In this study, epoxy (EP)/binary spherical alumina (S-Al2O3) composites with a high loading of 50 vol% were fabricated by incorporating different sizes of S-Al2O3 into EP to increase the thermal ...conductivity and yet retain the flowability of the composites. Notably, a distinctly reduced viscosity (21.8 Pa·s) and a highly increased thermal conductivity (1.364 W/m·K) were achieved by a binary S-Al2O3 mixture with 80% 30 μm and 20% 5 μm alumina that would have a theoretical maximum packing volume, thus permitting larger available free volume for the motion of particles and hence reducing the friction between them. Also, these EP/S-Al2O3 binary composites possessed superior electrical insulation, high thermal stability, significantly reduced thermal expansion coefficient and good mechanical properties. These combined desirable properties indicate that binary S-Al2O3 mixtures with an optimized size distribution and maximum packing volume are best candidates to develop high-performance epoxy-based underfill materials which would improve the flip-chip reliability.
Sprouting is a natural process that enhances the nutritional and sensory profile of cereal-based foods. The present work addressed the possibility of using refined flour from sprouted wheat (SWF) to ...improve the bread-making performance of some flours in place of conventional improvers - i.e. enzymatic improver (EI) and malt (M). Either 0.5% EI or M was added to the control flour (CTRL), as conventionally used in bakeries, whereas SWF was used up to 2%. Unlikely EI and M, 1.5% SWF showed a gluten aggregation strength similar to that of the CTRL, suggesting no worsening of the protein network characteristics. As for the leavening properties, dough development increased, thanks to the enrichment with 1.5% SWF. In addition, presence of SWF improved the amount of gas production during leavening-resulting in bread with high specific volume - and the crumb softness during storage. Addition of SWF may represent a valid alternative to enzymatic improvers or malt for improving the technological performance of wheat flours.
•Sprouting was carried out in an industrial plant under controlled conditions.•Sprouting enhanced the enzymatic activities of the flour.•Sprouted wheat flour (SWF) improved dough properties even at low percentage (1.5%).•SWF can replace conventional processing aids, as malt or other enzymatic improvers.
•NMR cryoporometry was adopted to the characterization pore size distribution in coal.•NMR intensity result for the coal was calibrated to get reliable pore size distribution.•NMR cryoporometry ...yields a higher pore volume magnitude, compared to low-temperature liquid nitrogen adsorption and desorption (LTNAD).•Pore size distribution can be directly obtained by NMR cryoporometry, based on the linear relation between pore volume and signal intensity and the relationship between the melting point and pore size.
The characterization of coal pore structure is extremely important to coalbed methane exploitation and the prevention of gas disaster in coal mines. Various techniques have been employed to characterize the pore size distribution (PSD) in coals. Nuclear magnetic resonance (NMR) cryoporometry is a relative new technique that can be applied to obtain PSD of porous materials. However, seldom works has been done on coals by NMR cryoporometry. In this paper, PSD of six coal samples ranges from medium to high rank are measured by NMR cryoporometry. Low-temperature liquid N2 adsorption and desorption (LTNAD) experiments are also carried out on the same samples for the comparison analysis. NMR cryoporometry can directly obtain the PSD from the linear relation between pore volume and signal intensity and the relationship between the melting point and pore size. It was also found that there is a good correlation between the results obtained by NMR cryoporometry and LTNAD. It was found that NMR cryoporometry yields higher pore volume value than LTNAD. Drying induced pores shrinkage/collapse in LTNAD measurement is the main reason causing pore volume measured by NMR cryoporometry is larger than by LTNAD. We also found the difference between NMR and LTNAD correlated with the coal moisture content. Based on the obtained experimental data, it is found that the influence of moisture content on the difference between these two techniques decreases with the increase of pore specific volume.
•Starches isolated from frozen soft and hard wheat dough were investigated.•Freezing effect was more pronounced in hard group than in the soft group.•Freezing-treated hard wheat starch (HWS) had more ...damaged starch.•HWS showed lower amounts of proteins, lipids and amylose after freezing treatment.•Freezing-treated HWS had a lower bread specific volume and harder crumb firmness.
Properties of starches isolated from soft and hard wheat dough after freezing/thawing (F/T) treatment were investigated. Significance of results was observed between isolated hard wheat starch (HWS) and soft wheat starch (SWS), but both cultivars showed an increase in the amounts of damaged starch and leaching proteins, lipids, and amylose with F/T cycles. The freezing-treated HWS exhibited a higher swelling power and peak, trough, breakdown and final viscosity than SWS after F/T treatment. The onset, peak and conclusion gelatinization temperatures and the enthalpy of the isolated HWS determined by differential scanning calorimetry, decreased throughout F/T cycles. Concomitantly, the bread containing freezing-treated HWS exhibited a lower bread specific volume and harder crumb firmness, which might be associated with its significant structural changes induced by F/T treatment.
Deep eutectic solvents (DESs) make up a most-recent category of ‘green’ solvents with a potentially promising future. Insignificant vapor pressure, biodegradability, low cost, task-specific ...engineering, and high absorption for gases such as CO2 are the most important characteristics of most DESs. To apply DESs in various industries, knowledge of their physical properties is vital. Since the viscosity of a DES is a strong function of temperature, as well as the ratio of the hydrogen bond donating and accepting components, to estimate the viscosity behavior, a model based on sound theory is proposed in this study, i.e., the free volume theory. Since DESs are strongly associating components, this theory is enriched by using associating equations of state, namely CPA and PC-SAFT. In this study, a large density and viscosity databank of 27 DESs of different nature, also with varying molar ratios of the hydrogen bond donor and acceptor, were used to propose the model. In this way, a global model is presented for the first time to estimate the viscosities of DESs. The pseudo-component approach, with a 2B association scheme, was considered for the DESs. Both the CPA and the PC-SAFT EoSs, coupled with the free volume theory, showed reliable results, with average AARD% values in viscosity for all of the investigated DESs equal to 2.7% and 2.7%, respectively. Furthermore, both models reliably showed the trend of nearly logarithmic increase in DES viscosity with decreasing temperature. Also, both models accurately estimated the viscosity behavior of the DESs by not only changing the molecular nature of the hydrogen bond donor with a fixed hydrogen bond acceptor, but also at all of the various molar ratios investigated.
•General models are proposed for the viscosities of various families of DESs.•The viscosities of the DESs are modeled by the free volume theory.•The CPA and PC-SAFT EoSs are coupled with the free volume theory.•Total AARD% values below 3% show the reliable results of both proposed models.
In order to simulate nanofluid MHD transportation in a permeable cavity, Darcy law is utilized. Impacts of radiation parameter, buoyancy and Lorentz forces on nanofluid characteristics have been ...depicted via CVFEM. Al2O3-water nanofluid is selected considering shape factor and Brownian motion impacts on its properties. Results reveal that conduction mode improves with rise of magnetic forces. So, thermal boundary layer becomes thinner with increase of magnetic forces.
•Nanofluid natural convection in porous media is simulated using CVFEM.•Radiation and magnetic field effects are taken into account.•Darcy model is selected for porous media.•Nuave augments with rise of radiation parameter.
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