This study presents a sustainable digital transformation framework to integrate sustainable practices into digital transformation initiatives within Small and Medium Enterprises (SMEs). The methodology includes a literature review, a framework creation, and a case study with passive participation. The framework was structured to help industries implement responsible digitalization initiatives in five key stages: setting objectives, fostering stakeholder-focused engagement, defining sustainable objectives and dimensions, creating a sustainable model, and executing the project. Validating the proposal in the context of an SME allowed us to discern the tangible benefits of sustainability practices for the organization, further reinforcing the relevance and applicability of the framework. In conclusion, this research offers valuable information for SMEs considering starting a sustainable digitalization process.

With the rapid deployment of the Internet of Things and cloud computing, it is necessary to enhance authentication protocols to reduce attacks and security vulnerabilities which affect the correct performance of applications. In 2019 a new lightweight IoT-based authentication scheme in cloud computing circumstances was proposed. According to the authors, their protocol is secure and resists very well-known attacks. However, when we evaluated the protocol we found some security vulnerabilities and drawbacks, making the scheme insecure. Therefore, we propose a new version considering login, mutual authentication and key agreement phases to enhance the security. Moreover, we include a sub-phase called evidence of connection attempt which provides proof about the participation of the user and the server. The new scheme achieves the security requirements and resists very well-known attacks, improving previous works. In addition, the performance evaluation demonstrates that the new scheme requires less communication-cost than previous authentication protocols during the registration and login phases.

Inspection of pipeline infrastructure is an essential part of pipeline integrity management to prevent from leakage and flow reduction is of great importance in water, gas, and oil distribution. However, current methods are limited in low resolution and low accuracy that fail to 3D reconstructions of pipelines. In this work, a theoretical laser propagation model based on a free-form laser profilometry method is established, and a fully functional laser system that incorporates a conic mirror within an integrated optical system containing all the elements necessary to retrieve the displacement information. The developed optical device exhibit high resolution, high accuracy, and high acquisition speed comparing with current technologies. Furthermore, the device can be completely sealed to be protected from the pipeline environment. This work paves the path towards autonomous laser scanners for underwater pipeline inspection.

Nanocomposites of LiZrO₂ – LiBaZrO₃: xMn²⁺ (x = 0–0.06 molar ratios) were prepared by the co-precipitation method. The prepared samples were characterized by X-ray diffraction (XRD), UV-visible spectrometry, photoluminescence (PL), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) techniques. Analysis of XRD data shows two phases: the cubic phase of BaZrO₃ perovskite and the tetragonal phase of ZrO₂. Mn²⁺ ions were predominantly distributed in the tetrahedral sites and a few ions are situated at the octahedral sites of the composites. UV-visible spectroscopy of these samples presents two optical band energies, decreasing exponentially with increasing concentration of the Mn²⁺ ion. PL spectra of Mn²⁺-doped samples display three broad emission bands: a band centered at wavelength,λ =416 nm (blue), another with peak maximum atλ =527 nm (green) and the third (with relatively the lowest intensity) at about 600 nm (orange-red). The blue (λ =416 nm) band was dominant at low Mn²⁺ concentrations (x≤0.03) but the green band (λ =527 nm) became dominant at higher Mn²⁺ concentrations (x>0.03). The CIE coordinates revealed colour changes from blue to green at a concentration of 0.05 mole ratio and white light at 0.06 mole ratio. The phosphor presented in this work is a promising material for use in display devices such as flat panel displays, colour plasma displays, signage lights and backlights.

A simultaneous double divergent projection of structured light to measure large and complex surfaces at short illumination distances is reported. When the structured and divergent lighting is projected, a moiré pattern is created, with the variable period associated with the out-of-plane surface that is analyzed. A theoretical description of the mathematical model and an algorithm to correct the measurements due to the divergence of the illumination are presented, which aim to establish the correct phase–height relationship. The mathematical model and the proposed method are verified numerically and experimentally. Measurements of the complex surfaces show high accuracy with low uncertainty. The system has been shown to allow rapid measurements in an efficient and easy way using a single camera.