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Moth eye protuberances, for instance, exhibit highly developed and well-organized nanostructures that allow them to adapt to a wide range of environmental conditions and achieve remarkable antireflective performance, which has inspired and been emulated by scientific advancement. Innovative studies have focused on bioinspired and imitating moth-eye patterns to provide a textured surface in multilayer antireflective coatings (ARC) using nanomaterials, polymers, or composites to eliminate undesired reflection in standard optical components and optoelectronic industrial applications. Multilayer AR systems provide a number of advantages over single-layer designs. Still, their limited applicability is due to obstacles such as mismatched properties at interfaces, high costs, poor mechanical durability, and wetting concerns. Using MgF2 and polytetrafluoroethylene, we develop a technique for fabricating high-performance AR nanostructures on borosilicate crown glass and Fluorine-doped Tin Oxide substrates via the glancing angle deposition technique. By inducing porosity and changing the deposition angle (α) at 550 nm, the refractive index of MgF2 is reduced from 1.38 to 1.14. In agreement with optical modelling predictions, high-performance ARC has been successfully produced on different substrates. Besides this, introducing a thin layer of polytetrafluoroethylene on MgF2 ARC via vapor deposition having a refractive index of 1.21 deposited at α ∼80° results in inducing water-repellent properties in ARC. Hence, our fabricated ARC yields stable AR efficiency with outstanding directional uniformity, durability, and negative temperature stability, having hydrophobic characteristics.

The Quantum Dot Cellular Automata (QCA) is an emerging quantum electronics technology in which quantum cells are the fundamental building blocks. In this work, a Binary to Gray (BTG) code converter design is proposed and implemented using the QCA Designer Tool. This code converter design requires fewer cells than earlier designs and also increases the converter’s implementation bit size to five. The primary objective of this proposal is to introduce a BTG code converter design that excels in temperature stability and energy efficiency. The cell count in the proposed converter design for two-bit, three-bit, and four-bit is decreased by 68.55 %, 66.52 %, and 67.77 %, respectively and the overall area improved by 46.15 %, 52.17 %, and 57.58 % for 2- bit,3-bit and 4-bit, respectively by considering a latency of 0.75. The five-bit BTG has an area of 0.20 µm2 with a cell count of 141 and a latency of 0.75. To validate the functionality of the proposed design, extensive simulations were carried out using the QCA Designer tool, QCA DesignerE tool, and QCA Pro tool respectively.

The inferior temperature stability of piezoelectric response is the main drawback of KNN-based ceramics. Here, the Ba-doped 0.97(K0.48Na0.52)(Nb0.96Sb0.04)O3-0.03Bax(Bi0.5Ag0.5)1-xZrO3 (abbreviated as KNNS-BxBAZ) textured ceramics were prepared by the template grain growth (TGG) method. Excellent comprehensive properties (d33=(406 ± 15) pC/N, TC = 274 °C, strain is 0.17%) were achieved in KNNS-BxBAZ textured ceramics with x = 0.2. Meanwhile, its piezoelectric and strain properties also show superior temperature stability (d33 maintained within ±20% change in a wide temperature range from 25 °C to 200 °C and strain variation was less than 5% in the temperature range from room temperature to 165 °C). The high O-T phase transition temperature (TO-T is 110 °C) induced by incorporating Ba ions accounts for the enhanced temperature stability of piezoelectric properties. In addition, the crystal texture always maintains the contribution of piezoelectric anisotropy to the piezoelectric properties during elevated temperature, which significantly improved the temperature stability of piezoelectric properties. This work provides an effective strategy for simultaneously achieving high piezoelectric response and excellent temperature stability in KNN-based ceramics.

The poor temperature stability of the BaTiO3 ceramic has always been the main problem limiting their application. This situation has been improved but sacrifices the intrinsic polarization, which significantly reduces the dielectric constant. In this work, the mechanism of multiple polarization was creatively introduced, and the temperature stability and dielectric properties of BaTiO3-based ceramics are simultaneously enhanced. In particular, the Ba0.9925Bi0.005Ti0.995Ca0.005O2.995 (BBTC0.5) ceramic sample achieved excellent temperature stability (−14.8% to 8.85%) over an ultra-wide temperature range (−47 to 400 °C) and exhibited colossal permittivity (27,125, 25 °C, 1 kHz) and low dielectric loss (0.07, 25 °C, 1 kHz). The dielectric properties, complex impedance spectra combined with XPS results indicate that the defective dipole clusters (Ti3+-VO..-Ti3+, BiBa. and CaTi″-VO..) along with surface effects lead to colossal permittivity effect. More importantly, SEM images show the presence of the second phase at grain boundaries, which prevent the carriers within the grains from accumulating at the grain boundaries. As a result, the dielectric loss was reduced and the temperature stability was further extended. This strategy breaks the traditional limitation of single/noncomprehensive enhancement by single-polarization mechanism, and is of great theoretical and practical significance to promote the research and application of high-performance BaTiO3-based ceramic materials.

Work on giant dielectric CaCu3Ti4O12 (CCTO) ceramics has been continuously ongoing to obtain materials with a high dielectric constant (ε') and low dielectric loss tangent (tanδ) with both values stable over a wide temperature range. Various methods have been used to modify the materials, such as doping and co-doping with different transition metals at Ca or Cu sites, molar variation of metals (Cu, Ca and Ti), including altering in the methods and conditions of ceramic preparation. In general, the most common problem found in this type of research is that increasing ε' also increases tanδ. Thus, in this work, a one-step polymer pyrolysis (PP) procedure was used to obtain Co2+-doped CaCu3-xCoxTi4.2O12 (x = 0.00, 0.03, 0.05, and 0.07) powders. Then, all powders were sintered to obtain ceramics using two different sintering conditions, 1050 °C for 10 h and 1080 °C for 5 h. The influence of Co2+ ions and sintering conditions on the microstructure, dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics was investigated. Substitution of Co2+ ions at Cu sites can reduce tanδ values and increase ε' in samples with x = 0.03 and 0.05. However, the tanδ and ε' values were concurrently reduced for x = 0.07. Remarkably, a ceramic with x = 0.07 sintered at 1080 °C for 5 h exhibited very low tanδ(∼0.009) and colossal ε' (∼11551) at 1 kHz and 30 °C, over a broad temperature range (−60 to 150 °C), with stability of Δε' ≤ ±15 %. This ceramic is a suggested candidate material for X8R capacitors. Moreover, increasing the Co2+ doping level could significantly raise the nonlinear coefficient (α) of the ceramics from ∼ 3.48 to 34.30. Additionally, the very high Eb values of ceramics with x = 0.07 sintered at 1050 °C for 10 h and 1080 °C for 5 h were significantly increased by ∼26.34 and 17.45 times, respectively, compared to an undoped ceramic. A widened temperature range where Δε' ≤ ±15 % and tanδ

The temperature control unit (TCU) is widely used in lithography tools or other precision equipment to achieve a high level of temperature stability. Still, there is no systematic analysis of the thermal model in the present study about how to build a precise TCU. In this paper, we provide a new perspective for analyzing the outlet temperature performance of TCU. We analyzed the thermal model of TCU’s sub-devices and thermal model of environmental disturbance over the frequency domain, then obtained the influence of different processes on the TCU output temperature at different frequencies. The above thermal models are brought into two commonly used process control frameworks to comprehensively consider the temperature control effect under the combination of control and hardware. The relationship expressions from the temperature spectrum performance to the fluctuation index are derived to obtain the quantitative TCU temperature performance. We built a TCU experimental platform with the water medium and verified the accuracy of TCU thermal models, thermal disturbance models, and the accuracy of temperature fluctuation index derivation, all within a 5% error. The TCU temperature accuracy reaches ± 1mk under one sigma statistics as a thermal engineering application case.

Among the lead-free compositions identified as potential capacitor materials, BiScO3-BaTiO3 (BS-BT) relaxor dielectrics exhibit good energy storage performance. In this research, 0.4BS-0.6BT is considered as the parent composition, with NaNbO3 (NN) addition intended to substitute the A and B site cations. The NN modified BS-BT ceramics exhibit excellent temperature stability in terms of their dielectric properties, with the room-temperature dielectric constant on the order of 500–1 000 and variation less than 10% up to 400 °C. In addition, NN has a high band-gap energy leading to increased breakdown strength and energy storage properties in modified compositions. The highest breakdown strength was achieved for 0.4BS-0.55BT-0.05NN, being on the order of 430 kV/cm, and a high energy density of 4.6 J/cm3 with high energy efficiency of 90% was simultaneously achieved. Of particular importance is that the variation of the energy density was below 5% due to the temperature-insensitive dielectric constant, while ∼90% energy efficiency was retained over the temperature range of 25–160 °C. The improved temperature stability with NN addition makes this composition promising for high temperature capacitor and dielectric energy storage applications.

Lead-free ceramics with both high piezoelectric response and good temperature stability are urgently demanded for electromechanical conversion devices. Unfortunately, owing to coexistence of polymorphic phases near room temperature (RT), enhanced piezoelectric properties were usually achieved with occurrence of strong temperature dependence in modified BaTiO3 (BT)-based ceramics. In this work, we demonstrate that tailoring grain orientations of tetragonal BT-based ceramics can effectively produce substantially enhanced and thermally stabilized piezoelectric response. Both c- and c-oriented tetragonal (Ba0.85Ca0.15) (Zr0.05Ti0.95)O3 (BCZT) ceramics with texture degrees F>90% were synthesized via templated grain growth. Interestingly, the ceramics textured along the c polar axis show much higher microscopic and macroscopic piezoelectric properties than those with nonpolar c texture, indicating an “extender” ferroelectricity nature. Compared with randomly oriented samples, the c-oriented ceramics exhibit simultaneously ∼1.6 times higher piezoelectric strain d33∗ (∼760 pm/V), 4.4 times higher piezoelectric figure of merit d33×g33 (8.8 × 10−12 m2/N), and better temperature stability (strain variation ≤5% between RT and 110 °C). Such thermally stabilized strain response can be mainly attributed to wide temperature range of tetragonal phase and stable domain structure. This work provides a promising route for further developing lead-free piezoceramics with high and temperature-insensitive performance, which can greatly broaden their application areas.

The sintering and dielectric properties of (1 − x)Li2Mg0.95Co0.05SiO4 + xTiO2 ceramics created by the solid state reaction method were investigated. X-ray diffraction and energy-dispersive X-ray spectroscopy were used to obtain phase composition of the ceramics, and scanning electron microscopy was used to observe their microstructure. A network analyzer was used to measure dielectric properties, while mechanical, simultaneous-thermal, and dynamic mechanical analyzers were used to obtain mechanical and chemical properties. Li2Mg0.95Co0.05SiO4 (LMCS) and TiO2 co-exist in the composite system. TiO2 addition resulted in decreasing grain size and crystallite size, increasing starting temperature of shrinkage, increasing activation energy, and increasing elasticity and stiffness. A 4%/volume addition of TiO2 and sintering at 1075 °C changed the LMCS τf to 1.57 ppm/°C and resulted in dielectric properties of εr = 6.33 and Q × f = 17,000 GHz (16 GHz) with a relative density equals to 96.13%.

Na0.5Bi0.5TiO3 (NBT)-based ceramics have been widely used as dielectric materials for energy storage capacitors because of their environmental friendliness and excellent ferroelectric properties. However, their energy storage performance still needs to be further improved to satisfy the increasing demand. Herein, we report a novel 0.90(Na0.5Bi0.5)0.7Sr0.3TiO3-0.10Bi(Ni0.5Sn0.5)O3 (0.90NBST-0.10BNS) ceramic with significantly improved energy density (5.0 J cm−3), enhanced recoverable energy density (4.18 J cm−3) and high energy efficiency (83.64%) through the incorporation of Bi(Ni0.5Sn0.5)O3 (BNS), due to the increased breakdown strength and the relaxation ferroelectric (RFE) properties. The first-order reversal curve (FORC) measurements confirm that the addition of BNS improves RFE properties by breaking the order of long-range ferroelectricity. The 0.90NBST-0.10BNS ceramic also possesses an outstanding temperature and frequency stability of energy storage properties in the range of 20 °C–140 °C and 1 Hz–100 Hz, respectively. More importantly, the discharge properties characterized by a preeminent power density (36.19 MW cm−3), transient energy release times (144.2 ns), and high discharge energy density (1.16 J cm−3) also synchronously observed in 0.90NBST-0.10BNS ceramic. These results show that the 0.90NBST-0.10BNS ceramic with outstanding comprehensive performances is a promising energy storage ceramic candidate for capacitors in high power systems.

This paper proposed a new approach to achieve full characteristic of highly non-linear current density–electric field (J-E) curve, which depends on various key factors in terms of filler concentration, temperature, input voltage level, and structuration of ZnO particles (i.e. aligned or randomly dispersed). The homogeneity of particle distribution within the polymer matrix, together with the chain-like structure of the aligned composites elaborated with various ZnO volume fraction was verified via microscopic investigations. Numerical simulation was also conducted through COMSOL Multiphysics, giving an estimation of field distribution around ZnO phase. Experimental characterization in addition to analytical models was established using varying (sinusoidal) or direct current (DC) tests. The DC test was carried out in order to identify the conduction profile as well as the percolation threshold of ZnO samples. Temperature also has considerable influence on the switching field and the dielectric permittivity of the nonlinear composites. In the sinusoidal test, current discrimination was adopted using bipolar polarization loop, allowed the detailed quantification of conductivity values, while prediction in the capacitive current density enabled to distinguish the relative permittivity. These results demonstrated that the electrical properties of ZnO compound, such as conductivity and permittivity, substantially enhanced with the increasing filler content, especially when the samples were subjected to dielectrophoretic manipulation. Further analysis was carried out on sinusoidal unipolar polarization to predict the dielectric loss factor as function applied field. Finally, by playing on different pertinent parameters, it was possible to efficiently control the electric and mechanical characteristics of ZnO composite. Such properties are highly important in application of microvaristors used as protection devices. By associating with other features of ZnO like piezoelectricity, this material is undoubtedly of high interest in medical use where multifunctional system design becomes mandatory.

One of the most important properties of cellulolytic enzyme is its ability to convert cellulosic polymer into monomeric fermentable sugars which are carbohydrate by nature can efficiently convert into biofuels. However, higher production costs of these enzymes with moderate activity-based stability are the main obstacles to making cellulase-based applications sustainably viable, and this has necessitated rigorous research for the economical availability of this process. Using water hyacinth (WH) waste leaves as the substrate for cellulase production under solid state fermentation (SSF) while treating the fermentation production medium with CuO (cupric oxide oxide) bionanocatalyst have been examined as ways to make fungal cellulase production economically feasible. Herein, a sustainable green synthesis of CuO bionanocatalyst has been performed by using waste leaves of WH. Through XRD, FT-IR, SEM, and TEM analysis, the prepared CuO bionanocatalyst's physicochemical properties have been evaluated. Furthermore, the effect of CuO bionanocatalyst on the temperature stability of raw cellulases was observed, and its half-life stability was found to be up to 9 h at 65 °C. The results presented in the current investigation may have broad scope for mass trials for various industrial applications, such as cellulosic biomass conversion., Competing Interests: Declaration of competing interest Authors of the manuscript declare there is no conflict of interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A survey of existing stationary phases classified by the United States Pharmacopeia reveals that 120 groups of chromatographic supports mostly utilize silica-silane chemistry, polymeric materials along with some niche metal oxides. In this work, the synthesis and characterization of transition-metal free geopolymers as a new class of stationary phases for hydrophilic interaction liquid chromatography and normal phase separations is reported. The geopolymers were synthesized by reaction of synthetic aluminosilicate with potassium silicate (fumed silica dissolved in KOH) in a water-in-oil emulsion. For comparative purposes of peak shapes, a geopolymer from natural metakaolin was also synthesized. The geopolymers were examined by X-ray diffraction, energy dispersive spectroscopy, laser diffraction, and N 2 -adsorption isotherms. This two-step approach gives spherical microparticles with surface area and pore size comparable to silica phases (150 m 2 /g and 120 Å respectively). Both synthetic aluminosilicates based and natural metakaolin based geopolymers occupy a unique "spot" in the HILIC selectivity chart when compared to 35 HILIC phases. An additional promising feature of geopolymers is high pH and temperature stability which are used to tune selectivity for small polar analytes. High pH separations are shown with carboxylic acids. Geopolymers also show mixed mode behavior in retention with ion-exchange properties in purely aqueous mobile phases. The separation of derivatized sugars is demonstrated and compared with porous graphitic carbon (Hypercarb™) as another pH-stable stationary phase., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Gram-negative pathogens secrete effector proteins into human cells to modulate normal cellular processes and establish a bacterial replication niche. Shigella and pathogenic Escherichia coli possess homologous effector kinases, OspG and NleH1/2, respectively. Upon translocation, OspG but not NleH binds to ubiquitin and a subset of E2~Ub conjugates, which was shown to activate its kinase activity. Here we show that OspG, having a minimal kinase fold, acquired a novel mechanism of regulation of its activity. Binding of the E2~Ub conjugate to OspG not only stimulates its kinase activity but also increases its optimal temperature for activity to match the human body temperature and stabilizes its labile C-terminal domain. The melting temperature (T m ) of OspG alone is only 31 °C, as compared to 41 °C to NleH1/2 homologs. In the presence of E2~Ub, the T m of OspG increases to ~42 °C, while Ub by itself increases the T m to 39 °C. Moreover, OspG alone displays maximal activity at 26 °C, while in the presence of E2~Ub, maximal activity occurs at ~42 °C. Using NMR and molecular dynamics calculations, we have identified the C-terminal lobe and, in particular, the C-terminal helix, as the key elements responsible for lower thermal stability of OspG as compared to homologous effector kinases., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Enzymes activity and stability at extreme temperature can be intensified by regularly applying protein engineering. In the present study, two amino acids were perceived to mark the temperature dependability of xylanase from Geobacillus thermodenitrificans C5. Six mutants of G. thermodenitrificans C5 were built through site-directed mutagenesis by interchanging the residue with proline and glutamic acid (R81P, H82E, W185P, D186E, double mutant W185P/D186E and triple mutant H82E/W185P/D186E). Both mutant and wild type enzymes were quantified in host E. coli BL21. In comparison to wild type, the temperature was enhanced by 4 °C, 5 °C and 11 °C in H82E, W185P/D186E and H82E/W185P/D186E mutant models, respectively. The mutant H82E and the combined substitutions (H82E/W185P/D186E) showed the most pronounced shifts in their half-lives for thermal inactivation. Half-life was increased 13 times at 60 °C, 15 times at 65 °C, 9 times at 70 °C and 5 times at 75 °C by H82E/W185P/D186E mutant. Mutations in xylanase enzyme causes rigidification of essential chain and filling of groove that leads to stabilization of mutants and finally resulted into enhancement in their thermostability., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Deforestation and forest degradation cause the deterioration of resources and ecosystem services. However, there are still no operational indicators to measure forest status, especially for forest degradation. In the present study, we analysed the thermal response number (TRN, calculated by daily total net radiation divided by daily temperature range) of 163 sites including mature forest, disturbed forest, planted forest, shrubland, grassland, savanna vegetation and cropland. TRN generally increased with latitude, however the regression of TRN against latitude differed among vegetation types. Mature forests are superior as thermal buffers, and had significantly higher TRN than disturbed and planted forests. There was a clear boundary between TRN of forest and non-forest vegetation (i.e. grassland and savanna) with the exception of shrubland, whose TRN overlapped with that of forest vegetation. We propose to use the TRN of local mature forest as the optimal TRN (TRN opt ). A forest with lower than 75% of TRN opt was identified as subjected to significant disturbance, and forests with 66% of TRN opt was the threshold for deforestation within the absolute latitude from 30° to 55°. Our results emphasized the irreplaceable thermal buffer capacity of mature forest. TRN can be used for early warning of deforestation and degradation risk. It is therefore a valuable tool in the effort to protect forests and prevent deforestation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Raman and infrared spectra of polycrystalline D,L-glycolic and L-(+) lactic acid are presented and assigned both by an ab initio calculation of normal modes of free conformers and by self-consistent-charge density-functional-theory computational program DFTB+. Temperature dependent Raman spectra from 295 K to 10 K reveal great stability of crystal lattices, since no soft modes and no band splittings that could be attributed to changes of the number of molecules per unit cell were observed. A semiempirical calculation with GULP program was used to estimate the strength of hydrogen bonds in crystals: in glycolic acid they have energies of -0.337 eV/mol, -0.329 eV/mol, -0.262 eV/mol and -0.242 eV/mol, while in lactic acid two hydrogen bonds have energies of -0.283 eV/mol and -0.202 eV/mol., (Copyright © 2014 Elsevier B.V. All rights reserved.)