• Title/Summary/Keyword: chemical testing

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Subchronic oral toxicity study of Technical of IAP-3006 in Rats (IAP-3006원제의 랫드에 대한 아급성경구독성시험)

  • Seo, Dong-Seok;Kim, Jae-Young;Jeong, Jae-Hwang;Bark, Hak-Soo;Yu, Wook-Joon;Go, Sang-Beom;Kim, Jeong-Heon;Jang, Dong-Hyouk;Seo, Mu-Yeb;Cho, Bin-Haing;Sung, Ha-Jung
    • The Korean Journal of Pesticide Science
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    • v.7 no.4
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    • pp.271-279
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    • 2003
  • To investigate the toxicological effects of technical of IAP-3006, we performed subchronic oral toxicity study in Sprague-Dawley (SD) rats. In the subchronic dietary study, rats of both sexes were fed diets containing technical of IAP-3006 at concentrations of 0, 1000, 10,000, or 15,000 ppm for 90 days. No clinical signs and mortality were observed in animals treated with technical of IAP-3006 throughout the experimental period. There were also no significant changes in body weights, feed consumption, and any gross or histopathological lesions. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analyses, the data were in biologically normal ranges and did not show a dose-dependent manner. From these results, it is suggested that subchronic oral toxicity NOEL of technical of IAP-3006 in rats may be over 15,000 ppm.

Effect of D-(+)-Glucose on the Stability of Polyvinyl Alcohol Fricke Hydrogel Three-Dimensional Dosimeter for Radiotherapy

  • Yang, Yuejiao;Chen, Jie;Yang, Liming;Chen, Bin;Sheng, Zhenmei;Luo, Wenyun;Sui, Guoping;Lu, Xun;Chen, Jianxin
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.608-612
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    • 2016
  • D-(+)-glucose (Glc) was added to the original Fricke polyvinyl alcohol-glutaraldehyde-xylenol orange (FPGX) hydrogel dosimeter system to make a more stable FPGX hydrogel three-dimensional dosimeter in this paper. Polyvinyl alcohol was used as a substrate, which was combined with Fricke solution. Various concentrations of Glc were tested with linear relevant fitting for optimal hydrogel production conditions. The effects of various formulations on the stability and sensitivity of dosimeters were evaluated. The results indicated that D-(+)-Glc, as a free radical scavenger, had a great effect on stabilizing the dose response related to absorbency and reducing the auto-oxidization of ferrous ions. A careful doping with Glc could slow down the color change of the dosimeter before and after radiation without any effect on the sensitivity of the dosimeter.

Trend of In Silico Prediction Research Using Adverse Outcome Pathway (독성발현경로(Adverse Outcome Pathway)를 활용한 In Silico 예측기술 연구동향 분석)

  • Sujin Lee;Jongseo Park;Sunmi Kim;Myungwon Seo
    • Journal of Environmental Health Sciences
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    • v.50 no.2
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    • pp.113-124
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    • 2024
  • Background: The increasing need to minimize animal testing has sparked interest in alternative methods with more humane, cost-effective, and time-saving attributes. In particular, in silico-based computational toxicology is gaining prominence. Adverse outcome pathway (AOP) is a biological map depicting toxicological mechanisms, composed of molecular initiating events (MIEs), key events (KEs), and adverse outcomes (AOs). To understand toxicological mechanisms, predictive models are essential for AOP components in computational toxicology, including molecular structures. Objectives: This study reviewed the literature and investigated previous research cases related to AOP and in silico methodologies. We describe the results obtained from the analysis, including predictive techniques and approaches that can be used for future in silico-based alternative methods to animal testing using AOP. Methods: We analyzed in silico methods and databases used in the literature to identify trends in research on in silico prediction models. Results: We reviewed 26 studies related to AOP and in silico methodologies. The ToxCast/Tox21 database was commonly used for toxicity studies, and MIE was the most frequently used predictive factor among the AOP components. Machine learning was most widely used among prediction techniques, and various in silico methods, such as deep learning, molecular docking, and molecular dynamics, were also utilized. Conclusions: We analyzed the current research trends regarding in silico-based alternative methods for animal testing using AOPs. Developing predictive techniques that reflect toxicological mechanisms will be essential to replace animal testing with in silico methods. In the future, since the applicability of various predictive techniques is increasing, it will be necessary to continue monitoring the trend of predictive techniques and in silico-based approaches.

Effect of pH and Concentration on Electrochemical Corrosion Behavior of Aluminum Al-7075 T6 Alloy in NaCl Aqueous Environment

  • Raza, Syed Abbas;Karim, Muhammad Ramzan Abdul;Shehbaz, Tauheed;Taimoor, Aqeel Ahmad;Ali, Rashid;Khan, Muhammad Imran
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.213-226
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    • 2022
  • In the present study, the corrosion behavior of aluminum Al-7075 tempered (T-6 condition) alloy was evaluated by immersion testing and electrochemical testing in 1.75% and 3.5% NaCl environment at acidic, neutral and basic pH. The data obtained by both immersion tests and electrochemical corrosion tests (potentiodynamic polarization and electrochemical impedance spectroscopy tests) present that the corrosion rate of the alloy specimens is minimum for the pH=7 condition of the solution due to the formation of dense and well adherent thin protective oxide layer. Whereas the solutions with acidic and alkaline pH cause shift in the corrosion behavior of aluminum alloy to more active domains aggravated by the constant flux of acidic and alkaline ions (Cl- and OH-) in the media which anodically dissolve the Al matrix in comparison to precipitated intermetallic phases (cathodic in nature) formed due to T6 treatment. Consequently, the pitting behavior of the alloy, as observed by cyclic polarization tests, shifts to more active regions when pH of the solutions changes from neutral to alkaline environment due to localized dissolution of the matrix in alkaline environment that ingress by diffusion through the pores in the oxide film. Microscopic analysis also strengthens the results obtained by immersion corrosion testing and electrochemical corrosion testing as the study examines the corrosion behavior of this alloy under a systematic evaluation in marine environment.

Development of a Chloroform Reference Material for the Proficiency Testing of Hazardous Compounds in Commercial Consumer Chemical Products Under the Consumer Chemical Products and Biocide Safety Management Act (K-BPR)

  • Lee, Sang Tak;Lee, Jae-ung;Kim, Joo-Hyon;Oh, Han Bin
    • Mass Spectrometry Letters
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    • v.10 no.4
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    • pp.112-116
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    • 2019
  • In this study, a chloroform consumer chemical product (CCP) reference material (RM) is successfully developed, with potential to be used in the proficiency testing of hazardous compounds in CCPs for analysis and testing agencies. Validation experiments are rigorously conducted to evaluate whether the RM meets the requirements set by the ISO 13528 and ISO Guide 35, using a reliable GC/MS method for the analysis of chloroform. The obtained calibration plot linearity, limit of detection (LOD), and limit of quantitation (LOQ) are excellent. The developed RM meets the homogeneity and stability requirements; the between-unit (sbb) and within-unit (swb) standard deviations are less than 2.5%, and the stability is found to be guaranteed for 50 days.

Developing a Testing Method for Antimicrobial Efficacy on TiO2 Photocatalytic Products

  • Kim, Jee-Yeon;Park, Chang-Hun;Yoon, Je-Yong
    • Environmental Engineering Research
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    • v.13 no.3
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    • pp.136-140
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    • 2008
  • $TiO_2$ photocatalyst has been known to exhibit a notable disinfecting activity against a broad spectrum of microorganisms. A lot of commercial $TiO_2$ photocatalyst products have been developed for antimicrobial purposes. However, a standard method has not yet been proposed for use in testing antimicrobial activity. In this study, we developed a $TiO_2$ photocatalytic adhesion test method with film as the standard testing method for the evaluation of antimicrobial activity. This method was devised by modifying the previous antimicrobial products test method, which has been widely used, and considering the characteristics of $TiO_2$ photocatalytic reaction. The apparatus for testing the antimicrobial activity was composed of a Black Light Blue (BLB) lamp as UV-A light source, a Petri dish as the cover material, and a polypropylene film as the adhesion film. The standard $TiO_2$ photocatalyst sample, Degussa P25 $TiO_2$ - coated glass, could only be used once. The optimal initial concentration of the microorganism, proper light intensity, and light irradiation time were determined to be $10^6$ CFU/mL, 1.0 mW/$cm^2$, and 3 hr, respectively, for testing and evaluating antimicrobial activity on the $TiO_2$ surface.

A Study on the Light Cylinder Using Chemical Milling (케미컬 밀링을 이용한 실린더 경량화 연구)

  • Yoo Joon-Tae;Yoon Jong-Hoon;Jang Young-Soon;Yi Yeong-Moo;Kang Suk-Bong;Lee Jong-Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.4 s.247
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    • pp.451-456
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    • 2006
  • The process for reducing the weight of the structure is chiefly performed by the machine processing. But, increasing the weight for strength of welding zone and geometrical defect are occurred in machine processing. In this study, chemical milling is applied to reduce the weight of the cylinder. Before chemical milling is applied to the cylinder, specimen testing is performed. After the specimen testing, NaOH 15% is selected to perform the chemical milling. After the chemical milling, the velocity of reagent is 0.0016 mm/min and the thickness of cylinder is about 2.4 mm after chemical milling.

Atomic Absorption Spectrophotometric Analysis of Chromium, Nickel and Manganese in Stainless Steel (原子吸光分析에 의한 鋼鐵속에 있는 Cr, Mn 및 Ni 의 定量)

  • Hwang, Jae-Young;Tagliamonti, Josep J.;Parsons, Frank B.
    • Journal of the Korean Chemical Society
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    • v.10 no.3
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    • pp.133-135
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    • 1966
  • Rapid methods for determining chromium, nickel, and manganese in stainless steel by atomic absorption spectrophotometer are described. Use of suitable standards eliminates the need to separate each element prior to analysis. Comparison with the conventional wet chemical analysis shows that atomic absorption spectrophotometer is a reliable analytical tool in these applications.

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A Study on the Chemical Cleaning Process and Its Qualification Test by Eddy Current Testing

  • Shin, Ki Seok;Cheon, Keun Young;Nam, Min Woo;Min, Kyong Mahn
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.6
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    • pp.511-518
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    • 2013
  • Steam Generator (SG) tube, as a barrier isolating the primary coolant system from the secondary side of nuclear power plants (NPP), must maintain the structural integrity for the public safety and their efficient power generation. So, SG tubes are subject to the periodic examination and the repairs if needed so that any defective tubes are not in service. Recently, corrosion related degradations were detected in the tubes of the domestic OPR-1000 NPP, as a form of axially oriented outer diameter stress corrosion cracking (ODSCC). According to the studies on the factors causing the heat fouling as well as developing corrosion cracking, densely scaled deposits on the secondary side of the SG tubes are mainly known to be problematic causing the adverse impacts against the soundness of the SG tubes [1]. Therefore, the processes of various cleaning methods efficiently to dissolve and remove the deposits have been applied as well as it is imperative to maintain the structural integrity of the tubes after exposing to the cleaning agent. So qualification test (QT) should be carried out to assess the perfection of the chemical cleaning and QT is to apply the processes and to do ECT. In this paper, the chemical cleaning processes to dissolve and remove the scaled deposits are introduced and results of ECT on the artificial crack specimens to determine the effectiveness of those processes are represented.