scholarly journals Experimental Study on the Fire Resistance Performance of Partition Board under the Condition of Small Fire Source

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1818
Author(s):  
Butong Gao ◽  
Shanyang Wei ◽  
Wei Du ◽  
Huan Yang ◽  
Yunyun Chu
Keyword(s):  
Sample Surface ◽  
Pool Fire ◽  
Bunsen Burner ◽  
Measuring Point ◽  
Fire Source ◽  
Center Point ◽  
Rise Rate ◽  
Change Trend ◽  
Resistance Performance ◽  
Burn Through

Fire safety of ancient wooden buildings is one of the most important issues in the world. In this paper, partition boards with different thicknesses from 15 to 25 mm were heated by a 15-cm-diameter pool fire and a methane Bunsen burner. The temperatures and the carbonization rate of partition boards were measured and analyzed. The results show that when a pool fire was used to heat the wood sample at a distance of 30 cm, two flames appear on the sample surface. When a Bunsen burner heats the sample, the sample is burned until the center point is burned through. The thickness of the sample is increased by 5 mm, and the acceleration time of the temperature rise rate at the center is doubled. Under the condition of a pool fire, the thickness of the sample is increased by 5 mm, and the average carbonization rate at the center point is reduced by 40%. Under the condition of Bunsen burner, the average carbonization rate of the center point decreases exponentially when the thickness of the sample increases by 5 mm. In the case of the same fire source, the carbonization rate of the samples with different thicknesses has the same change trend in the horizontal and vertical directions. Compared with the pool fire, the burn-through time of the center point of the sample is reduced in the case of the Bunsen burner for a sample of the same thickness, and the average carbonization rate of each measuring point increases.

A Testing Method for the Luminance Difference of Stereoscopic Television

2013 ◽  
Vol 380-384 ◽  
pp. 955-958
Author(s):  
Dong Yan Wu ◽  
Jian Dong Cao ◽  
Yi Jin
Keyword(s):  
Quality Evaluation ◽  
Measuring Point ◽  
Testing Model ◽  
Testing Method ◽  
Luminance Difference ◽  
Center Point ◽  
Black Field ◽  
Left And Right ◽  
3D Tv

The luminance difference is one of the important factors of stereoscopic television. In this paper, according to the characteristics of stereoscopic television glasses, we use white window signal and black field signal to measure luminance difference of 3D TV. We adopt the left and right eye channel individually tested brightness. We chose the center point of stereoscopic television as measuring point. And then, we select a few of stereoscopic television as testing model. The proposed method may be helpful for the quality evaluation of stereoscopic television.

scholarly journals Combustion phenomena of pool fire in a ceiling vent compartment: the vent right above the fire source

2018 ◽  
Vol 211 ◽  
pp. 358-364
Author(s):  
Jin-mei Li ◽  
Jia-qing Zhang ◽  
Qiang Li ◽  
Bo-si Zhang ◽  
Yang Jiang
Keyword(s):  
Pool Fire ◽  
Fire Source ◽  
Ceiling Vent

scholarly journals Combustion phenomena of pool fire in a ceiling vent compartment: the vent far away from the fire source

2018 ◽  
Vol 211 ◽  
pp. 388-394 ◽  
Author(s):  
Qiang Li ◽  
Jia-qing Zhang ◽  
Jin-mei Li ◽  
Bo-si Zhang ◽  
Yang Jiang
Keyword(s):  
Pool Fire ◽  
Fire Source ◽  
Ceiling Vent

Explore on Pressure-Drop Performance of Nanofibrous Filtration Membrane

2011 ◽  
Vol 236-238 ◽  
pp. 1885-1888
Author(s):  
Han Wang ◽  
Zuo Yi Yang ◽  
Jin Yong Liu ◽  
Gao Feng Zheng ◽  
Ling Min Chen
Keyword(s):  
Pressure Drop ◽  
Membrane Filtration ◽  
Filtration Efficiency ◽  
Nanofibrous Membrane ◽  
Air Filtration ◽  
Fibrous Filter ◽  
Filtration Membrane ◽  
Filtration Area ◽  
Change Trend ◽  
Resistance Performance

High filtration efficiency of nanofibrous membrane has been proved in air filtration area, but, in addition to filtration efficiency, pressure drop is another important characteristic of fibrous filter. Because pressure-drop is related to energy wastage of filtration, it’s necessary to study. While there are not enough studies dedicated to pressure-drop of nanofibrous membrane filters. Here, different thickness PVA nanofibrous membranes were made by electrospinning, and they deposited on cotton scaffolds to form nanofibrous filter samples. Through testing these samples, we found as thickness of nanofibrous membrane increased, pressure-drop rose almost linearly, while filtration efficiency presented a different change trend. When thickness of nanofibrous membrane reaching a point, filtration efficiency attained extreme limit, even if increasing thickness nanofibrous membrane, filtration efficiency only rose limitedly, but pressure-drop still increased rapidly. At the same time, we found despite the thickness of nanofibrous membrane was thinner than conventional fibrous filter, pressure-drop of nanofibrous filter was obviously higher than conventional fibrous filter. So it’s remarkable phenomena. Through theoretical analysis and simulation, the causation of high pressure-drop of nanofibrous filter was discussed and provided. Decreasing diameter of fiber caused resistance performance change. It’s necessary to carry on a further research.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

A technique to prepare cross-sectional TEM specimens of semiconducting devices

1986 ◽  
Vol 44 ◽  
pp. 742-743
Author(s):  
A. K. Rai ◽  
P. P. Pronko
Keyword(s):  
Thin Films ◽  
Surface Region ◽  
Sample Surface ◽  
Specific Region ◽  
Cross Sectional ◽  
Thin Sections ◽  
The Past ◽  
Device Structures ◽  
Ion Implanted

Several techniques have been reported in the past to prepare cross(x)-sectional TEM specimen. These methods are applicable when the sample surface is uniform. Examples of samples having uniform surfaces are ion implanted samples, thin films deposited on substrates and epilayers grown on substrates. Once device structures are fabricated on the surfaces of appropriate materials these surfaces will no longer remain uniform. For samples with uniform surfaces it does not matter which part of the surface region remains in the thin sections of the x-sectional TEM specimen since it is similar everywhere. However, in order to study a specific region of a device employing x-sectional TEM, one has to make sure that the desired region is thinned. In the present work a simple way to obtain thin sections of desired device region is described.

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

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