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The study aims to develop an inexpensive metal oxide semiconductor gas sensor with high sensitivity, excellent selectivity for a specific gas and rapid response time.

This study synthesized Zn2SnO4 nanostructures using a hydrothermal method with a 1 M concentration of zinc chloride (ZnCl2) as the zinc source and a 0.7 M concentration of tin chloride (SnCl4) as the tin source. Thick films of nanostructured Zn2SnO4 were then produced using screen printing. The structural properties of Zn2SnO4 were confirmed using X-ray diffraction, and the formation of Zn2SnO4 nanoparticles was verified by transmission electron microscopy. Scanning electron microscopy was used to analyse the surface morphology of the fabricated material, while energy dispersive spectroscopy provided insight into the chemical composition of the thick film. These fabricated thick films underwent testing for various hazardous gases, including nitrogen dioxide, ammonia, hydrogen sulphide (H2S), ethanol and methanol.

The nanostructured Zn2SnO4 thick film sensor demonstrates a notable sensitivity to H2S gas at a concentration of 500 ppm when operated at 160°C. Its selectivity, response time and recovery time were assessed and documented.

The primary limitations of this research on metal oxide semiconductor gas sensors include poor selectivity to specific gases, limited durability and challenges in achieving detection at room temperature.

The nanostructured Zn2SnO4 thick film sensor demonstrates a strong response to H2S gas, making it a promising candidate for commercial production. The detection of H2S is crucial in various sectors, including industries and sewage plants, where monitoring this gas is essential.

Currently, heightened global apprehension about atmospheric pollution stems from the existence of perilous toxic and flammable gases. This underscores the imperative need for monitoring such gases. Toxic and flammable gases are frequently encountered in both residential and industrial environments, posing substantial hazards to human health. Noteworthy accidents involving flammable gases have occurred in recent years. It is crucial to comprehend the presence and composition of these gases in the surroundings for precise detection, measurement and control. Thus, there has been a significant push for extensive research and development in diverse sensor technologies using various materials and methodologies to monitor and regulate these gases effectively.

In this research, Zn2SnO4 nanostructures were synthesized using a hydrothermal method with ZnCl2 at a concentration of 1 M for zinc and SnCl4 at a concentration of 0.7 M for tin. Thick films of nanostructured Zn2SnO4 were then fabricated via screen printing technique. Following fabrication, all thick films were subjected to testing with various toxic gases, and the results were compared to previously published data. The analysis indicated that the nanostructured Zn2SnO4 thick film sensor demonstrated outstanding performance concerning gas response, gas concentration, selectivity and response time, particularly towards H2S gas.

Ascorbic acid, a water-soluble antioxidant, is an essential component of the human diet and is known for its potent antioxidant properties against several diseases. In recent years, there has been increasing interest in the development of nonenzymatic sensors due to their simplicity, efficiency and excellent selectivity. The aim of this study is to present a selective and sensitive method for the detection of ascorbic acid in aqueous system using a new electrochemical non-enzymatic sensor based on a gold nanoparticles Au-NPs-1,3-di(4-bromophényl)-5-tert-butyl-1,3,5-triazinane (DBTTA) composite.

Using the square wave voltammetry (SWV) technique, a series of Au-NPs-DBTTA composites were successfully developed and investigated. First, DBTTA was synthesized via the condensation of tert-butylamine and a4-bromoaniline. The structure obtained was identified by IR, 1H NMR and 13C NMR analysis. A glassy carbon electrode (GCE) was modified with 10–1 M DBTTA dissolved in an aqueous solution by cyclic voltammetry in the potential range of 1–1.4 V. Au-NPs were then deposited on the DBTTA/GCE by a chronoamperometric technique. SWV was used to study the electrochemical behavior of the modified electrode (DBTTA/Au-NPs/GCEs). To observe the effect of nanoparticles, ascorbic acid in a buffer solution was analyzed by SWV at the modified electrode with and without gold nanoparticles (Au-NPs).

The DBTTA/Au-NPs/GCE showed better electroanalytical results. The detection limit of 10–5 M was obtained and the electrode was proportional to the logarithm of the AA concentration in the range of 5 × 10⁻³ M to 1 × 10⁻¹ with very good correlation parameters.

It was also found that the elaborated sensor exhibited reproducibility and excellent selectivity against interfering molecules such as uric acid, aspartic acid and glucose. The proposed sensor was tested for the recognition of AA in orange, and satisfactory results were obtained.

This paper evaluates the risk-adjusted returns, selectivity, market timing skills and persistence of the performance of Nigerian pension funds.

Annual return data of 23 pension funds that operated in Nigeria between 2018 and 2022 were obtained from the National Pension Commission (PenCom). Risk-adjusted return was appraised using the Treynor ratio, Sharpe ratio and Jensen alpha, while the Treynor–Mazuy and Henriksson–Merton multiple regression models were applied to decompose selective and timing skills. Performance persistence was assessed using the contingency table and rank correlation models.

Evidence shows that pension funds deliver excess risk-adjusted returns and exhibit selective skills. However, the evidence does not support the presence of timing skills, and there is overwhelming evidence that good (bad) performance does not repeat.

An evaluation of the investment performance of pension funds is crucial for ensuring the financial stability of retirees, maintaining economic stability and making informed investment decisions. It serves the interests of pensioners, pension fund managers, regulators and the broader economy. Our evidence that pension funds generate positive excess returns is a departure from most of the literature on managed funds. We recommend that more Nigerians should leverage the pension fund industry to grow their wealth and prepare for retirement.

This study, to our knowledge, is the first to appraise all the key facets of the investment performance of pension funds in the Nigerian context.

The host–guest molecules are often used in various fields and applications. This paper aims to discuss the role of host–guest complexes in the textile industry, focusing on calixarenes as a potential adsorbent for hazardous dyes. The paper begins with an introduction to nanotechnology and its many uses, including textiles.

The risks associated with the utilisation of dyes and its adverse effects on the environment are then also highlighted. This paper also discusses the structure and characteristics of calixarenes and their potential use as an adsorbent to extract toxic metals from aqueous solutions. The paper also explains the molecular structure of calixarenes, especially the ability of its upper and lower rims, which can be altered to yield derivatives with various selectivities for diverse guest ions and small molecules. In addition, the application of various host–guest molecules in the textiles industry to extract dyes also had been discussed.

In conclusion, the paper highlights the essential in establishing a systematic review on the significance of selective adsorbents, such as calixarenes, to isolate particular targets from diverse matrices in the textile industry.

Only discussing several applications for several host–guest molecules.

The paper concisely describes various host–guest molecule applications in the textile industry, with each molecule being elaborated upon in detail.

This study aims to develop an electrochemical sensor for the detection of benzophenone (BP) as an alternative to conventional techniques that are known, expensive, complex and less sensitive.

The developed sensor is a platinum electrode modified with a plasticized polymer film based on ß-cyclodextrin, using PVC as the polymer, PEG as the plasticizer and ß-CD as the ionophore. This sensor is characterized by various techniques, such as optical microscopy, scanning electron microscopy and cyclic voltammetry. This latter is also used for analyzing kinetic processes at the electrode/electrolyte interface and to evaluate the selectivity and sensitivity of the sensor.

The results highlight the performance of our sensor. In fact, it exhibits a linear response extending from 10⁻¹⁹ to 10⁻¹³ M, with a correlation coefficient of 0.9836. What is more, it has an excellent detection limit of 10⁻¹⁹ M and a good sensitivity of 21.24 µA/M.

The results of this investigation demonstrated that the developed sensor is an analytical tool of choice for the monitoring of BP in the aqueous phase. The suggested sensor is fast, simple, reproducible and inexpensive.

This research aims to explore and theorize the role of embodied practices – orchestrated by service providers – in the social production of servicescapes. It is claimed that the social character of the servicescape is shaped not only by narratives and materialities but also through the body. Bodily physical behaviors like physical movements in space, gestures, facial expressions, postures and tactile engagements with the surrounding materiality constitute a body language that conveys information and expresses meanings. In this kinetic capacity, the body becomes a building agent in the social constitution of the servicescape. As the author empirically demonstrates in the context of city tourism with diverse experiential opportunities, it is due to the body’s discriminatory orientation, walking, looking, pointing and acting in selective ways that the city emerges as a servicescape of particular kind.

Market-oriented ethnography was conducted in Saint Petersburg, Russia, where the author observed the guiding practices of tour guides leading international tourists during two-day city excursions.

This research identifies and unpacks three clusters of embodied practices deployed by service providers as they guide customers at the servicescape: spatializing, emplacing and regulating. The role of the body and its association with narratives and materialities is identified in each cluster.

A number of embodied practices are provided for use by contact employees as they guide customers in the servicescape. Specific guidelines are also offered to service providers for the strategic employment of body language, their training is navigational skills and the coordination of body, narratives and materialities.

This study extends current materialistic and communicative approaches on the construction of servicescapes by claiming that the servicescape in not only a physical and narrative construction but something that is also configured through the body; provides three clusters of embodied practices deployed by service providers; theorizes the intertwined nature of narratives, materiality and the body; defines servicescapes as dynamic socio-spatial entities emerging from the constant {narrative-material-body} arrangements orchestrated by service providers; and sheds light on the mediating role of the body in the social production of servicescapes.

This paper aims to reveal the role of two theories that impact seniors’ entrepreneurial intentions. Both the socioemotional selectivity theory (SST) and the self-determination theory (SDT) re-shape seniors’ intentions to create entrepreneurial opportunities and activities after they retire.

This paper uses secondary data resources for developing the research concept, which might leverage seniors’ ultimate goal of creating entrepreneurial activities. A comprehensive past-paper analysis was performed. One hundred papers were initially considered for inclusion in this research. However, after a rigorous synthesisation process, 80 publications were selected for further analysis.

This paper presents an investigation of seniors’ entrepreneurship, with a specific emphasis on the SST and the SDT. It suggests potential models that could gauge senior entrepreneurs’ propensity to engage in entrepreneurial endeavours to support the socioeconomic advancement of society. Furthermore, this research discussed the limitations of the enlightening concepts presented to scholars and decision-makers.

The originality of this paper is illuminated by its idea of integrating two theories (the SST and the SDT), suggesting that these theories can possibly better observe senior entrepreneurs’ intentions in creating an entrepreneurial venture after they retire.

This study aims to prepare an imprinted composite membrane with grafted temperature-sensitive blocks for the efficient adsorption and separation of rhenium(Re) from aqueous solutions.

PVDF resin membrane was used as the substrate, dopamine and chitosan (CS) were used to modify the membrane surface and temperature-sensitive block PDEA was grafted on the membrane surface. Then acrylic acid (AA) and N-methylol acrylamide (N-MAM) were used as the functional monomers, ethyleneglycol dimethacrylate (EGDMA) as the cross-linker and ascorbic acid-hydrogen peroxide (Vc-H₂O₂) as the initiator to obtain the temperature-sensitive ReO4⁻ imprinted composite membranes.

The effect of the preparation process on the performance of CS–Re–TIICM was investigated in detail, and the optimal preparation conditions were as follows: the molar ratios of AA–NH₄ReO₄, N-MAM and EGDMA were 0.13, 0.60 and 1.00, respectively. The optimal temperature and time of the reaction were 40 °C and 24 h. The maximum adsorption capacity of CS–Re–TIICM prepared under optimal conditions was 0.1071 mmol/g, and the separation was 3.90 when MnO4⁻ was used as the interfering ion. The quasi first-order kinetics model and Langmuir model were more suitable to describe the adsorption process.

With the increasing demand for Re, the recovery of Re from Re-containing secondary resources becomes important. This study demonstrated a new material that could be separated and recovered Re in a complex environment, which could effectively alleviate the conflict between the supply and demand of Re.

This contribution provided a new material for the selective separation and purification of ReO4⁻, and the adsorption capacity and separation of CS–Re–TIICM were increased with 1.673 times and 1.219 time compared with other Re adsorbents, respectively. In addition, when it was used for the purification of NH₄ReO₄ crude, the purity was increased from 91.950% to 99.999%.

This empirical study aims to examine the COVID impact on the rate of return to schooling in 20 US industries.

An extended Mincer earnings equation with the COVID dummy variable and dummy interactive terms is used to examine the COVID effect on the rate of return to schooling for different industries. We use Heckman selection model to account for sample selection bias.

During COVID years, the change in the wage differential between college-and-above and below-college workers is different for industries, which leads to different changes in the rate or return to schooling among the 20 industries. During COVID, the rate of return to schooling increased for seven industries, decreased for seven industries and remained the same for six industries.

There is a lack of empirical tests of recession effects on the rate of return to schooling focusing on industry differentials. This study fills the research gap in this field. Our results will contribute to the ongoing discussion of the COVID impact on wages and returns from human capital investment.

This paper aims to investigate the effectiveness of immersive virtual reality (VR) media and the influence of user’s age in the context of destination marketing by exploring their impact on cognition (presence), affection (arousal), and behavioral (intention to visit and intention to recommend the destination) outcomes.

A laboratory experiment was conducted to compare the impact of using immersive VR (vs. 2D desktop) to experience a 360-degree virtual tour of Valencia on consumers’ behavior. The sample included 187 participants. Both self-reported and physiological measures were collected during the experimentation.

Results showed that participants in the immersive condition experienced a stronger sense of presence and higher physiological arousal than those exposed to nonimmersive content. Presence significantly mediated both the intention to visit and the intention to recommend the promoted venue. Physiological arousal mediated the relationship between media typology and the intention to recommend the destination. Upon introducing age as a moderating variable, the effect of physiological arousal on behavioral outcomes proves to be significant.

The study presents destination marketing organizations with a compelling use case for immersive technologies. It also offers design principles, potential applications and targeting strategies for VR marketing in hospitality management.

To the best of the authors’ knowledge, this study is the first to investigate the combined effect of physiological arousal and presence on behavioral intentions in VR destination marketing, while also examining the impact of age as an individual characteristic.