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This paper aims to concentrate on recent innovations in flexible wearable sensor technology tailored for monitoring vital signals within the contexts of wearable sensors and systems developed specifically for monitoring health and fitness metrics.

In recent decades, wearable sensors for monitoring vital signals in sports and health have advanced greatly. Vital signals include electrocardiogram, electroencephalogram, electromyography, inertial data, body motions, cardiac rate and bodily fluids like blood and sweating, making them a good choice for sensing devices.

This report reviewed reputable journal articles on wearable sensors for vital signal monitoring, focusing on multimode and integrated multi-dimensional capabilities like structure, accuracy and nature of the devices, which may offer a more versatile and comprehensive solution.

The paper provides essential information on the present obstacles and challenges in this domain and provide a glimpse into the future directions of wearable sensors for the detection of these crucial signals. Importantly, it is evident that the integration of modern fabricating techniques, stretchable electronic devices, the Internet of Things and the application of artificial intelligence algorithms has significantly improved the capacity to efficiently monitor and leverage these signals for human health monitoring, including disease prediction.

This study aims to explore the relationships between particular personal values (environmental, hedonic and utilitarian) and the intention to purchase slow fashion through the mechanism of attitude toward slow fashion in Indonesia.

This quantitative study uses an online questionnaire to obtain survey data from 429 respondents in cities in Indonesia. The respondents were mostly aged between 18 and 45 years, with the majority between 18 and 22 years (63.40 per cent). Confirmatory factor analysis and structural equation modeling are used to test and validate the proposed model's scale validity and relationship.

Environmental, utilitarian and hedonic values are positively related to attitudes toward slow-fashion products. Further, attitudes toward slow-fashion products positively influence purchase intention.

The study suggests marketing strategies to stimulate the intention to purchase slow fashion through advertising that emphasizes utilitarian, environmental and hedonic values, such as the pleasure in using slow-fashion products.

This study is the first to investigate the relationship of environmental and motivational values (hedonic and utilitarian) to the intention to purchase slow-fashion products. The findings contribute to the theoretical and practical understandings of slow fashion by identifying pre-positioned values that trigger positive attitudes toward slow-fashion products, thereby increasing purchase intention.

This paper aims to investigate the dimensional accuracy and surface roughness of printed masked stereolithography (m-SLA) parts. The fabricated specimens of photosensitive polymer resin have complex shapes and various features. The influence of four process parameters of m-SLA, including layer height, exposure time, light-off delay and print orientation, is studied on response characteristics.

The Box–Behnken design of response surface methodology is used to examine the effect of process parameters on the shrinkage of various geometrical dimensions like diameter, length, width, and height of different features in a complex shape. Additionally, a multi-response optimization has been carried out using the desirability function to minimize the surface roughness and printing time and maximize the dimensional accuracy.

The layer height and print orientation influence the surface roughness of parts. An increase in layer height results in increased surface roughness, and the orientation parallel to the z-axis of the machine gives the highest surface roughness. The dimensional accuracy of m-SLA parts is influenced by layer height, exposure time, and print orientation. Although not significant in dimensional accuracy and surface roughness, the light-off delay can affect printing time apart from other parameters like layer height and print orientation.

The effect of layer height and print orientation on dimensional accuracy, printing time, and surface roughness is investigated by researchers using simple shapes in other vat photopolymerization techniques. The present work is focused on studying the effect of these parameters and additional parameters like light-off delay in complicated geometrical parts in m-SLA.

Porosity is a commonly analyzed defect in the laser-based additive manufacturing processes owing to the enormous thermal gradient caused by repeated melting and solidification. Currently, the porosity estimation is limited to powder bed fusion. The porosity estimation needs to be explored in the laser melting deposition (LMD) process, particularly analytical models that provide cost- and time-effective solutions compared to finite element analysis. For this purpose, this study aims to formulate two mathematical models for deposited layer dimensions and corresponding porosity in the LMD process.

In this study, analytical models have been proposed. Initially, deposited layer dimensions, including layer height, width and depth, were calculated based on the operating parameters. These outputs were introduced in the second model to estimate the part porosity. The models were validated with experimental data for Ti6Al4V depositions on Ti6Al4V substrate. A calibration curve (CC) was also developed for Ti6Al4V material and characterized using X-ray computed tomography. The models were also validated with the experimental results adopted from literature. The validated models were linked with the deep neural network (DNN) for its training and testing using a total of 6,703 computations with 1,500 iterations. Here, laser power, laser scanning speed and powder feeding rate were selected inputs, whereas porosity was set as an output.

The computations indicate that owing to the simultaneous inclusion of powder particulates, the powder elements use a substantial percentage of the laser beam energy for their melting, resulting in laser beam energy attenuation and reducing thermal value at the substrate. The primary operating parameters are directly correlated with the number of layers and total height in CC. Through X-ray computed tomography analyses, the number of layers showed a straightforward correlation with mean sphericity, while a converse relation was identified with the number, mean volume and mean diameter of pores. DNN and analytical models showed 2%–3% and 7%–9% mean absolute deviations, respectively, compared to the experimental results.

This research provides a unique solution for LMD porosity estimation by linking the developed analytical computational models with artificial neural networking. The presented framework predicts the porosity in the LMD-ed parts efficiently.

This study aims to describe the development of a battery-operated portable colorimeter for on-site determination of water quality in aquaculture.

A simple and economical colorimeter is built using light sources of different wavelength and a light-dependent resistor combined with an electrical circuit. The whole system was fabricated as to fit into the pocket or palm for easy handling. The developed portable colorimeter was calibrated for estimation of nitrite. Further, the performance of developed portable colorimeters was compared with the commercially available colorimeter.

Three colorimeters with different light sources were developed and calibrated for determination of nitrite in water. Among them, colorimeter with yellow light source exhibited higher potential for determination of nitrite in the range of 0.5–3.5 ppm. Further, the results of the developed colorimeter are comparable with the commercial colorimeter.

The portable colorimeter developed in this study exhibits potential for determination of nitrite in aquaculture. Determination of nitrite at low concentrations is important for assessing the quality of culture as well as wastewater in aquaculture industry. The accuracy, portable nature, economy and simple operation of these portable colorimeters offer opportunity for on-site determination of water quality parameters in aquaculture.