Changes In Crystalline Structure Research Articles

Microparticles loaded with fish oil: stability studies, food application and sensory evaluation

Aim Evaluate the stability of microparticles loaded with fish oil produced by spray drying, spray chilling and by the combination of these techniques (double-shell) and use the microparticles for food application. Methods Samples were stored for 180 days at 6 °C and 24 °C (75% RH). Performed investigations included encapsulation efficiency, moisture content, aw, size (laser scattering), colour (L*, a*, b*), polyunsaturated fatty acids (PUFAs) (GC), thermal behaviour (DSC) and crystalline structure (XRD). Results Double-shell microparticles containing 26 wt% core material, 22.74 ± 0.02 µm (D0.5) and 2.05 ± 0.03 span index, 1.262 ± 0.026 wt% moisture content and 0.240 ± 0.001 of aw had PUFAs retention higher than 90 wt% during storage at 6 °C without changes in crystalline structure (β’-type crystals) and melting temperature (54 °C). The sensory evaluation suggested low fish oil release in oral phase digestion. Conclusions Double-shell microparticles were effective to protect and deliver PUFAs.

Comparison of Immobilization Methods for TiO₂-Embedded Expanded Polystyrene Balls and Growth Inhibition of Microcystis aeruginosa.

Two immobilization methods (i.e., ice water-soaked using a digital temperature controller vs. freeze-dried using liquid nitrogen) were applied for mass production techniques of TiO₂-embedded expanded polystyrene (TiEPS) balls with nanoscale TiO₂ particles embedded on EPS balls. No significant changes in crystalline structure of TiO₂ nanoparticles embedded on the TiEPS balls were observed during the mass production of TiEPS balls. Greater residuals of freeze-dried TiEPS balls suggested the improved immobilization methods for mass production procedures of TiEPS balls. Although similar growth inhibition between TiEPS balls using two immobilization methods was observed within 10 hrs, both growth and reproduction of M. aeruginosa can be more significantly inhibited by applying the freeze-dried TiEPS balls after 10 hrs. These results were mainly attributed to the difference in exposed surface area of embedded TiO₂ nanoparticles which generated various reactive oxygen species peroxidizing and leading to the inactivation and degradation of M. aeruginosa. Relatively greater k value (0.207 day-1) was estimated from freeze-dried TiEPS balls than that (0.089 day-1) from ice water-soaked TiEPS balls, suggesting that both growth and reproduction of M. aeruginosa were effectively inhibited with greater amounts of reactive oxygen species generated from freeze-dried TiEPS balls. Consequently, self-floating freeze-dried TiEPS balls can be readily applied to inhibit the excessive growth of harmful algae in the stagnant water body without the recovery process for long time.

Impact of the processing temperature on the crystallization behavior and mechanical properties of poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)

Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) are promising biopolymers, which could substitute petro-based plastics for packaging applications. To anticipate the behavior of PHBVs when transformed using conventional thermo-mechanical shaping processes, it is needed to better understand the effect of processing temperature on their crystallization behavior and final properties. The objectives of the present work were thus (1) to better understand the influence of the processing temperature on the PHBV macromolecular and crystalline structures, depending on its HV content, and (2) to define a processing window guaranteeing optimized mechanical properties of PHBV films. An innovative experimental strategy was proposed, enabling the study of melting and crystallization events, crystalline structure changes, and evolution of mechanical properties of PHBV according to processing temperature, using identical thermal cycles. A comprehensive dynamic monitoring of the studied PHBVs was achieved by coupling differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), step scan DSC (SDSC), observations of isothermal crystallization under polarized optical microscopy (POM), thermo-regulated wide angle X-ray analysis (WAXS), Nuclear Magnetic Resonance (NRM), and finally mechanical tests on PHBV films. The combination of these experiments revealed how inappropriate processing temperatures can result in irreversible changes in PHBVs’ macromolecular and crystalline structures, thermal behavior and mechanical performances. When increasing the HV content of the copolymer, adjusting the processing conditions according to these results revealed to be critical to match the functional properties targeted for a specific use.

Effect of chemical oxidation of spinel-type LiNi0.5Mn1.3Ti0.2O4 by soaking in HNO3, HCl and H2SO4

A new chemical oxidation method was proposed to mimic the crystalline structure change of cathode materials during charge-discharge process by chemical treatment as an efficient experimental data collection method for exploring cathode materials for lithium batteries by informatics such as machine learning. LiNi0.5Mn1.3Ti0.2O4 prepared by the solid-state reaction method was soaked in 2 ​mol/L HNO3 for 10 days, and the chemical delithiation about 53% was confirmed. Furthermore, from the information obtained by synchrotron XRD and XAFS measurements, it could be predicted that the chemical oxidation reaction was accompanied by delithiation. In HCl and H2SO4, which are different acids, the lattice parameter decreased with decreasing Li composition as in the case of HNO3. However, from the value of the metal-oxygen octahedral volume calculated from the crystal data obtained by structure refinement, it was concluded that the Li+ to H+ ion-exchange reaction rather than the oxidation reaction proceeded in HCl.

Effect of RF magnetron sputtering parameters on the optimization of the discharge capacity of ternary lithium oxide thin films

The increasing demand for lithium-ion batteries has stimulated the investigation of new compounds in order to reduce the costs and the toxicity of their cathodes. Materials constituted of ternary lithiated oxide compounds are a successful alternative to cobalt-rich cathodes. The main disadvantage of ternary compound materials (TCM) is that the maximum amount of electrical charge is only achieved at high redox potentials, a limiting factor if we consider the current development in electrolyte technology. In this work, we investigated the influence of sputtering deposition parameters on the charge capacity of TCM thin films, restraining their electrochemical potential to conventional values. To do so, we analyzed the impact that small changes in crystalline and morphological structures have on the charge capacity at low cell potentials. For this, we performed the RF mA gnetron sputtering of TCM thin films and carried out a factorial design of experiments to investigate their electrochemical properties, while limiting the charging potential to 4.20 V vs. Li|Li+. The films were deposited onto a rigid and conductive substrate with different parameters (power and pressure at room temperature). Electrochemical results showed that the discharge capacity is strongly influenced by the deposition parameters, reaching 250 mA h g−1 even at 4.20 V vs. Li. This value is superior to the ones of the conventional cobalt cathode and the bulk ternary electrode. Both deposition parameters exhibited a synergic dependency, which means that they need to be simultaneously varied for a response optimization. The discharge capacity of the analyzed samples was highly affected by the surface morphology of the film and its crystallographic properties, and not by its elemental composition. High discharge capacity was obtained without additional thermal treatments, which favors the manufacture of films over polymeric substrates for future electronic applications.

COMBINED EFFECT OF PYROMETALLURGICAL AND HYDROMETALLURGICAL PROCESSES ON QUARTZ ORE PURIFICATION

Recent advances in high-tech applications have highlighted the growing demand on highly pure silicates like quartz. Therefore, purification of quartz ore was determined as the subject of this study performed by pyrometallurgical followed by hydrometallurgical processes. In this research, the effect of thermal treatment (TT) followed by oxalic acid (OA) bleaching of quartz was examined to have a better understanding on the relationship between Fe remaining in concentrate and colour response. The level of TT temperature was found to have a significant effect on the purification of quartz by OA. The maximum Fe rejection rate was observed to occur both for non-treated and TT quartz up to 250°C. TT between 400°C and 900°C showed poor purification performance: decreasing L* value, and increasing a* and b* values. It is important to note that further increase in TT temperature to 1100°C resulted in the poorest bleaching: Fe rejection rate decreased, but colour response improved providing the highest L* value and the lowest a* and b* values. This finding was explained by the formation of dissolution resistant iron silicates. Moreover, the rate of Fe removal from quartz ore and differences observed in its colour response by OA bleaching were explained by changes in crystalline structure and formation of microcracks.

A New Method for Evaluating Li-Ion Battery Anode Materials Based on Surface Compositional and Structural Characterization

There is a global effort to develop safer lithium-ion batteries (LIB) with a high energy density and long lifetime. Material properties, their mutual interactions, and active interfaces are key factors in battery performance. Popular methods involve the mixing of different ingredients and development of a suitable fabrication process. Significant effort has been spent to understand the reaction mechanism of battery materials, but this is very challenging due to high system complexity. Different techniques have been developed to follow these reactions, and most significantly, the reactions between Li and electrode materials. Our team has developed a new method to characterize Li thermal diffusion and structural interaction on the surfaces of potential anode and cathode materials. This method is based on surface crystallographic and compositional characterization of deposited ultra-thin film of Li on potential single crystal or polycrystalline anode material. Surface crystallography characterization is done with w Low Energy Electron Diffraction (LEED) and surface composition with Auger Electron Spectroscopy (AES). This characterization monitors Li thermal diffusion into the electrode surface at room temperature and changes in surface crystalline structure and composition. The data provides a strong link between Lithium thermal diffusion and lithiation processes in LIB. The dynamic interaction of Li is monitored at the nanoscale level and gives the direct response how Li atoms interact with the substrate. The diffusion of evaporated Li on single crystals of HOPG, Si(111)-(211)-(100), SiC-6H, CVD-Diamond and LiNbO3 have been performed. The results shows that HOPG is the excellent reference substrate for this method as Li diffuses at room temperature and surface crystallography of HOPG remains unchanged. The structural reaction of Li with Si is very strong causing LEED pattern to disappear and there is no Li diffusion at room temperature as indicated from AES data. The data for SiC-6H and LiNbO3 shows better Li diffusional behavior than on Si but not as good as on HOPG. This method of using a single crystal substrate and basic surface characterization techniques is providing simple nanoscale access into the chemical reactions between Li and the substrate material that will result in better understanding of Lithium diffusion in the fabricated battery electrodes. The initial material classification for “native” Lithium thermal diffusion properties is proposed.

New Approach for Administration of Doxazosin Mesylate: Comparative Study between Liquid and Solid Self-nanoemulsifying Drug Delivery Systems

Self-nanoemulsifying drug delivery systems (SNEDDS) in both liquid and solid forms were suggested to improve water solubility of Doxazosin mesylate (DOX) a poorly water- soluble antihypertensive drug. Oleic acid: Smix (1:9 w/w) and Tween 80: co-surfactant mixture (Ethanol and PEG 400) (1:1, 2:1, 3:1 and 4:1) were chosen to prepare a liquid and solid forms of SNEDDS according to their solubility. TEM images revealed change in the crystalline nature of DOX into uniform particles with smooth surface. Characterization studies revealed droplet size ranges from 79.80±14.39 to 273.10±4.17 nm, zeta potential ranges from -5.57±0.10 to -21.13±0.46 mV and dissolution enhancement of more than two folds with more favorable properties for the solid forms. FTIR demonstrated significant physical changes in DOX crystalline structure. In conclusion, the solid SNEDDS containing oleic acid: Smix (1:9 w/w) and Tween 80: co-surfactant mixture (3:1 w/w) and adsorbent mixture of Avicel 101 and Aerosil 200 (40:1 w/w) might be a promising formula for better management of hypertension with expected shelf stability.

The role of Ag on the stress-induced ordering of oxygen in the Ti-15Zr-15Mo alloy

In this study, the effect of substitutional Ag on the stress-induced ordering of oxygen in the Ti-15Zr-15Mo (wt%) alloy was investigated by dynamic mechanical analysis. The Ti-15Zr-15Mo-xAg (x = 0, 1, and 3) samples were produced by argon arc melting, submitted to a posterior homogenization heat treatment, hot rolling, and solution heat treatment. The dynamic mechanical analysis was performed in the tensile mode, at a maximum strain amplitude of 0.02%, between 425 and 725 K, at 1 K/min, and frequencies from 10 up to 30 Hz. The results showed a broadened and asymmetric anelastic relaxation peak around 450 and 725 K in all samples, with step decay in Young’s modulus typical of stress-induced ordering phenomena. The peaks shifted towards high temperature with the increase of the frequency, indicating a thermally activated process. The peak fitting stated the presence of oxygen-type processes, produced by the interaction of matrix (Ti-O) and substitutional (Zr-O) elements, and one clustering (Ti-O-O). The amount of Ag exhibited a significant effect on the Qp−1 and Tp relationship and in the diffusional parameters D0 and τ0 of the metallic matrix, which could be related to the changes in the bcc crystalline structure’s atomic bonding. Thus, the results show that the interaction of interstitial oxygen in the Ti-15Zr-15Mo alloy can be tunable by the addition of Ag, which could bring novel insights about industrial applications beyond the biomedical area.

Anaerobic mixed consortium (AMC) mediated enhanced biosynthesis of silver nano particles (AgNPs) and its application for the removal of phenol

In this research, silver nano particle (AgNP), was synthesized through a novel anaerobic mixed consortium mediation method and applied for the removal of phenol. The best operating conditions for the fabrication of silver nanoparticles were identified through response surface methodology (RSM) and the maximum yield was found to be 2.65 g/100 ml of anaerobic mixed consortium at optimal conditions of pH-8.6, temperature-90 °C, silver nitrate concentration-3 mg/ml and inoculum volume-3 ml. The synthesized nano particle exhibited a maximum phenol removal of 87.65% was achieved at pH:5.8. The synthesized silver nanoparticles were characterized by superior surface area (19.26 m2/g) and the stability was confirmed by thermo gravimetric analysis (upto 500 °C). The surface morphology was well explained using High Resolution Transmission Emission Microscopy (HR-TEM) and Scanning Electron Microscope with EDS (SEM-EDS) techniques. X-ray Diffraction (XRD) analysis confirmed the changes in crystalline structure due to the adsorption of phenol. Kinetic experiments fitted well with the intra-particle diffusion model. The nature of adsorption of phenol was confirmed as monolayer by the goodness of fit with Langmuir isotherm (R2 > 0.9969).

Empirically Determining Substellar Cloud Compositions in the era of JWST

Most brown dwarfs have atmospheres with temperatures cold enough to form clouds. A variety of materials likely condense, including refractory metal oxides and silicates; the precise compositions and crystal structures of predicted cloud particles depend on the modeling framework used and have not yet been empirically constrained. Spitzer has shown tentative evidence of the silicate feature in L dwarf spectra and JWST can measure these features in many L dwarfs. Here, we present new models to predict the signatures of the strongest cloud absorption features. We investigate different cloud mineral species and determine how particle size, mineralogy, and crystalline structure change spectral features. We find that silicate and refractory clouds have a strong cloud absorption feature for small particle sizes ($\leq$ 1 $\mu$m). Model spectra are compared to five brown dwarfs that show evidence of the silicate feature; models that include small particles in the upper layers of the atmosphere produce a broad cloud mineral feature, and that better match the observed spectra than the Ackerman & Marley (2001) cloud model. We simulate observations with the MIRI instrument on JWST for a range of nearby, cloudy brown dwarfs, demonstrating that these features could be readily detectable if small particles are present. Furthermore, for photometrically variable brown dwarfs, our predictions suggest that with JWST, by measuring spectroscopic variability inside and outside a mineral feature, we can establish silicate (or other) clouds as the cause of variability. Mid-infrared spectroscopy is a promising tool to empirically constrain the complex cloud condensation sequence in brown dwarf atmospheres.

Type III Resistant Starch Prepared from Debranched Starch: Structural Changes under Simulated Saliva, Gastric, and Intestinal Conditions and the Impact on Short-Chain Fatty Acid Production.

Type III resistant starch (RS3) has high resistance to enzymatic digestibility and benefits colonic bacteria by producing short-chain fatty acids (SCFAs) via fermentation. Studies have delineated RS preparation and the description of RS fractions with different types of starch, but the digestion process has received little attention. The molecular and crystalline structure changes, thermal properties, and SCFA content of RS3 obtained from debranched starch were investigated in simulated salivary, gastric, and intestinal digestion systems. The average degree of polymerization and the melting enthalpy change of the digested RS3 residues increased; a high molecular order was reflected by the higher relative crystallinity. Fine structural changes suggested that enzyme-resistant starch might form during digestion by the rearrangement of short amylose chains into enzyme-resistant structures with higher relative crystallinity. After fermentation of human feces, RS3 increased the SCFA content, especially of butyric acid, indicating that this recrystallized RS3 could be a new prebiotic product.

Space–charge electret properties of polypropylene films with transcrystalline or spherulitic structures—A comparison of functionalities at interfaces

Spherulite-related space–charge electret properties of polypropylene (PP) have been widely discussed in the past decades. In the present paper, a less-common crystalline structure in PP—transcrystalline PP—is studied regarding its electret behavior in comparison with the typical spherulitic morphology. Polarized light microscopy and differential scanning calorimetry were employed to characterize the crystallite types and crystallinities of transcrystalline and spherulitic PP. Their electret functionality is investigated by means of thermally stimulated discharge experiments, where the cross-over phenomenon is observed on transcrystalline PP films, whereas surface-potential saturation and undercharging on the surface occur on the spherulitic samples. Besides, an asymmetrical behavior of positive and negative surface-charge stabilities is found on PP with spherulites, the negatively charged spherulitic surfaces show a better charge stability. It is shown that PP electrets are very sensitive to changes in the microscopic crystalline structures and their interfaces as well as in the molecular conformations controlled through adjustments of the respective processing steps. In addition, surface and bulk nanocomposites of PP or low-density polyethylene with inorganic particles are included in the comparison. In view of recent developments in the areas of PP-based electret-fiber filters and cellular-foam ferroelectrets, the observed changes in the charge-storage properties may have particular relevance, as the required film, fiber, or foam processing might significantly modify crystalline morphologies and nano-scale interfaces in PP electrets. Limitations in the charge-storage capabilities of interface structures may also be of interest in the context of high-voltage electrical-insulation materials where reduced space–charge accumulation and slightly increased charge transport can be advantageous.

Copper benzene-1,3,5-tricarboxylate (HKUST-1) – graphene oxide pellets for methane adsorption

Abstract Copper benzene-1,3,5-tricarboxylate (HKUST-1) is one of the materials holding the greatest potential for clean energy gases among microporous storage materials. Although this material is commercially available as a powder with particle size 10–20 μm, for easier handling adsorbents are preferentially employed as pellets or monoliths. Even under binder free conditions there could be a high price to pay for compacting: loss in crystallinity and in porosity. To determine the protection potential of graphene oxide (GO) a HKUST-1@GO composite was studied. The material of 16% GO was obtained in a single step solvothermal synthesis. The pristine HKUST-1 as well as HKUST1@GO formed consistent, integrated pellets when compressed at 25 and 50 bar without any binder. PowderXRD and N2 adsorption were used to monitor the changes in crystallinity and pore structure. It was found that GO has a protective effect against the 25 or 50 bar applied pressure, as 75% of the pore volume and the apparent surface area is saved in HKUST1@GO (vs. 43% and 47%, respectively, in HKUST-1) after compression. Presumably, the flexible GO sheets with high mechanical stability act as compressible spacers between the crystals thus preventing their amorphisation. Comparison of the adsorption properties of the HKUST-1 and HKUST-1@GO powders and pellets revealed that the performed compression deteriorated the structure of the MOF and thus reduced the CH4 uptake. Further studies are needed to optimize the compression pressure for a more reasonable loss in the gas uptake capacity.

Field emission of GaN nanofilms on Si substrates enhanced by hydrogen plasma treatment

The (002) oriented GaN nanostructured films prepared by pulsed laser deposition (PLD) on n-type Si (100) substrates were treated by H- and O-plasma, finding both treatments do not make the sizable changes in crystalline structure and morphology of GaN nanofilms. However, the field emission (FE) performance of GaN nanofilms is considerably improved by H-plasma treatment (H-GaN) but deteriorated by O-plasma treatment (O-GaN). The turn-on fields, Eon, for H- and O-plasma treated GaN nanofilms are determined to be 0.52 and 1.79 V μm−1, respectively, in contrast with that of pristine GaN nanofilms, 0.95 V μm−1. The improvement of FE performance by the H-plasma treatments could be attributed to the reasons of the reduced surface potential barrier, the increased electron concentration, the increased surface conductivity, and the increased effective emission area. The first-principles calculations represents that the experimental and theoretical work function results have the same trend with the descending sequence of O-plasma treated GaN > pristine GaN > the H-plasma treated GaN.

Integration of Fe3O4 nanospheres and micropyramidal textured silicon wafer with improved photoelectrochemical performance

Silicon (Si)-based composites have attracted extensive attention for photoelectrochemical (PEC) application. Herein, micropyramidal textured Si wafer was constructed by wet chemical etching method. Hydrothermally synthesized Fe3O4 nanospheres were further deposited on the micropyramids by a simple dip-coating approach. The integrated Fe3O4 nanospheres and Si micropyramids (denoted as Fe3O4@SiMPs) revealed 20 times of higher PEC efficiency than planar Si wafer, without obvious photocurrent decay and crystalline structure change during chronoamperometry test. The greatly enhanced PEC performance of Fe3O4@SiMPs is largely attributed to the seamless integration of Si micropyramids and Fe3O4 nanospheres. The micropyramidal textured structure can enhance light absorption by reducing the surface reflectance and enhancing the light trapping effect. The micropyramids and Fe3O4 nanospheres on the surface of planar Si wafer offer more specific surface area for the contact of electrode with electrolyte. The Fe3O4 nanospheres not only protect the micropyramids from corrosion, but also accelerate the PEC kinetics by promoting charge transfer between the electrode and the electrolyte. This study can inspire the optimal design of Si wafer-based nanocomposites as efficient PEC catalysts for overall water splitting.

Catalytic Conversion of Free Fatty Acids to Bio-Based Aromatics: A Model Investigation Using Oleic Acid and an H-ZSM-5/Al2O3 Catalyst.

The catalytic conversion of oleic acid to aromatics (benzene, toluene, and xylenes, BTX) over a granular H-ZSM-5/Al2O3 catalyst (ϕ 1.2–1.8 mm, 10 g loading) was investigated in a continuous bench-scale fixed-bed reactor (10 g oleic acid h–1). A peak carbon yield of aromatics of 27.4% was obtained at a catalyst bed temperature of 550 °C and atmospheric pressure. BTX was the major aromatics formed (peak carbon yield was 22.7%), and a total BTX production of 1000 mg g–1 catalyst was achieved within a catalyst lifetime of 6.5 h for the fresh catalyst. The catalyst was deactivated due to severe coke deposition (ca. 22.1 wt % on the catalyst). The used catalyst was reactivated by an ex situ oxidative regeneration at 680 °C in air for 12 h. The regenerated catalyst was subsequently recycled, and in total, 7 cycles of reaction-regeneration were performed. A gradual decrease in the peak carbon yield of BTX was observed with reaction-regeneration cycles (e.g., to 16.3% for the catalyst regenerated for 6 times). However, the catalyst lifetime was remarkably prolonged (e.g., >24 h), leading to a significantly enhanced total BTX production (e.g., 3000 mg g–1 catalyst in 24 h). The fresh, used, and regenerated catalysts were characterized by N2 and Ar physisorption, XRD, HR-TEM-EDX, 27Al, and 29Si MAS ssNMR, NH3-TPD, TGA, and CHN elemental analysis. Negligible changes in textural properties, crystalline structure, and framework occurred after one reaction-regeneration cycle, except for a slight decrease in acidity. However, dealumination of the H-ZSM-5 framework was observed after 7 cycles of reaction-regeneration, leading to a decrease in microporosity, crystallinity, and acidity. Apparently, these changes are not detrimental for catalyst activity, and actually, the lifetime of the catalyst increases, rationalized by considering that coke formation rates are retarded when the acidity is reduced.

Studies on electrospun polyvinylidene fluoride/aromatic hyperbranched polyester (gen-1) blend nanoweb for energy harvesting applications

In this work, we studied the piezoelectric characteristics of electrospun neat poly(vinylidene fluoride) (PVDF) and PVDF blended with aromatic hyperbranched polyester of Gen-1 (Ar-HBP-G1, 90/10) blend. Since, the piezoelectric output of PVDF is related to its chain (C–C) and dipole (C-F) orientations, FTIR and XRD were employed to confirm the changes in PVDF crystalline structure as a function of 10 wt-% Ar-HBP-G1 content. FTIR quantitative analysis showed an increase in β-crystalline phase in PVDF/HBP blend in comparison to unmodified PVDF. Further, fabrication of piezoelectric sensors was carried out using electrospun nanoweb samples, and their output voltage signals measured using dynamic pressure custom-made setup under an applied pressure of 1 kgf and frequency of 1.0 Hz. With increasing load i.e. 1 kgf → 3 kgf (under constant frequency of 1 Hz) and decreasing frequency from 1 Hz → 0.1 Hz (under constant load of 1 kgf), Vp-p showed increasing trend for both the samples. Compared to neat PVDF peak-to-peak output voltage (Vp-p) of 0.95 V, PVDF/Ar-HBP-G1 (90/10) showed significant enhancement in Vp-p at 6.42 V, which could play a vital role in preparing a piezoelectric sensor for energy harvesting applications.

Thermal management on external surfaces by thermochromic materials

Thermochromism is the property of a substance to change colour when subjected to a change in temperature. Generally, the custom activation temperature is around −10 °C to 69 °C. Thermochromism doesn't always need to be a change between two colours, but it can also change from colour to transparent. The material which has thermochromism property is used as thermochromic material, and it is also known as heat-sensitive colour change material. The colour transition occurs due to change in crystalline phase and structure when exposed to different temperature conditions. These thermochromic materials are mainly used as temperature indicators in many industrial sectors and utilized to impart heat control and colour changing abilities to windows, exterior walls and other construction components, like the rate of heat embrace by the surface of a vehicle can be applied by thermochromic material coating. By reducing the heat embracement by surface, it can endure the battery performance. This paper gives us a brief idea about the usage and impact of thermochromic material in electric vehicles.

Characterization of the baking-induced changes in starch molecular and crystalline structures in sugar-snap cookies

This study aims to understand the starch molecular structural changes from baking sugar-snap cookies. Changes in the whole-molecule size distribution and chain-length distribution of the parent wheat flour and from final cookie products were measured by size-exclusion chromatography with and without enzymatic debranching, and the results fitted by two biosynthesis-based models. Fraction crystallinity was also analyzed. After cooking, there was a significant decrease in average molecular sizes of amylopectin and in the average lengths of amylose chains, and some starch granules lost birefringence. However, the chain-length distributions of amylopectin showed no noticeable difference, resulting in little change in relative crystallinity and gelatinization temperatures. Both the short-range ordered structure and the periodic lamellar structure were disrupted. This study provides new insight into starch structural changes in sugar-snap cookies after baking, which play an important role in determining final cookie quality. For example, a decrease in size of amylose chains influences cookie sensory properties, and thus can be used as an additional tool for choice of grains.