• Fire Science and Engineering
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• v.29 no.6
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• pp.13-19
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• 2015

This study was performed to test the combustive properties of Pinus rigida specimens treated with phosphorus (P) and nitrogen (N) additives. Each Pinus rigida specimen was painted three times with 15 wt% P-N additive solutions at room temperature. After drying the treated specimens, the combustion properties were examined using a cone calorimeter (ISO 5660-1). The time to ignition (TTI) for the treated specimens was 90 to 148 s except for the specimen treated with PP/$4NH_4^+$, and the time to flameout (TF) was 556 to 633 s, which was longer than that of virgin plate. While the The specimens treated with P-N additives showed 12.5 to 43.4% higher mean heat release rate ($HRR_{mean}$) and 11.8 to 43.1% higher total heat release (THR) than virgin plate. The effective heat of combustion (EHC) was by 2.9 to 17.5% lower than that of virgin plate. It can thus be concluded that the combustion-retardation properties were partially improved compared to those of virgin plate.

• Fire Science and Engineering
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• v.24 no.5
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• pp.115-121
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• 2010

This study was performed to test the combustive properties of Pinus rigida-based materials by the treatment of ammonium salts. Pinus rigida plate was soaked in three 20 wt% ammonium salt solutions such as ammonium sulfate (AMSF), monoammonium phosphate (MAPP), and diammonium phosphate (DAPP), respectively, at the room temperature. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). Comparing with virgin pinus rigida plate, specimens treated with the ammonium salts had lower combustive properties and It is supposed that the combustion-retardation properties improved due to the treated ammonium salts in the virgin Pinus rigida. Also, the specimens with treated ammonium salts showed both the lower peak heat release rate (PHRR) and lower total heat release (THR) than those of virgin plate.

• Wind and Structures
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• v.5 no.2_3_4
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• pp.291-300
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• 2002

An efficient large eddy simulation algorithm is used to compute surface pressure distributions on an eleven story (target) building on the NIST campus. Local meteorology, neighboring buildings, topography and large vegetation (trees) all play an important part in determining the flows and therefore the pressures experienced by the target. The wind profile imposed at the upstream surface of the computational domain follows a power law with an exponent representing a suburban terrain. This profile accounts for the flow retardation due to friction from the surface of the earth, but does not include fluctuations that would naturally occur in this flow. The effect of neighboring buildings on the time dependent surface pressures experienced by the target is examined. Comparison of the pressure fluctuations on the single target building alone with those on the target building in situ show that, owing to vortices shed by the upstream buildings, fluctuations are larger when such buildings are present. Even when buildings are lateral to or behind the target, the pressure disturbances generate significantly different flows around this building. A simple grid-free mathematical model of a tree is presented in which the trunk and the branches are each represented by a collection of spherical particles strung together like beads on a string. The drag from the tree, determined as the sum of the drags of the component particles, produces an oscillatory, spreading wake of slower fluid, suggesting that the behavior of trees as wind breakers can be modeled usefully.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.633-638
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• 2013

This study was performed to test the combustive properties of pinus rigida specimens treated with bis-(dimethylaminomethyl) phosphinic acid, bis-(diethylaminomethyl) phosphinic acid (DEDAP), and bis-(dibuthylaminomethyl) phosphinic acid. Pinus rigida specimens were painted in three times with 15 wt% bis-(dialkylaminoalkyl) phosphinic acid solutions at the room temperature. After drying the treated specimens, combustive properties were examined by the cone calorimeter (ISO 5660-1). Combustion-retardation properties were found to be improved partially due to the treated bis-(dialkylaminoalkyl) phosphinic acids in the virgin pinus rigida. In particular, the specimens treated with DEDAP showed both the lower total heat release rate ($60.9MJ/m^2$) and effective heat of combustion (15.20 MJ/kg) than those of virgin plates. Compared with virgin pinus rigida plates, specimens treated with the bis-dialkylamimoalkyl phosphinic acid derivatives showed partially low combustive properties.

• The Korean Journal of Ceramics
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• v.4 no.4
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• pp.279-285
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• 1998

The $UO_2$ pellets are usually sintered under hydrogen gas atmosphere. Hydrogen gas may cause unexpected early failure of the refractory bricks in the sintering furnace. In this work, nitrogen was mixed with hydrogen to investigate the effect of nitrogen gas on a failure machanism of the refractory bricks and on the microstructure of the $UO_2$ pellet. The hydrogen-nitrogen mixed gas experiments show that the larger nitrogen the mixed gas contains, the less the refractory materials are reduced by hydrogen. The weight loss measurements at $1400^{\circ}C$ for fire clay and chamotte refractories containing high content of $SiO_2$ indicate that the weight loss rate for the mixed gas is about half of that for the hydrogen gas. Based on the thermochemical analyses, it is proposed that the weight loss is caused by hydrogen-induced reduction of free $SiO_2$ and/or $SiO_2$ bonded to $Al_2O_3$ in the fire clay and chamotte refractories. However, the retardation of the hydrogen-induced $SiO_2$ reduction rate under the mixed gas atmosphere may be due to the reduction of the surface reaction rate between hydrogen gas and refractory materials in proportion to volume fraction of nitrogen gas in the mixed gas. On the other hand, the mixed gas experiments show that the test data for $UO_2$ pellet still meet the related specification values, even if there exists a slight difference in the pellet microstructural parameters between the cases of the mixed gas and the hydrogen gas.

• Fire Science and Engineering
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• v.28 no.3
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• pp.55-61
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• 2014

This study was performed to test the combustive properties of pinus rigida specimens treated with methylpiperazinomethyl-bis-phosphonic acid $M^{n+}$ ($PIPEABPM^{n+}$)s and methylpiperazinomethyl-bis-phosphonic acid (PIPEABP). Pinus rigida Plates were painted in three times with 15 wt% $PIPEABPM^{n+}s$ and PIPEABP solutions at the room temperature respectively. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). It was indicated that the specimens treated with $PIPEABPM^{n+}s$ showed the lower speed to peak mass loss rate ($MLR_{peak}$), (0.104~0.121) g/s than that of PIPEABP plate. In adition, the specimens treated with $PIPEABPM^{n+}s$ showed both the lower total smoke release rate (TSRR), (224.4~484.0) $m^2/m^2$ and $CO_{mean}$ production (0.0537~0.0628) kg/kg than those of PIPEAB plate. Especially, for the specimens treated with $PIPEABPM^{n+}$ by reducing the smoke production rate except 2nd-smoke production rate (2nd-SPR), (0.0254~0.02270) g/s treated with $PIPEABPNi^{2+}$, 2nd-SPR (0.0117~0.0146) g/s was lower than that of PIPEABP plate. Thus, It is supposed that the combustion-retardation properties were improved by the partial due to the treated $PIPEABPM^{n+}s$ in the virgin plate.

• Fire Science and Engineering
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• v.28 no.4
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• pp.57-63
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• 2014

This study was performed to test the combustive properties of Medium Density Fibreboard (MDF) specimens treated with piperazinomethyl-bis-phosphonic acid (PIPEABP), methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP), and N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (MDEDAP). MDF Plates were painted in three times with 15 wt% solution of the alkylenediaminoalkyl-bis-phosphonic acids at the room temperature, respectively. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). It was indicated that the specimens treated with chemicals showed the later time to peak mass loss rate ($TMLR_{peak}$) = (340475) s than that of virgin plate by reducing the burning rate. In adition, the specimens treated with chemicals showed the higher $CO_{mean}$ production (0.0883~0.0963) kg/kg than that of virgin plate. Especially, the specimens treated with chemicals showed the higher mean smoke extinction area ($SEA_{mean}$) ($5m^2/kg{\sim}21.5m^2/kg$) than that of virgin plate. Thus, It is supposed that the combustion-retardation properties were improved by the partial due to the treated alkylenediaminoalkyl-bis-phosphonic acids in the virgin MDF Plate. However, It gave a negative effect on smoke reduction.

• Fire Science and Engineering
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• v.27 no.6
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• pp.70-76
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• 2013

Four kinds of new piperazinomethyl-bis-phosphonic acid $M^{n+}$ ($PIPEABPM^{n+}$) were synthesized and their combustive properties of Pinus rigida plates treated with $PIPEABPM^{n+}$ were tested. Pinus rigida specimens were painted in three times with 15 wt% $PIPEABPM^{n+}$solutions at the room temperature. After drying specimen treated with chemicals, com-bustive properties were examined by the cone calorimeter (ISO 5660-1). As a result, the combustion-retardation proper-ties were increased by due to the treated $PIPEABPM^{n+}$ solutions in the virgin pinus rigida. Especially, the specimens treated with $PIPEABPM^{n+}$ showed both the lower peak heat release rate ($HRR_{peak}$) (162.02~145.36) s and total heat release rate (THRR) (73.0~67.4) $MJ/m^2$ than those of virgin piperazinomethyl-bis-phosphonic acid (PIPEABP)-plate. Compared with virgin PIPEABP-plate, the specimens treated with the $PIPEABPM^{n+}$ showed low combustive properties. However the specimens treated with $PIPEABPM^{n+}$ showed both the shorter time to ignition (TTI) (67~23) s and the time to flameout (Tf) (472~433) s than those of virgin PIPEABP-plate by increasing the thermal conductivity.

• Fire Science and Engineering
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• v.27 no.4
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• pp.21-26
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• 2013

This study was performed to test the combustive properties of Pinus rigida plates treated with bis-(dimethylaminomethyl) phosphinic acid (DMDAP), bis-(diethylaminomethyl) phosphinic acid (DEDAP), and bis-(dibuthylaminomethyl) phosphinic acid (DBDAP). Pinus rigida specimens were painted in three times with 15 wt% bis-(dialkylaminoalkyl) phosphinic acid solutions at the room temperature. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). It is supposed that the combustion-retardation properties were improved by the partial due to the treated bis-(dialkylaminoalkyl) phosphinic acids in the virgin Pinus rigida. Especially, the specimens treated with chemicals showed both the lower total smoke release rate (TSRR) ($16.94{\sim}18.92m^2/m^2$) and lower $CO_{2mean}$ production (1.98~2.09 kg/kg) than those of virgin plate. However the specimens treated with chemicals showed both the higher peak mass loss rate (PMLR) (0.1250~0.1297 g/s) and higher 1st-smoke production rate (SPR) (0.0153~0.0167 g/s) than those of virgin plate. Compared with virgin Pinus rigida plate, the specimens treated with the bis-dialkylamimoalkyl phosphinic acids showed partially low combustive properties.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.39-44
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• 2012

To improve flame retardation of poly(ethylene terephthalate) (PET) against burning, resorcinol bis(diphenyl phosphate) (RDP), phosphorous containing flame retardant, was incorporated into PET backbone by radical reaction pathway. Radical endcapping of PET with RDP was confirmed by spectroscopic and thermal analysis. From 400 MHz $^{31}P$ solid state FT-NMR spectrum of PET with RDP (PET-RDP), phosphorus spectra peak in RDP was found at ca. -10 ppm. Furthermore, P-C bond stretching vibration peaks were found ca. $530cm^{-1}$ in FT-IR spectrums of PET-RDP. These results indicated that RDP can be chemically bound at the ends of PET by radical addition method. Thermal characteristics of pure PET (pPET) and PET-RDP were measured and evaluated by TGA thermal analysis. There was not significant changes in thermal characteristics of PET-RDP compared to that of pPET.