• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.66-74
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• 2016

Environmental pollution from abandoned metal mines has been awarded as serious problem and many techniques have been applied to remediate pollutants. Main objective of this research was to evaluate efficiency of heavy metal sorption capacity of spent mushroom media (SMM) in aqueous and soil matrix. Laboratory batch experiment was conducted and 4 different heavy metals (Cd, Pb, Cu, Zn) were evaluated. In aqueous phase, all 4 heavy metals showed high reduction efficiency ranged from 60-99% and Pb showed the highest sorption efficiency. In case of soil phase, much lower sorption efficiency was observed compared to aqueous phase. The highest reduction efficiency was observed in Cd (average of 38%). With scanning electron microscopy energy dispersive detector (SED-EDS) analysis, we confirmed sorption of heavy metals at the surface of SMM. Overall, SMM can be used as sorption materials for heavy metals in both aqueous and soil matrix and more research should be conducted to increase sorption efficiency of SMM in soil.

• Analytical Science and Technology
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• v.13 no.3
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• pp.282-290
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• 2000

In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-Vis spectroscopy, FT-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants (primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak $C_{18}$ column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt% by a quantitative analysis through UV spectroscopy.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.303-308
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• 1997

In this paper, we analyzed the spectroscopic properties of strip to analyzer urine qualitatively & quantitatively and make urine analyzer system stable by spectroscopy, and research the property of preamplifier unit. The analysis of spectroscopic properties of 10 pads in the strip is used for determine the wave length of light source of optic detector unit and used for basic materials which are necessary that we develop the algorithm analyzing the density grade of pad accurately. We make preamplifier unit by using the current to frequency method to measure the distribution of pad color. We implemented urine analyzer system. This system's hardware is composed of measuring unit for detect of distribution density of strip pad, main processing unit, communication unit, interface device, thermal printer, and indicator. The software consists of the program which manage the argument of test, proportion initial value of urine analyzer and calibrate analyzed result.

• Imaging Science in Dentistry
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• v.40 no.1
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• pp.33-38
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• 2010

Purpose : The purpose of this study was to evaluate the diagnostic efficacy of panoramic radiographs for detection of mandibular fractures. Materials and Methods : The sample was comprised of 65 patients (55 fractured, 10 non-fractured) with 92 fracture sites confirmed by multi-detector computed tomography (CT). Panoramic radiographs were evaluated for mandibular fractures by six examiners; two oral & maxillofacial radiologists (observer A&B), two oral & maxillofacial surgeons (observer C&D), and two general dentists (observer E&F). Results : Sensitivity of panoramic radiography for mandibular fractures was 95.7% in observer A&B, 93.5% in observer C&D and 80.4% in observer E&F. The lowest sensitivity was shown in symphyseal/parasymphyseal areas, followed by subcondylar/condylar regions. Conclusion : Panoramic radiography is adequate for detection of mandibular fractures. However, additional multidetector CT is recommended to ascertain some indecisive fractures of symphysis and condyle, and in complicated fractures.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.85-91
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• 2001

The regulation of Material safety data sheets(MSDS) was required for the chemicals in use in the workplace from July 1976. Under the provisions of the workplace hazardous materials information system, employers in Korea must be provided with accurate and comprehensive MSDS. To examine the reliability of MSDS for organic solvents, 63 organic solvents and MSDS were collected from the workplace of 39 companies located in Kyonggi province. Manufacture\`s MSDS were compared with the actual composition of the collected samples, and further examined the reliability by checking whether the chemicals analyzed were included in the MSDS correctly. 38 solvents were able to analyze their composition by gas chromatography-mass selective detector(GC-MSD). Among them, 28 solvents were incorrect in their composition and contents. In some case, health hazardous or carcinogenic chemicals which were not included in the MSDS were detected from samples. As a result of evaluating whether the MSDS correspond to the regulation required by Industrial Safety and Health Act (ISHA), the information in the MSDS including hazard classification, occupational exposure level, toxicity, regulatory information were incorrectly provided, and some MSDS did not disclose carcinogenic in their MSDS, and some MSDS were not written in the standard format. From this survey, continuous monitoring and promoting correct MSDS, and analyzing the components of the solvents were required to endure the reliability of MSDS for organic solvents.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.668-672
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• 2005

In this paper, a distance measuring system using a PSD sensor in proposed, which in suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. The parameters of the proposed function are extracted by using the measured data. Finally, the performance and the accuracy of the developed system are verified according to the comparison of the distance by the proposed function with the real distance.

• Geotechnical Engineering
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• v.7 no.1
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• pp.7-14
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• 1991

Determination of dynamic shear modulus of soil was made by measuring directly the velocity of ultrasonic shear waves transmitted through the specimen. The PUNDIT, a generator and detector of ultrasonic waves, has been used to measure the propagation velocity. Forty -six tests of compacted soil at seven different void ratios and seven varying degrees of saturation with four types of materials were made in this study. The primary importance in this study was the investigation of the relations among the para meters which influenced G-modulus, As a results of analysis, the dynamic shear modulus of soil tends to decrease with an increase of void ratio, and also it is affected by soil types. In case of using PUNDIT, the proper range of the specimen length is from 5cm to 8cm. And the degree of saturation doesn't affect the dyn- amic shear modulus of soil.

• Electrical & Electronic Materials
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• v.10 no.3
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• pp.233-238
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• 1997

We have investigated gas-detection characteristics of CuTBP (Copper-tetra-tert-butylphthalocyanine) chemiresistor devices exposed to air/200ppm N $O_{2}$ gases. The CuTBP films were made by Langmuir-Blodgett (LB) techniques. Sensitivity, response time, recovery time, and reproducibility of the devices were measured by current voltage characteristics. Interdigital electrode was used to improve the sensitivity. It was observed that a conductance G increases monotonically as the number of interdigital electrode finger pairs increases. As the number of interdigital electrode finger pairs increases, the sensitivity S( $G_{gas}$/ $G_{air}$) increases more than 50 times and stable. But the response time was delayed. The average recovery time of the CuTBP chemiresistor devices turned out to be about 100 second. We have also investigated applicability of the CuTBP chemiresistor device for a gas sensor.sor.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7897-7903
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• 2015

Background: To explored the value of 3D C-arm CT (CACT) guidance system in performing radiofrequency ablation (RFA) following transarterial chemoembolizationon (TACE) for hepatocellular carcinomas. Materials and Methods: RFA of hepatocellular carcinomas (HCC) were performed on 15 patients (21 lesions) with the assistance of CACT guidance system. Technical success, procedure time, complications and patient radiation exposure were investigated. The puncture performance level was evaluated on a five-point scale (5-1: excellent-poor). Complete ablation rate was evaluated after two months follow-up using enhanced CT scans. Results: The technical success rate of RFA procedure under CACT navigation system was 100 %. Mean total procedure time was $24.24{\pm}6.53min$, resulting in a mean effective exposure dose of $15.4{\pm}5.1mSv$. The mean puncture performance level rated for CACT guided RFA procedure was $4.87{\pm}0.35$. Complete ablation (CA) was achieved in 20 (95.2%) of the treated 21 tumors after the first RFA session. None of patients developed intra-procedural complications. Conclusions: 3D CACT guidance system enables reliable and efficient needle positioning by providing real-time intraoperative guidance for performing RFA on HCCs.

• Progress in Superconductivity and Cryogenics
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• v.6 no.2
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• pp.46-51
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• 2004

This paper presents the results of a series of performance and reliability tests for the Stirling cryocooler. Infrared sensor systems incorporating cryocoolers are required to be qualified to the appropriate specification for the performance and reliability. FPFD Stirling cryocooler is currently under development for cooling infrared detector. Manufactured Stirling cryocooler delivers approximately 0.9W cooling at 80K for 30W∼40W of input power. It takes approximately 2 minutes to cool down to 80K at the ambient temperature of 23$^{\circ}C$. Performance characteristics for the vibration, acoustic noise, EMI and leak rate of the Stirling cryocooler are evaluated. We performed low and high temperature keeping test from -32$^{\circ}C$ to +52$^{\circ}C$ and operating test at high and low temperature cyclic range with acceptance tests performed at scheduled intervals. Cooling capacity is determined as a function of the temperatures at the compressor, hot end and cold tip at the expander. Finally, we describe the experimental facility for the MTTF evaluation and some typical results of the Stirling cryocooler.