Valence Theory Research Articles

Effects of Zn2+/Si4+ co-doping on the cation distribution, crystal structure, and microwave dielectric characteristics of spinel-structured MgAl2O4 ceramics

Investigating the relationship between the structure and dielectric properties of cation-mixed spinel ceramics is crucial for overcoming the limitations of conventional microwave materials. In this study, MgAl2-x(Zn0.5Si0.5)xO4 (x = 0, 0.02, 0.04, 0.06, and 0.08) ceramics were prepared by a solid-state reaction method. The co-substitution for Al with Zn2+/Si4+ induces Al3+ cations for preferential occupation of the 8a site in the oxygen tetrahedra, forming a solid-solution ceramic at x ≤ 0.06. Enhanced ionic diffusion and compressive stress contribute to a dense microstructure (ρ > 95%) with uniform grain-size distribution after heating at 1650 °C for 4 h. Raman and 27Al NMR spectra reveal a relationship between cation distribution and covalency, consistent with the results of Rietveld refinement. The increases in cation disorder and degree of inversion are accompanied by an enhanced covalency of the Al–O bonds, which reduces intrinsic dielectric loss. In addition, the combination of Shannon ion polarizability and bond valence theory suggests that the increases in permittivity (εr) and the temperature coefficient of resonant frequency (τf) are related to the high polarizability of the dopant ions and the abnormal polarizability derived from the decreasing bond valence of the Al2–O site. The sample at x = 0.06 exhibits a low εr of 8.31, high Q × f of 194,159 GHz (at ∼11.35 GHz), and τf of -30.8 ppm/°C, indicating superior microwave application prospects as compared with traditional Mg-Al spinel ceramics.

Early neural development of social interaction perception: evidence from voxel-wise encoding in young children and adults.

From a young age, children have advanced social perceptual and reasoning abilities. However, the neural development of these abilities is still poorly understood. To address this gap, we used fMRI data collected 122 3-12-year-old children (64 females) and 33 adults (20 females) watched an engaging and socially rich movie to investigate how the cortical basis of social processing changes throughout development. We labeled the movie with visual and social features, including motion energy, presence of a face, presence of a social interaction, theory of mind (ToM) events, valence and arousal. Using a voxel-wise encoding model trained on these features, we find that models based on visual (motion energy) and social (faces, social interaction, ToM, valence, and arousal) features can both predict brain activity in children as young as three years old across the cortex, with particularly high predictivity in motion selective middle temporal region (MT) and the superior temporal sulcus (STS). Furthermore, models based on individual social features showed that while there may be some development throughout childhood, social interaction information in the STS is present in children as young as three years old and appears adult-like by age seven. The current study, for the first time, links neural activity in children to pre-defined social features in a narrative movie and suggests social interaction perception is supported by early developing neural responses in the STS.Significance Statement This study investigates the neural basis for social scene perception ability in children using fMRI data collected while participants watch a short, animated movie. Unlike most prior studies with movies, we labeled a range of visual and social features in the movie and used machine learning analyses to link each feature to fMRI responses in adults and children ages 3-12. Notably, our results demonstrate strong evidence that children as young as three years old show significant responses to most visual and social features in the movie, including social interaction responses in the superior temporal sulcus (STS), a region in the brain that is well known to be important in social interaction processing in adults.

Unveiling the nexus: unravelling the dynamics of financial inclusion, FinTech adoption and societal sustainability in Malaysia

Purpose This study aims to examine the impact of perceived benefits-risk dynamics on financial inclusion, the factor driving fintech adoption, the mediating effects of financial inclusion on perceived benefit-risk dynamics and fintech adoption, and the societal sustainability effects of fintech adoption. Design/methodology/approach This study used a quantitative study with 258 respondents in Sarawak, Malaysia. PLS-SEM was used to investigate the associations. Findings This study suggests that only non-monetary benefits and regulatory risks significantly influence financial inclusion. In addition, financial inclusion acts as an intermediary for non-monetary benefits and regulatory risks. Besides, a direct relationship exists between financial inclusion and fintech adoption, as well as between fintech adoption and societal sustainability. Research limitations/implications This model explores a few benefits and risks. Also, technological and legislative changes may alter research outcomes. Besides, this study only samples Sarawak, Malaysia. Therefore, country-specific factors, including technology infrastructure, financial services accessibility and cultural variations, may affect participant responses. This study offers a novel perspective on fintech by including Valence, Public Good and Sustainable Information Society theories. Practical implications Financial inclusion’s non-monetary benefits must be emphasised to remove barriers and meet user requirements. Fintech firms should also work with authorities to comply with regulations and help marginalised populations by prioritising sustainability. Social implications Fintech growth requires innovation, consumer protection and fair competition. Fintech firms can enhance financial inclusion to address inequalities (SDG10). Governments and fintech solutions should incorporate financial and digital literacy into education (SGG4). Originality/value Financial inclusion, fintech adoption and societal sustainability are examined using emotional, sociological and societal sustainability aspects.

Promoting sustainable consumption and circular economy: the intention of Vietnamese youth consumers to purchase products made from recycled plastics

Recycling is viewed as a key component in a circular economy and serves as an ideal solution for promoting sustainability. During the global plastic crisis, plastic recycling practices have been adopted worldwide, leading to the production of various products made from recycled plastics (PRP). Nevertheless, a gap persists between consumption and demand for such products, which is primarily attributed to a lack of comprehension from the consumer perspective. Given the pivotal role consumers play in the adoption of these products, this study explores consumers’ intentions to purchase PRP. This is particularly significant in Vietnam, which is an emerging economy aspiring to achieve the objectives of a circular economy and sustainable development. Utilizing an integrated cognitive-emotional framework comprising the Valence Theory and the Norm Activation Model, data from 564 Vietnamese students were gathered and analyzed using structural equation modeling. The results show that awareness of consequences is a major driver of consumer purchase intentions, followed by perceived ease of application and monetary incentives. The results also indicate that health concerns have the strongest effect on purchase intention and in the negative side, meaning that the health-related risk is the primary concern for consumers during the decision-making process. This research holds substantial value for academics and managers, as it aids in the theoretical exploration and the formulation of strategies to improve consumer acceptance of PRP.

Exploring the bonding and extraction separation effects of N donor ligands with different skeletons on Am(III) and Eu(III)

Designing ligands for effective separation of actinide(III)/lanthanide(III) is one of the key issues in the treatment of spent nuclear fuel. However, due to the chemical similarity of trivalent actinides and lanthanides, their separation faces a great challenge in the reprocessing of spent nuclear fuel. Nitrogen donor extractants are considered as promising reagents for separation of trivalent actinides and lanthanides. To the best of our knowledge, the pre-organized structure of the ligand has a strong influence on the extraction separation capacity. In this work, we designed four N-donor ligands (L1 and L2 with pyridine and bipyridine skeletons, respectively, and L3 and L4 both with phenanthroline skeletons) with different pre-organized structures and investigated their selective extraction for Am(III) and Eu(III) by using scalar relativistic density functional theory (DFT). The absolute minimum ESP values of these ligands and the higher HOMO level suggest that the ligand L2 may have a stronger affinity for Am(III)/Eu(III) ions than other ligands. The three average bond lengths of each complex indicate that the Am(III) and Eu(III) ions have larger bond lengths with N2 atoms than with N1 atoms. Various theoretical approaches have been used to evaluate the properties of the four ligands as well as the coordination structures, bonding properties and thermodynamic properties of the complexes of the four ligands with Am(III) and Eu(III). The WBIs, QTAIM, NBO, DOS and EDA analysis indicate that the metal–ligand bonds are mainly ionic in character, the Am-N bond has more covalency than the Eu-N bond because the Am 5f orbitals are more involved in bonding with ligand than Eu 4f orbitals. According to the extended transition state and natural orbital chemical valence theory (ETS-NOCV) analysis, electrons are obviously transferred from the lone pair of the ligand N atom to the hybrid s, d and f orbitals of the metal ion. The thermodynamic results show that the four ligands can coordinate well with the Am and Eu ions, and also have suitable separation capacity for Am and Eu. Among the four ligands, the L2 and L3 ligands have the strongest coordination ability for metals and the best extraction separation effect for Am and Eu. It can be seen that the bridging skeleton of the ligand and the number of N atoms on the five-membered ring and also different organic solvents have obvious effects on the extraction and separation capacity of the ligand. This study provides a theoretical basis for the efficient separation of Am(III)/Eu(III) by adjusting the preorganization level of ligands, and provides a theoretical basis for the design and screening of ligands by preorganization.

Tuning εr and τf by the combined effects of rattling RE3+ and compressed Ca2+ at the A-site in microwave dielectric ceramics CaREAlO4 (RE = Eu, Ho, Er, Yb)

The well-densified CaREAlO4 (RE = Eu, Ho, Er, Yb) microwave dielectric ceramics with the K2NiF4 structure are fabricated at 1360–1500 °C. Crystal structures were investigated via XRD and HRTEM, and no phase transition occurred. The ceramics exhibit low εr of 17.9–19.3 and relatively high Q × f values of 25,110 - 48,310 GHz, and tunable τf values ranging from −1.1 ppm/°C to +18.4 ppm/°C and then to −20.4 ppm/°C. The variations in εr and τf were ascribed to the mutual effects of rattling RE3+ and compressed Ca2+ characterized by bond valence theory and temperature coefficient of ion polarizability (ταm). The Q×f values of CaREAlO4 ceramics positively correlate with structure stability and lattice energy, the main intrinsic factors affecting Q×f.

DESCRIPTION OF THE CLITIC PRONOUN 'ME' IN PERSONAL LETTERS FROM TWO NORTHEASTERN REGIONS

This paper describes the syntactic-discursive behavior of the pronoun me in two epistolary materials from two different regions of Northeastern Brazil: Sertão of Pernambuco and Recôncavo in Bahia. Theoretically, this article is based on the Functionalism theories in linguistics, namely: Hopper and Thompson (1980), Neves (2012), Fuzer and Cabral (2014), and Halliday and Matthiessen (2014). It is also supported by the Valence Theory Grammar, which is approached according to: Neves (2000), Welker (2005), Perini (2007), and Rodrigues (2007). As part of its research methodology, the following steps were carried out: the selection of the contexts in which the phenomenon appears in the corpora, the collection of the socio-historical data regarding the missivists', the grammatical classification of the pronoun me, and the analysis of the verbal valence, accordingly with the assumptions of Functionalism. As a result of the analysis of the functionalities of the clitic me, it was observed that traditional grammars and descriptive grammars do not cover the particularities of the ethical dative pronoun, as they do not mention its capacity to be a discursive particle, a zero-switchable element in the sentence structure, not an actant, but in the communicative context it positions the writer and it can be associated with matters of morality and affection.

Forming loyalty toward green food: food or environmental issue? Evidence from plant-based food

ABSTRACT This study examines the formation of loyalty toward plant-based food (PBF) by including environmental factors (i.e. environmental concern and knowledge) and the perceived benefits and cost of the food as its drivers. This research employed data from 403 PBF customers, collected via an online survey from the Greater Jakarta region, Indonesia. To appraise the proposed loyalty formation toward PBF, this study used partial least square modeling. The results from data analysis show that incorporating the environmental concern theory and the valence theory offers an improved explanation of loyalty formation toward PBF. Environmental concern, environmental knowledge, and perceived benefits are predictors of loyalty. Additionally, three dimensions of PBF benefits have been identified: physical, social, and psychological. This study suggests that to gain loyalty among PBF customers, managers need to educate customers on salient environmental issues and highlight the benefits of consuming PBF for customers’ health and the environment.

Bitcoin adoption in online payments: examining consumer intentions and word-of-mouth recommendations

Online retailers in emerging markets like South Africa are adopting Bitcoin payments. This study explores factors driving consumer adoption and word-of-mouth (WOM) recommendations for Bitcoin in online transactions. Using an integrated model combining valency theory, social contagion theory, and the technology acceptance model (TAM), we analyse data from 521 South African online shoppers. Findings reveal that perceived usefulness, ease of use, social pressures, trust, and perceived risk significantly influence both adoption and WOM. Importantly, self-efficacy moderates the relationship between these factors and behaviour. This research contributes to the literature by offering a comprehensive understanding of Bitcoin adoption. For business and policy actors, enhancing consumer self-efficacy can foster trust, ease concerns, and encourage positive WOM, ultimately aiding successful Bitcoin implementation and promotion.

The Employees Intention to Work in Artificial Intelligence-Based Hybrid Environments

In this article, considering the era of Industry 4.0, humans and collaborative robots (cobots) will work closely to create a hybrid workforce. Although firms are carefully considering this transition, the implementation of cobots is often carried out without careful consideration of the motivation and behavior of the employees working in hybrid workplaces. In the scenario when employees do not understand their work with cobots, it is unlikely that value is brought to a firm in the dynamic business environment. Thus, this study has multiple objectives. The first was to investigate the role of negative and positive valence factors on the employees intention to work with cobots. The second objective was to examine the effects of the creativity dimensions of employees on their behavior toward cobots. We developed a model for a hybrid workplace based on the componential theory of individual creativity and valence theory, in which the behaviors of human workers are combined with the dimensions of the cobots. Data were collected from 596 working professionals from India, and the proposed model was tested using partial least squares. We confirmed most of the hypotheses about the creativity of employees in hybrid workplaces and the positive valence of cobots with our empirical analysis. Therefore, we proved that future human-cobot collaboration needs to be focused not only on the benefits that cobots bring but also on human aspects like skills and expertise. This article is a contribution to the body of knowledge on new-age technology adoption by shedding light on the human and cobot dimensions. The results of this article may serve as a foundation for future applications and research on hybrid work.

The AM-4 Family of Layered Titanosilicates: Single-Crystal-to-Single-Crystal Transformation, Synthesis and Ionic Conductivity.

Flexible crystal() structures, which exhibit() single-crystal()-to-single-crystal() (SCSC) transformations(), are attracting attention() in many applied aspects: magnetic() switches, catalysis, ferroelectrics and sorption. Acid treatment() for titanosilicate material() AM-4 and natural() compounds with the same structures led to SCSC transformation() by loss() Na+, Li+ and Zn2+ cations with large structural() changes (20% of the unit()-cell() volume()). The conservation() of crystallinity through complex() transformation() is possible due() to the formation() of a strong hydrogen bonding() system(). The mechanism() of transformation() has been characterized using single-crystal() X-ray() diffraction analysis(), powder() diffraction, Rietvield refinement, Raman spectroscopy and electron microscopy. The low migration() energy() of cations in the considered materials() is confirmed using bond()-valence and density() functional() theory() calculations, and the ion conductivity of the AM-4 family's materials() has been experimentally verified.

Re2TiO5: Special dielectric titanates exhibiting abnormally low permittivity and a positive coefficient of resonance frequency

AbstractIn this study, a series of rare‐earth titanates with the general formula Re2TiO5 (Re = Er, Tm, Yb, and Lu) were synthesized and their microwave dielectric properties were reported. The impact of differences in rare‐earth cation radii on the structure and dielectric properties was systematically analyzed. The findings indicated that ceramics of Re2TiO5 (Re = Er, Tm, Yb, and Lu) were crystallized into a cubic structure with space group Fd‐3m, as confirmed by Rietveld refinement and selected‐area electron diffraction patterns. The rare‐earth elements were analyzed for their impact on microwave dielectric properties, considering factors such as ionic polarizability, packing fraction, and bond valence theory. The resulting materials exhibited excellent microwave dielectric properties with a low permittivity (6.95–7.21), high‐quality factors (19 451–20 115 GHz), and low positive temperature coefficient of resonance frequency (19.34–20.90 ppm/°C). The origin of low permittivity was elucidated through the analysis of bond length, X‐ray photoelectron spectroscopy, and impedance spectroscopy. This series of titanates exhibited unusually low permittivity characteristics in the microwave frequency range, which could meet the low signal transmission delay requirements in wireless communication.

Unpacking associations between positive-negative valence and ambidexterity of big data. Implications for firm performance

Motivated by the importance of big data utilization and its impact on firm performance, the current study examines the influence of the perceived valence factors of the top management team (TMT) on the ambidexterity of big data utilization and firm performance. Despite the growing recognition of the significance of ambidexterity and the role of TMTs in leveraging big data, there remains a lack of empirical research that comprehensively examines the associations between TMT valence factors, the ambidexterity of big data utilization, and firm performance. By integrating valence theory and ambidexterity theory, this study fills this research gap and provides valuable insights into the relationship between TMT valence factors, big data utilization, and firm performance outcomes. Data were collected from 357 respondents, and the findings indicate that positive TMT valence factors – such as data proficiency, industry expertise, and knowledge diversity – as well as negative valence factors – such as data compatibility, complexity, and benefit disconfirmation – are negatively associated with ambidexterity. Furthermore, the findings of our study have important implications for organizations seeking to enhance their operational and financial performance through the effective utilization of big data. Notably, our results highlight that promoting ambidexterity in handling big data within firms results in improved operational and financial outcomes. These findings provide valuable insights into the relatively unexplored area of TMT valence factors and their impact on driving ambidexterity in big data utilization, ultimately leading to enhanced organizational performance.

Constructing the cationic rattling effect to realize the adjustability of the temperature coefficient in Nd2-xSmxO3 microwave dielectric ceramics

In this work, a series of dense Nd2-xSmxO3 (x = 0.0 − 2.0) ceramics were synthesized using a solid-state reaction method at 1400 − 1575 °C. The ceramics were confirmed to be hexagonal at x < 0.5, and a monoclinic phase was observed in the ceramics when x ≥ 1.0. The microwave dielectric properties of Nd2-xSmxO3 (x = 0.0 − 2.0) are εr = 19.48 − 22.96, Q×f = 48,447 (x = 0.0) − 21,363 (x = 0.5) − 34,761GHz (x = 2.0), and τf = -43.0 − +34.1 ppm/℃. The bond valence theory calculation demonstrates that the change of τf value from negative to positive is mainly affected by the rattling of Sm3+. Moreover, the series of ceramics were exposed to the air for different days to study the problem of rare earth oxide ceramics quickly decomposing in the air and found that Nd0.5Sm1.5O3 ceramic shows stable structure and performance.

Broadband emitting Fe3+‐doped double perovskite‐type antimonates phosphors for NIR spectroscopy applications

AbstractNear‐infrared (NIR) broadband emitting phosphors regarded as ideal miniaturized NIR light sources, have recently received considerable attention. Nevertheless, the lack of appropriate substitutes for poisonous Cr3+ still poses a significant obstacle. Here, by selecting double perovskite‐type antimonates compound Ca2LuSbO6 (CLSO) and Ca2YSbO6 (CYSO) as the hosts, the broadband NIR‐emitting CLSO: 0.008Fe3+ and CYSO: 0.01Fe3+ phosphors are firstly reported. The above materials exhibit a rare long‐wavelength NIR emission band peaking at 927 and 938 nm, respectively. Accordingly, their full widths at half maximum are 128 and 135 nm, respectively. Moreover, the mechanism of their concentration quenching and thermal quenching effect are discussed. The IQEs of CLSO: 0.008Fe3+ is measured to be 69%, which is superior to many available Fe‐activated phosphors. Integrating the bond valence theory analysis with electron paramagnetic resonance measurement, Fe3+ only substitutes the lattice site of the Sb atom to generate a [FeO6] octahedron accompanying lattice distortion. Significantly, the as‐fabricated phosphor‐converted light emitting diodes device shows substantial applications in night vision and NIR spectroscopy detection. This work contributes to novel insights into the photoluminescence and site occupancy of Fe3+, thereby paving a new avenue for exploring next‐generation environmentally‐friendly and nontoxic NIR light‐emitting materials.

Effects of ion occupancy and polarizability on the crystal structure and microwave dielectric properties of CaEuCO4 (C[dbnd]Ga, Al) ceramics

CaEuCO4 (CGa, Al) microwave dielectric ceramics were produced through a solid-state reaction. Orthorhombic olivine CaEuGaO4 (pnma) exhibits a lower permittivity (εr = 9.7), a higher quality factor (Q × f = 82,049 GHz), and a larger negative resonant frequency temperature coefficient (τf = −54.6 ppm/°C). CaEuAlO4, which has a similar chemical formula, exhibits a perovskite-like structure (I4/mmm, K2NiF4-type), and its microwave dielectric properties are εr = 18.9, Q × f = 43,132 GHz, and τf = −1.6 ppm/°C. The difference in their structures is mainly caused by the properties of the Ga (III) atom. The difference in their dielectric properties can be proved to be affected by the “rattling” effect of Eu3+ through the bond valence theory. The relationship between the covalence (fc) and the bond strength (S) was investigated, and the higher bond strength might be the main reason for the higher Q × f in CaEuGaO4 ceramic.

AN INVESTIGATION OF THE KEY DETERMINANTS OF INTENTION TO USE PAYMENT WITH CRYPTOCURRENCY: THE CASE OF RESTAURANT BUSINESSES

With the developments in technology, it has started to be used as an additional payment method in businesses due to the emergence and increasing popularity of cryptocurrencies. This study was aimed to measure the factors that affect the customers' intention to use cryptocurrency technology as a payment method in restaurants, by examining the four dimensions of mindfulness and the positive valences and the negative valences of the valence theory. In this context, an online survey was applied to 405 cryptocurrency users to collect data. Confirmatory factor analysis (CFA) was used to verify the measurement model, and the structural equation model (SEM) was used to test the model. The findings of the study reveal that the participants think that the convenience of using this method has no effect on the intention to use it, that using this method is beneficial, not risky, and that they will not have any privacy concerns if they use this method. This study offers valuable practical implications for restaurant operators in the context of cryptocurrency payment systems. This study successfully extended valence theory by adding awareness to valence theory.

Consumer intention to accept electric two-wheelers in India: a valence theory approach to unveil the role of identity and utility

Consumer intention to accept electric two-wheelers in India: a valence theory approach to unveil the role of identity and utility

Sustaining the environment through e-waste recycling: an extended valence theory perspective

PurposeThe escalating volume of electronic waste (e-waste) presents a significant environmental and health hazard, emphasizing the importance of promoting e-waste recycling. Therefore, this study aims to utilize a valence theory approach to comprehensively understand the factors influencing individuals' intention to recycle e-waste.Design/methodology/approachA survey-based research approach was employed to examine the factors influencing consumers' e-waste recycling intention. Data were collected through an online survey questionnaire from Malaysian individuals aged 18 and above. The hypotheses were tested using a sample of 300 respondents, employing partial least squares structural equation modeling as a symmetric analysis technique. Additionally, fuzzy-set Qualitative Comparative Analysis (fsQCA), an asymmetric analysis approach, was used to gain deeper insights. Non-probability purposive sampling was utilized in the sampling process.FindingsThe PLS-SEM analysis revealed that subjective norms and willingness to change significantly impact e-waste recycling intention. Furthermore, perceived convenience, environmental concerns and social media usage were found to support the intention to recycle e-waste. The fsQCA results enhanced the interpretation by uncovering intricate relationships among the antecedents and identifying specific configurations that accurately predict consumers' recycling intentions.Practical implicationsThe practical implications of this study emphasize the need for policymakers and practitioners to raise awareness regarding the benefits of e-waste recycling, enhance convenience in the recycling process and strengthen personal and subjective norms to encourage individuals to recycle their e-waste.Originality/valueThis study's originality lies in its adoption of a valence theory framework to comprehend the intentions behind e-waste recycling, as well as its inclusion of control variables during the analysis. This unique approach enhances the understanding of factors influencing e-waste recycling intention and provides valuable insights for policymakers and practitioners in developing effective strategies to promote e-waste recycling behavior.

A Review of the Some Fixed Point Theorems for Different Kinds of Maps

The focus of this article, reviewed a generalized of contraction mapping and nonexpansive maps and recall some theorems about the existence and uniqueness of common fixed point and coincidence fixed-point for such maps under some conditions. Moreover, some schemes of different types as one-step schemes ,two-step schemes and three step schemes (Mann scheme algorithm, Ishukawa scheme algorithm, noor scheme algorithm, .scheme algorithm, scheme algorithm Modified scheme algorithm arahan scheme algorithm and others. The convergence of these schemes has been studied .On the other hands, We also reviewed the convergence, valence and stability theories of different types of near-plots in convex metric space.