Effect of folding width on a flame spreading rate for accordion folded paper

Both experimental and theoretical methods were proposed to assess the effects of adjacent, parallel, and symmetric exterior wall structures on the combustion and flame spreading characteristics of rigid polyurethane (PUR) foam insulation. During the combustion of PUR specimens, the flame leading edge was found to transfer from a unique inverted ‘W’ shape to an inverted ‘V’ during flame propagation. This phenomenon is attributed to edge effects related to boundary layer theory. The effects of the adjacent façade angle on flame spreading rate and flame height were shown to be nonlinear, as a result of the combined influences of heat transfer, radiation angle, and the chimney restriction effects. A critical angle around 90 degree with maximum thermal hazards outwards by parallel fire was observed and consistent with the mass loss rate and flame height tendencies. For narrow spacing configurations or angles (e.g., 60 and 90 degrees), phenomenological two-pass processing in conjunction showed that increased preheating lengths were associated with enhanced heat transfer. The results of this study have implications concerning the design of safe façade structures for high-rise buildings, and provide a better understanding of downward flame spreading over PUR.

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Effect of Foaming Temperature on Microstructure, Mechanical Properties and Flame Spread Rate in PET–PEN Copolymer

Energies ◽

10.3390/en14040957 ◽

2021 ◽

Vol 14 (4) ◽

pp. 957

Author(s):

Byung Kyu Park ◽

Charn-Jung Kim ◽

Byeong Jun Lee

Keyword(s):

Thermal Expansion ◽

Coefficient Of Thermal Expansion ◽

Functional Materials ◽

Spreading Rate ◽

Indentation Hardness ◽

Polyethylene Naphthalate ◽

Flame Spreading ◽

Sem Image ◽

Thermal Expansion Coefficients ◽

Foaming Temperature

Polymer foams are expanding their applications into functional materials. Partial foam structure has been fabricated in polyethylene terephthalate–polyethylene naphthalate (PET–PEN) copolymer by solid state foaming. Through SEM image analyses, a potential to fabricate gradient foam structures with micropores and unfoamed skin layers has been identified. The post-foaming temperature Tf tune the pore size distribution. Radial distribution of micromechanical properties, indentation hardness and elastic modulus were measured for the partial foam and their values were around 0.12 GPa and 2.0 GPa, respectively, for the outer foamed region. Foaming temperature affects the glass transition temperature Tg, the coefficient of thermal expansion and the flame spreading rate. For the range of Tf ≤ 60°C, thermal expansion coefficients for T > Tg are about 0.5 m/m°C (steep expansion group, SEG). When Tf is above 80 °C, they are around 0.02 m/m°C (mild expansion group, MEG). The burning rate of SEG is 2.8 times higher than that of MEG.

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Crustal structure across the extinct mid‐ocean ridge in South China Sea from OBS receiver functions: insights into the spreading rate and magma supply prior to the ridge cessation

Geophysical Research Letters ◽

10.1029/2020gl089755 ◽

2020 ◽

Author(s):

Tran Danh Hung ◽

Ting Yang ◽

Ba Manh Le ◽

Youqiang Yu ◽

Mei Xue ◽

...

Keyword(s):

South China Sea ◽

South China ◽

Crustal Structure ◽

Spreading Rate ◽

Receiver Functions ◽

China Sea ◽

Magma Supply ◽

Mid Ocean Ridge ◽

Ocean Ridge

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SIFAT FISIK KAYU LAPIS BERBAHAN BAKU KAYU AKASIA (Acacia mangium Willd) DAN KELAMPAYAN (Anthocephalu spp)

Jurnal Riset Industri Hasil Hutan ◽

10.24111/jrihh.v3i2.1188 ◽

2011 ◽

Vol 3 (2) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Effendi Arsad

Keyword(s):

Tensile Strength ◽

Water Content ◽

Acacia Mangium ◽

Spreading Rate ◽

Wood Material

The utilization of acacia and kelampayan wood as plywood materials were done. There are two kinds of treatments with two cores samples. Wood core with thickness 2 mm and 3 mm with the spreading rate of adhesive 150 gr/m2, 200 gr/m2 and 250 gr/m2. Resuls showed that the water content of plywood are 9,01% - 14,29% for acacia and 9,17% - 10,58% for kelampayan wood material. The density of the plywood are 0,62 gr/cm3 – 0,73 gr/cm3 for acacia and 0,44 gr/cm3 – 0,57 gr/cm3. for kelampayan wood material. The tensile strength of plywood are tensile strength of plywood are 9,49 kg/cm2 – 14,73 kg/cm2 for acacia and 8,61 kg/cm2 – 12,58 kg/cm2 for kelampayan wood material.Keywords: acacia, kelampayan, the spreading rate of adhesive, physics characteristic, plywood

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Role of Vasavaleha in the management of Covid19

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11ispl1.2710 ◽

2020 ◽

Vol 11 (SPL1) ◽

pp. 259-261

Author(s):

Aamir Khan ◽

Rajni K. Gurmule

Keyword(s):

Immune System ◽

Human Body ◽

Respiratory Diseases ◽

Spreading Rate ◽

Host Immune System ◽

Shortness Of Breath ◽

Antitussive Effect ◽

Corona Viruses ◽

Very High

Vasavaleha is one of the best medicine given for respiratory diseases. Corona viruses typically affect the respiratory system, causing symptoms such as coughing, fever and shortness of breath. It also affects host immune system of human body. Spreading rate of this disease is very high. Whole world is seeking for the treatment which can uproots this diseases. There in no vaccine available till date against this pandemic disease. Ayurveda mainly focuses on prevention of diseases alongwith its total cure. Rajyakshma Vyadhi is MadhyamMarga Roga as per Ayurveda. It shows many symptoms such as Kasa, Shwasa etc. By overall view of Covid 19, shows its resemblance with Rajyakshma Vyadhi described in Ayurveda. Vasavaleha is a Kalpa which is described in Rogadhikara of Rajyakshma. It shows Kasahara, Shwashara properties. It consists of Vasa, Pipalli, Madhu and Goghrita. These components shows actions like bronchodilation, antitussive effect and many more other actions. Pipalli shows important Rasayana effect. So in present review, we have tried to focus on role of Vasavaleha in the management of Covid 19. This can be used as preventive as well as adjuvant medication in treating Covid 19. There is need of further clinical research to rule of exact action of Vasavaleha against Covid 19.

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