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Haruyuki Watanabe, Du-Yih Tsai, Yongbum Lee, Eri Matsuyama, Katsuyuki Kojima
IMPROVEMENT OF IMAGE QUALITY AND RADIATION DOSE REDUCTION IN DIGITAL RADIOGRAPHY USING AN INTEGRATED WAVELET-TRANSFORM-BASED METHOD

This study presents an improved wavelet-transform-based method for offering a possibility to reduce the radiation dose while maintaining a clinically acceptable image quality. The proposed method integrates a straightforward extension of our previously proposed wavelet-coefficient weighted method and the existing BayesShrink thresholding method. Experimental results demonstrated that the proposed method could improve the resolution characteristic while keeping the noise level within an acceptable limit. Our visual evaluation also showed that an approximately 40% reduction in exposure dose could be achieved with the proposed method in hip joint and lumbar spine radiographs.

Mieko Uchiyama, Yongbum Lee, Du-Yih Tsai, Kiyoko Kazama, Yasuko Minagawa, Mieko Sadakata, Mitsuko Sayama
QUANTITATIVE ASSESSMENT OF MUSCLE ACTIVITY IN MAMMOGRAPHY POSITIONING

The purpose of this study was to measure muscle activity in mammography positioning using surface electromyography. The subjects consisted of 15 females in their 30s-50s, and measurement was performed with positioning for mediolateral oblique view and cranio-caudal view. The sternocleidomastoid, biceps brachii, trapezius, and gastrocnemius muscles were evaluated. A multi-purpose, portable bio-amplifier (Polymate AP1000) was used for measurement. As a result, the activities of not only the muscles directly involved in mammography positioning but also those indirectly involved were high as compared with the normal state.

Sung Eun Hur, Sung Ki Lee, B. Dongjoo Shin, Hyun Kyoon Lim, Se Jin Park
FETAL BIOMETRY IN KOREAN FETUS

The purpose of the study was to create a fetal biometry standard from data on ultrasound-dated in Korean people. A total of 142 singleton gestations with ultrasonographic fetal biometry from 14 to 38 weeks made up the study population. BPD, HC, AC and FL were measured every second weeks. To assess sonographic accuracy, we measured wooden sticks in 0°, 10° and 70° in artificial box. BPD, HC, AC and FL were measured. Mean values of each percentiles (5, 25, 50, 75, 95) are displayed. The resulting values were plotted graphically. Inter-degree differences were not significant and 0.2 ± 0.1, 0.3 ± 0.2, 0.2 ± 0.1, respectively (0° VS 10°, 0° VS 70° and 10° VS 70°) We validated the accuracy and reliability of sonographic measurements according to fetal positions.

N. A. Lee, M. Yoon, N. W. Song
PHOTOCHEMICAL PROPERTIES AND CYTOTOXICITY OF TiO2 NANOPARTICLES DEPENDING ON THE DEGREE OF AGGLOMERATION

The purpose of this paper is to evaluate the photocatalytic activity and the cytotoxicity of the primary TiO2 nanoparticles (P-TiO2 NPs) comparing with aggregated TiO2 nanoparticles (A-TiO2 NPs). A-TiO2 NPs were suspended in pH 8 phosphate buffer and stabilized after magnetic stirring. P-TiO2 NPs were isolated from A-TiO2 NPs by using centrifuge method. The photocatalytic activity was measured by observing the photocatalytic oxidation rate of NADH and the cytotoxicity assessment was evaluated by using the MTT assay. The oxidation rate of NADH in ATiO2 NP suspension was slightly higher than that in P-TiO2 NP suspension. P-TiO2 NP showed about 20% higher cytotoxicity than A-TiO2 NP at the concentration of 0.3 mg/ml.

Byung Il Choi, Sang Bong Woo, Jong Chul Kim
MEASUREMENT OF ULTRA-LOW MOISTURE PERMEATION THROUGH EPOXY SEALING IN OLED ENCAPSULATION

As the next generation flexible display elements are very vulnerable to moisture, securing proper encapsulation is a decisive factor in enabling a long working life. Therefore, together with the recent development of plastic barrier film with very low permeability, interest in the permeability of sealant used for periment sealing has been increasing. In this study, the equipment to measure moisture permeability in periment sealing was established, and the permeability of different sealants was measured, whose resolution was approximately ~10-7 g·day-1.

H. Lan, S. H. Xue, X. Q. Fang, S. F. Yu, C. Cui, C. Z. Shen
DESIGN OF A LOW-TEMPERATURE BLACKBODY RADIATION RESOURCE WITH A FROST PREVENTION UNIT

A new type of blackbody radiation resource for providing target temperatures between -80 °C and + 100 °C is presented. The blackbody adopts a stirred fluid bath to achieve temperature uniformity along the cavity and uses nitrogen gas to flush the cavity. The temperature of nitrogen gas is the same as that of the bath because the gas is heat exchanged with the working fluid in the bath. In this way, the designed blackbody can prevent air condensation on the wall and the window of the cavity when operated at temperatures below dew point, and furthermore the temperature distribution along with the wall is uniform. The calculated and measured emissivity of the designed blackbody cavity is large than 0.997.

S. A. Ogarev, B. B. Khlevnoy, M. L. Samoylov
DEVELOPMENT OF NEW BLACKBODIES FOR TEMPERATURE AND RADIOMETRIC CALIBRATIONS

The paper describes in details three newly developed cavity-type blackbody models with variable working temperature for radiometry and thermometry calibrations within -60 °C to 2000 °C temperature range: BB2000/40, BB1200/10, BB100 series, and a universal high-temperature furnace for operation with Cu and Agcontaining removable fixed-point crucibles.

S. Lee, S. Kwon
THERMAL CONDUCTIVITY OF ALUMINUM FABRICATED BY EQUAL CHANNEL ANGULAR PRESSING

Equal channel angular pressing (ECAP) has the advantage of enabling an ultrafine grain size. Aluminum 1060 is used as a power plant material because of its favorable electrical properties. However, the weak strength of aluminum limits its application. In this study, the thermal conductivity and electrical conductivity of Al 1060 made by ECAP was investigated. ECAP was conducted through the die having a channel angle of 90° and a corner angle of 20° at a temperature of 473 K with a strain rate of 2 mm·s-1. The specimen was then processed with 1 to 8 passes by the route Bc method with 90° rotation. In the case of eight passes, the grain size was reduced to as small as 300 nm. The thermal conductivity gradually decreased with ECAP passes, because of the decreased grain size by ECAP.

S. Augustin, F. Fröhlich, C. Ament, T. Güther
HIGH SPEED TEMPERATURE SENSORS IN EMISSION SYSTEMS OF COMBUSTION ENGINES

Temperature sensors used in emission systems of combustion engines must register enormous temperature differences within the shortest periods of time. This serves to protect the engine parts with respect to their temperature stability and to govern the energy efficient functioning of the engine. Numerical calculations according to the Finite Elements Method are used to estimate static-thermal measurement errors and dynamic characteristics primarily concerning medium specificity and construction of the temperature sensors. Prediction models are used to correct the dynamic behavior and to predict the medium temperature faster accurately.

Davor Zvizdic, Martti Heinonen, Danijel Sestan
PRIMARY DEW-POINT GENERATION BETWEEN 1°C AND 60°C AT LPM

EUROMET collaborative project has been set up between Finish Centre for Metrology and Accreditation (MIKES) and Croatian Laboratory for process measurements (HMI/FSB-LPM) with the objective to provide HMI/FSB-LPM with two new primary dew-point generators. Both generators operate on single pressure – single pass principle and together cover the dew-point temperature range from -70°C to 60°C, with gas flow rates up to 2.6 L/min.
This article presents the design of the high range generator (HRS), which operates in a dew-point range between 1°C and 60°C. To investigate how close the generator is to the ideal saturation, MIKES conducted several efficiency tests, which will also be described. Results of the tests show that HRS generator is sufficiently efficient for a primary realization of the dew-point temperature scale in the specified ranges. The estimated standard uncertainties due to the non-ideal saturation efficiency are found to be between 0.02 °C and 0.05 °C.

Page 672 of 977 Results 6711 - 6720 of 9762