Analysis Of Thermal Properties Research Articles

THE EFFECT OF METHYL METHACRYLATE ON THE PROPERTIES OF SYNTHESIZED ACRYLATE EMULSIONS

The effect of methyl methacrylate (MMA) addition on the properties of synthesized acrylate emulsions based on butyl acrylate (BA) and 2-ethylhexyl acrylate (EHA) was investigated. The samples were synthesized by addition of MMA in copolymer structure, ranging from 10 to 50 wt% of the total mass of BA and EHA. Fourier transformation infrared (FTIR) spectroscopy was used to analyze the molecular structure of synthesized acrylate emulsions and the results confirmed that a quantitative polymerization reaction occurred. The analysis of thermal properties showed that the addition of methyl methacrylate increases the glass transition temperature of the acrylate films obtained by drying the synthesized emulsions. The tensile strength and elongation at break increased proportionally with the increase of the content of MMA in the synthesized samples. Since the obtained acrylate materials can be used to improve the water impermeability of paper and other materials, the obtained emulsion was applied in a thin layer on a sheet of paper and the resistance of the paper to water and oil was investigated. The results showed that all emulsions were impermeable both to water and oil.

Analysis of Thermal and Light Properties of Greenhouse Considering Greenhouse Sheets Characteristics in Hot and Humid Area in Asia

Food market in Asia is expanding at dramatic rate. In the near future, there will be about 400 million rich people who will eat raw vegetables as well as Japanese people, which is a great business opportunity for the farmer in Japan who has the know-how to produce high-quality vegetables. However, the weather conditions in Asia, especially in south-east Asia, can induce poor growth of plants because of its distinctive high temperature and humidity. In this case, putting a light shielding material on the outside of film can be a good method for cooling the greenhouse. In this study, the authors investigated the effects of some greenhouse shielding sheets on the environment of greenhouse in hot and humid regions of Asia. Consequently, it became possible to analyze the degree of suppression of the temperature rise of the greenhouse due to absorption of heat rays using shielding materials for the greenhouse at high temperature and its mechanism. It was suggested that focusing on the physical value of the film such as absorption rate is important by this simulation.

Numerical Analysis of Heat Transfer and Thermal Property in Vacuum Insulation Panel

Numerical Analysis of Heat Transfer and Thermal Property in Vacuum Insulation Panel

Sodium acetate trihydrate-based composite phase change material with enhanced thermal performance for energy storage

Sodium acetate trihydrate (CH3COONa·3H2O, SAT), as the medium-low temperature phase change material (PCM), has been broadly utilized in thermal energy storage system. The specific objective of this study was to develop a new SAT-based composite PCM (CPCM) in order to restrain the supercooling and phase segregation of pure SAT. In this dissertation, SAT-CN/Nano-Cu was synthesized by adding carboxymethyl cellulose (CMC), sodium chloride (NaCl) and Nano-copper (Nano-Cu). The experimental results manifest that CMC is resultful to constrain phase separation of pure SAT. Supercooling degree of pure SAT is reduced from 30°C to less than 5°C by the addition of varying NaCl content. The Nano-Cu was furnished to further prevent the supercooling phenomenon of CPCM as well as intensify the heat transfer characteristics of pure SAT. Thermal properties containing thermal conductivity, latent heat and specific heat capacity were systematically analyzed using DSC and thermal properties analyzer. The analysis results demonstrate that a satisfactory thermal conductivity, high latent heat and inclusive of an appropriate specific heat capacity are achieved by the SAT-CN/Nano-Cu. In short, this work reported optimum CPCM consisted of SAT, 3 wt% CMC, 4 wt% NaCl and 0.8 wt% Nano-Cu that possesses superior phase change performance. Additionally, admirable thermal stability is retained by the CPCM.

First-principles analysis of phonon thermal transport properties of two-dimensional WS2/WSe2 heterostructures* *Project supported by the National Natural Science Foundation of China (Grant Nos. 51720105007, 51806031, 11602149, and GZ1257) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. DUT16RC(3)116 and DUT19RC(3)006). The computing resources from Supercomputer Center of Dalian University of Technology and ScGrid are greatly acknowledged.

The van der Waals (vdW) heterostructures of bilayer transition metal dichalcogenide obtained by vertically stacking have drawn increasing attention for their enormous potential applications in semiconductors and insulators. Here, by using the first-principles calculations and the phonon Boltzmann transport equation (BTE), we studied the phonon transport properties of WS2/WSe2 bilayer heterostructures (WS2/WSe2-BHs). The lattice thermal conductivity of the ideal WS2/WSe2-BHs crystals at room temperature (RT) was 62.98 W/mK, which was clearly lower than the average lattice thermal conductivity of WS2 and WSe2 single layers. Another interesting finding is that the optical branches below 4.73 THz and acoustic branches have powerful coupling, mainly dominating the lattice thermal conductivity. Further, we also noticed that the phonon mean free path (MFP) of the WS2/WSe2-BHs (233 nm) was remarkably attenuated by the free-standing monolayer WS2 (526 nm) and WSe2 (1720 nm), leading to a small significant size effect of the WS2/WSe2-BHs. Our results systematically demonstrate the low optical and acoustic phonon modes-dominated phonon thermal transport in heterostructures and give a few important guidelines for the synthesis of van der Waals heterostructures with excellent phonon transport properties.

Thermal Property Analysis and Characteristic Study of Ploy Ethylene Glycol with Diverse Molecular Weight for Thermal Energy Storage Material

In this study, the investigation on thermal property and characteristic analysis of Poly Ethylene Glycol (PEGs) material by varying the molecular weights is examined. In this context, the study on thermal energy material storage is explored by using the different techniques such as Differential Scanning Calorimetry (DSC) for persistent heating rate and Thermal Gravity Analysis (TGA) for determining the amount of change of mass of the material in addition to the function of increasing temperature. Subsequently, the characterization of PEGs with different molecular weight is carried out to explore the property and insight of the material by using the Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) by examining the surface topology, crystallography in addition to this the X-Ray Diffraction (XRD) techniques for catch a glimpse of the crystal structure is studied. As an outcome, in the DSC techniques the results made known when the molecular weight increases, correspondingly the melting temperature and solidification temperature similarly increases however, the heat of fusion during the freezing cycle increases. In the TGA techniques, similarly specified increases in the volume of PEG with different molecular weight has resulted in an increase in the temperature. Subsequently, in the characterization of the PEGs, the SEM has shown an enormous amount of insignificant sphere-shaped crystal-like structures which are joined together and impinging on their neighbour’s which paved the way for the formation of a multi-layered lamellar structure in due course activated rise in the solidification temperature in its molecular weight. Henceforth, from the analytical studies, it’s been evident that the molecular weight greatly influences the mechanical and thermal properties of PEGs. In this concern, the PEGs blends are a potential benefit to replace pure components.

Heat-Treated Charge-Transfer Polymer Blend Membrane for Application in Polymer Electrolyte Fuel Cells

IntroductionWe developed polymer blend type electrolyte membranes (PEMs) using charge-transfer (CT) interactions for polymer electrolyte fuel cells (PEFCs) and evaluate effect of heat treatment to characteristics and performance of the CT polymer blend membranes.CT interaction is one of molecular interaction, and CT complex can be formed by electron accepting units and donating units which have optimal molecular structures. CT complex formation was applied to control the position of proton conductive groups in PEMs. By applying this characteristic, we have developed CT complex polymer hybrid membranes. Especially, CT polymer blend consisting of two polymers, electron-accepting sulfonated polyimide (SPI) and -donating polyether (Poly-DAN), showed high mechanical strength and gas barrier property.[1] During this study, it was confirmed that CT complex concentration increased by heat treatment. In this study, to further understand the effect of CT complex formation on PEM performance, heat treatment was performed to enhance the extent of CT complex formation in the membrane.ExperimentalIn this work, we used two model polymers with simple chemical structure. Sulfonated polyimide homopolymer (SPI) was used as the electron-accepting polymer, while polyether-containing electron-rich dialkoxynaphthalene (Poly-DAN) was used as the electron-donating polymer.[2]SPI/Poly-DAN blend membranes were prepared with or without a heat treatment step.SPI and Poly-DAN can form a CT complex in the blend membrane during solvent evaporation at 60 °C in vacuo, and CT blend membranes without heat treatment were thus obtained. Heat-treated CT blend membranes were obtained by heating at 150 °C in a N2 atmosphere for several hours. The heat-treated membranes were then immersed in water to remove thermally decomposed sulfuric acid moieties.Visible spectroscopy was used to confirm CT complex formation and the amount. Thermal property, mechanical strength and structural analysis of the CT blend membranes were evaluated by TGA, tensile test, 1H NMR etc. IEC, proton conductivity and fuel cell performance at 80˚C and 110 ˚C were also evaluated.Results and discussionA characteristic absorbance is observed in the visible spectra of the untreated and the heat-treated membranes at 530 nm. After heat treatment at 150 °C for 50 h, the concentration of CT complex in the membrane was significantly enhanced by about 13 times. The 1H NMR and FT-IR results suggest that the main chain structure of SPI does not significantly change during heat treatment. From DSC and XRD results, we suggested that Poly-DAN unit with low glass transition temperature inserted between two SPI main chains due to CT complex formation by heat treatment.After heat treatment, SPI/Poly-DAN blend membranes did not completely dissolve in DMSO, and the weight loss after water immersion of the heat-treated SPI/Poly-DAN blend membranes was smaller than that of the untreated membrane. These results indicate that a cross-linked structure was not only formed by CT complex formation but also due to chemical cross-linking during heat treatment. Because of chemical cross-linking of sulfonic acid by heat treatment, experimental IEC of SPI/Poly-DAN (1:0.05 mol) was smaller (2.51) than theoretical value (3.41).Heat-treated SPI/Poly-DAN blend membranes showed higher mechanical strength (50.8 MPa) than Nafion 212 (15.5 MPa) and highly chemical durability compared to the untreated membrane by the synergetic effect of enhanced CT complex formation and chemical cross-linking. Heat-treated SPI/Poly-DAN membranes showed comparable proton conductivity (32.3 mS cm−1, 80 °C, and 90% RH), although some cross-linking occurred between sulfonic acid units due to the heat treatment process.In fuel cell tests, heat-treated SPI/Poly-DAN membranes had maximum power densities of 255 mW cm−2 at 80 °C and 95% RH and 59.0 mW cm−2 at 110 °C and 31% RH, indicating that these heat-treated CT complex membranes could be used for fuel cell applications.References S. Feng et al., Journal of Membrane Science, 548 (2018).S. Feng et al., ACS Applied Energy Materials, 2, 8715–8723 (2019). Figure 1

Thermophysical Properties of IoNanofluids Composed of 1-ethyl-3-methylimidazolium Thiocyanate and Carboxyl-functionalized Long Multi-walled Carbon Nanotubes

The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies on the morphology and physicochemistry of carbon-based nanomaterials affecting thermal conductivity, viscosity, and density of INFs. We focus on the characterization of dispersions composed of long carboxylic group-functionalized multi-walled carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate. The thermal conductivity of INFs was measured using KD2 Pro Thermal Properties Analyzer (Decagon Devices Inc., Pullman, WA, USA). The viscosity was investigated using rotary viscometer LV DV-II+Pro (Brookfield Engineering, Middleboro, MA, USA). The density of INFs was measured using a vibrating tube densimeter Anton Paar DMA 5000 (Graz, Austria). The maximum thermal conductivity enhancement of 22% was observed for INF composed of 1 wt% long carboxylic group-functionalized multi-walled carbon nanotubes.

PBI/Clinoptilolite mixed‐matrix membranes for binary (N2/CH4) and ternary (CO2/N2/CH4) mixed gas separation

AbstractIn this work, polybenzimidazole (PBI)‐based mixed matrix membranes (MMMs) with natural zeolite were prepared and their transport properties for binary (N2/CH4) and ternary (CO2/N2/CH4) mixed‐gas separation were studied. The MMMs, were prepared with PBI as polymeric matrix and Mexican natural zeolite clinoptilolite enriched with cations of Ca2+ as filler. The thermal properties analysis of the PBI and MMMs studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicates that the MMMs membranes have Tg higher than 350°C and decomposition temperatures above 600°C compared with the pristine membranes. PBI membrane and MMMs were analyzed by X‐Ray Diffraction (XRD) and the diffraction patterns showed the zeolite signals combine with the amorphous dome from the polymeric matrix. In addition, the perm‐selectivity properties of the polymeric membranes and MMMs were tested with binary (N2/CH4; 10/90 mol%) and ternary (CO2/N2/CH4; 5/10/85 mol%) gas mixtures at different pressure rates (50, 150 and 300 psi). The perm‐selectivity properties of the MMMs membranes show an improvement in their values about 30% higher compared to the PBI polymeric membranes, favoring the permeation of CO2 and N2.

Thermal behaviour of waterproof coated fabrics and identification of chemical groups present in melt-blown polyester non-woven fabrics coated with waterproof acrylic polymer binder

Polyester non-woven fabrics are a good choice for base material in development of engineered waterproof fabrics. They find wide applications in bathroom floor lining, Roof lining, Car floor lining and many such applications. These fabrics not only provide strength and durability to the structure but also enhance the thermal as well as shelf-life of the structure. The presence of Chemical groups like ethylene functional group which is a chemical compound prominently present in polyester and observation of strong peaks of polyester functional groups aids in robust behaviour of the waterproof coated fabrics. These chemical groups present in the waterproof acrylic polymer binder also influences the development of durable fabrics with good hardness values. In this research a waterproof fabric for such applications is developed using a non-woven polyester fabric as the base material and roller coating process. The changes in the surface morphology of the fabrics is recorded and analysed using SEM micrographs. However, the analysis of thermal properties of these coated fabrics using DSC, TG/DTA instruments show melting of the coated material at 375 °C and TGA graphs show degradation of material occurring at 400 °C. The density measurement results show the fabrics ability to achieve lower values when nonwoven fabric layers are doubled which may be due to consumption of less binder and locking of air between layers. The Rockwell hardness results of 31.4 HRB (B scale) for single layer and 68.2 HRB for double layer proves the performance of the coated fabric at par with soft steel. The coated fabrics show zero air porosity when tested under air-permeability tester. The process of roller coating proves to be robust method of application of water proof polymer binder on non-woven fabrics.

Analysis of Wear, Tensile and Thermal Properties of Poly Methyl Methacrylate Filled with Licorice Particle and Pomegranate Peels

In the present work, analysis of wear behavior, tensile and thermal properties have been done for two sets Poly Methyl Methacrylate samples which is reinforced through licorice particles and pomegranate peels particles. Wear rate resistance is evaluated based on Taguchi’s experimental design L9 (MINITAB 18) under the three factors: weight fraction of fillers (1%, 2%, 3%, 4% and 5% wt.) sliding time (5, 8 and 11 min) and load applied (10, 15and 20N) using a pin-on-disk device. Results display that the samples (Poly Methyl Methacrylate +5% licorice particles and 5% pomegranate peels particles) show the best resistance wear of (0.045×10-6 and 0.10×10-6) respectively. Signal to noise (S/N) results showed that 5% weight fraction (licorice particles and pomegranate particles with PMMA), 11 minutes (sliding time) and 15N (applied load) give the best resistance wear. Statistical analysis of tensile and thermal tests, exhibit that the best mean value of the tensile strength, modulus of elasticity, thermal conductivity, and thermal diffusivity are (±73 MPa, ±70 MPa, ±4.800 GPa, ±4.300 GPa, ±.5600 W/m k, ±.5400 W/m k, ±.3800 mm2/sec, ±.2800 mm2/sec) respectively, of the samples (PMMA+5% licorice particles and 5% pomegranate peel particles). While that the best mean value of the elongation at break (±3.600%, ±3.500%) respectively, of the samples (PMMA + 1% licorice particles and 1% pomegranate peel particles). The results showed that the addition of licorice and pomegranate particles to poly methyl methacrylate resin has improved the properties of wear, tensile and thermal properties.

Fabrication of chondroitin sulfate calcium complex and its chondrocyte proliferation in vitro

Chondroitin sulfate (CS)-calcium complex (CSCa) was fabricated, and the structural characteristics of CSCa and its proliferative bioactivity to the chondrocyte were investigated in vitro. Results suggested calcium ions could bind CS chains forming polysaccharide-metal complex, and the maximum calcium holding capacity of CSCa reached 4.23 %. Characterization of CSCa was performed by EDS, AFM, FTIR, UV, XRD and 1H-NMR. It was found that calcium ions were integrated with CS by binding the sulfate or carboxyl groups. The thermal properties analysis indicated CSCa had a good thermal stability by TGA and DSC. CSCa could interact the calcium-sensing receptor increasing the intracellular calcium ions and influence the cell cycle. The TGF-β1 secretion induced by CSCa could activate the TGF-β/Smads pathway and change the genes associated proliferation expression ultimately leading to the chondrocyte proliferation. This research probably has an important implication for understanding the effect of CSCa on bone care as food supplements.

Analysis of Mechanical and Thermal Properties of Aluminum-Chromium-Nitride-Coated Stainless Steel 316L Micrometal Lattice Fabricated by Selective Laser Sintering

Cellular materials, especially ordered lattice structures, contain lesser quantity of material than their bulk counterparts. Only a few researches are focused on composite microlattices and their performance at high temperatures. The aim of this scientific work is to analyze the thermal and mechanical properties and corrosion resistance of stainless steel 316L micrometal lattice (MML) fabricated by selective laser sintering method and to compare the thermal properties and corrosion resistance of aluminum-chromium-nitride-coated stainless steel 316 MML with that of the uncoated MML. The coating on the fabricated MML is done by physical vapor deposition. The coated and uncoated MMLs are subjected to dilatometry, corrosion test, thermogravimetric analysis (TGA) and differential scanning calorimetry and SEM analysis, whereas the uncoated MML was subjected to tension test and compression test in addition to the above-said tests. Simulation of these MML structures is carried out to correlate the results obtained, with the real-time test results. In compression test, the MMLs withstand a higher load owing to their octahedral arrangement of struts, which aided in uniform load distribution throughout the lattice. Also, the coated samples are found to be less prone to oxidation when subjected to high temperature as the coating prevented the formation of oxide, whereas the uncoated sample oxidized at higher temperatures as indicated by a considerable mass gain in the TGA plot and from the EDS analysis, which indicates the presence of oxygen in the uncoated MML. Another key result to be noted is that the uncoated MML distorted to a greater extent than the coated MML at higher temperatures as indicated from the dilatometry tests. These findings will be of use in future design/manufacturing optimizations in aerospace and automotive industries which require lightweight and high strength materials.

Preparation, characterization and antioxidant properties of gelatin films incorporated with Origanum onites L. essential oil

This study aims to develop gelatin (GEL) films containing 0, 2, 4, 6, and 8% Origanum onites L. essential oil (OOEO) with glycerol as plasticizer using the casting technique. The physical, color, mechanical, structural, thermal, and antioxidant properties of enriched GEL films were also characterized. The GEL/OOEO combination significantly reduced tensile strength and film solubility of GEL-based films while significantly increasing ultraviolet and visible light barrier properties, thickness, and elongation at break (p ≤ 0.05). According to the results, the increased OOEO content has become darker yellow compared to the control GEL film. The amount of compounds in OOEO was determined using gas chromatography coupled with mass spectrometry, and it was determined that the most representative compounds of OOEO were carvacrol and thymol. As OOEO concentration increases, the decrease in the smooth, continuous surfaces and dense internal structures of GEL/OOEO films are observed with scanning electron microscopy. FTIR analysis showed some changes in the density of typical bands of control GEL and GEL/OOEO films. Analysis of thermal properties was determined by DSC, and films containing OOEO showed two different endothermic peaks at a lower temperature than control films. The antioxidant properties were significantly enhanced with increasing OOEO concentration reaching 21.78 and 46.52% of DPPH and 52.16 and 83.13% of ABTS radical inhibition, respectively. Therefore, GEL/OOEO films may be suitable for use as an environmentally friendly active film due to their excellent antioxidant properties with sufficient functional properties, depending on the desired application.

Impact of amylose content on the starch branch chain elongation catalyzed by amylosucrase from Neisseria polysaccharea

In this study, three rice starches with different amylose content were isolated from three rice varieties, followed by chain elongation using amylosucrase from Neisseria polysaccharea (NpAS). Herein, the chain elongation could induce the starch precipitation during the enzymatic reaction. With a higher content of amylose, an earlier precipitation occurred, leading to the decrease of transglycosylation efficiency of the enzyme. Results from X-ray diffraction and thermal property analysis indicated that the crystalline structure of the NpAS-modified starches largely formed at the precipitation point. The elongation at the surface of the starch precipitates, however, would not enable the formation of crystallites. In addition, the amylose might participate in the recrystallization of starch molecules. Digestion kinetics revealed that all of the NpAS-modified starches contained rapidly and slowly digested fractions, the latter of which had a digestion rate being dependent on the structural stability of crystallites (length of double helices). These findings may provide an efficient way to produce chain-elongated starches with desirable functionality and digestibility.

Porosity and tribological performance analysis on new developed metal matrix composite for brake pad materials

This paper deals with the development and performance of metal matrix composite for brake pad with NiSO4 as filler materials in terms of manufacturing ability and a good amount of porosity. Microstructure and surface roughness of the samples are analysed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively. Energy dispersive x-ray (EDX) and scanning transmission electron microscopy (STEM) are used to detect elemental distribution in the sample. X-ray diffraction (XRD) compound phase analysis is used to find the presence of compound in the brake pad samples. The analysis shows that brake pad compounds are present in original form. Thermal property analyser shows that thermal conductivity and thermal diffusivity of developed brake pad are more than market available brake pads. Sufficient amount of porosity is observed with gas sorption analyser (GSA) which is useful for conductive and convective heat transfer and preventing the overheating of brake pad system. The design of experiment and experimental analysis leads to the conclusion of near optimum parameter combination for maximum coefficient of friction and minimum wear rate. This paper reveals that the developed brake pad is better than selected market available composite brake pads on basis of hardness, thermal property, porosity distribution, and tribological performance analysis. The developed brake pad may be one of the good options for the commercially use in near future.

Characterization of Hybrid-nano/Paraffin Organic Phase Change Material for Thermal Energy Storage Applications in Solar Thermal Systems

In this work, the experimental investigations were piloted to study the influence of hybrid nanoparticles containing SiO2 and CeO2 nanoparticles on thermo-physical characteristics of the paraffin-based phase change material (PCM). Initially, the hybrid nanoparticles were prepared by blending equal mass of SiO2 and CeO2 nanoparticles. The hybrid-nano/paraffin (HnP) samples were prepared by cautiously dispersing 0, 0.5, 1.0, and 2.0 percentage mass of hybrid nanoparticles inside the paraffin, respectively. The synthesized samples were examined under different instruments such as field emission scanning electron microscope (FESEM), Fourier transform infrared spectrometer (FTIR), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), and thermal properties analyzer to ascertain the influence of hybrid nanoparticles on thermo-physical characteristics of the prepared samples. The obtained experimental results proved that the hybrid nanoparticles were uniformly diffused in the paraffin matrix without affecting the chemical arrangement of paraffin molecules. Prominently, the relative thermal stability and relative thermal conductivity of the paraffin were synergistically enriched up to 115.49% and 165.56%, respectively, when dispersing hybrid nanoparticles within paraffin. Furthermore, the hybrid nanoparticles appropriately amended the melting and crystallization point of the paraffin to reduce its supercooling, and the maximum reduction in supercooling was ascertained as 35.81%. The comprehensive studies indicated that the paraffin diffused with SiO2 and CeO2 hybrid nanoparticles at 1.0 mass percentage would yield a better outcome compared to the next higher mass fractions without much diminishing the latent heat of paraffin. Hence, it is recommended to utilize the hybrid-nano/paraffin with 1.0 mass fraction of the aforementioned hybrid nanoparticles for effectively augmenting the thermal energy capacity of low-temperature solar thermal systems.

Analysis of mechanical and thermal properties of carbon and silicon nanomaterials using a coarse-grained molecular dynamics method

The main concern in Molecular Dynamics (MD) simulations is the computational cost, and coarse-graining methods accelerate simulations by reducing the degrees of freedom in the system. Yet, the utilization of these methods should be carefully followed. In this paper, we presented an energy-based coarse-graining method for Tersoff and Stillinger-Weber potential functions. The presented coarse-graining method is based on the domain mapping and modification of potential function. The focus of this paper is on Carbon and Silicon materials; however, this method can be applied to model other materials for which Tersoff and Stillinger-Weber potentials are defined. This method has been validated by demonstrating the consistency of mechanical properties between all-atom and CG models in different case studies. According to the conducted simulations, the precision of the proposed CG technique in the modeling of the bulk behavior is near 100% while it yields completely reasonable results for other simulation setups.

Production and Characterization of Nanocomposite Film Based on Whey Protein Isolated/Copper Oxide Nanoparticles Containing Coconut Essential Oil and Paprika Extract

This study aimed to produce a whey protein isolate (WPI) based nanocomposite film containing copper oxide nanoparticles (CuONPs) with coconut essential oil (CEO) (0, 0.4, 0.8% w/v) and paprika extract (PE) (0, 0.03, 0.06% w/v) using a central compound design (CCD). Antioxidant capacity, water vapor permeability, mechanical properties, antimicrobial activity, morphological characteristics Fourier transform infrared (FTIR), X-ray diffraction (XRD), and thermal properties of films were investigated. In addition to the properties of CuONPs, CEO, and PE, this effect was due to hydrogen interactions between them and the biopolymer matrix. As confirmed by the FTIR and XRD, the co-application of PE and CEO due to the synergistic effect of pigment on the antimicrobial properties of CEO and increasing the content of antimicrobial compounds in the film showed the highest activity against Staphylococcus aureus and Escherichia coli. The results of the thermal property analysis of the films showed the formation of a complex between the nanocomposite film with CEO and PE. In summary, the results of the present study showed that nanocomposite films containing the combination of PE and the CEO could be useful in food packaging.

Active Region Irradiance during Quiescent Periods: New Insights from Sun-as-a-star Spectra

Abstract How much energy do solar active regions (ARs) typically radiate during quiescent periods? This is a fundamental question for storage and release models of flares and ARs, yet it is presently poorly answered by observations. Here we use the “Sun-as-a-point-source” spectra from the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory to provide a novel estimate of radiative energy losses of an evolving AR. Although EVE provides excellent spectral (5–105 nm) and temperature (2–25 MK) coverage for AR analysis, to our knowledge, these data have not been used for this purpose due to the lack of spatial resolution and the likelihood of source confusion. Here we present a way around this problem. We analyze EVE data time series, when only one large AR 11520 was present on the disk. By subtracting the quiet-Sun background, we estimate the radiative contribution in EUV from the AR alone. We estimate the mean AR irradiance and cumulative AR radiative energy losses in the 1–300 Å and astronomical standard ROSAT-PSPC, 3–124 Å, passbands and compare these to the magnetic energy injection rate through the photosphere, and to variations of the solar cycle luminosity. We find that while AR radiative energy losses are ∼100 times smaller than typical magnetic energy injection rates at the photosphere, they are an order of magnitude larger or similar to the bolometric radiated energies associated with large flares. This study is the first detailed analysis of AR thermal properties using EVE Sun-as-a-star observations, opening doors to AR studies on other stars.