Fabrication of 0.24Pb(In1/2Nb1/2)O3-0.42Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 transparent ceramics by conventional sintering technique

0.24Pb(In_1/2Nb_1/2)O₃-0.42Pb(Mg_1/3Nb_2/3)O₃-0.34PbTiO₃ transparent ceramics were fabricated by a conventional sintering technique. Through optimization of sintering conditions of calcination and sintering temperatures and time, the obtained ceramics showed high optical transmittance of 53% and 71% at light wavelengths of 1300 and 2000 nm, respectively. The ceramics showed a rhombohedral to tetragonal phase transition at ~120°C and a tetragonal to cubic phase transition at 222°C. These transition temperatures were higher than those of 0.67Pb(Mg_1/3Nb_2/3)-0.33PbTiO₃ ceramics. In addition, the ceramics had a ferroelectric hysteresis loop, a large piezoelectric constant d₃₃ of 407 pC/N, and a planar electromechanical coupling factor k_p of 52%. These results suggest that the transparent ceramics may be used as a temperature-stable, linear electro-optic material.     

Gamers,Surfers, Social Media Users: Unpacking the role of interest in English

Across stages of acquisition, second language (L2) competencies are contingent on the variation among individuals learning the language, in both informal and formal learning contexts. This study investigates a group of outliers whose extreme test scores serve as a foundation to examine them as individuals. The study addresses the outliers' characteristics as good L2 readers but poor first language (L1) readers. Combining quantitative (test results, survey, and language logs) and qualitative (focus groups and interviews) data among 21 adolescents in Norway (aged 16–17 years), the study identifies dimensions of individual language use in L1 Norwegian and L2 English. Findings revealed that they explained their English proficiency by the role of interest and their extensive use of English technology and tools outside school. In‐depth analysis identified three profiles: the Gamer, who spends up to 8 hr daily playing online games while using English mainly; the Surfer, who spends hours on the Internet, searching for authentic language situations, commonly involving English; and the Social Media User, who produces and consumes information in English through social media. Additionally, the Gamers read printed novels voluntarily outside the classroom. This study offers unique perspectives and new directions for future L2 research.     

Common due date assignment scheduling for a no-wait flowshop with convex resource allocation and learning effect

This article addresses the no-wait flowshop scheduling problem with simultaneous consideration of common due date assignment, convex resource allocation and learning effect in a two machine setting. The processing time of each job can be controlled by its position in a sequence and also by allocating extra resource, which is a convex function of the amount of a common continuously divisible resource allocated to the job. The objective is to determine the optimal common due date, the resource allocation and the schedule of jobs such that the total earliness, tardiness and common due date cost (the total resource consumption cost) are minimized under the constraint condition that the total resource consumption cost (the total earliness, tardiness and common due date cost) is limited. Polynomial time algorithms are developed for two versions of the problem.     

Individual-based multi-objective optimal structured treatment interruption for HIV infection

In this paper, based on the measurable quantities from an individual patient that has infection to human immunodeficiency virus (HIV) and his/her condition is near to acquired immune deficiency syndrome (AIDS), individual-based multi-objective optimal treatments have been proposed. Firstly, the most effective parameters of the patient in computing Long-term non-progressor (LTNP) equilibrium are derived using global sensitivity analysis (GSA). To accomplish GSA effectively, Latin hypercube sampling (LHS) and partial rank correlation coefficients (PRCC) are utilized to rank each of the parameters based on each state of the 5-dimensional model. Then, these results are used by Dempster–Shafer (D–S) evidence theory (DSET) to rank the most effective parameters comprehensively. Now, these effective identified parameters are estimated using extended Kalman filter (EKF), which its covariance matrices are optimized based on particle swarm optimization (PSO) algorithm. Thus, the proposed methodology gives a calibrated model corresponding to the individual patient. Based on this calibrated model, the LTNP equilibrium related to the individual patient is derived. Using the derived individual-based LTNP equilibrium optimal structured treatment interruption (STI) strategies are extracted by defining suitable multi-objective optimization problem and solving it through using non-dominated sorting genetic algorithm-II (NSGA-II). The results demonstrate that the proposed optimal treatments are able to effectively reach LTNP equilibrium with using the minimum and maximum drug usage of 3.6% and 35.1% of full drug usage treatment. Meanwhile, the different optimal treatments give the decision-makers enough flexibility to choose the suitable treatment based on existing facilities and necessities.     

Broccoli leaf powder as an attractive by-product ingredient: effect on batter behaviour,technological properties and sensory quality of gluten-free mini sponge cake

Broccoli by-products, in particular leaves, are rich sources of nutritional and bioactive components thus could constitute a valuable food additive. Although an upsurge in quantity of gluten-free products is observed further studies are required on improvement of their nutritional quality and palatability. This study aimed to investigate the influence of broccoli leaf powder (BLP) on dough behaviour, and technological characteristics and sensory quality of gluten-free mini sponge cake (GFS). Broccoli leaf powder replaced an equivalent amount (2.5%, 5%, 7.5%; w/w) of corn and potato starches in GFS formulation. Applied BLP increased the instrumental firmness of GFS but sensorial attributes (elasticity, crustiness, mastication and adhesiveness) were similar to the control. All broccoli GFS were vividly green, had small size pores properly distributed. Among them, sample with 2.5% BLP was distinguished for its desirable sensory quality, despite a slightly perceived cabbage aroma and taste. Moderate amount of BLP allows to preserve a good quality GFS improving its attractiveness and palatability.     

Developing high-performance laminated Cu/TiC composites through melt infiltration of Ni-doped freeze-cast preforms

Nacre-inspired laminated composites have been proven to possess a unique combination of strength and toughness. In this study, we fabricated nacre-mimetic Cu/TiC composites via unidirectional freezing of aqueous TiC slurries containing different amounts of NiO additives, followed by ice sublimation, carbothermal reduction of NiO to Ni during sintering and then gas-pressure infiltration of the Cu melt. The introduction of Ni greatly facilitated the densification of ceramic lamellae and enhanced the interfacial bonding between Cu and TiC. The resultant composites displayed outstanding damage tolerance and anisotropic electrical conductivities. Specifically, for an ～31?vol% TiC–Cu composite containing 24?wt% Ni in the ceramic lamellae (based on the TiC content), a fracture toughness (K_Jc) of 72.5?±?1.0?MPa·m^1/2, work of fracture of 53.4?±?3.5?kJ/m², bending strength of 725?±?11?MPa and longitudinal electrical conductivity of 22.7?MS/m (～60% of the Cu matrix) were achieved, which were approx. 81%, 536%, 122% and 97% higher than those of the Ni-free composite, respectively. Noticeable toughening was demonstrated to be a consequence of multiple cracking, plastic deformation and uncracked-ligament bridging of the metal layers, as well as crack deflection and blunting. On the other hand, significant strengthening resulted from tailoring the microstructures in the ceramic layers and at the Cu/TiC interface as a result of Ni doping. We believe that the facile strategy adopted herein provides an effective way to solve the problems of wetting and bonding related to metal infiltration and can be readily extended to the preparation of other nacre-inspired metal?ceramic composites.     

Application of adhesively bonded single lap joints for fracture assessment of adhesive materials

In this study, a method has been proposed to obtain the failure envelope of brittle adhesives using the experimental failure loads of precracked single lap joints (SLJs). The proposed technique is based on the principles of linear elastic fracture mechanics (LEFM), on J-integral relations, and on results of a numerical analysis. Compared to the previous approaches, the introduced experimental method has some advantages such as low manufacturing costs and simpler test procedure. The proposed method can also provide a wide range of mode mix ratios without the need of an additional apparatus. The fracture envelope obtained from the proposed method was then verified by performing some fracture tests including double cantilever beam (DCB), end-notched flexure (ENF), and single leg bending (SLB) specimens. Good correlation was seen between the fracture envelopes of the proposed method and the ones obtained from the fracture mechanics experiments.     

Physics‐based model of lithium‐ion batteries running on a circuit simulator

The authors developed a physics‐based equivalent circuit model of a lithium‐ion battery (LIB) whose parameters are continually updated, reflecting the theoretical calculation results of the Butler‐Volmer equation, diffusion equations of the lithium‐ion and lithium, and Nernst equations of the liquid and solid phases. The developed model was applied to the charge/discharge simulations of an LIB, and the experimental and simulated results of constant current discharges and pulsed‐charge/discharge were found to be in excellent agreement. In particular, using the developed model, analyzing transient responses of the LIB derived from the transition of the electric double layer charging to the electrode reaction is possible. These results demonstrate that the electrochemical performance of an LIB can be calculated on a circuit simulator using the developed model.     

正电子湮没研究Al、Nb共掺CaCu3Ti4O12陶瓷高介电常数机理

关于CaCu₃Ti₄O₁₂陶瓷的高介电常数机理，目前广泛接受的是非本征的内阻挡层电容模型。该模型认为在多晶中元素变价、缺陷和非化学计量比等导致的半导化晶粒被绝缘晶界层，即内阻挡层所包围。其中内阻挡层的厚度对材料的介电性能影响较大，而扫描电子显微镜（SEM）测试表明样品晶界呈稀烂的果酱状，SEM难以测量晶界区域绝缘内阻挡层厚度。本文采用正电子湮没技术表征其厚度，通过对CaCu₃Ti₄O₁₂陶瓷共掺不同浓度的Al、Nb（CaCu₃Ti_4-xAl_0.5xNb_0.5xO₁₂，x=0.2%、0.5%、5.0%）改变其晶粒和晶界的微观结构，研究CaCu₃Ti₄O₁₂陶瓷高介电常数机理。正电子湮没结果显示，掺杂样品符合多普勒展宽谱S参数的变化趋势与平均寿命的变化趋势一致。x=0.5%掺杂样品的介电常数最高，其平均寿命、S参数和湮没长寿命成分均最小，阻挡层最薄。实验结果验证了描述CaCu₃Ti₄O₁₂陶瓷高介电常数机理的内阻挡层电容模型的预测。