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Electric Furnace (electric + furnace)
Selected AbstractsTest method for concrete spalling using small electric furnaceFIRE AND MATERIALS, Issue 4 2010Ren Zhao Abstract Concrete spalling can cause severe damage to concrete structure when exposed to fire. The spalling mechanisms are not very well understood. For the testing of spalling, full-scale structural members should be used, as spalling tests are sensitive to size effects. Full-scale testing in large furnace is costly and is not suitable for testing large number of concrete mixture trials. The standard and hydrocarbon fire time,temperature curves have rapid temperature rise during the initial phase. This temperature rise requires a gas furnace with high heating capacity and cannot be generated by electric muffle furnace commonly available in many laboratories. This paper presents a method to carry out spalling test in small-scale specimens with exposure to rapid temperature rise using a commonly available electric furnace in the laboratories. The tests are based on 150,mm diameter cylinders that are laterally confined to simulate full-scale structural members. The cylinder surface is exposed to rapid temperature rise by exposing through vertical and/or horizontal holes in pre-heated small electric furnace. Some unconfined 100,mm diameter cylinders were also exposed horizontally to test the performance of confinement. The paper shows that the hydrocarbon fire and standard fire exposure can be simulated by manipulating the exposure location of the surface of the concrete cylinder. Ordinary Portland cement concrete cylinders with different strengths were tested and different spalling patterns were observed. The spalling patterns matched the test results from a gas furnace fire test simulating the fire curves. The tests demonstrated that the method is an effective and convenient technique to predict the spalling risk of a concrete. Copyright © 2009 John Wiley & Sons, Ltd. [source] Film boiling heat transfer around a vertical finite-length cylinder with a convex hemispherical bottomHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2010Takashi Yamada Abstract The film boiling heat transfer around a vertical silver cylinder with a convex hemispherical bottom was investigated experimentally in quiescent water at atmospheric pressure. The experiments have been carried out using a quenching method. The diameter and length of the test cylinder are 32 mm and 48 mm, respectively. The test cylinder was heated to about 600 °C in an electric furnace and then cooled in saturated or subcooled water with an immersion depth of about 100 mm. The degree of liquid subcooling was varied from 0 K to 30 K. The analytical solutions for saturated and subcooled boiling are obtained by applying a two-phase boundary layer theory for vapor film with a smooth interface. The experimental data correlates within ±15% based on the proposed prediction method. Also, the lower limit of film boiling was examined in terms of wall heat flux and degree of superheating. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20289 [source] A comparative experiment in the consolidation of cremated boneINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 2 2004D. Rossi Abstract This experiment assessed whether consolidation of cremated remains facilitated cross-sectioning and grinding, which often are required for microstructural analyses such as the histomorphometric estimation of age and the examination of pathological lesions. Green, bovine femoral diaphyses were cremated at three temperature ranges (346,357°C; 610,755°C; 684,838°C) in an electric furnace and then consolidated with Acryloid B-72 or Butvar B-98 using simple brushing and immersion techniques. After consolidation was complete, bone pieces were cross-sectioned and ground to a thickness of 100,120,,m. Results indicate that specimens treated with Acryloid B-72 are harder and stronger than Butvar treated and untreated control specimens. Acryloid B-72 is, therefore, recommended for the consolidation of cremated remains in preparation for microstructural analysis. Copyright © 2004 John Wiley & Sons, Ltd. [source] Performance of a new furnace for high-resolution synchrotron powder diffraction up to 1900,K: application to determine electron density distribution of the cubic CaTiO3 perovskite at 1674,KJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2004Masatomo Yashima Accurate crystal structure analysis at high temperatures is an important challenge in science and technology. A new electric furnace for the measurement of high-resolution (,d/d = 0.03%) synchrotron radiation powder diffraction profiles from materials at high temperatures (up to 1900,K in air) has been designed and fabricated. This furnace consists of a ceramic refractory with MoSi2 heaters, an aluminium body cooled by flowing water, and a sample stage with a spinner and a controller for sample-height adjustment. In situ synchrotron powder diffraction measurement for a calcium titanate perovskite specimen at 1674,K has been performed using the furnace at beamline 3A of the Photon Factory. The electron density distribution of the cubic perovskite at 1674,K was successfully obtained using a combination of Rietveld refinement, the maximum-entropy method (MEM) and MEM-based pattern-fitting techniques. The Ti atoms exhibit covalent bonding with the O atoms in the cubic CaTiO3 perovskite at this temperature, while the Ca atoms are ionic. These results indicate that the new furnace yields high-quality data for accurate crystal structure analysis. [source] Plant Location and the Advent of Slab Casting by U.S. Steel Minimills: An Observation-Based AnalysisECONOMIC GEOGRAPHY, Issue 4 2006Frank Giarratani Abstract: The advent of slab casting for steel that is produced in electric furnaces resulted in a wave of new investments in the construction of steel minimills. From 1989 to 2001, 10 new plants were constructed in the United States on the basis of new technologies. Some were built in established steel industry agglomerations, while others were built in greenfield locations,regions that had little or no prior steelmaking activity. This research brings new evidence to bear on location decisions concerning modern steelmaking. The findings are based on direct observation and visits to the plants of all the new mills that were created by these investments. While the analysis reinforces the importance of transfer costs in decision making, it also argues that critical locational elements cannot be fully understood unless analyses take account of the characteristics of specific products, plants, and firms. [source] | ||||||||||