Dong-Su Bae, Chi-Eun Sung, Hyeon-Jee Jeon,Sang-Pill Lee, Jin-Kyung Lee, Un-Bong Baek, Seung-Hoon Nahm
The effect of hydrogen content on hydrogen embrittlement of high toughness API X70 line-pipe steels was studied. The hardness of conventional API X70 steel was measured before and after hydrogen charging. The various hydrogen contents for API X70 steel were charged at 10MPa gas pressure. The tensile test for hydrogen charged API steel was conducted at room temperature. The hardness increased slightly with hydrogen content. The fracture surfaces were changed from dimple type to quasi-cleavage type with hydrogen content. And external cracks were observed just only at 100% hydrogen content.
XX IMEKO World Congress
· TC20
· 2012
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Young-Do Jo, Jin-Jun Kim
The current method for determining the flammable limits for a gas in a closed spherical vessel is based on a specification of the maximum pressure increase during the combustion, usually from 5 to 10% of the initial ambient pressure. This approach is completely arbitrary and is not fundamentally based. For most hydrocarbons this pressure boundary and hence the flammable limit is easy to determine experimentally since an abrupt pressure drop occurs at the flammable limit as the fuel concentration in air is adjusted. However, for some species, particularly hydrogen mixed with air, the drop in...
XX IMEKO World Congress
· TC20
· 2012
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E. Zaharovits, E. Zaharovits, F. Iacobescu
Correct measurement of electrical energy in order to ensure consumer protection in commercial transactions and billing is of great importance. Static electrical energy meters have been developed as complex measuring instruments, due to technical changes in recent decades, as well as to meet the increasingly complex demands of electrical energy consumers. These modern measuring instruments - static electricity meters - are used in power system of Romania for various applications. This paper discusses some of the features of static electrical energy meters, belonging to both "smart" and...
XX IMEKO World Congress
· TC20
· 2012
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Mateusz Kotarski, Janusz Smulko
Taguchi gas sensors are commonly used sensors to measure gas concentration. The detection method utilizes only sensor DC resistance changes for determination of various gases concentration. Unfortunately, such technique leads to false results due to cross-sensitivity of gas sensors at presence of other gases. Such adverse effects can be reduced by applying fluctuation enhanced sensing and temperature modulation of sensor which gather more information about ambient atmosphere than the DC resistance. The measurement setup of voltage fluctuations across the gas sensor as well as the selected...
XX IMEKO World Congress
· TC19
· 2012
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J.M. Lee, K.B. Lee, S.H. Lee, T.S. Park
The efficiency of a 226 Ra aqueous solution source in the radium-radon secular equilibrium against the gamma reference ionization chamber in KRISS has been obtained both by calculating from the photon energy-dependent efficiency curve of the ionization chamber and by measuring with an 226 Ra standard source. The two results of calculation and measurement have showed such a good agreement that the gamma reference ionization chamber may be used to certificate the radioactivity of 226 Ra aqueous solutions in the secular equilibrium and its traceability could be linked to the multi-radionuclide...
XX IMEKO World Congress
· TC19
· 2012
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Jungho Kim, Hyeonseo Park, Kil-Oung Choi
Cosmic-ray-induced neutrons are important to estimate the environmental dose for the aircraft crews. New Bonner spheres were designed for high-energy neutrons up to 10 GeV and their response functions were evaluated using the MCNPX transport code. The spheres consisted of an inner polyethylene shell covering the 3 He-filled spherical proportional counter, an outer polyethylene shell, and an inlet metal shell. Cosmic-ray-induced neutrons were measured at Korea Research Institute of Standards and Science together with the 10 existing Bonner spheres. Results of the neutron spectra showed that...
XX IMEKO World Congress
· TC19
· 2012
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O. Postolache, P. Girão, M. Pereira, C. Grueau, H. Teixeira, M. Leal
The use of greenhouses with controlled microclimate according to the plants needs is an important way to increase the production of fruits and vegetables and has recently become one of the hottest topics in precision agriculture. In order to know and to control the greenhouse microclimate, smart sensing nodes with wireless communication capabilities are recommended. As one of the promissory protocols associated with wireless sensor networks can be mentioned ZigBee due to its low cost, low power consumption, extended ranges and architecture flexibility. In the present work, a network of...
XX IMEKO World Congress
· TC19
· 2012
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Fernando M. Janeiro, Filipe Carretas, Konrad Kandler, Pedro M. Ramos, Frank Wagner
Cloud base height is an important parameter for climate studies as well as aviation safety. Ceilometers or LIDARs can measure this parameter but are usually expensive instruments. In this paper, a low-cost method to measure cloud base height based on consumer digital cameras and stereophotogrammetry is presented. The performance of the system is evaluated by comparison with LIDAR measurements. It is shown that the prototype can also measure the wind speed and direction at cloud height.
XX IMEKO World Congress
· TC19
· 2012
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I. J. Kim, J. K. Suh, K. H. Cho, J. H. Jung, Y. C. Myoung, E. Hwang
An interlaboratory comparison study was performed. It was on the determination of bromine contents in plastic samples by using electric furnace combustion ion chromatography (C-IC) method, which had been proposed a new Korean standard procedure for the measurement of halogen (bromine, chlorine, fluorine). Two candidate reference materials were used as test materials. Range of bromine contents in the materials was 100 – 1 000 mg/kg. Instrumental neutron activation analysis was applied to determine the bromine contents in the materials, which were used as the reference values of thhis study....
XX IMEKO World Congress
· TC19
· 2012
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L. Piper, A. Lay Ekuakille, P. Vergallo, V. Pelillo
Pollutant measurement prediction is a topic of great interest in the area of environmental measurements and health protection. Stationary description of pollutants is an approach in which the amount of pollutant per time unit is considered constant. But in many circumstances, this quantity is subject to a flow delay. In this paper we introduce a novel pseudo-stationary modeling based on Delay Differential Equations (DDE) that can better reflect forced and spontaneous emissions of pollutants from industrial plants and natural processes respectively. Emissions of Volatile Organic Compouund...
XX IMEKO World Congress
· TC19
· 2012
· Download