire factors, when the hearing-impaired people can hear relatively better than the other hearing-impaired, they would be more significantly willing to use the hearing aids. In the light of what has been learned, the study discussed the limits of its research and proposed implications.

• Safety and Health at Work
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• v.6 no.4
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• pp.268-278
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• 2015

Background: This study aimed to assess the whole-body vibration (WBV) exposure among large blast hole drill machine operators with regard to the International Organization for Standardization (ISO) recommended threshold values and its association with machine- and rock-related factors and workers' individual characteristics. Methods: The study population included 28 drill machine operators who had worked in four opencast iron ore mines in eastern India. The study protocol comprised the following: measurements of WBV exposure [frequency weighted root mean square (RMS) acceleration ($m/s^2$)], machine-related data (manufacturer of machine, age of machine, seat height, thickness, and rest height) collected from mine management offices, measurements of rock hardness, uniaxial compressive strength and density, and workers' characteristics via face-to-face interviews. Results: More than 90% of the operators were exposed to a higher level WBV than the ISO upper limit and only 3.6% between the lower and upper limits, mainly in the vertical axis. Bivariate correlations revealed that potential predictors of total WBV exposure were: machine manufacturer (r = 0.453, p = 0.015), age of drill (r = 0.533, p = 0.003), and hardness of rock (r = 0.561, p = 0.002). The stepwise multiple regression model revealed that the potential predictors are age of operator (regression coefficient ${\beta}=-0.052$, standard error SE = 0.023), manufacturer (${\beta}=1.093$, SE = 0.227), rock hardness (${\beta}=0.045$, SE = 0.018), uniaxial compressive strength (${\beta}=0.027$, SE = 0.009), and density (${\beta}=-1.135$, SE = 0.235). Conclusion: Prevention should include using appropriate machines to handle rock hardness, rock uniaxial compressive strength and density, and seat improvement using ergonomic approaches such as including a suspension system.

• Safety and Health at Work
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• v.2 no.4
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• pp.348-354
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• 2011

Objectives: This cross-sectional study was performed in the Dental School of Prince of Songkla University to ascertain noise exposure of dentists, dental assistants, and laboratory technicians. A noise spectral analysis was taken to illustrate the spectra of dental devices. Methods: A noise evaluation was performed to measure the noise level at dental clinics and one dental laboratory from May to December 2010. Noise spectral data of dental devices were taken during dental practices at the dental services clinic and at the dental laboratory. A noise dosimeter was set following the Occupational Safety and Health Administration criteria and then attached to the subjects' collar to record personal noise dose exposure during working periods. Results: The peaks of the noise spectrum of dental instruments were at 1,000, 4,000, and 8,000 Hz which depended on the type of instrument. The differences in working areas and job positions had an influence on the level of noise exposure (p < 0.01). Noise measurement in the personal hearing zone found that the laboratory technicians were exposed to the highest impulsive noise levels (137.1 dBC). The dentists and dental assistants who worked at a pedodontic clinic had the highest percent noise dose (4.60 ${\pm}$ 3.59%). In the working areas, the 8-hour time-weighted average of noise levels ranged between 49.7-58.1 dBA while the noisiest working area was the dental laboratory. Conclusion: Dental personnel are exposed to noise intensities lower than occupational exposure limits. Therefore, these dental personnel may not experience a noise-induced hearing loss.

• Analytical Science and Technology
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• v.34 no.5
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• pp.212-224
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• 2021

The intent of the present work was to develop a simple, sensitive, accurate, precise, rapid and economical UV- spectrophotometric and reverse phase high pressure liquid chromatographic method for the simultaneous estimation of Spironolactone and Furosemide in bulk and combined tablet dosage forms. UV-Spectrophotometry was carried out by simultaneous equation method using 0.02 M potassium dihydrogen phosphate buffer pH 3.5: Acetonitrile (50:50) v/v as a solvent. The linearity range was 2-14 ㎍ mL^-1 for Spironolactone and Furosemide with a correlation coefficient > 0.99. The chromatographic separation was achieved on 250 mm × 4.6 mm, hypersil BDS C18 column with particle size 5 ㎛, by using an isocratic mixture of 0.02 M potassium dihydrogen phosphate buffer pH 3.5: Acetonitrile: tert butyl methyl ether (49:50:1) v/v/v as a solvent at a flow rate of 1 mL min^-1 and UV detection was carried out at 254 nm. The retention time were observed to be 3.666 and 6.661 minutes for Furosemide and Spironolactone respectively. The two developed methods were validated according to the ICH guidelines for accuracy, precision, linearity, LOD, LOQ and were found to be within the limits. It can be concluded that these two methods could be successfully used for the simultaneous estimation of Spironolactone and Furosemide in bulk and combined tablet dosage forms.

• Safety and Health at Work
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• v.12 no.4
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• pp.439-444
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• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

• The Journal of Internal Korean Medicine
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• v.41 no.6
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• pp.1078-1088
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• 2020

Objective: The purpose of this study was to investigate the effect of amorfrutin of licorice for Type2 diabetes mellitus. Method: The PubMed, CNKI, Wanfang, OASIS, NDSL, J-STAGE, and CiNii databases were searched from the beginning of the search to September 20, 2020, with no limits on language. Extractions and selections from the literature were made by two authors. The study included in vivo experiments with amorfrutins in high-fat diet-induced obesity C57BL/6 mice and leptin receptor-deficient db/db mice and in silico studies. Results & Conclusion: Four studies were finally selected. We confirmed that amorfrutin treatment considerably improved insulin sensitivity and glucose tolerance and reduced plasma insulin and glucose. Amorfrutins bind to and selectively activate Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), which plays an important role in glucose metabolism. Amorfrutins also strongly bind to the glucagon receptor (GCGR) and work as antagonist. Using the amorfrutins from licorice could therefore be helpful in treating type2 diabetes mellitus.

• Natural Product Sciences
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• v.27 no.2
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• pp.128-133
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• 2021

The Coumarin (1,2-benzopyrone) is the main secondary metabolite of Mikania laevigata Sch. Beep ex Baker and Mikania glomerata Spreng., which are popularly known as guaco. These plants have been used mainly in traditional medicine in the treatment of respiratory diseases because their bronchodilator effect. However, there are around 200 species of Mikania, which are quite similar in appearance. From these, only M. leavigata and M. glomerata have high concentrations of coumarins. In this line, the falsification of products Mikania based has been frequent. In this sense, this work demonstrated the application of the easy, fast, e not destructive method based in Nuclear Magnetic Resonance in quantitative mode (qNMR) for the determination of coumarin in both commercial and homemade guaco products. Thus, in the first step the compounds were extract from guaco leaves and syrups using chloroform (CHCl₃), with or without ultrasound. About the method, was linear with a R² = 0.9947 for 1,2-benzopyrone, with detection and quantification limits with were 0.11 and 0.36 mg mL^-1 respectively. In the same line, the method was safe with RSD <0.3% and with recovery ranging from 93-101%. To confirm the applicability of the method, in the last step was applied to 10 real samples (6 from leaves and 4 from syrups). The content of the coumarin in the leaf extract ranged from 0.62 to 1.30 mg mL^-1. For syrups I, II and IV, the content of coumarin was in accordance with the manufacturers. However, for de Syrup III, the concentration was 155% higher. In summary, the qNMR is a rapid method with minimal sample preparation that can be used to quantify coumarin in home-made plant extracts as well as in commercial samples as syrup for instance. This method is applicable for quality control of different plants-based products.

• Journal of Astronomy and Space Sciences
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• v.38 no.1
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• pp.1-21
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• 2021

The observation of stellar occultations constitutes one of the most important techniques for determining the dimensions and establishing the physical parameters of small Solar System bodies. The most substantial calculations are obtained from multiple observations of the same event, which turns the observation of stellar occultations into highly collaborative work and groups teams of observers through international networks. The above situation also requires the participation of both professional and amateur observers in these collaborative networks. With the aim of promoting the participation of professional and amateur groups in the collaborative observation of stellar occultations, we present the methodology developed by the Astronomical Observatory of the Technological University of Pereira (OAUTP) for the observations of occultations due small Solar System bodies. We expose the three fundamental phases of the process: the plan to make observations, the capture of the events, and the treatment of the data. We apply our methodology using a fixed station and a mobile station to observe stellar occultations due to MBAs (354) Eleonora (61) Danae (15112) Arlenewolfe (3915) Fukushima (61788) 2000 QP181 (425) Cornelia (257) Silesia (386) Siegena and (41) Daphne, and due to TNOs 1998BU48 and (529823) 2010 PP81. The positive detections for the objects (257) Silesia (386) Siegena and (41) Daphne allow us to derive lower limits in the diameter of the MBAs of 63.1 km, 166.2 km and 158.7 km and offsets in the astrometric position (Δαc cos��c, Δ��c) of 622.30 ± 0.83, 15.23 ± 9.88 mas, 586.06 ± 1.68, 43.03 ± 13.88 mas and -413.44 ± 9.42, 234.05 ± 19.12 mas, respectively.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.273-282
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• 2022

The narrative of the film, Sweet Smell of Success has a multi-layered structure. In Clifford Odets's scenario work, numerous lines for the main plot and subplots repeated a cycle of creation, decomposition, deletion, and modification to enhance the density of the story. As a result, whenever an actor spoke a line or paused, an action or an event that would trigger another line was created, giving depth and persuasiveness to the character's performance. The music of Sweet Smell of Success has multi-layered elements. The non-diegetic music was covered by the orchestral pieces performed by Elmer Bernstein's big band orchestra and the jazz pieces performed by Fred Katz's combo band. The diegetic music was mostly covered by the jazz pieces performed by the Chico Hamilton Quintet. The practical task of the film music was to reinforce or supplement the effect of the narrative driver, and the additional task was to realize the estrangement effect and the aesthetics of stagnation. The possibility and significance of intertextuality of subplots and double sound of this film are not simply confined to the limits of the film noir genre.