Temperature Range ΔT Research Articles

Enhanced low-field energy storage performance and dielectric stability in (Bi0.4Sr0.2K0.2Na0.2)(Ti1-xZrx)O3high-entropy ceramics via B-Site modification

The current global energy situation is tense, necessitating the development of high-efficiency, low-cost, and eco-friendly energy materials. In this study, a series of perovskite lead-free relaxor ferroelectric ceramics, denoted as (Bi0.4Sr0.2K0.2Na0.2)(Ti1-xZrx)O3 (BSKNT-xZr) were designed to enhance the storage performance. The findings indicate that all samples exhibit a single perovskite structure. As the Zr4+ content increases, the configurational entropy of the samples increases, the cell volume expands, and the hysteresis loops become finer, while maintaining a high maximum polarization (Pm) and effectively enhancing the energy storage performance. For the ceramics with x = 0.10, the energy density (Wtot), recoverable energy density (Wrec), and energy storage efficiency (η) values were determined to be 3.16 J/cm3, 2.67 J/cm3, and 84.3%, respectively, under an electric field of 230 kV/cm. Moreover, the introduction of Zr4+ reduces the relative permittivity and broadens the temperature range (ΔT) that simultaneously satisfies Δε/ε150°C ≤ ±15% and 0 ≤ tanδ ≤ 0.02. This investigation underscores the potential of BSKNT-xZr ceramics as high-performance, cost-effective, and environmentally friendly energy materials for addressing global energy requirements.

Numerical and three-factor design investigation for melting process of phase-change spherical capsules in a solar thermal energy storage system

The application of spherical phase-change capsules in solar thermal energy storage systems (STESS) can enhance the sustainability and stability of energy output in solar energy utilization, making it a recent research hotspot. Nonetheless, the influence of neglecting three-dimensional effects through structural simplification on the phase-change process and the criteria for selecting the mushy zone constant in numerical studies are still not well-defined. In this context, a detailed analysis is conducted to investigate the variations in liquid fraction, temperature, flow field, and the time required for complete PCM melting caused by the structural simplification method. Subsequently, a three-factor design analysis is performed on parameters including spherical radius (R), mushy zone constant (Amush) and phase-change temperature range (ΔT) with the aim of establishing a rational basis for selecting the mushy zone constant. Results show that the simplification of the 3D spherical encapsulation structure into a two-dimensional (2D) circular encapsulation structure introduces notable discrepancies in the PCM melting process. In contrast to the 2D circular encapsulation structure, the 3D spherical encapsulation structure demonstrates a reduction in the time required for complete PCM melting by 23 % to 36 %. The influence of simplifying the 3D spherical encapsulation structure into a 2D axisymmetric encapsulation configuration on the numerical simulation of the PCM melting process becomes more pronounced with the increase of R. For the 3D spherical encapsulation structure, the hierarchy of significance regarding the factors influencing the PCM melting process manifests in the sequence: R, Amush, (R × Amush), and ΔT. Furthermore, the formulated correlation based on the aforementioned four factors enables precise prediction of the time required for complete PCM melting within the 3D spherical encapsulation structure and offers a foundation for selecting the appropriate Amush value in numerical simulation. The present work contributes novel insights into the accuracy and rationality of numerical simulations for phase-change processes in the STESS.

Elastocaloric effect with plateau-shape adiabatic temperature change in Ni–Co–Fe–Ga strain glass alloy

Elastocaloric effect (eCE) is a very promising candidate for using in non-vapor compression refrigeration, which is highly efficient and eco-friendly. However, designing elastocaloric alloys with a wide reversible working temperature window at low stress is still challenging. In this work, the transition behaviors, microstructural evolutions and the eCE of a series of Ni55−x Co x Fe19Ga27 alloys were systematically studied. The Ni44Co11Fe19Ga27 strain glass (STG) alloy exhibits a plateau-shape eCE, which show an average temperature change (ΔT Adia) of ∼2.3 K covering a wide reversible working temperature range (ΔT rev) from 135 K to 200 K. The unique eCE behavior of STG stems from that the random distribution of local free energy of the martensite coupled with the small transition energy barriers, which leads to a wide transition-temperature range and decreased hysteresis. The Ni44Co11Fe19Ga27 STG alloy achieves a balance between the considerable ΔT Adia and wide ΔT rev, resulting in an optimal comprehensive elastocaloric performance and contributing to improving the efficiency of elastocaloric refrigeration.

Selective adsorption of volatile compounds of oyster peptides by V-type starch for effective deodorization

Oyster peptides extracted from oysters have strong off-odors, which hinders consumer acceptance. The “empty” V-type starches (V6a, V6h, V7a, V7h, V8a, and V8h) prepared from high amylose maize starch were used as adsorbents to improve the flavor of oyster peptides. The total adsorption rates measured through headspace gas chromatography mass spectrometry (HS-GC-MS) follow the order of V6a > V7a > V6h > V7h > V8a > V8h. Moreover, the V-type starches with different structures exhibit adsorption selectivity. The V6- and V7-type starches with a smaller cavity size show selective adsorption capacity for alcohols, acids, ketones and other similar classes of volatile compounds, while the V8-type starches with a larger cavity selectively adsorb amines. In addition, successful preparation of “empty” V-type starches were confirmed through X-ray diffraction (XRD), and the inclusion complexes (ICs) between V-type starches and volatile compounds of oyster peptides were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and differential scanning calorimetry (DSC). It was found that the O/C ratio of V6a-ICs, V6h-ICs, and V7a-ICs increased, while that of V7h-ICs, V8a-ICs, and V8h-ICs decreased after the deodorization. Pearson's correlations indicated that the adsorption rates of aldehydes, alcohols, ketones, and alkanes have a significant negative correlation with temperature range (ΔT) and enthalpy change (ΔH). While a significant positive correlation was observed between the ratio of peak intensity at 1047/1022 cm−1 and the amine adsorption rate. These results suggested that V-type starch can improve the flavor of aquatic products effectively.

Invar Effect in the Wide and Higher Temperature Range by Coherent Coupling in Fe‐Based Alloy

AbstractInvar alloys with zero thermal expansion (ZTE), isotropy, high operation temperature, and wide temperature range are of great significance in fields such as aerospace and modern industry. However, it is difficult to simultaneously meet the above characteristics in one material. The traditional methods like element or vacancies doping would increase the operation temperature but at the expense of ZTE behavior. Here, by the coherent coupling between two cubic phases, the isotropic ZTE metallic material with the higher cut‐off temperature (560 K) and a wide operation temperature range (ΔT = 200 K) is obtained in Fe2.75Co0.25PtB0.25. The operation temperature range is much higher than that of commercial Fe0.65Ni0.35 Invar alloy and meets the applications at elevated temperatures. High‐angle annular dark field images and synchrotron X‐ray diffraction prove that by the coherent interfacial coupling between the A1 and its coherent L12 nanodomains, the original negative thermal expansion or positive thermal expansion performances for them can be changed into the same ZTE performances. This thermal expansion regulation strategy realized by coherent coupling will lead to an innovative and significant revolution for ZTE design and promote its development and application.

Controlled damping ethylene‐vinyl acetate copolymer/styrene ethylene butylene styrene foam in wide temperature range prepared by supercritical nitrogen

AbstractHerein, ethylene‐vinyl acetate copolymer/styrene ethylene butylene styrene (EVA/SEBS) blend foam with wide effective damping temperature range (ΔT) was prepared via supercritical nitrogen. The influence of the ratio of EVA and SEBS on the foaming and damping properties was studied. ΔT gradually widened into the high temperature region with the increase of SEBS content, and higher SEBS gave denser and more uniform cell structure and reduced the density of the blend foam. When the content of SEBS was 40 phr, the density of the blended foam was 0.185 g/cm3, and the ΔT was −3~54°C. These damping foams were lightweight and this work showed that damping performance could be controlled by simply adjusting blend content, which is of great significance to broaden the application environment of damping materials.Highlights EVA/SEBS foam was prepared by supercritical nitrogen. EVA and SEBS blends can broaden the damping temperature range. The damping temperature range was −3.0~54.6°C when SEBS content was 40 phr.

Starch chain-length distributions determine cooked foxtail millet texture and starch physicochemical properties

Starch chain-length distributions play an important role in controlling cereal product texture and starch physicochemical properties. Cooked foxtail millet texture and starch physicochemical properties were investigated and correlated with starch chain-length distributions in eight foxtail millet varieties. The average chain lengths of amylopectin and amylose were in the range of DP 24–25 and DP 878–1128, respectively. The percentage of short amylopectin chains (Ap1) was negatively correlated with hardness but positively correlated with adhesiveness and cohesion. Conversely, the amount of amylose intermediate chains was positively correlated with hardness but negatively correlated with adhesiveness and cohesion. Additionally, the amount of amylose long chains was negatively correlated with adhesiveness and chewiness. The relative crystallinity (RC) of starch decreased with reductions in the length of amylopectin short chains in foxtail millet. Pasting properties were mainly influenced by the relative length of amylopectin side chains and the percentage of long amylopectin branches (Ap2). Longer amylopectin long chains resulted in lower gelatinization temperature and enthalpy (ΔH). The amount of starch branched chains had important effects on the gelatinization temperature range (ΔT). These results can provide guidance for breeders and food scientists in the selection of foxtail millet with improved quality properties.

An insight into the impact of climate factors associated with altitude on wheat volatiles' fingerprints at harvest using multivariate statistical analysis.

Climate changes associated with global warming are increasingly affecting the quality of cultivated crops. Cultivation at different altitudes and similar latitudes may offer an extraordinarily useful opportunity to obtain a diversificated dataset of climate variables and to further investigate their effect on crop quality. This study evaluated the effect of climate indices - temperature, rainfall precipitation and solar radiation data - on commercial parameters and the volatile organic compound (VOC) profile of wheat at harvest. Three common and durum wheat varieties, including two heritage wheats, were sown in experimental fields sited at three altitudes for 3 years consecutively, and they were analyzed for their yield, grading parameters, and VOC profiles. The datasets were processed by partial least squares regression (PLS-R) and the results indicate that summer days (SU25) and diurnal temperature range (ΔT) are the climate indices mainly responsible for the VOC profile changes in both common and durum wheat. Accumulated growth degree days (GDD), consecutive dry days (CDD), and accumulated solar radiation (ASR) induced species-specific responses. Terpenes represented the chemical class of VOCs most affected by stresses, followed by ketones and alcohols, which were affected by CDD, GDD, and ASR. This study showed a selective response of wheat to abiotic stresses associated with climate variables in terms of VOC synthesis. Its findings may be relevant in several fields, from plant ecology to agronomy and food quality, with implications for local economic strategies. © 2023 Society of Chemical Industry.

Coherence of terrestrial vertebrate species richness with external drivers across scales and taxonomic groups

AbstractAimUnderstanding connections between environment and biodiversity is crucial for conservation, identifying causes of ecosystem stress, and predicting population responses to changing environments. Explaining biodiversity requires an understanding of how species richness and environment covary across scales. Here, we identify scales and locations at which biodiversity is generated and correlates with environment.LocationFull latitudinal range per continent.Time PeriodPresent day.Major Taxa StudiedTerrestrial vertebrates: all mammals, carnivorans, bats, songbirds, hummingbirds, amphibians.MethodsWe describe the use of wavelet power spectra, cross‐power and coherence for identifying scale‐dependent trends across Earth's surface. Spectra reveal scale‐ and location‐dependent coherence between species richness and topography (E), mean annual precipitation (Pn), temperature (Tm) and annual temperature range (ΔT).Results>97% of species richness of taxa studied is generated at large scales, that is, wavelengths km, with 30%–69% generated at scales km. At these scales, richness tends to be highly coherent and anti‐correlated with E and ΔT, and positively correlated with Pn and Tm. Coherence between carnivoran richness and ΔT is low across scales, implying insensitivity to seasonal temperature variations. Conversely, amphibian richness is strongly anti‐correlated with ΔT at large scales. At scales km, examined taxa, except carnivorans, show highest richness within the tropics. Terrestrial plateaux exhibit high coherence between carnivorans and E at scales km, consistent with contribution of large‐scale tectonic processes to biodiversity. Results are similar across different continents and for global latitudinal averages. Spectral admittance permits derivation of rules‐of‐thumb relating long‐wavelength environmental and species richness trends.Main ConclusionsSensitivities of mammal, bird and amphibian populations to environment are highly scale dependent. At large scales, carnivoran richness is largely independent of temperature and precipitation, whereas amphibian richness correlates strongly with precipitation and temperature, and anti‐correlates with temperature range. These results pave the way for spectral‐based calibration of models that predict biodiversity response to climate change scenarios.

The effect of the use of salep powder obtained from different wild orchid species in Turkey on the rheological, thermal, and sensory properties of ice cream

The aim of this study is to investigate the effect of salep species grown in different regions of Turkey on the rheological and microstructural properties of ice cream mix and the thermal and sensory properties of ice cream. For this purpose, ten different types of salep grown in different regions (Mersin, Yozgat, Muğla, Kahramanmaraş, Adana, Van, Muş) in the natural microflora of Turkey were used in a formulation of an ice cream mix. The flow behavior, frequency sweep, and 3-ITT rheological properties of ice cream mixes were studied. All samples showed shear thinning, viscoelastic solid-like, and recoverable character. The K and n values ​​for the ice cream mixes were determined as 0.03-35.08 Pasn and 0.33-0.80, respectively, and significantly differed according to salep varieties (p < 0.05). The zeta potential values of ice cream mix samples ranged from -25.87 mV to -33.95 mV and were significantly affected by salep varieties (p < 0.05). The use of different salep varieties significantly affected the thermal properties of ice cream such as freezing point temperature (Tf), temperature range (ΔT), and enthalpy of fusion (ΔHf). In conclusion, the results of this study showed that the use of different salep varieties can significantly affect the rheological, thermal, and sensory properties of ice cream, and the selection of salep varieties may be vital for the desired quality of ice cream.

Large size, sensitive response thermally expandable microspheres for the manufacture of suede‐like leather

AbstractA large size, sensitive response thermally expandable microspheres (TEMs) for suede‐like leather manufacture was prepared by suspension polymerization using acrylonitrile (AN), methyl methacrylate (MMA) and vinyl acetate (VAC) as the shell monomers and iso‐pentane as the foaming component. The effect of the interfacial tension and viscosity of polymerization system on the particle size of TEMs, and in turn, the effect of the particle size of TEMs on the expansion temperature, expansion ratio and thermal response performance were investigated in detail. The results showed that increasing the interface tension and viscosity of the polymerization system was beneficial for preparing large size TEMs. Under the optimized conditions of 300 rpm, 25 wt% iso‐pentane dosage, and 9:3:1 mass ratio of AN/MAA/VAC, the TEMs shown above 100 μm particle size and 4 times expansion ratio at 150°C. Moreover, TEMs with 18% encapsulation ratio (Er) of the foaming component can complete foaming in the narrow temperature range (ΔT ≤ 10°C), showing a sensitive thermal response. The mixture of waterborne polyurethane and quantitative TEMs was coated on the surface of synthetic leather base, and a new type of suede‐like leather was obtained after foaming, which can substitute genuine suede leather.

The effects of fermentation of Qu on the digestibility and structure of waxy maize starch.

The fermentation of Qu (FQ) could efficiently produce enzymatically modified starch at a low cost. However, it is poorly understood that how FQ influences the waxy maize starch (WMS) structure and the digestion behavior. In this study, WMS was fermented by Qu at different time and starches were isolated at each time point, and its physico-chemical properties and structural parameters were determined. Results showed that the resistant starch (RS), amylose content (AC), the average particle size [D(4,3)] the ratio of peaks at 1,022/995 cm–1, and the onset temperature of gelatinization (To) were increased significantly after 36 h. Conversely, the crystallinity, the values of peak viscosity (PV), breakdown (BD), gelatinization enthalpy (ΔH), and the phase transition temperature range (ΔT) were declined significantly after 36 h. It is noteworthy that smaller starch granules were appeared at 36 h, with wrinkles on the surface, and the particle size distribution was also changed from one sharp peak to bimodal. We suggested that the formation of smaller rearranged starch granules was the main reason for the pronounced increase of RS during the FQ process.

Temperature control of battery modules through composite phase change materials with dual operating temperature regions

The phase change material (PCM)-based battery thermal management technology still remains a contradiction of guaranteeing a suitable operating temperature (20–40 ℃) of the batteries under regular working conditions, while avoiding the malfunction of the PCM under high ambient temperature (>40 ℃). Therefore, a novel composite PCM (CPCM) possessing dual phase change temperature regions (PCTRs) is designed herein by in-situ constructing a phase-changeable polymer (PCP) framework in the polyethylene glycol (PEG)/expanded graphite (EG) slurry. As prepared, the lower PCTR at 31.7–42.1 ℃ from the PCP framework provides a latent heat of 35.0 J g−1, while the higher PCTR at 42.1–51.2 ℃ from the PEG offers a latent heat of 68.3 J g−1. Additionally, the nanoscaled PCP framework strongly adsorbs the PEG, preventing the leakage phenomenon (mass loss < 1%), and the uniformly dispersed EG endows the CPCM with a high thermal conductivity of 1.98 W m−1 K−1. In consequence, under the normal ambient temperature of 25 ℃, the lower PCTR effectively keeps the battery module operating within the suitable temperature range of 25.9–34.9 ℃ and with a low temperature difference (ΔT) of 2.4 ℃ at the discharge rate of 1C. For comparison, the battery module adopting classical CPCM with a single PCTR at 40.9–55.1 ℃ demonstrates a much higher temperature range and maximum ΔT at 28.0–40.9 ℃ and 4.8 ℃, respectively. Under the high ambient temperature of 40 ℃, the higher PCTR starts to work like the single PCTR of traditional CPCMs, and controls the Tmax and ΔT of the module below 49.2 and 2.2 ℃ at the discharge rate of 1C, respectively, preventing thermal hazards.

Modeling daily global solar radiation using only temperature data: Past, development, and future

Accurate determination on global solar radiation (Rs) is essential in many disciplines and sectors. This study comprehensively reviewed 78 existing models and developed 4 new models (N1-1∼N1-4) for estimating daily Rs using only temperature data. The best model was then applied to forecast daily Rs using temperature data in weather forecast. All models were calibrated and tested using data collected from 105 radiation stations scattered across China. Daily data of temperature were also collected from 703 additional meteorological stations to classify diurnal temperature range (ΔT) zones in China. The results showed that China could be divided into five ΔT zones. The newly developed model N1-4 was the most accurate among all models for various ΔT zones, with values of coefficient of determination, index of agreement, mean bias error, mean absolute bias error, root mean square error, and relative root mean square error in the ranges of 0.660–0.737, 0.888–0.919, −0.023–0.100 MJ m−2 d−1, 2.691–3.195 MJ m−2 d−1, 3.725–4.231 MJ m−2 d−1, and 0.224–0.352, respectively. The generalized coefficients of the N1-4 model were also derived and further used for estimating daily Rs in areas with or without Rs data when there are only temperature data. The model N1-4 was successfully applied to predict daily Rs in varying ΔT zones with forecast temperature data for a lead time of 1–8 days. This new model is recommended for forecasting daily Rs in zones with high ΔT for a long lead time and in zones with low ΔT for a short lead time.

Effect of B2O3 addition on thermal and optical properties of TeO2–ZnO–Bi2O3–TiO2 glasses

New tellurite glasses with composition (in mol%): 60TeO2–(30-x)ZnO–5Bi2O3–5TiO2-xB2O3 (where x = 0, 2.5, 5.0, 7.5 and 10.0) were fabricated using conventional melt quenching method. Compositional dependence of the glasses on their density, thermal, refractive index and optical properties were investigated. X-Ray Diffraction analysis was carried out to confirm the nature of the thus formed glasses. Density, refractive index, and absorption spectra were measured at room temperature from which other glass characteristics such as polaron radius, oxygen packing density, field strength, B3+ interatomic distance, band gap energy, and Urbach tail were determined. Thermal characterisation to determine the change in glass transition temperature, glass crystallisation, melting point, and glass stability was carried out using Differential Scanning Calorimetry. A discussion was made in order to understand the results in terms of the ratio of bridging oxygen to non-bridging oxygen ions (BO/NBO). It was found that the addition of B2O3 results in increasing oxygen packing density, glass transition temperature, BO/NBO ratio and band gap energy, while decreasing density, refractive index, field strength, glass stability and Urbach tail energy. With increasing B2O3 concentration density changed from 5.879 to 5.646 g cm−3, refractive index 1.875 to 1.741, working temperature range (ΔT = 66 °C) and phonon energy within the range of 736–740 cm−1.

Formation of a quasi-equilibrium domain structure of crystals of the TGS group near TC

In the temperature range ΔT ≈ 321 K ÷ 322 K, the kinetics of the nonequilibrium domain structure of triglycine sulphate crystals, both pure and with specially introduced defects, has been studied by means of piezoresponse force microscopy technique. The temporal change in the domain structure as a set of regions with a scalar order parameter of P (r, t) = +1 and −1 for oppositely polarized domains was analysed by the behaviour of the space-time correlation function C(r,t) = ·Р(r,t)Р(0,t)Ò. At different distances from the Curie point Tc, the characteristic length Lc, as a scale measure of the average domain size, increases with time according to the power law Lc(t)~(t−t0)a. A decrease of the exponent a with distance from Tc can be a consequence of the transition of the domain structure of TGS crystals from a non-conservative state to aconservative one.

The Effect of Cold Press Chia Seed Oil By-Products on the Rheological, Microstructural, Thermal, and Sensory Properties of Low-Fat Ice Cream.

This study aimed to investigate the utilization of cold-pressed chia-seed oil by-products (CSOB) in a low-fat ice cream formulation as a fat replacer and stabilizer. In the study, ice cream emulsion mixtures were formulated by using 0.2–0.4% xanthan gum (XG), 2.5–12.5% fat, and 1–3% CSOB. Optimization was performed using the response surface methodology (RSM) and full factorial central composite design (CCD) based on the flow behavior rheological properties of the emulsions obtained from 17 different experimental points. All of the emulsion samples showed non-Newtonian shear-thinning flow behavior. The consistency coefficient (Κ) values of the emulsion samples were found to be 4.01–26.05 Pasn and were significantly affected by optimization parameters (p < 0.05). The optimum formulation was determined as 0.29% XG, 2.5% CSOB, 2.5% fat. The low-fat (LF-IC) and full-fat control samples (FF-IC) were compared to samples produced with an optimum formulation (CBLF-IC) based on the steady shear, frequency sweep, and 3-ITT (three interval thixotropy test) rheological properties, thermal properties, emulsion stability, light microscope images, and sensory quality. CBLF-IC showed similar rheological behavior to FF-IC. The mix of CBLF-IC showed higher emulsion stability and lower poly-dispersity index (PDI) value and fat globule diameters than those of FF-IC and LF-IC. The thermal properties of the samples were significantly affected by the addition of CSOB in an ice cream mix. CBLF-IC exhibited a lower temperature range (ΔT), enthalpy of fusion (ΔHf), and freezing point temperature (Tf) than those of FF-IC and LF-IC. While CBLF-IC exhibited a higher overrun value than other samples, it showed similar sensory properties to the FF-IC sample. The results of this study suggested that CSOB could be used successfully in low-fat ice cream production. This study also has the potential to gain new perspectives for the evaluation of CSOB as a fat substitute in a low-fat ice cream.

Graphene으로 개질된 폴리우레탄-에폭시 복합체의 기계적 물성과 Damping 특성

Polyurethane (PU) has received extensive attention in structural engineering due to its excellent mechanical properties and damping properties. In this research, graphene-modified PU-epoxy composites are prepared for the application in structural engineering. The mechanical properties and damping properties of the composites with different contents of graphene are investigated. The damping properties of the composites were also investigated by performing dynamic mechanical analysis (DMA). The results showed that with the increase of graphene content, the tear strength of the composites decreased from 52 to 39 ㎫. Due to the enhancement of appropriate amount of graphene, the tensile strength and elongation at break increase to the maximum value, being 16 ㎫ and 675%, respectively. And DMA tests showed that the damping properties reach the optimal values when the graphene content is 0.2%. The large damping temperature range (ΔT<SUB>0.5</SUB>) is 33 ℃, from -2.9 to 30.1 ℃. The peak of loss factor (η<SUB>max</SUB>) is 0.92 and the integral area (TA) is 36 ℃, much higher than those of the pure PU-epoxy composites. In addition, scanning electron microscopy (SEM) results show that agglomeration appears with higher graphene content.

Low-frequency ultrasonication modulates the impact of annealing on physicochemical and functional properties of rice flour

Ultrasonication (US) is a green technology used to physically modify flours to increase their industrial range of applicability. The aim of this work was to study the combined effect that dual US and annealing (ANN) treatments have on starch and protein structure of rice flour, at 20, 40, 50 and 60 °C. Results showed clear modifications of functional, thermal and pasting properties of flours, as well as rheological properties of gels made from them. US + ANN led to generation of small-size particles, which markedly increased the swelling power and starch damage. X-Ray Diffraction and FTIR indicated that starch crystallinity and protein secondary structure was affected by the shear forces of cavitation. The combination of US + ANN improved the crystalline structure arrangement within the starch granules, causing narrowing of the gelatinization temperature range (ΔT). Pasting viscosities were significantly decreased by ultrasonication, following an increasing trend with increasing temperature, while pasting temperature was increased, agreeing in the achievement of a thermodynamically more stable structure. The rheological properties indicated a reduction of the elastic (G′) and viscous (G″) moduli after ultrasonication, as well as lower values of tan (δ), reflecting a higher predominance of elastic modulus versus viscous one than the non-sonicated flours. The rice flour's properties were found to be highly sensitive to the applied treatment conditions, showing a synergetic effect when sonicating at the highest studied temperature.

Kretschmann-Based Optical Sensor via Thermally Tunable Refractive Index

This study discusses whether the prism used in a Kretschmann-based surface plasmon sensor can be fabricated from a thermotropic liquid crystal (TLC) material. The refractive index of the TLC prism can be thermally tuned to match the excitation requirements for the surface plasmon modes along the metal–TLC interface of the proposed sensing platform. The TLC material was chemically prepared in vitro and was thermally and optically characterized. The measurements reported a wide mesophase temperature range ΔT (~35 °C) and a relatively high clearing temperature TC (~84 °C) which constitutes a stable thermal control for the TLC optical parameters. The experimentally measured refractive indices of the TLC material reflect a linear change in line with the temperatures at several selected wavelengths in the visible region. A design of the surface plasmon sensor was proposed, which provided a linear response to the investigated analytes refractive index. This work highlights the importance of employing TLC material in designs compatible with detecting refractive index changes by thermal tuning and presents refractive index interrogation as an alternative method for exciting surface plasmon modes.