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The present communication aims to investigate the influence of cobalt substitution on the structural, mechanical and elastic properties of nickel–zinc ferrite thick films. The changes observed in the crystallite size (D), lattice constant (a), texture coefficient [TC(hkl)] and mechanical and elastic properties of the thick films due to cobalt substitution have been reported systematically.

Ni–Zn ferrites with the stoichiometric formula Ni_0.7−xCo_xZn_0.3Fe₂O₄ (where, x = 0, 0.04, 0.08, 0.12, 0.16 and 0.20) were synthesized via solution combustion technique using sucrose as the fuel and poly-vinyl-alcohol as the matrix material. The thick films of the ferrites were fabricated on alumina substrates by the screen printing method. The thickness of the films was 25 μm, as measured by the gravimetric method. The thick films were subjected to X-ray diffraction and Fourier transform infrared spectroscopy.

The detailed study of variation of lattice parameter (a), sintering density, micro-strain and elastic properties with cobalt (Co+2) substituted was carried out. The remarkable increase in lattice parameter (from 8.369 A^° to 8.3825 A^°), bulk density and average grain size (69-119 nm) with the cobalt content was due to larger ionic radius of Co²⁺ compared to Ni²⁺. Texture analysis [TC(hkl)] reveals all thick films have adequate grain growth in the (311) plane direction. The main absorption bands of spinel ferrite have appeared through infrared absorption spectra recorded in the range of 300-700 cm⁻¹.

The variation in stiffness constants (for isotropic material, C11 = C12), longitudinal elastic wave (Vl), transverse elastic wave (Vt), mean elastic velocity (VMean), rigidity modulus (G), Poisson’s ratio(s) and Young’s modulus (E) with cobalt (Co+2) composition has been interpreted in terms of binding forces found.

Plasma spray coating technologies are capable of depositing a wide range of compositions without significantly heating the substrate. The objective is to characterise plasma sprayed metallic coatings on a Fe‐based superalloy.

NiCrAlY, Ni‐20Cr, Ni3Al and Stellite‐6 metallic coatings were deposited on a Fe‐based superalloy (32Ni‐21Cr‐0.3Al‐0.3Ti‐1.5Mn‐1.0Si‐0.1C‐Bal Fe) by the shrouded plasma spray process. The coatings were characterised in relation to coating thickness, porosity, microhardness and microstructure. The high temperature oxidation behaviour of the coatings was investigated in brief. The techniques used in the present investigation include metallography, XRD and SEM/EDAX.

All the coatings exhibited a lamellar structure with distinctive boundaries along with the presence of some porosity and oxide inclusions. The microhardness of the coatings was observed to vary with the distance from the coating‐substrate interface. The St‐6 coating had the maximum microhardness, whereas the lowest hardness was exhibited by the Ni3Al coating. The phases revealed by XRD of the coatings confirmed the formation of solid solutions, whereas EDAX analysis of the as‐sprayed coatings confirmed the presence of basic elements of the coating powders. So far as high temperature oxidation behaviour is concerned, all of the coatings followed the parabolic rate law and resulted in the formation of protective oxide scales on the substrate superalloy.

The plasma spray process provides the possibility of developing coatings of Ni3Al as well as commercial available NiCrAlY, Ni‐20Cr and St‐6 powders on Fe‐based superalloy Superfer 800H

To characterise the high temperature oxide scales for some plasma sprayed NiCrAlY coated Ni‐ and Fe‐based superalloys.

Ni‐22Cr‐10Al‐1Y metallic coatings were deposited on two Ni‐based superalloys; Superni 601 and Superni 718 and one Fe‐based superalloy; Superfer 800H by the shrouded plasma spray process. Oxidation studies were conducted on uncoated as well as plasma spray coated superalloys in air at 900°C under cyclic conditions for 50 cycles. Each cycle consisted of 1 h heating followed by 20 min of cooling in air. The thermogravimetric technique was used to approximate the kinetics of oxidation. X‐ray diffraction, SEM/EDAX and EPMA techniques were used to analyse the oxide scales.

All of the coated, as well as the uncoated, superalloys followed an alnost‐parabolic rate of oxidation. The NiCrAlY coating was found to be successful in maintaining its continuous contact with the superalloy substrates in all the cases. The oxide scales formed on the exposed NiCrAlY coated superalloys were found to be intact and spallation‐free. The main phases analysed for the coated superalloys were oxides of nickel, chromium and aluminium and spinel of nickel and chromium, which are expected to be useful for developing oxidation resistance at high temperatures.

The coated superalloys showed remarkable cyclic oxidation resistance under simulated laboratory conditions. However, it is suggested that these coated superalloys also should be tested in actual industrial environments of boilers and gas turbines, etc. so as to obtain more practical and reliable oxidation data.

The knowledge of the reaction kinetics and the nature of the surface oxide scales formed during oxidation is important for evaluating the alloys for their use and degradation characteristics in high temperature applications such as steam boilers, furnace equipment, heat exchangers and piping in chemical industry, reformer, baffle plates/tubes in fertilizer plants, jet engines, pump bodies and parts.

The purpose of this chapter is to critically evaluate the development of technological infrastructure and the propensity of Latin America and the Caribbean (LAC) destinations to adopt digitalisation in their hotel sectors. This paper focuses on technological readiness, the types of digitalisation and its influence on the hotel sector in a post-pandemic environment.

The chapter is a critical and conceptual overview of digitalisation in the Latin America and the Caribbean hotel sectors, the contribution of the hotel sector to tourism economies, and digitalisation in LAC post COVID-19. A comprehensive examination of the academic literature is combined with the Network Readiness Index (NRI) and Travel and Tourism Competitiveness Index (TTCI) on several LAC countries focusing on different scopes including ICT readiness, ICT environment and business usage from 2010 to 2020. The paper uses empirical data collected from NRI and TTCI on several LAC countries examining changes in development of information and communications technology (ICT) by conducting a longitudinal analysis over a ten-year period.

The chapter argues that digitalisation in the hotel sector has been given a lot of attention regarding the adoption of digitalisation during the pandemic by a continuation of activities involving check-in and check-out, providing safety for guests and staff and the recovery of the hotel sector by both hoteliers and academics. Yet, LAC have been slow when it comes to the development of ICT. This is shown on the NRI and the TTCI by their position on ICT infrastructure, ICT environment and business usage. Nevertheless, while their positions on the indexes are less than favourable, their scores are improving, but at a very slow rate.

Limited academic literature is available on digitalisation in LAC countries. There is no consistent data on the NRI and TTCI year to year for some of the countries examined in this study.

This study provides a comprehensive review of technological infrastructure development of countries of Latin America and Caribbean countries with an emphasis on digitalisation in a hospitality context. The chapter is a critical examination of digitalisation in the hotel sector in a post-pandemic environment.

Machining of curved channels using electrical discharge machining (EDM) is a novel approach. In this study, an experimental setup was designed, developed and mounted on die-sinking EDM to manufacture curve channels in AISI P20 mold steel.

The effect of specific machining parameters such as peak current, pulse on time, duty factor and lift over material removal rate (MRR) and tool wear rate (TWR) were studied. Multi-objective optimization was performed using Taguchi technique and Jaya algorithm.

The experimental results revealed current and pulse on time to have the predominant effect over material removal and tool wear diagnostic parameters with contributions of 39.67, 32.04% and 43.05, 36.52%, respectively. The improvements in material removal and tool wear as per the various optimization techniques were 35.48 and 10.91%, respectively.

Thus, Taguchi method was used for effective optimization of the machining parameters. Further, nature-based Jaya algorithm was implemented for obtaining the optimum values of TWR and MRR.

In Indian thermal power plants, the main cause of boiler tube failure is the presence of molten sulphates and vanadates, which deteriorate the tube material at high temperatures. To combat the hot corrosion failure of metals, thermal spray technology is adopted. This study aims to investigate and study the effect of hot corrosion behaviour of carbon nanotube (CNT)-reinforced ZrO₂-Y₂O₃ composite coatings on T-91 boiler tube steel in a molten salt environment at 900 °C for 50 cycles.

A plasma spray technique was used for development of the coatings. The samples were exposed to hot corrosion in a silicon tube furnace at 900 °C for 50 cycles. After testing, the test coupons were analysed by X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and cross-sectional analysis techniques to aid understanding the kinetics of the corrosion reaction.

CNT-based reinforced coatings showed lower weight gain along with the formation of protective oxide scales during the experimentation. Improvement in protection against hot corrosion was observed with increase in CNT content in the coating matrix.

It is pertinent to mention here that the high temperature behaviour of CNT-reinforced ZrO₂-Y₂O₃ composite on T-91 steel at 900°C temperature in molten salt environment has never been studied. Thus, the present research was conducted to provide useful results for the application of CNT-reinforced composite coatings at elevated temperature.

The purpose of this paper is to study thickness dependent variation in microwave properties of the Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films and enhancement of power efficiency of Ag thick film EMC patch antenna.

X‐band microwave properties of the Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films were measured by superstrate technique using Ag thick film EMC patch antenna as the resonant element. The complex permittivity and permeability of these thick films were also measured by this technique. The microwave response of the EMC patch, complex permeability and permittivity of Mg_0.8Mn_0.1Al_0.1Zn_0.8Fe_1.2O₄ and Mg_0.9Al_0.1Zn_0.8Fe_1.2O₄ thick films and their thickness dependency were investigated.

The XRD patterns reveal the cubic spinel crystal system was obtained for both compositions. The crystallite size obtained was 134.68 nm for Mg_0.8Mn_0.1Al_0.1Zn_0.8Fe_1.2O₄ and 155.99 nm for Mg_0.9Al_0.1Zn_0.8Fe_1.2O₄ The superstrate technique has been used successfully to evaluate the complex permittivity and permeability of the ferrite thick films in the X band. The EMC patch also show thickness and composition dependent frequency agility and enhancement of power efficiency.

The complex permeability of Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films measured by superstrate technique is reported in this paper. The superstrate of Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films makes the Ag thick film EMC patch antenna frequency agile and power amplification is obtained.

The aim of this paper is to investigate permittivity of nano structured Ni_0.7‐xCo_xZn_0.3Fe₂O₄ thick films at microwave frequencies.

Nanosized Ni_0.7‐xCo_xZn_0.3Fe₂O₄ ferrites with x=0, 0.04, 0.08 and 0.12 were prepared by sucrose precursor technique using the constituent metal nitrates. Thick films of the ferrites were fabricated on alumina substrates by screen‐printing technique. Microwave dielectric constant (ε′) and the loss factor (ε″) for the thick films were measured by VSWR slotted section method in the 8‐18 GHz range of frequencies. Microwave attenuation properties were studied using a waveguide reflectometer set up.

Both the ε′ and ε″ were found to vary with frequency and composition x. It is observed that, value of ε′ increases with increase in x, due to the increase in bulk density and reduction in porosity of the material, that resulted due to the substitution of cobalt in Ni‐Zn ferrite. The microwave transmission loss offered by the thick films was found to increase with the increase in cobalt concentration x. Within the band width of 4 GHz (from 12‐16 GHz), all the films except that with x=0.04 offered the reflection loss of less than 3 dB.

The dielectric constant of Ni_0.7‐xCo_xZn_0.3Fe₂O₄ thick films have been reported for the first time. These thick films provide scope for cost effective planar ferrite devices.

The purpose of the paper is to examine the financial management behavior (FMB) mediation mechanism in self-control, optimism, deliberative thinking and investment decisions in the Tanzanian stock market.

A sample of 268 individual investors in the Tanzanian stock market was obtained through questionnaires. The data were analyzed using structural equation modeling.

The findings show that self-control, optimism and deliberative thinking are significantly and positively related to FMB and investment decisions. The findings also confirmed the mediating role of FMB in the influence of self-control, optimism and deliberative thinking on investment decisions among Tanzanian individual investors. These findings imply that people with good self-control, optimistic and deliberative thinking are more likely to save money, have better FMB and prefer to make investment decisions.

The study deals with individual investors. Future research could examine the effects of psychological traits on investment decisions by adding or modifying the items of particular constructs and studying institutional investors.

Individual investors can use the information to study and evaluate their financial behavior and stock investment decisions. This research can be used by security firms to better understand investor behavior, forecast future market trends and advice investors. Individual investors require psychological features to manage their behavior in various aspects, ranging from affective behavior to cognition, which are relevant for investing decisions.

Few studies have examined the influence of self-control, optimism and deliberative thinking on the investment decisions of individual investors. The unique empirical analysis developed in this paper is that it examines the mediation mechanisms of FMB with respect to self-control, optimism and deliberative thinking and investment decisions among individual investors in the Tanzanian stock market.

This paper aims to explore factors impacting wearable fitness tracking (WFT) device continued usage intention from perspectives of technology attributes (autonomy benefits), health attributes (self-health management benefits, diet-control benefits and health self-efficacy), and consumer attributes (age, gender, technological innovativeness, symbolic benefits, social benefits and hedonic benefits).

The study integrates constructs from the technology acceptance theories and the health promotion model to develop the research model and hypothesis. The empirical analysis was conducted using data from 217 respondents from India. Logistic regression was used to identify factors that discriminate between groups with low and high continued usage intentions.

Results indicate higher continued usage intention for WFT devices is driven by perceived benefits-health, autonomy, social and hedonic, and individual characteristics-technological innovativeness and perceived health self-efficacy. Further, perceived symbolic benefits, diet control benefits, age, and gender does not discriminate between the groups with low and high continued usage intentions.

The results may be limited to the context of the sample and the factors considered. The study suggests future research areas.

The paper offers insights for marketers, governments, insurance firms, and related healthcare services on promoting higher usage of WFT devices to yield dual benefits of preventive healthcare and higher profitability.

The study extends existing research by examining factors across consumer, health, and technological domains in a single framework and adds to the limited research in the context of usage of WFT devices in developing countries.