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The CuGaTe2thermoelectric material has garnered widespread attention as an inexpensive and nontoxic material for mid-temperature thermoelectric applications. However, its development has been hindered by its low intrinsic carrier concentration and high thermal conductivity. This study investigates the band structure and thermoelectric properties of (CuGaTe2)1–x(ZnSe)x(x= 0, 0.25%, 0.5%, 1%, 1.5%, and 2%). The research revealed that the incorporation of Zn and Se atoms enhanced the level of band degeneracy and electron density of states near Fermi level, significantly raising carrier concentration through the formation of ZnGa−point defects. Simultaneously, when the doping content reached 1.5%, the ZnTe second phase emerged, collaborating with point defects and high-density dislocations, effectively scattering phonons and substantially reducing lattice thermal conductivity. Therefore, introducing ZnSe can simultaneously optimize the material’s electrical and thermal transport properties. The (CuGaTe2)0.985(ZnSe)0.015sample reaches peak ZT of 1.32 at 823 K, representing a 159% increase compared to pure CuGaTe2.

Incorporating donor doping into Mg3Sb1.5Bi0.5to achieve n-type conductivity is one of the crucial strategies for performance enhancement. In pursuit of higher thermoelectric performance, we herein report co-doping with Te and Y to optimize the thermoelectric properties of Mg3Sb1.5Bi0.5, achieving a peak ZTexceeding 1.7 at 703 K in Y0.01Mg3.19Sb1.5Bi0.47Te0.03. Guided by first-principles calculations for compositional design, we find that Te-doping shifts the Fermi level into the conduction band, resulting in n-type semiconductor behavior, while Y-doping further shifts the Fermi level into the conduction band and reduces the bandgap, leading to enhanced thermoelectric performance with a power factor as high as >20 μW cm–1K–2. Additionally, through detailed micro/nanostructure characterizations, we discover that Te and Y co-doping induces dense crystal and lattice defects, including local lattice distortions and strains caused by point defects, and densely distributed grain boundaries between nanocrystalline domains. These defects efficiently scatter phonons of various wavelengths, resulting in a low thermal conductivity of 0.83 W m–1K–1and ultimately achieving a high ZT. Furthermore, the dense lattice defects induced by co-doping can further strengthen the mechanical performance, which is crucial for its service in devices. This work provides guidance for the composition and structure design of thermoelectric materials.

Heavy haul train manipulation is extremely challenging due to cyclic pneumatic brake application and safe operation demand. To reduce the driving difficulties and enhance transportation efficiency, this article proposes a trajectory optimization method to conduct optimal speed profile with pneumatic brake application regimes. The discontinuous characteristics and safe guidelines of cyclic pneumatic brake application are fully included in trajectory optimal model to find out optimal brake regimes without stopping release, which ensures transportation efficiency to the largest extent. Integer variables and convex relaxation are introduced in optimal model construction process to linearize time-accumulated constraints of cyclic pneumatic brake application and regularize the nonconvex relationship between operation time and speed. With the aforementioned deduction and matrix construction, the trajectory optimization problem can be constructed as mixed integer programming model with quadratic constraints (QCMIP) and solved by mature solvers. Finally, simulation experiments with commercial freight line data are carried out to verify the effectiveness of the proposed optimal method. Comparisons with the piecewise affine (PWA) linearization method and dynamic programming (DP) method verify the superior performance of the proposed optimal method.

This article reports on the preparation of native/waxy corn starch (NCS/WCS)‐based films with the addition of pullulan (PUL). Our study investigated the effects of varying amounts of PUL and amylose contents on the structure, mechanical and physicochemical properties of corn starch films. Notably, it was observed that WCS films with low amylose content exhibited superior transparency, while NCS films with high amylose content demonstrated enhanced tensile strength (up to 7.35 ± 0.18 MPa). Fourier transform infrared spectroscopy (FTIR) analysis indicated that the addition of PUL did not change the molecular interactions within the corn starch films. The X‐ray diffraction (XRD) results supported that the WCS films were amorphous, while the NCS film exhibited B‐type and V‐type crystals. Moreover, an increase in PUL content led to a gradual reduction in the crystallinity of both WCS films and NCS films. The addition of PUL improved the mechanical properties and oxygen barrier characteristics of these films but had an adverse impact on their water vapor barrier properties. These findings offer valuable insights for the selection of additives for corn starch film, which can further enhance the practical application potential of corn starch films in food and other industries. This article reports on the preparation of native/waxy corn starch‐based films with the addition of pullulan. Our study investigates the effects of varying amounts of pullulan and amylose content on the structure, mechanical and physicochemical properties of corn starch films.

Drug delivery directly across the tympanic membrane (TM) could eliminate systemic exposure to antibiotics prescribed for otitis media, the most common reason for pediatricians to prescribe antibiotics. Here, we hypothesized that inducing inflammation of the TM could enhance drug flux across the TM. We demonstrated that the flux of ciprofloxacin across the TM was greatly increased by treatment with the proinflammatory agent histamine. That enhancement was blocked by concurrent treatment with blockers of histamine receptor 1. Treatment of the TM with histamine was able to enhance drug flux sufficiently to eradicate otitis media in vivo in chinchillas, but only if the histamine was applied prior to treatment with antibiotics.

• The vacancy of Cu atom can increase the band gap and reduce the sound velocity. • Cu vacancies increase the density of the samples, and significantly increase the carrier concentration. • Cu vacancies generate many defects, which scatter phonons at multiple scales and realize thermoelectric decoupling. • The highest ZT value of Cu 0.96 GaTe 2 reaches 1.23 at 823 K, and the average ZT value reaches 0.575. The ternary chalcopyrite CuGaTe 2 has emerged as a promising p -type thermoelectric material with its advantages of low cost, good stability, and non-toxic elements. However, its thermoelectric performance is limited by the intrinsic low electrical conductivity and high lattice thermal conductivity. In this work, A deficiency of Cu in Cu 1– x GaTe 2 semiconductors can be used to optimize the electrical properties by improving the carrier concentration and to reduce thermal conductivity through multi-scale phonon scattering, which is predicted and guided by the First-principles density functional theory calculations. The carrier concentration is increased to 1020, which compensates for the low electrical performance caused by the intrinsic low n H of CuGaTe 2. The average power factor of Cu 0.96 GaTe 2 reaches 106.3% higher than that of the original CuGaTe 2. In addition, the lattice thermal conductivity of the defective samples is greatly reduced at high temperatures, which is mainly due to the reduction of sound speed and phonon scattering. All the above factors contribute to the highest dimensionless figure of merit (ZT) value of 1.23 at 823 K in Cu 0.96 GaTe 2 , which is 114% higher than the pristine CuGaTe 2 , and the average ZT is 171.4% higher. [Display omitted] [ABSTRACT FROM AUTHOR]

• Gd and Ho have increased the DOS of the valence band near the Fermi level, and the d electrons of Gd and Ho have made extraordinary contributions. • Gd and Ho are effective n-type cation site dopants with higher doping efficiency and better carrier concentration than the anion site dopants chalcogenide elements. • For Mg 3.2 Gd 0.02 Sb 1.5 Bi 0.5 and Mg 3.2 Ho 0.02 Sb 1.5 Bi 0.5 samples, we obtain high zT values of 1.61 and 1.55 at 725 K, respectively. • Gd as well as Ho are an alternative effective n-type doping element for higher thermoelectric performance. Mg-based thermoelectric materials have attracted more and more attention because of their rich composition elements, green environmental protection, and lower price. In recent years, the thermoelectric properties of n-type Mg 3 Sb 2 materials have been optimized by doping chalcogenide elements (S, Se, and Te) at the anionic position. In this work, n-type Mg 3.2 A x Sb 1.5 Bi 0.5 (A = Gd, Ho; x = 0.01, 0.02, 0.03, and 0.4) samples were prepared by the cation site doping of lanthanide elements (Gd and Ho). The research results show that Gd and Ho doped n-type Mg 3.2 Sb 1.5 Bi 0.5 samples are entirely comparable to the S, Se, and Te doped n-type Mg 3.2 Sb 1.5 Bi 0.5 samples, demonstrating more excellent thermoelectric properties. Doping with lanthanides (Gd and Ho) at the Mg site increases the carrier concentration of the material to 8.161 × 1019 cm−3. Doping induces the contribution of more electron, thus obtaining higher conductivity. The maximum zT value of the Mg 3.2 Gd 0.02 Sb 1.5 Bi 0.5 and the Mg 3.2 Ho 0.02 Sb 1.5 Bi 0.5 samples reaches 1.61 and 1.55, respectively. This work theoretically and experimentally demonstrates Gd and Ho are efficient n-type dopants for Mg 3.2 Sb 1.5 Bi 0.5 thermoelectric material. [ABSTRACT FROM AUTHOR]

The previous works commonly adjust the carrier concentration through acceptor doping, but at the same time, the decrease of the Seebeck coefficient limits the further improvement of electrical properties in Cu3SbSe4-based materials. In this work, a microwave-assisted hydrothermal synthesis method was used to synthesize Cu3SbSe4/TiO2hollow microspheres. Part of TiO2participates in the reaction, replaces the Sb site of Cu3SbSe4to form holes, and the rest is dispersed in the matrix in the form of the second phase. The first-principles calculations reveal that the doping of Ti significantly changes the band structure and phonon spectrum, thereby regulating carrier concentration while increasing phonon scattering. In addition, experimental results show that the energy filtering effect generated by the extra-mixed TiO2nano particles, which suppresses the decrease of Seebeck coefficient by acceptor doping. Consequently, the highest average power factor 897.5 μW m−1 K−2and the zTpeak value of 0.70 can be obtained in Cu3SbSe4/6%TiO2sample at 298–623 K. This work provides a new sight to improve the thermoelectric properties in Cu3SbSe4through carrier concentration regulation and nano-phase composition.

• Ag doping and Se alloying optimize the thermoelectric performance of Te. • Se alloying effectively reduces lattice thermal conductivity of Te by refining grain of Te and introducing high density-defects. • Ag doping regulates the micro morphology and increases the grain size of Te-Se solid solution. • Ag doping successfully compensates the lost carrier mobility due to Se alloying while retains the ability of Te-based matrix to scatter high-frequency (ω) and medium-frequency phonons. • Sb doping effectively optimizes the carrier concentration of Te. Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity (κ L) of tellurium by introducing multidimensional lattice defects. However, extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix. In this paper, we propose that the incorporation of Ag could successfully compensate the lost carrier mobility (μ H) due to Se alloying through the regulation of microstructure, resulting in the higher power factor (PF) than that of samples without Ag. After composition optimization, the κ L decreased from 1.29 W m−1 K−1 of Te 0.99 Sb 0.01 to 1.05 W m−1 K−1 of Te 0.94 Ag 0.02 Se 0.03 Sb 0.01 at 350 K, while the PF remained unchanged or even slightly increased. Benefit from the synergistic effect of carrier mobility compensation and phonon scattering, a maximum zT of 0.91 at 573 K and an average zT of 0.57 (between 298 and 573 K) are achieved in Te 0.94 Ag 0.02 Se 0.03 Sb 0.01. This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials. [Display omitted] [ABSTRACT FROM AUTHOR]

• AgCl-doping and Sb-alloying enhance thermoelectric performance of SnTe stepwise. • AgCl-doping simultaneously enlarges band gap and achieves band convergence of SnTe. • Dense point defects effectively reduce lattice thermal conductivity of SnTe. • Sb-alloying effectively optimizes carrier concentration of SnTe. As an eco-friendly thermoelectric material, SnTe has attracted extensive attention. In this study, we use a stepwise strategy to enhance the thermoelectric performance of SnTe. Firstly, AgCl is doped into SnTe to realize band convergence and enlarge the band gap of AgCl-doped SnTe. AgCl-doping also induces dense point defects, strengthens the phonon scattering, and reduces the lattice thermal conductivity. Secondly, Sb is alloyed into AgCl-doped SnTe to further optimize the carrier concentration and simultaneously reduce the lattice thermal conductivity, leading to improved thermoelectric dimensionless figure of merit, ZT. Finally, (Sn 0.81 Sb 0.19 Te) 0.93 (AgCl) 0.07 has approached the ZT value as high as ∼0.87 at 773 K, which is 272 % higher than that of pristine SnTe. This study indicates that stepwise AgCl-doping and Sb-alloying can significantly improve thermoelectric performance of SnTe due to synergistic band engineering, carrier concentration optimization and defect engineering. [ABSTRACT FROM AUTHOR]

Colloidal delivery systems are required to encapsulate, protect, and release active food ingredients, such as vitamins, nutraceuticals, and minerals. In this study, lipid droplets were encapsulated within biopolymer microgels fabricated from egg white proteins using an injection–gelation process. Confocal fluorescence microscopy indicated that lipid droplets were dispersed within a network of cross-linked proteins within the microgels. The properties of the lipid-loaded microgels were compared to those of simple oil-in-water emulsions stabilized by egg white proteins. Light scattering and microscopy measurements indicated that both delivery systems exhibited good stability under acid conditions (pH 3–5) but aggregated at higher pH values as a result of a reduction in electrostatic repulsion. Simulated gastrointestinal tract studies indicated that lipid droplets encapsulated within protein microgels were digested more slowly than free lipid droplets. Our results therefore suggest that egg white protein microgels may be useful for encapsulation and controlled release of hydrophobic bioactive agents.

N-Type Mg3Sb2-based Zintl compounds have recently been discovered to be a promising class of thermoelectric materials. Effective n-type dopants are crucial for realizing high thermoelectric performance. Here, using first-principles defect calculations, we investigate that Tm and Ce are effective n-type dopants in Mg3Sb2and explain why n-type conduction can be successfully achieved by a simple doping without extra Mg. Under Mg-rich conditions, the maximal achievable free carrier concentrations for Tm and Ce substitution on Mg sites at 750 K exceed 1020cm–3, approaching the optimal carriers of ∼1020cm–3. Under Mg-poor conditions, the miraculous n-type conduction achieved by a simple extrinsic n-type doping can be explained by the sufficiently low defect formation energy for the substitutional donor defect.

In the typical Western diet, fruits and vegetables are often consumed with food products that exist as oil-in-water emulsions, such as creams, dressings, and sauces. Studies have shown that coingestion of fruits and vegetables with emulsions can increase the bioavailability of beneficial lipophilic bioactive agents, such as nutraceuticals or vitamins. Agricultural produce, however, may also be contaminated with low levels of detrimental lipophilic agents, such as hydrophobic pesticides. We therefore examined the impact of coingesting a common agricultural product (tomatoes) with model food emulsions on the bioaccessibility of a hydrophobic pesticide (chlorpyrifos). The impact of emulsifier types (phospholipids, whey protein, Tween 80) and dietary fiber types (xanthan, chitosan, β-glucan) on the bioaccessibility of the pesticide was measured using a simulated gastrointestinal model. Chlorpyrifos bioaccessibility depended on the type of emulsifier used to formulate the emulsions: phospholipids > Tween 80 > whey protein. Dietary fiber type also influenced pesticide bioaccessibility by an amount that depended on the nature of the emulsifier used. Overall, our results suggest that the bioaccessibility of undesirable pesticides on fruits and vegetables will depend on the nature of the emulsions they are consumed with.

Commercial, titanium dioxide (TiO2) ingredients used as color additives (E171) in foods and beverages contain an appreciable fraction of particles in the nanoscale range. At present, little information is available regarding the potential impact of food-grade TiO2nanoparticles on the gastrointestinal fate of co-ingested bioactives, such as nutraceuticals. In this study, the impact of TiO2on the bioaccessibility of β-carotene solubilized in model food emulsions was investigated using a simulated gastrointestinal tract model. Raman spectroscopy showed that there was no charge transfer between β-carotene and TiO2but that some β-carotene absorbed to the surface of TiO2particles. The initial particle size of the food emulsion did not significantly affect β-carotene bioaccessibility, probably because the same amount of free fatty acids (FFAs) was released by the end of digestion. The addition of TiO2at levels typically found in foods also had no significant impact on β-carotene bioaccessibility and FFA release, which suggested that this type of inorganic particle does not interfere with the gastrointestinal fate of these lipophilic bioactive agents. This information is important for ensuring the safety of inorganic nanoparticle utilization within the food industry.

Dynamic light scattering (DLS) is a non-destructive, well-established technique for size characterization of proteins, nanoparticles, polymers and colloidal dispersions. However, current DLS techniques are only applied to particle groups of single composition due to the limitation of its inversion algorithm. In this paper, we propose a particle size distribution inversion algorithm based on the Tikhnonov regularization method that can be applied to the dual-substance particle mixture. The algorithm retrieves particle size distributions of two substances respectively by taking advantage of their refractive index difference. The simulation results reveal that the algorithm has excellent accuracy and stability when the scattering angle is 30°. Instead of the original identity matrix, the first-order difference matrix and second-order difference matrix is used as the regular matrix when utilizing the Tikhnonov algorithm, which obviously improves the anti-interference, accuracy and stability of the algorithm. Furthermore, the inversion of particle size distribution is carried out at 0.01%–1% noise level, which shows that the algorithm has an available anti-noise ability. Finally, experimental particle size measurements for mixture of polystyrene beads and toner particles demonstrate that the proposed algorithm is superior to the traditional Tikhnonov algorithm in applicability and accuracy.

Optimizing the performance of thermoelectric materials by reducing its thermal conductivity is crucial to enhance its thermoelectric efficiency. Novel thermoelectric materials like the CuGaTe2compound are hindered by high intrinsic thermal conductivity, which negatively impacts its thermoelectric performance. In this paper, we report that the introduction of AgCl by the solid-phase melting method will influence the thermal conductivity of CuGaTe2. The generated multiple scattering mechanisms are expected to reduce the lattice thermal conductivity while maintaining sufficient good electrical properties. The experimental results were supported by first-principles calculations confirming that the doping of the Ag will decrease the elastic constants, bulk modulus, and shear modulus of CuGaTe2, which makes the mean sound velocity and Debye temperature of Ag-doped samples lower than those of CuGaTe2, indicating the lower lattice thermal conductivity. In addition, the Cl elements within the CuGaTe2matrix escaping during the sintering process will create holes of various sizes within the sample. These combined effects of holes and impurities will induce phonon scattering, which further reduces the lattice thermal conductivity. Based on our findings, we conclude that the introduction of AgCl into CuGaTe2has shown a lower thermal conductivity without compromising the electrical performance, resulting in an ultra-high ZT value of 1.4 in the (CuGaTe2)0.96(AgCl)0.04sample at 823 K.

In this study, we develop a synergistic modulation of the thermal conductivity and power factor of Cu3SbSe4-based materials through Sn and Zr or Hf co-doping by using a facile microwave-assisted solvothermal method. A series of Cu3Sb1-xMxSe4(M = Zr or Hf, x = 0, 0.02, 0.04, 0.06 and 0.08) compounds are firstly synthesized through the microwave-assisted solvothermal method combined with spark plasma sintering (SPS) process. The effect of Zr and Hf doping on the thermoelectric properties of Cu3Sb1-xMxSe4(M = Zr or Hf) has been investigated. With increasing the content of Hf and Zr, the thermal conductivity of Cu3Sb1-xMxSe4(M = Zr or Hf) is obviously decreased to 0.518 Wm−1K−1of Cu3Sb0.92Hf0.08Se4and 0.433 Wm−1K−1of Cu3Sb0.92Zr0.08Se4at 623 K, respectively. In addition, Sn doping further improves the low electrical conductivity and boosts the power factor, yielding a peak zTvalue of ~0.82 of Cu3Sb0.91Sn0.03Hf0.06Se4at 623 K, which is ~228% higher than that of the pristine Cu3SbSe4. Our work provides a new methodology for the decoupling of thermal and electrical properties of the Cu3SbSe4-based thermoelectric materials.