Abstract

Abstract
The growing adoption of microgrids necessitates efficient management of electrical energy storage units to ensure reliable and sustainable power supply. This paper investigates a thermal management system (TMS) for maintaining the longevity of large-scale batteries. To streamline the thermal modeling of batteries, the McCormick relaxation method is employed to linearize a nonlinear and interdependent heat generation model. The thermal model of the battery follows a nonlinear behavior where the generated heat makes the battery system temperature soar, thereby affecting the thermal performance of the battery. To showcase the efficacy of the proposed approach, four distinct case scenarios are studied, highlighting the critical importance of batteries within microgrid operations. A comparative analysis is conducted between linear and nonlinear models for TMS performance. A quantitative assessment based on simulation results demonstrates the precision of the linearized model, particularly in a multitemporal optimal power flow and day-ahead scheduling of microgrids incorporating energy storage units. Controlling the battery temperature within a permissible range (from 15 degrees C to 40 degrees C) is achieved by using a heating, ventilation, and air conditioning (HVAC) system. The paper explores the economic implications of energy storage units in microgrids by extracting and comparing daily operational costs with and without battery integration. The findings reveal that the inclusion of energy storage units yields substantial economic benefits, with potential profit margins of approximately 20 % during typical working days and 60 % on weekends.

Abstract
This cross-sectional study addresses Portuguese online shoppers' behavior toward Chinese online retailers, assessing the impact of financial, product, and time-convenience risks and demographic traits on their willingness to buy from those e-stores. The research relies on a survey of 1,432 participants who have shopped online at least once. Approximately half of the sample already buys from Chinese websites; age, financial, and time-convenience risks explain 21.5% of the variance of their purchase intention. On the other hand, participants who buy on Chinese websites present significantly lower values of all risks and the intention to buy from Chinese websites, possibly reflecting a satisfactory transaction experience. Furthermore, a generation gap is evident as younger people feel more confident in dealing intuitively with and solving online issues, giving them the confidence necessary to purchase online from Chinese e-stores - perhaps geographically and ideologically distant - but brought closer by e-expertise (online dexterity).

Abstract
The refractive index of the pigs heart was measured at wavelengths between 255 and 850 nm to calculate the dispersion. The total transmittance and total reflectance spectra of the pig heart were measured between 200 and 1000 nm to calculate the spectral absorption coefficient. Using Kramers-Kronig relations, the dispersion of the heart was matched to experimental refractive index values.

Abstract
This study aimed to test an Instructional Design model prototype for Virtual Reality (VR) in Higher Education. Aqualitative research methodologywas used, employing questionnaires and observations for data collection. The research had three main objectives: (1) to identify the applicability and effectiveness of the VR Instructional Design model, (2) to evaluate participants' experience with immersion, interactivity, and usability of the VR environment, and (3) to obtain feedback from participants about their VR experience. The study involved two sessions. In the first session, participants were introduced to the VR environment, and their initial adaptation difficulties were observed. Informal interviews and a questionnaire collected feedback on immersion, interactivity, interest, and educational potential of VR. The second session indicated the need for revisions in applicability and ease of use. Based on student feedback, session planning should consider initial adaptation, teacher training, equipment availability, interaction elements, resources, realism, immersion, safety, comfort, session duration, communication, collaboration, and clear content delivery. Providing alternative plans for technical failures is essential. Despite these challenges, participants expressed interest in participating in VR sessions and activities.

Abstract
The generation of short pulses in fiber lasers using saturable absorbers made of graphene oxide (GO), focusing on film thickness, was studied and optimized. The saturable absorber comprised a GO thin film deposited onto a single-mode fiber using the spray coating technique. Water-dispersed GO with a concentration of 4 mg/mL, characterized by a high proportion of monolayer flakes, was employed. This thin film was integrated into a cavity ring laser featuring an erbium-doped fiber amplifier (EDFA), resulting in a fiber laser emitting at a central emission wavelength of approximately 1564 nm and having a total cavity length of approximately 120 m. By controlling intracavity polarization, short-pulsed light was generated through mode-locking, Q switching, or a combination of both regimes. This work presents a comprehensive characterization of the cavity ring laser operating under the mode-locking regime. It encompasses an analysis of the spectral behavior, focusing on the evolution of the Kelly's sidebands with increasing pump power, as well as an assessment of its temporal stability. Moreover, the effects of the aging of the saturable absorber material were studied after a time period of 6 months after the fabrication. It was observed that the general characteristics of spectral signal of the laser were maintained, with long-term stability .