Initial Thermal Decomposition Research Articles

An experimental method to study emissions from heated tobacco between 100-200°C.

BackgroundCigarette smoke emissions are mainly produced by distillation, pyrolysis and combustion reactions when the tobacco is burnt. Some studies have shown that heating tobacco to temperatures below pyrolysis and combustion temperatures has the potential to reduce or eliminate some toxicants found in cigarette smoke. In this study, we designed a bench-top tube furnace that heats tobacco between 100-200°C and systematically studied the effects of heating temperatures on selected gas phase and aerosol phase compounds using an ISO machine-smoking protocol.ResultsAmong a list of target chemical compounds, seven toxicants (nicotine, carbon monoxide, acetaldehyde, crotonaldehyde, formaldehyde, NNN and NNK) were quantifiable but not at all temperatures examined. The levels of the compounds generally displayed an increasing trend with increasing temperatures. The observed carbon monoxide and aldehydes represented the initial thermal breakdown products from the tobacco constituents. Water was the largest measured component in the total aerosol phase collected and appeared to be mainly released by evaporation; nicotine release characteristics were consistent with bond breaking and evaporation. Quantifiable levels of NNK and NNN were thought to be the result of evaporative transfer from the tobacco blend.ConclusionsThese results demonstrate the practical utility of this tool to study low-temperature toxicant formation and emission from heated tobacco. Between 100 to 200°C, nicotine and some cigarette smoke compounds were released as a result of evaporative transfer or initial thermal decomposition from the tobacco blend.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-015-0096-1) contains supplementary material, which is available to authorized users.

Synthesis, characterization and properties of aromatic copolyimides containing Bi-benzimidazole moiety

A new aromatic heterocyclic diamine monomer, 2,2-bis (4’-aminophenyl)- 5,5-bi-1H-benzimidazole (BAPBBI), was synthesized via a one-step reaction of 3,3’,4,4’-biphenyltetramine and p-aminobenzoic acid in polyphosphoric acids with the high yield and purity. FTIR, 1H NMR, 13C NMR, mass spectra and elemental analysis were employed to confirm the chemical structures. A series of copolyimide films containing the bi-benzimidazole moieties were prepared by the reaction of pyromellitic dianhydride (PMDA), 4,4’-oxydianiline (ODA) and BAPBBI with various molar ratios. The combination of polybenzimidazole and polyimide by introducing BAPBBI into the main chains brings the highly rigid structure and the enhanced macromolecular interactions, resulting in the enhancement in the thermal stability and the mechanical properties. For instance, these polyimides are endowed with a higher glass transition temperature of 408–438 °C and an initial thermal decomposition of 550–580 °C. They exhibit a strong tensile strength of 123–233 MPa, and a tensile moduli of 2.66–12.84 GPa without post stretching. Meanwhile the stretched films at 450 °C exhibited the enhanced mechanical properties with the tensile strength of 195–554 MPa and the tensile modulus of 4.69–38.57 GPa.

Synthesis of Methylacryloypropyl-POSS/Poly(fluorine-acrylate) Core-Shell Nanocomposites and Effect on Thermal Properties of Materials

Core-shell nanocomposites were prepared from acrylates, fluorine- containing methacrylate monomers and methylacryloypropyl polyhedral oligomeric silsesquioxanes (MAP-POSS) by emulsion polymerization. The properties of latex and nanocomposites were characterized by FTIR, NMR, TEM, laser particle diameter analyzer, DMA and TGA. The results showed that the particle diameter of composite latexes was about 33.5 nm, dynamic mechanical loss peak temperature Tp of the nanocomposites had the best high value at 99.6°C when 7 wt.% MAP-POSS was added, which is 7.8°C higher than the pure polyacrylates. MAP-POSS could increase the thermal stability of materials, the initial thermal decomposition temperature increases about 34°C.

Synthesis and Characterization of a Novel Metal–Organic Compound: 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-Oxide (DOPO)–Mg

Abstract For the first time, a metal was introduced into the structure of the flame retardant, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). A novel metal–organic composite, DOPO–Mg, was synthesized upon the reaction between melt DOPO and activated magnesium powder. The results show that DOPO–Mg has a high initial thermal decomposition temperature of up to 400 °C (5%). In addition, it was an amorphous-like material with minimal water absorption, which decomposed without a melting point. The product after the combustion of DOPO–Mg was magnesium pyrophosphate.

Preparations and Tribological Properties of COPNA Copolymer Materials

The cured condensed polynuclear aromatic (COPNA) resin has excellent thermal stability and self-lubricating property which is popular for friction materials. However the cured resin has brittleness and poorly molding process due to its high cross-linking density. In this paper, the allyl-COPNA-BMI copolymer resin is prepared via a solution polymerization method, its structure, and its mechanical and tribological properties are investigated with FT-IR, SEM, TGA techniques. The copolymer anti-friction and anti-wear behaviors are tuned by varying the N,N’-4,4’-diphenylmethane-bismaleimide(BMI) monomer loading. The mechanical properties of the copolymer is the best when the BMI loading is 20 wt% upon these results. The tensile and impact strength of the copolymer/BMI 20 wt% is 12MPa and 13.9MPa, respectively. The lowest friction coefficient of copolymer/BMI 30wt% is 0.27, and its abrasion rate is 0.601510-6mm3/Nm. The initial thermal decomposition temperature of the copolymer/BMI 40wt% is 400 oC and 46.5 wt% of char residue ratio at 642 oC. The copolymer resins exhibit good thermal stability, abrasive resistance and mechanical properties compared to the pure COPNA.

An investigation into the relationship between the formation of thermal cracked components and PM reduction during diesel combustion using water emulsified fuel

Water-in-diesel emulsion fuel (W/O) operated in diesel engines, shows a significant reduction of particulate matter (PM). In this paper, PM reduction characteristics by thermal decomposition of W/O10 and W/O20 (10vol.% and 20vol.% of water in W/O respectively) are identified in diesel combustion atmosphere using a plug flow reactor with a co-flow diffusion burner. To analyze initial thermal decomposition at diesel diffusion combustion, the W/O fuels are thermally decomposed in the plug flow reactor first, then the thermally decomposed W/O fuels are introduced into a co-flow diffusion burner as fuel and PM are generated. In high temperature atmosphere without oxygen in the reactor, W/O10 and W/O20 are thermally decomposed and both of them almost produce light hydrocarbons (LHCs) higher than a diesel fuel, which means thermal decomposition before combustion are encouraged by the W/O. Excitation-emission matrix (EEM) method shows that polycyclic aromatic hydrocarbons (PAHs) are produced by both W/O fuels and diesel fuel during the thermal decomposition period but some W/O fuels oxidize a huge amount of PAHs in the later diffusion combustion. CO, CO2 measurements after the combustion of the thermal decomposed substances in the diffusion burner via high temperature reactor reveal that diffusion combustion of W/O fuels contribute to Soluble Organic Fraction (SOF) and Solid reduction which leads to reduction of CO and increase of CO2 respectively.

Polystyrene/kaolinite nanocomposite synthesis and characterization via in situ emulsion polymerization

The polymer nanocomposites polystyrene (PS)/kaolinite (Kao) were synthesized by in situ emulsion polymerization. First Kao was modified using dimethylsulfoxide (DMSO) by a displacement method (Kao-DMSO) and then styrene monomer was intercalated into kaolinite. Two types of nanocomposites were synthesized using 1 and 3 % weight (wt) of Kao-DMSO, respectively, (based on the monomer). The comparison between TGA analyses of nanocomposites with 3 % Kao-DMSO and virgin PS revealed that the thermal decomposition of the nanocomposites with clay began at 20 °C above the temperature of the initial thermal decomposition of virgin PS. This result showed the effect of clay on the thermal stability of PS. The influence of 3 % Kao-DMSO clay on nanocomposites was also observed during a flame retarding test, in which the burning rate was reduced by 50 % when compared to the burning rate for virgin PS.

Post-irradiation hardness development, chemical softening, and thermal stability of bulk-fill and conventional resin-composites

ObjectivesTo measure bottom/top hardness ratio of bulk-fill and conventional resin-composite materials, and to assess hardness changes after dry and ethanol storage. Filler content and kinetics of thermal decomposition were also tested using thermogravimetric analysis (TGA). MethodsSix bulk-fill (SureFil SDR, Venus bulk fill, X-tra base, Filtek bulk fill flowable, Sonic fill, and Tetric EvoCeram bulk-fill) and eight conventional resin-composite materials (Grandioso flow, Venus Diamond flow, X-flow, Filtek Supreme Ultra Flowable, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested (n=5). Initial and 24h (post-cure dry storage) top and bottom microhardness values were measured. Microhardness was re-measured after the samples were stored in 75% ethanol/water solution. Thermal decomposition and filler content were assessed by TGA. Results were analysed using one-way ANOVA and paired sample t-test (α=0.05). ResultsAll materials showed significant increase of microhardness after 24h of dry storage which ranged from 100.1% to 9.1%. Bottom/top microhardness ratio >0.9 was exhibited by all materials. All materials showed significant decrease of microhardness after 24h of storage in 75% ethanol/water which ranged from 14.5% to 74.2%. The extent of post-irradiation hardness development was positively correlated to the extent of ethanol softening (R2=0.89, p<0.001). Initial thermal decomposition temperature assessed by TGA was variable and was correlated to ethanol softening. ConclusionsBulk-fill resin-composites exhibit comparable bottom/top hardness ratio to conventional materials at recommended manufacturer thickness. Hardness was affected to a variable extent by storage with variable inorganic filler content and initial thermal decomposition shown by TGA. Clinical significanceThe manufacturer recommended depth of cure of bulk-fill resin-composites can be reached based on the microhardness method. Characterization of the primary polymer network of a resin-composite material should be considered when evaluating its stability in the aqueous oral environment.

Synthesis, characterization, and properties of a novel polyhedral oligomeric octamethyldiphenylsulfonylsilsesquioxane

A novel polyhedral oligomeric octamethyldiphenylsulfonylsilsesquioxane (OMDPSS) was synthesized from octaphenylsilsesquioxane and benzenesulfonyl chloride via a Friedel–Crafts reaction in high yield. OMDPSS was characterized by Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, and 29Si NMR spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS), wide-angle X-ray diffraction, differential scanning calorimetry, and elemental analysis, and found to be an amorphous polyhedral oligomeric silsesquioxane with a (RSiO3/2)8 structure. OMDPSS exhibited good solubility in commonly used solvents and superior thermal stability according to thermogravimetric analysis. Its initial thermal decomposition temperature (T d5%) was found to be 401 °C in air and 428 °C in nitrogen.

Outdoor natural weathering of bamboo flour/polypropylene foamed composites

Color and physico-mechanical properties change from 10 months of natural outdoor weathering for injection molded bamboo flour (BF)/polypropylene (PP) foamed composites were investigated. The composite surface morphology, before and after exposure, was observed by using environmental scanning electron microscopy (ESEM). Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the chemical structures. Natural weathering was shown to cause more discoloration and surface deterioration, while the physico-mechanical properties, rheological behavior, and thermal stability were less negatively affected for composites with higher BF amount ranging from 0 to 35 wt%. The rheological behavior results indicated decreases in the storage and loss moduli and the complex viscosity of weathered composites. Crossover frequency was found to increase and the average molecular weight decreased. The initial thermal decomposition temperature declined in foamed PP by 25℃ and in 35% BF/PP foamed composite by 6℃, indicating a slight decline in thermal stability, as shown by thermogravimetric (TG) analysis. Photodegradation, photooxidation, and matrices chain scission in the composites were confirmed by FTIR and XPS analyses.

Preparation and characterization of nanocomposite films by hybrid cationic ring opening polymerization of glycidyl-POSS

Epoxy-polyhedral oligomeric silsesquioxanes (G-POSS) monomers were synthesized from 3-glycidyloxypropyl-trimethoxysilane (GTMS) by hydrolytic condensation. The G-POSS-containing nanocomposite film was prepared by hybrid cationic ring-opening polymerization from G-POSS and GTMS. The curing reaction kinetics, dynamical mechanical properties, thermal degradation properties and morphological structures of G-POSS/GTMS system were investigated by non-isothermal DSC, dynamic mechanical analysis (DMA), TGA, AFM and SEM. The results show that the curing reaction activation energy Ea decrease when GTMS is added into the reaction system, and the curing reaction kinetics can be simulated by the Šesták–Berggren (S–B) model. DMA and TG analysis results show that the glass transition temperature Tg and initial thermal decomposition temperature Tid of materials is 4 and 65 °C higher than pure polymerized G-POSS, respectively, when the content of GTMS is 2 wt%. AFM analysis shows that the membrane surface of pure polymerized G-POSS has uniform distribution of less than 1.76 nm high protrusion. SEM analysis shows that have uniform spherical particle distribution on the membrane surface with about 20–25 nm diameter.

Preliminary understanding of initial reaction process for subbituminous coal pyrolysis with molecular dynamics simulation

A series of molecular dynamics simulations using the ReaxFF reactive force field was carried out to investigate the mechanism of initial thermal decomposition associated with pyrolysis of a kind of subbituminous coal. The calculation results show that the primary decomposition reactions of Hatcher subbituminous model begin with intramolecular changes such as the cleavage of unstable CC and CO bonds. The formation mechanisms for typical pyrolysis products were explored. For example, the initial pathway for the formation of CO is by the decarbonylation of carbonyl or carboxyl group, while CO2 is mainly produced by hydrogen transfer and decarboxylation of carboxyl groups. CH4 can be formed mainly by CH3 free radical abstracting a hydrogen atom from the hydroxyl group. H2 is formed by two hydrogen atoms from one or two groups bonding together, which makes the residue fragments more stable. Hydrogen can also react with oxygen-containing free radicals or unsaturated bonds. Combining ReaxFF molecular dynamics (RMD) simulation and density functional theory (DFT) calculation, we find that the free radical C9H9O is an important fragment during the pyrolysis process of Hatcher subbituminous model. As a precursor for cresol, it can capture hydrogen radical to form intermediate C9H10O and may continue to produce o-cresol and ethylene in the presence of hydrogen resource. These simulation results for the initial pyrolysis process and the reaction mechanisms agree with previous experimental observations.

Synthesis, characterization, and properties of a polyhedral oligomeric octadiphenylsulfonylsilsesquioxane

ABSTRACTA novel polyhedral oligomeric octadiphenylsulfonylsilsesquioxane (ODPSS) was synthesized from octaphenylsilsesquioxane and benzenesulfonyl chloride via a Friedel–Crafts reaction with a high yield. ODPSS was identified by Fourier transform infrared spectroscopy, 1H‐NMR, 13C‐NMR, 29Si‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI–TOF MS), wide‐angle X‐ray diffraction, and elemental analysis to be a kind of polyhedral oligomeric silsesquioxane of a T8R8 structure. ODPSS exhibited superior thermal stability according to thermogravimetric analysis. Its initial thermal decomposition temperature (Tonset) was at 491°C in air and 515°C in nitrogen. Thermal and mechanical properties of epoxy resin (EP) composites with ODPSS added were studied by differential scanning calorimetry and tensile testing. The results show that the incorporation of ODPSS at a low loading content not only improved the glass‐transition temperature of the EP composites but also enhanced their tensile strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40892.

Combination effects of carbon nanotubes, MMT and phosphorus flame retardant on fire and thermal resistance of fiber-reinforced epoxy composites

The present work aims to enhance thermal stability and flame retardancy of the epoxy/glass composites containing carbon nanotubes (CNTs). To achieve this purpose ammonium polyphosphate (APP) as a micro filler and montmorillonite (MMT) as nanofiller have been used. Since good dispersion is necessary to achieve thermal and flame resistivity in nanocomposites, it was found that combination of ultrasonication and high shear flow can result in a good dispersion of nanoparticles in polymer matrix. Thus, all samples were prepared according to this method. In order to study thermal resistance and flame retardancy of the samples, thermal gravimetric analysis (TGA) and limiting oxygen index (LOI) have been employed, respectively. TGA results showed that combination of 0.5 wt% CNTs with either 5 wt% MMT or 15 wt% APP can increase the initial thermal decomposition temperature up to 62 °C for the former polymer composite and 47 °C for the latter one. Overall stabilization effect (OSE) and integral procedure decomposition temperature (IPDT) parameters have also been calculated from TGA data. These results showed that the sample containing a combination of APP and CNT has the highest value of OSE. Moreover, IPDT of this sample has increased about 9 % compared with the neat epoxy. LOI of the samples showed that the addition of MMT and CNTs together could increase LOI about 8 % and introduction of APP to these samples increased LOI about 10 %, as well.

Molecular dynamics simulation on thermal decomposition mechanism of CL-20with different polymorphs

The initial thermal decomposition pathways of the supercell structures of e, β and γ modifications at different temperatures were studied by molecular dynamics simulations, using the ReaxFF force field, the NPT and NVT ensembles and the Berendsen methods.The results show that the initial pathway of different CL-20polymorphs is only the N-NO2dissociation to forming·NO2radical fragments, and the main thermal decomposition products are N2, H2O, CO, CO2, NO2, NO3, HNO2, HNO3, N2O5, N2O2and NO.The reaction rate constants of main products with the same modification increase with the increasing of temperature.

Synthesis and characterization of a novel laser ablation sensitive triazene incorporated epoxy resin

New triazene monomer was synthesized and further employed as a crosslinking agent partner with epoxy matrix using ethyl methyl imidazole as a curing agent in order to investigate the effect of triazene moieties on polymeric properties for laser ablation application. The synthesized triazene monomer was characterized by analytical and spectroscopic methods, while the surface morphology of resist after laser ablation was visualized by optical laser scanning images and scanning electron microscopy. Thermogravimetrical investigations indicate the loss of nitrogen being the initial thermal decomposition step and exhibit sufficient stabilities for the requirements for laser ablation application. Fourier transform infra-red, nuclear magnetic resonance, and gas chromatography analyses showed the successful synthesis of triazene. The ablation results from the optical laser scanning images revealed that the etching depth could be controlled by varying the concentration of triazene monomer in the formulation of epoxy. The shear strength analysis revealed that that the shear strength increased with increasing the amount of triazene in the formulation of direct ablation sensitive resist.

A graphene hybrid material functionalized with POSS: Synthesis and applications in low-dielectric epoxy composites

Abstract A graphene hybrid material functionalized with octa-aminophenyl polyhedral oligomeric silsesquioxanes (OapPOSS) was synthesized and a new application of OapPOSS-g-GO was reported. The structure of OapPOSS-g-GO was confirmed by TEM, HRTEM, SEM, FTIR, XRD, Raman and Uv–vis. The OapPOSS functionalized graphene nanosheets can disperse homogeneously in various organic solvents. Moreover, the thermal stability of the OapPOSS-g-GO was improved and the initial thermal decomposition temperature was significantly increased from 75.2 to 394.5 °C compared to that of pure GO by thermal gravimetric analysis (TGA). With the incorporation of only 0.2 wt% OapPOSS-g-GO, at 10 4 Hz the dielectric constant and dielectric loss of OapPOSS-g-GO/epoxy composites dropped by 9% and 49% compared to the neat epoxy composites. This dramatically reduced dielectric constant and dielectric loss can be explained in terms of cage silsesquioxane cores of the OapPOSS and the movement of OapPOSS and polymer chains being limited by GO nano-platelet, resulting in a loose and the immobile epoxy structure. This approach provides a strategy to reduce the dielectric constant of epoxy composite materials with ultra-low filler content.

용액 농도에 따른 항균성 알긴산 아연 필름의 제조 및 그 특성

Alginate를 농도 별로 용액상태로 제조한 후 필름 메이커를 이용하여 필름 형태로 만든 후 3 wt%의 <TEX>$ZnCl_2$</TEX> 수용액에 필름을 고화시킨 후 수세하여 <TEX>$60^{\circ}C$</TEX>의 건조기에서 약 20분 동안 건조시켜 zinc alginate 필름을 제조하였다. 필름의 특성을 조사하기 위하여 항균성 및 점도와 FTIR, TGA, SEM, EDS 및 접촉각, 인장측정, 용해도분석 등을 측정하였다. 항균성 시험 결과, zinc alginate 필름에서는 두 균주(포도상구균, 폐렴간균) 모두 우수한 항균력이 나타나는 것을 확인하였다. 9 wt%의 sodium alginate로 제조한 zinc alginate 필름의 표면은 다른 농도별 필름보다 균일한 형태를 나타내었으며, <TEX>$ZnCl_2$</TEX> 응고액에 잘 고화될 때 단단하고 거친 느낌의 단면 형태를 확인하였다. Zinc alginate 필름의 인장강도는 가교결합에 의해 sodium alginate 용액의 농도가 증가함에 따라 증가하였으며, 초기 열 분해 온도가 점차적으로 높아지고 있는 형태를 보였다. Zinc alginate films were prepared by a film maker from sodium alginate solutions of different weight ratios and then they solidified into 3 wt% content <TEX>$ZnCl_2$</TEX> coagulation solution and washed and dried at a <TEX>$60^{\circ}C$</TEX> oven for 20 min. The characteristics were measured by several methods (antimicrobial activity, viscosity, FTIR, TGA, SEM, EDS, contact angle, tensile strength and solubility) and the film properties were investigated. The antimicrobial test showed that the zinc alginate films result in excellent antimicrobial activity in the two strains (Klebsiella pneumonia, Staphylococcus). The surface of zinc alginate film from the solution of 9 wt% sodium alginate showed more uniform shape than any other films and the cross-section were hard and rough when the films were well-solidified by the <TEX>$ZnCl_2$</TEX> solution. The tensile strength of zinc alginate films increased along with the concentration of sodium alginate solution due to the cross-linking, and the initial thermal decomposition temperature increased gradually.

Thermal stability and sensitivity of RDX-based aluminized explosives

The thermal decomposition characteristics and thermal sensitivity are key indicators for reflecting the thermal stability of explosives in storage and application. The thermal decompositions in different degrees are used to determine the dominant factor which controls the thermal stability of composite explosive. Four kinds of RDX-based aluminized explosives are marked as RA1, RA2, RA3, and RA4 with the Al content increasing from 10 to 40 mass%. The initial thermal decomposition behaviors were studied by DPTA and the complete thermal decompositions were studied by DSC and TG. The thermal sensitivities were characterized by 5-s explosion point. The effects of micron-sized Al particles and their contents on thermal decomposition were investigated. The evolved gas amount (V i) from DPTA test follows RA3 < RA4 < RA2 < RA1, indicating that RA3 has the best thermal stability at ambient storage conditions. However, according to TG and DSC tests, the characteristic temperatures of thermal decomposition (T p, T b, and T SADT), the thermodynamic parameters (∆H e, ∆S ≠, and ∆H ≠), the kinetic parameters (E a and A), and the 5-s explosion points all follow RA4 < RA3 < RA2 < RA1. The results indicate that the Al particles play different roles in the different degrees of thermal decomposition. In the initial decomposition, the Al particles have not been activated and are considered as inert materials that hinder the decomposition of explosive. In the complete decomposition, the Al particles catalyze the thermal decomposition, and such catalysis becomes more obvious as the Al content increases to a certain degree.

Flammability and thermal properties of epoxy/glass/MWNT Composites

ABSTRACTThe aim f this work is to study the effect of nanotubes on flammability properties of epoxy/glass composites. Multiwalled carbon nanotubes (MWNT) and its functionalized derivative (amino functionalized nanotubes) were incorporated into epoxy resin. To disperse MWNTs in the epoxy resin, different ways were employed. Microscopic observations showed that, the best dispersion state was gained by using ultrasonication method and high shear flow simultaneously. Thermal resistance of cured epoxy resins containing various amounts of nanotubes (0.25–0.7 wt %), was investigated by thermo gravimetric analysis (TGA). Introducing MWNTs and amino‐MWNTs to samples increased the initial thermal decomposition temperature for about 32 and 37°C, respectively. LOI measurements of composite samples showed an increase up to 32. Cone calorimetry test was carried out on epoxy/glass and epoxy/glass containing 0.5% MWNT. The results showed that, introducing 0.5% MWNTs decreases maximum average rate of heat emission for about 26%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39849.