Density functional study of spectroscopy, electronic structure, linear and nonlinear optical properties of l-proline lithium chloride and l-proline lithium bromide monohydrate: For laser applications

AbstractUsing density functional theory (DFT), a systematic study of structure, bonding, vibration, excitation energies and non-linear optical properties has been carried out for noncentrosymmetric l-proline lithium chloride monohydrate and l-proline lithium bromide monohydrate for the first time. The calculated vibrational frequencies and the S0→S1 transition energy were compared with the earlier reported experimental results and found in good agreement. HOMO–LUMO energy gap was calculated by CIS, B3LYP and CISD using 6-31G(d,p), 3-21G, 6-31++G respectively and the obtained results are compared. For the calculation of excitation energies we used time dependent DFT (TDDFT). Both the molecules show the considerably lower dipole moment in excited state in comparison with the ground state. Mulliken charge and molecular electrostatic potential were studied. The first order hyperpolarizability for LPLCM and LPLBM are 2.15675×10−30esu and 3.78984×10−30esu respectively which are 5 and 10 times higher than prototype urea (0.3728×10−30esu) molecule. The global chemical reactivity descriptors were also calculated. The calculated results of polarizability, first and second hyperpolarizability confirm that these molecules are good non-linear optical materials and can be used for laser device fabrications

Hybrid deposition additive manufacturing: novel volume distribution, thermo-mechanical characterization, and image analysis

(c) The Author/sCAUL read and publish agreement 2022The structural integrity of additive manufacturing structures is a pronounced challenge considering the voids and weak layer-to-layer adhesion. One of the potential ways is hybrid deposition manufacturing (HDM) that includes fused filament fabrication (FFF) with the conventional filling process, also known as “HDM composites". HDM is a potential technique for improving structural stability by replacing the thermoplastic void structure with a voidless epoxy. However, the literature lacks investigation of FFF/epoxy HDM-based composites regarding optimal volume distribution, effects of brittle and ductile FFF materials, and fractographic analysis. This research presents the effects of range of volume distributions (10–90%) between FFF and epoxy system for tensile, flexure, and compressive characterization. Volume distribution in tensile and flexure samples is achieved using printable wall thickness, slot width, and maximum width. For compression, the printable wall thickness, slot diameter, and external diameter are considered. Polylactic acid and acrylonitrile butadiene styrene are used to analyze the brittle and ductile FFF structures. The research reports novel application of image analysis during mechanical characterization using high-quality camera and fractographic analysis using scanning electron microscopy (SEM). The results present surprising high tensile strain (0.038 mm/mm) and compressive strength (64.5 MPa) for lower FDM-percentages (10%, 20%) that are explained using in situ image analysis, SEM, stress–strain simulations, and dynamic mechanical analysis (DMA). In this regard, the proposed work holds novelty to apply DMA for HDM. The optimal volume distributions of 70% and 80% alongside fractographic mechanisms for lower percentages (10%, 20%) can potentially contribute to structural applications and future material-based innovations for HDM.fals

High-performance visible light photodetectors based on inorganic CZT and InCZT single crystals

Herein, the optoelectrical investigation of cadmium zinc telluride (CZT) and indium (In) doped CZT (InCZT) single crystals-based photodetectors have been demonstrated. The grown crystals were configured into photodetector devices and recorded the current-voltage (I-V) and current-time (I-t) characteristics under different illumination intensities. It has been observed that the photocurrent generation mechanism in both photodetector devices is dominantly driven by a photogating effect. The CZT photodetector exhibits stable and reversible device performances to 632 nm light, including a promotable responsivity of 0.38 AW−1, a high photoswitch ratio of 152, specific detectivity of 6.30 × 1011 Jones, and fast switching time (rise time of 210 ms and decay time of 150 ms). When doped with In, the responsivity of device increases to 0.50 AW−1, photoswitch ratio decrease to 10, specific detectivity decrease to 1.80 × 1011 Jones, rise time decrease to 140 ms and decay time increase to 200 ms. Moreover, these devices show a very high external quantum efficiency of 200% for CZT and 250% for InCZT. These results demonstrate that the CZT based crystals have great potential for visible light photodetector applicationsAuthors from KKU express their appreciation to the Deanship of Scientifc Research at King Khalid University for funding this work through research groups program under grant number R.G.P. 2/42/4

Exploring thermoelectric materials for renewable energy applications: The case of highly mismatched alloys based on AlBi1-xSbx and InBi1-xSbx

The high throughput thermoelectric devices are considered promising futuristic energy source to control global warming and realize the dream of green energy and sustainable environment. The ability of the highly mismatched alloys (HMAs), to show the intriguing impact on the physical properties with controlled modifications, has extended their promise to thermoelectric applications. Here, we examine comprehensively the potential of the two prototypical HMAs such as AlBi1-xSbx and InBi1-xSbx for thermoelectric applications within density functional theory together with the Boltzmann transport theory. For comprehensive understanding, alloying of these materials has been performed over the entire composition range. From our calculations, we found, the replacement of Sb with Bi leads to a significant evolution in the energy band-gap and effective masses of the charge carriers that consequently deliver enhancement in thermoelectric response. Improvement of magnitude 1.25 eV and 0.986 eV has been respectively recorded in band-gaps of AlBi1-xSbx and InBi1-xSbx for the across composition alloying. Similarly, by the electronic-structure engineering of HMAs, thermoelectric properties such as, the Seebeck coefficients over Fermi-level were found to be improved from 82.90 µV/K to 107.52 µV/K for AlBi1-xSbx and 60.32 µV/K to 92.73 µV/K for InBi1-xSbx. As a result, the thermoelectric figure of merit (ZT) and power factor show considerable enhancement as a function of alloying composition for both alloys at room temperature. However, at a higher temperature, the thermal conductivity of these materials experience an exponential increase, results in lower ZT values. Overall, the observed evolution in the electronic structure and thermoelectric response for replacing Sb over Bi is significant in AlBi1-xSbx as compared to InBi1-xSbx. Hence, with the capability of significant and controlled evolution in electronic-structure and subsequent thermoelectric properties, HMAs particularly AlBi1-xSbx are believed potential candidates for thermoelectric applications

Investigation of GaBi1-xSbx based highly mismatched alloys: Potential thermoelectric materials for renewable energy devices and applications

The high-performance thermoelectric materials are considered a potential resource for clean and sustainable energy. Highly mismatched alloys (HMAs), that are admired for the dramatic modifications in their electronic band structures can essentially play important role in developing high-performance thermoelectric materials. Here, we explore the potential of GaBi1-xSbx based HMAs for their thermoelectric applications via density functional theory coupled with the Boltzmann transport theory. To perform a comprehensive analysis, four different Sb alloying compositions such as GaBi, GaBi0.875Sb0.125, GaBi0.75Sb0.25, and GaBi0.625Sb0.375, are considered. It is found that the Sb replacement over Bi in GaBi1-xSbx has stimulated two major modifications in the electronic band structure: the band-gap enhancement, and contraction in the curvature of conduction band minimum. These features have remarkably evolved the thermoelectric properties of GaBi1-xSbx as a function of Sb contents. The significant increase in Seebeck coefficient and decrease in the electrical conductivity of GaBi1-xSbx alloy as a function of Sb content have resulted in large values of thermoelectric power factor as well as the figure of merit (ZT). Considerable improvement in the ZT values as a function of Sb has been recorded that approaches to ~1.0 for GaBi0.625Sb0.375 at room temperature. The occurrence of optimal thermoelectric coefficient values, at attainable doping levels below the Fermi level reveals the predominantly p-type nature of the GaBi1-xSbx. Hence, GaBi1-xSbx (GaBi0.625Sb0.375 in particular) exhibits interesting thermoelectric properties at room temperature, and is therefore believed to be good candidate material for room temperature based thermoelectric devices and applications

Preparation and characterization of layer-diffusion processed InBi2Se4 thin films for photovoltaics application

In this research work, optoelectronic properties of Indium bismuth selenide (InBi2Se4) thin films are studied for their potentials for photovoltaic applications. The InBi2Se4 films are prepared via a thermal co-evaporation technique on glass substrate using Bi2S3 powders and indium granules. The as-deposited films are then annealed at different temperatures to convert into InBi2Se4 thin films. Results show that the obtained InBi2Se4 films possess excellent optoelectronic properties as an optimum bandgap of 1.2 eV was obtained for the film annealed at 350oC. Based on characterisation results of current and voltage realiationships, both as-deposited and annealed InBi2Se4 thin films show a linear relationship between current and annealing temperature. It was also noted that with increasing grain-size of the film, the current is also increased at a fixed applied voltage

Cultural references in films: an audience reception study of subtitling into Arabic

This thesis focuses on the issue of cultural references in translation and aims to address some of the identified gaps in the literature. The short descriptive study aims to identify the most used strategies in translating cultural references into Arabic, given that the typologies used to deal with cultural references have been mostly developed considering European languages/contexts. Also, given that the developed typologies used have often ignored the multimodal context in which cultural references participate, focusing mostly on the verbal nature, this study will adopt a multimodal approach. This will allow for the examination of the multimodal context in which the cultural references are built, as well as how this was addressed/not addressed. Additionally, given that most studies conducted until now have focused mainly on theoretical or descriptive approaches, with few studies focusing on how audiovisual products are received and perceived, this study will include reception and perception studies. The reception study aims to investigate the impact of the strategies (those found to be commonly used, as well as alternative strategies) on the viewer’s understanding of the cultural references, while the perception study aims to investigate how viewers perceive the strategies tested in the reception study. Eventually, this thesis aims to contribute to the study of AVT in general and to the study of AVT into Arabic in specific, filling in the mentioned gaps. Moreover, this thesis is expected to provide readers a cross-cultural understanding of various aspects concerning Arabic AVT, specifically about the reception and perception of cultural references. It also has the potential to significantly impact the practice of translators in Saudi Arabia, given that the data can be used by the translation industry for a possible revision of the subtitling norms into Arabic. The developed model that examines cultural references in its multimodal filmic context, which is capable of supporting both the analysis of verbal and non-verbal cultural references, can also be used in future research to expand the traditional understanding of these references by considering the intermodal relationships between different modes, as well as acknowledging the need to address visual resources in translation

Cultural References in Films: An Audience Reception Study of Subtitling into Arabic

This article focuses on the issue of capturing cultural references in subtitled translations. It addresses three shortcomings in current translation scholarship. First, most of the studies in audiovisual translation focused on cultural references are primarily based on European languages and contexts. Second, the typologies resulting from those studies focus solely on verbal references and often ignore the multimodal meaning-making situation in which cultural references are construed or their non-verbal nature. Third, most of the extant studies on the translation strategies used are descriptive, rather than grounded in empirical reception studies. This article will report and discuss the data collected on an experimental study examining the reception of cultural references on films subtitled into Arabic. It will revisit the traditional understanding of cultural references as limited to the verbal mode and examine the impact of domesticating and Foreignisation methods on Saudi-Arabian viewers’ meaning-making process