•There were pure samples of three phenyl derivatives of cyclopropene.•Combustion energies of these compounds were determined by bomb calorimetry.•Sublimation enthalpies of were obtained on ...differential microcalorimeter.•Enthalpies of formation in the solid and gas states have been calculated.•Enthalpies of three new group contributions to Cohen additive scheme were estimated.
The energies of combustion of crystalline 1-methyl-2,3,3-triphenylcyclopropene (C22H18), methyl2,3-diphenylcycloprop-2-ene-1-carboxylate (C17H14O2) and 1,2,3-triphenylcyclopropene (C21H16), were determined in isoperibolic calorimeter at T = 298.15 K. The enthalpies of sublimation were measured by isothermal heat-conducting differential microcalorimeter (“Setaram”) at T = 298.15 K. The enthalpies of formation in the crystalline and gaseous states were calculated. The values of enthalpies of three group contributions: C-(Cd)2(Cb)2, C-(Cd)2(CO)(H) and C-(Cd)2(Cb)(H), which absents in the Cohen additive scheme, were estimated.
This paper presents a complete methodology for the assessment and modelling of the flammability and fire resistance of carbon fibre (CF) reinforced thermosets (three different types of epoxy) and a ...thermoplastic resin (PEEK) used for the fuselage of modern aircrafts. A global ranking of the composites is presented for thermally thin conditions (1 mm thick) using thermogravimetric analysis (TGA) and cone calorimeter measurements and four parameters for thermally intermediate conditions (4 mm thick) including a fire growth parameter, a smoke parameter, a toxicity parameter and the final mass residue. In addition, the shielding/charring effect of CF layers was characterised by modelling the reduction in the imposed heat flux due to this layer together with the previously determined thermal properties. By measuring the temperature at the back insulated surface of the composite in the cone calorimeter, we can also assess the fire resistance (integrity) of the composite and the heat transferred to the insulation behind this fuselage composite material in the aircraft application.
•Comparative study of flammability and fire resistance of carbon fibre reinforced thermosets and thermoplastic.•Application of a ranking method based on flammability and toxicity parameters for carbon fibre polymer composites.•Modelling effects of carbon fibre layers using the concept of heat flux ratio.•Assessment of heat transferred to the insulation behind a composite material.
This study presents the evaluation of an emergent co-product generated during the production of jaboticaba juice by steam drag: the jaboticaba pomace. A comparison of physicochemical, technological ...and morphological properties of the jaboticaba powders obtained from the pomace, from the whole fruit and from the peel was performed. All the powder samples underwent the same processing: freeze-drying, milling and sieving. The powders appeared reddish, with an average diameter of approximately 64.83–103.51μm and pH values of 3.45–3.74, water activity of 0.3133–0.3270, water holding capacity of 2.63–4.28g H2O/g and oil holding capacity of 2.79–2.98g oil/g. Differential scanning calorimetry analysis showed that the endothermic peak temperature was 158.9–164.4°C. Proximate composition analysis showed a large amount of total dietary fibre and insoluble dietary fibre in jaboticaba pomace (20.54 and 16.42g/100g, respectively), while jaboticaba peel had a good amount of soluble dietary fibre (10.72g/100g). Jaboticaba pomace had a large quantity of phenolic compounds (43.39mg GAE/g d.w.), especially monomeric anthocyanin (3.92mg cyanidin-3-glucoside/g d.w.), compared to the whole fruit. Jaboticaba pomace is valuable due to its high phenolic content (2.5 times higher than the whole fruit) and total dietary fibre content (2.2 times higher than the whole fruit). The results obtained in this study reinforce the idea that this co-product could be re-used in the development of functional ingredients and show that the industrialisation of these materials is one possible alternative for food diversification. Pomace powder could be added to many types of foods, such as cereals, snacks, drink mixes, and breads, or could be used for pharmaceuticals, such as slow-release antioxidants in packaging films.
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•Jaboticaba pomace is an emerging co-product from Brazil.•The co-product obtained during jaboticaba juice extraction is a source dietary fibre.•The co-product obtained during jaboticaba juice extraction is a source polyphenols.•Scanning electron micrographs of samples showed no differences.•The thermal and thermodynamic properties of samples were studied.
Scintillating molybdate crystals recently got significant attention for their applications in rare event searches, such as neutrinoless double beta decay experiments. In this paper, we report on the ...light collection of cryogenic calorimeters operating at 10 mK, using CaMoO 4 (CMO), Li 2 100 MoO 4 (LMO), and Na 2 Mo 2 O 7 (NMO) crystal absorbers. Scintillation signals from gamma rays and alpha particles are studied. Germanium (Ge) and Silicon (Si) wafers, which work as light absorbers, coupled to Metallic Magnetic Calorimeters (MMC), are used as scintillation light detectors. By comparing the scintillation signals with "direct hit" X-ray signals of known energies, which occurred in the light absorber, we assess the light collection of the crystal scintillation. 8 keV copper X-rays are analyzed in the case of both the Ge and Si wafer detectors. The light measurement with LMO and NMO crystals at millikelvin temperatures is 9.6 and 7.6 times less compared with the CMO for 2.615 MeV gamma rays from 208 Tl. Additionally, we found that for NMO, the detected scintillation light for alpha particles is quenched by a factor of 0.06 compared to that of gamma rays for a given energy by investigating the light signal from 2.615 MeV gamma rays and 5.4 MeV alpha particles. For the CMO, in the same way, the quenching factor is measured to be 0.22. The quenching factor for 4.785 MeV alpha particles ( 6 Li neutron capture) in LMO crystal is about 0.28 compared to the scintillation from 2.615 MeV gamma rays.
A novel α, ω-dicarboxyl aromatic polyphosphonate (HP-1001-COOH) was synthesized and characterized. It was used as a reactive flame retardant for diglycidyl ether of bisphenol A (DGEBA)/methyl ...tetrahydrophthalic anhydride (MeTHPA) cured system. The thermal, mechanical and flame retardant properties of the cured epoxy resins were examined. The glass transition temperature (Tg) of the cured epoxy resins decrease with the increasing of the HP-1001-COOH content. The mechanical properties of cured films were slightly affected, although the crosslinking density decreases with the incorporation of HP-1001-COOH. The onset decomposition temperatures and the maximum-rate decomposition temperatures decrease, while the char yields increase with the increase of the phosphorus content. When the mass fraction of HP-1001-COOH is 30 wt%, the epoxy thermosets reaches a LOI value of 32.4% and successfully pass UL-94 V-0 rating. The heat release rate (HRR), peak heat release rate (P-HRR), total heat release (THR), average of effective heat of combustion (AvEHC) and total smoke production (TSP) of the flame retardant epoxy resins decrease significantly compared with neat epoxy resin. The macro-morphology and micro-morphology of the residues after cone calorimeter tests show that the flame retardant epoxy thermosets compact char layers are formed to prevent the transmission of heat and gases during combustion process, and the main structure in the char residues of the phosphorus-containing epoxy resins are polyaromatic carbons and phosphate esters.
•An overview of previously described heat-flux thermopile sensors is presented•A new inexpensive high-temperature inverse drop calorimeter was designed and built•The performance of the calorimeter ...was tested in drop and drop solution experiments
A new high-temperature (up to at least 1273 K) setup for inverse drop calorimetry was designed and assembled. This calorimeter uses a differential thermopile as a heat-flow sensor. The thermopile design features significant number of thermocouple junctions at the bottom of the measurement crucible in addition to those surrounding its side surface. The samples, held at room temperature, can be introduced through an autosampler into the crucible inside the calorimetric cell, heated up by means of a homebuilt three-winding wire furnace with large isothermal zone. The calorimeter performance in drop experiments was verified and compared with that of a commercially available device of the same kind. In addition, a few drop solution experiments were made; obtained, as a result, enthalpies of formation of CsPbX3 (X = Br, I) were found to be in agreement with those reported earlier.
In this study, a refrigerant evaporating temperature control algorithm was developed for the variable refrigerant flow (VRF) system, and its effect was quantitatively examined through a ...multi-calorimeter experiment and a field test in actual buildings. As previous studies on refrigerant evaporating temperature control have been predominantly conducted through experiments and simulation, aspects such as the impact of refrigerant evaporating temperature control on energy-saving and indoor temperature in an actual building and the change in the energy efficiency of the VRF system due to the Thermo on–off change of indoor units, have not been examined. As such, in this study, an algorithm that predicts the indoor load based on the indoor temperature change and controls the refrigerant evaporating temperature based on the load was developed. Before applying the developed algorithm to actual buildings, the effectiveness of refrigerant evaporating temperature control was evaluated through an experiment. Changes in the performance and efficiency of the VRF system according to the evaporating temperature and the number of operating indoor units were measured in a multi-calorimeter, and the effect of refrigerant evaporating temperature control on the reduction in the actual number of operating indoor units due to the Thermo off was examined under part-load conditions. In addition, the developed algorithm was applied to the office and education buildings in a factory located in Thai Nguyen city, Vietnam, and its energy-saving effect on the indoor temperatures was verified as per the energy effect verification process provided by the International performance measurement and verification protocol (IPMVP). The verification results confirmed that conducting refrigerant evaporating temperature control saves energy by increasing the Thermo on rate and the refrigerant evaporating temperature. It was additionally confirmed through the actual operation data that refrigerant evaporating temperature control has the effect of improving the indoor thermal environment by increasing the accuracy of indoor temperature control.
With today's challenges regarding antibiotic resistance and the importance of the implementation of prudent use of antibiotics, fast and reliable diagnostic tools for bacterial infections and ...subsequent antimicrobial susceptibility testing are of utmost relevance. Isothermal microcalorimetry (IMC) is a broadly applicable method, with which metabolic heat flow in reproducing bacteria can be measured in real time. To the best of the authors' knowledge, this is the first report on examination of 124 urine samples from feline and canine urinary tract infection with an IMC-based prototype instrument. A concentration-dependent time of peak heat flow by dilution series with Escherichia coli and Enterococcus faecalis reference strains demonstrated the general good performance of the prototype for detection of these bacteria. With diagnostic culture being set as a gold standard, the diagnostic sensitivity of IMC compared to bacteriological culture was 80 %, the diagnostic specificity was 97 %. With a Cohens' kappa value (κ) of 0.80, the two methods show good concordance. The results from our study demonstrate that the IMC technology is suitable to allow reliable, but much faster detection of bacteria than conventional culture, especially for Escherichia coli. Thus, implementing IMC technology could markedly speed up the bacteriological diagnostic process in veterinary medicine.
Five SO42−/TiO2-MXOY solid super acids (SSA: Cu@Ti:SSA, Zr@Ti:SSA, Fe@Ti:SSA, Mn@Ti:SSA, Mo@Ti:SSA) were successfully prepared by sol–gel method, and its chemical structure and element content were ...characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy (EDS). Then, a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite (AM) were was introduced into an unsaturated polyester resin (UPR) to enhance the flame retardance. The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index (LOI), cone calorimeter test (CCT) and thermogravimetric analysis (TGA). The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA. Moreover, their heat release rate (HRR), total heat release (THR), the smoke production rate (SPR) and CO and CO2 yield were much decreased. In addition, the initial decomposition temperature of UPR/AM/SSA was delayed, indicating that their thermal stability was increased, and the residual char of UPR/AM/SSA was also increased due to strong catalytic of SSA ability for esterification and dehydration. Furthermore, the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy (SEM), and it was found that the char layer structure was more continuous and dense after the addition of the SSA. In sum up, the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.
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